Split (3)

train · 130k rows

description stringlengths 2.98k 3.35M	abstract stringlengths 94 10.6k	cpc int64 0 8
CROSS-REFERENCE TO RELATED APPLICATION [0001] This application claims the benefit of U.S. provisional patent application No. 61800374. BACKGROUND [0002] In many urban areas, the sounds of vehicle horns and emergency vehicle sirens are common place. While these horns and sirens serve an important purpose, they also create noise pollution, a known contributor to deleterious cardiovascular effects in humans. In many developed areas, residences and businesses are located above busy traffic areas, a situation in which surrounding infrastructure effectively amplifies the sound reaching these residences and exacerbates noise pollution problems. Additionally, many sirens utilize simple acoustic horns in order to amplify their sound level—horns which have directional properties that are not optimized for their intended use. For example, the main purpose of emergency vehicle sirens is to alert vehicles on the street ahead of the emergency vehicle, and on adjoining side-streets, so that those vehicles will yield the right-of-way. However, these sirens do not focus their transmitted acoustic energy at ground level, and can often be clearly heard on the upper floors of office buildings or residences, where the sound they produce does not serve a useful purpose. In addition, the reflections of the sound waves often make it difficult for other drivers to determine the location of the emergency vehicle. [0003] What is needed to solve the problem of reducing noise pollution resulting from sirens and other acoustic sources is a device that targets its acoustic energy only in the directions needed. A siren with a three-dimensional sound radiation pattern (wide horizontal beam pattern angle and narrow vertical beam pattern angle), so that the siren can be heard ahead and to the sides of the vehicle, but is strongly attenuated in the vertical direction, accomplishes this objective. SUMMARY [0004] A sound projection system, comprising a plurality of sound emitters mounted on a vehicle; the sound emitters having a configurable phase of emission; the sound emitters collectively having a beam pattern; and the sound emitters configured such that they focus the beam pattern in a selected direction. DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS [0005] FIG. 1 depicts a side view of the beam pattern of a common siren mounted on an emergency vehicle. [0006] FIG. 2 depicts a top view of a narrow beam pattern siren mounted on an emergency vehicle. [0007] FIG. 3 depicts a top view of the beam pattern of a pair of vertically-mounted line speaker arrays mounted on an emergency vehicle [0008] FIG. 4 depicts a top view of the beam pattern of a pair of vertically-mounted line speaker arrays mounted on an emergency vehicle [0009] FIG. 5 depicts a control system DETAILED DESCRIPTION [0010] Our solution to the problem of directing a siren or loudspeaker's radiation pattern is a multi-element array of acoustic emitters that can be mounted on a vehicle. These multiple, spatially-separated sound emitters may be appropriately phased resulting in a three-dimensional sound radiation pattern that focuses transmitted acoustic energy in the directions where it most usefully serves its intended purpose. The speaker phasing may be fixed, creating a desired sound propagation pattern for a given waveform, or it may vary in real-time enabling arbitrary input waves to be appropriately directed. Line arrays of acoustic emitters are commonly used in auditoriums, concerts, fairgrounds, and other public assembly areas. However, they are not currently employed on vehicles. Phased beam shaping is used with ultrasound measurement devices, fixed public address systems, and home theater systems, but is not described in prior art for mobile emergency alerting systems. [0011] As shown in FIG. 2 , in a preferred embodiment of this device would produce a sound distribution pattern substantially focused in a horizontal plane 210 , and further focused primarily towards the front and sides of the vehicle (horizontal beam angle greater than 90° and less than) 270° with a narrow vertical beam angle of less than 60°. This can be achieved by using two or more audio sources separated by a fixed horizontal distance, while controlling the relative phase of the signals emitted by each audio source. The relative phasing of each audio source's output may be accomplished mechanically using varying length horns, electronically by applying fixed phase delays to each source input, electronically by varying the phase delay of each source in real-time as a function of frequency, or a priori by using appropriately-phased pre-recorded inputs for each element of the audio source array. The result is that the combined beam pattern for all the speaker elements can be designed for a wide range of frequencies and sound distribution goals. Single speakers such as horns with rectangular mouths are capable of providing different beam angles along the vertical and horizontal plane, but these patterns are highly frequency dependent, and are not optimized for the urban environment. [0012] For an emergency vehicle's siren, the correct phase for each constituent frequency can be calculated and using the acoustic principle of superposition, the resultant multi-frequency signal can be generated and prerecorded for each speaker element. This ensures consistent playback with the desired beam pattern. The system can also be used as a loudspeaker, in which case a real-time controller can use a simple algorithm to alter an arbitrary signal waveform (to include Speech) for optimum broadcast. [0013] An alternative embodiment could alter the projected beam pattern in real-time, dependent on the user's needs. For example, a narrower horizontal pattern could be employed in urban area with many tall buildings to reduce unwanted sound reflections and destructive interference, while a broader beam pattern 310 of FIGS. 3 and 410 of FIG. 4 , could be used in suburban or rural areas, or when traveling along a wide highway. This real-time beam pattern variation can also be a function of vehicle speed or other parameter enabling sound to be focused further ahead of fast moving vehicle, and having greater side lobes when the vehicle is moving slower. [0014] Another method of controlling the sound distribution pattern is to use sound emitters with multiple waveguides. Each waveguide would introduce a unique phase angle to the source signal, and the output from these waveguides would interfere in a similar manner as unique signals from multiple sources. The advantage of this approach is that it does not require any additional signal processing hardware. The disadvantage is that it is not possible to tune each frequency uniquely. [0015] As shown in FIG. 5 , a specific embodiment of the invention may be described as follows: An emergency vehicle is equipped with a DABS system comprised of (1) sound emitters 510 , (2) a sound generator/multi-channel phase controller 520 , and (3) a amplifier 530 . The sound emitters are anticipated to be electronically-controlled, amplified speakers capable of rebroadcasting input audio signals at volumes controlled by the operator. The input audio signals may be comprised of single or multiple frequencies, and the frequency content may be static or dynamic and controlled by system controls 550 . An example of this type of electronically-controlled, amplified speaker are conventional PA systems such as the Anchor Audio MegaVox Pro Public Address System (119 dB, 15 lbs, 15 lbs, AC/DC power supply, 400 Hz-10 kHz frequency response). In the specific embodiment, a vehicle may be equipped with an array of four Anchor MegaVox Pro Public Address units mounted on the roof of the vehicle using steel brackets and electronically connected to a four channel audio source. [0016] The four outputs of the four channel audio source will be appropriately time-shifted for each of the four Anchor MegaVox Pro Public Address units to affect a steerable audio beam which will be steered based on multiple inputs. The four channel audio source may be a computer, or embedded DSP such as a DSpace MicroAutoBox-II embedded controller. This system has sixteen analog (0-5V, 16-bit) inputs 540 , and four analog (0-4.5V, 12-bit) outputs. It also has 40 digital inputs and outputs. The inputs to the DSpace MicroAutoBox-II may include information on the state of the vehicle, and the user's requirements; as specific examples, inputs may include: on/off, Degree of beam focus (narrow to wide), mode (e.g., city/suburb), time of day, steering wheel angle, and vehicle speed. [0023] It may also include measurements of the ambient environment (noise level), and measurements of the system output (measured output of each speaker for closed-loop system control). [0024] Additionally, it may be possible to use the same multi-channel controller approach in conjunction with single tone emitters such as sirens. The input signal to each of the sirens may be time-shifted by the controller using open-loop control to affect a steerable beam, or they may be paired with microphones and modulated with closed-loop control to improve performance. [0025] If it is desired to modulate the output timing of each of the sound emitters mechanically, this can be affected by using solenoid-driven horns (hollow tubes) placed in front of each sound emitter. Each solenoid would mechanically adjust the length of the tube through which sound waves would have to pass after being generated by each sound emitter. The control of the tube lengths, mechanically affected by solenoids, would be controlled by a digital system controller, such as the DSpace MicroAutoBox-II described above. [0026] A one dimensional, line array allows the beam to be steered in directions perpendicular the line array. A two dimensional array enables the beam to be steered is two dimensions. Notes from Human Factors in Auditory Warnings—Edited by Neville A Stanton & Judy Edworthy, Published by Ashgate Publishing Ltd 1999 (this text is incorporated by reference into this specification). [0027] There are three main types of information that allow the brain to localize sound. The first two are known as binaural cues because they make use of the fact that we have two ears, separated by the width of our head. A sound which emanates from either side of the mid-line will arrive first at the ear closest to it and will also be loudest at the ear closest to it. At low frequencies the brain recognizes differences in the time of arrival of the sound between the ears, and at higher frequencies the salient cue is the loudness/intensity difference between the sound at each ear. The use of these two types of cue is known as the ‘duplex’ theory and was proposed by Lord Raleigh as long ago as 1877. For single frequencies these cues are, however, spatially ambiguous. The inherent ambiguity has been described as the ‘cone of confusion’ and this arises from the fact that for any given frequency there are numerous spatial positions that generate identical timing/intensity differences and these can be graphically represented in the form of a cone, the apex of which is at the level of the external ear. The cone of confusion is the main reason for our not being able to localize pure tones (Blauert, 1997; Wightman and Kistler, 1993). The ‘kilo’ siren is characterized by a two-tone sound (670- 1100 Hz, 55 cycles/min); the ‘Pulsar’, a pulsating sound (500-1800 Hz, 70 cycles/min.); the ‘wail’, a continuous sound rising and falling (500-1800 Hz, 11 cycles/min) and the ‘yelp’, a continuous and fast warbling sound (500-1800 Hz, 55 cycles/min). [0028] Difficulties in determining the direction from which emergency vehicle sirens are approaching are widely acknowledged. In fact the emergency vehicle siren has been described as ‘an extremely limited audible warning device’ (De Lorenzo and Eilers, 1991). A recent study in the Annals of Emergency Medicine has shown that an ambulance is most susceptible to collisions with other vehicles when crossing road junctions. This happens, primarily, because the drivers of the cars or trucks are unable to determine accurately the direction of the approaching ambulance. In one year, in the USA alone, 537 injuries and 62 deaths arose from accidents involving ambulances (Hunt et al., 1995).	A plurality of sound emitters mounted on a vehicle having a configurable phase of emission and configured such that they focus the beam pattern in a selected direction.	8
CROSS-REFERENCE TO RELATED APPLICATION(S) [0001] This application is a continuation of U.S. patent application Ser. No. 11/729,444, filed Mar. 28, 2007, which claims priority to and the benefit of U.S. Provisional Patent Application Ser. No. 60/787,901, filed Mar. 31, 2006, and claims priority from European Patent Application EP06006832.7, filed Mar. 31, 2006, the entire disclosures of which are incorporated herein by reference. BACKGROUND [0002] The invention relates to a locking assembly for securing a rod member in a receiver part connected to a shank for use in spinal or trauma surgery. The invention further relates to a bone anchoring device using such a locking assembly and to a tool for cooperating with such a locking assembly. [0003] U.S. Pat. No. 6,224,598 B1 discloses a threaded plug closure adapted for use in securing a rod member to a bone screw implant, said closure comprising a plug having a threaded cylindrically- shaped outer surface, said plug being received between a pair of arms of a medical implant during use, a central coaxial bore passing entirely through said plug, said central bore having an internal threaded surface which is shaped to receive a set screw. The plug closure and the set screw can be independently installed and the set screw tightened to cooperatively provide capture and locking of the rod in order to secure the rod against translational and rotational movement relative to the bone screw. [0004] US 2003/0100896 A1 discloses a bone anchoring device with a shank and a receiving part connected to it for connecting to a rod. The receiving part has a recess having a U-shaped cross-section for receiving the rod with two open legs and an internal thread on the open legs. A locking assembly is provided comprising a nut member with an external thread which cooperates with the internal thread of the legs and a set screw. The nut member has on one end slits for engagement with a screw tool. The shank has a spherically shaped head which is pivotably held in the receiving part and a pressure element is provided which exerts pressure on the head when the nut member is tightened. By tightening the set screw the rod is fixed in the receiving part. Hence, the rod and the head can be locked independently from each other. The internal thread and the cooperating external thread of the nut member are designed as a flat thread. The implant has a compact design, since an outer ring or nut to prevent splaying of the legs is not necessary. [0005] The outer diameter of the locking assembly is under various aspects determined by the required tightening torque and the thread form. In turn, the overall dimensions of the upper portion of the bone anchoring device are determined by the size of the locking assembly. [0006] Therefore, there is a need for a locking assembly and a bone anchoring device with a locking assembly which has the same reliability as the known devices but which has smaller dimensions of the upper portion. Furthermore, there is a need for a tool for such a locking assembly. SUMMARY [0007] The locking assembly according to the invention can be designed with a smaller outer diameter compared to the known locking assemblies. Therefore, the size of the bone anchoring device can be reduced. The bone anchoring device with such a reduced size is particularly suitable for application to the cervical spine or other areas where a limited available space requires compact implants. [0008] Furthermore, the locking assembly is structured so as to allow nesting of two or more locking elements. [0009] With the tool according to the invention a simultaneous but independent fixation of the locking elements of the locking assembly is possible. [0010] Further features and advantages of the invention will become apparent and will be best understood by reference to the following detailed description of embodiments taken in conjunction with the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS [0011] FIG. 1 shows a cross-sectional view of an embodiment of the bone anchoring device with the locking assembly. [0012] FIG. 2 shows a perspective elevational view of the bone anchoring device of FIG. 1 . [0013] FIG. 3 shows a perspective view from the top of the locking assembly. [0014] FIG. 4 shows a cross-sectional view of the locking assembly of FIG. 3 . [0015] FIG. 5 shows a side view of the locking assembly of FIG. 3 . [0016] FIG. 6 shows a perspective view of a tool. [0017] FIG. 7 shows a cross-sectional view of the lower part of the tool cooperating with the locking assembly. [0018] FIG. 8 shows a perspective view of the locking assembly and the lower part of the tool. [0019] FIG. 9 shows a perspective view of the locking assembly with cooperating portions of the tool shown in section wherein the other parts of the tool are omitted. [0020] FIG. 10 shows a perspective view of a modification of the first locking element of the locking assembly. [0021] FIG. 11 shows a perspective view of a further modification of the first locking element of the locking assembly. [0022] FIG. 12 shows a second embodiment of the locking assembly in a top view. [0023] FIG. 13 shows a further embodiment of the locking assembly in a perspective view. [0024] FIG. 14 shows the locking assembly of FIG. 13 in a top view. [0025] FIG. 15 shows the locking assembly of FIG. 13 in a sectional view along line A-A of FIG. 14 . [0026] FIG. 16 shows a tool cooperating with the locking assembly of FIG. 13 in a sectional view. DETAILED DESCRIPTION OF THE INVENTION [0027] FIGS. 1 and 2 show the locking assembly used in a polyaxial bone anchoring device 1 . The bone anchoring device comprises a bone screw 2 having a shank 3 with a bone thread and a spherically-shaped head 4 . The bone screw 2 is received in a receiving part 5 which has a first end 6 and a second end 7 and is of substantially cylindrical construction. The two ends are perpendicular to a longitudinal axis L. Coaxially with the longitudinal axis L a bore 8 is provided which extends from the first end 6 to a predetermined distance from the second end 7 . At the second end 7 an opening 9 is provided, the diameter of which is smaller than the diameter of the bore 8 . The coaxial bore 8 tapers towards the opening 9 . In the embodiment shown it tapers in form of a spherically shaped section 10 . However, the section 10 can have any other shape such as, for example, a conical shape. [0028] The receiving part 5 , further, has a U-shaped recess 11 which starts at the first end 6 and extends in the direction of the second end 7 to a predetermined distance from said second end. By means of the U-shaped recess two free legs 12 , 13 are formed ending towards the first end 2 . Adjacent to the first end 6 , the receiving part 5 comprises an internal thread 14 at the inner surface of the legs 12 , 13 . In the embodiment shown, the internal thread 14 is a flat thread having horizontal upper and lower thread flanks. [0029] Additionally, a pressure element 15 is provided which has a substantially cylindrical construction with an outer diameter sized so as to allow the pressure element 15 to be introduced into the bore 8 of the receiving part and to be moved in the axial direction. On its lower side facing towards the second end 7 , the pressure element 15 comprises a spherical recess 16 cooperating with a spherical section of the head 4 . On its opposite side the pressure element 15 has a U-shaped recess 17 extending transversely to the longitudinal axis L by means of which two free legs 18 , 19 are formed. The lateral diameter of this U-shaped recess is selected such that a rod 20 which is to be received in the receiving part 5 can be inserted into the recess 17 and guided laterally therein. The depth of this U-shaped recess 17 is larger than the diameter of the rod 20 so that the legs 18 , 19 extend above the surface of the rod 20 when the rod is inserted. [0030] The bone anchoring device comprises a locking assembly 30 . The locking assembly 30 includes, as shown in particular in FIGS. 2 to 5 a first locking element 31 and a second locking element 32 . The first locking element has a first end 33 and a second end 34 and a substantially cylindrical shape between the first and the second end and with an outer surface having an external thread 35 which is, in the embodiment shown, a flat thread which matches with the internal thread 14 of the receiving part 5 . Further, the first locking element comprises a coaxial bore 36 extending from the second end 34 in the direction of the first end 33 . The coaxial bore 36 comprises an internal thread, which is in the embodiment shown a metric thread. The first locking element 31 further comprises a coaxial recess 37 starting from the first end 33 and extending to a predetermined distance from the second end 34 . The mean diameter of the recess 37 is larger than the diameter of the coaxial bore 36 . As can be seen in particular in FIG. 3 , by means of the recess 37 a substantially ring-shaped wall is formed. A plurality of longitudinal grooves 38 are formed extending from the first end 33 along the wall to the bottom 39 of the recess 37 . The grooves 38 shown in this embodiment have an approximately semi-circular cross section. They are equidistantly distributed in a circumferential direction of the recess 37 . Preferably, at least two grooves are formed. The wall of the recess 37 can have a slanted surface 40 adjacent to the first end 33 in order to facilitate the introduction of a tool. The depth of the recess 37 is selected such that the length of the bore 36 is still sufficient to cooperate with the second locking element 32 for a good fixation. On the other hand the depth of the recess 37 is such that an area sufficient for engagement with a tool is provided. [0031] The second locking element 32 is shaped as a set screw with an external thread 42 cooperating with the internal thread of the coaxial bore 36 . The axial length of the second locking element 32 is such that when the second locking element 32 is completely screwed into the first locking element 31 it projects slightly from the second end 34 of the first locking element. As can be seen in particular in FIG. 4 , the second locking element 32 comprises a coaxial recess 43 with grooves 44 extending in longitudinal direction, similar to the recess 37 and the grooves 38 of the first locking element. The recess 43 and the grooves 44 serve for a form-fit cooperation with a tool to be described hereinafter. [0032] A tool for cooperating with the locking assembly is shown in FIGS. 6 to 9 . The tool 50 comprises a tube 51 and a bar 52 which is slidable in the tube 51 . The tube 51 has an end section 53 for cooperation with the locking assembly and a second end with a grip portion 58 which has, for example, a hexagonal outer shape. As can be seen in particular in FIGS. 7 to 9 , the end section 53 has a reduced outer diameter, corresponding to the inner diameter of the recess 37 of the first locking element. The end section 53 comprises a plurality of projections 54 the number of which is less than or equal to the number of the grooves 38 of the first locking element. The projections 54 are structured and designed to engage with the grooves 38 of the first locking element to provide a form-fit connection between the end section 53 of the tool and the recess 37 of the first locking element. The axial length of the end section 53 is preferably equal to or larger than the depth of the recess 37 . [0033] The bar 52 comprises an end section 55 which is structured and designed to cooperate with the recess 43 of the second locking element 32 . For this purpose, the end section 55 has a plurality of projections 56 the number of which is equal to or less than the number of grooves 44 of the second locking element and which are structured and designed to engage with the grooves 44 . On its opposite end, the bar 52 has a grip portion 57 which allows to grip the bar 52 and to rotate it independently from the tube 51 . The length of the bar 52 is selected such that when the end section 53 of the tube is engaged with the first locking element, the second locking element 32 can be independently engaged by the end section 55 of the bar and screwed into the first locking element. [0034] In operation, first, at least two usually preassembled bone anchoring devices comprising the bone screw 2 , the receiving part 5 and the pressure element 15 are screwed into the bone. Thereafter, the rod 20 is inserted into the U-shaped recess 11 of the receiving part 5 . Then, the locking assembly 30 , comprising the first locking element 31 and the second locking element 32 which are preferably preassembled, is screwed-in between the legs 12 , 13 of the receiving part 5 . The first locking element is tightened by applying the tool 50 such that the end section 53 of the tube engages with the recess 37 and the grooves 38 of the first locking element to form a form-fit connection. In this way, pressure is exerted by the lower side of the first locking element onto the free legs 18 , 19 of the pressure element which presses onto the head 4 of the bone screw 2 to lock the head in its rotational position relative to the receiving part 5 . [0035] Then, the second locking element 32 is tightened by application of the tool in that the end section 56 of the bar engages the recess 43 of the second locking element and torque is applied. In this way, the position of the rod 20 relative to the receiving part is fixed. [0036] A fine tuning of the position of the receiving part 5 relative to the bone screw 2 and of the rod 20 relative to the receiving part can be performed by loosening either the first locking element 31 or the second locking element 32 . [0037] FIG. 9 shows a perspective view of the locking assembly 30 with the end sections 53 and 56 of tool engaging the locking elements with the tool shown in section. For the purpose of illustration only, the remainder of the tool is not shown. As can be seen in FIG. 9 , the end sections of the tool and the recesses of the first and second locking elements form a form-fit connection for the application of torque to screw-in the locking elements. The external thread 35 of the first locking element is of continuous form, without recesses or interruptions. Therefore, the dimension of the locking element can be reduced. This guarantees safe locking of the first locking element. The area required for engagement of the tool with the first locking element is located within the recess 37 . This allows to design the first locking element 31 with a reduced diameter. If the number of grooves 38 is increased, the depth of the grooves can be reduced. Hence, the size of the first locking element can be reduced corresponding to the increase of the number of grooves. [0038] The size of the outer dimension of the first locking element 31 determines the size of the receiving part and the other elements of the bone anchoring device. Further, since the external thread of the first locking element remains intact over its whole length, the height of the locking element can be reduced. [0039] FIG. 10 shows the first locking element 31 with a modified shape of the grooves. The grooves 38 ′ have a triangular cross section. FIG. 11 shows the first locking element 31 with a further modification of the shape of the grooves. The grooves 38 ″ have a square cross section. However, the cross section of the grooves may have another shape as well. [0040] FIG. 12 shows a second embodiment of the locking assembly. The locking assembly 300 comprises three locking elements. The first locking element 301 is shaped like the locking element 31 of the first embodiment. The second locking element 302 differs from the second locking element 30 of the first embodiment in that is has coaxial threaded bore, like the first locking element, to receive the third locking element 303 . It is also possible to design the locking assembly with more than three nested locking elements such that each of the locking elements has a threaded coaxial bore to receive a further locking element. In this manner, for certain applications, an improved fixation can be achieved, for example, if used in complex minimally invasive surgery procedures. [0041] The locking assembly according to a further embodiment includes one single locking element 400 which has an external thread 401 and a coaxial bore 402 extending through the entire locking element from the first end 403 to the second end 404 . A coaxial ring-shaped recess 405 extends from the first end 403 in the direction of the second end. The wall of the recess comprises a plurality of longitudinal grooves 406 for engagement with a tool. By means of the recess 405 and the coaxial bore 402 , a coaxial hollow cylindrical section 407 is formed in the locking element. [0042] A tool for engagement with the locking element is adapted to be engageable with the ring-shaped recess 405 . FIG. 16 shows an exemplary tool 500 cooperating with the locking element 400 . The end section 501 comprises a ring-shaped projection 502 adapted to engage the recess 405 in a form-fitting manner. The end section also 501 comprises a central projection 503 with a retaining spring 504 engaging the coaxial bore 402 for facilitating alignment and handling of the locking element. [0043] The locking element can be used in such applications where it is necessary to introduce an instrument or a wire through the bore 402 , for example in the case of minimally invasive surgery. [0044] Further modifications are possible. The external and the internal thread can have any thread shape, such as, for example, a metric thread. Using a flat thread, a saw-tooth thread or a negative angle thread for the external thread of the first locking element and the cooperating internal thread of the receiving part, however, has the advantage that it prevents splaying of the legs of the receiving part. Therefore, an outer ring or a nut to prevent splaying is not needed. By using the locking assembly of the invention together with a flat thread as the external thread, the implant can be further downsized. [0045] The number of the grooves and the shape of the grooves can vary. [0046] It is conceivable to design the first locking element with a recess having a quadrangular or hexagonal or otherwise polygonal cross section with or without grooves. In this case, the end section of the tool has a matching shape. This also provides for a form-fit connection between the tool and the first locking element with the external thread of the first locking element remaining intact. [0047] The second locking element 32 or the third locking element 303 in the case of the locking assembly 300 of the second embodiment or, in general, the inmost locking element in the case of a locking assembly having multiple locking elements may not need to have a recess with grooves as shown in the embodiment. It is sufficient, that the inmost locking element has a recess for engagement with screwing-in tool, such as a hexagon recess. The corresponding end section of the tool is then adapted to this shape. [0048] The disclosure is not limited to the polyaxial bone anchoring device as shown in the first embodiment. It can be used in the case of a monoaxial bone anchoring device in which the receiving part is fixedly connected to the shank of the bone screw as well. Furthermore, the polyaxial bone anchoring device can have a different construction. It is possible to have a design of the receiving part which allows that the screw is inserted from the bottom instead from the top of the receiving part. [0049] The locking assembly can also be used in such kind of bone anchoring devices in which the receiving part is designed and structured so that the rod is fixed laterally apart from the central axis of the bone screw.	A locking assembly for securing a rod in a receiving part of a bone anchoring device includes a first locking element having a first end and a second end and a longitudinal axis of rotation and an outer surface provided with an external thread, a coaxial bore passing entirely through said first locking element and an internal thread provided at said bore, a second locking element having a longitudinal axis of rotation and an outer surface with an external thread cooperating with the internal thread of said first locking element. The first locking element has a recess between the first end and the second end, that defines a circumferentially closed wall portion. The interior of the wall portion has a longitudinally extending structure for engagement with a tool. Furthermore, a tool is provided which has sections which can be independently engaged with the first and second locking element, respectively.	5
TECHNICAL FIELD The invention of the present application refers broadly to the field of automotive mechanics. More specifically, however, it is concerned with carburetors for use with internal combustion engines. In a preferred embodiment, the invention relates to an improved carburetor including means for heating the air/fuel mixture after those two components are combined and vaporized. BACKGROUND OF PRIOR ART Because of a number of factors, not the least important of which is the rising cost of gasoline, the development of fuel efficient automobiles has become an urgent project of the world's technological community. Nor is there any indication that fuel costs will decline in the foreseeable future so as to reduce the importance of the development of more fuel efficient cars. A number of factors bear upon the efficiency of the typical internal combustion engine used in the majority of automobiles produced in the United States and other countries. One of these factors is the degree to which the air/gasoline mixture introduced into the cylinders of the engine is vaporized. Many carburetors, which effect this function, currently in use on automobiles today do not effectuate sufficient vaporization in order to maximize the engine efficiency. Degree of vaporization is basically the function of two factors: (1) the amount of dispersal and atomization of fuel droplets at the time the fuel is combined with air; and (2) the temperature of the mixture as it is introduced into the cylinders of the engine for combustion. With respect to the first of these factors, the typical carburetor relies upon a reduced pressure created within an induction pipe by an increased velocity of air flow to atomize gasoline being sucked out of a choke tube. Frequently, this process is not adequate to accomplish a desired degree of atomization. With respect to the second factor, heating of air introduced into the induction pipe prior to its entry therein is relied upon to raise the temperature of the air/fuel mixture to the necessary level. An inadequately heated mixture often results since the temperature of the gasoline is lower than that of the air as it enters the induction pipe. Consequently, a transfer of heat energy from the air to the gasoline occurs at time of mixing, and the heated air temperature becomes lowered. Additionally, heat is expended during the vaporization process. A final cause of heat loss is the transfer of thermal energy from the air between the time it absorbs heat from the engine exhaust until the time it enters the induction pipe. Another factor which reduces the efficiency of the automobile engine while it is operating is the inability to selectively regulate the relative amounts of air and gasoline which make up the mixture going into the cylinders in response to the conditions under which the car is being operated. During acceleration periods, a greater percentage of gasoline with respect to the percentage of air in the mixture is necessary than at higher highway cruising speeds. At these higher speeds and under conditions in which there is not frequent acceleration and deceleration, however, the percentage of gasoline with respect to the percentage of air can be significantly reduced without any appreciable reduction in efficiency of the automobile engine. Typically, cars commercially available on the market do not include mechanisms for selectively varying the air/gasoline ratio of the mixture being introduced at the cylinders of the engine. It is these problems extant in the art to which the invention of the present application is directed. It provides a structure which causes the air/gasoline mixture to be heated virtually up until the point at which the mixture enters the engine cylinders. Additionally, it effectuates more complete atomization of the gasoline prior to it being combined with air so that more complete vaporization will occur. It also provides means for selectively regulating the volumes of both air and gasoline which combine to form the mixture introduced into the cylinders. BRIEF SUMMARY OF THE INVENTION The present invention is an apparatus for qualitatively conditioning the air/fuel mixture which enters the cylinders of an internal combustion engine. The apparatus includes a mixing chamber in which combining of the air and fuel occurs. Inlet means are provided to supply both fuel and air to the chamber. The chamber is in communication with a plenum through an entrance to the plenum. The air/fuel mixture, therefore, can pass from the chamber into the plenum and through the plenum to an outlet. Structure is provided for heating the air/fuel mixture while it passes through the plenum. After leaving the plenum through the outlet, the mixture is conveyed to the cylinders where it is combusted. In one embodiment of the invention, a plurality of ducts can extend through the plenum, and exhaust gas taken from the engine exhaust pipe can be passed through these ducts. The heat from the exhaust gas will, thereby, be transferred to the air/fuel mixture after it is combined. Passage of the combustable mixture through the plenum can be facilitated by providing an air jet within the plenum, the jet having a nozzle disposed proximate, and directed toward, the plenum's outlet. Such a structure creates a reduced air pressure and suction to cause the mixture to flow through the plenum. The air ejected by the jet can be heated prior to its exiting the nozzle, but, in some cases, it may still have a lower temperature than that of the mixture exiting the plenum. In order to reheat the mixture, it can be passed through a second plenum having a conduit extending therethrough. As with the ducts in the first plenum, exhaust gas from the engine exhaust pipe can be passed through this conduit to provide a source of thermal energy. In one embodiment, the invention includes structure for leaning the gasoline/air ratio in the mixture entering the cylinders. This can be accomplished by use of apparatus for selectively regulating the volume of gasoline, relative to that of air, which is introduced into the mixing chamber. In applications of the invention wherein it is used on an automobile, means can be provided for selectively regulating this volume remotely from the occupant compartment of the automobile. A perferred embodiment of the invention includes a fuel dispersal and atomizing device within the mixing chamber for facilitating maximum vaporization of the gasoline as it is mixed with air. The device can include a circularly cylindrical, tubular fuel dispersal element which projects into the mixing chamber from a fuel inlet port. A bore, extending the length of the element, communicates, at an end by which the element is captured, with the fuel inlet port. The free end of the element is occluded by an imperforate portion of a disc-like closure member. A multiplicity of perforations are provided in the lateral wall of the dispersal element, through which perforations fuel in the bore passes radially outward and is partially atomized. The disc-like closure member can include a peripheral portion which extends radially beyond the lateral wall of a dispersal element. That peripheral portion of the disc-like element can also include perforations disposed in the flow path of the vaporizing gasoline, and a second stage of atomization can occur as the gasoline passes through these perforations. The invention of this application is thus a carburetor which provides improved efficiency of operation of the engine with which it is used. Specific advantages of the invention will become apparent with reference to the accompanying drawings, detailed description of the invention, and claims. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a side elevational view of an embodiment in accordance with the present invention; FIG. 2 is a view taken along line 2--2 of FIG. 1; FIG. 3 is a side elevational view in cross section showing air jets, a second plenum, and a conduit by which the second plenum is heated; FIG. 4 is a side elevational view in cross section showing the mixing chamber and means for leaning the air/fuel ratio; FIG. 5 is a plan view of the fuel dispersal and atomizing device of FIG. 6 and; FIG. 6 is an elevational view of a fuel dispersal and atomizing device in accordance with one embodiment of the present invention, some portions thereof being broken away. DETAILED DESCRIPTION OF THE INVENTION Referring now to the drawings wherein like reference numerals denote like elements throughout the several views, FIGS. 1 and 2 illustrate a carburetor made in accordance with a preferred embodiment of the present invention. The carburetor, generally illustrated by the reference numeral 10, is shown, particularly in FIG. 2, as attached to an upper portion of an intake manifold 12 of the type typically on internal combustion engines which drive automobiles, trucks, and other vehicles. It will be understood that the carburetor 10 illustrated can appropriately be used both on 8 cylinder engines as used in large automobiles, trucks, and larger vehicles, and on 4 and 6 cylinder engines as used in small automobiles. The carburetor 10 can be attached to the intake manifold 12 by appropriate means such as bolts 14. The carburetor 10 includes an updraft section 16, a cross draft section 18, and a downdraft section 20. It thus can efficiently utilize, and be positioned in a comparatively small, space. Referring now to FIG. 4, the updraft section 16 includes a mixing chamber 22 in which air and fuel are mixed. A fuel line 24 is provided to channel fuel from a tank or fuel heater (not shown) to a fuel inlet at the updraft assembly. The fuel line 24 can be coupled to the updraft assembly 16 by threading it into a female threaded orifice 26 formed in the wall of the updraft section 16. Fuel enters first into a first chamber 28 which provides fuel for both the main jet 30 and the idling jet 32. Fuel is continuously fed from chamber 28 to the idling jet 32 which comprises a needle valve having an orifice 34 and a needle element 36 which can be selectively moved axially with respect to the orifice 34 to manually adjust the fuel rate of flow therethrough. Typically, this setting is made and maintained during normal operation of the engine. Adjustments are made only when it is felt that the idle of the engine is either too fast or too slow. Adjustments can be made by loosening or tightening a lock nut 38 positioned on a shaft 40 extending from the needle element 36. A reservoir 42 is provided to hold a ready supply of fuel to the main jet assembly 30. A float 44 is disposed within the reservoir 40 and positioned so that, as the float 44 rises, a port 46 from the fuel entry chamber 28 can be closed by a needle valve element 48 positioned on the float 44. Closure of the port 46 occurs as the reservoir 42 fills and the float 44 rises. As fuel from the reservoir 42 passes through a passage 50 to the main jet orifice 52, the fuel in the reservoir 42 will drop, the float 44 will lower, and additional fuel will pass into the reservoir 42 until the float 44 again rises to close the port 46. The main jet 30 can be set in a fixed position so that a needle portion 54 thereof can be positioned relative to the main jet orifice 52 with a desired rate of fuel flowing through the orifice 52 per unit time. Fuel passes through the main jet orifice 52 into a second chamber 56 which feeds a fuel dispersal and atomizing device 58 and a line augmenting flow through the idling jet 32. The dispersal and atomizing device 58 extends up through the main jet reservoir 42 and can serve as means for aligning the float 44 for vertical movement. The device 58 further extends through a generally horizontal plate 62 defining the upper wall of the reservoir 42 and into the mixing chamber 22. The device 58 includes a fuel dispersal element 64 which can be a circularly cylindrical, tubular member which projects from the inlet port 66 into the mixing chamber 22. At its first end, the element's lateral wall encircles the port 66 providing access to the mixing chamber 22, and a second end of the element 64 which extends into the chamber 22 has a multiplicity of perforations 68 formed through the lateral wall. The second end of the bore 70 formed in the tube 64 is closed by a closure member. This member can comprise a generally circular disk 72 mounted to the tubular element 64 at its second end. In one embodiment, the disk 72 can be disposed to define a plane generally perpendicular to the axis along which the tubular member 64 projects. An interior portion 74 of the disk 72 is made imperforate to occlude the second end of the cylindrical element 64. Fuel which passes up the cylindrical member 64 by means hereinafter defined is thus forced to pass through the perforations 68 through the lateral wall of the member 64 and into the mixing chamber 22. By passing through these perforations 68, the fuel is dispersed in all directions and finally atomized. The peripheral portion 76 of the disk 72 which extends laterally beyond the wall of the dispersal element 64 can also be perforated so that fuel droplets, as they rise, are passed through a second dispersal and atomization stage. Some fuel droplets may evade this second stage conditioning and pass outside the disk 72, but a large percentage of the droplets will, in fact, be passed through these perforations 78. Flow will generally be in a path illustrated by arrows 79. Fuel line 60 extends from chamber 56 to the idling orifice 34. When the main jet 30 is open, therefore, fuel flow through the idling jet 32 will be augmented by fuel passing through line 60. If main jet 30 is closed, fuel flow to idling jet 32 through line 60 will be precluded. An air intake 80 provides a source of heated air into the mixing chamber 22. The thermal energy which the air has can be obtained by passing it near a hot exhaust pipe (not shown). As the heated air enters the mixing chamber 22, heat will be transferred to the already partially vaporized fuel droplets. As a result, a high degree of vaporization will occur. The air/fuel vapor will, thereafter, pass through a plenum entrance 82 into the cross draft section 18 of the carburetor 10. The cross draft section 18 includes a plenum 84 extending between the updraft and the downdraft sections 16, 20. The air/fuel mixture passes through the plenum 84 and exits, at the opposite end thereof through the plenum outlet 86 into the downdraft section 20 of the carburetor 10. As the mixture passes through the plenum 84, it is free to circulate around a plurality of ducts 88 extending through the plenum 84. The ducts 88 can have a substantially cylindrical inner wall 90 which defines an inner passage 92. Hot exhaust gases from the exhaust manifold or exhaust pipe can be made to pass through this inner passage 92. A substantially cylindrical outer wall 94, and in certain embodiments coaxial with the inner wall 90, is radially spaced outwardly from the inner wall 90 to define an annular chamber 96 between the two walls 90, 94. Provision of these ducts 88 effectuates a high degree of thermal energy transfer from the exhaust gases passing within the inner wall 90 to the air/fuel mixture circulating about the outer wall 94. Means can be provided to induce flow of the mixture through the plenum 84. One or a series of air jets 98 can be positioned so that the nozzles 100 of the jets 98 are proximate, and directed toward, the plenum outlet 86. The reduced pressure which thereby results at the outlet end of the plenum 84 will cause the mixture to pass through the plenum 84 and about the ducts 88. Additionally, this creation of a vacuum at the outlet end of the plenum 84 will also effectuate the passing of fuel upwardly through the fuel dispersal and atomizing element 58. Flow control valve means 102 can be provided to control the volume of air ejected by the nozzles 100 of the air jets 98 and to heat the air prior to its being introduced into the first plenum 84. Since it is an objective of the invention of this application to maintain the temperature of the air/fuel mixture at a high level by the provision of heating means in the plenum 84, the objective would be somewhat frustrated by inserting cold air at this point. As with the intake air injected into the mixing chamber 22, therefore, this air can be passed proximate either the exhaust manifold or exhaust pipe prior to being injected into the plenum 84 so that it will contain a significant amount of thermal energy. The air/fuel mixture thus augmented by additional hot air from the air jets 98 passes through the plenum outlet 86 into the downdraft section 20 of the carburetor 10. The downdraft section 20 comprises a second plenum 104 immediately adjacent the first plenum 84. The air/fuel mixture can be conditioned both quantitatively and qualitatively at this stage. Qualitatively, additional heat can be added to the mixture by the provision of a conduit 106 extending through this second plenum 104, through which conduit exhaust gas is passed. The conduit 106 can be similar in cross sectional construction to that of the ducts 88 in the first plenum 84. Exhaust gases can enter this conduit 106 through an entry in one end thereof, pass through the conduit 106, and, thereafter, be vented. Quantitatively, an additional air source 108 can be provided at this stage to reduce the relative proportion of fuel in the air/fuel mixture. A flow control valve 110 is provided for this purpose. As with air introduced into the mixture through the air jets 98 disposed in the first plenum 84, air introduced at this stage would also be preheated. As can be seen, therefore, the addition of heated air to the mixture at the various sections of the carburetor 10 provide additional heat to maximize the vaporization of the air/fuel mixture which eventually makes its way to the intake manifold 12. A conventional butterfly valve 112 is mounted in a restriction 114 providing communication between the second plenum 104 and the intake manifold 12. A disc-shaped valve element 116 is caused to pivot about a shaft 118 and to open the restriction 114 in response to pressure brought to bear upon the acceleration peddle mounted in the occupant compartment of the vehicle in which the carburetor 10 is mounted. No further discussion of this particular structure will be made since its function and operation is well known in the art. When starting a vehicle on a particularly cold morning, the air/fuel mixture going to the cylinders must be extremely rich. The invention of this application provides means for by-passing the first plenum 84 and pumping fuel directly from the updraft section 16 of the carburetor 10 to the downdraft section 20. A tubular bridge 120 is provided for this purpose. Valve means (not shown) can be included to selectively actuate flow of fuel through the tubular bridge 120. At its end 122 at which it communicates with the updraft section 16, the bridge 120 is attached to the wall thereof so that fuel supplied by the fuel line 24 to the first chamber 28 can be permitted to pass through the tubular bridge 120. Once the fuel reaches the second plenum 104, it is fed into the intake manifold 12 by manipulation of the acceleration peddle to open the butterfly throttle valve 112. When the vehicle is accelerated to higher speeds and the speed is maintained relatively constant, the richness of the mixture can be decreased by use of leaning means for selectively regulating the volumetric flow of fuel through the main jet orifice 52 per unit time. As previously discussed, when the engine is not running the main jet valve needle can be adjusted so that the fuel flow rate is optimal considering all of the conditions under which the vehicle is operated. The leaning means, however, provides the operator of the vehicle with the ability to regulate the flow of fuel during operation. A strut 124 can be made to extend from the wall of the updraft section 16 of the carburetor 10. A clamp portion 126 at the end of the strut 124 can secure a sleeve 128 supporting a bowden cable 130. One end of the cable 130 is mounted within the occupant compartment of the vehicle so that the vehicle's operator can manipulate the cable. The other end is attached to one end of a lever 132 pivotally mounted to the strut 124. The other end of the lever 132 is attached to the adjusting end of the needle control valve element 54. Pulling of the cable 130 by the vehicle's operator will cause a counterclockwise rotation of the lever 132 and a consequential axial movement of the needle valve element 54 into the orifice 52. This will reduce the fuel flow through the main jet orifice 52 and idling orifice 34 and lean the air/fuel mixture transiting to the intake manifold. Numerous characteristics and advantages of the invention have been set forth in the foregoing description of a preferred embodiment. This description is, of course, only illustrative in many respects. Changes may be made in details, particularly in matters of shape, size, and arrangement of parts without exceeding the scope of the invention. It will be understood that the scope of the invention is defined in the language of the appended claims.	An improved carburetor (10) is disclosed and claimed by this application. The carburetor (10) includes an updraft section (16), a crossdraft section (18), and a downdraft section (20). The updraft section (16) includes a mixing chamber (22) in which fuel and air are mixed. This mixture formed therein passes into a plenum (84) of the crossdraft section (18) through which a plurality of ducts (88) extend. A hot fluid passes through these ducts (88) to heat the mixture passing through the plenum (84). The mixture, thereafter, passes through a plenum outlet (86) into another plenum (104) of the downdraft section (20) and to an intake manifold (12) for distributing the mixture to the cylinders of the engine.	5
TECHNICAL FIELD [0001] This disclosure relates to the field of vehicle controls. More specifically, this disclosure relates to altering transmission operation based on determined accuracies of clutch torque estimations. BACKGROUND [0002] Many vehicles are used over a wide range of vehicle speeds, including both forward and reverse movement. Some types of engines, however, are capable of operating efficiently only within a narrow range of speeds. Consequently, transmissions capable of efficiently transmitting power at a variety of speed ratios are frequently employed. Transmission speed ratio is the ratio of input shaft speed to output shaft speed. When the vehicle is at low speed, the transmission is usually operated at a high speed ratio such that it multiplies the engine torque for improved acceleration. At high vehicle speed, operating the transmission at a low speed ratio permits an engine speed associated with quiet, fuel efficient cruising. [0003] A common type of automatic transmission includes a gearbox capable of alternately establishing a fixed number of power flow paths, each associated with a fixed speed ratio. The gearbox includes a number of shift elements such as clutches and brakes. A particular power flow path is established by engaging a particular subset of the shift elements. To shift from one power flow path to another power flow path with a different speed ratio, one or more shift elements must be released while one or more other shift elements must be engaged. Some shift elements are passive devices such as one way clutches, while other shift elements engage or disengage in response to commands from a controller. For example, in many automatic transmissions, the shift devices are hydraulically controlled friction clutches or brakes. The controller regulates the torque capacity of the shift element by regulating an electrical current to a solenoid, which adjusts a force on a valve which, in turn, adjusts a pressure in a hydraulic circuit. [0004] A modern automatic transmission is controlled by a microprocessor which adjusts the torque capacity of each shift element, including any lock-up clutch, at regular intervals. At each interval, the controller gathers information indicating the driver's intent, such as the positions of the shifter (PRNDL), the accelerator pedal, and the brake pedal. The controller also gathers information about the current operating state of the vehicle, such as speed, and of the engine. Increasingly, information is also available from other sources, such as anti-lock brake controllers and GPS systems. Using this information, the controller determines whether to maintain the currently established power flow path or to shift to a different power flow path. If the controller decides to shift to a different power flow path, the controller then adjusts the torque capacities of the off-going shift elements and the on-coming shift elements in a coordinated manner in order to make the transition as smooth as possible. [0005] The control of the clutches in the transmission can be based on a pressure-based control or a torque-based control. In a torque-based control scheme, the desired clutch torque is can be converted to a pressure command using a feed-forward controller that transforms torque into pressure and optionally compensates for clutch dynamics. SUMMARY [0006] According to one embodiment, a method of operating a transmission is provided. The method first includes operating the transmission according to a first shift schedule for a given driving condition. The method then includes operating the transmission according to a second, different shift schedule for the given driving condition in response to a magnitude of uncertainty of estimated clutch torque. [0007] Operating the transmission according to the second shift schedule may occur in response to the magnitude of uncertainty of estimated clutch torque exceeding a threshold for a predetermined time. [0008] The magnitude of uncertainty in clutch torque may be stored in memory. Operating the transmission according to the second shift schedule may include avoiding the particular gear in which the uncertainty occurs in based on the stored magnitude of uncertainty of clutch torque while transitioning into the particular gear. [0009] According to another embodiment, another method of operating a transmission is provided. The method includes first operating the transmission in a plurality of gears using a plurality of clutches. The method then includes increasing a shift time between gears based on a calculated uncertainty of estimated clutch torque to reduce the uncertainty of estimated clutch torque. [0010] According to yet another embodiment, a transmission assembly for a vehicle is provided. The transmission assembly includes a transmission having a plurality of clutches configured to selectively operate the transmission in a plurality of gears. The transmission assembly also includes a controller programmed to (i) control one or more of the clutches according to a first set of instructions, and (ii) control the one or more clutches according to a second set of instructions in response to a magnitude of uncertainty of estimated clutch torque exceeding a threshold. BRIEF DESCRIPTION OF THE DRAWINGS [0011] FIG. 1 is a schematic representation of a transmission; [0012] FIG. 2 is a flow chart for operating a transmission in a fixed gear ratio with the torque converter lockup clutch fully engaged; [0013] FIG. 3 is a flow chart for shifting a transmission with the torque converter lockup clutch fully engaged; [0014] FIG. 4 is a flow chart for operating a transmission in a fixed gear ratio with the torque converter lockup clutch fully disengaged; [0015] FIG. 5 is a flow chart for shifting a transmission with the torque converter lockup clutch fully disengaged; [0016] FIG. 6 is a flow chart for operating a transmission in a fixed gear ratio with the torque converter lockup clutch partially engaged; [0017] FIG. 7 is a flow chart for shifting a transmission with the torque converter lockup clutch partially engaged; [0018] FIG. 8 is a flow chart for adapting a detailed gearbox model based on an aggregate gearbox loss model; [0019] FIG. 9 is a flow chart for selecting the method of estimating component torques which produce the lowest uncertainty of torque prediction; [0020] FIG. 10 is a flow chart illustrating one embodiment of estimating and utilizing clutch torque uncertainties; and [0021] FIG. 11 is a flow chart illustrating another embodiment of estimating and utilizing clutch torque uncertainties. DETAILED DESCRIPTION [0022] Embodiments of the present disclosure are described herein. It is to be understood, however, that the disclosed embodiments are merely examples and other embodiments can take various and alternative forms. The figures are not necessarily to scale; some features could be exaggerated or minimized to show details of particular components. Therefore, specific structural and functional details disclosed herein are not to be interpreted as limiting, but merely as a representative basis for teaching one skilled in the art to variously employ the present invention. As those of ordinary skill in the art will understand, various features illustrated and described with reference to any one of the figures can be combined with features illustrated in one or more other figures to produce embodiments that are not explicitly illustrated or described. The combinations of features illustrated provide representative embodiments for typical applications. Various combinations and modifications of the features consistent with the teachings of this disclosure, however, could be desired for particular applications or implementations. [0023] Controlling a hydraulically actuated automatic transmission requires manipulating a number of pressure commands to achieve a desired result. The desired result may be, for example, an upshift or downshift with particular torque and speed characteristics as a function of time. For an upshift, for example, the desired result may be a torque transfer phase that takes a specified amount of time, followed by a specified speed ratio vs. time profile during the inertia phase. In open loop control, the controller uses a model of the transmission to calculate what pressure commands will produce the desired result and then commands those pressure values. The model may be an empirical model based on testing a representative transmission or may be derived from physical laws and nominal transmission characteristics such as dimension. However, the actual behavior of the transmission may differ from the model for several reasons. First, there are part to part variations among transmissions of the same design. Second, a particular transmission varies over time due to gradual wear or unusual events. Third, the transmission responds to a large number of environmental factors such as temperature, atmospheric pressure, etc. [0024] To improve control in the presence of these variations, called noise factors, a controller may utilize closed loop control. Closed loop control improves the result within a particular event, such as a shift. In closed loop control, the controller measures the property that defines the desired behavior, such as speed ratio. The difference between the measured value and a target value is called the error. The commanded pressure is set to the open loop term plus one or more closed loop terms. A proportional term (p term) is proportional to the error, a derivative term (d term) is proportional to the derivative of the error, and an integral term (i term) is proportional to an integral of the error. Each closed loop term has a coefficient of proportionality. These coefficients are set during calibration such that, despite the presence of noise factors, the result converges rapidly toward the desired behavior with minimal oscillation. [0025] Adaptive control improves the result over a number of events. After an event, the controller utilizes the measurements made during the event to revise the model. (Sometimes this is done implicitly rather than explicitly, such as by modifying the open loop terms.) As the model becomes more representative of the particular transmission and the present conditions, the open loop control of future events becomes better. This minimizes the error that the closed loop terms need to accommodate. [0026] Both closed loop control and adaptive control require measurement or estimation of the properties that define the desired behavior. Ideally, this would be accomplished by having a separate sensor for each property. Unfortunately, sensors add cost and weight to a design and introduce failure modes. Also, some parameters are difficult to measure because the sensor would need to be buried in an inaccessible location of the transmission. Consequently, in practice, the number and type of sensors is restricted. When there is no sensor for the property that defines the desired behavior, a model may be utilized to estimate the value based on the available measured properties. These models are subject to the same types of noise factors as the models used to compute the open loop terms. Furthermore, a model may include assumptions that make it valid only under certain operating conditions, such as when in 2nd gear. In order to estimate the property in all of the relevant operating conditions, the controller may need to use multiple models. In some operating conditions, more than one of the models may be valid, leading to possibly conflicting estimates. In such cases, the controller must determine which estimate to trust. The controller may use the trusted model to revise the other models in order to improve the estimate in operating conditions in which the trusted model is unusable. [0027] A number of models will be discussed with reference to a particular transmission layout. Methods of utilizing these models to estimate unmeasured parameters are discussed with reference to a particular collection of available sensor readings. Finally, methods of adapting the models are discussed. Although the discussion references a particular transmission layout and sensor array, a person of skill in the art may apply the methods discussed to different transmission layouts and sensor arrays. [0028] FIG. 1 illustrates a representative front wheel drive automatic transmission. The transmission is contained in a housing 10 that is fixed to vehicle structure. An input shaft 12 is driven by the vehicle engine. The input shaft may be connected to the engine via a damper that isolates the transmission from engine torque pulsations. An output element 14 drives vehicle wheels. The output element 14 may be driveably connected to the wheels via final drive gearing and a differential. The final drive gearing transmits the power to a parallel axis and multiplies the torque by a fixed final drive ratio. The final drive gearing may include layshaft gears, a chain and sprockets, and/or planetary gearing. The differential divides the power between left and right front wheels while permitting slight speed differences as the vehicle turns. Some vehicles may include a power take-off unit that transfers power to rear wheels. [0029] A torque converter 16 has an impeller 18 fixed to input shaft 12 and a turbine 20 fixed to turbine shaft 22 . Torque converter 16 transmits torque from input shaft 12 to turbine shaft 22 while permitting turbine shaft 22 to rotate slower than input shaft 12 . When turbine shaft 22 rotates substantially slower than input shaft 12 , a torque converter stator 24 is held against rotation by one way clutch 26 such that the torque applied to turbine shaft 22 is a multiple of the torque supplied at input shaft 12 . When the speed of turbine shaft 22 approaches the speed of input shaft 12 , one way clutch 26 overruns. Torque converter 16 also includes a lock-up clutch 28 that selectively couples input shaft 12 to turbine shaft 22 . [0030] Gear box 30 establishes a number of speed ratios between turbine shaft 22 and output element 14 . Specifically, gear box 30 has three planetary gear sets and five shift elements that establish six forward and one reverse speed ratio. Simple planetary gear sets 40 , 50 , and 60 each have a sun gear ( 42 , 52 , 62 ), a carrier ( 44 , 54 , 64 ), and a ring gear ( 46 , 56 , 66 ) that rotate about a common axis. Each planetary gear set also includes a number of planet gears ( 48 , 58 , 68 ) that rotate with respect to the carrier and mesh with both the sun gear and the ring gear. Carrier 44 is fixedly coupled to ring gear 66 and output element 14 , carrier 54 is fixedly coupled to ring gear 46 , ring gear 46 is fixedly coupled to carrier 64 , and sun gear 52 is fixedly coupled to turbine shaft 22 . [0031] The various speed ratios are established by engaging various combinations of shift elements. A shift element that selectively holds a gear element against rotation may be called a brake whereas a shift element that selectively couples two rotating elements to one another may be called a clutch. Clutches 72 and 74 selectively couple turbine shaft 22 to carrier 64 and sun gear 62 , respectively. Brakes 76 and 78 selectively hold sun gear 62 and sun gear 42 , respectively, against rotation. Brake 80 selectively holds carrier 64 against rotation. Finally, one way clutch 82 passively holds carrier 64 against rotation in one direction while allowing rotation in the opposite direction. Table 1 illustrates which shift elements are engaged to establish each speed ratio. [0000] TABLE 1 72 74 76 78 80/82 Ratio Step Reverse X X −3.00 71% 1st X X 4.20 2nd X X 2.70 1.56 3rd X X 1.80 1.50 4th X X 1.40 1.29 5th X X 1.00 1.40 6th X X 0.75 1.33 [0032] Shift elements 72 - 80 may be hydraulically actuated multi-plate wet friction clutches or brakes. As part of the transmission assembly, a controller 84 controls the pressure of transmission fluid routed to each shift element. This controller may adjust an electrical current to one or more variable force solenoids to control the pressure supplied to each clutch. When pressurized fluid is first supplied to a shift element, it moves a piston into a stroked position. Then, the piston forces the plates together causing the shift element to transmit torque. The torque capacity is negligible until the piston reaches the stroked position. Once the piston reaches the stroked position, the torque capacity increases approximately linearly with the fluid pressure. When the pressure is relieved, a return spring moves the piston to a released (not stroked) position. The controller receives signals from a turbine speed sensor 86 , an output speed sensor 88 , and an output torque sensor 90 . [0033] In order to estimate the speeds of particular elements and the torques on particular elements to the values measured by sensors 86 - 90 , models are needed. Such models may be derived based on the speed and torque relationships of each of the components disregarding any parasitic power losses. If a group of components that are fixededly coupled to one another is modeled as a rigid element, then the sum of the torques exerted on that group, called a shaft, is proportional to the rotational acceleration of the shaft. The coefficient of proportionality is called the rotational moment of inertia, J, which can be estimated based on the dimensions and material density or can be measured experimentally. [0000] Στ= Ja [0000] Gearbox 30 of FIG. 1 has six such shafts: turbine shaft 22 and sun 52 ; sun 42 ; output 14 , carrier 44 , and ring 66 ; carrier 54 and ring 46 ; carrier 64 and ring 56 ; and sun 62 . [0034] Disregarding parasitic losses, the speeds of the elements of a planetary gear set and their relative torques are related to the number of teeth on the sun gear, N sun , and the number of teeth on the ring gear, N ring . Specifically, for a simple planetary gear set, [0000] N sun ω sun +N ring ω ring =( N sun +N ring )ω carrier [0000] N ring τ sun =N sun τ ring [0000] τ sun +τ carrier +τ ring =0 [0035] For a double-pinion planetary gear set, [0000] N ring ω ring −N sun ω sun =( N ring −N sun )ω carrier [0000] N ring τ sun =N sun τ ring [0000] τ sun +τ carrier +τ ring =0 [0036] A friction clutch selectively couples two elements, called the hub and the shell. In the examples herein, the top edge of the clutch symbol in FIG. 1 will be treated as the shell and the bottom edge of the symbol will be treated as the hub, although the choice is arbitrary. The torques applied to each element are a function of the clutch torque capacity, τ cap , and relative speeds of the elements. Specifically, [0000] { τ hub = τ cap   if   ω hub < ω shell abs  ( τ hub ) <= τ cap   if   ω hub = ω shell τ hub = - τ cap   if   ω hub > ω shell } τ hub + τ shell = 0 [0000] Disregarding parasitic losses, the torque capacity of a released clutch is zero. [0037] For gearbox 30 in FIG. 1 , each of the three planetary gear sets provide one equation relating the speeds of the six shafts. When the gearbox is engaged in a particular gear ratio (not shifting), the two engaged clutches each provide one equation relating the speeds of the shafts. With six shafts and five equations, we must have one measured speed in order to be able to calculate all of the speeds. This additional speed could be provided by turbine speed sensor 86 or by output speed sensor 88 . For example when third gear is engaged (clutch 74 and brake 78 engaged), the speeds of the six shafts can be determined by simultaneously solving the six equations: [0000] N 42 ω 42 +N 46 ω 46,54 =( N 42 +N 46 )ω 14,44,66 (from gear set 40) [0000] N 52 ω 22,52 +N 56 ω 56,64 =( N 52 +N 56 )ω 46,54 (from gear set 50) [0000] N 62 ω 62 +N 66 ω 14,44,66 =( N 62 +N 66 )ω 56,64 (from gear set 60) [0000] ω 22,52 =ω 62 (from clutch 74 being engaged) [0000] ω 42 =0 (from brake 78 being engaged) [0000] ω 14,44,66 =measured [0000] The second speed sensor may be used to confirm that third gear is in fact engaged. Each speed is proportional to the measured speed. The equations can be solved in advance to find the coefficient of proportionality for each shaft for each gear ratio. [0038] For gearbox 30 , there are 21 element torques to be calculated, three for each planetary gear set, two for each clutch, plus the input torque and the output torque. Each of the three planetary gear sets provides two torque equations. Each of the five shift elements provides one torque equation. Each of the six shafts provides one torque equation. (By convention, output torque is defined as the torque exerted by the gearbox on the output, whereas other torques are defined as the torque exerted by the component on the shaft. Therefore, output torque appears on the opposite side of the shaft torque equation from component torques.) Each shaft equation requires the shaft acceleration which is determined by numerically differentiating the shaft speed. Collectively, this provides 17 torque equations. When the gearbox is engaged in a particular gear ratio, the three disengaged clutches each provide an additional torque equation. Therefore, one sensed torque is required, which is provided by torque sensor 90 . For example when third gear is engaged, the torques can be determined by simultaneously solving the 21 equations: [0000] N 46 τ 42 =N 42 τ 46 [0000] τ 42 +τ 44 +τ 46 =0 [0000] N 56 τ 52 =N 52 τ 56 [0000] τ 52 +τ 54 +τ 56 =0 [0000] N 66 τ 62 =N 62 τ 66 [0000] τ 62 +τ 64 +τ 66 =0 [0000] τ hub 72 +τ shell 72 =0 [0000] τ hub 74 +τ shell 74 =0 [0000] τ hub 76 +τ shell 76 =0 [0000] τ hub 78 +τ shell 78 =0 [0000] τ hub 80 +τ shell 80 =0 [0000] τ input +τ 22 +τ shell 72 +τ hub 74 =J 22,52 a 22,52 [0000] τ 42 +τ hub 78 =J 42 a 42 [0000] τ 44 +τ 66 =τ output +J 14,44,66 a 14,44,66 [0000] τ 46 +τ 54 =J 46,54 a 46,54 [0000] τ 56 +τ 64 +τ hub 72 +τ hub 80 =J 56,64 a 56,64 [0000] τ 62 +τ shell 74 +τ hub 76 =J 62 a 62 [0000] τ hub 72 =0 (from clutch 72 being disengaged) [0000] τ hub 76 =0 (from brake 76 being disengaged) [0000] τ hub 80 =0 (from brake 80 being disengaged) [0000] τ output =measured [0000] These equations can be manipulated such that each torque is expressed as a sum of two terms, one term proportional to the measured torque and the other proportional to the measured acceleration. The coefficients of proportionality can be determined in advance for each gear ratio. The hub and shell torque of the applied shift elements, 74 and 78 in this example, indicate a lower limit on the respective shift element torque capacity. However, the actual torque capacity cannot be determined using this model. [0039] The above model disregards parasitic losses. However, the model can be modified to account for some types of parasitic losses. For example, a disengaged shift element does not necessarily have zero torque capacity. This type of parasitic drag can be accounted for in the model by calculating the torque capacity of disengaged clutches as a function of the speeds of the hub and the shell, or as a function of the speed difference. Windage losses can be accounted for by adding a windage term in each shaft torque equation where the windage term is a function of the shaft speed. Mesh efficiency can be accounted for by slightly increasing or decreasing the tooth counts in the equation that relates the sun gear torque to the ring torque. Whether the tooth count is increased or decreased depends on the relative speeds and the direction of the torque. When losses are modeled this way, the individual component torques (e.g., clutch torques) can still be computed based on a single measured speed and a single measured torque, although it may not be possible to pre-simplify the equations. [0040] An alternative approach to modeling parasitic losses is to model the aggregate losses of the gearbox. The aggregate power loss of the gearbox may be tabulated as a function of the measured speed and measured torque and possible other factors such as fluid temperature. This table may be populated empirically using a dynamometer, using detailed component models, or some combination of the two. One disadvantage of using an aggregate loss model is that it is not as amenable to calculating individual component torques as a detailed component by component loss model. [0041] During a shift between ratios, the calculations of component torque must be modified. A typical upshift includes three phases: a preparatory phase, a torque transfer phase, and an inertia phase. During the preparatory phase, pressure is commanded to the on-coming shift element in order to stroke the piston so that it is ready for engagement. Also, the torque capacity of the off-going shift element may be reduced from a holding capacity well in excess of the transmitted torque to a value close to the actual transmitted torque. During the torque transfer phase, the torque capacity of the off-going shift element is gradually reduced and the torque capacity of the on-coming shift element is gradually increased. During this phase, there is little or no slip across the off-going shift element but considerable slip across the on-coming shift element. When the off-going shift element torque capacity reaches zero, the power flow path associated with the upshifted gear is established. Therefore, the torque ratio is equal to the upshifted torque ratio. However, the speed ratio is still equal or nearly equal to the original speed ratio. When the off-going shift element is completely released, the torque transfer phase ends and the inertia phase begins. During the inertia phase, the torque capacity of the on-coming shift element is controlled to eliminate the slip across the on-coming shift element and bring the speed ratio to the upshifted speed ratio in a controlled manner. [0042] A downshift also includes an inertia phase and a torque transfer phase, although they occur in the opposite order. During the inertia phase, the torque capacity of the off-going shift element is controlled to bring the speed ratio to the downshifted speed ratio in a controlled manner, which involves a progressively increasing slip across the off-going shift element. The on-coming shift element may be prepared for engagement by commanding pressure in order to stroke the piston. During the inertia phase, the torque capacity of the on-coming shift element is gradually increased while the torque capacity of the off-going element is reduced to zero. [0043] During the shift, neither the on-coming nor the off-going shift element can be assumed to have zero slip. Although it may be intended for the off-going shift element to have zero slip during the torque phase of an upshift and for the on-coming shift element to have zero slip during the torque phase of a downshift, the controller cannot assume this to be the case. Therefore, one of the component speed equations that is used when the transmission is in a fixed gear is not available during the shift. Consequently, both speed sensors 86 and 88 contribute speed equations. In some shifts, more than one clutch is released and more than one clutch is engaged. In such shifts, more than two shafts speeds must be determined with sensors. [0044] Similarly, during the shift, neither the on-coming nor the off-going shift element can be assumed to have zero torque capacity. Although it may be intended for the on-coming shift element to have zero torque capacity during the preparatory phase of an upshift and during the inertia phase of a downshift, the controller cannot assume this to be the case. Sometimes, the pressure intended to merely stroke the piston actually causes a torque capacity increase. Therefore, one of the component torque equations that is used when the transmission is in a fixed gear is not available during the shift. If the transmission is not equipped with a second torque sensor, then a model may be used to estimate the input torque to provide the additional component torque equation. [0000] τ input =τ turbine +τ hub 28 [0045] When torque converter lock-up clutch 28 is disengaged, the torque at the hub of lock-up clutch 28 is zero. Therefore, a model of the torque converter can provide the additional torque estimate needed during shifting. For a particular torque converter geometry (diameter, blade angles, etc), the hydro-dynamic torques exerted on the torque converter elements are functions of the turbine speed and the impeller speed. Environmental factors, such as fluid temperature, may also impact the relationship to some degree. A suitable torque converter model is described in U.S. Patent Publication 2013/0345022 which is hereby incorporated by reference herein. Specifically, [0000] τ impeller =f 1(ω impeller /ω turbine ,temp, . . . )ω impeller 2 [0000] τ turbine =f 2(ω impeller /ω turbine ,temp, . . . )ω impeller 2 [0000] τ turbine +τ impeller +τ stator =0 [0000] The functions f1 and f2 can be determined experimentally and stored by the controller as tables. The turbine speed is directly measured using sensor 86 . The impeller speed is equal to the engine crankshaft speed and can be obtained using a third speed sensor or by communication with an engine controller. [0046] When lock-up clutch 28 is engaged, on the other hand, a model of the engine torque can provide the additional torque estimate needed during shifting. The transmission controller may obtain the current engine torque estimate by requesting it from the engine controller which maintains an engine torque model. Specifically, [0000] τ engine +τ impeller +τ shell 28 =J 12 a 12 [0000] When lock-up clutch 28 is fully engaged, the impeller torque is zero. When the lock-up clutch is slipping, the hydro-dynamic model above may be used to estimate the impeller torque. [0047] During the shift, accurate control of torque capacity is important in order to achieve a smooth shift. For example, during the torque transfer phase, the increase in torque capacity of the on-coming shift element must be carefully coordinated with the decrease in torque capacity of the off-going shift element. If the torque capacity of the on-coming shift element is ramped up too slowly, relative to the input torque and the rate of decrease of off-going shift element torque capacity, then an engine flare occurs. If, on the other hand, the on-coming shift element torque is ramped up too quickly, then a tie-up condition occurs. Both result in an excessive decrease in output torque. [0048] Open loop control of shifts is aided by having a model for each shift element. The torque capacity of each clutch is adjusted by adjusting an electrical current to a solenoid in the valve body. A valve in the valve body responds by adjusting the pressure in a fluid circuit in proportion to the force generated by the solenoid. The fluid is routed to a clutch apply chamber where it pushes a piston to compress a clutch pack with interleaved friction plates and separator plates. A return spring forces the piston back when the pressure is relieved. In an exemplary steady state model of a hydraulically actuated friction clutch or brake, the torque capacity is a function of the electrical current supplied. This function generally has two segments. In a first segment, from zero current up to the current required to overcome the force of the return spring, the torque capacity is zero. Beyond the current required to overcome the return spring, the torque capacity increases linearly with respect to the current. In an alternative model, the fluid pressure is a function of the electrical current and the torque capacity is a function of the fluid pressure. This alternative model may be useful if a pressure sensor is available to provide a pressure feedback signal. In some models, other factors such as temperature may be considered. A dynamic model of the hydraulically actuated shift element may account for the time delay while the piston moves from the released position to the stroked position. [0049] At each time step, the controller determines a desired torque capacity for each shift element and then determines what electric current to command to the corresponding solenoid using the shift element model. This open loop control method, however, is subject to inaccuracy due to various noise factors. When a torque capacity estimate based on a measurement is available, the inaccuracies can be reduced using closed loop terms. When a clutch is slipping, such as the on-coming element in an upshift torque phase or the off-going element in a downshift torque phase, the gearbox model described above provides such an estimate. Furthermore, the estimated torque capacity can be used to adaptively revise the shift element model. Consequently, control is improved even when the shift element is not slipping, such as the off-going element in an upshift or the on-coming element in a downshift. [0050] When the transmission is in a fixed gear ratio, there are multiple models which predict gearbox input torque. This provides an opportunity to adaptively refine one or both models. One estimate is produced by the gearbox model in combination with a torque sensor reading and a speed sensor reading. This model may include component parasitic loss models or an aggregate parasitic loss model. When lock-up clutch 28 is fully engaged, a second gearbox input torque estimate is based on an engine model. If the estimates differ, the engine model may be modified to bring that estimate closer to the gearbox based estimate. Alternatively, or additionally, the aggregate gearbox loss model may be modified to bring the gearbox based estimate closer to the engine model based estimate. Similarly, when lock-up clutch 28 is disengaged, a second gearbox input torque estimate is based on a torque converter model. If the estimates differ, the torque converter model, the aggregate gearbox loss model, or both may be modified to bring the estimates closer together. Also, when lock-up clutch 28 is disengaged, both the engine model and the torque converter model estimate impeller torque. If these two estimates differ, one or both models may be modified to bring the estimates closer together. [0051] Several of the models described above can be represented in controller 84 as one or more lookup tables. A lookup table stores predicted values of a model output variable for various combinations of values of one or more model input variables. When there is only one input variable, the lookup table is referred to as one dimensional. For example, a one dimensional lookup table may be used to represent the clutch transfer function model by storing values of clutch torque capacity at various commanded pressures. When the output variable is dependent upon multiple input variables, higher dimensional lookup tables are used. For example, the aggregate gearbox loss model for 3rd gear may be represented as a three dimensional lookup table based on gearbox input torque, gearbox input speed, and temperature. If the model includes multiple output variables, it may be represented by multiple lookup tables. For example, the torque converter model may have one lookup table for impeller torque and another lookup table for turbine torque. [0052] To find a value for a model output variable based on particular values of the model input variables, the controller finds the stored points that are closest to the particular values and then interpolates. For example, to find the predicted gearbox losses at 1200 rpm input speed and 75 Nm input torque, the controller may interpolate between the stored loss values at (1000 rpm, 70 Nm), (1500 rpm, 70 Nm), (1000 rpm, 80 Nm), and (1500 rpm, 80 Nm). To find an input variable corresponding to a desired output variable, reverse interpolation is used. For example, to find the open loop pressure command for a desired clutch torque capacity of 95 Nm, the controller may interpolate between a stored point that yields 92 Nm and a stored point that yields 96 Nm. This reverse interpolation yields a unique solution only when the underlying function is monotonic. Alternatively, the model may be re-formulated such that torque capacity is an input variable and commanded pressure is an output variable. [0053] Several methods are known for adaptively updating a model represented as a lookup function. These include both stochastic adaptation methods and periodic adaptation methods. Stochastic adaptation methods update the values in the lookup table in response to individual observed results. One such method is described in European Patent Application EP 1 712 767 A1, which is incorporated by reference herein. When the observed result differs from the value estimated by the lookup table, the stored values for nearby values of the model input variables are modified such that a new prediction for the same model input values is closer to the observed result. In the example above, stored gearbox loss estimates at (1000 rpm, 70 Nm), (1500 rpm, 70 Nm), (1000 rpm, 80 Nm), and (1500 rpm, 80 Nm) were used to predict gearbox losses at 1200 rpm input speed and 75 Nm input torque. If the interpolation yields an estimate of 1.5 Nm of loss and the observed loss is 2.5 Nm, those four stored values might each be increased by 0.2 Nm such that a new estimate at the same operating point would be 1.7 Nm. For stability, the adaptation is not allowed to change the stored values by too much at once. The adaptation may be restricted in various ways. For example, adaptation may only be allowed when the operating point is sufficiently close to one of the stored values. In this example, adaptation may not be performed for the observation at 1200 rpm and 75 Nm but may be allowed for operating points within 100 rpm at 2 Nm of one of the stored values. Also, there may be pre-defined bounds outside which adaptation is not performed. For example, in the gearbox loss model, stored values may not be permitted to become negative since actual losses would never be negative. In a periodic adaptation method, multiple observations are stored and then a curve fitting process is performed to calculate new values for model parameters. As with stochastic adaptation methods, there may be restrictions on the rate of adaptation and there may be boundaries beyond which adaptation is not permitted. [0054] During operation of a transmission, there are several operating conditions in which more than one model is available to predict a particular parameter. In such a circumstance, the controller may select one of the estimates as the trusted value. This selection may be based on a priori information about which model tends to be more accurate. The selection may also be based on other criteria such as when the inputs to one model are relatively constant and the inputs to the other model are changing rapidly making the former model more trustworthy. The controller may utilize the trusted value to adapt the less trusted model, making the less trusted model more trustworthy in other circumstances. Alternatively, the controller may select a value that is a weighted average of the multiple estimates, with weighting factors based on the degree of trust of each model. In that case, both models may be subject to adaptation to bring the estimates closer to the selected value. This approach is most useful if each model is also adapted in other circumstances based on independent models. If one model is correct and the other model is inaccurate, the correct model will be re-adapted toward its original prediction in those other circumstances. [0055] FIG. 2 illustrates a process for operating a transmission, such as the transmission of FIG. 1 , when the torque converter lockup clutch 28 is fully engaged and the transmission is to remain in the current gear ratio. This process is repeated at regular intervals while the transmission remains in this condition. The gearbox output torque is measured at 102 using torque sensor 90 , for example. The turbine speed is measured at 104 using speed sensor 86 , for example. The acceleration rate of the turbine may be determined by numerically differentiating the turbine speed signal or may be measured by a separate sensor. Since the turbine speed and the engine speed are equal in this operating condition, an engine speed sensor or impeller speed sensor could be used instead of a turbine speed sensor. At 106 , a detailed gearbox model is used to estimate the torques of each transmission component of interest, such as gears and shift elements. These torques are proportional to the gearbox output torque measured at 102 corrected for parasitic losses, which may be based on the speed measured at 104 , and inertia effects based on the acceleration measured at 104 . In this condition, the gearbox input torque is equal to the engine torque after accounting for any torque used to accelerate the torque converter inertia. Therefore, the gearbox input torque may be computed at 108 based on an engine model and the acceleration measured at 104 . The gearbox input torque may also be computed at 110 using a gearbox aggregate loss model, the gearbox output torque measured at 102 , and correcting for inertia based on the acceleration measured at 104 . Since two estimates of gearbox input torque are available, the controller arbitrates between these estimates at 112 . For example, the arbitration routine may use a weighted average of the two estimates with the weighting factors based on prior assessments of the trustworthiness of each model. If either model produces a result that is considered unreasonable, the arbitration routine may disregard that estimate and use the other estimate. At 114 and 116 , the controller uses the resulting estimate to adapt the engine model and aggregate loss model respectively. In this condition, the controller commands a high pressure to each engaged shift element for the current gear ratio to ensure that the clutches remain fully engaged. [0056] FIG. 3 illustrates a process for operating a transmission during a shift when the torque converter lockup clutch is fully engaged. This process is repeated at regular intervals during the shift. Steps that are common with FIG. 2 use the same reference number. At 118 , the detailed gearbox model is used to estimate the torques of each transmission component of interest, such as gears and shift elements. During the shift, the detailed gearbox model requires two input torque values, so both the measured torque from 102 and the estimated gearbox input torque from 108 are utilized. The desired clutch torque capacities, as required to generate the desired shift feel, are computed at 120 . At 122 , a clutch model for each clutch is used to calculate the pressure required to produce the desired torque, which is used as an open loop term for clutch pressure control. At 124 , the difference between the desired clutch torque capacity and the corresponding estimates from 118 is used to compute closed loop terms. At 126 , the control commands a pressure equal to the sum of the open loop term and the closed loop terms. At 128 , the commanded pressure from 126 and the estimated shift element torque from 118 may be used to adapt the clutch models, such that future shifts are improved due to reduced reliance on closed loop feedback. [0057] FIG. 4 illustrates a process for operating a transmission when the torque converter lockup clutch is fully disengaged and the transmission is to remain in the current gear ratio. This process is repeated at regular intervals while the transmission remains in this condition. As in the process of FIG. 2 , a turbine torque estimate is generated at 110 based on measured gearbox output torque, turbine speed, and turbine acceleration, using an aggregate gearbox loss model. Additionally, impeller speed and acceleration are measured at 130 . At 132 , a torque converter model is used with the measured impeller speed and measured turbine speed to estimate the impeller torque and the turbine torque. At 134 , the engine model is used to produce a second estimate of impeller torque. Since there are two estimates of impeller torque and two estimates of turbine torque, arbitration is performed at 136 and 138 to select values. The selected values may be used to adapt the engine model, torque converter model, and aggregate gearbox loss model at 114 , 140 , and 116 respectively. FIG. 5 illustrates a process for operating the transmission during a shift when the torque converter lockup clutch is fully disengaged. As in the method of FIG. 3 , both the turbine torque and the gearbox output torque are used at 118 with the detailed gearbox model to estimate the shift element torques. These shift element torques estimates may be used at 128 to adapt the corresponding clutch models. Since only one turbine torque estimate is produced, only the impeller torque aspect of the torque converter model is adapted at 140 . [0058] FIG. 6 illustrates a process for operating a transmission when the torque converter lockup clutch is partially engaged and the transmission is to remain in the current gear ratio. This process is repeated at regular intervals while the transmission remains in this condition. In this condition, the gearbox input torque is the sum of the turbine torque and the lockup clutch torque. Similarly, the engine torque is the sum of the lockup clutch torque and the impeller torque. The gearbox input torque is estimated at 110 based on the measured gearbox output torque and the aggregate loss model. The turbine torque and impeller torque are estimated at estimated at 132 based on measured impeller and turbine speeds. The engine torque is estimated at 142 based on the measured impeller speed, which is equal to the engine speed. The lockup clutch torque is estimated in three ways. At 144 , the lockup clutch torque is estimated by subtracting the impeller torque estimate from the engine torque estimate. At 146 , the lockup clutch torque is estimated by subtracting the turbine torque estimate from the gearbox input torque estimate. At 148 , the lockup clutch torque is estimated using a lockup clutch model. The arbitrated lockup clutch torque estimate produced at 146 is then used to adapt the lockup clutch model at 148 . FIG. 7 illustrates a process for shifting the transmission while the lockup clutch is slipping. At 154 , the gearbox input torque is estimated by adding the estimated clutch torque produced by the lockup clutch model at 148 to the turbine torque estimate produced at 132 . [0059] FIG. 8 illustrates a process for adapting the detailed gearbox model. This process is executed much less frequently than the processes of FIGS. 2-7 . This process propagates the gradual adaptation of the aggregate gearbox loss model to the detailed gearbox model. Stochastic adaptation may be unsuitable for this because many parameters in the detailed gearbox model may contribute, to varying degrees, to the losses at a particular operating point. A stochastic adaptation algorithm may be unable to determine which parameter to adapt. However, since the relative contribution differs at different operating points, it may be possible to identify which parameter to adjust after observing an appropriate variety of operating points. At 160 , the detailed gearbox model is used to estimate the gearbox input torque corresponding to a variety of gearbox output torques, gearbox input speeds, and gear ratios. The collection of output torques, input speeds, and gear ratios may be predetermined or may be derived from the operating points observed since the previous execution of the process. At 162 , the aggregate gearbox loss model is used to estimate the gearbox input torque at the same collection of operating points. The values from the two models are compared at 164 to calculate a set of error terms. The number of error terms is equal to the number of operating points considered. At 166 , the process computes the sensitivity of each error term to changes in various parameters of the detailed gearbox model. These parameters may be, for example, particular values in lookup tables. Computing the sensitivities may involve repeating the calculations from 160 and 164 with each parameter slightly perturbed from its nominal value. The number of parameters should be equal to or larger than the number of operating points. At 168 , revised parameter values that minimize the error terms are computed. This may involve, for example, a least squares curve fit. Finally, at 170 , the parameter values are adapted toward the values calculated at 168 . To avoid instability, the process may adjust the parameter values to an intermediate value between the original value and the value computed at 168 . [0060] The processes of FIGS. 2-8 provide the ability to compute torque estimates for gears and shift elements within a gearbox based on an output torque sensor, impeller and turbine speed sensors, and a variety of models. The processes also provide the ability to adapt the models such that they accurately represent the current behavior of the system despite part to part variation and component changes over time. The above are but examples of estimating torques for gears and shift elements within a gearbox. [0061] In a torque based clutch control scheme, such as those described above, the desired clutch torque is converted to a pressure command using a feed-forward controller which transforms torque into pressure and optionally compensates for clutch dynamics. In this system, the clutch torque is independently estimated and compared against the expected clutch torque to dynamically adapt the clutch-torque-to-pressure transfer function. To achieve the best shifting performance and consistency, the control system can include both feed-forward and feedback compensators. Based on a desired clutch torque, a nominal feed-forward clutch pressure could be commanded based on one of the models which transforms torque into pressure. To provide robustness, this nominal pressure would be adjusted to compensate for any differences between the desired clutch torque and the achieved clutch torque as estimated by an independent model. In addition to adjusting the clutch torque command, the estimated clutch torque is also compared against the expected clutch torque to dynamically adapt the clutch-torque-to-pressure transfer function. [0062] As explained above, the clutch torque is typically not directly measured. However, it can be estimated with a combination of physical models, sensor measurements and state estimates. A challenge in estimating the clutch torques is that the accuracy of the clutch torque estimates depends on the state of the system. For a given clutch, the estimated clutch torque may be accurate within +/−50 Nm for one shift (e.g., from 2 nd to 3 rd gear) and may be accurate within +/−5 Nm for another shift (e.g., from 5 th gear to 3 rd gear). Moreover, the accuracy of the estimates used to calculate clutch torques can also vary (age, temperature, etc.) and this variability is transferred to the clutch torque estimates. [0063] In certain conditions, an estimated clutch torque might have such a significant amount of uncertainty that it is best to not use it to correct the transfer function model and/or use it for feedback control. Knowing the confidence intervals of the clutch torque estimates is therefore important to closed-loop clutch control. FIGS. 9-11 are described below. [0064] The uncertainty in estimating the clutch torque for a particular shift can be directly estimated as the clutch torque estimator is a linear system. For example, a clutch torque model can be defined by [0000] Tq clutch =C Tq input Tq input +C Tq output Tq output +C α 1 α 1 + . . . +C α n α n [0000] where Tq clutch is the clutch torque, Tq input is the input torque, Tq output is the output torque, a 1 . . . a n are the accelerations of elements 1 to n and C tqinput , C tqoutput , C α1 . . . C αn are the coefficient of the clutch torque model. This is just one exemplary model which can be used to estimate clutch torques. Other models are discussed herein. Estimating clutch torques using multiple models or calculations is broadly captured at 180 . For this particular model, the uncertainty in the estimated clutch torque in terms of a standard deviation σ is illustrated at 182 and can be defined by [0000] σ Tq clutch =(( C Tq input σ Tq input ) 2 +( C Tq output σ Tq output ) 2 +( C α 1 σ α 1 ) 2 + . . . +( C α n σ α n ) 2 ) 0.5 [0065] Because the clutch coefficients vary from clutch to clutch and from shift to shift, so too can the uncertainty of the estimated clutch torque. As the uncertainty in the estimated input torque, output torque and accelerations changes, the system can dynamically estimate the uncertainty or confidence of the estimated clutch torque for any clutch and any shift. [0066] Consider the clutch application schedule shown in Table 1 above. When the transmission is locked in 3 rd gear, clutches 74 and 78 are locked. The clutch torque on clutch 74 could be estimated by: (M1) using the model for the locked 3 rd gear operation, (M2) using the model for a shift between 2 nd and 3 rd gear in which clutch 78 remains locked and clutch 76 and 74 are slipping, or (M3) using the model for a shift between 3 rd gear and 4 th gear in which clutch 78 is locked and clutches 74 and 72 are slipping. All three of these methods are valid system representations. If the torque and acceleration terms were known perfectly, then the models would predict the exact same clutch torques. The difference between method M1 compared to methods M2 and M3 is that M1 is derived using two acceleration constraint equations (no net acceleration across clutches 74 and 76 ) whereas M2 and M3 are derived using only one acceleration constraint equation. [0067] By assuming both clutches 74 and 78 are locked, clutch torque model M1 takes a reduced form which only includes two estimation terms as in: [0000] Tq clutch,M1 =C Tq input ,M 1 Tq input +C Tq output ,M 1 Tq output [0068] For clutch torque models M2 and M3, only one clutch is assumed to be locked and two clutches are assumed to be potentially slipping. These models would require three estimation terms as in: [0000] Tq clutch,M2 =C Tq input ,M 2 Tq input +C Tq output ,M 2 Tq output +C α,M2 α [0000] Tq clutch,M3 =C Tq input ,M 3 Tq input +C Tq output ,M 3 Tq output +C α,M3 α [0069] When the torque on a clutch can be estimated using multiple means and models, the control system can select which estimated clutch torque has the lowest uncertainty at 184 . This clutch torque with the lowest uncertainty can be used as the “true” estimated clutch torque for the remaining transmission controls at 186 . [0070] In another embodiment, each of the multiple means and models of estimated clutch torques can be used to quantify the estimated clutch torque uncertainty. For example, the control strategy can use the estimated clutch value with the lowest uncertainty as the “true” estimated clutch torque. The system can then calculate the error between the other estimates and this “true” estimated clutch torque. The magnitude and variation of these errors can be used to estimate the other estimated clutch torque uncertainties. [0071] If the clutch torque uncertainty is higher than a calibratable threshold at 188 , the system can choose to not use the estimated clutch torque in feedback controls at 190 . If the uncertainty is higher than another calibratable threshold at 192 , the system can choose to not use the clutch torque estimate to modify the clutch transfer function at 194 . [0072] Another more-active approach to estimating and utilizing clutch torque uncertainties is also contemplated. The system can monitor whether a clutch torque uncertainty is large for an extended period of time at 196 or when a particular shift is infrequently encountered at 198 . During these times, the pressure-to-torque transfer function could become outdated and less effective. In these situations, the system may want to actively alter the transmission control logic to identify the clutch transfer function behavior at 200 . [0073] One way to alter the transmission control logic includes choosing an alternate shift schedule. For example, if the estimated clutch torque has a high uncertainty for one of the clutches necessary for 3 rd gear, the transmission logic could perform a shift to 4 th gear directly from 2 nd gear during a given driving condition, rather than shifting from 2 nd gear to 3 rd gear and then from 3 rd gear to 4 th gear during that driving condition. This would obviate a transition into a gear in which clutch torque estimations are uncertain for given driving scenarios. [0074] Another way to alter the transmission control logic includes increasing the target shift time. Longer shifts have slower dynamics. As a result, the uncertainty in the input torque, output torque, and acceleration measurements/estimates will decrease. These lower uncertainties translate into reduced clutch torque uncertainties due to more accurate front-end measurements. [0075] In view of the description above, the accuracy of each measurement and state estimate used within the transmission control system can be quantified, tested, and verified. This process uses a high-quality reference sensor to provide a truth value, and the sensed or estimated value is compared against the truth value. This testing is typically performed across the full range of operating conditions and subjected to numerous noise factors. Multiple hardware units are tested to quantify the part-to-part variation and testing is conducted over long periods to identify the change of time. Depending on the system, the final accuracy can be defined as a percentage (e.g., +/−2%), a fixed range (e.g., +/−10 Nm) or a combination of the two (e.g., whichever is larger +/−2% or +/−10 Nm). A single accuracy metric could be defined or it could be defined as a function of operating condition, temperature, age or any other relevant quantity. [0076] A benefit of estimating clutch torque is the ability to adapt the clutch transfer function between commanded pressure and clutch torque. The clutch torque estimate, however, does not always have the same level of accuracy. The uncertainty in the estimate can vary as a function of gear (or gears during a shift), temperature, load and many other factors. The uncertainty in estimating the clutch torques during a shift from 2 nd gear to 3 rd gear, for example, would be much higher during a hard tip-in of a cold soaked vehicle, then it would be for a light constant accelerator pedal shift of a warmed up vehicle. This disclosure provides a method of calculating the uncertainty and a method for including or excluding data for clutch transfer function adaptation. [0077] One challenge with clutch transfer function adaptation is that the behavior of the clutch can change over time. A particular clutch transfer function might become out of date either because the shifts involving that clutch are not frequently encountered, or because when they are encountered the clutch torque estimate has a high uncertainty. To address this situation, the system can actively identify situations when the clutch torque uncertainty would be low and alter the shift schedule so that the clutch with the out-of-date transfer function is included in the shift. Because this shift has a low uncertainty, the clutch torque estimate can be used to adapt the clutch transfer function and improve future shifts involving that clutch. [0078] While exemplary embodiments are described above, it is not intended that these embodiments describe all possible forms encompassed by the claims. The words used in the specification are words of description rather than limitation, and it is understood that various changes can be made without departing from the spirit and scope of the disclosure. As previously described, the features of various embodiments can be combined to form further embodiments of the invention that may not be explicitly described or illustrated. While various embodiments could have been described as providing advantages or being preferred over other embodiments or prior art implementations with respect to one or more desired characteristics, those of ordinary skill in the art recognize that one or more features or characteristics can be compromised to achieve desired overall system attributes, which depend on the specific application and implementation. As such, embodiments described as less desirable than other embodiments or prior art implementations with respect to one or more characteristics are not outside the scope of the disclosure and can be desirable for particular applications.	A transmission for a vehicle includes a plurality of clutches that are individually selectively engaged to establish particular power flow paths. The amount of torque flowing through any clutch can be estimated while the clutch is being engaged, being disengaged, or being held locked. The estimated magnitude of clutch torque aids in proper control of the transmission, including how and when to shift between gears. A method and system for determining the uncertainty of estimated clutch torque is provided. Based on the magnitude of uncertainty of estimated clutch torque, the shift schedule can alter to specifically avoid actions that would increase the uncertainty, or the time between shifting gears can increase to reduce the effects of the uncertainty.	5
TECHNICAL FIELD [0001] The invention relates to stress relief in a pressurized fluid flow system, in particular a system in which fluid flows at high pressure through a component bore. The invention is particularly applicable where a component or element with a primary bore requires a secondary bore which has an intersection with the primary bore. BACKGROUND TO THE INVENTION [0002] High pressure fluid flow systems need to be designed to resist significant operational stresses. An example of such a fluid flow system is a fuel injector for use in the delivery of fuel to a combustion space of an internal combustion engine. For heavy-duty applications, such as fuel injection for diesel engines for trucks, fuel injectors must be capable of delivering fuel in small quantities at very high pressures (of the order of 300 MPa). [0003] Tensile stress is a significant cause of failure in such systems—cracks will be propagated by tensile stress but not by compressive stress. The intersection between two fluid bores has a significant failure risk associated with it in such a system, as it generally acts as a concentrator for tensile stress. In order to reduce the cost of products, it is also desirable to reduce material grade. This would usually reduce material strength, which can increase the failure risk at such intersections. [0004] Such intersections will often be required in a design for a fuel injector. FIG. 1 shows an example of such a component stack used in such a fuel injector design. This fuel injector, discussed in full in European Patent Application No. 09168746.7, is discussed here to illustrate where such intersections may be required in such a design. [0005] FIG. 1 shows a schematic view of a part of a fuel injector for use in delivering fuel to a combustion space of an internal combustion engine. The fuel injector comprises a valve needle 20 (shown in part) and a three way needle control valve (NCV) 10 . The injector includes a guide body 12 . The NCV 10 is housed within a valve housing 14 and a shim plate 16 , which spaces apart the guide body 12 and the valve housing 14 . [0006] The valve needle 20 is operable by means of the NCV 10 to control fuel flow into an associated combustion space (not shown) through nozzle outlet openings. The lower part of the valve needle (not shown) terminates in a valve tip which is engageable with a valve needle seat so as to control fuel delivery through the outlet openings into the combustion space. An upper end of the valve needle 20 is located within a control chamber 18 defined within the injector body. This upper end slides within a guide bore 22 in the guide body 12 and acts as a piston. The control chamber 18 has two openings. One, at the top of the control chamber 18 , leads to a first axial drilling 42 in the shim plate 16 . The other, at the side of the control chamber 18 , opens into a flow passage 52 in the guide body 12 that itself leads to a second axial drilling 44 in the shim plate 16 . Both these axial drillings 42 , 44 connect, through a cross slot 46 , to a shim plate chamber 36 used for the NCV 10 . [0007] The NCV 10 controls the pressure of fuel within the control chamber 18 . The NCV includes a valve pin with an upper guide portion 32 a and a lower valve head portion 32 b . The guide portion 32 a slides within a guide bore 34 defined in a NCV housing 14 . The valve head 32 b slides within the chamber 36 between two valve seats 48 , 50 . High pressure fuel reaches the NCV 10 through a supply passage 30 extending through the guide body 12 and the shim plate 16 , the supply passage 30 communicating with the NCV through a passage entering the guide bore 34 from the side. Fuel can leave the NCV through the cross slot 46 as discussed above or through a drain passage 38 communicating with a low pressure drain. [0008] As previously stated, the NCV 10 controls the pressure in the control chamber 18 and hence movement of the valve needle 20 . In one position of the NCV 10 , fuel flows through the NCV 10 through the cross slot 46 and into the control chamber 18 to pressurise it, and in another position fuel cannot flow into the control chamber 18 but instead drains from it through to the cross slot 46 and hence to the drain 40 . The specific details of this arrangement are described in more detail in European Patent Application No. 09168746.7. [0009] The significance of the FIG. 1 arrangement to the teaching of this specification is that it illustrates the use of cross drillings in high-pressure injector designs. Two separate examples are shown: flow passage 52 is a cross drilling in the guide body 12 into the control chamber 18 ; and fuel supply 30 flows into guide bore 34 through a cross drilling in the valve housing 14 . Both these cross drillings experience cycling between low and very high pressure, and are thus exposed to very high tensile stresses. This creates a significant risk of early component failure through crack propagation. [0010] It is therefore desirable to protect components exposed to high tensile stresses against these stresses, and hence against fatigue limiting component life. The geometry of the intersection may be designed to reduce such stresses, but it is difficult to do this robustly and it will lead to increased production costs (both in machining and in process development). There are also conventional approaches that may be used to reduce net tensile stress by building in residual compressive stresses. Such processes include shot peening (in which a surface is bombarded with shot at a force sufficient to cause plastic deformation) and autofrettage (in which the chamber to be treated is subjected to exceptionally high pressure), but such processes are very expensive, may affect production processes and also may lead to robustness problems. [0011] It is therefore desirable to prevent fatigue failure in regions of very high tensile stress, such as cross drillings into a main bore, without the problems of the prior art as discussed above. SUMMARY OF THE INVENTION [0012] According to the present invention, there is provided a method of reducing tensile stress within a drilled element at an intersection between a primary bore and a secondary bore, the method comprising: loading the drilled element with a first loading element, wherein the first loading element loads a first face of the drilled element; generating a compressive hoop stress where the first face of the drilled element is loaded by the first loading element, wherein the intersection is sufficiently close to the first face of the drilled element such that the compressive hoop stress counteracts tensile stress in the drilled element at the intersection. [0013] This approach achieves reduction in tensile stress at the failure point without the need for pre-processing steps (such as shot peening and autofrettage) which are expensive and which may also cause robustness issues. The approach taught simply uses loading forces to move the intersection towards a compressive stress regime, which is well tolerated, from a tensile stress regime, which is likely to lead to failure. [0014] In preferred approaches, the loading force provides Poisson effect stress in the stress relief layer which further provides compressive stress in the drilled element at the intersection. [0015] In advantageous approaches, the primary bore extends between the first face and a second face of the drilled element, and the method further comprises loading the second face of the drilled element with a second loading element such that a loading force provides a bending moment in the drilled element which provides compressive stress in the drilled element at the intersection. [0016] In a further aspect, the invention provides a drilled element within a system for pressurised fluid flow, wherein the drilled element has a primary bore and a secondary bore with an intersection therebetween, wherein the primary bore extends from a first face of the drilled element, wherein tensile stress within the drilled element is reduced according to one of the methods described above. [0017] The drilled component may be substantially cylindrical. A ratio of the outer diameter of the drilled element to the diameter of the primary bore may be greater than 5, preferably greater than 8. [0018] In a further aspect, the invention provides a system for pressurised fluid flow comprising a drilled element as indicated above and a first loading element, wherein a stress relief layer is provided between the first face of the drilled element and a corresponding face of the first loading element, whereby loading force is provided to the drilled element from the first loading element through the stress relief layer; whereby the stress relief layer extends underneath at least the intersection between the primary bore and the secondary bore, but does not extend over at least a part of the first face of the drilled element. [0019] In embodiments, the stress relief layer is disposed around and adjacent to the primary bore. In particular arrangements the stress relief layer is integrally formed on the first face of the drilled element. [0020] The stress relief layer may be substantially annular. A ratio of the outer diameter of the stress relief layer to the diameter of the primary bore may be between 2 and 7, particularly between 2.5 and 5, and most particularly between 3 and 4. [0021] The ratio between the distance from the centre of the secondary bore to a face of the stress relief layer adjacent to the first loading element to the diameter of the primary bore may be less than 2, preferably less than 1. [0022] In particular arrangements, the stress relief layer may extend further under the intersection than in another part of the first face. One or more load balancing regions may then be provided between the first face of the drilled element and the corresponding face of the first loading element. [0023] In a further aspect, the invention provides a system for pressurised fluid flow comprising a drilled element as indicated above and a first loading element and a second loading element, wherein a first stress relief layer is provided between the first face of the drilled element and a corresponding face of the first loading element and a second stress relief layer is provided between a second face of the drilled element and a corresponding face of the second loading element, wherein the primary bore extends between the first face and the second face of the drilled element, and whereby a first loading force is provided to the drilled element from the first loading element through the first stress relief layer and whereby a second loading force is provided to the drilled element from the second loading element through the second stress relief layer; whereby the first stress relief layer extends underneath at least the intersection between the primary bore and the secondary bore, but does not extend over at least a part of the first face of the drilled element. [0024] It is preferred that the second stress relief layer is generally disposed further from the primary bore than the first stress relief layer. This combination of loading forces—their application and location—provides a bending moment in the drilled element which provides compressive stress in the drilled element at the intersection. A ratio of the width of the drilled element to the height of the drilled element in such arrangements may be at least 2, preferably at least 4. In particular arrangements where both the stress relief layer and the second stress relief layer are substantially annular, the inner diameter of the second stress relief layer may be greater than the outer diameter of the stress relief layer. [0025] The term “stress relief layer” here is used to describe layers which serve to relieve stress from a part of the drilled component by the mechanisms described. These layers lie between two faces—a face of the drilled element and a face of the loading element—and only cover a part of the relevant faces, which means that the loading force will be transmitted through the stress relief layer. It will of course be appreciated by the person skilled in the art that these layers can in some sense be considered stress concentrators (in that they will lead directly to local compressive stresses), but the term “stress relief layer” is used here in the light of the functional role of these layers. [0026] In some embodiments, the secondary bore is substantially orthogonal to the primary bore. In others, the secondary bore forms an acute angle with the primary bore between the intersection and the stress relief layer. [0027] In particular embodiments, the primary bore is tapered such that when the drilled element is loaded between the first and second loading elements, the loading forces cause the walls of the primary bore to become substantially parallel. The taper in at least part of the primary bore may be at least 0.1%. [0028] In all these arrangements, the system for pressurised fluid flow may be a fuel injector for use with an internal combustion engine. BRIEF DESCRIPTION OF THE DRAWINGS [0029] The invention will now be described, by way of example only, by reference to the following drawings in which: [0030] FIG. 1 shows part of a prior art fuel injector in which embodiments of the present invention would be suitable for use; [0031] FIG. 2 shows a basic schematic diagram illustrating component elements used in embodiments of the present invention; [0032] FIGS. 3A to 3D provide a series of diagrams to illustrate the effects of vertical loading in a part of the arrangement shown in FIG. 2 ; [0033] FIGS. 4A and 4B indicate stress regimes for high pressure cycling of a bore and drilling intersection where the effects illustrated in FIG. 3 do, and do not, apply; [0034] FIG. 5 indicates qualitatively the relationship between face relief size and compressive stress distribution in the arrangement shown in FIG. 2 ; [0035] FIG. 6 indicates qualitatively the relationship between face relief size and cross drilling height in the arrangement shown in FIG. 2 ; [0036] FIG. 7 indicates the effect of changing external diameter relative to internal bore diameter in the arrangement shown in FIG. 2 ; [0037] FIG. 8 indicates the effect of changing cross drilling height in the arrangement shown in FIG. 2 ; [0038] FIG. 9 indicates the effect of changing the size of the face relief in the arrangement shown in FIG. 2 ; [0039] FIGS. 10A to 10C indicates a modification to the arrangement shown in FIG. 2 that illustrates a further aspect of embodiments of the invention; [0040] FIG. 11 indicates the effect of changing component height relative to width in the arrangement shown in FIG. 2 ; [0041] FIG. 12 shows an embodiment of a component with a face relief which is not radially symmetric; [0042] FIG. 13 shows an arrangement similar to that of FIG. 2 but in which the cross drilling is not orthogonal to the primary bore; and [0043] FIGS. 14A and 14B shows an arrangement similar to that of FIG. 2 but with a tapered primary bore, shown unloaded in FIG. 14A and loaded in FIG. 14B . DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS [0044] FIG. 2 shows elements used in embodiments of the invention. FIG. 2 provides a generalised representation of a component 100 used for high pressure fluid flow. This component 100 is shown here as being radially symmetric about a primary bore 110 , though as will be described further below, such radial symmetry need not be provided in all embodiments. The component 100 is in use compressed between other parts in a component stack—these other parts will define a fluid path in to and out of the primary bore 110 , and the compression will prevent leakage at the boundary between the component 100 and these other parts, which act as loading elements on the component 100 . [0045] The component 100 has a secondary bore 120 that intersects with the primary bore 110 at an intersection 130 . In a high pressure fluid flow regime, particularly one which cycles rapidly and repeatedly between high and low pressures, such an intersection 130 will generally be exposed to significant tensile stress unless steps are taken to alleviate this. While this conventionally might be done by shot peening or autofrettage, an alternative approach described here involves the use of a stress relief layer 140 , here termed a “face relief”, to counteract tensile stress at the intersection 130 with the secondary bore 120 . This face relief 140 is located around the primary bore 110 on one face (here, the lower face 150 ) of the component 100 , and at least a part is disposed underneath the intersection 130 . A greater part of the lower face 150 has no face relief region, as this only occupies a small proportion of the area of the lower face in the region of the primary bore 110 . [0046] It is not unusual to have a face relief region of this general kind in a component for use in a component stack such as that of a fuel injector. The conventional purpose of such a face relief is to concentrate the load provided by the loading element in a small area around a bore in order to prevent fluid leakage—this is known as a sealing contact pressure. What is not conventionally provided is a component design which uses a face relief in such a way as to control tensile stress at an intersection between cores. Such an arrangement is provided here, as will now be discussed with reference to FIGS. 3A to 3D . [0047] FIG. 3A shows the effect of loading on a solid component capable of some degree of elastic deformation. The upper part of the component is not shown (it can be assumed that this will be loaded in such a way as to provide a balance of forces). Contact pressure from below, as shown, will result in compression in the vertical direction and consequently lateral expansion according to the Poisson Effect. The degree of expansion (or strain) is a function of the Poisson's ratio of the material and from the geometry of the component. The Poisson's ratio may be determined according to known methods (the Poisson's ration of a typical steel—as might be used in a fuel injector component—is approximately 0.3). [0048] FIG. 3B shows the application of such loading to a component with a central bore, rather than to a solid component. As shown in FIG. 3A , the horizontal deformation resulting from the vertical compression promote expansion of the outer diameter of the loaded component but also contraction of the inner diameter of the central bore. [0049] FIG. 3C shows the effect of restraining the radial displacement of the external diameter of the loaded component from above with a much larger component with a much greater outer diameter but a similar central bore—the loaded component shown in FIG. 3C may be considered equivalent to the face relief 140 of FIG. 2 , with the much larger component (not shown in FIG. 3C ) being equivalent to the bulk part of the component 100 . The effect of the much larger component is to fix the outer diameter of the loaded component in position. This means that the radial displacement resulting from the Poisson's ratio of the material may only act on the central bore of the loaded component (which is not pinned by the much larger component, as it also has a central bore). This provides a significant compressive hoop stress. A resulting hoop stress will also be present in the much larger component, though its value will fall away with increased distance from the loaded component. [0050] FIG. 3D shows the significance of this arrangement for an intersection with a secondary bore. As discussed above, this is normally a region of increased tensile stress, particularly during pressurised flow. The compressive hoop stress resulting from the Poisson effect is however also present at the intersection point. In fact, if located in a region where this Poisson effect applies strongly the control drilling will act as a stress raiser for this compressive stress (much as it conventionally acts as a tensile stress raiser in a pressurised fluid flow regime). [0051] FIG. 4A shows stress against time at the intersection point in a conventional arrangement (line 401 ) and where the Poisson effect regime of FIG. 3D applies (line 402 ). Where there is no compressive stress provided by the Poisson effect (or by any other mechanism—an additional mechanism is discussed further below), cycling between high and low pressure leads to repeated very high net tensile stress at the intersection (as shown by line 401 ). When Poisson effect compressive stress is provided as indicated above, this makes no change to the amplitude of the variations in stress between the high and low pressure regimes, but it does move the baseline strongly into the compressive regime, and hence the stress at peak pressure into the weakly tensile regime (as shown here by line 402 —with appropriate design choices the intersection could be kept in the compressive regime at all operating pressures). Components will typically tolerate far higher compressive stresses than tensile stresses, as tensile stresses will cause cracks to open, whereas compressive stresses will hold cracks closed. This is as further shown in the modified Haigh diagram of FIG. 4 B—for a given material, its yield stress σ y and fatigue limit σ f , operation with uncompensated tensile stress (point 403 ) is outside the strength criteria envelope (top right area of FIG. 4B ), whereas operation with compensated stress (point 404 ) is well within the strength criteria envelope. As illustrated on the graph, the hoop compressive stresses are reducing the mean stress but keeping the same stress amplitude (moving vertically from point 403 to point 404 ). [0052] In FIG. 3D , the intersection is shown as lying within the face relief. This is not necessary for the compressive hoop stress to have an effect, as this stress will be translated up into the main component, albeit with significantly diminishing effect the further that the secondary bore, and hence the intersection, lie from the face relief. The size of the face relief is also a significant factor in determining the compressive hoop stress that will be seen at the diameter of the primary bore, and hence at the intersection. These factors are explored qualitatively in FIGS. 5 and 6 . [0053] FIG. 5 illustrates qualititatively the change in compressive stress seen at the intersection for a given loading force F and cross drilling height h (as shown in FIG. 2 ) against annular width x of the face relief. Position 510 shows a low resultant compressive hoop stress—as can be seen, the small face relief creates a small region 511 of high compressive hoop stress in the main component, but this region 511 is so small that the intersection between bores lies outside it and the compressive hoop stress seen at the intersection is minimal. Position 520 shows—for this geometry—an optimal compressive hoop stress at the intersection. The compressive hoop stress seen in the stressed region 521 is smaller than for region 511 , but the region is significantly larger in size, so the intersection lies well within it. Position 530 again shows an even lower net compressive hoop stress—the face relief is now so large that while the stressed region 531 is large, the compressive hoop stress within this region is minimal. [0054] This analysis suggests that it is desirable for the intersection simply to be located as close to the face relief as possible and for the face relief to be as small as possible. This is not in fact the case, as other potential failure mechanisms need to be considered. FIG. 6 shows qualitatively the compressive stress curves for a given force F with varying annular width x, different curves being shown for different intersection heights h. The peak compressive stresses show track through a broadly optimum intersection height to face relief ratio h/x—curve 601 tracks this ratio through the minima of separate stress curves 610 , 620 and 630 for different heights. With a small face relief, as shown at position 611 on curve 610 , there is very high compressive hoop stress provided, but the extremely small size of the face relief and the extreme proximity of the cross drilling to the face of the component will create other high stresses and hence other major fatigue risks in the design. With a larger face relief, as shown at position 621 on curve 620 , there is enough compressive stress generated through the face relief to be effective, and no new fatigue risks are created. With a very large face relief, as shown at position 631 on curve 630 , there is simply not enough compressive stress generated by the face relief to be useful. [0055] FIGS. 7 to 9 indicate the effect on stress at the intersection of varying certain of the variables shown in FIG. 2 determined by finite element analysis of the system. [0056] FIG. 7 shows the effect of varying the outer diameter D′ of the component for a fixed face relief size relative to the diameter d of the primary bore. Where the ratio D′/d is small, there is no useful compressive stress effect—this ratio needs to be at least 5 before the effect becomes useful. This is because if the ratio D′/d is small then the part simply does not have enough bulk to prevent outer diameter deformation as shown in FIG. 3B , that deformation not leading to compressive stress. When the ratio reaches 8, then there is useful compressive stress provided at both the top and bottom of the lateral drilling (and hence also the intersection). [0057] FIG. 8 shows the effect of varying drilling height h for fixed face relief size and component diameters—in this case, the ratio of face relief outer diameter D to primary bore diameter is chosen to be 3. The compressive stress effect begins to be apparent when the value of h/d is reduced to 2, and becomes more significant when this ratio is reduced further. A large compressive stress effect is present when h/d is 1 or lower. [0058] FIG. 9 shows the effect of varying the outer diameter D of the face relief with other component diameters and drilling height h fixed. As indicated previously, too small a face relief provides a great compressive stress concentration but located too low in the component to affect the drilling, whereas too large a face relief provides insufficient compressive stress to relieve the tensile stress at the intersection effectively. In this arrangement, a useful effect is found when D/d lies between 2 and 7, a stronger effect is found when D/d lies between 2.5 and 5, and a very strong effect when D/d lies between 3 and 4. [0059] FIGS. 10A to 10C indicate a modification to the arrangement shown in FIG. 2 that illustrates a further aspect of embodiments of the invention. In this arrangement, the component 100 a is as shown in FIG. 2 but it also has a further face relief 170 on an upper face 160 of the component, as is apparent from FIG. 10A . The upper face relief 170 has a much larger inner and outer diameter than the lower face relief 140 . For a relatively thin component 100 a , this leads to another mechanism for providing compressive stress at the intersection 130 . [0060] FIG. 10B indicates the effect of loading the component 100 a from above and from below. The action of the loading forces through the two face reliefs 140 , 170 results in a bending moment in the component 100 a . As can be seen from FIG. 10B , this bending moment leads to creation of compressive hoop stress in the bore region at the smaller lower face relief 140 and tensile hoop stress in the bore region at the upper face 160 of the component 100 a . If the component 100 a is relatively thick in relation to its outer diameter, this effect will be small, but if it is thin, it will be significant. As is shown in FIG. 10C , which shows stresses in the region of the intersection 130 , the intersection again acts as a stress concentrator and so a concentrator for the compressive hoop stress resulting from this bending moment. [0061] This effect is present for a thin component even without a larger diameter face relief 170 as shown in FIG. 10A . FIG. 11 indicates the variation in stress at the intersection with the ration between component height H and component diameter D′ for a given bore diameter d and intersection height h. It can be seen that compressive hoop stress is not present at a significant degree until D′/H is 2 or greater (H/D′ is 0.5 or less), but that the effect has become much more significant when D′/H is 4 or greater (H/D′ is 0.25 or less). [0062] The Poisson effect compressive stress shown in FIGS. 3A to 3D and the bending moment compressive stress shown in FIGS. 10A to 10C can be used together to build in compressive stress at the intersection 130 in the arrangement of FIG. 2 . Either effect may be used on its own to provide a compressive effect at the intersection—while in embodiments shown here the bending moment effect is used primarily to augment the Poisson effect compressive stress, there are arrangements in which it may be valuable on its own. [0063] FIG. 12 shows a further embodiment of a component design which uses a face relief to provide compressive hoop stress at an intersection. This component 100 b is viewed from below, and it can be seen that the face relief 140 a provided about the primary bore 110 is not axially symmetric. The face relief 140 a is provided with a larger land 141 underneath the intersection 130 than in other parts of the face relief 140 a . This radial asymmetry is chosen in order to concentrate compressive hoop stress further in the region of the intersection 130 , rather than radially symmetrically around the primary bore 110 (noting that this radial symmetry will already be broken by the stress concentrating effect of the presence of the intersection 130 ). Some compensation may however be required for having an asymmetric face relief 140 a , as otherwise the loading force may impart a net turning moment on the component which could lead to a risk of failure or leakage. In consequence, compensatory lands 142 and 143 are provided to balance the effect of the asymmetry of the face relief 140 a. [0064] A further modification to the arrangement of FIG. 2 is shown in FIG. 13 . In this arrangement, the secondary bore 120 b is not orthogonal to the primary bore 110 , but is instead at an angle to it. This may be used to balance the stresses at the intersection, as in this arrangement the lower part of the intersection 130 would normally be more stressed, but as it is closer to the face relief it will also be provided with a greater compressive hoop stress to compensate. [0065] If the face relief is not required to provide a sealing force for fluid flow, more flexibility in design is available. For example, in the arrangement of FIGS. 10A to 10C , the further face relief 170 may not be required to provide a sealing force, and may not need to be an annulus as is shown in FIG. 10A . Alternatively, for example, this face relief 170 may be provided as a plurality of pads disposed symmetrically around the primary bore 110 . [0066] FIGS. 14A and 14B show a potential modification to the primary bore 110 a in embodiments of a component using the approaches to stress relief provided above. Many such components will operate with a needle shaped piston 170 reciprocating within the primary bore 110 a —possibly in such a way as to seal off flow from secondary bore 120 into the primary bore 110 a . Use of the face relief 140 to generate a compressive hoop stress may lead to some change in shape of the bores. For example, the stresses at the intersection 130 will tend to distort the secondary bore 120 at the intersection 130 into a vertically elongated “rugby ball” shape. In the primary bore 110 a , the use of compressive hoop stress may lead to a reduction in the diameter of the primary bore 110 a in the region of the lower face 150 of the component compared to that at the upper face 160 of the component. It is however desirable for the needle shaped piston 170 to be a relatively tight fit within the bore to ensure efficient sealing without leakage. This can be accomplished by providing the primary bore 110 a with a taper in its unloaded state (shown in FIG. 14A ), such that loading, and compressive hoop stress in the region of the intersection 130 , will distort the primary bore 110 a (as shown in FIG. 14B ) to one of a substantially constant diameter in the operational range of the piston (ie. a true or parallel bore)—an alternative approach is to taper the piston and not the bore. For the force conditions found within a heavy-duty fuel injector operating under pressures of approximately 300 MPa, the approximate taper in diameter required may be approximately 10 μm over a length of 3 to 5 mm. [0067] Further modifications to these embodiments, and other arrangements falling within the scope of the claims, may be provided by the person skilled in the art following the teaching provided in this specification.	A method of reducing tensile stress within a drilled element 100 at an intersection 130 between a primary bore 110 and a secondary bore 120 comprises the following steps. A first face of the drilled element 100 is loaded with a first loading element. A compressive hoop stress is generated where the first face of the drilled element 100 is loaded by the first loading element, and the intersection 130 is sufficiently close to the first face of the drilled element 100 such that the compressive hoop stress counteracts tensile stress in the drilled element 100 at the intersection 130 . A suitable drilled element 100 and fluid flow systems, such as a fuel injector, including such a drilled element 100 are also described.	5
RELATED APPLICATIONS This application claims priority from Mexican application Serial No. MX/a/2009/014047 filed Dec. 18, 2009, which is incorporated herein by reference in its entirety. FIELD OF INVENTION The present invention relates to the field of burners, particularly burners used in household appliances, such as stoves. BACKGROUND Currently in the market there are a considerable amount of burners for use in household appliances, initially the primary objective of these, was to provide of a flame which would have an impact on the utensils needing to be heated, without considering efficiency of use or ecological aspects of the combustibles used in heating; with time the design of burners has evolved towards the resolution of the aspects mentioned above, among others. As background to the present invention, the applicant has had knowledge of the documents which are described below. Published patent application EP 0554511, describes a gas burner with atmospheric gas with a pre-mixer for primary gas, with a one ring burner which has ducts for gas exit and a cover for the burner, designed if appropriate, as one sole piece with the ring, as a solution produced for atmospheric burners which in particular has a NO content in the burn gas produced, as well as CO content is considerably reduced, and in particular in a very wide range of adjustment between the open and closed positions. The above is achieved due to the central axis of the exit ducts having a deviation angle of 0° regarding an assigned radius to the respective aperture of the exit. The invention in the present application differs considerably from that contained in the publication EP0554511, where among other aspects which differentiate it, the burner in the present invention is made up of a burner with three rings, with a combustion ports design which are not described in the aforementioned document. U.S. Pat. No. 1,598,996 describes gas burners for general use where the inner parts are freely accessible which allow the burner to be cleaned quickly and conveniently to eliminate carbon, grease and other deposits. At the same time, this burner has an upper lid which can be removed from the burner for the aforementioned purposes, and which at the same time has a firm connection which seals the burner's body against any possibility of combustible leakage between the lid's contact surface and the burner's body. Additionally, the burner has two parts where the body of the burner is coupled to a mixture tube which is adapted to be removed by a sliding movement. The burner has means to ensure a mix of air and combustibles previous to ignition and the burning of the combustible, to reduce carbon deposits to a minimum and produce the flame with the greatest possible intensity. Chinese Utility Model application with a publication number CN 201251184, describes a stove burner which contains: a primary induction channel, a secondary induction channel and a third induction channel which are in an injector, and are respectively connected in a fixed manner and communicate via a first gas channel, a second gas channel and a third gas channel. The gas for the dented inner ring's cover enters the second gas channel from the second induction channel; the gas for the cover of the dented outer ring enters into the first gas channel and the third gas channel from the first induction channel and the third induction channel. As a result, the gas can be completely mixed with air when it enters the injector. Three fire holes are arranged on the cover of the dented outer ring. The first fire hole is arranged on the inner elevation of the cover of the dented outer ring. The third fire hole is arranged on the extreme upper face of the cover of the dented outer ring. The second fire hole is arranged on the extreme upper face of the cover of the dented outer ring between the first fire hole and the third fire hole. The second fire hole and the third fire hole are inclined towards the center of the cover of the dented outer ring, and the elevation angle of the second fire hole is greater than the same of the third fire hole. As a result, the heat of the flame in the fire hole is more highly concentrated in the burner's interior and the formation of carbon monoxide and nitrogen and oxygen compounds are reduced. A block of fire rings is firmly placed on the outer surface of the cover of the dented outer ring to reduce heat loss. In regards to the inventions detailed in the aforementioned documents, not one of them has the structural and operational characteristics of the burner, object of the present invention, for example, none of the previous inventions possesses at least two concentric sections of flames, which are produced due to the combination of Venturi ducts which end in intermediate or central sections of the concentric sections of the flames. None of the aforementioned inventions possess concentric sections which have different types of combustion ports in order to generate inclined flames which produce more efficient heating. Due to the previous discussion, none of the documents antecede the present invention. One of the objectives of the present invention is to provide a burner with at least two sections, each section with two segments which produce longer and more inclined flames through which more efficient heating can be attained. Another of the objectives of the present invention is to provide a burner with at least two sections, which has combustion ports with straight or heliocoid arrangements which produce longer and more inclined flames. Another of the objectives of the present invention is to provide a burner with three sections, in which the inner ring forms the first section, where this can function in conjunction with or independently from the other two flame sections, thus controlling heat intensity. Yet another objective of the present invention provides a burner with at least two sections which consists of means to control the exit velocity of the air-gas mixture reducing it to the point where no detachment of flame occurs. BRIEF DESCRIPTION OF THE DRAWINGS The following description of the drawings is set forth which accompany the present description and which help serve illustrate it. FIG. 1 shows an isometric view of the upper part of a stove with the burner of the present invention. FIG. 2 shows a lateral view of the head of the three section burner with its outer and inner lids. FIG. 3 refers to a cross section view of the head with three sections with its outer and inner lids. FIG. 4 is an isometric view of the upper part of the head of the three section burner. FIG. 5 shows an upper plant view of the head of the three section burner. FIG. 6 shows a cross section of the three section burner. FIG. 7 refers to an isometric view of the lower part of the head of the three section burner. FIG. 8 is an isometric view of the stove's upper part as well as the burner head and its support. FIGS. 9 through 12 show various views of the supports of the head of the three section burner. FIG. 13 shows a cross section of the head of the three section burner with its respective combustion ports. FIG. 14 refers to an isometric view of the support of the burner head with its lateral and central spaces. FIG. 15 is an isometric view through the lower part of the support base of the head of the three section burner. FIG. 16 shows a cross section of the three section burner in an embodiment which contains the closest spark plug to the outer ring. FIG. 17 shows a view with conventional perspective of the upper part of the three section burner in an embodiment which contains the lighting spark plug closest to the internal ring. FIG. 18 refers to an enlarged view of the three section burner. FIG. 19 shows a view in plant of the circumference arch of the burner's combustion ports. FIG. 20 is an isometric view of the circumference arch of the burner's combustion ports. FIG. 21 shows a cross section of the flow of secondary air in the burner. FIG. 22 shows another cross section of the flow of secondary air in the burner. FIG. 23 shows an isometric view with a cut. FIG. 24 shows an upper view of a first embodiment. FIG. 25 shows an upper view of a detailed view of the first embodiment. FIG. 26 shows an isometric view with a cut of the first embodiment. DETAILED DESCRIPTION OF THE INVENTION The following describes in detail form the burner with at least two sections of the present invention, using reference numbers which appear in each of the drawings 1 - 26 to identify the parts referred to in the description. The burner with at least two sections, preferably with three sections with either inclined or straight flames object of the present invention ( 1 ), comprises as principal elements the following: at least one lid per each section; an inner ( 2 ), and another outer ( 3 ); a burner head ( 4 ) which contains the two flame sections, an inner ring ( 5 ), a intermediate segment ( 6 ) and an outer segment ( 7 ), each segment containing combustion ports, in corresponding form identified with numbers ( 8 ), the combustion ports of the inner ring ( 5 ), combustion ports ( 9 ) of the intermediate segment ( 6 ) and combustion ports ( 10 ) of the outer segment ( 7 ), the gas exit combustion ports in their ensemble are helicoids, curved or straight, or any of the previous with an inclination, both in the inner segment ( 5 ) as in the outer ( 7 ) being such that if they are helicoid the flames will have an inclination. The flame inclination can have a clockwise or an anti-clockwise direction, where the direction on both burners can be the same or opposite directions; some mixture chambers ( 21 ) and ( 22 ) between each of the sections of the burner's main body, which are all separated by a space ( 23 ), in the wall's upper part of the mixture chambers ( 21 ) there are combustion ports of reduced size ( 24 ) whose function is to transmit the gas-air mixture between the sections; at least one Venturi duct in each section and the inner ring placed in the lower part of the burner's head ( 4 ), which form an integral part of the same, two lateral ( 11 ) and ( 12 ) and one central ( 13 ), through which the gas-air mixture enters the burner ( 1 ); four exits ( 27 ) thru ( 30 ) with a design similar to ingots, truncated cones, are found in the lower surface ( 26 ) of the head of the burner ( 4 ), these exits create a separation between the plane of the burner's cover ( 31 ) and the lower surface ( 26 ) of the burner's head; a support ( 32 ) which joins to the stove's surface for example via perforations and screws, in this support are lodged the Venturi ducts ( 11 ) to ( 13 ) of the burner head ( 4 ) in the lower part of the support ( 32 ) a gas distributor ( 14 ) is lodged which has three exits, two laterals ( 15 ) and ( 16 ) and one central ( 17 ) unto which the corresponding gas nozzles are connected, two lateral ( 18 ) and ( 19 ) and one central ( 20 ), the gas distributor ( 14 ) is designed in such a way that it can be connected to a valve, not shown, with double gas exits or a simple exit valve, in this way, the inner ring can function in conjunction with the other two sections, or in an embodiment of the present invention, independently of the other two sections, thus controlling the heating intensity; at least one arm ( 25 ), connected and granting mechanical rigidity to the burner head as well as guarantee the three rings concentricity as well as their separation, alternately a first set of arms runs on the axis of the Venturi conduits ( 11 ), ( 12 ) and ( 13 ); alternatively the remaining arms give the appearance coupled to the functions described above to the arm sets; a lighting spark plug ( 61 ) placed close to the outer segment and another lighting spark plug placed close to the inner ring ( 62 ) so that this may move the flame to the remaining sections. The inner lids ( 2 ) and the outer ( 3 ) are made of imprinted and/or porcelain steel or any other known material known in the art such as steel smelting and/or sintering. The lids are placed over the combustion ports of the burner and its correct placement is controlled by the bolts ( 63 ) of the lids with a poka-yoke design which avoid incorrect placement, the inner lid ( 2 ) is placed over the inner ring ( 5 ) and the outer lid ( 3 ) is placed over the intermediate segments ( 6 ) and the outer segments ( 7 ). In the burner ( 1 ) there are inclined combustion ports ( 33 ) and main combustion ports ( 34 ) which can be curved or straight on the outer segment ( 7 ); straight or radial combustion ports ( 35 ) in the intermediate segment ( 6 ), the difference between these last two being the velocity which can be acquired by the air mixture—gas which passes between the combustion ports, in the first, said mixture acquires higher velocity due to the curvature. Main combustion ports ( 34 ), these can be straight or have an inclined angle in reference to the radius, or in a preferred embodiment follow a circumference arch ( 64 ), in other alternative embodiments, they can follow almost any type of curvature, i.e. exponential, elliptical, parabolic, hyperbolic etc. The characteristics of this type of combustion ports is that due to its inclinations or curvature the gas-air mix enters into it with a relatively low velocity and pressure, inside the combustion port with the curvature and the inclination of the combustion port, the mix accelerates and pressure is reduced, to the point where the mixture's exit velocity is slightly higher than the velocity of the burning gas to avoid gas return flashbacks, but avoiding reaching the limit where flame separation is produced; another advantage is that due to higher velocity of the particle inside the channel or combustion port passage, flames which are longer and more inclined are produced, which create a larger contact area between the flames and the objects to be heated, it is worth mentioning that the channel or combustion port passage has a particular cross section ( 36 ) which increasingly reduces the area of combustion port through which the volume of the gas-air mix passes, in drawing 13, it can be seen that two steps ( 38 ) in the deep part of the combustion port, these also help achieve an optimal velocity of the gas-air mix to be inside the operation zone between the flashback and the flame release; the steps ( 38 ) has a first slope between 10° and 30°, followed by a second slope between 0° and 15°, followed by a third slope between 30° to 80° and a fourth and last slope between 0° and 15°. The moving combustion ports or carry over ( 33 ), also named inclined combustion ports posses the same inclination or curvature of the main or curved combustion ports ( 34 ); specifically these can be straight or have an inclination angle with reference to the radius, or in a preferred embodiment follow the circumference arch ( 64 ), in other alternative embodiments, they can follow almost any type of curve i.e. exponential, elliptical, parabolic, hyperbolic etc. The characteristics of this type of combustion ports is that due to their inclination or curvature, the gas-air mix enters into it with a relatively low velocity and pressure, inside the combustion port with the curvature, the mix accelerates and pressure is reduced to the point where the mixture's exit velocity is slightly higher than the velocity of the burning gas to avoid gas flashbacks, but avoid reaching the limit where flame separation is produced; another advantage is that due to higher velocity of the particle inside the channel or combustion port passage, flames which are longer and more inclined are produced, which creates a larger contact area between the flames and the objects to be heated, it is worth mentioning that the channel or combustion port passage has a particular cross section ( 36 ) which reduces the area of combustion port through which the volume of the gas-air mix passes, in drawing 13, it can be seen that two steps ( 38 ) in the deep part of the combustion port, these also help achieve an optimal velocity of the gas-air mix to be inside the operation zone between the flashback and the flame release; the steps ( 38 ) have a first slope between 10° and 30°, followed by a second slope between 0° and 15°. These ports are characterized by having lesser height in regards to the lid than the curved combustion ports ( 34 ). Radial or straight combustion ports ( 35 ) are radial combustion ports to the burner's circumference; they have a particular cross section in that they also use steps ( 38 ) to control its velocity. Barrier rails ( 71 ), as shown in FIG. 26 . These are walls or flow restrictions, they are named after the barrier rails in bullfighting rings; where said barrier rails help dissipate the gas air mixture and by doing so, the particles which enter the combustion ports have a lesser velocity, in the case of the burner with straight combustion ports, they are placed between combustion ports ( 33 and 34 ) of the outer segment ( 40 ) and in close proximity to the Venturi main channel exit ( 39 ). Labyrinths ( 37 ). They are walls or flow restrictions which guide the flow towards the straight or radial combustion ports ( 35 ), said labyrinths help dissipate the gas air mixture and by doing so, the particles which enter the combustion ports have a lesser velocity. There are two zones with high mixture velocity; one is found on the combustion ports closest to the Venturi's download and the other in the zone of the combustion ports of the intermediate ring. If the mixture exits the combustion ports at this velocity, a separation of flame will occur, for this reason some walls with grooves are added with the purpose of creating velocity losses to the mixture due to friction. Zone of combustion ports dissipation ( 64 ). Zones where the combustion ports are in close proximity to the Venturi, zone with walls or flow restrictions resembling an alley which help dissipate the energy of the gas-air mixture and thus the particles which enter this zone have a lesser velocity due to their proximity to the Venturi. Should this zone of combustion port dissipation ( 64 ) not be used, the gas-air mixture exits the combustion ports at a high velocity and flame separation occurs, thus walls resembling a meandering alley are added in combination with shallow combustion ports with the objective of producing energy loss to the gas-air mixture. Flame moving chambers are placed between each section; in this case, the first is ( 44 ) and the second ( 45 ). They have a gas volume with a tenuous flame, and acting as a stability chamber as well, in addition to their function of moving the flame. The flame moving chambers ( 44 ) and ( 45 ) also have a radial stair stepped combustion port, respectively ( 46 ) and ( 47 ), and these have the peculiar function that when the burner is found at a minimal regimen or to have a minimal flame, said chamber conserves or maintains a small flame which exits the deepest part of the stair step's cross section ( 38 ); this flame helps re-light (in its case) the intermediate ring, granting the burner flame stability; the four mini-combustion ports ( 24 ) are the connection between the burner's sections ( 40 ) to ( 43 ) and are also the connection between the outer segment ( 7 ) and the intermediate ( 6 ). Venturis. The lateral Venturi ducts ( 11 ) and ( 12 ) are placed decentralized from the main channel ( 39 )between the combustion ports of the outer segment ( 7 ) and the combustion ports of the intermediate segment ( 6 ); this is so that if said Venturis were to be centrally placed in the intermediate circumference of said main channel, the gas-air mixture, would exit at such a high velocity and pressure, which would be undesirable for the combustion ports surrounding the Venturi since that would create the phenomenon of flame detachment, so it was determined to move it towards the center of the burner, this un-alignment creates space to mount barrier rails or labyrinths or to remove the Venturi from the combustion ports so that the gas-air mixture might experience a loss of velocity and dissipation some energy. The Venturi ducts ( 11 ), thru ( 13 ) are placed on an axis, the burner in the present invention requires at least two Venturis for its own function, the sections are divided into two segments ( 40 ) and ( 41 ), for the outer segment ( 7 ); and ( 42 ), ( 43 ) for the intermediate segment ( 6 ); so that the main channel ( 39 ) between the outer segment ( 7 ) and the intermediate segment ( 6 ) is truncated by the gas moving chambers ( 44 ) and ( 45 ), which are placed 180° from each other in relation to the burner's center, the Venturi ( 11 ) feeds a section of the segments ( 40 ), ( 42 ) and the Venturi ( 12 ) opposite to 180° in relation to the burner's center feeds the segment section ( 41 ), ( 43 ), while the central Venturi ( 13 ) feeds the outer ring ( 5 ). Each of the Venturi ducts ( 11 ) thru ( 13 ) are aligned with gas nozzles, two lateral ( 18 ) and ( 19 ) and one central ( 20 ), which are placed on the lower part of the corresponding Venturi ducts, the nozzle ( 18 ) under the Venturi duct ( 11 ), the nozzle ( 19 ) under the Venturi duct ( 12 ), and the nozzle ( 20 ), under the central Venturi duct ( 13 ). In a preferred embodiment, a valve controls the three rings in unison, via the gas distributor ( 14 ), in a different embodiment, there is a double valve or two valves, one which controls the feeding of the sections and another which controls the feeding of the inner ring ( 5 ), in this last one, the spark plug will be placed in near proximity to the inner ring ( 5 ) so that this may move the flame to the remaining sections, in this embodiment, the inner ring will be lit first and this must remain lit while the other two sections are in use, in this same embodiment, the inner ring may be solely lit, without lighting the other two sections, but it is not possible to operate in the reverse. Inner ring ( 5 ). The combustion ports ( 8 ) of the inner ring ( 5 ) may or may not have the same curvature or inclination of those present in the other two sections; this ring may have radial or straight combustion ports or combustion ports whose inclination is opposite to that of the combustion ports of the outer segment, thus its function is somewhat independent of the other two sections. It is independent if the valve has a double exit and one of the exits supplies the flow solely to the intermediate burner, however heat flow and combustion products of the intermediate and outer rings have an effect on the inner ring's ( 5 ) performance. Locating ring ( 65 ). It is found surrounding the central Venturi and aids in centering the burner unto its base ( 66 ), the remaining Venturi has a rib ( 67 ) along the length of its axis which fits itself unto the support ( 32 ) to avoid rotation. The support ( 32 ) of the burner ( 1 ), has a circular design in its upper part, on its periphery it possesses four perforations ( 48 ) thru ( 51 ) which aid in joining the support to the stove's surface rendering it immovable via any means of mechanic fastening, for example fasteners or screws and nuts; the support ( 32 ) has three spaces, which are projected towards the lower part of the support ( 32 ), two laterals ( 52 ) and ( 53 ) and one central ( 54 ) which communicate among each other and are placed on a diametric axis of the support ( 32 ), the lateral spaces are hinged by vertical walls ( 55 ) and ( 56 ), their lower part ( 57 ) being open, whereas the central space ( 54 ) does not have any walls; when the burner's head ( 4 ) is assembled unto the support ( 32 ), the lateral spaces ( 52 ) and ( 53 ) lodge the lateral Venturi ducts ( 11 ) and ( 12 ), and the central space ( 55 ) the central Venturi duct ( 13 ). The spaces described above help cover the nozzles ( 18 ) through ( 20 ) which feed the Venturi, they also have a separation ( 68 ) between the burners' covers plane and the lower part of said support ( 32 ), this separation allows proper aeration of the segments ( 6 ) and ( 7 ) as well as provides the air for the mixture of primary air in the nozzle zone and the lower part of the central Venturi duct ( 13 ). The lower part of the support ( 32 ), lodges a gas distributor ( 14 ), to which we have previously referred, the corresponding gas nozzles; two lateral ( 18 ) and ( 19 ) and one central ( 20 ) are placed on the lower part of the corresponding Venturi ducts, the spreading bolt ( 19 ) under the Venturi duct ( 12 ) and the spreading bolt ( 20 ) under the central Venturi duct ( 13 ), between each of the nozzles and the Venturi ducts, there are spaces, two lateral ( 58 ) and ( 59 ) and one central ( 60 ). The four exits ( 27 ) through ( 30 ) have a design similar to ingots, truncated cones, found on the lower surface ( 26 ) of the burner head ( 4 ), previously mentioned, create a separation, where said separation allows the flow of secondary air ( 69 ) towards the combustion ports or flames of the intermediate segment and the inner ring, towards the edge which forms the burner's base with the intermediate segment's wall, just beneath the combustion ports which have a bevel or radio ( 70 ), which allow better air flow between the burner's base lower face and the burners' covers plane, transporting more secondary air towards the combustion ports of the intermediate segment ( 6 ) and the inner ring ( 5 ). The above mentioned exits ( 27 ) through ( 30 ) also help avoid the cover's yellowing due to the transfer of heat between the base and the burner head ( 4 ), since by making an air mass flow between the separation created by these two parts, the air which passes through here cools the burner's head base ( 4 ) functioning as a heat exchanger and acts as an insulator to heat transmission by radiation to the cover. Primary air. This is the air which is introduced into the burner and mixes with the gas before this reaches the combustion ports. Secondary air. This is the air supplied externally to the flame at the moment in which combustion occurs. Given that there are no openings in the support ( 32 ), the primary air is not contaminated with hot air and combustion products emanating from the oven, allowing for a more efficient combustion and avoiding disturbances to the burner's flames. In a preferred embodiment the support ( 32 ) can be totally sealed, or without openings, except for the upper part, the Venturis are found immersed within this support ( 32 ), where there is a volume of air, this volume of air is maintained due to the separation which exists between the burner head ( 4 ) and the support ( 32 ), said air volume is fed to the Venturi; the lateral Venturi ducts ( 11 ) and ( 12 ) have some spaces ( 58 ) and ( 59 ) in their lower part which allow for air flow. The central Venturi has some lateral spaces ( 60 ); in a preferred embodiment the spaces are in the lower part which feed the Venturis on their extremes, they can be covered and air pulled from above the burner's covers (through the space between the burner's base and the burner's lid; in an alternative embodiment, a “spider” type can be present, this being where there is a single support for the nozzles and the tubes are aligned with the Venturi. Whereas the above description contains many specific facts, these specific facts are not to be considered as limitations in attaining the invention's reach, but simply as exemplifications of the described embodiments. Those with technical ability in the subject of suspensions will visualize many other variations and different possible reaches, which are within this invention's reach.	The present invention relates to the field of burners, particularly in burners intended for household use, such as stoves. A three ring burner is described, which produces longer and more inclined flames through which a more efficient heating is accomplished; combustion ports in the rings with straight or helicoid arrangements; where the inner ring can function in conjunction with or independently from the other two flame rings, thus controlling the heating intensity and the flame by means of controlling the velocity of the gas-air current; as main parts comprising; a burner head, which contains three concentric flame rings, one inner ring, one intermediate ring and one outer ring, each flame ring containing combustion ports, the collection of combustion ports are helicoid both in their inner ring as well as the outer ring, two lids on the burner head, one inner and the other outer; one cover for the burners which forms the surface of the heating apparatus; Venturi ducts on the lower part of the burner head; a support firmly joined to the surface of the heating apparatus, in this support are lodged Venturi ducts from the burner head; a gas distributor lodged in the lower part of the support, where the gas distributor has three gas exits, two laterals and one central.	5
CROSS-REFERENCE TO RELATED APPLICATIONS The present application is related to copending U.S. patent application Ser. No. 685,701 which is assigned to the same Assignee and has the same inventive entity as the present case. BACKGROUND OF THE INVENTION The present invention pertains to digital communications and transmission systems and more particularly to framing information transmitted along with data used to identify various fields within the data stream. In the past, framing patterns have been limited to a small number of bits. For example, the T-carrier systems used in telephony originally employed a framing pattern consisting of alternating ones and zeros. Later, this framing pattern was replaced by two interleaved patterns, one to identify frames and a second pattern to identify a "superframe", a larger frame consisting of 12 ordinary frames. The first pattern is a basic pattern of alternating ones and zeros. These framing bits occur in alternate framing bit positions and identify the framing bit position within a frame of 193 bits. The second framing pattern, interleaved with the first, is a pattern of (111000). This framing pattern identifies the alignment of the superframe relative to the ordinary frames. Another modification to the framing pattern introduced extended superframe. Extended superframing is a technique wherein the basic framing pattern occurs only every fourth frame and identifies a 24 frame pattern. Since this framing pattern is only 6 bits long, a relatively high potential for false framing is created. This can occur when a particular data bit pattern corresponds to the framing bit pattern. In a superframe transmission system, the alternating ones and zeros with a period of four frames was sometimes imitated by the sign bit of a PCM encoded 2 KHZ sine wave from certain types of data modems. If the carrier system lost framing while this 2 KHZ modem signal was being transmitted on one of the voice channels, the framing circuit could mistake the sign bit of the voice channel for the framing bit. This situation would result in misframing for all 24 channels for considerable periods of time. Similar problems would result with other framing patterns. The above problem could be solved by use of a longer and more complex framing pattern, but this introduces several new problems when previously known techniques are employed. The first problem is that as the framing pattern length is increased, the amount of hardware needed to generate and detect the framing pattern increases correspondingly. For example, a 12 bit framing pattern would require twice as much transmission and detection hardware as a 6 bit framing pattern. Thus, longer framing patterns necessitate increased pattern generation and detection hardware. A second problem is that as the framing pattern length is increased, the time required to transmit the entire framing pattern increases proportionally. For T-carrier systems, the framing bit position is 1 bit out of a 193 bits and occurs only eight thousand times per second. For the extended superframing situation, the framing bit occurs only two thousand times per second. Since the entire framing pattern must be received before it can be recognized, searching for a long pattern through all possible bit positions in either the original T1 carrier or the extended superframing systems would require a great amount of time if a longer pattern were used. Another problem with short framing bit patterns arises when multiple levels of multiplexing are employed in a system. Unless a different framing pattern is used for each multiplexing level, there is a danger of a higher level framing circuit falsely locking onto a lower level framing bit pattern. Separate framing patterns for each level would require long patterns, so that the pattern at each level could be orthogonal to patterns at lower levels. In present day T-carrier multiplexers, the problem is dealt with by using different frame length for each level of multiplexing. This causes lower level patterns to slide through the higher level patterns, eliminating confusion between them. However, the situation also requires demultiplexing of all channels in the high level stream in order to recover even one data channel at the lowest level of multiplexing. SUMMARY OF THE INVENTION One digital telecommunications system is connected to another digital telecommunications system by transmission equipment. Framing data and transmission data are interleaved and transmitted from one system to the other. A pseudo random framing detector circuit for recovering periodic framing data from the interleaved data is contained in each digital telecommunications system. The pseudo random framing detector circuit includes a clock which is connected to the transmission equipment. The clock operates in response to the interleaved data which is received via the transmission equipment to produce a periodic clock signal of a predetermined frequency. A frame sizing circuit is connected to the clock. The frame sizing circuit operates in response to the periodic signal of the clock to produce a second periodic signal of a period which is equal to the length in bits of the framing data plus the transmission data. The pseudo random framing detector circuit also includes a gating circuit. In addition, a shift-register arrangement of the detector circuit is connected to the frame sizing circuit and to the transmission equipment. The shift-register arrangement includes a number of tap outputs and an input. The shift-register arrangement cyclically operates in response to the second periodic signal to produce a number of tap output signals on the corresponding number of tap outputs. At least two of the tap outputs of the shift-register arrangement are connected to the gating circuit. Each of the connected tap outputs is a logic 1 bit positional representation corresponding to any polynomial of maximal length for a particular size of the shift-register arrangement. The gating circuit is connected to those tap outputs of the shift-register arrangement which are a logic 1 bit positional representation of any maximal length polynomial. The gating circuit cyclically operates in response to these tap output signals to produce the framing data. The pseudo random framing detector circuit also includes framing control circuit. In addition, the detector circuit includes a switch. The switch arrangement is connected to the transmission equipment, to the framing control circuit, to the gating circuit and to the input of the shift-register arrangement. The switch operates in response to the framing control circuit to connect the gating circuit to the input of the shift-register arrangement or the switch operates to connect the transmission equipment to the input of the shift-register arrangement. The framing control circuit is also connected to the frame sizing circuit. The framing control circuit operates to select the switch in order to input the framing data to the shift-register arrangement or operates the switch in order to input the interleaved data to the shift-register arrangement. The framing control circuit is also connected to the logic of the system. The framing control circuit also operates to transmit the framing data to the logic of the system. A BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic diagram of a pseudo random framing transmitter circuit embodying the principles of operation of the present invention. FIG. 2 is a pseudo random framing detector circuit embodying the principles of operation of the present invention. DESCRIPTION OF THE PREFERRED EMBODIMENT Referring to FIG. 1, the transmitter section of a pseudo random framing circuit is shown. Bit clock 101 is connected to divide by M circuit 102. Divide by M circuit 102 is connected to the clock input of N-stage shift-register 103. N-stage shift-register 103 has two or more output tap connections to exclusive OR gate 104. Exclusive OR gate 104 has its output connected to the input of N-stage shift-register 103. In addition, the output of exclusive OR gate 104 is also connected to the transmission equipment via the FRAMING BITS OUT lead. Thus, the framing pattern output on the FRAMING BITS OUT lead is generated using a transmit shift-register with feedback logic which implements a polynomial which gives a maximal length pseudo random pattern. The input to the first stage of the shift-register (and also the framing pattern output) is the output of the feedback logic 104. With a maximal length polynomial, the length of a repeating pattern is (2 raised to the power N) minus 1 or (2 N )-1, where N is the length in bits of a shift-register. This relationship is shown in Chapter 3 of SHIFT REGISTER SEQUENCES by Golomb Soloman, revised edition, 1981, published by Aegean Park Press. SHIFT REGISTER SEQUENCES by Golomb Soloman is hereby incorporated by reference and made a part hereof. For example, a 10 bit shift-register produces a random pattern of 1023 bits before the same pattern is repeated. This is accomplished by having the shift-register 103 shift to the right by 1 bit position each time a framing bit is required. The larger the value of N chosen, the less the probability that a data sequence will imitate a framing sequence. A 10 bit shift-register seems to be a practical implementation. The N-stage shift-register 103 has tap outputs available from each bit or stage of the shift-register. Some of these tap outputs are shown connected to the input of exclusive OR gate 104. The number of connections from the shift-register 103 to gate 104 and their relative position within the shift-register may be inferred from tables found in the Soloman reference cited above. For example, a 10 bit shift-register would provide a period of 1023 bits before repeating a sequence. One polynomial corresponding to this period is 2011 octal or base eight. To determine the connections from the shift-register to the exclusive OR gate for this polynomial, the octal representation should be depicted in binary. With this binary depiction, the first 10 bits from the right are chosen. Each bit position corresponds to one tap output of the shift-register. In the binary form of this polynomial, a 1 in a particular bit position indicates a connection from that corresponding tap output to the exclusive OR gate 104. For the polynomial 2011, connections from the shift-register to exclusive OR gate 104 would exist for bit position 0 (the right most bit position) and bit position 3. For each shift-register length, N, there are a number of different tap output configurations (polynomials) which give maximal length sequences. These polynomials may be found in the Soloman reference. For example, for a 10 bit shift-register, the Soloman reference shows many polynomials of maximal length, that is 1023. Table III-5 of the Soloman reference indicates there would be 60 possible polynomials however, not all would be of maximal length. It has been shown that maximal length pseudo random sequences produced by polynomials are optimum with respect to auto-correlation and cross-correlation. Thus, for the same length shift-register N, numerous sequences can be generated, each having minimum correlation with shifted versions of itself or with sequences produced by other polynomials. As a result, use of different polynomials to generate different tap output configurations permits multiple levels of multiplexing data without confusion between framing bits of different levels. In addition, this eliminates the need for different frame lengths for each level of multiplexing. A simple example will serve to illustrate the principles discussed above. Assume that the length of shift-register 103 is 4 bits. For a 4 bit long shift-register, the Soloman reference indicates that there are three possible polynomials. Two of these three polynomials are of maximal length. The octal representation of these two maximal length polynomials is 23 and 31. For our example, we will consider the maximal length polynomial 23 in octal. The octal 23 yields a binary representation of 10011. Since, we are working with a 4 bit shift-register, the first 4 bits from the right are chosen, which yields 0011, reading from left to right. In this case, bit positions 0 and 1 (right justified) are connected from shift-register 103 to exclusive OR gate 104. TABLE 1______________________________________4 BIT - 15 STATE SEQUENCESTATE # BIT POSITIONS______________________________________1 00012 10003 01004 00105 10016 11007 01108 10119 010110 101011 110112 111013 111114 011115 00111 0001______________________________________ Table 1 shows the contents for a 4 bit shift register 103 with tap output connected for polynomial 23 octal. The bit positions of shift-register 103 are shown for each state of the shift-register sequence. The shift-register state of all four zeros is illegal. The bit position shown in Table 1 are bits 0 through 3, right justified. Bit 3, the left most bit, for example, of state #1 contains a 1 in bit position zero and a zero in bit positions 1, 2 and 3. Bit 3 is a zero for state #1, as can be seen from Table 1. As shown in Table 1, the output of exclusive OR gate 104 generates 15 pseudo random states before state #1 is repeated. This is exactly what is expected, since as previously stated a maximal length polynomial yields (2 N )-1 pseudo random states. For this example, N is equal to 4. Therefore, we should see (2 4 )-1 or 15 different states. This is exactly what is observed from Table 1. Circuit 101 generates the frequency of clock signals. The rate at which divider 102 divides the clock, produced by bit clock 101, is given by M. Where M is the number of bits in a frame including the framing bit. For example, in standard T1 carrier framing, M would be equal to 193, 192 data bits plus 1 framing bit. Now turning to FIG. 2, the receiver section of the pseudo random framing circuit is shown. The output of the receiver portion of the transmission equipment (not shown) is connected via the RECEIVED BITS IN lead to bit clock recovery 201 and to switch 205. In addition, the transmission equipment is also connected via the RECEIVED BITS IN lead to framing control circuit 206. Bit clock recovery 201 is connected to divide by M circuit 202, which sizes the frame. Divide by M circuit 202 has its output connected to the clock input of framing control circuit 206 and to the clock input of N-stage shift-register 203. Framing control circuit 206 is connected to the RESET lead of divide by M circuit 202. Further, framing control circuit 206 is connected to switch 205. Switch 205 is a signal pole double throw switch, or a logic circuit wired to perform the switch function, normally operated to gate the output of exclusive OR gate 204 to the input of N-stage shift-register 203. Switch 205 may be operated by framing control circuit 206 to disconnect the output of exclusive OR gate 204 from the input of N-stage shift-register 203 and to connect the output of the transmission equipment directly to N-stage shift-register 203 via the RECEIVE BITS IN lead. N-stage shift-register 203 is connected to exclusive OR gate 204 via a number of tap outputs from shift-register 203. The output of exclusive OR gate 204 is connected to switch 205, as mentioned above. In addition, the output of exclusive OR gate 204 is connected to framing control circuit 206. Lastly, framing control circuit 206 is connected to the logic of the digital communications system via the IN FRAME lead. Receive bits are applied via the RECEIVED BITS IN lead to bit clock recovery circuit 201. Bit clock recovery circuit 201 drives divide by M circuit 202. M is the number of bits including framing bits within a particular frame. Divide by M circuit 202 produces a preliminary framing signal. Since the divide ratio M is equal to the number of bits per frame, a candidate framing bit, which may or may not be the actual framing bit, is identified in the incoming bit stream. The output of divide by M circuit 202 causes the N-stage shift-register 203 to shift 1 bit to the right. Initially, framing control circuit 206 operates switch 205 such that the RECEIVED BITS IN lead is connected to the input of the N-stage shift-register 203. This shifting continues for N complete cycles of the divide circuit 202. At that time, if the candidate bit is the actual framing bit, the contents of the receive shift-register 203 will agree with the contents of the transmit shift-register. At this time, the frame control circuit 206 may operate switch 205 so that the proper pseudo random framing pattern is continuously generated locally by 203 and 204, without reference to the incoming received bits. Framing control circuit 206 compares the predicted framing bits from the output of exclusive OR gate 204 with the candidate framing bits which are received via the transmission channel. Framing control logic 206 may be implemented by using an up/down counter for counting the number of agreements in a known number of bits. If the framing control circuit 206 concludes that there is sufficient agreement between the candidate and the predicted framing bits, it produces a signal on the IN FRAME lead. If framing control logic 206 determines that there is insufficient comparison between the candidate and predicted framing bits, control circuit 206 indicates via the RESET lead to divide by M circuit 202 to reset divide circuit 202, and at the same time operates switch 205 so that the input of shift-register 203 is connected to the RECEIVED BITS IN lead. As a result, divide by M circuit 202 selects a different candidate bit position within the frame to be tested as the framing bit. This process continues until proper comparison is found. At that time, the corresponding signal on the IN FRAME lead is produced to indicate the comparison. Although the preferred embodiment of the invention has been illustrated, and that form described in detail, it will be readily apparent to those skilled in the art that various modifications may be made therein without departing from the spirit of the invention or from the scope of the appended claims.	This invention is a circuit for detecting a framing pattern consisting of a pseudo random shift register sequence. This circuit utilizes an extremely long framing pattern without either a large amount of memory or the need to receive a large number of bits in order to recognize the framing pattern. The use of lengthy framing patterns minimizes the chance of false framing caused by patterns in bit positions other than the framing bit position. In addition, the incoming data stream may be connected directly to the shift register mechanism.	7
FIELD OF THE INVENTION [0001] The present invention relates in general to information processing systems. In particular, the present invention relates to networks in which information processing systems are utilized. Still more particularly, the present invention relates to a browser method and system for displaying information from a network. BACKGROUND [0002] The development of computerized distributed information resources, such as the “Internet,” allows users to link to a computer network and retrieve vast amounts of electronic information previously unavailable in an electronic medium. Such electronic information increasingly is displacing more conventional means of information transmission, such as newspapers, magazines, and even television. [0003] Electronic information transferred between computer networks (e.g., the Internet) can be presented to a user in hypertext, a metaphor for presenting information in a manner in which text, images, sounds, and actions become linked together in a complex, non-sequential web of associations that permit the user to “browse” through related topics, regardless of the presented order of the topics. For example, traveling among links to the word “iron” in an article displayed within a graphical user interface in a computer system might lead the user to the periodic table of the chemical elements (i.e., linked by the word “iron”), or to a reference to the use of iron in weapons in Europe in the Dark Ages. The term “hypertext” is used to describe documents, as presented by a computer, that express the nonlinear structure of ideas, as opposed to the linear format of books, film, and speech. The combination of hypertext documents connected by their links in the Internet is referred to as the World Wide Web (WWW). [0004] Networked systems utilizing hypertext conventions typically follow a client/server architecture. A “client” is usually a computer that requests a service provided by another computer (i.e., a server). A “server” is typically a remote computer system accessible over a communications medium such as the Internet. Based upon such requests by the user at the client, the server presents information to the user as responses to the client. The client typically contains a program, called a browser, that communicates the requests to the server and formats the responses for viewing (browsing) at the client. [0005] The browser retrieves a web page from the server and displays it to the user at the client. A “web page” (also referred to by some designers simply as a “page”) is a data file, or document, written in a hyper-text language that may have viewable objects such as text, graphic images, and even multimedia objects, such as sound recordings or moving video clips associated with that data file. [0006] When a client workstation sends a request to a server for a web page, the server first transmits (at least partially) the main hypertext file associated with the web page, and then loads, either sequentially or simultaneously, the other files associated with the web page. The constructed web page is then displayed on a client display screen. A web page may be larger than the physical size of the display screen, and devices such as graphical user interface scroll bars can be utilized by the viewing software (i.e., the browser) to view different portions of the web page. [0007] Many web pages are filled with numerous viewable objects, drastically increasing download time from the server to the client. Some of these viewable objects are important and interesting; for example, a navigation bar. Others are more likely to be annoying to the user; an example is advertisements. Current browsers allow the user to configure that either all viewable objects are downloaded, or none at all. This “all or nothing” approach does not provide the user with an acceptable solution to managing downloaded web pages. [0008] From the foregoing, it can be seen that a need exists for a method and system for managing viewable objects in downloaded web pages. SUMMARY OF THE INVENTION [0009] It is therefore one object of the present invention to provide for an improved browser method and system. [0010] It is therefore another object of the present invention to provide an improved information processing system. [0011] It is still another object of the present invention to provide to a method and system for selectively disabling the display of viewable objects. [0012] In the preferred embodiment, a browser selectively disables the display of viewable objects in a document. The document contains control tags that describe how associated data is to be displayed. A browser interprets the control tags and formats the associated data to display viewable objects on a display-screen. The user selects a portion of the display screen, containing viewable objects, that the user desires to be blocked. In response to this selection, the browser saves a description of the user-selected area. [0013] When the browser subsequently retrieves the document, the browser compares the saved description to locations on the display screen associated with the control tags in the document. When the viewable object associated with a compared control tag is outside the saved description, the browser downloads and displays the viewable object. When the viewable object associated with the compared control tag is within the saved description, the browser blocks the display of the viewable object by not downloading the object and by blanking the screen at that location or by replacing the viewable object with an icon. In this way, the user can select which objects are downloaded and visible on the screen and which are not. BRIEF DESCRIPTION OF THE DRAWINGS [0014] [0014]FIG. 1 is a pictorial representation of a computer system that may be utilized to implement a preferred embodiment of the present invention. [0015] [0015]FIG. 2 is a block diagram of a representative hardware environment of the processing unit of the computer system illustrated in FIG. 1. [0016] [0016]FIG. 3 is a block diagram of software stored within the memory of the computer system depicted in FIG. 1. [0017] [0017]FIG. 4 is a block diagram illustrative of a client/server architecture in accordance with a preferred embodiment of the present invention. [0018] [0018]FIG. 5 is a detailed block diagram of a client/server architecture in accordance with a preferred embodiment of the present invention. [0019] [0019]FIG. 6 is a diagram illustrative of a computer network that can be implemented in accordance with a preferred embodiment of the present invention. [0020] [0020]FIGS. 7 a and 7 b are pictorial representations of the interfaces that are used to control the operation of the preferred embodiment. [0021] [0021]FIG. 7 c is a pictorial representation of a display screen after the operation of the preferred embodiment. [0022] [0022]FIG. 8 is a block diagram of the data structures of the preferred embodiment. [0023] [0023]FIGS. 9, 10, 11 , and 12 are flowcharts that describe the operation of the preferred embodiment. DESCRIPTION OF THE PREFERRED EMBODIMENT [0024] Technical Overview [0025] The development of computerized distributed information resources, such as the “Internet,” allows users to link with servers and networks, and thus retrieve vast amounts of electronic information heretofore unavailable in an electronic medium Such electronic information increasingly is displacing more conventional means of information transmission, such as newspapers, magazines, and even television. The term “Internet” is an abbreviation for “Internetwork,” and refers commonly to a collection of computer networks that utilize the TCP/IP suite of protocols, well-known in the art of computer networking. TCP/IP is an acronym for “Transport Control Protocol/Internet Protocol,” a software protocol developed by the Department of Defense for facilitating communications between computers. [0026] Electronic information transferred between computer networks (e.g., the Internet) can be presented to a user in hypertext, a metaphor for presenting information in a manner in which text, images, sounds, and actions become linked together in a complex non-sequential web of associations that permit the user to “browse” through related topics, regardless of the presented order of the topics. These links are often established by both the author of a hypertext document and by the user, depending on the intent of the hypertext document. For example, traveling among links to the word “iron” in an article displayed within a graphical user interface in a computer system might lead the user to the periodic table of the chemical elements (i.e., linked by the word “iron”), or to a reference to the use of iron in weapons in Europe in the Dark Ages. The term “hypertext” is utilized to describe documents, as presented by a computer, that express the nonlinear structure of ideas, as opposed to the linear format of books, film, and speech. [0027] Hypertext, especially in an interactive format where choices are controlled by the user, is structured around the idea of offering a working and learning environment that parallels human thinking-that is, an environment that allows the user to make associations between topics rather than moving sequentially from one topic to the next, as in an alphabetic list. Hypertext topics are linked in a manner that allows users to jump from one subject to other related subjects during a search for information. [0028] Networked systems utilizing hypertext conventions typically follow a client/server architecture. A “client” is a member of a class or group that utilizes the services of another class or group to which it is not related. In the context of a computer network such as the Internet, a client is a process (i.e., roughly a program or task) that requests a service provided by another program. The client process utilizes the requested service without having to know any working details about the other program or the service itself. In networked systems, a client is usually a computer that accesses shared network resources provided by another computer (i.e., a server). [0029] A “server” is typically a remote computer system accessible over a communications medium such as the Internet. The server scans and searches for raw (e.g., unprocessed) information sources (e.g., newswire feeds or newsgroups). Based upon such requests by the user, the server presents filtered electronic information to the user as server responses to the client process. The client process may be active in a first computer system, and the server process may be active in a second computer system, and communicate with one another over a communications medium that allows multiple clients to take advantage of the information-gathering capabilities of the server. A server can thus be described as a network computer that runs administrative software that controls access to all or part of the network and its resources, such as disk drivers or printers. A computer acting as a server makes resources available to computers acting as workstations on the network. [0030] Client and server can communicate with one another utilizing the functionality provided by a hypertext transfer protocol (HTTP). The World Wide Web (WWW) or, simply, the “web,” includes all servers adhering to this protocol, which are accessible to clients via a Universal Resource Locator (URL). Internet services can be accessed by specifying Universal Resource Locators that have two basic components: a protocol to be used and an object pathname. For example, the Universal Resource Locator address, “http://www.uspto.gov” (i.e., the “home page” for the U.S. Patent and Trademark Office), specifies a hypertext transfer protocol (“http”) and a pathname (“www.uspto.gov”) of the server. The server name is associated with a unique numeric value (i.e., a TCP/IP address). Active within the client is a first process, known as a “browser” that establishes the connection with the server and presents information to the user. The server itself executes corresponding server software that presents information to the client in the form of HTTP responses. The HTTP responses correspond to “web pages” constructed from a Hypertext Markup Language (HTML), or other server-generated data. [0031] A “web page” (also referred to by some designers simply as a “page” or a “document”) is a data file written in a hyper-text language, such as HTML, that may have text, graphic images, Java applets, ActiveX controls, and even multimedia objects, such as sound recordings or moving video clips associated with that data file. The page contains control tags and data. The control tags identify the structure; for example, the headings, subheadings, paragraphs, lists, and embedding of images. The data consists of the contents, such as text or multimedia, that will be displayed or played to the user. A browser interprets the control tags and formats the data according to the structure specified by the control tags to create viewable objects that the browser displays, plays, or otherwise performs to the user. The data that the browser formats can be contained within the page, or it can be in another file on the same or a different server and embedded into the page. Thus, a control tag can direct the browser to retrieve a page from another source and place it at the location specified by the control tag. In this way, the browser can build a viewable object that contains multiple components, such as spreadsheets, text, hotlinks, pictures, sound, and video objects. A web page can be constructed by loading one or more separate files into an active directory or file structure that is then displayed as viewable objects within a graphical user interface. [0032] When a client workstation sends a request to a server for a web page, the server first transmits (at least partially) the main hypertext file associated with the web page, and then loads, either sequentially or simultaneously, the other files associated with the web page. A given file may be transmitted as several separate pieces via TCP/IP protocol. The constructed web page is then displayed as a viewable object on the workstation monitor. A web page may be “larger” than the physical size of the monitor screen, and devices such as graphical user interface scroll bars can be utilized by the viewing software (i.e., the browser) to view different portions of the web page. [0033] As various pages are visited via hypertext links displayed within a web browser, URLs representative of the pages visited during a given web navigation session are typically recorded by the web browser. Because the number of pages is enormous, a user searching for particular or important pages can find it difficult to find those particular or important pages. Navigating through existing pages can be a time consuming task, and often important pages are not visited. Many current browsers provide the user with a “bookmark” list, also known as a “favorites” list. This bookmark list stores favorite URL's of the user. When the user browses a page that the user would like to browse again, the user can save the URL for that page in the bookmark list. In the future, when the user wishes to browse that page again, the user selects the page from the bookmark list, which frees the user from having to remember the URL. [0034] Detailed Description [0035] With reference now to the figures and in particular with reference to FIG. 1, there is depicted an embodiment of a computer system that may be utilized to implement the preferred embodiment. Computer system 110 includes processing unit 112 , display device 114 , keyboard 116 , pointing device 118 , printer 120 , and speakers 126 . Processing unit 112 receives input data from input devices such as keyboard 116 , pointing device 118 , and local area network interfaces (not illustrated) and presents output data to a user via display device 114 , printer 120 , and speakers 126 . Pointing device 118 is preferably utilized in conjunction with a graphical user interface (GUI) in which hardware components and software objects are controlled through the selection and the manipulation of associated graphical objects displayed within display device 114 . Although computer system 110 is illustrated with a mouse for pointing device 118 , other graphical-pointing devices such as a graphic tablet, joystick, track ball, or track pad could also be utilized. [0036] Keyboard 116 is that part of computer system 110 that resembles a typewriter keyboard and that enables a user to control particular aspects of the computer. Because information flows in one direction, from keyboard 114 to processing unit 112 , keyboard 116 functions as an input-only device. Functionally, keyboard 116 represents half of a complete input/output device, the output half being video display terminal 114 . Keyboard 116 includes a standard set of printable characters presented in a QWERTY pattern typical of most typewriters. In addition, keyboard 116 includes a calculator-like numeric keypad at one side. Some of these keys, such as the “control,” “alt,” and “shift” keys can be utilized to change the meaning of another key. Other special keys and combinations of keys can be utilized to control program operations or to move either text or cursor on the display screen of video-display terminal 114 . [0037] Video-display terminal 114 is the visual output of computer system 110 . As indicated herein, video-display terminal 114 can be a cathode-ray tube (CRT) based video display well-known in the art of computer hardware. But, with a portable or notebook-based computer, video display terminal 114 can be replaced with a liquid crystal display (LCD) based or gas, plasma-based, flat-panel display. [0038] Pointing device 118 features a casing with a flat bottom that can be gripped by a human hand. Pointing device 118 can include buttons on the top, a multidirectional detection device such as a ball on the bottom, and a cable 129 that connects pointing device 118 to processing unit 112 . [0039] Computer system 110 can be implemented utilizing any suitable computer such as the IBM Aptiva computer, a product of International Business Machines Corporation, located in Armonk, N.Y. But, a preferred embodiment of the present invention can apply to any hardware configuration that allows browsing of documents, regardless of whether the computer system is a complicated, multi-user computing apparatus or a single-user workstation. Computer system 110 is thus a configuration that includes all functional components of a computer and its associated hardware. In general, a typical computer system includes a console or processing unit such as processing unit 112 , with one or more disk drives, a monitor such as video display terminal 114 , and a keyboard such as keyboard 116 . [0040] To support storage and retrieval of data, processing unit 112 further includes diskette drive 122 , hard-disk drive 123 , and CD-ROM drive 124 , which are interconnected with other components of processing unit 112 . [0041] Referring to FIG. 2, there is depicted a block diagram of the principal components of processing unit 112 . CPU 226 is connected via system bus 234 to RAM 258 , diskette drive 122 , hard-disk drive 123 , CD-ROM drive 124 , keyboard/pointing-device controller 284 , parallel-port adapter 276 , network adapter 285 , display adapter 270 , and modem 287 . Although the various components of FIG. 2 are drawn as single entities, each may consist of a plurality of entities and may exist at multiple levels. [0042] Processing unit 112 includes central processing unit (CPU) 226 , which executes instructions. CPU 226 includes the portion of computer system 110 that controls the operation of the entire computer system, including executing the arithmetical and logical functions contained in a particular computer program. Although not depicted in FIG. 2, CPUs such as CPU 226 typically include a control unit that organizes data and program storage in a computer memory and transfers the data and other information between the various parts of the computer system. Such CPUs also generally include an arithmetic unit that executes the arithmetical and logical operations, such as addition, comparison, multiplication, and so forth. CPU 226 accesses data and instructions from and stores data to volatile random access memory (RAM) 258 . [0043] While any appropriate processor can be utilized for CPU 226 , it is preferably one of the Power PC line of microprocessors available from IBM. Alternatively, CPU 226 can be implemented as one of the 80×86 or Pentium processors, or any other type of processor, which are available from a number of vendors. Although computer system 110 is shown to contain only a single CPU and a single system bus, it should be understood that the present invention applies equally to computer systems that have multiple CPUs and to computer systems that have multiple buses that each perform different functions in different ways. [0044] RAM 258 comprises a number of individual volatile memory modules that store segments of operating system and application software while power is supplied to computer system 110 . The software segments are partitioned into one or more virtual memory pages that each contain a uniform number of virtual memory addresses. When the execution of software requires more pages of virtual memory that can be stored within RAM 258 , pages that are not currently needed are swapped with the required pages, which are stored within non-volatile storage devices 122 , 123 , or 124 . RAM 258 is a type of memory designed such that the location of data stored in it is independent of the content. Also, any location in RAM 258 can be accessed directly without having to work through from the beginning. [0045] Hard disk drive 123 and diskette drive 122 are electromechanical devices that read from and write to disks. The main components a disk drive in particular can include are a spindle that mounts a disk, a drive motor that spins the disk when the drive is in operation, one or more read/write heads that perform the actual reading and writing, a second motor that positions the read/write heads over the disk, and controller circuitry that synchronizes read/write activities and transfers information to and from computer system 110 . A disk itself is typically a round, flat piece of flexible plastic (e.g., floppy disk) or inflexible metal (e.g. hard disk) coated with a magnetic material that can be electrically influenced to hold information recorded in digital (i.e., binary) form. A disk is, in most computers, the primary method for storing data on a permanent or semipermanent basis. Because the magnetic coating of the disk must be protected from damage and contamination, a floppy (e.g., 5.25 inch) disk or micro-floppy (e.g., 3.5 inch) disk is encased in a protective plastic jacket. A hard disk, which is very finely machined, is typically enclosed in a rigid case and can be exposed only in a dust-free environment. [0046] Keyboard/pointing-device controller 284 interfaces processing unit 112 with keyboard 116 and graphical-pointing device 118 . In an alternative embodiment, there is a separate controller for keyboard 116 and graphical-pointing device 118 . [0047] Display adapter 270 translates graphics data from CPU 226 into video signals utilized to drive display device 114 . [0048] Finally, processing unit 112 includes network adapter 285 , modem 287 , and parallel-port adapter 276 , which facilitate communication between computer system 110 and peripheral devices or other computer systems. Parallel-port adapter 276 transmits printer-control signals to printer 120 through a parallel port. Network adapter 285 connects computer system 110 to an unillustrated local area network (LAN). A LAN provides a user of computer system 110 with a means of electronically communicating information, including software, with a remote computer or a network logical-storage device. In addition, a LAN supports distributed processing, which enables computer system 110 to share a task with other computer systems linked to the LAN. [0049] Modem 287 supports communication between computer system 110 and another computer system over a standard telephone line. Furthermore, through modem 287 , computer system 110 can access other sources such as a server, an electronic bulletin board, and the Internet or World Wide Web. [0050] The configuration depicted in FIG. 1 is but one possible implementation of the components depicted in FIG. 2. Portable and “laptop” based computers are other possible configurations. The hardware depicted in FIG. 2 may vary for specific applications. For example, other peripheral devices such as optical-disk media, audio adapters, or chip-programming devices, such as PAL or EPROM programming devices well-known in the art of computer hardware and the like, may be utilized in addition to or in place of the hardware already depicted. [0051] As will be described in detail below, aspects of the preferred embodiment pertain to specific method steps implementable on computer systems. In an alternative embodiment, the invention may be implemented as a computer program-product for use with a computer system. The programs defining the functions of the preferred embodiment can be delivered to a computer via a variety of signal-bearing media, which include, but are not limited to, (a) information permanently stored on non-writable storage media (e.g., read only memory devices within a computer such as CD-ROM disks readable by CD-ROM drive 124 ); (b) alterable information stored on writable storage media (e.g., floppy disks within diskette drive 122 or hard-disk drive 123 ); or (c) information conveyed to a computer by a communications media, such as through a computer or telephone network, including wireless communications. Such signal-bearing media, when carrying computer-readable instructions that direct the functions of the present invention, represent alternative embodiments of the present invention. [0052] With reference now to FIG. 3, there is illustrated a block-diagram representation of the software configuration of computer system 110 in accordance with the preferred embodiment. As noted above, the software executed by computer system 110 can be stored within one or more of RAM 258 , the nonvolatile storage provided by diskette drive 122 , hard-disk drive 123 , CD-ROM drive 124 , or a remote server accessible via modem 287 or network adapter 285 . [0053] As illustrated, the software configuration of computer system 110 includes operating system 390 , which is responsible for directing the operation of computer system 110 . For example, operating systems typically include computer software for controlling the allocation and usage of hardware resources such as memory, CPU time, disk space, and peripheral devices. A suitable operating system 390 and associated graphical-user-interface manager 392 (e.g., Microsoft Windows, AIX, or OS/2) could be used. Other technologies also could be utilized, such as touch-screen technology or human-voice control. The operating system is the foundation upon which applications 395 , such word-processing, spreadsheet, and web browser programs are built. [0054] In accordance with the preferred embodiment, operating system 390 includes graphical-user-interface (GUI) manager 392 although they could be packaged separately. GUI 392 manages the graphical-user-interface with which a user of computer 110 interacts. [0055] Operating system 390 communicates with applications 395 and browser 399 through messages conforming to the syntax of the application-program-interface (API) supported by operating system 390 . Operating system 390 further communicates with graphical-pointing device-driver 396 , printer device-driver 397 , and display-adapter device-driver 398 . For example, operating system 390 sends graphics data to display-adapter device-driver 398 , which in turn translates the messages into bus signals utilized to control display adapter 270 . In addition, graphical-pointing device-driver 396 translates signals from pointing device 118 through keyboard/pointing-device controller 284 into Cartesian coordinates and a selection status, which are then relayed to GUI manager 392 . [0056] CPU 226 is suitably programmed to carry out the preferred embodiment by browser 399 , as described in more detail in the flowcharts of FIGS. 9 - 12 . In the alternative, the function of FIGS. 9 - 12 could be implemented by control circuitry through the use of logic gates, programmable-logic devices, or other hardware components in lieu of a processor-based system. [0057] Browser 399 includes bookmark list 310 , which is further described under the description for FIG. 8, below. In an alternative embodiment, bookmark list 310 could be packaged separately from browser 399 . Although browser 399 is drawn as being separate from operating system 390 , they could be packaged together. [0058] [0058]FIG. 4 illustrates a block diagram of a client/server architecture, in accordance with a preferred embodiment. User requests 491 are sent by client process 480 to server 488 . Server 488 can be a remote computer system accessible over a computerized, distributed-information resource such as the Internet or other communications network. Server 488 performs scanning and searching of information sources and, based upon these user requests, presents the filtered electronic information as server responses 493 to the client process. The client process may be active in a first computer system, and the server process may be active in a second computer system, communicating with one another over a communications medium, thus providing distributed functionality and allowing multiple clients to take advantage of the information-gathering capabilities of the server. [0059] [0059]FIG. 5 illustrates a detailed block diagram of a client/server architecture in accordance with a preferred embodiment of the present invention. Although the client and server are processes that are operative within two computer systems, these processes being generated from a high-level programming language (e.g., PERL), which is interpreted and executed in a computer system at runtime (e.g., a workstation), they could be implemented in a variety of hardware devices, either programmed or dedicated. [0060] Computer system 110 , functioning as a client, and server 488 communicate by utilizing the functionality provided by HTTP. Active within client 110 is a first process, browser 399 , which establishes connections with server 488 and presents information to the user. [0061] Server 488 executes the corresponding server software, which presents information to the client in the form of HTTP responses 590 . The HTTP responses 590 correspond with the web pages represented using HTML or other data generated by server 488 . Server 488 provides HTML 594 . Server 488 also provides Common Gateway Interface (CGI) 596 , which allows client 110 to direct server 488 to commence execution of a specified program contained within server 488 . This may include a search engine that scans received information in the server for presentation to the user controlling the client. Using this interface and HTTP responses 590 , the server can notify the client of the results of that execution upon completion. [0062] [0062]FIG. 6 is a diagram illustrative of a computer network 680 , which can be implemented in accordance with a preferred embodiment of the present invention. Computer network 680 is representative of the Internet, which can be described as a known computer network based on the client-server model discussed herein. Conceptually, the Internet includes a large network of servers 488 that is accessible by clients 110 , typically users of personal computers and previously described above under the description for FIGS. 1 and 2. Clients 110 access the network of servers 488 through private Internet access provider 684 (e.g., Internet America) or an on-line service provider 686 (e.g., America On-Line, Prodigy, and Compuserve). Each of clients 110 may run browser 399 to access servers 488 via the access providers. Each server 488 operates a web site that supports files in the form of documents and pages. A network path to servers 488 is identified by a Universal Resource Locator (URL) having a known syntax for defining a network collection. [0063] [0063]FIG. 7 a illustrates a pictorial representation of example interfaces that are used to control the operations of the preferred embodiment. Bookmark control 730 is a pull-down menu that the user can access to control the operations of the preferred embodiment. Bookmark control 730 contains menu options “add URL” 732 , “delete URL” 734 , “configure blocking” 736 , “PTO home page” 740 , and “Local Weather” 742 . Menu options 732 , 734 , and 736 are options that the user can access while menu options 740 and 742 are bookmarks, which when the user selects them, browser 399 will access their respective associated pages. [0064] When the user selects “add URL” 732 , browser 399 adds the current viewed page, for example URL 705 , to bookmark list 310 . By using menu options 732 , the user previously added bookmarks 740 and 742 . [0065] Menu option “delete URL” 734 allows the user to request the removal of a bookmark from bookmark list 310 . [0066] Menu option “configure blocking” 736 allows the user to control the configuration of the blocking function. When the user selects menu option 736 , browser 399 displays the example dialog shown in FIG. 7 b , described below. [0067] Referring again to FIG. 7 a , the example page, which browser 399 downloaded from URL 705 , contains viewable objects 715 , 745 , 710 , and 725 . Browser 399 creates these viewable objects by interpreting the control tags in the downloaded document and formatting data associated with the control tags, as further described below under the description for FIG. 8. Referring again to FIG. 7 a , viewable object 715 was created from an image tag. Viewable object 710 was created from an applet tag. Viewable object 725 was created from a ActiveX control tag. [0068] [0068]FIG. 7 b depicts an example screen shown by browser 399 in response to the user selecting menu option 736 , described above under the description for FIG. 7 a . Referring again to FIG. 7 b , the user may select control buttons file-save URL 770 , file-exit 765 , remove selected blocking 760 , or remove all blocking 755 . When the user draws rectangle 775 around the desired area of the screen to be blocked, in this example viewable object 710 , and selects button 770 , browser 399 will block the display of the data within the rectangle, as further described below under the description for FIGS. 7 c , 10 , and 11 . If the URL associated with the displayed page does not already exist in bookmark list 310 , then browser 399 will add a bookmark name and the URL, as further described below under the description for FIGS. 8 and 10. Although in this example, rectangle 775 is shown, other geometric shapes could also be used, such as a square, a circle, an oval, a triangle, or in general in a polygon. When the user selects button 765 , browser 399 exits from the displayed screen and returns to the invoking screen, such as the one shown in FIG. 7 a. [0069] Referring again to FIG. 7 b , when the user draws a polygon around a screen area and selects button 760 , then browser 399 removes blocking for this selected area, as further described below under the description for FIG. 12. [0070] Referring again to FIG. 7 b , when the user selects button 755 , browser 399 removes all of the blocking previously requested for the displayed web page, as further described below under the description for FIG. 12. [0071] [0071]FIG. 7 c illustrates a pictorial representation of a display screen after blocking the area defined by rectangle 775 , according to the preferred embodiment. The user previously drew rectangle 775 around viewable object 710 and then selected file-save URL 770 , as shown above under the description for FIG. 7 b . Referring again to FIG. 7 c , in response to the user's request, browser 399 added URL 705 to bookmark list 310 and displayed icon 786 indicating the location at which the applet would have been placed had it not been blocked. [0072] [0072]FIG. 8 illustrates a block diagram of the data structures of the preferred embodiment. Page 850 represents a page (or document) in HTML format stored on a server and downloaded to the client in response to request from browser 399 . Bookmark list 310 is a data structure maintained by browser 399 . [0073] Page 850 contains example HTML control tags that browser 399 interprets to display the sample viewable object on display screen 114 shown in FIG. 7 a . Referring again to FIG. 8, tag 815 , when interpreted by browser 399 , causes browser 399 to download the file named “lottery.gif” from a server, format its data, and display viewable object 715 , as previously described above under the description for FIG. 7 a . Referring again to FIG. 8, tag 810 , when interpreted by browser 399 , causes browser 399 to download the applet “freegift.class” from a server and display viewable object 710 , as previously described above under the description for FIG. 7 a . Referring again to FIG. 8, tag 825 , when interpreted by browser 399 , causes browser 399 to display viewable object 725 , as previously described above under the description for FIG. 7 a. [0074] Bookmark list 310 is the list against which the user operates via menu 730 shown in FIG. 7 a . Referring again to FIG. 8, bookmark list 310 contains example bookmark entry 811 . When the user draws a rectangle around the viewable object the user wishes to block and selects menu option 732 , browser 399 assigns the current page being viewed a value for bookmark name 812 and stores the page URL, for example URL 705 , in URL field 814 . Browser 399 then stores a description of the selected display-screen area in blocked area 816 , in the form of x and y coordinates of the upper left-hand corner of the rectangle along with the length of the rectangle on the x-axis and the height of the rectangle on the y-axis. Although the example coordinates in blocked area 816 are specific to a rectangle, the coordinates saved could also be modified to represent any polygon. Since the user can select multiple blocked areas, blocked-area field 816 through blocked-area field 818 are provided in entry 811 of bookmark list 310 . Thus, in the preferred embodiment, bookmark list 310 contains the blocked display-areas, but any list that is capable of saving blocked display-areas could be used. [0075] FIGS. 9 - 12 illustrate flowcharts that describe the operation of the preferred embodiment. Referring to FIG. 9, there is illustrated the main logic of browser 399 that responds to requests from the user. At block 900 , browser 399 starts. Control then continues to block 905 , where browser 399 gets the next operation requested by the user and determines which operation the user requested. [0076] The user can request to add an entry to the bookmark list 925 , can select a bookmark entry for downloading 930 , can remove blocking 935 , and can exit 940 . Browser 399 can perform many other functions-e.g., printing, copying, pasting, and viewing the source of pages-in addition to those shown in FIG. 9. These other functions are omitted for clarity of illustration. [0077] If the user has requested that an entry in the bookmark list be added, then control continues to block 950 where the entry is added or as further described under the description for FIG. 10, below. The user can request this operation by selecting menu option 732 , as previously described under the description for FIG. 7 a . Referring again to FIG. 9, control then returns to block 905 . [0078] If the user requested that a bookmark entry be downloaded, then control continues to block 960 where browser 399 downloads, formats, and displays the page as further described under the description for FIG. 11, below. The user can request this operation by selecting one of the bookmarks in bookmark menu 730 ; for example menu option 740 or 742 , as described above under the description for FIG. 7 a . Referring again to FIG. 9, control then returns to block 905 . [0079] If the user requested that blocking of a previously blocked area be removed, then control continues to block 965 where browser 399 removes the blocking, as farther described under the description for FIG. 12, below. The user can request this operation by selecting menu option 755 or 760 , as described above under the description for FIG. 7 b . Referring again to FIG. 9, control then returns to block 905 . [0080] If the user has requested an exit operation, then control stops at block 970 . [0081] Referring to FIG. 10, there is illustrated sample logic that adds an entry in bookmark list 310 . Control starts at block 1000 . Control then continues to block 1003 where browser 399 determines whether there is a preexisting entry in bookmark list 310 for the URL that is to be added. If the determination at block 1003 is true, then control continues to block 1015 , as described below. If the determination at block 1003 is false, then control then continues to block 1004 where browser 399 creates an entry in bookmark list 310 , such as entry 811 . Further, browser 399 stores a bookmark value in bookmark name field 812 , which is a description of the page that the user finds meaningful, and stores an address of the page in URL field 814 . Control then continues to block 1007 where browser 399 initializes the blocked area fields-such as blocked area 816 and blocked area 818 -to none. [0082] Control then continues to block 1015 where browser 399 retrieves a description of the area or areas that the user selected to be blocked. Control then continues to block 1020 where browser 399 calculates the starting points of the area on the screen and the size of the area on the screen that the user selected. In the preferred embodiment, browser 399 calculates the x and y coordinates to the upper left-hand corner of a rectangle that the user draws along with the height of the rectangle on the y-axis and the length of the rectangle on the x-axis. But, the user could also draw a circle, oval, square, or polygon. Control then continues to block 1025 where browser 399 stores these calculated values in the bookmark list, such as in blocked-area field 816 . Control then continues to block 1030 where browser 399 determines whether there are more areas to block. If there are selected more areas to block, then control returns to block 1015 . In this way browser 399 can add values to other blocked-area fields such as blocked-area field 818 . When browser 399 has processed all of the areas, then the determination at block 1030 will be false and control continues to block 1035 where the function returns. [0083] Referring to FIG. 11, there is illustrated sample logic that downloads and displays a specified page. At block 1100 , the logic begins. Control then continues to block 1105 , where browser 399 retrieves URL 814 associated with the bookmark name specified by the user. The user might have specified a bookmark name by selecting a bookmark name in menu control 730 in FIG. 7 a . Referring again to FIG. 11, control then continues to block 1110 where browser 399 downloads the page associated with URL 814 . [0084] Control then continues to block 1115 where browser 399 begins processing the tags in the downloaded page, and retrieves the first tag in the page. Control then continues to block 1117 where browser 399 determines whether the tag embeds data from another source external to the downloaded page. Examples of tags that embed data from other sources are image tags, applet tags, and ActiveX control tags. [0085] If this determination is false, then control continues to block 1132 where browser 399 performs the standard processing for this tag, and control then continues to block 1135 where browser 399 determines whether there are any more tags to be processed. If the determination at block 1135 is true, then control returns to block 1115 where browser 399 retrieves the next tag in the page. [0086] If the determination at block 1117 is true, then control continues to block 1118 where browser 399 determines whether this bookmark entry 811 contains any blocked-area fields 816 - 818 . If the determination at block 1118 is false then control continues to block 1132 , as described above. If the determination at block 1118 is true, then control then continues to block 1119 where browser 399 interprets the tag in the page and calculates the starting position and offsets on display screen 114 where browser 399 will display the data associated with this tag. Control then continues to block 1120 where browser 399 determines whether the data to be displayed would fall within any of blocked-area fields 816 - 818 in bookmark entry 811 associated with this URL in bookmark list 310 . If this determination is false, then control continues to block 1130 where browser 399 downloads the image specified by the tag, after which control continues to block 1135 as described above. [0087] If the determination at block 1120 is true, then control continues to block 1125 where browser 399 blocks the screen area where this image would have been displayed had it been downloaded and processed. In the preferred embodiment, browser 399 displays an icon on the screen in place of the blocked image that indicates that the image has been blocked. This icon could be a rectangle with a cross through it. But, the browser could simply display empty space at this location. Control then continues to block 1135 , as described above. [0088] When the determination at block 1135 is false, then there are no tags left to process in the downloaded page, and control continues to block 1140 where the function returns. [0089] Referring to FIG. 12, there is illustrated sample logic that removes blocking from either one selected block area or from all blocked areas associated with a particular URL. Control begins at block 1200 . Control then continues to block 1240 where browser 399 retrieves the bookmark list entry 811 associated with the current page. Control then continues to block 1241 where browser 399 gets the next blocked area in the bookmark list entry 811 . Control then continues to block 1243 where browser 399 determines whether this blocked area is to be unblocked. If the user selected menu option 755 in FIG. 7 b then the determination at block 1243 in FIG. 12 will be true for all blocked areas in bookmark list entry 811 . If the user selected menu option 760 in FIG. 7 b , then the determination at block 1243 in FIG. 12 will be true only for the areas that the user selected for unblocking. Referring again to FIG. 12, if the determination at block 1243 is false then control continues to block 1249 where browser 399 determines if there are any more blocked areas in bookmark entry 811 . If the determination at block 1249 is false then the function returns at block 1255 . If the determination at block 1249 is true then control returns to block 1241 . [0090] If the determination at block 1243 is true, then control continues to block 1244 where browser 399 finds the control tag in the page that is associated with this blocked area, that is, the tag that would display data within the blocked area. Control then continues to block 1245 where browser 399 downloads the data specified by this tag and presents the data on display screen 114 . Control then continues to block 1247 where browser 399 sets the blocked-area field to none indicating that this area is not blocked. Control then continues to block 1249 , as described above. [0091] While this invention has been described with respect to the preferred and alternative embodiments, it will be understood by those skilled in the art that various changes in detail may be made therein without departing from the spirit, scope, and teaching of the invention. For example, browsers may become widely employed in consumer applications such as operator panels for consumer electronics, appliances, and automobiles. Accordingly, the herein disclosed invention is to be limited only as specified in the following claims.	A browser selectively disables the display of viewable objects in a document. The document contains control tags that describe how associated data is to be displayed. A browser interprets the control tags and formats the associated data to display viewable objects on a display-screen. The user selects a portion of the display screen, containing viewable objects, that the user desires to be blocked. In response to this selection, the browser saves a description of the user-selected area. When the browser subsequently retrieves the document, the browser compares the saved description to locations on the display screen associated with the control tags in the document. When the viewable object associated with a compared control tag is outside the saved description, the browser downloads and displays the viewable object. When the viewable object associated with the compared control tag is within the saved description, the browser blocks the display of the viewable object by not downloading the object and by blanking the screen at that location or by replacing the viewable object with an icon. In this way, the user can select which objects are downloaded and visible on the screen and which are not.	8
FIELD OF THE INVENTION The present invention relates generally to industrial weaving looms and their operation. More particularly, the present invention relates to identifying a faulty loom component that is causing the loom needlessly to stop operation. BACKGROUND OF THE INVENTION Industrial air-jet looms are complicated pieces of equipment. Such looms weave thousands of threads to create a desired fabric. As a result, an industrial loom has many intricate parts that must operate in conjunction one with another to create the resulting fabric. In order to accomplish this result, industrial looms perform certain operations. For example, such looms engage in a shedding operation whereby the longitudinal or warp threads are divided or opened, a picking operation whereby the weft thread is inserted between the divided warp, and a beating operating whereby the reed strikes the weft thread into position in the fabric. The warp threads travel through the loom under a certain tension. During the performance of any of the above-described operations, it is known that a warp thread may break or slacken. In such an event, the thread is either omitted or mis-woven to such an extent that the resulting fabric is unacceptable. The prior art has recognized this problem and provided devices that detect warp yarn breaks or slacking. Once detected, the loom is stopped to facilitate repair of the thread. Described more particularly, it is known to provide an industrial loom with electrically conducting metal elements that extend in a direction parallel with the weft thread. The metal elements extend the entire width of the fabric and are positioned over the warp. A plurality of drop wires, one for each of the thousands of threads, are positioned over and about the metal elements. As there may be thousands of threads, these are also thousands of corresponding drop wires closely aligned along the length of the metal elements. The drop wires are supported in position by warp threads. If a warp thread breaks, the drop wire supported by that thread falls gravitationally onto one of the electrically charged metal elements. The drop wire bridges or short-circuits that metal element and completes an electrical connection for stopping the loom. Once the loom has stopped, the operator checks the loom to determine which thread had broken, effects repair of that thread and restarts the loom. It can be difficult for the operator to determine which drop wire has fallen. In some cases, the operator may not be able to see the fallen drop wire and need to run his or her hand over all of the drop wires in a "hunt-and-peck" like fashion to locate the one that has fallen. Various devices have been proposed to assist the operator in this effort. For example, U.S. Pat. No. 3,725,911 discloses a stop motion device with a selective indicator for a multi-threaded textile machine. The device includes a number of thread slack-detection switches, each having an indicator lamp. A four-layer diode is provided to complete a circuit and thereby stop the motion of the loom machine and to light the relevant indicator lamp. In this fashion, the machine operator is appraised of which thread affected stoppage of the machine. Another such device is shown in U.S. Pat. No. 4,321,951 to Hintsch, which discloses a warp yarn stop motion device. This patent describes a sub-divided locating rail connected with pilot lights at the end of each section. Should a drop wire fall onto a rail section, the pilot lights at the end of that section are illuminated to identify the section of the rail within which a broken warp thread is located. As indicated above, the drop wires are supported by the warp threads. These threads travel through the loom, under tension, at significant speed. The drop wires are preferably of a lightweight material that will not gravitationally displace the thread due to its own weight. As each thread is provided with a drop wire, the drop wires must also be relatively thin in dimension. As a result of these structural considerations and due to the action of the thread passing therethrough, the drop wires become worn and pliable. The drop wires seemingly "dance" about the metal elements and, once sufficiently worn and pliable, will twist or otherwise contact a metal element even though the supporting thread is neither broken nor slack. Nevertheless, the loom will stop automatically because contact of the drop wire and the electrically-charged metal element will bridge or short-circuit the element and complete the electrical connection for stopping the loom. This condition is referred to as a "false warp stop." In the event of a false warp stop, the operator must search for the offending drop wire. However, once the loom stops, the offending drop wire typically returns to its initial position and will appear to be in good working order. The operator will restart the machine, but the offending drop wire will inevitably twist again and stop the loom. Upon restarting the machine, any indicator lamp that may have been illuminated will be turned off automatically. The indicator lamp will not be activated again until the drop wire touches the metal element, either due to a broken or slackened thread, or due to a false warp stop. It is to be understood that, in many commercial weaving facilities, one operator will be responsible for many looms. To find an offending drop wire that has caused a false warp stop, the operator will restart the loom, causing any indicator lamp to be switched off. Thus, while the operator's attention may be necessarily directed to other looms, any initial indication of the location of the offending wire is readily forgotten. The operator typically requires such additional indication in order to search for a fallen drop wire, let alone an offending drop wire causing false warp stops. Thus, the operator may have to watch and wait for that one machine until the offending wire causes another false warp stop. Such a process is indefinite, time consuming, impractical, and many times impossible. When an industrial loom machine experiences repeated false warp stops, the efficiency of the weaving process suffers significantly. It is not uncommon for several operators to work together in order to identify the failing or offending drop wire. In such cases, cost of effecting the repair is increased further due to the manpower needed to identify the offending drop wire and the downtime experienced while the operator or operators search for the offending drop wire. Thus, there is a need in the prior art for a device that assists in the identification and detection of an offending drop wire so as to save loom downtime and repair costs. SUMMARY OF THE INVENTION The present invention solves the above-described problems in the prior art by providing a false warp stop diagnostic apparatus that assists in the identification and detection of a drop wire that is causing a false warp stop. Generally described, the false warp stop diagnostic apparatus of the present invention is for use with an industrial loom with at least one electrically-conducting warp bar and a plurality of associated drop wires, and comprises a connector suitable for operative engagement with the warp bar, a source of electrical energy for injecting a current, a plurality of rectifiers connected in parallel between a pair of junctions, any one of which rectifiers may be fired in response to a short-circuit of said warp bar caused by contact of one of the drop wires with the warp bar, and an indicator device connected in series with each of said rectifiers, whereby an injection of current into the gate fires the rectifier and the indicator device is activated indicating that the warp bar has experienced a false warp stop. The preferred embodiment of the present invention further provides a reset switch in series with the rectifiers such that operation of said reset switch returns said rectifier to a "no current" status and deactivates the indicator device. Thus, the rectifier is deactivated only when the reset switch is operated. Accordingly, the indicator device is likewise deactivated only when the reset switch is activated. It will be appreciated by those of ordinary skill in the art that industrial looms often are configured in sections, typically six, reflected in the number of metal elements or warp bars. The preferred embodiment of the present invention is readily adaptable to such a configuration, as the connector may be configured accordingly and a corresponding number of rectifiers and indicator devices may be likewise provided. In use, an offending drop wire causes a false warp stop on a warp bar. The loom is stopped. The warp bar connector, having been placed in operative engagement with the warp bars, provides an electrical connection with the rectifiers and indicator devices. A current is induced in a circuit including the subject warp bar experiencing the false warp bar stop, and as a result, current is injected into the gate so as to fire the rectifier associated with that warp bar. The indicator device associated with that warp bar is activated. The operator can restart the loom. Even so, the indicator device remains activated. The operator can then inspect that warp bar indicated by the indicator device to determine which drop wire is causing the false wrap stop. In this manner, the preferred embodiment of the present invention assists in the quick identification of the offending drop bar. The repair can be made in a significantly reduced time period, with significant savings in loom downtime and repair costs. Thus, it is an object of the present invention to provide a diagnostic testing device for a false warp stop. It is a further object of the present invention to provide a diagnostic testing device that assists in identifying an offending drop wire that causes a false warp stop. It is a further object of the present invention to provide a false warp stop diagnostic device that is also effective to sense a fallen drop wire resulting from a broken or slack warp thread. It is a further object of the present invention to provide a false warp stop diagnostic device that improves the efficiency of an industrial loom. Other objects, features and advantages of the present invention will become apparent from reading the following specification when taken in conjunction with the accompanying drawing. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic side view of an industrial loom, including warp bars and drop wires. FIG. 2 is a perspective view showing the front or forward portion of an industrial loom fitted with a connector in accordance with the preferred embodiment of the present invention. FIG. 3 is a perspective view of a drop wire and warp bar as shown in FIG. 1. FIG. 4 is a schematic view of a connector and display housing embodying the present invention. FIG. 5 is a schematic view of a current diagram of the embodiment shown in FIG. 4. FIG. 6A is a schematic diagram of the connector of the preferred embodiment of the present invention. FIG. 6B is a schematic drawing showing the underside of the connector of the preferred embodiment. DETAILED DESCRIPTION Referring now in more detail to the drawing, in which like numerals indicate like parts throughout the several views, FIG. 1 shows a schematic of a preferred embodiment of the present invention at 10 and a side view of an industrial loom, generally indicated at 11. The longitudinal warp threads or beam 12 are wrapped about a roller 14. The warp threads travel over a back roller 15, through the eyes of heddles 17, through the interces of a reed 20, past the shuttle valve 22, over the breast beam 25 to a fabric take-up roller 27. Thus, the resulting fabric 28 is created and wound about the take-up roller 27. FIG. 1 shows an "open shed" arrangement, where individual warp threads shown representatively at 12a and 12b are divided by the action of the heddles 17. Once the warp threads 12a and 12b are separated by the heddles 17, the weft thread (not shown) is inserted therethrough by the shuttle valve 22 in a direction substantially perpendicular to the longitudinal warp threads 12. Once the weft thread has been inserted between the warp threads 12a and 12b, the heddles 17 are horizontally realized to close the shed. The weft thread is beaten into place by the reed 20. More specifically, the reed 20 provides a comb-like device that travels back and forth as represented by the arrows 29. It will be appreciated by one of ordinary skill that the foregoing operations of an industrial loom 11 are well known and need not be described further herein for purposes of the present invention. FIG. 1 also shows a plurality of metal elements or warp bars 32-37. Each warp thread 12 is threaded through a drop wire 40 as described herein. Each drop wire 40 is provided with an opening 41 through which the warp thread 12 is passed. By means of the tension in the thread 12, the drop wire 40 is held in the inoperative, elevated position shown in FIG. 3. FIG. 3 shows an isolation warp bar 32 and a single drop wire 40. The drop wire 40 includes a slot 43 through which the warp bar 32-37 projects so that the drop wire slot 43 is centered generally with respect thereto when in the elevated, inoperative position. The warp bars 32-37 conventionally provide an electrically conducting portion 45 that is mounted in a contact portion 47 in the warp bars so as to be electrically insulated therefrom. The details of such a mounting are well known to one of ordinary skill in the art. When the drop wire 40 drops due to a slack or broken thread 12, the electrically conducting portion 45 of the warp bars 32-37 and the contact portion 47 of the warp bar 32-37 is bridged. Suitable conductors 48 and 50 are electrically connected to the warp bars 32-37 as shown in FIG. 3. FIG. 4 shows a preferred embodiment of the present invention generally at 10. It is to be appreciated that while this embodiment is shown separate and apart from a loom 11, an alternative embodiment could be provided that is integral with the loom 11. The embodiment of the false warp stop diagnostic apparatus shown in FIG. 4 includes a connector 70, a display 72 and a connector wire 74. The connector 70 provides a housing 75 that defines a plurality of slots 82-87. The slots are configured for mating receipt of the warp bars 32-37, respectively. The connector may be made of any suitable material, including plastic or steel. It is to be understood that the connector 70 is to be positioned over the warp bars 32-37 at one end thereof so that the connector does not interfere with the operation of the drop wires 40 or the warp threads 12. The connector 70 is therefore preferably rectangular in shape, of sufficient length to extend over all of the warp bars 32-37 and of such width as to not interfere with operation of the loom 11. A mounting bracket 77 is provided to permit the connector 70 to be retrofit to a loom 11. The connector is fitted with two mounting knobs 78 and 79 to further facilitate attachment to the loom 11. The connector 70 is also of sufficient depth to insure electrical and mechanical contact with the warp bars 32-37 within the slots 82-87. The connector includes contact points on its top side having wires 82a-87a connected thereto, respectively, that are joined together with wire 81a to form a connecting wire 100. FIG. 4 further shows a display 72 that includes a housing 110 with a front side 111. The front side 111 is fitted with a plurality of display lights 112-117. The display lights 112-117 are electrically connected to correspond to the warp bars 32-37, respectively, as described hereinbelow and shown in the drawings. The display housing 110 further includes a reset button 120 on the front face 111. The reset button is also electrically connected as shown in FIG. 5 and described hereinbelow. Further, a power cord 122 that may be utilized as described below. FIGS. 6A and 6B show the connector and the pushbutton test connector provided with the loom stop device. Referring to FIG. 6A, the connector 70 contains two posts 80 and 81. Post 81 is connected by a wire 81a to the display 72. The connector includes a bottom portion 200 from which threaded members 204 and 205 project to engage a retaining member 201. Member 201 includes two threaded openings 207 and 208 configured for receipt of the posts 204 and 205. In this manner, the connector 70 is secured by means of the knobs 78 and 79. The pushbutton test connector 210 is configured for receipt by the posts 80 and 81. The connector 70 includes spring-loaded contacts 230 which are secured so that a contact projects from the plurality of openings 220 defined in the top of the slots 82-87. A spring 232 is wrapped about a portion of the contact 230 so as to provide tension thereto. It will be understood by those of ordinary skill that the contact projects into the slot 82-87 a sufficient distance to engage the warp bars 32-37, respectively. The position of the contacts 230 may be altered depending on the configuration of the warp bars 32-37. The contacts 230a-230f each engage an upper metal plate (Not Shown) that contacts, in turn, the warp bars 32-37 by means of the contacts 230a-230f. The top plate of the connector 70 rests above the upper metal plate. The springs 232 rest against the upper metal plate in order to impart tension to the contacts 230a-230f. The contacts 230a'-230f' are electrically connected to wires 82a, 83a, 84a, 85a, 86a and 87a which are in turn connected to the display 72 as described. FIG. 5 shows a circuit diagram of the present invention. The warp bars 32-37 are connected to and switchably drive the gates of a plurality of silicon controlled rectifiers (SCRs) 162-167 respectively. 12 volts is delivered to terminal 80 from the loom 11. The warp bars 32-37 are thus electrified, in parallel, as described hereinabove, between the terminal 80 and the second terminal 81. The circuitry of the present invention further provides a current delivered from a power source such as battery 153. The power source may be either a direct current source or an alternating current source 122 utilizing a rectifier (not shown). Battery 153 is connected to a normally closed reset switch 150 that connects two contact points 157 and 158. The plurality of indicator lights are connected in parallel. Each indicator light is, in turn, connected in series with one of SCRs 162-167. The circuits controlling each of lamps 112-117 are identical. Therefore, the operation is described in connection with the circuit for activating lamp 112. Initially, when the loom is in operation, no current flows through lamp 112 and contact 132 is isolated from contact 142 because no drop wire establishes a connection through the conductors of warp bar 32. When a drop wire 40 shorts the contacts of warp bar 32, contacts 230a and 230a' become closed, completing the circuit between positive terminal 80 and gate resistor 172. This injects sufficient current into the gate terminal of SCR 162 to cause the SCR to fire in response to its cathode to anode voltage. When the SCR fires, current flows through lamp 112. Once SCR 162 fires, it will remain in a conducting state until the anode to cathode current falls below a relatively low value that is characteristic of the particular SCR, known as the holding current. Therefore, lamp 112 will remain illuminated, even if the loom is restarted and drop wire 40 no longer bridges the contacts of warp bar 32 since the SCR is latched in an on condition. The resistance of lamp 112 is selected to assure that the current through the lamp and SCR 162 is higher than the holding current. This condition maintains until operation of reset switch 120, which opens the connection between terminals 157 and 158. The opening of the circuit extinguishes current flow through SCR 162 and the SCR switches to its off condition, and will remain in same unless re-triggered by another pulse of current into the gate circuit, as described hereinabove. In the preferred embodiment, gate resistor 172 is 60K ohms and resistor 182 is on the order of 2K ohms. Thus, resistor 182 shunts most current away from the gate junction, thereby helping to protect same from punch through. While this invention has been described in detail with particular reference to preferred embodiments thereof, it will be understood that variations and modifications can be effected within the spirit and scope of the invention as described hereinbefore and as defined in the appended claims.	A diagnostic device for testing a false warp stop in an industrial loom caused by a failing or offending drop wire. The device provides a connector that is operably engaged with the warp bars of an industrial loom. When a drop wire becomes worn or pliable and bridges the warp bar to stop the loom, the connector assists to create a circuit that includes the affected warp bar, a power source, a rectifier and an indicator device. The indicator device is activated by completion of the circuit and remains actuated even after the loom is restarted. The apparatus is thus effective to help locate a failing drop wire as opposed to a drop wire that has fallen due to a slack or broken warp thread.	3
RELATED APPLICATIONS [0001] This application claims priority under 35 U.S.C. §119(e) to U.S. Provisional Application Ser. No. 61/223,102, filed Jul. 6, 2009. FIELD OF THE INVENTION [0002] The invention relates generally to electric door systems and operators for the same and more particularly to a sliding door system and an operator for moving doors. In one preferred embodiment, the sliding door system includes an operator that requires an individual to assist in the initial movement of a door of a commercial cooler/freezer. BACKGROUND OF THE INVENTION [0003] Conventionally, heavily insulated doors, such as for walk-in cooler/freezer, have often used swinging doors that need to be manually opened and closed. However, manual operation of freezer or cooler doors can be quite inconvenient and burdensome, especially when the doors are heavily insulated and weighty and are opened frequently. In addition, swinging doors can also be hazardous to individuals in close proximity to the doors. Specifically, individuals opening the doors as they enter or exit the freezer or cooler unit can strike others in close proximity with the door and cause serious physical harm to the person. [0004] Sliding doors for walk-in freezer or cooler units are well known in the industry. Manually operated doors have the advantage of being relatively inexpensive, but frequently are difficult and inconvenient to open and shut. As a consequence, it is not uncommon for workers to leave the door in the open position for extended periods of time, particularly when the worker intends to make repeated trips into and out of the cooler/freezer. Leaving the door open, of course, results in substantial energy loss, and economic waste. It also is known to use sliding doors that are motor-driven. Unfortunately, due to the weight of the doors and the especially the energy required to initially move the doors from their sealing position, relatively large electrical motors are required to open the doors. What has been needed in the industry, but has not been available, is an inexpensive door system that is easily and inexpensively installed, that opens easily and closes when it is desired to close the door. [0005] Many of the designs that have been proposed have proven unreliable and costly, due to their highly complex designs. In addition, such prior designs have also been found to be difficult to install and difficult to service and maintain by maintenance personnel. [0006] As such, there remains a need for an system for an electric door that includes an operator which can be installed with existing low power electrical service and which overcomes the unreliability, costs and difficulties noted above and provides a simple, straightforward and inexpensive system for sliding doors. SUMMARY OF THE INVENTION [0007] In one embodiment of the invention, a system for moving a door between open and closed positions to selectively allow access to an enclosed space. The system comprising a door, the door being slidably movable between a first closed position and a second open position, the door being operative to close an opening to an enclosed space, an actuator operative to initiate movement of the door from its first closed position toward its second open position, and a control unit, the control unit including a motor, the control unit being responsive to initial movement of the door and being operative to actuate the motor, the motor being selectively operative to slidingly move the door toward the open position in response to the initial door movement after the door has initially moved from its closed position. [0008] In yet another embodiment of the invention, an operator for moving a door between open and closed positions to selectively allow access to an enclosed space. The operator comprises an actuator operative to initiate door movement from its first closed position toward its second open position and a control unit, the control unit including a motor, the control unit being responsive to initial door movement and being operative to actuate the motor, the motor being selectively operative to slidingly move the door toward the open position in response to the initial door movement after the door has initially moved from its closed position. BRIEF DESCRIPTION OF THE DRAWINGS [0009] While the invention concludes with claims which particularly point out and distinctly claim the invention, it is believed the present invention will be better understood from the following description taken in conjunction with the accompanying drawings, in which like reference numbers identify the same elements in which: [0010] FIG. 1 is a perspective view of the system and operator for moving a door constructed in accordance with the principles of the present invention; [0011] FIG. 2 is another perspective view of the system and operator for moving a door constructed in accordance with the principles of the present invention; [0012] Reference will now be made in detail to certain exemplary embodiments of the invention, examples of which are illustrated in the accompanying drawings. DETAILED DESCRIPTION [0013] Referring now to the drawings, FIGS. 1 and 2 show a perspective view of one embodiment of an electric door system and operator, generally designated in the drawings by the numerals 10 and 100 , respectively, and constructed in accordance with the principles of the present invention. The electric door system 10 includes a door frame 20 and door 30 . Typically both the door frame 20 and door 30 may be constructed of stainless steel, plastic, a combination of both materials or some other resilient material or materials and are constructed for an individual, material or equipment to pass through. However, it will be understood that both the door frame 20 and door 30 may be constructed of any material or in any size or shape, as known in the art. It will be further understood that the door frame 20 is configured for placement between an interior or enclosed space and an exterior. In one embodiment, the interior or enclosed space may be a walk-in freezer or a cooler. In yet other embodiments, the door 20 may be a freezer door or cooler door. [0014] In the exemplarily embodiments illustrated in FIGS. 1 and 2 , the electric door system 10 may further include an actuator 40 , illustrated in the present FIGS. 1 and 2 as a rotatable handle bar 40 that manually assists movement of the door 20 . However, it will be understood that although illustrated in the present FIGS. 1 and 2 as a rotatable handle bar that manually assists movement of the door 20 , the actuator 40 may be any device that assists in any movement of the door 20 as known in the art. The handle bar 40 , as shown in the embodiments illustrated in FIGS. 1 and 2 , rotates a pivot in a sleeve 40 A about an axis 41 . The sleeve 40 A and its internal pivot include a radially projecting kick-off lever 40 B that is configured to interact with a pry plate 45 secured on the frame adjacent to the edge of the door 30 . With this configuration or leverage system, a manually applied rotational force applied against the end of the handle 40 will apply a force against the pry plate 45 , and urge the door toward its open position. It will be further understood that the purpose of the handle is to provide a mechanical advantage for a manual force applied against the end of the handle, and for this reason, the length of the handle 40 may be relatively long as compared to the radially projecting lever. By using the mechanical advantage of the relatively long handle 40 , a moderate manual force applied against the handle 40 acts to apply a multiplied force against the pry plate 45 . This multiplied force is used to move the door in an upward, outward direction to unseal the door, and start movement of the door 30 along the track 50 , as explained in greater detail below. As those skilled in the art will appreciate, other types of handles also might be used, as for example, a grab handle, a pull handle, or a recessed handle, or alternatively, the initial movement of the door could be effected without a handle. [0015] In the exemplary embodiments illustrated in FIGS. 1 and 2 the system 10 may also include a track 50 for directing sliding movement of the door 30 . The track 50 , as shown in the embodiments illustrated in FIGS. 1 and 2 , is positioned above the access opening to the cooler/freezer, and for a length that spans the opening. It may be mounted, at least in part, to the door frame 20 . A roller system attached to the door 30 roll in the track 50 , and the track 50 functions to guide movement of the roller system, and hence control the sliding path of the door 3 . Typically the track 50 may be constructed of steel, aluminum, plastic, a combination of these materials. In one specific embodiment, the track 50 may be configured for the door 30 to move from a closed position to an open position. In particular, the “closed position,” as that term is used throughout the present disclosure is when the door 30 prevents or otherwise restricts access to the interior space. Furthermore, the “open position,” as that term is used throughout the present disclosure is when the door 30 allows or otherwise does not restrict access to the interior space. [0016] Referring now to the embodiments illustrated in FIGS. 1 and 2 , the system 10 and operator 100 includes a control unit 70 with an associated motor 70 A and an encoder 70 B. As specifically illustrated, the encoder 70 B senses rotational movement of the motor (which corresponds to movement of the door), and generates a signal that the control unit 70 recognizes, and in turn, activates the motor 70 A, whenever the door 30 is moved a predetermined distance. As is known in the art, the track 50 may include detents to direct the door 30 in a downward and inward direction as the door approaches its closed position. When such a configuration is used, opening the door 30 from its closed, sealed position requires sufficient energy to lift the door upwardly to initiate movement toward the open position. After this initial movement, however, substantially less energy is required to move the door 30 toward the open position. Consequently, when the motor 70 A is used in conjunction with door movement, described above, the motor 70 A requires sufficient power only to move the door for the remainder of the opening movement and for the closing movement. In other words, the initial opening movement can be effectuated by a manual activator, such as the handle mechanism 40 , and the remainder of the movement can be achieved with a motor 70 A that is much smaller, lighter duty, and less expensive, than a motor used for moving the door 30 throughout its entire range of movement, including the initial opening movement. Furthermore, the lighter duty motor does not require expensive, heavy-duty control components needed for heavy duty motors. Hence, the encoder 70 B shown at the bottom of the motor 70 A, or another type of sensor unit for detecting the initial displacement of the door 30 , can be used to initiate the motor only after the initial opening displacement is detected. In one specific embodiment, the control unit 70 is configured to generate a movement signal only after detecting motion of the door 30 past a predetermined span along the length of the track 50 . [0017] In the exemplary embodiments illustrated in FIG. 1 the system 10 may also include a guide rail 80 , which guides the bottom portion of the door 30 as the door slides from between its closed and open positions. [0018] The door 30 of a cooler/freezer normally is kept in its closed position in order to avoid excessive loss of energy. In use, an individual wishing to gain access to the interior space of the cooler/freezer initially grasps and rotates the handle 40 . This manual movement of the handle 40 applies a force against the pry plate 45 . This force results in an initial movement of the door 30 that move the rollers out of the detents in the track 50 , unsealing the door 30 and moving it upwardly and outwardly toward the open position. After this initial opening displacement, the control unit 70 senses the displacement of the door 30 through use of the encoder 70 B and activates the motor 70 A. Once activated, the motor 70 A completes movement of the door 30 to the open position without any further force needed by the individual and thereafter holds the door 30 in the open position. Closing of the door 30 can be initiated after an number of selected events. For example, the control 70 could be programmed to close the door 30 after a predetermined amount of time. Alternatively, or in addition, the system could be programmed to reverse direction of the motor 70 A and close the door 30 upon the displacement of the door 30 toward the closed position. In either event, the motor 70 A would cease complete displacement of the door 30 at its closed and sealed position. [0019] Advantageously, the electric door system and operators illustrated in the exemplary embodiments of FIGS. 1-2 allow for, inter alia, a simple and low cost way to open a sliding door, and alleviate the need for a high powered electric motor and the control components necessary to operate it. That is, the electric door system and operators developed in accord with the principles described herein help eliminate the difficulties noted above and provides a simple, straightforward and less arduous system for sliding doors. [0020] The foregoing description of the preferred embodiments of the present invention have been presented for purposes of illustration and description. It is not intended to be exhaustive or to limit the invention to the precise form disclosed. Obvious modifications or variations are possible in light of the above teachings. The embodiments were chosen and described to provide the best illustration of the principles of the invention and its practical application to thereby enable one of ordinary skill in the art to utilize the invention in various embodiments and with various modifications as are suited to the particular use contemplated. All such modifications and variations are within the scope of the invention as determined by the appended claims when interpreted in accordance with the breadth to which they are fairly, legally and equitably entitled. The drawings and preferred embodiments do not and are not intended to limit the ordinary meaning of the claims in their fair and broad interpretation in any way.	A system for moving a door between open and closed positions to selectively allow access to an enclosed space. The system comprising a door, the door being slidably movable between a first closed position and a second open position, the door being operative to close an opening to an enclosed space, an actuator operative to initiate movement of the door from its first closed position toward its second open position, and a control unit, the control unit including a motor, the control unit being responsive to initial movement of the door and being operative to actuate the motor, the motor being selectively operative to slidingly move the door toward the open position in response to the initial door movement after the door has initially moved from its closed position	4
This is a division of application Ser. No. 08/278,260 filed Jul. 21, 1994, U.S. Pat. No. 5,474,707. FIELD OF THE INVENTION This invention relates to a deuterated cyclohexane derivative which is a novel liquid crystal compound useful as an electro-optic liquid crystal display material and to a liquid crystal composition containing the same. More particularly, it relates to a liquid crystal composition which is not crystallized in low temperatures and yet are not inferior to generally used liquid crystal compositions in electro-optic characteristics, such as nematic-isotropic phase transition temperature, threshold voltage, refractive index anisotropy, dielectric constant anisotropy, a response time, and voltage holding ratio. This invention also relates to a liquid crystal display using the liquid crystal composition, which is capable of making a display in a stable manner without suffering from crystallization and exhibits excellent electro-optical characteristics. BACKGROUND OF THE INVENTION Liquid crystal displays have found broad applications to watches, calculators, measuring instruments, automobile control panels, word processors, pocket computers, printers, computers, and TV sets. Liquid crystal display systems include a twisted nematic (TN) mode, a supertwisted nematic (STN) mode, a dynamic scattering (DS) mode, a guest-host (GH) mode, and a ferroelectric liquid crystal (FLC) mode. The liquid crystal display driving system has started with a static driving system, developed into a multiplex driving system, and recently further developed from a simple matrix system into an active matrix system. Liquid crystal materials to be used in these displays are required to satisfy various characteristics in accordance with the display system or driving system. In particular, (1) to show a liquid crystal phase in a low-to-high broad temperature range to be driven in a broad temperature range, (2) to have a low threshold voltage to be driven at a low voltage, and (3) to have a low viscosity and a short response time are important characteristics common to all liquid crystal materials irrespective of the display system or driving system. For the time being, a liquid crystal compound satisfying all the requirements (1to (3) by itself is not available, and a plurality of liquid crystal compounds must be mixed to provide a liquid crystal composition which will exhibit desired characteristics. Among a wide variety of liquid crystal compounds heretofore developed, those having a cyclohexane skeleton have been used comparatively widely because they satisfy the requirements (1) to (3) comparatively. Liquid crystal compounds having a cyclohexane skeleton area characterized by their low viscosity as compared with those having other cyclic structures. However, they are not deemed to be pronouncedly superior to those having other structures as for low-temperature characteristics. In order to decrease the melting point of a liquid crystal material, it is effective to mix an increased number of compounds. For example, it has been a practice to mix a plurality of such analogues as have the same basic skeleton, composed of rings and a linking group(s), but different numbers of carbon atoms at the terminal group. Nevertheless, it is extremely difficult to reduce the melting point of a liquid crystal material so as to prevent crystallization in a low temperature region even by the above-described method. It has therefore been demanded to develop a liquid crystal compound which has a cyclohexane skeleton and thereby has a relatively low viscosity, which has a reduced melting point or is hardly crystallized in a low temperature region without adversely affecting other characteristics, and which has improved co-solubility with other liquid crystal compounds. Various liquid crystal compounds having different liquid crystal phase temperature ranges have been mixed in order to obtain a liquid crystal material satisfying the requirement (1). For example, where it is desired to increase a nematic-isotropic phase transition temperature (hereinafter referred to as T N-I point), a liquid crystal compound having a high T N-I point could be added in an increased proportion. However, because such a compound also has a high lower limit for the nematic phase (hereinafter referred to a T C-N point), the resulting liquid crystal composition necessarily has an increased T C-N point. As a result, the liquid crystal composition often suffers from crystallization, resulting in a failure of practical use. Hence, a practically useful liquid crystal composition showing a nematic phase over a low-to-high broad temperature range has generally been prepared by mixing 10 to 20 kinds of liquid crystal compounds selected by experience so as to contain a compound having a low melting point, a compound showing a nematic phase at about room temperature, and a compound having a high T N-I point. On actually making a choice of liquid crystal compounds, consideration should be given to not only broadening of an operating temperature range but optimization of electro-optic characteristics and viscosity according to the end use. That is, the liquid crystal compounds to be combined together to provide a liquid crystal composition should satisfy various requirements, inclusive of compatibility among themselves, to some extent. Therefore, although a large number of liquid crystal compounds are available, the choice of compounds usable for preparation of a practically useful liquid crystal composition is considerably limited. For instance, liquid crystal compositions for active matrix driving system, such as TFT or MIM, which are now getting predominant among various liquid crystal displays, are demanded to satisfy not only the above-described requirements (1) to (3) but a fourth requirement for a high voltage halding ratio. Should the liquid crystal composition have a low voltage holding ratio, a so-called flicker phenomenon would take place, in which the luminance of pixels that should have been driven flickers. In general, in order that a liquid crystal composition may have a high voltage holding ratio, it must be chemically stable against heat or light applied in a device and have a high specific resistivity. As a result of investigations in pursuit of liquid crystal compounds meeting these demands, known compounds having an ester group, a cyano group, a pyrimidine ring or a dioxane ring, which have been employed for TN and STN displays, turned out to be unsuitable for an active matrix driving system because they reduce the voltage holding ratio. Further, in the active matrix driving system, since the display system is the same as a conventional TN mode, the liquid crystal composition to be used must have positive dielectric anisotropy (.sup.Δ ε) as a whole. However, among conventionally employed liquid crystal compounds having positive dielectric anisotropy (hereinafter referred to as p-type liquid crystal compounds), even those having a relatively high .sup.Δ ε similarly reduce the voltage halding ratio. That is, the compounds shown below were revealed to be unsuited to active matrix driving. ##STR4## wherein R represents an alkyl group. In order to adjust the .sup.Δ ε of a liquid crystal composition for active matrix driving to a proper positive value, p-type liquid crystal compounds having a fluorine atom or a chlorine atom as a functional group have been used for the present time. Examples of such compounds are shown below. ##STR5## wherein R and R' each independently represent an alkyl group, an alkenyl group or an alkoxylalkyl group. However, although it is possible to achieve electro-optic characteristics necessary for active matrix driving by using these compounds, it is very difficult to prepare a liquid crystal composition having a sufficiently low T C-N point because many of liquid crystal compounds useful for active matrix driving have a relatively high T N-I point. In order to solve this problem, it has been proposed to reduce the T C-N point of a liquid crystal composition by adding a plurality of such analogous compounds as have the same skeleton but with the number of carbon atoms at the terminal alkyl group varied from 2 to 7, which are selected from the above-mentioned fluorine-containing p-type liquid crystal compounds. However, this approach does not accomplish reduction in T C-N point to a considerable degree. Moreover, the viscosity of the compound tends to increase as the number of carbon atoms of the terminal alkyl group increases, resulting in deterioration of the response characteristics, the requirement (3). Thus, a liquid crystal composition for active matrix driving which fulfills all the characteristics (1) to (4) has not yet been developed. Under these circumstances, the characteristics (2), (3) and (4) take precedence over the characteristic (1), we cannot help using liquid crystal composition for active matrix driving. As for the characteristic (1), we cannot help using liquid crystal compounds whose T C-N point is not sufficiently low. As an expected result, the currently available liquid crystal compositions are often crystallized in low temperatures. The liquid crystal compositions used in STN liquid crystal displays are demanded to meet the requirements (1) to (3) and, in addition, (5) to have a high elastic constant ratio (K 33 /K 11 ) for achieving high contrast. The characteristic (2) (to have a low threshold voltage) is also important for the liquid crystal compositions for STN displays widespread in general-purpose equipment, such as laptop computers. For reduction of the threshold voltage of a liquid crystal composition, it is effective to increase the dielectric anisotropy .sup.Δ ε or to reduce the elastic constant K according to the following formula: ##EQU1## wherein V th represents a threshold voltage; k represents a proportionality factor; K represents an elastic constant; and .sup.Δ ε represents a dielectric anisotropy. Liquid crystal compounds having a very large .sup.Δ ε include, for example, those represented by formula: ##STR6## wherein R represents an alkyl group. Use of a large quantity of such a compound with too large a .sup.Δ ε is liable to raise such problems as an increase in electrical current. This deteriorates reliability on actual use as a liquid crystal display. A liquid crystal composition having a small elastic constant can be prepared by mixing a mother liquid crystal material comprising a p-type liquid crystal compound, a tricyclic liquid crystal compound of three ring system having a high T N-I point, a relatively small elastic constant, and a negative .sup.Δ ε (hereinafter referred to as an n-type liquid crystal compound) or a tricyclic p-type liquid crystal compound. p-Type liquid crystal compounds having a high elastic constant ratio K 33 /K 11 include, for example, compounds represented by formula: ##STR7## wherein R' represents an alkyl group, an alkenyl group or an alkoxylalkyl group; and X represents a hydrogen atom or a fluorine atom. In an attempt to satisfy the threshold voltage characteristics and the contrast characteristics in STN displays, a mixture comprising the above-mentioned p-type liquid crystal compound and the tricyclic p- or n-type liquid crystal compound tends to be crystallized in a low temperature. Hence, similarly to the case of the active matrix driving system, it has been a practice to add several kinds of analogues having the same skeleton with different carbon atom numbers in the moiety R' or, in cases where R' is an alkenyl group, to add several kinds of analogues in which the position of the double bond differs, to thereby prepare a liquid crystal composition with a reduced T C-N point. However, the elastic constant ratio K 33 /K 11 of such analogous compounds largely differs with a difference in the carbon atom number or a difference in the double bond position. As a result, cases are often met with, in which the resulting liquid crystal composition has a reduced elastic constant ratio K 33 /K 11 and thereby reduced contrast. Where the method of adding analogues is followed, there is a limit of possible reduction of T C-N point, the viscosity increases, and the response time is slow. It would be very difficult to design the composition of a liquid crystal composition while taking these problems into consideration. Under the present situation, liquid crystal compositions for an STN mode which have a low threshold voltage of about 1.2 V have been prepared. However, not having a sufficiently high elastic constant ratio K 33 /K 11 as mentioned above, these compositions have failed to provide STN liquid crystal displays having low-voltage driving properties and high contrast. As hereinabove discussed, a liquid crystal composition satisfying the requirement (1) (to have a broad temperature range for the liquid crystal phase) should have a low T C-N point. Since not a few materials actually undergo crystallization even at a temperature higher than their T C-N point, a highly reliable liquid crystal display should use a liquid crystal composition which is not crystallized even in a low temperature region so as to eliminate display defects due to changes in environmental temperature all over the display area. A liquid crystal composition consisting of a plurality of liquid crystal single substances often shows a supercooling phenomenon. Therefore, a T C-N point of a liquid crystal composition is measured by once cooling to a low temperature sufficient for solidification or transition into a glassy state with liquid nitrogen, etc. (for example, to -70° C.) thereby to crystallize, then gradually increasing the temperature, and, during the temperature rise, measuring a transition temperature from the solid to a nematic phase. However, in the case of a practical liquid crystal composition comprising 10 to 20 kinds of components, because it is not an eutectic mixture, cases not infrequency occur in which the composition crystallizes even if it is preserved at a temperature higher than the lower limit of the nematic phase as measured by the above-mentioned method. The possible temperature range for driving is virtually narrower than the measured temperature range. It is not a rare case that a liquid crystal composition having a T C-N point of -70° C. is crystallized at room temperature. While liquid crystal displays installed on automobiles or aircraft are demanded to stably exhibit a nematic phase in a temperature widely ranging from -40° to 110° C., a liquid crystal composition which is not crystallized even in storage at -55° C. has not yet been developed. Some of the liquid crystal compositions practically used in displays installed on automobiles is crystallized in about 1 week in storage at, e.g., -25° C. It should now be understood that a liquid crystal composition, even having a very low T C-N point, is not always prevented from crystallization at a temperature above the T C-N point. Accordingly, what is demanded for a liquid crystal composition that satisfies the requirement (1) to show high reliability is not a low T C-N point but non-crystallization in a low temperature range. As discussed above, a liquid crystal composition is prepared by mixing various liquid crystal compounds selected so as to agree with a particular display system or a particular driving system but there are limits of improvements of characteristics that can be achieved only with the liquid crystal compounds currently employed. In particular, many of general-purpose liquid crystal compositions are designed with weight on satisfaction of electro-optic characteristics. On reviewing these general-purpose liquid crystal compositions, particularly those for an active matrix driving system, such as TFT or MIM, and those for STN liquid crystal displays, there are few materials that have a broad temperature range for the liquid crystal phase, are not crystallized in lower temperatures, and are thereby highly reliable. The general-purpose liquid crystals substantially satisfying the requirements (2) to (5) are regarded as highly reliable and practical liquid crystal materials provided that they are not crystallized for a period of about 1 month even in storage in a relatively low temperature, which varies depending on the end use, though. However, the temperature of the environment in which the liquid crystal display containing such a reliable liquid crystal composition operates is naturally limited. For the above-described reasons, there has not yet been obtained such a liquid crystal composition that is not crystallized in a lower temperature and therefore has high reliability while sufficiently satisfying electro-optic characteristics demanded in carrying out various display systems or driving systems. SUMMARY OF THE INVENTION An object of the present invention is to provide a novel liquid crystal compound having a cyclohexane skeleton, which, when mixed with other liquid crystal compounds to prepare a liquid crystal composition, reduces the viscosity of the liquid crystal composition, does not narrow the temperature range for the liquid crystal phase of the composition, and undergoes neither crystallization nor phase separation even in a low temperature region. Another object of the present invention is to provide a liquid crystal composition comprising the above-mentioned liquid crystal compound, which does not suffer from crystallization in a low temperature region while exhibiting excellent electro-optic characteristics, i.e., a threshold voltage, a contrast, and response properties. A further object of the present invention is to provide a liquid crystal display using the above-mentioned liquid crystal composition, particularly a liquid crystal display for an active matrix driving system or for a TN or STN display system which does not suffer from display defects all over the display area even in a low temperature region. In order to accomplish the above objects, the present invention provides a compound having a deuterated cyclohexane ring, represented by formula (I): ##STR8## wherein Y 1 and Y 2 each independently represent a fluorine atom, a chlorine atom, a cyano group, a cyanato group (OCN), a thiocyanate group (SCN), a trifluoromethoxy group (OCF 3 ), a difluoromethoxy group (OCF 2 H), a 2,2,2-trifluoroethoxy group (OCH 2 CF 3 ), a trifluoromethyl group (CF) 3 , R, --OR, --COOR or --OCOR, wherein R represents an alkyl group having from 1 to 20 carbon atoms, an alkenyl group having from 2 to 20 carbon atoms or an alkoxylalkyl group having from 2 to 20 carbon atoms, provided that at least one of Y 1 and Y 2 represents R, --OR, --COOR or --OCOR; Z, Z 1 , Z 2 , Z 3 , and Z 4 each independently represent a single bond, --CH 2 CH 2 --, --CH═CH--, --C≡C--, --COO--, --OCO--, --CH 2 O--, --OCH 2 --, --(CH 2 ) 4 --, --(CH 2 ) 3 --O-- or --O--(CH 2 ) 3 --; ring A represents a group of formula (II): ##STR9## wherein X 1 , X 2 , X 3 , X 4 , X 5 , X 6 , X 7 , X 8 , X 9 , and X 10 each independently represent a hydrogen atom (H) or a deuterium atom (D), provided that at least one of them represents a deuterium atom (D); rings K L, J, M and N each independently represent a trans-1,4-cyclohexylene group, a 1,4-cyclohexenylene group, a trans-1,4-cyclohexylene group substituted with 1 to 4 substituents selected from a fluorine atom, a chlorine atom, a cyano group and a methyl group, a 1,3-dioxane-2,6-diyl group, a pyrimidine-2,5-diyl group, a pyridine-2,5-diyl group, a pyrazine-2,5-diyl group or a group of formula (III): ##STR10## wherein X 11 , X 12 , X 13 , X 14 , X 15 , X 16 , X 17 , X 18 , X 19 , and X 20 each independently represent a hydrogen atom (H) or a deuterium atom (D), provided that at least one of them represents a deuterium atom (D); in which the ring of formula (III) may be the same or different with ring A; and k, l, m, and n each independently represent 0 or 1, provided that the sum of k, l, m, and n is 0, 1 or 2. DETAILED DESCRIPTION OF THE INVENTION As defined above, the substituents as X 1 to X 10 or X 11 to X 20 in the deuterated cyclohexane ring represented by formula (II) or (III) each independently represent a hydrogen atom (H) or a deuterium atom (D), with at least one of X 1 to X 10 and at least one of X 11 to X 20 being a deuterium atom (D). Therefore, even with the cyclic structures other than ring A, the linking groups, and the terminal groups being fixed, formula (I) includes a great number of compounds with variations in position of the deuterium atom (D) and number of the substituents on ring A. It is not an unknown technique to substitute a hydrogen atom (H) of a liquid crystal compound with a deuterium atom (D), as having been reported in the following publications: 1) H. Gasporoux, et al., Ann. Rev. Phys. Chem., Vol. 27, p. 175 (1976), 2) G. W. Gray, et al., Mol. Cryst. Liq. Cryst., Vol. 41, p. 75 (1977), 3) A. J. Leadbetter, et al., J. Phys., [Paris] coll C3, Vol. 40, p. 125 (1979), 4) A. Kolbe, et al., Z. Naturforsch., Vol. 23a, p. 1237 (1968), 5) J. D. Rowell, et al., J. Chem. Phys., Vol. 43, p. 3442 (1965), 6) W. D. Philips, et al., J. Chem. Phys., Vol. 41, p. 2551 (1964), 7) A. F. Martins, et al., Mol. Cryst. Liq. Cryst., Vol. 14, p. 85 (1971), and 8) E. T. Samulski, et al., Phys. Rev. Lett., Vol. 29, p. 340 (1972). Literature (1) reports substitution of the hydrogen atom (H) of the carboxyl group of a 4-alkoxybenoic acid with a deuterium atom (D). All the literature other than (1) relates to substitution of the hydrogen atom (H) in the terminal group or the hydrogen atom (H) bonded to a benzene ring with a deuterium atom (D). No cases has been reported in which a hydrogen atom (H) bonded to a cyclohexane ring is substituted with a deuterium atom (D) as in the compound of formula (I) of the present invention. Choices and combinations of rings A, J, K, L, M and N, Z, Z 1 , Z 2 , Z 3 , Z 4 , Y 1 , Y 2 , k, l, m, and n lead to creation of a large number of compound. Any of these compounds could exhibit the above-mentioned favorable properties on account of the cyclohexane ring substituted with a deuterium atom (D). Preferred of the compounds represented by the formula (I) are bicyclic compounds, tricyclic compounds, and tetracyclic compounds represented by formulae (I-1) to (I-6) hereinafter shown. The preferred bicyclic compounds are represented by formula (I-1): ##STR11## wherein Y 1 , Y 2 , Z and rings A and J are as defined above in formula (I). More specifically, bicyclic compounds represented by formula (I-1') are preferred: ##STR12## wherein ring A, Y 1 , and Y 2 are as defined above; ring J 1 represents a trans-1,4-cyclohexylene group, a 1,4-cyclohexenylene group, a 1,4-phenylene group, a 1,4-phenylene group substituted with one or two fluorine atoms, or the group represented by formula (III) described above; and Z 5 represents a single bond, --CH 2 CH 2 --, --(CH 2 ) 4 -- or --COO--. More preferred of the compounds (I-1') are those represented by the following formulae (I-1'a), (I-1'b) and (I-1'c): ##STR13## wherein ring A, Y 1 , Y 2 , and Z 5 are as defined above; and W 1 , W 2 , and W 3 each independently represent a hydrogen atom or a fluorine atom. ##STR14## wherein ring A, Y 1 , and Y 2 are as defined above; ring C represents ##STR15## and Z 6 represents a single bond or --CH 2 CH 2 --. ##STR16## wherein ring A, Y 1 , Y 2 , and Z 6 are as defined above; and ring D represents a trans-1,4-cyclohexylene group or the group of formula (III) described above. The most preferred of them are those represented by formulae (I-1'a'), (I-1'b'), and (I-1'c'): ##STR17## wherein ring A, Z 5 , W 1 , and W 2 are as defined above; Y 3 represents an alkyl group having from 1 to 20 carbon atoms or an alkenyl group having from 2 to 20 carbon atoms; and Y 4 represents a fluorine atom, a cyano group, a cyanato group (OCN), a trifluoromethoxy group (OCF 3 ), an alkyl group having from 1 to 20 carbon atoms, an alkenyl group having from 2 to 20 carbon atoms, an alkoxyl group having from 1 to 20 carbon atoms an alkenyloxy group having from 3 to 20 carbon atoms, or an alkoxyalkyl group having from 2 to 20 carbon atoms. ##STR18## wherein ring A and ring C are as defined above; and the two Y 5 's each independently represent an alkyl group having from 1 to 20 carbon atoms. ##STR19## wherein ring A and ring D are as defined above; and the two Y 6 's each independently represent an alkyl group having from 1 to 20 carbon atoms, an alkenyl group having from 2 to 20 carbon atoms, an alkoxyl group having from 1 to 20 carbon atoms, or an alkoxylalkyl group having from 2 to 20 carbon atoms. Specific examples of the compounds of formula (I-1'a') are shown below. In the followings, the numerical values in the brackets shown by [] are the phase transition temperatures of the compounds, in which C represents a crystal phase, Sm a smectic phase, S A a smectic A phase, S B a smectic B phase, N a nematic phase, and I an isotropic liquid phase, the parentheses shown by () represent the monotropic phases, and # indicates that the melting point is not clear due to non-crystallization. For example, "C 44 N" means that the phase transition temperature from the crystal phase to the nematic phase is 44° C. ##STR20## Specific examples of the compounds represented by formula (I-1'b') are shown below. ##STR21## Specific examples of the compounds represented by formula (I-1'c') are shown below. ##STR22## The preferred tricyclic compounds include those represented by formulae (I-2) and (I-3): ##STR23## wherein Y 1 , Y 2 , Z, Z 3 , and rings A, J and M are as defined above in formula (I). ##STR24## wherein Y 1 , Y 2 , Z, Z 1 , and rings A, K and J are as defined above in formula (I). More specifically, tricyclic compounds represented by formulae (I-2') and (I-3') are preferred: ##STR25## wherein rings A, Z 6 , Y 1 , and Y 2 are as defined above; ring J 2 represents a trans-1,4-cyclohexylene group, a 1,4-cyclohexenylene group, a 1,4-phenylene group, a 1,4-phenylene group substituted with one or two substituents selected from a fluorine atom and a methyl group, or the group of formula (III); ring M 1 represents a 1,4-phenylene group or a 1,4-phenylene group substituted with a fluorine atom or a methyl group; and Z 7 represents a single bond, --CH 2 CH 2 --, --C≡C-- or --(CH 2 ) 4 . ##STR26## wherein ring A, Y 1 and Y 2 are as defined above; ring K 1 represents a trans-1,4-cyclohexylene group or a 1,4-cyclohexenylene group; the two Z 8 's each independently represent a single bond, --CH 2 CH 2 -- or --(CH 2 ) 4 --; and J 3 represents a 1,4-phenylene group or a 1,4-phenylene group substituted with one or two fluorine atoms. More preferred of these tricyclic compounds are those represented by formulae (I-2'a) to (I-2'f), (I-3'a), and (I-3'b): ##STR27## wherein ring A, ring D, Z 6 , W 1 , W 2 , W 3 , Y 1 , and Y 2 are as defined above, and Z 8 represents a single bond, --CH 2 CH 2 -- or --(CH 2 ) 4 --. ##STR28## wherein ring A, W 1 , W 2 , W 3 , Y 1 , and Y 2 are as defined above. ##STR29## wherein ring A, Z 6 , W 1 , W 2 , W 3 , Y 1 , and Y 2 are as defined above; and W 4 and W 5 each independently represent a hydrogen atom or a fluorine atom. ##STR30## wherein ring A, Z 6 , W 1 ,W 2 , W 4 , W 5 , Y 1 , and Y 2 are as defined above. ##STR31## wherein ring A, Z 6 , W 1 , W 2 , Y 1 , and Y 2 are as defined above. ##STR32## wherein ring A, Z 6 , W 1 , W 2 , Y 1 , and Y 2 are as defined above. ##STR33## wherein ring A, Z 6 , Z 8 , W 1 , W 2 , W 3 , Y 1 , and Y 2 are as defined above. ##STR34## wherein ring A, W 1 , W 2 , W 3 , Y 1 , and Y 2 are as defined above. Still more preferred of these tricyclic compounds are those represented by formulae (I-2'a') and (I-2'b'): ##STR35## wherein ring A, ring D, Z 6 , Y 6 , W 1 , and W 2 are as defined above; and Y 7 represents a fluorine atom, a chlorine atom, a cyano group, a difluoromethoxy group (OCF 2 H), a 2,2,2-trifluoroethoxy group (OCH 2 CF 3 ), a trifluoromethoxy group (OCF 3 ), an alkyl group having from 1 to 20 carbon toms, an alkenyl group having from 2 to 20 carbon atoms, an alkoxyl group having from 1 to 20 carbon atoms or an alkoxylalkyl group having from 2 to 20 carbon atoms. ##STR36## wherein ring A, Y 5 , W 1 , and W 2 are as defined above; and Y 8 represents a fluorine atom, an alkyl group having from 1 to 20 carbon atoms or an alkoxyl group having from 1 to 20 carbon atoms. The same preference as described above for the compounds of formulae (I-2'a') and (I-2'b') also applies to the compounds of formulae (I-2'c), (I-2'd), (I-2'e) and (I-2'f). Specific examples of the compounds of formula (I-2'a') are shown below. In the following, the numerical values in the brackets shown by [] are the phase transition temperatures of the compounds, in which C represents a crystal phase, Sm a smectic phase, S A a smectic A phase, S B a smectic B phase, N a nematic phase, and I an isotropic liquid phase, the parentheses shown by () represent the monotropic phases, and # indicates that the melting point is not clear due to non-crystallization. For example, "C 44 N" means that the phase transition temperature from the crystal phase to the nematic phase is 44° C. ##STR37## The preferred tetracyclic compounds of formula (I) include those represented by formula (I-4), (I-5) and (I-6): ##STR38## wherein Y 1 , Y 2 , Z, Z 3 , Z 4 , and rings A, J, M and N are as defined above in formula (I). ##STR39## wherein Y 1 , Y 2 , Z, Z 1 , Z 2 , and rings A, K, L and J are as defined above in formula (I). ##STR40## wherein Y 1 , Y 2 , Z, Z 1 , Z 3 , and rings A, K, J and M are as defined above in formula (I). More specifically, the preferred tetracyclic compounds include those represented by formula (I-4'), (I-5'), and (I-6'): ##STR41## wherein ring A, ring J 1 , Z 6 , Y 1 , and Y 2 are as defined above in which the two Z 6 's are independent to each other; ring M 2 and ring N each independently represent a trans-1,4-cyclohexylene group, a 1,4-phenylene group, a 1,4-phenylene group substituted with a fluorine atom, or the group of formula (I[I); and Z 9 represents a single bond, --CH 2 CH 2 -- or --C≡C--. ##STR42## wherein ring A, ring J 3 , Z 6 , Y 1 , and Y 2 are as defined above, in which the three Z 6 's are independent to each other. ##STR43## wherein ring A, ring K 1 , ring J 3 , Z 6 , Z 9 , Y 1 , and Y 2 are as defined above, in which the two Z 6 's are independent to each other; and ring M 3 represents a 1,4-phenylene group or a 1,4-phenylene group substituted with a fluorine atom. More preferred of these tetracyclic compounds are those represented by formulae (I-4'a) to (I-4'f), (I-5'a), and (I-6'a) to (I-6'c): ##STR44## wherein ring A, ring D, Z 6 , W 1 , W 2 , W 3 , W 4 , Y 1 , and Y 2 are as defined above, in which the two Z 6 's are independent to each other. ##STR45## wherein ring A, ring D, Z 6 , W 1 , W 2 , Y 1 , and Y 2 are as defined above, in which the two D rings are independent to each other, and the three Z 6 's are independent to each other. ##STR46## wherein ring A, ring D, Z 6 , Z 8 , W 1 , W 2 , Y 1 , and Y 2 are as defined above, in which the two Z 6 's are independent to each other. ##STR47## wherein ring A, ring D, Z 6 , W 1 , W 2 , W 4 , W 5 , Y 1 , and Y 2 are as defined above, in which the two Z 6 's are independent to each other. ##STR48## wherein ring A, ring D, Z 6 , W 1 , W 2 , W 4 , W 5 , Y 1 , and Y 2 are as defined above, in which the two Z 6 's are independent to each other. ##STR49## wherein ring A, W 1 , W 2 , Y 1 , and Y 2 are as defined above. ##STR50## wherein ring A, Z 6 , W 1 , W 2 , Y 1 , and Y 2 are as defined above. ##STR51## wherein ring A, Z 6 , W 1 , W 2 , W 4 , W 5 , Y 1 , and Y 2 are as defined above, in which the two Z 6 's are independent to each other. ##STR52## wherein ring A, Z 6 , W 1 , W 2 , W 4 , W 5 , Y 1 , and Y 2 are as defined above, in which the two Z 6 's are independent to each other. ##STR53## wherein ring A, W 1 , W 2 , Y 1 , and Y 2 are as defined above. Specific examples of the compounds represented by formulae (I-4'), (I-5') and (I-6') are shown below. In the followings, the numerical values in the brackets shown by [] are the phase transition temperatures of the compounds, in which C represents a crystal phase, Sm a smectic phase, S A a smectic A phase, S B a smectic B phase, N a nematic phase, and I an isotropic liquid phase, the parentheses shown by () represent the monotropic phases, and # indicates that the melting point is not clear due to non-crystallization. For example, "C 44 N" means that the phase transition temperature from the crystal phase to the nematic phase is 44° C. ##STR54## In the above-described compounds, it is preferable that ring A is represented by formula (II) wherein 1 to 8 of X 2 , X 3 , X 4 , X 5 , X 6 , X 7 , X 8 , and X 9 are deuterium atoms (D). Of these deuterated cyclohexane rings, preferred are those represented by formulae (II-a), (III-a), (II-b), (III-b), (II-c), and (III-c): ##STR55## wherein at least one of X 2 , X 3 , X 4 , and X 5 and at least one of X 12 , X 13 , X 14 , and X 15 each represent a deuterium atom (D). ##STR56## wherein at least one of X 6 , X 7 , X 8 , and X 9 and at least one of X 16 , X 17 , X 18 , and X 19 each represent a deuterium atom (D). ##STR57## wherein at least one of X 2 , X 3 , X 4 , and X 5 , at least one of X 6 , X 7 , X 8 , and X 9 , at least three of X 12 , X 13 , X 14 , and X 15 , and at least one of R 16 , R 17 , R 18 , and R 19 each represent a deuterium atom (D). The compounds of formula (I) according to the present invention can be prepared in the same manner as for corresponding compounds of formula (I) wherein the group of formula (II) and the group of formula (III) are each a 1,4-cyclohexylene group having no deuterium, with the exception that deuterated cyclohexanone derivatives, etc. are used as starting materials or a deuteration step is introduced in the stage of intermediates, while depending on the central skeleton composed of rings and linking groups and the position and the number the deuterium atoms (D) bonded to the ring(s). For example, a bicyclic liquid crystal compound represented by formula (R-1): ##STR58## wherein ring A is a cyclohexane ring having one or more deuterium atoms (D), which is deuterated 1-(trans-4-propylcyclohexyl)-4-ethoxybenzene, can be prepared through processes A to J hereinafter illustrated. In what follows, "d n -" attached to a chemical name or a structural formula indicates that the hydrogen atoms (H) bonded to the cyclohexane ring are substituted by n deuterium atom or atoms (D). ##STR59## 4-Propylcyclohexanone is dissolved in a solvent, e.g., dichloromethane, and heated with heavy water (D 2 O) in the presence of a base to obtain 4-propylcyclohexanone-2,2,6,6-d 4 , which is then reacted with a Grignard reagent prepared from 1-ethoxy-4-bromobenzene. The resulting d 4 -phenylcyclohexanol derivative is dehydrated to obtain a d 3 -phenylcyclohexene derivative. The d 3 -phenylcyclohexene derivative is catalytically reduced, and the cis-compound is removed to obtain 1-(trans-4-propylcyclohexyl-2,2,6-d 3 )-4-ethoxybenzene. ##STR60## Cyclohexane-1,4-dione monoethyleneacetal is reacted with a Grignard reagent prepared from 1-ethoxy-4-bromobenzene, and the product is dehydrated and then hydrogenated in the same manner as in process A (if desired, ethyleneacetal is re-introduced). The acetal moiety is removed to obtain 4-(4-ethoxyphenyl)cyclohexanone, which is then deuterated in the same manner as in process A to obtain 4-(4-ethoxyphenyl)cyclohexanone-2,2,6,6-d 4 . The deuterated compound is reacted with a Grignard reagent prepared from propyl bromide, and the product is dehydrated and hydrogenated. The cis-compound is separated to obtain 1-(trans-4-propylcyclohexyl-3,3,5-d 3 )-4-ethoxybenzene. ##STR61## The 4-(4-ethoxyphenyl)cyclohexanone-2,2,6,6-d 4 obtained in process B as an intermediate is reacted with a Wittig reagent represented by formula (IV): CH.sub.3 OCH═PPh.sub.3 (IV) wherein Ph represents a phenyl group, which is prepared with methoxymethyltriphenylphosphonium chloride. The product is then treated with an acid to obtain 4-(4-ethoxyphenyl)cyclohexane-2,2,6,6-d 4 -carbaldehyde, which is isomerized to a trans-form and reacted with a Wittig reagent prepared from ethyltriphenylphosphonium salt, followed by hydrogenation to obtain 1-(trans-4-propylcyclohexyl-3,3,5,5,-d 4 )-4-ethoxybenzene. ##STR62## Isomerization of the carbaldehyde derivative described in process C is carried out in the presence of heavy water (D 2 O) to obtain 4-(4-ethoxyphenyl)cyclohexane-1,2,2,6,6-d 5 -carbaldehyde, which is then treated in the same manner as in process C to obtain 1-(trans-4-propylcyclohexyl-3,3,4,5,5-d 5 )-4-ethoxybenzene. ##STR63## The 4-(4-ethoxyphenyl)cyclohexanone obtained in process B as an intermediate is reacted with a Wittig reagent of formula (IV) to obtain 4-(4-ethoxyphenyl)cyclohexanecarbaldehyde, which is led to 1-(trans-4-propylcyclohexyl-4-d)-4-ethoxybenzene via 4-(4-ethoxyphenyl)cyclohexane-1-d-carbaldehyde in the same manner as in process D. ##STR64## Cyclohexane-1,4-dione is deuterated in the same manner as in process A to obtain d 8 -cyclohexane-1,4-dione. The product is converted to a monoethyleneacetal, which is then reacted in the same manner as in process C to obtain 1-(trans-4-propylcyclohexyl-2,2,3,3,5,5,6-d 7 )-4-ethoxybenzene. ##STR65## Cyclohexane-1,4-dione monoethyleneacetal is deuterated, and the product is treated in the same manner as in process B to obtain 4-(4-ethoxyphenyl)cyclohexanone-3,3,5-d 3 . From the product is obtain 1-(trans-4-propylcyclohexyl-2,2,4,6-d 4 )-4-ethoxybenzene in the same manner as in process E. ##STR66## 1-(4-Ethoxyphenyl)-4-propylcyclohexene which is used as an intermediate for a compound having a non-deuterated cyclohexane ring as ring A of formula (R-1), is subjected to hydroboration and then oxidized with chromic acid, etc. to obtain 2-(4-ethoxyphenyl)-5-propylcyclohexanone. This compound is then subjected to deuteration and isomerization to a trans-form in the same manner as in process D, and the carbonyl group is removed by reduction to obtain 1-(trans-4-propylcyclohexyl-1,3,3-d 3 )-4-ethoxybenzene. ##STR67## 2-(4-Ethoxyphenyl)-5-propylcyclohexanone, which is the intermediate in process H, is reduced with lithium aluminum hydride-d 4 , dehydrated, hydrogenated, and then isomerized to a trans-form to obtain 1-(trans-4-propylcyclohexyl-2-d)-4-ethoxybenzene. ##STR68## Phenol is reacted in heavy water and low-concentration deuterium chloride (DCl) at a high temperature (230° to 250° C.) under pressure to obtain d 6 -phenol. d 6 -Phenol is refluxed in hydrochloric acid to obtain 3,5-d 2 -phenol. 3,5-d 2 -Phenol is reacted with propionyl chloride in the presence of aluminum chloride, and the product is subjected to Wolff-Kishner reduction to obtain 4-propyl-(3,5-d 2 )-phenol, which is then hydrogenated using rhodium-on-carbon as a catalyst. The resulting cyclohexanol derivative is oxidized with chromic anhydride, etc. to obtain 4-propyl-(3,5-d 2 )-cyclohexanone, which is led to 1-(trans-4-propylcyclohexyl-3,5-d 2 )-4-ethoxybenzene in the same manner as in process A. Bicyclic deuterated liquid crystal compounds other than the compound of formula (R-1) can also be obtained with ease in accordance with processes A to J or an appropriate combination thereof. A tricyclic deuterated liquid crystal compound represented by formula (R-2): ##STR69## wherein ring A is a cyclohexane ring having one or more deuterium atoms (D), which is deuterated 1-[4-(trans-4-propylcyclohexyl)cyclohexyl]-3,4-difluorobenzene, can be prepared through any of the following processes K to O. ##STR70## 4-(Trans-4-propylcyclohexyl)cyclohexanone is deuterated in the same manner as in process A to obtain 4-(trans-propylcyclohexyl)cyclohexanone-2,2,6,6-d 4 . This compound is reacted with a Grignard reagent prepared from 1-bromo-3,4-difluorobenzene, and the product is further treated in the same manner as in process A to obtain 1-[4-(trans-4-propylcyclohexyl)cyclohexyl-2,2,6-d 3 ]-3,4-difluorobenzene. ##STR71## 1-(3,4-Difluorophenyl)-4-(trans-4-propylcyclohexyl)cyclohexene-2,6,6-d.sub.3, the intermediate of process K, is subjected to hydroboration and then oxidation in the same manner as in process H to obtain 2-(3,4-difluorophenyl)-5-(trans-4-propylcyclohexyl)cyclohexanone-3,3-d.sub.2. The product is subjected to deuteration and isomerization to a trans-form in the same manner as in process D, and the carbonyl group is removed by reduction to obtain 1-[4-(trans-4-propylcyclohexyl)cyclohexyl-1,2,2,5,5-d 5 ]-3,4-difluorobenzene. ##STR72## The same reactions as in process L are carried out, except that after the hydroboration deuteration was not conducted and only isomerization is conducted, to obtain 1-[4-(trans-4-propylcyclohexyl)cyclohexyl-2,2-d 2 ]-3,4-difluorobenzene. ##STR73## The deuterated cyclohexane-1,4-dione monoethyleneacetal obtained in process G is reacted with a Grignard reagent prepared from 4-propylcyclohexyl bromide, and the product is dehydrated and then hydrogenated in the same manner as in process G to obtain 4-(trans-4-propylcyclohexyl)cyclohexanone-3,3,5-d 3 , from which is obtained 1-[4-(trans-4-propylcyclohexyl)cyclohexyl-3,3,5-d 3 ]-3,4-difluorobenzene in the same manner as in process K. ##STR74## The 4-(trans-4-propylcyclohexyl)cyclohexanone-3,3,5-d 3 obtained in process N is further deuterated to obtain 4-(trans-4-propylcyclohexyl)cyclohexanone-2,2,3,3,5,6,6-d 7 . From this compound are obtained 1-[4-(trans-4-propylcyclohexyl)cyclohexyl-2,2,3,3,5,6-d 6 ]-3,4-difluorobenzene and 1-[4-(trans-4-propylcyclohexyl)cyclohexyl-2,2,3,5,5,6-d 6 ]-3,4-difluorobenzene in the same manner as in process K. Tricyclic deuterated liquid crystal compounds other than the compound of formula (R-2) can also be obtained with ease in accordance with processes K to O or an appropriate combination thereof. Further, tetracyclic deuterated liquid crystal compounds are also prepared easily in accordance with processes A to O or an appropriate combination thereof. While the deuterated liquid crystal compounds hereinabove described are those in which the saturated hydrocarbon ring is a cyclohexane ring, compounds having a saturated hydrocarbon ring having 3 to 5 carbon atoms are also preferred. The deuterated liquid crystal compounds which can be used in the present invention can be prepared by applying the syntheses described in the above-mentioned literature. Therefore, the positions of deuterium atoms (D) are not limited to those specifically described in processes A to O and may be at any of the positions on the saturated hydrocarbon ring. While it will suffice if at least one deuterium atom (D) should be bonded, all the hydrogen atoms (H) on the saturated hydrocarbon ring may be substituted with deuterium atoms (D). In process J, for example, the intermediate of formula: ##STR75## may be replaced with any of compounds of the following formulae to obtain a large variety of deuterated liquid crystal compounds. ##STR76## Typical examples of compounds which can be used for preference to obtain the liquid crystal composition of the present invention are shown below. Unless otherwise indicated, in compounds (1) to (425) hereinafter given, R 1 represents an alkyl, alkoxylalkyl or alkenyl group having from 1 to 20 carbon atoms; R 2 represents an alkyl group or an alkoxyl group; R 3 and R 4 each represent an alkyl group having from 1 to 20 carbon atoms; and R 5 represents an alkyl or alkenyl group having from 1 to 20 carbon atoms. Rings A, A' and B in compounds (1), (2), (21) to (28), (41) to (43), (45) to (59), (90) to (104), (150) to (179), (210) to (303), and (335) to (349), and rings A and A' in compounds (75) to (89), (350) to (364), (265) to (378), (382) to (388), (403) to (409), (416), (417), (424), and (425) each represent a group selected from the groups: ##STR77## Rings A and A' in compounds (3) to (20), (39), (40), (44), (60) to (74), (105) to (149), (180) to (209), (304) to (334), (379) to (381), (389) to (402), (410) to (415), and (418) to (423), and rings B and B' in compounds (75) to (89) and (350) to (364) each represent a group selected from the groups: ##STR78## Rings A and B or rings A' and B' in compounds (75) to (89), (255) to (269), (301), (303), and (350) to (364) may be the same or different. The above illustrated groups are those merely showing the position of the substituent(s), deuterium atom(s). ##STR79## Preparation Examples of compounds (1) to (364) are shown below. PREPARATION EXAMPLE 1 Preparation of Compound (1) Compound (1) can be prepared by processes A, B or F, except for replacing 4-ethoxyphenylmagnesium bromide with a 4-alkyl(or alkoxyl)cyclohexylmagnesium bromide or by processes C, D, E or G, except for replacing 4-(4-ethoxyphenyl)cyclohexanone with a 4-(4-alkyl or alkoxylcyclohexyl)cyclohexanone. PREPARATION EXAMPLE 2 Preparation of Compound (2) Compound (2) can be prepared in the same manner as in Preparation Example 1, except for replacing the 4-alkyl(or alkoxyl)cyclohexylmagnesium bromide with a 2-[4-alkyl(or alkoxyl)cyclohexyl]ethylmagnesium bromide or replacing the 4-(4-alkyl or alkoxylcyclohexyl)cyclohexanone with a 4-[2-(4-alkyl or alkoxylcyclohexyl)ethyl]cyclohexanone. PREPARATION EXAMPLE 3 Preparation of Compound (3) Compound (3) can be prepared in accordance with processes A to J. PREPARATION EXAMPLE 4 Preparation of Compound (4) Compound (4) can be prepared in the same manner as in Preparation Example 3, except for replacing the 4-alkyl(or alkoxyl)phenylmagnesium bromide as a Grignard reagent with 4-fluorophenylmagnesium bromide. PREPARATION EXAMPLE 5 Preparation of Compound (5) A compound of formula (P1): ##STR80## is prepared in the same manner as in Preparation Example 3, except for replacing the 4-alkyl(or alkoxyl)phenylmagnesium bromide as a Grignard reagent with phenylmagnesium bromide. Compound (P1) is directly chlorinated with sulfuryl chloride, etc. in the presence of a catalyst to obtain compound (5). Alternatively, compound (P1) is once nitrated and then reduced to obtain an aniline derivative represented by formula (P2): ##STR81## which is then diazotized and decomposed to obtain compound (5). PREPARATION EXAMPLE 6 Preparation of Compound (6) Compound (6) is prepared in the same manner as in Preparation Example 3, except for using a Grignard reagent prepared from 4-bromo-1-trifluoromethoxybenzene. PREPARATION EXAMPLE 7 Preparation of Compound (7) Compound (3) wherein R 2 is OCH 3 , which is prepared in Preparation Example 3, is demethylated using hydrobromic acid, trimethylsilyl iodide, aluminum chloride or boron tribromide, or aluminum chloride and dimethyl sulfide (or ethanethiol) to obtain a phenol derivative represented by formula (P3): ##STR82## The phenol derivative (P3) is reacted with chlorodifluoromethane in the presence of a base to obtain compound (7). Alternatively, the phenol derivative (P3) is converted to a formic ester and then reacted with dimethylaminosulfur trifluoride (hereinafter abbreviated as DAST), etc. to obtain compound (7). PREPARATION EXAMPLE 8 Preparation of Compound (8) The intermediate compound (P1) is reacted with oxalyl dichloride in the presence of a Lewis acid, e.g., aluminum chloride, to obtain a benzoyl chloride derivative represented by formula (P4): ##STR83## Compound (P4) is esterified with an alcohol R 3 OH to obtain compound (8). PREPARATION EXAMPLE 9 Preparation of Compound (9) The intermediate compound (P3) is esterified with a carboxylic acid R 3 COOH or R 3 COCl in a usual manner to obtain compound (9). PREPARATION EXAMPLE 10 Preparation of Compound (10) Compound (10) can be prepared in the same manner as in Preparation Example 3, except for replacing the 4-alkyl(or alkoxyl)phenylmagnesium bromide with a Grignard reagent prepared from 1-bromo-3,4-difluorobenzene. PREPARATION EXAMPLE 11 Preparation of Compound (11) Compound (11) can be prepared in the same manner as in Preparation Example 10, except for using a Grignard reagent prepared from 1-bromo-4-chloro-3-fluorobenzene. Alternatively, an intermediate compound represented by formula (P5): ##STR84## is prepared b using 1-bromo-3-fluorobenzene, and compound (P5) is chlorinated in the same manner as in Preparation Example 5. PREPARATION EXAMPLE 12 Preparation of Compound (12) Compound (12) can be prepared in the same manner as in Preparation Example 3, except for replacing the 4-alkyl(or alkoxyl)phenylmagnesium bromide with a Grignard reagent prepared from 4-bromo-2-fluoro-1-trifluoromethoxybenzene. PREPARATION EXAMPLE 13 Preparation of Compound (13) A phenol derivative represented by formula (P6): ##STR85## in obtained in the same manner as in Preparation Example 7, except for replacing the 4-methoxyphenylmagnesium bromide with a Grignard reagent prepared from 4-bromo-2-fluoroanisole. Compound (P6) is then led to compound (13) in the same manner as in Preparation Example 7. PREPARATION EXAMPLE 14 Preparation of Compound (14) The intermediate compound (P5) is converted to an acid chloride of formula (P7): ##STR86## which is then led to compound (14) in the same manner as in Preparation Example 8. PREPARATION EXAMPLE 15 Preparation of Compound (15) Compound (15) can be prepared in the same manner as in Preparation Example 3, except for replacing the 4-alkyl(or alkoxyl)phenylmagnesium bromide with a Grignard reagent prepared from 1-bromo-3,4,5-trifluorobenzene. PREPARATION EXAMPLE 16 Preparation of Compound (16) Compound (16) can be prepared in the same manner as in Preparation Example 3, except for replacing the 4-alkyl(or alkoxyl)phenylmagnesium bromide with a Grignard reagent prepared from 1-bromo-4-chloro-3,5-difluorobenzene. Alternatively, a compound represented by formula (P8): ##STR87## is obtained by using a Grignard reagent prepared from 1-bromo-3,5-difluorobenzene, and compound (P8) is chlorinated in the same manner as in Preparation Example 5. PREPARATION EXAMPLE 17 Preparation of Compound (17) 2,6-Difluorophenol is brominated and then reacted with methyl iodide, etc. to obtain 4-bromo-2,6-difluoroanisole, which is led to compound (17) in the same manner as in Preparation Example 13. PREPARATION EXAMPLE 18 Preparation of Compound (18) The intermediate compound (P4) is reacted with aqueous ammonia to obtain an amide derivative represented by formula (P9): ##STR88## The amide derivative (P9) is dehydrated with thionyl chloride, etc. for cyanogenation to obtain compound (18). Alternatively, the intermediate compound (P1) is iodinated with iodine-periodic acid to obtain a compound of formula (P10): ##STR89## which is then reacted with cuprous cyanide to obtain compound (18). PREPARATION EXAMPLE 19 Preparation of Compound (19) Compound (19) can be prepared from the intermediate compound (P7) or (P5) according to Preparation Example 18. PREPARATION EXAMPLE 20 Preparation of Compound (20) Compound (20) can be prepared in the same manner as in Preparation Example 18, except for replacing compound (P1) with compound (P8). Alternatively, compound (P8) is reacted with an alkyl lithium to obtain a phenyllithium derivative, which is then reacted with carbon dioxide to obtain a benzoic acid derivative of formula (P11): ##STR90## Compound (P11) is converted to an acid chloride by using thionyl chloride, etc., which is further reacted in the same manner as in Preparation Example 18 to obtain compound (20). PREPARATION EXAMPLE 21 Preparation of Compound (21) A monoethyleneacetal of cyclohexane-1,4-dione is reacted with a Wittig reagent of formula (IV) to obtain a cyclohexanecarbaldehyde derivative represented by formula (P12): ##STR91## which is again reacted with the compound of formula (IV) to obtain a cyclohexaneethanal derivative of formula (P13): ##STR92## Compound (P13) is reacted with a 4-alkyl(or alkoxyl)phenylmagnesium bromide, and the product is dehydrated with an acid. Where the acetal moiety has been removed, an acetal moiety is again introduced into the product. The acetal compound is hydrogenated, followed by decomposition of the acetal moiety to obtain a cyclohexanone derivative represented by formula (P15): ##STR93## From compound (P15) is obtained compound (21) in accordance with process B, C, D or E. The above-described process may be carried out by starting with a compound prepared by previously deuterating cyclohexane-1,4-dione monoethyleneacetal as in process G or a compound prepared by deuterating cyclohexane-1,4-dione and then introducing a monoacetal moiety thereinto as in process F. Further, compound (21) wherein R 1 is an alkyl group or an alkoxylalkyl group can also be prepared by deuterating a 4-substituted cyclohexanone according to process A, reacting the resulting deuterated cyclohexanone derivative with a Wittig reagent of formula (VI) twice to obtain a 4-substituted cyclohexaneethanal, and using this compound in place of compound (P13) in the above-described process. PREPARATION EXAMPLE 22 Preparation of Compound (22) Compound (22) can be prepared in the same manner as in Preparation Example 21, except for replacing the 4-alkyl(or alkoxyl)phenylmagnesium bromide with 4-fluorophenylmagnesium bromide. PREPARATION EXAMPLE 23 Preparation of Compound (23) Compound (23) can be prepared in the same manner as in Preparation Example 21,except for using a Grignard reagent prepared from 1-bromo-4-chlorobenzene. Alternatively, it is also prepared by once obtaining a compound of formula (P16): ##STR94## by using phenylmagnesium bromide in Preparation Example 21, and then treating compound (P16) in the same manner as in Preparation Example 5. PREPARATION EXAMPLE 24 Preparation of Compound (24) Compound (24) can be prepared in the same manner as in Preparation Example 21, except for using a Grignard reagent prepared from 4-bromo-1-trifluoromethoxybenzene. PREPARATION EXAMPLE 25 Preparation of Compound (25) Compound (21) wherein R 2 is OCH 3 , which is prepared in Preparation Example 21, is demethylated in the same manner as in Preparation Example 7 to obtain a phenol derivative represented by formula (P17): ##STR95## Compound (25) can be prepared from this phenol derivative (P17) in the same manner as in Preparation Example 7. PREPARATION EXAMPLE 26 Preparation of Compound (26) Compound (26) can be prepared from compound (P16) in the same manner as in Preparation Example 8. PREPARATION EXAMPLE 27 Preparation of Compound (27) Compound (27) can be prepared form compound (P17) in the same manner as in Preparation Example 9. PREPARATION EXAMPLE 28 Preparation of Compound (28) Compound (28) can be prepared in the same manner as in Preparation Example 21, except for using a Grignard reagent prepared from 4-bromo-1,2-difluorobenzene. PREPARATION EXAMPLE 29 Preparation of Compound (29) Compound (29) can be prepared in the same manner as in Preparation Example 21, except for using a Grignard reagent prepared from 1-bromo-4-chloro-3-fluorobenzene. Alternatively, an intermediate compound of formula (P18): R1 ? ? ##STR96## which is obtained by using 1-bromo-3-fluorobenzene, is chlorinated in the same manner as in Preparation Example 5 to obtain compound (29). PREPARATION EXAMPLE 30 Preparation of Compound (30) Compound (30) can be prepared in the same manner as in Preparation Example 21, except for replacing the 4-alkyl(or alkoxyl)phenylmagnesium with a Grignard reagent prepared from 4-bromo-2-fluoro-1-trifluoromethoxybenzene. PREPARATION EXAMPLE 31 Preparation of Compound (31) A phenol derivative represented by formula (P19): ##STR97## is obtained in the same manner as in Preparation Example 25, except for replacing 4-methoxyphenylmagnesium bromide with a Grignard reagent prepared from 4-bromo-2-fluoroanisole. Compound (31) can be prepared from compound (P19) in the same manner as in Preparation Example 7. PREPARATION EXAMPLE 32 Preparation of Compound (32) An acid chloride represented by formula (P20): ##STR98## is obtained from compound (P18), and compound (P20) is treated in the same manner as in Preparation Example 8 to obtain compound (32). PREPARATION EXAMPLE 33 Preparation of Compound (33) Compound (33) can be prepared in the same manner as in Preparation Example 21, except for using a Grignard reagent prepared from 1-bromo-3,4,5-trifluorobenzene. PREPARATION EXAMPLE 34 Preparation of Compound (34) Compound (34) can be prepared in the same manner as in Preparation Example 21, except for using a Grignard reagent prepared from 1-bromo-4-chloro-3,5-difluorobenzene. Alternatively, a compound of formula (P21): ##STR99## is once prepared by using a Grignard reagent prepared from 1-bromo-3,5-difluorobenzene, which is then chlorinated in the same manner as in Preparation Example 5 to obtain compound (34). PREPARATION EXAMPLE 35 Preparation of Compound (35) 2,6-Difluorophenol is brominated and then methylated with methyl iodide, etc. to obtain 4-bromo-2,6-difluoroanisole. A phenol derivative of formula (P22): ##STR100## is obtained using the resulting 4-bromo-2,6-difluoroanisole, which is then led to compound (35) in the same manner as in Preparation Example 31. PREPARATION EXAMPLE 36 Preparation of Compound (36) In the same manner as in Preparation Example 18, an amide derivative of formula (P23): ##STR101## is obtained. Compound (P23) is dehydrated with thionyl chloride, etc. for cyanogenation to obtain compound (36). Alternatively, the intermediate compound (P16) is iodinated with iodine-periodic acid to obtain an iodobenzene derivative of formula (P24): ##STR102## which is then reacted with cuprous cyanide to obtain compound (36). PREPARATION EXAMPLE 37 Preparation of Compound (37) Compound (37) can be prepared from compound (P18) or compound (P20) in the same manner as in Preparation Example 36. PREPARATION EXAMPLE 38 Preparation of Compound (38) Compound (38) can be prepared in the same manner as in Preparation Example 36, except for replacing compound (P16) with compound (P21). Alternatively, compound (P21) is reacted with an alkyl lithium to obtain a phenyllithium derivative, which is then reacted with carbon dioxide to obtain a benzoic acid derivative of formula (P25): ##STR103## Compound (P25) is converted to an acid chloride by using thionyl chloride, etc., which is further reacted in the same manner as in Preparation Example 36 to obtain compound (38). PREPARATION EXAMPLES 39 AND 40 Preparation of Compounds (39) and (40) A compound represented by formula (P26): ##STR104## which corresponds to compound (3) wherein R 1 is an alkyl group or an alkoxylalkyl group; and R 2 is an alkyl group, is reduced with metallic lithium or metallic sodium to obtain a mixture of compounds (39) and (40). The mixture as obtained is usually usable as such. If desired, the mixture can be separated into each compound. Where only compound (39) is desired, it is prepared as follows. A compound of formula (P27): ##STR105## is prepared by using a Grignard reagent prepared from a 2-bromo-5-alkylanisole. Compound (P27) is demethylated and then hydrogenated to obtain a cyanohexanone derivative of formula (P28): ##STR106## Compound (P28) is reduced with lithium aluminum hydride or sodium borohydride and then dehydrated to obtain compound (39). Where only compound (40) is desired, it can be prepared in the same manner as for compound (39), except for using a Grignard reagent prepared from a 5-bromo-2-alkylanisole. PREPARATION EXAMPLES 41 AND 42 Preparation of Compounds (41) and (42) A compound represented by formula (P29): ##STR107## which corresponds to compound (21) wherein R 1 is an alkyl group or an alkoxylalkyl group; and R 2 is an alkyl group, is reduced with metallic lithium or metallic sodium to obtain a mixture of compounds (41) and (42). The mixture as produced is usually usable as such. If desired, the mixture can be separated into each compound. Where only compound (41) is desired, it is prepared as follows. A compound of formula (P30): ##STR108## is obtained by using a Grignard reagent prepared from a 2-bromo-5-alkylanisole. Compound (P30) is demethylated and then hydrogenated to obtain a cyanohexanone derivative of formula (P31): ##STR109## Compound (P31) is reduced with lithium aluminum hydride or sodium borohydride and then dehydrated to obtain compound (41). Where only compound (42) is desired, it can be prepared in the same manner as for compound (41), except for using a Grignard reagent prepared from a 5-bromo-2-alkylanisole. PREPARATION EXAMPLE 43 Preparation of Compound (43) Compound (43) can be prepared by reacting the compound of formula (P3) with a compound of formula X-R 5 , wherein X represents a chlorine atom, a bromine atom, an iodine atom, or a leaving group, such as a p-toluenesulfonyl group; and R 5 represents an alkenyl group, in the presence of a base. PREPARATION EXAMPLE 44 Preparation of Compound (44) Compound (44) can be prepared in the same manner as in Preparation Example 43, except for using the intermediate compound of formula (P17). PREPARATION EXAMPLE 45 Preparation of Compound (45) Compound (45) can be prepared in accordance with process B, C, D or E, except for replacing the monoacetal of cyclohexane-1,4-dione with a monoacetal of bicyclohexane-4,4'-dione. Alternatively, compound (45) wherein R 1 is an alkyl or alkoxylalkyl group can be prepared by hydrogenating compound (P3) to obtain a cyclohexanone derivative of formula (P32): ##STR110## reacting compound (P32) with a Grignard reagent, and subjecting the product to dehydration and hydrogenation in accordance with process A. If desired, the cis-cyclohexane ring is isomerized to a trans-form. PREPARATION EXAMPLE 46 Preparation of Compound (46) Compound (46) can be prepared in the same manner as in Preparation Example 45, except for using 4-fluorophenylmagnesium bromide as a Grignard reagent. PREPARATION EXAMPLE 47 Preparation of Compound (47) Compound (47) can be prepared in the same manner as in Preparation Example 45, except for using a Grignard reagent prepared from 1-bromo-4-chlorobenzene. Alternatively, a compound of formula (33): ##STR111## is obtained in the same manner but using phenylmagnesium bromide as a Grignard reagent, and compound (P33) is led to compound (47) in the same manner as in Preparation Example 5. PREPARATION EXAMPLE 48 Preparation of Compound (48) Compound (48) can be prepared in the same manner as in Preparation Example 45, except for using a Grignard reagent prepared from 4-bromo-1-trifluoromethoxybenzene. PREPARATION EXAMPLE 49 Preparation of Compound (49) Compound (45) wherein R 2 is OCH 3 as prepared in Preparation Example 45 is demethylated in the same manner as in Preparation Example 3 to obtain a phenol derivative of formula (P34): ##STR112## from which Compound (49) can be prepared in the same manner as in Preparation Example 3. PREPARATION EXAMPLE 50 Preparation of Compound (50) Compound (50) can be prepared in the same manner as in Preparation Example 45, except for replacing the 4-alkyl(or alkoxyl)phenylmagnesium bromide with a Grignard reagent prepared from 1-bromo-3,4-difluorobenzene. PREPARATION EXAMPLE 51 Preparation of Compound (51) Compound (51) is prepared in the same manner as in Preparation Example 45, except for using a Grignard reagent prepared from 1-bromo-4-chloro-3-fluorobenzene. Alternatively, an intermediate compound of formula (P35): ##STR113## is once prepared in the same manner but using a Grignard reagent prepared from 1-bromo-3-fluorobenzene, and compound (P35) is chlorinated in the same manner as in Preparation Example 5 to obtain compound (51). PREPARATION EXAMPLE 52 Preparation of Compound (52) Compound (52) can be obtained in the same manner as in Preparation Example 45, except for replacing the 4-alkyl(or alkoxyl)phenylmagnesium bromide with a Grignard reagent prepared from 4-bromo-2-fluoro-1-trifluoromethoxybenzene. PREPARATION EXAMPLE 53 Preparation of Compound (53) A phenol derivative represented by formula (P36): ##STR114## is prepared in the same manner as in Preparation Example 49, except for replacing 4-methoxyphenylmagnesium bromide with a Grignard reagent prepared from 4-bromo-3-fluoroanisole. Compound (53) can be prepared from compound (P36) in the same manner as in Preparation Example 7. PREPARATION EXAMPLE 54 Preparation of Compound (54) Compound (54) can be prepared in the same manner as in Preparation Example 45, except for replacing the 4-alkyl(or alkoxyl)phenylmagnesium bromide with a Grignard reagent prepared from 1-bromo-3,4,5-trifluorobenzene. PREPARATION EXAMPLE 55 Preparation of Compound (55) Compound (55) can be prepared in the same manner as in Preparation Example 45, except for using a Grignard reagent prepared from 1-bromo-4-chloro-3,5-difluorobenzene. Alternatively, compound (55) can also be obtained by chlorinating a compound of formula (P37): ##STR115## which is similarly obtained by using a Grignard reagent prepared from 1-bromo-3,5-difluorobenzene, in the same manner as in Preparation Example 5. PREPARATION EXAMPLE 56 Preparation of Compound (56) Compound (56) can be obtained in the same manner as in Preparation Example 53, except for using a Grignard reagent prepared from 4-bromo-2,6-difluoroanisole, the intermediate prepared in Preparation Example 17. PREPARATION EXAMPLE 57 Preparation of Compound (57) An acid chloride of formula (P38): ##STR116## is obtained from compound (P33) in the same manner as in Preparation Example 8. The acid chloride (P38) is reacted with aqueous ammonia to obtain an amide derivative of formula (P39): ##STR117## The amide derivative (P39) is dehydrated with thionyl chloride, etc. for cyanogenation to obtain compound (57). Alternatively, the intermediate of formula (P33) is iodinated with iodine-periodic acid to obtain a compound of formula (P40): ##STR118## which is then reacted with cuprous cyanide to obtain compound (57). PREPARATION EXAMPLE 58 Preparation of Compound (58) Compound (58) can be obtained from the intermediate compound (P35) in the same manner as in Preparation Example 57. PREPARATION EXAMPLE 59 Preparation of Compound (59) Compound (59) can be prepared in the same manner as in Preparation Example 57, except for replacing compound (P33) with compound (P37). Alternatively, compound (37) is reacted with an alkyl lithium to obtain a phenyllithium derivative, which is then reacted with carbon dioxide to obtain a benzoic acid derivative of formula (P41): ##STR119## Compound (P41) is converted to an acid chloride by using thionyl chloride, etc., which is further reacted in the same manner as in Preparation Example 57 to obtain compound (59). PREPARATION EXAMPLE 60 Preparation of Compound (60) Compound (60) can be prepared in accordance with process K, L, M, N or O, except for replacing 3,4-difluorophenylmagnesium bromide as a Grignard reagent with a 4-alkyl(or alkoxyl)magnesium bromide. PREPARATION EXAMPLE 61 Preparation of Compound (61) Compound (61) can be prepared in the same manner as in Preparation Example 60, except for using 4-fluorophenylmagnesium bromide as a Grignard reagent. PREPARATION EXAMPLE 62 Preparation of Compound (62) Compound (62) can be prepared in the same manner as in Preparation Example 60, except for using a Grignard reagent prepared from 1-bromo-4-chlorobenzene. Alternatively, a compound of formula (P42): ##STR120## is obtained in the same manner but using phenylmagnesium bromide as a Grignard reagent, and compound (62) is prepared therefrom in the same manner as in Preparation Example 5. PREPARATION EXAMPLE 63 Preparation of Compound (63) Compound (63) can be prepared in the same manner as in Preparation Example 60, except for using a Grignard reagent prepared from 4-bromo-1-trifluoromethoxybenzene. PREPARATION EXAMPLE 64 Preparation of Compound (64) Compound (60) prepared in Preparation Example 60 wherein R 2 is OCH 3 is demethylated to obtain a phenol derivative of formula (P43): ##STR121## which is then led to compound (64) in the same manner as in Preparation Example 3. PREPARATION EXAMPLE 65 Preparation of Compound (65) Compound (65) is obtained in accordance with process K, L, M, N or O. PREPARATION EXAMPLE 66 Preparation of Compound (66) Compound (66) can be prepared in the same manner as in Preparation Example 60, except for using a Grignard reagent prepared from 1-bromo-4-chloro-3-fluorobenzene. Alternatively, compound (66) can be obtained by once preparing a compound of formula (P44): ##STR122## in the same manner but using 1-bromo-3-fluorobenzene and chlorinating compound (P44) in the same manner as in Preparation Example 5. PREPARATION EXAMPLE 67 Preparation of Compound (67) Compound (67) can be prepared in the same manner as in Preparation Example 60, except for replacing the 4-alkyl(or alkoxyl)phenylmagnesium bromide with a Grignard reagent prepared from 4-bromo-2-fluoro-1-trifluoromethoxybenzene. PREPARATION EXAMPLE 68 Preparation of Compound (68) A phenol derivative represented by formula (P45): ##STR123## is prepared in the same manner as in Preparation Example 64, except for replacing 4-methoxyphenylmagnesium bromide with a Grignard reagent prepared from 4-bromo-2-fluoroanisole. Compound (64) can be obtained from compound (P45) in the same manner as in Preparation Example 7. PREPARATION EXAMPLE 69 Preparation of Compound (69) Compound (69) can be obtained in the same manner as in Preparation Example 60, except for replacing the 4-alkyl(or alkoxyl)phenylmagnesium with a Grignard reagent prepared from 1-bromo-3,4,5-trifluorobenzene. PREPARATION EXAMPLE 70 Preparation of Compound (70) Compound (70) can be prepared in the same manner as in Preparation Example 60, except for using a Grignard reagent prepared from 1-bromo-4-chloro-3,5-difluorobenzene. Alternatively, a compound of the formula (P46): ##STR124## which is obtained in the same manner but using a Grignard reagent prepared from 1-bromo-3,5-difluorobenzene, is chlorinated in the same manner as in Preparation Example 5 to obtain compound (70). PREPARATION EXAMPLE 71 Preparation of Compound (71) Compound (71) can be prepared in the same manner as in Preparation Example 68, except for using 4-bromo-2,6-difluoroanisole, the intermediate compound obtained in Preparation Example 17. PREPARATION EXAMPLE 72 Preparation of Compound (72) An acid chloride of formula (P47): ##STR125## is obtained from the intermediate compound of formula (P42) in the same manner as in Preparation Example 8, and the acid chloride (P47) is reacted with aqueous ammonia to obtain an amide derivative of formula (P48): ##STR126## The amide derivative (P48) is dehydrated with thionyl chloride, etc. for cyanogenation to obtain compound (72). Alternatively, the intermediate of formula (P42) is iodinated with iodine-periodic acid to obtain a compound of formula (P49): ##STR127## which is then reacted with cuprous cyanide to obtain compound (72). PREPARATION EXAMPLE 73 Preparation of Compound (73) Compound (73) can be prepared from the compound of formula (P44) in the same manner as in Preparation Example 72. PREPARATION EXAMPLE 74 Preparation of Compound (74) Compound (74) can be prepared in the same manner as in Preparation Example 72, except for replacing compound (P42) with compound (P44). Alternatively, it can be prepared from compound (P46) via a benzoic acid derivative of formula (P50): ##STR128## in the same manner as in Preparation Example 59. PREPARATION EXAMPLE 75 Preparation of Compound (75) Compound (75) can be prepared in accordance with process K to O, except for using a deuterated compound of formula (P51): ##STR129## in place of the 4-(4-substituted cyclohexyl)cyclohexanone and replacing 3,4-difluorophenylmagnesium bromide as a Grignard reagent with a 4-alkyl(or alkoxyl)phenylmagnesium bromide. It can also be prepared by using compound (P32) in place of compound (P51) in accordance with processes H to L. Further, it may be prepared in the same manner as in Preparation Example 45, except for starting with a monoethyleneacetal of deuterated bicyclohexane-4,4'-dione represented by formula (P52): ##STR130## Alternatively, a compound of formula (P53): ##STR131## is reacted in the same manner in place of compound (P52) to obtain a cyclohexanone derivative of formula (P54): ##STR132## from which compound 75) can be prepared in accordance with processes B to G. Compound (P51) can be obtained by deuteration of compound (P32). Compound (P52) can be obtained by deuteration of bicyclohexane-4,4'-dione followed by introduction of a monoacetal moiety. Compound (P53) can be obtained by deuteration of bicyclohexane-4,4-dione monoethyleneacetal. PREPARATION EXAMPLE 76 Preparation of Compound (76) Compound (76) can be prepared in the same manner as in Preparation Example 75, except for using 4-fluorophenylmagnesium bromide as a Grignard reagent. PREPARATION EXAMPLE 77 Preparation of Compound (77) Compound (77) can be prepared in the same manner as in Preparation Example 75, except for using a Grignard reagent prepared from 1-bromo-4-chlorobenzene. Alternatively, a compound of formula (P55): ##STR133## is once obtained in the same manner but using phenylmagnesium bromide as a Grignard reagent, from which compound (77) can be prepared in the same manner as in Preparation Example 5. PREPARATION EXAMPLE 78 Preparation of Compound (78) Compound (78) can be obtained in the same manner as in Preparation Example 75, except for using a Grignard reagent prepared from 4-bromo-1-trifluoromethoxybenzene. PREPARATION EXAMPLE 79 Preparation of Compound (79) Compound (75) prepared in Preparation Example 75 wherein R 2 is OCH 3 is demethylated according to process A to J to obtain a phenol derivative of formula (P56): ##STR134## which is then led to compound (79) in the same manner as in Preparation Example 3. PREPARATION EXAMPLE 80 Preparation of Compound (80) Compound (80) can be prepared in the same manner as in Preparation Example 75, except for replacing the 4-alkyl(or alkoxyl)phenylmagnesium bromide with a Grignard reagent prepared from 1-bromo-3,4-difluorobenzene. PREPARATION EXAMPLE 81 Preparation of Compound (81) Compound (81) can be prepared in the same manner as in Preparation Example 75, except for replacing the 4-alkyl(or alkoxyl)phenylmagnesium bromide with a Grignard reagent prepared from 1-bromo-4-chloro-3-fluorobenzene. Alternatively, a Grignard reagent prepared from 1-bromo-3-fluorobenzene may be used to obtain an intermediate compound of formula (P57): ##STR135## which is then chlorinated in the same manner as in Preparation Example 5 to obtain compound (81). PREPARATION EXAMPLE 82 Preparation of Compound (82) Compound (82) can be prepared in the same manner as in Preparation Example 75, except for replacing the 4-alkyl(or alkoxyl)phenylmagnesium bromide with a Grignard reagent prepared from 4-bromo-2-fluoro-1-trifluoromethoxybenzene. PREPARATION EXAMPLE 83 Preparation of Compound (83) A phenol derivative of formula (P58): ##STR136## is prepared in the same manner as in Preparation Example 79, except for replacing 4-methoxyphenylmagnesium bromide with a Grignard reagent prepared from 4-bromo-2-fluoroanisole. Compound (P58) can be led to compound (83) in the same manner as in Preparation Example 7. PREPARATION EXAMPLE 84 Preparation of Compound (84) Compound (84) can be prepared in the same manner as in Preparation Example 75, except for replacing the 4-alkyl(or alkoxyl)phenylmagnesium bromide with a Grignard reagent prepared from 1-bromo-3,4,5-trifluorobenzene. PREPARATION EXAMPLE 85 Preparation of Compound (85) Compound (85) can be prepared in the same manner as in Preparation Example 75, except for replacing the 4-alkyl(or alkoxyl)phenylmagnesium bromide with a Grignard reagent prepared from 1-bromo-4-chloro-3,5-difluorobenzene. Alternatively, a Grignard reagent prepared from 1-bromo-3,5-difluorobenzene may be used to obtain an intermediate compound of formula (P59): ##STR137## which is then chlorinated in the same manner as in Preparation Example 5 to obtain compound (85). PREPARATION EXAMPLE 86 Preparation of Compound (86) Compound (86) can be prepared in the same manner as in Preparation Example 83, except for using 4-bromo-2,6-difluoroanisole, which is an intermediate product of Preparation Example 17. PREPARATION EXAMPLE 87 Preparation of Compound (87) Compound (P55) is treated in the same manner as in Preparation Example 8 to obtain an acid chloride of formula (P60): ##STR138## The acid chloride (P60) is reacted with aqueous ammonia to obtain an amide derivative of formula (P61): ##STR139## which is then dehydrated with thionyl chloride, etc. for cyanogenation to obtain compound (87). Alternatively, compound (P55) is iodinated with iodine-periodic acid to obtain a compound of formula (P62): ##STR140## which is then reacted with cuprous cyanide to obtain compound (87). PREPARATION EXAMPLE 88 Preparation of Compound (88) Compound (88) can be prepared from compound (P57) in the same manner as in Preparation Example 87. PREPARATION EXAMPLE 89 Preparation of Compound (89) Compound (89) can be prepared in the same manner as in Preparation Example 87, except for replacing compound (P55) with compound (P59). Alternatively, compound (59) is reacted with an alkyl lithium to obtain a phenyllithium derivative, which is then reacted with carbon dioxide to obtain a benzoic acid derivative of formula (P64): ##STR141## Compound (P64) is converted to an acid chloride by using thionyl chloride, etc., which is further reacted in the same manner as in Preparation Example 87 to obtain compound (89). PREPARATION EXAMPLE 90 Preparation of Compound (90) Compound (90) can be prepared by reacting a deuterated bicyclohexaneethanal derivative of formula (P65): ##STR142## with a 4-alkyl(or alkoxyl)phenylmagnesium bromide, and subjecting the product to dehydration and then hydrogenation. Compound (P65) can be obtained by deuterating a 4-(4-substituted cyclohexyl)cyclohexanone, reacting the deuterated compound with a Wittig reagent of formula (IV), if desired again deuterating the product, and again reacting the product with the Wittig reagent of formula (IV). PREPARATION EXAMPLE 91 Preparation of Compound (91) Compound (91) can be prepared in the same manner as in Preparation Example 90, except for using 4-fluorophenylmagnesium bromide as a Grignard reagent. PREPARATION EXAMPLE 92 Preparation of Compound (92) Compound (92) can be prepared in the same manner as in Preparation Example 90, except for using a Grignard reagent prepared from 1-bromo-4-chlorobenzene. Alternatively, phenylmagnesium bromide may be used as a Grignard reagent to obtain a compound of formula (P66): ##STR143## which can then be led to compound (92) in the same manner as in Preparation Example 5. PREPARATION EXAMPLE 93 Preparation of Compound (93) Compound (93) can be prepared in the same manner as in Preparation Example 90, except for using a Grignard reagent prepared from 4-bromo-1-trifluoromethoxybenzene. PREPARATION EXAMPLE 94 Preparation of Compound (94) Compound (90) prepared in Preparation Example 90 wherein R 2 is OCH 3 is demethylated in the same manner as in Preparation Example 3 to obtain a phenol derivative of formula (P67): ##STR144## which is then led to compound (94) in the same manner as in Preparation Example 3. PREPARATION EXAMPLE 95 Preparation of Compound (95) Compound (95) can be prepared in the same manner as in Preparation Example 90, except for using a Grignard reagent prepared from 1-bromo-3,4-difluorobenzene. PREPARATION EXAMPLE 96 Preparation of Compound (96) Compound (96) can be prepared in the same manner as in Preparation Example 90, except for using a Grignard reagent prepared from 1-bromo-4-chloro-3-fluorobenzene. Alternatively, a Grignard reagent prepared from 1-bromo-3-fluorobenzene may be used to obtain a compound of formula (P68): ##STR145## which can then be led to compound (96) in the same manner as in Preparation Example 5. PREPARATION EXAMPLE 97 Preparation of Compound (97) Compound (97) can be prepared in the same manner as in Preparation Example 90, except for replacing the 4-alkyl(or alkoxyl)phenylmagnesium bromide with a Grignard reagent prepared from 4-bromo-3-fluoro-1-trifluoromethoxybenzene. PREPARATION EXAMPLE 98 Preparation of Compound (98) A phenol derivative of formula (P69): ##STR146## is prepared in the same manner as in Preparation Example 94, except for replacing 4-methoxyphenylmagnesium bromide with a Grignard reagent prepared from 4-bromo-2-fluoroanisole. Compound (P69) is led to compound (98) in the same manner as in Preparation Example 7. PREPARATION EXAMPLE 99 Preparation of Compound (99) Compound (99) can be prepared in the same manner as in Preparation Example 90, except for replacing the 4-alkyl(or alkoxyl)phenylmagnesium bromide with a Grignard reagent prepared from 1-bromo-3,4,5-trifluorobenzene. PREPARATION EXAMPLE 100 Preparation of Compound (100) Compound (100) can be prepared in the same manner as in Preparation Example 90, except for using a Grignard reagent prepared from 1-bromo-4-chloro-3,5-difluorobenzene. Alternatively, a Grignard reagent prepared from 1-bromo-3,5-difluorobenzene may be used to obtain a compound of formula (P70): ##STR147## which is then chlorinated in the same manner as in Preparation Example 5 to obtain compound (100). PREPARATION EXAMPLE 101 Preparation of Compound (101) Compound (101) can be prepared in the same manner as in Preparation Example 98, except for using 4-bromo-2,6-difluoroanisole, which is an intermediate product of Preparation Example 17. PREPARATION EXAMPLE 102 Preparation of Compound (102) Compound (P66) is treated in the same manner as in Preparation Example 8 to obtain an acid chloride of formula (P71): ##STR148## The acid chloride (P71) is reacted with aqueous ammonia to obtain an amide derivative of formula (P72): ##STR149## which is then dehydrated with thionyl chloride, etc. for cyanogenation to obtain compound (102). Alternatively, the intermediate of formula (P66) is iodinated with iodine-periodic acid to obtain a compound of formula (P73): ##STR150## which is then reacted with cuprous cyanide to obtain compound (102). PREPARATION EXAMPLE 103 Preparation of Compound (103) Compound (103) can be prepared from compound (P68) in the same manner as in Preparation Example 102. PREPARATION EXAMPLE 104 Preparation of Compound (104) Compound (104) can be prepared in the same manner as in Preparation Example 102, except for replacing compound (P66) with compound (P70). Alternatively, compound (P70) is treated in the same manner as in Preparation Example 56 to obtain a benzoic acid derivative of formula (P74): ##STR151## which is then converted to an acid chloride with thionyl chloride, etc., and the acid chloride is treated in the same manner as in Preparation Example 102 to obtain compound (104). PREPARATION EXAMPLES 105 TO 119 Preparation of Compounds (105) to (119) Compounds (105) to (119) can be prepared in the same manner as in Preparation Examples 60 to 74, respectively, except for replacing the intermediate 4-(4-substituted cyclohexyl)cyclohexanone with a corresponding 4-[2-(4-substituted cyclohexyl)ethyl]cyclohexanone of formula (P75): ##STR152## PREPARATION EXAMPLE 120 Preparation of Compound (120) Compound (P10) and 2-methyl-3-butyn-2-ol are reacted in the presence of a catalyst, e.g., palladium chloride, and the reaction product is treated with a base while heating to obtain a phenylacetylene derivative of formula (P76): ##STR153## This compound (P76) is then reacted with a 4-alkyl(or alkoxyl)phenylmagnesium bromide in the presence of a catalyst to obtain compound (120). PREPARATION EXAMPLE 121 Preparation of Compound (121) Compound (121) can be prepared in the same manner as in Preparation Example 120, except for using 4-fluorophenylmagnesium bromide as a Grignard reagent. PREPARATION EXAMPLE 122 Preparation of Compound (122) Compound (122) can be prepared in the same manner as in Preparation Example 120, except for using a Grignard reagent prepared from 1-bromo-4-chlorobenzene. Alternatively, phenylmagnesium bromide may be used as a Grignard reagent to obtain a compound of formula (P77): ##STR154## Compound (P77) is nitrated and reduced to obtain an aniline derivative, which is then diazotized and decomposed in the same manner as in Preparation Example 5 to obtain compound (122). PREPARATION EXAMPLE 123 Preparation of Compound (123) Compound (123) can be prepared in the same manner as in Preparation Example 120, except for using a Grignard reagent prepared from 4- bromo-1-trifluoromethoxybenzene. PREPARATION EXAMPLE 124 Preparation of Compound (124) Compound (120) prepared in Preparation Example 120 wherein R 2 is OCH 3 is demethylated in the same manner as in Preparation Example 3 to obtain a phenol derivative of formula (P78): ##STR155## which is then led to compound (124) in the same manner as in Preparation Example 3. PREPARATION EXAMPLE 125 Preparation of Compound (125) Compound (125) can be prepared in the same manner as in Preparation Example 120, except for using a Grignard reagent prepared from 1-bromo-3,4-difluorobenzene. PREPARATION EXAMPLE 126 Preparation of Compound (126) Compound (126) can be prepared in the same manner as in Preparation Example 120, except for using a Grignard reagent prepared from 1-bromo-4-chloro-3-fluorobenzene. Alternatively, a Grignard reagent prepared from 1-bromo-3-fluorobenzene may be used to obtain a compound of formula (P79): ##STR156## which is then chlorinated in the same manner as in Preparation Example 5 to obtain compound (126). PREPARATION EXAMPLE 127 Preparation of Compound (127) Compound (127) can be prepared in the same manner as in Preparation Example 120, except for replacing the 4-alkyl(or alkoxyl)phenylmagnesium bromide with a Grignard reagent prepared from 4-bromo-2-fluoro-1-trifluoromethoxybenzene. PREPARATION EXAMPLE 128 Preparation of Compound (128) A phenol derivative of formula (P80): ##STR157## is prepared in the same manner as in Preparation Example 124, except for replacing 4-methoxyphenylmagnesium bromide with a Grignard reagent prepared from 4-bromo-2-fluoroanisole. Compound (P80) can be led to compound (128) in the same manner as in Preparation Example 7. PREPARATION EXAMPLE 129 Preparation of Compound (129) Compound (129) can be prepared in the same manner as in Preparation Example 120, except for replacing the 4-alkyl(or alkoxyl)phenylmagnesium bromide with a Grignard reagent prepared from 1-bromo-3,4,5-trifluorobenzene. PREPARATION EXAMPLE 130 Preparation of Compound (130) Compound (130) can be prepared in the same manner as in Preparation Example 120, except for using a Grignard reagent prepared from 1-bromo-4-chloro-3,5-difluorobenzene. Alternatively, a Grignard reagent prepared from 1-bromo-3,5-difluorobenzene may be used to obtain a compound of formula (P81): ##STR158## which is then chlorinated in the same manner as in Preparation Example 5 to obtain compound (130). PREPARATION EXAMPLE 131 Preparation of Compound (131) Compound (131) can be prepared in the same manner as in Preparation Example 128, except for using a Grignard reagent prepared from 4-bromo-2,6-difluoroanisole. PREPARATION EXAMPLE 132 Preparation of Compound (132) Compound (P77) is treated in the same manner as in Preparation Example 8 to obtain an acid chloride of formula (P82): ##STR159## The acid chloride (P82) is reacted with aqueous ammonia to obtain an amide derivative of formula (P83): ##STR160## which is then dehydrated with thionyl chloride, etc. for cyanogenation to obtain compound (132). PREPARATION EXAMPLE 133 Preparation of Compound (133) Compound (133) can be prepared from compound (P79) in the same manner as in Preparation Example 132. PREPARATION EXAMPLE 134 Preparation of Compound (134) Compound (134) can be prepared in the same manner as in Preparation Example 132, except for replacing compound (P77) with compound (P81). Alternatively, compound (P81) is treated in the same manner as in Preparation Example 57 to obtain a benzoic acid derivative of formula (P84): ##STR161## which is then led to compound (134) in the same manner as in Preparation Example 57. PREPARATION EXAMPLE 135 Preparation of Compound (135) (a) Compound (P10) and a 4-alkyl(or alkoxyl)phenylmagnesium bromide are reacted in the presence of a palladium or nickel catalyst to obtain compound (135). (b) Compound (P32) and a 4-alkyl(or alkoxyl)phenylmagnesium bromide are reacted, followed by dehydration to obtain a cyclohexene derivative of formula (P85): ##STR162## Compound (P85) is oxidatively dehydrogenated using chloranil, dichlorodicyanobenzoquinone (hereinafter abbreviated as DDQ), etc. to obtain compound (135). (c) Compound (135) can also be prepared in accordance with process A to J, except for using a Grignard reagent prepared from a 4'-bromo-4-alkyl(or alkoxyl)biphenyl of formula (P86): ##STR163## Compound (P86) used here can be obtained by direct bromination of a 4-alkyl(or alkoxyl)biphenyl or by reacting a 4-alkyl(or alkoxyl)phenylmagnesium bromide with 4-bromo-1-iodobenzene in the presence of a palladium or nickel catalyst. PREPARATION EXAMPLE 136 Preparation of Compound (136) Compound (136) can be prepared in the same manner as in Preparation Example 135-(a) or (b), except for using 4-fluorophenylmagnesium bromide as a Grignard reagent. It can also be prepared in the same manner as in Preparation Example 135-(c), except for using the above Grignard reagent and 4-bromo-4'-fluorobiphenyl prepared from 4-bromo-1-iodobenzene. PREPARATION EXAMPLE 137 Preparation of Compound (137) Compound (137) can be prepared in the same manner as in Preparation Example 135-(a) or (b), except for using a Grignard reagent prepared from 1-bromo-4-chlorobenzene. Alternatively, a compound of formula (P87): ##STR164## is once prepared in the same manner as in Preparation Example 135-(a) or (b) except for using phenylmagnesium bromide, or in the same manner as in Preparation Example 135(c) except for starting with 4-bromobiphenyl. Compound (P87) is nitrated and reduced to obtain an aniline derivative, which is then diazotized and decomposed to obtain compound (137) in the same manner as in Preparation Example 5. PREPARATION EXAMPLE 138 Preparation of Compound (138) Compound (138) can be prepared in the same manner as in Preparation Example 135-(a) or (b), except for using a Grignard reagent prepared from 4-bromo-1-trifluoromethoxybenzene. It can also be prepared in the same manner as in Preparation Example 135-(c), except for using the above Grignard reagent and 4'-bromo-4-trifluoromethoxybiphenyl prepared from 4-bromo-1-iodobenzene. PREPARATION EXAMPLE 139 Preparation of Compound (139) Compound (135) prepared in Preparation Example 135 wherein R 2 is OCH 3 is demethylated in the same manner as in Preparation Example 3 to obtain a bisphenol derivative of formula (P88): ##STR165## which is then led to compound (139) in the same manner as in Preparation Example 3. PREPARATION EXAMPLE 140 Preparation of Compound (140) Compound (140) can be prepared in the same manner as in Preparation Example 135-(a) or (b), except for using a Grignard reagent prepared from 1-bromo-3,4-difluorobenzene. It can also be prepared in the same manner as in Preparation Example 135-(c), except for using the above Grignard reagent and 4-bromo-3',4'-difluorobiphenyl prepared from 4-bromo-1-iodobenzene. PREPARATION EXAMPLE 141 Preparation of Compound (141) Compound (141) can be prepared in the same manner as in Preparation Example 135-(a) or (b), except for using a Grignard reagent prepared from 1-bromo-4-chloro-3-fluorobenzene. Alternatively, a compound of formula (P89): ##STR166## is once prepared in the same manner as in Preparation Example 135-(a) or (b) except for using 1-bromo-3-fluorobenzene, and compound (P89) is then chlorinated in the same manner as in Preparation Example 5 to obtain compound (141). Compound (P89) can also be obtained from 4-bromo-3'-fluorobiphenyl according to Preparation Example 135-(c). PREPARATION EXAMPLE 142 Preparation of Compound (142) Compound (142) can be prepared in the same manner as in Preparation Example 135-(a) or (b), except for replacing the 4-alkyl(or alkoxyl)phenylmagnesium bromide with a Grignard reagent prepared from 4-bromo-2-fluoro-1-trifluoromethoxybenzene. It can also be prepared in the same manner as in Preparation Example 135-(c), except for using the above Grignard reagent and 4'-bromo-3-fluoro-4-trifluoromethoxybiphenyl prepared from 4-bromo-1-iodobenzene. PREPARATION EXAMPLE 143 Preparation of Compound (143) An intermediate compound of formula (P90): ##STR167## is prepared in the same manner as in Preparation Example 139-(a) or (b), except for replacing 4-methoxyphenylmagnesium bromide with a Grignard reagent prepared from 4-bromo-2-fluoroanisole, and compound (P90) is then led to compound (143) in the same manner as in Preparation Example 7. Compound (90) may also be obtained by reacting the above Grignard reagent with 4'-bromo-3-fluoro-4-methoxybiphenyl prepared from 4-bromo-1-iodobenzene, followed by demethylation in accordance with Preparation Example 135-(c). PREPARATION EXAMPLE 144 Preparation of Compound (144) Compound (144) can be prepared in the same manner as in Preparation Example 135-(a) or (b), except for replacing the 4-alkyl(or alkoxyl)phenylmagnesium with a Grignard reagent prepared from 1-bromo-3,4,5-trifluorobenzene. It can also be prepared in the same manner as in Preparation Example 135-(c), except for using the above Grignard reagent and 4'-bromo-3,4,5-trifluorobiphenyl prepared from 4-bromo-1-iodobenzene. PREPARATION EXAMPLE 145 Preparation of Compound (145) Compound (145) can be prepared in the same manner as in Preparation Example 135-(a) or (b), except for using a Grignard reagent prepared from 1-bromo-4-chloro-3,5-difluorobenzene. It can also be prepared in the same manner as in Preparation Example 135-(c), except for using the above Grignard reagent and 4'-bromo-4-chloro-3,5-difluorobiphenyl prepared from 4-bromo-1-iodobenzene. Alternatively, compound (145) can be prepared by obtaining a compound of formula (P91): ##STR168## in the same manner as in (a) or (b) except for using a Grignard reagent prepared from 1-bromo-3,5-difluorobenzene, and then chlorinating compound (P91) in the same manner as in Preparation Example 5. Compound (P91) may be prepared by using the above Grignard reagent and 4-bromo-3',5'-difluorobiphenyl prepared from 4-bromo-1-iodobenzene in accordance with (c). PREPARATION EXAMPLE 146 Preparation of Compound (146) Compound (146) can be prepared in the same manner as in Preparation Example 143-(a) or (b), except for using a Grignard reagent prepared from 4-bromo-2,6-difluoroanisole, the intermediate compound of Preparation Example 17. PREPARATION EXAMPLE 147 Preparation of Compound (147) Compound (P87) is treated in the same manner as in Preparation Example 8 to obtain an acid chloride of formula (P92): ##STR169## The acid chloride (P92) is reacted with aqueous ammonia to obtain an amido derivative of formula (P93): ##STR170## which is then dehydrated with thionyl chloride, etc. for cyanogenation to obtain compound (147). PREPARATION EXAMPLE 148 Preparation of Compound (148) Compound (148) can be prepared in the same manner as in Preparation Example 147, except for starting with compound (P89). PREPARATION EXAMPLE 149 Preparation of Compound (149) Compound (149) can be prepared in the same manner as in Preparation Example 147, except for replacing compound (P87) with compound (P91). Alternatively, compound (P91) is treated in the same manner as in Preparation Example 57 to obtain a benzoic acid derivative of formula (P94): ##STR171## which is then led to compound (149) in the same manner as in Preparation Example 57. PREPARATION EXAMPLE 150 Preparation of Compound (150) Compound (150) can be prepared in the same manner as in Preparation Example 120, except for replacing compound (P10) with compound (P24). PREPARATION EXAMPLES 151 TO 164 Preparation of Compounds (151) to (164) Compounds (151) to (164) can be prepared in the same manner as in Preparation Examples 121 to 134, respectively, except for replacing compound (P10) with corresponding compound (P24). PREPARATION EXAMPLE 165 Preparation of Compound (165) Compound (165) can be prepared in the same manner as in Preparation Example 135-(a), except for replacing compound (P10) with compound (P24). It can also be prepared in the same manner as in Preparation Example 135-(b), except for replacing compound (P32) with a compound of formula (P95): ##STR172## which is obtained by hydrogenation of compound (P17). PREPARATION EXAMPLES 166 TO 179 Preparation of Compounds (166) to (179) Compounds (166) to (179) can be prepared in the same manner as in Preparation Examples 136 to 149, respectively, except for replacing compound (P10) with corresponding compound (P24) or replacing compound (P32) with corresponding compound (P95). PREPARATION EXAMPLE 180 Preparation of Compound (180) Compound (180) can be prepared in the same manner as in Preparation Example 120, except for replacing compound (P10) with a compound of formula (P96): ##STR173## Compound (P96) is obtained either by direct iodination of compound (P5) with iodine-periodic acid or by nitrating compound (P5) followed by reduction to prepare an aniline derivative of formula (P97): ##STR174## and decomposing its diazonium salt with potassium iodide, etc. PREPARATION EXAMPLES 181 TO 194 Preparation of Compounds (181) to (194) Compounds (181) to (194) can be prepared in the same manner as in Preparation Examples 121 to 134, respectively, except for replacing compound (P10) with corresponding compound (P96). PREPARATION EXAMPLE 195 Preparation of Compound (195) Compound (195) can be prepared in the same manner as in Preparation Example 135, except for replacing compound (P10) with compound (P96). PREPARATION EXAMPLES 196 TO 209 Preparation of Compounds (196) to (209) Compounds (196) to (209) can be prepared in the same manner as in Preparation Examples 136 to 149, respectively, except for replacing compound (P10) with compound (P96). PREPARATION EXAMPLE 210 Preparation of Compound (210) Compound (210) can be prepared in the same manner as in Preparation Example 120, except for replacing compound (P10) with a compound of formula (P98): ##STR175## Compound (P98) is obtained either by direct iodination of compound (P18) with iodine-periodic acid or by nitrating compound (P18) followed by reduction to prepare an aniline derivative of formula (P99): ##STR176## and decomposing its diazonium salt with copper iodide, etc. PREPARATION EXAMPLES 211 TO 224 Preparation of Compounds (211) to (224) Compounds (211) to (224) can be prepared in the same manner as in Preparation Examples 121 to 134, respectively, except for replacing compound (P10) with corresponding compound (P98) PREPARATION EXAMPLE 225 Preparation of Compound (225) Compound (225) can be prepared in the same manner as in Example 135-(a), except for replacing compound (P10) with compound (P98). PREPARATION EXAMPLES 226 TO 239 Preparation of Compounds (226) to (239) Compounds (226) to (239) can be prepared in the same manner as in Preparation Examples 136 to 149, respectively, except for replacing compound (P10) with corresponding compound (P98). PREPARATION EXAMPLE 240 Preparation of Compound (240) Compound (P32) is reacted with a Wittig reagent of formula (IV), and the product is isomerized to a trans-form in the presence of a base to obtain a bicyclohexanecarbaldehyde derivative of formula (P100): ##STR177## Compound (P100) is oxidized and then reacted thionyl chloride to obtain an acid chloride of formula (P101): ##STR178## Compound (P101) is then reacted with a 4-alkyl(or alkoxyl)phenol of formula (P102): ##STR179## in the presence of a base to obtain compound (240. PREPARATION EXAMPLE 241 Preparation of Compound (241) Compound (241) can be prepared in the same manner as in Preparation Example 240, except for replacing compound (P102) with 4-fluorophenol. PREPARATION EXAMPLE 242 Preparation of Compound (242) Compound (242) can be prepared in the same manner as in Preparation Example 240, except for replacing compound (P102) with 4-chlorophenol. PREPARATION EXAMPLE 243 Preparation of Compound (243) Compound (243) can be prepared in the same manner as in Preparation Example 240, except for replacing compound (P102) with 4-trifluoromethoxyphenol. The 4-trifluoromethoxyphenol can be obtained by acetylating 4-trifluoromethoxybenzene with acetyl chloride in the presence of a Lewis acid, e.g., aluminum chloride, oxidizing the acetylated compound with hydrogen peroxide in formic acid, followed by hydrolysis. 4-Trifluoromethoxyphenol may be prepared by reacting a Grignard reagent prepared from 4-bromo-1-trifluoromethoxybenzene with t-butyl hydroperoxide or reacting the Grignard reagent with boric acid and oxidizing the ester with hydrogen peroxide in a basic condition. It is also obtainable by nitrating (trifluoromethoxy)benzene, reducing the product to 4-trifluoromethoxyaniline, converting it to a diazonium salt, and decomposing the diazonium salt in sulfuric acid. PREPARATION EXAMPLE 244 Preparation of Compound (244) Compound (244) can be prepared in the same manner as in Preparation Example 240, except for replacing compound (P102) with 4-difluoromethoxyphenol. The 4-difluoromethoxyphenol can be obtained by converting hydroquinone monobenzyl ether to a formic ester, fluorinating the ester with DAST, and reductively debenzylating the product. It may also be obtained by nitrating(difluoromethoxy)benzene, reducing the nitro-compound to 4-difluoromethoxyaniline, converting it to a diazonium salt, and decomposing the diazonium salt in sulfuric acid. It is also obtainable by converting 4-bromophenol to a formic ester, fluorinating the ester with DAST to obtain 4-bromo-1-difluoromethoxybenzene, preparing a Grignard reagent therefrom, and reacting the Grignard reagent with t-butyl hydroperoxide, or reacting the Grignard reagent with boric acid and oxidizing the boric ester with hydrogen peroxide in a basic condition. PREPARATION EXAMPLE 245 Preparation of Compound (245) Compound (245) can be prepared in the same manner as in Preparation Example 240, except for replacing compound (P102) with 3,4-difluorophenol. PREPARATION EXAMPLE 246 Preparation of Compound (246) Compound (246) can be prepared in the same manner as in Preparation Example 240, except for replacing compound (P102) with 3-fluoro-4-chlorophenol. PREPARATION EXAMPLE 247 Preparation of Compound (247) Compound (247) can be prepared in the same manner as in Preparation Example 243, except for replacing 4-trifluoromethoxyphenol with 3-fluoro-4-trifluoromethoxyphenol. The 3-fluoro-4-trifluoromethoxyphenol can be obtained by acetylating 3-fluoro-4-trifluoromethoxybenzene with acetyl chloride in the presence of a Lewis acid, e.g., aluminum chloride, oxidizing the acetylated compound with hydrogen peroxide in formic acid, followed by hydrolysis. It can also be obtained by reacting a Grignard reagent prepared from 4-bromo-1-trifluoromethoxybenzene with t-butyl hydroperoxide or reacting the Grignard reagent with boric acid, and oxidizing the boric ester with hydrogen peroxide in a basic condition. It is also obtainable by nitrating 3-fluoro-4-trifluoromethoxyphenol or 3-fluoro-4-trifluoromethoxybenzene, reducing the nitro-compound to 4-trifluoromethoxybenzene, reducing the nitro-compound to 4-trifluoromethoxyaniline, converting it to a diazonium salt, and decomposing the diazonium salt in sulfuric acid. PREPARATION EXAMPLE 248 Preparation of Compound (248) Compound (248) can be prepared in the same manner as in Preparation Example 244, except for replacing 4-difluoromethoxyphenol with 3-fluoro-4-difluoromethoxyphenol. The 3-fluoro-4-difluoromethoxyphenol can be prepared by converting 2-fluoro-4-benzyloxyphenol to a formic ester, fluorinating the ester with DAST, and reductively debenzylating the product. It may also be obtained by nitrating 3-fluoro-4-difluoromethoxybenzene, reducing the product to 3-fluoro-4-trifluoromethoxyaniline, converting it to a diazonium salt, and decomposing the diazonium salt in sulfuric acid. It is also obtainable by brominating 3-fluoro-4-difluoromethoxybenzene, preparing a Grignard reagent from the resulting 4-bromo-2-fluoro-1-difluoromethoxybenzene, reacting the Grignard reagent with t-butyl hydroperoxide or reacting the Grignard reagent with boric acid, and oxidizing the boric ester with hydrogen peroxide under a basic condition. PREPARATION EXAMPLE 249 Preparation of Compound (249) Compound (249) can be prepared in the same manner as in Preparation Example 240, except for replacing compound (P102) with 2,4,5-trifluorophenol. The 3,4,5-trifluorophenol can be prepared by decomposition of a diazonium salt of 3,4,5-trifluoroaniline in sulfuric acid. It is also obtained by reacting a Grignard reagent prepared from 1-bromo-3,4,5-trifluorobenzene with t-butyl peroxide or converting the same Grignard reagent to a boric ester, and oxidizing the ester with hydrogen peroxide under a basic condition. PREPARATION EXAMPLE 250 Preparation of Compound (250) Compound (250) can be prepared in the same manner as in Preparation Example 240, except for replacing compound (P102) with 4-chloro-3,5-difluorophenol. The 4-chloro-3,5-difluorophenol can be prepared by reacting a Grignard reagent prepared from 1-bromo-4-chloro-3,5-difluorobenzene with t-butyl hydroperoxide or converting the same Grignard reagent to a boric ester, and oxidizing the product with hydrogen peroxide under a basic condition. It is also prepared by nitrating 2-chloro-1,3-difluorobenzene (obtainable by decomposing a diazonium salt of 2,6-difluoroaniline in the presence of cuprous chloride or in hydrochloric acid), reducing the nitro-compound to obtain 4-chloro-3,5-difluoroaniline, and decomposing its diazonium salt in sulfuric acid. PREPARATION EXAMPLE 251 Preparation of Compound (251) Compound (251) can be prepared in the same manner as in Preparation Example 248, except for replacing 3-fluoro-4-difluoromethoxyphenol with 3,5-difluoro-4-difluoromethoxyphenol. The 3,5-difluoro-4-difluoromethoxyphenol can be obtained by converting 2,6-difluorophenol to a formic ester, fluorinating the ester with DAST, brominating the resulting 2,6-difluoro-1-difluoromethoxybenzene, preparing a Grignard reagent from the resulting 4-bromo-2,6-difluoro-1-difluoromethoxybenzene, and reacting the Grignard reagent with t-butyl hydroperoxide or converting the Grignard reagent to a boric ester, and oxidizing the ester with hydrogen peroxide under a basic condition. Alternatively, 3,5-difluoro-4-difluoromethoxyphenol can also be obtained by nitrating 3,5-difluoro-4-difluoromethoxybenzene, reducing the product to 3-fluoro-4-trifluoromethoxyaniline, and decomposing a diazonium salt of the 3-fluoro-4-trifluoromethoxyaniline in sulfuric acid. PREPARATION EXAMPLE 252 Preparation of Compound (252) Compound (252) can be prepared in the same manner as in Preparation Example 240, except for replacing compound (P102) with 4-cyanophenol. PREPARATION EXAMPLE 253 Preparation of Compound (253) Compound (253) can be prepared in the same manner as in Preparation Example 240, except for replacing compound (P102) with 3-fluoro-4-cyanophenol. PREPARATION EXAMPLE 254 Preparation of Compound (254) Compound (254) can be prepared in the same manner as in Preparation Example 240, except for replacing compound (P102) with 3,5-difluoro-4-cyanophenol. The 3,5-difluoro-4-cyanophenol can be obtained by nitrating 2,6-difluoroaniline, diazotizing the resulting 4-nitro-2,6-difluoroaniline, decomposing the diazonium salt in the presence of a cuprous cyanide to obtain 4-nitro-2,6-difluoro-1-cyanobenzene, reducing the product to obtain 4-cyano-3,5-difluoroaniline, and decomposing its diazonium salt in sulfuric acid. PREPARATION EXAMPLE 255 Preparation of Compound (255) Compound (255) can be prepared in the same manner as in Preparation Example 240, except by using an acid chloride of formula (P103): ##STR180## Compound (P103) can be obtained by reacting compound (P51) with a Wittig reagent of formula (IV), isomerizing the product to a trans-form, and, if desired, further deuterating the product. PREPARATION EXAMPLES 256 TO 269 Preparation of Compounds (256) to (269) Compounds (256) to (269) can be prepared in the same manner as in Preparation Examples 241 to 254, respectively, except for using a corresponding compound (P103) as an acid chloride. PREPARATION EXAMPLE 270 Preparation of Compound (270) Compound (270) can be prepared in the same manner as in Preparation Example 240, except for using an acid chloride of formula (P104): ##STR181## Compound (P104) is obtained from a deuterated 4-(4-substituted cyclohexyl)cyclohexanone (obtainable by processes K, N or O) in the same manner as in Preparation Example 255. PREPARATION EXAMPLES 271 TO 284 Preparation of Compounds (271) to (284) Compounds (271) to (284) can be prepared in the same manner as in Preparation Examples 241 to 254, respectively, except for using a corresponding compound (P104) as an acid chloride. PREPARATION EXAMPLE 285 Preparation of Compound (285) Compound (285) can be prepared in the same manner as in Preparation Example 240, except for using an acid chloride of formula (P105): ##STR182## Compound (P105) is obtained from a deuterated cyclohexanone derivative of formula (P106): ##STR183## in accordance with Preparation Example 255. Compound (P106) is obtained by deuterating compound (P75). Compound (P106) is also obtainable by reacting a Grignard reagent of formula (P107): ##STR184## which is prepared from a 4-substituted cyclohexaneethanal by reduction and bromination, with a monoethyleneacetal of deuterated cyclohexane-1,4-dione, followed by dehydration and hydrogenation PREPARATION EXAMPLES 286 TO 299 Preparation of Compounds (286) to (299) Compounds (286) to (299) can be prepared in the same manner as in Preparation Example 241 to 254, respectively, except for using a corresponding acid chloride of formula (P105). PREPARATION EXAMPLE 300 Preparation of Compound (300) Compound (300) can be prepared by reacting a 4-substituted cyclohexanecarboxylic acid chloride of formula (P108): ##STR185## with a 4'-substituted-bicyclohexan-4-ol of formula (P109): ##STR186## in the presence of a basic catalyst. Compound (P109) is obtainable by reducing a deuterated 4-(4-substituted cyclohexyl)cyclohexanone (obtainable by process K, N or O) using lithium aluminum hydride (or a deuterated compound thereof), sodium borohydride, etc. PREPARATION EXAMPLE 301 Preparation of Compound (301) Compound (301) can be prepared in the same manner as in Preparation Example 300, except for replacing compound (P108) with a deuterated 4-substituted-cyclohexanecarboxylic acid chloride of formula (P110): ##STR187## Compound (P110) can be prepared by deuteration of compound (P108). It can also be prepared from a compound of formula (P111): ##STR188## which is obtained by deuteration of a 4-substituted cyclohexanone, in the same manner as in Preparation Example 255. Compound (P111) can be obtained by deuterating cyclohexane-1,4-dione monoethyleneacetal and reacting the deuterated product with a Wittig reagent, followed by hydrogenation and decomposition of the acetal moiety. Alternatively, the deuterated product may be reacted with a Grignard reagent, followed by dehydration, hydrogenation, and decomposition of the acetal moiety. Compound (P111) can also be obtained by deuterating cyclohexane-1,4-dione and then introducing a monoethyleneacetal moiety, which is then treated in the same manner as described above. PREPARATION EXAMPLE 302--PREPARATION OF COMPOUND (302) Compound (302) can be prepared in the same manner as in Preparation Example 300, except for replacing compound (P109) with a compound of formula (P112): ##STR189## Compound (P112) can be obtained by reducing compound (P111) wherein R 1 is an alkyl or alkoxyl group with lithium aluminum hydride (or a deuterated compound thereof), sodium borohydride, etc. PREPARATION EXAMPLE 303--PREPARATION OF COMPOUND (303) Compound (303) can be prepared in the same manner as in Preparation Example 300, except for using compound (P110) and compound (P112). PREPARATION EXAMPLE 304--PREPARATION OF COMPOUND (304) A Grignard reagent prepared from a bromobenzene derivative of formula (P113): ##STR190## is reacted with a fluoroiodobenzene derivative of formula (P96) in the presence of a palladium or nickel catalyst to obtain compound (304). Compound (304) can also be prepared by reacting a Grignard reagent prepared from a compound of formula (P114): ##STR191## with a 4-substituted cyclohexanone, followed by dehydration and hydrogenation. PREPARATION EXAMPLE 305--PREPARATION OF COMPOUND (305) Compound (305) can be prepared in the same manner as in Preparation Example 60, except for replacing the deuterated 4-(4-substituted cyclohexyl)cyclohexanone with a deuterated 4"-substituted-tercyclohexan-4-one of formula (P115): ##STR192## Compound (P115) is obtained by hydrogenating a phenol derivative of formula (P116): ##STR193## and deuterating the resulting 4"-substituted tercyclohexan-4-one. It is also obtained by reacting a Grignard reagent prepared from a brominated bicyclohexane derivative of formula (P117): ##STR194## with deuterated cyclohexane-1,4-dione monoethyleneacetal, followed by dehydration, hydrogenation, and removal of the acetal moiety. PREPARATION EXAMPLES 306 TO 319--PREPARATION OF COMPOUNDS (306) TO (319) Compounds (306) to (319) can be prepared in the same manner as in Preparation Examples 61 to 74, respectively, except for using a corresponding compound (P115). PREPARATION EXAMPLE 320--PREPARATION OF COMPOUND (320) Compound (320) can be prepared in the same manner as in Preparation Example 135, except for replacing compound (P10) with compound (P49). PREPARATION EXAMPLES 321 TO 334--PREPARATION OF COMPOUNDS (321) TO (334) Compounds (321) to (334) can be prepared in the same manner as in Preparation Examples 136 to 149, respectively, except for using a corresponding compound (P49). PREPARATION EXAMPLE 335--PREPARATION OF COMPOUND (335) Compound (335) can be prepared in the same manner as in Preparation Example 135, except for replacing compound (P10) with compound (P40). PREPARATION EXAMPLES 336 TO 349--PREPARATION OF COMPOUNDS (336) TO (349) Compounds (336) to (349) can be prepared in the same manner as in Preparation Examples 136 to 149, respectively, except for using a corresponding compound (P40). PREPARATION EXAMPLE 350--Preparation of Compound (350) Compound (350) can be prepared in the same manner as in Preparation Example 135, except for replacing compound (P10) with compound (P62). PREPARATION EXAMPLES 351 TO 364-- Preparation of Compounds (351) to (364) Compounds (351) to (364) can be prepared in the same manner as in Preparation Examples 136 to 149, respectively, except for using a corresponding compound (P62). As hereinabove illustrated, while the deuterated liquid crystal compounds which can be used in the present invention take on an infinite variety of skeleton structure and substituents, those having one or two saturated hydrocarbon groups substituted with deuterium atom (D) and, as a whole, having 2 to 4 cyclic structures, inclusive of the deuterated saturated hydrocarbon rings, are preferred. Inter alia, compounds represented by formulae (I-A) to (I-L) shown below are preferred. ##STR195## wherein Z 1 represents a straight-chain alkyl group having from 1 to 20 carbon atoms; X 1' , X 2' , and X 3' each represent a hydrogen atom (H) or a deuterium atom (D), provided that at least one of them is a deuterium atom (D); and Y 1 represents a hydrogen atom or a fluorine atom. ##STR196## wherein Z 2' represents a straight-chain alkyl group having from 1 to 20 carbon atoms; X 4' , X 5' , X 6' , and X 7' each represent a hydrogen atom (H) or a deuterium atom (D), provided that at least one of them is a deuterium atom (D); and Y 2' represents a hydrogen atom or a fluorine atom. ##STR197## wherein Z 3' represents an alkyl or alkenyl group having from 1 to 20 carbon atoms; and X 8' , X 9' , X 10' , and X 11' each represent a hydrogen atom (H) or a deuterium atom (D), provided that at least one of them is a deuterium atom (D). ##STR198## wherein Z 4' represents a straight-chain alkyl group having from 1 to 20 carbon atoms; and X 12' , X 13' , and X 14' each represent a hydrogen atom (H) or a deuterium atom (D), provided that at least one of them is a deuterium atom (D). ##STR199## wherein Z 5' represents an alkyl group having from 1 to 20 carbon atoms; and X 15' , X 16' , X 17' , and X 18' each represent a hydrogen atom (H) or a deuterium atom (D), provided that at least one of them is a deuterium atom (D). ##STR200## wherein Z 6' represents a straight-chain alkyl or alkenyl group having from 1 to 20 carbon atoms; and X 19' , X 20' , X 21' , and X 22' each represent a hydrogen atom (H) or a deuterium atom (D), provided that at least one of them is a deuterium atom (D). ##STR201## wherein Z 7' represents an alkyl or alkenyl group having from 1 to 20 carbon atoms; Z 8' represents an alkyl group having from 1 to 20 carbon atoms; and X 23' , X 24' , X 25' , and X 26' each represent a hydrogen atom (H) or a deuterium atom (D), provided that at least one of them is a deuterium atom (D). ##STR202## wherein Z 9' represents an alkyl group having from 1 to 20 carbon atoms; Z 10' represents an alkyl group having from 1 to 20 carbon atoms; and X 27' , X 28' , and X 29' each represent a hydrogen atom (H) or a deuterium atom (D), provided that at least one of them is a deuterium atom (D). ##STR203## wherein Z 11' represents an alkyl group having from 1 to 20 carbon atoms or Z 12' --O--(CH 2 ) m --, wherein Z 12' represents an alkyl group having from 1 to 10 carbon atoms, and n represents an integer of from 2 to 7; and X 30' , X 31' , and X 32' each represent a hydrogen atom (H) or a deuterium atom (D), provided that at least one of them is a deuterium atom (D). ##STR204## wherein Z 13' represents an alkyl group having from 1 to 20 carbon atoms; and X 33' , X 34' , X 35' , and X 36' each represent a hydrogen atom (H) or a deuterium atom (D), provided that at least one of them is a deuterium atom (D). ##STR205## wherein Z 14' represents an alkenyl group having from 2 to 18 carbon atoms; and X 37' , X 38' , X 39' , and X 40' each represent a hydrogen atom (H) or a deuterium atom (D), provided that at least one of them is a deuterium atom (D). ##STR206## wherein Z 15' represents an alkyl group having from 1 to 15 carbon atoms; and X 41' , X 42' , and X 43' each represent a hydrogen atom (H) or a deuterium atom (D), provided that at least one of them is a deuterium atom (D). Specific examples of the above-described deuterated liquid crystal compounds of formula (I) are shown in Tables 1 to 3 together with their phase transition temperatures. In the Tables, Cr, Sm, N, and I represent a crystal phase, a smectic phase, a nematic phase, and an isotropic liquid phase, respectively. In the column "Phase Transition Temperature", the parentheses indicate that the phase is monotropic, and the numeral between two phases is the transition temperature from the left phase to the right one. For example, "C 42 N 46 I" means that the transition temperature from a crystal phase to a nematic phase is 42° C. and that from a nematic phase to an isotropic liquid phase is 46° C. TABLE 1__________________________________________________________________________ Phase TransitionCompound TemperatureNo. Structural Formula (°C.)__________________________________________________________________________ ##STR207## C42 N46 I2 ##STR208## C40 N45 I3 ##STR209## C9 (N5) I4 ##STR210## C29 (N-24) I5 ##STR211## C37 N30 I6 ##STR212## C-2 (N-30) I7 ##STR213## C10 I8 ##STR214## C19 (N-3) I9 ##STR215## C-11 Sm92 I10 ##STR216## C32 N44 I__________________________________________________________________________ TABLE 2__________________________________________________________________________ Phase TransitionCompound TemperatureNo. Structural Formula (°C.)__________________________________________________________________________11 ##STR217## C52 (N29) I12 ##STR218## C62 N73 I13 ##STR219## C42 N119 I14 ##STR220## C44 N120 I15 ##STR221## C12 Sm49 N118 I16 ##STR222## C41 N122 I17 ##STR223## C99 N193 I18 ##STR224## C64 N94 I19 ##STR225## C67 N91 I20 ##STR226## C41 N98 I__________________________________________________________________________ TABLE 3__________________________________________________________________________ Phase TransitionCompound TemperatureNo. Structural Formula (°C.)__________________________________________________________________________21 ##STR227## C45 Sm71 N153 I22 ##STR228## C49 Sm87 N206 I23 ##STR229## C69 N214 I24 ##STR230## C29 Sm142 N162 I25 ##STR231## C63 N97 I26 ##STR232## C88 N218 I27 ##STR233## C83 N148 I28 ##STR234## C82 N200 I29 ##STR235## C-13 Sm249 N310 I30 ##STR236## C74 N276 I__________________________________________________________________________ Compound with corresponding non-deuterated compounds, the deuterated liquid crystal compounds of formula (I) according to the present invention have approximately equal or slightly lower phase transition temperatures, and they appear to produce no considerable difference. However, because the compounds of formula (I) are extremely superior to the corresponding non-deuterated compounds in compatibility with general-purpose liquid crystal materials, particularly in a low temperature range, they produce such an excellent effect that crystals are hardly crystallized in liquid crystal materials. The following typical example of liquid crystal compositions is to demonstrate the above-described effect. A liquid crystal composition was prepared from 85% by weight of a currently employed, general-purpose mother liquid crystal material having the following composition and 15% by weight of Compound No. 13 in Table 2. Composition of General-Purpose Liquid Crystal Material: ##STR237## This liquid crystal composition was not crystallized even after storage at -20° C. for 1 month. For comparison, a liquid crystal composition was prepared from 85% by weight of the same general-purpose liquid crystal material as used above and 15% by weight of a compound represented by formula: ##STR238## which has the same skeleton as Compound No. 13 but is not deuterated. When this comparative liquid crystal composition was similarly preserved at -20° C., crystallization was observed after 5 days. It is thus understood that the compounds of formula (1) having a deuterated cyclohexane ring exhibit excellent compatibility with a general-purpose liquid crystal material to provide a practically useful liquid crystal material which is hardly crystallized even at a low temperature. Further, addition of the deuterated liquid crystal compound of the present invention to a liquid crystal composition provides a liquid crystal composition which is not crystallized in a low temperature region and also exhibits improved electro-optical characteristics. These effects will be apparent from the following examples. The electro-optical characteristics of liquid crystal compositions were measured as follows unless otherwise specified. A liquid crystal display composed of a pair of electrode-backed substrates, at least one of the substrates being transparent, at a cell gap of 6 μm, and a liquid crystal composition sealed therebetween is prepared for characteristic measurement. A threshold voltage and a response time are measured at 25° C. A response time is the time where the rise time and the decay time become equal, the rise time being the time required from voltage application to occurrence of a change in light transmittance, and the decay time being the time required from power cut-off to restoration of the initial state. .sup.Δ n is a refractive index anisotropy. All the percents of the compositions are by weight. A liquid crystal mixture (a-1) comprising 50% by weight of a compound of formula: ##STR239## and 50% by weight of a compound of formula: ##STR240## has the following characteristics: T N-I Point: 117° C. T C-N Point: 11° C. Threshold Voltage: 2.14 V .sup.Δ ε: 4.8 .sup.Δ n: 0.090 Response Time: 25 msec Since the above compounds constituting liquid crystal mixture (a-1) have a relatively high voltage holding ratio, they are widely used as liquid crystal material particularly for active matrix driving. A liquid crystal composition (b) for active matrix driving having the following composition was prepared from 70% of liquid crystal mixture (a-1) and 30% of a non-deuterated liquid crystal compound for active matrix driving. Composition of Liquid Crystal Composition (b): ##STR241## Liquid crystal composition (b) had the following characteristics. T N-I Point: 111° C. Threshold Voltage: 1.83 V .sup.Δ ε: 7.0 .sup.Δ n: 0.087 Response Time: 30 msec A liquid crystal composition (B) was also prepared from 70% of liquid crystal mixture (a-1) and 30% of Compound No. 18 in Table 2. Composition of Liquid Crystal Composition (B): ##STR242## Liquid crystal composition (B) had the following characteristics. T N-I Point: 110° C. Threshold Voltage: 1.81 V .sup.Δ ε: 7.0 .sup.Δ n: 0.087 Response Time: 28 msec It is obvious from these results that liquid crystal composition (B) has a lower threshold voltage and a shorter response time. Further, when each of liquid crystal mixture (a-1), liquid crystal composition (b), and liquid crystal composition (B) was preserved at +10° C., the former two compositions are crystallized after 3 days, while composition (B) showed no crystallization even after 1 month's storage. It is now understood that the liquid crystal composition according to the present invention has improved electro-optical characteristics and is not crystallized even in a low temperature region. Further, a liquid crystal composition (p) having the following composition was prepared using compounds generally used for an STN mode. Composition of Liquid Crystal Composition (p): ##STR243## Liquid crystal composition (p) had the following characteristics. T N-I Point: 84° C. Threshold Voltage: 1.60 V .sup.Δ ε: 9.9 .sup.Δ n: 0.099 K 33 /K 11 : 2.3 A liquid crystal composition (P) was also prepared in the same manner, except for replacing the three bicyclic compounds having a cyano group with those which have the same structure but have their cyclohexane ring deuterated. Composition of Liquid Crystal Composition (P): ##STR244## Liquid crystal composition (P) had the following characteristics. T N-I Point: 84° C. Threshold Voltage: 1.59 V .sup.Δ ε: 9.9 .sup.Δ n: 0.099 K 33 /K 11 : 2.4 It is obvious that liquid crystal composition (P) has a lower threshold voltage and a higher K 33 /K 11 value. When each of liquid crystal compositions (p) and (P) was preserved at 0° C., composition (p) was crystallized after 1 day's storage, while it was after 14 days' storage that composition (P) showed crystallization. It is now understood that the liquid crystal composition according to the present invention has improved electro-optical characteristics and is hardly crystallized even in a low temperature region. As can be seen from the above-described processes for preparing the compounds (I) and Tables 1 to 3, the compounds of the present invention take on an infinite variety in the number or position of deuterium atoms (D) or steric configuration, while the skeleton being equal. For example, where Compound No. 18, which is useful for active matrix driving, is prepared in accordance with process J, there are obtained 8 analogues different in degree of deuteration as shown below. ##STR245## Where process C is followed, there would be obtained 9 analogues shown below. ##STR246## Thus, only two processes provide as many analogues as 17. Application of other processes will further increase the number of analogues obtained. While incorporation of only one of the deuterated liquid crystal compounds of the present invention into a liquid crystal composition suffices to produce the above-mentioned effects, a liquid crystal composition containing two or more analogues prepared through the above-described various processes is particularly preferred because the effect of preventing crystallization in a low temperature region is pronouncedly manifested. An increase in number of analogues combined shows no tendency to deterioration of electro-optical characteristic. Therefore, liquid crystal displays using the liquid crystal composition of the present invention exhibit satisfactory driving characteristics even at an extremely low temperature at which conventional displays could not serve. The effects of the composition containing two or more analogues of the deuterated liquid crystal compounds will be demonstrated below. A comparative liquid crystal composition (a-2) containing conventional compounds for active matrix driving and a liquid crystal composition (A) containing several analogues of the deuterated compounds having the similar structures to the conventional compounds were prepared. Composition of Liquid Crystal Composition (a-2): ##STR247## Composition of Liquid Crystal Composition (A): ##STR248## The electro-optical characteristics of liquid crystal compositions (A) and (a-2) were as follows. ______________________________________ (A) (a-2)______________________________________T.sub.N--I Point 117° C. 119° C.Threshold Voltage 1.91 V 1.96 VΔg 5.5 5.5Δn 0.086 0.086Response Time 28 msec 33 msec______________________________________ It is apparent that composition (A) according to the present invention has a lower threshold voltage and a shorter response time. In storage at +10° C., composition (A) of the present invention was not crystallized even after 1 month's storage, whereas composition (a-2) did after only 1 day. Other various liquid crystal compositions of the present invention containing the deuterated liquid crystal compounds similarly exhibit improved electro-optical characteristics and the effect of preventing crystallization in low temperatures, as will be demonstrated in Examples hereinafter given. Further, the present invention provides such a liquid crystal composition that is not crystallized even in storage for 3 months or longer at -55° C., at which it has been said any known liquid crystal composition for active matrix driving necessarily is crystallized. A liquid crystal composition (M) having the following composition and characteristics affords a typical example. Composition of Liquid Crystal Composition (M): ##STR249## T N-I Point: 112° C. T C-N Point: -70° C. Threshold Voltage: 1.9 V .sup.Δ ε: 5.5 .sup.Δ n: 0.086 Response Time: 24 msec Voltage Holding Ratio: 99% (/100° C.) A liquid crystal display prepared by using liquid crystal composition (M) exhibits satisfactory driving characteristics even in a low temperature region. Therefore, the liquid crystal composition of the present invention provides an epoch-making liquid crystal display that serves in a low temperature region in which conventional liquid crystal displays for active matrix driving could never be used. Such a liquid crystal display is extremely useful as a component of equipment which is demanded to be stably operated even in low temperatures, such as equipment installed in the automobile console box or the cockpit of aircraft. In order for a liquid crystal display for active matrix driving to be general-purpose for office automation (OA) equipment, it is keenly demanded that the liquid crystal composition to be used should have a threshold voltage of not more than 1.2 V. However, as previously stated, a liquid crystal composition designed to meet this demand involves a tendency toward crystallization. In application to OA equipment, a liquid crystal composition which is not crystallized at -25° C. for at least 1 month is generally regarded to be practical, but such a composition that has a threshold voltage of not more than 1.2 V and a T N-I point of not lower than 85° C. and yet is not crystallized at -25° C. for 1 month or longer has not yet been developed. For example, a liquid crystal composition (n) having the following composition affords an example of a conventional composition having a low threshold voltage. Composition of Liquid Crystal Composition (n): ##STR250## The characteristics of liquid crystal composition (n) were as follows. The measurement was made using a liquid crystal cell with a cell gap of 4.5 μm. T N-I Point: 87° C. Threshold Voltage: 1.15 V .sup.Δ ε: 9.1 .sup.Δ n: 0.080 Response Time: 38 msec Composition (n), while having a low threshold voltage and a high T N-I point, was crystallized in storage at 0° C. for 1 day or longer and therefore proved impractical. To the contrary, a liquid crystal composition (N) containing the deuterated liquid crystal compounds was prepared. Composition of Liquid Crystal Composition (N): ##STR251## The electro-optical characteristics of composition (N) as measured in the same manner as for composition (n) were as follows. T N-I Point: 86° C. T C-N Point: -30° C. Threshold Voltage: 1.10 V .sup.Δ ε: 9.2 .sup.Δ n: 0.080 Response Time; 33 msec Voltage Holding Ratio: 98.5% (/100° C.) It is seen that composition (N) has a high T N-I point and a threshold voltage of 1.2 V or lower, and a short response time. When composition (N) was preserved at -25° C. for 1 months or longer, it was not crystallized. A liquid crystal display for TFT driving prepared by using composition (N) shows satisfactory driving characteristics even in a low temperature region. It has thus been proved that the liquid crystal compositions of the present invention exhibit improved electro-optical characteristics and also are not crystallized in a low temperature region. A liquid crystal composition (t) having the following composition is offered as an example of a liquid crystal composition containing the above-mentioned bicyclic compounds having a cyano group which are useful in STN liquid crystal displays. Composition of Liquid Crystal Composition (t): ##STR252## The characteristics of liquid crystal composition (t) are shown below. T N-I Point: 83° C. Threshold Voltage: 1.12 V .sup.Δ ε: 17 .sup.Δ n: 0.116 K 33 /K 11 : 2.5 Composition (t) is an excellent liquid crystal composition for STN mode with which low power driving and high contrast display can be achieved as seen from its low threshold voltage and large K 33 /K 11 value. Composition (t) is also excellent in scarcely involving such problems as an increase of electric current value. Nevertheless, this composition is crystallized in storage at -25° C. for 5 days. The problem of crystallization can be solved by a liquid crystal composition (T) having the following composition and characteristics. Composition of Liquid Crystal Composition (T): ##STR253## T N-I Point: 82° C. Threshold Voltage: 1.10 V .sup.Δ ε: 17 .sup.Δ n: 0.116 K 33 /K 11 : 2.5 Contrast: Satisfactory It is seen that composition (T) has a lower threshold voltage than composition (t). An STN display having a twisted angle of 260° which is prepared by using composition (T) exhibits satisfactory driving characteristics even in a low temperature region. Further, composition (T) is not crystallized even in storage at -40° C. for 3 months or longer, which is a great advantage for practical use. Thus, the liquid crystal compositions according to the present invention bring about the happiest solution to the problem of crystallization in low temperatures and are expected to be useful in a low-temperature environment where a conventional display has been of no practical use. As a matter of course, the liquid crystal display of the present invention is useful for an ordinary TN mode as well as for an active matrix driving system and an STN mode. The liquid crystal compositions according to the present invention comprises at least one deuterated liquid crystal compound having, as a partial structure, a saturated hydrocarbon ring with its one or more hydrogen atoms (H) substituted with deuterium atoms (D). The liquid crystal compositions of the present invention preferably contains a liquid crystal compound having one or more deuterated cyclohexane rings. More preferred are those containing a deuterated liquid crystal compound having 2 to 4 cyclic structures per molecule, one or two of which are deuterated cyclohexane rings. A total content of the deuterated liquid crystal compounds in the liquid crystal composition of the present invention is preferably from 5 to 100% by weight, still preferably from 30 to 90% by weight. As will be demonstrated in Examples hereinafter described, the liquid crystal composition for active matrix driving preferably has a dielectric anisotropy (.sup.Δ ε) of from +3 to +12 as a whole, and that for TN and STN modes preferably comprises the deuterated liquid crystal compound having a .sup.Δ ε of not less than +8. The present invention will now be illustrated in greater detail with reference to Examples, but it should be understood that the present invention is not construed as being limited thereto. In Examples, the structure of deuterated compounds were confirmed by comparing with known non-deuterated compounds having the same retention time or the same Rf value in capillary gas chromatography and thin layer chromatography, taking the nuclear magnetic resonance spectrum (NMR), mass spectrum (MS), and infrared absorption spectrum (IR) as factors for comparison. The degree of deuteration was determined with JNM-GSX400 (400 MHz; 1 H), manufactured by JEOL Ltd. All the percents and ratios are given by weight unless otherwise indicated. EXAMPLE 1 Synthesis of 1-Cyano-4-(trans-4-propylcyclohexyl-2, 2,6-d 3 )benzene ##STR254## (1-a) Deuteration of 4-propylcyclohexane: In 100 ml of heavy water (degree of deuteration: 99.8%) was dissolved 11.5 g of sodium methoxide. To the solution was added a solution of 88.9 g of 4-propylcyclohexanone and 1.0 g of tetrabutylammonium bromide in 100 ml of dichloromethane, and the mixture was stirred at the refluxing temperature of the solvent for 6 hours. After completion of the reaction, the reaction mixture was allowed to cool to room temperature, and the aqueous layer was separated and extracted with 50 ml of dichloromethane. The extract and the above separated organic layer were combined and added to 50 ml of heavy water (degree of deuteration: 99.96%) having dissolved therein 4.0 g of sodium methoxide. The mixture was stirred at the refluxing temperature of the solvent for 10 hours. The organic layer was separated, and the aqueous layer was extracted with dichloromethane. The extract and the organic layer were combined, washed with water, and dried over anhydrous sodium sulfate. The solvent was removed by distillation to obtain 88.6 g of 4-propylcyclohexanone-2,2,6,6-d 4 . (1-b) Synthesis of 1-phenyl-4-propyl-1-cyclohexene-2,6,6-d 3 : In 20 ml of dried tetrahydrofuran (THF) was added 10.2 g of magnesium shavings, and a solution of 56.0 g of bromobenzene in 240 ml of THF was added thereto dropwise at such a rate that mild refluxing might continue. After the addition, the mixture was stirred for 1 hour. To the mixture was added dropwise a solution of 33.0 g of 4-propylcyclohexanone-2, 2,6,6-d 4 prepared in (1-a) in 100 ml of THF over a period of 1 hour while cooling with ice with care so that the inner temperature might not exceed 40° C. After stirring at room temperature for 1 hour, dilute hydrochloric acid was added thereto until the aqueous layer became weakly acidic. The reaction product was extracted with two 300 ml portions of ethyl acetate, and the organic layer was washed with a saturated sodium chloride aqueous solution, and dried over anhydrous sodium sulfate. The solvent was removed by distillation under reduced pressure to obtain crude 1-phenyl-4-propyl-1-cyclohexanol-2, 2,6,6-d 4 as an oily substance. The whole portion of the crude product was dissolved in 200 ml of toluene, and 2.5 g of potassium bisulfate was added thereto. The mixture was heated under reflux with stirring for 1 hour while removing water as a distillate. After allowing to cool to room temperature, the reaction mixture was washed successively with water, saturated aqueous solution of sodium bicarbonate, water, and saturated aqueous solution of sodium chloride, and dried over anhydrous sodium sulfate. Removal of the solvent by distillation under reduced pressure gave 47.5 g of 1-phenyl-4-propyl-1-cyclohexene-2,6,6-d 3 . (1-c) Synthesis of (trans-4-propylcyclohexyl-2,2,6-d 4 )benzene: In an autoclave was put 40.0 g of the 1-phenyl-4-propyl-1-cyclohexene-2, 6,6-d 3 obtained in (1-b), and 340 ml of ethyl acetate was added thereto to dissolve. To the solution was added 4.0 g of palladium-on-carbon, and the mixture was stirred at room temperature under a hydrogen pressure of 4 kg/cm 2 for 3 hours. The reaction mixture was filtered using Celite to remove the catalyst, and the solvent was removed by distillation under reduced pressure to obtain a cis/trans mixture of (4-propylcyclohexyl-2,2,6-d 3 )benzene. The isomeric mixture was dissolved in 200 ml of N,N-dimethylformamide (DMF), and 17.0 g of potassium t-butoxide was added thereto, followed by stirring at 110° C. for 3 hours. After completion of the reaction, 100 ml of water was added thereto, the mixture was neutralized with dilute hydrochloric acid and the product was extracted twice with hexane. The hexane layer was washed with water and dried over anhydrous sodium sulfate. The solvent was removed by distillation under reduced pressure, and the resulting crude product was purified by silica gel column chromatography using hexane as an eluent to obtain 34.2 g of a 86/14 isomeric mixture of (trans-4-propylcyclohexyl-2,2,6-d 3 )benzene and (cis-4-propylcyclohexyl-2,2,6-d 3 ) benzene. (1-d) Synthesis of 4-(trans-4-propylcyclohexyl-2,2,6-d 3 ) benzamide: In 100 ml of dichloromethane was dissolved 20.0 g of the 86/14 isomeric mixture prepared in (1-c), and 17 g of anhydrous aluminum chloride was added thereto, followed by cooling with ice. A solution of 14 g of oxalyl dichloride in 70 ml of dichloromethane was added thereto dropwise with care so that the inner temperature might not exceed 10° C. After stirring for 1 hour with ice-cooling, the reaction mixture was poured into ice-dilute hydrochloric acid, and the product was extracted with dichloromethane. The dichloromethane layer was added dropwise to 250 ml of 29% aqueous ammonia at 10° C. or lower. After stirring at 5° to 10° C. for 1 hour, the precipitated crystals were collected by filtration and dried under reduced pressure to obtain 20.0 g crude crystals of 4-(trans-4-propylcyclohexyl-2, 2,6-d 3 )benzamide (containing a small amount of the cis-form). (1-e) Synthesis of 1-cyano-4-(trans-4-propylcyclohexyl-2,2,6-d 3 )benzene: The whole portion of the 4-(trans-4-propylcyclohexyl-2, 2,6-d 3 )benzamide prepared in (1-d) was added to 100 ml of thionyl chloride, followed by refluxing for 1 hour with stirring. The excess thionyl chloride was removed by distillation under reduced pressure, the residue was allowed to cool, water and toluene were added thereto, followed by stirring, and the organic layer was separated. The aqueous layer was extracted with toluene. The organic layer and the extract were combined, washed with water, and dried over anhydrous sodium sulfate. The solvent was removed by distillation, and the resulting crude product was purified by silica gel column chromatography using toluene as an eluent. Recrystallization from methanol afforded 9.4 g of 1-cyano-4-(trans-4-propylcyclohexyl-2, 2,6-d 3 )benzene. The phase transition temperatures of this compound were as follows. 42° C. (m.p.) (Cr→N), 46° C. (N-I) For reference, non-deuterated 1-cyano-4-(trans-4-propylcyclohexyl) benzene has the following phase transition temperatures according to literature (Koji Okano Shunsuke Kobayashi (ed.), EKISHO KISOHEN, Baihukan (1985)). 42° C. (m.p.) (Cr→N), 45° C. (N-I) EXAMPLE 2 Synthesis of 1-Cyano-4-(trans-4-propylcyclohexyl-3, 3,5,5-d 4 )benzene ##STR255## (2-a) Deuteration of 4-phenylcyclohexanone; Commercially available 4-phenylcyclohexanone was deuterated in the same manner as in Example 1-(1-a) to obtain 4-phenylcyclohexanone-2,2,6,6-d 4 . (2-b) Synthesis of trans-4-phenylcyclohexane-2,2,6,6-d 4 carbaldehyde: In 35 ml of THF was suspended 14.2 g of methoxymethyltriphenylphosphonium chloride, and the solution was cooled to -5° C. To the solution was added 4.6 g of potassium t-butoxide, followed by stirring at room temperature for 1 hour to prepare a Wittig reagent. To the Wittig reagent was added dropwise a solution of 5.7 g of 4-phenylcyclohexanone-2, 2,6,6-d 4 prepared in (2-a) in 10 ml of THF at -5° C. over 5 minutes. After stirring at room temperature for 5 hours, the reaction mixture was poured into water, and hexane was added thereto. The organic layer was separated, and the triphenylphosphine oxide precipitate was removed by filtration. The filtrate was washed with water and dried over anhydrous sodium sulfate. The solvent was removed by distillation, and the resulting crude product was purified by silica gel column chromatography using a 5:1 mixed solvent of hexane and ethyl acetate as an eluent to recover 5.2 g of 4-phenylcyclohexane-2,2,6,6-d 4 carbaldehyde as an oily substance, which was a mixture of diastereomers assigned to the cis and trans configurations of the cyclohexane ring. The product was dissolved in 50 ml of ethanol, and 1 ml of a 20% sodium hydroxide aqueous solution was added thereto, followed by stirring at room temperature for 3 hours. Water was added thereto, the mixture neutralized with 1N hydrochloric acid, the reaction product extracted with ethyl acetate, and the extract washed with water and dried over anhydrous sodium sulfate. The solvent was distilled off, and the resulting crude product was purified by silica gel column chromatography using a 5:1 mixed solvent of hexane and ethyl acetate. Recrystallization from hexane yielded 3.1 g of trans-4-phenylcyclohexane-2, 2,6,6-d 4 carbaldehyde as white crystals. (2-c) Synthesis of trans-1-phenyl-4-(1-propenyl)cyclohexane-3, 3,5,5-d 4 : In a mixture of 3 ml of THF and 10 ml of toluene was suspended 1.8 g of ethyltriphenylphosphonium iodide, and the suspension was cooled to 15° C. To the suspension was added 0.52 g of potassium t-butoxide, followed by stirring at room temperature for 1 hour to prepare a Wittig reagent. To the thus prepared Wittig reagent was added dropwise a solution of 0.60 of the trans-4-phenylcyclohexane-2,2,6,6-d 4 carbaldehyde prepared in (2-b) in 2 ml of toluene at 15° C. over 5 minutes. After stirring at room temperature for 2 hours, the reaction mixture was poured into water, toluene added thereto, and the organic layer separated and concentrated. Hexane was added to the organic layer, and the triphenylphosphine oxide precipitate was removed by filtration. The filtrate was washed with a 1:1 mixed solvent of water and methanol and dried over anhydrous sodium sulfate. The solvent was removed by distillation, and the resulting crude product was purified by silica gel column chromatography using hexane as an eluent to obtain 0.56 g of trans-1-phenyl-4-(1-propenyl)cyclohexane-3,3,5,5-d 4 . (2-d) Synthesis of trans-1-phenyl-4-propylcyclohexane-3, 3,5,5-d 4 : The whole portion of the trans-1-phenyl-4-(1-propenyl) cyclohexane-3,3,5,5-d 4 obtained in (2-c) was hydrogenated in the same manner as in Example 1-(1-c), except for replacing the palladium-on-carbon with Raney nickel, to obtain 0.55 g of trans-1-phenyl-4-propylcyclohexane-3,3,5,5-d 4 . (2-e) Synthesis of 1-cyano-4-(trans-4-propylcyclohexyl-3,3,5,5-d 4 )benzene: The whole portion of the trans-1-phenyl-4-propylcyclohexane-3, 3,5,5-d 4 obtained in (2-d) was treated in the same manner as in (1-d) and (1-e) to obtain 0.28 g of 1-cyano-(trans-4-propylcyclohexyl-3, 3,5,5-d 4 )benzene. The phase transition temperatures of this compound are shown in Table 1 above. EXAMPLE 3 Synthesis of 1-Cyano-2-fluoro-4-(trans-4-propylcyclohexyl-2, 2,6-d 3 )benzene The title compound was prepared in the same manner as in Example 1, except for replacing bromobenzene with 3-fluoro-1-bromobenzene. The phase transition temperatures of this compound are shown in Table 1. EXAMPLE 4 Synthesis of 1-Fluoro-4-(trans-4-pentylcyclohexyl-2, 2,6-d 3 )benzene The title compound was prepared in the same manner as in Example 1, except for replacing bromobenzene with 4-fluoro-1-bromobenzene and replacing 4-propylcyclohexanone with 4-pentylcyclohexanone. The phase transition temperatures of this compound are shown in Table 1. EXAMPLE 5 Synthesis of 1-Methoxy-4-(trans-4-pentylcyclohexyl-2, 2,6-d 3 )benzene The title compound was prepared in the same manner as in Example 1, except for replacing bromobenzene with 4-bromoanisole and replacing 4-propylcyclohexanone with 4-pentylcyclohexanone. The phase transition temperatures of this compound are shown in Table 1. EXAMPLE 6 Synthesis of 1,2-Difluoro-4-(trans-4-pentylcyclohexyl-2, 2,6-d 3 )benzene The title compound was prepared in the same manner as in Example 1, except for replacing bromobenzene with 1-bromo-3, 4-difluorobenzene and replacing 4-propylcyclohexanone with 4-pentylcyclohexanone. The phase transition temperatures of this compound are shown in Table 1. EXAMPLE 7 Synthesis of 1-Trifluoromethoxy-4-(trans-4-pentylcyclohexyl-2, 2,6-d 3 )benzene The title compound was prepared in the same manner as in Example 1, except for replacing bromobenzene with 4-bromo-1-trifluoromethoxybenzene and replacing 4-propylcyclohexanone with 4-pentylcyclohexanone. The phase transition temperatures of this compound are shown in Table 1. EXAMPLE 8 Synthesis of 1-Methyl-4-(trans-4-pentylcyclohexyl-2, 2,6-d 3 )benzene The title compound was prepared in the same manner as in Example 1, except for replacing bromobenzene with 4-bromotoluene and replacing 4-propylcyclohexanone with 4-pentylcyclohexanone. The phase transition temperatures of this compound are shown in Table 1. EXAMPLE 9 Synthesis of Trans-4-(trans-4-propyl-cyclohexyl)-1-butylcyclohexane-2, 2,6,6-d 4 ##STR256## 4-(Trans-4-propylcyclohexyl)cyclohexanone was deuterated in the same manner as in (1-a) to obtain 4-(trans-4-propylcyclohexyl) cyclohexanone-2,2,6,6-d 4 , which was then reacted with a Wittig reagent in the same manner as in (2-b) to obtain 4-(trans-4-propylcyclohexyl)cyclohexane-2,2,6,6-d 4 carbaldehyde. The carbaldehyde was reacted with a Wittig reagent prepared from propyltriphenylphosphonium bromide in the same manner as in (2-c), and the product was hydrogenated in the same manner as in (2-d) to obtain trans-4-(trans-4-propylcyclohexyl)-1-butylcyclohexane-2, 2,6,6-d 4 . The phase transition temperatures of this compound are shown in Table 1. EXAMPLE 10 Synthesis of 1-Cyano-4-[2-(trans-4-propylcyclohexyl-2, 2,6,6-d 4 )ethyl]benzene ##STR257## 4-Propylcyclohexanone-2,2,6,6-d 4 obtained in (1-a) was reacted with a Wittig reagent prepared from methoxymethyltriphenylphosphonium chloride in the same manner as in (2-b) to obtain trans-4-propylcyclohexane-2,2,6,6-d 4 carbaldehyde. The reaction with the Wittig reagent was repeated once again to obtain trans-4-propylcyclohexane-2, 2,6,6-d 4 ethanal. The ethanal was reacted in the same manner as in (1-b) through (1-e) in place of trans-4-propylcyclohexanone-2, 2,6,6-d 4 to obtain the title compound. The phase transition temperatures of this compound are shown in Table 1. EXAMPLE 11 Synthesis of 1-Cyano-4-(trans-4-ethenylcyclohexyl-3, 3,5,5-d 4 )benzene Trans-4-phenylcyclohexane-2,2,6,6-d 4 carbaldehyde prepared in (2-b) was reacted with a Wittig reagent prepared from methyltriphenylphosphonium iodide in the same manner as in (2-c) to obtain trans-1-ethenyl-4-phenylcyclohexane-2, 2,6,6-d 4 . This compound was further reacted in the same manner as in (1-d) and (1-e) to obtain the title compound. The phase transition temperatures of this compound are shown in Table 2. EXAMPLE 12 Synthesis of 1-Cyano-4-[trans-4-(trans-1-propenyl) cyclohexyl-3,3,5,5-d 4 ]benzene The same procedure as in Example 11 was repeated, except for replacing the Wittig reagent prepared from methyltriphenylphosphonium iodide with that prepared from ethyltriphenylphosphonium bromide, to obtain trans-1-(cis-1-propenyl)-4-phenylcyclohexane-2, 2,6,6-d 4 . This compound (1.0 g) was dissolved in 5 ml of toluene, and 10 ml of 10% hydrochloric acid was added to the solution. To the mixture was further added 0.25 g of sodium benzenesulfinate, followed by heating under reflux for 10 hours. After allowing to cool, 50 ml of toluene was added to the reaction mixture, and the aqueous layer was separated. Any insoluble matter was removed, and the mother liquor was washed successively with 2% hydrochloric acid, saturated aqueous solution of sodium bicarbonate, and water. The solvent was removed by distillation under reduced pressure to obtain an about 3/1 isomeric mixture of trans-1-(trans-1-propenyl)-4-phenylcyclohexane-2, 2,6,6-d 4 and trans-1-(cis-1-propenyl)-4-phenylcyclohexane-2, 2,6,6-d 4 . The resulting product was purified by silica gel column chromatography using a hexane-ethyl acetate mixed solvent as an eluent. Recrystallization from ethanol gave 0.62 g of trans-1-(trans-1-propenyl)-4-phenylcyclohexane-2, 2,6,6-d 4 . This compound was further reacted in the same manner as in (1-d) and (1-e) to obtain the title compound. The phase transition temperatures of this compound are shown in Table 2. EXAMPLE 13 Synthesis of 3,4-Difluoro-1-[trans-4-(trans-4-propylcyclohexyl) cyclohexyl-2,2,6-d 3 ]benzene ##STR258## (13-a) Deuteration of 4-(trans-4-propylcyclohexyl) cyclohexanone: 4-(Trans-4-propylcyclohexyl)cyclohexanone-2,2,6,6-d 4 was obtained in the same manner as in (1-a), except for replacing trans-4-propylcyclohexanone with 4-(trans-4-propylcyclohexyl cyclohexanone. (13-b) Synthesis of 3,4-difluoro-1-[trans-4-(trans-4-propylcyclohexyl) cyclohexyl-2,2,6-d 3 ]benzene: 3,4-Difluoro-1-[trans-4-(trans-4-propylcyclohexyl) cyclohexyl-2,2,6-d 3 ]benzene was obtained in the same manner as in Example 6, except for replacing 4-pentyloxycyclohexanone-2, 2,6,6-d 4 with 4-(trans-4-propylcyclohexyl) cyclohexanone-2,2,6,6-d 4 prepared in (13-a). The phase transition temperatures of this compound are shown in Table 2. EXAMPLE 14 Synthesis of 3,4-Difluoro-1-[trans-4-(trans-4-butylcyclohexyl) cyclohexyl-2,2,6-d 3 ]benzene The title compound was prepared in the same manner as in Example 13, except for replacing 4-(trans-4-propylcyclohexyl) cyclohexanone with 4-(trans-4-butylcyclohexyl) cyclohexanone. The phase transition temperatures of this compound are shown in Table 2. EXAMPLE 15 Synthesis of 3,4-Difluoro-1-[2-[trans-4-(trans-4-propylcyclohexyl) cyclohexyl-2,2,6,6-d 4 ]ethyl]benzene (15-a) Synthesis of 4-(trans-4-propylcyclohexyl)cyclohexane-2, 2,6,6-d 4 ethanal: 4-(Trans-4-propylcyclohexyl)cyclohexanone-2,2,6,6-d 4 obtained in (13-a) was treated in the same manner as in the first half of Example 10 to obtain 4-(trans-4-propylcyclohexyl) cyclohexane-2,2,6,6-d 4 ethanal. (15-b) Synthesis of 3,4-difluoro-1-[2-[trans-4-(trans-4-propylcyclohexyl) cyclohexyl-2,2,6,6-d 4 ]ethyl]benzene: A Grignard request was prepared from 1-bromo-3,4-difluorobenzene. 4-(Trans-4-propylcyclohexyl)cyclohexane-2, 2,6,6-d 4 ethanal prepared in (15-a) and the resulting Grignard reagent were reacted in the same manner as in Example 6 to obtain the title compound. The phase transition temperatures of this compound are shown in Table 2. EXAMPLE 16 Synthesis of 3,4-Difluoro-1-[trans-4-(trans-4-propylcyclohexyl-3, 3,5,5-d 4 )cyclohexyl]benzene ##STR259## (16-a) Synthesis of 4-[trans-4-(3,4-difluorophenyl) cyclohexyl]cyclohexanone-2,2,6,6-d 4 : A Grignard reagent was prepared from 1-bromo-3,4-difluorobenzene and magnesium in THF, and a THF solution of bicyclohexane-4,4'-dione monoethyleneacetal was added thereto dropwise while cooling with ice. After allowing the mixture to react at room temperature for 1 hour, the reaction mixture was worked-up in a conventional manner to obtain crude crystals of 4-[4-hydroxy-4-(3,4-difluorophenyl) cyclohexyl]cyclohexanone ethyleneacetal. The crude crystals were dissolved in toluene, and a small amount of potassium bisulfate was added thereto, followed by refluxing for 10 hours while removing water. After cooling to room temperature, water was added to the reaction mixture, and the product was extracted with toluene. The solvent was removed by distillation to obtain white crystals of 4-[4-(3, 4-difluorophenyl)-3-cyclohexyl]cyclohexanone ethyleneacetal. Triethylamine and a catalytic amount of palladium-on-carbon were added to a toluene solution of the product, and the mixture was allowed to react in an autoclave at a hydrogen pressure of 5 kg/cm 2 for 3 hours. The catalyst was removed by filtration, and the filtrate was concentrated. The resulting crude product were recrystallized from ethanol to obtain white crystals of 4-[trans-4-(3,4-difluorophenyl) cyclohexyl]cyclohexanone ethyleneacetal. Formic acid was added to a toluene solution of the product, followed by stirring at room temperature for 4 hours. Water was added thereto, and the organic layer was separated, washed with a sodium bicarbonate aqueous solution, and dried. The solvent was removed by distillation, and the residue was recrystallized from ethanol to obtain white crystals of 4-[trans-4-(3, 4-difluorophenyl)cyclohexyl]cyclohexanone. The resulting product was deuterated in the same manner as in (1-a) to obtain 4-[trans-4-(3,4-difluorophenyl)cyclohexyl]cyclohexanone-2,2,6,6-d 4 . (16-b) Synthesis of 4-[trans-4-(3,4-difluorophenyl) cyclohexyl]cyclohexane-2,2,6,6-d 4 carbaldehyde: 4-[Trans-4-(3,4-difluorophenyl)cyclohexyl]cyclohexane-2,2,6,6-d 4 carbaldehyde was obtained from 4 -[trans-4-(3,4-difluorophenyl) cyclohexyl]cyclohexanone-2,2,6,6-d 4 obtained in (16-a) in the same manner as in (2-b). (16-c) Synthesis of 3,4-Difluoro-1-[trans-4-[trans-4-(cis-1-propenyl) cyclohexyl-3,3,5,5-d 4 ]cyclohexyl]benzene: 3,4-Difluoro-1-[trans-4-[trans-4-(cis-1-propenyl) cyclohexyl-3,3,5,5-d 4 ]cyclohexyl]benzene was obtained from 4-[trans-4-(3,4-difluorophenyl) cyclohexyl]cyclohexane-2,2,6,6-d 4 carbaldehyde obtained in (16-b) in the same manner as in (2-c). (16-d) Synthesis of 3,4-difluoro-1-[trans-4-(trans-4-propylcyclohexyl-3, 3,5,5-d 4 )cyclohexyl]benzene: 3,4-Difluoro-1-[trans-4-[trans-4-(cis-1-propenyl)cyclohexyl-3, 3,5,5-d 4 ]cyclohexyl]benzene obtained in (16-c) was hydrogenated in the same manner as in (2-d) to obtain 3,4-difluoro-1-[trans-4-(trans-4-propylcyclohexyl-3, 3,5,5-d 4 )cyclohexyl]benzene. The phase transition temperatures of this compound are shown in Table 2. EXAMPLE 17 Synthesis of 3,4-Difluoro-1-[trans-4-[trans-4-(trans-1-propenyl) cyclohexyl-3,3,5,5-d 4 ]cyclohexyl]benzene The title compound was obtained by isomerizing the side chain of 3,4-difluoro-1-[trans-4-[trans-4-(cis-1-propenyl)cyclohexyl-3, 3,5,5-d 4 ]cyclohexyl]benzene obtained in (16-c) to a trans-form in the same manner as in Example 12. The phase transition temperatures of this compound are shown in Table 2. EXAMPLE 18 Synthesis of 3,4,5-Trifluoro-1-[trans-4-(trans-4-propylcyclohexyl) cyclohexyl-2,2,6-d 3 ]benzene The title compound was obtained in the same manner as in Example 13, except for replacing 1-bromo-3,4-difluorobenzene with 1-bromo-3,4,5-trifluorobenzene. The phase transition temperatures of this compound are shown in Table 2. EXAMPLE 19 Synthesis of 3,4,5-Trifluoro-1-[trans-4-(trans-4-butylcyclohexyl) cyclohexyl-2,2,6-d 3 ]benzene The title compound was obtained in the same manner as in Example 14, except for replacing 1-bromo-3,4-difluorobenzene with 1-bromo-3,4,5-trifluorobenzene. The phase transition temperatures of this compound are shown in Table 2. EXAMPLE 20 Synthesis of 3,4,5-Trifluoro-1-[2-[trans-4-(trans-4-propylcyclohexyl) cyclohexyl-2,2,6,6-d 4 ]ethyl]benzene The title compound was obtained in the same manner as in Example 15, except for replacing 1-bromo-3,4-difluorobenzene with 1-bromo-3,4,5-trifluorobenzene. The phase transition temperatures of this compound are shown in Table 2. EXAMPLE 21 Synthesis of 4-Trifluoromethoxy-1-[trans-4-trans-4-propylcyclohexyl) cyclohexyl-2,2,6-d 3 ]benzene The title compound was obtained in the same manner as in Example 13, except for replacing 1-bromo-3,4-difluorobenzene with 4-bromo-1-trifluoromethoxybenzene. The phase transition temperatures of this compound are shown in Table 2. EXAMPLE 22 Synthesis of 3-Fluoro-4-cyano-1-[trans-4-(trans-4-propylcyclohexyl) cyclohexyl-2,2,6-d 3 ]benzene The title compound was obtained in the same manner as in Example 3, except for replacing 4-propylcyclohexanone-2, 2,6,6-d 4 with 4-(trans-4-propylcyclohexyl)cyclohexanone-2, 2,6,6-d 4 . The phase transition temperatures of this compound are shown in Table 2. EXAMPLE 23 Synthesis of 4-Methyl-1-[trans-4-[trans-4-(trans-1-propenyl) cyclohexyl-3,3,5,5-d 4 ]cyclohexyl]benzene 4-[Trans-4-(4-methylphenyl)cyclohexyl]cyclohexanone-2, 2,6,6-d 4 was obtained from bicyclohexane-4,4'-dione monoethyleneacetal and 4-bromoanisole in the same manner as in Example 16. The product was then led to the title compound as white crystals in the same manner as in Example 17. The phase transition temperatures of this compound are shown in Table 3. EXAMPLE 24 Synthesis of 4-(Trans-4-pentyl-cyclohexyl-2, 2,6-d 3 )-4'-ethylbiphenyl ##STR260## (24-a) Synthesis of (trans-4-pentylcyclohexyl-2,2,6-d 3 ) benzene: (Trans-4-pentylcyclohexyl-2,2,6-d 3 )benzene was obtained in the same manner as in (1-a) through (1-c), except for replacing 4-propylcyclohexanone with 4-pentylcyclohexanone. (24-b) Synthesis of 1-(trans-4-pentylcyclohexyl-2,2,6-d 3 )-4-iodobenzene: In a mixed solvent of 200 ml of acetic acid, 7 ml of sulfuric acid, 40 ml of water, and 25 ml of 1,2-dichloroethane were dissolved in 57 g of (trans-4-pentylcyclohexyl-2, 2,6-d 3 )benzene prepared in (24-a), 37.5 g of iodine, and 28.2 g of periodic acid dihydrate, and the mixture was heated for 1 hour with stirring. After allowing to cool, 200 ml of a 20% aqueous solution of sodium hydrogensulfite was added to the reaction mixture, followed by stirring for a while. The reaction product was extracted with 500 ml of hexane. The organic layer was washed with water and dried, and the solvent was distilled off. The residue was recrystallized from ethanol to obtain 58 g of 1-(trans-4-pentylcyclohexyl-2, 2,6-d 3 )-4-iodobenzene. (24-c) Synthesis of 4-(trans-4-pentylcyclohexyl-2,2,6-d 3 )-4'-ethylbiphenyl: A Grignard reagent was prepared from 15 g of 4-bromoethylbenzene and 2.4 g of magnesium in 100 ml of THF, and to the reaction system was added dropwise a solution of 19.5 g of 1-(trans-4-pentylcyclohexyl-2,2,6-d 3 )-4-iodobenzene and 1.25 g of tetrakis (triphenylphosphine)palladium (0 ) in 100 ml of THF at 30° C. After stirring for 1 hour, 1% hydrochloric acid was added thereto, and the product was extracted with ethyl acetate. The extract was washed with water and dried. The solvent was distilled off, and the thus obtained oily crude product was purified by silica gel column chromatography using hexane as an eluent to obtain 19.0 g of 4-(trans-4-pentylcyclohexyl-2,2,6-d 3 )-4'-ethylbiphenyl. The phase transition temperatures of this compound are shown in Table 3. EXAMPLE 25 Synthesis of 4-(Trans-4-propylcyclohexyl-2, 2,6-d 3 )-3',4'-difluorobiphenyl The title compound was obtained in the same manner as in Example 24, except for replacing (trans-4-pentylcyclohexyl-2, 2,6-d 3 )benzene with (trans-4-propylcyclohexyl-2, 2,6-d 3 )benzene in (24-b) and replacing 4-bromoethylbenzene with 1-bromo-3,4-difluorobenzene in (24-c). The phase transition temperatures of this compound are shown in Table 3. EXAMPLE 26 Synthesis of 4-(Trans-4-propylcyclohexyl-2, 2,6-d 3 )-4'-cyanobiphenyl 4-(Trans-4-propylcyclohexyl-2,2,6-d 3 )biphenyl was obtained in the same manner as in Example 25, except for replacing 1-bromo-3,4-difluorobenzene with bromobenzene. The product was cyanogenated in the same manner as in (1-d) and (1-e) to obtain the title compound. The phase transition temperatures of this compound are shown in Table 3. EXAMPLE 27 Synthesis of 3,4-Difluoro-1-[4-(trans-4-propylcyclohexyl-2,2,6,6-d 3 )phenyl]ethynylbenzene ##STR261## (27-a) Synthesis of 4-[4-(trans-4-propylcyclohexyl-2,2,6-d 3 )phenyl]-2-methyl-3-butyn-2-ol In 40 ml of triethylamine were dissolved 14.4 g of 1(trans-4-pentylcyclohexyl-2,2,6-d 3 )-4-iodobenzene prepared in Example 25 and 5.1 g of 2-methyl-3-butyn-2-ol. To the solution were added 0.15 g of cuprous iodide and 0.2 g of dichlorobis(triphenylphosphine)palladium (II), followed by stirring at room temperature for 1 hour. To the reaction mixture was added 100 ml of water, and the product was extracted with 100 ml of ethyl acetate. The organic layer was washed with water and then with a saturated sodium chloride aqueous solution, and dried over anhydrous sodium sulfate. The solvent was distilled off, and the residue was purified by silica gel column chromatography using a 4:1 mixture of toluene and ethyl acetate as an eluent to obtain 12.2 g of 4-[4-(trans-4-propylcyclohexyl-2,2,6-d 3 )phenyl]-2-methyl-3-butyn-2-ol. (27-b) Synthesis of 1-ethynyl-4-(trans-4-propylcycloxhexyl-2,2,6-d 3 )benzene: In 30 ml of toluene was suspended 2.0 g of sodium hydride, and a solution of the whole portion of the 4-[4-(trans-4-propylcyclohexyl-2,2,6-d 3 )phenyl]-2-methyl-3-butyn-2-ol obtained in (27-a) in 70 ml of toluene was added dropwise to the suspension at room temperature over 30 minutes. The mixture was heated under reflux for 1 hour with stirring, followed by allowing the cool to room temperature. The reaction mixture was poured into 100 ml of water, and the organic layer was separated, washed successively with water and a saturated sodium chloride aqueous solution, and dried over anhydrous sodium sulfate. The solvent was removed by distillation, and the residue was purified by silica gel column chromatography using hexane as an eluent to obtain 8.8 g of 1-ethynyl-4-(trans-4-propylcyclohexyl-2,2,6-d 3 )benzene. (27-c) Synthesis of 3,4-difluoro-1-[4-(trans-4-propylcyclohexyl-2,2,6-d 3 )phenyl]ethynylbenzene: In a mixture of 12 ml of triethylamine and 30 ml of DMF were dissolved 3.5 g of 1-ethynyl-4-trans-4-propylcyclohexyl-2,2,6-d 3 )benzene and 3.0 g of 1-bromo-3,4-difluorobenzene. To the solution were added 0.06 g of cuprous idodide and 0.06 g of dichlorobis(triphenylphosphine)palladium (II), and the mixture was stirred at room temperature for 30 minutes and then heated under reflux for 3 hours. After cooling to room temperature, 100 ml of water was added thereto, and the reaction product was extracted with 100 ml of toluene. The organic layer was washed with water and then with a saturated sodium chloride aqueous solution, and dried over anhydrous sodium sulfate. The solvent was removed by distillation, and the residue was purified by silica gel column chromatography using hexane as an eluent and recrystallized from ethanol to obtain 3.8 g of 3,4-difluoro-1-[4-(trans-4-propylcyclohexyl-2,2,6-d 3 )phenyl]ethynylbenzene. The phase transition temperatures of this compound are shown in Table 3. EXAMPLE 28 Synthesis of 4-Butyl-1-[4-(trans-4-propyl-cyclohexyl-2,2,6-d 3 )phenyl]ethynylbenzene The title compound was obtained in the same manner as in Example 27, except for replacing 1-bromo-3,4-difluorobenzene with 4-bromo-1-ethylbenzene. The phase transition temperatures of this compound are shown in Table 3. EXAMPLE 29 Synthesis of 4-(Trans-4-pentylcyclohexyl)-4'-(trans-4-propylcyclohexyl-2,2,6-d 3 )biphenyl (29-a) Synthesis of 1-bromo-4-(trans-4-pentylcyclohexyl)benzene: In 30 ml of dichloromethane was dissolved 11.1. g of trans-4-pentylcyclohexylbenzene, and 0.1 g of iron powder and 0.05 g of iodine were added thereto. To the mixture was added dropwise 7.7 g of bromine dissolved in 20 ml of dichloromethane at 0° C. or lower. The mixture was stirred at -10° C. for 6 hours and then allowed to warm to room temperature. Water and then an aqueous solution of sodium hydrogensulfite were added to the reaction mixture, and the product was extracted with hexane. The extract was washed successively with a sodium bicarbonate aqueous solution, water and a saturated sodium chloride aqueous solution, and dried. The solvent was removed by distillation, and the resulting crude crystals were recrystallized from ethanol to give 4.8 g of 1-bromo-4-(trans-4-pentylcyclohexyl)benzene. ( 29-b) Synthesis of 4-(trans-4-pentylcyclohexyl)-4'-(trans-4-propylcyclohexyl-2,2,6-d 3 )biphenyl: A Grignard reagent was prepared from 2.4 g of 1-bromo-4-(trans-4-pentylcyclohexyl)benzene prepared in (29-a) in the same manner as in (24-c). The resulting Grignard reagent was reacted with 2.2 g of 1-(trans-4-pentylcyclohexyl-2,2,6-d 3 -4-iodobenzene prepared in Example 25 in the same manner as in (24-c) to obtain 2.6 g of 4-(trans-4-pentylcyclohexyl)-4'-(trans-4-propylcyclohexyl-2,2,6-d 3 )biphenyl. The phase transition temperatures of this compound are shown in Table 3. EXAMPLE 30 Synthesis of 2-Fluoro-4-(trans-4-pentylcyclo-hexyl)-4'-(trans-4-pentylcyclohexyl-2,2,6-d 3 )biphenyl A Grignard reagent was prepared from commercially available 2-fluoro-4-bromobiphenyl, and the resulting Grignard reagent was reacted with 4-pentylcyclohexanone in the same manner as in (1-b) and (1-c) to obtain 2-fluoro-4-(trans-4-pentylcyclohexyl)biphenyl. The product was brominated in the same manner as in (29-a) to obtain 2-fluoro-4-(trans-4-pentylcyclohexyl)-4'-bromobiphenyl. A Grignard reagent was prepared therefrom and reacted with 4-pentylcyclohexanone-2,2,6,6-d 4 in the same manner as in Example 4 to obtain 2-fluoro-4-(trans-4-pentylcyclohexyl)-4'-(trans-4-pentylcyclohexyl-2,2,6-d 3 )biphenyl. The phase transition temperatures of this compound are shown in Table 3. EXAMPLE 31 Preparation of Liquid Crystal Composition A mother liquid crystal composition (A) having the following composition was prepared. Composition of Mother Liquid Crystal composition (A): ##STR262## wherein the cyclohexane rings are in a trans-configuration. Composition (A) showed a nematic (N) phase at 54.5° C. or lower. A liquid crystal composition (B) was prepared from 85% of liquid crystal composition (A) and 15% of 3,4-difluoro-1-[trans-4-(trans-4-propylcyclohexyl)cyclohexyl-2,2,6-d 3 ]benzene obtained in Example 13 shown in Table 2 (Compound No. 13). The upper temperature limit for the N phase of composition (B) was 62.2° C. When composition (B) was preserved at -20° C., no crystallization was observed even after 1 month. COMPARATIVE EXAMPLE 1 A liquid crystal composition (C) was prepared from 85% of composition (A) and 15% of non-deuterated 3,4-difluoro-1-[trans-4-(trans-4-propylcyclohexyl)cyclohexyl]benzene of formula: ##STR263## The upper temperature limit for the N phase of composition (C) was 62.3° C. When composition (C) was preserved at -20° C., crystallization was observed after 5 days. From the results of Example 31 compared with Comparative Example 1, it is seen that the deuterated compound of formula (I) has excellent compatibility with a general-purpose liquid crystal material to provide a practical liquid crystal composition which is hardly crystallized even in a low temperature region. EXAMPLE 32 Liquid crystal composition (B) having the following composition and characteristics was prepared. ##STR264## T N-I Point: 110° C. Threshold Voltage: 1.81 V Δ.sub.ε : 7.0 Δ n : 0.087 Response Time: 28 msec When composition (B) was preserved at 10° C., no crystallization was observed after 1 month. EXAMPLE 33 Liquid crystal composition (B') having the following composition and characteristics was prepared. ##STR265## T N-I Point: 108° C. Threshold Voltage: 1.74 V Δ.sub.ε : 7.2 Δ n : 0.086 Response Time: 24 msec When composition (B') was preserved at 10° C., no crystallization was observed after 1 month. COMPARATIVE EXAMPLE 2 Liquid crystal composition (a-1) having the following composition and characteristics was prepared. ##STR266## T N-I Point: 117° C. T C-N Point: 11° C. Threshold Voltage: 2.14 V Δ.sub.ε : 4.8 Δ n : 0.090 Response Time: 25 msec When composition (a-1) was preserved at 10° C., crystallization was observed after 3 days. COMPARATIVE EXAMPLE 3 Liquid crystal composition (b) having the following composition and characteristics was prepared. ##STR267## T N-I Point: 111° C. Threshold Voltage: 1.83 V Δ.sub.ε : 7.0 Δ n : 0.087 Response Time: 30 msec When composition (b) was preserved at 10° C., crystallization was observed after 3 days. EXAMPLE 34 Liquid crystal composition (C) having the following composition and characteristics was prepared. ##STR268## T N-I Point: 116° C. Threshold Voltage: 2.10 V Δ.sub.ε : 5.2 Δ n : 0.086 Response Time: 25 msec When composition (C) was preserved at 0° C., no crystallization was observed after 1 month. COMPARATIVE EXAMPLE 4 Liquid crystal composition (c) having the following composition and characteristics was prepared. ##STR269## T N-I Point: 116° C. Threshold Voltage: 2.15 V Δ.sub.ε : 5.1 Δ n : 0.086 Response Time: 28 msec When composition (c) was preserved at 0° C., crystallization was observed after 4 days. EXAMPLE 35 Liquid crystal composition (D) having the following composition was prepared. ##STR270## T N-I Point: 109° C. Threshold Voltage: 1.83 V Δ.sub.ε : 6.2 Δ n : 0.085 Response Time: 29 msec When composition (D) was preserved at 0° C., no crystallization was observed after 1 month. COMPARATIVE EXAMPLE 5 Liquid crystal composition (d) having the following composition and characteristics was prepared. ##STR271## T N-I Point: 110° C. Threshold Voltage: 1.86 V Δ.sub.ε : 6.2 Δ n : 0.085 Response Time: 32 msec When composition (d) was preserved at 0° C., crystallization was observed after 3 days. EXAMPLE 36 Liquid crystal composition (E) having the following composition and characteristics was prepared. ##STR272## T N-I Point: 94° C. Threshold Voltage: 1.66 V Δ.sub.ε : 6.2 Δ n : 0.082 Response Time: 31 msec When composition (E) was preserved at 10° C., no crystallization was observed even after 1 month. EXAMPLE 37 Liquid crystal composition (E') having the following composition and characteristics was prepared. ##STR273## T N-I Point: 95° C. Threshold Voltage: 1.69 V Δ.sub.ε : 6.1 Δ n : 0.082 Response Time: 33 msec When composition (E') was preserved at 5° C., crystallization was observed after 1 month. COMPARATIVE EXAMPLE 6 Liquid crystal composition (e) having the following composition and characteristics was prepared. ##STR274## T N-I Point: 95° C. Threshold Voltage: 1.74 V Δ.sub.ε : 6.1 Δ n : 0.082 Response Time: 35 msec When composition (e) was preserved at 10° C., crystallization was observed after 3 days. EXAMPLE 38 Liquid crystal composition (F) having the following composition and characteristics was prepared. ##STR275## T N-I Point: 103° C. Threshold Voltage: 1.70 V Δ.sub.ε : 6.1 Δ n : 0.087 Response Time: 23 msec When composition (F) was preserved at 10° C., no crystallization was observed after 1 month. COMPARATIVE EXAMPLE 7 Liquid crystal composition (f) having the following composition and characteristics was prepared. ##STR276## T N-I Point: 104° C. Threshold Voltage: 1.79 V Δ.sub.ε : 6.0 Δ n : 0.087 Response Time: 27 msec When composition (f) was preserved at 10° C., crystallization was observed after 10 days. EXAMPLE 39 Liquid crystal composition (G) having the following composition and characteristics was prepared. ##STR277## T N-I Point: 125° C. Threshold Voltage: 2.18 V Δ.sub.ε : 5.4 Δ n : 0.089 Response Time: 21 msec When composition (G) was preserved at 0° C., no crystallization was observed after 1 month. COMPARATIVE EXAMPLE 8 Liquid crystal composition (g) having the following composition and characteristics was prepared. ##STR278## T N-I Point: 125° C. Threshold Voltage: 2.20 V Δ.sub.ε : 5.3 Δ n : 0.089 Response Time: 24 msec When composition (g) was preserved at 0° C., crystallization was observed after 3 days. EXAMPLE 40 Liquid crystal composition (H) having the following composition and characteristics was prepared. ##STR279## T N-I Point: 121° C. Threshold Voltage: 2.23 V Δ.sub.ε : 5.1 Δ n : 0.088 Response Time: 25 msec When composition (H) was preserved at -10° C., no crystallization was observed after 1 month. COMPARATIVE EXAMPLE 9 Liquid crystal composition (h) having the following composition and characteristics was prepared. ##STR280## T N-I Point: 121° C. Threshold Voltage: 2.29 V Δ.sub.ε : 5.0 Δ n : 0.089 Response Time: 27 msec When composition (h) was preserved at -10° C., crystallization was observed after 4 days. EXAMPLE 41 Liquid crystal composition (I) having the following composition and characteristics was prepared. ##STR281## T N-I Point: 120° C. Threshold Voltage: 2.10 V Δ.sub.ε : 4.8 Δ n : 0.090 Response Time: 17 msec When composition (I) was preserved at 0° C., no crystallization was observed even after 1 month. COMPARATIVE EXAMPLE 10 Liquid crystal composition (i) having the following composition and characteristics was prepared. ##STR282## T N-I Point: 121° C. Threshold Voltage: 2.21 V Δ.sub.ε : 4.7 Δ n : 0.091 Response Time: 20 msec When composition (i) was preserved at 0° C., crystallization was observed after 3 days. EXAMPLE 42 Liquid crystal composition (J) having the following composition and characteristics was prepared. ##STR283## T N-I Point: 115° C. Threshold Voltage: 1.98 V Δ.sub.ε : 5.2 Δ n : 0.088 Response Time: 19 msec When composition (J) was preserved at 0° C., no crystallization was observed after 1 month. COMPARATIVE EXAMPLE 11 Liquid crystal composition (j) having the following composition and characteristics was prepared. ##STR284## T N-I Point: 115° C. Threshold Voltage: 2.07 V Δ.sub.ε : 5.0 Δ n : 0.088 Response Time: 23 msec When composition (j) was preserved at 0° C., crystallization was observed after 2 days. EXAMPLE 43 Liquid crystal composition (K) having the following composition and characteristics was prepared. ##STR285## T N-I Point: 98° C. Threshold Voltage: 1.65 V Δ.sub.ε : 6.6 Δ n : 0.080 Response Time: 33 msec When composition (K) was preserved at -10° C., no crystallization was observed after 1 month. COMPARATIVE EXAMPLE 12 Liquid crystal composition (k-1) having the following composition and characteristics was prepared. ##STR286## T N-I Point: 92° C. Threshold Voltage: 1.60 V Δ.sub.ε : 6.8 Δ n : 0.080 Response Time: 38 msec When composition (k-1) was preserved at -10° C., crystallization was observed after 5 days. COMPARATIVE EXAMPLE 13 Liquid crystal composition (k-2) having the following composition and characteristics was prepared. ##STR287## T N-I Point: 98° C. Threshold Voltage: 1.68 V Δ.sub.ε : 6.5 Δ n : 0.080 Response Time: 35 msec When composition (k-2) was preserved at -10° C., crystallization was observed after 9 days. EXAMPLE 44 Liquid crystal composition (L) having the following composition and characteristics was prepared. ##STR288## T N-I Point: 93° C. Threshold Voltage: 1.50 V Δ.sub.ε : 7.3 Δ n : 0.079 Response Time: 35 msec When composition (L) was preserved at -10° C., no crystallization was observed after 1 month. COMPARATIVE EXAMPLE 14 Liquid crystal composition (l) having the following composition and characteristics was prepared. ##STR289## T N-I Point: 94° C. Threshold Voltage: 1.54 V Δ.sub.ε : 7.2 Δ n : 0.080 Response Time: 38 msec When composition (l) was preserved at -10° C., crystallization was observed after 7 days. EXAMPLE 45 Liquid crystal composition (M) having the following composition and characteristics was prepared. ##STR290## T N-I Point: 112° C. T C-N Point: -70° C. Threshold Voltage: 1.9 V Δ.sub.ε : 5.5 Δ n : 0.086 Response Time: 24 msec Voltage Holding Ratio: 99% (/100° C.) When composition (M) was preserved at -55° C., no crystallization was observed even after 3 months. A liquid crystal display for TFT driving prepared by using composition (M) exhibited satisfactory driving characteristics even in a low temperature region. EXAMPLE 46 Liquid crystal composition (N) having the following composition was prepared. ##STR291## T N-I Point: 86° C. T C-N Point: -30° C. Threshold Voltage: 1.10 V Δ.sub.ε : 9.2 Δ n : 0.080 Response Time: 33 msec When composition (N) was preserved at -25° C., no crystallization was observed even after 3 months. A liquid crystal display for TFT driving having a cell thickness of 4.5 μm which was prepared by using composition (N) exhibited satisfactory driving characteristics even in a low temperature region. COMPARATIVE EXAMPLE 15 Liquid crystal composition (n) having the following composition and characteristics was prepared. ##STR292## T N-I Point: 87° C. Threshold Voltage: 1.15 V Δ.sub.ε : 9.1 Δ n : 0.080 Response Time: 38 msec When composition (n) was preserved at 0° C., crystallization was observed after 1 day. The above measurement was made using a liquid crystal cell having a cell thickness of 4.5 μm. EXAMPLE 47 Liquid crystal composition (P) having the following composition and characteristics was prepared. ##STR293## T N-I Point: 84° C. Threshold Voltage: 1.59 V Δ.sub.ε : 9.9 Δ n : 0.099 K 33 /K 11 : 2.4 When composition (P) was preserved at 0° C., crystallization was observed after 14 days. EXAMPLE 48 Liquid crystal composition (P') having the following composition and characteristics was prepared. ##STR294## T N-I Point: 84° C. Threshold Voltage: 1.58 V Δ.sub.ε : 9.9 Δ n : 0.099 K 33 /K 11 : 2.4 When composition (P') was preserved at 0° C., no crystallization was observed after 1 month. COMPARATIVE EXAMPLE 16 Liquid crystal composition (o) having the following composition and characteristics was prepared. ##STR295## T N-I Point: 139° C. Threshold Voltage: 2.11 V Δ.sub.ε : 6.0 Δ n : 0.078 K 33 /K 11 : 2.5 When composition (o) was preserved at 10° C., crystallization was observed after 1 day. COMPARATIVE EXAMPLE 17 Liquid crystal composition (p) having the following composition and characteristics was prepared. ##STR296## T N-I Point: 84° C. Threshold Voltage: 1.60 V Δ.sub.ε : 9.9 Δ n : 0.099 K 33 /K 11 : 2.3 When composition (p) was preserved at 0° C., crystallization was observed after 1 day. EXAMPLE 49 Liquid crystal composition (Q) having the following composition was prepared. ##STR297## T N-I Point: 82° C. Threshold Voltage: 1.38 V Δ.sub.ε : 12.5 Δ n : 0.098 K 33 /K 11 : 2.3 When composition (Q) was preserved at 0° C., no crystallization of crystals was observed after 1 month. COMPARATIVE EXAMPLE 18 Liquid crystal composition (q) having the following composition and characteristics was prepared. ##STR298## T N-I Point: 82° C. Threshold Voltage: 1.40 V Δ.sub.ε : 12.5 Δ n : 0.099 K 33 /K 11 : 2.2 When composition (q) was preserved at 0° C., crystallization was observed after 1 day. EXAMPLE 50 Liquid crystal composition (S) having the following composition and characteristics was prepared. ##STR299## T N-I Point: 101° C. Threshold Voltage: 1.23 V Δ.sub.ε : 23 Δ n : 0.145 K 33 /K 11 : 3.7 When composition (S) was preserved at -10° C., no crystallization of crystals was observed even after 1 month. COMPARATIVE EXAMPLE 19 Liquid crystal composition (r) having the following composition and characteristics was prepared. ##STR300## T N-I Point: 191° C. Threshold Voltage: 1.17 V Δ.sub.ε : 36 Δ n : 0.176 K 33 /K 11 : 4.6 When composition (r) was preserved at room temperature (20° C.), crystallization was observed on the next day. COMPARATIVE EXAMPLE 20 Liquid crystal composition (s) having the following composition and characteristics was prepared. ##STR301## T N-I Point: 103° C. Threshold Voltage: 1.29 V Δ.sub.ε : 22 Δ n : 0.146 K 33 /K 11 : 3.6 When composition (s) was preserved at -10° C., crystallization was observed after 3 days. EXAMPLE 51 Liquid crystal composition (T) having the following composition and characteristics was prepared. ##STR302## T N-I Point: 82° C. Threshold Voltage: 1.10 V Δ.sub.ε : 17 Δ n : 0.116 K 33 /K 11 : 2.5 When composition (T) was preserved at -40° C., crystallization of crystals was observed even after 1 month. An STN liquid crystal display having a twisted angle of 260° prepared by using composition (T) showed satisfactory driving characteristics even in a low temperature region. COMPARATIVE EXAMPLE 21 Liquid crystal composition (t) having the following composition and characteristics was prepared. ##STR303## T N-I Point: 83° C. Threshold Voltage: 1.12 V Δ.sub.ε : 17 Δ n : 0.116 K 33 /K 11 : 2.5 When composition (t) was preserved at -25° C., crystallization was observed after 5 days. EXAMPLE 52 Liquid crystal composition (U) having the following composition and characteristics was prepared. ##STR304## T N-I Point: 132° C. Threshold Voltage: 2.62 V Δ.sub.ε : 3.9 Δ n : 0.092 Response Time: 31 msec When composition (U) was preserved at 10° C., no crystallization of crystals was observed even after 1 month. COMPARATIVE EXAMPLE 22 Liquid crystal composition (u) having the following composition and characteristics was prepared. ##STR305## T N-I Point: 133° C. Threshold Voltage: 2.70 V Δ.sub.ε : 3.7 Δ n : 0.092 Response Time: 38 msec When composition (u) was preserved at 10° C., crystallization was observed even after 3 days. EXAMPLE 53 Liquid crystal composition (V) having the following composition and characteristics was prepared. ##STR306## T N-I Point: 127° C. Threshold Voltage: 2.71 V Δ.sub.ε : 3.8 Δ n : 0.109 Response Time: 37 msec When composition (V) was preserved at 10° C., no crystallization of crystals was observed even after 1 month. COMPARATIVE EXAMPLE 23 Liquid crystal composition (v) having the following composition and characteristics was prepared. ##STR307## T N-I Point: 127° C. Threshold Voltage: 2.73 V Δ.sub.ε : 3.8 Δ n : 0.109 Response Time: 40 msec When composition (v) was preserved at 10° C., crystallization was observed even after 5 days. EXAMPLE 54 Liquid crystal composition (W) having the following composition and characteristics was prepared. ##STR308## T N-I Point: 128° C. Threshold Voltage: 2.56 V Δ.sub.ε : 4.0 Δ n : 0.096 Response Time: 32 msec When composition (W) was preserved at 10° C., no crystallization of crystals was observed even after 1 month. COMPARATIVE EXAMPLE 24 Liquid crystal composition (w) having the following composition and characteristics was prepared. ##STR309## T N-I Point: 130° C. Threshold Voltage: 2.64 V Δ.sub.ε : 3.8 Δ n : 0.095 Response Time: 37 msec When composition (w) was preserved at 10° C., crystallization of crystals was observed even after 3 days. While the invention has been described in detail and with reference to specific embodiments thereof, it will be apparent to one skilled in the art that various changes and modifications can be made therein without departing from the spirit and scope thereof.	A liquid crystal display comprising a compound of the formula ##STR1## wherein each of Y 1 and Y 2 is independently F, Cl, CN, OCN, SCN, OCF 3 , OCF 2 H, OCF 2 CF 3 , CF 3 , R, --OR, --COOR or --OCOR, wherein R is alkyl, alkenyl or alkoxyalkyl, provided that at least one of Y 1 and Y 2 is R, --OR, --COOR or --OCOR; each of Z, Z 1 , Z 2 , Z 3 and Z 4 is independently a single bond. CH 2 CH 2 --, --CH═CH--, --C═C--, --COO--, --OCO--, --CH 2 O--, OCH 2 --, --(CH 2 ) 4 --, --(CH 2 ) 3 --O-- or --O--(CH 2 ) 3 --: ring A is a group of formula (II): ##STR2## wherein each of X 1 , X 2 , X 3 , X 4 , X 5 , X 6 , X 7 , X 8 , X 9 , and X 10 is independently H or D, provided that at least one of them is D; each of rings K, L, J, M and N is independently trans-1,4-cyclohexylene, 1,4-cyclohexenylene, substituted trans-1,4-cyclohexylene, 1,4-phenylene, substituted 1,4-phenylene, 1,3-dioxane-2,6-diyl, pyrimidine-2,5-diyl, pyridine-2,5-diyl, pyrazine-2,5-diyl or a group of formula (III): ##STR3## wherein each of X 11 , X 12 , X 13 , X 14 , X 15 , X 16 , X 17 , X 18 , X 19 , and X 20 is independently H or D, provided that at least one of them is D; in which the ring of formula (III) may be the same as or different from ring A; and k, l, m, and n each independently is 0 or 1, provided that the sum of k, l, m, and n is 0, 1 or 2. The compound is useful as an electro-optic liquid crystal display material.	2
BACKGROUND OF THE INVENTION The present invention relates to mobile electronic devices, and more particularly to mobile electronic devices capable of preserving user-defined settings during over-air updates of device settings. Mobile electronic devices, such as notebook computers, cellular phones, personal data assistants (PDAs) and pocket PCs, are becoming increasingly sophisticated. This increased sophistication has brought with it more complex software and a higher incidence of coding errors, called software bugs. This increased sophistication has also led to more frequent availability of software upgrades that enhance the functionality of such devices. To remove software bugs and enable software upgrades, software updates are disseminated and applied on such devices. To more efficiently disseminate software updates to a large installed base of mobile electronic devices, techniques that download software updates to such devices over-air have been deployed. In such wireless download schemes, a software update is typically loaded on a software update server in a network infrastructure and is pushed or pulled from the server to a plurality of such devices. A technical challenge that arises during over-air software updates is how to update device settings without affecting user-defined settings. A software image on a mobile electronic device typically includes device settings that affect, for example, how the device interfaces with the user. These device settings are often initialized to default values that a user of the device can modify to match his or her preferences. Unfortunately, a conventional software update server has no knowledge of which device settings a user has modified. Without such knowledge, there is no way to perform a selective update of device settings via an over-air software update that preserves the user-defined settings. If device settings are globally updated as part of a software update, the user-defined settings are overwritten. The user must then once again modify the device settings to match his or her preferences, consuming the user's time and causing frustration. On the other hand, if device settings are not updated as part of a software update, the device may not perform at a desired level after the update. Old device settings that are no longer required will persist, new device settings that are required by the updated software will not become operative, and device setting default values will not be optimized for the updated software. Incompatibilities arising between the updated software and old device settings may even render the device inoperable. SUMMARY OF THE INVENTION The present invention, in a basic feature, enables user-defined settings to be preserved during an over-air update of device settings of a mobile electronic device. Generally speaking, preservation of user-defined settings is accomplished through fragmentation of device settings on the mobile electronic device into default settings and user settings that may be separately maintained, referenced and updated. In one aspect, the present invention provides a mobile electronic device comprising a memory adapted to store at least one device setting including a default setting determined independent of any user of the device and a user setting determinable by a user of the device; a wireless interface adapted to receive a software update; and a processor communicatively coupled to the wireless interface and the memory and adapted to update the default setting in response to the software update. The software update may update the default setting to a valid or invalid value. The default setting may be maintained in a first file and the user setting may be maintained in a second file. In some embodiments, the memory is adapted to store a plurality of device settings each including a default setting determined independent of any user of the device and a user setting determinable by a user of the device wherein each default setting is updated in response to the software update. In another aspect, the present invention provides a mobile electronic device comprising a memory adapted to store at least one device setting including a default setting determined independent of any user of the device and a user setting determinable by a user of the device; a user interface adapted to receive a user input; and a processor communicatively coupled to the user interface and the memory and adapted to update the user setting in response to the user input. The user input may update the user setting to a valid or invalid value. In some embodiments, the memory is adapted to store a plurality of device settings each including a default setting determined independent of any user of the device and a user setting determinable by a user of the device wherein one or all of the user settings are updated in response to the user input. In another aspect, the present invention provides a mobile electronic device comprising a memory adapted to store at least one device setting including a default setting determined independent of any user of the device and a user setting determinable by a user of the device; and a processor communicatively coupled to the memory and adapted in response to interrogation of the device setting to select for application on the device one of the default setting and the user setting. In some embodiments, the processor selects the user setting for application on the device if the user setting is a valid and selects the default setting for application on the device if the user setting is invalid. These and other aspects of the invention will be better understood by reference to the following detailed description taken in conjunction with the drawings that are briefly described below. Of course, the invention is defined by the appended claims. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a system diagram of a network in accordance with an embodiment of the present invention. FIG. 2 is a block diagram of a mobile electronic device in accordance with an embodiment of the present invention. FIG. 3 is a block diagram showing updated and non-updated software elements within a mobile electronic device in accordance with an embodiment of the present invention. FIG. 4 is a block diagram showing updated and non-updated device settings within a mobile electronic device in accordance with an embodiment of the present invention. FIG. 5 is a flow diagram showing operation of a mobile electronic device in accordance with an embodiment of the present invention. DESCRIPTION OF THE PREFERRED EMBODIMENT In FIG. 1 , a network in accordance with an embodiment of the present invention is shown. The network includes a software update server 110 in a network infrastructure. Server 110 may reside in an enterprise network or a service provider network, for example. Server 110 has wired connectivity with an access point 150 , such as a cellular base station or a wireless LAN access point. The connectivity may be direct or via one or more intervening data communication nodes such as routers, switches and bridges. Access point 150 has wireless connectivity with a plurality of mobile electronic devices 120 , 130 , 140 via respective over-air links. Over-air links may include various types of links over which data may be transmitted, such as a cellular link or LAN link. Mobile electronic devices 120 , 130 , 140 shown include a notebook computer 120 , a cellular phone 130 and a PDA 140 , although other types of devices having a wireless interface, for example pocket PCs, may be deployed. In other embodiments, the mobile electronic devices in the network may be homogenous, that is, all may fit within the some product class (e.g. cell phones). Software update server 110 stores and distributes software updates to an installed base of mobile electronic devices, such as devices 120 , 130 , 140 . The installed base may include, for example, a group of mobile electronic devices owned by a common enterprise or used by a subscriber group. Software update types include, for example, patches with corrective code and upgrades with code that supports new features or functionality. Software updates also include device setting updates. In some embodiments, server 110 prepares and downloads to devices a delta package in lieu of a complete replacement software image. In such embodiments, server 110 compares a current version of software running on devices with a new version and creates a delta package reflective of differences. The delta package contains information sufficient to enable devices to self-update to the new version of software, such as a set of commands that instruct devices how to modify the current version. Devices receive the delta package from server 110 and execute the delta package to update to the new version. In some embodiments, software updates are pulled from server 110 pursuant to requests made by devices 120 , 130 , 140 . In other embodiments, software updates are pushed by server 110 to devices 120 , 130 , 140 independent of any request. Turning to FIG. 2 , a representative mobile electronic device 200 in accordance with an embodiment of the present invention is shown. Device 200 includes a wireless interface 210 adopted to transmit and receive data in accordance with a wireless communication protocol, such as a cellular or wireless LAN protocol. Device 200 further includes a user interface 230 adapted to transmit outputs and receive inputs from a user of device 200 . User interface 230 may, for example, include a display and a mechanism for user input such as a keypad or a touch-sensitive navigation tool. Device 200 further includes a main memory 240 adapted to store device software and settings. In some embodiments, memory 240 is a flash memory. Device 200 further includes a processor 220 adapted to execute device software stored in main memory 240 and interoperate with elements 210 , 230 , 240 to perform various features and functions supported by device 200 . Turning to FIG. 3 , main memory 240 is shown in more detail to include device software 310 , 320 and device settings 350 . Device software 310 , 320 includes software programs, such as an operating system, with instructions adapted for execution by processor 220 to perform various features and functions supported by device 200 . Device software is logically partitioned into updated device software 310 and non-updated device software 320 . Updated device software 310 includes program elements that are updated in response to a delta package 250 received from a software update server over wireless interface 210 . Non-updated device software 320 includes program elements that are not updated in response to delta package 250 . Device settings 350 include a multiple of settings that affect, for example, how device 200 interfaces with the user. Purely by way of example, different device settings may affect language presentation, text presentation, volume, ring tone and screen saver type. Device settings 350 are logically partitioned into default settings 330 and user settings 340 . Each device setting includes one default setting and one user setting. Default settings 330 are device settings that may be updated in response to software updates, such as delta package 250 , but are not updated in response to user inputs. User settings 350 are device settings that may be updated in response to user inputs, but are not updated in response to software updates. In some embodiments, default settings 330 and user settings 340 are maintained in separate data tables and files. Turning now to FIG. 4 , device settings 350 are illustrated in greater detail by way of example. In the example shown, default settings 330 include five old default settings 331 a and six new default settings 331 b arranged in tabular format, with each setting having a reserved table location. Old default settings 331 a include old default values OldDefVal 1 through OldDefVal 5 . Application of delta package 250 converts old default settings 331 a into new default settings 331 b whereby old default values OldDefVal 1 and OldDefVal 3 through OldDefVal 5 are replaced with new default values NewDefVal 1 and NewDefVal 3 through NewDefVal 5 . Additionally, application of delta package 250 results in replacement of old default value OldDefVal 2 with invalid value InvalidVal. Finally, application of delta package 250 results in addition of a new default setting having a value of DefVal 6 in a new table entry appended to the end of the table. Further in the example shown, user settings 340 include individual user settings arranged in tabular format and having reserved locations. The first, fourth and fifth user settings have valid values UserVal 1 , UserVal 4 and UserVal 5 , respectively, while the remaining user settings are invalid. Reservation of table locations for particular settings enables the formation of logical groups of settings from aligned settings in different tables. In particular, each aligned default setting and user setting together form a device setting. Thus, after application of delta package 250 , the first device setting is defined by the tuple <NewDefVal 1 , UserVal 1 >, the second device setting is defined by the tuple <InvalidVal, InvalidVal>, the third device setting is defined by the tuple <NewDefVal 3 , InvalidVal>, and so on. Device settings whose default settings are invalid (that is, have invalid values) are inoperative, whereas device settings whose default settings are valid (that is, have valid values) are operative. Moreover, when the default setting and the user setting of a device setting are both valid, the user setting is preferred. That is, the user setting is returned in response to an interrogation of the device setting when the default setting and the user setting are both valid. It will be appreciated that preserving table entries for device settings rendered inoperative maintains the alignment between default settings and user settings required for formation of device settings. In other embodiments, table entries for inoperative device settings are removed and device software has a program that executes after software updates to restore alignment. Referring now to FIG. 5 , a flow diagram shows operation of mobile electronic device 200 in accordance with an embodiment of the present invention. Before the flow diagram begins, device 200 is booted and default settings 330 and user settings 340 initialize to their current values. Device 200 then monitors for an event ( 510 ). If the event is a software update, device software 310 and default settings 330 are updated ( 520 ). Software updates are prompted by receipt from a software update server over wireless interface 210 of a delta package including updated device software 310 and one or more valid or invalid update values for default settings. Current values for affected default settings are replaced with the update values. Any update values that pertain to new device settings are appended as a new table entry. Device 200 monitors for the next event ( 510 ) after completing the software update. If the event is a user settings update, user settings are updated ( 530 ). User settings updates are prompted by input by a user on user interface 230 of one or more valid update values for user settings, or a reset instruction. Current values for affected user settings 340 are replaced with the valid update values. If a reset instruction is input, all current user settings 340 are reset to invalid. Device 200 monitors for the next event ( 510 ) after completing the user settings update. Finally, if the event is a request for a device setting, the user setting for the device setting is interrogated and it is determined whether the user setting is valid ( 540 ). If the user setting is valid, the valid user setting is returned for application on device 200 ( 550 ). If the user setting is invalid ( 560 ), the default setting for the device setting is interrogated and returned for application on device 200 ( 560 ). Device 200 monitors for the next event ( 510 ) after processing the request for the device setting. It will be appreciated by those of ordinary skill in the art that the invention can be embodied in other specific forms without departing from the spirit or essential character hereof. The present description is therefore considered in all respects to be illustrative and not restrictive. The scope of the invention is indicated by the appended claims, and all changes that come with in the meaning and range of equivalents thereof are intended to be embraced therein.	A mobile electronic device with fragmented device settings enables preservation of user-defined settings during over-air software updates. Such a device in one aspect comprises a memory adapted to store at least one device setting including a default setting determined independent of any user of the device and a user setting determinable by a user of the device; a wireless interface adapted to receive a software update; and a processor communicatively coupled to the wireless interface and the memory and adapted to update the default-setting in response to the software update.	7
RELATED APPLICATION This application is a continuation-in-part of application Ser. No. 13/652,315 filed Oct. 15, 2012, which claims the benefit of U.S. Provisional Application No. 61/546,796 filed Oct. 13, 2011, which is incorporated herein by reference in its entirety. FIELD OF THE INVENTION The claimed invention relates to PTFE (polytetrafluorethylene) jacketed tantalum tipped and also PTFE tipped thermowells, more particularly to thermowells for use in unusually difficult industrial applications. BACKGROUND OF THE INVENTION Thermowells are commonly used in industry to protect sensitive temperature measurement instruments such as thermocouples, RTDs (Resistance Temperature Detectors), or thermometers from conditions of process fluids that may cause the bare instrument to suffer damage. The claimed invention relates to a new configuration for the construction of such thermowells for use in unusually difficult industrial applications such as pharmaceutical and chemical process plants, semiconductor manufacturing facilities and other similar facilities with process environments that may include some or all of: Highly corrosive fluids Difficult mechanical conditions such as rapid or turbulent fluid flows Reasonably high process temperatures and/or pressures. In such industrial applications, maintaining tight control over process temperatures via quick detection and feedback of temperature changes is highly desirable to maintain the most efficient and effective processes. This problem is usually taken care of by employing carbon steel, stainless steel or other common metal thermowells. For highly corrosive environments where common metals do not stand up, the wells may be coated with corrosions resistant materials such as PTFE or made from solid PTFE or similar material. In certain cases where unusually aggressive instances of the situations described above are encountered, PTFE jackets much thicker than coatings are employed, often with corrosion resistant tantalum cups to improve the sensitivity may be employed. However all the above solutions have limitations that prevent their use in the most aggressive environments while achieving sensitivities that foster efficient processes. They may: Have length limitations Not be strong enough to handle fast moving or agitated fluids or If fabricated to overcome such limitations, lose sensitivity slowing reaction times to process temperature changes. These situations provide an opportunity to overcome such limitations by using a combination of some previously employed design elements plus new design elements in a unique combination that allows much improved fluid temperature measurement and control in aggressive fluid environments. OBJECTS AND SUMMARY OF THE INVENTION In view of the above-described shortcomings in the art, it is an object of the claimed invention to provide a corrosion resistant thermowells with thin wall tips, preferably, one that can be used in unusually difficult industrial applications such as pharmaceutical and chemical process plants, semiconductor manufacturing facilities and other similar facilities with process environments that may include some or all of: highly corrosive fluids, difficult mechanical conditions such as rapid or turbulent fluid flows, and/or reasonably high process temperatures and/or pressures. The importance of well-designed, high quality thermowells used widely in industrial applications cannot be overemphasized. They need to be strong, highly corrosion resistant, and allow for quick response to changes in temperature. Further, there is a need to provide a design with the flexibility to be tuned to avoid vibrations that can be induced by fluid flows. There have been many instances of thermowell failures, many of which have been attributed to such vibrations induced by fluid flows. One such well-publicized event occurred in 1995, when the failure of a thermowell from vibration at the Monju nuclear power plant in Japan caused leakage of molten sodium coolant resulting in the shutdown of the plant. It is an object of the claimed invention are to provide a thermowell that protects the most sensitive and responsive thermocouples, RTDs, or thermometers that are usually thin to provide high sensitivity; for example, those as small as 1/16″ diameter. It is an object of the claimed invention to provide a thermowell that provides high corrosion resistance by allowing the basic metal well to be encapsulated by a jacket made from a corrosion resistant material, preferably a highly corrosion resistant material, such as polytetrafluoroethylene (PTFE). It is an object of the claimed invention to provide a thermowell that enables the basic metal well to be made from commercially available pipes or tubes. Such pipe or tube enable a wide choice in preparing a design that is flexible enough to incorporate as needed, large diameters, heavy wall thicknesses, high strength metals and/or corrosion resistant metals where users require that for a wide variety of fluid measurement applications. It is an object of the claimed invention to provide a thermowell that provides enhanced conductivity and thus responsiveness by employing a cup, at the point which temperature needs to be measured, made from corrosion resistant metal conductive material (such as tantalum) or from a thin-walled corrosion resistant plastic material (such as PTFE) while controlling costs by utilizing at the point which temperature needs to be measured, a small diameter and thin wall design. It is an object of the claimed invention to provide the thermowell as aforesaid that further enhances conductivity and responsiveness while controlling costs by utilizing a step-down diameter for the tip. It is an object of the claimed invention to provide a thermowell that enables the use of commercially available thermocouples, RTDs, and thermometers that feature thin diameters and spring loading. The former enables greater instrument sensitivity and the latter ensures close contact of the tip to the metal housing at the bottom. It is an object of the claimed invention to provide the thermowell as aforesaid that allows for comparatively easy and accurate insertion of thin diameter thermocouples, RTDs, and thermometers by creating a centering insertion guide using a strong metal tube (such as a stainless steel tube) that leads to a conductive material such as copper at the tip. In the tantalum tipped embodiment the copper at the tip also acts as a reinforcement for the thin wall cup to permit use of the wells at higher pressures. In the PTFE tipped embodiment the copper at the tip also acts as a reinforcement for the thin PTFE wall at the tip to permit use of the wells at higher pressures. It is an object of the claimed invention to provide the thermowell as aforesaid whose design permits the manufacture of varying lengths—short ones to be used in piping systems, often inserted into elbows or tees, and long ones to reach far into large process vessels and normally installed in vessel nozzles It is an object of the claimed invention to provide the thermowell as aforesaid that can be tuned to avoid vibrations induced by fluid flows by utilizing a highly flexible arrangement of design elements. It is an object of the claimed invention to provide the thermowell as aforesaid that can be specified with flanged connections to ensure strong connections to industry standard piping and vessel systems. It is an object of the claimed invention to provide the thermowell as aforesaid that further ensures quick response to fluid temperature changes by incorporating a conductive paste at the critical contact surface. In accordance with an exemplary embodiment of the claimed invention, a device provides isolation between a temperature sensor and a fluid to be measured. A metal guide tube of the device receives the temperature sensor. The metal guide tube has a top end and a bottom end. A conductive well of the device has a top end and a bottom end having a base. The top end has an outer diameter greater than an outer diameter at the bottom end. The outer diameter at the bottom end being partially threaded with buttress threads. The conductive well surrounds the bottom end of the metal guide tube. The conductive well is brazed to the metal guide tube. A metal tube of the device surrounds the top end of the conductive well and a remaining portion of the metal guide tube. The conductive well is brazed to the metal tube. A corrosion resistant jacket subassembly of the device has at least two outer diameters excluding a corrosion resistant flare and encapsulates the metal tube and a remaining portion of the conductive well not surrounded by the metal tube. A thin walled, corrosion resistant and heat conductive metal cup of the device has an outer diameter smaller than a larger of the two outer diameters of the corrosion resistant jacket subassembly. The corrosion resistant and heat conductive metal cup is located at a base of the conductive well and entirely covers a bottom end of the corrosion resistant jacket subassembly. A metal flange of the device secures a top end of the device and surrounds the metal guide tube at the top end opposite the corrosion resistant and heat conductive cup. A metal half coupling of the device is connected to the metal flange. The corrosion resistant flare at the end of the corrosion resistant jacket subassembly seals to a bottom face of the metal flange. The corrosion resistant flare has an outside diameter covering part or all of the bottom face of the flange and an inside diameter substantially equal to the larger of two outer diameters of the corrosion resistant jacket subassembly. The base of the conductive well comprises an opening to receive a tip of the temperature sensor. In accordance with an exemplary embodiment of the claimed invention, the aforesaid conductive well is a copper conductive well. In accordance with an exemplary embodiment of the claimed invention, the aforesaid corrosion resistant and heat conductive cup is a tantalum cup covering the base of the conductive well to provide a quick response to temperature changes. In accordance with an exemplary embodiment of the claimed invention, the aforesaid corrosion resistant and heat conductive cup is a vanadium cup covering the base of the conductive well to provide a quick response to temperature changes. In accordance with an exemplary embodiment of the claimed invention, the aforesaid metal tube is made from one of the following: carbon steel, stainless steel or alloy. In accordance with an exemplary embodiment of the claimed invention, the aforesaid corrosion resistant jacket subassembly is a polytetrafluoroethylene (PTFE) jacket. In accordance with an exemplary embodiment of the claimed invention, the aforesaid conductive well is a threaded conductive well and the corrosion resistant jacket subassembly is threaded to fit onto the threaded conductive well. In accordance with an exemplary embodiment of the claimed invention, the aforesaid corrosion resistant and heat conductive cup is swaged over the corrosion resistant jacket subassembly to provide a leak tight seal. In accordance with an exemplary embodiment of the claimed invention, the aforesaid corrosion resistant jacket subassembly comprises two components that are fused or welded together. In accordance with an exemplary embodiment of the claimed invention, a face at the base of the aforesaid conductive well is installed using a thin layer of conductive paste to further improve response time. In accordance with an exemplary embodiment of the claimed invention, a device provides isolation between a temperature sensor and a fluid to be measured. A metal guide tube of the device receives the temperature sensor. The metal guide tube has a top end and a bottom end. A conductive well of the device has a top end and a bottom end having a base. The top end has an outer diameter greater than an outer diameter at the bottom end. The conductive well surrounds the bottom end of the metal guide tube. The conductive well is brazed to the metal guide tube. A metal tube of the device surrounds the top end of the conductive well and a remaining portion of the metal guide tube. The conductive well is brazed to the metal tube. A corrosion resistant jacket subassembly of the device has at least two outer diameters excluding a corrosion resistant flare and encapsulates the metal tube and a remaining portion of the conductive well not surrounded by the metal tube. A thin walled, corrosion resistant plastic tip of the device has an outer diameter smaller than a larger of the two outer diameters of the corrosion resistant jacket subassembly. The corrosion resistant plastic tip is located at a base of the conductive well and entirely covers and contiguous with the bottom end of the corrosion resistant jacket subassembly. A metal flange of the device secures a top end of the device and surrounds the metal guide tube at the top end opposite the corrosion resistant plastic tip. A metal half coupling of the device is connected to the metal flange. The corrosion resistant flare at the end of the corrosion resistant jacket subassembly seals to a bottom face of the metal flange. The corrosion resistant flare has an outside diameter covering part or all of the bottom face of the flange and an inside diameter substantially equal to the larger of two outer diameters of the corrosion resistant jacket subassembly. The base of the conductive well comprises an opening to receive a tip of the temperature sensor. In accordance with an exemplary embodiment of the claimed invention, the aforesaid corrosion resistant plastic tip is a corrosion resistant plastic film or membrane covering the base of the conductive well and responsive to temperature changes. In accordance with an exemplary embodiment of the claimed invention, the aforesaid corrosion resistant jacket subassembly is threaded to fit onto the conductive well that is partially threaded with buttress threads. In accordance with an exemplary embodiment of the claimed invention, the aforesaid corrosion resistant plastic tip is a contiguous part of the corrosion resistant jacket subassembly. BRIEF DESCRIPTION OF THE DRAWINGS FIGS. 1A-B are cross-sectional schematic views of a corrosion resistant thermowell with thin wall tip in accordance with an exemplary embodiment of the claimed invention; FIGS. 2A-2B are detailed cross-sectional schematic views of the respective thin wall tip area of the corrosion resistant thermowells of FIGS. 1A-B in accordance with an exemplary embodiment of the claimed invention; FIGS. 3A-3B show various schematic views of the metal flange of the corrosion resistant thermowell in accordance with an exemplary embodiment of the claimed invention; FIG. 4 is a cross-sectional schematic view of the metal tube of the corrosion resistant thermowells in accordance with an exemplary embodiment of the claimed invention; FIGS. 5A-B are cross-sectional schematic views of the respective conductive wells of the corrosion resistant thermowells of FIGS. 1A-B in accordance with an exemplary embodiment of the claimed invention; FIGS. 6A-6B are cross-sectional schematic views of a respective section or sub-assembly of the PTFE jacket of the corrosion resistant thermowells of FIGS. 1A-B in accordance with an exemplary embodiment of the claimed invention; FIG. 7 is a cross-sectional schematic view of a section or sub-assembly of the PTFE jacket of the corrosion resistant thermowell in accordance with an exemplary embodiment of the claimed invention; FIGS. 8A-B are cross-sectional schematic views of a respective tip of the PTFE jacket of the corrosion resistant thermowells of FIGS. 1A-B in accordance with an exemplary embodiment of the claimed invention; FIG. 9 is a schematic view of the heat conductive cup of the corrosion resistant thermowell of FIG. 1A in accordance with an exemplary embodiment of the claimed invention; FIG. 10 is a schematic view of the conductive support tip of the corrosion resistant thermowell of FIG. 1B in accordance with an exemplary embodiment of the claimed invention; FIG. 11 is a cross-sectional view of a threaded half coupling component/part of the corrosion resistant thermowell in accordance with an exemplary embodiment of the claimed invention; FIG. 12 is a cross-sectional view of the metal guide tube of the corrosion resistant thermowell in accordance with an exemplary embodiment of the claimed invention, and While in the illustrated embodiments features of the invention have been put forward, it is to be understood that the invention is not limited to the precise form illustrated, and the changes may be made thereto without departing from the spirit or substance of the invention. DETAILED DESCRIPTION OF THE EMBODIMENTS Referring to the drawings in detail, FIGS. 1A-B show the thermowells 20 in accordance with an exemplary embodiment of the claimed invention. Thermowells are commonly used in process containment devices such as process vessels or pipes to protect sensitive temperature measuring devices such as thermocouples, RTDs, or thermometers from damage due to rapid fluid flows and/or aggressively corrosive environments. The claimed thermowell provides extreme corrosion resistance at temperatures up to the allowable temperatures for the polytetrafluorethylene (PTFE) material, i.e., 260° C. (500° F.). As shown in FIGS. 1A-1B , the claimed thermowell 20 has a shell comprising a metal flange 21 , a metal tube 22 and a conductive well 23 , that can be made from readily available metals. The shell provides the basic structure and strength of the thermowells 20 . The particular design features of the claimed thermowells 20 allow for the use of an unusually wide range of lengths and diameters. Long lengths (up to 4 meters or more) are often needed to provide quick response to changes in fluid temperature at a remote point, one that can be reached by insertion of long length thermowell 20 into a flanged opening in a process vessel or pipe. Large diameters (up to 100 mm or more) are often needed to provide extra strength to such long length thermowells 20 to resist rapid and/or turbulent fluid flows. The common metals used for the metal flange 21 , the metal tube 22 and the conductive well 23 can be, but not limited to, carbon steel, stainless steel, or other alloys such as Monel®. Monel® is a registered trademark of Huntington Alloys Corporation. As shown in FIGS. 1A-B and 5 A-B, in accordance with an exemplary embodiment of the claimed invention, a highly conductive material such as copper can be used at the tip to provide the conductive well 23 with superior sensitivity to changes in temperature at the remote point where the measuring tip of the thermocouple or thermometer is located. As shown in FIGS. 1A-B , in accordance with an exemplary embodiment of the claimed invention, the metal tube 22 is welded or brazed to the metal flange 21 . As shown in FIGS. 2A-B , in accordance with an exemplary embodiment of the claimed invention, the conductive well 23 is brazed to the metal tube 22 . As shown in FIGS. 1A-B , to enhance the protection against corrosive environments, in accordance with an exemplary embodiment of the claimed invention, the metal components/parts (metal flange 21 , metal tube 22 , conductive well 23 ) that would normally come into contact with the fluid requiring temperature measurement are covered with highly corrosion resistant materials. In accordance with an exemplary embodiment of the claimed invention, a jacket 24 made of PTFE (or PTFE jacket 24 ) covers the face of the metal flange 21 of FIGS. 3A-B , the metal tube 22 , and most of the conductive well 23 . It is appreciated that other plastics can be used to achieve alternate properties. As shown in FIGS. 6A-B , 7 and 8 A-B, in accordance with exemplary embodiment of the claimed invention, the PTFE jacket 24 comprises corrosion resistant flare 35 and two components or parts 25 and 26 . Preferably, these two components 25 and 26 are fused or welded together to form the PTFE jacket 24 . A feature of the conductive well 23 and the mating jacket tip 26 is a thread 40 . The PTFE jacket 24 tends to expand in length with the increasing temperature, thereby causing the heat conductive cup 27 or the thin corrosion resistant tip 27 ′ to move away from the tip of the temperature measuring device, the thermocouple, RTD or thermometer residing in a pocket 31 . If such expansion is not constrained or minimized, the transmission or conduction of the changing temperatures would slow dramatically, which would be counter to the basic purpose of the thermowells. In accordance with an exemplary embodiment of the claimed invention, the PTFE jacket 24 is shrunk over the metal tube 22 to constrain the expansion of the PTFE jacket 24 . In accordance with another embodiment of the claimed invention, the PTFE jacket 24 is mechanically fastened to its mating conductive well 23 to constrain the expansion of the PTFE jacket 24 , for example by pinning or threading the PTFE jacket 24 to the conductive well 23 . Alternatively, in accordance with an exemplary embodiment of the claimed invention, as shown in FIGS. 1A-B , 2 A- 2 B, 5 A- 5 B, 6 A- 6 B, 8 A- 8 B, the PTFE jacket 24 and the conductive well 23 have mating buttress threads 40 , which, because of their flat, shelf-like mating surfaces, form a strong constraint preventing the undesirable movement of the heat conductive cup 27 or the thin corrosion resistant tip 27 ′ away from the temperature measuring device. Turning now to FIGS. 1A-B , 9 and 10 , because PTFE is not a good conductor, in accordance with an exemplary embodiment of the claimed invention, the bottom most portion of the conductive well 23 is covered with a highly corrosion resistant tantalum cup 27 or thin corrosion resistant tip 27 ′. As shown in FIG. 2A , in accordance with one exemplary embodiment of the claimed invention, the heat conductive cup or tantalum cup 27 is swaged over the PTFE jacket 24 to provide a leak tight seal between its inner surface and the outer surface of the jacket tip 26 . In addition to its excellent corrosion resistance, tantalum is an excellent conductor of heat thus providing the potential for a quick response to changes in fluid temperature. Alternatively, as shown in FIG. 2B , in accordance with an exemplary embodiment of the claimed invention, a thin corrosion resistant tip 27 ′, integral with jacket tip 26 as shown in FIG. 8B , provides a leak tight seal with the main body of the jacket tip 26 . Of course the material, PTFE, of the thin corrosion resistant tip 27 ′, is not a good conductor. But when certain extremely corrosive fluids attack tantalum, PTFE may be necessary for those applications. In accordance with an exemplary embodiment of the claimed invention, the corrosion resistant tip 27 ′ is made very thin to provide adequate response time. In accordance with an exemplary embodiment of the claimed invention, FIG. 9 shows a small size thin walled tantalum cup 27 that is used for all lengths and diameters of the corrosion resistant theremowells with thin wall tantalum tips 20 (hereinafter “tantalum tipped thermowells” 20 ) of FIG. 1A . The small diameter of the tantalum cup 27 allows for use of a thin cup with advantages described herein. First, when the tantalum cup 27 is supported by the base machined at the tip of the conductive well 23 , the assembly can be used at higher fluid pressures than if just a thin unsupported cup is used. Second, the tantalum cup 27 is smaller in diameter than the metal tube 22 , thereby permitting the tantalum cup 27 to be subjected to higher pressures than the typically used larger diameter cups. Third, the use of the small thin walled tantalum cup 27 in the claimed invention reduces the cost of the device because tantalum is a high cost material. In accordance with an exemplary embodiment of the claimed invention, FIG. 2B shows the thin corrosion resistant PTFE tip 27 ′. The PTFE tip 27 ′ is supported by a thin, small diameter conductive support tip 38 that allows for the PTFE corrosion resistant tip 27 ′ to be thin walled. So even though PTFE is not a good conductor, the thin wall of the PTFE tip 27 ′ minimizes its resistance to temperature transmission. Thus the temperature probe residing in the pocket 31 will still be sensitive to temperature changes, albeit more slowly than with the tantalum cup 27 . In certain cases, where needed, corrosion resistant metals other than tantalum, for example vanadium, may be substituted for the tantalum, and achieve much the same advantages gained with the tantalum. Turning now to FIGS. 1A-B , 11 and 12 , in accordance with an exemplary embodiment of the claimed invention, the two remaining metal components or parts: the threaded metal half coupling 28 is welded to the metal flange 21 , and the metal guide tube 29 , advantageously allows standard, commercially available thin temperature measuring devices to be inserted into the conductive well 23 , reside in the pocket 31 , reach the bottom of the conductive well 23 , and make contact with the tantalum cup 27 as shown in FIG. 2A or make contact with a thin wall metal tip 38 that supports the PTFE tip 27 ′ as shown in FIG. 2B , without bending or kinking As shown in FIGS. 2A-B , in accordance with an exemplary embodiment of the claimed invention, to keep the metal guide tube 29 in place it is brazed to the conductive well 23 . As shown in FIGS. 2A-B and 5 A-B, to improve the response time to fluid temperature changes, in accordance with an exemplary embodiment of the claimed invention, the tip of the conductive well 23 has a specially machined thin base with a hole or pocket 31 for thermocouple, RTD, or thermometer, machined to fit the 1/16″ or larger tip of the temperature measuring device. The design of the claimed invention advantageously allows for such small diameter thermocouples, even in long length thermowells 20 . It is noted that the small diameter thermocouples improve response times. Also, as shown in FIGS. 2A-B , in accordance with an exemplary embodiment of the claimed invention, the face 45 at the base of the conductive well 23 or face 45 of the conductive support tip 38 , may also be installed using a thin layer of conductive paste 30 to further improve the response time. Various omissions, modifications, substitutions and changes in the forms and details of the device illustrated and in its operation can be made by those skilled in the art without departing in any way from the spirit of the present invention. Accordingly, the scope of the invention is not limited to the foregoing specification, but instead is given by the appended claims along with their full range of equivalents.	A corrosion resistant thermowells with thin wall tips for use in unusually difficult industrial applications such as pharmaceutical and chemical process plants and semiconductor manufacturing facilities. These facilities have process environments that may include at least one of the following: highly corrosive fluids, difficult mechanical conditions such as rapid or turbulent fluid flows, and/or reasonably high process temperatures and/or pressures. The corrosion resistant thermowells provide isolation between a temperature sensor and a fluid to be measured.	6
BACKGROUND OF THE INVENTION 1. Field of the invention The use of surfactants, usually anionic or nonionic in kind, in the textile pretreatment of specifically cellulosic fibers is well known. 2. Description of the prior art The textile pretreatment of man-made fibers removes the manufacturer's spin finishes, further-processing finishes and coning oils from the fibers. From wovens specifically of cellulosic fibers the pretreatment removes sizes, inter alia. In the case of knits, including cellulosics, the primary concern is the removal of further-processing finishes and coning oils. All these processes involve a thorough wash in an aqueous medium with surfactants. In a modern finishing operation, the textile pretreatment auxiliaries are metered into the textile pretreatment stage in liquid form by directly pumping the products from the drums in which they were supplied by the textile auxiliaries manufacturer into the washers. For a surfactant to be used in today's pretreatment it has to be liquid and pumpable. The other properties desired of a textile pretreatment surfactant besides detergency are wettability, emulsifiability, foam control and good released-soil dispersion. With many surfactants good pumpability is frequently achieved by deep dilution with water to an active content of about 20-30%, since nonionic aqueous surfactant mixtures frequently pass through a marked gel phase at an active content of about 40-80%. This gel phase is marked by a high viscosity of at least 200 mPas (measured at 20° C. in a 30% strength by weight aqueous solution), which prevents the metered addition of such surfactant mixtures by pumping. It should be expressly pointed out that with nonionic surfactants good detergency is ascribed to the appearance of pronounced gel phases on dilution with water. For instance, ethoxylated fatty acids have surfactant properties and are usually dilutable with water without gel phases, but are poor detergents; the same is true of alkyl alkoxylates based on short-chain alcohols. Alkoxylated fatty alcohols based on saturated or unsaturated alcohols are frequently pasty, inhomogeneous, pass through pronounced gel phases on dilution with water and hence are difficult to use on their own in textile pretreatment. It is an object of the present invention to provide a nonionic surfactant mixture which is liquid and readily pumpable, which does not have a pronounced gel phase on dilution with water and which nonetheless possesses the high detergency of a surfactant that does pass through a gel phase. SUMMARY OF THE INVENTION Surprisingly, it has been found that surfactants that are viscous on their own and pass through pronounced gel phases with water become pumpable, and water-dilutable without pronounced gel phases, on addition of small amounts of additives that on their own do not have a strong surfactant action. The present invention accordingly provides a surfactant mixture comprising 33-95 parts by weight, preferably 60 to 80 parts by weight, of at least one alkoxylated fatty alcohol (component I) of the formula I ##STR1## where R 1 is C 9 -C 18 -alkyl or C 9 -C 18 -alkenyl, R 2 is hydrogen or methyl, and n is from 5 to 30, and 5-67 parts by weight, preferably 20-40 parts by weight, of at least one alkoxylated fatty acid (component II) of the formula II ##STR2## where R 1 is C 9 -C 18 -alkyl or C 9 -C 18 -alkenyl, R 2 is hydrogen or methyl, and n is from 5 to 30, or 5-67 parts by weight, preferably 20-40 parts by weight, of at least one alkoxylated alcohol (component III) of the formula III ##STR3## where R 3 is C 1 -C 6 -alkyl, R 2 is hydrogen or methyl, and n is from 5 to 30, or 5-67 parts by weight, preferably 20-40 parts by weight, of a mixture of at least one alkoxylated fatty acid (component II) and at least one alkoxylated alcohol (component III). DESCRIPTION OF THE PREFERRED EMBODIMENTS Component I is an alkoxylated fatty alcohol of the formula I, preferably an alkoxylated fatty alcohol with a pronounced gel phase, of the formula I, where R 1 is C 10 -C 15 -alkyl or C 10 -C 15 -alkenyl and n is from 5 to 8. Particularly suitable alkoxylated fatty alcohols are prepared from alcohols of the type coco fatty alcohol, oleyl alcohol, C 14/15 oxo alcohol, isotridecyl alcohol and C 9/11 oxo alcohol. Component II is an alkoxylated fatty acid of the formula II, preferably an ethoxylated fatty acid that is dilutable with water without gel phase. Component III is an alkoxylated lower alcohol, preferably with a molecular weight above 500. The aforementioned alkoxylated compounds can be used both in the form of block copolymers or in the form of random copolymers. In the case of the use of a mixture, the ratio of alkoxylated fatty acid (component II) to alkoxylated alcohol (component III) is customarily 1-9:9-1. Preferably, the surfactant mixture of this invention comprises 33.3 parts by weight of component I and 66.6 parts by weight of component II or component III or 80 parts by weight of component I and 20 parts by weight of component II or component III. As part of the textile pretreatment, the claimed surfactant mixtures of this invention, which are based on nonionic components, may include other auxiliaries important for the pretreatment, for example, anionic complexing agents for the peroxide bleach, P-free dispersants of anionic provenance, e.g. gluconates, heptagluconates, acrylates, etc., foam inhibitors based on silicone or of the trialkyl phosphate type. Such auxiliaries are customarily included in an amount of up to 30% by weight, preferably 1-25% by weight, based on the surfactant mixture. To intensify the washing process, the claimed nonionic systems may include washing surfactants of the anionic kind, for example alkane- or olefin-sulfonates, preferably linear alkanesulfonates, ethercarboxylates, sarcosides, petroleum sulfonates, alkylbenzenesulfonates, etc. The surfactant mixtures of this invention provide the textile industry with surfactant mixtures for use as textile auxiliaries for man-made fibers and natural fibers, especially for the textile pretreatment of man-made fibers. The hitherto adopted way of rendering nonionic surfactants pumpable, viz. prediluting with water, skipping the gel phases and supplying the textile industry with dilute surfactant systems, has become redundant as a result. The surfactant mixtures of this invention make it possible to use alkoxylated fatty alcohols which are otherwise difficult to accommodate in textile pretreatment. Advantageously, the surfactant mixtures of this invention have high detergency in the textile pretreatment even without gel phases. That is, the above statement that individual surfactants which are dilutable with water without gel phases, such as coco fatty acid ethoxylated with 10 mol of ethylene oxide, have only a moderate detergency in the textile sector, does not apply to the surfactant mixtures of this invention. In addition to good detergency, the surfactant mixtures exhibit excellent foam formation, which is stable over a wide pH range. EXAMPLES A1) The surfactant used was a C 14/15 oxo alcohol with about 8 mol of ethylene oxide (component I). Product data: ______________________________________Appearance at 20° C. white soft pastePour point about 20° C.Drop point about 30° C.HLB about 12Cloud point (DIN 53917) 78 ± 2° C.; not pumpable5 g in 25 cm.sup.3 of 25%strength aqueous BDG______________________________________ This surfactant was blended with the following surfactants: ______________________________________A: Coco fatty acid · 10 EO (component II)B: Oleic acid · 5 EO (component II)C: Butanol · 10 EO · 10 PyO (random) (component III)D: C.sub.12/15 oxo alcohol · 7.5 EO · 4 (component I)E: C.sub.10/12 Ziegler alcohol (component I) linear · 4 EO · 4 PyO______________________________________ The following mixtures were prepared and tested for their pourability at room temperature: ______________________________________Surfact-ant Ratio Appearance Viscosities______________________________________A1 pure paste 1:1 or 1:2 with H.sub.2 OA 1:1 clear, liquid low, lowB 1:1 clear, liquid low, lowC 1:1 clear, liquid low, lowD 1:1 clear, liquid low, lowE 1:2 low, lowA 1:2 clear, liquid low, lowC 1:2 clear, liquid low, lowD 1:2 clear, liquid low, lowE 1:2 clear, liquid low, lowA 2:1 clear, liquid low, lowB 2:1 clear, liquid low, lowC 2:1 clear, liquid low, lowD 2:1 clear, liquid low, lowE 2:1 clear, liquid low, lowA 3:1 clear, liquid low, lowB 3:1 clear, liquid low, lowC 3:1 clear, liquid low, lowD 3:1 clear, liquid low, lowE 3:1 clear, liquid low, lowA 4:1 clear, liquid low, lowC 4:1 clear, liquid low, lowD 4:1 clear, liquid low, lowE 4:1 clear, liquid low, low______________________________________ The foam heights and the persistance of the foam after 30, 60 and 120 sec in aqueous solutions were determined for a number of stable, pumpable mixtures having low gel phases (viscosity less than 100 mPas, measured at 20° C., in a 50% strength by weight or 33.3% strength by weight solution) on dilution with water. At the same time the deter-gency was determined in % whitening (reflectance) of cotton test fabrics. ______________________________________ DetergencyFoam height (cm) (% reflectance)30 sec 60 sec 120 sec 40° C. 80° C.______________________________________A1acid 21 19 17.5 50.5 51neutral 26 23 20 48.2 58alkaline 26 23 21 48.2 58A1/A 1:2acid 26 23 20 49 53neutral 22 20 18 47 57alkaline 22 21 19 48 47A1/C 1:2acid 30 25 23 48 47neutral 22 20 17 47 49alkaline 26 22 18 48 50A1/D 1:2acid 25 21 17 46 47neutral 20 17 14 47 49alkaline 23 17 15 48 49A1/E 1:2acid 27 22 19 49 47neutral 22 17 14 51 48alkaline 18 14 13 50 49A1/C 4:1acid 24 22 20 50 49neutral 30 26 22 51 50alkaline 22 20 18 50 51A1/E 4:1acid 23 21 18 49 49neutral 28 23 21 50 51alkaline 21 19 16 51 49______________________________________ The mixtures of this invention are stable, produce no increase in the foam heights and are similar in detergency to the surfactant used alone.	Surfactant mixture comprising 33-95 parts by weight of at least one alkoxylated C 9 -C 18 fatty alcohol (component I) having 5 to 30 oxyalkylene groups and 5-67 parts by weight of at least one alkoxylated C 9 -C 18 fatty acid (component II) having 5 to 30 oxyalkylene groups or 5-67 parts by weight of at least one alkoxylated C 1 -C 6 alcohol (component III) having 5 to 30 oxyalkylene groups or 5-67 parts by weight of a mixture of at least one alkoxylated fatty acid (component II) and at least one alkoxylated alcohol (component III).	3
BACKGROUND [0001] 1. Field of the Invention [0002] The present application relates to a cable for transmitting signals. [0003] 2. Background Arts [0004] A Japanese Patent Application laid open No. 2005-135840A has disclosed a cable implemented with connectors in respective ends thereof. The connector disclosed therein includes a function to reshape a receiving signal and/or a transmitting signal. [0005] Recently, one type of a cable for transmitting a signal, which includes in a connector attached to an end thereof a signal processing circuit, such as clock data recovery (CDR) circuit, is preferably applied to the connection between servers, storage, switches, and so on in the data center. Such application has used cables with the type of, the twisted-pair cable, the twin-Ax cable, which is often named as “twinax” cable, and so on with the connector in the end thereof. SUMMARY OF THE INVENTION [0006] An aspect of the present application relates to a cable for connecting between two apparatuses. The cable comprises a connector and a metal wire. The connector includes a circuit unit electrically connected to one of the systems and plugged to the one of the systems. The metal core is electrically connected to the circuit unit in the connector. A feature of the cable of the present application is that the circuit unit provides at least one of a transmitter and a receiver. The transmitter receives an input signal in the differential form from the system and generates a transmitting signal in the single-ended form to the metal wire. The receiver receives the transmitting signal in the single-ended form from the metal wire and generates an output signal in the differential form to the system. BRIEF DESCRIPTION OF THE DRAWINGS [0007] The foregoing and other purposes, aspects and advantages will be better understood from the following detailed description of a preferred embodiment of the invention with reference to the drawings, in which: [0008] FIG. 1 schematically illustrates a cable for transmitting a signal according to an embodiment of the present application; [0009] FIG. 2 shows a functional block diagram of a portion of the cable shown in FIG. 1 ; [0010] FIG. 3 shows a functional block diagram of a retiming circuit as an example of the circuit unit of the present application; [0011] FIG. 4 is a side cross section of an example of the connector of the present application; [0012] FIG. 5A views a top surface and FIG. 5B views a back surface of the circuit board according to an embodiment of the present application; [0013] FIGS. 6A and 6B view top and back surfaces, respectively, of another circuit board modified from the circuit board of the embodiment; [0014] FIGS. 7A and 7B view top and back surfaces, respectively, of still another circuit board also modified from the embodiment shown in FIGS. 5A and 5B ; [0015] FIGS. 8A and 8B view top and back surfaces, respectively, of still another circuit board modified from the embodiment shown in FIGS. 5A and 5B ; [0016] FIGS. 9A and 9B view top and back surfaces, respectively, of still another circuit board modified from the embodiment shown in FIGS. 5A and 5B ; and [0017] FIGS. 10A and 10B view top and back surfaces, respectively, of still another circuit board modified from the embodiment shown in FIGS. 5A and 5B . DESCRIPTION OF EMBODIMENTS [0018] Some embodiments according to the present application will be described as referring to drawings. However, it is intended that the present invention is not limited to those particular embodiments and modification disclosed, but that the invention include all embodiments falling within the scope of the appended claims. In the description of the drawings, numerals or symbols same with or similar to each other will refer to elements same with or similar to each other without duplicated explanations. [0019] FIG. 1 schematically illustrates a cable 1 A according to an embodiment of the present invention. As shown in FIG. 1 , the cable 1 A comprises a cable bundle 20 and two connectors 10 each attached to respective ends of the cable bundle 20 . The cable bundle 20 includes a plurality of co-axial cables 21 . One of connectors 10 is to be plugged with an external apparatus 101 and electrically connected to the external apparatus 101 . The other connector 10 is also to be plugged with other external apparatus 102 to constitute the electrical connection thereto. [0020] FIG. 2 schematically shows a functional block diagram of the cable 10 . Two connectors 10 each provides a circuit unit 12 , which may include a signal shaper such as a clock data recovery (CDR), a repeater, and so on, having a type of an integrated circuit (IC) 121 . The circuit unit 12 in one of the connector 10 is electrically connected to the external apparatus 101 by plugging the connector 10 with the external apparatus 101 , and the circuit unit 12 in the other of the connector 10 is also coupled with the external apparatus 101 by plugging the other connector 10 with the external apparatus 102 . [0021] The circuit unit 12 includes a transmitter 122 and a receiver 123 , where the transmitter 122 constitutes a part of the IC 121 , receives an input signal S 1 in a pair of input terminals, 121 a and 121 b . The input signal S 1 has the arrangement of the differential signal comprising a positive phase signal Sa 1 and a negative phase signal Sb 1 . The transmitter 122 also provides a terminator 124 which may be a combined circuit of a capacitor and a resistor with resistance of 50 ohm, connected between one of output terminals, 121 c and 121 d , and the ground GND. The terminator 124 may be connected from the one of the output terminals, 121 c and 121 d , and a power line. [0022] The transmitter 122 reshapes the input signal S 1 and outputs the reshaped signals to the paired output terminals, 121 c and 121 d , differentially. Because one of the output terminals 121 d is terminated by the terminator 124 , one of the positive phase signal and the negative phase signal is not transmitted. The other of the output terminals 121 c is connected to one 21 of co-axial cables in the cable bundle 20 . The one of the output terminals 121 c may be electrically connected to the metal wire 21 a of the co-axial cable through a coupling capacitor. The transmitted signal S 2 is the single-ended signal including one of the positive phase signal Sa 1 and the negating phase signal Sb 1 . The transmitted signal S 2 is carried to the other connector 10 through the co-axial cable 21 . [0023] The receiver 123 , which is also involved within the IC 121 , provides a pair of input terminals, 121 e and 121 f . One of the input terminals 121 e is coupled with the metal wire 21 a of the co-axial cable 21 through a coupling capacitor not illustrated in the figures. The other of input terminals 121 f is grounded through the terminator 125 that includes a resistor and a capacitor. The input terminal 121 f may be terminated to the power line. Thus, the IC 121 receives in one of the input terminals 121 e the transmitted signal S 2 , which is the single-ended signal, from the other connector 10 through the co-axial cable 21 . [0024] The receiver 123 in the IC 121 re-shapes the transmitted signal S 2 and provides an output signal S 3 in the pair of output terminals, 121 g and 121 h , to the external apparatuses, 101 or 102 . The output signal S 3 has the arrangement of the differential signal including the positive phase signal Sa 2 and the negative phase signal Sb 2 . FIG. 2 illustrates an arrangement of the circuit unit 12 including both of the transmitter 122 and the receiver 123 . However, the circuit unit 12 may provide only one the transmitter 122 and the receiver 123 . For instance, the arrangement, where the circuit unit 12 in one of the connectors 10 provides only the transmitter 122 , while, the circuit unit 12 in the other connector 10 provides only the receiver 123 , may be applicable to the cable 1 A. [0025] FIG. 3 shows an exemplary block diagram of the IC 121 implemented within the cable 1 A. The transmitter 122 in the IC 121 may provide an equalizer 122 a , a clock data recovery (CDR), and a driver 122 c , where all of them are connected in series and have the differential arrangement. The differential input of the equalizer 122 a is connected to the input terminals, 121 a and 121 b , of the IC 121 , and the differential output of the equalizer 122 a is connected to the differential input of the CDR 122 b , the differential output of the CDR 122 b is connected to the differential input of the driver 122 c , and the differential output 122 c is connected to the pair of output terminals, 121 c and 121 d. [0026] The receiver 123 in the IC 121 also comprises an equalizer 123 a , a CDR 123 b , and a driver 123 c , each having the differential arrangement and connected in series between the pair of input terminals, 121 e and 121 f , and the pair of the output terminals, 121 g and 121 h . In an example shown in FIG. 3 , the IC has the arrangement of, what is called, the re-timing circuit. However, the IC may have other types of the signal re-shaping circuit such as a repeater. When the IC has the arrangement of the repeater, the CDRs implemented in the re-timing circuit shown in FIG. 3 may be removed. [0027] FIGS. 4 and 5 show the arrangement of the connector 10 , where FIG. 4 is a side cross section of the connector 10 , while FIGS. 5A and 5B are top and bottom views of the connector 10 . [0028] The connector 10 of the present embodiment further includes a circuit board 13 having a rectangular substrate made of dielectric material and interconnections provided on both of a top surface 13 a and a back surface 13 b of the dielectric substrate. The circuit board 13 demarcates an area to which the circuit unit 12 is assembled from other areas to which an interface 14 to the external apparatuses, 101 or 102 , and another interface 15 for the cable bundle 20 . [0029] The present embodiment shown in FIGS. 5A and 5B provides the circuit units in both of the top surface 13 a and the back surface 13 b of the circuit board 13 . Specifically, a part of the circuit unit 12 A is mounted on the top surface 13 a , while, another part of the circuit unit 12 B is mounted on the back surface 13 b . As shown in FIG. 5A , the part of the circuit unit 12 A constitutes one IC 121 that includes two transmitters 122 and two receivers 123 . On the other hand, another part of the circuit unit 12 B constitutes another IC 121 that also includes two transmitters 122 and two receivers 123 . FIGS. 5A and 5B omit the terminators 124 and 125 attributed to the circuit units, 12 A and 12 B. [0030] The interface 14 includes a plurality of electrodes, 14 a to 14 d , in both of the top surface 13 a and the back surface 13 b . Specifically, the top surface 13 a provides two pairs of the electrodes, 14 a and 14 b , and two pairs of another electrodes, 14 c and 14 d . The former pairs of the electrodes, 14 a and 14 b , may be those for the input signals S 1 and connected to the input terminals, 121 a and 121 b , of the transmitter 121 corresponding thereto. The later pairs of the electrodes, 14 c and 14 d , may be those for the output signals S 3 and connected to the output terminals, 121 g and 121 h , of the receiver 1232 corresponding thereto. FIGS. 5A and 5B only illustrate the electrodes for the input and output signals, and omit other electrodes for the ground and the power lines. [0031] The other interface 15 , which is disposed on the top surface 13 a of the circuit board 13 , provides four pads 15 a and another four pads 15 b . These pads, 15 a and 15 b , which are electrically connected with respective ends of the metal wire 21 a of the co-axial cable 21 , have width 1.2 to 2.0 times greater than a diameter of the metal wire 21 a and a gap to the next pads greater than the width thereof. [0032] The former pads 15 a may be those for the transmitter and two of them are connected by the AC mode to the output terminal 121 c of the transmitter 122 in the part 12 A of the circuit unit 12 , while, other two are connected also in the AC mode to the output terminal 121 c of the transmitter in another part 12 B of the circuit unit 12 as interposing via holes 16 a . The latter pads 15 b may be those for the receiver. Two of the latter pads 15 b are connected in the AC mode to the input terminal 121 e in the part 12 A of the circuit unit 12 , while, other two of the latter pads 15 b are connected also in the AC mode to the output terminal 121 e in another part 12 B of the circuit unit 12 through via holes 16 b. [0033] Referring to FIG. 4 , the connector 10 further provides a housing 17 to enclose the circuit unit 12 and the circuit board 13 therein. The housing 17 has a parallelepiped arrangement along a the longitudinal direction of the circuit board 13 and having a lid 17 a facing the top surface 13 a of the circuit board 13 and a bottom 17 b facing the back surface 13 b of the circuit board 13 . The housing 17 provides a front opening to constitute an electrical connector accompanied with the interface 14 . The co-axial cables 21 are guided from the rear of the housing 17 . In the embodiment shown in FIG. 4 , a distance from the bottom 17 b of the housing 17 to the back surface 13 b of the circuit board is shorter than a distance from the lid 17 a of the housing 17 to the top surface 13 a of the circuit board 13 . That is, the circuit board 13 is set in the housing 17 offset from the center thereof in the vertical direction. [0034] Advantages of the cable 1 A will be described. The external apparatuses, 101 or 102 , generally processes information by differential signals and outputs these differential signals. The cable 1 A of the embodiment in the transmitter 122 receives the input signal S 1 as the differential signal from the external apparatuses, 101 or 102 , and carries the differential signal as the transmitted signal S 2 by the single-ended signal on the co-axial cable 21 . The cable 1 A in the receiver 123 receives thus carried transmitted signal S 2 as the single-ended signal and generates the output signal S 3 as the differential signal. Thus, the transmitted signal S 2 is transmitted on the signal metal line as the single-ended signal; accordingly, this arrangement becomes free from the skew between two signals constituting the differential signal. The skew between two signals results in the transmission loss. [0035] Also, the single metal line like the co-axial cable 21 comparing with, for instance, a twisted pair cable and/or a twin-Ax cable, makes it possible to form the cable 1 A in further flexible and slim. Accordingly, the cable 1 A between two external apparatuses, 101 and 102 , may enhance the workability of the installation. Moreover, when the signal metal cable has a core cross section substantially equal to sum of core cross sections of the twisted pair cable, or the twin-Ax cable, the transmission loss of the transmitted signal S 2 may be reduced because of the reduction of the series resistance. A communication with a longer haul becomes available. [0036] The metal wire 21 a of the co-axial cable 21 , like the present arrangement, may be directly connected to respective output terminals, 121 c and 121 e of the circuit unit 12 without interposition other electrical components, such as a balun, a common mode choke, and so on to transmit the differential signal. Accordingly, the cable 1 A of the embodiment not only becomes free from the loss due to those electronic components, but the connector may be formed in compact. [0037] The transmitter 122 of the present embodiment provides the pair of output terminals, 121 c and 121 d , one of which is terminated to the ground GND through the terminator 124 and the other is connected to the metal wire 21 a of the co-axial cable 21 . This arrangement effectively brings the function to convert the input signal S 1 with the differential mode into the transmitted signal S 2 of the single-ended arrangement. [0038] Also, the receiver 123 of the present embodiment provides the pair of input terminals, 121 e and 121 f , one of which receives the transmitted signal S 2 , while, the other is grounded. This arrangement preferably realizes the function to convert the transmitted signal S 2 with the single-ended arrangement into the output signal S 2 of the differential arrangement. [0039] The connector 10 provides the circuit board 13 that demarcates the area for mounting the circuit unit 12 from the interfaces, 14 and 15 , the latter of which provides the pads, 15 a and 15 b . This arrangement of the connector 10 preferably realizes the mechanism to electrically connect the external apparatuses, 101 and 102 , the circuit unit 12 , and the co-axial cable 21 . [0040] The part 12 A of the circuit unit 12 is mounted on one of the surface, namely, the top surface 13 a of the circuit board, while, the other part 12 B of the circuit unit 12 is mounted on another of the surface, namely, the back surface 13 b of the circuit board 13 . Thus, the circuit board 13 may provide enough room to mount the circuit unit 12 , which enables the interconnections on the circuit board 13 to wire with widened spaces and to reduce the crosstalk between the interconnections. [0041] The interface 14 may provide electrodes on the top surface 13 a of the circuit board 13 and other electrodes on the other surface, namely, the back surface 13 b of the circuit board 13 . The former electrodes are electrically connected to the part 12 A of the circuit unit 12 , while, the latter electrodes are electrically connected to the other part 12 B of the circuit unit 12 . Thus, the electrodes in the interface 14 may be connected to the circuit unit 14 in respective surfaces, 13 a and 13 b , of the circuit board 13 without interposing via holes. [0042] The pads, 15 a and 15 b , may be provided in only one of surfaces, 13 a or 13 b , of the circuit board 13 . This arrangement of the pads, 15 a and 15 b , enables the co-axial cable 21 in the metal wires thereof to be fixed to respective pads, 15 a and 15 b , by the single side soldering, which may enhance the efficiency of the soldering process. [0043] The circuit board 13 is set within the housing such that a distance from the back surface 13 b thereof to the housing 17 is shorter than a distance from the top surface 13 a to the housing 17 ; that is the circuit board 13 is offset in the vertical direction from the middle of the housing. In a conventional arrangement of the cable, in particular, the conventional arrangement of the circuit board in the connector, the co-axial cables are fixed to the circuit board in both of the top and back surfaces. When the circuit board 13 is offset form the vertical midway of the housing 17 , the surface closer to the housing possibly becomes hard to assemble electronic components thereon. The present embodiment, however, the co-axial cables 21 are fixed only to the top surface 13 a of the circuit board 13 . Accordingly, the back surface 13 b , which is closer to the housing 17 , may be left to mount electronic components thereon. [0044] (First Modification) [0045] FIGS. 6A and 6B are plan views of the circuit board 13 A modified from the aforementioned circuit board 13 , where FIG. 6A shows the top surface 13 a , while, FIG. 6B shows the back surface 13 b thereof. The description below is only for features distinguishable from those of the aforementioned embodiment, and portions not described below are substantially same with those shown in FIG. 5 . [0046] The circuit board 13 A of the modified embodiment provides the area to mount the circuit unit 12 only in one of the top surface 13 a and the back surface 13 b . That is, the whole circuit unit 12 is mounted in the top surface 13 a . As illustrated in FIG. 6A , the circuit unit 12 , which is constituted by a unique IC 121 that includes four transmitters 122 and four receivers 123 . FIGS. 6A , and 6 B omit the terminators, 124 and 125 . [0047] The electrodes, 14 a and 14 b , provided on the top surface 13 a in the interface 14 are connected to the input terminals, 121 a and 121 b , of the transmitter 122 corresponding thereto. Similarly, the electrodes, 14 c and 14 d , formed on the top surface 13 a in the interface 14 are coupled with the output terminals, 121 g and 121 h , of the receiver 123 corresponding thereto. The electrodes, 121 a and 121 b , provided in the back surface 13 b in the interface 14 are connected to the input terminals, 121 a and 121 b , of the transmitter 122 corresponding thereto through the via holes 16 c . Similarly, the electrodes, 14 c and 14 d , formed on the back surface 13 b in the interface 14 are connected to the output terminals, 121 g and 121 h , of the receiver 123 through the via holes 16 D. The pads 15 a for the transmission are connected in the AC mode to the output terminals 121 c of the transmitter 122 only in the top surface 13 a , while, the pads 15 b for the reception are connected in the AC mode to the input terminals 121 e of the receiver 123 only in the topo surface 13 a. [0048] The arrangement of the modified embedment shown in FIGS. 6A and 6B may also enhance the workability of the installation of the cable connecting two external apparatuses, 101 and 102 , but may suppress the transmission loss due to the skew between two signals whose phases are opposite to each other. Moreover, the embodiment shown in FIGS. 6A and 6B installs the whole circuit unit 12 only in one of surfaces 13 a of the circuit board 13 A, which not only makes the assembly for mounting the circuit unit 12 on the circuit board 13 A simple and shortens the process thereof, but also widens the area to mount other electrical components on the back surface 13 b. [0049] The electrodes, 14 a to 14 d , in the interface 14 may be formed in each surfaces, 13 a and 13 b , of the circuit board 13 A, and those electrodes, 14 a to 14 d , are electrically connected to the circuit unit 12 mounted on the top surface 13 a . Even in such an arrangement of the electrodes, 14 a to 14 d , and the circuit unit 12 may show the advantages described above. [0050] (Second Modification) [0051] FIGS. 7A and 7B are plan views of the circuit board 13 B according to the second modification of the first embodiment shown in shown in FIGS. 5A and 5B , where FIG. 7A illustrates the top surface 13 a , while, FIG. 7B shows the back surface of the circuit board 13 B. Explanations below concentrate on points distinguishable from former embodiment and modification, and arrangements not explained are substantially same with those shown in FIGS. 5A to 6B . [0052] The circuit board 13 B of the present modification provides interfaces, 15 A and 15 B, substituted from the interface 15 . The former interface 15 A, which is provided on the top surface 13 a , has two pads 15 a and other two pads 15 b . Also, the interface 15 B provided in the back surface 13 b , has two pads 15 a for the transmission and other two pads 15 b for the reception. Two pads 15 a in the first interface 15 A are connected in the AC mode to the output terminals 121 c of the transmitter 122 corresponding thereto through the interconnection of the top surface 13 a . Two pads 15 a in the second interface 15 B are connected in the AC mode to the output terminals 121 c of the transmitter 122 corresponding thereto through the interconnection on the back surface 13 b and the via holes 16 b . Two pads 15 b in the top interface 15 A are connected in the AC mode to the input terminals 121 e of the receiver 123 corresponding thereto through the interconnection on the top surface 13 a , while, two pads 15 b in the back interface 15 B are connected also in the AC mode to the input terminals 121 e of the receiver 123 corresponding thereto through the interconnection on the back surface 13 b and the via holes 16 a. [0053] The arrangement thus described, similar to the aforementioned arrangements, not only enhance the workability of the installation of the cable 10 connecting two external apparatuses, 101 and 102 , but may suppress the transmission loss due to the skew between two signals whose phases are opposite to each other. Also, the arrangement shown in FIGS. 7A and 7B provides the pads, 15 a and 15 b , for the transmission and the reception in both of top and back surfaces, 13 a and 13 b , of the circuit board 13 B, which enables to widen a space between pads and metal wires 21 a and to reduce the crosstalk between the pads and/or metal wires. [0054] Two types of the crosstalk should be considered, one of which is between the input signals S 1 or between the output signals S 2 , and another is between the input signal S 1 and the output signal S 2 . The former crosstalk is often called as the far end crosstalk (FEXT), and the latter is called as the near end crosstalk (NEXT). The arrangement to widen the space between the pads and the metal wires is effective to reduce both types of the crosstalk. [0055] (Third Modification) [0056] FIGS. 8A and 8B are views of the top surface and the back surface of the circuit board 13 C according to the third modification. Similar to the description for the former modifications, the description below concentrates on points distinguishable from those of the aforementioned modifications, and the arrangements not explained are substantially same with or similar to those of the aforementioned modifications. [0057] The circuit board 13 of the present modification provides, instead of the interface 15 in the side of the co-axial cable 21 , the top interface 15 A in the top surface 13 a and the back interface 15 B in the back surface 13 b . Each interfaces, 15 A, and 15 B, provides two types of pads, 15 a and 15 b . Two pads 15 a for the transmission in the top interface 15 A are connected in the AC mode to the output terminals 121 c of the transmitter 122 corresponding thereto in the top surface 13 a of the circuit board; also, the pads 15 a for the transmission in the back interface 15 B are connected in the AC mode to the transmitter 122 in the back surface 13 b . Two pads 15 b for the reception on the top interface 15 A are connected in the AC mode to the input terminals 121 e of the receiver 123 in the top surface 13 a , while, the pads 15 b for the reception in the back interface 15 B are connected in the AC mode to the input terminals 121 e of the receiver 123 but in the back surface 13 a of the circuit board. [0058] The arrangement thus described as referring to FIGS. 8A and 8B , similar to the aforementioned arrangements, not only enhance the workability of the installation of the cable 10 connecting two external apparatuses, 101 and 102 , but may suppress the transmission loss due to the skew between two signals whose phases are opposite to each other. Also, two types of pads, 15 a and 15 b , are provided in both surfaces, 13 a and 13 b , of the circuit board 13 C, which may widen the space between the pads and metal wires 21 a to reduce the crosstalk between the pads and the metal wires 21 a. [0059] (Fourth Modification) [0060] FIG. 9A is a plan view of the top surface 13 a and FIG. 9B is a plan view of the back surface 13 b of the circuit board 13 D according to the fourth modification of the invention. Similar to the aforementioned modifications, the explanation below concentrates on points different from those of the aforementioned one, and left points not explained are substantially same with those of the former embodiments. [0061] The circuit board 13 D of the present modification provides, substituted from the interfaces, 15 A and 15 B, a top interface 15 C and a back interface 15 D. The top interface 15 A provides two pads 15 a for the transmission and other two pads 15 b for the reception. A feature of the top interface 15 C of the present modification is that these pads, 15 a and 15 b , are arranged close to one edge of the circuit board 13 D to form a room along the other edge opposite to the one edge, that is, the pads, 15 a and 15 b , are unevenly arranged on the top surface 13 a . Accordingly, these pads, 15 a and 15 b , in the top interface 15 A have spaces to the next pads narrower than those of the former modification 13 C shown in FIG. 8A . [0062] Also, the back interface 15 D provides two pads 15 a for the transmission and the other two pads 15 b for the reception. A feature of the arrangement of these pads, 15 a and 15 b , in the back interface 15 D is that a portion of the pads, namely the pads 15 a for the transmission, are arranged along one edge of the circuit board 13 D, while, another portion of the pads, namely the pads 15 b for the reception, are disposed along another edge of the circuit board 15 D, namely, the pads, 15 a and 15 b , are also unevenly arranged in the back surface 13 b of the circuit board. Accordingly, a wide room is left between the pads in a center portion of the circuit board 13 D. The room between the pads may dispose other electronic components. [0063] (Fifth Modification) [0064] FIG. 10A is a plan view of the top surface 13 a ; while, FIG. 10B is a plan view of the back surface 13 b of the circuit board 13 E according to the fifth modification of the invention. Similar to the aforementioned modifications, the explanation below concentrates on points different from those of the aforementioned one, and left points not explained are substantially same with those of the former embodiments. [0065] The circuit board 13 E of the present modification provides, instead of the parts, 12 A and 12 B, of the circuit unit 12 , other parts, 12 C and 12 D, of the circuit unit 12 . The part 12 C is mounted on the top surface 13 a of the circuit board 13 E, while, another part 12 D is provided in the back surface 13 b of the circuit board 13 E. Each parts, 12 C and 12 D, constitutes respective ICs. Specifically, the former part 12 C includes four transmitters 122 , while, the latter part 12 D includes four receivers 123 . [0066] The electrodes, 14 a and 14 b , in the interface 14 of the top surface 13 a are connected to the input terminals, 121 a and 121 b , of the transmitter corresponding thereto through the interconnections on the top surface 13 a . The electrodes, 14 a and 14 b , in the interface 13 , which are provided on the back surface 13 b , are connected to the input terminals, 121 a and 121 b , of the transmitter 122 in the top surface 13 a through the via holes 16 c . The electrodes, 14 c and 14 d , in the interface 14 of the top surface 13 a are connected to the output terminals, 121 g and 121 h , of the receiver 123 provided in the back surface 13 b through the via holes 16 d , and the electrodes, 14 c and 14 d , in the interface 14 of the back surface 13 b are connected to the output terminals, 121 g and 121 h , of the receiver 1232 in the back surface 13 b. [0067] For the interface 15 to the co-axial cables 21 , the circuit board 13 E of the present modification provides the interfaces, 15 E and 15 F, the former of which is disposed in the top surface 13 a and the latter is in the back surface 13 b . The interface 15 E includes four pads 15 a for the transmission and the other interface 15 F also provides four pads 15 b but for the reception. The pads 15 a are connected in the AC mode to the output terminals 121 c of the transmitters 122 in the topo surface 13 a . The pads 15 b in the interface 15 F are connected in the AC mode to the input terminals 121 e of the receivers 123 in the other part 12 D of the circuit unit 12 . [0068] In the present modification, the whole transmitters 122 are provided in one of the surfaces 13 a of the circuit board 13 E, and the whole receivers 123 are disposed in another of the surfaces 13 b of the circuit board 13 E. Even for such an arrangement, the advantages same as those of the aforementioned examples may be obtained. Moreover, the components for the transmission and those for the reception are fully isolated by the circuit board 13 E. Specifically, the pads 15 a for the transmission and the transmitters 122 are arranged in one surface 13 a of the circuit board 13 E, while, the pads 15 b for the reception and the receivers 123 are disposed in another surface 13 b . Such an arrangement may effectively suppress the near end crosstalk (NEXT). Moreover, when the electrodes, 14 a and 14 b , for the transmission are arranged on the one surface 13 a and the other electrodes, 14 c and 14 d , for the reception are arranged in the other surface 13 b , which may remove the via holes, 16 c and 16 d , may further suppress the NEXT. [0069] The cable according to the present invention thus described is not restricted to those embodiments or modifications, and may further modify in various ways. For instance, the transmitter and/or the receiver in the circuit unit terminate one of the outputs or one of the inputs thereof to the ground or the power line through the terminator. However, the method to convert a differential signal into a single-ended signal is not restricted to this arrangement. An active circuit, such as the single-ended push-pull, or the like may be also utilized in the conversion. Accordingly, the appended claims are intended to encompass all such modifications and changes as fall within the true spirit and scope of this invention.	A cable for transmitting signals between two systems is disclosed. The cable provides a connector, which encloses a circuit unit comprising at least one of a transmitter and a receiver and plugged with the system, and a co-axial cable pulled out from the connector. The circuit unit includes at least a transmitter and a receiver. The transmitter receives an input signal in the differential form from the system and outputs a transmitting signal in the single-ended form to the co-axial cable. The receiver receives the transmitting signal in the single-ended form from the co-axial cable and outputs an output signal in the differential form to the system.	7
FIELD OF THE INVENTION This invention relates to a sewing machine, particularly an industrial sewing machine, having a needle which is arranged to be driven up and down by means of a needle bar, a feed dog for the forward transfer of a workpiece in co-ordination with the needle movement, an actual feed rate sensing device for supplying an electric signal and a sensor for detecting a workpiece edge. BACKGROUND OF THE INVENTION A sensing machine of this type is known from DOS No. 2316993 according to which, for the purpose of exactly positioning a corner stitch in a seam or seam portion, the actual feed of the workpiece is determined and an intervention takes place in the material transfer in the seam area prior to a corner stitch for the purpose of varying the length of one or more stitches. Quite apart from the complicated and therefore expensive mechanisms involved, e.g. in the form of a motor adjustment of the stitch regulating lever, there is also a modification to the action conditions of the feed dog on the workpiece, so that the complete stitch length adjustment is subject to tolerances. In addition, such a construction does not permit any modification in a very short time. The modification of the action conditions by varying the size of the thrust components of a feed dog performing a quadrangular movement, only makes it possible to inadequately calculate beforehand stitch length changes. This is particularly difficult if consideration is given to the processing of widely differing materials, such as e.g. jersey material on the one hand and cotton on the other, because in both cases action on the material feed leads to completely different results, so that subsequent corrections are constantly necessary for obtaining adequate results. SUMMARY OF THE INVENTION The object of the invention is therefore to so construct a sewing machine for the exact positioning of corner stitches that, compared with conventional means, this can be achieved with increased precision, reasonable cost and high operating reliability. According to the invention, there is provided a sewing machine, particularly an industrial sewing machine, comprising a needle which is arranged to be driven up and down by means of a needle bar, a feed dog for forward transfer of a workpiece in co-ordination with needle movement, an actual feed rate sensing device arranged to supply an electric signal corresponding to the feed rate of said workpiece, at least one sensor for detecting a workpiece edge and a device for displacing the longitudinal axis of said needle parallel to the sewing direction as a function of the actual feed rate sensing device and the detection of a workpiece edge by said at least one sensor. In general, a displacement of the longitudinal axis of the needle per se, as well as a then correspondingly necessary hook of so-called zig-zag sewing machines mounted in rotary manner about a horizontal or vertical axis are known. Thus, the construction according to the invention is able to make use of proven, tested constructional techniques. However, what is completely novel is the use of such a displacement of the longitudinal axis of the needle parallel to the sewing direction, in order to increase or decrease the stitch length and to bring about an exact positioning of a corner stitch as a function of the actual feed determined. The method according to the invention makes it possible to carry out the corner stitch positioning without it being necessary to in any way vary the set desired stitch length. This obviates the mechanical expenditure linked therewith and there is no need to fear imprecisions. The procedure according to the invention not only makes it possible to carry out such a stitch length change more rapidly than in the prior art, but also with less effort and cost. According to a further development of the invention, a second sensor is associated in spaced manner with a first sensor. Such a second sensor makes it possible in per se known manner to reduce the speed of the main shaft after detecting a material edge located upstream of a seam extremity in the sewing direction. A computer may be provided for controlling the device for displacing the longitudinal axis of said needle as a function of output signals from the actual feed rate sensing device and the said at least one sensor. This makes it possible to distribute the stitch length change over a plurality of stitches, either uniformly or in a progressively varying manner, i.e. increasing from stitch to stitch, or to carry out the change only with respect to a single stitch. It can naturally also look after the other functions involved in computer-controlled sewing machines. Preferably, the device for displacing the longitudinal axis of the needle comprises a pivoting means on which said needle bar is mounted and which is arranged to be driven by means of an electric motor. In this manner, a precise force and travel transfer can be ensured. An exact, backlash-free force transfer can be achieved if the pivoting means has a U-shaped bearing part with sliding bearings for the needle bar provided therein. The electric motor preferably comprises a stepping motor whereby a particularly simple digital control of the motor can be achieved. According to a preferred embodiment of the invention, the stepping motor has a spindle, on which is arranged a nut for the force-path transfer on said pivoting means. By means of this arrangement, a favourable transmission ratio can be obtained with limited effort and expenditure. A further increase in positioning precision is possible if the sewing machine is provided with a crank drive having a crank and with a device for the electronic determination of the angle position of the crank of the crank drive, i.e. the exact momentary angle position and not only the needle bottom position is determined. This can e.g. be brought about by counting off the pulses of a per se known encoder. The present invention also provides a method for positioning a corner stitch of a seam portion of a material workpiece, using the above-described sewing machine in which a seam is sewn with a predetermined speed, predetermined stitch length and predetermined distance from its end point to an edge of said material workpiece, the actual stitch length being determined and, after detecting a workpiece edge by a sensor, a stitch length correction being carried out by displacing the axis of the needle if the seam portions still to be sewn cannot be divided with substantially no residue by the actual feed length per stitch. A very accurate and simple corner stitch positioning can be achieved through this method. If the sewing machine is provided with a crank drive having a crank and a device for the electronic detection of the angle position of the crank of said crank drive, a stitch length correction can be initiated immediately or only starting with the following stitch as a function of an output signal from the said drive for detecting the angle position of the crank. This arrangement makes it possible to increase the precision in that, as a function of the degree of completion of the stitch which has just been formed when the sensor responds, it is possible to decide whether the time for performing a stitch length compensation is sufficient, i.e. whether said stitch can be completed without acting on the stitch length, or whether intervention should only take place during the following stitch. If the sewing machine includes a computer having an input switch, it is possible, by means of the input switch, for the computer to give the distance of the desired end point of the seam portion from the material edge and thus to carry out a stitch length correction as a function of the actual stitch length for obtaining the desired distance. Preferably, on continuing the seam after reaching the end point of a seam portion, the seam is continued in such a way that the axis of said needle is restored to the initial position in a progressive manner from stitch to stitch. This permits a gradual stitch length change in the vicinity of a seam portion extremity, so that the seam pattern is not disturbed by abrupt stitch length changes. BRIEF DESCRIPTION OF THE DRAWINGS The invention will now be further described, by way of example, with reference to the drawings, in which: FIG. 1 is a diagrammatic front view of one embodiment of a sewing machine according to the invention; FIG. 2 is a perspective view of a device for displacing the longitudinal axis of the needle of the sewing machine shown in FIG. 1; FIG. 3 is a circuit-like representation of components co-operating during the positioning of a corner stitch; FIG. 4 is a diagrammatic view of a seam area around a seam portion extremity; and FIGS. 5 and 6 show a flow chart for illustrating the operating sequence. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT The sewing machine 1 shown in FIG. 1 comprises an arm 2 in which, by means of a needle bar 4, is mounted a needle 3, which can be moved up and down. A stitch forming area 5 is located below the needle 3 and a feeding device 7 is provided there in a base plate 6. The feeding device 7 acts through a recess 8 of a throat plate 9 formed in the base plate 6 on material 62 to be transferred by means of a feed dog 10. In the sewing direction N, which is opposite to the material feed direction, are provided two spaced sensors 11, 12, which can e.g. be constructed as reflected light barriers. FIG. 2 shows in greater detail the stitch formation area 5, as well as the drive and mounting of the needle 3. The needle 3 is fixed to the needle bar 4, which is mounted so as to move up and down in a bracket 13, which is constructed in the form of a horizontal U. A first bearing 14 is arranged in the upper U-shank 15 and a second bearing 16 in the lower shank 17. The needle bar 4 is driven by means of an arm shaft 18 and a crank 19 fixed thereto with an eccentric crank pin 20, which engages in a link 21, which is connected to the needle bar 4 via a clamp 22 with a set screw 23. As a result of the thus constructed crank drive 24, the rotary movement of the arm shaft 18 is converted into an up and down movement of the needle bar 4. Below the arm shaft 18, the bracket 13 is pivotably mounted in the arm 2, this not being shown in detail in FIG. 2 so as not to overburden the representation. The U-shank 17 of the bracket 13 has a lug 26, which is connected to a rocking shaft 28 engaging in an eye 27. The other end of the rocking shaft 28 is located in a clamp 29, which is arranged at one end of a lever 30, whose other end has cylindrical shoulders 31 traversed by a bolt 32 for the articulated mounting of two links 33, which are formed by two webs 34, 35. The free ends of the webs 34, 35 are in each case traversed by a respective further bolt 36, the bolts 36 extending from the sides of a nut 37 which is mounted in a rotationally or longitudinally displaceable manner on the spindle 38 of a stepping motor 39. As a result of the aforementioned arrangement, it is possible when rotating the spindle 38 to bring about a pivotal movement of the bracket 13 about an axis 25 by means of the links 33, lever 30, rocking shaft 28, lug 26 and U-shank 17. Thus, as a function of the rotation direction of the spindle 38, the longitudinal axis 40 of the needle 3 is moved forwards or backwards out of its zero position parallel to the sewing direction N. The arm 2 also contains a presser foot bar 41 displaceable against the feed dog 10 by means of a not shown spring. A presser foot housing 43 is fixed to said bar 41 by means of a screw 42. The presser foot housing 43 contains a workpiece actual feed rate sensing device 44, which essentially comprises a frustum-shaped wheel 45, which through the aforementioned arrangement is pressed onto the workpiece and is consequently in frictional contact therewith. Wheel 45 constitutes an abutment for the feed dog 10 and is rotated in accordance with the actual forwards movement of the workpiece. The rotary movement of the wheel 45 is converted in per se known manner into electrical pulses which are proportional thereto. This can e.g. take place in that a plurality of permanent magnets is arranged on the periphery of the wheel 45 and which is moved past Hall probes during a rotary movement, pulses being emitted through the varying magnetic field. The sensing device 44 is connected to a computer 47 by a cable 46. As shown in FIG. 3, the computer 47 is connected by cables 48, 49 to the sensors 11, 12 respectively. There is also a diagrammatically represented connection 52 to the drive motor 53 of the arm shaft 18, the drive connection being indicated by the dotted line 54. An encoder 63 is fitted to the drive motor 53 and is connected by means of connections 50, 51 to the computer 47. The connection 50 is used for transferring a so-called zero pulse, which is emitted for each rotation of the arm shaft 18, e.g. when the needle 3 is in the bottom position. By means of the connection 51, pulses are supplied to the computer 47 and are proportional to the speed or rotation angle of the arm shaft 18. An input switch 55 is arranged on the computer 47. FIG. 3 also diagrammatically shows a carrier 56 for the feed dog 10, which is mounted by means of a feed crank 57. Driving takes place in a co-ordinated manner with the drive of the needle 3 via a diagrammatically represented driving connection 58. In addition, a hook 59 is arranged below the stitch forming area 5. For producing a positioned corner stitch, a sewing machine according to the invention functions in the following way. Whenever the sewing machine 1 is switched on, the computer 47 automatically controls a so-called zero passage. For this purpose, the stepping motor 39 is controlled by the computer 47 in such a way that the nut 37 on the spindle 38 is moved into its extreme left-hand position until the stepping motor 39 is mechanically locked. This locked position of the stepping motor 39 is briefly maintained and following thereon, the stepping motor 39 is controlled in such a way by the computer 47 that the nut 37 on the spindle 38 is moved back, the pulses supplied to the motor 39 being dimensioned in such a way that the needle 3 assumes its zero position. Before the start of the actual sewing process, a desired stitch length is set by means of a stitch regulating lever 60. Using the input switch 55, the distance A from seam end E to workpiece edge K2 is fed into the computer 47. Sewing a seam along a line 61 can now be commenced, the stitches being produced with a stitch length C. After starting the sewing machine 1, the operator has no further influence on the control sequence. The sewn seam along the line 61 is parallel to the workpiece edge K1 which, as shown in FIG. 4, is at right angles to the workpiece edge K2. The transfer of the workpiece 62 takes place through the co-operation of the feed dog 10 with the frustum-shaped wheel 45 of the presser foot housing 43. As a function of the stitch length size, such a seam is sewn with a speed of the arm shaft 18 of up to 4500 r.p.m. The speed of the arm shaft 18 is reduced to approximately 500 r.p.m. after the workpiece edge K2 has been detected by the sensor 12. Through the pulsing of the sensor 12, the computer 47 is made to detect the next zero pulse on the encoder 63. This is followed by a count of the pulses emitted by the actual feed rate sensing device 44 until the next zero pulse is detected. Thus, the computer 47 is able to calculate the actual stitch length C produced in the workpiece 62. The actual stitch length C corresponds to the path by which the workpiece 62 is advanced by the feed dog 10 with respect to the fixed sewing machine 1 during a rotation of the arm shaft 18. Thus, the actual stitch length C is determined directly by counting the pulses emitted by the actual feed rate sensing device 44 during a 360° rotation of the arm shaft 18. Therefore, the actual stitch length C is determined independently of the particular momentary arm shaft speed. However, it is also conceivable to determine the actual stitch length C over several rotations of the arm shaft 18, which would lead to a more precise determination. Following further advance of the workpiece 62, the workpiece edge K2 is detected by the sensor 11, which is positioned adjacent to the needle 3. By means of this signal supplied by the cable 49 to the computer 47, the latter initiates the interrogation of the angle position W of the crank 19 by means of the connection 51. On detecting the angle position W the computer 47 is able: (a) To decide whether the just sewn stitch should be completed without intervention, or whether a stitch length correction should take place relative to this stitch. It must be borne in mind that a stitch length correction in the manner according to the invention can naturally only take place if the needle 3 is in the disengaged position. For reasons of simplicity, it is assumed that with an angle position W>180°, the just sewn stitch is produced without intervention, whilst for an angle position <180° a correction is to take place relative to this stitch. Obviously, with respect to the criterion, the computer 47 can also be programmed in a different way. (b) To calculate the partial feed T of the actual stitch length C by which the workpiece 62 has been or can be advanced since producing the preceding perforation D. A programme part is provided in the computer 47 for calculating the partial feed T, T being calculated by means of a fixed programmed-in function (e.g. sine function) as a dependent variable with the angle position W (= determined angle position of the crank drive 24). This function can be calculated in accordance with the transfer conditions or can be determined recursively. (c) To calculate the residual distance R, whilst taking account of the aforementioned, determined partial feed T, the fed-in distance A and the fixed distance B contained in the computer programme corresponding to the distance of the sensor 11 from the zero position of the axis 40 of the needle 3 and the decision made according to (a). If the computer 47 has decided in accordance with (a) that a correction should take place during the just sewn stitch, because e.g. W<180°, then R=B-A+T is obtained for the residual distance. However, R=B-A-C+T for the residual distance if W>180°. The residual distance R calculated in accordance with the aforementioned criteria is subsequently divided by the determined actual stitch length C using the computer 47. If this division does not take place without a remainder, a residual amount is left which is used for the stitch length correction. This can fundamentally take place in such a way that the length of a single stitch is corrected, that the length of the following stitches is in each case modified by the same amount, or that the stitch length is increased or decreased gradually from stitch to stitch, in order to achieve a gentle optical transition. In each case, the fundamental decision as to whether there must be a stitch length increase or decrease in dependent on the criterion according to (a), i.e. there is either a rounding up or a rounding down of the number of stitches still to be sewn. Thus, a stitch length increase is brought about by displacing the needle 3 in the sewing direction B, or a stitch length decrease is brought about by displacing the needle 3 counter to the sewing direction N, which is achieved by a corresponding control of the stepping motor 39, so that the latter is correspondingly rotated counterclockwise or clockwise and the resulting movement is transferred to the bracket 13. Fundamentally, the stitch length correction in each case takes place in such a way that the stepping motor 39 is so controlled by the computer 47 that, by means of the bracket 13, the longitudinal axis 40 of the needle 3 is displaced with respect to its zero position. The amount of the displacement of the bracket 13 or the longitudinal axis 40 brought about by the stepping motor 39 for each controlled step and which is generally called the "resolution", is dependent on the design of the stepping motor 39, i.e. the number of steps per rotation and the pitch of the spindle 38. These components are preferably matched in such a way that a total resolution via the stepping motor 39 and the spindle 38 of approximately a tenth of a millimeter is obtained. The hook 59, which is shown in diagrammatic manner only in FIG. 3, which is mounted so as to pivot about a horizontal axis and which is known per se in connection with zig-zag sewing machines, permits a reliable loop take-up, even in the case of a deflection of the needle 3. In the case of conventional hooks, an approximately ±3.5 mm deflection is possible. It is fundamentally possible to use hooks, which are rotatably mounted about a vertical axis running parallel to the needle bar 4. After sewing a predetermined number of stitches with a corrected stitch length C', the needle 3 is held in its bottom position in the corner point E, controlled by the computer 47. This takes place by means of the diagrammatically represented connection 50 between the computer 47 and the drive motor 53. The seam can be ended at this point in per se known manner by operating a thread cutter, etc. It is also possible to continue sewing in a direction differing from the line 61, for which purpose the workpiece must now be pivoted about the axis of the needle 3. This can take place automatically by suitable means or also manually. For this purpose, the presser foot housing 43 is raised and a stop 64 parallel to the line 61 is moved, so that it does not then impede pivoting of the workpiece 62. By automatic control or pulsing by means of a trip switch by an operator, it is then possible to lower the presser foot and slide back the stop 64, so that sewing can be continued. In computer-controlled manner and preferably progressively, i.e. stitch by stitch by the calculated correction amount, the needle 3 is pivoted back into its zero position, so that the sewing pattern appears uniform in the vicinity of the corner point. The above-described operation is represented in summary and supplemented form by the flow chart of FIGS. 5 and 6.	In a sewing machine, particularly an industrial sewing machine, with a needle which can be driven up and down by means of a needle bar, a feed dog for the forward transfer of the workpiece in co-ordination with the needle movement, an actual feed rate sensing device which supplies a corresponding electric signal and at least one sensor for detecting a workpiece edge, for the purpose of increasing the accuracy of the positioning of the corner stitch of a seam portion with acceptable constructional expenditure, a device is provided for displacing the longitudinal axis of the needle parallel to the sewing direction as a function of the actual feed rate sensing device on the one hand and the detection of a workpiece edge by the sensor on the other. Such a sewing machine is operated according to a method in which a seam is sewn with a predetermined speed, a predetermined stitch length and a predetermined distance from its end point to a material edge, the actual stitch length is determined and after a sensor has detected a workpiece edge a stitch length correction is brought about by displacing the needle axis, if the seam portion still to be sewn cannot be divided with substantially no residue by the actual feed length per stitch.	3
FIELD OF THE INVENTION The present invention relates to production of pulp useful in the manufacture of paper. BACKGROUND OF THE INVENTION Wood represents about 30-45% of total pulp production costs. Thus, increasing the yield of wood conversion into pulp, i.e. the percentage of the wood fed to a pulping operation that usefully becomes part of the pulp solids, is an effective way of achieving the desirable goal of decreasing overall pulp manufacturing costs, by decreasing wood consumption. Increasing pulp yield provides other benefits such as increased pulp mill through-put and decreased load of black liquor solids to recover. As a consequence there occurs a debottlenecking of the kraft recovery system. Another important factor in pulp manufacturing costs is the bleaching chemical cost, that can represent 15-20% of the total costs. Total bleach chemical consumption is influenced by the so-called pulp bleachability which is defined as the bleach chemical requirement to achieve a given level of final pulp brightness (e.g. 90% ISO brightness). Thus, increasing pulp bleachabllity during the manufacturing process results in decreased bleach chemical costs. Those investigating in this field have made many attempts to increase pulp yield and bleachability. Most of the processes proposed are either effective to increase yield or to increase bleachability, but not both at the same time. As a matter of fact, many of the alternate methods proposed to increase pulp yield result in decreased pulp bleachability. Prior attempts by others with regard to improving yield in the kraft pulp industry can be divided basically into two categories. One category is processes that use additives together with the wood pulping chemicals to enhance pulping efficiency and to protect pulp carbohydrates. These include: (1) the so-called kraft-anthraquinone pulping whereby anthraquinone (AQ) or any of its derivatives are added together with the pulping chemicals during wood pulping. Besides enhancing the rate of removal from the pulp of the undesirable fractions (lignins) present in the wood, AQ has the property of protecting the desirable fraction (carbohydrates) present in the wood. Anthraquinone acts by oxidation of the carbohydrate reducing end groups, thus increasing overall pulp yield. (2) The so-called kraft-polysulfide pulping whereby polysulfides (PS) are added together with the pulping chemicals to protect the wood carbohydrate fraction. Purportedly, PS have the ability of oxidizing carbohydrate reducing end groups, thus avoiding the so-called “peeling reaction” promoted by the alkali and increasing process yield. (3) The so-called kraft-anthraquinone-polysufide pulping whereby AQ and PS are added together with the wood pulping chemicals. The benefits of these two additives in improving pulp yield have been considered to be synergistic. It should be noted that the kraft-AO, kraft-PS and kraft-PS-AO processes are effective in improving pulping yield but they have no reported positive effect on pulp bleachability. In a second category, yield improvements have been based in a more accurate control of kraft pulping kinetics, so that the losses of carbohydrates through peeling reactions and hemicellulose dissolution are minimized. The processes developed for this purpose, the so-called extended delignification processes or modified kraft cooking processes, include among others the isothermal cooking (ITC®), the low solids cooking (Lo-solids®), the extended modified continuous cooking (EMCC®), the rapid displacement heating cooking (RDH®″), and the Super-Batch® cooking processes. The four basic principles that are used more or less extensively in these processes are: (1) a constant temperature profile throughout the cook, (2) a constant alkali profile throughout the cook, (3) a high sulfidity throughout the cook, particularly in the beginning and the end of the cook and (4) a low content of solids in the cooking medium throughout the cook. It should be noted that all these new processes result in yield improvements in the order of 1-2% at most. Considering that wood and bleach chemicals have the largest impact on pulp manufacturing costs, and that through-put limitations as well as bottlenecked recovery systems are major problems in modern pulp mills, there remains a need for a method to increase pulp yield and bleachability in the manufacturing process so that overall pulp production cost is decreased. BRIEF SUMMARY OF THE INVENTION One aspect of the invention is a method for producing pulp, comprising digesting lignocellulosic wood, containing one or more xylan derivatives selected from the group consisting of xylan bound with lignin, xylan bound with hexenuronic acid, and mixtures thereof, with an aqueous alkaline pulping solution containing sulfide and having an initial free hydroxyl ion concentration of at least 1 mole per liter, under conditions whereunder xylan is dissociated from said one or more xylan derivatives, and the pH of said solution remains above 12.5; and then while the pH of said solution is above 12.5, adding a sufficient amount of an acidic agent to said pulping solution to precipitate dissociated xylan from said pulping solution while minimizing precipitation of lignin from said pulping solution. DETAILED DESCRIPTION OF THE INVENTION As used herein, “xylan” and “xylans” means polysaccharides composed of repeating units of the formula: The term “xylan derivatives” means one or more polysaccharides wherein xylan having the aforementioned structure is substituted with one or more substituents and particularly with one or more sugars or with a hexenuronic acid, which is a uronic acid. Examples of xylan derivatives include L-arabino-D-xylans, L-arabino-D-glucurono-D-xylans, L-arabino-(4-O-methyl-D-glucurono)-D-xylans, O-acetyl derivatives of any of the foregoing, xylan bound with lignin, and xylan bound with hexenuronic acid (such as wish hexenuronoxylan or 4-deoxy-β-L-threo-hex-4-enopyranosyluronic acid-xylan). The term “bound” is used herein to mean that two entities, such as xylan and lignin, are “bound” to each other if they are held together covalently, ionically, by another attractive force, or by being physically engaged with each other such as by intermolecular entanglement. Two entities are considered “bound” if the “bound” form precipitates under conditions under which one of the entities, unbound, would precipitate and one of them, unbound, would not. Two entities are considered “disassociated” if they are no longer “bound”; thus, disassociation can occur by cleaving of covalent bonds, by neutralizing ionic or other attractive forces, or by disentangling or otherwise disengaging the two entities. Wood is a complex raw material comprising four major components: cellulose (45-50%), hemicelluloses (15-30%), lignin (20-30%) and extractives (1-5%). The hemicellulose fraction includes two major groups: xylan and xylan derivatives; and glucomannan and glucomannan derivatives. The xylan derivatives are predominant in the hardwoods (about 20%) and are present in appreciable amounts in the softwoods. Conventionally, the aim of wood pulping is to remove into the pulping liquid the lignin and the extractive fractions while retaining in the solid fraction as much as possible of the carbohydrates (cellulose and hemicelluloses). Nevertheless, during pulping a significant fraction of the carbohydrates are also dissolved into the pulping liquid and their value to the pulp is lost. The lignin, he extractives and a significant fraction of the carbohydrates go into solution and become part of the so-called black liquor. The non-dissolved carbohydrate fraction remains as pulp fibers. Conventionally, about 50% of the wood is dissolved in the black liquor, of which about 25-30% is lignin and extractives and the balance 20% are carbohydrates. In the case of hardwoods, about 10% of the dissolved carbohydrates are xylan and xylan derivatives. The yield of the pulping process is directly related to the amount of cellulose and hemicelluloses that are retained in the pulping operation. Wood pulping via the conventional kraft process is carried out with a mixture of sodium hydroxide and sodium sulfide at appropriate proportions. This mixture is the so-called white liquor. Both sodium hydroxide and sodium sulfide are effective in removing wood lignin and extractives but sodium hydroxide also dissolves fractions of the cellulose and hemicelluloses. The extent of removal of these wood components affects the yield of the process. The high alkalinity of pulping solutions is generally understood to contribute to loss of cellulose and hemicelluloses for at least three reasons, which are: (1) solubilization of hemicelluloses due to the high alkalinity of the white liquor; (2) alkali hydrolysis of cellulose and hemicelluloses chains resulting in reduction of their polymerization degree and solubilization of the low molecular weight fragments; and (3) successive elimination of cellulose and hemicellulose chain end units through the “peeling” reaction, which occurs at the reducing end group of cellulose and hemicellulose chains. After one unit is removed a new reducing end unit is created and the process progresses. Thus, it is all the more unexpected that the process of this invention succeeds even though it employs conditions that are even more highly alkaline and would therefore be expected to lead to even worse losses of pulp yield. In the process of this invention the wood is digested at a high alkalinity, corresponding to a free hydroxyl ion (OH − ) concentration of at least 1 mole per liner and preferably at least 1.25 moles per liter, from the beginning of the “cook” (i.e. the digestion). This high alkalinity (which corresponds to a pH of at least 14) makes the xylan and xylan derivatives soluble in the pulping liquid. Prior art processes in which pulping starts at a lower initial pH than the method of the present invention, necessarily precipitate significant amounts of xylan derivatives such as those containing xylan-lignin and xylan-hexenuronic acid linkages because these substances precipitate from the very beginning, or closer to the beginning, of the digestion. Thus, for a given kappa number, pulps produced the prior way require much higher quantities of chemicals to reach any given brightness degree, i.e., they show poorer bleachability. Xylan-lignin and xylan-hexenuronic acid linkages are hard to oxidize with conventional bleaching chemicals. If the initial alkalinity corresponds to a free hydroxyl ion concentration of 1 mole per liter or higher, the xylan derivatives remain in solution for sufficient time so that linkages by which a xylan derivative is bound to its substituent (such as xylan-lignin and xylan-hexenuronic acid linkages) are largely hydrolyzed. This hydrolysis is very important to lessen precipitation of xylan derivatives or e.g. lignin and hexenuronic acid into the pulp solids, along with the xylans when the pH is lowered to, or below, the point at which the xylan precipitates. In this invention, the higher the initial free hydroxyl ion concentration, and the longer the free hydroxyl ion concentration and thus the pH stay high, the longer it takes for the xylan and xylan derivatives to begin to precipitate. Since a key feature of this invention is to start the digestion at a high enough free hydroxyl ion concentration, and to carry out the digestion for a sufficient period of time, that linkages in xylan derivatives such as xylan-lignin and the xylan-hexenuronic acids are cleaved before the pH of the pulping liquid reaches the point at which xylan precipitates, and since as the digestion proceeds the pH of the pulping liquid decreases such that the xylan and xylan derivatives can eventually start to precipitate, it can be helpful to add additional highly alkaline material (such as alkali metal hydroxides and/or sulfides) during the digestion to keep the pH higher, and above the point at which the xylan precipitates, than would otherwise be the case. The particulars of the kraft cooking process as well as its operational conditions can readily be ascertained and practiced by those skilled in the art. For the purposes of this invention, conventional cooking conditions can be used except for the active alkali which must be higher than usual (at least 20-30% NaOH based on wood weight). Active alkali is defined here as the sum of NaOH and Na 2 S concentrations present in the cooking liquor and is expressed as NaOH. Alkalinity is preferably provided by sodium hydroxide or potassium hydroxide. The sulfidity of the cooking liquor and the ratio of pulping liquid to wood can be maintained the same as those used in conventional kraft cooking processes. Thus, in general, a sulfide content of about 15 wt. % to 40 wt. % is effective. Sulfide is preferably provided by sodium sulfide but other compounds can be employed such as polysulfides. A ratio of pulping liquid to wood of about 2:1 to 4:1 (by weight) is effective. The cooking temperature and the reaction time are adjusted so that the desired pulp kappa number is achieved. Generally, during the digestion a temperature on the order of 155 to 180° C. is effective, as is a residence time on the order of 1 to 6 hours. Because of the high initial active alkali the reaction temperature and/or time must be reduced to maintain the pulp kappa number at the desired target. Ideally one should adjust the reaction temperature to meet the desired kappa number and maintain fixed the reaction time. Kappa number is a non-dimensional value which indicates the total amount of oxidizable material present in the pulp after cooking. It is used as a reference for the bleach plant operation. Chemically, it is defined as the number of milliliters of 0.1 N potassium permanganate solution which is consumed by 1 gram of bone dry pulp according to standard procedures (an example of such standard procedure is Tappi method TAPPI um 245). The qualities of the wood chips used as feed material, and of the pulping liquid, can be maintained the same as those used in conventional kraft cooking. Also the type of equipment (digester) required to cook the wood need not be changed. At the end of the pulping cycle, just before the content of cooking digester is emptied out into a blow tank, the pH of the pulping liquid is lowered to cause xylan precipitation and therefore promote yield enhancement. Carbonic gas is preferred to lower the pH because this gas causes no side effects in a pulp mill, as carbonates are already part of the black liquor cycle and formation of additional carbonates in the black liquor do not pose a problem for the black liquor recovery cycle. The most preferred conditions in this step are those which provide selective precipitation of xylans, in which the pH is lowered as nearly as possible to a pH value that results in xylan precipitation but not lignin precipitation. The exact pH value where xylan precipitation selectively (without lignin precipitation) occurs depends on many variables such as temperature, type of wood fiber, xylan content, etc. In general a pH of about 12.5 is effective. However, pH values under 12.4 must be avoided, otherwise lignin precipitation occurs. The conditions for CO 2 application can vary, depending upon the cooking system used. In general, the CO 2 should be applied at the same conditions existing in the digester at the end of the cooking cycle. The temperature should be in the range of 110-150° C. and the pressure in the range of 2-8 atm. The amount of CO 2 dosed into the reactor will depend on the pH of the pulping liquid and the final pH desired. In general, to reach a final pH of 12.4, the requirement of CO 2 will be in the range of 30-40 kg/ton of pulp. The CO 2 will be injected at a pressure slightly higher than that existing in the digester at the end of the cooking cycle. The physical point into which CO 2 is injected can be decided in the light of the type of equipment used. In batch reactors (digesters), the CO 2 should be injected in the digester blow line. In continuous digesters the CO 2 is added to liquors coming from the cooking zone which have high pH values and this liquor is then recycled back to the digester washing zone which contains lower alkali concentration. At this zone which coincides with the end of the cooking cycle the xylans precipitate. After the acidification of the pulping liquid with CO 2 or otherwise to the proper pH value, the contents of the digester are transferred into another vessel such as a blow tank, and the pulp derived from the wood chips is separated out from the black liquor, washed, screened and stored. This method is carried out prior to any bleaching step, i.e. prior to addition of any compound that provides bleaching or oxidizing conditions in the pulp. The pulp produced in accordance with this invention can then be bleached. Another major advantage of this process as compared to the prior art is the production of pulp of higher bleachability. Bleachability is defined as the chemical requirement to bleach the pulp to a given brightness degree. The higher the bleachability of a given pulp the lower the quantity of bleaching chemicals needed to reach a given brightness degree (for example 90% ISO brightness). Due to the low content: of xylan-lignin and xylan-hexenuronic acid derivatives in pulp produced by the present invention, a smaller quantity of bleaching chemicals is required in order to reach a given brightness degree. In the process of this invention, bleaching chemical savings on the order of 10-15% have been shown in relation to a reference. Without intending to be bound by any particular theory for the efficacy of the present invention, the tendency of xylan derivatives such as xylan-lignin and xylan-hexenuronic acid compounds to impair pulp bleachability is consistent with the proposition that they contain covalent bonds which are difficult to cleave with conventional bleaching chemicals, and the efficacy of the present invention is consistent with the proposition that this problem is overcome by cleavage of these linkages via alkali hydrolysis in solution in the pulping liquid at the higher pH values described herein, whereupon the xylans that precipitate back onto the fibers in the pulp solids are unsubstituted xylans that do not need to be bleached since they are already white. As compared to the prior art this invention presents the advantages of not requiring the use of any other chemical or enzyme additive to perform the digesting. Also extensive modification of existing cooking equipment is not required to allow for the so-called modified cooking processes (e.g. RDH®, ITC®, Lo-solids®, Super-Batch®, EMCC®, etc.). All that is needed is a point of CO 2 injection at the end of the cooking cycle. Furthermore, the present invention achieves higher yield gains as compared to the prior art, on the order of 3-4%. The simplicity of the process is apparent from the examples listed below, which are all based on well controlled laboratory experiments performed in duplicate and which were conducted with eucalyptus wood. EXAMPLE 1 This preliminary laboratory experiment indicated the potential yield benefits derived from the acidification of the reaction media with CO 2 at the end of the kraft cooking cycle. One thousand grams of bone dry equivalent wood chips prepared from 7-year old trees were cooked in a laboratory digester under the following conditions: initial pH of 14, 24% active alkali based on wood weight expressed as NaOH, 30% sulfidity based on active alkali, expressed as NaOH, 170° C., 90 min reaction time to reach 170° C., 60-min reaction; time at the 170° C. temperature and liquor:wood ratio of 3:1. At the end of the cooking cycle, the pH of the pulping liquid was 13.39 and the residual alkali about 16.6 g/L as NaOH. At this point, the pulping liquid was washed out and the remaining pulp was analyzed for pulp yield, kappa number and lignin content. Four other cooks were performed under very similar operating conditions and at the end of the cooking cycle, each one of them received a different dose of CO 2 so that different final pH values could be obtained. As shown in Table 1, pH values of 13.06, 12.80, 12.30, 11.37 and 10.51 were obtained with different CO 2 , doses. The yield, kappa number and lignin content of the pulps obtained this way are presented in Table 1. The results show 1.7% yield gain when the pH was reduced from 13.39 to 13.06 without increasing pulp kappa number and lignin content. Dropping the pH even further to a value of 12.80 improved the yield by 2.8% without affecting kappa number and lignin content. This benefit was achieved at the expense of about 27 kg CO 2 addition to the reaction medium. Further decreasing the reaction medium pH to 12.30 resulted in additional yield gain but lignin precipitation occurred as can be noted by the increased pulp kappa number and lignin content. The application of this technique to bleachable grade pulp production is limited by lignin precipitation since this additional lignin will drastically affect pulp bleachability. The exact pH value at which CO 2 addition should be stopped cannot be drawn from the data presented in Table 1 since the pH points evaluated are not sufficiently close to each other. However, it is obvious that the optimum pH value ranges between 12.80 and 12.30. TABLE 1 Treatment* of pulp and black liquor with CO 2 Lig- Yield Yield CO 2 Dose, Kappa Yield, nin Without Increase, pH kg/t pulp Number % % lignin, % % 13.39 — 17.6 52.7 1.901 49.8 0.0 13.06 17.5 17.6 53.4 1.901 51.5 1.7 12.80 26.7 17.7 54.5 1.931 52.6 2.8 12.30 31.5 20.1 56.4 2.714 53.7 3.9 12.37 35.4 20.8 55.8 2.995 52.8 3.0 10.52 35.9 24.4 56.2 3.782 52.4 2.6 65° C., 4% consistency, 10 min. EXAMPLE 2 The previous example showed the benefits of decreasing final pH of a digestion performed at an alkalinity higher than usual, i.e., ending the digestion cycle at a pH of 13.39. Conventional kraft digestion usually is conducted to final pH values in the range of 11.5-12.5. In order to arrive at more meaningful conclusions the results of digestion under very high alkalinity were compared with those of conventional kraft digestion. In this example, results of conventional kraft digestion conducted to a final pH of 12.45 are compared with those of a digestion effected at high alkalinity (pH 13.41) and with another effected at a high alkalinity with subsequent CO 2 acidification to pH 12.46 as taught in the method of this invention. These three pulp samples were submitted to bleachability studies as well (examples 3 and 4). A diagram containing the experimental procedure is shown in FIG. 3, where samples A, B and C are defined. One thousand grams of bone dry equivalent wood chips, prepared from 9-year old eucalyptus trees were digested in a laboratory digester under the following conditions: Initial pH of 14, active alkali of 18% and 24% based on wood weight for the conventional (sample A) and high alkalinity (sample B) digestions, respectively, expressed as NaOH. The reaction time at the temperature of 170° C. were fixed as 145 min and 32 min, for the conventional and high alkalinity digestions, respectively. The other digestion conditions were kept similar for both digestion types, i.e., 30% sulfidity based on active alkali, expressed as NaOH, 90 min reaction time to reach 170° C. temperature, liquor/wood ratio of 3:1. At the end of the cooking cycle, the pH of the reaction media was 12.45 for the conventional digestion (sample A) and 13.41 for the high alkalinity digestion (sample B). The high alkalinity digestion was repeated and at the end of the digestion cycle the pH of the pulping liquid was dropped with CO 2 to a value of 12.46 (sample C). All tests were performed in duplicate. Then, the three pulp samples were oxygen delignified (example 3) and bleached with the sequence D(EOP)D under similar bleaching conditions as described in example 4. The results shown in Table 2 indicate that performing the digestion at high initial pH (sample B) penalizes pulp yield by 2.1% as compared with a conventional digestion (sample A). Also there is a penalty of 17% in pulp viscosity while the pulp brightness is increased by 37%. The yield loss is explained by the high alkalinity used in the digestion which dissolves more wood xylans (Table 3). The viscosity loss is caused by the excessive alkalinity which favors the cleavage of carbohydrate glycosidic bonds, resulting in decreased pulp degree of polymerization and viscosity. On the other hand, the improved brightness derived from digestion at high alkalinity is explained by the minimization of lignin condensation that leads to a pulp residual lignin containing less powerful cromophores of the styrene and stilbene types. When Sample B was treated according to the process of this invention, i.e., it was acidified with CO 2 at the end of he cooking cycle (Sample C) in order to attain a final pHl similar to the one of the conventional digestion, there occurred a yield increase of 1.8% in relation to the reference (Sample A). This yield increase derived from the xylan precipitation caused by the acidification. A proof of that is given in Table 3 where it is seen that the content of xylans of Sample C is about 1.7% higher than that of the reference pulp (Sample A). This alone can explain the increase of 1.8% in overall yield. On the other hand, the content of xylans of Sample B is about 1.9% lower than that of the reference which also explains the lower yield of this sample in relation to the reference. It should be noted that the acidification step had only a slight effect on pulp viscosity and brightness. In comparing samples A, B and C it is seen that the viscosity penalty increased only about 3% due to the acidification. This is probably explained by the increased amount of xylan in pulp sample C. The brightness gain derived from digestion at high alkalinity dropped slightly after acidification from 37 to 30%. From the discussions relative to Tables 2 and 3 it is evident that the yield gains obtained according to the method of this invention are mainly caused by the precipitation of unsubstituted xylans effected by the addition of CO 2 at the end of the digestion cycle. The mechanism of the xylan precipitation can be explained this way: In order to precipitate a pure xylan it is necessary to solubilize the xylan derivative at the beginning of the digestion cycle with excess alkali and to maintain it in solution for sufficient time that its linkages with lignin and with hexenuronic acids are hydrolyzed by the excess alkali. The xylan produced this way is then precipitated back onto the fibers when the pH is dropped, without increasing pulp lignin content and without penalizing pulp bleachability. TABLE 2 Treatment of pulp and black liquor with CO2 in accordance with testing procedure depicted in FIG. 3 . CO 2 Pulp Pulp Dose, Lig- Viscos- Bright- Yield Sam- Final kg/t Kappa Yield nin, ity, ness, Change, ple pH pulp Number % % mPa · s % ISO % A 12.47 — 16.4 53.1 1.832 52.5 25.5 — A 12.43 — 16.5 53.8 1.804 52.9 24.7 — Avg. 12.45 — 16.5 53.4 1.818 52.7 25.1 Ref B 13.43 — 16.7 51.4 1.859 44.8 33.1 — B 13.39 — 16.6 51.3 1.786 42.1 34.3 — Avg. 13.41 — 16.6 51.3 1.822 43.5 33.7 −2.1 C 12.47 33.8 16.9 54.5 1.887 42.8 32.2 — C 12.45 32.5 16.6 55.3 1.801 40.9 33.2 — Avg. 12.46 33.2 16.7 54.9 1.844 41.9 32.7 +1.8 65° C., 4% consistency, 10 min. TABLE 3 Pulp Carbohydrate Composition Carbohydrate, % Sample A Sample B Sample C Glucose 79.5 80.8 78.3 Xylose 13.2 11.3 14.9 Mannose 1.3 0.8 1.4 Galactose 0.7 0.6 0.8 Arabinose 0.4 0.5 0.4 Rhamnose 0.5 0.3 0.4 Total 95.6 95.3 96.2 EXAMPLES 3 AND 4 One key issue when digesting wood at high alkalinity is the behavior of the resulting pulp in the subsequent bleaching operation, refining and papermaking. Pulps produced at high alkalinity tend to be brighter (Table 2) than conventional ones. Hence, it is anticipated that they will perform better in the subsequent bleaching operation. The three pulp samples generated in example 2 were further bleached by an ECF (elemental chlorine free) bleaching process through the sequence O/OD(EOP)D. The brightness target was 90% ISO. Following the recommendation of the Technical Association of Pulp and Paper Industry (Tappi), as detailed in the Tappi publication TIS 0606-21 entitled “recommended pulp bleaching stage designation method”, the O/OD(EOP)D designation represents a sequence which comprises four separate stages, the 0/0 stage first, then a D-stage, then an (EOP) stage and then another D-stage, with a washing step between these stages. In the 0/0 stage the total alkali dose is injected in the first stage and the oxygen dose is split not necessarily evenly between the two O-stages. In the (EOP) stage, alkali, oxygen and hydrogen peroxide are injected in the same stage, apart from each other by fractions of minutes. The conditions used in the various bleaching stages were as follows: 0/0-stage: 10% consistency, (85+95° C.), (30+60 min), 600 kPa pressure, (1.5+0% NaOH) and (1.5+0.5% O 2 ). First D-stage: 10% consistency, 75° C., 60 min, 3.0 final pH and a kappa factor of 0.20; kappa factor is defined as the dosage of chlorine dioxide applied in the stage, expressed as % active chlorine, divided by pulp kappa number. (EOP)stage: 10% consistency, 85° C., (15+75) min, 200 kPa pressure, 10.5 final pH, 1.4% NaOH, 0.5% O 2 , 0.5% H 2 O 2 ), 0.03% Mg. Second D-stage: 10% consistency, 75° C., 240 min, 3.8 final pH and variable amounts of chlorine dioxide depending upon pulp previous treatment and type. The control of pH in the chlorine dioxide bleaching stages was achieved through small additions of NaOH or H 2 SO 4 together with chlorine dioxide as required. The results in Table 4 (example 3) show that the oxygen delignification (0/0-stage) performance was not significantly affected by cooking conditions as measured by kappa drop across the 0/0-stage. However, the pulp digested at high alkalinity (sample B) showed 3.8% higher brightness gain across the 0/0-stage indicating that this pulp presents higher bleachability with oxygen than the conventional one (sample A). Furthermore, sample B showed lower viscosity loss across the 0/0-stage which is explained by its lower initial viscosity. When sample B was treated according to the process of this invention to produce sample C, no significant changes were observed in the subsequent oxygen delignification performance. However, the higher brightness gain was maintained indicating that xylan precipitation according to the process of this invention will improve pulp bleachability with oxygen as compared to conventional kraft cooking processes. TABLE 4 Double-Stage Oxygen Delignification Results (O/(-stage) O/O-Stage 1 Results Sample A Sample B Sample C Kappa In 16.5 16.6 16.7 Kappa Drop, % 40.8 39.3 39.9 Viscosity Drop, % 39.9 30.3 31.6 Brightness Gain, % ISO 19.5 23.3 23.8 Yield, % on unbleached pulp 98.3 98.4 98.2 1 O/O: 10% consistency, (85 + 95° C.), (30 + 60 min), 600 kPa pressure, (1.5 + 0% NaOH) and (1.5 + 0.5% 02) The results in Table 5 (Example 4) indicate that the bleachability of the pulp digested at high alkalinity (Sample B) through the sequence O/OD(EOP)D, as measured by the total amount Of ClO 2 consumed to reach a final brightness of 90±0.2%, is higher than that of the pulp digested conventionally (sample A). Sample B consumed 16% less chlorine dioxide when bleached with the sequence O/OD(EOP)D. When sample B was treated according to the process of this invention to produce sample C, the benefits of a higher pulp bleachability were almost completely maintained. The total amount of chlorine dioxide was still 14% lower than that of the reference (sample A), indicating that digesting at high alkalinity coupled to CO 2 acidification at the end of the cooking cycle result not only in improved yield but also in improved pulp bleachability. TABLE 5 D(EOP)D bleaching results. ClO 2 Bright- Viscos- Rever- Pulp Kappa ClO 2 Consumption % Savings ness ity, sion Sample In D 0 D 1 Total (%) (% ISO) mPa · s (%) A 9.9 0.753 0.888 1.641 — 89.8 24.2 2.15 A 9.8 0.745 0.884 1.629 — 90.0 22.6 2.26 Avg. 9.8 0.749 0.886 1.635 Ref. 89.9 23.4 2.20 B 10.0 0.760 0.597 1.357 — 89.7 20.1 2.31 B 10.1 0.768 0.613 1.381 — 90.0 18.9 2.18 Avg. 10.1 0.764 0.605 1.369 16.3 89.8 19.5 2.24 C 9.9 0.753 0.639 1.392 — 90.1 18.3 2.15 C 10.0 0.760 0.662 1.422 — 90.0 19.1 2.28 Avg. 10.0 0.756 0.651 1.407 13.9 90.0 18.7 2.21 The improved pulp bleachability is explained based on the fact that pulp samples cooked at high alkalinity (samples B and C) contain less condensed lignin, less xylan-lignin linkages and less xylan-hexenuronic acid linkages in relation to the sample digested conventionally (samole A). The results shown in Table 6 clearly indicate that samples B and C contain less condensed phenolic lignin units and less hexenuronic acids than sample A. The content of lignin-xylan linkages was not measured. However, it is inferred that sample B would have less of this type of linkage because the content of xylans in this sample (Table 3) is much lower than that of the reference pulp (sample A). When sample B is treated according to the method of this invention to generate sample C, a significant amount of xylan is precipitated back onto the fibers. However, this xylan is not linked to lignin or hexenuronic acids. This is evident from the fact that there was no increase in kappa number when xylan was precipitated back through acidification (Table 2). Also the content of hexenuronic acids in the pulp was not changed to any extent after acidification (Table 6). Overall it can be stated that the increase in pulp bleachability obtained according to the process of this invention is due to the digesting of the wood at high alkalinity, which results in a pulp containing less condensed lignin, less xylan-lignin derivatives and less xylan-hexenuronic acid derivatives. TABLE 6 Pulp residual lignin characteristics and pulp hexenuronic acid content Lignin Functional Groups and Pulp Hexenuronic Acid content Sample A Sample B Sample C Aliphatic OH, mmol/g lignin 3.14 3.67 3.65 Phenolic OH, mmol/g lignin 2.34 2.93 2.95 Condensed Phenolic-OH, mmol/g 0.61 0.31 0.33 Acid COOH, mmol/g lignin Hexenuronic Acids, mmol/kg 0.39 0.34 0.35 pulp 29.5 16.4 17.1 EXAMPLE 5 As shown in Table 2, there was a significant drop in pulp viscosity when the digestion was performed at high alkalinity (sample B) as compared to the reference (Sample A). The acidification of the reaction media at the end of the digestion cycle according to the method of this invention (Sample C) had no significant impact on pulp viscosity. Thus, the viscosities of samples B and C were similar but significantly lower than that of the reference (sample A). Viscosity gives the average degree of polymerization of the carbohydrate chains and is an indirect measurement of pulp strength. However, the ultimate proof of pulp strength is only obtained through refining of the pulp and direct measurement of its strength properties. Hence, 250-gram samples A, B and C were prepared according to the procedures of Example 2 and bleached according to the procedures of Examples 3 and 4. These samples were refined in a PFI mill at 0, 1000, 2000, 3000 and 4000 revolutions and tested for strength properties according to Tappi standard procedures. The results shown in Table 7, reported at a drainage degree of 40°SR, indicate that the values of pulp tear strength were not substantially affected by the process of this invention. The average values among the samples A, B and C are similar within experimental error. In addition, the values of tensile strength of samples A and C are quite similar. Sample B showed a slightly lower tensile value which is explained by its lower content of xylans. Sample C showed a high tensile index due to its high xylan content derived from xylan precipitation in the acidification step. An important fact observed in Table 7 is the lower requirement of energy to refine sample C in relation to samples A and B. The fact that sample C had a very high content of xylan, derived from the acidification of the reaction media with CO 2 , improved pulp refinability. Refinability can be defined as the energy requirement during the refining of a pulp sample to reach a certain drainage degree (e.g., 40°SR). Drainage degree is usually expressed as degree Shopper Riegler (°SR) or Canadian Standard Freeness (CSF). This refinability improvement is easily seen by the lower number of PFI revolutions required to reach a drainage degree of 40° SR. As compared to the reference (sample A) the pulp sample produced according to the method of this invention required 8% less PFI revolutions which can be directly translated into energy. On the other hand, sample B which contained much less xylans required 9% more energy to reach a 40°SR drainage degree in relation to the reference (sample A). In summary, the method of this invention does not result in any impairment of pulp strength properties while improving pulp refinability. The improvement in pulp refinability is achieved because of the high content of xylans contained in the pulp. TABLE 7 Pulp Strength Properties and Refinability Tear Index at 40 Tensile Index at PFI Revolutions to Sample °SR, mN · m 2 /g 40 °SR, N · m/g reach 40 °SR A 10.0 107.3 2712 A 10.3 110.3 2588 Avg. 10.2 108.8 2650 B 10.8 94.7 2832 B 10.9 96.6 2964 Avg. 10.8 95.6 2898 C 10.5 111.4 2398 C 10.0 112.8 2462 Avg. 10.3 112.1 2430 The results shown in Tables 2-7 clearly indicate a significant overall yield benefit due to the pulp acidification with CO 2 at the end of the cooking cycle. There is also a significant increase in pulp brightness which had a large positive effect on pulp bleachability as shown in Examples 3 and 4. The penalty in pulp viscosity did not translate into any significant pulp strength loss while improving pulp refinability (Example 5). All these benefits were achieved at the expense of a CO 2 application of about 33 kg per ton of pulp. Experimentally, this invention was demonstrated for eucalyptus wood. However it is applicable to any type of wood that contains significant amounts of xylans or xylan derivatives. These may include any wood species of the hardwood (angiosperm) and softwood (gymnosperm) classes. The process was developed for kraft cooking. However it is also applicable to any type of alkaline cooking that ends at a pH above 12.5. This may include the soda, soda/Anthraquinone (AQ), soda-polysulfide (PS), soda-AQ-PS, kraft-AQ, kraft-PS and kraft-AQ-PS pulping processes. It is also applicable to any of the kinetically modified cooking processes (ITC®, RDH®, Lo-solids®, Super-Batch®, Ennerbatch®, EMCC®), etc. The examples given were for wood pulping at the temperature of 170° C., liquor:wood ratio of 3:1, active alkali of 24% and sulfidity of 30%. However, other operational conditions can be used depending on the type of wood. These may include temperatures in the range of 140-180° C., times at temperature of 30-180 min, liquor:wood ratios of 5:1 to 2:1, final cooking pH from 12.5-14 and sulfidity from 5-40%. The examples are given for pulp samples of kappa number around 17-18 but the technique is also applicable for pulps of kappa number ranging from 12 to 45. The acidification step should preferably be done with CO 2 because this acid is more adapted to the cooking cycle. It will result in the formation of sodium and calcium carbonates which are common chemicals existing in the cooking and recovery cycle. However, other mineral acids compatible with the recovery cycle could be used. Also, low alkalinity streams extracted from the digester itself could be used to lower the pH of the pulping liquid. The physical point of CO 2 injection into the cooking cycle can be in the bottom of the digester or in the blow fine. However other points of injection along the digester body or in the liquor circulation streams are also possible. The purity of the CO 2 used to acidify the reaction media may vary from 70-100%. When lower purity CO 2 is to be used the impurities should be compatible with the recovery cycle. The impure CO 2 should not contain substances other than oxygen, nitrogen, argon, and sulfur compounds. Particulate material can cause problems in the injection and control equipment and should be absent.	A method for producing pulp, comprising digesting lignocellulosic wood, containing one or more xylan derivatives selected from the group consisting of xylan bound with lignin, xylan bound with hexenuronic acid, and mixtures thereof, with an aqueous alkaline pulping solution containing sulfide and having an initial free hydroxyl ion concentration of at least 1 mole per liter, under conditions whereunder xylan is dissociated from said one or more xylan derivatives and the pH of the solution remains above 12.5; and then while the pH of said solution is above 12.5, adding a sufficient amount of an acidic agent to said pulping solution to precipitate dissociated xylan from said pulping solution while minimizing precipitation of lignin from said pulping solution. Carbon dioxide is a preferred acidic agent.	3
BACKGROUND OF THE INVENTION The present invention relates to a pearly-lustered container suitable for use with cosmetics or the like. A conventional pearly-lustered container of this kind is proposed, for example, in Japanese Patent Publication No. 41596/78, according to which the container body has a double-layer structure composed of an outer layer of a transparent synthetic resinous material mixed with a predetermined amount of pearly essence and an inner layer of an opaque synthetic resinous material colored in a desired color. It is described in this prior art literature that, with such a structure, since rays of light incident on the container are diffuse-reflected by pearl essence particles mixed in the transparent resin of the outer layer, the container surface assumes a pearly luster, and that when the outer layer is sufficiently thick, light reflected from the neighborhood of the outer layer surface and light diffuse-reflected by the pearl essence particles distributed throughout the outer layer are superimposed on each other to add a cubic effect to the appearance of the container. In practice, however, containers of this prior art arrangement, now on the market, have their outer and inner layers both formed of polyethylene resin to a thickness of about 250 microns. The polyethylene resin is very economical and the most practical resin but has poor transparency. Therefore, as the thickness of the layer increases, its light transmission efficiency gradually decreases, finally resulting in the layer becoming almost semitransaprent. Accordingly, an increase in the thickness of the outer layer permits an increase in the amount of pearl essence mixed in the layer but, in this case, although the reflectivity of incident light which is reflected by the pearl essence particles present near the surface of the outer layer is high, the reflectivity by the pearl essence particles deep in the outer layer in the vicinity of the inner layer is impaired by the low transparency of the polylethylene resin. Furthermore, in order to make the container attractive in appearance, the opaque inner layer is colored by using a coloring pigment so that coloring agent particles may be seen through the outer layer. Accordingly, an increase in the amount of pearl essence mixed for heightening the pearly luster impairs the light transparency of the outer layer. Thus, the amount of pearl essence mixed in the outer layer is also limited. With such a conventional pearly-lustered container as described above, a decrease in the amount of pearl essence employed decreases the quantity of light reflected by the pearl essence particles and, in addition, only the pearl essence particles in the vicinity of the surface of the outer layer contribute to radiation of the pearly luster, and the pearl essence particles deep in the outer layer do not much contribute to it. Moreover, mixing of the pearl essence which does not much contribute to radiation of the pearly luster is economically disadvantageous because the pearl essence itself is expensive. SUMMARY OF THE INVENTION It is therefore an object of the present invention to provide a pearly-lustered container which is free from the abovesaid defects of the conventional containers, brilliant with a pearly radiance and economically advantageous. Briefly stated, the container of the present invention has a thin outer layer of a synthetic resinous material mixed with a required amount of powdered pearl essence for giving a pearly luster, a relatively thick intermediate layer of a transparent or semitransparent synthetic resinous material mixed with a predetermined amount of coloring pigment for producing therein a desired color tone, and an inner layer of a white opaque synthetic resinous material for forming a background. According to the present invention, rays of light incident on the outer surface of the container are in part diffuse-reflected by pearl essence particles for producing the pearly luster and in part reflected at the boundary between the outer and the intermediate layer, and these reflected rays are superimposed on each other to give a splendid pearly luster to the container surface on a background of a desired color tone. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a front view of a tubular container embodying the present invention, and FIG. 2 is an enlarged sectional view of the circled portion of FIG. 1. DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 illustrates an embodiment of the present invention as being applied to a tubular container. A neck portion 2 of a tubular body 1 has an opening at its upper end for taking out the contents of the tube. On the neck portion 2 are formed screw threads 3 which helically extend around its outer peripheral surface for threaded engagement with a container cap. The lower end of the neck portion 2 adjoins a funnel-shaped shoulder portion 4 of the tubular body 1. As shown in the enlarged sectional view of FIG. 2 the the body 1 has a triple-layer structure comprising an outer layer a, an intermediate layer b and an inner layer c. The outer layer is a thin, preferably 90 to 110 micron thick, layer formed of colorless or transparent polyethylene resin mixed with a required amount of very fine pearl essence powder containing, as basic components, mica, titanium and so forth for giving a pearly luster to the container. The reduced thickness of this layer is to keep its transparency high. The intermediate layer b is formed of transparent resin of olefine series mixed with a required amount of pigment of transparent or semitransparent desired color tone to make the layer transparent or translucent in the desired color tone. It is desirable that the intermediate layer b be formed as thick as possible, preferably, 200 to 300 microns, so as to add a feeling of depth to the appearance of the container and provide it with chemical and physical strength. The inner layer c is formed of white opaque synthetic resin of olefine series colored by titanium white or the like. The outer, intermediate and inner layers a, b and c are formed as a unitary structure with one another. It is also possible to coat the outer surface of the outer layer a with a transparent film d which protects a trade name or the like printed thereon and gives a luster thereto. According to the illustrated embodiment, the container body 1 has a laminated structure of three layers, i.e. the outer, intermediate and inner layers a, b and c as described above. The three layers can easily be formed by extrusion molding as a unitary structure with one another through using three extruders connected to a die. The coating of the outer surface of the outer layer a can be effected by continuously forming a transparent film as of polyester series through the use of a coating machine after the formation of the container body 1. As described above, the container body of the pearly-lustered container of the present invention is composed of a thin outer layer of synthetic resin mixed with a required amount of powdery pearl essence for giving a pearly luster, such as mica, titanium and so on, an intermediate layer of colorless synthetic resin mixed with a predetermined amount of transparent or translucent coloring pigment for producing a desired color tone, and an inner layer of white opaque synthetic resin for forming a background. With such a structure, light incident on the container, after refracted by the transparent film d forming a surface layer, enters the outer layer a to strike against shiny fine particles of the pearl essence innumerably scattered in the outer layer a, and a pearly luster is given by diffuse reflection from the surfaces of the particles. The incident rays of light in part pass between the pearl essence particles to enter the intermediate layer b but, on account of different refractive indexes of the outer and intermediate layers a and b, the incident rays are in part reflected at the boundary between the two layers to shine on the pearl essence particles from behind in the outer layer a and they are diffusely reflected back to the outside of the container. In this case, since the outer layer a is thin, the attenuation of the reflected light is small and the diffuse reflection of the reflected light also effectively gives the pearly luster. The light which is not reflected at the boundary between the outer and intermediate layers a and b is refracted by the intermediate layer b to strike against transparent or translucent coloring pigment particles present in the intermediate layer b and only colored light specified by the pigment passes through the pigment particles to shine on the background formed by the inner layer c of opaque white resin. By such an action of the incident light, the light reflected from the surfaces of the pearl essence particles in the outer layer a and the light reflected at the boundary between the outer layer a and the intermediate layer b and reflected from the back of each pearl essence particle in the outer layer a are superimposed on eah other. Accordingly, as compared with providing pearly luster by reflected light from the surface of the pearl essence particles as in the conventional pearly-lustered container, the container surface of the invention assumes a profound and gorgeous luster by virtue of the light reflected from the back of the pearl essence particles. Moreover, since the pearly luster is given on a background of a desired color formed by the colored transparent intermediate layer b on the white inner layer c, the cubic effect of the pearly luster is heightened. Besides, according to the present invention, since the pearl essence for providing the pearly luster is mixed in a thin layer, the pearl essence can be utilized more effectively than in the case of mixing the pearl essence in a thick layer. Therefore, the container of the present invention also is advantageous from the economical point of view. It will be apparent that many modifications and variations may be effected without departing from the scope of the novel concepts of the present invention.	A pearly-lustered container includes, a body of a triple-layer structure. A thin outer layer is formed of a synthetic resinous material mixed with powdered pearl essence for giving a pearly luster. A relatively thick intermediate layer is formed of a transparent synthetic resinous material mixed with coloring pigment for bringing out a desired color tone. An inner layer is formed of a white opaque synthetic resinous material to function as a screen.	8
CROSS-REFERENCE TO RELATED APPLICATIONS This application is a continuation-in-part of U.S. patent application Ser. No. 07/735,321, filed Jul. 24, 1991, now U.S. Pat. No. 5,327,850, issued Jul. 12, 1994, and entitled ROADWAY MARKER, which is a continuation-in-part of U.S. patent application Serial No. 07/694,873, filed May 2, 1991, also entitled ROADWAY MARKER, now abandoned. TECHNICAL AREA This invention relates to roadway markers and, more particularly, to low profile, lightweight roadway markers. BACKGROUND OF THE INVENTION Roadway markers are utilized in a variety of traffic control situations. Many roadway markers are affixed to a roadway to permanently delineate lanes of traffic on the roadway. Other roadway markers are used to temporarily delineate construction or work areas. Both permanent and temporary roadway markers are attached to a roadway with a suitable adhesive. Permanent roadway markers have a low profile and remain in place to permanently define traffic lanes, identify obstacles, and perform other well-known functions, such as providing daytime visibility, and night time reflectivity, especially on wet nights when flush pavement markers disappear under a film of water. While having a low profile, many permanent roadway markers are raised to create a rumble sound in an automobile when the tires of the automobile impact a row of markers. The most commonly used permanent marker is formed of ceramic and has a partially hemispherical, button-like shape. In recent years, alternative roadway markers having inclined surfaces covered with a retroreflective medium in the form of a surface tape or embedded prisms have been developed for use as permanent roadway markers. Many firms currently market roadway markers similar to that illustrated in U.S. Pat. No. 3,332,327. One example of such a product is the Model 88 sold by Stimsonite Corporation. Similar products are sold by Ray-o-lite Div. of Pac-Tech, Pavement Markers, Inc., and Apex International. The shells of these markers are variously transparent or opaque and have the form of a truncated pyramid. One or two lenses are either insert molded or molded integrally into the sides of these markers. The lenses are made retroreflective by including large cube-corner patterns on the inside of the sloped faces. After coating these inner faces with a light-reflecting material, e.g., aluminum, the plastic shell is filled with a relatively rigid material such as epoxy resin and the bottom surface covered with sand or glass beads to enhance the adhesion of the marker to the roadway. Other roadway markers, essentially the same as those aforementioned in many ways, but differing in either shape or lens construction, are also currently available. The Stimsonite Model 948 is more elongated and lower in profile, but narrower in width. The Ray-o-lite Model 2001 has a similar shape. The markers of the type discussed in U.S. Pat. No. 4,726,706, such as the Stimsonite 953, differ in lens construction. Their lenses are "air-gap" reflectors rather than metallized like previous markers. The marker described in U.S. Pat. No. 4,875,798 is roughly the same shape as the Stimsonite Model 948, but is not filled and utilizes a reflective sheeting rather than an integrally molded reflective lens. As is pointed out in many of the foregoing patents, the outer face of prior markers are sloped from the roadway at an angle large enough for good reflectivity and small enough to allow a wiping action by vehicle tires, i.e., from 15° to 45° and preferably 30° to the surface of the road. The reflective materials used are either methyl methacrylate or polycarbonate. Both of these materials exhibit good optical qualities but are either extremely brittle, abrade very easily, or both. To overcome the problems associated with these characteristics, the Stimsonite Model 948 bonds a thin veneer of untempered glass to the outside face of the reflector. See U.S. Pat. No. 4,340,319. Ray-o-lite reportedly uses a chemical treatment that purports to do the same. Both of these solutions to the brittleness and abrasive problem are, from a manufacturing point of view, expensive. Further, they are unsatisfactory. In the case of the Stimsonite Model 948, the glass is very thin and still abrades quite readily. The Ray-o-lite product, while abrasion resistant, turns dark when installed on the road, thus rendering the marker substantially ineffective. The marker described in U.S. Pat. No. 4,875,798 utilizes a very thin (2 mm) reflective sheeting for its reflective lens. The lens as disclosed lies at an angle from 15° to 45° to the roadway. This exposes the face of the lens to a tremendous amount of abuse by vehicle tires. After a short amount of time the reflectors of these markers become abraded, and begin to peel off of the marker body, thus reducing their effectiveness. The sheeting described in U.S. Pat. No. 4,588,258 (Hoopman) incorporated into the marker described in U.S. Pat. No. 4,875,798 (May) is made of a rigid thermoplastic such as polycarbonate, as noted in the May patent. While these patents do not disclose whether the sheeting is or is not metallized, markers incorporating this technology have been produced both with and without metallization. Both types are initially quite bright, as predicted in the patent. However, over a long period of time, the reflectors fail due to the forces described above. As noted above, abrasion is one of the major problems faced by roadway markers, particularly permanent roadway markers. Abrasion becomes particularly acute when pavement markers are used in areas where abrasive materials, such as sand and salt, are distributed over the roadway surface during the winter months. The sand and salt are continuously brought into contact with the reflectors of the pavement markers of the type described above by the wiping action of the tires. The combination of the abrasive materials and the wiping action of the tires tends to scratch the surface of the reflective lenses of such markers, rapidly diminishing their optical effectiveness and reflective quality. High speed photography has revealed that the area of a typical marker that receives the most abuse is the "shoulder" of the marker, where the planes of the reflector face and the top of the marker join. At the initial impact, a tire rests on the pavement just in front of the marker and on the shoulder of the marker. Contrary to what is stated in a number of patents, the tires never "wipe" the face of the markers clean. Whatever wiping occurs is due to the effect of high speed jets of air and, when the road is wet, water that is carried in the tread of the tire. It is estimated that the speed of this air and water stream is in the vicinity of 250 feet/second. It is the speed of the water, not the action of tires that cleans pavement markers. The action of the tire on the face of the marker is entirely deleterious. The tire scurfs, abrades, and coats the marker shoulder with black marks. Obviously it would be desirable to provide a raised pavement marker that obtains the positive effect of the air/water stream without the negative effects of an actual tire impact on the reflective lens of the marker. As discussed more fully below, the present invention achieves this result by providing a raised pavement marker with a curved front face. The radius of curvature is only slightly less than the radius of the tire as it ramps over the marker. As a result, while the tire does not wipe the face of the marker, the air/water stream benefit is retained. Temporary roadway markers serve to notify motorists that a construction area is near and that caution is needed. They often direct roadway traffic to pass along the portions of the roadway unaffected by construction, while protecting workers within a construction area from roadway traffic. After construction is completed, temporary roadway markers are loosened and removed. To be effective, temporary roadway markers must alert traffic to the presence of a construction area. Typically, temporary roadway markers warn oncoming motorists by the use of visual cues, such as reflective surfaces. Some temporary roadway markers also use physical cues, such as causing a vehicle to create a rumbling noise on contact with a marker. Temporary roadway markers are designed and manufactured so as to only last a short period of time-the life of a typical construction project, for example, six months. As compared to permanent roadway markers, temporary roadway markers in general are much more simplistic in construction, less expensive to manufacture, and lower in performance standards both initially and over time. The Stimsonite Model 66 and the roadway marker described in U.S. Pat. No. 4,428,320 (Oplt et al.) are both examples of temporary roadway markers. The Stimsonite Model 66 includes an air-gap reflector angled at 45° to provide night visibility. In actual use the Stimsonite Model 66 marker provides very little initial reflectivity (66% lower than a permanent marker), which quickly fades with time. The molded lenses crack when the honeycombed body of the marker crushes under vehicle impacts. Water and dirt then get into the air-gap and eliminate reflectivity in the entire lens. The sheeting of the Oplt et al. marker is a much more efficient reflector. Being an embossed metallized polycarbonate microprism and mounted at an angle of 72°, it provides as much reflectivity as the "permanent" markers do, and for a much lower manufacturing cost. However, the reflective tape must be mounted within 20° of the vertical in order to maintain its effectiveness, due to the structure of the embossed cube-corner microprisms. The honeycombed interior of the Oplt et al. marker makes the marker lightweight, which is desirable. Although the roadway marker is lightweight, one disadvantage of an Oplt et al. type roadway marker is its high manufacturing cost. Due to its construction, an Oplt et al. type roadway marker must be injection molded. Injection molding is expensive when compared to other manufacturing processes. Another disadvantage of Oplt et al. and Stimsonite Model 66 temporary roadway markers is the fact that they are usually molded from a low cost resin such as high impact polystyrene in such a fashion as to reduce the weight of the final part. What results is a marker with a honeycombed base pattern that is essentially hollow. Because such markers are extremely sensitive to the impact of vehicle tires they do not last long on the road, often less than 30 days. As best understood at present, the typical vertical forces exerted on a raised marker by a small passenger vehicle tire are 200 ft. lbs. Larger vehicles can increase this force to as high as 1,000 ft. lbs. In testing, neither the Stimsonite Model 66 nor the Oplt et. al. type marker was found able to withstand even 60 ft. lbs. of vertical force. Another problem that arises with the use of hollow markers is that of adhesion to the roadway. Quite often installation contractors will eschew the use of more permanent adhesives and bond the markers with an elastomeric adhesive, such as a synthetic butyl rubber pad. The effect of the hollow marker on butyl is to cut through it like a cookie cutter, placing the plastic marker in direct contact with the pavement, resulting in immediate breakage, loss of adhesion, or both. In order to overcome the costs disadvantage associated with injection molding, roadway markers having a constant cross-sectional shape along their longitudinal axis have been developed. The constant cross-sectional shape allows such roadway markers to be made by an inexpensive extrusion manufacturing process. Such roadway markers are described in parent U.S. patent applications Ser. No. 07/735,321 and Ser. No. 07/694,873 more fully referenced above, the subject matter of which applications is incorporated herein by reference. In addition to their constant cross-sectional shape, roadway markers of the type described in the foregoing patent applications include a base area suitable for adhesive attachment to a roadway surface, as well as a raised rumble portion. The base area of the marker is relatively large and includes a plurality of adjacent, parallel grooves of arcuate cross section. The arcuate grooves increase the adhesive surface of the marker. The longitudinal lower edges of the base curve downwardly to assist in gripping the roadway surface. The top of the raised rumble portion is scalloped to reduce the weight of the roadway marker. The longitudinal lateral sides of the raised rumble portion of the roadway marker may include a recess for receiving a strip of reflective tape. The two orthogonal sides are sheared straight, or inclined, depending upon the intended use of the marker. While extruded roadway markers of the type described above have a number of advantages over previously developed roadway markers of the injection molded type, previously developed extruded roadway markers, like injection molded roadway markers are subject to improvement, particularly in the area of viewability over extended periods. The present invention is directed toward providing roadway markers, particularly extruded roadway markers having improved viewability over extended periods of time. SUMMARY OF THE INVENTION In accordance with this invention, roadway markers with large, rectangularly shaped bases and a raised rumble portion containing at least one concave curved edge are provided. The concave curved edge is intended to be the traffic facing, i.e., the leading, edge of the markers. The concavity begins at the base of the roadway marker and rises upwardly. The concavity may have a constant radius of curvature, or the radius of curvature may decrease with increased elevation. The height-to-width ratio of the roadway marker and the average radius of curvature are such that automobile tires impacting the roadway marker do not impact the surface of the concavity. Rather, tires impacting the roadway marker hit the marker above the edge concavity. As a result, a gap exists between an impacting tire and the surface of the concavity. Water squeezed from a wet tire impacting the roadway marker will enter this gap and wash the surface of the concavity. In accordance with further aspects of this invention, a reflective tape is attached to the surface of the edge concavity, beginning slightly below the upper end of the curvature so as to lie in the gap between the concavity and an impacting tire. Because the edge is concave, the amount of light reflected by the reflective tape back toward the driver of an oncoming car is greater than the amount of light reflected from tape attached to an inclined flat edge as in the prior art. Further, because the reflective tape lies in a gap, the likelihood of the reflective tape being abraded or dislodged due to tire impact is greatly reduced. The viewability of the reflective tape is also improved by tire water washing dirt and debris from the tape. In accordance with other aspects of this invention, the edge of the roadway marker located parallel to the edge containing the concavity contains a similar concavity. Either concave edge can form the binding edge of the roadway marker or, when used between lanes of traffic moving in opposite directions, both concave edges can face oncoming traffic. Preferably, both concave edges support a layer of reflective tape that starts below the upper end of the concavity. In accordance with still other aspects of this invention, preferably, the roadway marker has a relatively low profile. In accordance with still further aspects of this invention, the roadway marker has a constant cross section along its length and is created by extruding a suitable plastic material. In accordance with yet further aspects of this invention, preferably, the upper surface of the roadway marker is scalloped whereby humps are created where the concave edges and the scallop join one another. In accordance with yet still other aspects of this invention, the lower surface of the roadway marker includes a plurality of parallel grooves of arcuate cross section. BRIEF DESCRIPTION OF THE DRAWINGS The foregoing and other advantages and features of this invention will become better understood by reference to the following detailed description of preferred embodiments of the invention when taken in conjunction with the accompanying drawings, wherein: FIG. 1 is an isometric view of a roadway marker formed in accordance with this invention; FIG. 2 is an end elevational view of the roadway marker illustrated in FIG. 1; FIG. 3 is an enlarged portion of one end of FIG. 2 depicting a roadway marker wherein the radius of curvature of the concavity of the illustrated edge is constant; FIG. 4 is an enlarged view of one end of FIG. 2 depicting a roadway marker wherein the radius of curvature of the concavity of the illustrated edge decreases with a rise in elevation; FIG. 5 is an end view illustrating another embodiment of the embodiment of the invention illustrated in FIG. 1; FIG. 6 is an end elevational view illustrating a dry tire impacting an embodiment of the invention of the type illustrated in FIG. 5; FIG. 7 is a further end elevational view illustrating a dry tire impacting an embodiment of the invention of the type illustrated in FIG. 5; FIG. 8 is another end elevational view illustrating a wet tire impacting an embodiment of the invention of the type illustrated in FIG. 5; FIG. 9 is an end view of an embodiment of the invention that includes letters associated with various parameters used to create actual embodiments of the invention; FIG. 10 is a partial end view of a still further embodiment of the invention; FIG. 11 is a partial end view of yet another embodiment of the invention; FIG. 12 is an end view of still another embodiment of the invention; and FIG. 13 is an isometric view of yet another embodiment of the invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIGS. 1 and 2 illustrate the general shape of a preferred embodiment of a roadway marker 11 formed in accordance with the invention. The roadway marker 11 illustrated in FIGS. 1 and 2 has a constant cross section from one end to the other along a longitudinal center line A--A. The constant cross section allows the illustrated roadway marker to be extruded using conventional nonmetallic, i.e., plastic, extrusion technology, and sheared to any desired length. The roadway marker 11 illustrated in FIG. 1 includes a base 13 and a raised rumble portion 15. The bottom of the base 13 is substantially planar and of rectangular shape. A large bottom allows a roadway marker to be strongly attached to a roadway surface by any suitable adhesive, such as epoxy, butyl, or hot melt bituminous adhesive. The bottom of the base 13 includes a series of parallel grooves 17. The grooves 17 are disposed adjacent and parallel to one another. The grooves 17 also lie parallel to the longitudinal center line A--A. The grooves 17 extend the entire length of the marker 11 and have an arcuate cross section. When compared to a base with a flat bottom, the arcuate cross section increases the size of the adhesion surface of the bottom. The larger adhesion surface allows the base to be better attached to a roadway. Arcuate grooves have even a larger surface area than do the V-shaped grooves of some prior art roadway markers. This translates into better roadway attachment. The raised rumble portion 15 is comprised of two regions--a center scalloped recess 19 and concave curved edges 21 and 23. Because the concave curved edges are identical, the roadway marker can be positioned such that either edge can form the traffic facing edge when the marker is used on a road with traffic moving in a single direction, or both edges can form traffic facing edges when the marker is used on a road with traffic coming from opposite directions. The center scalloped recess and the concave curved edges cause the raised rumble portion 15 to have the cross-sectional shape of a pair of humps 25 and 27. The humps are located between the centered scalloped recess 19 and the curved edges 21 and 23. This cross-sectional shape is constant throughout the length of the roadway marker 11 along centerline A--A. Because the primary function of the scalloped recess 19 is to reduce the weight of the roadway marker, the exact shape of this recess is not critical. While shown as curved, the scalloped recess could have some other form. One important aspect of the scalloped recess 19 is its average radius of curvature. In this regard, although the exact specifications of the curvature are not critical, the average radius of curvature of the scalloped recess should be substantially less than the radius of curvature of smaller-sized automobile tires. Since smaller-sized automobile tires have a radius of curvature of thirteen (13) inches, this means that the average radius of curvature of the scalloped recess should be substantially less than thirteen (13) inches. Exemplary dimensions are included in the table set forth below. An average radius of curvature substantially less than the radius of curvature of smaller-sized automobile tires prevents automobile and other vehicle tires from seating in the recess 19 when a tire passes over the roadway marker 11. While, like ceramic roadway markers, a roadway marker formed in accordance with the present invention can be produced without any mechanism for enhancing the reflectivity of the roadway marker, preferably, as shown in FIGS. 1 and 2, a reflective medium is added to the surfaces of the concave curved edges of a roadway marker formed in accordance with the invention. More specifically, the embodiments of the invention shown in FIGS. 1 and 2 include a layer of reflective tape 31 applied to the surfaces of the concave curved edges 21 and 23. The reflective tape 31 lies atop the surface of the concave curved edges 21 and 23. The elevational location of the tape along the concave curved edges 21 and 23 is best shown in FIG. 9 and described below. FIGS. 3 and 4 are enlarged views of one of the concave curved edges 21 of the embodiment of the invention illustrated in FIGS. 1 and 2, the layer of reflective tape 31 being eliminated for purposes of clarity. The curved edge shown in FIG. 3 has a constant radius of curvature (c). The center of the radius is defined in the manner shown in FIG. 9 and described below. The radius of curvature of the concave curved edge 21 shown in FIG. 4 decreases with increased elevation. This is shown by overlaying the concave curved edge 21 with a grid 27 and a plurality of lines 29a, 29b, and 29c that lie tangent to the curvature of the leading edge 21. The first tangent line is located shortly after where the concave curved edge 21 begins to rise and the last is located where the edge ends. As can be seen, the rate of change of the angle of inclination of the tangent lines 29 increases as the leading edge 21 curves upwardly. This shows that the radius of curvature of the concave curved edge 21 decreases as the edge curves upwardly since the rate of change for a constant radius curve would remain constant. While the preferred curvature of the concave curved edge 21 shown in FIG. 4 is based on the tractfix or scheile curve, defined in part as "a curve such that the part of the tangent between the point of tangency and a given straight line is constant" in other words, the outside of the so-called "frictionless" curve and the involute of the "catenary" curve-other curves similar in configuration are satisfactory, such as catenary, hyperbolic, and parabolic curves. When plotted, it will be found that curves having these shapes are close to juxtaposed in the short distances plotted. FIG. 5 illustrates that the concave curved edges 21 and 23 can include an undercut region 33 for receiving the reflective tape 31. Placing the tape in an undercut provides additional protections against tire abrasion. FIGS. 6 and 7 illustrate an important feature of the invention, namely, that the radius of curvature of the concave curved edges 21 and 23 of a roadway marker formed in accordance with the invention be chosen such that vehicle tires (e.g., automobile, truck, trailer) impacting the concave curved edges do not impinge on the surface of the curves. More specifically, FIG. 6 illustrates an automobile tire 41 moving in the direction of the arrow 43. Located in front of the tire 41 is a roadway marker 11 formed in accordance with the invention. The roadway marker 11 is affixed to a pavement 45 and positioned such that one of the concave curved edges 21 faces the tire 41. This is the normal positioning of a roadway marker formed in accordance with this invention. The tire 41 includes the usual footprint region 47 where the tire is flat. The flatness is, of course, created by the weight of the automobile or other vehicle supported by the tire. By way of example, a normally inflated fifteen (15) inch radius tire has a footprint of approximately seven (7) inches. The footprint results in the tire radius at the center of the footprint being decreased by about one and one-half (11/2) inches, i.e., the distance between the center of rotation of the tire and the pavement 45 on which the tire rides is approximately thirteen and one-half (131/2) inches for a fifteen (15) inch radius tire. As clearly shown in FIG. 6, the radius of curvature of the concave curved edge 21 of the roadway marker 11 is such that when the tire 41 impacts the hump 25 that occurs where the end of the concave curved edge 21 meets the recess 19, the tire 41 does not impact the surface of the concave curved edge 21. As a result, the tire 41 never rides on the surface of the concave curved edge 21 and, thus, does not impinge on the layer of reflective tape 31 located on the surface of the concave curved edge 21. In essence, the reflective tape lies in a gap between the surface of the concave curved edge and the surface of tires impacting a roadway marker formed in accordance with this invention. Consequently, most tires impacting a roadway marker formed in accordance with this invention will not apply friction to the reflective tape and, thus, will not contribute to the destruction or removal of reflective tape either located directly on the surface of the concave curved edge 21 (FIGS. 1 and 2) or located in an undercut region of the concave curved edge (FIG. 5). FIG. 6 illustrates the "ideal" shape of a tire impacting a roadway marker formed in accordance with this invention. In actuality, radius of curvature of the leading edge of a pneumatic tire as it rolls over a pavement is not the radius of curvature of the tire as shown in FIG. 6. Rather, as shown in FIG. 7, a bulge, whose average radius of curvature is less than the radius of curvature of the tire, is usually located at the leading edge of the tire. While the average radius of curvature of the tire bulge varies depending upon the radius of the tire and the pneumatic pressure in the tire, the average radius of curvature of the tire bulge lies in the two (2) inch to five (5) inch range. In order to maintain the gap described above, obviously, the average radius of curvature of the concave curved edge should be less than the lower end of this range, i.e., less than two (2) inches. FIG. 8 illustrates what occurs when a wet tire 51 passes over a roadway marker 11 formed in accordance with the invention. As the tire 51 impacts the hump 25 between the leading edge 21 and the recess 19, water droplets 53 are squeezed from the grooves in the tire 51 and wash across the surface of the concave curved edge 21. In essence, the water droplets 53 swirl around the surface of the concave curved edge 21 facing the tire. As a result, reflective tape 31 located on this surface is washed by the water droplets 53, resulting in the removal of dirt and debris. FIG. 9 is a cross-sectional view of a roadway marker formed in accordance with this invention that includes a plurality of letters depicting various parameters of the marker. The following table lists dimensional ranges for the parameters, plus the presently preferred values used in one actual embodiment of the invention. ______________________________________Reference Dimensional PreferredLetter Range Value______________________________________a 2-10 inches 2.50 inchesb 0-0.5 inches 0.10 inchesc 0.5-5.0 inches 1.25 inchesd 0-4.0 inches 0.29 inchese 0.125-4.0 inches 0.72 inchesf 0-1.5 inches 0.84 inchesg 1.0-4.0 inches 2.00 inchesh 0.4-4.0 inches 0.53 inchesi 0.05-0.3 inches 0.10 inchesj 0.20-1.0 inches 0.50 inches______________________________________ FIG. 10 illustrates a concave curved edge of a further alternative embodiment of the invention. Like the embodiments of the invention illustrated in FIGS. 1 and 2, and 5, the embodiment of the invention illustrated in FIG. 10 includes reflective tape 31 located on the surface of the concave curved edges of the roadway marker 11. However, rather than lying directly on the surface, or in an undercut region of the concave curved edges, a lip 35 located just below the hump 25 that lies between the illustrated concave curved edge 21 and the recess 19 provides protection for the tape 31. FIG. 11 illustrates an embodiment of the invention that, like the embodiments of the invention illustrated in FIGS. 1 and 2, and 5, includes a reflective tape 31 located on the surface of the concave curved edges of a roadway marker 11 formed in accordance with the invention. However, rather than lying directly on the surface of the concave curved edges, or in an undercut region, the tape 31 rests against a lip 37 located at the base of the tape 31. The upper edge of the tape 31 is unprotected. In all of the previously described embodiments of the invention, both edges, i.e., the leading and trailing edges, of roadway markers formed in accordance with the invention have been identically shaped regardless of whether they support, or do not support, reflective tape. Thus, these embodiments of the invention are symmetrical whereby either edge can form the traffic facing edge when a roadway marker formed in accordance with the invention is mounted on a roadway surface having traffic moving in one direction, or both edges can form traffic facing edges when a roadway marker formed in accordance with this invention is mounted on a roadway surface having traffic moving in opposite directions. In contrast, FIG. 12 illustrates a unidirectional embodiment of the invention. More specifically, the roadway marker 61 illustrated in FIG. 12 includes a leading edge 63 and a sloping, trailing edge 65. The leading edge has a convex curved shape of the type previously described. The base includes a plurality of parallel arcuate grooves 67. Rather than including a recess, after the point where the concave curved edge 63 reaches a hump 69, the hump tapers to the trailing edge of the roadway marker 61. Preferably, located on the surface of the concave curved leading edge 63 is a reflective tape 71. As with the previously described embodiments of the invention, the reflective tape 71 can be located in an undercut region 73, as shown, or directly on the surface of the concave curved edge 63 (FIGS. 1 and 2) or protected by upper or lower lips (FIGS. 10 and 11). FIG. 13 illustrates yet another embodiment of the invention. Rather than the raised rumble portion including a scalloped recess located between concave curved edges 81 and 83, a convex protrusion 85 is located therebetween. As with the other embodiments of the invention, the cross-sectional shape of the roadway marker is constant along its longitudinal axis B--B and the concave curved edges 81 and 83 have a constant or variable radius of curvature sized such that tires hitting the concave curved edges do not apply friction to strips of reflective tape 87 applied to the concave curved edges. The convex protrusion 85 rises upwardly between the concave curved edges 81 and 83. The radius of curvature of the convex protrusion lies in the 2-10 inch range, with 3.375 inches being preferred. The base of the marker illustrated in FIG. 13 is the same as the base of the previously described markers, i.e., the base includes a plurality of parallel grooves 89. As illustrated in the drawings, preferably, roadway markers formed in accordance with the invention have a constant cross section. This allows such embodiments of the invention to be manufactured by extrusion. That is, the illustrated embodiments of the invention all can be formed by extruding a suitable plastic through a dye having a shape corresponding to the desired cross-sectional configuration. The extrudate is then cured and hardened. The manufacture of roadway markers using an extrusion method greatly decreases the cost of such markers. Moreover, extrusion allows roadway markers performed in accordance with the present invention to be easily manufactured in varying length. This allows the embodiments of the invention to be used as "rumble" strips, as well as spaced-apart roadway markers. The continuous nature of the base allows less adhesive to be used to create a strong bond between the base of the roadway marker and a road surface when compared to bases that are interrupted by hollow regions such as that described in the Oplt et al. patent referenced above. Adhesive tends to ooze into the hollows of Oplt et al. type bases, reducing adhesive effectiveness. On the other hand, while, preferably, the embodiments of the invention are made by extrusion, embodiments of the invention could be molded, if desired. That is, molded roadway markers including concave curved edges can be formed in accordance with the invention even though, at present, such roadway markers appear to be less desirable because they are less economical to manufacture than extruded roadway markers. Further, damaged and/or eroded reflective tape can be replaced, provided the bodies of markers formed in accordance with the invention remain intact, making embodiments of the invention reusable and, thus, still more economical. While preferred embodiments of the invention have been illustrated and described, it will be appreciated that, within the scope of the appended claims, various changes can be made therein without departing from the spirit and scope of the invention. Thus, it is to be understood that, within the scope of the appended claims, the invention can be practiced otherwise than as specifically described herein.	Roadway markers (11) with large rectangularly shaped bases and a raised rumble portion containing at least one concave curved edge (21, 23) are disclosed. The concave curved edges (21, 23) face oncoming traffic. The concavity may have a constant radius of curvature or may decrease with increased elevation. The height-to-width ratio of the roadway marker and the average radius of curvature are such that automobile tires (41) impacting the roadway marker (11) do not impact the surface of the concavity. Rather, tires (41 ) impacting the roadway marker ( 11 ) hit the marker above the edge concavity. As a result, a gap exists between impacting tires and the surface of the concavity. Water squeezed from a wet tire impacting the roadway marker will enter the gap and wash the surface of the concavity. A reflective tape (31) is attached to the surface of the concavity. In some embodiments of the invention concavities are located in opposite edges of the raised rumble portion. In other embodiments, a single concavity is located along only one edge of the raised rumble portion. In the two-edge versions of the invention, preferably, a recess (19) is located between the parallel concave curved edges.	4
BACKGROUND OF THE INVENTION 1. Field of the Invention The invention is directed to a textile machine, for example, a warp knitting machine, having, on a carrier and next to each other, stroke elements which are longitudinally displaceable by means of pattern dependent activatable individual control elements. 2. Description of Related Art Such a textile machine is known from German Patent 12 24 863 to Lebrand, et al. In this device, guides attached to a guide bar are pulled by means of harness cords, from a lower, neutral position, to an upper working position and, by means of a common, spring biased return rail, are again returned to the neutral position. Such a construction is disadvantageous because the plurality of harness cords make access to the machine difficult, requires the use of a considerable amount of space and harness cords are only able to exercise tensile forces, An object of the present invention is to provide a textile machine of the prior art type in which the individual control of stroke elements can occur without the use of harness cords. SUMMARY OF THE INVENTION In accordance with the illustrative embodiments demonstrating features and advantages of the present invention, there is provided a textile machine for a warp knitting machine, a weaving loom or other textile equipment. The textile machine has a carrier and a thread-gripping plurality of stroke elements mounted side-by-side on the carrier. These stroke elements are individually and longitudinally displaceable in a stroke direction. Also included is a pattern-following plurality of control elements mounted on the carrier and electrically activatable to be brought into a first and a second position for affecting displacement of the stroke elements. The textile machine also has a single, common, activating arrangement running the length of the carrier and reciprocatable in the stroke direction for carrying into a working position those ones of the stroke elements associated with selected ones of the control elements that are in the second position. Machines constructed in accordance with the teachings of the present invention can have control elements provided to a carrier. These control elements can be electrically activatable, and can be brought into either of two positions. A preferred activating arrangement that is reciprocated in the stroke direction, stretches the length of the carrier and in one of its first positions, takes the stroke element into a working position. In such an embodiment, the control elements and the activating arrangements are provided proximate to the stroke element so that access to the machines is not hindered by harness cords or the like. The necessary cables for electrical activation may be displaced without any problems. The carrier with the appropriate control elements, lifting elements, and activating arrangement, can be built as a unit and replaced if necessary. Because of the limited availability of space, it is desirable to use comparatively small control elements with appropriately small displacement movements. These are sufficient however since the control elements do not carry out the stroke of the stroke elements but only need to activate the coupling between the activating arrangement and the chosen stroke element. It is advantageous to provide a return spring to each stroke element and that the coupling between the activating arrangement and the stroke element operates as a force transfer. The thus resulting pressure forces can be transferred from the activating arrangement onto the stroke element through comparatively small striker surfaces. In an advantageous embodiment, the control elements are provided to the activating arrangement and will grip, in their second position, onto the appropriate stroke elements. The control elements thus lie in the power train. A very desirable alternative may be found in that the control elements are provided to the carrier and in their first position hold a coupling element adjustable with the appropriate stroke element in a non-working position out of contact with the activation arrangement. This allows greater freedom in the design of the control element since the displacing forces do not run over the control element. It is advantageous to provide the coupling element with a latch hinged to the stroke element and which is frictionally held in the non-working position by the control element. Since the latch is held in place by frictional forces, it is sufficient for the control element to transmit comparatively small forces onto the latch handle. The holding ability in the non-working position is improved in that a striker is provided to each latch handle which is pressed against by the appropriate control element. An appropriate mode of achieving this which can also be used in combination, is found in that the mutually interactive surface of the control element and the handle are roughened. It is exceedingly advantageous to provide the latch or the control element with a depression into which the other element can intrude. In this way, there is provided a safety means which ensures that even under vibrations, the latch is held in its non-working position. A very small depression is all that is necessary, suitably in the order of a few tenths of a millimeter, for example 0.3 mm. It is advantageous that the activating arrangement, before displacement of the selected stroke element, carries out a movement whereby it brings the latch into the non-working position, working against the force of a spring. Herein the activating element does not run on a straight path. The appropriate sidewards component may be obtained by means of a linkage. It is particularly advantageous to provide the control elements as one sided, fixed piezoelectric transducers. These have a very small space requirement. Furthermore, they do not generate substantial forces. The displacement of their free ends however, is sufficient to move from a first position into a clearly differentiable second position. It is advantageous to provide the transducers parallel and next to each other, separated from the stroke elements. The free ends of the transducers are displaceable in the longitudinal direction of the carrier. In this manner, it is possible to arrange the transducers with a separation from each other that is so small that it corresponds to the division between neighboring stroke elements. From U.S. Pat. No. 5,390,512, it is already known to provide the free end of a one end, fixed piezoelectric transducer with a thread guide and to so arrange matters that this thread guide is displaced by one needle space upon activation of the transducer. This displacement movement is nevertheless small in comparison to the conventional stroke movement which in the longitudinal direction of displaceable stroke elements can be between 2 and 50 mm and runs perpendicular to this stroke motion. In a preferred embodiment, every transducer is provided in the same level as the appropriate stroke element and grips symmetrically to the stroke element. This leads to a space saving mode of construction and to an even loading during the displacement motion. It is also advantageous that the control elements are grouped together in a construction unit and its electronic leads are grouped together in a cable with a single contact plug. Each construction unit can be simply built and readily swapped out with other units. It is furthermore desirable that the stroke elements are each provided with a setting means with a separatable thread guide attached thereto. If the thread guide is abraded or damaged, it is merely necessary to exchange this thread guide. The total remaining construction can thus remain without interference. BRIEF DESCRIPTION OF THE DRAWINGS The invention may further be elucidated by the following drawings, which further illustrate the preferred embodiments: FIG. 1 is a cross-section of the carrier showing a stroke element in the at-rest position; FIG. 2 is a partial, cross-sectional view of the latch of FIG. 1; FIG. 3 is a partial, cross-sectional, elevational view of the carrier of FIG. 1 showing the stroke element in the working position; FIG. 4 is an enlarged perspective view of the latch of FIG. 1; FIG. 5 is a front elevational view of a group of control elements and stroke elements in the embodiment of FIG. 1; FIG. 6 is the embodiment of FIGS. 1 through 5 shown in a side elevational view as installed in a warp knitting machine; FIG. 7 is a modified embodiment of a hook-forming, stroke element; FIG. 8 is a cross-sectional, elevational view through a carrier according to a further embodiment; FIG. 9 is a front, elevational view of a group of control elements and stroke elements in accordance with the embodiment of FIG. 8; FIG. 10 is a detailed, perspective view of a stroke element in accordance with the embodiment of FIG. 8, showing the appropriate control element in the second position; and FIG. 11 is a detailed, perspective view of a stroke element in accordance with the embodiment of FIG. 8 with the appropriate control element in the first position. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The embodiment of FIGS. 1 through 6 show a carrier (1) which stretches across the entire breadth of a warp knitting machine. The stroke elements (2) are placed in a row next to each other. They comprise a setting member (3) and a thread guide (4) in the form of a hook-shaped gripping means. The thread guides (4) are removably fixed in the setting members (3). The stroke element (2), is displaceable from the at-rest position shown in FIG. 1, in which the hook of the thread guide is provided in a bore (5) which is provided in a covering means (6). Element (2) is displaceable against the force of a return spring (7) into the working position shown in FIG. 3, in which the hook of the thread guide (4) is released. In the at-rest position therefore, the threads which were grasped in the working position are clamped tight. For the displacement of the stroke element (2), an activating arrangement (8) is provided over the breadth of the machine in the form of a ledge, which is attached to a lever arm (9) of a linkage (10) which is cyclically driven by a cam (11) via a drive lever (12) and a rod means (13). The fixed bearings (14 and 15) of the linkage (10) are attached to the carrier (1). The activating arrangement (8) operates together with latches (16) which are hinged to stroke elements (2) by hinges (17) and are biased in a clockwise direction by springs (18). These springs (18) are counteracted when the latch follows the activating arrangement (8) through its downward gravitational force. Every latch (16) can take up two positions, namely an active position "a" wherein the activating arrangement (8) contacts a striker (19) on the latch and a non-working position "b" in which the activating means (8) moves past the striker (19) as shown in FIG. 2. In the active position "a" the activating arrangement (8) is coupled in a force transmitting manner with stroke element (2) via latch (16) so the former is moved into the working position of FIG. 3. In the non-working setting "b," per contra, the stroke element (2) is not influenced, thus remains in the at-rest position of FIG. 1. A block (20) is affixed to carrier (1) in which a plurality of control elements (21) in the form of single end, fixed (cantilevered) piezoelectric transducers are held. The control elements are controlled by electrical potential over conductors in a common cable (22). The cable (22) is provided with a plug (23), which provides a connection to a pattern-forming control apparatus (24). By the application of potential, the free end (25) of control element (21) is so displaced that the control element can take up two positions. In the first position (c) (see FIG. 5), the control element (21) lies with its free end (25) in frictional connection onto latch (16) and presses this against a rod formed striker (26). This, in combination with a rough surface on free end (25) and on the latch (16), as well as in combination with a depression (27) on latch (16) (which forms a striker (28)) ensures that the latch maintains its non-working position (b) even when the machine generates vibrations. During a displacement of the free end (25) of the control element, a second position (d) is reached in which the latch (16) is released. The released latch therefore follows the movement of the activating arrangement (8) out of the position of FIG. 1 into the position of FIG. 2 and further into the position of FIG. 3. Thus, selected stroke elements (2) are thus taken together with the activating arrangement (8) and pushed to the outside. So that in each work cycle, one can make a choice among all the stroke elements (2), all the control elements (21) are brought into the second position (d) for a short time and all the latches (16) are pushed into the non-working position (b) by the activating arrangement (8), which is made possible by the corresponding design of the linkage (10). Thereafter, the translation of certain control elements (21) from the second position (d) into the first position (c) is activated so that the selected latches remain in the non-working position (b). Only the other, free latches return to the working position (a), which leads to activation of the stroke element (2). When the non-selected control elements (21) are brought from positions (d) to (c), which may be the case with piezoelectric transducers, it is ensured that the latches 16 are held tight irrespective of electrical current interruption. This prevents an undesired release of the stroke elements (2), for example, during failure of the control means. The control elements (21) are put together in a group of sixteen control elements, which can be constructed together as a building unit (29). The latches (16) are always located between two rod-formed strikers (26) and are thus securely guided. FIG. 6 shows the manner of utilization of the carrier (1) in a warp knitting machine. This machine has two guide bars (31 and 32) with which the fabric ground is laid and a pattern guide bar (33) with which the pattern threads are provided for the formation of a pattern. Furthermore, the needles (34) are provided proximal to a knock-over arrangement (35). Proximal to the knock-over arrangement, a cutting arrangement (36) is provided. This is followed by a suction extraction arrangement (37). Over the latter, there is located the stroke element (2) with a thread guide (4) in the shape of a hook-formed gripping means. In this manner, the pattern threads can be gripped by the hook of the thread guide (4), clamped tight and cut off by the cutting arrangement (36). As soon as a new pattern should be laid, the pattern thread is again laid in front of the needle (34) and released by thread guide (4). By this means, the pattern thread can form pattern segments which may be separated from areas free of these patterning threads. See German Patent Application P 44 33 222.4-26 (U.S. Ser. No. 526,545). In the embodiment of FIG. 7, the corresponding items numbers are raised by 100. The thread guide (104) is in the form of a regular thread guide having an apertured head portion, which moves from the at-rest position (not shown) into the illustrated working position in order to lay a hook out of the provided thread. In place of the covering means (6), guide pegs (106) and (106a) are provided. In the embodiment of FIGS. 8 through 11, the item numbers for the corresponding components are raised by 200. The difference here lies in that the control elements (221) are fixed to the activating mechanism (208) which is moved up and down by rod means (210) and is thus connected to carrier (201) via rod means (209). The control elements (221), which may be in the form of piezoelectric transducers as shown in FIG. 9, can lie with their free ends (225) either sidewardly displaced and thus in the first position (c), or in the second position (d) against a striker on stroke element (202). The stroke element (202) has a central recess (238) into which the free end (225) of the control element (221) may enter in the displaced position (first position (c)). In this position, during the downward movement of the activating element (208), the stroke element (202) is not carried with it. The free end (225) carries a transverse beam (239) with which, in the second position (d), a pressure force is transferred to the stroke element (202) so that the stroke element (202) is carried downwardly. The carriers can be affixed to the machine itself or can be provided in an axially displaceable manner so that the threads influenced by stroke motion can also permit overlaps and underlaps to be formed. Instead of the illustrated use, the same principle can also be used in the design formation in weaving looms.	Textile machine in particular a warp knitting machine having attached, side-by-side, on a carrier (1), stroke elements (2) which grip on the threads, which are individually displayable in the longitudinal direction. To the carrier (1), are provided control element (21) which are electrically activatable and can be brought into two positions. A common activating arrangement (8) which runs along the length of the carrier (1) and is driveable to and fro in the stroke direction, influences the stroke element (2) in the first position of the appropriate control element (21) in the at-rest position and carries it with it in its second position in a working mode. In this manner it is possible to control the individual stroke elements without the need for harness cords.	3
FIELD [0001] The present disclosure relates to a double postcard check mailer including a check component and a payee data correction component and a method of use therefor. BACKGROUND [0002] This section provides background information related to the present disclosure which is not necessarily prior art. [0003] There are many legal proceedings and settlements that result in the need for the distribution of cash proceeds and related information to a plurality of recipients. Typical examples of such proceedings are class action litigation proceedings and bankruptcy proceedings. The number of recipients may be in the thousands or more. An administrator of the proceedings often distributes the funds to the recipients. The administrator may transmit the funds to the recipients by placing a check made out to the recipient in an envelope, paying the applicable postage (e.g., first class letter rate), and sending the check to the recipient via the federal mail system. If information regarding the recipient changes, e.g., a change of address or name, the recipient would have to initiate a telephone call or send a letter requesting such a change be made to the administrator's records. SUMMARY [0004] This section provides a general summary of the disclosure, and is not a comprehensive disclosure of its full scope or all of its features. [0005] In one aspect of the disclosure, a mailing apparatus is disclosed. The mailing apparatus comprises a check component including a check having a front side and a back side. The front side includes a payee field, a maker field, a written amount field, an account number field, a routing number field, and a numeric amount field. The back side includes an endorsement line. The mailing apparatus further comprises a payee data correction component detachably coupled to the check component. The payee data correction component includes a payee data correction form having a front side and a back side. The front side includes a maker address field in a substantially central or right-central area of the front of the payee data correction form, and a payee data correction field at a substantially top left portion of the front of the payee data correction form. The top front edge of the check folds downwardly towards the bottom front edge of the payee data correction component, such that when the mailing apparatus is folded, the back of the check and the back of the payee data correction form are external and the front of the check and the front of the payee data correction from are internal. [0006] In another aspect of the disclosure, a method of administering distribution of funds in one of a legal proceeding, a class action litigation proceeding and a bankruptcy proceeding is disclosed. The method comprises receiving a name of a payee and payee data, wherein the payee is one of a plurality of claimants in the proceeding. The payee data includes at least one of a mailing address and contact information of the payee, and the payee is owed at least one future payment through the one of the class action proceeding and the bankruptcy proceeding. The method further comprises storing the name of the payee and the payee data in a database and generating a mailer based on an amount of one of the at least one future payment. The name of the payee, and the payee data, the mailer including a check component and a payee data correction component detachably coupled to the check component. When the mailer is folded, the mailer has dimensions in compliance with U.S. Postal Regulations governing the applicability of postcard postage rates. The method further comprises applying a predetermined amount of postage to the mailer, the predetermined amount being in compliance with the postcard shipping rates. The method also includes sending the mailer to the payee, paying funds to the payee once the payee cashes the check component, and receiving the payee data correction component from the payee. The payee data correction component includes at least one of a corrected name of the payee and a corrected address of the payee. The method also comprises updating at least one of the stored name of the payee and the stored payee data in the database based on the corrected name of the payee and the corrected address of the payee received in the payee data correction component. [0007] Further areas of applicability will become apparent from the description provided herein. The description and specific examples in this summary are intended for purposes of illustration only and are not intended to limit the scope of the present disclosure. DRAWINGS [0008] The drawings described herein are for illustrative purposes only of selected embodiments and not all possible implementations, and are not intended to limit the scope of the present disclosure. [0009] FIG. 1 is a drawing illustrating a perspective front view of a front side of a mailer having a check component and a payee data correction component, according to some embodiments of the present invention; [0010] FIG. 2 is a drawing illustrating a perspective rear view of a back side of the mailer having a check component and a payee data correction component, according to some embodiments of the present invention; [0011] FIG. 3 is a drawing illustrating a perspective front view of the mailer being folded, according to some embodiments of the present invention; [0012] FIG. 4 is a drawing illustrating a perspective front view of the mailer after the mailer has been folded, according to some embodiments of the present invention; [0013] FIG. 5 is a drawing illustrating a perspective front view of the mailer as it is being opened, according to some embodiments of the present invention; [0014] FIG. 6 is a drawing illustrating a perspective front view of the mailer being unfolded, according to some embodiments of the present invention; [0015] FIG. 7 is a drawing illustrating a perspective front view of the mailer as the check component is being detached from the payee data correction component, according to some embodiments of the present invention; and [0016] FIG. 8 is a method illustrating a method of use for the mailer, according to some embodiments of the present invention. [0017] Corresponding reference numerals indicate corresponding parts throughout the several views of the drawings. DETAILED DESCRIPTION [0018] Example embodiments will now be described more fully with reference to the accompanying drawings. [0019] FIG. 1 illustrates the front side 100 A of a mailing apparatus, or mailer 100 . The mailer 100 is comprised of a check component 102 , the front side 102 A of which is shown in FIG. 1 , and a payee data correction component 104 , the front side 104 A of which is shown as well in FIG. 1 . The check component 104 is comprised of a check that is made out to the payee from the maker. It is appreciated that the payee may be a recipient or claimant in a proceeding, such as a class action or bankruptcy proceeding. [0020] The check component 102 is comprised of a first tab 106 , a maker field 108 , a check number field 110 , a numeric amount field 112 , a payee field 116 , a written amount field 114 , a memo field 118 , a maker signature field 120 , a routing number field 140 , and an account number field 142 . It is appreciated that the provided layout of the front side 102 A of the check component 102 is exemplary and that other layouts are contemplated and are within the scope of this disclosure. [0021] The front side 104 A of the payee data correction component 104 is comprised of a payee data correction field 122 , which may include a name field 124 , a current address field 126 , a city field 128 , a state field 130 , a postal code field 132 and, if required, a country field. The front side 104 A of the payee data correction component 104 further comprises an instruction field 134 , a maker address field 136 , a postage area 138 , and a second tab 107 , the front side 107 A of which is shown in FIG. 1 . [0022] In some embodiments, the dimensions of the mailer 100 are selected such that the mailer 100 can be mailed using postcard shipping rates, as may be defined by United States Postal Regulations. As distributions in a class-action litigation proceeding or bankruptcy proceeding may be incremental distributions in smaller amounts, e.g., $10.00 or less, the postcard shipping rates reduce the overall overhead associated with the distribution of funds. In an example embodiment, the height of the mailer is less than 8½ inches, such that when the mailer 100 is folded, the mailer 100 is less than or equal to 4¼ inches in height. Similarly, the width of the mailer 100 is less than or equal to 6 inches. The example embodiment can be tailored within dimension restrictions established by the United States Post Office. [0023] As will be discussed in further detail below, the mailer 106 is folded such that the front side 106 A of the first tab 106 and the front side 107 A of the second tab 107 are pressed together thereby sealing the mailer 100 . It is appreciated that other means for fastening the mailer when folded are also contemplated and within the scope of this disclosure. For example, a tab or sticker may be used to seal the mailer 100 after folding. [0024] Referring back to the individual components of the front side 102 A of the check component 102 , the fields provided in the example are fields that may be used to generate a check. For example, the maker field 108 identifies the maker of the check. In this example, the maker of the check 102 is “Payer X Claims Settlement Fund” located in Anytown, USA at P.O. Box 820. Additional information such as a telephone number or other information can also be provided in this field. The check number field 110 identifies a number of the check 102 . The numeric amount field 112 indicates a numeric amount of the check 102 , i.e., the amount of funds to be distributed to the payee. The written amount field 114 identifies the amount of funds to be distributed in a written format. The payee field 116 identifies the identity of the entity to which the funds identified in the written amount and numeric amount fields 112 and 114 are to be distributed. The memo field 118 indicates a note or memo from the maker. For example, a number identifying the exact payment that is being made. The authorized signature field 120 provides an area for the maker or a representative of the maker to execute or sign. The routing number field 140 indicates a routing number corresponding to the bank issuing the check. The account number field 142 indicates an account from which the funds identified in field 112 and 116 are to be withdrawn from to distribute to the payee. [0025] Referring now to the payee data correction component 104 , the payee data correction component 104 can be used by the payee to update information of the payee so as to allow for more efficient distribution of future correspondence or payments to the payee. For example, if the payee has moved, and is receiving address forwarding services, the mailer 100 may arrive to the payee as a result of address forwarding. In the case where multiple payments are made or other future correspondences or legal papers are sent to the payee, the payee data correction form 104 allows the payee to update his or her information for subsequent distributions and/or other future correspondences, even after the address forwarding service has stopped. [0026] The payee data correction field 122 is located at the top left corner of the front of the front side 104 A of payee data correction component 104 . As will be described later, the payee data correction component 104 is detached from the check component 102 to form a postcard that can be sent to the maker listed in the maker address field 136 . The placement of the maker address field 136 can be at the position where an address is typically found in a postcard. The address correction field 122 can be located at the position where the return address of the sender is typically found on a postcard. [0027] In operation, a payee sending back the address correction component 104 would provide his or her name in the name field 124 , his or her current address in the address field 126 , his or her city in the city field 128 , his or her state in the state field 130 , and his or her zip code in the postal code field 132 . It is appreciated that the name field 124 may be pre-printed to include the payee's name on the form prior to an initial mailing of the mailer 100 to the payee. The payee would then place an appropriate amount of postage onto the postage field 138 and would deposit the postcard in the mail, which would be forwarded to the maker. The maker can receive the payee data correction form 104 and can update a database listing a plurality of recipients with the updated payee data. [0028] In some embodiments, the check component 102 and the payee data correction component 104 are detachably coupled. This can be achieved by having a first perforated line 144 across a horizontal axis of the mailer 100 . Further, a second perforated line 146 can detachably couple the first tab 106 to the check portion of the check component 102 , and a third perforated line 148 can detachably couple the second tab 107 to the payee data correction form of the payee data correction component 104 . [0029] FIG. 2 illustrates the back side 100 B of the mailer 100 . The back side 100 B of the mailer 100 is comprised of the back side 102 B of the check component 102 and the back side 104 B of the payee data correction component 104 . The back side 102 B of the check component 102 is comprised of a return address field 150 , an endorsement line 152 , a payee address field 154 , and a prepaid postage field 156 . Furthermore, the check component 100 may include the first tab 106 and the second tab 107 , the backs 106 B and 107 B of which are shown in FIG. 2 . As previously discussed, the mailer is folded and fastened by glue or other fastening means by the tabs 106 and 107 . When folded, the back of the check component 102 B will be externally facing such that the check amount and the information on the front side 102 of the check component 102 is kept confidential from the handler of the mailer 100 . [0030] The back 102 B of the check component 102 includes a return address field or maker return address field 150 which indicates a return address of the maker and a payee address field 154 which indicates an address of the payee. As the mailer 100 is folded into a postcard, the deliverer of the mailer 100 will use the payee address field 154 to deliver the mailer to the intended recipient. The endorsement line 152 is where the payee would sign and endorse the check 102 to allow distribution of the funds thereto. It is appreciated that in FIG. 2 , the characters of the back side 102 B of the check component 102 are shown upside-down. This is so when the mailer 100 is folded, the writing on the backside 102 B of the check 102 appears right side up and the endorsement line 152 appears on the correct end of the check 102 . It is appreciated, however, that other configurations of the back side 102 B of the check 102 are contemplated within the scope of the disclosure. For instance, the prepaid postage field 156 and the maker return address field 150 could be located at the top of the back 102 B of the check component 102 and the payee address field 154 may be at the middle right and towards the bottom of the back side 102 B of the check component 102 . In the example provided, there is no additional data provided on the back of the payee data correction form 104 B. It is appreciated, however, that additional fields may be provided where the payee can edit other types of data in addition to the name and address of the payee. [0031] FIG. 3 illustrates the mailer 100 being folded. As can be appreciated, the mailer 100 is being folded such that the first tab 106 and the second tab 107 are glued together. The front side 102 A of the check component 102 is folded downwardly towards the front side 104 A of the payee data correction component 104 . [0032] FIG. 4 illustrates the mailer 100 after the first tab 106 and the second tab 107 have been secured to one another. As can be appreciated, the mailer 102 has the form of a post card, such that the maker return address field 150 appears at the top-left section of the back side 102 B of the check 102 and perpendicular to the endorsement line 152 . The payee address field 154 appears in the front-center or front-right-center portion of the back side 102 B of the check component 102 . After sealing, the mailer 100 may be deposited in the mail to the payee. [0033] FIGS. 5 , 6 , and 7 illustrate the mailer 100 being opened. In FIG. 5 , a user may detach the tabs 106 and 107 (not shown) from the check component 102 and the payee data correction component 104 (not shown). As shown in FIG. 6 , the user can separate the top of the check component 102 from the bottom of the payee data correction form 104 . As shown in FIG. 7 , the payee can detach the payee data correction component 104 from the check component 102 by pulling the two components 102 and 104 apart. The payee can correct his or her information by filling out the payee data correction field 122 . In doing so, the payee merely provides his or her name 124 , current address 126 , city 128 , state 130 and postal code 132 . The payee further provides sufficient postage in the postage area 138 , and deposits the payee data correction component 104 in the mail. [0034] FIG. 8 illustrates a method 200 for distributing funds to a claimant or fund recipient. At step 202 , an administrator of a fund, such as an administrator of a class action lawsuit or bankruptcy proceeding, or a similar entity will receive a list of payees and associated payee data. It is appreciated that the payees are people or entities that are to have funds distributed thereto. Payee data can include an address, a city, a state, and a postal code of the payee and may further include information such as a telephone number, a current payment amount for the amount of funds to be distributed to the payee, a total payment amount for the amount of funds to be distributed to the payee, and/or a frequency of the distribution of funds. [0035] At step 204 , the list of payees and the associated payee data may be stored in a database (not shown). At step 206 , a plurality of mailers are generated, each mailer 100 , being in substantially the form and format described above, and including a check component 102 and payee data correction component 104 . The database contents can be used when the mailer 100 is generated to provide the specific data for each mailer 100 that is to be sent to each payee. For example, for a first mailer 100 , a printing module (not shown) may retrieve a name of a payee, the address of the payee, and the amount to be distributed. The retrieved information can be used to generate the mailer 100 , by way of a template, for example. Thus, the information contained on the check component and the payee correction component is based on the payee data. [0036] Once all the mailers are generated, the mailers 100 are sent by mail to the payees, as shown at step 208 . At step 210 , the mailers 100 are received and cashed by the individual payees. Upon receiving the mailers, the payees detach the check component 102 from the payee data correction component 104 , and deposit or otherwise cash the check component 102 at a bank or other check cashing institution. If one or more of the payees determines that the payee data indicated on the mailer 100 is incorrect, the one or more payees will remove and fill out the payee data correction component 104 , apply the appropriate postage thereto, and deposit the payee data correction component 104 in the mail, as shown at step 212 . [0037] After the mailers 100 have been sent, the administrator (maker) waits for any payee data correction components 104 to be received, as shown at step 214 . When such a component 104 is received, the payee data of that payee providing the payee data correction component 104 is updated in the database based on the information contained in the payee data correction component 104 , as shown at step 316 . [0038] It is appreciated that the foregoing method may be performed continuously until all the funds of a proceeding are distributed to the payees. It is appreciated that this method may also be executed at each round of distributions, such that with each round of distributions the administrator can update the information of a payee upon receiving the payee correction form. [0039] The foregoing description of the embodiments has been provided for purposes of illustration and description. It is not intended to be exhaustive or to limit the disclosure. Individual elements or features of a particular embodiment are generally not limited to that particular embodiment, but, where applicable, are interchangeable and can be used in a selected embodiment, even if not specifically shown or described. The same may also be varied in many ways. Such variations are not to be regarded as a departure from the disclosure, and all such modifications are intended to be included within the scope of the disclosure. [0040] Example embodiments are provided so that this disclosure will be thorough, and will fully convey the scope to those who are skilled in the art. Numerous specific details are set forth such as examples of specific components, devices, and methods, to provide a thorough understanding of embodiments of the present disclosure. It will be apparent to those skilled in the art that specific details need not be employed, that example embodiments may be embodied in many different forms and that neither should be construed to limit the scope of the disclosure. In some example embodiments, well-known processes, well-known device structures, and well-known technologies are not described in detail. [0041] The terminology used herein is for the purpose of describing particular example embodiments only and is not intended to be limiting. As used herein, the singular forms “a,” “an,” and “the” may be intended to include the plural forms as well, unless the context clearly indicates otherwise. The terms “comprises,” “comprising,” “including,” and “having,” are inclusive and therefore 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. The method steps, processes, and operations described herein are not to be construed as necessarily requiring their performance in the particular order discussed or illustrated, unless specifically identified as an order of performance. It is also to be understood that additional or alternative steps may be employed. [0042] When an element or layer is referred to as being “on,” “engaged to,” “connected to,” or “coupled to” another element or layer, it may be directly on, engaged, connected or coupled to the other element or layer, or intervening elements or layers may be present. In contrast, when an element is referred to as being “directly on,” “directly engaged to,” “directly connected to,” or “directly coupled to” another element or layer, there may be no intervening elements or layers present. Other words used to describe the relationship between elements should be interpreted in a like fashion (e.g., “between” versus “directly between,” “adjacent” versus “directly adjacent,” etc.). As used herein, the term “and/or” includes any and all combinations of one or more of the associated listed items. [0043] Although the terms first, second, third, etc. may be used herein to describe various elements, components, regions, layers and/or sections, these elements, components, regions, layers and/or sections should not be limited by these terms. These terms may be only used to distinguish one element, component, region, layer or section from another region, layer or section. Terms such as “first,” “second,” and other numerical terms when used herein do not imply a sequence or order unless clearly indicated by the context. Thus, a first element, component, region, layer or section discussed below could be termed a second element, component, region, layer or section without departing from the teachings of the example embodiments. [0044] Spatially relative terms, such as “inner,” “outer,” “beneath,” “below,” “lower,” “above,” “upper,” and the like, may be used herein for ease of description to describe one element or feature's relationship to another element(s) or feature(s) as illustrated in the figures. Spatially relative terms may be intended to encompass different orientations of the device in use or operation in addition to the orientation depicted in the figures. For example, if the device in the figures is turned over, elements described as “below” or “beneath” other elements or features would then be oriented “above” the other elements or features. Thus, the example term “below” can encompass both an orientation of above and below. The device may be otherwise oriented (rotated 90 degrees or at other orientations) and the spatially relative descriptors used herein interpreted accordingly.	A double postcard check mailer and a method of use therefore are described. The mailer is comprised of a check component and a payee data correction component detachably coupled to the check component. The mailer, when folded, has the dimensions of a double postcard. The mailer is sent to the payee of the check. The payee detaches the check component from the payee data correction component and cashes the check component. The payee further fills out the payee data correction component with updated information, such as a corrected address, and deposits the completed payee data correction component in the mail with postcard shipping postage. The original sender of the mailer receives the payee data correction component and updates the payee's information based on the data received in the completed payee data correction component.	1
FIELD OF THE INVENTION [0001] The invention relates to a method for synchronizing two stations over a wireless network. The invention is particularly relevant to mesh wireless networks, in particular mesh WLAN (wireless local area network) based on the IEEE 802.11s standard. BACKGROUND OF THE INVENTION [0002] The IEEE 802.11s standardization committee group is currently working on an extension of the 802.11 standard for such type of networks. The current IEEE 802.11s standard specification, version D1.03, incorporated herein by reference, defines an IEEE 802.11 Wireless LAN (WLAN) Mesh using the IEEE 802.11 MAC/PHY layers that supports both individually addressed and group addressed delivery over self-configuring multi-hop topologies. Mesh networks according to the 802.11s standard, or so-called meshes, operate as wireless co-operative communication infrastructures between numerous individual wireless transceivers. A mesh may be centralized or decentralized. Stations or mesh nodes (MP) in the mesh communicate with their neighboring adjacent nodes only and thus act as repeaters to transmit message data from nearby nodes to peers that are too far to reach. Terminology specific to the 802.11s standard will be used in the following paragraphs to illustrate the invention and whenever applicable, the terms used should be understood as defined in the 802.11s standard. [0003] By definition, in a network based on the 802.11s standard mesh points MPs communicate over a mesh. A mesh includes two or more mesh points. A mesh point MP is an IEEE 802.11 entity that contains an IEEE 802.11-conformant medium access control and physical layer interface to the wireless medium that supports mesh services as defined in the 802.11s standard. [0004] Mesh points are synchronized when they have established a common time reference thereby enabling efficient reservation of the wireless medium for data transfer, beaconing and advanced power save modes. The current 802.11s specification defines a protocol for synchronization if mesh points desire to synchronize with one another. Synchronization is not mandatory over a mesh however, when feasible, it greatly improves communication between mesh points. 802.11s D1.03 defines a synchronization capability field (see 802.11s D1.03 7.3.2.53.5 Synchronization Capability field) with 3 sub-fields: a Supporting Synchronization sub-field, a Synchronizing with peer MP subfield and a Synchronizing with peer MP subfield. The Supporting Synchronization sub-field is set to 1 if the MP supports timing synchronization with peer MPs and 0 otherwise. The Requests Synchronization from Peer subfield is set to 1 if the MP requests MP peers attempting to communicate with it to synchronize with it and 0 otherwise. The Synchronizing with peer MP subfield set to 1 if the non-access point MP is currently a synchronizing MP and 0 otherwise. The synchronization capability field is contained in a mesh capability element as explained in 802.11s 7.3.2.53 to advertise mesh services. It is contained in Beacon frames transmitted by MPs and is also contained in probe request/response messages and (re)association request/response messages. In the current synchronization procedure, synchronization is treated as a mesh-wide property and the parameters for this mesh wide property are established by the MP that initiates the mesh, see Section 11A10.3.2. [0005] However, this procedure has various disadvantages. Firstly, it can happen that the MP that establishes the mesh does not initiate synchronization, and this could then never be changed, and the mesh could not develop into a synchronized mesh. Secondly, the procedure is unclear as to what happens when two or more MPs simultaneously start a mesh. Thirdly, the procedure is unclear as to what happens if two synchronized meshes need to be merged. SUMMARY OF THE INVENTION [0006] It is an object of the invention to propose a simple synchronization procedure in a mesh. [0007] It is another object of the invention to overcome the drawbacks of a mesh-wide synchronization as defined in the current 802.11s synchronization procedure. [0008] To this end, the invention relates to a synchronization method between a first and a second station over a mesh wireless network. The two stations first establish a communication link between them According to the invention the first station transmits to a second station a synchronization element containing a capability information bit indicative of a capability of the first station to synchronize with another station and a status information bit indicative of whether the first station has established a synchronized peer link with another station in a mesh to which the second station belongs. One of the two stations also transmits to the other station a request for synchronization receives a response representative of the acceptance by the second station of the synchronization procedure. The other station is constrained to accept the synchronization if it does not conflict with another currently synchronization. [0009] Prior to any synchronization procedure, a link must be established between the two stations. During peer-link establishment, stations may advertise to each other their respective attributes. Peer-link establishment is often specific to the communication standard in use over the wireless network and no details will be given here. Synchronization and peer-link establishment could be dissociated however both steps can easily be merged and carried out in parallel in the a handshake exchange between the two stations. [0010] A synchronization method of the invention employs two bits to communicate the synchronization status of a given mesh point. The status of the two bits is specific to a given mesh point and does not indicate a general synchronization of the whole mesh although one can infer whether a mesh is fully synchronized, not synchronized or partly synchronized from the status of the two bits of all mesh points present in the mesh. A mesh may include mesh points that are not capable of synchronizing in general and such mesh is at best only partly synchronized. Also, a mesh may have different synchronization profiles that coexist. [0011] The capability information bit is comparable with the Supporting Synchronization bit of the 802.11s D1.03 in that it indicates if the mesh point associated with it supports timing synchronization with peer mesh points. [0012] In an examplary embodiment, the status information bit may be set to 1 if the station is synchronized and 0 if the station is not synchronized with its peer stations in the mesh. Status information bit may also be set to 0 if the first station is currently carrying a synchronization process which is not finalized. Status 1 indicates that the first station is synchronized with its peer stations in the mesh, or at least with the ones that also indicate a status information bit of 1. However a status information bit set to 1 may not necessarily indicate that the first station is synchronized with the second station. Indeed, for example, the first and second stations may belong to distinct meshes that are independently synchronized with no common clock. In such case, a status 1 would only indicate that the first station is synchronized with peer mesh points in the mesh to which it belongs but not with the mesh points in the other mesh, including the second station. [0013] The invention covers the following case scenarios. [0014] First, the first and second stations may belong to the same mesh and one of the two stations has recently joined the mesh. The mesh was previously synchronized. The invention provides a procedure that the new station, either the first or the second station, will follow to adopt the synchronization parameters of the mesh. In an examplary embodiment, the first station joins the existing mesh and requests synchronization. In another examplary embodiment, the second station joins the mesh and the first station present in the mesh transmits the request to the second station joining the network. [0015] Next, in another scenario, the first and second stations belong to two distinct meshes and attempt to synchronize with each other. This situation may occur when two meshes merge. As will be explained hereinafter, once the stations are synchronized in pair, the synchronization protocol can be propagated to other peer mesh points not yet synchronized in either mesh. [0016] The invention further covers a third situation where two synchronization protocols coexist in the mesh. The first and second stations, each having its own set of synchronization parameters attempt to synchronize in the aim to have only one synchronization profile in the mesh in the end. [0017] The inventors have realized that simplification of the existing synchronization protocol of the 802.11s D1.03 standard was greatly needed and have thus devised a synchronization procedure that permits to initially restrict the synchronization to a limited number of mesh points or even a pair of mesh points MPs. A further advantage of one or more embodiments is that the invention uses at its best the capability of organically spreading information and control data over a mesh. Indeed, mesh points MPs act as repeaters to communicate the synchronization parameters over the entire mesh. [0018] The foregoing has outlined rather broadly the features and technical advantages of the present invention so that those skilled in the art may better understand the Description of the Drawings that follows. One should appreciate that he may readily use the conception and the specific embodiments disclosed as a basis for modifying or designing other structures for carrying out the same purposes of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS [0019] For a more complete understanding of the present invention, and the advantages thereof, reference is now made to the following description taken in conjunction with the accompanying drawings, wherein like numbers designate like objects, and in which: [0020] FIG. 1 is a mesh according to the invention; [0021] FIG. 2 shows a handshake diagram for synchronization between two mesh points; [0022] FIG. 3 shows a mesh to illustrate synchronization between two stations in the mesh according to the invention; and, [0023] FIG. 4 shows two meshes where synchronization occurs between mesh points of each mesh. DETAILED DESCRIPTION OF EMBODIMENTS [0024] FIG. 1 shows mesh 100 based on the 802.11s D1.03 specification. Mesh 100 includes mesh points (MP) 110 - 170 . In this embodiment mesh 100 is decentralized, i.e. there is no central controller, and MPs 110 - 170 communicate using a multi-hop technology where MPs 110 - 170 may only communicate with nearby MPs that have established a link. Two stations have established a link when they have successfully carried out a link establishment procedure. For example, 802.11s D1.03 describes a link establishment procedure in section 11A.1. The link establishment procedure and the synchronization procedure may be dissociated in time or carried out simultaneously depending on implementation. [0025] FIG. 1 shows links set up between MPs 110 - 170 . For example, MP 120 may only communicate directly with MPs 130 , 140 and 110 and MP 120 may also communicate with MP 150 indirectly via MP 110 or MP 140 . [0026] In order to facilitate data transfer and control over mesh 100 , mesh 100 may be synchronized. Two MPs have established a synchronized link if the MPs share the values for a set of time parameters and have agreed upon a procedure for maintaining these parameters. These parameters may be for example: the mesh time, the start time of the mesh super-frame the start of the next super-frame and/or the duration of the mesh super-frame. In the invention, contrary to the previous 802.11s D1.03 standard, synchronization is dealt with at the level of an MP pair instead of being a mesh wide property. An advantage of this approach is that it renders the overall synchronization procedure more flexible. Synchronization is thus particular to a communication or so-called peer-link between two MPs. As a consequence, mesh 100 may be fully synchronized in which case all MPs 110 - 170 share the same synchronization parameters, partly synchronized, i.e. only selected MPs 110 - 170 share the same synchronization profile or not synchronized at all. A given MP will nevertheless not associate a synchronization profile with a link that conflicts with other profiles associated with other links that are currently open. The proposed protocol also defines how a given synchronization profile may be propagated through the mesh. Propagation may not be mandatory and this may be left to implementers choice. [0027] In an exemplary embodiment, mesh 100 allows individual MPs 110 - 170 to maintain two sets of synchronization profiles: an empty profile, thus not synchronized and a synchronization profile. One may also devise a protocol where more than two profiles exist at a given MP, however such implementation will not be described but can be easily devised from the following description. [0028] During set-up, MPs 110 - 170 may become aware of each other's synchronization capabilities. In the assumption that each MP holds only two synchronization profiles, [0029] MPs can advertise their synchronization capability by means of a synchronization capability element of 1 bit. This synchronization capability element is set to 1 if the respective MP can support synchronization and 0 otherwise. The synchronization capability element may be included in mesh beacons that all MPs transmit or in control and/or data frames that are exchanged during the peer-link establishment procedure. In the event that MPs can support more synchronization profiles, the synchronization element may include several bits indicating what profiles are supported. A look up table where profiles are stored may be available at all MPs and MPs refer to the entry in the table to indicate the supported profile(s). [0030] In the invention, a second additional element is introduced, namely a status information element to signal whether the MP transmitting it has already established a synchronized link with another MP. [0031] FIG. 2 shows communication handshake between MP 1 and MP 2 for synchronization. Prior to attempting to synchronize with each other, MP 1 and MP 2 have established a peer link according to the procedure defined in the 802.11s D1.03 standard. During the procedure the above cited empty synchronization profiles of MP 1 and MP 2 are by default associated indicating that the link is initially not synchronized. In an embodiment of the invention, there can be only one profile associated with any link between two MPs. By means of the proposed procedure, MPs must come to agree on this profile. Additionally, the profile may not conflict with other already existing profiles. Hence, initially and by default, the empty profile is associated with the link and MP 1 and MP 2 are aware of this fact. This does not conflict with any other profile that may exist because the empty profile concords with any other profile. [0032] In this embodiment, MP 1 attempts to modify the existing non-synchronized link between MP 1 and MP 2 into a synchronized link. To do that, MP 1 transmits a request synchronization message 210 to peer MP 2 . Message 210 may include the synchronization capability element and the status information element respectively representative of the synchronization capability and synchronization status of MP 1 , that is bits “11”. [0033] Message 210 may further include a synchronization profile that MP 1 proposes for the profile to be associated with the link between MP 1 and MP 2 . The proposed synchronization profile may be currently supported by MP 1 in its communications with another peer MP. Alternatively, message 210 may contain no profile and MP 1 leaves it to MP 2 to propose a profile. [0034] It must be noted that in principle, MP 1 will only attempt to synchronize the peer-link between MP 1 and MP 2 if MP 2 supports synchronization. MP 1 may be aware of MP 2 capabilities by MP 2 having beforehand advertised its capability and status using the two one-bit elements of the invention during link establishment. However MPs that lack the ability to synchronize and that nevertheless receive request for synchronization messages of the type mentioned above may simply ignore or deny the request. [0035] In the example of FIG. 2 , MP 2 is capable of synchronizing with another peer MP and thus reacts to message 210 by means of synchronization response message 220 . Message 220 may contain an accept, a decline or a decline with a proposed altered profile. Message 220 may also contain parameters for a synchronization profile if MP 1 had initially not submitted a proposal for the profile. If MP 2 accepts the synchronization parameters received from MP 1 , the peer-link between MP 1 and MP 2 is from this point on, synchronized. Synchronization may also be established once confirmation that response message 220 is transmitted or after a fixed period of time after message 220 is sent depending on the communication protocol in place on the mesh. Next, MP 1 and MP 2 update their respective status information bits so that it reflects the current synchronized status. [0036] In the situation where message 220 includes a strict decline or if MP 2 ignores request 210 and does not transmit message 220 , the peer link between MP 1 and MP 2 remains non-synchronized. Such situation may occur when MP 1 and MP 2 belong to distinct meshes supporting non-compatible synchronization parameters or when MP 2 is new to the mesh of MP 1 and is not capable of synchronizing. [0037] In the situation where message 220 includes a decline with altered synchronization parameters, MP 1 may further accept or decline in a synchronization response 230 . In a similar fashion if MP 1 had not initially offered synchronization parameters, message 220 may include proposed parameters that MP 1 can accept or refuse. The above scenario may typically occur when two distinct meshes merge. MP 1 and MP 2 each belongs to one of the two independent meshes (or parts of the same mesh where several synchronization profiles coexist) and attempt to synchronize. If the proposed handshake is successful, it is then beyond the scope of the invention whether synchronization is propagated to other peer MPs of either mesh. The one of the two between MP 1 and MP 2 that has adopted new parameters does so by using the described handshake on links established with other peers. [0038] In general the following rules apply. [0039] If the synchronization request message 210 contains the non-empty profile of MP 1 and MP 2 is not synchronized with other peers, MP 2 accepts the non-empty profile. [0040] If the synchronization request message 210 contains the non-empty profile of MP 1 and MP 2 is synchronized with other peers, MP 2 may accept the non-empty profile of MP 1 , decline the non-empty profile of MP 1 or propose its own non-empty profile. [0041] If the synchronization request message 210 contains the empty profile of MP 1 and MP 2 is synchronized with other peers, MP 2 proposes to MP 1 in message 220 its current non-empty profile. [0042] If the synchronization request message 210 contains the empty profile of MP 1 and MP 2 is not synchronized with other peers, MP 2 proposes to MP 1 in message 220 its current non-empty profile. [0043] The first and third situations often correspond to a situation in which one of the MP 1 or MP 2 is new to a synchronized mesh. It must be noted that in such case synchronization may be initiated either by the node joining the mesh or by one of the nodes of the synchronized mesh. Alternatively, like the fourth situation, they can also correspond to a situation in which a node introduces synchronization in a mesh by synchronizing its link with a neighbor. [0044] The second situation typically would correspond to the case where two meshes merge. Two meshes may merge via a non-synchronized link, i.e. neither of MP 1 and MP 2 attempts to synchronize the new link between the two meshes. Alternatively, MP 1 or MP 2 attempts to synchronize the link by sending a synchronization request message 210 with a specific profile to its peer. [0045] Often when MP 2 receives the non-empty profile of MP 1 in message 210 , it will compare it with its own profile. At least it will check whether it conflicts or coincides. A typical situation is depicted in FIG. 3 where only profile A exists in mesh 300 . All MPs 310 - 340 have established synchronized links with their respective nearby peers and all share synchronization profile A. Only peer-link between MP 330 and 340 , shown in dashed line, is not synchronized. MPs 330 and 340 attempt to synchronize using the handshake exchange previously detailed in reference to FIG. 2 . In this situation, MP 340 will accept the profile (assuming MP 330 is the initiator of the process) without altering its own profile. The synchronization of mesh 300 will thus be successful. [0046] Another situation is depicted in FIG. 4 where MPs 410 - 430 share the same profile A and MPs 440 - 460 share the same profile B, not compatible with profile A. MPs 410 - 460 may all belong to the same mesh or to two distinct meshes. MPs 430 and 460 attempt to synchronize, and to this end, MP 430 initiates the process and transmits its profile in message 210 . MP 460 checks the received profile of MP 430 and realizes that it does not coincide and conflicts with its own profile. MP 460 cannot accept the profile without altering its own profile. [0047] If MP 460 decides to accept the profile that conflicts with its current profile, MP 460 will set its 1-bit status information element to 0 to signal to its nearby peers, e.g. MP 450 , that it is not synchronized with them. Peer MPs will temporarily ignore MP 460 when updating the parameters associated with their synchronization profile. MP 460 may then send a synchronization request message 210 to its peer MPs with which it has established a peer link with a distinct and conflicting synchronization profile, profile B in this embodiment. MP 460 negotiates a new synchronization profile for this existing link that does not conflict with the profile of its own link, namely profile A. The negotiated profile may be an empty profile to indicate that the link is not synchronized. The “re”synchronization also implies a tear down of other agreements between the MPs which depend on the synchronization. An example of this is provided by the reserved time slots for data communication (termed MDAOPs in the draft version D1.03 of 802.11s) that may have existed between these two MPs. [0048] As soon as MP 460 has reached synchronization with at least one its peer neighbor MPs, it then sets its status information element to 1 to signal that it is synchronized with peer MPs. [0049] In another embodiment, priority values may further be included in the synchronization request message 210 to associate a priority with the proposed profile so as to coerce a given profile. [0050] Also, as an alternative to actively sending a synchronization request message 210 , MP 1 could set a request bit in a broadcast frame, such as a beacon and the request bit could force neighbors to copy the synchronization profile.	An efficient synchronization procedure applicable to mesh WLAN based on the 802.11s standard is proposed. A first and second stations initiate the process and establish a communication link between them. Next, the first station transmits to the second station a synchronization element that contains: a capability information element indicative of a capability of the first station to synchronize, and a status information element indicative of whether the first station has established a synchronized peer link with another station. One of the two stations may then initiate the actual handshake for synchronization. The initiator transmits a request for synchronization and receives a response from the other station representative of the acceptance by the other station of the synchronization, the request and the acceptance being restrained in that the stations may not entertain conflicting synchronization procedures with different links. The request may include a set of the synchronization profile.	7
[0001] This application is a Divisional of application Ser. No. 09/376,375 filed Aug. 18, 1999, the entire disclosure of which is hereby incorporated by reference. BACKGROUND OF THE INVENTION [0002] 1. Field of the Invention [0003] The present invention relates to a full automatic washing machine, and more particularly, to a penetration type washing machine which makes washing by penetrating washing water through laundry; a method for controlling the same; and, a tub cover for the same. [0004] 2. Background of the Related Art [0005] Being a device for peeling off contaminant by applying energies, such as impact, to the laundry, there are pulsator washing machines, drum washing machines, agitator washing machine, and the like according to types of energy application. Washing of the laundry is made by applying impacts to the laundry using pulsator or agitator, or dropping the laundry using rotation of the drum. [0006] [0006]FIG. 1 illustrates a cross section of a related art pulsator type washing machine, referring to which a related art pulsator type washing machine will be explained. [0007] There is an inner tub 3 having a plurality of washing holes 5 formed therein rotatably mounted inside of an outer tub 2 provided for storage of washing water, inside of which inner tub 3 there is a pulsator 4 rotatably mounted therein. There is a drain valve 9 under the outer tub 2 for draining the washing water outside of the washing machine. A rotation power from a motor 8 mounted on an underside of the outer tub 2 is transmitted to a dewatering shaft 6 a coupled to the inner tub 3 and the washing shaft 6 coupled to the pulsator 4 , for rotating the inner tub 3 and the pulsator 4 . The washing shaft 6 and the dewatering shaft 6 a are coupled/decoupled by a clutch 7 . [0008] There is a tub cover 11 on the outer tub 2 , which will be explained with reference to FIG. 2. The tub cover 11 , of substantially an annular form, has an upper surface portion 11 a disposed on top both of the outer tub 2 and the inner tub 3 , a tight fit portion 11 b extended in an upper and a lower direction from an end of the upper surface portion 11 a for tight fit to an inside surface of the outer tub 2 , and a fastening portion 11 c projected from the tight fit portion 11 b in a substantially vertical direction for being fastened to the outer tub 2 with screws 14 . The tub cover 110 is provided for prevention of noise and overflow of foam as well as prevention of infiltration of foreign matters into a space between the inner tub and the outer tub. [0009] The operation of the aforementioned related art pulsator type washing machine will be explained with reference to FIGS. 1 and 2. [0010] The washing machine is operative in a washing cycle, a rinsing cycle, and a dewatering cycle, by proceeding through each of which mode in a sequence the washing can be done. In the washing cycle, upon putting the washing machine into operation after placing the laundry in the inner tub 3 , the washing water is supplied until it fills to certain levels of the inner tub 3 and the outer tub 2 . Upon finishing the water supply, the motor 8 makes intermittent rotations in regular and reverse directions in a state the inner tub 3 is standstill, that leads the pulsator 4 to rotate in the regular and reverse directions for washing the laundry. That is, the pulsator 4 repeats the regular/reverse direction rotation, to rotate the laundry in of the inner tub 3 and to form water circulation, as well. Then, the laundry is washed by the impact from the pulsator 4 , the water circulation, friction with the inner tub 3 , and softening effect of the detergent, and the like. After proceeding the washing cycle for a preset time period, the drain valve 9 is opened, to drain contaminated washing water to outside of the washing machine. Then, clean washing water is supplied to inside of the inner tub 3 , and the pulsator 4 is rotated, to make rinsing cycles for a preset number of times. In the dewatering cycle, the inner tub 3 is rotated in a high speed together with the pulsator 4 in one direction in a state the washing shaft 6 and the dewatering shaft 6 a are coupled. Consequently, the washing water is discharged to the outer tub 2 through the washing holes 5 , and drained to outside of the washing machine through the drain valve 9 . [0011] However, the related art washing machines, making the washing mostly using mechanical energies, of such as pulsator or agitator, is required to have a rotating power of a certain speed for making an adequate washing, that causes entangle of or damage to the laundry. And, the related art washing machine is involved in an increased washing water and detergent consumed during the washing because the washing machine is operative under a state the washing water is filled in the inner tub and the outer tub, as well as an increased overall washing time period due to increased water supply and drain time periods, that are not directly related to the washing time period. [0012] Accordingly, there has been researches for making washing without rubbing the laundry or applying impact to laundry, one of which is the penetration type washing machine. That is, according to what is known, if a relative flow speed of water passing through between textile fibers of the laundry is greater than a certain level, the water can make a washing, without rubbing or twisting the laundry. A washing machine employing such a principle is a penetration type washing machine. In general, as disclosed in U.S. Pat. No. 5,191,667 a related art penetration type washing machine is provided with a washing water sprayer for spraying the washing water to the laundry in an inner tub over a required speed, and a separate pump for pumping the washing water to the washing water sprayer. Therefore, the related art penetration type washing machine has problems in that a complicated system and a large sized pump for obtaining a spraying power for the washing are required. Therefore, the related art penetration type washing machine has been mostly used as a supplementary means for the pulsator type washing machine. [0013] And, though JP S51-13416 discloses a washing machine which makes a penetration washing by rotating an inner tub, the washing machine has the following problems. [0014] First, as the inner tub rotates only in one direction, the washing water penetrates a fixed position of the laundry, to cause a wash difference in which a washed portion and a non-washed portion are happened. [0015] Second, the only use of penetration washing makes a washing efficiency poor. Because, though the penetration type washing machine can prevent damage to, and entangling of the laundry, in general, the washing efficiency is poor compared to the pulsator type washing machine. [0016] Third, since the washing machine fails to provide a guide means for guiding the washing water to an inside surface of the inner tub when the washing water is pumped to an upper portion between the inner tub and the outer tub, and then, circulated into the inner tub, the washing machine has a poor pumping efficiency. [0017] Use of a related art tub cover for the penetration type washing machine causes leakage of spray of the washing water. That is, as shown in FIG. 2, since the related art tub cover 11 is merely fastened to the outer tub 2 with screws 14 , the washing water leaks through gaps between the tight fit portion 11 b of the tub cover 11 and the outer tub, and the fastening portion 11 c and a top of the outer tub 2 . And, a pumped washing water splashes from an inside of the tub cover to outside of the outer tub 2 , to generate noise as the splash hits a washing water case, and to deteriorate washing and rinsing performances of the washing machine as the splash causes a loss of the washing water. Moreover, the leaked or splashed washing water to outside of the outer tub 102 wets various electric components of the washing machine, that is liable to cause malfunction or disorder of the washing machine. [0018] The above references are incorporated by reference herein where appropriate for appropriate teachings of additional or alternative details, features and/or technical background. SUMMARY OF THE INVENTION [0019] An object of the invention is to solve at least the above problems and/or disadvantages and to provide at least the advantages described hereinafter. [0020] Accordingly, the present invention is directed a penetration type washing machine, a method for controlling the same, and a tub cover for the same that substantially obviates one or more of the problems due to limitations and disadvantages of the related art. [0021] An object of the present invention is to provide a penetration type washing machine, and a method for controlling the same, which has a simple structure and can improve a washing efficiency. [0022] Another object of the present invention is to provide a tub cover for use in a penetration type washing machine which can improve a pumping efficiency and a washing efficiency. [0023] Additional features and advantages of the invention will be set forth in the description which follows, and in part will be apparent from the description, or may be learned by practice of the invention. The objectives and other advantages of the invention will be realized and attained by the structure particularly pointed out in the written description and claims hereof as well as the appended drawings. [0024] To achieve these and other advantages and in accordance with the purpose of the present invention, as embodied and broadly described, the method for controlling a full automatic washing machine, includes a washing cycle, a rinsing cycle, and a dewatering cycle, wherein the washing or the rinsing cycle includes the step of rotating an inner tub at a high speed higher than a preset speed in one direction, thereby making a centrifugal force caused by high speed rotation of the inner tub, to push laundry against a wall of the inner tub, to enforce washing water in the inner tub to penetrate through the laundry at a speed higher than required to make the washing done, and to pump the washing water penetrated through the laundry and discharged into an outer tub upward, to recirculate to the inner tub. [0025] In other aspect of the present invention, there is provided a tub cover mounted on a top of an outer tub of a washing machine for preventing noise and foam overflow, including an upper tub cover for being fastened to the outer tub, and a lower tub cover under the upper tub cover spaced therefrom for being fastened to the upper tub cover, thereby forming washing water passages between the upper tub cover and the lower tub cover. [0026] It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory and are intended to provide further explanation of the invention as claimed. [0027] 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 objects and advantages of the invention may be realized and attained as particularly pointed out in the appended claims. BRIEF DESCRIPTION OF THE DRAWINGS [0028] The invention will be described in detail with reference to the following drawings in which like reference numerals refer to like elements wherein: [0029] The accompanying drawings, which are included to provide a further understanding of the invention and are incorporated in and constitute a part of this specification, illustrate embodiments of the invention and together with the description serve to explain the principles of the invention: [0030] In the drawings: [0031] [0031]FIG. 1 illustrates a section of a related art pulsator type washing machine; [0032] [0032]FIG. 2 illustrates a section showing an enlarged view of “A” part in FIG. 1; [0033] FIGS. 3 A˜ 3 C illustrate sections of a penetration type washing machine in accordance with a preferred embodiment of the present invention, wherein FIG. 3A illustrates a penetration washing process, FIG. 3B illustrates an agitation washing process, and FIG. 3C illustrates a restoration circulation washing process; [0034] FIGS. 4 ˜ 6 illustrate sections of a tub cover in accordance with a first preferred embodiment of the present invention; [0035] [0035]FIG. 7 illustrates a disassembled perspective view of a tub cover in accordance with a second preferred embodiment of the present invention; [0036] [0036]FIG. 8 illustrates a perspective assembly view of the tub cover in FIG. 7 with partial sections of the components; [0037] [0037]FIG. 9 illustrates an assembled sectional view of a tub cover, a modified version from FIG. 8; [0038] [0038]FIG. 10 illustrates a perspective view of a tub cover in accordance with a third preferred embodiment of the present invention; [0039] [0039]FIG. 11 illustrates a section showing the tub cover in FIG. 10 fitted to a washing machine; [0040] [0040]FIG. 12 illustrates an operation principle of the tub cover shown in FIG. 10; [0041] [0041]FIG. 13 illustrates a perspective view of a tub cover modified from one shown in FIG. 10; [0042] [0042]FIG. 14 illustrates a disassembled perspective view of a tub cover in accordance with a fourth preferred embodiment of the present invention; [0043] [0043]FIG. 15 illustrates a section showing an assembled view of the tub cover in FIG. 14; [0044] [0044]FIG. 16 illustrates a section showing an enlarged part “B” in FIG. 15; [0045] [0045]FIG. 17 illustrates a disassembled view of the tub cover shown in FIG. 14; [0046] [0046]FIG. 18 illustrates a section showing a modified version of a fastening structure of the tub cover in accordance with a fourth preferred embodiment of the present invention; [0047] FIGS. 19 ˜ 22 illustrates sections showing different modifications of the tub cover in FIG. 14; [0048] [0048]FIG. 23 illustrates a cross section showing another modification of the tub cover in FIG. 14; [0049] [0049]FIG. 24 illustrates a disassembled perspective view of a tub cover in accordance with a fifth preferred embodiment of the present invention; [0050] [0050]FIG. 25 illustrates a partial cut away perspective view for explaining an operation of the tub cover shown in FIG. 24; [0051] [0051]FIG. 26 illustrates a disassembled perspective view showing a modification from the tub cover in FIG. 24; [0052] [0052]FIG. 27 illustrates a disassembled perspective view of a tub cover in accordance with a sixth preferred embodiment of the present invention; [0053] [0053]FIG. 28 illustrates a section across line I-I in FIG. 27; [0054] [0054]FIG. 29 illustrates a section across line II-II in FIG. 27; [0055] [0055]FIG. 30 illustrates a disassembled perspective view showing a modification of the tub cover shown in FIG. 27; [0056] [0056]FIG. 31 illustrates a section across line III-III in FIG. 30; [0057] [0057]FIG. 32 illustrates a disassembled perspective view showing another modification of the tub cover shown in FIG. 27; [0058] [0058]FIG. 33 illustrates a section across line IV-IV in FIG. 32; [0059] [0059]FIG. 34 illustrates a bottom view of a tub cover in accordance with a seventh preferred embodiment of the present invention; [0060] [0060]FIG. 35 illustrates a bottom perspective view of the tub cover shown in FIG. 34; [0061] [0061]FIG. 36 illustrates a longitudinal section view of the tub cover shown in FIG. 34; [0062] [0062]FIGS. 37A and 37B illustrate bottom perspective views each showing a modification of the tub cover shown in FIG. 34; [0063] [0063]FIG. 38 illustrates a bottom view showing a tub cover in accordance with an eighth preferred embodiment of the present invention; [0064] [0064]FIG. 39 illustrates a bottom perspective view of the tub cover shown in FIG. 35; and, [0065] [0065]FIGS. 40 and 41 illustrate bottom perspective views each showing a modification of the tub cover shown in FIG. 38. DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS [0066] Reference will now be made in detail to the preferred embodiments of the present invention, examples of which are illustrated in the accompanying drawings. A penetration type washing machine, and a method for controlling the same will be explained with reference to FIGS. 3 A˜ 3 C. [0067] Referring to FIGS. 3 A˜ 3 C, there is an inner tub 103 having a plurality of washing holes 104 rotatably mounted in an outer tub 102 , with a pulsator 105 formed as a unit with the inner tub 103 . There is a fluid balancer 108 provided on a top of the inner tub 103 for balancing the inner tub 103 during rotation. And, there is a tub cover 400 on a top of the outer tub 102 for preventing noise, suppressing foam formation, and guiding the washing. There is a motor 107 for generating a rotation power under the outer tub 102 and a drain valve 109 . The motor 107 is preferably a variable speed motor, with a rotating shaft thereof being directly coupled to a single driving shaft 106 which rotates the inner tub 103 and the pulsator 105 without introduction of additional power transmission device. The aforementioned penetration type washing machine of the present invention facilitates a penetration washing, an agitation washing, and a restoration circulation washing by varying a rotation speed of the motor 107 . [0068] The operation of the aforementioned penetration type washing machine of the present invention will be explained with reference to FIGS. 3 A˜ 3 C. [0069] The penetration type washing will be explained with reference to FIG. 3A. When the washing machine is put into operation, the motor 107 is rotated in a high speed. Then, the driving shaft 106 connected to the motor 107 is rotated, and the pulsator 105 and the inner tub 103 connected to the driving shaft is also rotated in a high speed. As has been explained in the related art, the penetration washing requires a relative flow speed of the washing water passing through the laundry to be higher than a certain level, and the flow speed should be enough to generate a centrifugal force that can force the washing water to flow from the inner tub to the outer tub and, therefrom to circulate to the inner tub again. When the pulsator 105 and the inner tub 103 is rotated at a high speed, a centrifugal force is generated, to push the laundry in the inner tub 103 to a wall of the inner tub 103 , and to push the washing water in the inner tub 103 to the outer tub 102 through the washing holes 104 in the inner tub 103 , when the washing water penetrates through between textile fabrics of the laundry, thereby making the penetration washing. And, the washing water pushed out to the outer tub 102 and the washing water present on a bottom surface of the outer tub 102 is pumped upward along a space between the inner tub 103 and the outer tub 102 by the centrifugal force, until the washing water hits the tub cover 400 where the washing water turns a flow direction to flow into the inner tub 103 again. The washing water flowed into the inner tub 103 has a substantially high pressure caused by the centrifugal force coming from the high speed rotation of the inner tub 103 . Therefore, the washing water can apply an impact to the laundry by the pressure from the centrifugal force and a gravity of the washing water, to provide a beating effect to the laundry, that improves a washing efficiency. [0070] In the meantime, as has been explained in the related art, in the case when the inner tub rotates only in one direction, the wash difference is happened in which extents of wash differ depending on portions of the laundry because positions of the laundry are always fixed. Therefore, the inner tub is rotated in a reverse direction after the inner tub is rotated in a regular direction for a preset time period. Then, the laundry pushed to wall of the inner tub is gathered to a center of the inner tub when the inner tub changes its direction of rotation from regular direction to reverse direction, and the laundry is pushed onto the wall again as the inner tub is accelerated. Accordingly, as a position of the laundry through which the washing water penetrates is changed, the wash difference can be prevented. [0071] In the meantime, as has been explained, the penetration type washing machine of the present invention permits, not only the penetration type washing, but also agitation type and restoration circulation washings by changing a speed and a direction of rotation of the motor. FIG. 3B illustrates an agitation washing process, referring to which the agitation washing process will be explained. [0072] The agitation washing is available by setting the rotation speed to be below a certain level. That is, if the rotation speed of the motor is set to be comparatively low, the pulsator and the inner tub 103 also rotate at a low speed, at which the centrifugal force is dropped unable to push up the washing water between the inner tub 103 and the outer tub 102 , but to keep a certain level. And, the laundry pushed to the wall of the inner tub 103 drops down to the bottom of the inner tub 103 to be submerged in the washing water. Under this state, a water circulation caused by rotation of the inner tub 103 and the pulsator 105 facilitates an agitation washing in a principle identical to a related art pulsator type washing machine. The availability of the penetration washing as well as the agitation washing can provide an excellent washing efficiency. [0073] [0073]FIG. 3C illustrates a section showing a restoration circulation washing process, referring to which the restoration circulation process will be explained. [0074] If the inner tub 103 which is rotating at a high speed in a penetration washing is stopped or has a speed dropped, the laundry pushed to the inside wall of the inner tub 103 by an inertia is gathered to a central portion of the inner tub 103 to hit one another. That is, the hitting among the laundry or with the pulsator 105 can make washing. In this instance, for conduction of the restoration circulation washing, though the rotating inner tub 103 may be stopped, the restoration circulation washing is available without a separate restriction. Because the inner tub repeats regular and reverse rotations in the penetration washing, the restoration circulation washing is automatically and continuously made whenever the direction of rotation is changed. [0075] Upon completion of the penetration washing, the agitation washing, and the restoration circulation washing, a dewatering cycle is conducted. And, upon completion of the dewatering cycle, a water re-supply process is conducted to conduct a following rinsing process. Though the penetration type washing machine of the present invention may only carry out the penetration type washing, it is preferable that the penetration type washing machine carry out an appropriate combination of the penetration type washing, an agitation type washing and a restoration circulation washing depending on an extent of contamination and an amount of the laundry. And, as has been explained, one washing cycle or a rinsing cycle may be divided into small intervals for repeating the penetration washing and the agitation washing in the intervals, or different from this, it is also possible that re-water supply is made to conduct the agitation washing after completion of the penetration washing. [0076] Advantages of the penetration type washing machine and a method for controlling the same of the present invention will be explained. [0077] As the penetration type washing machine of the present invention makes the penetration type washing mostly, entangling of, and damage to the laundry is reduced compared to the pulsator type washing machine. The re-supply of the washing water into the inner tub in the penetration type washing facilitates consumption of less washing water, with use of less detergent, and faster washing water supply and drain, that minimizes waste of time in the supply and drain of the washing water. Moreover, the washing water in the outer tub do nothing but interferes the rotation of the inner tub 103 in the pulsator type washing machine because the washing water in the outer tub generates a friction when the inner tub is rotated even though the washing water in the inner tub act an important role as the washing water in the inner tub is brought into contact with the laundry to make washing. Therefore, in order to make a smooth rotation, it is important for the inner tub to make a less contact with the washing water in the outer tub as far as possible. By the way, the penetration type washing machine of the present invention has a small amount(approx. 50%) of washing water supplied to the inner tub and the outer tub, and the washing water is pumped into the inner tub again in conducting the washing. That is, as the outer tub has less amount of washing water, rotation of the inner tub is smoother. Different from the related art penetration type washing machine, the penetration type washing machine has a simple system as no separate pumping device are required, and facilitates a satisfactory washing efficiency while preventing entangling of, or damage to the laundry by an appropriate combination of the penetration washing, the agitation washing and the restoration circulation washing. The penetration type washing machine of the present invention has the washing water in the inner tub 103 pumped up to the top portion thereof through a space between the inner tub 103 and the outer tub 102 at a substantially high pressure, to be recirculated into the inner tub 103 . Consequently, the high pressure of the washing water pumped upward may cause leakage if the related art tub cover is used as it was. Though this leakage may be prevented by providing gasket on a top surface of the outer tub 102 , accurate fitting of the gasket to a large diametered outer tub 102 is not practicable. Therefore, it is preferable that the tub cover structure of the penetration type washing machine is changed, appropriately. The tub cover of the present invention will be explained. [0078] A first embodiment tub cover of the present invention will be explained with reference to FIGS. 4 ˜ 6 . The first embodiment tub cover is substantially identical to the one of the related art except that a leakage prevention means is additionally provided in the first embodiment tub cover. [0079] That is, similar to the related art tub cover, the first embodiment tub cover 400 includes an upper surface portion 411 , a tight fit portion 413 , and a fastening portion 412 . However, different from the related art, the fastening portion 412 has a downward projection at an approx. center thereof in parallel to the tight fit portion 413 , and there is a slot on a top portion of the outer tub 102 for insertion of the projection 415 thereto. And, there is a sealing member 417 in a space formed between the tight fit portion 413 and the projection 415 for prevention of leakage. [0080] And, referring to FIG. 5, a length of the projection 415 may be formed shorter, for providing the sealing member 417 in a space formed below the projection 415 . [0081] And, as shown in FIG. 6, the sealing member may be disposed on a top end of the outer tub 102 . In detail, as the sealing member 417 is fitted to the top end of the outer tub 102 , a support 102 b is projected in an outward radial direction of the outer tub 102 from a portion below the top end portion 102 a of the outer tub 102 . And, a horizontal portion 441 is formed at an outer circumference of the upper surface portion 411 of the tub cover 400 , with an end of the horizontal portion 441 bent downward, to form a tight fit portion 413 which fit to an inside surface of the support 102 b in the outer tub 102 , without providing the fastening portion. And, in order to make the assembly easy, the sealing member 417 is preferably attached to the horizontal portion 441 of the tub cover with adhesive 452 . And, it is preferable that a position the support 102 b in the outer tub 102 is projected is to be below the top end of the outer tub 102 , to provide a space between the top end 102 a of the outer tub 102 and the support 102 b. Because if leakage of the washing water is happened despite of the sealing member 417 , the leakage of washing water may be collected in the space. The washing water collected in the space is drained using overflow hose(not shown) connected to an air vent hose. The first embodiment tub cover can prevent leakage of the washing water even if the washing water is pumped to the tub cover 400 at a high pressure by means of the sealing member 417 . And, as the fitting of the tub cover 400 to the outer tub 102 only requires insertion of the projection 415 at the tub cover to the slot in the outer tub 102 , the assembly is simple. And, as the slot serves as a guide, for accurate fitting of the tub cover 400 to the outer tub 102 , preventing vibration during operation of the washing machine. [0082] In the meantime, even if the first tub cover 400 can prevent leakage of the washing water, neither spray of the washing water caused by hitting the tub cover can be prevented, nor an exact guide of the washing water into the inner tub 103 is possible. Therefore, the following second to seventh embodiments tub covers of the present invention will provide improved tub covers. The second embodiment tub cover will be explained with reference to FIGS. 7 and 8. [0083] The second embodiment tub cover 200 includes an upper tub cover 201 fastened to the outer tub 102 , and a lower tub cover 203 mounted under the upper tub cover 201 with a space therefrom, wherein there are washing water guide passages P 1 and P 2 formed between the upper and lower tub covers. The upper tub cover 201 has a substantially annular form of an upper surface portion 211 , a tight fit portion 214 projected from an outer end of the upper surface portion 211 vertically for tight fit to an inside wall of the outer tub 102 , and a fastening portion 215 extended from the tight fit portion 214 in a horizontal direction for fastening to a top end of the outer tub, forming an “L” section, substantially. The lower tub cover 203 has an upper surface portion 221 , and a vertical portion 225 projected downward from an outer end of the upper surface portion 221 , with a plurality of reinforcing brackets 224 connected between the upper surface portion and the vertical portion. There are a plurality of height adjustment members 222 formed at fixed intervals. In order to couple the upper tub cover 201 to the lower tub cover 203 , it is preferable that the height adjustment members 222 have a female thread 223 , and the upper surface portion 221 of the upper tub cover 201 has a plurality of fastening holes 212 formed at positions corresponding to the height adjustment members 222 . [0084] Referring to FIG. 8, a fastened state will be explained. The upper tub cover 201 and the lower tub cover 203 are fastened with screws 213 , and the upper tub cover 203 is fastened to a top end of the outer tub 102 with screws. Therefore, as shown in FIG. 8, the washing water pumped to the tub cover 200 is guided by the guide passage P 1 and P 2 between the upper tub cover and the lower tub cover, to guide the washing water into the inner tub 103 smoothly, which improves a pumping efficiency. And, the spray of the washing water can be prevented. And, a pressure of the washing water sprayed to the inner tub 103 from the tub cover 200 is adjustable by adjusting a space S between the upper tub cover and the lower tub cover, i.e., a height of the height adjustment member 222 . By the way, there is a possible leakage through a gap between the fastening holes in the upper tub cover 201 and the screws in FIG. 8. Therefore, as shown in FIG. 9, it is preferable that height adjustment members 222 a are formed on the upper tub cover 201 , and pass-through holes are formed in the lower tub cover 203 . Because the washing water flowing from the tub cover 200 to the inner tub 103 advances in a tangential direction of an inside diameter of the inner tub 103 by the centrifugal force. [0085] A tub cover having modified such drawback is the third embodiment tub cover, which will be explained with reference to FIGS. 10 ˜ 11 . [0086] The third embodiment tub cover 300 includes an upper surface portion 301 and a tight fit portion 303 , and there are a plurality of deflectors 302 on an underside of the upper surface portion 301 for deflecting a flow direction of the washing water. The deflector 302 is fitted in a radial direction for deflecting the washing water advancing in a tangential direction to a center direction. There are a plurality of deflectors fitted as fixed intervals to divide the flow paths. As shown in FIG. 12, this structure permits the washing water pumped and flowed into the tub cover 300 hits the deflectors 302 , to change a direction of flow toward, not the tangential direction, but the center direction, substantially. And, as shown in FIG. 13, there may be a guide rib 305 on the deflector 302 for reducing a friction of the washing water. And, a plate drop preventor 305 may preferably be fitted at a bottom of the deflector 302 for preventing drop of the washing water, flowing into the tub cover, into a space between the inner tub 103 and the outer tub 102 by gravity, but to be supplied to the inner tub 103 . Of course, the drop preventor 305 may be provided with a larger area or the lower tub cover of the second embodiment may be provided. And, the height adjustment members 222 and 222 a in the second embodiment may be formed to have forms of the deflectors 302 , for combined use of the height adjustment members 222 and 222 a as the deflectors. [0087] Because outlets of the washing water passages P 2 are substantially horizontal in the first to third embodiments tub covers, the washing water flows out substantially in the horizontal direction. Opposite to this, the following fourth to seventh embodiment tub covers are provided with an adjustable spray angle, with a convenience of assembly. [0088] The fourth embodiment tub cover will be explained with reference to FIGS. 14 ˜ 16 . [0089] Alike the second embodiment tub cover, the fourth embodiment tub cover also include an upper tub cover 501 and a lower tub cover 503 for forming a washing water passage. The upper tub cover 501 has an upper surface portion 521 , a tight fit portion 522 , and a fastening portion 523 , and the lower tub cover 503 also has an upper surface portion 512 and a vertical portion 511 , except that there are a plurality of guide members 505 fitted at fixed intervals provided between the upper tub cover and the lower tub cover for combined use as the height adjustment members and the deflectors in the aforementioned embodiments. The guide member 505 is preferably formed extended from inlet to outlet of the flow passage to cover the entire washing water passage. In this embodiment, the horizontal passage P 2 is formed to direct a lower portion of the inner tub 103 , and the upper tub cover 501 and the lower tub cover 503 are provided with downward curvatures to provide a stream lined horizontal passage P 2 for minimize a friction. The lower tub covet 503 is mounted spaced from the fluid balancer 108 by a preset distance T 1 , with a chamfer 507 in the fluid balancer 108 to suit to a contour of the passage P 2 . Because this configuration can prevent bumping between the fluid balancer 108 and the tub cover 500 . And, in order to prevent bumping between the fluid balancer 504 and the outer tub 102 and 502 , a second gap T 2 formed between the fluid balancer 504 and the outer tub 102 and 502 may be further provided. The distance T 1 is preferably identical to the gap T 2 between the fluid balancer 108 and the outer tub 102 , substantially. [0090] A fastening structure of the fourth embodiment tub cover of the present invention will be explained with reference to FIG. 17. [0091] Alike the previous embodiment, if the upper tub cover, the guide member and the lower tub cover are fastened with screws, the washing water may leak. Therefore, it is preferable that the upper tub cover 501 , the guide members 505 and the lower tub cover 503 are fabricated separately and jointed them together by means of welding and the like. Of course, it is possible that either the upper tub cover 501 and the guide members 505 may be fabricated as a unit, to which the lower tub cover 503 is welded, or the lower tub cover 503 and the guide members 505 may be fabricated as a unit, to which the upper tub cover 501 is welded. In this instance, for the sake of convenience of assembly and preventing projection of the upper tub cover 501 to an outward radial direction, there is a stepped portion 532 at one side of the lower tub cover 503 for catching a bottom end of the upper tub cover 501 . As shown in FIG. 18, fastening with screws is also possible, particularly, fastening the lower tub cover 503 to the guide member 505 with screws 534 is effective in view of leakage prevention. Similar to the previous embodiments, this embodiment tub cover serves for a smooth guidance of the washing water, prevention of spray, and prevention of leakage. In addition to this, this embodiment tub cover can further improve a pumping performance and washing performance because the washing water passage is streamlined with a preset curvature, which minimizes a loss caused by friction to guide the washing water into a lower portion of the inner tub 103 effectively. By the way, in this embodiment, fore ends of the upper tub cover 501 and the lower tub cover 503 , i.e., a width W of an outlet of the washing water may be adjusted for adjusting the pressure of the washing water. That is, the more the width W of the outlet of the washing water is reduced, the higher the pressure of the washing water. The width W may preferably be adjusted by decreasing or increasing a fore end of the upper tub cover 501 by an angle θ toward a fore end direction of the lower tub cover 503 . And, as shown in FIGS. 20 and 21, the fore end of the upper tub cover 501 may be extended or shortened with respect to the fore end of the lower tub cover 503 , for adjusting an angle of spray of the washing water. That is, if the fore end of the upper tub cover is shortened by a distance H 1 with respect to the fore end of the lower tub cover 503 , the washing water is sprayed upward, and extended by a distance H 2 , sprayed downward. In conclusion, this embodiment allows an appropriate adjustment of the spray pressure and the spray angle. And, as shown in FIG. 23, a radius R 1 formed by the fore end of the upper tub cover 501 and a radius R 2 formed by the fore end of the lower tub cover 503 may preferably be made different, to improve a washing water supply efficiency. [0092] In the meantime, as the guide members 505 are not curved, the washing water is adapted to hit the guide member 505 as a right angle, to cause a friction and a consequential reduction of a pumping efficiency. And, the abrupt change of the flow direction of the washing water causes noise coming from impact. And, because the third embodiment tub cover has the deflectors fitted perpendicular to the washing water flow, a portion of the washing water hit onto the deflector turns a flow direction, not to the inner tub, but backwardly opposite to the flow direction of the washing water due to a reaction force. And, a vortex may be occurred in a space formed by an outer circumference of the deflector and the tight fit portion. Those are causes of dropping the pumping efficiency. Accordingly, the following embodiment is a modification for improving such problems. [0093] The fifth embodiment tub cover is the one in which those disadvantages are improved, which will be explained with reference to FIG. 24. [0094] The guide member 505 of this embodiment is formed to have a curvature, for guiding the washing water smoothly with a minimum friction at the guide member 505 . As the inner tub 103 rotates in regular and reverse directions, it is preferable that regular direction guide members 505 a and reverse direction guide members 505 b are provided, respectively. Because others are the same with the fourth embodiment, the explanation will be omitted. According to this, as shown in FIG. 25, since the washing water pumped by high speed rotation of the inner tub 103 is supplied to the inner tub 103 smoothly with a minimum friction, the pumping efficiency can be improved. However, as shown in FIG. 24, if the regular direction guide members 505 a and the reverse direction guide members 505 b are integrated, a fore end 505 c has no curvature, which has a great friction. Therefore, the fore end 505 also need to have a curvature, preferably. To do this, as shown in FIG. 26, the regular direction guide members 505 a and the reverse direction guide members 505 b are preferably provided with curvatures throughout entire lengths, with the fore ends thereof connected with a curved portion 507 c . Thus, since the washing water pumped during a regular direction rotation of the inner tub 103 is guided by the regular direction guide member 507 a , with a reduced friction, and the washing water pumped during a reverse direction rotation of the inner tub 103 is guided by the reverse direction guide member 507 b , with a reduced friction, the curved members 507 a and 507 b can improve the pumping efficiency. [0095] In the meantime, even though the aforementioned tub covers of the present invention can prevent spray of the washing water effectively, once sprayed, the sprayed washing water flows to outside of the outer tub 102 . Therefore, the following sixth embodiment tub cover is provided for an effective prevention of spray to outside of the outer tub 102 . The sixth embodiment tub cover will be explained with reference to FIG. 27. [0096] Similar to the fourth and fifth embodiment tub covers, the sixth embodiment tub cover 700 includes an upper tub cover 701 and a lower tub cover 703 each having a curvature, and a guide members 705 . And, the upper tub cover 701 has an upper surface portion 714 , a tight fit portion 715 and a fastening portion 711 . The lower tub cover 703 also has an upper surface portion 722 and a vertical portion 721 . However, in this embodiment, the tight fit portion 715 of the upper tub cover 701 is projected upward to form a projection 715 a, to form a recess 712 between an outer circumference and the projection 715 a, to collect the sprayed washing water. Then, the washing water collected in the recess 712 is drained into the inner tub 103 by washing water drain means 720 . The washing water drain means 720 is sloped flow passages 713 recessed in the upper surface of the upper tub cover at fixed intervals, with walls 713 a and 713 b on both sides of the passage 713 . The sloped flow passage 713 is sloped inward downwardly. [0097] In this embodiment, the guide member 705 may only be provided on the vertical flow passage 705 , because the walls 713 a and 713 b of the sloped flow passages 713 act as the guide members in the horizontal flow passage P 2 . Accordingly, as shown in FIG. 28, the washing water sprayed and collected in the recess 712 of the upper tub cover 701 flows into the inner tub 103 along the sloped flow passage 713 . And, as shown in FIG. 29, the pumped washing water flows to the inner tub 103 through the flow passages formed between the upper tub cover 701 and the lower tub cover 703 , when the walls 713 a and 713 b divide the passage. The walls 713 a and 713 b are formed with curvatures for guiding the washing water with a reduced friction in correspondence to the regular and reverse rotation. [0098] The washing water drain means may be as shown in FIG. 30 and 31 . That is, a plurality of drain holes 725 are formed in the recess of the upper tub cover 701 at fixed intervals. And, guide members for guiding the washing water into the inner tub 103 from the drain holes 725 are preferably provided in the lower tub cover 703 . Because if there are no guide members, the washing water drained through the drain holes will flow the space between the inner tub 103 and the outer tub 102 again, to resist against the circulation of the washing water as the lower tub cover 703 also has a curvature. The guide member has one pair of walls 726 and 727 formed vertical to the upper surface of the lower tub cover 703 at a width slightly greater than the width of the discharge hole 725 and a sloped passage 728 connecting the walls 726 and 727 and sloped downwardly in an inner radial direction. The walls 726 and 727 also serve as the height adjustment member. And, a front portion 723 with a supply hole 724 may be provided in front of the walls 726 and 727 . [0099] The operation of this embodiment tub cover will be explained. The pumped washing water is collected in the recess 712 of the upper tub cover 701 . The washing water collected in the recess 702 flows into the lower tub cover 703 through the drain holes 725 , and into the inner tub 103 along the sloped passage 728 . Thus, spray of the washing water out of the outer tub 102 can be prevented. In the meantime, as shown in FIG. 32 and 33 , it is, of course, possible that the upper surface of the upper tub cover 701 is provided with a slope α without the washing water drain means, for natural flow of the washing water sprayed to the upper tub cover 701 into the inner tub 103 along the upper surface of the upper tub cover 701 . In this instance, it is preferable that the guide member 705 is extended to the horizontal passage, i.e., to form a vertical portion 705 a and a horizontal portion 705 b. [0100] The second to sixth embodiment tub covers have complicated structures and high cost because the tub covers include the upper tub covers, the lower tub covers and guide members, which are comparatively many components that is difficulty in assembly. Therefore, the following seventh and eighth embodiment tub covers provide tub covers which have simple structures but have effects the same with the aforementioned embodiments. Different from the foregoing second to sixth tub covers, the following embodiment tub covers have one single tub cover(corresponding to an upper tub cover in the related art). And, different from the first embodiment tub cover, these embodiment tub covers are provided with means on a bottom surface of the tub cover for guiding the washing water into the inner tub. The pumped washing water can be guided into the inner tub only using a tub cover corresponding to an upper tub cover without using a lower tub cover owing to the following reason. The penetration washing requires fast running of the motor for pumping the washing water. That is, in the penetration washing, the washing water should be pumped upwardly to move upward to overcome a gravity of the washing water itself. Therefore, as the washing water pumped toward the tub covet does not fall down even if the lower tub cover is used substantially, formation of the washing water passage is possible even if no lower tub cover is used. And, in the case of agitating washing, since the washing water is not circulated and the tub cover only serves for prevention of noise, and foam reduction, the lower tub cover may be dispensed with, too. The seventh embodiment tub cover will be explained in detail with reference to FIGS. 34 to 36 . [0101] The seventh embodiment tub cover 800 includes a tight fit portion 810 for tight fit on an inside surface of a top end of the outer tub, an upper surface portion 811 extended upwardly from the tight fit portion 810 at an angle for serving as a guide for the washing water, and a fastening portion 810 a projected from the tight fit portion 810 in a horizontal direction for being fastened to the outer tub with screws. The upper surface portion 811 may preferably have a curvature, rather than at a right angle to the tight fit portion 810 for reducing friction with the washing water. And, there is a vertical deflector 813 formed downwardly at a fore end of the upper surface portion 811 for downward guide of the washing water to a lower portion of the inner tub, and preferably there is a vertical protector 811 a on an outer circumference of the upper surface portion 811 for protecting the spray of the washing water to outside of the outer tub. There are a plurality of main deflectors 812 formed on an underside of the upper surface portion 811 at fixed intervals, for deflecting a direction of the washing water pumped to the tub cover to a center direction of the inner tub. The main deflector 812 is formed to connect an inner and an outer diameters of the upper surface portion of the tub cover, with an angle θ 1 to a radial direction of the tub cover. And, supplementary deflectors 814 may be further provided for smoother guide of the washing water. The supplementary deflector 814 has a fore end started from the inner diameter, extended along a concentric circle with the tub cover substantially, and an aft end ended at a position of the main deflector 812 . In this instance, the fore end of the supplementary deflector is preferably spaced from the fore end of the main deflector 812 by a preset distance L 2 . Therefore, the tub cover 800 is divided by the main deflectors 812 by fixed intervals S, wherein a space between the intervals S has a main flow passage W 1 formed by the main deflector 812 and the supplementary deflector 814 and a supplementary passage W 2 formed by the supplementary deflector 814 and the vertical deflector 813 . [0102] The operation of this embodiment will be explained. [0103] The washing water pumped to the tub cover 800 is guided by the tub cover 800 into the inner tub with a minimum friction. In detail, the washing water risen upwardly is brought in contact with a bottom surface of the tub cover 800 . Then, the washing water is guided by the main deflectors 812 and the supplementary deflectors 814 to deflect a flow direction from a tangential direction to a center direction of the inner tub. And, the washing water having a direction changed by the main passage W 1 formed by the main deflector 812 and the supplementary deflector 814 hits onto the vertical deflector 813 again, to deflect a flow direction from horizontal to vertical downwardly, to supply the washing water to the inner tub lower portion. Most of the pumped washing water is guided by the main flow passages to be sprayed into the inner tub 103 , while a portion of the pumped washing water flows into the inner tub 103 directly from the supplementary flow passage W 2 . Because most of the pumped washing water is guided by the main flow passages and the outlet P of each main passage W 1 has a small width L 2 and a limited number, that built up a pressure of the washing water, the washing water is intensely sprayed from the outlets, to improve the washing efficiency. In comparison to this, in the related art, since the washing water is sprayed from an entire inner diameter of the tub cover, the washing efficiency is poor because the spraying pressure is dispersed. Though the washing water flowed in a horizontal direction and hit onto the vertical deflector 813 turns its flow direction downwardly into the inner tub, a portion of the washing water is scattered by the impact of the hit. However, this embodiment tub cover can minimize scattering of the washing water, generation of noise, and foam formation because the washing water hits the supplementary deflector 814 before the washing water hits the vertical deflector 813 . And, the washing water still scattered is prevented from leaking beyond an outer wall of the outer tub 102 by the projection 811 a on the tub cover 800 . And, as shown in FIG. 37A, a damping member 815 may preferably be provided at the outlet P side of the main passage W 1 , so that the washing water hits the damping member 815 beforehand, for effective prevention of the scattering of the washing water occurred when the washing water hits the vertical deflectors 813 . The damping member 815 is disposed substantially perpendicular to a flow direction of the washing water, i.e., connected from a fore end of the supplementary deflector 814 to a fore end of the main deflector 812 , with a height lower than heights of the main deflector 812 and the supplementary deflector 814 . As shown in FIG. 37B, instead of the damping member, a sloped portion 817 may be provided at an outlet P of the main flow passage. [0104] The following eighth embodiment tub cover is a modification from the seventh embodiment tub cover to suit to a case of both direction, i.e., regular and reverse direction rotation of the inner tub 103 . An overall structure of the eighth embodiment tub cover will be explained with reference to FIG. 8. [0105] Alike the seventh embodiment tub cover, the eighth embodiment tub cover 800 of the present invention also includes the main deflectors, the supplementary deflectors, and the vertical deflectors, except that first main deflectors 812 and second main deflectors 812 a are provided in correspondence to the both direction rotation, and a structure of the supplementary deflectors 814 a is modified. In detail, the first main deflectors 812 are formed on an underside of the upper surface portion of the tub cover 800 at fixed intervals, and the second deflectors 812 a are formed in symmetry to the first main deflectors 812 . And, a fore end of the supplementary deflector 814 a has a fore end started from the inner circumference and extended along a concentric circle of the tub cover, and an aft end connected to the inner circumference of the tub cover. That is, the fore end of the supplementary deflector 814 a is positioned spaced from the fore end of the first main deflector 812 , and the aft end of the supplementary deflector 814 a is positioned spaced from the fore end of the second main deflector 812 a. And, preferably there are a plurality of ribs 818 between the first main deflectors and the second main deflectors 812 a for preventing distortion, and more preferably concentric to the tub cover circumference. And, a portion of an outer rib may be cut away. The ribs 818 are fitted under the following reasons. The washing water passed over the main deflectors 812 and 812 a may cause a vortex between the first and the second main deflectors 812 and 812 a, or may flow to the outlet of the main flow passage, to interfere the washing water flow in the main flow passage. Therefore, the ribs 818 are provided to confine the washing water between the first and second deflectors 812 and 812 a to some extent, for preventing interference to the washing water in the main flow passage. Thus, the tub cover is divided by the first main deflectors 812 and the second main deflectors 812 a into fixed intervals S. And, a space between the intervals S has a main flow passage W 1 formed by the main deflector 812 and a just prior supplementary deflector 812 a, and a supplementary passage W 2 formed by the supplementary deflector 812 a and the vertical deflector 813 . And, there is a space formed by the first main deflector 812 and an adjacent second main deflector 812 a. Accordingly, when the inner tub rotates in a regular direction (a counter clockwise direction on the drawing), most of the washing water pumped to the tub cover is guided by the tub cover as shown in arrows of solid lines to be sprayed into the inner tub through the regular direction outlets P 3 with a minimum friction. Opposite to this, when the inner tub rotates in a reverse direction (a clockwise direction on the drawing), most of the washing water pumped to the tub cover is guided by the tub cover as shown in arrows of dotted lines to be sprayed into the inner tub through the reverse direction outlets P 4 with a minimum friction. Therefore, the eighth embodiment tub cover can cope with all the regular and reverse direction rotation, effectively. [0106] In the meantime, as shown in FIG. 39, a portion of the regular direction outlet P 3 and the reverse direction outlet P 4 a may be cut away to form an opening 816 , for minimizing the scattering of the washing water caused by the washing water hitting onto the vertical deflector 813 . In the meantime, as shown in FIGS. 40 and 41, identical to the seventh embodiment, either the damping member 815 or the sloped portion 817 is provided for effective prevention of the washing water scattering. And, it is preferable that a sealing member is provided between the tub cover and the outer tub. [0107] As has been explained, the penetration type washing machine, the method for controlling the same, and the tub cover for the same have the following advantages. [0108] First, the penetration type washing machine can make washing using an appropriate combination of the penetration washing, the agitating washing, and the restoration circulation washing. Therefore, a washing efficiency can be improved while damage to, and entangling of the laundry is minimized. And, the washing can be carried out only with a small amount of washing water, consumption of water and detergent may be reduced, with consequential reduction of drain time period, to reduce an overall washing time. [0109] Second, the tub cover of the present invention can improve a pumping efficiency of the washing water because leakage or scattering of the pumped washing water can be prevented and the washing water can be guided into the inner tub without friction loss. And, the noise and foam caused by the circulated washing water at the high speed rotation of the inner tub can be minimized. [0110] Third, as the tub cover of the present invention facilitates spray of the pumped washing water toward a center of the inner tub, a washing efficiency can be improved. [0111] It will be apparent to those skilled in the art that various modifications and variations can be made in the penetration type washing machine, the method for controlling the same, and the tub cover for the same of the present invention without departing from the spirit or scope of the invention. Thus, it is intended that the present invention cover the modifications and variations of this invention provided they come within the scope of the appended claims and their equivalents. [0112] The foregoing embodiments and advantages are merely exemplary and are not to be construed as limiting the present invention. The present teaching can be readily applied to other types of apparatuses. The description of the present invention is intended to be illustrative, and not to limit the scope of the claims. Many alternatives, modifications, and variations will be apparent to those skilled in the art. In the claims, means-plus-function clauses are intended to cover the structures described herein as performing the recited function and not only structural equivalents but also equivalent structures.	Method for controlling a full automatic washing machine, the method comprising a washing cycle, a rinsing cycle, and a dewatering cycle, wherein the washing or the rinsing cycle includes the step of rotating an inner tub at a high speed higher than a preset speed in one direction, thereby making a centrifugal force caused by high speed rotation of the inner tub, to push laundry against a wall of the inner tub, to enforce washing water in the inner tub to penetrate through the laundry at a speed higher than required to make the washing done, and to pump the washing water penetrated through the laundry and discharged into an outer tub upward, to recirculate to the inner tub.	3
FIELD OF THE INVENTION The present invention is directed to novel compounds, to a process for their preparation, their use and pharmaceutical compositions comprising the novel compounds. The novel compounds are useful in therapy, and in particular in the prevention of platelet aggregation. BACKGROUND AND PRIOR ART A number of converging pathways lead to platelet aggregation. Whatever the initial stimulus, the final common event is a cross linking of platelets by binding of fibrinogen to a membrane binding site, glycoprotein IIb/IIIa (GPIIb/IIIa). The high anti-platelet efficacy of antibodies or antagonists for GPIIb/IIIa is explained by their interference with this final is common event. However, this efficacy may also explain the bleeding problems that have been observed with this class of agent. Thrombin can produce platelet aggregation largely independently of other pathways but substantial quantities of thrombin are unlikely to be present without prior activation of platelets by other mechanisms. Thrombin inhibitors such as hirudin are highly effective anti-thrombotic agents, but again may produce excessive bleeding because they function as both anti-platelet and anti-coagulant agents (The TIMI 9a Investigators (1994), Circulation 90, pp. 1624-1630; The Global Use of Strategies to Open Occluded Coronary Arteries (GUSTO) IIa Investigators (1994) Circulation 90, pp. 1631-1637; Neuhaus K. L. et. al. (1994) Circulation 90, pp. 1638-1642). Aspirin, which is known to have a beneficial effect on platelet aggregation, (see e.g. Antiplatelet Trialists' Collaboration (1994), Br. Med. J. 308, pp. 81-106; Antiplatelet Trialists' Collaboration (1994), Br. Med. J. 308, pp. 159-168) has no effect on aggregation produced by other sources of ADP, such as damaged cells or ADP released under conditions of turbulent blood flow. A pivotal role for ADP is supported by the fact that other agents, such as adrenaline and 5-hydroxytryptamine (5HT, serotonin) will only produce aggregation in the presence of ADP. The inventors of the present invention started from the point that an antagonist of the effect of ADP on its platelet membrane receptor, the P 2T -purinoceptor, would provide a more efficacious anti-thrombotic agent than aspirin but with less profound effects on bleeding than antagonists of the fibrinogen receptor. U.S. Pat. No. 4,543,255 discloses carbocyclic analogues of 2-amino-6-substituted purine 2'-deoxyribofuranosides and of 2-amino-6-substituted-8-azapurine 2'-deoxyribofuranosides. The compounds of this prior art patent are disclosed as having inhibitory effect against herpes viruses. WO 90/06671 discloses the use of carbocyclic analogues of various nucleosides for the treatment of Hepatitis B virus. The problem underlying the present invention was to find novel compounds having improved P 2T -receptor antagonist activity and with significant advantages with respect to known anti-platelet agents, such as improved efficacy, reduced side-effects, non-toxicity, and better selectivity for the P 2T -receptor. The problem mentioned above has now been solved by providing novel compounds which are 5,7-disubstituted 1,2,3-triazolo 4,5-d!pyrimidin-3-yl derivatives, as will be described below. OUTLINE OF THE INVENTION The novel compounds according to the present invention are defined by the general formula (I) ##STR2## wherein B is O or CH 2 ; X is selected from NR 1 R 2 , SR 1 , and C 1 -C 7 alkyl; Y is selected from SR 1 , NR 1 R 2 , and C 1 -C 7 alkyl; R 1 and R 2 is each and independently selected from H, or C 1 -C 7 alkyl optionally substituted upon or within the alkyl chain by one or more of O, S, N or halogen; R 3 and R 4 are both H, or R 3 and R 4 together form a bond; A is COOH, C(O)NH(CH 2 ) p COOH, C(O)N (CH 2 ) q COOH! 2 , C(O)NHCH(COOH)(CH 2 ) r COOH, or 5-tetrazolyl, wherein p, q and r is each and independently 1, 2 or 3; The definition of alkyl is intended to include straight, branched, and cyclic alkyl chains, as well as saturated and unsaturated alkyl chains. The O, S and N substituents may be substituents upon or within the alkyl chain. By this definition we mean C 1 -C 7 alkyl where one methylene within the chain may optionally be replaced by O, S or NH and in which the alkyl chain may be optionally substituted by one or more of OH, SH, NH 2 or halogen. Halogen includes chloro and fluoro. Within the scope of the invention are also pharmaceutically acceptable salts of the compounds of the formula (I), as well as prodrugs such as esters and amides thereof. Also within the scope of the invention are compounds of the formula (I) in tautomeric, enantiomeric and diastereomeric forms. Preferred compounds of the invention are compounds of the formula (I) wherein X is NR 1 R 2 ; Y is SR 1 ; A is C(O)NHCH(COOH)(CH 2 ) r COOH; and wherein R 1 , R 2 , and r are as defined above. Especially preferred compounds of the invention are compounds of the formula (I) wherein X is NR 1 R 2 wherein R 1 is hydrogen and R 2 is as defined above; Y is SR 1 where R 1 is C 1 -C 5 alkyl optionally substituted by one or more halogens; and A is C(O)NHCH(COOH)CH 2 COOH The most preferred compounds of the invention are (E)-N- 1- 7-(Butylamino)-5-(propylthio)-3H-1,2,3-triazolo 4,5-d!pyrimidin-3-yl!-1,5,6-trideoxy-β-D-ribo-hept-5-enofuranuronoyl!-L-aspartic acid; 1R-(1α,2β,3β,4α)!-N- 3- 4- 7-(Butylamino)-5-(propylthio)-3H-1,2,3-triazolo 4,5-d!pyrimidin-3-yl!-2,3-dihydroxycyclopentyl!propanoyl!-L-aspartic acid; 1R-(1α(E),2β,3β,4α)!-N- 3- 4- 7-(Hexylamino)-5-(propylthio)-3H-1,2,3-triazolo!4,5-d!pyrimidin-3-yl!-2,3-dihydroxycyclopentyl!-2-propenoyl!-L-aspartic acid; and 1R-(1α(E),2β,3β,4α)!-N- 3- 4- 5- (3,3,3-Trifluoropropyl)thio!-7 2-(methylthio)ethylamino!-3H-1,2,3-triazolo 4,5-d!pyrimidin-3-yl!-2,3-dihydroxycyclopentyl!-2-propenoyl!-L-aspartic acid, monoammonium salt. The novel compounds of the present invention are useful in therapy, in particular in the prevention of platelet aggregation. The compounds of the present invention are thus useful as anti-thrombotic agents, and are thus useful in the treatment or prophylaxis of unstable angina, coronary angioplasty (PTCA), and myocardial infarction. The compounds of the present invention are also useful in the treatment or prophylaxis of primary arterial thrombotic complications of atherosclerosis such as thrombotic stroke, peripheral vascular disease, myocardial infarction (i.e. without thrombolysis). Still further indications where the compounds of the invention are useful are for the treatment or prophylaxis of arterial thrombotic complications due to interventions in atherosclerotic disease such as angioplasty, endarterectomy, stent placement, coronary and other vascular graft surgery. Still further indications where the compounds of the invention are useful are for the treatment or prophylaxis of thrombotic complications of surgical or mechanical damage such as tissue salvage following surgical or accidental trauma, reconstructive surgery including skin flaps, and "reductive" surgery such as breast reduction. The compounds of the invention are also useful for the prevention of mechanically-induced platelet activation in vivo, such as cardio-pulmonary bypass (prevention of microthromboembolism), prevention of mechanically-induced platelet activation in vitro such as the use of the compounds in the preservation of blood products, e.g. platelet concentrates, prevention of shunt occlusion such as renal dialysis and plasmapheresis, thrombosis secondary to vascular damage/inflammation such as vasculitis, arteritis, glomerulonephritis, and organ graft rejection. Still further indication where the compounds of the present invention are useful are indications with a diffuse thrombotic/platelet consumption component such as disseminated intravascular coagulation, thrombotic thrombocytopenic, purpura, haemolytic uraemic syndrome, thrombotic complications of septicaemia, adult respiratory distress syndrome, anti-phosholipid syndrome, heparin-induced thrombocytopaenia and pre-eclampsia/eclampsia. Still further indications where the compounds of the invention are useful are for the treatment or prophylaxis of venous thrombosis such as deep vein thrombosis, veno-occlusive disease, haematological conditions such as thrombocythaemia and polycythaemia, and migraine. In a particularly preferred embodiment of the present invention, the compounds are used in the treatment of unstable angina, coronary angioplasty and myocardial infarction. In another particularly preferred embodiment of the invention, the compounds of the present invention are useful as adjunctive therapy in the prevention of coronary arterial thrombosis during the management of unstable angina, coronary angioplasty and acute myocardial infarction, i.e. perithrombolysis. Agents commonly used for adjunctive therapy in the treatment of thrombotic disorders may be used, for example heparin and/or aspirin, just to mention some. METHODS OF PREPARATION The compounds of the present invention may be prepared as follows. A) (i) The starting material 4,5-diamino-2,6-dimercaptopyrimidine is subjected to an alkylation reaction followed by diazotization, giving a compound of the formula (II) ##STR3## wherein R 1 is as defined in formula (I). (ii) The product of the formula (11) of step (i) is reacted with a compound of the formula (III) ##STR4## wherein P 2 is protecting group; and L is a leaving group; in an inert solvent and in the presence of a base. Solvents which may be used include DMF, and bases which may be used include sodamide. The reaction is carried out at temperatures from -20° to 50° C. Preferably the reaction is carried out at ambient temperature, the solvent is acetonitrile and the base sodium hydride. A suitable protecting group includes an acyl group such as benzoyl, and a suitable leaving group includes a halogen such as bromine. The reagent of formula (III) used in this step, is prepared by the halogenation of a suitably protected ribose. Thereafter the group X=NR 1 R 2 wherein R 1 and R 2 are as defined in formula (I) above may be introduced by reaction with a compound of the formula HNR 1 R 2 wherein R 1 and R 2 are as defined in formula (I) above, in an inert solvent at temperatures from 0° to 150°. Preferably the solvent is 1,4-dioxane and the temperature 100° C. The protecting groups P 2 may be removed by treatment with a nucleophile, for example an alkoxide in an alcohol solvent, preferably sodium methoxide in methanol at 60° C. The product achieved in this step is a compound of the formula (IV) ##STR5## wherein X is NR 1 R 2 ; Y is SR 1 ; and wherein R 1 and R 2 are as defined in formula (I) above. (iii) The product formula (IV) of step (ii), is reacted with a suitable carbonyl compound or with an ortho ester in an inert solvent and in the presence of a mineral or organic acid catalyst at a temperature between -15° and 100°, giving a compound of the formula (V) ##STR6## wherein X is NR 1 R 2 ; Y is SR 1 ; B is O; and P 1 is a protecting group, preferably P 1 /P 1 together form a ring. Preferably P 1 /P 1 is ethoxymethylidene, introduced using triethyl orthoformate in 1,4-dioxane at 50° C. and in the presence of trichloroacetic acid. B) (i) 4,6-dihydroxy-2-mercaptopyrimidine is alkylated followed by nitration, whereafter the two alcohols are converted to leaving, groups, giving a compound of the formula (VI) ##STR7## wherein is R 1 is as defined in formula (I); and M is a leaving group; Examples of leaving groups that may be used are halogens. The compound of formula (VI) is reacted with a suitably protected 5,6-dihydroxy-2-azabicyclo 2.2.1!heptan-3-one, preferably 3aS-(3aα,4β,7β,7aα!-tetrahydro-2,2-dimethyl-4,7-methano-1,3-dioxolo 4,5-c!pyridin-6(3aH)-one, in the presence of a base such as butyl-lithium in an inert solvent such as tetrahydrofuran at temperatures of 10° C. to 100° C., giving a compound of the formula (VII) ##STR8## wherein Y is SR 1 ; R 1 is as defined in formula (I); M is a leaving group; and P 1 is a protecting group. Preferably P 1 /P 1 together form a ring such as isopropylidene, and preferably the leaving group is chlorine. Preferably the base is sodium hydride, the solvent DMF and the reaction carried out at ambient temperature. (ii) The nitro function and the lactam in the product of the formula (VII) of step (i) is reduced, followed by cyclization to a triazole. Methods of reduction of the nitro group which may be mentioned include hydrogenation using transition metal catalysts such as palladium on charcoal under an atmosphere of hydrogen, at a pressure of 1-5 Bar, in a suitable solvent eg ethanol. Preferably iron in an acidic solvent is used, such as acetic acid at temperatures between 20° and 150° C., most preferred is a temperature of 100° C. Methods of reduction of the lactam which may be mentioned include the use of complex metal hydrides such as lithium aluminium hydride in an inert solvent such as tetrahydrofuran, at temperatures of 0° to 100° C. Preferably sodium borohydride in methanol is used at temperatures of 0° to 30°. The diamino alcohol thereby formed is cyclised by a diazotization reaction using metal nitrites or alkyl nitrites in a suitable solvent, for example use of sodium nitrite in dilute aqueous HCl at temperatures of -20° to 100° C. Preferably isoamyl nitrite in acetonitrile is used at 80° C. The group X=NR 1 R 2 is introduced by reaction with a compound of formula HNR 1 R 2 in an inert solvent at temperatures from 0° to 150° C., giving a compound of the formula (V) wherein X is NR 1 R 2 ; Y is SR 1 ; R 1 and R 2 are as defined in formula (I); B is CH 2 ; and P 1 is a protecting group. Preferably 1,4-dioxane is used as the solvent, and the reaction performed at a temperature of 100° C. Preferably P 1 /P 1 together form a ring, where P 1 /P 1 being isopropylidene is most preferred. C) (i) The product of step A) and B), i.e. a compound of the formula (V) achieved in step A) and B) respectively, is oxidised and subjected to an olefination reaction, giving a compound of the formula (VIII) ##STR9## wherein B is O or CH 2 ; X, Y and P 1 are as defined in formula (V) of step A) and B) respectively; A is COOR 11 wherein R 11 is a lower (ar)alkyl; and R 3 and R together form a bond. Methods of oxidation which may be mentioned include the Swern reaction and use of the Dess Martin reagent, in appropriate solvents at temperatures between -78° and 120° C. Preferably the Pfitzner-Moffatt oxidation in DMSO as solvent is used at ambient temperature, and the protecting groups P 1 /P 1 together form a ring, most preferred is the case where P 1 /P 1 is isopropylidene. Methods of olefination which may be mentioned include the Peterson reaction and the Horner Emmons reaction. Preferably a Wittig reaction is used with a phosphorus ylide such as a (carboalkoxymethylene)triphenylphosphorane, particularly preferred is (t-Butoxycarbonylmethylene)triphenylphosphorane. (ii) R 11 is removed by de-esterification using acidic or basic or hydrogenolytic conditions, and deprotection is finally performed, giving a compound of the formula (I) wherein X is NR 1 R 2 ; Y is SR 1 ; B is O or CH 2 ; R 1 and R 2 are as defined in formula (I); R 3 and R 4 together form a bond; and A is COOH. Groups R 11 which may be mentioned include methyl, ethyl, isopropyl, t-butyl and benzyl. Groups R 11 may be removed by hydrolysis using acid or basic conditions. Basic hydrolysis may be performed using metal hydroxides or quaternary ammonium hydroxides such as sodium hydroxide in a solvent such as aqueous ethanol at a temperature between -10° and 100°. We prefer lithium hydroxide in aqueous tetrahydrofuran at ambient temperature. Acidic hydrolysis may be performed using mineral acid such as HCl or strong organic acid such as trifluoroacetic acid in a suitable solvent eg aqueous 1,4-dioxane. Benzyl groups may be removed by hydrogenolysis using transition metal catalysts eg palladium on charcoal under an atmosphere of hydrogen, at a pressure between 1 and 5 Bar, in a suitable solvent such as acetic acid. We prefer R 11 =t-Butyl and hydrolysis using trifluoroacetic acid in dichloromethane. The protecting groups in the case of acyl and benzyl may be removed as described for R 11 above, silyl protecting groups may be removed by the use of e.g. fluoride ion. Lower alkyl groups may be removed by the use of for example boron tribromide. Methylidene and ethoxymethylidene may be removed by the use of for example mineral or organic acid. All these methods may be performed at a temperature of between -80° C. and 150° C. Preferably R 11 is t-butyl and P 1 /P 1 are isopropylidene both of which are simultaneously removed using trifluoroacetic acid in dichloromethane at ambient temperature. D) (i) A compound of the formula (I) wherein X is SR 1 , NR 1 R 2 , or C 1 -C 7 alkyl; Y is SR 1 , NR 1 R 2 , C 1 -C 7 alkyl; R 1 and R 2 are as defined in formula (I); B is O or CH 2 ; R 3 and R 4 are hydrogen or together form a bond; and A is COOH; is reacted with a compound having the structure NH 2 (CH 2 ) p COOR 11 , NH (CH 2 ) q COOR 11 ! 2 , or NH 2 CH(COOR 11 )(CH 2 ) r COOR 11 , wherein p, q and r are 1, 2 or 3, and R 11 is a lower (ar)alkyl; using methods as employed in pep tide synthesis, e.g. the use of a coupling agent. Coupling, agents which may be used include 1,1'-carbonyldiimidazole, N-ethoxycarbonyl-2-ethoxy-1,2-dihydroquinoline. A compound of the formula (I) wherein X is SR 1 , NR 1 R 2 , or C 1 -C 7 alkyl; Y is SR 1 , NR 1 R 2 ; C 1 -C 7 alkyl; B is O or CH 2 ; R 3 and R 4 are hydrogen or together form a bond; and A is C(O)NH(CH 2 ) p COOR 11 , C(O)N (CH 2 ) q COOR 11 ! 2 , or C(O)NHCH(COOR 11 )(CH 2 ) r COOR 11 where p, q and r are 1, 2 or 3, and R 11 is a lower (ar)alkyl. is achieved in this step. Groups R 11 which may be mentioned include methyl, ethyl, isopropyl, t-butyl and benzyl. The coupling reaction is carried out in a suitable solvent at a temperature between -15° C. and 120° C. Preferably dicyclohexylcarbodimide or bromo-tris-pyrrolidinophosphonium hexafluorophosphate in N,N-Dimethylformamide (DMF) is used at a temperature between 0° C. and room temperature. (ii) The product of formula (I) of step (i) is de-esterified, giving a compound of the formula (I) wherein B is O or CH 2 ; X is NR 1 R 2 , SR 1 , or C 1 -C 7 alkyl; Y is SR 1 , NR 1 R 2 , or C 1 -C 7 alkyl; R 1 and R 2 is each and independently H, or C 1 -C 7 alkyl optionally substituted upon or within the alkyl chain by one or more of O, S, N or halogen; R 3 and R 4 are both H, or R 3 and R 4 together form a bond; and A is C(O)NH(CH 2 ) p COOH, C(O)N (CH 2 ) q COOH! 2 , or C(O)NHCH(COOH)(CH 2 ) r COOH, wherein p, q and r is each and independently 1, 2 or 3. Groups R 11 which may be mentioned include methyl, ethyl, isopropyl, t-butyl and benzyl. Groups R 11 may be removed by hydrolysis using acid or basic conditions. Basic hydrolysis may be performed using metal hydroxides or quaternary ammonium hydroxide such as sodium hydroxide in a solvent such as aqueous ethanol at a temperature between 10° and 100°. We prefer lithium hydroxide in aqueous tetrahydrofuran at ambient temperature. Acidic hydrolysis may be performed using mineral acid such as HCl or strong organic acid such as trifluoroacetic acid in a suitable solvent eg aqueous 1,4-dioxane. Benzyl groups may be removed by hydrogenolysis using transition metal catalysts eg, palladium on charcoal under an atmosphere of hydrogen, at a pressure between 1 and 5 Bar, in a suitable solvent such as acetic acid. We prefer R 11 =t-Butyl and hydrolysis using trifluoroacetic acid in dichloromethane. E) (i) The product achieved in step C(ii) is reduced, giving a compound of the formula (I) wherein B, X, Y, R 1 and R 2 are as defined in step C(ii) above; A is COOH; and R 3 and R 4 are both hydrogen. Methods of reduction which may be used include hydrogenation using transition metal catalysts, for example palladium on charcoal under an atmosphere of hydrogen in a suitable solvent such as acetic acid at a pressure of 1 to 5 bar. Preferably diimide generated from a suitable precursor such as 2,4,6-triisopropylbenzene sulfonylhydrazide is used at a temperature between 60° and 100° C., in a solvent of tetrahydrofuran (THF). F) (i) A suitably protected 5-amino-1-(β-D-ribo-furanosyl)-1,2,3-triazole-4-carboxamide, preferably 5-Amino-1- 2,3-O-(1-methylethylidene)-β-D-ribo-furanosyl!-1,2,3-triazole-4-carboxamide is treated with a base followed by treatment with an ester having the formula R 1 COOR 5 where R 1 is as defined in structure (I) and R 5 is a lower alkyl. Thereafter protection is performed, giving a compound of the formula (IX) ##STR10## wherein Y is C 1 -C 7 alkyl; P 1 is a protecting group, and preferably P 1 /P 1 together form a ring; P 2 is a protecting group; and M is OH. Protecting groups P 2 which may be mentioned include lower alkyl or acyl groups. Preferably P 2 is acetyl, introduced by the treatment with acetyl chloride and triethylamine in a suitable solvent, e.g. dichloromethane at ambient temperature. Most preferably P 1 /P 1 is isopropylidene and P 2 is acetyl. (ii) The compound of the formula (IX) where M is OH, is halogenated and the group X=NR 1 R 2 is introduced by treatment with a compound of formula HNR 1 R 2 in an inert solvent at temperatures from 0° to 150°. Thereafter the protecting group P 2 is removed, giving a compound of the formula (V) wherein X is NR 1 R 2 ; R 1 and R 2 are as defined in formula (I); Y is C 1 -C 7 alkyl; B is O; and P 1 is a protecting group, and preferably P 1 /P 1 together form a ring. Most preferred is the case where P 1 /P 1 is isopropylidene. Halogenating agents which may be mentioned include P(III) or P(V), or S(II) or S(IV) halides such as phosphorous trichloride at temperatures of 0° to 150°. The reactions may be performed in the halogenating agent as solvent or other inert solvents such as methylene chloride. We prefer thionyl chloride in DMF/chloroform at reflux. A preferred solvent used for the introduction of the group X=NR 1 R 2 is 1,4-dioxane at a temperature of 100°. Protecting group P 2 may be removed under these conditions. Alternatively it may be removed using acidic or basic hydrolytic methods. Preferably ammonia in methanol is used at ambient temperature. (iii) The product of formula (V) of step (ii) is subjected to the same reactions as described in steps C(i) and (ii), giving a compound of the formula (I) wherein X is NR 1 R 2 ; R 1 and R 2 are as defined in formula (I); B is O; Y is C 1 -C 7 alkyl; A is COOH; and R 3 and R 4 together form a bond. G) (i) A suitable protecting group P 3 was introduced into a protected 5-amino-1-(β-D-ribo-furanosyl)-1,2,3-triazole-4-carboxamide, preferably 5-amino-1- 2,3-O-(1-methylethylidene)-β-D-ribo-furanosyl!-1,2,3-triazole-4-carboxamide. The resulting intermediate was treated with a base, preferably sodium hydride, followed by treatment with a reagent of the formula ##STR11## where L is a leaving group, preferably imidazolyl, giving a compound of the formula (X) ##STR12## wherein P 1 is a protecting group, preferably where P 1 /P 1 together form a ring; and P 3 is a protecting group, preferably a silyl group. Most preferred is the case where P 1 /P 1 is isopropylidene and P 3 is t-butyldimethylsilyl. (ii) The product of formula (X) of step (i) was treated with a base such as butyl lithium in an inert solvent such as THF at a temperature between -20° C. and 50° C., followed by treatment with an alkylating agent R 1 G where G is a leaving group, such as a halogen, and wherein R 1 is as defined in formula (I). Preferably sodium hydride is used as a base, in DMF at ambient temperature, and G is iodine. Thereafter P 3 was removed from the above compound, and replaced with a new protecting group P 2 . Preferably P 2 is an acyl group. Preferably P 3 is a silyl group, removed by treatment with fluoride ion, and replaced with an acyl group. Most preferred is P 3 being a t-butyldimethylsilyl group, removed by reaction with tetra-n-butylammonium fluoride in THF followed by introduction of a protecting group P 2 by reaction with acetyl chloride in dichloromethane at ambient temperature. Halogenation is finally performed, giving a compound of the formula (IX) wherein M is a leaving group, for example a halogen and preferably chlorine; P 1 is a protecting group, preferably P 1 /P 1 together form a ring: and P 2 is a protecting group, preferably acetyl; and Y is SR 1 . Halogenating agents which may be mentioned include P(III) or P(V), or S(II) or S(IV) halides such as phosphorous trichloride at temperatures of 0° C. to 150° C. The reactions may be performed in the halogenating agent as solvent or other inert solvents such as methylene chloride. Preferably thionyl chloride in DMF/chloroform is used at reflux. (iii) The product of step (ii) was reacted with an alkyl nucleophile, eg. a Grignard reagent in an inert solvent such as THF at a temperature between -20° C. and 150° C. Preferably the alkyl nucleophile is an alkyltin species used in the presence of a Pd(II) catalyst. Thereafter the protecting group P 2 was removed, giving a compound of the formula (V) wherein X is C 1 -C 7 alkyl; Y is SR 1 ; R 1 is as defined for formula (I); B is O; and P 1 is a protecting group, preferably where P 1 /P 1 together form a ring, which most preferably is isopropylidene. The protecting group P 2 may be removed by acidic or basic hydrolytic methods. Preferably P 2 is acetyl, removed by the treatment with ammonia in methanol at ambient temperature. H) (i) A compound of the formula (I) wherein X is NR 1 R 2 ; Y is SR 1 ; R 1 and R 2 are as defined in formula (I); B is O; R 3 and R 4 are both hydrogen; and A is C(O)NHCH(COOR 11 )(CH 2 ) r COOR 11 , where r is 1, 2 or 3, and R 11 is as defined above; was treated with an oxidant such as magnesium monoperoxyphthalate in an inert solvent such as THF at temperature between -20° C. and 100° C., followed by treatment with a compound of the formula HNR 1 R 2 in an inert solvent at temperatures from 0° C. to 150 C., giving a compound of the formula (I) wherein X is NR 1 R 2 ; Y is NR 1 R 2 ; B is O; R 3 and R 4 are both hydrogen; and A is C(O)NHCH(COOR 11 )(CH 2 ) r COOR 11 , where r is 1, 2 or 3, and R 11 is as defined in step D) above. Preferably m-chloroperoxybenzoic acid is used as an oxidant in a solvent of ethanol at ambient temperature, and the displacement is carried out in 1,4-dioxane at 100° C. I) A compound of the formula (I) wherein X is SR 1 Y is SR 1 ; B is O; R 3 and R 4 are both hydrogen; and A is COOH; may be prepared by reacting a compound of the formula (II) wherein R 1 is as defined in formula (I), with a compound of the formula (XI) ##STR13## wherein R 12 is a lower (ar)alkyl and P 4 is a protecting group such as an acetyl group. The reaction may be carried out by heating the compounds together in the presence of an acid such as trichloroacetic acid at reduced pressure and at a temperature between 50° and 175° C. Preferably R 12 is ethyl, P 4 is acetyl and the reaction is carried out at 140° C. in the presence of p-toluenesulfonic acid under water pump vacuum. The protecting groups and the group R 12 may then be removed by hydrolysis under acidic or basic conditions, giving a compound of the formula (I) wherein X is SR 1 Y is SR 1 ; R 1 is as defined for formula (I); B is O; R 3 and R 4 are both hydrogen; and A is COOH; Examples of hydrolyzing agents and conditions that may be used, are metal alkoxides in alcohol at temperatures between 0° and 100° C., or alternatively trifluoroacetic acid in dichloromethane may be used. Preferably R 12 is ethyl and P 4 is acetyl, and lithium hydroxide in aqueous tetrahydrofuran is used at ambient temperature. A compound of the formula (XI) which is one of the starting materials in this reaction step, is initially prepared from (E)-Methyl 5,6-dideoxy-2,3-O-(1-methylethylidene)-β-D-ribo-hept-5-enofuranosiduronic acid, ethyl ester by hydrolysis with an aqueous acid, eg aqueous acetic acid and reaction with an acylating agent such as acetyl chloride in the presence of a base eg pyridine and a suitable solvent eg methylene chloride, followed by reduction, e.g. hydrogenation using transition metal catalysts such as palladium on carbon under atmosphere of hydrogen in a suitable solvent, e.g. ethanol at a pressure between 1 and 3 bar. J) A compound of the formula (I) wherein X is NR 1 R 2 ; Y i SR 1 ; R 1 and R 2 are as defined in formula (I); B is O or CH 2 ; R 3 and R 4 are both hydrogen; and A is 5-tetrazolyl; was prepared as follows. The product in step A(iii) or the product of step B(ii), i.e. a compound of the formula (V) wherein B is O or CH 2 and X and Y are as defined in formula (V) above, and P 1 is a protecting group, preferably where P 1 /P 1 together form a ring, was oxidised followed by an olefination reaction and a subsequent reduction. Methods of oxidation which may be mentioned include the Swern reaction and use of the Dess Martin reagent in appropriate solvents at temperatures between -78° and 120° C. Preferably the Pfitzner-Moffatt oxidation was performed in a solvent of DMSO at ambient temperature using a compound of the formula (V) wherein P 1 /P 1 is isopropylidene. Methods of olefination which may be mentioned include the Peterson reaction and the Horner Emmons reaction. We prefer a Wittig reaction with the phosphorus ylid (triphenylphosphoranylidene)acetonitrile. Methods of reduction which may be mentioned include hydrogenation using transition metal catalysts such as platinum under an atmosphere of hydrogen in a suitable solvent eg acetic acid at temperatures between 0° and 100°. We prefer palladium on charcoal under a pressure of 4 Bar in a solvent of ethanol at ambient temperature. The product thus achieved was a compound of the formula (XIII) ##STR14## wherein B is O or CH 2 ; P 1 is a protecting group, preferably where P 1 /P 1 together form a ring and most preferably where P 1 /P 1 is isopropylidene; and R 1 and R 2 are as defined in formula (I). This compound of the formula (XII) was reacted with an azide such as sodium azide in an inert solvent, e.g. DMF, at a temperature between 0° C. and 175° C. Isopropylidene is a preferred protecting group. Preferably tributyltin azide in toluene is used at a temperature of 110° C. The protecting groups are thereafter removed by treatment with a mineral or organic acid in an inert solvent at a temperature between 0° C. and 100° C. Preferably trifluoroacetic acid in dichloromethane is used at ambient temperature. A product of the formula (I) wherein X is NR 1 R 2 ; Y is SR 1 ; R 1 and R 2 are as defined in formula (I); B is O or CH 2 ; R 3 and R 4 are both hydrogen; and A is 5-tetrazolyl; was thus achieved. K) A compound of the formula (I) wherein X is SR 1 , NR 1 R 2 or C 1 -C 7 alkyl; Y is SR 1 , NR 1 R 2 or C 1 -C 7 alkyl; R and R 2 are as defined in formula (I); B is CH 2 or O; R 3 and R 4 together form a bond; and A is COOR 11 wherein R 11 is as defined in formula (I) above; is reduced, giving a compound of the formula (VIII) wherein R 3 and R 4 are hydrogen; and X, Y, B, A, R 11 and Pd 1 are as defined above. Methods of reduction which may be mentioned include hydrogenation using transition metal catalysts, e.g. palladium on charcoal under an atmosphere of hydrogen in a suitable solvent such as acetic acid at a pressure of 1 to 5 bar. Preferably diimide generated from a suitable precursor such as 2,4,6-triisopropylbenzenesulfonylhydrazide at a temperature between 60° C. and 100° C. is used in a solvent of tetrahydrofuran. (ii) The product of step (i) is subjected to the same reaction conditions as described in step D(ii), giving a compound of the formula (I) wherein X is SR 1 , NR 1 R 2 or C 1 -C 7 alkyl; Y is SR 1 , NR 1 R 2 or C 1 -C 7 alkyl; R 1 and R 2 are as defined in formula (I); B is CH 2 or O; and A is COOH. The compounds of the formula (I), as well as salts, and prodrugs such as esters or amides thereof, may be isolated from their reaction mixtures using conventional techniques. Salts of the compounds of formula (I) may be formed by reacting the free acid, or a salt thereof, or the free base, or a salt or derivative thereof, with one or more equivalents of the appropriate base or acid. The reaction may be carried out in a solvent or medium in which the salt is insoluble or in a solvent in which the salt is soluble, e.g. water, ethanol, tetrahydrofuran or diethyl ether, which may be removed in vacuo, or by freeze drying. The reaction may also be a metathetical process or it may be carried out on an ion exchange resin. The non-toxic physiologically acceptable salts are preferred, although other salts may be useful, e.g. in isolating or purifying the product. Pharmaceutically acceptable esters of the compounds of formula I may be made by conventional techniques, e.g. esterification or transesterification. Pharmaceutically acceptable amides of the compounds of formula I may be made by conventional techniques, e.g. reaction of an ester of the corresponding acid with ammonia or an appropriate amine. DETAILED DESCRIPTION OF THE INVENTION The invention will now be described in more detail by the following examples, which are not to be construed as limiting the invention. Temperatures are given in degrees Celsius in the Examples if nothing else has been indicated. EXAMPLES Example 1 1R-(1α(E),2β,3β,4α)-3- 4- 7-(Butylamino)-5-(propylthio)-3H-1,2,3-triazolo 4,5-d!pyrimidin-3-yl!-2,3-dihydroxycyclopentyl!-2-propenoic acid, sodium salt! a) 2-(Propylthio)-4,6(1H,5H)-pyrimidinedione Propyl iodide (136 ml) was added to a suspension of 4,6-dihydroxy-2-mercaptopyrimidine (200 g) in water (800 ml), containing sodium hydroxide (55.6 g). The reaction mixture was stirred for 2 weeks then concentrated to half volume, 2N hydrochloric acid added and the product isolated by filtration (167 g). MS (EI): 186 (M + , 100%). b) 6-Hydroxy-5-nitro-2-(propylthio)-4(1H)-pyrimidinone The product of step a) (70 g) was added slowly to ice-cooled fuming nitric acid (323 ml). The reaction mixture was stirred for 1 hour then poured onto ice and the product isolated by filtration (65 g). MS (EI): 231 (M + ), 41 (100%). c) 4,6-Dichloro-5-nitro-2-(propylthio)pyrimidine N,N-Dimethylaniline (150 ml) was added dropwise to a stirred suspension of the product of step b) (134 g) in phosphoryl chloride (500 ml) and the resulting solution heated at reflux for 1 hour. The cooled reaction mixture was poured onto ice then extracted with diethyl ether (3×500 ml). The combined extracts were dried and concentrated. Chromatography (SiO 2 , isohexane:diethyl ether, 19:1 as eluant) gave the subtitle compound (128 g). MS (EI):271, 269, 267 (M + ), 41 (100%). d) 3aS-(3aα,4β,7βaα)5- 6-Chloro-5-nitro-2-(propylthio)-pyrimidin-4-yl!-tetrahydro-2,2-dimethyl-4,7-methano-1,3-dioxolo 4,5-c!pyridin-6(3aH)-one Sodium hydride (60%, 4.00 g) was added portionwise to 3aS-(3aα,4β,7β,7aα! tetrahydro-2,2-dimethyl-4,7-methano-1,3-dioxolo 4,5-c!pyridin-6(3aH)-one (18.3 g) in THF (500 ml). On stirring for 1 hr the solution was added dropwise to the product of step c) (54.0 g) in THF (500 ml). The reaction mixture was stirred at r.t for 45 minutes then concentrated and purified by chromatography (SiO 2 , dichloromethane:isohexane, 3:2 as eluant) to afford the subtitle compound (79.2 g). MS (APCI) 417, 415 (M+H + ), 415 (100%). e) 3aS-(3aα,4β,7β,7aα)! 5- 5-Amino-6-chloro-2-(propylthio)-pyrimidin-4-yl!-tetrahydro-2,2-dimethyl-4,7-methano-1,3-dioxolo 4,5-c!pyridin-6(3aH)-one Reduced iron powder (50 g) was added to a solution of the product of step d) (50.0 g) in glacial acetic acid (1.8 L) and the reaction mixture heated at reflux for 15 minutes. The cooled reaction mixture was concentrated and the residue taken into ether (2 L) then washed with sodium bicarbonate solution (2×1L). The organic phase was dried and concentrated to afford the sub-title compound (42.6 g). MS (APCI) 387, 385 (M+H + ), 385 (100%). f) 3aR-(3aα,4α,6α,6aα)-6- 5-Amino-6-chloro-2-(propylthio)-4-pyrimidinylamino!-tetrahydro-2,2-dimethyl-4H-cyclopenta-1,3-dioxole-4-methanol Sodium borohydride (8.37 g) was added to an ice-cooled solution of the product of step e) (42.6 g) in methanol (1.3L). After stirring for 1 hour the solution was poured into water (2L) and extracted with diethyl ether (2×1L). The combined extracts were dried and concentrated. Purification (SiO 2 , dichloromethane:ethyl acetate, 1:1 as eluant) gave the subtitle compound (36.1 g). MS (APCI) 419, 417 (M+H + ), 417 (100%). g) 3aR-(3aα,4α,6α,6aα)!-6- 7-Chloro-5-(propylthio)-3H-1,2,3-triazolo 4,5-d!pyrimidin-3-yl!-tetrahydro-2,2-dimethyl-4H-cyclopenta-1,3-dioxole-4-methanol Isoamyl nitrite (24.9 ml) was added to a solution of the product of step f) (36.0 g) in acetonitrile (80 ml) and the solution heated at 70° for 1 hour. The cooled reaction mixture was concentrated and purified (SiO 2 , dichloromethane:ethyl acetate, 4:1 as eluant) to afford the subtitle compound (33.6 g). MS (EI) 401, 399 (M+H + ), 43 (100%). h) 3aR-(3aα,4α,6α,6aα)!-6-!7-(Butylamino)-5-(propylthio)-3H-1,2,3-triazolo!4,5-d!pyrimidin-3-yl!-tetrahydro-2,2-dimethyl-4H-cyclopenta-1,3-dioxole-4-methanol The product from step g) (16.75 g) and n-butylamine (30 ml) in 1,4-dioxane (500 ml) were heated under reflux for 1 h. The reaction mixture was concentrated and the residue purified (SiO 2 , dichloromethane:ethyl acetate, 4:1 as eluant) to afford the subtitle compound (17.8 g). MS (APCI) 437 (M+H + , 100%). i) 3aR-(3aα,4α(E),6α,6aα)!-3- 6- 7-(Butylamino)-5-(propylthio)-3H-1,2,3-triazolo 4,5-d!pyrimidin-3-yl!-tetrahydro-2,2-dimethyl-4H-cyclopenta-1,3-dioxol-4-yl!-2-propenoic acid, 1,1-dimethylethyl ester A stirred solution of the product of step h) (0.5 g), pyridine (0.093 ml) and trifluoroacetic acid (0.048 ml) in DMSO (25 ml) was treated with 1,3-dicyclohexylcarbodiimide (0.72 g) and the mixture stirred at room temperature for 24 hours. (t-Butoxycarbonylmethylene)triphenylphosphorane (0.69 g) was added and the reaction stirred for a further 18 hours. The reaction mixture was cooled to 0°, diluted with ethyl acetate (100 ml) and oxalic acid (0.51 g) added. After 30 min the mixture was filtered and the filtrate washed with saturated sodium bicarbonate solution (100 ml), dried and concentrated. Chromatography (SiO 2 , hexane:ethyl acetate, 5:1 as eluant) gave the subtitle compound (0.55 g). MS (FAB): 533 (M+H + , 100%). j) 1R-(1α(E),2β,3β,4α)-3- 4- 7-(Butylamino)-5-(propylthio)-3H-1,2,3-triazolo 4,5-d!pyrimidin-3-yl!-2,3-dihydroxycyclopentyl!-2-propenoic acid, sodium salt A solution of the product from step i) (0.8 g) in 50% aqueous trifluoroacetic acid (100 ml) was stirred at room temperature for 5 hours. The reaction mixture was concentrated and the product recrystallised from ethyl acetate (30 ml). The free acid was taken into methanol:water (2:3, 30 ml) and applied to a Dowex 50×100 ion exchange resin (sodium form), eluting with water. Lyophilisation gave the title salt as a colourless solid (0.43 g). NMR δH (d 6 -DMSO): 6.59 (1H, dd), 5.89 (1H, d), 4.94 (1H, m), 4.45 (1H, t), 4.12 (1H, t), 3.45 (2H, m), 2.83 (3H, m), 2.47 (1H, m), 2.00 (1H, m), 1.5 (4H, m), 1.20 (2H, m), 082 (3H, t), 0.71 (3H, t). Example 2 1R-(1α(E),2β,3β,4α)!-N- 3- 4- 7-(Butylamino)-5-(propylthio)-3H-1,2,3-triazolo 4,5-d!pyrimidin-3-yl!-2,3-dihydroxycyclopentyl!-2-propenoyl!-L-aspartic acid, disodium salt a) 1R-(1α(E),2β,3β,4α)-N- 3- 4- 7-(Butylamino)-5-(propylthio)-3H-1,2,3-triazolo 4,5-d!pyrimidin-3-yl!-2,3-dihydroxycyclopentyl!-2-propenoyl!-L-aspartic acid, bis(1,1-dimethylethyl) ester L-Aspartic acid di-tertiary butyl ester hydrochloride (0.46 g) and triethylamine (0.23 ml) were added to a solution of the compound of Example 1 (0.6 g) in DMF (25 ml). 1-Hydroxybenzotriazole (0.22 g) was added and the solution cooled in an ice-bath before adding 1,3-dicyclohexylcarbodiimide (0.34 g). The reaction mixture was stirred at 0° for 30 min then at room temperature for 3 days. After removing the solvent, chromatography (SiO 2 , chloroform:methanol, 40:1 as eluant) gave the subtitle compound (0.63 g). MS (FAB): 664 (M+H + ), 57 (100%). b) 1R-(1α(E),2β,3β,4α)-N- 3- 4- 7-(Butylamino)-5-(propylthio)-3H-1,2,3-triazolo 4,5-d!pyrimidin-3-yl!-2,3-dihydroxycyclopentyl!-2-propenoyl!-L-aspartic acid, disodium salt A solution of the product of step a) (0.60 g) in dichloromethane (30 ml) containing trifluoroacetic acid (30 ml) was stirred at room temperature for 2 hours. The solution was concentrated and the residue purified (HPLC Nova-Pak® C18 column, 0.1% aqueous ammonium acetate:methanol 50:50 to 0:100 over 15 mins as eluant) to give the title salt as a colourless solid (0.19 g). NMR δH (d 6 -DMSO): 6.74 (1H, dd), 6.12 (1H, d), 5.07 (1H, m), 4.38 (1H, m), 4.05 (1H, t), 3.95 (2H, m), 3.12 (2H, t), 2.85 (1H, m), 2.49 (1H, m), 2,30-2.45 (2H, m), 2.0 (1H, m), 1.75 (2H, m), 1.52 (2H, m), 1.47 (2H, m), 1.0 (3H, t), 0.98 (3H, t). Example 3 1S-(1α,2β,3β,4α)-4- 7-(Butylamino)-5-(propylthio)-3H-1,2,3-triazolo- 4,5-d!pyrimidin-3-yl!-2,3-dihydroxy-cyclopentanepropanoic acid, sodium salt a) 1S-(1α(E),2β,3β,4α)!-3- 4- 7-(Butylamino)-5-(propylthio)-3H-1,2,3-triazolo 4,5-d!pyrimidin-3-yl!-2,3-dihydroxycyclopentyl!-2-propenoic acid, ethyl ester A stirred solution of the product of Example 1h) (0.6 g), pyridine (0.112 ml) and trifluoroacetic acid (0.058 ml) in DMSO (25 ml) was treated with 1,3-dicyclohexylcarbodimide (0.87 g) and the mixture stirred at room temperature for 24 hours. (Carbethoxymethylene)triphenylphosphorane (0.90 g) was added and the reaction stirred for a further 18 hours. The reaction mixture was cooled to 0°, diluted with ethyl acetate (100 ml) and oxalic acid (0.51 g) added. After 30 min the mixture was filtered and the filtrate washed with saturated sodium bicarbonate solution (100 ml), dried and concentrated. The residue was taken into dichloromethane (50 ml)/trifluoroacetic acid (50 ml) and stirred overnight. The solvent was removed and the residue purified by chromatography (SiO 2 , dichloromethane:ethyl acetate, 1:1 as eluant) to give the subtitle compound (0.36 g). MS (FAB): 465 (M+H + , 100%). b) 1S-(1α,2β,3β,4α)!-4- 7-(Butylamino)-5-(propylthio)-3H-1,2,3-triazolo- 4,5-d!pyrimidin-3-yl!-2,3-dihydroxy-cyclopentanepropanoic acid, ethyl ester 2,4,6-Triisopropylbenzenesulfonohydrazide (0.50 g) was added to a solution of the product of step a) (0.35 g) in dry THF (175 ml) and the resulting solution heated at 70° for 3 hours. The cooled reaction mixture was purified by chromatography (SiO 2 , dichloromethane:ethyl acetate, 1:1 as eluant) to give the subtitle compound (0.16 g). MS (EI): 466 (M + ), 43 (100%). c) 1S-(1α,2β,3β,4α)!-4- 7-(Butylamino)-5-(propylthio)-3H-1,2,3-triazolo- 4.5-d!pyrimidin-3-yl!-2,3-dihydroxy-cyclopentanepropanoic acid, sodium salt Lithium hydroxide monohydrate (14 mg) was added to a solution of the product of step b) (0.16 g) in THF (10 ml)/water (10 ml). The solution was stirred at room temperature for 18 hours before removing the solvent in vacuo. Purification (HPLC Nova-Pak® C.18 column, 0.1% aqueous ammonium acetate:methanol 50:50 to 0:100 over 15 mins as eluant) gave the title acid which was taken into methanol (2 ml) and 1N sodium hydroxide solution (0.28 ml) added. The solution was concentrated to give the title salt (0.13 g). MS (ESI): 439 (M-Na+H + , 100%). NMR δH (D 2 O) 5.07 (1H, m), 4.65 (1H, t), 4.08 (1H, t), 3.49 (2H, t), 3.05 (2H, m), 2.62 (1H, m), 2,36 (2H, m), 2.17 (1H, m), 2.00 (1H, m), 1.70 (2H, m), 1.65 (2H, m), 1.61 (2H, m), 1.40 (2H, m), 1.00 (3H, t), 0.97 (3H, t). Example 4 1R-(1α(E),2β,3β,4α)!-3- 4- 7-(Butylamino)-5-(pentylthio)-3H-1,2,3-triazolo 4,5-d!pyrimidin-3-yl!-2,3-dihydroxycyclopentyl!-2-propenoic acid, sodium salt a) 2-(Pentylthio)-4,6(1H,5H)-pyrimidinedione To a solution of 4,6-dihydroxy-2-mercaptopyrimidine (14.4 g) in 2N sodium hydroxide solution (100 ml) was added pentyl iodide (15.6 ml) in ethanol (25 ml) and the resulting reaction mixture stirred at room temperature for four days. The ethanol was removed at reduced pressure and N,N-dimethylformamide (80 ml) and pentyl iodide (1.56 ml) added then the reaction mixture stirred for an additional 16 hours. The solution was made acidic by addition of 2N HCl solution and the aqueous layer decanted. The remaining gum was dissolved in methanol and evaporated to dryness then azeotroped with toluene (×2). The solid was triturated with ether, filtered and dried to give the subtitle compound as a white solid (11.9 g). MS (EI) 214 (M + ), 144 (100%). b) 6-Hydroxy-5-nitro-2-(pentylthio)-4(1H)-pyrimidinone Prepared according to the method of Example 1b) using the product of step a). MS (EI): 259 (M + ), 43 (100%). c) 4,6-Dichloro-5-nitro-2-(pentylthio)-pyrimidine Prepared according to the method of Example 1c) using the product of step b). MS (FAB): 295, 297, 299 (M+H + ), 41 (100%). d) 3aS-(3aα,4β,7β,7aα)! 5- 6-Chloro-5-nitro-2-(pentylthio)-pyrimidin-4-yl-tetrahydro-2,2-dimethyl-4,7-methano-1,3-dioxolo 4,5-c!pyridin-6(3aH)-one Prepared according to the method of Example 1d) using the product of step c). MS (FAB): 445, 443 (M+H + ), 443 (100%). e) 3aS-(3aα,4β,7β,7aα)! 5-Amino-6-chloro-2-(pentylthio)-pyrimidin-4-yl!-tetrahydro-2,2-dimethyl-4,7-methano-1,3-dioxolo 4,5-c!pyridin-6(3aH)-one Prepared according to the method of Example 1e) using the product of step d). MS (EI): 414, 412 (M + ), 412 (100%). f) 3aR-(3aα,4α,6α,6aα)-6- 5-Amino-6-chloro-2-(pentylthio)-4-pyrimidinylamino!-tetrahydro-2,2-dimethyl-4H-cyclopenta-1,3-dioxole-4-methanol Prepared according to the method of Example 1f) using the product of step e). MS (EI): 418, 416 (M + ), 327 (100%). g) 3aR-(3aα,4α,6α,6aα)!-6- 7-Chloro-5-(pentylthio)-3H-1,2,3-triazolo- 4,5-d!pyrimidin-3-yl!-tetrahydro-2,2-dimethyl-4H-cyclopenta-1,3-dioxole-4-methanol Prepared according to the method of Example 1g) using the product of step f). MS (APCI): 430, 428 (M+H + ), 338 (100%). h) 3aR-(3α,4α,6α,6aα)!-6- 7-(Butylamino)-5-(pentylthio)-3H-1,2,3-triazolo- 4,5-d!pyrimidin-3-yl!-tetrahydro-2,2-dimethyl-4H-cyclopenta-1,3-dioxole-4-methanol Prepared according to the method of Example 1h) using the product of step g). MS (FAB): 465 (M+H + , 100%). i) 3aR-(3aα,4α(E),6α,6aα)!-3- 6-7-(Butylamino)-5-(pentylthio)-3H-1,2,3-triazolo 4,5-d!pyrimidin-3-yl!-tetrahydro-2,2-dimethyl-4H-cyclopenta-1,3-dioxol-4-yl!-2-propenoic acid, 1,1-dimethylethyl ester Prepared according to the method of Example 1i) using the product of step h). MS (FAB): 561 (M+H + ), 505 (100%). j) 1R-(1α(E),2β,3β,4α)!-3- 4- 7-(Butylamino)-5-(pentylthio)-3H-1,2,3-triazolo 4,5-d!pyrimidin-3-yl!-2,3-dihydroxycyclopentyl!-2-propenoic acid, sodium salt Prepared according to the method of Example 1j) using the product of step i). MS (FAB): 487 (M+Na+H + ), 465 (100%). NMR δH (d 6 -DMSO) 9.00 (1H, t), 6.43 (1H, dd), 5.70 (1H, d), 4.97 (1H, q), 4.32 (1H, t), 3.87 (1H, t), 3.50-3.47 (2H, m), 3.12-3.04 (2H, m), 2.68 (1H, m), 2.38-2.34 (1H, m), 1.93-1.89 (1H, m), 1.64 (2H, m), 1.62 (2H, m), 1.37-1.30 (6H, m)0.91 (3H, t) 0.87 (3H, t). Example 5 The following compound was prepared according to the method of Example 4: 1R-(1α(E),2β,3β,4α)!-3- 4- 7-(Ethylamino)-5-(pentylthio)-3H-1,2,3-triazolo 4,5-d!pyrimidin-3-yl!-2,3-dihydroxycyclopentyl!-2-propenoic acid, sodium salt a) 3aR-(3aα,4α,6α,6aα)!-6- 7-(Ethylamino)-5-(pentylthio)-3H-1,2,3-triazolo- 4,5-d!pyrimidin-3-yl!-tetrahydro-2,2-dimethyl-4H-cyclopenta-1,3-dioxole-4-methanol MS (FAB): 437 (M+H + , 100%). b) 3aR-(3aα,4α(E),6α,6aα)!-3- 6- 7-(Ethylamino)-5-(pentylthio)-3H-1,2,3-triazolo 4,5-d!pyrimidin-3-yl!-tetrahydro-2,2-dimethyl-4H-cyclopenta-1,3-dioxol-4-yl!-2-propenoic acid, 1,1-dimethylethyl ester MS (FAB): 533 (M+H) + , 477 (100%). c) 1R-(1α(E),2β,3β,4aα)!-3- 4- 7-(Ethylamino)-5-(pentylthio-3H-1,2,3-triazolo 4,5-d!pyrimidin-3-yl!-2,3-dihydroxycyclopentyl!-2-propenoic acid, sodium salt MS (FAB): 459 (M+Na+H + ), 437 (100%). NMR δH (d 6 -DMSO) 8.99 (1H, t), 6.55 (1H, dd), 5.76 (1H, d), 4.98 (1H, q), 4.32 (1H, t), 3.90 (1H, t), 3.81-3.50 (2H, m), 3.16-3.08 (2H, m), 2.74-2.70 (1H, m), 2.46-2.37 (1H, m), 1.98-1.89 (1H, m), 1.71-1.67 (2H, m), 1.37-1.24 (4H, m), 1.19 (3H, t), 0.86 (3H, t,). Example 6 1S-(1α,2β,3β,4α)-4- 7-(Butylamino)-5-(pentylthio)-3H-1,2,3-triazolo 4,5-d!pyrimidin-3-yl!-2,3-dihydroxy-cyclopentanepropanoic acid, sodium salt Prepared according to the method of Example 3b) using the product of Example 4. MS (APCI): 467 (M+H + ), 295 (100%). NMR δH (d 6 -DMSO) 8.97 (1H, t), 4.93-4.86 (1H, m), 4.32 (1H, t), 3.88 (1H, t), 3.49-3.45 (2H, m), 3.07-3.05 (2H, m), 2.28-2.08 (1H, m), 2.01-1.92 (3H, m), 1.74-1.55 (7H, m), 1.37-1.33 (6H, m), 0.90 (3H, t), 0.86 (3H, t). Example 7 1S-(1α,2β,3β,4α)-4- 7-(Ethylamino)-5-(pentylthio)-3H-1,2,3-triazolo 4,5-d!pyrimidin-3-yl!-2,3-dihydroxy-cyclopentanepropanoic acid, sodium salt Prepared according to the method of Example 3b) using the product of Example 5. MS (FAB): 461 (M+Na+H + ), 154 (100%). NMR δH (d 6 -DMSO) 8.96 (1H, t), 4.91 (1H, q), 4.33 (1H, t), 3.75 (1H, t), 3.51 (2H, m) 3.08-3.06 (2H, m), 2,30-2.24 (1H, m), 2.06-1.93 (3H, m), 1.75-1.55 (5H, m), 1.37-1.09 (4H, m), 1.15 (3H, t), 0.87 (3H, t). Example 8 1R-(1α,2α,3α,5β)!3- 7-(Butylamino)-5-(propylthio)-3H-1,2,3-triazolo- 4,5-d!pyrimidin-3-yl!-5- 2-(1H-tetrazol-5-yl)ethyl!-1,2-cyclopentanediol a) 3aR-(3aα,4α(E),6α,6aα)!-3- 6- 7-(Butylamino)-5-(propylthio)-3H-1,2,3-triazolo 4,5-d!pyrimidin-3-yl!-2,2-dimethyl-tetrahydro-4H-cyclopenta-1,3-dioxole-4-yl!-2-propenonitrile Prepared according to the method of Example 1i) using the product of Example 1h) and (triphenylphosphoranylidene)acetonitrile. MS (EI): 457 (M + ), 414 (100%). b) 3aR-(3aα,4α,6α,6aα)!-3- 6- 7-(Butylamino)-5-(propylthio)-3H-1,2,3-triazolo 4,5-d!pyrimidin-3-yl!-2,2-dimethyl-tetrahydro-4H-cyclopenta-1,3-dioxole-4-yl!-propanenitrile The product of step a) (0.75 g) in ethanol (300 ml) containing 10% palladium on carbon (0.37 g) was stirred under 4 atmospheres of hydrogen for 48 hours. The catalyst was removed by filtration and the filtrate concentrated to afford the subtitle compound (0.34 g). MS (FAB): 460 (M+H + , 100%). c) 3aS-(3aα,4α,6α,6aα)!-N-Butyl-5-(propylthio)-3- 6- 2-(1H-tetrazol-5-yl)ethyl!-tetrahydro-2,2-dimethyl-4H-cyclopenta-1,3-dioxol-4-yl!-3H-1,2,3-triazolo 4,5-d!-pyrimidin-7-amine The product of step b) (0.40 g) and tributyltin azide (0.70 g) in toluene was heated at reflux for 48 hours then concentrated. Purification by chromatography (SiO 2 , dichloromethane:methanol, 95:5 as eluant) gave the subtitle compound (0.19 g). MS (FAB): 503 (M+H + , 100%). d) 1R-(1α,2α,3β,5β)-3- 7-(Butylamino)-5-(propylthio)-3H-1,2,3-triazol- 4,5-d!pyrimidin-3-yl!-5- 2-(1H-tetrazol-5-yl)ethyl!-1,2-cyclopentanediol Prepared according to the method of Example 1j) using the product of step c). MS (FAB): 463 (M+H + , 100%). NMR δH (d 6 -DMSO) 8.64 (1H, t), 5.11 (1H, m), 4.96 (1H, m), 4.85 (1H, m), 4.38 (1H, m), 3.83 (1H, m), 3.50 (2H, m), 3.07 (2H, m), 2.97 (2H, m), 2.41 (1H, m), 2.00 (2H, m), 1.80 (2H, m), 1.69 (2H, m), 1.61 (2H, m), 1.35 (2H, m), 0.97 (3H, m), 0.91 (3H, t). Example 9 1R-(1α,2β,3β,4β)!-N- 3- 4- 7-(Butylamino)-5-(propylthio)-3H-1,2,3-triazolo 4,5-d!pyrimidin-3-yl!-2,3-dihydroxycyclopentyl!propanoyl!-L-aspartic acid a) 1R-(1α,2β,3β,4α)-N- 3- 4- 7-(Butylamino)-5-(propylthio)-3H-1,2,3-triazolo 4,5-d!pyrimidin-3-yl!-2,3-dihydroxycyclopentyl!propanoyl!-L-aspartic acid, bis(1,1-dimethylethyl) ester N,N-Diisopropylethylamine (0.35 ml) was added to a solution of L-aspartic acid di-tertiary butyl ester, hydrochloride (0.28 g), bromo-tris-pyrrolidino-phosphonium hexafluorophosphate (0.44 g) and the product of Example 3 (0.44 g) in DMF (20 ml). The reaction mixture was stirred at room temperature for 1 hr then concentrated. Chromatography (SiO 2 , ethyl acetate as eluant) gave the sub-title compound (0.49 g). MS (APCI) 666 (M+H + , 100%). b) 1R-(1α,2β,3β,4α)!-N- 3- 4- 7-(Butylamino)-5-(propylthio)-3H-1,2,3-triazolo 4,5-d!pyrimidin-3-yl!-2,3-dihydroxycyclopentyl!propanoyl!-L-aspartic acid Prepared according to the method of example 2b) using the product of step a). NMR δH (d 6 -DMSO) 9.03 (1H, brs), 7.79 (1H, d), 4.92 (1H, m), 4.35 (1H, m), 4.19 (1H, t), 3.75 (2H, m), 3.49 (2H, t), 3.08 (2H, m), 2.43 (1H, m), 2.32 (1H, m), 2.18 (3H, m), 1.91 (1H, m), 1.73 (3H, m), 1.58 (2H, m), 1.34 (2H, m), 1.00 (3H, t), 0.98 (3H, t). Example 10 1R-(1α(E),2β,3β,4α)-N- 3- 4- 7-(Hexylamino)-5-(propylthio)-3H-1,2,3-triazolo 4,5-d!pyrimidin-3-yl!-2,3-dihydroxycyclopentyl!-2-propenoyl!-L-aspartic acid a) 3aR-(3aα,4α,6α,6aα)-6- 7-(Hexylamino)-5-(propylthio)-3H-1,2,3-triazolo 4,5-d!pyrimidin-3-yl!-tetrahydro-2,2-dimethyl-4H-cyclopenta-1.3-dioxole-4-methanol Sodium borohydride (1.16 g) was added to an ice-cooled solution of the product of step 1e) (5.90 g) in methanol (200 ml). After stirring for 1 hour the solution was concentrated and the residue purified by chromatography (SiO 2 , diethyl ether as eluant). The resulting intermediate was taken into acetonitrile (300 ml) and isoamyl nitrite (2.8 ml) added. The reaction mixture was stirred at 60° for 30 minutes then concentrated and the residue taken into 1,4-dioxane (300 ml). Hexylamine (20 ml) was added and the reaction mixture stirred at room temperature for 2 hours. The reaction mixture was concentrated and the residue purified (SiO 2 , diethyl ether as eluant) to afford the subtitle compound (4.69 g). MS (APCI) 465 (M+H + , 100%). b) 1R-(1α(E),2β,3β,4α)!-3- 4- 7-(Hexylamino)-5-(propylthio)-3H-1,2,3-triazolo 4,5-d!pyrimidin-3-yl!-2,3-dihydroxycyclopentyl!-2-propenoic acid Prepared by the method of example 1i) followed by the method of example 1j), using the product of step a). NMR δH (D 2 O) 9.03 (1H, t), 6.96 (1H, dd), 5.89 (1H, d), 5.31 (1H, s), 5.10 (1H, s), 5.00 (1H, m), 4.29 (1H, t), 4.02 (1H, t), 3.49 (2H, m), 3.01 (2H, m), 2.83 (2H, m), 2.49 (1H, m), 2.01 (1H, m), 1.72 (2H, m), 1.65 (2H, m), 1.29 (6H, m), 0.98 (3H, t), 0.86 (3H, t). c) 1R-(1α(E),2β,3β,4α)!-N- 3- 4- 7-(Hexylamino)-5-(propylthio-3H-1,2,3-triazol 4,5-d!pyrimidin-3-yl!-2,3-dihydroxycyclopentyl!-2-propenoyl!-L-aspartic acid, bis(1,1-dimethylethyl) ester Prepared according to the method of example 9a) using the product of step b). MS (APCI) 692 (M+H + , 100%). d) 1R-(1α(E),2β,3β,4α)-N- 3- 4- 7-(Hexylamino)-5-(propylthio)-3H-1,2,3-triazolo 4,5-d!pyrimidin-3-yl!-2,3-dihydroxycyclopentyl!-2-propenoyl!-L-aspartic acid Prepared according to the method of example 2b) using the product of step c). NMR δH (d 6 -DMSO) 7.94 (1H, d), 7.23-7.11 (1H, s), 6.75 (1H, dd), 6.17 (1H, d), 5.19 (1H, s), 5.08 (1H, s), 5.00 (1H, m), 4.31 (2H, m), 3.96 (1H, m), 3.62 (2H, m), 3.07 (2H, m), 2.81 (1H, m), 2.49-2.31 (3H, m), 2.01 (1H, m), 1.67 (2H, m), 1.61 (2H, m), 1.31 (6H, m), 0.96 (3H, t), 0.85 (3H, t). Example 11 The following compounds were prepared according to the method of example 1. a) 1R-(1α(E),2β,3β,4α)!-3- 4- 7-(3,3-Dimethylbutylamino)-5-(propylthio)-3H-1,2,3-triazolo 4,5-d!pyrimidin-3-yl!-2,3-dihydroxycyclopentyl!-2-propenoic acid i) 3aR-(3aα,4α,6α,6aα)!-6- 7-(3,3-Dimethylbutylamino)-5-(propylthio)-3H-1,2,3-triazolo 4,5-d!pyrimidin-3-yl!-tetrahydro-2,2-dimethyl-4H-cyclopenta-1,3-dioxole-4-methanol MS (APCI) 465 (M+H + , 100%). ii) 3aR-(3aα,4α(E),6α,6aα)!-3- 6- 7-(3,3-Dimethylbutylamino)-5-(propylthio)-3H-1,2,3-triazolo 4,5-d!pyrimidin-3-yl!-tetrahydro-2,2-dimethyl-4H-cyclopenta-1,3-dioxol-4-yl !-2-propenoic acid, 1,1-dimethylethyl ester MS (APCI) 561 (M+H + , 100%). iii) 1R-(1α(E),2β,3β,4α)!-3- 4- 7-(3,3-Dimethylbutylamino)-5-(propylthio)-3H-1,2,3-triazolo 4,5-d!pyrimidin-3-yl!-2,3-dihydroxycyclopentyl!-2-propenoic acid NMR δH (d 6 -DMSO) 8.59 (1H, t), 6.84 (1H, dd), 5.84 (1H, d), 5.03-4.96 (1H, m), 3.98 (1H, m), 3.52 (2H, m), 3.07 (2H, m), 2.81 (1H, m), 2.43 (1H, m), 1.97 (1H, m), 175 (2H, m), 1.55 (2H, m), 0.99 (3H, t), 0.95 (9H, s). b) 1R-(1α(E),2β,3β,4α)!-3- 4- 7-(2-Methoxy)ethylamino)-5-(propylthio)-3H-1,2,3-triazolo 4,5-d!pyrimidin-3-yl!-2,3-dihydroxycyclopentyl!-2-propenoic acid i) 3aR-(3aα,4α,6α,6aα)!-6- 7-(2-Methoxy)ethylamino)-5-(propylthio)-3H-1,2,3-triazolo 4,5-d!pyrimidin-3-yl!-tetrahydro-2,2-dimethyl-4H-cyclopenta-1,3-dioxole-4-methanol MS (FAB) 439 (M+H + , 100%). ii) 3aR-(3aα,4α(E),6α,6aα)-3- 6- 7-(2-Methoxy)ethylamino)-5-(propylthio)-3H-1,2,3-triazolo 4,5-d!pyrimidin-3-yl!-tetrahydro-2,2-dimethyl-4H-cyclopenta-1,3-dioxol-4-yl!-2-propenoic acid, 1,1-dimethylethyl ester MS (FAB) 535 (M+H + , 100%). iii) 1R-(1αa(E),2β,3β,4α)!-3- 4- 7-(2-Methoxy)ethylamino)-5-(propylthio)-3H-1,2,3-triazolo 4,5-d!pyrimidin-3-yl!-2,3-dihydroxycyclopentyl!-2-propenoic acid MS (FAB) 439 (M+H + , 100%). Example 12 1R-(1α,2β,3β,4α)-N- 3- 4- 7-(Hexylamino)-5-(propylthio)-3H-1,2,3-triazolo 4,5-d!pyrimidin-3-yl!-2,3-dihydroxycyclopentylpropanoyl!-L-aspartic acid a) 1R- 1α,2β,3β,4α!!-4- 7-(Hexylamino)-5-(propylthio)-3H-1,2,3-triazolo 4,5-d!pyrimidin-3-yl!-2,3-dihydroxycyclopentanepropanoic acid Prepared according to the method of example 3b) using the product of step 10b). MS (APCI) 467 (M+H + , 100%). b) 1R-(1α,2β,3β,4α)!-N- 3- 4- 7-(Hexylamino)-5-(propylthio)-3H-1,2,3-triazolo 4,5-d!pyrimidin-3-yl!-2,3-dihydroxycyclopentylpropanoyl!-L-aspartic acid, bis(1,1-dimethylethyl) ester Prepared according to the method of example 9a) using the product of step a). MS (APCI) 694 (M+H + , 100%). c) 1R-(1α,2β,3β,4α)!-N- 3- 4- 7-(Hexylamino)-5-(propylthio)-3H-1,2,3-triazolo 4,5-d!pyrimidin-3-yl!-2,3-dihydroxycyclopentylpropanoyl!-L-aspartic acid Prepared according to the method of example 2b) using the product of step b). NMR δH (d 6 -DMSO) 8.90 (1H, brs), 7.61 (1H, d), 4.97 (1H, m), 4.36 (1H, t), 4.21 (1H, m), 3.47 (2H, m), 3.77 (1H, m), 3.07 (2H, t), 2.51 (2H, m), 2,28 (1H, m), 2.20 (2H, m), 1.93 (1H, m), 1.77 (1H, m), 1.62 (3H, m), 1.59 (3H, m), 1.33 (6H, m), 1.00 (3H, t), 0.88 (3H, t). Example 13 1R-(1α(E),2β,3β,4α)-N- 3- 4- 5- (3,3,3-Trifluoropropyl)thio!-7- 2-(methylthio)ethylamino!-3H-1,2,3-triazolo 4,5-d!pyrimidin-3-yl!-2,3-dihydroxycyclopentyl!-2-propenoyl!-L-aspartic acid, monoammonium salt a) 2- (3,3,3-Trifluoropropylthio!-4,6(1H,5H)-pyrimidinedione Prepared according to the method of example 1a). MS (APCI, negative ionization) 239 (M-H + ), 143 (100%). b) 2- (3,3,3-Trifluoropropyl)thio!-6-hydroxy-5-nitro-4(1H)-pyrimidinone Prepared according to the method of example 1b) using the product of step a). MS (APCI, negative ionization) 284 (M-H + , 100%). c) 4,6-Dichloro-2- (3,3,3-trifluoropropyl)thio!-5-nitro-pyrimidine Prepared according to the method of example 1c) using the product of step b). NMR δH (CDCl 3 ) 3.30 (2H, m), 2.60 (2H, m) d) 3aS-(3aα,4β,7β,7α)!5- 6-Chloro-2- (3,3,3-trifluoropropyl)thio!-5-nitro-pyrimidin-4-yl!-tetrahydro-2,2-dimethyl-4,7-methano-1,3-dioxolo 4,5-c!pyridin-6(3aH)-one Prepared according to the method of example 1d) using the product of step c). NMR δH (CDCl 3 ) 4.77 (1H, s), 4.73 (1H, d), 4.56 (1H, d), 3.33 (2H, m), 3.05 (1H, s), 2.58 (2H, m), 2.33 (1H, d), 2.20 (1H, t), 1.53 (3H, s), 1.36 (3H, s) e) 3aS-(3aα,4β,7β,7aα)!5- 5-Amino-6-chloro-2- 3,3,3-trifluoropropyl)thio!pyrimidin-4-yl!-tetrahydro-2,2-dimethyl-4,7-methano-1,3-dioxolo 4,5-c!pyridin-6(3aH)-one Prepared according to the method of example 1e) using the product of step d). MS (APCI) 439 (M+H + , 100%). f) 3aR-(3aα,4α,6α,6aα)!-6- 5-Amino-6-chloro-2- (3,3,3-trifluoropropyl)thio!-4-pyrimidinyl!amino!-tetrahydro-2,2-dimethyl-4H-cyclopenta-1,3-dioxole-4-methanol Prepared according to the method of example 1f) using the product of step e). MS (APCI) 443 (M+H + , 100%). g) 3aR-(3aα,4α,6α,6aα)!-6- 5- (3,3,3-Trifluoropropyl)thio!-7- 2-(methylthio)ethylamino!-3H-1,2,3-triazolo 4,5-d!pyrimidin-3-yl!-tetrahydro-2,2-dimethyl-4H-cyclopenta-1,3-dioxole-4-methanol Prepared according to the method of example 1g), followed by the method of example 1h) using the product of step f). MS (APCI) 509 (M+H + , 100%). h) 3aR-(3aα,4α(E),6α,6aα)!-3- 6- 5- (3,3,3-Trifluoropropyl)thio!-7- 2-(methylthio)ethylamino!-3H-1,2,3-triazolo 4,5-d!pyrimidin-3-yl!-tetrahydro-2,2-dimethyl-4H-cyclopenta-1,3-dioxol-4-yl!-2-propenoic acid, 1,1-dimethylethyl ester Prepared according to the method of example 1i) using the product of step g). MS (APCI) 605 (M+H + ), 549 (100%). i) 1R-(1α(E),2β,3β,4α)!-3- 4- 5- (3,3,3-Trifluoropropyl)thiol-7- 2-(methylthio)ethylamino!-3H-1,2,3-triazolo 4,5-d!pyrimidin-3-yl!-2,3-dihydroxycyclopentyl!-2-propenoic acid Prepared according to the method of example 1j) using the product of step h). MS (APCI) 509 (M+H + , 100%). j) 1R-(1α(E),2,3β,4α)!-N- 3- 4- 5- (3,3,3-Trifluoropropyl)thio-7- 2(methylthio)ethylamino!-3H-1,2,3-triazolo 4,5-d!pyrimidin-3-yl!-2,3-dihydroxycyclopentyl!-2-propenoyl!-L-aspartic acid, bis(1,1-dimethylethyl) ester Prepared according to the method of example 9a) using the product of step i). MS (APCI) 736 (M+H + ), 624 (100%). k) 1R-(1α(E),2β,3β,4α)!-N- 3- 4- 5- (3,3,3-Trifluoropropyl)thio!-7- 2-(methylthio)ethylamino!-3H-1,2,3-triazolo 4,5-d!pyrimidin-3-yl!-2,3-dihydroxycyclopentyl!-2-propenoyl!-L-aspartic acid, monoammonium salt Prepared according to the method of example 2b) using the product of step j). NMR δH (d 6 -DMSO) 7.90 (1H, d), 6.76-6.68 (1H, dd), 6.15 (1H, d), 4.99 (1H, m), 4.30 (2H, m), 3.71 (2H, t), 3.30 (2H, m), 2.74 (5H, m), 2.50 (1H, m), 2.42 (2H, m) 2.11 (3H, s), 1.98 (1H, m). Example 14 (E)-1- 7-(Butylamino)-5-(propylthio)-3H-1,2,3-triazolo 4,5-d!pyrimidin-3-yl!-1,5,6-trideoxy-β-D-ribo-hept-5-enofuranuronic acid a) 2,6-Bis(propylthio)-4,5-pyrimidinediamine n-Propyl iodide (2.52 ml) was added to a stirred solution of 4,5-diamino-2,6-dimercaptopyrimidine (2.0 g) in 1N potassium hydroxide solution (26.4 ml). On stirring for 24 hours the solid was collected by filtration to give the subtitle compound as a pink solid (2,2 g). MS (EI): 258 (M + , 100%). b) 5,7-Bis(propylthio)-1H-1,2,3-triazolo 4,5-d!pyrimidine A solution of sodium nitrite (0.6 g) in water (7 ml) was added to a stirred suspension of the product of step a) (2.0 g) in acetic acid:water (1:1, 90 ml) at 50°. The reaction mixture was stirred at 50° for 1 hour and the solid collected by filtration to give the subtitle compound (1.71 g). MS (EI): 269 (M + ), 43 (100%). c) 5,7-Bis(propylthio)-3-(2,3,5-tri-O-benzoyl-β-D-ribo-furanosyl)-3H-1,2,3-triazolo 4,5-d!pyrimidine Hydrogen bromide gas was bubbled into an ice-cooled solution of 1-O-acetyl-2,3,5-tri-O-benzoyl-β-D-ribofuranose (2.02 g) in dichloromethane (15 ml) for 15 min. The reaction was stirred at 0° for 1 hour then at room temperature for 15 min. The solution was concentrated and the residue azeotroped with dichloromethane (3×50 ml). Sodium hydride (60%, 0.19 g) was added to a stirred suspension of the product of step b) (1.08 g) in acetonitrile (29 ml). After stirring at room temperature for 15 min the bromo sugar described above, in acetonitrile (10 ml), was added and stirring continued for 24 hours. The reaction mixture was partitioned between ethyl acetate and water, the organic layer was dried and concentrated. Chromatography (SiO 2 , dichloromethane:diethylether, 39:1, as eluant) gave a mixture of 5,7-bis(propylthio)-3-(2,3,5-tri-O-benzoyl-β-D-ribo-furanosyl)-3H-1,2,3-triazolo 4,5-d!pyrimidine MS (FAB): 714 (M+H + ), 105 (100%)! and 5,7-bis(propylthio)-2-(2,3,5-tri-O-benzoyl-β-D-ribo-furanosyl)-2H-1,2,3-triazolo 4,5-d!pyrimidine MS (FAB): 714 (M+H + ), 105 (100%)! (1.9 g). Further elution gave 5,7-bis(propylthio)-1-(2,3,5-tri-O-benzoyl-β-D-ribo-furanosyl)-1H-1,2,3-triazolo 4,5-d!pyrimidine as a colourless foam (0.46 g). MS (FAB): 714 (M+H + ), 105 (100%). d) N-Butyl-5-(propylthio)-3-(β-D-ribo-furanosyl)-3H-1,2,3-triazolo 4,5-d!pyriridin-7-amine n-Butylamine (7.37 g) was added to a solution of the mixture of isomers from step c) (9.0 g) in 1,4-dioxane (100 ml), water (30 ml). The solution was heated at 100° for 40 hours then concentrated. The residue was taken into a 0.1M solution of sodium methoxide in methanol (250 ml) and the reaction mixture heated at reflux for 30 mnin. On cooling to room temperature, acetic acid was added to pH7 and the solution concentrated. Chromatography (SiO 2 , chloroform:isopropyl alcohol, 85:15, as eluant) gave the subtitle compound as a colourless glass (2.0 g). MS (Electrospray): 399 (M+H + , 100%). e) N-Butyl-5-(propylthio)-3- 2,3O-(ethoxymethylene)-βD-ribo-furanosyl!-3H-1,2,3-triazolo 4,5-d!pyrimidin-7-amine A solution of the product of step d) (0.40 g) in 1,4-dioxane (5 ml) was treated with trichloroacetic acid (0.44 g) and triethyl orthoformate (0.44 g). The resulting solution was heated at 50° for 90 min. The cooled solution was diluted with dichloromethane (100 ml), washed with saturated sodium bicarbonate solution (50 ml) and water (50 ml), then dried and concentrated. Chromatography (SiO 2 , hexane:ethyl acetate, 2:1, as eluant) gave the subtitle compound as a colourless solid (0.32 g). MS (FAB): 455 (M+H + ), 267 (100%). f) (E)-1- 7-(Butylamino)-5-(propylthio)-3H-1,2,3-triazolo 4,5-d!pyrimidin-3-yl!-1,5,6-trideoxy-β-D-ribo-hept-5-enofuranuronic acid, ethyl ester A stirred solution of the product of step e) (3.25 g), pyridine (0.57 g) and trifluoroacetic acid (0.41 g) in DMSO (30 ml) was treated with 1,3-dicyclohexylcarbodiimide (4.42 g) and the mixture stirred at room temperature for 24 hours. Carboethoxymethylenetriphenylphosphorane (3.98 g) was added and the reaction stirred for a further 18 hours. The reaction mixture was cooled to 0°, diluted with ethyl acetate (400 ml) and oxalic acid (3.51 g) added. After 30 min the mixture was filtered and the filtrate washed with saturated sodium bicarbonate solution (200 ml), dried and concentrated. Chromatography (SiO 2 , hexane:ethyl acetate, 5:1, as eluant) gave an intermediate which was taken into 80% acetic acid (aq) (25 ml) and heated at 36° for 2 days. The solution was concentrated and the residue purified by chromatography (SiO 2 , hexane:ethyl acetate, 2:1, as eluant) to give the subtitle compound as a colourless solid (1.84 g). MS (FAB): 467 (M+H + ), 267 (100%). g) (E)-1- 7-(Butylamino)-5-(propylthio)-3H-1,2,3-triazolo 4,5-d!pyrimidin-3-yl!-1,5,6-trideoxy-β-D-ribo-hept-5-enofuranuronic acid Prepared according to the method of Example 3c) using the product of step f). NMR δH (d 6 -DMSO) 9.10 (1H, t), 6.82 (1H, dd), 6.15 (1H, d), 5.89 (1H, d), 476 (1H, t), 4.60 (1H, t), 4.39 (1H, t), 3.50 (2H, m), 3.08 (2H, m), 1.69 (2H, m), 1.61 (2H, m), 134 (2H, m), 0.98 (3H, t), 0.91 (3H, t). MS (FAB): 439 (M+H + ), 267 (100%). Example 15 (E)-N- 1- 7-(Butylamino)-5-(propylthio)-3H-1,2,3-triazolo 4,5-d!pyrimidin-3-yl!-1,5,6-trideoxy-β-D-ribo-hept-5-enofuranuronyl!-L-aspartic acid a) (E)-N- 1- 7-(Butylamino)-5-(propylthio)-3H-1,2,3-triazolo 4,5-d!pyrimidin-3-yl!-1,5,6-trideoxy-β-D-ribo-hept-5-enofuranuronyl!-L-aspartic acid, bis(1,1-dimnethylethyl) ester Prepared according to the method of Example 2a) using the product of Example 14. MS (Electrospray): 666 (M+H + , 100%). b) (E)-N- 1- 7-(Butylamino)-5-(propylthio)-3H-1,2,3-triazolo 4,5-d!pyrimdin-3-yl!-1,5,6-trideoxy-β-D-ribo-hept-5-enofuranuronoyl!-L-aspartic acid Prepared according to the method of Example 2b) using the product of step a). NMR δH (d 6 -DMSO): 12.57 (2H, brs), 9.09 (1H, t), 8.42 (1H, d), 6.70 (1H, dd), 6.13 (2H, m), 5.78 (1H, d), 5.60 (1H, d), 4.71 (1H, m), 4,56 (2H, m), 4.40 (1H, q), 3.50 (2H, q), 3.07 (2H, m), 2.63 (2H, m), 1.68 (2H, m), 1.60 (2H, m), 1.35 (2H, m), 0.98 (3H, t), 0.91 (3H, t). Example 16 The following compound was prepared according to the method of Examples 14 and 15: (E)-N- 1- 7-Amino-5-(propylthio)-3H-1,2,3-triazolo 4,5-d!pyrimidin-3-yl!-1,5,6-trideoxy-β-D-ribo-hept-5-enofuranuronoyl!-L-aspartic acid, monoammonium salt a) 5-(Propylthio)-3-(β-D-ribo-furanosyl)-3H-1,2,3-triazolo 4,5-d!pyrimidin-7-amine A solution of the mixture of isomers from Example 14c) (12.0 g) in methanol (1 L) was cooled to 0° and saturated with ammonia gas. The solution was stirred at room temperature for 72 hours then concentrated. Chromatography (SiO 2 , dichloromethane:methanol, 14:1, as eluant) gave the subtitle compound as a colourless solid (4.94 g). MS (Electrospray): 343 (M+H + , 100%). b) 5-(Propylthio)-3- 2,3O-(ethoxymethylene)-β-D-ribo-furanosyl!-3H-1,2,3-triazolo 4,5-d!pyrirdin-7-amine MS (Electrospray): 399(M+H + , 100%). c) (E)-1- 7-Amino-5-(propylthio)-3H-1,2,3-triazolo 4,5-d!pyrimidin-3-yl!-1,5,6-trideoxy-β-D-ribo-hept-5-enofuranuronic acid, ethyl ester MS (Electrospray): 411 (M+H + , 100%). d) (E)-1- 7-Amino-5-(propylthio)-3H-1,2,3-triazolo 4,5-d!pyrimidin-3-yl!-1,5,6-trideoxy-β-D-ribo-hept-5-enofuranuronic acid ester MS (Electrospray): 383 (M+H + , 100%). e) (E)-N- 1- 7-Amino-5-(propylthio)-3H-1,2,3-triazolo 4,5-d!pyrimidin-3-yl!-1,5,6-trideoxy-β-D-ribo-hept-5-enofuranuronoyl!-L-aspartic acid, bis(1,1-dimethylethyl) ester MS (Electrospray): 610 (M+H + , 100%). f) (E)-N- 1- 7-Amino-5-(propylthio)-3H-1,2,3-triazolo 4,5-d!pyrimidin-3-yl!-1,5,6-trideoxy-β-D-ribo-hept-5-enofuranuronoyl!-L-aspartic acid, monoammonium salt NMR δH (d 6 -DMSO): 8.53 (1H, brs), 8.18 (1H, brs), 6.66 (1H, dd), 6.62 (1H, d), 6,15 (1H, d), 4.78 (1H, t), 4.54 (1H, t), 4.39 (1H, t), 4.25 (1H, m), 3.05 (2H, m), 2.53-2.25 (2H, m), 1.68 (2H, m), 0.97 (3H, t). Example 17 (E)-N- 1- 7-(Butylamino)-5-(propylthio)-3H-1,2,3-triazolo 4,5-d!pyrimidin-3-yl!-1,5,6-trideoxy-β-D-ribo-heptofuranuronoyl!-L-aspartic acid, monoammonium salt a) (E)-1- 7-(Butylamino)-5-(propylthio)-3H-1,2,3-triazolo 4,5-d!pyrimidin-3-yl!-1,5,6-trideoxy-β-D-ribo-heptofuranuronic acid, ethyl ester Prepared according to the method of Example 3b) using the product of step 14f). MS (Electrospray): 469 (M+H + , 100%). b) (E)-1- 7-(Butylamino)-5-(propylthio)-3H-1,2,3-triazolo 4,5-d!pyrimidin-3-yl!-1,5,6-trideoxy-β-D-ribo-heptofuranuronic acid Prepared according to the method of Example 3c) using the product of step a). MS (Electrospray, negative ionization): 439 (M-H + , 100%). c) (E)-N- 1- 7-(Butylamino)-5-(propylthio)-3H-1,2,3-triazolo 4,5-d!pyrimidin-3-yl!-1,5,6-trideoxy-β-D-ribo-heptofuranuronoyl-L-aspartic acid, bis (1,1-dimethylethyl) ester Prepared according to the method of Example 2a) using the product of step b). MS (Electrospray): 668 (M+H + , 100%). d)(E)-N- 1- 7-(Butylamino)-5-(propylthio)-3H-1,2,3-triazolo 4,5-d!pyrimidin-3-yl!-1,5,6-trideoxy-β-D-ribo-heptofuranuronoyl!-L-aspartic acid, monoammonium salt Prepared according to the method of Example 2b) using the product of step c). NMR δH (d 6 -DMSO): 9.07 (1H, t), 7.69 (1H, d), 6.04 (1H, d), 5.50 (2H, brs), 4.76 (1H, t), 4.18 (2H, m), 3.91 (1H, m), 3.49 (2H, q), 3.08 (2H, t), 2.46-2.23 (2H, m), 2.18 (2H, t), 1.93 (1H, m), 1.70 (3H, m), 1.60 (2H, m), 1.34 (2H, m), 0.99 (3H, t), 0.91 (3H, t). Example 18 (E)-N- 1,5,6-Trideoxy-1- 7-(hexylamino)-5-(propylthio)-3H-1,2,3-triazolo- 4,5-d!pyrimidin-3-yl!-β-D-ribo-hept-5-enofuranuronoyl!-L-aspartic acid, monoammonium salt a) 3-(5-O-Benzoyl-β-D-ribo-furanosyl)-N-hexyl-5-(propylthio)-3H-1,2,3-triazolo 4,5-d!pyrimidin-7-amine Prepared according to the method of Example 14d) using n-hexylamine. MS (FAB): 531 (M+H + ), 295 (100%). b) 3- 5O-Benzoyl-2,3-O-(1-methylethylidene)-β-D-ribo-furanosyl!-N-hexyl-5-(propylthio)-3H-1,2,3-triazolo 4,5-d!pyrimidin-7-amine The product of step a) (4.93 g) in acetone (120 ml), containing 2,2-dimethoxypropane (11.4 ml) was treated with p-toluenesulfonic acid (4.4 g). The resulting solution was stirred at room temperature for 2 hours, basified with triethylamine (3.25 ml) and concentrated. Chromatography (SiO 2 , cyclohexane:ethanol, 95:5 as eluant) gave the subtitle compound (5.03 g). MS (Electrospray): 571 (M+H + , 100%). c) N-Hexyl-3- 2,3-O-(1-methylethylidene)-β-D-ribo-furanosyl!-5-(propylthio)-3H-1,2,3-triazolo 4,5-d!pyrimidin-7-amine A solution of the product of step b) (5.02 g) in a 0.1M solution of sodium methoxide in is methanol (88 ml) was heated at reflux for 30 min. Acetic acid (1 ml) was added and the reaction concentrated. Chromatography (SiO 2 , dichloromethane:acetonitrile, 95:5 as eluant) gave the subtitle compound (3.63 g). MS (EIectrospray): 467 (M+H + , 100%). d) (E)-1,5,6-Trideoxy-1- 7-(hexylamino)-5-(propylthio)-3H-1,2,3-triazolo- 4,5-d!pyrimidin-3-yl!-2,3-O-(1-methylethylidene)-β-D-ribo-hept-5-enofuranuronic acid, 1,1-dimethylethyl ester Prepared according to the method of Example 1i) using the product of step c). MS (FAB): 563 (M+H + , 100%). e) (E)-1,5,6-Trideoxy-1- 7-(hexylamino)-5-(propylthio)-3H 1,2,3-triazolo- 4,5-d!pyrimidin-3-yl!-β-D-ribo-hept-5-enofuranuronic acid Prepared according to the method of Example 1j) using the product of step d). MS (FAB): 467 (M+H + ), 295 (100%). f)(E)-N- 1,5,6-Trideoxy-1- 7-(hexylamino-5-(propylthio)-3H-1,2,3-triazolo-4,5-d!pyrimidin-3-yl!-βD-ribo-hept-5-enofuranuronoyl!-L-aspartic acid, bis(1,1-dimethylethyl) ester Prepared according to the method of Example 9a) using the product of step e). MS (FAB): 694 (M+H + ), 295 (100%). g) (E)-N- 1,5,6-Trideoxy-1- 7-(hexylamino-5-(propylthio)-3H-1,2,3-triazol- 4,5-d!pyimidin-3-yl!-β-D-ribo-hept-5-enofuranuronoyl!-L-aspartic acid, monoarmonium salt Prepared according to the method of Example 2b) using the product of step f). MS (FAB): 582 (M+H + ), 295 (100%). NMR δH (d 6 -DMSO) 8.74 (1H, t), 8.00 (1H, m), 6.66 (1H, dd), 6.23 (1H, d), 6.15 (1H, m), 4.76 (1H, m), 4,55 (1H, t), 4.40 (1H, t), 4.27 (1H, t), 3.50 (2H, m), 3.07 (2H, m), 2.51 (2H, m), 1.68 (4H, m), 1.30 (6H, m), 0.98 (3H, m), 0.87 (3H, m). Example 19 (E)-1- 7-(N-Butyl-N-methyl-amino)-5-(propylthio)-3H-1,2,3-triazolo 4,5-d!-pyrimidin-3-yl!-1,5,6-trideoxy-β-D-ribo-hept-5-enofuranuronic acid a) N-Butyl-N-methyl-5-(propylthio)-3-(β-D-ribo-furanosyl)-3H-1,2,3-triazolo- 4,5-d!pyrimidin-7-amine Prepared according to the method of Example 14d), using N-methylbutylamine. MS (FAB): 413 (M+H + ), 281 (100%). b) N-Butyl-N-methyl-5-(propylthio)-3- 2,3-O-(1-methylethylidene)-β-D-ribo-furanosyl!-3H-1,2,3-triazolo 4,5-d!pyrimidin-7-amine Prepared according to the method of Example 18b) using the product of step a). MS (FAB): 453 (M+H + ), 281 (100%). c) (E)-1- 7-(N-Butyl-N-methyl-amino)-5-(propylthio)-3H-1,2,3-triazolo 4,5-d!-pyrimidin-3-yl!-1,5,6-trideoxy-2,3-O-(1-methylethylidene)-β-D-ribo-hept-5-enofuranuronic acid, 1,1-dimethylethyl ester Prepared according to the method of Example 1i) using the product of step b). MS (FAB): 549 (M+H + , 100%). d) (E)-1- 7-(N-Butyl-N-methyl-amino)-5-(propylthio)-3H-1,2,3-triazolo 4,5-d!-pyrimidin-3-yl!-1,5,6-trideoxy-β-D-ribo-hept-5-enofuranuronic acid Prepared according to the method of Example 1j) using the product of step c). MS (FAB): 453 (M+H + , 100%). NMR δH (d 6 -DMSO) 6.51 (1H, dd), 6.12 (1H, d), 5.83 (1H, d), 4.71 (1H, t), 4,51 (1H, t), 4.31 (1H, m), 3.76 (2H, m), 3.71 (3h, s), 3.08 (2H, m), 1.69 (4H, m), 1.61 (2H, m), 1.34 (2H, m), 0.94 (6H, m). Example 20 (E)-N- 1- 7-(Butylamino)-5-(methylthio)-3H-1,2,3-triazolo 4,5-d!pyrimidin-3-yl!-1,5,6-trideoxy-β-D-ribo-hept-5-enofuranuronoyl!-L-aspartic acid a) 3-(2,3,5-Tri-O-benzoyl-β-D-ribo-furanosyl)-5,7-bis(methylthio)-3H-1,2,3-triazolo 4,5-d!pyrimidine, and 2-(2,3,5-Tri-O-benzoyl-β-D-ribo-furanosyl)-5,7-bis(methylthio)-2H-1,2,3-triazolo 4,5-d!pyrmidine Prepared according to the method of Example 14c) using 5,7-bis(methylthio)-1H-triazolo 4,5-d!pyrimidine (prepared by the method described by J. A. Montgomery, A. T. Shortnacy, G. Amett, W. H. Shannon, J. Med. Chem., 1977, 20, 401.). Chromatography (SiO 2 , dichloromethane:ethyl acetate, 99:1 as eluant) gave the subtitle compounds (13.3 g). MS (Electrospray): 658 (M+H + , 100%). b) N-Butyl-3- 2,3-O-(1-methylethylidene)-β-D-ribo-furanosyl!-5-(methylthio)-3H-1,2,3-triazolo 4,5-d!pyrimidin-7-amine n-Butylamine (13.5 ml) was added to a solution of the mixture of isomers from step a) (22.5 g) in dioxane (175 ml)/water (25 ml). The solution was stirred at room temperature for 24 hours then concentrated. The residue was taken into a 0.1M solution of sodium methoxide in methanol (500 ml) and heated at reflux for 30 mimn. On cooling to room temperature the solution was concentrated and the residue taken into DMF (80 ml). p-Toluenesulfonic acid (5.91 g) and 2,2-dimethoxypropane (50 ml) were added and the reaction mixture stirred at room temperature for 24 hours. The solution was concentrated and the residue partitioned between ethyl acetate (500 ml) and saturated sodium bicarbonate solution (500 ml), the organic phase was dried and concentrated. Chromatography (SiO 2 , hexane:ethyl acetate, 7:3 as eluant) gave the subtitle compound as a colourless solid (3.67 g). MS (Electrospray): 411 (M+H + , 100%). c)(E)-1- 7-(Butylamino)-5-(methylthio)-3H-1,2,3-triazolo 4,5-d!pyrimidin-3-yl!-1,5,6-trideoxy-2,3-O-(1-methylethylidene)-β-D-ribo-hept-5-enofuranuronic acid, ethyl ester Prepared according to the method of Example 1i) using the product of step b) and (carbethoxymethylene)triphenylphosphorane. MS (FAB): 479 (M+H + , 100%). d)(E)-1- 7-(Butylamino)-5-(methylthio)-3H-1,2,3-triazolo 4,5-d!pyrimidin-3-yl!-1,5,6-trideoxy-β-D-ribo-hept-5-enofuranuronic acid, ethyl ester The product of step c) (1.4 g) was taken into a 2M solution of HCl in methanol (75 ml) and the reaction mixture stirred at room temperature for 15 min then concentrated. The residue was taken into ethyl acetate (300 ml), washed with saturated sodium bicarbonate solution (3×100 ml), dried and concentrated. Chromatography (SiO 2 , dichloromethane:methanol, 97:3 as eluant) gave the subtitle compound as a colourless solid (1.10 g). MS (FAB): 439 (M+H + ), 239 (100%). e) (E)-1- 7-(Butylamino)-5-(methylthio)-3H-1,2,3-triazolo 4,5-d!pyrimidin-3-yl!-1,5,6-trideoxy-β-D-ribo-hept-5-enofuranuronic acid Prepared according to the method of Example 3c) using the product of step d). MS (FAB): 411 (M+H + ), 154 (100%). f) (E)-N- 1- 7-(Butylamino)-5-(methylthio)-3H-1,2,3-triazolo 4,5-d!pyrimidin-3-yl!-1,5,6-trideoxy-β-D-ribo-hept-5-enofuranuronoyl!-L-aspartic acid, bis(1,1-dimethylethyl) ester Prepared according to the method of Example 2a) using the product of step e). MS (FAB): 638 (M+H + ), 239 (100%). g) (E)-N- 1- 7-Butylamino)-5-(methylthio)-3H-1,2,3-triazolo 4,5-d!pyrimidin-3-yl!-1,5,6-trideoxy-β-D-ribo-hept-5-enofuranuronoyl-L-aspartic acid Prepared according to the method of Example 2b) using the product of step f). MS (FAB): 526 (M+H + ), 239 (100%). Example 21 (E)-1- 5-Butyl-7-(butylamino)-3H-1,2,3-triazolo 4,5-d!pyrimidin-3-yl!-1,5,6-trideoxy-β-D-ribo-hept-5-enofuranuronic acid a) 5-Butyl-3,4-dihydro-3- 2,3-O-(1-methylethylidene)-β-D-ribo-furanosyl!-7H-1,2,3-triazolo 4,5-d!pyrimidin-7-one Sodium (4.6 g) was dissolved in ethanol (200 ml) then 5-amino-1- 2,3-O-(1-methylethylidene)-β-D-ribo-furanurosyl!-1H-1,2,3-triazole-4-carboxamide (prepared as described by G. Biagi et al, Farmaco, 1992, 47, 525) (6.0 g) added and the mixture heated to reflux. Methyl valerate (10.5 ml) was added and reflux maintained for 17 hours. The mixture was neutralised using Dowex 50×8-200 (H + form), filtered and the filtrate concentrated. The residue was taken into ethanol, acetic acid added and the solution concentrated. Chromatography (SiO 2 , hexane:ethyl acetate, 7:3 as eluant) gave the subtitle compound as a colourless oil (3.08 g). MS (FAB): 366 (M+H + ). b) 5-Butyl-3,4-dihydro-3- 5-O-acetyl-2,3-O-(1-methylethylidene-β-D)-ribo-furanosyl!-7H-1,2,3-triazolo 4,5-d!pyrimidin-7-one Triethylamine (0.42 g) and acetyl chloride (0.3 g) were added sequentially to an ice-cooled solution of the product from step a) (1.41 g) in dichloromethane (50 ml). The mixture was stirred at 5° for 30 min then washed with brine, dried and concentrated. Chromatography (SiO 2 , dichloromethane:methanol, 95:5 as eluant) gave the subtitle compound (1.2 g). MS (EI): 408 (M+H + ). c) 5-Butyl-7-chloro-3- 5-O-acetyl-2,3-O-(1-methylethylidene)-β-D-ribo-furanosyl!-3H-1,2,3-triazolo 4,5-d!pyrimidine The product from step b) (1.19 g) and DMF (299 mg) in chloroform (30 ml) was heated to reflux, thionyl chloride (3.47 g) was added and reflux maintained for 45 min. After cooling in an ice bath, the mixture was added slowly to a stirred, saturated solution of sodium bicarbonate. The mixture was extracted with dichloromethane (3×200 ml) and the combined organics dried, filtered and concentrated. Chromatography (SiO 2 , hexane:ethyl acetate, 5:1 as eluant) gave the subtitle compound (1.14 g). MS (EI): 427, 425 (M+H + ). d) N,5-Di(butyl)-3- 2,3-O-(1-methylethylidene)-β-D-ribo-furanosyl!-3H-1,2,3-triazolo 4,5-d!pyrimidin-7-amine Prepared according to the method of Example 1h) using the product of step c). MS (EI): 420 (M + ). e) (E)-1- 5-Butyl-7-(butylamino)-3H-1,2,3-triazolo 4,5-d!pyrimidin-3-yl!-1,5,6-trideoxy-2,3-O-(1-methylethylidene)-β-D-ribo-hept-5-enofuranuronic acid, 1,1-dimethylethyl ester Prepared according to the method of Example 1i) using the product of step d). MS (FAB): 517 (M+H + , 100%). f) (E)-1- 5-Butyl-7-(butylamino)-3H-1,2,3-triazolo 4,5-d!pyrimidin-3-yl!-1,5,6-trideoxy-β-D-ribo-hept-5-enofuranuronic acid Prepared according to the method of Example 1j) using the product of step e). NMR δH (d 6 -DMSO): 8.87 (1H, t), 6.71 (1H, dd), 6.20 (1H, m), 5.89 (1H, d), 4.75 (1H, m), 4,56 (1H, t), 4.37 (1H, t), 3.54 (2H, q), 2.73 (2H, t), 1.74 (2H, m), 1.62 (2H, m), 1.35 (4H, m), 0.91 (6H, t). Example 22 (E)-1- 7-Butyl-5-(propylthio)-3H-1,2,3-triazolo 4,5-d!pyrimidin-3-yl!-1,5,6-trideoxy-β-D-ribo-hept-5-enofuranuronic acid a) 5-Amino-1- 5-O- (1,1-dimethylethyl)dimethylsilyl!-2,3-O-(1-methylethylidene)-β-D-ribofuranurosyl!-1H-1,2,3-triazole-4-carboxamide A solution of 5-amino-1- 2,3-O-(1-methylethylidene)-β-D-ribofuranurosyl!-1H-1,2,3-triazole-4-carboxamide (prepared as described by G. Biagi et al, Farmaco, 1992, 47, 525) (10.0 g), imidazole (2,20 g) and tert-butyidimethylsilyl chloride (4.98 g) in DMF (200 ml) was stirred at room temperature for 16 hours. The solution was concentrated and the residue purified (SiO 2 , dichloromethane:ethyl acetate, 1:1 as eluant) to give the subtitle compound (12.0 g). MS (EI): 398 (M-CH 3 + ), 73 (100%). b) 3,6-Dihydro-3- 5-O- (1,1-dimethylethyl)dimethysilyl!-2,3-O-(1-methylethylidene)-β-D-ribo-furanosyl!-5-mercapto-7H-1,2,3-triazolo 4,5-d!pyrimidin-7-one The product of step a) (26.0 g) in DMF (100 ml) was added, over 1 hour, to a stirred suspension of sodium hydride (60%, 2.52 g) in DMF (200 ml). 1,1-Thiocarbonyldiimidazole (11.2 g) was added and the reaction mixture heated at reflux for 1 hour then concentrated. The residue was taken into water (1 L), acidified with glacial acetic acid and the subtitle compound isolated by filtration (14.1 g). MS (FAB): 456 (M+H + ), 69 (100%). c) 3- 5-O- (1,1-Dimethylethyl)diethylsilyl!-2,3-O-(1-methylethylidene)-β-D-ribo-furanosyl!-3,4-dihydro-5-(propylthio)-7H-1,2,3-triazolo 4,5-d!pyrimidin-7-one The product of step b) (19.3 g) was added to a stirred suspension of sodium hydride (60%, 1.41 g) in DMF (200 ml). After 15 min iodopropane (3.55 ml) was added and the mixture stirred for 1 hour then concentrated. The residue was partitioned between water (1 L) and dichloromethane (1 L). The organic layer was dried and concentrated to give the subtitle compound (18 g). MS (FAB): 498 (M+H + ), 73 (100%). d) 3- 2,3-O-(1-Methylethylidene)-β-D-ribo-furanosyl!-3,4-dihydro-5-(propylthio)-7H-1,2,3-triazolo 4,5-d!pyrimidin-7-one Tetrabutylammonium fluoride (1M in THF, 40.6 ml) was added to a stirred solution of the product of step c) (20.2 g) in THF (300 ml) and the reaction mixture stirred at room temperature for 12 hours. The solution was concentrated and the residue partitioned between water (1 L) and ethyl acetate (1 L). The organic phase was dried and concentrated to give the subtitle compound (14.1 g). MS (Electrospray): 382 (M-H + , 100%). e) 3- 5-O-Acetyl-2,3-O-(1-methylethylidene)-β-D-ribo-furanosyl!-3,4-dihydro-5-(propylthio)-7H-1,2,3-triazolo 4,5-d!pyrimidin-7-one Prepared according to the method of Example 21b) using the product of step d). MS (Electrospray): 443 (M+H + , 100%). f) 3- 5-O-Acetyl-2,3-O-(1-methylethylidene)-βD-ribo-furanosyl!-7-chloro-5-(propylthio)-3H-1,2,3-triazolo 4,5-d!pyrimidine Prepared according to the method of Example 21c) using the product of step e). MS (FAB): 444, 446 (M+H + ). g) 3- 5-O-Acetyl-2,3-O-(1-methylethylidene)-β-D-ribo-furanosyl!-7-butyl-5-(propylthio)-3H-1,2,3-triazolo 4,5-d!pyrimidine Bis(triphenylphosphine)palladium(II) chloride (40 mg) and tetrabutyltin (0.81 ml) were added to a solution of the product from step f) (500 mg) in 1-methyl-2-pyrrolidinone (5 ml) and the mixture stirred at 100° for 2 hours, then at room temperature for 72 hours. The mixture was partitioned between water (100 ml) and ethyl acetate (200 ml), the organic layer washed with brine (50 ml), dried and concentrated. Chromatography (SiO 2 , hexane:ethyl acetate 85:15 as eluant) gave the subtitle compound (230 mg). MS (FAB): 466 (M+H + ). h) 7-Butyl-3- 2,3-O-(1-methylethylidene)-β-D-ribo-furanosyl!-5-(propylthio)-3H-1,2,3-triazolo 4,5-d!pyrimidine Prepared according to the method of Example 16a) using the product of step g). MS (FAB): 424 (M+H + ). i) (E)-1- 7-Butyl-5-(propylthio)-3H-1,2,3-triazolo 4,5-d!pyrimidin-3-yl!-1,5,6-trideoxy-β-D-ribo-hept-5-enofuranuronic acid, 1,1-dimethylethyl ester Prepared according to the method of Example 1i) using the product of step h). MS (FAB): 520 (M+H + ). j) (E)-1- 7-Butyl-5-(propylthio)-3H-1,2,3-triazolo 4,5-d!pyrimidin-3-yl!-1,5,6-trideoxy-β-D-ribo-hept-5-enofuranuronic acid Prepared according to the method of Example 2b) using the product of step i). NMR δH (CDCl 3 ): 7.00 (1H, d), 6.52 (1H, s), 6.01 (1H, d), 5.30 (2H, brs), 4.94 (1H, s), 4,56 (1H, t), 4.76-4.81 (2H, d), 3.12 (4H, brs), 1.80 (2H, q), 1.70 (2H, q), 1.37 (2H, q), 0.99 (3H, t), 0.89 (3H, t). Example 23 (E)-N- 1- 5,7-Di(butylamino)-3H-1,2,3-triazolo 4,5-d!pyrimidin-3-yl!-1,5,6-trideoxy-β-D-ribo-heptofuranuronoyl!-L-aspartic acid, monoamimonium salt a) (E)-N- 1- 7-Butylamino-5-(methylsulfonyl)-3H-1,2,3-triazolo 4,5-d!-pyrimidin-3-yl!-1,5,6-trideoxy-β-D-ribo-heptofuranuronoyl!-L-aspartic acid, bis(1,1-dimethylethyl) ester 3-Chloroperoxybenzoic acid (50%, 0.12 g) in ethanol (1 ml) was added, over 1 hour, to a stirred solution of the product of Example 17c) (0.1 g) in ethanol (2 ml). After stirring at room temperature for 16 hours the solution was diluted with dichloromethane (50 ml) then washed with aqueous sodium metabisulfite solution (30 ml) and aqueous sodium carbonate solution (2×20 ml). The organic layer was dried and concentrated to give the subtitle compound (90 mg). MS (FAB): 700 (M+H + ), 299 (100%). b) (E)-N- 1- 5,7-Di(butylamino)-3H-1,2,3-triazolo 4,5-d!pyrimidin-3-yl!-1,5,6-trideoxy-β-D-ribo-heptofuranuronoyl!-L-aspartic acid, bis(1,1-dimethylethyl) ester Prepared according to the method of Example 1h) using the product of step a). MS (FAB): 665 (M+H + , 100%). c) (E)-N- 1- 5,7-Di(butylamino)-3H-1,2,3-triazolo 4,5-d!pyrimidin-3-yl!-1,5,6-trideoxy-β-D-ribo-heptofuranuronoyl-L-aspartic acid, monoammonium salt Prepared according to the method of Example 2b) using the product of step b). MS (Electrospray): 553 (M+H + , 100%). Example 24 (Z)-1- 7-(Butylamino)-5-(propylthio)-3H-1,2,3-triazolo 4,5-d!pyrimidin-3-yl!-1,5,6-trideoxy-β-D-ribo-hept-5-enofuranuronic acid a) N-Butyl-5-(propylthio)-3- 2,3-O-(1-methylethylidene)-β-D-ribo-furanosyl!-3H-1,2,3-triazolo 4,5-d!pyrimidin-7-amine Prepared according to the method of Example 18b) using the product of Example 14e). MS (FAB): 439 (M+H + ), 267 (100%). b) (Z)-1- 7-(Butylamino)-5-(propylthio)-3H-1,2,3-triazolo 4,5-d!pyrimidin-3-yl!-1,5,6-trideoxy-2,3-O-(1-methylethylidene)-β-D-ribo-hept-5-enofuranuronic acid, 1,1-dimethylethyl ester Prepared according to the method of Example 1i) using the product of step a), the subtitle compound was isolated as a minor product. MS (FAB): 535 (M+H + , 100%). c) (Z)-1- 7-(Butylamino)-5-(propylthio)-3H-1,2,3-triazolo 4,5-d!pyrimidin-3-yl!-1,5,6-trideoxy-β-D-ribo-hept-5enofuranuronic acid Prepared according to the method of Example 1j) using the product of step b). MS (FAB): 439 (M+H + ), 267 (100%). NMR δH (d 6 -DMSO) 8.76 (1H, t), 6.22 (1H, m), 6.14 (1H, m), 5.85 (1H, d), 5.48 (1H, m), 4.84 (1H, t), 4.25 (1H, m), 3.50 (2H, m), 3.09 (2H, m), 1.71 (2H, m), 1.63 (2H, m), 1.35 (2H, m), 0.99 (3H, t), 0.91 (3H, t). Example 25 N-Butyl-5-(propylthio)-3- 5,6-dideoxy-6-(1H-tetrazol-5-yl)-β-D-ribo-hexofuranosyl!-3H-1,2,3-triazolo 4,5-d!pyrimidine-7-amine a) (E)-1- 7-(Butylamino)-5-(propylthio)-3H-1,2,3-triazolo 4,5-d!pyrimidin-3-yl!-1,5,6-trideoxy-2,3-O-(1-methylethylidene)-β-D-ribo-hept-5-enofuranurononitrile Prepared according to the method of Example 1i) using the product of step 24a) and (triphenylphosphoranylidene)acetonitrile. MS (FAB): 460 (M+H + , 100%). b) (E)-1- 7-(Butylamino)-5-(propylthio)-3H-1,2,3-triazolo 4,5-d!pyrimidin-3-yl!-1,5,6-trideoxy-2,3-O-(1-methylethylidene)-β-D-ribo-heptofuranurononitrile Prepared according to the method of Example 8b) using the product of step a). MS (APCI): 462 (M+H + , 100%). c) N-Butyl-5-(propylthio)-3- 5,6-dideoxy-2,3-O-(1-methylethylidene)-6-(1H-tetrazol-5-yl)-β-D-ribo-hexofuranosyl!-3H-1,2,3-triazolo 4,5-d!pyrimidine-7-amine Azidotrimethylsilane (0.30 g) and dibutyltin oxide (32 mg) were added to a solution of the product of step b) (0.60 g) in toluene (6 ml) and the resulting solution heated under reflux for 72 hours. On cooling to room temperature the solvent was removed and the residue purified by chromatography (SiO 2 , ethyl acetate:isohexane:acetic acid, 100:100:1 as eluant) to give the subtitle compound (0.26 g). MS (FAB): 505 (M+H + ), 267 (100%). d) N-Butyl-5-(propylthio)-3- 5,6-dideoxy-6-(1H-tetrazol-5-yl)-β-D-ribo-hexofuranosyl!-3H-1,2,3-triazolo 4,5-d!pyrimidine-7-amine Prepared according to the method of Example 1j) using the product of step c). The crude product was triturated with ethyl acetate to give the title compound (0.13 g). MS (FAB): 465 (M+H + ), 267 (100%). NMRδH (d 6 -DMSO) 9.08 (1H, t), 6.08 (1H, d), 5.65 (1H, d), 5.35 (1H, m), 4.76(1H, t), 4.30 (1H, t), 3.98 (1H, m), 3.50 (2H, m), 3.06 (2H, m), 2.92 (2H, m), 2.05 (2H, m), 1.63 (4H, m), 1.34 (2H, m), 0.97 (3H, t), 0.91 (3H, t). Example 26 1,5,6-Trideoxy-1- 5,7-bis(propylthio)-3H-1,2,3-triazolo 4,5-d!pyrimidin-3-yl!-β-D-ribo-heptofuranuronic acid, sodium salt a) (E)-1,2,3-Tri-O-acetyl-5,6-dideoxy-β-D-ribo-hept-5-enofuranuronic acid, ethyl ester (E)-Methyl 5,6dideoxy-2,3-O-(1-methylethylidene)-β-D-ribo-hept-5-enofuranosiduronic acid, ethyl ester (prepared as described by A. J. Cooper, R. G. Salomon, Tetrahedron Lett., 1990, 31, 3813) (8.0 g) was heated at 80° in a mixture of acetic acid (256 ml) and water (64 ml) for 16 hours and then left at room temperature for 48 hours. Evaporation afforded a residue which was taken into pyridine (160 ml) and treated with acetic anhydride (19.8 ml). After 24 hours the reaction mixture was diluted with ethyl acetate (500 ml) and washed with dilute HCl. Drying and evaporation afforded an oil which was purified by chromatography (SiO 2 , isohexane:ethyl acetate, 5:1 as eluant) to afford the subtitle compound (5.34 g). MS (FAB+RbI): 431, 429 (M+Rb + ), 285 (100%). b) 1,2,3-Tri-O-acetyl-5,6-dideoxy-β-D-ribo-heptofuranuronic acid, ethyl ester Prepared according to the method of example 8b) using the product of step a). MS (FAB+RbI): 433, 431 (M+Rb + ), 185 (100%). c) 2,3-Di-O-acetyl-1,5,6-trideoxy-1- 5,7-bis(propylthio)-3H-1,2,3-triazolo 4,5-d!pyrimidin-3-yl!-β-D-ribo-heptofuranuronic acid, ethyl ester and 2,3-di-O-acetyl-1,5,6-trideoxy-1 5,7-bis(propylthio)-2H-1,2,3-triazolo 4,5-d!pyrimidin-2-yl!-β-D-ribo-heptofuranuronic acid, ethyl ester. The product of step b) (1.00 g) and the product of step 14b) (0.78 g) were mixed with p-toluenesulfonic acid (12 mg) and stirred thoroughly under water pump vacuum. The mixture was plunged into an oil bath at 140°. Heating was continued for 10 mins then the flask cooled and the reaction mixture taken into chloroform. Washing with saturated sodium bicarbonate solution, drying, evaporation and chromatography (SiO 2 , dichloromethane:ethyl acetate, 15:1 as eluant) gave the subtitle compounds (5.34 g) as an inseparable mixture. d) 1,5,6-Trideoxy-1- 5,7-bis(propylthio)-3H-1,2,3-triazolo 4,5-d!pyrimidin-3-yl!-β-D-ribo-heptofuranuronic acid, sodium salt Prepared according to the method of example 3c) using the product of step c). MS (FAB+RbI) 433, 431 (M+Rb + ). Pharmaceutical Compositions The novel compounds of the present invention may be administered parenterally, intravenously, by inhalation, or orally. A preferred route of administration is intravenous infusion. The dosage will depend on the route of administration, the severity of the disease, age and weight of the patient, as well as other factors normally considered by the attending physician, when determining the individual regimen and dosage level as the most appropriate for a particular patient. Examples of pharmaceutical compositions which may be used, and suitable adjuvants, diluents or carriers, are as follows: for intravenous injection or infusion--purified water or saline solution; for inhalation compositions--coarse lactose; for tablets, capsules and dragees--microcrystalline cellulose, calcium phosphate, diatomaceous earth, a sugar such as lactose, dextrose or mannitol, talc, stearic acid, starch, sodium bicarbonate, and/or gelatin; for suppositories--natural or hardened oils or waxes. When a compound according to the present invention is to be used in aqueous solution, e.g. for infusion, it may be necessary to incorporate other excipients. In particular there may be mentioned chelating or sequestering agents, antioxidants, tonicity adjusting agents, pH-modifying agents and buffering agents. Solutions containing a compound of the formula (I) may, if desired, be evaporated, e.g. by freeze-drying or spray-drying, to give a solid composition which may be reconstituted prior to use. The compositions may also comprise suitable preserving, stabilising and wetting agents, solubilisers, e.g. water-soluble cellulose polymer such as hydroxypropyl methylcellulose, or a water-soluble glycol such as propylene glycol, sweetening and colouring agents and flavourings. Where appropriate, the compounds may be formulated in sustained release form. According to a further aspect of the invention, there is provided the use of a compound according to the formula (I) or a pharmaceutically acceptable salt thereof, for the manufacture of a medicament for the treatment of platelet aggregation disorders. According to still a further aspect of the invention, there is provided a method for the treatment of any disorder where platelet aggregation is involved, whereby an effective amount of a compound according to the formula (I) is administered to a patient suffering from said disorder. Pharmaceutically acceptable salts of the compounds of the formula (I) include alkali metal salts, e.g. sodium and potassium salts; alkaline earth metal salts, e.g. calcium and magnesium salts; salts of the group III elements, e.g. aluminium salts; and ammonium salts. Salts with suitable organic bases, e.g. salts with hydroxylamine; lower alkylamines, e.g. methylamine or ethylamine; with substituted lower alkylamines, e.g. hydroxysubstituted alkylamines; or with monocyclic nitrogen heterocyclic compounds, e.g. piperidine or morpholine; and salts with amino acids, e.g. with arginine, lysine etc., or an N-alkyl derivative thereof; or with an aminosugar, e.g. N-methyl-D-glucamine or glucosamine. The just mentioned salts are only examples of salts which may be used in accordance with the present invention, and the list is not in any way to be construed as exhaustive. Preferred pharmaceutically acceptable salts of the compounds of the formula (I) are alkali metal salts and ammonium salts, more preferably sodium salts and monoammonium salts. Biological Evaluation The potency of the compounds of the present invention to act as inhibitors of platelet aggregation was determined from their ability to act as P 2T receptor antagonists, as illustrated in the following screen: Quantification of P 2T receptor agonist/antagonist activity in washed human platelets. Preparation Human venous blood (100 ml) was divided equally between 3 tubes, each containing 3.2% trisodium citrate (4 ml) as anti-coagulant The tubes were centrifuged for 15 min at 240G to obtain a platelet-rich plasma (PRP) to which 300 ng/ml prostacyclin was added to stabilize the platelets during the washing procedure. Red cell free PRP was obtained by centrifugation for 10 min at 125G followed by further centrifugation for 15 min at 640G. The supernatant was discarded and the platelet pellet resuspended in modified, calcium free, Tyrode solution (10 ml) CFT, composition: NaCl 137 mM, NaHCO 3 11.9 mM, NaH 2 PO 4 0.4 mM, KCl 2.7 mM, MgCl 2 1.1 mM, dextrose 5.6 mM, gassed with 95% O 2 /5% CO 2 and maintained at 37°. Following addition of a further 300 ng/ml PGI 2 , the pooled suspension was centrifuged once more for 15 min at 640G. The supernatant was discarded and the platelets resuspended initially in 10 ml CFT with further CFT added to adjust the final platelet count to 2×10 5 /ml. This final suspension was stored in a 60 ml syringe at 3° with air excluded. To allow recovery from PGI 2 -inhibition of normal function, platelets were used in aggregation studies no sooner than 2 hours after final resuspension. In all studies, 3 ml aliquots of platelet suspension were added to tubes containing CaCl 2 solution (60 μl of 50 mM soln, final conc. 1 mM). Human fibrinogen (Sigma, F 4883) and 8-sulphophenyltheophylline (8-SPT, to block any P 1 agonist activity of compounds) were added to give final concentrations of 0.2 mg/ml (60 μl of 10 mg/ml solution of clottable protein in saline) and 300 nM (10 μl of 15 mM solution in 6% glucose), respectively. Platelets or buffer as appropriate were added in a volume of 150 μl to the individual wells of a 96 well plate. All measurements were made in triplicate in platelets from each donor. Protocol a) Assessment of agonist/antagonist potency Aggregation responses in 96 well plates were measured using the change in absorbance given by the plate reader at 660 nm. The absorbance of each well in the plate was read at 660 nm to establish a baseline figure. Saline or the appropriate solution of test compound was added to each well in a volume of 10 μl to give a final concentration of 0, 0.01, 0.1, 1, 10 or 100 mM. The plate was then shaken for 5 min on an orbital shaker on setting 10 and the absorbance read at 660 nm. Aggregation at this point was indicative of agonist activity of the test compound. Saline or ADP (30 mM; 10 μl of 450 mM) was then added to each well and the plate shaken for a further 5 min before reading the absorbance again at 660 nm. Antagonist potency was estimated as % inhibition of the control ADP response. The compounds of the present invention exhibited anti-aggregatory activity when tested as described above.	Compounds of the formula (I) ##STR1## wherein B is O or CH 2 ; X is selected from NR 1 R 2 , SR 1 , and C 1 -C 7 alkyl; Y is selected SR 1 , NR 1 R 2 , and C 1 -C 7 alkyl; R 1 and R 2 is each and independently selected from H, or C 1 -C 7 alkyl optionally substituted upon or within the alkyl chain by one or more of O, S, N or halogen; R 3 and R 4 are both H, or R 3 and R 4 together form a bond; A is COOH, C(O)NH(CH 2 ) p COOH, C(O)N (CH 2 ) q COOH! 2 , C(O)NHCH(COOH)(CH 2 ) r COOH, or 5-tetrazolyl, wherein p, q and r is each and independently 1, 2 or 3; as well as pharmaceutically acceptable salts and prodrugs thereof, pharmaceutical compositions comprising the novel compounds and use of the compounds in therapy. Also within the scope of the invention are novel intermediates to the novel compounds. The novel compounds are in particular useful in the prevention of platelet aggregation.	2
CROSS REFERENCE TO RELATED APPLICATION This application is being filed contemporaneously with application for U.S. Design Pat. Serial No. 29/225,626, filed Mar. 18, 2005, entitled VACUUM PACKAGING MACHINE, which is hereby incorporated by reference herein. BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is broadly concerned with packaging equipment. More particularly, the present invention concerns a vacuum packaging machine of the type used for the purpose of creating evacuated and sealed packages of food. 2. Description of the Prior Art It is known to provide a vacuum packaging apparatus for use in evacuating the air in an open-ended package and sealing the evacuated package. A typical apparatus of this type presents a chamber sized only for receipt of the open end of the package with the remainder of the package disposed outside of the chamber, and a vacuum pump communicating with the chamber for evacuating the chamber and the package through the open end. The sealing mechanism may include a heating element disposed outside the vacuum chamber and extending along the front of the base beyond the ends of the vacuum chamber. The heating element in this design is fixed to the base so that when the lid is lowered onto the base, the heating element is pressed against a portion of the package external of the chamber. Upon evacuation of the package, current is delivered to the heating element, melting the package material to seal the package closed. U.S. Pat. No. 5,638,664 discloses an improved packaging apparatus which eliminates the problems inherent in the above types of vacuum packaging devices. The '664 patent has a package sealing element located within a concavity formed in the base, and is entirely within the confines of the evacuation chamber. However, the design also makes use of a liquid trap in the form of an elongated channel rearward of the sealing element, as well as a forward resilient member serving as a part of the vacuum seal. This base design can present problems in that the trap and seal arrangement collects liquids or other food particles and thus can be unsanitary if not cleaned on a regular basis. Furthermore, this patented design employs an elongated inflatable bladder beneath the resistance heating element which is inflated in timed relationship to air evacuation from a package. This bladder is directly coupled with the vacuum pump of the unit and thus is a closed part of the system. SUMMARY OF THE INVENTION The present invention provides a greatly improved vacuum packaging apparatus or machine especially designed for household consumer use. With respect to a first aspect of the present invention, the vacuum packaging machine includes a base presenting an upper package end-supporting surface, and a lid operatively coupled with the base and having a lower surface. The lid is movable between an open position permitting placement of the package open end upon the base upper surface, and a closed position where the base upper surface and lid lower surface are in proximity. The base and lid cooperatively define an evacuation chamber surrounding the package open end when the cover is in the closed position thereof. The machine also includes a vacuum source and an evacuation port in communication with the chamber. The evacuation port is operatively coupled with the vacuum source in order to evacuate the package through the open end. The machine further includes a sealing component proximal to the chamber and operable to seal the open end after evacuation of the package. Moreover, the upper package end-supporting surface of the base in the area thereof bounded by the chamber presents a readily cleanable, essentially flat surface free of concavities. The portion of the base within the confines of the evacuation chamber is consequently substantially flat and uninterrupted, and free of slots or other concavities which can collect fluids or solid food particles and lead to unsanitary conditions. That portion of the base can simply be cleaned by wiping it with a cloth (preferably utilizing also a sanitary cleaning fluid). Another aspect of the present invention concerns a vacuum packaging machine including a base and a lid operatively coupled with the base. The lid is movable between an open position permitting placement of the package open end between the lid and base, and a closed position where the lid and base are in proximity. The base and lid cooperatively define an evacuation chamber surrounding the package open end when the cover is in the closed position thereof. A vacuum source is provided within said base, and an evacuation port in the lid is in communication with the chamber. The machine further includes a sealing component proximal to the chamber and operable to seal the open end after evacuation of the package. Yet further, the machine includes a conduit assembly operatively coupling the evacuation port with the vacuum source in order to evacuate the package through the open end. The conduit assembly includes a first conduit extending from the evacuation port to a connection port on the lid outside the boundaries of the chamber, a second conduit within the base extending from a connection port on the base outside the confines of the chamber and coupled with the vacuum source, and sealing structure between the lid and base connection ports affording a seal between the connection ports when the lid is in the closed position thereof. A third aspect of the present invention concerns a vacuum packaging machine including a base and a lid operatively coupled with the base. The lid is movable between an open position permitting placement of the package open end between the lid and base, and a closed position where the lid and base are in proximity. The base and lid cooperatively define an evacuation chamber surrounding the package open end when the cover is in the closed position thereof. The machine also includes a vacuum source, as well as an evacuation port in communication with the chamber and operatively coupled with the vacuum source in order to evacuate the package through the open end. The machine further includes a sealing component proximal to the chamber and operable to seal the package open end after evacuation of the package. The sealing component includes an elongated expandable bladder having the interior thereof vented to the atmosphere, and a resistance heatable sealing element disposed above the bladder. The base presenting a housing in which the bladder is located, and the vacuum source is operatively coupled with the housing for inducing negative pressure conditions therein. The bladder is operable, under the influence of induced negative pressure conditions within the housing, to expand and shift the sealing element towards the chamber for sealing of the package open end. Other aspects and advantages of the present invention will be apparent from the following detailed description of the preferred embodiments and the accompanying drawing figures. BRIEF DESCRIPTION OF THE DRAWING FIGURES Preferred embodiments of the invention are described in detail below with reference to the attached drawing figures, wherein: FIG. 1 is a perspective view of a vacuum packaging machine in accordance with the invention; FIG. 2 is a perspective view similar to that of FIG. 1 , but depicting the lid of the machine in its open position; FIG. 3 is a vertical sectional view of the vacuum packaging machine illustrating the lid in a partially opened condition and depicting the internal details of construction of the machine; FIG. 4 is a vertical sectional view similar to that of FIG. 3 , but showing the machine in use during evacuation and sealing of a package; and FIG. 5 is a front view of the vacuum packaging machine with certain parts broken away and other parts illustrated in phantom. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT Turning now to the drawings, and particularly FIGS. 1 and 2 , a vacuum packaging machine 10 in accordance with the invention broadly includes a base 12 and a lid 14 pivotally coupled to the base and shiftable between a closed position ( FIG. 1 ) and an open position ( FIG. 2 ). The overall machine 10 further includes a vacuum source 16 within base 12 , a conduit assembly 18 having components within base 12 and lid 14 , and a package sealing assembly 20 supported by base 12 and lid 14 . In more detail, the base 12 is in the form of a housing 22 including a bottom wall 24 , circumscribing sidewalls 26 formed to present a forward access notch 27 and a rearward, central, lid-mounting recess 27 a , and an upper, smooth and substantially uninterrupted top wall 28 . The top wall preferably presents a package end-supporting surface 28 a that serves to support the open end of the package during the evacuation and sealing steps. The housing 22 has a vacuum pump and control section 30 astride the lidded package evacuated and sealing section 32 . Referring to FIG. 4 , it will be observed that projecting downwardly from the top wall 28 is an elongated, laterally extending, rectangular in cross-section bladder housing 34 . The housing presents a tubular vacuum conduit insert 35 and a venting outlet 35 a (see FIG. 5 ). The package sealing assembly 20 preferably includes an elongated resilient elastomeric bladder 36 seated within housing 34 with venting outlet 35 a extending through the housing wall and into the interior of the bladder to vent bladder 36 to the atmosphere. A sponge-like, closed cell elongated sealing member 38 is located atop bladder 36 . Although the sealing member 38 is illustrated within the bladder housing 36 , the principles of the present invention are equally applicable to a arrangement wherein only the bladder is sealed within the housing (for purposes which will be described) but maintains its operable connection to the sealing member 38 to control movement thereof. An elongated resistance heatable package end sealing element 40 rests on the member 38 , and is preferably secured thereto by suitable means (such as fasteners, adhesive, etc.). It will be appreciated that a number of the components of the illustrated embodiment are similar to those disclosed in U.S. Pat. No. 5,638,664, which is hereby incorporated by reference herein as is necessary for a full and complete understanding of the present invention. The top wall 28 of the base 12 further includes an elongated strip 42 of flexible resilient material surmounting and covering the upper open end of bladder housing 34 and the components therein. The strip 42 may be formed of TEFLON® or other suitable material, and is adhesively secured in place in order to affect a seal over the housing while substantially maintaining the continuous and uninterrupted nature of top wall 28 . The strip is sufficiently flexible to permit movement of the sealing member (and element 40 ), as well as being sufficiently conductive to transfer heat from the element 40 to the package, when sealing of the package is affected. The top wall 28 also includes a rearward connection port 44 surrounded by a resilient annular gasket-type sealing member 46 ; the importance of this port and seal arrangement will be made clear hereinafter. The housing section 30 includes a control panel 48 having a readout 50 and appropriate control buttons 52 to initiate and control the operation of the machine 10 . Lid 14 is fabricated in the form of a housing 54 having top wall 56 , circumscribing sidewalls 58 and bottom wall 60 . A central, depending, rearmost extension 62 is secured to the housing 54 and is received within base recess 27 a . A pivot pin 64 connected to the base serves to pivotally mount the lid 14 to base 12 . The bottom wall 60 of lid housing 54 has a rectangular stepped opening 65 therein which receives an evacuation and sealing assembly 66 . The assembly forms part of the package sealing assembly 20 and cooperates with the above-noted components in the base 12 to seal the package, as will be described. More particularly, the assembly 66 includes an apertured synthetic resin plate 68 having a tubular insert 70 aligned with an evacuation port 71 . The lower surface of plate 68 supports a generally rectangular, circumscribing resilient sealing element 72 as well as inboard, elongated, laterally spaced ribs 74 . The purpose of element 72 and ribs 74 is to form closed evacuation chamber 76 (see FIG. 4 ) when lid 14 is closed. Finally, an elongated, resilient backing strip 75 is supported on plate 68 and is adapted to come into registry with resistance sealing element 40 when lid 14 is closed. The bottom wall 60 also has a connection port 78 therein with a rigid, annular gasket-type sealing member 80 disposed about and in registry with connection port. The port 78 is located to mate with base connection port 44 when the lid 14 is closed, and with the annular seals 46 and 80 also in sealing engagement with another. This unique arrangement provides the necessary communication between the evacuation port 71 , which is preferably located within the lid 14 , and the vacuum source 16 , which is preferably located within the base. It will be appreciated, that the sealing arrangement between the connection ports 44 and 78 could also accommodate a design in which locations of the evacuation port and vacuum source are reversed, with the former being in the base and latter being in the lid. The vacuum source 16 is preferably a conventional vacuum pump 82 having a vacuum output conduit 84 and an exhaust conduit 86 vented to the atmosphere through the bottom wall 24 . As noted previously, the pump 62 is preferably housed within section 30 of base 12 , generally below and rearward of control panel 48 . The conduit assembly 18 includes a first, generally U-shaped conduit 88 within housing 54 of lid 14 . As best seen in FIGS. 3–5 , the conduit 88 is secured to insert 70 at one end thereof, and is connected at the other end in mating relationship with connection port 78 via coupler 90 . The overall assembly 18 further includes conduits within base housing 22 , namely a second, depending conduit 92 secured to the underside of wall 28 in registry with connection port 44 and having a T-coupler 94 at the lower end thereof. One leg of T-coupler 94 is connected to vacuum pump conduit 84 . The other leg is connected with a third conduit 96 which is secured to insert 35 to communicate with the interior of bladder housing 34 . As shown in FIG. 1 , the machine 10 is provided with an electrical cord 97 for connecting to a conventional wall socket (not shown) to provide power to the various electrical components. It will be appreciated, however, that the principles of the present invention are equally applicable to a battery-powered machine or a machine utilizing other suitable sources for powering the necessary components. In the use of machine 10 , lid 14 is first opened, exposing the upper package end-supporting surface 28 a defined by base top wall 28 . Next, the user places the open end 98 of a flexible bag or package 100 (see FIG. 4 ) on the surface 28 a generally above sealing element 40 , with the end 98 preferably being within the confines of the chamber 76 (i.e., within the area bounded by the element 72 ). The lid 14 is then closed, with sealing element 72 coming into engagement with top wall 28 and the upper ply of end 98 in order to create a substantially air tight evacuation chamber 76 . Moreover, closure of the lid 14 causes the annular sealing elements 80 and 44 to come into sealing engagement, thus communicating the connection ports 44 and 78 which are of course well outside the boundaries of chamber 76 . Furthermore, with closure of the lid 14 , the backing member 75 comes into registry with sealing element 40 beneath strip 42 . Next, the control buttons 52 are manipulated in order to first evacuate air from package 100 and then to seal the open end 98 . Alternatively, these steps may be automatically initiated by the panel 48 whenever the lid 14 is closed. In either case, the vacuum pump 82 is operated which first serves to evacuate air from package 100 . The pump 82 exhausts the air from the package through port 71 , insert 70 , first conduit 88 , connection ports 78 , 44 , second conduit 90 , vacuum conduit 84 and exhaust conduit 86 . During this same time, a vacuum is drawn in third conduit 96 and thereby the bladder housing 34 . Because the interior of the bladder is vented to atmosphere, the negative pressure created within the housing 34 by the pump 82 serves to expand bladder 36 . It has been determined that the illustrated embodiment advantageously ensures that bladder expansion proceeds relatively slowly as compared with evacuation of package 100 , and thus the bladder expansion does not impede the desired package air evacuation. However, if necessary, the conduit assembly 18 may be provided with a flow restrictor or valve (both not shown) within the third conduit 96 to ensure such operational timing. After a predetermined time of vacuum pump operation calculated to remove substantially all air from package 100 while effecting vacuum induced expansion of bladder 36 , the formerly open end 98 of package 100 is closed. At this point the resistance heating element 40 is energized, quickly developing sufficient heat to fuse the plies of open end 98 , thus sealing the package 100 . The backing strip 75 ensures sufficient engagement (through the strip 42 ) between the element 40 and package 100 to provide the desired sealing of the open end 98 . After such sealing, the lid 14 is again opened, and the evacuated and sealed package is removed. A particular feature of the construction of machine 10 resides in provision of an essentially flat, continuous sealing surface 28 defined by part of the illustrated top wall 28 , which is entirely free of concavities or other surface features which collect fluids or solids. Thus, this upper surface is readily cleanable and more sanitary. The preferred forms of the invention described above are to be used as illustration only, and should not be utilized in a limiting sense in interpreting the scope of the present invention. Obvious modifications to the exemplary embodiments, as hereinabove set forth, could be readily made by those skilled in the art without departing from the spirit of the present invention. The inventors hereby state their intent to rely on the Doctrine of Equivalents to determine and assess the reasonably fair scope of the present invention as pertains to any apparatus not materially departing from but outside the literal scope of the invention as set forth in the following claims.	A vacuum packaging machine ( 10 ) is provided having a base ( 12 ) and a pivotally mounted lid ( 14 ) which cooperatively define a package air evacuation chamber ( 76 ) adapted to receive the open end ( 98 ) of a filled flexible package ( 100 ), thereby allowing evacuation of air from the package ( 100 ) and heat sealing of end ( 98 ). The machine ( 10 ) is characterized by an essentially flat and uninterrupted, easily cleanable base upper wall ( 28 ) which eliminates concavities in the like which can lead to unsanitary collection of fluids or solids. The machine ( 10 ) also has a vacuum source ( 16 ) and a vacuum conduit assembly ( 18 ) the latter having conduits within base ( 12 ) and lid ( 14 ).	1
FIELD OF THE INVENTION [0001] The present invention relates to management of warehouse functions, and more particularly to computer program-implemented management of warehouse functions. BACKGROUND OF THE INVENTION [0002] Material handing rules, customer requirements, storage constraints, and efficiency, place complex demands on the modern warehouse. Warehouse management systems enable a warehouse to dispatch tasks and manage inventory. Currently many decisions within a warehouse, however, are left for an operator and/or supervisor to perform, demanding a high degree of training, but still yielding sub-optimal results and occasionally, serious mistakes. [0003] A common warehouse management system 10 is illustrated in FIG. 1 . The system has a number of system defined rules 20 . The rules execution function 40 uses the attributes of a specific request 30 and an applicable system defined rule to manipulate a database 50 containing such information as quantity of inventory, location of inventory, etc. The warehouse management system 10 then provides the user with a solution 60 . For example, a particular item may have just been received. The user can enter the description of the item, and the warehouse management system will tell the user where current stock of the same item is located, so that the new quantity can be added to the existing quantity in the same location. [0004] Effectiveness can be increased by customizing the warehouse management system in accordance with the users specific business, processes, and needs. Customization in traditional systems entails going back to the software vendor or a third party, to make modifications to the system defined rules and or adding additional rules to model processes of the specific user. However such customization results in increased systems costs, difficulty in upgrading, and may also make it difficult for the user to change their area or way of business in response to changing customer needs. SUMMARY OF THE INVENTION [0005] The present invention enables the efficient management of inventory, personnel and space in a warehouse or supply chain. A rules engine, in the warehouse management system, provides a flexible and customizable repository for modeling many different types of processes used to effectively manage a warehouse. A warehouse management system is then able to provide intelligent solutions in response to requested actions performed in the warehouse. Thus a decision making process of warehouse management systems is automated, removing it from the operator and thereby reducing mistakes and increasing efficiency. [0006] Intelligent solutions are obtained from manipulation of a warehouse database, by the rules engine. The rules engine allows each individual warehouse to create rules to model the processes followed by the warehouse. The rules engine is also able to execute the rules, which manipulate the warehouse database to find intelligent solutions. [0007] In one embodiment, the present invention is implemented as a process for obtaining intelligent solutions for management of warehouse functions. The process of obtaining intelligent solutions includes the steps of receiving a request to perform an action in the warehouse. The request to perform an action is comprised of a list of attributes, which act to characterize the requested action. A hierarchical search, based upon the specific attributes, is then performed on a database. The database contains various information about the items in a warehouse. An intelligent solution is provided based upon information contained in the database, which best matches, the attributes of the requested action. [0008] In so doing, the rules execution function intelligently: suggests material allocations for picking, suggests put away locations for LPNs, assigns tasks to resources with appropriate training and equipment, assigns cost groups to transactions, and assures internal, customer, and carrier compliant labels. [0009] In a second embodiment of the present invention, a warehouse management system provides a means for obtaining an intelligent solution to a requested management action performed in the warehouse. The warehouse management system includes a means for defining rules to model the requested management action based upon logic defined by the user. The warehouse management system also includes a means for manipulating a database. The database contains elements describing the items contained in the warehouse. The method of manipulating the database is based upon the defined rules and the requested management action. [0010] In a third embodiment of the present invention, a warehouse management system provides for a rules creation function and a rules execution function. The rules creation function is capable of translating user defined logic, which models warehouse processes, into user defined rules. The rules execution function is capable of manipulating a database, containing information about the contents of a warehouse, according to the user defined rules and system defined rules. The manipulation of the database according to the user defined rules and system defined rules provides the rules execution function with the ability to provide intelligent solutions to a requested action. [0011] In so doing, the rules execution function processes requests by starting at a highest priority criteria of an applicable rule, and continues searching in the order of priority unit a matching criteria is found or until it reaches a lowest priority criteria. The rules execution function then searches a strategy associated with the matching criterion. Additional attributes of the request and strategy sequence determine which strategy is selected for the matching criteria. The rule execution function then searches one or more solutions associated with the matching strategy using additional attributes and solution sequence. The solution selected is the one or more solutions that satisfy all the restrictions of the rule. [0012] In a forth embodiment of the present invention, automated management of a warehouse is implemented by creating user defined rules. The user defined rules, along with system defined rules are then executed to obtain an intelligent solution. [0013] In fifth embodiment of the present invention, a process for creating user defined rules is implemented by defining one or more solutions and selecting one or more criteria. The criteria are the standards or tests upon which the user defined rules select a particular solution. [0014] In a sixth embodiment of the invention, user defined rules are created in a hierarchical structure that allows for efficient operation. Creating a rule is divide into four main steps: identifying a rule type; selecting and prioritizing one or more criteria, defining one or more strategies for each of the selected criteria, and finally defining one or solutions for each of the selected criteria and or solutions. BRIEF DESCRIPTION OF THE DRAWINGS [0015] The present invention is illustrated by way of example and not by way of limitation, in the figures of the accompanying drawings and in which like reference numerals refer to similar elements and in which: [0016] FIG. 1 shows a block diagram of a warehouse management system, according to the prior art. [0017] FIG. 2 shows a block diagram of a warehouse management system, according to one embodiment of the present invention. [0018] FIG. 3 shows a hierarchical structure of a possible user defined rule. [0019] FIG. 4 shows a flow diagram of a process for creating a user defined rule, according to another embodiment of the present invention. [0020] FIG. 5 shows a hierarchical structure of a possible user defined rule created by a rules creation function. According to another embodiment of the present invention. [0021] FIG. 6 shows a flow diagram of a second embodiment of a warehouse management system. [0022] FIG. 7 shows a hierarchical structure of a possible user defined rule created by a rules creation function, according to another embodiment of the present invention. [0023] FIGS. 8A-8D shows an example of a possible graphical user interface implementation of a rules creation function, according to another embodiment of the present invention. [0024] FIG. 9 shows a block diagram of a warehouse management system, according to another embodiment of the present invention. [0025] FIG. 10 shows a block diagram of a warehouse management system, according to another embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION [0026] Reference will now be made in detail to the embodiments of the invention, examples of which are illustrated in the accompanying drawings. While the invention will be described in conjunction with the preferred embodiments, it will be understood that they are not intended to limit the invention to these embodiments. On the contrary, the invention is intended to cover alternatives, modifications and equivalents, which may be included within the spirit and scope of the invention as defined by the appended claims. Furthermore, in the following detailed description of the present invention, numerous specific details are set forth in order to provide a thorough understanding of the present invention. However, it will be obvious to one of ordinary skill in the art that the present invention may be practiced without these specific details. In other instances, well known methods, procedures, and components have not been described in detail as not to unnecessarily obscure aspects of the present invention. [0027] Referring now to FIG. 2 , a diagram of a warehouse management system 70 in accordance with one embodiment of the present invention is shown. The warehouse management system 70 includes a rules engine 80 communicatively coupled to a warehouse database 140 . The rules engine includes a rules creation function 100 , one or more user defined rules & system defined rules 110 , and a rules execution function 130 . [0028] The rules engine 80 provides an intelligent solution 150 in response to a requested action 120 performed in the warehouse. The intelligent solution 150 is obtained by manipulation of the warehouse database 140 by the rule rules execution function 130 , based upon the user defined rules and or system defined rules 110 . The user defined rules and system defined rules 110 are capable of modeling any warehouse process 90 . The warehouse database 140 contains information about the contents of a warehouse and elements describing them. [0029] The rules engine 80 has two primary features: a rules creation function 100 and a rules execution function 130 . The rules creation function 100 is used to create user defined rules that model the various warehouse processes 90 (also referred to as user defined logic). The rules execution function 130 uses the user defined rules and system defined rules 110 , along with the attributes of a requested action 120 , to manipulate the warehouse database 140 in order to provide the intelligent solution. [0030] FIG. 3 shows a hierarchical structure of a user defined rule 160 , in accordance with another embodiment of the present invention. The user defined rule 160 includes one or more criteria 170 , one or more strategies 180 , and one or more solutions 190 . [0031] The user defined rule consists of a complete relationship between the criteria 170 , strategies 180 , and solutions 190 , used to fulfill a particular warehouse process. The relationship between each level of the hierarchical structure consists of one or more restrictions. A user defined rule can be based on nearly any field in a warehouse database. [0032] FIG. 4 shows the process of creating a user defined rule 200 as implemented by a rules creation function, in accordance with one embodiment of the present invention. The process of creating a user defined rule 200 includes: identifying the rule type 210 ; selecting applicable criteria, and prioritizing the criteria 220 ; defining strategies for each criteria 230 ; and finally defining solutions 250 . [0033] The rule type 210 is the name of the rule that implements a particular warehouse process, such as pick, put away, task type assignment, cost group assignment, or label format assignment. [0034] The criteria 220 used for each rule type are then selected. Criteria are the standards on which judgments or decisions are based. Examples of criteria may include: Item category, item, customer, freight carrier, order type, default, etc. It is also possible to define and sequence any sub-criteria, such as perishable, summer seasonal, winter season, for a criterion such as item category. Not all the available criteria need to be assigned in the rule type. In fact, it is unlikely that an organization will need more than three or four criteria in each rule. Next the criteria need to be prioritized. The most specific criteria is designated as having the highest priority, with the next less specific criteria given the next highest priority, until the most general criteria is given the lowest priority. The priority determines the order in which a rules execution function will search for a criterion that matches one or more attributes of a requested action. [0035] An example of a possible user defined rule is depicted in FIG. 5 . The example illustrates the selection of three criteria: item 260 , item category 270 , and organization 280 . Item category has three sub-criteria sequenced in the order of perishable 300 , summer seasonal 310 , winter seasonal 320 . Item 260 is the most specific criteria and is thus assigned the highest priority, denoted by (10). Item category 270 is assigned an intermediate priority, denoted by (20). Organization 280 is the most general criteria and is thus assigned the lowest priority, denoted by (30). [0036] The strategies are an ordered sequence of solutions that are used to try to fulfill complex requested actions. Strategies are defined, such as quality, never comingle, refrigerate, off season, on season, default put away, etc. The strategies are then associated with the applicable criteria. Common occurrences of strategies can be combined, potentially creating a many to many relationship. [0037] For example, FIG. 5 shows the defining of five strategies: never comingle 350 , refrigerate 360 , off season 370 , on season 380 , default put away 390 . Each strategy is associated with applicable criteria. The summer seasonal 310 and winter seasonal 320 criteria each have common occurrences of the on season 380 and off season 370 strategies. Therefore the two on season and two off season strategies can be combined creating multiple to multiple relationships with summer and winter season criteria. [0038] Solutions are then defined and are associated with applicable strategies or criteria. Sequencing of the solutions will determine the order chosen. Again, common occurrences of solutions can be combined, potentially creating a many to many relationship. [0039] For example, FIG. 5 shows the defining of six solutions: put in empty locator 410 , put into any location but do not comingle 420 , put into refrigerated location 430 , put into location with rack #> 3 440 , put in location with rack #<= 3 450 , put into any locator 460 . [0040] As can be seen from FIG. 5 , the solutions along with permitted associations between solution and strategy, strategy and criteria, and solution and criteria, represent the various restrictions of a rule. [0041] The schematic represented by FIG. 5 , however, would grow to complex to construct for all but the simplest cases. In another embodiment of the invention, a navigator-like approach can be taken, instead, to map out real-life systems. For example: [0000] Rule Type Criteria Sub-Criteria Strategy Solution [0042] The example of FIG. 5 can be mapped out as: [0000] Put Away Rules (10) Item PR11568 (10) Never Commingle Strategy (10) Put away into empty locator (20) Put away into any locator, do not commingle (20) Category Perishable (10) Refrigerated Strategy (10) Put into refrigerated locator Summer Seasonal (10) On Season Strategy (mar-sep) (10) Put away into locator with rack > 3 (20) Put away into any locator (20) Off Season Strategy (oct-feb) (10) Put away into locator with rack <=3 (20) Put away into any locator Winter Seasonal (10) On Season Strategy (oct-feb) (10) Put away into locator with rack <=3 (20) Put away into any locator (20) Off Season Strategy (mar-sep) (10) Put away into locator with rack > 3 (20) Put away into any locator (30) Default Default (10) Default Put Away Strategy (10) Put away into empty locator (20) Put away into any locator, do not commingle (30) Put away into any locator [0043] To read the navigator-like text schematic, one searches down the hierarchy of criteria until an attribute of the requested action matches. The first strategy that is applicable and currently effective for the matching criteria is selected. Then one goes down the solutions of the strategies in order. The numbers in parentheses indicates the priority of the corresponding criterion or the sequence of the strategy or solution. [0044] FIG. 6 shows a warehouse management system in accordance with an alternative embodiment of the present invention. A rules creation function 470 receives user defined logic 465 and creates user defined rules 555 therefrom. A rules execution function 565 uses the user defined rules 555 to manipulate a database 570 in order to provide an intelligent solution 575 in response to one or more attributes of a requested action 560 . [0045] The rules creation function 470 is used to perform the following steps to create the user defined rules 555 : specify an entity 475 , select a: rule type 480 , select applicable criteria and prioritize the selected criteria 490 , define one or more strategies 500 , define one or more solutions 510 , sequence the solutions 520 , assign the solutions to the related strategies and or the criteria 530 , sequence the strategies 540 , and assign the strategies to the related criteria 550 . [0046] The rules creation function can be used to obtain an integrated warehouse management systems across a full chain of related entities. For example, the management systems for the raw material supplier, manufacturer, distributor, carriers, and other entities, could be integrated. Therefore, the rules creation function also provides for specifying the entity 470 for each rule type. [0047] FIG. 7 illustrates a possible picking rule used by a warehouse that carries strawberries. An example of user defined logic for picking strawberries can be summarized as including restrictions based upon quality and expiration, and restrictions based upon the customer. For example strawberries have lot grades of Excellent, Good, and Average. Restaurants and Retailers require Excellent strawberries when available, and Good strawberries only if necessary. However, Jam Manufacturers only need Average strawberries. The Warehouse wants to fill orders on a first expired first out (FEFO) basis. [0048] In the above example, the warehouse's requirements (Organization 640 ) are the most general. Specific customers have more restrictive requirements. Therefore, the Customer criterion 610 is selected and given highest priority. The Customer criterion 610 has Restaurants & Retailers 620 , and Jam Manufacturer 630 sub-criteria. The Restaurants & Retailers 620 sub-criterion is sequence before the Jam Manufacture 630 sub-criterion because it is more restrictive. [0049] The strawberry example requires four solutions. First the Restaurants & Retailers require picking of Excellent strawberries and the warehouse wants to fill the order on a FEFO (First Expire First Out) basis. If Excellent strawberries are not available they will accept Good strawberries. Again the warehouse will want to fill the order on a FEFO basis. Because Jam Manufactures only need Average strawberries, the warehouse will want to try to fill the order with Average strawberries, but will supply Good or Excellent if necessary. In the absence of the above requirements, the warehouse will supply strawberries on just a FEFO basis. This leads to four solutions: Excellent & FEFO pick 710 , Good & FEFO pick 720 , Average & FEFO pick 730 , Default FEFO pick 740 . [0050] The requirements of the Restaurants & Retailers can first be satisfied by the Excellent & FEFO pick and then by the Good & FEFO pick. The Jam Manufacturers requirements can be satisfied by the Average & FEFO pick and then by the Default FEFO pick. The warehouses restrictions are simply satisfied by the Default FEFO pick. Therefore, three strategies are required: Excellent/Good 670 , Average/Default 680 , and Default 690 . [0051] FIGS. 8A-8D depict a possible graphical user interface implementation for using a rules creation function in accordance with an embodiment of the present invention. FIG. 8A shows two view of a criteria priority form. The first view is used to select and prioritize applicable criteria; while the second view is used to specify and sequence sub-criteria. FIG. 8B shows two views of a defining solutions form. The first view is used to define solutions; while the second view is used to sort the solutions. FIG. 8C is a strategy form. The strategy form is used to define strategies and associate the defined solutions with the defined strategies. FIG. 8D is a strategy assignment form. The strategy assignment form is used to assign the defined strategies to the selected criteria. Furthermore, the rule creation function illustrated in FIGS. 8A-8D corresponds to the picking rule in FIG. 7 . [0052] First, criteria priority form, FIG. 8A , is used to specify criteria and their priority for each rule type. The rule type is specified 800 , then the specific criteria may be selected from a list of criteria, or may be defined in the Name and Description columns 810 . Priority is assigned to each criterion in the Priority column of the form 820 . The priority numbers need not be consecutive. The criteria with the lowest priority number will be examined first, the criteria with the next lowest priority number will be examined next, and so forth. Multiples of ten can be used at first to allow easy insertion of criteria in the future without having to reassign all the priority numbers. It is also possible to specify sub-criteria for each selected criteria. [0053] FIG. 8A illustrates the selection and sequencing of the criteria for picking of strawberries. The Customer criteria is selected and given highest priority. The Organization is also selected, from the list of available criteria, and assigned lowest priority. The Restaurant & Retailers and Jam Manufacturers sub-criteria for the Customer criterion are also specified. [0054] Next the various solutions are created using the defining solutions form, FIG. 8B . The rule type is specified 800 , then a solution name and a description of the solution is designated 830 , 840 . The body of the solution is then entered 900 . Each row corresponds to an element, and multiple rows can be joined with AND and OR operators 915 . By entering opening and closing parentheses at the beginning and ending of lines 920 970 , complex compound statements can be formed. The sequence column 910 is used to specify the sequence in which the elements are linked together. The sequence numbers need not be consecutive. The element with the lowest sequence number will be examined first, the element with the next lowest sequence number will be examined next, and so forth. Multiples of ten can be used at first to allow easy insertion of elements in the future without have to reassign all the element numbers. [0055] Objects 930 and parameters 940 form the heart of each line, and may be based on any field in a database. The objects 930 , parameters 940 , and their value fields 960 are context sensitive, so that only parameters particular to the selected object can be selected, and the user will only be prompted for a value if it is necessary. A quantity function 965 is specified for picking and put away rules, or a return value is specified for cost group, task, and label format rules. [0056] The sort tab 890 allows the list of locators, for a pick or put away task, to be sorted. The objects and parameters that can be used to specify sortation are a subset of those for which restrictions can be specified. Multiple sort criteria, such as FIFO and FEFO, can be used to break ties at lower levels. [0057] The rules engine comes preconfigured with several basic solutions. These solutions will not have the user defined checkbox 860 checked, and they cannot be edited. Solutions that are user defined can be edited, as long as they are not enabled 850, and the user defined checkbox cannot be unchecked. When solutions are enabled via the checkbox, they can be assigned to strategies, but enabled solutions cannot be edited. Upon enabling the solution, the solution will be checked for correct syntax. [0058] Solutions can be either entity (i.e. warehouses and the like) specific, or shared between entities by checking the common for all entities checkbox 880 . For pick, put away, and cost group rules, making solutions common to all entities does not necessarily mean that all entities use that solution, only that it is possible for a strategy in another entity to use that solution. However, for task type and label format rules, making solutions common to all entities means that all entities use that solution, as there are no strategies or criteria assignment for these types of solutions. [0059] The minimum pick task button 870 , available only for a picking task solution, attempts to minimize the number of picks required for a task, subject to the restrictions, but regardless of the sort criteria. Units of measure and unit of measure conversions are defined in the units of measure form, and assigned to the subinventory as the pick unit of measure. [0060] FIG. 8B illustrates the defining of the Excellent & FEFO solution for the strawberry example. [0061] Third, strategies are constructed from one or more solutions. Strategies are a sequence of solutions that will be tried to allocate material or space to fulfill a request. Solutions can be reused for multiple strategies. Solutions can also be valid only during specific period of time. [0062] As illustrated in the strategies form, FIG. 8C , the rule type 800 is specified along with specifying the strategy 980 and a description of the strategy 990 . The applicable previously defined solution names are then specified 1030 . The sequence number 1040 specifies the order in which the solutions are executed. The sequence numbers need not be consecutive. The solution with the lowest sequence number will be examined first, the solution with the next lowest sequence number will be examined next, and so forth. Multiples of ten can be used at first to allow easy insertion of solutions in the future without have to reassign all the sequence numbers. [0063] The solutions available to be assigned to the particular strategy are only those solutions that are of the same rule type as the strategy, and are further limited by the current organization. [0064] Solutions can also be valid only during specific period of time 1020 . Always is also an option for the effective date. The user defined check box 1000 is identical to the one in the solutions form. Preconfigured strategies cannot be modified. When a strategy is enabled 1010, it cannot be changed. Furthermore, solutions that are used in an enabled strategy cannot be disabled. All strategies that used a particular solution must be disabled before the solution is disabled, this prevents potential data corruption problems. [0065] FIG. 8C , illustrates the defining of the excellent/good solution, and the assigning of the Excellent & FEFO pick and Good & FEFO pick to the solution. [0066] Finally, strategies are assigned to criteria using the strategy assignment form, FIG. 8D . A criteria selected in the criteria priority form is specified 1060 , along with the sub-criteria if applicable 1070 . As before, sequence numbers 1080 are used to order the strategies. Strategies of different types can be assigned to the same criteria. However, the rules engine stops searching for a strategy when it comes to the first applicable strategy. Therefore, if multiple strategies of the same type are effective during the same period, only the one with the lowest sequence number will be selected. [0067] FIG. 8D , illustrates the assigning of the Excellent/Good strategy to the Restaurants & Retailers sub-criteria of the customer criteria. [0068] The implementation of translating the above specified logic into code for use by the rules engine is well know to persons in the art, and therefore will not be described. [0069] In another embodiment of the invention, a rules execution function is capable of utilizing a user defined rule in response to a requested action to manipulate a warehouse database. The rules execution function is then able to provide an intelligent solution. [0070] The rules execution function processes the requested action, by comparing the attributes of the requests to the criteria of an applicable rule. The rules execution function starts at the highest priority criteria, and continues searching in the order of priority until a criterion matching an attribute is found or until it reaches the lowest priority criteria. Additional attributes and strategy sequence determine which strategy is selected for the matching criterion. The rules execution function then searches the solutions associated with the matching strategy using additional attributes and solution sequence. The solution selected is one or more solutions that satisfy all the restrictions of the rule. [0071] In an alternative feature, if a “Partial Success Allowed” box on the strategy is checked, then the rules execution function goes through all the solutions in a strategy in sequence until it allocates the entire request. For example, the rules execution function will go through all the solutions in a strategy until enough material is found in the locators to fulfill the pick request. Similarly, the rules execution function will go through all the solutions in a strategy until enough capacity is found for the put away task. [0072] Using the strawberry example, of FIG. 7 , the warehouse receives a request for 3 cases of strawberries from a restaurant. The warehouse actually has 8 cases of excellent strawberries, 6 cases of good strawberries, and 10 cases of average strawberries as indicated in the database. For this example, the rules execution function finds a match between the restaurant attribute of the request and the Customer 610 criterion, Restaurants & Retailers sub-criterion 620 of the rule. Therefore, the rules execution function proceeds to the Excellent/Good strategy 670 . The strategy specifies that excellent strawberries will be picked first based upon the FEFO requirement of the warehouse 710 . The rules execution function will output a pick request for the 3 of the 8 cases of excellent strawberries that will expire first. [0073] Next the warehouse receives a request for 14 cases of strawberries from a jam producer. The rules execution function starts with the Customer criterion 610 , first looking at the Restaurants & Retailers sub-criteria 620 . Because the Restaurants & Retailers sub-criteria 620 does not match the jam producer attribute of the request, it will proceed to the next sequenced sub-criteria, Jam Manufacturer 630 . A match is found and the Average/Default strategy 680 is selected. The Average & FEFO pick solution 730 will be used first to fill the order. However, there are only 10 cases of—Average strawberries. Therefore, the rules execution function will also use the Default FEFO pick 740 to satisfy the order. The four cases of good strawberries that expire first will be selected to complete the order. [0074] For pick and put away tasks, the rules execution function stops going through additional solutions as soon as the entire task has been allocated. If a pick or put away task cannot be fully allocated within a solution, partial success will allow a task to be allocated across several solutions. [0075] In the case of a cost group assignment rule, the rules execution function returns a value as soon as the rules execution function comes to a solution where all the restrictions pass. For task type and label format assignments, the rules execution function goes through all solutions available under the criteria, in the specified sequence. [0076] The rules execution function stops searching for a strategy when it comes to the first applicable strategy. Therefore if multiple strategies of the same type are affective during the same period, only the one with the lowest sequence number will be selected. [0077] For the assignment type rules, the rules execution function returns a single value which is the type of label to be used, type of resource required for the task, or the cost group to be assigned to the transaction. [0078] For any move request, there must be applicable picking and put away rules. The rule execution function requires both picking and put away rules for every move order in order to ensure that a suggestion is never made to pick material that is unavailable or to place material in an area without adequate capacity. [0079] Unless the request should fail if specific restrictions are not met, and the task to unallocated or unassigned, a general default solution should always be the last solutions in the strategy or criteria. [0080] FIG. 9 shows another embodiment of the warehouse management system. A rules creation function 1110 receives user defined logic 1100 for implementing various warehouse processes. The rules creation function 1110 creates user defined rules 1120 from the user defined logic 1100 . The warehouse management system also comes preconfigured with system defined rules 1120 . A rules execution function 1140 manipulates a database 1150 in response to a requested action 1130 and an applicable user defined rule or system defined rule 1120 . The rules execution function 1140 outputs an intelligent solution as a result of manipulating the database 1150 . The requested action 1130 can be any of a pick request, put away request, cost group request, move request, or any other action to be performed in the warehouse. While the intelligent solution 1160 can be one or more pick suggestions, put away suggestions, task type assignments, cost group assignments, label format assignments, or any other action performed in the warehouse. [0081] Thus the warehouse management system provides for intelligent: picking; putting away; assigning transactions to cost groups; ensuring internal, carrier, and customer compliant labeling; assigning tasks to a resource with appropriate training or equipment; or any other process necessary to the operation of a warehouse. [0082] For example, the rules engine provides for intelligent solutions for put away location of new material, based upon virtually any user defined logic. Some possibilities include: minimizing item fragmentation, requiring no lot commingling in a locator, directing hazardous materials to a corresponding hazardous storage location, or placing season items in a sub-inventory department depending on time or year. [0083] Picking rules can also be created to factor any user defined logic. Some examples are to ensure stock rotation, or to meet customer requirements such as stock condition or quality, lot expiration date, or country of origin. Other logic examples include: first in first out (FIFO), first expired first out (FEFO), picking to deplete a location in order to free up additional warehouse space, or by cost group ownership, customer requirements that an entire order be filled by a single lot, or warehouse preferences that an item be picked from a single location can also be factored. [0084] Some examples of task type assignment logic that can be factored include: personnel skill sets, equipment requirements and capacity. For instance, hazardous tasks can be assigned only to personnel with the appropriate training received to work with hazardous goods, while put away to the top rack can be limited to personnel who operate high-reach forklifts. [0085] Cost group assignments can be based upon: sales channels such as internet order and in-store orders, vendor site, item categories such as refurbished, consigned, and company owned inventor, or even by item. [0086] User defined logic can also be used to select the appropriate label format, type, and printer, based on customer, carrier, item category, or transportation method. Other criteria may include: barcode symbologies, label durability, and lot control. [0087] FIG. 10 shows another embodiment of the warehouse management system. The warehouse management system comprises a user interface and repository module 1110 , a code generation module 1120 , and a run-time code execution module 1130 . The user interface and repository module 1110 supports the definition and storage of business rules. The code generation module 1120 supports the automated generation of code based upon the business rule. The run-time code execution module 1130 executes the generated code during the operation of the warehouse management system. [0088] The user interface and repository module 1110 allows the user to define and record business rules, using common business terms, into an organized set of logical conditions, preferences, measurements and effectivities. Once defined by the user, the organized set of logical conditions, preferences, measurements and effectivities, are automatically translated and implemented by the code generation module 1120 into an efficient set of code and operations to execute the process embodied in the business rule. The set of code and operations can then be automatically invoked by the warehouse management system whenever a transaction 1150 (such as a request to find the optimal inventory holding to satisfy an order) is processed. When invoked by the warehouse management system, the run-time execution module 1130 selects an appropriate business rule embodied in the code for a particular requested transaction. The run-time execution module 1130 then combines data from a warehouse database 1140 with the business rule embodied in the code in order to determine an intelligent result 1160 . [0089] Hence, embodiment of the present invention provide for a highly flexible way of defining and then implementing business rules, without having to resort to customization by the warehouse management system vendor or a third party software programmer. [0090] The foregoing descriptions of specific embodiments of the present invention have been presented for purposes of illustration and description. They are not intended to be exhaustive or to limit the invention to the precise forms disclosed, and obviously many modifications and variations are possible in light of the above teaching. The embodiments were chosen and described in order to best explain the principles of the invention and its practical application, to thereby enable others skilled in the art to best utilize the invention and various embodiments with various modifications as are suited to the particular use contemplated. It is intended that the scope of the invention be defined by the Claims appended hereto and their equivalents.	A novel rules engine which automates many warehouse processes, and provides for efficient management of a warehouse. The rules engine provides a flexible and customizable structure for modeling the many different types of processes governing the function of a warehouse. The rules engine translates business level logic into code for manipulating the warehouse database. The rules engine allows a user to create their own user logic for working with the database, which operates at a level of abstraction more feasible for the user. The rules engine understands the user logic by the way the user decides how to string various restrictions together. The rules engine implements the translation via its internal understanding of the structure of the particular application. Thus, the rules engine allows the user to define logic without understanding how to manipulate a database.	6
BACKGROUND [0001] 1. Field of the Invention [0002] The present invention relates generally to coverings for stair steps and, more particularly, to a removable mat for step treads of a stair. [0003] 2. Background Information [0004] Stairs consist of steps retained by side supports. A step typically consists of a horizontal member or tread and a vertical member or riser. In some instances stairs are constructed without risers. Therefore, the steps consist of only treads supported on each side by a support. The stair treads may be made from a variety of materials including wood, stone, plastic or other natural and man-made material. In all cases, it has been found advantageous to provide a tread covering. A tread covering can provide a safety aspect associated with the use of the stairs. This is especially true of stairs that are exposed to the elements such as stairs for recreational vehicles (RVs), trailers, campers, boats, docks, and the like. [0005] In response to the above-identified problem, various solutions have been developed. Typical tread coverings include carpet, rubber, or the like that is placed on the stair tread. One such step cover is illustrated in U.S. Pat. No. 115,717 issued to Dieterich et al. on Jun. 6, 1871 (hereinafter “the '717 patent”). The '717 patent provides a step cover consisting of a sheet or slab of vulcanized rubber or gutta-percha beveled on all four edges and contained within a frame. The frame is composed of overlapping and beveled strips that are secured together by screws. The step cover of the '717 patent, however, is disadvantageous for various reasons including the fact that it covers only the top side of the step and is secured to the step by screws. [0006] In U.S. Pat. No. 161,305 issued to Walter on Mar. 23, 1875 (hereinafter “the '305 patent”) there is disclosed a stair pad having a strip of carpet in a frame. The frame has a curved front edge that wraps over the curved edge of a step. Again, the stair pad of the '305 patent is disadvantageous for various reasons including those described above with respect to the '717 patent. In a similar manner, U.S. Pat. No. 815,391 issued to Weinstock on Mar. 20, 1906 (hereinafter “the '391 patent”), discloses a stair carpet holder having a frame with a biased hook on the front thereof for engaging the front stair edge. The stair carpet holder of the '391 patent, however, suffers from at least the same disadvantages as the others. [0007] U.S. Pat. No. 6,088,976 issued to Roy on Jul. 18, 2000 (hereinafter “the '976 patent”) discloses a removable non-skid step pad. The step pad includes a pad that is fastened around the stair tread. The pad portion of the '976 patent, however, does not extend about the entire tread and is designed to be placed on the tread in a specific manner that cannot be reversed. [0008] In view of the above, it would be advantageous to provide a stair mat that has a textured stepping surface that extends entirely around the tread. [0009] It would be further advantageous to provide a stair mat as indicated above that has a non-skid bearing surface that extends entirely about the tread, particularly in conjunction with the stepping surface. SUMMARY [0010] In accordance with the invention, there is provided a mat for a tread of a stair step wherein the step does not have a corresponding riser. The mat has a textured stepping surface that extends entirely around the tread. The mat is secured to itself once wrapped around the tread. Hook and loop fasteners are preferably used to secure one end of the mat with another. [0011] The mat preferably consists of a textured (e.g. corrugated) indoor-outdoor type carpet as the stepping surface such as a polypropylene carpet. The carpet includes a backing that consists of at least one layer of a rubber or similar elastomeric that provides a non-slip surface. The backing naturally also extends entirely around the tread and is adapted to be in contact with the tread surface. [0012] In one form, the subject invention is a mat for a stair tread. The mat includes a length of textured material having a first end and a second end, a backing material on one side of the textured material, and a closure formed as a first part disposed on a first end of the textured material and a second part disposed on the backing material on a second end opposite said first end. The closure securing the length of textured material onto a stair tread wherein the textured material extends 3600 about the stair tread. [0013] In another form, the subject invention is a mat for a tread of a riser-less stair. The mat includes a length of corrugated carpet defining a top surface, a bottom surface, a longitudinal length having first and second ends, and a short length having third and fourth ends. The longitudinal length of corrugated carpet is sufficient to extend entirely around a short length of the stair tread when installed on the stair tread. A non-skid material is disposed on the bottom surface of the corrugated carpet. A fastener is associated with the corrugated carpet and the non-skid material and is adapted to releasably hold the corrugated carpet around the stair tread. [0014] In another form, the subject invention is a mat for a riser-less step tread. The mat includes a length of polypropylene carpet having an underside surface and first and second longitudinal ends, a rubber backing disposed on the underside surface, and a releasable fastener having a first strip of first fastening material disposed on the polypropylene carpet at the first longitudinal end, and a second strip of second fastening material complementary to the first fastening material disposed on the backing at the second longitudinal end. The fastener allowing the polypropylene carpet to wrap around the tread and be secured thereon, wherein the polypropylene carpet creates a 360° surface around the tread. BRIEF DESCRIPTION OF THE DRAWINGS [0015] In the drawings: [0016] [0016]FIG. 1 is a perspective view of a flight of exemplary stairs on which the subject invention may be utilized; [0017] [0017]FIG. 2 is an enlarged side view of an exemplary embodiment of a mat made in accordance with the principles of the subject invention; [0018] [0018]FIG. 3 is a top plan view of the exemplary mat of FIG. 2 with one corner folded down to better illustrate the various features of the subject invention; [0019] [0019]FIG. 4 is a side view of the exemplary mat of FIG. 2 illustrating the manner in which the mat is installed on a stair tread; [0020] [0020]FIG. 5 is a perspective view of the stairs of FIG. 1, with each tread having the subject mat installed thereon; and [0021] [0021]FIG. 6 is a sectional view of one of the treads of the stairs of FIG. 4 taken along line 6 - 6 thereof showing a mat installed thereon. [0022] Corresponding reference characters indicate corresponding parts throughout the several views. DESCRIPTION OF THE PREFERRED EMBODIMENT [0023] Referring to FIG. 1, there is depicted an illustration of an exemplary flight of stairs generally designated 10 in which the subject invention may be used. It should be appreciated that the stairs 10 is only exemplary of the many types of stairs that can utilize the subject invention as described herein. While the stairs 10 is shown by itself, it should be appreciated that the stairs 10 may be part of or attached to a structure such as an RV, mobile home, camper, dock or the like. [0024] The stairs 10 includes a first side support, stringer or the like 12 and a second side support, stringer or the like 14 . Situated between the first and second side supports 12 and 14 is a plurality of treads 16 forming steps. The stairs 10 , and particularly the treads 16 do not have risers associated therewith. Thus the stairs 10 may be considered an open-tread stair or a riser-less stair. It should be appreciated that the subject invention is thus applicable to any type of open-tread or riser-less stair. Moreover, it should be appreciated that the number of steps or treads 16 in the flight of stairs 10 is irrelevant. The subject invention is applicable equally to a single step and a stair having a plurality of steps. [0025] Referring to FIGS. 2 and 3, an exemplary embodiment of a mat, generally designated 20 , in accordance with the principles of the subject invention is shown. The mat 20 has an outer surface 22 and an inner surface 24 . The outer surface 22 provides a stepping surface while the inner surface 24 provides a backing, contact or bearing surface. When installed on a tread as shown in FIGS. 4 and 5 and described below, the stepping surface 22 faces outward relative to the tread 16 while the contact surface 24 faces inward relative to the tread 16 . [0026] The stepping surface 22 is preferably formed of a textured material 26 that is preferably at least somewhat weatherproof or impervious to weather (e.g. rain, sleet, snow, sunshine, etc.). The textured material 26 is also preferably relatively easy to clean and is durable. One such material may be an indoor/outdoor type carpet such as a polypropylene carpet. In one form, the stepping surface 22 is formed of a corrugated polypropylene carpet. Of course, other carpets and/or materials may be used. [0027] The contact surface 24 is preferably formed of a non-skid material 28 . The non-skid material 28 forms a backing for the textured material 26 . The non-skid material 28 may be a rubber, elastomeric or other type of non-skid material that provides a positive traction (non-slip) surface. In one form as shown, the non-skid material 28 may consist of multiple plies 36 , 38 of material (having two or more layers). One ply 36 may be an underlayment such as roping, cording, or the like that provides a good foundational material. A second ply 38 may be an elastomeric or other non-skid material. Of course, the backing 28 may be formed of a single material, a single layer of a composite material, or the like. [0028] The mat 20 further includes a first retention portion 32 and a second retention portion 34 . The first and second retention portions 32 and 34 together form a releasable fastener 30 (see FIG. 4) that allows the mat 20 to join ends to thus be securely installed on a stair tread, and to easily release the two ends to uninstall (remove) the mat from the stair tread. In a preferred form, the fastener 30 comprises a loop portion and a hook portion. It should be appreciated that while the first portion 32 is depicted as the loop portion and the second portion 34 is depicted as the hook portion, the two are interchangeable. [0029] The loop portion 32 may constitute a strip of loop material that is applied to the textured material 26 . The hook portion 34 may constitute a strip of hook material that is applied to the backing 28 . Preferably, and as best seen in FIG. 3, the first (loop) portion 32 preferably extends at least, but not necessarily, substantially from one short side of the mat 20 to another short side of the mat 20 . The second portion 34 also preferably extends at least, but not necessarily, substantially from one short side of the mat 20 to another short side of the mat 20 . It should be appreciated that the mat 20 in FIG. 3 has one corner folded over in order to clearly illustrate the position and configuration of the second (hook) portion 34 . [0030] Referring to FIG. 4, the mat 20 is depicted being folded together as is done when the mat 20 is installed on a stair tread 16 . As the mat 20 is bent or folded around the tread 16 , the first and second portions 32 and 34 join. The mat 20 is thus formed into a continuous loop. Moreover, as the first and second portions 32 and 34 are releasably joined, the textured material 26 extends 360° about the mat 20 . As well, the backing material 28 extends 3600 about the mat 20 . [0031] In FIG. 5, there is depicted the exemplary flight of stairs 10 as first depicted in FIG. 1. In FIG. 5, each tread 16 has a mat 20 disposed thereon. As indicated above, the textured material 26 extends entirely around the short length of the tread 16 but not necessarily its length. The length may be variable both due to different size steps and desired amount of tread coverage. In this manner, if the mat 20 rotates on the tread 16 either intentionally or not, the textured material 26 always presents itself on the top of the tread 16 . [0032] The mat 20 may be manufactured in various sizes, colors, stepping materials, and the like. Various designs may be incorporated into the stepping material. Each mat may cover a given amount of stair tread to accommodate various step sizes. [0033] [0033]FIG. 6 shows a sectional view of the mat 20 installed on the tread 16 . It can be clearly seen that the textured material 26 extends 3600 around the short length of the tread 16 while the amount of the long length of the tread 16 that may or may not be covered depends on the size of the mat 20 . As well, the backing material 28 also extends 360° around the short length of the tread 16 . [0034] While this invention has been described as having a preferred design, the subject 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 subject 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 that fall within the limits of the appended claims.	A stair mat for a tread of a step includes a textured material such as corrugated, polypropylene carpet having a non-skid backing material such as rubber The stair mat is flexible and is adapted to surround the tread 16 such that the textured material extends 360° about the tread. The stair mat includes a closure such as Velcro® that is formed as a hook strip disposed on one side of the mat adjacent a first longitudinal end, and a loop strip disposed on another side of the mat adjacent a second longitudinal end.	4
FIELD OF THE INVENTION [0001] The present invention relates to the design of an environmentally benign total chlorine free (TCF) multistage delignifying bleaching sequences for non-wood AS/AQ (alkaline sulfite-anthraquinone) wheat straw pulp. Commercially available non-chlorinated chemicals have been sequenced into three novel processes to achieve paper of high utility. BACKGROUND OF INVENTION [0002] Wheat straw represents a large potential source of fiber; which is needed to manufacture paper where wood supply is scarce or expensive. Generally, straw is burned as waste and this results in environmental damage as well as lost of a possible cash crop. Many countries around the world including Pakistan, China, Turkey, Egypt, Spain, India and others use straw pulp to support to manufacture paper because of its ready availability (as industrial waste) and unavailability of wood (lack of enough forests). Since the use of wheat straw requires pulping and bleaching steps, this adds significantly to damaging environment through hazardous effluent discharges that adversely affect the eco-system. Many inventions are thus directly towards reducing the effluent load without affecting consumer supplies but none has fulfilled the gap between the industry need and the requirements of keeping environment clean. [0003] The goal in bleaching chemical pulps is to remove essentially the chromophoric groups (mostly the residual lignin) capable of absorbing visible light. Hypo-bleaching (using hypochlorites and acids), which is significantly damaging to environment, is the traditional approach still practiced because of its effectiveness to fully bleach the pulp at a low cost. However, the pulp quality deterioration and production of hazardous and persistent organochlorines are the major disadvantages in the use of hypochlorite and hypochlorous acid bleaching. [0004] Concerns about the environment and health due to chlorine bleaching resulted in the development of elemental chlorine free (ECF) and totally chlorine free (TCF) bleaching processes. The ECF sequences involve the use of chlorine dioxide that helps reduce the adsorbable organically bound halogens (AOX) while reducing dioxin discharges in wastewaters. The U.S. Pat. No. 5,164,043 to Griggs describes the use of ClO 2 as the delignifying and bleaching agent that selectively oxidizes lignin; however, the said invention remains difficult to handle, and exposes paper mill personnel to health hazard. [0005] TCF bleaching involves oxidative degradation of color rendering groups in the pulp. Oxygen, ozone, peroxides and peracids are the most common TCF agents for pulp bleaching but none of the TCF agents is alone capable of bleaching the pulp with full brightness without compromising its properties. TCF bleaching is relatively friendlier to ecology as compared to other bleaching sequences reported so far. [0006] During bleaching, chromophoric groups such as lignin must be degraded and washed away while celluloses are preserved to give structure and strength to the paper. A few studies have reported TCF bleaching sequences for different types of wheat straw pulp [Hedjazi, S. et al 2009; Niu, C. et al 2007 and Wang, H. et al 2003]. The availability of bleaching equipment (e.g., ozone generators) with complete workplace safety equipment and the cost of processing at the production (mill scale) are hurdles in the use of this process. Another practical approach for bleaching is the use of biological enzymes. A few studies on wheat straw recommend the use of enzymatic treatment prior to bleaching; however, the shelf life and cost remain the limitation factors in the complete adoption of this process. Also the enzymes alone have never been reported used to bleach the pulp with full brightness. The incorporation of enzymatic stage in a bleaching sequence is to selectively degrade the lignin contents and ultimately reduce the use of chlorinated or elemental chlorine free chemicals [Tolen et al., U.S. Pat. No. 7,368,036] or TCF sequence [Han, S. et al 2002 and Rancero, M. B. et al 2003]. [0007] The various processes of papermaking involve comparable steps except the choice of pulping and bleaching chemicals and their sequences for application in light of different composition of lingo-cellulosic contents of the raw materials used for paper making. The sequence of treatment developed for one type of fibrous pulp may not prove be applicable to other types, leaving a large unmet need for the development of new and improved bleaching strategies to treat different pulp varieties. [0008] The present invention reports selective and efficient bleaching sequences for AS/AQ wheat straw pulp where the conventional bleaching agents have been utilized in such a way that the amounts used, the reacting conditions employed and the sequences applied proved the preservation and protection of every type of pulp and paper properties with very low effluent load. REFERENCES [0000] Hedjazi, S. et al., “Alkaline Sulphite-anthraquinone (AS/AQ) pulping of wheat straw and totally chlorine free bleaching of pulps”, Industrial crops and products, 29 (1): 27-36 (2009) Niu, C. et al., “A study on the short sequence of totally chlorine free bleaching of wheat straw soda—AQ pulp”, Zhonghua Zhiye, 28 (8): 43-47 (2007) Wang, H. et al., “Strengthened ozone-TCF bleaching of low-kappa number wheat straw pulp”, Zhonghua Zhiye, 22 (8): 9-12 (2003) Han, S. et al., “TCF bleaching properties of wheat-straw pulps pre-treated by enzyme in a laccase-mediator system”, linchan Huaxue Yu Gongye, 22 (4): 5-9 (2002) Rancero, M. B. et al., “TCF bleaching of wheat straw pulp using ozone and xylanase, Part A: Paper Quality Assessment”, Bioresource Technology, 87 (3): 305-314 (2003) SUMMARY OF INVENTION [0014] The invention comprises of multistage TCF bleaching sequences ( FIG. 1 ) for delignifying bleaching of AS/AQ wheat straw pulp to achieve a high quality paper and to significantly reduce the bleaching-effluent load. [0015] Prior to the beginning of treatment sequence, shives (non/semi-bleachable pulp components) are removed from the AS/AQ pulp. The next step is the removal of metal ions from the straw pulp. Iron is the most crucial among the metals for the wheat straw; and its presence reduces the selectivity of bleaching responses towards pulp. Thus acidic pre-treatment is carried out to remove the metal residues of the straw pulp as much as possible without inducing significant degradation of pulp. The next step is oxygen delignification in alkaline media to degrade lignin contents followed by extended delignifying bleaching using aqueous solution of commercially available inorganic salt, oxone (Ps). Further comprised of three different embodiments optimized as additional bleaching steps to AOPs-stage AS/AQ straw pulp to achieve the brightness>80% ISO: YP 0 i.e., Incorporation of reductive sequence prior to peroxide treatment: ISO Brightness 82.0%, acid insoluble lignin 1.12% and CED viscosity 10.60 Cp EP 0 i.e., A conventional extraction stage prior to peroxide treatment: ISO Brightness 82.5%, acid insoluble lignin 0.7% and CED viscosity 11.93 Cp P 0 P 1 i.e., Two consecutive peroxide stages: Brightness 81.6%, acid insoluble lignin 1.02% and CED viscosity 11.90 Cp [0019] Washing step follows every stage in each of the developed sequences. Three different embodiments as addition bleaching steps results in three sequence options: AOPsYP 0 , AOPsEP 0 and AOPsP 0 P 1 where all are effective in removal of lignin at large and protecting cellulose fiber from damaging with different bleaching agents. BRIEF DESCRIPTIONS OF THE DRAWINGS [0020] FIG. 1 Flow sheet of the developed TCF bleaching sequences [0021] FIG. 2 Selectivity towards delignification in terms of % decrease in acid soluble lignin and % increase of α-cellulose for acid (A) and EDTA (Q) pre-treated AS/AQ wheat straw pulp. [0022] FIG. 3 Effectiveness of chemical additive sequence during O-treatment where M I represents addition of MgCO 3 solution followed by NaOH solution addition; MII represents combined addition of solutions of MgCO 3 and NaOH and MIII represents addition of NaOH solution followed by MgCO 3 solution addition [0023] FIG. 4 AS/AQ wheat straw pulp exposures to dithionite (Y): Yellowness (CIE %) verses time and temperature. [0024] FIG. 5 Advantage of incorporating Y stage in AOPsYP 0 sequence towards reducing the peroxide consumption [0025] FIG. 6 Advantage of utilization of stabilizer U towards brightness increase in peroxide bleaching stage [0026] FIG. 7 Load comparison of effluents for Hypo (H) verses TCF bleaching sequences: AOPsYP 0 , AOPsEP 0 and AOPsP 0 P 1 DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT [0027] The letters, abbreviation or terms used to express bleaching and/or other embodiments are described as follows: A—Acidification [0028] O—Oxygen delignification Ps—Oxone [0029] E—Alkaline extraction Y—Sodium dithionite P—Peroxide [0030] P 0 —1 st stage Peroxide P 1 —2 nd stage Peroxide Q—Chelating agent H—Hypo-bleaching (Calcium hypochlorite) W—Wash water Un—unbleached AS/AQ wheat straw pulp TCF—Total chlorine free AS/AQ—Alkaline sulfite-anthraquinone; AS/AQ wheat straw pulp used for this invention was prepared under conditions described in Table I: [0000] TABLE I AS/AQ pulping Conditions Chemical doses on oven dried pulp pressure Temp. Time 14.0% sodium sulphite 145-160 psi 180-185° C. 45 min. 0.05% anthraquinone 0.025% Surfactant Consistency—Concentration of pulp suspensions in water calculated as: [percent consistency={(weight of oven-dried pulp specimen/net weight of original pulp specimen)×100}] Medium Consistency—ranges usually 6-20% CED viscosity—Viscosity of 0.5% cellulose solution, using 0.5 M cupriethylenediamine as a solvent Kappa Number—Determination of the relative hardness, bleachability, or degree of delignification of the pulp Brightness—Numerical value of the blue reflectance factor of the handsheets Whiteness—Extent to which paper reflects light of all wavelengths throughout the visible spectrum Yellowness—Degree of discoloration of pulp Opacity—Property of the paper which governs the extent to which one sheet of paper visually obscures printed matter on the underlying sheet of similar paper Grammage—Density of paper in grams per square meter Bulk—Flexibility of printing paper and is the physical thickness of the piece of a paper in relation to its weight Tear Index—Tearing resistance of a paper sheet divided by its grammage Tensile Index—Rupturing of test paper piece stretched at constant rate of elongation with respect to its grammage Burst Index—Maximum hydrostatic pressure required to produce rupture in a test specimen with respect to its grammage Elongation—Percentage of tensile strain produced in test specimen before rupture Caliper—Thickness of paper Porosity—Measure of total circulating air voids in a sheet structure. It is highly important in determining the printability on a paper sheet. [0031] Standard methods used throughout the process are cited in Table II. [0000] TABLE II Standard Methods used During this Process Tests International standard methods CED Viscosity TAPPI Method: T 230 om-94 Kappa Number TAPPI Method: T 236 cm-85 α-cellulose TAPPI Method: T 230 cm-99 Consistency TAPPI Method: T 240 om-93 Formation of Handsheets TAPPI Method: T 205 sp-95 Brightness TAPPI Method: T 452 om-98 Grammage ISO Method: ISO 536: 1995 (E) Burst Index TAPPI Method: T 403 om-97 Tensile Index ISO Method: ISO 1924-2: 1994 (E) Tear Index ISO Method: ISO 1974: 1990 (E) Caliper TAPPI Method: T 411 om-97 Bulk ISO Method: 534: 1998 (E) Acid Insoluble Lignin TAPPI Method: T 222 om-98 DETAILED DESCRIPTION OF THE INVENTION [0032] This invention provides bleaching sequences comprised of environmentally benign total chlorine free oxidative and/or reductive reagents. AS/AQ wheat straw pulp cooked at the conditions described in the Table 1 showed the values ISO brightness: 43.9%, Kappa number: 12.4, CED viscosity: 13.1 Cp, acid insoluble lignin: 7.6%, α-cellulose: 76.6% and burst index: 2.8 kPa·m 2 g −1 . [0033] Shives are fibrous bundles in straw pulp, which are responsible for reducing the strength and runnability of unbleached pulp and appear as dust particles in bleached paper. To prepare the unbleached AS/AQ pulp, it was screened through 0.15 mm slot screen reduce the shive contents as much as possible. Dewatering the pulp to medium consistency and then acidification thereafter followed the de-shiving. A-Treatment [0034] Acidification of the wheat straw pulp comprised the doses of 0.5% to 2.0% of 4.0 N sulfuric acid on oven dried pulp basis, preferably 2.0% on oven dried pulp; consistency may range from 10.0 to 30.0% (15.0% optimized due to increased in % ISO brightness) while the treatment was selected to be carried out at ambient temperature for 10-15 minutes. The effects of temperature rage 25° C. to 75° C. and time 10 to 30 minutes were investigated on straw pulp. Any increase in ambient temperature and delay in treatment time period decreased the pulp brightness, which is set forth as primary target to decide on the preferred condition for the entire processes involved in bleaching sequences (Table II). Acid solubilized the sequestered metals of wheat straw pulp helped reduce the kappa number and lignin. Along with this, the pulp brightness also increased during acid treatment. [0000] TABLE III Conditions of Acidification and Chelation pulp % of chemicals Treatment consistency on o.d.p Temp. Time A 15.0% 2.0% H 2 SO 4 Ambient temp: 10-15 min. (25-35° C.) Q 3.0% 1.0% EDTA 80° C. 60.0 min. [0035] The presence of metal ions catalyses the cellulose degradation and discolors the pulp. FIG. 2 describes that the mild pre-treatment of wheat straw pulp with sulfuric acid resulting in more selectivity towards delignification when oxygen treated, by retarding cellulose degradation as compared to conventional EDTA chelation (Q). Metal removal also preserves the pulp strength properties during oxygen delignification. Acid is a preferred pre-treatment method for this invention over EDTA because of its ability of removing 90% iron from AS/AQ wheat straw pulp as compared to chelating agent that removes only 25% iron. [0036] Both the A and Q treated AS/AQ wheat straw pulps were washed with distilled water to neutral pH to avoid any further addition of metal ions from fresh/washed water. The water-washed pulp was pressed to medium consistency preferably >10.0%. O-Treatment [0037] In this treatment, the pulp is directed to a revolving digester for oxygen delignification, where the process is carried out at 10.0% consistency and comprised of the addition and homogenous distribution of aqueous solution of MgCO 3 to pulp fiber followed by the addition and homogenous mixing of aqueous solution of NaOH. Oxygen was then fed after about 5 to 10 minutes at 70 to 75 psi gauge pressure and the process was then continued for 60 minutes in continuous circulating closed loop digester (Table IV). [0000] TABLE IV Conditions for oxygen delignification Pulp Oxygen Percentage of chemicals consistency pressure on oven dried pulp Temp. Time 10.0% 70-75 psi 2.0% NaOH 100° C. 60 min. 0.3% MgCO 3 [0038] FIG. 3 describes the addition of MgCO 3 solution to AS/AQ pulp fiber before NaOH solution addition and it was found more effective for delignification during O-treatment and protection of other pulp properties such as viscosity, strength etc. The selection of either MgCO 3 or MgSO 4 for delignification process does not necessarily affect the pulp properties as that the brightness is increased by only 1 unit % ISO when MgCO 3 is preferred for the process. By following the presented method up to this stage in this invention, kappa number of the pulp was reduced to approximately 38% with reference to A-treated pulp (˜46% overall reduction in kappa number) with essentially no damage to cellulose component of pulp which is also evident from the CED viscosity results (Table IX). [0039] The delignified pulp is washed to remove the solubilized lignin contents due to oxygen treatment and pressed to consistency>10%. Ps-Treatment [0040] This step of invention comprises of extended delignification and bleaching of AO treated AS/AQ pulp with commercially available product: oxone (Ps) in which peroxymonosulphate is an active agent for the reaction. Oxone treatment comprises of the addition of 0.5-10.0% alkali and 3.0-7.0% oxone charge. [0041] Increasing the alkali dose from 0.5-1.0-1.5% dose slightly effects the brightness from 64.5% to 64.8% to 65.1% ISO respectively. Further alkali addition reduces the brightness percent ISO. No significant brightness jump is observed beyond this alkali consumption; thus the dose preferred for this stage is 0.5%. Absence of alkali in Ps-stage shows>7.0 units decreased brightness level (57.2% ISO) as compared to Ps-stage with 0.5% alkali. [0042] Oxone charge for the Ps-treatment may range from 3.0 to 10.0% on oven dried pulp; but increasing the charge in the presence of 0.5% alkali from 3.0 to 5.0% aqueous oxone solution on oven dried pulp increases the brightness by two units while further increase from 5.0%-10.0% oxone charge on oven dried pulp increases the brightness by only about <0.4 units of ISO brightness. [0043] Ali et al. patent (U.S. Pat. No. 5,656,130) describes the use of peroxyacid salts at temperature (˜20° C. to 50° C.) to pulp bleaching mill after conventional bleaching stages to further increase the brightness without substantial loss in pulp fiber strength. While practicing the present invention an elevated temperature of 65° C. is preferred to increase the selectivity of oxone towards lignin removal. The Ps-treatment can be carried out at fairly flexible temp. (Ambient-95° C.), time (30-180 min.) and consistency (5%-35%) ranges. Preferred Ps-treatment conditions are mention herein as Table V: [0000] TABLE V Conditions for Ps-treatment Pulp Aqueous oxone consistency for solution charge Aqueous Ps-treatment on oven dried pulp alkali dose Temp. Time 10.0% 5.0% 0.5% NaOH 65° C. 30 min. [0044] A further 23.3% decrease in acid insoluble lignin contents was found with CED viscosity 12.90 Cp (further loss of 0.76%) without α-cellulose degradation and brightness level of 64.5% ISO. [0045] Ps-treated pulp was again washed and pressed by conventional method to increase the consistency>10.0%. [0046] Ps-treated pulp AOPs-staged pulp was then bleached further by following the sequence routes mentioned herewith: [0000] Reductive-Oxidative YP 0 Extraction-Oxidative EP 0 Oxidative-Oxidative P 0 P 1 YP 0 -Treatment [0047] YP 0 -treatment comprises of two stages each followed by washing to remove soluble products and extractives formed during bleaching. Sodium dithionite (Y) is used as reductive reaction step in one of the bleaching sequences AOPsYP 0 of this invention. [0000] TABLE VI Bleaching Conditions for Y stage Pulp consistency Dithionite solution on for Y-treatment oven dried pulp Temp. Time 3.0% 0.2% 70° C. 30 min. [0048] The sensitive embodiments of this step are the temperature and time. Temperature range (60° C.-70° C.) is the more crucial towards brightness increase. Lower temperature range practically leave no impact on pulp optical properties; while 70° C.-80° C. does not results in considerable brightness increase ( FIG. 4 ). Increasing the temperature beyond 80° C. starts degrading dithionite which does not show any practical advantage in terms of brightness rather yellowing of paper starts. [0049] Likewise, the increased time of pulp exposure to dithionite also leads to its coloration ( FIG. 4 ). Preferred reaction time for this stage is opted to be 30 minutes after which the pulp is immediately washed to avoid any loss in stability of dithionite and pulp coloration. Y-stage increases the brightness by only 2.3 units with reference to the AOPs stage-treated pulp (66.8% ISO); but FIG. 5 describes this Y-treatment prior to peroxide reduces the consumption of costly hydrogen peroxide for pulp bleaching as well as increases the pulp final brightness. [0050] Air contact may lead to the poor dithionite performance; even then the conventional bleaching equipment performs well by the use of low consistency pulp as low consistency itself minimizes the air mixing with pulp. [0051] The P 0 -stage (Table VII) herein comprises of the addition aqueous solution of alkali and stabilizer U followed by hydrogen peroxide addition. [0000] TABLE VII Bleaching Conditions for Hydrogen Peroxide Pulp H 2 O 2 charge consistency for on oven Chemical doses on P 0 -stage dried pulp oven dried pulp Temp. Time 10.0% 3.0% 1.5% NaOH solution 90° C. 60 min. 0.1% Stabilizer U [0052] Stabilizer U is a silicate free commercial product (Peroxide Stabilizer: Universal Chemical Industries, Karachi, Pakistan), having its application in textiles to bleach fabrics with peroxide. Its use in this invention is to scavenge active oxygen of hydrogen peroxide and to make it available for pulp only; thus lowering the consumption of hydrogen peroxide during bleaching ( FIG. 6 ). [0053] While optimizing alkali dose in the P-stage in the presence of stabilizer U and peroxide, brightness values preferred the selection of 1.5% alkali for this P 0 -stage. Any further increase beyond this dose does not significantly increase pulp brightness. Conventionally used temperature (90° C.) and time (1.0 hr.) are effective and used for this stage bleaching. EP 0 -Treatment [0054] EP 0 -treatment also comprises of two stages: alkaline extraction (E) and oxidative/hydrogen peroxide (P 0 ) stage, each followed by washing. Like Y-stage in YP 0 -treatment incorporation of E-stage in replacement to Y-stage is another option to improve the final stage brightness of AOPs treated pulp and to reduce the load of hydrogen peroxide consumption on pulp. E-stage utilizes conventional conditions of extraction only (Table VIII). [0000] TABLE VIII Conditions for alkaline extraction Pulp consistency Aqueous alkali solution for E-Stage on oven dried pulp Temp. Time 10.0% 3.0% 70° C. 120 min. [0055] Alkaline extracted washed pulp follows hydrogen peroxide bleaching at conditions described in Table VII and then washing where [AOPsEP 0 ] shows the targeted brightness of 80+(82.5% ISO). P 0 P 1 -Treatment [0056] P 0 P 1 -Treatment is a two-stage hydrogen peroxide treatment each stage followed by washing. Single stage hydrogen peroxide treatment is not found to be effective to achieve 80+% ISO brightness. Multiple peroxide stages not only reduce the consumption load of chemical but also help to increase the brightness. Conditions for peroxide stages are the same as mentioned in Table VII with only difference that P 1 -stage uses only 2.0% hydrogen peroxide as compared to P 0 which uses 3.0% hydrogen peroxide on oven dried pulp basis. [0057] Table IX shows the selectivity of the sequences throughout the bleaching stages of AOPsYP 0 , AOPsEP 0 and AOPsP 0 P 1 sequences as protectors to the celluloses in AS/AQ wheat straw pulp where acid soluble lignin gradually washes away to negligible level which is also supported by the kappa number values of each sequence; and the α-cellulose (%) contents surprisingly enhanced to some extent as compared to the conventional approaches where bleaching process degrades the cellulose contents. [0000] TABLE IX Chemical Characteristics of AS/AQ Wheat Straw Pulp and Paper Bleach Kappa α-Cellulose Acid Insoluble Lignin CED Viscosity Stage Status Number ± SD* (%) ± SD* (%) ± SD* (Cp) ± SD* Un Un 12.4 ± 0.49 76.6 ± 0.90 7.6 ± 0.40 13.10 ± 0.11 A A 10.8 ± 0.59 76.8 ± 0.92 6.1 ± 0.26 13.28 ± 0.19 O AO 6.70 ± 0.21 77.4 ± 1.63 4.2 ± 0.36 13.00 ± 0.20 Ps AOPs 2.09 ± 0.03 77.1 ± 1.47 3.22 ± 0.15 12.90 ± 0.13 Y AOPsY — 77.1 ± 1.53 3.13 ± 0.11 12.70 ± 0.09 P 0 AOPsYP 0 — 77.5 ± 1.79 1.12 ± 0.09 10.60 ± 0.17 E AOPsE — 77.2 ± 1.44 1.23 ± 0.14 12.33 ± 0.13 P 0 AOPsEP 0 — 81.2 ± 3.58 0.7 ± 0.08 11.93 ± 0.17 P 0 AOPsP 0 — 78.7 ± 2.19 2.01 ± 0.13 12.43 ± 0.15 P 1 AOPsP 0 P 1 — 79.5 ± 3.01 1.02 ± 0.10 11.90 ± 0.08 *SD = Standard deviation [0058] Other physical data of AS/AQ wheat straw bleached pulp samples are also described (Table X). All the physical properties of bleached AS/AQ wheat straw pulp results in values that are highly demanding to make business/office paper. [0000] TABLE X Physical Characteristics of AS/AQ Wheat Straw Pulp and Paper Unbleached Bleached (Un) AOPsYP 0 AOPsEP 0 AOPsP 0 P 1 Parameters Grammage (g · m −2 ) 72.6 68.8 69.1 69.1 Bulk (cc · g −1 ) 1.96 1.63 1.58 1.62 Caliper (μ) 142 112 109 112 Elongation (%) 2.41 4.03 5.01 3.17 Burst Index 2.8 2.8 3.2 4.1 (kPa · m 2 g −1 ) Tear Index 3.8 6.8 6.8 5.1 (mN · m 2 g −1 ) Tensile Index 61.3 41.3 43.8 71.2 (Nm · g −1 ) Optical Brightness (%) 43.9 82.0 82.5 81.6 Yellowness (%) 19.3 1.89 1.48 1.98 Whiteness (CIE %) 1.1 62.00 61.70 57.8 Opacity (%) 91.8 80.20 80.70 79.7 Others Yield (%) — 99.4 94.2 93.6 Porosity (ml · min −1 ) 180/213 380/423 383/428 235/305 Evidence for Environmentally Benign Process [0059] Every stage in each sequence comprises of totally chlorine free chemicals. Mild bleaching conditions are preferred through out of the processes. BOD of each final sequence is negligible. COD also shows considerable reduction as compared to hypo bleach pulp. Adsorbable organically bound halogens (AOX) which are the most crucial for any pulp and paper mill are kept at zero by using non-halogenated agents for bleaching throughout the processes of this invention as compared to hypo-bleaching (H) which imports huge carcinogenic load into pulp and paper mill effluents in the form of AOX. Thus all the three sequences of this invention for bleaching process are environmentally benign ( FIG. 7 ) and will also help to reduce the cost on effluent treatment plant processes.	This invention reports an environmentally benign method of delignifying bleaching sequences to gain more than 80% ISO brightness for alkaline sulfite-anthraquinone (AS/AQ) wheat straw pulp comprising of AOPsYP 0 , AOPsEP 0 and AOPsP 0 P 1 sequences that yielded surprising results in the field of pulp and paper technology; wherein the selectivity of sequences resulted in the protection of α-cellulose from degradation, produced significant drop in acid soluble lignin and yielded low viscosity losses reducing ecological impact of effluent load.	3
FIELD OF THE INVENTION The present invention relates generally to holders. More particularly, it is directed to holders for dental and similar personal items, wherein the holding unit have different geometrical shapes related to the shapes of the item being held and the amount of holding units may be increased or decreased at the user's will. BACKGROUND OF THE INVENTION Dental personal items, such as orthodontic retainers and/or their boxes, dentures and the like requires to be kept in a clean, dry and safe place due to its own nature in order to reduce the risk of contamination of such items with microorganisms that may transmit diseases to the user. In some instances, whenever the user is not using such items, they may be stored in a particular and hygienic place. Such care in storing such items is very important in order to promote the health of the user. In another instance the items are not used because the user forgets to use them because they are in a hidden place. Similarly, personal care products, such as dental floss, manual razors, toothbrushes and the like also require being kept in a clean and hygienic place. Unfortunately, such items are commonly kept at the top of the bathroom's wash basin, which is a highly humid and usually a place wherein bacteria and other microorganism may found an excellent reproductive environment. Similarly, jewelry items, such as rings, earrings and the like requires a safe place to be store, particularly whenever the user is not wearing such items. In many occasions, such items may be lost while the user is on the shower or results uncomfortable while the user is sleeping. Thus, a particular holder may be highly convenient in order to hygienically, properly and safely, save and store such personal items in order to reduce contact of said items with bacteria and other disease related microorganisms. SUMMARY OF THE INVENTION It is an object of the instant invention to provide a holder for dental items such as toothbrushes, orthodontic retainers and/or their boxes and similar items, wherein such items are kept in a clean, dry, accessible and safe area. Another object of the invention is to provide a holder for dental and jewelry items wherein the holding units of said holder may be varied to the convenience and needs of the user. Yet another object of the invention is to provide a holder, wherein the holding units used to hold different personal use items may be increase by the user, because it modular design. In still another object of the invention is to provide a holder wherein the holding units have different structural shapes or holding elements that are related to the items being held in order to properly and safely hold said items. In yet still another object is to provide a holder that may be secured in different manners, for instance using a standing base, a suction cup or a toothbrush support. BRIEF DESCRIPTION OF THE DRAWINGS The nature and objects of the present invention and its advantages will be more clearly and easily understood after reading the following non-restricted description of preferred embodiments thereof, made with reference to the following drawings, in which: FIG. 1A illustrates a perspective view of one of the embodiments according to the invention. FIG. 1B illustrates an exploded view of the embodiment according to the invention illustrated in FIG. 1A and its parts thereof. FIG. 1C illustrates an alternative manner of assembling and using some of the embodiments according to the invention. FIG. 2A illustrates a perspective view of a second of the embodiments according to the invention. FIG. 2B illustrates an alternative manner of assembling and using some of the embodiments according to the invention shown in FIG. 2A and FIG. 2C illustrates an exploded view of the FIG. 2B and its parts thereof. FIG. 3 illustrates a perspective view of a third of the embodiments according to the invention. FIG. 4A illustrates an alternative manner of assembling and using some of the embodiments according to the invention shown in FIG. 3 . FIG. 4B illustrates an exploded view of the FIG. 4A and its parts thereof. FIG. 5A illustrates a perspective view of the elongated main body used as central support in some of the embodiments of the invention. FIG. 5B and FIG. 5C illustrate two perspective views of the top section of the main elongated body illustrated in FIG. 5A . FIGS. 6A , 6 B, 6 C, 6 D and 6 E illustrate different views of the inserting unit used in different embodiments of the invention. FIG. 7 illustrates a cross sectional view of the tray-shaped unit used in some embodiments according to the instant invention. FIGS. 8A and 8B illustrate a preferred mechanism to fast different elements in some of the embodiments according to the instant invention having a single inserting unit. FIGS. 9A and 9B illustrate a preferred mechanism to fast different elements in some of the embodiments according to the instant invention having a two inserting units. FIGS. 10A , 10 B, 10 C and 10 D illustrate the manner in which the holding units are inserted into the inserting unit in different embodiments according to the invention. FIG. 11A to 11G illustrate perspective views of different holding units used in some embodiments of the instant invention. FIG. 12 illustrates another embodiment according to the invention. FIG. 13 illustrates an exploded view of the embodiment according to the invention illustrated in FIG. 12 and its parts thereof. FIG. 14A to 14D illustrate the parts and mechanism used to hold the embodiment illustrated in FIG. 12 over a given surface. These figures illustrate the supporting unit and the suction cup in more details. FIG. 15A to 15D illustrate different views of other embodiment according to the invention. FIG. 16A to 16D illustrate different exploded views of the respective embodiments illustrated in FIGS. 15A to 15D . FIGS. 17A and 17G illustrate cross sectional views of the holding units and the mechanism of coupling main elongated body and the holding units in the embodiments illustrated in FIGS. 15A to 15D . FIG. 18A to 18D illustrate different views showing alternative manners of assembling and using the embodiments illustrated in FIGS. 15A and 15D . FIG. 19A to 19D illustrate perspective views of another alternative manners of assembling the embodiments illustrated in FIGS. 15A and 15D . FIGS. 20A and 20D illustrate exploded views of the embodiments as shown in FIGS. 19A to 19D and its parts thereof. FIG. 21A to 21G illustrate perspective views of another embodiment according to the instant invention. FIG. 22A to 22G illustrate perspective views of another embodiment according to the instant invention. FIG. 23A to 23G illustrate different views showing alternative manners of assembling the embodiments of the invention illustrated in FIGS. 22A and 22G . FIG. 24A to 24G illustrate perspective views of an alternative manner of assembling the embodiments illustrated in FIGS. 22A and 22G . DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The following detailed description illustrates the invention by way of example and is not limited to the particular limitations presented herein as principles of the invention. This description is directed to enable one skilled in the art to make and use the invention by describing embodiments, adaptations, variations and alternatives of the invention. Potential variations of the limitations herein described are within the scope of the invention. Particularly, the size and shapes of the invention's elements illustrated in the discussion may be varied and still provide holders having different sizes or geometric shapes, that are within the scope of the instant invention. The instant invention is directed to a holder, useful in supporting different personal items, such as orthodontics retainers and/or their boxes, toothbrushes, dental floss, jewelry, manual razors and the like. Said holder is intended to be used mostly in the bathroom and dormitory area. Each embodiment of the invention provides one or more holding units, which is designed accordingly to the shape or geometry of the item being supported. The holder herein described may be made of a solid, strong material such as metal, plastic or any other suitable material and more preferably of plastic. Each part of the holder may be mold individually or it may be mold as a whole or as the entire holder. More particularly, FIG. 1A and FIG. 3 illustrate embodiments 10 and 20 of the invention comprising a series of common elements. For instance, on FIG. 1A , embodiment 10 is shown having all its parts already assembled. FIG. 1B illustrates an exploded view of the embodiment 10 , showing all its components. Similarly, FIG. 3 illustrates embodiment 20 already assembled while FIG. 4A illustrates the embodiment 20 over a stand 80 and FIG. 4B illustrates an exploded view of the embodiment 20 over a stand 80 . In both embodiments 10 and 20 , a main elongated body 22 is required. As illustrated in FIGS. 1-4 ; 5 A to 5 C, it comprises upper head 27 at the upper part of said main elongated body 22 . Said upper head 27 has at least one straight flange 28 placed from top to bottom of the external surface of said head 27 . It also comprises a groove 29 , located at the lower end of upper head 27 . Said head 27 is permanently connected to a first elongated section 23 . Main elongated body 22 also comprises a second elongated section 24 and a fastening section 25 located between the first elongated section 23 and the second elongated section 24 . Fastening section 25 has preferably a wider diameter than the diameter of the first and second elongated sections, 23 , 24 and it also has at it fastening section 25 , a threaded section 26 and a flat section 8 . As illustrated in FIGS. 1A and 1B , embodiment 10 comprises a single hollow inserting unit 30 . Details of said hollow inserting unit 30 are illustrated in FIGS. 6A to 6E . FIG. 6A illustrates a perspective view of said hollow inserting unit 30 , FIG. 6C represents its cross sectional view while FIG. 6E represents its bottom view. Said inserting unit 30 comprises a cylindrical top section 32 having an upper part 33 and a lower part 34 . Said cylindrical top section 32 is connected to a hollow rectangular main body 37 at its lower part 34 . Cylindrical top section 32 comprises at least one straight flange 35 placed from top to bottom of the external surface of top section 32 . It also comprises groove 36 below its lower end 34 . On the other hand, hollow rectangular main body 37 comprises an external sliding channel 38 on each one of its sides. At the upper surface of each channel 38 it also comprises indentation 39 ; which is a small hole on the surface of said external channel's surface 38 . At the interior surface of the hollow rectangular body 37 , there is an internal hollow section 101 and at least one internal sliding channel 52 , as illustrated in FIGS. 6C and 6E . Furthermore, an internal bump 41 is located at the lower end of the hollow internal section 101 of inserting unit 30 , as illustrated more clearly on FIG. 6C . A main difference between embodiment 10 and 20 , embodiment 20 requires a second hollow inserting unit 31 . As illustrated in FIGS. 3 , 4 A and 4 B. Embodiment 20 comprises a second hollow inserting unit 31 , which has the same characteristics or limitations of first inserting unit 30 . For instance, second inserting unit 31 as illustrate on FIGS. 6B and 6D , comprises a cylindrical top section 42 having an upper part 43 and a lower part 44 . Said cylindrical top section 42 is connected to a hollow rectangular main body 47 at its lower part 44 . Cylindrical top 42 comprises at least one straight flange 45 placed from top to bottom of the external surface of top section 42 . It also comprises groove 46 below its lower end 44 . On the other hand, hollow rectangular main body 47 comprises an external sliding channel 48 on each one of its sides. At the upper surface of each channel 48 it also comprises indentation 49 , which is a small hole on the surface of external channel 48 . At the interior surface of the hollow rectangular body 47 , there is a hollow internal cavity 102 having at least one internal sliding channel 53 as illustrated in FIG. 6D . Furthermore, an internal bump 51 is located at the lower end of the hollow internal section 102 of inserting unit 31 . Inserting units, 30 and 31 may have the same or different length. In one aspect of the embodiment, it is preferably that one is longer than the other, as illustrated in FIG. 4B . Embodiments 10 and 20 also comprise a tray unit 54 , having at its upper section a tray-shaped holding section 56 and at its lower external surface a hollow cylindrical section 55 , as illustrated in FIGS. 1-4 and 7 . Inside said hollow cylindrical section 55 , there is an internal hollow cavity 103 , having at least one internal channel 57 . It also comprises an internal bump 58 at the lower section. The embodiment 10 and 20 also provides multiple holding units 11 to 17 , each of them comprising sliding section 18 as illustrated on FIGS. 11A to 11G , a flange 9 as illustrated on FIGS. 10B and 11C , which is located at the upper end of said sliding section 18 and on its external surface. Additionally, as illustrated on FIGS. 10B and 10D , there is a stopping flange 7 at top of the sliding section 18 which is wider than the external channel 38 of the inserting unit 30 or external channel 48 of the inserting unit 31 , to interrupt the movement once the top flange 7 of the sliding section 18 hit the top 6 at the sides of the external channel 38 of the inserting unit 30 or the external channel 48 of the inserting unit 31 . FIGS. 11A-11G illustrate different designs of the holding units 11 to 17 , having different geometries or shapes, which had been designed particularly according to the geometry of different personal use items intended to be supported by the embodiments of the described holder. For instance, holding unit 11 illustrated in FIG. 11A comprises two extended arms-shaped holding elements 60 and 61 preferable of different length and preferable aligned, having a curved distal ends 19 and 21 and a flange 62 located between the sliding section 18 and the distal curved end 21 to keep some distance between items store on the holding unit 11 , these extended arms are useful in holding orthodontic retainers and jewelry items. Holding unit 12 illustrated in FIG. 11B , comprises a set of lace-shaped holding elements 63 and 64 , having an adjusting ring 65 to increase or decrease the sizes of the lace-shaped holding elements 63 and 64 , which is useful in holding orthodontic retainers among others items. On the other hand, holding unit 13 on FIG. 11C comprises a box-shaped holding element 66 , capable of swivel by effect of the joint connector 67 , which is useful in holding dental floss and similar items; on the other hand, holding unit 14 illustrated in FIG. 11D comprises a rectangular-shaped unit 68 with a joint connector 67 that allows it to rotate or swivel and further comprising a hole 69 at its center. Said holding unit 14 is useful in holding toothbrushes and similar items. Similarly, holding unit 15 on FIG. 11E comprises semi-circular wires 70 and 71 , each one of them having a curved distal ends 72 , 73 and a round solid distal end 74 , which are useful in holding orthodontic retainers and jewellery items. Furthermore, holding unit 16 on FIG. 11F comprises U-shaped structure 75 with a joint connector 67 that allows it to swivel or rotate and having its distal ends 76 , 77 bend over at an upright position, which is useful for holding manual razors and the like. FIG. 11G shows a holding unit 17 comprising a D-shaped structure 78 having a series of solid round units 79 around the external surface of said D-shaped structure 78 , which is useful to hold orthodontic retainers and jewelry items among others items. Embodiment 10 , as illustrated in FIGS. 8A and 8B , may be assembled by reversibly inserting head 27 of main elongated body 22 inside the hollow cavity 101 of rectangular body of inserting unit 30 . In this manner, straight flange 28 on head 27 is cooperatively inserted inside channel 52 on the internal surface of inserting unit 30 . Similarly, groove 29 on head 27 is cooperatively matched or inserted with internal bump 41 at the lower end of the internal hollow cavity 101 at inserting unit 30 . As a result, main elongated body 22 is secured or fastened to the first inserting unit 30 in a strong but reversible manner. Assembling of embodiment 10 also requires the insertion of head 32 of inserting unit 30 inside the hollow cavity 103 of tray-shaped unit 54 . In such connection, straight flange 35 of head 32 at inserting unit 30 is inserted into internal channel 57 of the tray-shaped unit 54 , while groove 36 of inserting unit 30 is cooperatively snap on internal bump 58 located at the lower section of internal cavity 103 at lower section 55 on tray-shaped unit 54 . In this manner the whole frame of the main structure of embodiment 10 is provided. FIGS. 8A and 8B illustrated the herein disclosed assembling of main structure of embodiment 10 . The required multiple holding elements 11 to 17 are reversibly inserted to the main structure of embodiment 10 by inserting the sliding section 18 of the holding units 11 to 17 into the particular external sliding channel 38 at the rectangular sides on the inserting unit 30 , until the top flange 7 of the sliding section 18 at the holding unit, stop over top 6 on rectangular sides at the inserting unit 30 as illustrated on FIG. 10A to 10D . In this manner, flange 9 on the sliding section 18 is cooperatively coupled to indentation 39 on the upper section of channel 38 of the inserting unit 30 , thus providing strength to the reversible connection between the corresponding holding unit and inserting unit 30 . On the other hand, the assembling of embodiment 20 , as illustrated in FIGS. 9A and 9B , requires a second inserting unit 31 which will be located between main elongated body 22 and first inserting unit 30 . As illustrated in FIGS. 9A and 9B , the main elongated body 22 may be connected to second inserting unit 31 by reversibly inserting head 27 of main elongated body 22 inside the hollow cavity 102 of rectangular body 47 of inserting unit 31 . In this manner, straight flange 28 on head 27 is cooperatively inserted inside channel 53 on the internal surface of second inserting unit 31 . Similarly, groove 29 on head 27 is cooperatively matched or inserted with internal bump 51 at the lower end of the internal hollow cavity 102 at inserting unit 31 . As a result, elongated body 22 is secured or fastened to the second inserting unit 31 in a strong but reversible manner. Assembling of embodiment 20 also requires that the cylindrical top section 42 of second inserting unit 31 is inserted into the bottom section of the first hollow inserting unit 30 , wherein straight flange 45 and groove 46 on the upper head 42 of second inserting unit 31 are respectively and reversibly inserted or matched into internal channel 52 and internal bump 41 on the hollow section 101 of the first inserting unit 30 . Insertion of head 32 of first inserting unit 30 on the hollow section 103 of tray-shaped unit 54 , as explained above for embodiment 10 , provides the whole frame of the main structure of holder 20 as illustrated in FIG. 9B . The required multiple holding units 11 to 17 are reversible inserted to the main structure of embodiment 20 by inserting the sliding section 18 of the corresponding holding units into the particular sliding channels 38 and 48 at the rectangular sides on the first and second inserting units 30 , 31 , respectively, as explained previously and illustrated in FIG. 10A to 10D . In this manner, indentation 39 or 49 at the external sliding channel 38 or 48 is cooperatively coupled or snapped to flange 9 at sliding section 18 of the holding unit, thus providing strength to the reversible connection between the holding unit and the respective inserting units matching said holding units. Embodiments 10 and 20 may be fastened or assembled to a toothbrush support 85 , using a fastening means like a threading said nut 81 as illustrated in FIG. 1C for embodiment 10 . Embodiment 10 is illustrated in FIGS. 1A and 1B having three holding units. On the other hand, the assembling of embodiment 40 , as illustrated in FIG. 2A , requires a fourth holding unit 13 , which is reversible inserted to the main structure of embodiment 40 by inserting the sliding section 18 of the corresponding holding unit into the particular sliding channels 38 at the rectangular sides on the first inserting units 30 , as explained previously and illustrated in FIG. 10A to 10D . In this manner, indentation 39 at the external sliding channel 38 is cooperatively coupled or snapped to flange 9 at sliding section 18 of the holding unit, thus providing strength to the reversible connection between the holding unit and the respective inserting unit matching said holding unit. The FIG. 2B , shows the embodiment 40 supported by a stand 80 , using any suitable fastening mechanism, such as threading nut 81 . FIG. 2C illustrates an exploded view of the embodiment 40 over a stand 80 . FIG. 4A shows embodiment 20 supported by a stand 80 , using any suitable fastening mechanism, such as threading nut 81 , while FIG. 4B illustrates an exploded view of the embodiment 20 over a stand 80 . For instance, lower elongated section 24 of main elongated body 22 is inserted into the hole 82 of stand 80 , after the threaded nut 81 is already inside slot 83 . Threading said nut 81 firmly connect main elongated body 22 to stand 80 , as illustrated in FIGS. 2B and 4A . Stand 80 is particularly designed with an enclosed section 84 , in order to retain any small amount of water coming from any items being hold. Embodiments 10 , 20 and 40 illustrates a manner of alternatively increasing or decreasing the number of holding units 11 to 17 presented in each particular embodiment by adding or subtracting inserting units elements such as 30 and 31 at the convenience or needs of the user. The scope of the invention also incorporates embodiments wherein the amount of inserting units may be increased in order to provide extra holding units elements. Similarly, to the discretion of the user, a particular embodiment of the invention may be used to hold one or more personal items. Alternatively, due to the versatility of some holding units, the user may also selects among the holding units those particular holding units that he or she understands fulfill his or her personal needs. Thus, each holding element type adds versatility to the invention. FIG. 12 illustrates a perspective view of another embodiment of the invention 50 while in FIG. 13 an exploded view of embodiment 50 is shown. Embodiment 50 comprises all parts comprised by embodiment 10 , comprising a main elongated body 22 , an inserting unit 30 , a tray-shaped unit 54 , and multiple holding elements, wherein all these parts have the same limitations or characteristics as described previously for embodiment 10 and/or 20 . Such parts may be reversibly interconnected as previously described and explained in the description of embodiment 10 or 20 above. In addition to the parts of embodiment 10 , the embodiment 50 comprises a supporting unit 88 and a suction cup 86 having a flange 87 , which are illustrated in FIGS. 14A to 14D , where in addition is shown the way of connecting the supporting unit 88 to the inserting unit 30 and the suction cup 86 to the supporting unit 88 . The assembly of embodiment 50 requires a supporting unit 88 having internal channel 89 and slot 91 at the back side and an external sliding channel 92 . At the upper section of said external channel 92 , it also comprises a flange 93 and holes 94 passing through its body and preferably located near the upper and bottom ends of the external channel 92 . Suction cup 86 may be reversible connected to supporting unit 88 by inserting flange 87 of the suction cup 86 into internal channel 89 of the supporting unit 88 . The FIG. 14 shows suction cup 86 and supporting unit 88 partially connected. Alternatively, suction cup 86 may be permanently connected to supporting unit 88 as a single piece. As illustrated in FIG. 14D , one of the sides of inserted unit 30 may be inserted into external channel 92 of supporting unit 88 , thus connecting reversibly both parts; supporting unit 88 and inserting unit 30 . Embodiment 50 may be assembled to a wall by means of a suitable fastening means using supporting unit 88 . For instance, fastening supporting unit 88 to a wall requires passing two nails, screws or any suitable fastening means through openings 94 or gluing the back 95 of the supporting unit and further sliding the corresponding side 59 of the inserting unit 30 through the external channel 92 on the supporting unit 88 , allows the fastening of embodiment 50 to a wall. Alternatively, suction cup 86 may be used to hold embodiment 50 to a given surface such as a mirror surface or a wall when flange 87 is inserted into internal channel 89 of supporting unit 88 and further assembling supporting unit 88 to the inserting unit 30 , allowing the flange 93 to cooperatively coupled to indentation 39 of inserting unit 30 , as already explained. Suction cup 86 may then be press to a desirable surface in order to support embodiment 50 to a given or selected surface. FIG. 15A-15D illustrates examples of embodiments of the invention 90 A to 90 D, which comprise a main elongated body 22 as the previously described for embodiments 10 and 20 ; and comprise holding units 96 A to 96 D as illustrated on the exploded views on FIG. 16A to 16D . The FIG. 17A to 17D illustrate cross sectional views of holding units 96 A to 96 D comprising a main body 97 A to 97 D and its holding element 99 A to 99 D. The FIG. 17E to 17G illustrate the mechanism of coupling the holding unit 96 B to the main elongated body 22 , which applies to all embodiment 90 A to 90 D illustrated in FIG. 15A to 15D . The holding units 96 A to 96 D as shown here for holding unit 96 B comprise a hollow cylindrical internal section 104 with at least one internal channel 98 and an internal bump 100 , which is located at the lower end of said hollow cylindrical section 104 and a holding element 99 A to 99 D. Embodiments 90 A to 90 D are assembled by inserting the upper head 27 or top section of main elongated body 22 inside hollow internal section 104 of the corresponding holding unit 96 A to 96 D in a manner that during the insertion process, the straight flange 28 on the head 27 at the main elongated body 22 is slip in the internal channel 98 , while the internal bump 100 is snap into the groove 29 on the head 27 at the main elongated body 22 . Regarding the holding unit 96 A to 96 D, and as illustrated in FIGS. 16A to 16D and FIG. 20A to 20D , it have different geometries capable of adapting to the item being held. For instance, holding unit 96 A comprises a multi-functional holding unit having a round or semi-round tray-type structure 105 surrounded by hooks 106 , 109 , holes 107 and a small box 110 as illustrated in FIG. 20A ; holding unit 96 B comprises two extended arms 111 and 114 as illustrated in FIG. 20B . On the other hand, holding unit 96 C comprises a box-shaped holding element 115 as illustrated in FIG. 20C ; while FIG. 20D shows the holding unit 96 D comprising a lace-shaped holding elements 116 and 117 with an adjusting ring 118 . It is understood that any other variation of the holding unit having similar hanging or holding elements as the one herein described are within the scope of the instant invention. FIG. 18A to 18D shows an alternative manner of assembling embodiments 90 A to 90 D using a toothbrush holder 85 fastened with a threaded nut 81 and it shows examples of use of the instant invention. For instance dental floss 200 is shown stored at embodiment 90 A and 90 C as shown in FIGS. 18A and 18C respectively, in another instance orthodontic retainer 201 is shown stored on embodiment 90 A and 90 D as shown on FIG. 18A and FIG. 18D respectively. FIG. 19A to 19D show another alternative of assembly embodiment 90 A to 90 D using an optional supporting base or stand 80 and fastening means 81 , while FIG. 20A to 20D show the exploded view of FIG. 19A to 19D illustrating the embodiment 90 A to 90 D over a stand 80 . Other embodiments of the invention, 120 A to 120 G are illustrated in FIG. 21A to 21G . All of them comprise a main elongated body 122 having first elongated section 123 , a second elongated section 124 and a fastening section 125 , located between the first elongated section 123 and the second elongated section 124 . Fastening section 125 has preferably a wider diameter than the diameter of the first and second elongated sections, 123 , 124 and it also has at it fastening section 125 , a threaded section 126 and a flat section 128 . It also comprises holding elements 150 A to 150 G, having different geometries and permanently connected at the surface of the first elongated section 123 at main elongated body 122 . FIG. 22A to 22G shows embodiment of the invention 130 A to 130 G comprising a main elongated body 122 comprising a head section 127 at top of main elongated body 122 , comprising the head section 127 a straight flange 128 and groove 129 . Said head may be used to be inserted in an inserting unit 30 or 31 as previously described in embodiments 10 and 20 , or in holding unit 96 A to 96 D of embodiment 90 A to 90 D in order to provide additional embodiments that are inside the scope of the instant invention. It also comprises holding elements 150 A to 150 G, having different geometries and permanently connected at the surface of the first elongated section 123 at main elongated body 122 . With regards to the geometry of the holding elements, it may be anyone of the already illustrated above in holding units 11 to 17 . For illustration purposes, embodiment 130 A has a set of extended arms holding elements 150 A as illustrated in FIG. 22A and previously described for embodiment 10 and 20 . On the other hand, embodiment 130 B comprises lace-shaped holding elements having a size adjusting ring in order to increase or decrease the internal size of lace-shaped holding elements 150 B as illustrated in FIG. 22B as previously described for embodiment 10 and 20 . As illustrated on FIG. 22C embodiment 130 C comprises a box-shaped holding element 150 C. The embodiment 130 D comprises a rectangular-shaped holding element 150 D with a hole at it center as shown on FIG. 22D , while FIG. 22E shows the embodiment 130 E comprising a semi-circular wires holding elements 150 E. The FIG. 22F illustrates the embodiment 130 F comprising a U-shaped structure holding element 150 F bend over at an upright position, which is useful for holding manual razors. The FIG. 22G illustrates the embodiment 130 G comprising a D-shaped structure holding element 150 G having a series of solid round units around the external surface of said D-shaped structure holding element, which is useful to hold orthodontic retainers and jewelry items as previously described for embodiment 10 and 20 . It is understood that any other variation of the holding unit having similar hanging or holding elements as the one herein described are within the scope of the instant invention. FIG. 23A to 23G shows an alternative manner of assembling embodiments 130 A to 130 G using a toothbrush holder 85 and fastened with a threaded nut 81 . FIG. 24A to 24G show another alternative manner of assembly embodiment 130 A to 130 G using an optional supporting base or stand 80 and fastening means 81 .	Holders for maintaining personal items such as dental and hygienic products are disclosed. The holders include a series of sections, particularly, holding sections having different geometrical structures related to the different items intended to be hold. In this manner, they may be assembled at the convenience of the user and its holding units may be increased or decreased as well as selected based upon the particular structure of the holding units at the will of the users. The holder may be self-standing when using a disclosed base or alternatively, it may be secured to a commonly used toothbrush supporting base or even be supported via a suction cup over a given surface.	5
This is a Continuation of Application Ser. No. 07/836,839 filed Feb. 19, 1992, now abandoned. BACKGROUND OF THE INVENTION The present invention relates to a radio pager capable of changing the reception frequency thereof, as desired, and, more particularly, to a radio pager having a casing which allows a crystal oscillator to be replaced with ease. Generally, when call signals are transmitted by a plurality of frequencies, a radio pager has to change the reception frequency thereof in matching relation to the frequency of the call signal. With a radio pager having a local oscillation circuit implemented by a crystal oscillator, it has been customary to change the reception frequency by replacing the crystal oscillator and adjusting a plurality of tuning circuits including an antenna tuning circuit. Specifically, the tuning frequency of the tuning circuit has to be changed in conformity to the frequency of the call signal. However, the adjustment of the tuning frequency needs expert techniques and a jig for effecting the adjustment and, therefore, cannot be easily entrusted to a service company in charge of the paging system, as distinguished from a manufacturer. On the other hand, in the case of a radio pager having a synthesizer type local oscillation circuit, changing the reception frequency results in a decrease in the life of a battery since such a local oscillation circuit consumes far greater current than the local oscillation circuit implemented by a crystal oscillator. Further, a current trend is toward a radio pager having a small and thin configuration and, in addition, having a casing which is mechanically strong. It is necessary, therefore, to assemble the casing by use of a number of screws or similar fastening means. As a result, designing a casing allowing a printed circuit board to be readily removed therefrom or a casing having a socket for replaceable part is extremely difficult to design. Therefore, to replace the crystal oscillator, the printed circuit board has to be removed from the casing by a number of troublesome steps. SUMMARY OF THE INVENTION It is, therefore, an object of the present invention to provide a radio pager capable of changing the reception frequency without aggravating current consumption. It is another object of the present invention to provide a radio pager having a casing which promotes the ease of replacement of a crystal oscillator. In accordance with the present invention, a radio pager capable of changing a reception frequency thereof has a receiving section for receiving a call signal having a predetermined frequency and including a modulated identification code, a demodulator for demodulating the call signal to reproduce the identification code, a memory storing an identification code assigned to the radio pager and reception frequency information, a comparing section for comparing the identification code demodulated by the demodulator with the identification code stored in the memory, and an alerting section for alerting a user of the radio pager to a call if the identification codes are identical as determined by the comparing section. The receiving section has a reception frequency selecting device for selectively receiving one of call signals having a plurality of predetermined frequencies. Also, in accordance with the present invention, a radio pager capable of changing a reception frequency thereof has a printed circuit board on which a crystal oscillator constituting a local oscillator is mounted, and a casing for accommodating the printed circuit board and formed with a first opening for allowing the crystal oscillator and printed circuit board to be selectively connected or disconnected, and a second opening for allowing the crystal oscillator to be selectively inserted into or pulled out from the casing. BRIEF DESCRIPTION OF THE DRAWINGS The above and other objects, features and advantages or the present invention will become more apparent from the following detailed description taken with the accompanying drawings in which: FIG. 1 is a block diagram schematically showing an electrical arrangement of a conventional radio pager; FIG. 2 is a vertical section showing a specific construction of a casing included in the pager of FIG. 1; FIG. 3 is a block diagram schematically showing an electrical arrangement of a radio pager embodying the present invention; FIG. 4 is a flowchart demonstrating a specific operation of the embodiment; FIG. 5 is a vertical section of a casing included in the embodiment; and FIG. 6 is a bottom view of the casing shown in FIG. 5. DESCRIPTION OF THE PREFERRED EMBODIMENT To better understand the present invention, a brief reference will be made to a conventional radio pager, shown in FIG. 1. The conventional pager is of the type allowing one to change the reception frequency by replacing a crystal oscillator included in a local oscillation circuit and adjusting a plurality of tuning circuits including an antenna tuning circuit. As shown, the pager has an antenna tuning circuit 12 between an antenna 10 and an RF (Radio Frequency) amplifier 14. The antenna tuning circuit 12 is so constructed as to minimize the transmission loss at a desired reception frequency. An RF amplifier 14 delivers an output thereof to a bandpass filter (BSPF) 16. The output of the BPF 16 is applied to one input terminal of a mixer 18. Applied to the other input terminal of the mixer 18 is a local oscillation signal from a local oscillation circuit 20. The mixer 18 combines the two inputs to produce a desired IF (Intermediate Frequency) signal. A crystal oscillator 22 is connected to the local oscillation circuit 20 via a socket 24 and is replaceable for implementing a desired reception frequency. The IF signal from the mixer 18 is fed to an IF amplifier 26 to be amplified thereby. The resulting output or the IF amplifier 26 is routed through a BPF 28 to a demodulator 30. In response, the demodulator 30 demodulates the data signal having been modulated and delivers the demodulated data signal to a decode controller 32. A memory 34 stores an address assigned to the radio pager and is connected to the decode controller 32. If an address included in the data signal from the demodulator 30 is identical with the address stored in the memory 34, the decode controller 32 feeds an alert control signal to an alerting section 36. In response, the alerting section 36 drives a loudspeaker 38 or a light emitting diode (LED) 40 to alert the user of the pager to the call. The memory 34 stores, in addition to the address, information designating either of the loudspeaker 38 and LED 40. The conventional pager having the above construction has to have the tuning frequency of the tuning circuit 12 changed in conformity to the frequency of a call signal. This is not practicable without resorting to expert techniques and a jig for adjustment and, therefore, cannot be easily entrusted to a service company in charge of the paging system as distinguished from a manufacturer, as discussed earlier. FIG. 2 shows a specific configuration of the casing of a conventional radio pager. As shown, the casing 42 accommodates a printed circuit board 44 on which circuit part 46 and a crystal oscillator 48 are mounted. The crystal oscillator 48 is affixed to the printed circuit board 44 by having the terminal electrodes 50 and 52 thereof soldered, as at 54 and 56, to wirings provided on the circuit board 44. Since the pager shown in FIG. 2 is relatively thin, it is powered by a coin type battery 58 which is removable through an opening 42a formed in the casing 42. Usually, the opening 42a is closed by a lid 60. The problem with such a casing structure is that one cannot change the reception frequency, i.e., crystal oscillator 48 without removing the whole printed circuit board 44 from the casing 42 and then replacing the crystal oscillator 48. A casing which allows the printed circuit board 44 to be easily removed from the casing 42 or a casing having the socket 24, FIG. 1, is difficult to design, as also stated previously. It is, therefore, necessary to perform a substantial number of steps in the event of replacing the crystal oscillator 48. Referring to FIG. 3, a radio pager embodying the present invention is shown and has an antenna tuning circuit 72 between an antenna 70 and an RF amplifier 74. The tuning circuit 72 is made up of a trimmer capacitor TC, capacitors C 1 -C 4 , transistors Tr 1 -Tr 3 , and resistors R 1 -R 6 and constructed to minimize the transmission loss at a desired reception frequency. The resistors R 1 -R 6 play the role of bias resistors for applying a voltage which the transistors Tr 1 -Tr 3 need for switching operations. An RF amplifier 74 delivers an output thereof to a BPF 76. The BPF 76 is implemented as a SAW filter and limits the frequency band of about ±3 to ±5 megahertz of reception frequency. The output of the BPF 76 is applied to one input terminal of a mixer 78. The mixer 78 receives a local oscillation signal from a local oscillation circuit 80 at the other input terminal thereof. A crystal oscillator 82 is connected to the local oscillation circuit 80 via a socket 84 and is replaceable to implement a desired reception frequency. An IF signal from the mixer 78 is fed to an IF amplifier 86. The amplified IF signal from the IF amplifier 86 is routed through a BPF 88 to a demodulator 90. In response, the demodulator 90 demodulates the data signal having been modulated and delivers the resulting data signal to a decode controller 92. A memory 94 is connected to the decode controller 92 and stores an address assigned to the pager. If an address included in the data signal from the demodulator 90 is identical with the address stored in the memory 94, the decode controller 92 feeds an alert control signal to an alerting section 96. On receiving the alert control signal, the alerting section 96 drives a loudspeaker 98 or an LED 100 to alert the user to the call. The memory 94 stores, in addition to the address assigned to the pager, information designating either of the loudspeaker 98 and LED 100 and information representative of reception frequencies. Control signal lines L 1 -L 3 extend from the decode controller 92 to the bases of the transistors Tr 1 -Tr 3 , respectively. At least when a power switch, not shown, provided on the pager is turned on, the decode controller 92 reads the reception frequency information out of the memory 94 and changes the logical level of one of the control signal lines L 1 -L 3 matching the reception frequency to a high level. A specific operation of the embodiment will be described with reference to FIG. 4. The reception frequency information is written to the memory 94 beforehand by a service company in charge of the paging system. In FIG. 4, as the power switch of the pager is turned on (step S1), the decode controller 92 reads the reception frequency information out of the memory 94 (S2) and then changes the logical level of one of the control signal lines L 1 -L 3 matching the information to a high level (S3). As a result, one or the transistors Tr 1 -Tr 3 connected to the high level control line is rendered conductive (S4). Therefore, one of the capacitors C 1 -C 3 connected to the transistor having been turned on is connected in parallel to the trimmer capacitor TC (S5). In such an arrangement, only if the capacitors C 1 -C 3 are each provided with a particular capacitance which minimizes the transmission loss at a particular reception frequency band (S6), the reception frequency can be readily changed without resorting to any fine adjustment. If desired, the decode controller 92 may be so constructed as to read the information out of the memory 94 periodically since the information is susceptible to static electricity and other similar disturbances. FIGS. 5 and 6 show a specific structure of a casing which accommodate the circuitry described above with reference to FIG. 3. As shown, the casing 102 accommodates a printed circuit board 104 therein on which the crystal oscillator 82 and circuit part 106 are mounted. The crystal oscillator 82 is affixed to and electrically connected to the printed circuit board 104. Specifically, terminal electrodes 112 and 114 provided on the side of the crystal oscillator 82 facing the circuit board 104 are soldered, as at 116 and 118, to terminals 108 and 110 of the circuit board 104 which are implemented as through holes. The circuit board 104 is affixed to the inner periphery of the casing 102. The casing 102 is formed with a first opening 102a in alignment with opening 104a formed in the circuit board 104. To attach or detach the crystal oscillator 82, a soldering iron may be inserted into the casing 102. In the illustrative embodiment, a coin type battery 120 is inserted into or removed from a battery chamber 122 formed in the casing 102 through a second opening 102b also formed in the casing 102. A lid 124 usually closes the second opening 102b. The printed circuit board 104 partly extends into the battery chamber 122. The crystal oscillator 82 is mounted on the part of the circuit board 104 which is located in the battery chamber 122. Therefore, the crystal oscillator 82 can be inserted into or removed from the casing 102 by way of the battery chamber 122 and second opening 102b. The crystal oscillator 82 is replaced with another to change the reception frequency of the pager, as follows. First, a soldering iron is inserted into the casing 102 through the first opening 102a to melt the solder 116 and 118 to thereby disconnect the crystal oscillator 82 from the printed circuit board 104. Then, the lid 124 is removed to pull out the battery 120 from the casing 102 via the second opening 102b. Thereafter, the crystal oscillator 82 having been disconnected from the circuit board 104 is removed from the casing 102. Subsequently, a substitute crystal oscillator 82 and the battery 120 are sequentially inserted into the battery chamber 122 in this order through the second opening 102b. After the opening 102b has been closed by the lid 124, a soldering iron is again inserted into the casing 102 through the first opening 102a to melt the solder 116 and 118. As a result, the substitute crystal oscillator 82 is electrically connected to the circuit board 104. A logotype label, for example, may be adhered to the outer periphery of the casing 102 around the first opening 102a to close it except when replacement is needed. In summary, it will be seen that the present invention provides a radio pager having a simple design and capable of readily changing the reception frequency thereof without aggravating current consumption. Various modifications will become possible for those skilled in the art after receiving the teachings of the present disclosure without departing from the scope thereof.	A radio pager capable of changing the reception frequency thereof, as desired, and having a replaceable crystal oscillator. A reception frequency selecting device selects one of call signals having a plurality of predetermined frequencies which matches the crystal oscillator. A casing is formed with a first opening for allowing the crystal oscillator to be selectively attached to or detached from a printed circuit board, and a second opening for allowing the oscillator to be selectively inserted into or pulled out of the casing.	6
BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to articles of clothing and in particular to a halter top. More particularly, the present invention relates to a halter top and a method of making a halter top from a pair of pants. 2. Description of the Prior Art Reducing waste and recycling articles is a major concern for the environment. When an item that would have been discarded can be recycled into useful and purposeful items and at the same time provide a unique and fashionable article of clothing, two objectives are simultaneously accomplished. It is well known in the art to provide a garment for supporting and covering the breasts to improve the wearer's comfort and appearance. It is also well known in the art to recycle some articles of clothing into certain objects. For example, it is well known to recycle denim jeans into other articles, such as seat cushions, handbags or quilts. Clothing fashions are constantly changing. As a result of these constant changes, there is a continuing desire for exciting, new and different articles of clothing. But at the same time, there is a need to keep clothing affordable. Thus, there is a need to develop new and simple methods of manufacturing, as well as find inexpensive sources for material. There is also a need to develop purposeful objects from recycled items. SUMMARY OF THE INVENTION The novel features of the present invention relate to creating a garment for covering and supporting the breasts, commonly referred to as a brassiere or a halter top, from a pair of pants. The halter top is trimmed from the pants in nearly a single sequence. Connecting straps are also formed from material removed from the pants and attached in a configuration such that the former back pockets from the pants now make-up the cups of the halter top or brassiere and cover the wearer's breasts. The former waistband from the pants now surrounds the chest of the wearer with the waistband fastening in the posterior of the torso. The method according to the present invention involves using the waistband and the back pocket portion of a pair of pants in conjunction with portions of the seams of the pants to make the halter top. The method preferably includes the steps of trimming around the waistband and back pockets of the pants and removing the seams of the pant legs to form connecting straps. The method also includes removing a portion of the seam of the crotch area of the pants to form connecting straps in a "Y" configuration for holding the halter top in place. The "Y" configuration provides attachment of the connecting straps to the former waistband and former back pockets of the pants between the breasts, holding the former back pockets in place a fixed distance apart. The waistband and back pockets remain as originally attached on the pair of pants. The shoulder and side straps are trimmed to a desired length from the seam of the pants. The shoulder and side straps are attached to support and hold the halter top on the wearer. The new halter top is positioned on the torso so that the former back pockets of the pants now make-up the cups of the halter top and cover the breasts and chest area of the wearer. The former waistband of the pants now surrounds the torso and fastens in the posterior of the torso. The connecting straps formed from the seams of the pant legs now traverse the shoulders of the wearer and extend between the former back pockets and the former waistband. In the preferred embodiment of the present invention, a pair of denim pants is used to make the halter top. However, any type of pant or short pants with back pockets would be suitable. In addition, any material forming a halter top such that the breast cups resemble back pockets of a pair of pants and the body strap resembles a waistband from a pair of pants is also an embodiment of the present invention. It is an object of the present invention to produce an article of clothing that is simple and inexpensive to make. It is another object of the present invention to recycle used articles of clothing into new, useful, different and fashionable articles of clothing. It is a further object of the present invention to construct a stylish halter top entirely out of pieces taken from a pair of pants. Other advantages of the present invention will be more apparent from the following detailed description of the preferred embodiment taken in connection with the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a front view of a halter top according to the present invention; FIG. 2 is a rear view of a halter top according to the present invention; FIG. 3 is a side perspective of a halter top according to the present invention; FIG. 3A is a side perspective of a halter top according to the present invention with a neck strap and a cup strap without connection to the body strap; FIG. 4 is a diagram of the method of making a halter top's breast cups and body strap according to the present invention; FIG. 5 is a diagram of the method of making a halter top's connecting straps according to the present invention; FIG. 6 is a diagram of the method of making a halter top's cup strap according to the present invention; FIG. 7 is a diagram of the method of assembling a halter top's shoulder straps according to the present invention; FIG. 8 is a diagram of the method of assembling a halter top's side straps according to the present invention; FIG. 9 is a diagram of the method of assembling a halter top's cup strap branches according to the present invention; and FIG. 10 is a diagram of the method of assembling a halter top's cup strap stem according to the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT A preferred embodiment of a halter top 10 constructed in accordance with the present invention is shown in FIG. 1 wherein the halter top 10 includes a right breast cup 1, a left breast cup 2, a body strap 3, connecting straps 4-7 and a cup strap 8. There are several configurations in which the connecting straps and cup strap can be attached to the halter top. The preferred embodiment has a connecting strap 4 for the right shoulder, a connecting strap 5 for the left shoulder, a right side connecting strap 6, a left side connecting strap 7, and a cup strap 8. The body strap 3 has a first end 3A and a second end 3B. The right and left shoulder straps 4 and 5 each have first ends 4A and 5A, and second ends 4B and 5B. The right and left side straps 6 and 7 each have first ends 6A and 7A, and second ends 6B and 7B. A further embodiment, shown in FIG. 3A, has a connecting strap 18 around the neck of the wearer. Each end of the neck strap 18 is connected to the top of the right and left breast cups 1 and 2. The breast cups 1 and 2 are the former back pockets 1' and 2' from the posterior of a pair of pants 10' as shown in step 1 of FIG. 4. The breast cups 1 and 2 are intended to support and cover the wearer's breasts in a fashion similar to a brassiere. The back pocket portion from the former pants 10' is inverted and positioned over the chest in a manner covering the breasts of the wearer, similar to known halter tops and brassieres. The former back pockets 1' and 2' are now worn, on the anterior chest portion of the torso. The body strap 3 is the former waistband 3' from the pair of pants 10', which functions to hold the top on the wearer's chest area of the torso. A fastener 9 connects the end 3A to the end 3B. The fastener 9 once held the pants in place around the waist as a fastener 9'. The waistband 3' and pockets 1' and 2' are now worn as a top resulting in the former pockets of the posterior of the pants and the former waistband being upside down and backward. The halter top 10 is held in place on the torso not only by the body strap 3, but by the several connecting straps 4-7 and the cup strap 8 as well. All of the connecting straps are formed from the seams which have been removed from the former pair of pants 10'. The right and left shoulder straps 4 and 5, and the right and left side straps 6 and 7 have first ends A and second ends B. The first ends are connected to one of the breast cups 1 or 2, and the second ends are connected to the body strap 3. The right shoulder strap 4 is formed from the former seams of the pant legs as shown in Step 2 of FIG. 5. The first end 4A of the right shoulder strap 4 is connected at or near the top of the right breast cup 1. The right shoulder strap 4 travels over the wearer's right shoulder and down the back of the wearer. The second end 4B of the right shoulder strap 4 is connected to the body strap 3 in the posterior of the torso. The right shoulder strap 4 supports the halter top 10 in place on the wearer by hanging from the right shoulder The left shoulder strap 5 is also formed from the former seams of the pant legs also shown in Step 2 of FIG. 5. The first end 5A of the left shoulder strap 5 is connected at or near the top of the left breast cup 2. The left shoulder strap 5 travels over the wearer's left shoulder and down the back of the wearer. The second end 5B of the left shoulder strap 5 is connected to the body strap 3 in the posterior of the torso. The left shoulder strap 5 supports the halter top 10 in place on the wearer by hanging from the left shoulder. The right and left shoulder straps 4 and 5 are similar to the shoulder straps of known halter tops and brassieres. In addition to the right and left shoulder straps 4 and 5, the right side strap 6 and the left side strap 7 provide additional support for maintaining the top 10 in position on the wearer's torso. The right and left side straps 6 ant 7 are also preferably formed from the seams of the pant legs as shown in Step 2 of FIG. 5. The right and left side straps 6 and 7 are attached between the sides of the breast cups 1 and 2 and the body strap 3 to assist in holding the halter top 10 in place on the torso and at the same time holding the right and left breast cups 1 and 2 in place on the breasts. The first end 6A of the right side strap 6 is attached to the right breast cup 1 on the right side of the right breast cup 1. The second end 6B of the right side strap 6 is attached to the body strap 3 near the posterior of the torso on the wearer's right side. The first end 7A of the left side strap 7 is attached at the left breast cup 2 on the left side of the left breast cup 2. The second end 7B of the left side strap 7 is attached to the body strap 3 near the posterior of the torso on the wearer's left side. Finally, the breast cups 1 and 2 themselves are held a fixed distance apart from each other by a cup strap 8. The cup strap has two branches A and B and a stem C, all having a first end and a second end. The first ends of each of the two branches A and B are connected to the breast cups 1 and 2. The second ends of the two branches A and B are connected together. The first end of the stem C is connected to the joined second ends of the two branches A and B. Finally, the second end of the stem C is connected to the body strap 3. The cup strap 8 is preferably formed from the seam of the crotch of the pants as shown in FIG. 6. As would be obvious to one skilled in the art, the stem C of the cup strap could be eliminated and the breast cups 1 and 2 are held together without any connection to the body strap 3 in between the breast cups 1 and 2. A method of manufacturing the above described halter top 10 preferably includes removing the necessary pieces from a pair of pants as indicated above. In one embodiment the halter top is made from denim jeans, but any type of pant or short pants with back pockets would be suitable as will become apparent in the following description. The method is shown in flow diagram form in FIGS. 4-10. Begin removing the waistband and back pockets of the pants by any means such as cutting, along line 11, as shown in FIG. 4, which separates the waistband and back pockets from a pair of pants. It is best to start in the front of the pants just below the waistband 3' as shown in FIG. 4, at the fly or zipper 11'. Following line 11 along the waistband 3' removes the right pant leg and right front pocket from the pants. Continuing along line 11 around the right side of the waistband detaches the right side of the pant leg. When line 11 reaches the right back pocket 1', it preferably follows the outline of the back pocket 1'. In the preferred embodiment, the right back pocket 1' remains attached to the waistband 3'. After following up and around the right back pocket 1', continue down the left side of the right back pocket to the waistband in between the right and left back pocket 1' and 2'. Maintain the path along line 11 and continue along the waistband 3' between the back pockets 1' and 2'. Line 11 continues up and along the sides of the left back pocket 2', which remains intact with the waistband 3'. After following the outline of the left back pocket 2', removal along line 11 continues back to the waistband 3' where the left pant leg is completely severed from the waistband along the left side of the pants. The pant leg scraps should be reserved as material for the connecting straps. The fly or zipper, front pockets and pant legs have all been detached. Next, the connecting straps preferably are formed directly from the pants. However, it is possible to use any other suitable material. The connecting straps may be formed from the seam of the pant leg, as shown in FIG. 5. Removal of the seam follows along lines 12 and 13. The shoulder straps, 4 and 5, are formed from the seam of the pant leg by removing the seam along lines 12 and 13 shown in FIG. 5. The shoulder straps 4 and 5 should be long enough to traverse the shoulder of a wearer beginning at the anterior of the torso just above the breast and ending just under the shoulder blade in the posterior of the torso. Referring to FIG. 5, the side straps 6 and 7, are also preferably formed from the seam of the pant legs by following along lines 12 and 13. The side straps 6 and 7 should be long enough to attach the first ends 6A and 7A of the side straps 6 and 7 to the outer sides of breast cups 1 and 2 respectively, and the second ends 6B and 7B of the side straps 6 and 7 to the body strap 3 at a point preferably under the wearer's arm. The cup strap 8 may be formed from the seam of the pant legs by removing the seam along lines 12 and 13, or from the crotch area by removing the seam along lines 14, 15, and 16 as shown in FIG. 6. The seam removed from the crotch area is in a "Y" configuration. This allows attachment between the right and left breast cups 1 and 2 with each branch of the "Y", and at the same time provides attachment to the body strap 3 with the stem of the "Y" as shown in FIG. 6. The cup strap 8 holds the breast cups 1 and 2 at a fixed distance from each other, and provides additional support by attaching to the body strap 3 as well. Assembly of the halter top 10 using the pieces removed from the pants is shown in FIGS. 7-10. The right shoulder strap 4 and left shoulder strap 5 assembly is shown in FIG. 7. The right side strap 6 and left side strap 7 assembly is shown in FIG. 8. The cup strap 8 assembly is shown in FIGS. 9 and 10. Assembly of the halter top begins by attaching the first end 4A of the right shoulder strap 4 to the top of the right breast cup 1. The second end 4B of the right shoulder strap 4 is attached to the body strap 3 in the posterior of the torso, near the fastener 9. This procedure is repeated with the left breast cup 2 and left shoulder strap 5. When the right and left shoulder straps 4 and 5 are in place, the halter top 10 is held in place on the torso by hanging from the shoulders of the wearer. The first end 6A of the right side strap 6 is attached to the outer side of the right breast cup 1. The second end 6B of the right side strap 6 is attached to the body strap 3 near the posterior of the torso. This procedure is repeated with the left breast cup 2 and the left side strap 7. The right and left side straps 6 and 7 are located under the arms along the outer sides of the torso. When the halter top 10 is on the torso, hanging from the shoulders, the right and left side straps 6 and 7 will provide additional support along the sides of the wearer and prevent the breast cups 1 and 2 from being displaced from the breasts of the wearer, and also provide a novel and unique look. Finally, the cup strap 8 is attached to the front of the halter top between the breast cups. The cup strap 8 is in a "Y" configuration as best shown in FIG. 6. The first end of branch A is attached to the inner side of the right breast cup 1. The first end of branch B is attached to the inner side of the left breast cup 2. The second end of stem C is attached to the body strap 3 between the right and left breast cups 1 and 2. While the invention has been set forth and described in terms of a preferred embodiment, it is apparent that other forms of the present invention can be adopted by one skilled in the art. Accordingly, the scope of the present invention is limited only by the following claims.	A halter top made from recycling a pair of pants. The halter top embodies a body strap formed from the waistband of the pair of pants, a right and a left breast cup formed from the back pockets of the pair of pants, and connecting straps for holding the halter top in place formed from the seams of the pair of pants. The method of making the halter top involves detaching pieces of the pair of pants in nearly a single sequence and reassembling the pieces to form the top.	0
BACKGROUND OF THE INVENTION This invention relates to waste water treatment systems, and more particularly, to such systems wherein provision is made for the oxidation of organic matter contained in the waste water while the same is being moved in a closed path. Many waste water treatment facilities in use today are of the so called "activated sludge" type. Typically, such systems are provided with an oxidation or aeration basin or vessel in which the waste water follows a flow path that is a closed loop. In the usual case, raw waste water containing organic solids is introduced into the flow path after prior treatment to remove grit to prevent such grit from entering the oxidation vessel and accumulating therein. The input stream mixes with the recirculating stream, that is, the mixed liquor, and an oxygen containing medium, usually air, is introduced into the vessel to oxidize the organic material. Part of the mixed liquor is withdrawn and typically routed to a settling basin. Typically, the grit chamber used constitutes a separate vessel upstream of the oxidation vessel wherein grit is removed. Grit is normally considered to be small inorganic particles such as sand or cinders which have a size about 200 U.S. mesh. To remove such grit, prior art grit chambers utilized raw or partially treated waste water as a fluid medium to effect liquid scour and allow centrifugal separation. To provide liquid velocity necessary to effect separation, mechanical devices such as pumps, impellers, air diffusers, or the like are required. Alternately, the necessary liquid velocity was provided by that of the incoming waste water which frequently would be mechanically advanced by a pump remote from the treatment facility. SUMMARY OF THE INVENTION It is the principal object of the invention to provide a new and improved waste water treatment system including a combined oxidation and grit removal means. An exemplary embodiment of the invention achieves the foregoing object in a structure including an oxidation vessel for receipt of waste water and including means defining an elongated, closed loop path for the flow of waste water within the vessel. Means are provided for directing waste water along the path as well as means for introducing oxygen into the waste water within the vessel. An elongated grit chamber is disposed within the vessel and has an inlet and an outlet. The inlet and the outlet are spaced from each other along the path. Means are provided for introducing raw waste water into the grit chamber near the inlet thereof. As a consequence of the foregoing construction, the need for separate oxidation and grit separation vessels required by the prior art is eliminated as is the need for special mechanical means associated with the grit chamber for providing a liquid velocity necessary to effect separation of the grit from the incoming stream. Other objects and advantages will become apparent from the following specification taken in connection with the accompanying drawings. DESCRIPTION OF THE DRAWINGS FIG. 1 is a somewhat schematic, plan view of a waste water treatment system made according to the invention; FIG. 2 is an enlarged, plan view of a grit chamber portion of the treatment system; FIG. 3 is a side elevation of the grit chamber portion. DESCRIPTION OF THE PREFERRED EMBODIMENT an exemplary embodiment of a waste water treatment system made according to the invention is illustrated in FIG. 1 and is seen to include a oxidation vessel 10 in the form of a so called oxidation ditch. The vessel is in the form of a oval having a central island 12 which thereby defines an elongated, closed loop flow path for the flow of waste water as schematically illustated by arrows 14. The sides of the vessel 10 may be earthen or lined as desired. Aeration rotors 16 of conventional construction extend across the flow path at various locations about the vessel 10 and are rotated in a conventional fashion to provide the bifold function of impelling the waste water along the flow path in the direction of the arrows and for introducing an oxygen containing medium, namely air, into the waste water. As is well known, the rotors 16 will typically be only partially submerged in the waste water within the vessel 10. A grit chamber, generally designated 18, is disposed within the vessel 10 at any suitable location therein. As illustrated in FIG. 1, the grit chamber 18 is wholly within the conventional configuration of the vessel 10 but it is to be understood that if desired, a recess in one of the outer walls of the vessel 10 or in one of the walls of the central island 12 could be used as well. The grit chamber 18 is elongated in the direction of flow within the vessel 10 and at its upstream end includes an inlet 20. At its downstream end, and spaced from the inlet 20, is an outlet 22. Preferably, the inlet end 20 is provided with a flow control gate 24 which may take on any desired form and which may be set at any of a variety of positions between fully open and fully closed so as to control the amount of flow of mixed liquor from the remainder of the vessel 10 into the interior of the grit chamber 18 through the inlet 20. To prevent unwanted entry of mixed liquor into the grit chamber 18 at locations other than the inlet 20, spaced inwardly from the outer wall of the vessel 10 is an upstanding wall 26 which extends above the intended liquid level of mixed liquor within the vessel 10. An inlet for raw sewage or waste water to be treated is schematically shown at 28 and is located near the inlet 20 for the grit chamber 18. Raw sewage or waste water containing grit as well as organic material is introduced at that point and mixed with the mixed liquor entering the grit chamber 18 through the inlet 20. A grit removal station 30 is also provided and generally will be adjacent the outlet 22 of the grit chamber 18. Grit accumulating within the grit chamber 18 is removed at the station 30 by means to be shown. The overall system is completed by a suitable outlet 32 at a desired location from which mixed liquor may be diverted to a settling tank or the like. FIGS. 2 and 3 illustrate the grit chamber 18 in greater detail. With reference to FIG. 2, the location of the wall 26 with respect to an outer wall 34 of the vessel 10 is apparent. The bottom of the vessel is designated 36 (FIG. 3). Between the walls 26 and 34, the bottom 36 is provided with a hopper-like depression 38, the downstream side 40 of which acts as a baffle. Just down stream of the depression 38 there may be provided an upstanding baffle 42. Incoming waste water or raw sewage will enter the grit chamber via the conduit 28 to be mixed with mixed liquor entering the grit chamber through the inlet 20. The velocity of the mixed liquor through the grit chamber 18, which velocity is generated by the rotors 16, will scour grit particles 44 from organic material within the grit chamber. The higher density of the inorganic grit will cause the same to settle out on the bottom 36 of the vessel 10 within the grit chamber 18 and the velocity of the mixed liquor within the grit chamber 18 will tend to cause the grit 44 to move to the depression 38 to accumulate therein. Smaller grit particles, which wll tend to remain in suspension longer, will be prevented from leaving the outlet 22 of the grit chamber to enter the remainder of the vessel 10 by either the downstream side 40 of the depression 38 or the baffle 42, or both. At the same time, because the organic material will remain suspended due to turbulence and the velocity of the mixed liquor stream, the same will pass over the baffle 42 to exit the grit chamber 18 and enter the remainder of the vessel 10. An elevating conveyor 46 which may be of any suitable type such as an auger conveyor, a bucket conveyor or the like, has one end 48 within the depression 38 and an upper end 50 disposed exteriorly of the vessel 10. When there has been sufficient grit accumulation within the depression 38, the conveyor 46 may be energized to remove the accumulated grit therefrom. Alternately, a pump operated suction line may be used as the elevating conveyor in lieu of an auger or bucket conveyor. In some cases, heavier grit particles, which will tend to settle out more rapidly than lighter grit particles, may settle out well upstream of the depression 38. In order to prevent an accumulation of such heavier grit particles that would impede flow of the mixed liquor through the grit chamber, a scraper, generally designated 52 may be employed. Two shafts 54 and 56 are disposed within the grit chamber 18 with the former being near the upstream end of the depression 38 and the latter being adjacent to the inlet 20. Sprockets 58 are carried by the shafts and the shaft 56 may be driven selectively by a motor 60. Chains 62 are trained about the sprockets as illustrated adjacent the walls 26 and 34 and scraper flights such as metal bars 64 extend between the chains 62. The lower run of the chains 62 is closely adjacent to the bottom 36 of the vessel within the grit chamber 18 and as a consequence, upon energization of the motor 60, the scraper flights 64 move grit particles 44 accumulating near the inlet 20 downstream to the depression 38 to be accumulated therein. From the foregoing it will be appreciated that the invention provides a number of advantages over prior art structures. For one, separate vessels for grit separation and oxidation or aeration, as required by the prior art are avoided since the grit chamber of the present invention is located within an aeration or oxidation vessel 10. Construction expense is thus minimized. At the same time, operating expense is similarly minimized. The invention avoids any need for separate pumps, impellers or diffusers etc. for separating grit from organic material in the incoming waste water stream. Nonetheless, sufficient liquid scouring of the organic material necessary to achieve separation of the grit occurs by reason of the velocity of the mixed liquor moving within its closed path. This velocity is, of course, provided by the rotors 16 or other such means conventionally used but since they are required in any event to achieve the desired movement of the liquid as well as the introduction of oxygen into the mixed liquor, the operating cost of the grit chamber of the present invention is no different than that of an oxidation vessel alone (save for periodic use of the scraper and the grit removing conveyor). Moreover, maintenance of velocity inducing mechanical equipment heretofore associated with prior art grit chambers is avoided as is the expense of its initial purchase. In addition, many grit chambers have a relatively high head loss, much of which is avoided by the present invention. This in turn decreases pumping requirements in the overall system thereby enabling the use of less expensive pumping equipment and minimizing running costs. Finally, because the present invention separates the grit from the liquid by way of the velocity of a mixed liquor as opposed to a raw sewage or the like, such organic material as may be present in the grit when removed from the grit chamber will be at least partially treated by oxidation. Consequently, grit removed from the chamber will have a lesser concentration of untreated organic materials than with prior art constructions. Such untreated organic materials in high concentrations increase noxious odors providing a disposal problem for the grit which is minimized or avoided entirely by the present invention.	A waste water treatment system including an oxidation vessel for receipt of waste water and including structure defining an elongated, closed loop path for the flow of waste water within the vessel. One or more rotors (a) direct waste water along the path and (b) introduce oygen into the waste water within the vessel. An elongated grit chamber is disposed within the vessel and has an inlet and an outlet. The inlet and the outlet are spaced from each other along the flow path and there is provided a further inlet for introducing raw waste water into the grit chamber near the first mentioned grit chamber inlet.	8
FIELD OF THE INVENTION The present invention generally relates to a computer system and data processing techniques for detecting fraud and abuse in commercial instruments. More particularly, the present invention relates to a data processing system that works in concert with specifically delineated software to ensure checks issued and presented through the banking system contain no material alterations to printed check information, such as the payee name, issue date, check number and check amount. BACKGROUND OF THE INVENTION For many centuries, money has been used to permit market transactions of goods and services. Money was often in the form of coinage and other types of currency and thus immediately liquid--and subject to immediate loss. To expand the available transactions, banks became available to extend credit for goods and services in the market. Such credit extensions were leveraged on deposits and took the form of various types of commercial paper including promissory notes, letters of credit, drafts and, more commonly, checks on account. These financial instruments have provided substantial capital and increased asset liquidity and thus supported greater--debt based--economic growth. However, transactions based on paper have long suffered significant losses as a result of acts of fraud. Specifically, paper was easily stolen and modified in ways that misled the drawee bank into inappropriately releasing check defined currency. For the most part, this involved altering the check in a way undetectable to the bank. When presented for payment, the modified check would be honored with the resulting financial loss to be allocated between the drawee bank (bank of first deposit) and check writer of the funds usurped by the altered or fraudulently created check. To combat this fraud, banks have employed many techniques for confirming check validity. For example, checks will routinely include information about the drawing account and amount to be drawn. Special patterns and designations are applied to the blank paper check stock to discourage replication. In fact, centuries ago, checks required a personal "chop" to permit cashing. Notwithstanding these techniques, modern practices of check writing and encashment remains mired in scams and fraud, resulting in billions of dollars of lost funds and is growing at an alarming rate due to the use of technology such as image scanners, personal computers and laser printers. Moreover, banks and other institutions are responsible for cashing many pre-printed checks of the type now typically used for payroll, dividends, etc. These checks are computer generated by the check issuer with specialized accounting software to track the transactions on an aggregate basis and to record individual account activity. In some ways, these automated issuance systems make it easier for check forgers to alter or reproduce fraudulent checks. Banks also, in an effort to reduce the costs of processing presented checks and posting them to customer accounts, have implemented sophisticated equipment and software to greatly automate these processes. One of the unfortunate results of this automation, however, is that fewer customer checks are physically handled and reviewed by bank personnel, making it more likely that these reproductions of originally issued checks with altered payees will go undetected. Even when physically inspected, however, many of these falsified items so clearly match the appearance of an original check drawn on the same customer account that the counterfeit is still not detected. These types of fraudulent items are resulting in losses of approximately five billion dollars per year and are growing at an alarming rate. As an example of this widespread type of check fraud, in 1993, two checks for $80,000.00 were stolen from the Philadelphia Post Office. These checks included a printed name identifying the payee on the check. In addition, these checks included information of the check number, account number and dollar amount. The fraud was perpetrated by creating a duplicate check in the same font/typeface on security paper with MICR (Magnetic Ink Character Recognition) encoding used by banks to read the key pieces of information about a check in an automated fashion. This was done so the copy was identical to the check stock that was initially issued. The sole difference from the original item was that the payee had been changed. An account had been opened in the fictitious payee's name and the duplicate check was deposited into the account. The duplicated check was presented for payment and the funds were transferred to the falsified account, which was then closed out after the deposit funds were withdrawn. Since the check number, account number and the amount were all accurate, and the check appeared to be the original, the check was honored and the fraud uncovered only after the funds had been removed from the fictitious payee's account. The foregoing example is not a lone event. Similar schemes are being perpetrated by check fraud rings worldwide at an astounding rate. Computer generated paychecks for stock dividends, payrolls and similar automated check preparation systems are now used extensively throughout the U.S. to issue millions of checks each day. Each check must include the printed payee as discussed above, and thus each is subject to the same kind of potential fraud. To prevent this and other types of fraud, the present invention has been created. OBJECTS AND SUMMARY OF THE PRESENT INVENTION It is an object of the present invention to provide a data processing system for managing check preparation and processing to prevent check alteration. It is another object of the present invention to provide a data processor for confirming validity of checks presented for payment in a manner that precludes payee substitution. The above and other objects of the present invention are realized in a unique data processing system that reads, interprets, and converts alpha characters found in payee names to a numeric value. The numeric information from the payee is combined with selected information from the MICR line and other parts of the check (check number, account number, issue date and dollar amount), and the combined information is used in a check digit routine. The result of the check digit routine is conveyed to the drawee bank. The drawee bank will use this information to validate the check upon presentment before final payment. The method used to convey the check digit routine can vary. The check digit information can be transmitted to the drawee bank as part of the current Positive Pay file within which the check issuer provides the drawee bank with a list of checks issued against which the bank can match items such as the check number, account number and dollar amount when presented for payment. Alternatively or in addition thereto, the value of the check digit may be placed on the face of the check in the "aux on us" field in the MICR line or on the face of the check, via the check issuance system. In accordance with the varying aspects of the present invention, a first computer system is used to manage the check printing and accounting process. This computer system includes additional software processes for generating a numerical coded value corresponding to, among other things, the individual name of the payee--a numeric value that is based on the transformation of the alpha characters of the payee. The check issuer and the corresponding drawee bank will agree on a set or sets of numeric manipulations (hereinafter referred to as the "algorithm") to be employed for the specific customer's checks that will result in the check digit. This algorithm can vary by customer, by drawee account, by check serial range, or by check if needed. To protect against fraud, the algorithms are shared only by the check issuer and the drawee bank and only disclosed to other interested parties as agreed to by the check issuer and the bank. A second computer system, located at the drawee bank, will have complementary software. This second system is also programmed to track and record disbursements associated with checks presented for payment by customer account. In addition, the system will recalculate the numeric value of the check digit using the agreed upon algorithm and compare it to the original check digit calculated when the check was issued. Any discrepancies will be reviewed by bank and check issuer personnel to determine the validity of the item(s) prior to final payment. The foregoing features of the present invention are more fully and readily understood from the following detailed description of the presently preferred embodiments and presently preferred methods of practicing the invention. BRIEF DESCRIPTION OF THE FIGURES The invention will become more readily apparent from the following description of a specific illustrative embodiment thereof presented hereinbelow in conjunction with the accompanying drawings, of which: FIG. 1 depicts a typical check of the type used with the present invention; FIG. 2 depicts a functional block diagram of the key hardware components of the present invention; FIG. 3 depicts a logic flow chart for the computer management controlling logic for the present invention relating to the check issuance process; and FIG. 4 depicts a logic flow chart for the computer management controlling logic for the present invention relating to the check review process by the drawee bank. DETAILED DESCRIPTION OF THE INVENTION First briefly in overview, the present invention provides a computer programmed apparatus and process integrated into a fraud prevention system utilized by both sides of check processing transactions. The check issuance workflow begins the process, with a computer controlled accounting and printing system. This system generates a plurality of checks of varying amounts, bank accounts and payees. This is iteratively processed with the resulting checks physically generated via per se well-known high speed printers. The checks are then typically sorted and placed in individual envelopes for mailing to the designated individuals or corporate payees. The check amounts, payee and account data are tracked and the system databases are updated after a batch run. For each payee, the system selectively assesses the payee's alpha-characters and using a pre-determined specialized algorithm, calculates a corresponding numeric rendition of the payee name either alone or in combination with other payee/check information, and ultimately, a corresponding check digit value. During the printing process, the check digit of this numeric rendition is applied to the check MICR Line or some other location on the check face prior to passing the check to the enveloping process, or it is captured and transmitted later as part of the check issuance file sent to the drawee bank. The second aspect of the inventive system involves the check presentation processing. The system provides a second computer remote from the printing system and typically found at the drawee bank where checks will be presented. This computer hardware and software will track the receipt of the presented checks in conventional means, recording each presented check for posting against the check issuer's account(s). The computer system will further include the enhancement of being able to use digital image technology or other ICR (Intelligent Character Recognition) to locate and interpret the printed payee and/or other relevant fields on the check including but not limited to the check serial number, dollar amount and issue date. The alpha characters in the payee name will be captured, "recognized" by the software, and converted to numerics according to a pre-defined algorithm. A check digit is calculated. This is then compared to the expected check digit received from the issuer or otherwise printed on the check. A match between the expected and calculated check digit confirms that the selected relevant fields such as the payee name, dollar amount, issue date and check number have not been altered. With the foregoing background in mind, attention is first directed to FIG. 1, wherein a typical check is depicted having certain common characteristics important for understanding the instant invention. In particular, the check will have a payee designated 10, (in this example the payee's name is John Jones) which is typed in the central portion of the check and an issue date 20. The payee name and issue date are printed in a character font that is readable by the image scanner. The check includes other ancillary indicia, and several special purpose printed regions, including the MICR line comprised of the check number 30, the account number 40, and the amount of the check 50. To implement the present fraud detection system, the MICR line is augmented with a further numeric value--which may be encoded in the "Aux on us" field which is not shown. If the MICR line is not used, the check digit value may be placed on another check face location, pre-defined by the parties to the transaction, see for example item 60 in FIG. 1. Also, the algorithms are assigned identifying numbers--the number of the selected algorithm being placed on the check along with the check digit so that the drawee bank will know which algorithm to employ. As mentioned before, an alternative is to leave the check free of the check digit value and algorithm number, and electronically transmit the check digit to the drawee's bank in the paid issuance file. The coordination of algorithm selection may be by other means as found appropriate under the circumstances. For example, to implement multiple algorithm use, authorized individuals of the check issuer and drawee bank agree on one or more algorithms that will be employed. A selected algorithm may use a selected combination of information (payee name, check number, account number, issue date and dollar amount) to calculate the check digit. Often, the algorithm uses the payee name and possibly other check and payee information in its calculations. In order to calculate the check digit, a first part of the algorithm involves converting all alpha characters of the check information to numerics. There are many possible ways to establish the alpha conversion of the payee value to a numeric code. One simple yet effective algorithm is delineated in Table 1 below herein each letter is sequentially assigned a corresponding numeric value. TABLE I______________________________________A B C D . . . X Y Z SPACE0 1 2 3 . . . 23 24 25 26______________________________________ In accordance with this simple transformation, the payee name "John Jones" is converted to the digital value 9147132691413418; this large value is then utilized in a second part of the algorithm. The second part of the algorithm involves converting the numeric value of the selected check/payee information along with the numeric value of the payee name to a check digit. Specifically, in this example, the individual values are multiplied by a constant (e.g., "371"). This procedure is repeated for the selected check information including the check number, issue date and account number with the resulting string of products summed to provide a final, composite value: ______________________________________Payee: 9 1 4 7 1 3 . . . 3 7 1 3 7 1 27 + 7 + 4 + 21 + 7 + 3 . . . +Check 5 8 8 6 3 5 . . .& Acct 3 7 1 3 7 1 . . .no. 15 + 56 + 8 + 18 + 21 + 5+ . . . +Chk amt. 1 0 5 2 3 6 2 3 7 1 3 7 1 3 3 + 0 + 5 + 6 + 21 + 6 + 6 +Issue 0 5 1 0 9 5date 3 7 1 3 7 1 0 + 35 + 1 + 0 + 63 + 5 = 517______________________________________ The calculated value 517 is subtracted from the next largest whole number that ends with zero (520) resulting in the value "3" as the check digit. For additional complexity and security, a second check digit can be formed from the sum of the digits (5+2+0=7), thus resulting in the payee check digit "73", see item 60 of FIG. 1. In this example, the first three digits of item 60 "001" reflect the specific algorithm used to develop the check digit. In this way, one thousand (1,000) separate algorithms may be used in rotation. The above calculations are illustrative of a transformation algorithm that combines the converted alpha characters from the payee name with the associated check number, issue date, account number and amount drawn to determine a positive identifying check digit value for imprinting onto the check face or transmission. The above algorithm is for illustrative purposes only, as it is contemplated that other numeric transformation techniques having greater complexity and security may be used. Turning now to FIGS. 2A and 2B, a block diagrams depict the associated hardware used to implement the above fraud detection system. As presented therein, the system is segregated into two CPUs representing the check issuance and drawee bank process, blocks 100 and 200, respectively. These are general purpose digital computers having the memory and processing power commensurate with the level of processing demand placed on the CPU by the institution. Banks are traditionally heavy data processors and thus the CPUs are likely to be mainframe systems. With the advent of distributed processing, many aspects of mainframe processing are now done on a network of workstations and it is likely that such a network could also be used in conjunction with the present invention. Each computer system further comprises memory (blocks 140 and 240) for storage of the controlling programs and requisite data files, and communication ports (blocks 120 and 220) that permit transfer of data such as the electronic form of the paid issuance file (see below). A reader sorter, block 250, is used for reading and interpreting check MICR and other data, as well as for segregating checks in processing. The reader/sorter 250 further includes an image camera 260 for capturing the payee name and issue date from the face of the check when presented. These captured ALPHA and numeric characters are then converted to numeric values and combined with information read from the MICR line and the check digit routine is recalculated. Both 130 and 210 have access to the same software to calculate and re-calculate the algorithmic check digit routines previously outlined in this document. The check issuance system further includes the printing system 110 for printing checks, and a communication subsystem for linking to other (possibly branch offices) locations for data transmission. Turning now to FIG. 3, the controlling logic as it relates to the check fraud prevention system is depicted in flow chart form. Starting at block 300, logic for the check creating process is initiated. At block 310, the database for check generation is accessed. This is typically a batch process for e.g., payroll or the like. The system utilizes tracking or index variables (I) to index between entries in the database DB (I). Accordingly, each account (I) is processed sequentially, block 320, to discern if a check is to be prepared, test 330--if negative, logic branches to block 340 and the system indexes to the next entry, I=I+1. If a check is to be generated, "yes" to test 330, logic proceeds to block 350 wherein the amount is selected (or calculated). Alternatively, it can be assumed that a check will issue for each payee name. At block 360, the account number and payee name are pulled, and the check number and issue date selected. At block 370, the algorithm number is parsed from memory and the corresponding algorithm pulled for use. It is expected that many distinct algorithms will reside in memory and be available for use. At block 380, the account values (name, number, issue date and check amount) are transformed in accordance with the governing algorithm--resulting in the check digit value (described above) reflecting the payee name with the associated check number, amount, and account information. The calculated value is stored, block 390, with the algorithm number and the process is then iteratively indexed through the entire batch for that run, block 400. Thereafter, test 410 discerns whether this is a print run; if yes, logic proceeds to block 420 to determine if the check digit is to be printed. If no, logic proceeds to block 430 and the check digit is stored in the paid issuance file, PI(X). In either event, logic proceeds to check printing block 440, in which checks are printed with or without the check digit number as determined above, and block 450 for check print confirmation. Turning now to FIG. 4, the logic underlying the check confirmation process is delineated. The process is initiated at start block 500, and continues to block 510 wherein the check presented for payment is input into the system and given an index (J) for tracking during processing. The presented check is then scanned, block 520, with the payee and other check date included in the captured image. If the algorithm number and check digit are included on the face of the check they are also captured. At block 520 and 530, the MICR data is inputted and stored at (J) index value location in the system. The system at block 540 interprets the payee name and other appropriate check data, including the algorithm number and check digit if printed on the face or MICR line of the check, then applies the appropriate algorithm to the captured MICR line and image to generate a check digit value CD (J). At test 550, if the algorithm number and/or check digit are not found on the check, the system queries as to the existence of a paid issuance file, previously transferred from the drawee bank. If yes to test 550, logic branches to block 560 and paid issuance file is pulled, PI(X). At block 570, CD2(J) is pulled from the paid issuance file, and logic proceeds to test 580. CD(J) is pulled from its location and the logic proceeds to test 580. At test 580, the system compares the CD(J) with the CD2(J) read from the check or the paid issuance file; if a match exists, processing continues to block 600 and check (J) is passed. However, if a match is not made, the system logic is branched to special processing sequence, block 590. In block 590, the specialized software will attempt to "re-read" the check information fields as necessary and re-test the resulting values to determine if the revised check digit matches that provided by the check issuer. This process may be necessary since the software which reads and interprets these fields may arrive at more than one possible letter or number for each value in the field. The software will iteratively evaluate all field positions for which more than one possible value exists to determine if the changed value will result in CD2(J) being equal to CD(J). If it is successful in finding a value that will make CD2(J)=CD(J), logic proceeds to 600. If not, the image of the check in question will be displayed to an operator, along with the interpreted values from the payee name, issue date, check number, and check amount fields. The operator will visually inspect the check image and the interpreted values to determine if the software made an error in its interpretation of one or more of the fields. If it has, the operator will key the correct values, over-writing the errors made by the software. Once keying is completed, the algorithm software will again be invoked to recalculate the check digit using the appropriate algorithm and the revised field values. If the revised check digit is found equal to that calculated by the check issuer, the item is paid in block 600. If CD2(J) does not equal CD(J) in block 593, the image is passed to a second operator in block 594 who will contact the issuer and determine if the item should be returned to the bank of first deposit in block 595. It should be noted that all of the processing outlined above occurring at the drawee bank occurs within right of return guidelines as outlined in the Uniform Commercial Code. As used herein, payee information includes at least the payee name, and optionally, the account number, check number and check amount. The foregoing logic has been illustrated as sequential; as is universally recognized, many other approaches for accomplishing the same result are available including continuous processing, menu indexing, etc.; the use of the above recitation was selected to demonstrate the inventive concepts in a straight forward and illustrative manner. Although the invention has been described in detail for the purpose of illustration, it is to be understood that such detail is solely for that purpose and that variations can be made therein by those skilled in the art without departing from the spirit and scope of the invention except as it may be limited by the claims.	A system and method for detecting and thus preventing check fraud utilizing a digital computer with image capture and interpretation systems. The system converts the payee information, issue date and the MICR line information (account number, check number and dollar amount) to a check digit which is then placed into the MICR line of a check, printed on its face or transmitted via the paid issuance file to the drawee bank. The drawee bank, upon presentment utilizes a transformation algorithm to convert the printed payee information and issue date on the check into a numerical value that is combined with MICR line information and a check digit is calculated based upon pre-agreed logic. This unique data processing system quickly confirms properly presented checks while effectively precludes payee and other alterations in a cost effective manner.	6
BACKGROUND OF THE INVENTION This invention relates to a quick and convenient device and method for setting up and taking down canvas and other fabric canopy covers on boats, trucks, buildings, other structures and even ground surfaces. It is a form of temporary building, storage cover or tent when used in relation to ground surfaces and some other structures. Fabric covers are one of the oldest arts of civilization for temporary coverings and dwellings. In current practice, canopies with tube supports for canvas and other fabric coverings have become quite common. Particularly for boats, they have become popular for quick set-up and removal in response to weather conditions affecting comfort and safety related to marine activities. Most of the canopy support practices employed currently utilize a simple bolting of ends of canopy tubes and rods through their diameters to support members at either or both sides of the tubes. One of the most popular on the market uses an eye in a flat attachment to a canopy tube for bolting to a threaded member attached to a boat frame. These most popular current devices involve tedious turning in and out of bolts. There is always the likelihood of the bolts being lost, particularly in rough marine conditions when the covers are most likely to be required. Bolt ends are often sharp and injurious in present methods. Various wrenches and screwdrivers are required and may be time-consuming to find or may be lost or dropped overboard in the use-conditions for which they are intended. Nearly all use-conditions for canopies are fraught with these same problems in various manners and to various degrees. Most use-conditions are benefited by this invention in similar ways. Some of the most commonly-used methods are so simple that they are not patented. No patented or unpatented methods have been found with the advantages and working relationship of parts utilized in this invention. SUMMARY OF THE INVENTION The primary object of the instant invention is to provide a hinge device for supporting canopies. A related object of this invention is to provide such a device that makes attaching and detaching canopies quicker and easier than with prior devices. Another related object of this invention is to provide such a device that decreases breakage of canopy support members, thereby reducing costs to the consumer. Another object of this invention is to provide such a device wherein all parts fit together without loose parts, such as separate bolts, which could be lost, which is the case with canopy support members in the prior art. Even another object of this invention is to provide such a device which does not require wrenches, screwdrivers or other tools to assemble. A further object of the instant invention is to provide methods of using the canopy-support hinge device. This invention accomplishes the above and other objects by providing a device consisting of a canopy-support hinge base member and a canopy-tube hinge bolt member, said base member having a cylindrical hinge-bolt aperture with a select linear orifice in the outer portion of the hinge-bolt aperture open to receive the hinge bolt when said hinge bolt is turned side-to-side as the oppositely-disposed sides of the bolt are flat and parallel linearly to the axis of the bolt. The open edge of the hinge-bolt aperture in the hinge base is wide enough to receive the hinge bolt at the parallel sides but not wide enough to allow the hinge bolt to pass through the said aperture when the hinge bolt is rotated to a position in which its parallel flat sides are not tangentially in-line with the open edge of the said aperture. The hinge base is provided with a hinge-bolt-head channel wide enough to receive the bolt head from side-to-side. The canopy-tube attachment means is too wide to enter the hinge-bolt-head channel, however, such that the hinge bolt can be inserted into the cylindrical hinge-bolt aperture in the hinge base only with the canopy-tube attachment means at the opposite surface of the hinge base from the hinge-bolt-head channel. An insertable-rod canopy-support attachment means is projected at a select angle from the opposite end of the attachment means from the flanged hinge bolt head. Canopy support members are inserted into the attachment means and the canopy material is attached by snapping or tying at sides of the hinges to form canopy coverings. This forms a convenient type of canopy. It is also a form of tent. A wide variety of portable, temporary and relatively permanent types of canopies, coverings and tents utilizing this invention are foreseeable. Canopies for windows on buildings also are described by vertical mountings of this invention. For vertical window canopies, it is desirable to construct the flats on the hinge bolt selectively non-parallel to the axis of the insertable rod such that the hinge bolts can be inserted or removed only when the angle of the canopy support members exceeds the range of the operating angle. Use methods are described for utilizing this hinge system for reliable, convenient and quick set-up and quick removal of fabric coverings, dwellings and shelters. The objects, advantages and features of the invention will become readily apparent from the following detailed description of the specific embodiments thereof when read in conjunction with the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS This invention can be understood more clearly by reference to the enclosed drawings wherein: FIG. 1 is an end view of a side-mount hinge base in assembly with a hinge bolt from an end of a hinge bolt. FIG. 2 is a side view of a side-mount hinge base in assembly with a hinge bolt from a side of a hinge bolt. FIG. 3 is a side view of a horizontal or deck-mount hinge base in assembly with a hinge bolt from a side of an insertable-rod attachment member. FIG. 4 is a side view of an insertable-rod attachment member in assembly with a tubular section of a canopy support member and an end of a hinge bolt with a 45-degree slant between the rod and flats on the hinge bolt. FIG. 5 is a side view of an insertable-rod attachment member in assembly with a tubular section of a canopy support member and an end of a hinge bolt with a 90-degree slant between the rod and flats on the hinge bolt. FIG. 6 is a top view of a pair of deck-mounted or horizontal-mounted hinge bases in assembly with a section of canopy tube extended between them. FIG. 7 is a side view of a vertically-mounted canopy hinge in use relationship to a window canopy. FIG. 8 is a side view of a hinge bolt with a straight insertable rod. FIG. 9 is a side view of a hinge bolt with an insertable rod at a 45-degree angle from the axis of the hinge bolt. FIG. 10 is an end view of a pair of canopy hinges in use relationship to a right-angled canopy tube covering a boat deck or other structure and illustrating a deck-mounted hinge at the left side and a side-mounted hinge at the right side. FIG. 11 is a side view of a tent-type covering with an obtuse angle between end canopy supports and acute angles between end canopy supports and a base. FIG. 12 is a side view of canopy tube hinges supporting a cover over the forward and aft sections of a boat. DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring to FIG. 1, a canopy-hinge bolt 1 is held in swivelable relationship to a side-mount canopy hinge base 2 by hinge-bolt aperture 3 with aperture open side 4 through which parallel bolt flats 5 are inserted when insertable-rod 6 is rotated to a position to cause the parallel bolt flats to be in line with the aperture open side. Except when the bolt flats are in line with the open side of the aperture, the hinge bolt is prevented from being dislodged from the bolt aperture by flanged bolt head 7 at one end and by rod base 8 at the other end. The hinge bolt can be inserted only in the designed direction as a result of bolt-head channel 9 that is sufficiently wide to allow entry of the bolt head but too narrow for entry of the rod base. The rod is insertable into the inside diameter of tubular portions of canopy support members as a canopy-attachment means. A circumferential indentation 10 is provided for attaching a canopy tube attachment 16 with indentation 21 as shown in FIG. 5 or for optional gluing material or for a resilient member to assist firmness of holding power between the rod and tubular members into which it is inserted. Tubular members attached to the rod are prevented from traveling over the rod by stopper ridge 11. The hinge base illustrated in FIG. 1 is attached to sides of vertical walls by threaded fasteners extended through fastener orifices 12 inserted from opposite side of the base. Referring to FIG. 2, the same components are illustrated attached to a vertical wall 13 from a different view. In this view, the hinge bolt is rotated to a position in which the parallel bolt flats are at right angles to the open side of the aperture and the diameter of the bolt is represented by broken lines. Referring to FIG. 3, a deck-mount hinge base 14 utilizes the same hinge bolt in the same working relationship. The deck-mount hinge is the same except for its construction with an aperture housing 15 with the axis of the bolt aperture at right angles to the axis of the fastener orifices. The deck-mount hinge base is used on either horizontal or vertical surfaces for support of canopy weight. Typical uses of the deck-mount hinge base are for supporting canopy frames for decks of marine craft, ground-surface tents and vertical-surface window awnings. By contrast, a typical use of the side-mount hinge base is for supporting canopy weight vertically from a side wall of a marine vehicle or other structure. Referring to FIG. 4, a hinge bolt is shown separately from a hinge base. A canopy tube attachment section 16 is shown with a matching tubular indentation 17 for a resilient member 18 to assist snugness of contact for holding the tube to the insertable bolt. The bolt flats are shown at an angle not parallel to the axis of the insertable rod. In this case, the angle is 45 degrees from the axis of the insertable rod. In lieu of the resilient member, gluing substance could be utilized for a relatively permanent attachment of the tube to the rod. The indentation in the rod would convey glue around the circumference of the two members being attached. The purpose of this angle is to provide the capability of inserting the bolt at an angle different from normal operating angles of canopy support members. An example would be a window awning. The bolt could be insertable at 45 degrees down from horizontal. Then the material of the awning would be fastened above the hinges to prevent the awning from falling below right angles to a building on which it were mounted. The awning canopy could be raised and lowered within its range of operation without causing the flats to be in line with the open side of the aperture unless the awning were detached at the top. Referring to FIG. 5, the same components are shown but without the resilient member 10 and instead a matching tubular indentation 44 on the canopy attachment tube 16 to hold the tube 16 on the device. Also, the bolt flats are at right angles to the axis of the insertable rod 16. Referring to FIG. 6, a pair of deck-mount hinges is shown in oppositely-disposed relationship with a canopy tube section 19 extended between them. It can be noted that the rod is positioned at the outside on both sides of deck 20 or other structure. This allows canvas or other material used for a canopy to hang over the side of the deck for maximized coverage and protection from weather conditions. Referring to FIG. 7, a use method for a window awning canopy 21 is shown in relationship to deck-mount hinges. An awning top 22 is fastened above the hinge and optionally below it also. Referring to FIG. 8, a hinge bolt with a straight connector rod is illustrated for straight bar attachments and for tubular attachments with separate angles for special design applications. Referring to FIG. 9, a connector rod is shown at an angle between a right angle and a straight angle. It demonstrates applications for A-shaped canopy applications. Referring to FIG. 10, a front view of a rectangular canopy illustrates a deck with a deck-mount hinge on the left and a side-mount hinge on the right. The deck could also be any surface such as the ground for a tent or other covering. With either deck-mount or side-mount embodiments of this invention, the canopy material can hang over the sides as illustrated by left overhang 23 and right overhang 24 materials. Typically, the same embodiment would be used for both sides, although the two different types may be used a different locations throughout a boat covering or other application. Referring to FIG. 11, a method of using the hinges for a canopy is illustrated with an obtuse angle between left end canopy member 25 and right end canopy member 26. The obtuse angle between the two ends leaves an acute angle between a left base 27 and the left end canopy member and between a right base 29 and the right end canopy member respectively. These acute angles enable either a vertical left end anchor 29 or an angled left end anchor 30 and either a vertical right end anchor 31 or an angled right end anchor 32 to be employed as the only tie down means necessary besides the anchoring of the left hinge 33 and the right hinge 34. Central canopy support member 35 with central hinge 36 and additional such members and hinges are optional for the length of tent or covering for which this invention is utilized. This enclosure could be set up over a marine location also for covering boats. Either a rounded or an A-frame canopy may be desirable for some storage or dwelling applications. Referring to FIG. 12, a boat 37 is shown in relationship to a relatively short cabin canopy support member 38 and a longer aft canopy support member 39. They are attached at their base to forward hinge 40 and aft hinge 41. They are anchored with forward and aft extension members 42 and 43 respectively. The extension members can be fabric portions of the canopy covering, a windshield in the case of the forward boat position, or either solid or flexible cords. While specific embodiments of the invention have been described in detail hereinabove, it is to be understood that various modifications may be made from the specific details described hereinabove without departing from the spirit and scope of the invention as set forth in the appended claims.	A canopy-support hinge comprising a base member and bolt member is provided. The hinge base member is provided with an open side having a hinge bolt aperture. The open side of said base member is narrower than the diameter of the bolt aperture. The hinge bolt member is provided with two flat parallel sides to make the bolt narrow enough to be passed through the open side but to be contained when the bolt is rotated to different positions. A flanged bolt head and connector means on the bolt member for attaching canopy support tube members thereto renders this device advantageous for forming canopies on boats and on other structures.	4
BACKGROUND OF THE INVENTION [0001] This invention relates generally to washing machines, and, more particularly, to methods and apparatus for controlling agitation time and agitation speed during agitation phases of wash cycles. [0002] Washing machines typically include a cabinet that houses an outer tub for containing wash and rinse water, a perforated clothes basket within the tub, and an agitator within the basket. A drive and motor assembly is mounted underneath the stationary outer tub to rotate the clothes basket and the agitator relative to one another, and a pump assembly pumps water from the tub to a drain to execute a wash cycle. See, for example, U.S. Pat. No. 6,029,298. [0003] Periodically as the washing machine is used, the agitator is actuated by a control mechanism and imparts an oscillatory motion to articles and liquid in the basket, thereby producing mechanical washing action and energy to clean articles in the basket. Traditionally, the agitator is actuated for a fixed time period and at a fixed, predetermined actuation speed or intensity during agitation phases of a wash cycle. For certain laundry loads, however, the agitation speed and/or the agitation duration may be excessive. Aside from energy considerations associated with unnecessary agitation, excessive agitation extends the time for the wash cycle to complete and can lead to excessive wear of laundered articles washed in the machine. BRIEF DESCRIPTION OF THE INVENTION [0004] In one aspect, a controller for a washing machine including an agitation element operable at a plurality of speeds during an agitation phase of a wash cycle is provided. The controller comprises a microcomputer configured to adjust an actuation of the agitation element in response to at least one input, said at least one input indicative of a characteristic of a laundry load. [0005] In another aspect, an agitation phase control system for a washing machine is provided. The control system comprises a drive system comprising an agitation element, and a controller operatively coupled to said drive system. The controller is configured to vary operation of said agitation element in response to laundry load characteristics. [0006] In another aspect, a washing machine is provided. The washing machine comprises a cabinet, a basket mounted within said cabinet, an agitation element mounted within said basket, and a drive system coupled to said agitation element. The drive system is configured to move said agitation element in an oscillatory manner at a plurality of speeds. A controller is operatively coupled to said drive system, and the controller comprises a microcomputer and a memory, and the memory comprises a plurality of agitation time values and a plurality of agitation speed values. The microcomputer is configured to select one of said agitation time values and one of said agitation speed values in response to laundry load inputs. [0007] In another aspect, a method for controlling a washing machine in an agitation phase of a wash cycle is provided. The washing machine includes an agitation element therein and a controller operatively coupled thereto, and the method comprises accepting at least one laundry load input, and operating the agitation element at one of a plurality of settings based upon the laundry load input. [0008] In still another aspect, a method for controlling a washing machine in an agitation phase of a wash cycle is provided. The washing machine includes a multi-speed drive system coupled to an agitation element and a controller operatively coupled to the drive system. The method comprises accepting a laundry soil level input, selecting one of a plurality of agitation time parameter settings in response to said soil level input, accepting a laundry load size input, selecting one of a plurality of agitation speed parameter settings in response to said load size input, and operating the drive system in accordance with the selected agitation time parameter setting and the selected agitation speed parameter setting. BRIEF DESCRIPTION OF THE DRAWINGS [0009] [0009]FIG. 1 is a perspective cutaway view of an exemplary washing machine. [0010] [0010]FIG. 2 is front elevational schematic view of the washing machine shown in FIG. 1. [0011] [0011]FIG. 3 is a schematic block diagram of a control system for the washing machine shown in FIGS. 1 and 2. [0012] [0012]FIG. 4 is a washer agitation control algorithm executable by the controller shown in FIG. 3. DETAILED DESCRIPTION OF THE INVENTION [0013] [0013]FIG. 1 is a perspective view partially broken away of an exemplary washing machine 50 including a cabinet 52 and a cover 54 . A backsplash 56 extends from cover 54 , and a control panel 58 including a plurality of input selectors 60 is coupled to backsplash 56 . Control panel 58 and input selectors 60 collectively form a user interface input for operator selection of machine cycles and features, and in one embodiment a display 61 indicates selected features, a countdown timer, and other items of interest to machine users. A lid 62 is mounted to cover 54 and is rotatable about a hinge (not shown) between an open position (not shown) facilitating access to a wash tub 64 located within cabinet 52 , and a closed position (shown in FIG. 1) forming a sealed enclosure over wash tub 64 . As illustrated in FIG. 1, machine 50 is a vertical axis washing machine. [0014] Tub 64 includes a bottom wall 66 and a sidewall 68 , and a basket 70 is rotatably mounted within wash tub 64 . A pump assembly 72 is located beneath tub 64 and basket 70 for gravity assisted flow when draining tub 64 . Pump assembly 72 includes a pump 74 and a motor 76 . A pump inlet hose 80 extends from a wash tub outlet 82 in tub bottom wall 66 to a pump inlet 84 , and a pump outlet hose 86 extends from a pump outlet 88 to an appliance washing machine water outlet 90 and ultimately to a building plumbing system discharge line (not shown) in flow communication with outlet 90 . [0015] [0015]FIG. 2 is a front elevational schematic view of washing machine 50 including wash basket 70 movably disposed and rotatably mounted in wash tub 64 in a spaced apart relationship from tub side wall 64 and tub bottom 66 . Basket 12 includes a plurality of perforations therein to facilitate fluid communication between an interior of basket 70 and wash tub 64 . [0016] A hot liquid valve 102 and a cold liquid valve 104 deliver fluid, such as water, to basket 70 and wash tub 64 through a respective hot liquid hose 106 and a cold liquid hose 108 . Liquid valves 102 , 104 and liquid hoses 106 , 108 together form a liquid supply connection for washing machine 50 and, when connected to a building plumbing system (not shown), provide a fresh water supply for use in washing machine 50 . Liquid valves 102 , 104 and liquid hoses 106 , 108 are connected to a basket inlet tube 110 , and fluid is dispersed from inlet tube 110 through a known nozzle assembly 112 having a number of openings therein to direct washing liquid into basket 70 at a given trajectory and velocity. A known dispenser (not shown in FIG. 2), may also be provided to produce a wash solution by mixing fresh water with a known detergent or other composition for cleansing of articles in basket 70 . [0017] In an alternative embodiment, a known spray fill conduit 114 (shown in phantom in FIG. 2) may be employed in lieu of nozzle assembly 112 . Along the length of the spray fill conduit 114 are a plurality of openings arranged in a predetermined pattern to direct incoming streams of water in a downward tangential manner towards articles in basket 70 . The openings in spray fill conduit 114 are located a predetermined distance apart from one another to produce an overlapping coverage of liquid streams into basket 70 . Articles in basket 70 may therefore be uniformly wetted even when basket 70 is maintained in a stationary position. [0018] A known agitation element 116 , such as a vane agitator, impeller, auger, or oscillatory basket mechanism, or some combination thereof is disposed in basket 70 to impart an oscillatory motion to articles and liquid in basket 70 . In different embodiments, agitation element 116 may be a single action element (i.e., oscillatory only), double action (oscillatory movement at one end, single direction rotation at the other end) or triple action (oscillatory movement plus single direction rotation at one end, singe direction rotation at the other end). As illustrated in FIG. 2, agitation element 116 is oriented to rotate about a vertical axis 118 . [0019] Basket 70 and agitator 116 are driven by motor 120 through a transmission and clutch system 122 . A transmission belt 124 is coupled to respective pulleys of a motor output shaft 126 and a transmission input shaft 128 . Thus, as motor output shaft 126 is rotated, transmission input shaft 128 is also rotated. Clutch system 122 facilitates driving engagement of basket 70 and agitation element 116 for rotatable movement within wash tub 64 , and clutch system 122 facilitates relative rotation of basket 70 and agitation element 116 for selected portions of wash cycles. Motor 120 , transmission and clutch system 122 and belt 124 collectively are referred herein as a machine drive system. As will be appreciated below, the motor drive system is a multiple speed drive in that it is capable of operating agitation elements at different speeds to optimize the wash cycle agitation phase. [0020] Washing machine 50 also includes a brake assembly (not shown) selectively applied or released for respectively maintaining basket 70 in a stationary position within tub 64 or for allowing basket 70 to spin within tub 64 . Pump assembly 72 is selectively activated to remove liquid from basket 70 and tub 64 through drain outlet 90 and a drain valve 130 during appropriate points in washing cycles as machine 50 is used. In an exemplary embodiment, machine 50 also includes a reservoir 132 , a tube 134 and a pressure sensor 136 . As fluid levels rise in wash tub 64 , air is trapped in reservoir 132 creating a pressure in tube 134 that pressure sensor 136 monitors. Liquid levels, and more specifically, changes in liquid levels in wash tub 64 may therefore be sensed, for example, to indicate laundry loads and to facilitate associated control decisions. In further and alternative embodiments, load size and cycle effectiveness may be determined or evaluated using other known indicia, such as motor spin, torque, load weight, motor current, voltage or current phase shifts, etc. [0021] Operation of machine 50 is controlled by a controller 138 which is operatively coupled to the user interface input located on washing machine backsplash 56 (shown in FIG. 1) for user manipulation to select washing machine cycles and features. In response to user manipulation of the user interface input, controller 138 operates the various components of machine 50 to execute selected machine cycles and features. [0022] In an illustrative embodiment, clothes are loaded into basket 70 , and washing operation is initiated through operator manipulation of control input selectors 60 (shown in FIG. 1). Tub 64 is filled with water and mixed with detergent to form a wash fluid, and basket 70 is agitated with agitation element 116 for cleansing of clothes in basket 70 . That is, agitation element is moved back and forth in an oscillatory back and forth motion. In the illustrated embodiment, agitation element 116 is rotated clockwise a specified amount about the vertical axis of the machine, and then rotated counterclockwise by a specified amount. The clockwise/counterclockwise reciprocating motion is sometimes referred to as a stroke, and the agitation phase of the wash cycle constitutes a number of strokes in sequence. Acceleration and deceleration of agitation element 116 during the strokes imparts mechanical energy to articles in basket 70 for cleansing action. The strokes may be obtained in different embodiments with a reversing motor, a reversible clutch, or other known reciprocating mechanism. [0023] As explained further below, and unlike convention machines utilizing a fixed stroke rate (i.e., number of strokes per unit time) and a fixed time period in the agitation phase, the present invention accommodates adjustment of the stroke rate and the agitation time period to optimize the agitation phases of wash cycles. Optimization of the agitation phases reduces wear on clothes and reduces energy consumption by the machine. [0024] After the agitation phase of the wash cycle is completed, tub 64 is drained with pump assembly 72 . Clothes are then rinsed and portions of the cycle repeated, including the agitation phase, depending on the particulars of the wash cycle selected by a user. [0025] [0025]FIG. 3 is a schematic block diagram of an exemplary washing machine control system 150 for use with washing machine 50 (shown in FIGS. 1 and 2). Control system 150 includes controller 138 which may, for example, be a microcomputer 140 coupled to a user interface input 141 . An operator may enter instructions or select desired washing machine cycles and features via user interface input 141 , such as through input selectors 60 (shown in FIG. 1) and a display or indicator 61 coupled to microcomputer 140 displays appropriate messages and/or indicators, such as a timer, and other known items of interest to washing machine users. A memory 142 is also coupled to microcomputer 140 and stores instructions, calibration constants, and other information as required to satisfactorily complete a selected wash cycle. Memory 142 may, for example, be a random access memory (RAM). In alternative embodiments, other forms of memory could be used in conjunction with RAM memory, including but not limited to flash memory (FLASH), programmable read only memory (PROM), and electronically erasable programmable read only memory (EEPROM). [0026] Power to control system 150 is supplied to controller 138 by a power supply 146 configured to be coupled to a power line L. Analog to digital and digital to analog converters (not shown) are coupled to controller 138 to implement controller inputs and executable instructions to generate controller output to washing machine components such as those described above in relation to FIGS. 1 and 2. More specifically, controller 138 is operatively coupled to machine drive system 148 (e.g., motor 120 , clutch system 122 , and agitation element 116 shown in FIG. 2), a brake assembly 151 associated with basket 70 (shown in FIG. 2), machine water valves 152 (e.g., valves 102 , 104 shown in FIG. 2) and machine drain system 154 (e.g., drain pump assembly 72 and/or drain valve 130 shown in FIG. 2) according to known methods. In a further embodiment, water valves 152 are in flow communication with a dispenser 153 (shown in phantom in FIG. 3) so that water may be mixed with detergent or other composition of benefit to washing of garments in wash basket 70 . [0027] In response to manipulation of user interface input 141 controller 138 monitors various operational factors of washing machine 50 with one or more sensors or transducers 156 , and controller 138 executes operator selected functions and features according to known methods. Of course, controller 138 may be used to control washing machine system elements and to execute functions beyond those specifically described herein. [0028] Controller 138 operates the various components of washing machine 50 in a designated wash cycle familiar to those in the art of washing machines. However, and unlike known washing machines, controller 138 executes optimized agitation phases in wash cycles for actuation of agitation element 116 (shown in FIG. 2). Excessive agitation of clothes may therefore be minimized, thereby reducing associated wear on clothes, and energy consumption required by the agitation phase. Agitation phases of the wash cycle may be adjusted for selected or detected load sizes, types, and characteristics as further described below. [0029] [0029]FIG. 4 is an exemplary washer agitation control method in the form of an algorithm 170 executable by controller 138 (shown in FIG. 3) for achieving optimal agitation of articles in basket 70 (shown in FIGS. 1 and 2). Algorithm 170 may be a user selected option, such as through user manipulation of one of input selectors 60 (shown in FIG. 1), or may be automatically activated or deactivated by machine controls in various embodiments. [0030] The methodology set forth below recognizes that effectiveness of a wash cycle agitation phase is primarily dependant upon two parameters, an amount of chemical cleansing action and an amount of mechanical cleansing action. While the chemical cleansing action is partly dependent upon the soil level of articles to be washed, detergent compositions and compositions of any additives utilized in the wash cycle, the primary machine parameter that contributes to chemical cleansing action in the agitate phase is the agitate time duration. In other words, chemical cleansing action in the agitate phase of a wash cycle is a function of the agitation time. Thus, chemical cleansing action may be approximated by the relationship: SR C ∝t agitate (1) [0031] where SR C is the chemical cleansing action and t agitate is the agitate time period. [0032] The mechanical cleansing action is partly dependant upon many machine parameters, but is primarily influenced by three parameters: the agitate time period, the amount of mechanical energy introduced into the basket during agitation, and the size of the laundry load. Therefore, it may be seen that the mechanical action is approximated by the relationship: SR m ∝ t agitate * E Agitate Load Load ( 2 ) [0033] where SR m is the mechanical cleansing action, t agitate is the agitation time period, E Agitate Load is the mechanical energy input by drive system 151 (shown in FIG. 3) during the agitate phase, and Load is the size of the load to be washed. The Load may be indicated by a selected or detected load size input (e.g., small, medium, large). [0034] Considering the mechanical energy input E Agitate Load it may be deduced that the primary machine parameter affecting the energy input is the speed or intensity of the agitate phase of the wash cycle. In other words, the rate of oscillatory strokes (i.e., oscillatory movements per unit time) primarily determines the mechanical energy input to clothes or laundry articles. It is therefore evident that the mechanical energy input is a function of agitation speed, and that the mechanical energy input may be approximated by the relationship: E Agitate Load ∝N Agitate (3) [0035] where N Agitate is the agitation speed. [0036] Inspection of equations (1) through (3) and substitution of Equation (3) into equation (2) reveals that: SR m ∝ t agitate * N Agitate Load . ( 4 ) [0037] Now comparing Equations (1) and (4), it is apparent that mechanical action and chemical action are each a function of the agitate time duration, but only mechanical actuation is a function of the agitation speed and the load size. Therefore, the agitate phase of the wash cycle can be controlled by making control decisions based upon the parameters that have the greatest overall effect on agitate cycle efficacy. [0038] In one embodiment, controller 138 (shown in FIG. 3), through algorithm 170 makes control decisions for agitation phases of wash cycles based upon characteristics of the laundry load to be washed in machine 50 (shown in FIG. 1). Specifically, and in an exemplary embodiment, controller 138 adjusts agitation parameters based upon the laundry load size and the soil level of the laundry load. The soil level of the laundry affects the time duration of the agitation phase to optimize chemical cleansing action, and the load size affects the agitation speed or intensity of agitation element 116 (shown in FIG. 2) to optimize mechanical cleansing action. [0039] In an exemplary embodiment, algorithm 170 begins by accepting agitation inputs 174 that affect the agitation phase of the wash cycle. Inputs may be accepted through input selectors 60 (shown in FIG. 1) and stored into controller memory 142 for later use when the agitation phase or portion of the wash cycle is commanded. In a further embodiment, controller 138 , or more specifically microcomputer 140 , may prompt a user for required inputs on display 61 (shown in FIGS. 1 and 3). [0040] Once inputs are accepted 174 , microcomputer 140 determines 176 whether the inputs include a SOIL LEVEL parameter. If the inputs do not include a SOIL LEVEL parameter, in one embodiment algorithm 170 returns to accept 174 additional inputs. [0041] In a further and/or alternative embodiment controller 138 may retrieve 177 (shown in phantom in FIG. 4) a default soil level parameter from controller memory 142 if no direct soil level input is made by a machine user, or if a soil level input is not received within a predetermined time period. The default parameter may be associated with a particular wash cycle selected by the user, or may be independent of the selected wash cycle. [0042] In another further and/or alternative embodiment, controller 138 may detect 178 (shown in phantom in FIG. 4) a soil level in the laundry load by known methods and techniques, including but not limited to the use of turbidity sensors and the like to monitor soil level of the water in the machine during use. [0043] If a SOIL LEVEL parameter has been accepted 174 , controller sets 180 agitation time or agitation duration according to the input SOIL LEVEL parameter. For example, in an illustrative embodiment, control system 150 (shown in FIG. 3) includes four SOIL LEVEL setting parameters, namely a light soil setting, a medium soil setting, a heavy soil setting, and a stain soil setting. Depending upon which of the soil level settings is selected, controller 138 sets an appropriate agitation time value corresponding to the selected setting. In general, as the accepted soil setting increases, the agitation duration increases to improve chemical cleansing action and to remove the soil, and as the accepted soil setting decreases the agitation duration decreases. Actual agitation time values may be calculated according to the above relationships or empirically determined for each of the available soil level settings. For instance, an exemplary agitation time versus soil level table for a load of cotton garments is set forth below in Table 1. TABLE 1 SOIL LEVEL SETTING AGITATION DURATION Light 9 minutes Medium 12 minutes Heavy 15 minutes Stain 18 minutes [0044] A control lookup table, such as Table 1, may be stored in controller memory 142 (shown in FIG. 3) so that microcomputer 140 may select the appropriate time duration value for the selected soil level setting. Chemical cleansing action during agitation portions is therefore substantially optimized. [0045] To improve the mechanical cleansing action of the agitation phase of a wash cycle, and further according to algorithm 170 , controller 138 determines 192 whether a load size input has been accepted 174 . If the inputs do not include a LOAD SIZE parameter, in one embodiment algorithm 170 returns to accept 174 additional inputs. [0046] In a further and/or alternative embodiment controller 138 may retrieve 184 (shown in phantom in FIG. 4) a default load size parameter from controller memory 142 if no direct load size input is made by a machine user, or if a load size input is not received within a predetermined time period. The default parameter may be associated with a particular wash cycle selected by the user, or may be independent of the selected wash cycle. [0047] In another further and/or alternative embodiment, controller 138 may detect 186 (shown in phantom in FIG. 4) a laundry load size according to known methods and techniques. Load size may be inferred from an implicit measurement of machine operation, such as operating pressure via pressure sensor 136 (shown in FIG. 2), spin torque, motor current, load weight, level sensors, voltage and/or current phase shifts, spin acceleration rates, brake stop time, or other known indicia of load size during wash operations. [0048] If a LOAD SIZE input parameter has been accepted 174 , controller sets 188 agitation speed or intensity according to the accepted LOAD SIZE parameter. For example, in an illustrative embodiment, control system 150 (shown in FIG. 3) includes five LOAD SIZE setting parameters, namely an extra small load size setting, a small load size setting, a medium load size setting, a large load size setting, and a giant load size setting. Depending upon which of the load size settings is selected, controller 138 sets an appropriate agitation speed value corresponding to the selected load size setting. As the load size setting increases, the agitation speed increases to improve mechanical cleansing action during the agitation phase, and as the load size setting decreases the agitation speed decreases. Actual agitation speed or intensity values may be calculated according to the above relationships or may be empirically determined for each of the available load size settings. For instance, an exemplary agitation speed versus load size table for a load of cotton garments is set forth below in Table 1. TABLE 2 AGITATION SPEED LOAD SIZE SETTING (strokes per minute) Extra Small 100 Small 130 Medium 140 Large 155 Giant 155 [0049] A control lookup table, such as Table 2, may be stored in controller memory 142 (shown in FIG. 3) so that microcomputer 140 may select the appropriate agitation speed value for the selected load size setting. Mechanical cleansing action during agitation portions of the wash cycle is therefore substantially optimized. [0050] While four soil level settings and five load settings are set forth above in exemplary tables 1 and 2, it is anticipated that Tables 1 and 2 may include greater or fewer than four and five settings, respectively, without departing from the scope of the present invention. Further it is contemplated that additional soil level versus agitation time and load size settings versus agitation speed tables be included in controller memory 142 to provide agitation time and speed values for a variety of wash cycle types and profiles suited for particular garments or fabrics. Thus, agitation time and speed values may be customized across a wide variety of wash cycles and options that a user may select. [0051] Once the agitation time duration value is set 180 and the agitation speed value is also set 188 , controller 138 executes 190 the agitation phase of the wash cycle when appropriate according to a main control program. When the agitation phase is complete, algorithm 170 ends 192 . [0052] It is believed that those in the art of electronic controllers could construct and program controller 150 to implement the above-described methodology without further discussion. [0053] A clothes washer control apparatus and method is therefore provided to substantially eliminate excessive wash cycle agitation. Consequently, laundry may be washed with less wear due to machine operations, and energy consumption in agitate portions is reduced. By controlling agitation portions of the wash cycle in response to the most pertinent input variables to the agitation process, both chemical and mechanical washing action are improved in an efficient and effective wash cycle. [0054] While the invention has been described in terms of various specific embodiments, those skilled in the art will recognize that the invention can be practiced with modification within the spirit and scope of the claims.	A controller for a washing machine including an agitation element operable at a plurality of speeds during an agitation phase of a wash cycle is provided. The controller comprises a microcomputer configured to adjust an actuation of the agitation element in response to at least one input, said at least one input indicative of a characteristic of a laundry load.	3
BACKGROUND The invention relates to a process for blending liquid flows, particularly in the approach system to a paper machine, as well as a device for implementing the process. In paper-making, a pulp suspension is distributed evenly over a wire and the greater part of the water is removed from the pulp in the first part. Before the suspension is fed onto the wire, impurities, in particular, are removed. The pulp suspension also contains gas, particularly air, as free air in the form of bubbles and as dissolved air. This air, especially in the form of bubbles, causes problems in the paper production process, particularly if present in larger quantities. As a result there may be problems with foam, instabilities in the process, pulsations in the approach system to the paper machine, reduced dewatering performance and, as a further consequence, small holes may appear in the paper web. A process to achieve maximum possible degassing is described, for example, in U.S. Pat. No. 4,219,340. The evacuation is, however, very complex and in many cases, there is no need for complete evacuation. In the approach system to the paper machine, different pulp components (long fibres, short fibres, broke, etc.) are currently fed into a tank and blended. The various chemicals are added (e.g. wet strength agent, dye, filler, etc.). As an alternative, the individual components and also additives can be fed into a mixing pipe. The problem with these set-ups is that the substances are not mixed adequately and also contain a large proportion of gas, both in the individual flows of the pulp components and in the white water. EP 0 543 866 B1 shows a plant, for example, in which several pumps are used to remove the gas from the pulp that has been blended beforehand and from the white water coming from the paper machine. The plant is not capable, however, of mixing pulp components and additives. Although the sensors for measuring quantities and consistency are located in the de-aerated pulp, there is no device here to mix the dilution water homogenously into the pulp. SUMMARY The present invention is intended to prevent these disadvantages and is thus characterized by the individual liquid flows being merged, blended with one another, and degassed, all at the same time. Since the mixture is degassed at the same time, a constant status is achieved after blending, which means it is possible to do without the large mixing tanks needed hitherto. In addition, it is possible to obtain exact measurements of the pulp data, particularly the consistency. It is a particular advantage if individual liquid components are blended with one another, during which process additives can also be mixed into the pulp as this produces a homogenous pulp suspension from which also a homogenous paper web can be produced. It has proved favourable to blend dilution water, e.g. white water from a paper machine, into the individual liquid flows, where the entire white water can also be mixed into the suspension. When the pulp components are blended with the white water, the white water can then also be de-aerated together with the suspension. Thus, a level of de-aerating can be achieved in many cases that renders complex vacuum de-aerating unnecessary. An advantageous configuration of the invention is characterized by the blended and degassed suspension being fed to a storage tank, e.g. machine chest, standpipe. With this storage tank it is possible to obtain a yet more uniform suspension and particularly, to eliminate any pulsations, however it is important to have a small volume so that any grade or colour change can be carried out promptly. As the suspension has been well blended beforehand, there is no longer any need for the mixing chest required previously. Particularly low volumes and thus, particularly favourable grade changes, are obtained if the blended and degassed suspension is fed directly to a pump. A favourable further development of the invention is characterised by at least one characteristic value of the suspension being measured after blending and degassing, where the consistency of the pulp suspension can be measured and, advantageously, the dilution water is added according to the consistency of the blended and degassed pulp suspension. Since the dilution water is mixed in well, it is also possible to obtain high accuracy. Other pulp data, however, such as ash content, brightness, or freeness, can also be measured online with particular accuracy. The invention also relates to a device for blending liquid flows, particularly in the approach system to a paper machine. According to the invention, this is characterized by a degassing device, particularly a rotor with degassing holes, being provided in a mixing pipe. In this way, the pulp suspension can be blended particularly well, and degassed at the same time. An advantageous further development of the invention is characterized by several pipes for liquid flows, particularly pulp components, leading into the mixing pipe, into which a dilution water pipe can also discharge. As a result, the consistency of the pulp suspension especially can be regulated particularly well to the desired value. Blending and homogenising is much more intensive here compared to a mixing chest. A particularly favourable embodiment of the invention is characterized by the white water pipe of a paper machine discharging into the mixing pipe. Thus, the entire white water can also be degassed together with the liquids added, particularly pulp components. A favourable variant of the invention is characterized by the mixing pipe being connected to a storage tank after the degassing device, where this storage tank can be designed as a standpipe. Here, the standpipe together with the white water tank can form a communicating vessel, which makes the system self-regulating. An alternative advantageous embodiment of the invention is characterised by the mixing pipe being connected to a pump after the degassing device. This results in particularly low storage volumes and thus, a particularly favourable means of changing the grade or colour of paper produced. An advantageous embodiment of the invention is characterized by a measuring device for at least one of the suspension's characteristic values being provided after the degassing device, where the measuring device can be a consistency meter and where it is an advantage if this consistency meter is connected to a valve in the dilution water pipe via a controller. In this way, the consistency of the pulp suspension can e set particularly accurately in the feed to the paper machine. In addition, other measuring devices, e.g. for brightness, ash content or freeness, can be used and will provide particularly accurate measuring values, especially on account of the virtually gas-free and homogenous suspension. BRIEF DESCRIPTION OF THE DRAWINGS The invention will now be described in examples and referring to the drawings, where FIG. 1 shows a state-or-the-art plant, FIG. 2 contains a diagram of a variant of the invention, FIG. 3 shows a further variant of the invention, FIG. 4 another variant of the invention, FIG. 5 an embodiment of the invention, and FIG. 6 a further embodiment of the invention. DETAILED DESCRIPTION According to the state of the art, the approach system to a paper machine shown in FIG. 1 , also known as the supply system, incorporates a white water tank 10 , a feed pump 12 , a centrifugal cleaner 14 , a gas separation tank 16 with its vacuum device 17 , a headbox pump 18 , a screen 20 , a headbox 22 for the paper machine, and white water collecting troughs (not shown). Pulp components used in paper-making, e.g. virgin pulp, recycled fibres and/or broke, and fillers, that are diluted together with the white water obtained from the wire section of the paper machine 24 , are brought through a pipe 11 to the white water tank 10 where all of the white water from the paper machine is collected. The pulp suspension is pumped from the white water tank 10 to the centrifugal cleaner 14 by a feed pump 12 . The accept pulp from the first stage of the centrifugal cleaner 14 is carried into the gas separation tank 16 by the pressure generated by the feed pump, assisted by the vacuum prevailing in this tank. From the gas separation tank 16 , the largely gas-free pulp suspension, from which the gas has been removed entirely if possible by the vacuum device 17 , flows to a fan pump 18 that pumps the pulp suspension to the screen 20 , from where the accept pulp flows into the headbox 22 of the paper machine 24 . The gas separation tank 16 is located typically on a level T above the machine level K. FIG. 2 shows the diagram of a plant according to the invention. Various liquid components are fed to a mixing pipe 1 through pipework 2 , 2 ′, 2 ″, where these components can be, for example, virgin pulp, recycled fibres and/or broke. Furthermore, pipework 3 , 3 ′ that discharges into the mixing pipe 1 is provided for additives, such as dyes, fillers, etc. Dilution water is added through pipe 4 , where this can be part of the white water or clear filtrate from a disc filter. When all pulp and additives have been added, the suspension is blended by a degassing rotor 5 with drive motor 6 and degassed at the same time. The consistency of the blended and degassed pulp suspension is determined using a consistency meter 7 and the flow control valve 9 in the dilution water pipe 4 is regulated by a control device 8 . Further measuring devices 7 ′, e.g. for ash content, brightness, or freeness, can be located after the degassing rotor 5 , providing very exact measurements thanks to the degassing process. The blended and degassed pulp suspension then enters a machine chest 15 . The degassing rotor 5 causes a pressure build-up which is compensated by the height of the tank in such a way that the mixing pipe 1 has approximately atmospheric pressure. This is important because a large part of the gas and air is then present here in the form of bubbles and can be removed very easily by the degassing rotor 5 . After the machine chest 15 there is a flow meter 13 that controls a flow control valve 21 via flow regulator 19 . Controlling the rate of flow can only be achieved effectively if a constant pulp consistency is assured and if the consistency matches the planned value. By using the control system proposed, this can be guaranteed. After the flow meter 13 , the pulp suspension is fed through a headbox pump 18 to the paper machine headbox 22 . FIG. 3 shows a variant of the invention with a standpipe 25 that is used in place of the machine chest 15 . Together with the white water tank 10 , this standpipe 25 forms a system of communicating vessels, where the liquid surfaces in the standpipe 25 and the white water tank 10 are on the same level. This creates a self-regulating effect for the feed. Part of the white water is used here as dilution water 4 . FIG. 4 shows a similar variant, where virtually all of the white water 4 ′ here is fed into the mixing pipe 1 on the one hand, and the blended and degassed suspension is then brought directly to the headbox pump 18 . As a result, the storage volume of the plant is kept to a minimum and changes of colour and/or grade can be carried out within a very short time. FIG. 5 provides a detailed illustration of a blending and degassing device according to the invention, where this variant has a mixing pipe 1 into which a pipe 4 discharges white water. Several pipes 2 , 2 ′, 2 ″ for supplying different liquid components lead into the mixing pipe 1 . In addition, pipes 3 , 3 ′ are provided to supply various additives. The air extracted from the degassing rotor 5 is carried off through a pipe 28 . The degassing rotor 5 is driven by a drive 6 . After the degassing rotor 5 , measuring units 7 are provided to measure consistency and 7 ′ to measure other pulp data, such as ash content, brightness, and freeness. The blended and degassed suspension is fed through a pipe to a tank (chest) or to a feed pump to the headbox of a paper machine. With a suitable embodiment of the degassing rotor 5 , the suspension can be brought directly into a tank without any additional pump, with the rotor 5 providing sufficient pressure differential. FIG. 6 shows a further variant of the invention, where preliminary mixing in the mixing pipe 1 and actual blending of all liquid flows by the degassing rotor 5 are separated by a deflection baffle 27 . The mixing pipe 1 , into which dilution water 4 and feed pipes 2 , 2 ′, 2 ″ for individual pulp components discharge, has a deflection baffle 27 . This figure also shows an example of feed pipes 3 ″ for further additives after the deflection baffle 27 and shortly before the degassing rotor 5 , which arrangement provides favourable distribution of the individual substances. The invention avoids the need for large degassing tanks, which leads in turn to considerable savings in investment. Thus, a “short flow” concept can be implemented by simple and low-cost means.	The invention relates to a process for blending liquid flows, particularly in the approach system to a paper machine. It is characterized by the individual liquid flows being merged, blended with one another, and degassed, all at the same time. In addition, the invention relates to a device for implementing the process, where a degassing device 5 , particularly a rotor with degassing holes, is provided in a mixing pipe 1.	3
[0001] This application claims priority based on provisional application 61094875 filed Sep. 6, 2008 FIELD OF THE INVENTION [0002] The present invention relates generally to building materials but more particularly to a system for making a caisson ceiling. BACKGROUND OF THE INVENTION [0003] Caisson ceiling, also referred to as coffer ceilings are square or polygonal ornamental sunken panel used in a series as decoration for a ceiling or vault. Caisson ceilings are often found in luxury homes. Because they require expert craftsmanship and takes a lot of time to assemble, they are very costly and that is why they are only found in luxury homes. There exist a variety of modular systems borrowing their features and method of installation from suspended tile ceilings such as those found in office buildings. There are other systems using cheap lightweight molded plastic or metal modules that are glued or mechanically fastened to the ceiling. [0004] However, none of those systems use real wood that is easily assembled on site so as to provide for a quick installation. SUMMARY OF THE INVENTION [0005] In view of the foregoing disadvantages inherent in the known devices now present in the prior art, the present invention, which will be described subsequently in greater detail, is to provide objects and advantages which are: [0006] To provide for a ready made set of modules or at least ready to assemble modules that install quickly by way of a simple system of planks that allow for easy attachment. Low production costs as well as reduced labor costs make this system affordable. [0007] To attain these ends, the present invention generally comprises a series of precut pieces of natural wood or engineered wood product that gives the appearance of real wood. [0008] The system consists in a plurality of fixation modules fastened between at least two attachment planks in a one is to many configuration whereby the at least two attachment planks are further fastened to a ceiling and whereby the at least two attachment planks include a predetermined parallel and equidistant separation between each other; and a plurality of projecting elements extending laterally from a plurality of sideboards of the plurality of fixation modules for driving mechanical fasteners through the at least two attachment planks, whereby the plurality of sideboards is included in the plurality of fixation modules. [0009] Moreover, the caisson ceiling system has each of the plurality of sideboards further comprising a notch for frictionally inserting into each of the at least two attachment planks to thereby enable each of the plurality of sideboards to make a contact with the ceiling and a side of each of the at least two attachment planks. [0010] The plurality of projecting elements are located to make a contact with a surface of each of the at least two attachment planks whereby the surface is a lower surface facing a floor. [0011] A covering plank is attached to at least one of the plurality of sideboards, wherein the covering plank is configured to cover a central portion of the plurality of fixation modules while being disposed opposite to the at least two attachment planks. [0012] The covering plank is attached to at least one of the plurality of sideboards, wherein the covering plank is configured to cover the central portion of the plurality of fixation modules while being disposed opposite to the at least two attachment planks. [0013] The caisson ceiling system has each of the plurality of fixation modules comprising: [0014] a plurality of sideboards; [0015] a plurality of frames disposed between the plurality of sideboards along a length of the sideboards, wherein each of the plurality of frames comprising a panel; and a plurality of end boards coupled to a plurality of frame spacer planks for creating a separation among the plurality of frames along the length of the sideboards. [0016] Furthermore, the frames and panels are regular geometrical constructions, further comprising at least one of: a rectangular construction; a square construction; a pentagonal construction; a triangular construction; a hexagonal construction; and an octagonal construction. [0017] A method for assembling a caisson ceiling system, comprising: placing one panel each in a plurality of frames along a length of a plurality of sideboards in a linear enclosing configuration to generate a fixation module structure; mechanically fixing a plurality of attachment planks to a ceiling; coupling the fixation module structure to at least one attachment planks of the plurality of attachment planks; mechanically attaching a finishing plank at a central position of the fixation module structure through the plurality of sideboards, whereby the finishing plank is included in the plurality of attachment planks; a step of driving [0018] mechanical fasteners through and into the plurality of attachment planks through a plurality of projecting elements to thereby attach the fixation module structure to the ceiling. [0019] In some variations in the method of installation, the assembling of the fixation module structures is in a non linear staggered configuration. Also, the finishing plank more than a length of the fixation module structure to enable a stronger support for the caisson ceiling system. [0020] There has thus been outlined, rather broadly, the more important features of the invention in order that the detailed description thereof that follows may be better understood, and in order that the present contribution to the art may be better appreciated. There are additional features of the invention that will be described hereinafter and which will form the subject matter of the claims appended hereto. [0021] In this respect, before explaining at least one embodiment of the invention in detail, it is to be understood that the invention is not limited in its application to the details of 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. [0022] 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 the designing of 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. [0023] Further, the purpose of the foregoing abstract is to enable the U.S. Patent and Trademark Office and the public generally, and especially the scientists, engineers and practitioners in the art who are not familiar with patent or legal terms or phraseology, to determine quickly from a cursory inspection the nature and essence of the technical disclosure of the application. The abstract is neither intended to define the invention of the application, which is measured by the claims, nor is it intended to be limiting as to the scope of the invention in any way. [0024] These together with other objects of the invention, 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 which contains illustrated preferred embodiments of the invention. BRIEF DESCRIPTION OF THE DRAWINGS [0025] FIG. 1 Perspective view of the invention as installed on a ceiling. [0026] FIG. 2 Perspective view showing modules during the installation process. [0027] FIG. 3 Exploded view showing the various components of a pair of cojoined modules. [0028] FIG. 4 Exploded view showing the various components of a module before assembly. [0029] FIG. 5 Plan view of examples of panel motifs. [0030] FIGS. 6 a - b Plan and side cutaway views, respectively, of a panel installed in a module. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT [0031] A caisson system for ceiling ( 10 ) consists in at least one fixation fixation module ( 12 ) which is itself made from parts which will be described later. [0032] Each fixation module ( 12 ) is mechanically fastened to an attachment plank ( 14 ), which is itself mechanically fastened to a ceiling ( 16 ) which is defined here as either exposed support beams (joists, steel beams, etc) or finished dry wall ceiling, as commonly found in North American constructions. Each attachment plank ( 14 ) is set parallel to the walls, or perpendicular to the walls, depending on how you look at it, suffice to say that each attachment plank ( 14 ) has to be at a preset distance and parallel to the preceding one. [0033] For some installations, it may be necessary to use wedges to insure that the attachment planks ( 14 ) are straight and do not follow the irregularities that are sometimes found in old wooden joist construction wherein spacers and wedges are necessary to achieve perfect adjustments so that the attachment plank ( 14 ) is straight. These wedging techniques are well known in the construction and carpentry trade and need not be further discussed herein. [0034] Once the attachment planks ( 14 ) are affixed, the modules ( 12 ) are fitted between two attachment planks ( 14 ) like wagons on tracks. This is why it is important that each attachment plank ( 14 ) be parallel and equidistant from the preceding one (or the one that follows for that matter). [0035] A plurality of projecting elements ( 18 ) extending laterally from side boards ( 20 ), which form part of each of the fixation module ( 12 ), and are used for driving mechanical fasteners through and into the attachment planks ( 14 ) so as to affix the modules ( 12 ) onto the ceiling ( 16 ). Moreover, the sideboards have a notch ( 19 ) which is frictionally inserted into the attachment plank ( 14 ) so that the side boards make contact with the ceiling ( 16 ) and the side of the attachment plank ( 14 ). The projecting elements ( 22 ) are so located in relation to the notch ( 19 ) that they make contact with the face of the attachment plank ( 14 ). Once a pair of modules ( 12 ) is installed, a covering plank ( 22 ) is mechanically attached to the side boards ( 20 ) of adjoining modules ( 12 ) (as per FIG. 2 ). [0036] FIG. 4 shows an exploded view of a fixation module ( 12 ) with its side boards ( 20 ) frames ( 24 ), end boards ( 21 ) used in combination with frame spacer plank covering planks ( 26 ) to separate each frame ( 24 ) along the length of the side boards ( 20 ). Encased within each frames ( 24 ) are panels ( 28 ) which come in a variety of models and shapes, as 20 shown in FIG. 5 . It is to be understood that the frames ( 24 ) are not necessarily square in shape, they can be rectangular or any other geometric shape, providing that the frame spacer planks ( 26 ) have a shape that fills in the empty space of, for example, an octagonal frame. But, as can be seen in FIG. 5 , the panels ( 28 ) can be square or rectangular while the pattern on it can describe a geometric shape. This is the preferred embodiment since it uses a limited number of variations in the shapes of the frame spacer planks ( 26 ). Preferably, a finishing trim ( 30 ) can cover the perimeter of the caisson system for ceiling ( 10 ) as per FIG. 3 . [0037] The caisson system for ceiling ( 10 ) is assembled according to the following steps: [0038] The modules ( 12 ) are assembled either off site or on site by placing at least one frame ( 24 ), when there is more than one frame 924 ), a pair of end boards ( 21 ), spaced by a spacer covering planks ( 26 ) are used between two frames ( 24 ). Alternatively, two frames ( 24 ) can be cojoined. The aforementioned components are mechanically attached together and the panels ( 28 ) are placed inside the frames. Alternatively, the panels can be placed at the end of the installation. [0039] Attachment planks ( 14 ) are mechanically attached to the ceiling ( 16 ) and the modules ( 12 ) are fitted between two attachment planks ( 14 ). A plurality of projecting elements ( 18 ) extending laterally from the side boards ( 20 ) of each of the fixation module ( 12 ) are used for driving mechanical fasteners through and into the attachment planks ( 14 ) so as to affix the modules ( 12 ) onto the ceiling ( 16 ). Once at least two modules ( 12 ) are installed side to side, a covering plank ( 22 ) is mechanically attached to the side boards ( 20 ) of adjoining modules ( 12 ). [0040] The modules need not be set side by side as shown but rather staggered like one would lay a brick wall. The covering plank ( 22 ) can exceed the length of the modules ( 12 ) so as to span more modules and thus create a stronger caisson ( 10 ) by not having all joints lined up. [0041] If not already installed, the panels ( 28 ) can be installed at this point. For decorative purposes, some panels ( 28 ) within the caisson system for ceiling ( 10 ) can be replaced with a ventilation grille or a translucent module hiding a light source. In other words, a ventilation grille or a translucent module can occupy the space of a panel within a frame ( 24 ) in lieu of a panel. ( 28 ). [0042] As to a further discussion of the manner of usage and operation of the present invention, the same should be apparent from the above description. Accordingly, no further discussion relating to the manner of usage and operation will be provided. [0043] With respect to the above description then, it is to 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 one skilled in the art, and all equivalent relationships to those illustrated in the drawings and described in the specification are intended to be encompassed by the present invention. Therefore, the foregoing is considered as illustrative only of the principles of the invention. Further, since numerous modifications and changes will readily occur to those skilled in the art, it is not desired to limit the invention to the exact construction and operation shown and described, and accordingly, all suitable modifications and equivalents may be resorted to, falling within the scope of the invention.	A caisson system having an attachment plate fastened to ceiling joists; compressible spacers to allow for the attachment plate to be perfectly straight; caisson frames consisting of a combination of a pair of length planks and a pair of width planks to create a generally rectangular structure; length cover planks and width cover planks, along with tiles to finish the caisson frames.	4
CROSS REFERENCE TO RELATED APPLICATIONS [0001] This application is a continuation of international patent application no. PCT/EP2009/008977, filed Dec. 15, 2009, designating the United States of America, and published in German on Jul. 8, 2010 as WO 2010/075956, the entire disclosure of which is incorporated herein by reference. Priority is claimed based on European Patent Application no. EP 08021794.6, filed Dec. 16, 2008, which likewise is incorporated herein by reference. BACKGROUND OF THE INVENTION [0002] The invention relates to an expression vector that is suitable for efficient screening of (meta)genome libraries, preferably in Escherichia coli. [0003] Only about 1-5% of all known microorganisms are at present cultivable in the laboratory with current methods. Methods have been developed in recent times which should make it possible to use the genetic resources of non-cultivable microorganisms. This field is also called “metagenomics”, with the term “metagenome” denoting the genetic information of all organisms of a particular habitat, regardless of whether these are cultivable or not. [0004] By direct cloning of the DNA obtained from environmental samples into suitable vector systems (plasmids, cosmids, BACs, YACs) this resource becomes available for easy manipulation in the laboratory. These gene banks (metagenome libraries) can be used for example for searching for novel enzymes. Finding completely novel enzyme activities requires activity-based screening of prepared metagenome libraries. A precondition for this is a suitable detection system (agar plate assays, microtitre plate systems), which permits simultaneous screening of the largest possible number of clones (high-throughput screening). Furthermore, expression of the genes must be provided in a heterologous host. In addition to E. coli , other organisms such as Streptomyces lividans or Pseudomonas putida are also employed as host in metagenome studies. [0005] Problems with the metagenome technique relate in particular to expression of the genes found. These include inadequate transcription, for example because promoters are not recognized, toxicity of the products to the host, missing cofactors or chaperones and therefore incorrect folding of the proteins in the heterologous host, and missing secretion systems (W. R. Streit et al., Curr Opin Microbiol. 2004, 7(5), 492-8). [0006] Conventional (meta)genome libraries for screening in E. coli are generally constructed in artificial chromosomes (BAC), cosmid or fosmid systems or plasmids. Until now, (meta)genomic plasmid libraries have mainly been constructed using conventional cloning vectors, which generally have an individual, comparatively weak promoter (e.g. lac promoter) or are designed entirely for the use of internal promoters of the cloned DNA. This weak promoter was not originally intended for expression of the cloned DNA, but is present as promoter before the lacZ gene, which is often used as marker. In this connection, reference may be made for example to R. Ranjan et al., Biochem Biophys Res Commun., 2005, 335(1), 57-65; and A. Knietsch et al., Appl Environ Microbiol., 2003, 69(3), 1408-1416. [0007] The relative weakness of the promoter does not have any negative consequences in sequence-based screening of the (meta)genome library. However, if the same plasmid libraries are used for screening the activity of the target proteins encoded by the library, expression of the target proteins is then often based on the weak promoter located at the plasmid. With the cosmid/fosmid systems that are often used, the functional expression of the target genes is based exclusively on recognition and reading of the non- E. coli promoters located on the inserted DNA. In this connection, reference may be made for example to K. S. Hong et al., J Microbiol Biotechnol., 2007, 17(10), 1655-60. [0008] Owing to the weakness of the promoter or the non-recognition of non- E. coli promoters, some of the target proteins are barely expressed, or not at all, so that activity screening of the target proteins is far more difficult. These limitations make iterative activity screening of sub-libraries (cluster screening, cf. US 2008/220581=WO 2005/040376) impossible in most cases. Instead, complicated and time-consuming activity screening with individual clones, e.g. on agar plates, is necessary. [0009] Another problem in activity screening is that when constructing (meta)genome libraries it is not possible to influence the orientation of the open reading frame (ORF) on the cloned DNA. It is also possible for two successive open reading frames to have different directions of reading. In activity screening with conventional expression vectors, a large part of the sequence information contained in the (meta)genome library is therefore often lost because the promoter used only covers one of the two possible directions of reading. [0010] U.S. Pat. No. 6,780,405 (=WO 01/83785) discloses a regulated system for delivery of antigens. In this system, however, the DNA to be cloned into the insertion sequence is not under the control of both promoters. Instead, one of the two promoters controls the on or a gene for regulating the ori. Such a system is hardly suitable for screening metagenome libraries, as only 50% of the sequence information contained is captured. [0011] U.S. Pat. No. 6,030,807 discloses an operon that codes for enzymes that are linked with the use of L-arabinose. The operon does not, however, have an insertion sequence located between two promoters converging towards each other. The system also does not include a vector with two different promoters converging towards each other, between which an insertion sequence is arranged, in each case downstream. [0012] U.S. Pat. No. 6,977,165 (=WO 02/083910) discloses a method of production of a vector that includes at least one spliceable intron. The vector size is not, however, maximum 3000 bp. [0013] Schmeisser et al., Appl. Microbiol. Biotechnol 2007, 75(5), 955-62 is a review of the subject: Metagenomics, biotechnology with non-cultivable microbes. [0014] The publication does not contain any information on expression in plasmids with two promoters converging towards one another, and inducible separately from one another, between which an insertion sequence is arranged, in each case downstream, so that the expression of a DNA sequence cloned into the insertion sequence is placed under the control of both promoters. [0015] U.S. Pat. No. 7,005,423 (=WO 00/01846) discloses a method for identifying DNA that is responsible for a particular phenotype. However, that method does not use a vector with promoters that are inducible separately from one another, and flow towards one another. It is even a precondition of the method that both promoters are identical. The vector does not comprise at most 3000 bp. [0016] S. Kim et al., Prot. Expr Purif. 2006, 50(1), 49-57 discloses rare codon clusters on the 5′-terminus, which have an influence on heterologous expression of archaic genes in E. coli . The publication does not, however, contain any mention of an expression vector that comprises two promoters inducible separately from one another, and converging towards each other, between which an insertion sequence is arranged, in each case downstream, so that the expression of a DNA sequence cloned into the insertion sequence is placed under the control of both promoters. [0017] F. W. Studier, J. Mol. Biol. 1991, 219(1), 37-44 discloses the use of T7 lysozyme bacteriophage for improving an inducible T7 expression system. The system does not, however, have an expression vector that comprises two promoters inducible separately from one another, and converging towards each other, between which an insertion sequence is arranged, in each case downstream, so that the expression of a DNA sequence cloned into the insertion sequence is placed under the control of both promoters. SUMMARY OF THE INVENTION [0018] An object of the invention is to provide an expression system that is suitable for screening, in particular for activity screening, of (meta)genome libraries and has advantages over the systems of the prior art. [0019] Another object is to provide an expression system that is characterized by a high cloning efficiency linked to efficient, controllable expression. [0020] A further object of the invention is to provide an expression system which captures as large a proportion as possible of the sequence information contained in the (meta)genome library. [0021] These and other objects have been achieved by the invention as described and claimed hereinafter. [0022] A first aspect of the invention relates to an expression vector comprising two promoters P 1 and P 2 , inducible separately from one another, and converging towards each other, wherein preferably an insertion sequence is arranged between P 1 and P 2 , in each case downstream, so that the expression of a DNA sequence cloned into the insertion sequence is placed under the control of P 1 and P 2 ; wherein the insertion sequence is a polylinker and/or a sequence that makes integration of DNA sequences by recombination possible; and wherein the expression vector without insertion sequence comprises altogether at most 3000 bp. [0023] In this connection, “under the control of P 1 and P 2 ” means that the expression of the cloned, double-stranded DNA sequence can be controlled by P 1 and P 2 . One strand of the cloned, double-stranded DNA sequence is controlled by P 1 and the strand of the cloned, double-stranded DNA sequence complementary thereto is controlled by P 2 . Control is effected preferably in the sense of an operon. [0024] It was found, surprisingly, that the expression vector according to the invention is particularly suitable for activity screening of (meta)genome libraries, as both directions of reading are covered. The loss of half of the sequence information contained in the (meta)genome library or the need to screen double the number of clones, as must be accepted when using conventional expression vectors, can be avoided by the expression vector according to the invention. [0025] Preferably it is an expression vector for E. coli , with two strong promoters flanking the multiple cloning site. The promoters are convergent, i.e. their reading directions converge into each other (face-to-face). The promoters inducible independently of one another are preferably a T7 promoter and an ara promoter. BRIEF DESCRIPTION OF THE DRAWINGS [0026] FIG. 1 shows pF2F4, a preferred embodiment of an expression vector according to the invention with <SEQ.ID.NO: 1>. It is an expression vector for E. coli , in which two strong promoters flank the multiple cloning site. The promoters are convergent, i.e. their reading directions converge towards each other (face-to-face). The promoters that are inducible independently of one another are a T7 promoter and an arabinose promoter. [0027] FIG. 2 shows the regulatory plasmid pLac+ with <SEQ.ID.NO: 2>, with which, according to the invention, the host organism is preferably transformed together with the expression vector. [0028] FIG. 3 shows, in connection with example 1, pF2F4 with variously oriented alcohol dehydrogenase as reporter gene in E. coli BL21 (DE3) cells, in which pLacI or pLacI+ is propagated simultaneously. All measurements of T7 induction with 1% glucose in the medium, of Ara induction without further glucose addition. [0029] FIG. 4 A shows, in connection with example 1, pF2F4 with variously oriented alcohol dehydrogenase as reporter gene in E. coli BL21. FIG. 4 B shows pF2F4 with variously oriented alcohol dehydrogenase as reporter gene in E. coli DH10B. The pLacI+plasmid was coexpressed in all assays. [0030] FIG. 5 shows, in connection with example 2, the hit distribution after 3 h incubation time in the IPTG-induced cell extract of the rumen library in pF2F4. A1 is uninoculated as control. DETAILED DESCRIPTION [0031] An expression vector in the sense of the present invention is preferably a DNA sequence, which comprises at least one DNA sequence for replication in hosts (origin of replication); at least one DNA sequence coding for a sequence that is suitable for distinguishing hosts that contain the expression vector from hosts that do not contain the expression vector (called “selection marker sequence” within the scope of the present invention); at least one DNA sequence for insertion of foreign DNA (called “insertion sequence” within the scope of the present invention), and at least one DNA sequence that is recognized by an RNA polymerase as transcription start point. [0032] The expression vector according to the invention is suitable for the expression of peptides or proteins in prokaryotic or eukaryotic systems (hosts). [0033] Preferred prokaryotic systems comprise e.g. bacteria. Preferred bacteria comprise E. coli, Bacillus sp., Salmonella typhimurium, Staphylococcus sp., Pseudomonas sp., Streptomyces sp. and Caulobacter sp. and Borrelia sp. Preferred eukaryotic systems comprise e.g. yeasts or SF9 cells, Chinese hamster ovary cells, and other cells of higher organisms. Preferred yeasts comprise Saccharomyces cerevisiae, Schizosaccharomyces pombe and Pichia pastoris. [0034] Various aspects can play a role in selection of the host. An important aspect is the possibility of posttranslational modification of the expressed peptide/protein in the host cell. Another aspect is the suitability of the host cell for secretion of the expressed peptides/proteins. Depending on the biological source of the (meta)genome library, a person skilled in the art can decide which host appears to be the most suitable for expression. The biological source of the (meta)genome library is preferably of purely prokaryotic origin, purely eukaryotic origin or mixed prokaryotic and eukaryotic origin. The source can originate for example from a maritime or terrestrial environment. Possible examples of suitable sources are organisms that live in natural or in artificial, in particular human-influenced, environments. In this connection, comparatively extreme environments may also be considered, e.g. volcanoes, hot springs, deserts, icebound landscapes, glaciers, areas with unusually high or low pH, areas with high radiation exposure or other environmentally exposed biotopes. In a preferred embodiment the sources originate from water treatment works, biofilters or other industrial plant. [0035] Preferably the expression vector according to the invention is a plasmid, e.g. a bacterial plasmid or a yeast plasmid. [0036] In a preferred embodiment the expression vector according to the invention is a low-copy plasmid (on average <100 plasmids per cell). In another preferred embodiment the expression vector according to the invention is a high-copy plasmid (on average >100 plasmids per cell). [0037] The origin of replication (ori) used is relevant for the number of copies of the expression vector (not integrated into the chromosome) per cell. A large number of on are known to a person skilled in the art and he is able to select a suitable on for a particular preferred embodiment. For example, the following ori or on based on the following on can be used: E. coli oriC, ColE1-ori or the on from various plasmids known by a person skilled in the art such as pUC, pBR322, pGEM, pTZ, pBluescript, pMB1, pSC101, p15a, pR6K, M13-ori, or, for expression in yeast cells, the 2 μm on or, for expression in other eukaryotic hosts, ori such as SV40-ori. [0038] According to the invention, the expression vector, in particular the expression plasmid, can also contain several ori, for example 2 ori's. It can, for example, be a combination of a low-copy ori and a temperature-dependent ori or for example ori's that allow propagation in various host organisms (ori for E. coli and ori for Bacillus sp.). [0039] In addition to plasmids, other vectors may also be considered as expression vector according to the invention, for example phage, cosmids, phasmids, fosmids, bacterial artificial chromosomes, yeast artificial chromosomes, viruses and retroviruses (for example vaccinia, adenovirus, adeno-associated virus, lentivirus, herpes-simplex virus, Epstein-Barr virus, fowlpox virus, pseudorabies, baculovirus) and vectors derived therefrom. [0040] The expression vector or parts thereof can also be integrated into the genome. [0041] Any other vector can also be used for production of the expression vector according to the invention, provided it is replicable and capable of surviving in the selected system (host). [0042] Depending on the (meta)genome library and the host that appears suitable for expression, selection of the promoters P 1 and P 2 preferably takes place on a suitable vector. [0043] According to the invention, the term “promoter” comprises any transcription control sequence that makes it possible to express a peptide or protein in a suitable system, i.e. to transcribe the encoded DNA sequence into RNA and then translate it into the corresponding peptide or protein sequence. Therefore the term comprises not only the promoter sequence as such (the binding site of the RNA polymerase), but optionally, in addition also the enhancer sequence, the operator sequence, and the like. [0044] All nucleotide sequences in the DNA of the expression vector basically come into consideration according to the invention as promoters P 1 and P 2 , to which RNA polymerases bind, to start transcription. It is preferably RNA polymerase of native, naturally occurring organisms, e.g. E. coli . The term also comprises, with respect to a given host, promoters on which RNA polymerases of other organisms bind. For example, the RNA polymerase of the T7-bacteriophage can be co-expressed in E. coli , so as to be able to use the T7 promoter in E. coli , e.g. in E. coli BL21(DE3). [0045] Within the scope of the present invention, “P i ” designates optionally P 1 or P 2 . [0046] In a preferred embodiment, P 1 and P 2 are prokaryotic promoters. In another preferred embodiment, P 1 and P 2 are eukaryotic promoters. [0047] In a preferred embodiment, P 1 and P 2 can in each case both be addressed by the same organism, i.e. they can perform their functionality in the same organism and are compatible with the same organism. If, for example, the expression vector according to the invention is in a particular microorganism, preferably both promoters P 1 and P 2 can be recognized by the RNA polymerases contained in this microorganism; preferably no further organisms are required for this. [0048] Prokaryotic promoters usually comprise a so-called “−35 element” and the so-called “TATA box” or “Pribnow box”. The consensus sequence for the −35 element comprises the following six nucleotides: TTGACA. The consensus sequence for the Pribnow box comprises the six nucleotides TATAAT. In a preferred embodiment the two promoters P 1 and P 2 differ in at least 1 nucleotide within the whole of these two sequence segments, preferably in at least 2 nucleotides, more preferably at least 3 nucleotides, most preferably at least 4 nucleotides and in particular at least 5 nucleotides. In another preferred embodiment the two promoters P 1 and P 2 differ in at most 5 nucleotides within the whole of these two sequence segments, preferably at most 4 nucleotides, more preferably at most 3 nucleotides, and most preferably at most 2 nucleotides and in particular at most 1 nucleotide. [0049] In a preferred embodiment promoter P 1 differs in at least 1 nucleotide, preferably in at least 2 nucleotides, more preferably at least 3 nucleotides, and most preferably at least 4 nucleotides and in particular at least 5 nucleotides from the totality of the two aforementioned consensus sequences. In another preferred embodiment promoter P 1 differs in at most 5 nucleotides, preferably at most 4 nucleotides, more preferably at most 3 nucleotides, and most preferably at most 2 nucleotides and in particular at most 1 nucleotide from the totality of the two aforementioned consensus sequences. [0050] In a preferred embodiment, moreover, promoter P 2 differs in at least 1 nucleotide, preferably in at least 2 nucleotides, more preferably at least 3 nucleotides, and most preferably at least 4 nucleotides and in particular at least 5 nucleotides from the totality of the two aforementioned consensus sequences. In another preferred embodiment, moreover, promoter P 2 differs in at most 5 nucleotides, preferably at most 4 nucleotides, more preferably at most 3 nucleotides, and most preferably at most 2 nucleotides and in particular at most 1 nucleotide from the totality of the two aforementioned consensus sequences. [0051] The distance between the TATA box and the “−35 box” also has an influence on the strength of the promoter. Preferably the distance between the TATA box and the “−35 box” of promoter P 1 is 5 to 50 bp, preferably 10 to 30 bp, more preferably 12 to 25 bp, more preferably 15 to 20 bp, and most preferably 17 bp. Preferably the distance between the TATA box and the “−35 box” of promoter P 2 is 5 to 50 bp, preferably 10 to 30 bp, more preferably 12 to 25 bp, more preferably 15 to 20 bp, and most preferably 17 bp. [0052] Preferably P 1 and P 2 are externally regulated, i.e. they are functional promoters, whose activity can be altered (increased or decreased) by at least one other element (molecule, component, cofactor, transcription factor, etc.). [0053] Suitable promoters and their partial sequences are known by a person skilled in the art. Examples of suitable promoters comprise viral, vegetable, bacterial, fungal, human and animal promoters, e.g. cos-, tac-, trp-, tet-, trp-tet-, lpp-, lac-, lpp-lac-, laclq-, T7-, T5-, T3-, gal-, trc-, ara-, SP6-, I-PR- or in the I-PL-promoters or partial sequences thereof, which preferably find application in Gram-negative bacteria. Further advantageous promoters are contained for example in the Gram-positive promoters such as amy, npr, apr and SP02, in the yeast promoters such as ADC1, MFa, AC, P-60, CYC 1, GAPDH or in mammalian promoters such as CaM-kinase II, CMV, Nestin, L7, BDNF, NF, SV40, RSV, HSV-TK, metallothionein gene, MBP, NSE, beta-globin, GFAP, GAP43, tyrosine hydroxylase, kainate receptor subunit 1, glutamate receptor subunit B. In principle all natural promoters such as those mentioned above can be used. Furthermore, synthetic promoters can also be used advantageously. [0054] Preferably, P 1 ≠P 2 . [0055] In one preferred embodiment, one of the two promoters P 1 and P 2 is intrinsic with respect to the host used, i.e. at least one intrinsic RNA polymerase of the host is able to bind to the promoter and catalyse a transcription, and the other promoter is extrinsic with respect to the host used, i.e. no intrinsic RNA polymerase of the host is able to bind to the promoter and catalyse a transcription. In this connection, extrinsic means that the wild type of the host does not code for this RNA polymerase. In this connection, “catalyse transcription” means that the intrinsic RNA polymerases of the host achieve, in a corresponding in-vitro transcription assay, at most 10%, preferably at most 1%, more preferably at most 0.1% of the transcription rate as the extrinsic RNA polymerase present for this promoter. In this embodiment, the correspondingly required extrinsic RNA polymerase is coexpressed. [0056] In another preferred embodiment, gene expression by P 1 is regulated by an individual specific factor, namely by the regulator R 1 . In another preferred embodiment, gene expression by P 1 is regulated by at least two specific factors, namely by the regulators R 1 a and R 1 b , wherein R 1 a can for example be a repressor and R 1 b can for example be an activator. This applies analogously to P 2 and R 2 or R 2 a and R 2 b . [0057] In a preferred embodiment (a) the promoter P 1 and/or the promoter P 2 requires that, for binding of the RNA polymerase to the corresponding recognition sequence of the promoter, a regulator R 1 or R 2 is bound to the promoter, i.e. transcription takes place provided there is binding of R 1 to P 1 or of R 2 to P 2 . [0058] In another preferred embodiment (b) the promoter P 1 and/or the promoter P 2 requires that, for binding of the RNA polymerase to the corresponding recognition sequence of the promoter, a regulator R 1 or R 2 is not bound to the promoter, i.e. transcription takes place provided there is no binding of R 1 to P 1 or of R 2 to P 2 . An example of such interaction of promoter and regulator is the interaction of a T7 promoter extended by at least one lacO operator sequence in combination with the repressor LacI. [0059] In another embodiment (c) the promoter P 1 and/or the promoter P 2 requires that, for binding of the RNA polymerase to the corresponding recognition sequence of the promoter, a regulator R 1 or R 2 is bound to the promoter, but the regulator R 1 or R 2 can assume various conformations, without thereby permanently removing the binding to the promoter, and transcription then only takes place provided R 1 or R 2 is in one of the possible conformations. An example of said interaction of promoter and regulator is the interaction of the ara promoter with its activator/repressor AraC. [0060] Preferably the promoters P 1 and P 2 belong to different of these embodiments (a), (b) and (c), especially preferably (a) and (c). [0061] Preferably the system P 1 /R 1 and/or the system P 2 /R 2 is influenced by another element I 1 /I 2 (inductors) or a change of the external conditions. These inductors I 1 or I 2 can for example be biomolecules, which are synthesized by the host, or natural or artificial molecules, which are added from outside. In particular a temperature change may also be considered as a change of the external conditions. [0062] Especially preferably I 1 is an inductor for P 1 , but not for P 2 , and/or I 2 is an inductor for P 2 , but not for P 1 . [0063] In a preferred embodiment promoter P 1 and/or promoter P 2 comprises, in addition to the binding site for the RNA polymerase, at least one enhancer sequence located outside of this binding site and/or at least one operator sequence. [0064] Enhancers are typically localized in the 3′-untranslated region of the sequence to be expressed. These enhancer sequences can be of prokaryotic or eukaryotic origin. They can be variants of these sequences or can be synthetic enhancer sequences. [0065] In one embodiment the enhancer sequence is the wild-type enhancer sequence of the selected promoter. [0066] Preferably P 1 and P 2 comprise in each case independently of one another at most 1000 bp, preferably at most 900 bp and especially preferably at most 800 bp. [0067] The presence/embodiment of the Shine-Dalgarno sequence also has an influence on the expression rate in prokaryotic hosts. The consensus sequence of the Shine-Dalgarno sequence in E. coli is AGGAGG. In a preferred embodiment, in connection with promoter P 1 , a Shine-Dalgarno sequence is used that coincides in at least 4 nucleotides, preferably at least 5 nucleotides, more preferably 6 nucleotides, and most preferably completely with the consensus sequence. [0068] In a preferred embodiment, in connection with promoter P 2 , a Shine-Dalgarno sequence is used that coincides in at least 4 nucleotides, preferably at least 5 nucleotides, more preferably 6 nucleotides, and most preferably completely with the consensus sequence. [0069] The Kozak sequence has a similar influence on the expression rate in eukaryotic hosts. The Kozak sequence for mammals for example has the consensus sequence (GCC)GCCR-CCAUGG (<SEQ.ID.NO: 3>), wherein R is a purine, which is located 3 bp upstream of the start codon AUG and wherein a guanine is located downstream of the start codon and the Kozak sequence of yeasts has for example the consensus sequence (A/U)A(A/C)AA(A/C)AUGUC(U/C) (<SEQ.ID.NO: 4>). [0070] In one preferred embodiment the consensus sequence is used in connection with promoter P 1 in a eukaryotic host. [0071] In another preferred embodiment the consensus sequence is used in connection with promoter P 2 in a eukaryotic host. [0072] In yet another preferred embodiment, on the empty expression vector according to the invention, neither a Shine-Dalgarno sequence nor a Kozak sequence is arranged on the insertion sequence in both reading directions. This preferred embodiment relates to the expression vector in the original state, i.e. in the state in which no DNA to be expressed or other DNA has been cloned into the insertion sequence (e.g. the polylinker). Such a vector is also known as “empty vector” by a person skilled in the art. In this embodiment of the expression vector according to the invention, the sequence to be cloned into the insertion sequence then preferably comprises a Shine-Dalgarno sequence or a Kozak sequence. [0073] The in vivo promoter strength is defined by the RNA synthesis rate that is triggered by a single promoter sequence, and leads to a corresponding proportion of the desired target protein in the total protein content of the host organism. The promoters used lead to a content of an expressed target protein relative to the total protein content of preferably >1%, preferably >5%, more preferably >10%, and most preferably >25%, in particular >50%. [0074] The two promoters P 1 and P 2 converge together according to the invention, i.e. they are convergent, face-to-face. Convergent promoters are produced by arranging promoter P 1 on one DNA strand and promoter P 2 on the complementary DNA strand of the expression vector. In other words, according to the invention, promoter P 1 and the sequence complementary to promoter P 2 are arranged on one DNA strand and promoter P 2 and the sequence complementary to promoter P 1 are arranged on the complementary DNA strand of the expression vector. [0075] Convergent promoters are to be distinguished from bidirectional promoters, even though the two terms are occasionally used synonymously in the literature. [0076] In its true sense, a bidirectional promoter denotes a promoter region or two back-to-back cloned promoters, whose reading directions point away from each other, and with which two open reading frames flanking the promoter region are read. Such promoters are widely distributed, as they can be used in the coexpression of a reporter gene present in stoichiometric ratio to the target gene, in particular in cell cultures. In this connection, reference may be made for example to Sammarco et al., Anal. Biochem. 2005, 346(2), 210-216; Baron et al. Nucleic Acids Res. 1995, 23(17), 3605-6; and EP-A 1 616 012. [0077] In contrast, convergent promoters, such as the promoters P 1 and P 2 according to the invention, are two face-to-face cloned promoters, whose reading directions point toward each other. Owing to the circular structure of plasmids and other expression vectors in circular form, bidirectional promoters can also be oriented face-to-face in some way, although not relative to the insertion sequence, which according to the invention is preferably arranged between the two promoters P 1 and P 2 in each case downstream, so that the two promoters P 1 and P 2 flank the insertion sequence on both sides. In this way, by means of the promoters it is possible to control the expression of DNA sequences, which have previously been cloned into the region of the insertion sequence, and namely in both directions of reading. [0078] According to the invention, therefore preferably an insertion sequence is arranged between P 1 and P 2 , in each case downstream, so that the expression of a DNA sequence cloned into the insertion sequence is placed under the control of P 1 and P 2 . In other words P 1 and P 2 run both towards each other, and towards the insertion sequence. [0079] Such insertion sequences are known by a person skilled in the art. Preferably said insertion sequence is a polylinker. [0080] For the purpose of this description, a polylinker (also known by a person skilled in the art as multiple cloning site (MCS)) means a DNA segment in a vector, whose sequence contains various cleavage sites for restriction endonucleases following closely one after another. This makes flexible cloning possible, as the one that is most suitable in each case can be selected and used from the various restriction cleavage sites. The cleavage sites are in this case unique on the vector. [0081] In one preferred embodiment, the polylinker comprises at least 1, preferably at least 2 or at least 3, more preferably at least 4 or at least 5, and most preferably at least 6 or at least 7 and in particular at least 8 or at least 9 recognition sequences for restriction endonucleases, which optionally overlap. In this connection, the restriction endonucleases are preferably restriction endonucleases of type I, II or III, which are listed in the REBASE database (http://rebase.neb.com/rebase). Furthermore, in this connection, recognition sequences for restriction endonucleases are to be understood preferably as penta-, hexa-, hepta- or octamers preferably of a double-stranded DNA sequence. Preferably the hexa- or octamers are palindromic, i.e. on both strands in one direction (for example 5′-3′) they show the same base sequence, e.g. GAATTC or GCGGCCGC. In another preferred embodiment these recognition sequences are interrupted, i.e. between parts of the fixed recognition sequences there are freely selectable sequences, e.g. CACNNNNGTG or GCNNGC. [0082] In yet another preferred embodiment the polylinker comprises a sequence segment of at most 20 bp, preferably of at most 15 bp, on which there are at least 1 or at least 2, preferably at least 3 or at least 4, more preferably at least 5 or at least 6, and most preferably at least 7 or at least 8, and in particular at least 9 or at least 10 cleavage sites of restriction endonucleases, which optionally can overlap. In this connection, restriction endonucleases are preferably to be understood as restriction endonucleases of type I, II or III, which are listed in the REBASE database (http://rebase.neb.com/rebase). [0083] In addition to restriction endonucleases, basically homing endonucleases can also be considered. [0084] In one preferred embodiment, between the last by of promoter P 1 and the last by of promoter P 2 , an insertion sequence is arranged in face-to-face arrangement, which comprises at most 500 bp, preferably at most 200 bp, more preferably at most 100 bp, more preferably at most 50 bp, and most preferably at most 20 bp and in particular at most 6 bp. In this connection the expression “last bp” refers to the reading direction of the RNA polymerase. This preferred embodiment relates to the expression vector in the original state, i.e. in that state in which no DNA to be expressed or other DNA has yet been cloned into the insertion sequence (e.g. the polylinker) (empty vector). [0085] In an especially preferred embodiment, on the insertion sequence there are at most 100, preferably at most 50, preferably at most 20, preferably at most 10 cleavage sites, preferably at most 5 cleavage sites and especially preferably at most 1 cleavage site of restriction endonucleases, which preferably have a recognition sequence between 4 and 10 b and produce overhanging or smooth ends. Especially preferably, the restriction endonucleases are selected from the group comprising AanI (PsiI), AarI, AasI (DrdI), AatII, Acc65I (KpnI), AdeI (DraIII), Ajil (BmGBI), AjuI, Alfl, AloI, AluI, Alw21I (BsiHKAI), Alw261 (BsmAI), Alw44I (ApaLI), ApaI, BamHI, BauI (BssSI), BclI, Bail (NciI), BcuI (SpeI), BdaI, BfiI (BmrI), BfmI (SfcI), BfuI (BciVI), BglI, BglII, Bme13901 ScrFI), BoxI (PshAI), BpiI (BbsI), BplI, Bpu10I, Bpu1102I (BlpI), BseDI (BsaJI), BseGI (FokI), BseJI (BsaBI), BseLI (BslI), BseMI (BsrDI), BseMII (BspCNI), BseNI (BsrI), BseSI Bme1580I), BseXI (BbvI), Bsh1236 I (BstUI), Bsh1285 I (BsiEI), BshNI (BanI), BshTI (AgeI), Bsp68 I (NruI), Bsp119I (BstBI), Bsp120I (PspOMI), Bsp143I (Sau3AI), Bsp1407I (BsrGI), BspLI (NlaIV), BspOI (BmtI), BspPI (AlwI), BspTI (AflII), BsT1107I (BstZ17I), BstXI, Bsu15I ClaI), BsuRI (HaeIII), BveI (BspMI), CaiI (AlwNI), CfrI (EaeI), Cfr9I (XmaI), Cfr10I (BsrFI), Cfr13I (Sau96I), Cfr42I (SacII), CpoI (RsrII), CseI (HgaI), Csp6I (CviQI), DpnI, DraI, Eam1104I (EarI), Eam1105I (AhdI), Eci136II (EcoICRI), Eco24I (BanII), Eco31I (BsaI), Eco32 I (EcoRV), Eco47I (Avail), Eco47III (AfeI), Eco521 (EagI), Eco57I (AcuI), Eco57MI, Eco72I (PmlI), Eco81I (Bsu36I), Eco88I (AvaI), Eco91I (BstEII), Eco105I (SnaBI), Eco130I (StyI), Eco147I (StuI), EcoO109I (DraII), EcoRI, EcoRII, EheI (NarI), Esp3I (BsmBI), FaqI (BsmFI), FspAI, FspBI (BfaI), GsuI (BpmI), HhaI, Hin1I (AcyI), Hin1II (NlaIII), Hin4I, Hin6I (HinP1I), HincII (HinduII), HindIII, HinfI, HpaII, HphI, Hpy8I (MjaIV), HpyF3I (DdeI), HpyF 10 VI (MwoI), KpnI, Kpn2I (BspEI), KspAI (HpaI), LguI (SapI), Lsp1109I (BbvI), LweI (SfaNI), MauBI MbiI (BsrBI), MboI, MboII, MlsI (MscI), MluI, MnlI, Mph1103I (NsiI), MreI (Sse232I), MspI (HpaII), MssI (PmeI), MunI (MfeI), MvaI (BstNI), Mva1269I (BsmI), NcoI, NdeI, NheI, NmuCI (Tsp45I), NotI, NsbI (FspI), OliI (AleI), PaeI (SphI), PagI (BspHI), PasI, PauI (BssHII), PdiI (NaeI), PdmI (XmnI), PfeI (TfiI), Pfl231I (BsiWI), PfoI, PpiI, Ppu21I (BsaAI), PscI (PciI), Psp51I (PpuMI), Psp1406I (AclI), PstI, PsuI (BstYI), PsyI (Tth111I), PvuI, PvuII, RsaI, RsaI (MsII), SacI, SalI, SatI (Fnu4HI), ScaI, SI (PleI), SdaI (SbfI), SduI (Bsp1286I), SfaAI (AsISI), SphiI, SgrDI, SgsI (AscI), SmaI, SmiI (SwaI), SmoI (SmlI), SmuI (FauI), SsiI (AcyI), SspI, TaaI (HpyCH4III), Tail (MaeII), TaqI, TasI (Tsp509I), TatI, TauI, TrulI (MseI), TscAI (TspRI), TsoI, TstI, Van91I (PflMI), VspI (AseI), XagI (EcoNI), XapI (ApoI), XbaI, XceI (NspI), XhoI, XmaJI (AvrII) and XmiI (AccI). [0086] Especially preferably the insertion sequence comprises at most 50 bp and has at least 6 cleavage sites for restriction endonucleases. [0087] To ensure a translation in all three reading frames, in a preferred embodiment according to the invention a system of expression vectors is also comprised, in which the whole sequence or parts of the sequence of the polylinker are in each case displaced by one nucleotide with respect to the rest of the vector sequence. For illustration of this teaching, reference should be made to the works of Charnay et al. (1978) Nucl. Acid Res. 5: 4479 and Villa-Komaroff (1978) Proc. Natl. Acad. Sci. 75, 3727. [0088] In another preferred embodiment the empty expression vector according to the invention does not comprise a translation start, i.e. there is also no start codon ATG or GTG within the insertion sequence in both directions of reading. In this preferred embodiment, the sequence to be cloned into the insertion sequence then preferably contains said translation start including a start codon. [0089] In one preferred embodiment, there is no ribosome binding site on the insertion sequence in both directions of reading. It is thereby ensured that translation of the resultant mRNA cannot be initiated by the empty vector of the two promoters. Especially preferably the empty expression vector according to the invention contains neither ribosome binding sites nor start codons in the insertion sequence in both directions of reading. [0090] In an especially preferred embodiment, on the insertion sequence there is (still) no gene, e.g. for a particular antibiotic resistance, so that the empty expression vector only contains the insertion sequence as such between P 1 and P 2 . In this way it is ensured that both promoters relate functionally to the insertion sequence, i.e. to both DNA strands of the insertion sequence, so that cloning into the insertion sequence can take place undirected. In this connection, “undirected” means that according to the invention, ultimately it does not matter into which of the two DNA strands of the plasmid a particular sequence is inserted, as both promoters relate functionally to the insertion sequence, the inserted sequence is inevitably placed either under the control of P 1 or under the control of P 2 . Expression of the inserted sequence is thus ensured in each case. [0091] Conversely, if in the empty expression vector a gene were already to be placed under the control of e.g. P 1 , for example a gene for a particular antibiotic resistance, undirected cloning would not be possible (or at least would be associated with disadvantages), as a (further) insertion downstream of P 1 would always result in coupling of expression of the inserted sequence with the gene already present. For the case when the gene for antibiotic resistance is followed by a terminator, the inserted foreign DNA, which would be inserted after the gene, would only be under the control of the relevant promoter to a limited extent, or not at all, and the advantage according to the invention, of two promoters directed on the same insertion sequence, would be lost. [0092] Decoupling of expression of the inserted sequence from the gene that is under the control of P 1 would however necessitate a directed cloning into the insertion sequence downstream of P 2 , i.e. specifically into the other DNA strand. However, directed clonings require a corresponding 5′-3′-orientation of the sequence to be inserted, so that by means of such an expression vector ultimately it would still only be possible to screen 50% of a DNA variant library. [0093] In an alternative embodiment, the expression vector according to the invention can contain as insertion sequence, instead of or additionally to a polylinker, also a sequence that permits integration of DNA sequences by recombination. [0094] Methods for integrating DNA sequences into a vector, preferably an expression vector, are known by a person skilled in the art. For example, such a method is based on recombination via att-sites, as for example in the GATEWAY vectors of the company Invitrogen (Carlsbad, Calif., USA). Another method is described in Muyrers J. P. P, Zhang Y., and Stewart A. F. (2001) “Recombinogenic engineering—new options for cloning and manipulating DNA” TIBS 26: 325-331. The DNA to be cloned a (meta-)genome bank would then have to be pretreated with corresponding linkers. Methods for attaching linkers to DNA are known by persons skilled in the art. [0095] In one preferred embodiment, a secretion sequence that has the purpose that, after expression, the host secretes the expressed peptide or protein, is arranged after the last by of P 1 and/or after the last by of P 2 , but before the polylinker. For this, it is necessary that there is no stop codon between the secretion sequence and the polylinker. Then the cloned DNA sequences are preferably searched for sequences that produce, as a result of cloning, a fusion protein of signal peptide and encoded protein. Suitable secretion sequences are biologically defined and are known by a person skilled in the art. [0096] In another preferred embodiment, in addition to the polylinker and/or DNA sequences for recombination, the insertion sequence also comprises a so-called suicide sequence. Suicide sequences are sequences that lead to dying-off of certain hosts. For example, the suicide sequence codes for a restriction endonuclease (e.g. EcoRI), which through digestion of the genomic DNA leads to dying-off of hosts that do not encode an associated methyltransferase (e.g. EcoMI) which protects the own DNA. The cleavage sites of the polylinker are in this case arranged within the suicide sequence. If additional DNA sequences are now cloned into the polylinker, the suicide gene is interrupted and becomes inactive. This prevents the formation of so-called religands, i.e. vectors that are religated again without additional DNA, during cloning of the DNA and subsequent transformation of the vectors into suitable hosts. In this case, the expression vector according to the invention is preferably produced in a host that expresses the corresponding protective methyltransferase, whereas the banks are then constructed in a host that does not encode the protective methyltransferase. A great variety of other suicide systems are known by a person skilled in the art. For example, reference may be made to the pJET system from the company Fermentas (Vilnius, Lithuania); Quandt J and Hynes MF (1993) “Versatile suicide vectors which allow direct selection for gene replacement in gram-negative bacteria”, Gene 127, 15-21; Ortiz-Martin et al., (2006) “Suicide vectors for antibiotic marker exchange and rapid generation of multiple knockout mutants by allelic exchange in Gram-negative bacteria”, J Microbiol Methods. 67, 395-407; Schlieper et al., (1998) “A Positive Selection Vector for Cloning of Long Polymerase Chain Reaction Fragments Based on a Lethal Mutant of the crp Gene of Escherichia coli ”, Anal. Biochem. 257, 203-209 or Bej et al., (1988) “Model suicide vector for containment of genetically engineered microorganisms.”, Appl Environ Microbiol. 54, 2472-7. [0097] Convergent promoters are known from the prior art. Thus, in some commercial cloning plasmids there are two convergent promoters on either side of the polylinker (multiple cloning site, MCS), e.g. T7 and SP6 promoter in pDrive (Merck, Darmstadt). However, these cloning plasmids are not expression plasmids, as they do not serve for functional expression of the cloned genes in vivo, but only for generating RNA by in-vitro transcription, e.g. for Northern blots, and as primer sites that are often used for sequencing. Moreover, the convergent promoters are not independently inducible on these cloning vectors. Convergent promoters are also described for plasmids, with which sense and antisense RNA is said to be produced simultaneously, to obtain siRNA and dsRNA for gene silencing in eukaryotes (cf. e.g. Waterhouse et al., Plant Biology, 1998, 95, 13959-64; Zheng et al., PNAS, 2004, 101, 135-40. Convergent promoters also occur naturally in bacteria, e.g. in Bacillus , where two promoters effect the reading of two different gene products on the sense and antisense strand of the same DNA segment (Wang et al., J. Bacteriol., 1999, 181, 353-6). [0098] The use of a vector with two convergent promoters for screening a (meta)genome library is also described in the literature (cf. Lämmle et al., Journal of Biotechnology, 2007, 127, 575-92). This is the vector pJOE930 (Altenbuchner et al., Methods Enzymol., 1992, 216, 457-66), which bears two convergent, comparatively weak lac promoters and can be used for the cloning and IPTG-induced expression of metagenomic DNA. The palindromic sequence of the two lac promoters and the MCS enclosed by them cause instability of the empty vector in E. coli . Furthermore, owing to their similarity, the two promoters are not separately inducible. [0099] It was found, surprisingly, that separately inducible convergent promoters have advantages over convergent promoters that are not separately inducible. [0100] For the purpose of this description, separate inducibility of the promoters P 1 and P 2 means that promoter P 1 can be induced selectively by suitable measures, without promoter P 2 also being induced simultaneously to a significant extent, and vice versa. Preferably, in selective induction of promoter P 1 , promoter P 2 is induced by at most 10% of its maximum inducibility, preferably at most 1%, more preferably at most 0.5%, and most preferably at most 0.2% and in particular at most 0.1%, and vice versa. Separate inducibility of the promoters can be achieved in the simplest case by using promoters P 1 and P 2 that interact with different modulators (repressors, activators). [0101] The empty expression vector according to the invention has, without the insertion sequence, altogether at most 3000 bp, i.e. the complete sequence of the expression vector including P 1 and P 2 but excluding the insertion sequence comprises at most 3000 bp. [0102] In a preferred embodiment, the empty expression vector according to the invention comprises, after opening in the insertion sequence or after cutting out parts of the insertion sequence that are not required, altogether at most 3000 bp, preferably at most 2900 bp, preferably at most 2800 bp, preferably at most 2700 bp, more preferably at most 2600 bp, and most preferably at most 2550 bp and in particular at most 2500 bp. [0103] In another preferred embodiment the empty expression vector according to the invention as such comprises altogether at most 3000 bp, preferably at most 2900 bp, preferably at most 2800 bp, preferably at most 2700 bp, more preferably at most 2600 bp, and most preferably at most 2550 bp and in particular at most 2500 bp. [0104] In yet another preferred embodiment the empty expression vector according to the invention, without insertion sequence, comprises altogether at most 2900 bp, preferably at most 2800 bp, preferably at most 2700 bp, more preferably at most 2600 bp, and most preferably at most 2550 bp and in particular at most 2500 bp. [0105] Preferably the expression vector according to the invention does not code for a regulator of P 1 and/or a regulator of P 2 . [0106] In a preferred embodiment of the expression vector according to the invention, P 1 is a T7 promoter. The T7 promoter is known by a person skilled in the art. In this connection, for example reference may be made in its entirety to Studier and Moffatt (1986) “Use of bacteriophage T7 RNA polymerase to direct selective high-level expression of cloned genes” J Mol Biol 189, 113-130. The term “T7 promoter” denotes, in the sense of the present invention, a promoter that is recognized as transcription start by the T7-RNA polymerase and that has been expanded by at least one lacO operator sequence. Lad is then the repressor of the T7 promoter. [0107] In a preferred embodiment of the expression vector according to the invention, P 2 is a promoter that is regulated by arabinose (I 2 ), in particular the ara promoter. In a preferred embodiment it is an ara promoter from Gram-negative bacteria, preferably E. coli . In this case the expression vector according to the invention preferably does not code for the regulator AraC of the ara promoter. [0108] The ara promoter is known by a person skilled in the art. The arabinose operon consists of a controllable promoter region (ara promoter), and three structural genes (araB, araA and araD), which code for proteins for degradation of L-arabinose. AraC is expressed constitutively. The gene product serves as a repressor. It binds to the promoter and thus prevents transcription of the genes araB, araA and araD. If arabinose is present, it binds to AraC. As a result of arabinose being bound, AraC changes its shape, binds to other DNA sequences and thus becomes the activator. Therefore the RNA polymerase can now attach to the promoter, and transcription of the structural genes begins. When the arabinose has degraded completely, AraC changes conformation again and transcription stops again. For further details, reference may be made for example to Schleif R. (2000) Regulation of the L-arabinose operon of Escherichia coli . Trends Genet. 16, 559-65 in its entirety. [0109] In another preferred embodiment the expression vector according to the invention is characterized in that it codes in each case for at least one terminator T 1 or T 2 in the corresponding direction of reading of the promoters P 1 or P 2 . [0110] In a preferred embodiment of this, the expression vector has the following arrangement of P 1 , P 2 , T 1 , T 2 and of the insertion sequence: T 2 (antisense)—P 1 (sense)—insertion sequence (sense/antisense)—P 2 (antisense)—T 1 (sense). [0111] Especially preferably, T 1 is a T7-terminator. Especially preferably, T 2 is a terminator for the host RNA polymerase. [0112] In a preferred embodiment the terminator for the T7 promoter is the T7-terminator and the terminator for the ara promoter is a terminator sequence for the E. coli RNA polymerase. In an especially preferred embodiment no independent terminator is cloned for the ara promoter, instead the terminator of the gene of the expression vector located upstream cloned in antisense is used. [0113] Within the scope of the present invention, “T i ” denotes optionally T 1 or T 2 . [0114] In another especially preferred embodiment the expression vector is characterized in that an additional gene is located between P i and its terminator T i in the direction of reading of P i but after the second promoter P j . [0115] Furthermore, the expression vector according to the invention comprises a selection marker sequence, which is suitable for distinguishing hosts that contain the expression vector, from hosts that do not contain the expression vector. [0116] This can for example be achieved by the selection marker sequence endowing the host with antibiotic resistance, so that it is capable of surviving on nutrient media on which other hosts, which do not contain the expression vector, die. Suitable sequences that impart antibiotic resistance are known by a person skilled in the art. The antibiotic against which resistance is imparted by the selection marker sequence is preferably selected from the group comprising ampicillin, tetracycline, kanamycin, chloramphenicol, spectinomycin, hygromycin, sulphonamide, trimethoprim, bleomycin/phleomycin, Zeocin™, gentamicin and blasticidin. [0117] Alternatively, auxotrophic hosts (negative mutants) can be used, which are dependent on a particular nutrient for survival (amino acid, carbohydrate, etc.), which they cannot synthesize themselves. These hosts are then not capable of surviving on a nutrient medium that does not supply this nutrient. In this case the selection marker sequence on the expression vector according to the invention endows the host with the ability to synthesize this nutrient, so that capability of surviving on the deficient nutrient medium is induced by the expression vector. Suitable selection marker sequences are known by a person skilled in the art. [0118] In the case of yeast cells, the markers used can be those that enable auxotrophic yeast strains to grow without additional uracil, tryptophan, histidine, leucine or lysine in the medium. [0119] In the case of mammalian cells, the markers used can be for example sequences that code for the activity of DHFR, of cytosine-deaminase, of hygromycin-β-phosphotransferase (HPH), of puromycin-N-acetyl transferase (PAC), of thymidine kinase (TK) and of xanthine-guanine phosphoriboseultransferase (XGPRT). [0120] Alternatively, sequences can be used that code for a counterselection marker, for example the sacB gene of B. subtilis or the F-plasmid ccdB-gene or colicin-release-gene such as the kil-gene for colicinE1. [0121] Another example is the use of a fragment of the Mu phage as described in Schumann (1979) Mol. Gen. Genet. 174, 221-4. Other examples of such markers are described in Roberts et al. (1980) Gene 12, 123-7; Dean (1981) Gene 15, 99-102, Hennecke et al. (1982) Gene 19, 231-4 or Hashimoto-Gotoh et al. (1986) Gene 41, 125-8. [0122] Additionally, sequences can be used that permit selection on the basis of the blue/white coloration after adding IPTG/X-GAL. [0123] Additionally sequences can be inserted in the region between promoters P 1 and P 2 , which make screening by PCR possible. [0124] In one embodiment, expression vectors can be used that permit coexpression of the cloned sequence with a detectable marker. Said detectable marker can for example be a tag such as a His tag, a Poly-His tag, an MAT tag, a streptavidin tag, a streptavidin-binding tag, a GST tag, an antibody-binding tag, a Myc tag, a Swa11 epitope or a FLAG tag. In one embodiment they can also be fluorescent tags such as a GFP tag, a BFP tag or an RFP tag. [0125] In a preferred embodiment the expression vector according to the invention has at least 70%, preferably at least 80%, more preferably at least 85%, and most preferably of least 90% and in particular at least 95% homology to <SEQ ID NO: 1>. Homology is preferably determined using the algorithm according to Smith & Waterman (J Mol. Biol., 1981, 147(1), 195-7), using the BLOSUM62 matrix and values of 11.0 for the opening of a gap, or 1.0 for the widening of a gap. [0126] Another aspect of the invention relates to an expression system comprising the expression vector described above and separately occurring regulatory sequences, which code for a regulator R 1 of P 1 and/or for a regulator R 2 of P 2 . In this connection, “separately” means that the regulatory sequences are not located on the expression vector according to the invention, or one or more parts integrated into the host chromosome. Preferably the regulatory sequences are located on a vector (regulatory vector), which codes for a regulator R 1 of P 1 and/or for a regulator R 2 of P 2 . Preferably R 1 is Lad and/or R 2 is AraC. [0127] The regulatory vector according to the invention preferably codes for both regulators R 1 and R 2 of the two promoters P 1 and P 2 , which are located on the expression vector according to the invention. [0128] Possible regulatory vectors include, for example, plasmids, phage, cosmids, phasmids, fosmids, bacterial artificial chromosomes, yeast artificial chromosomes, viruses and retroviruses (for example vaccinia, adenovirus, adeno-associated virus, lentivirus, herpes-simplex virus, Epstein-Barr virus, fowlpox virus, pseudorabies, baculovirus) and vectors derived therefrom. [0129] The regulatory vector or parts thereof can also be integrated into the genome. [0130] Any other vector can be used for production of the regulatory vector according to the invention, provided it is replicable and capable of surviving in the selected system (host). [0131] Preferably the regulatory vector is a plasmid (called “regulatory plasmid” within the scope of the invention). [0132] Preferably the expression vector according to the invention is also a plasmid, so that the expression system according to the invention preferably comprises two plasmids: expression plasmid and regulatory plasmid. [0133] In a preferred embodiment the regulatory plasmid comprises more by than the expression vector or the expression plasmid. [0134] In one preferred embodiment the regulatory plasmid according to the invention is a low-copy plasmid (on average <100 plasmids per cell). In another preferred embodiment the regulatory plasmid according to the invention is a high-copy plasmid (on average >100 plasmids per cell). [0135] The regulatory vector also contains a selection marker sequence. Preferably the selection marker sequence of the regulatory vector is different from the selection marker sequence of the expression vector. [0136] The regulatory vector preferably serves for effective control both of P 1 and of P 2 . It is then the ara promoter and the T7 promoter, therefore the regulatory vector is preferably a vector expanded by an araC-variation and a part of the ara-regulatory region, which additionally bears the structural gene for the LacI repressor. [0137] AraC is the repressor/activator of the ara promoter, and Lad is the repressor of the T7 promoter. [0138] The LacI repressor performs two functions. On the one hand it binds to regulatory elements between T7 promoter and transcription start (operator sequence lacO) and prevents the start of transcription. On the other hand, in a preferred embodiment, expression of the T7-RNA polymerase in the expression host is also under the control of a lacO operator sequence. For as long as the Lad repressor is bound to this operator sequence, expression of the T7-RNA polymerase itself is suppressed and therefore also does not transcribe any sequences that are under the control of the T7 promoter. IPTG (I 1 ) binds to the lad repressor, which is inactivated as a result and can no longer bind to the operator sequences lacO and so transcription of the T7-RNA polymerase itself, and of the genes located downstream of the T7 promoter is released. [0139] This permits effective control of expression by IPTG- or L-arabinose-induction (inductor I 1 or inductor I 2 ). The expression vector according to the invention preferably comprises as cloning or expression component of the 2-component system on one side of the MCS, the T7-promoter/operator region, and on the other side the complete Ara-promoter-operator region (cf. FIG. 1 ). [0140] In the literature, the ara-regulator AraC is generally expressed on the same plasmid as the target gene. This is preferably not so with the expression vector according to the invention. In this way a plasmid is obtained that is reduced in size to the maximum, which offers advantages in the bottleneck of ligation/transformation, as the achievable transformation rates and hence achievable library sizes are larger, the smaller the plasmid used. Instead, araC can be cloned into the T7-regulatory plasmid, where, like lad, it is expressed independently of the expression plasmid. At the same time, the araC gene is preferably shortened, to ensure more efficient inductor binding. (Lee et al., (2007); Appl. Environ. Microbiol. 73, 5711-5715). [0141] In a special embodiment the regulatory vector bears additionally at least one gene for a transfer-RNA of the host organism. Preferably these genes are selected from the group comprising argU, argW, ileX, gluT, leuW, proL, metT, thrT, tyrU, thrU and argX of E. coli , which recognize the codons AGG, AGA, AUA, CUA, CCC, GGA or CGG. Through the presence of these additional transfer-RNA genes, target genes that have a usage of the amino acid codons in their sequence different from E. coli (codon usage) can also be expressed at higher yield by the expression vector. This can occur in particular for eukaryotic genes (e.g. human) or genes from other groups of microorganisms (e.g. actinomycetes). [0142] In another special embodiment the regulatory vector contains genes for one or more inhibitory proteins for one or more RNA polymerases. These one or more RNA polymerases are the RNA polymerase(s) that are used, i.e. the RNA polymerase of the host and/or an RNA polymerase foreign to the host, coexpressed in the host cell. [0143] In yet another special embodiment, the expression system, preferably the regulatory vector, contains the gene lysS, which codes for the T7-lysozyme. The T7-lysozyme can bind to the T7-RNA polymerase and inactivate it. Through the presence of this gene in the host cell, basal expression of T7-RNA polymerase is suppressed and expression does not take place until expression of the T7-RNA polymerase is increased by adding an external inductor (IPTG) and is no longer capable of binding sufficient T7-lysozyme. In this way, even very toxic proteins can be expressed under the control of the T7 promoter. As economically important enzymes often present hydrolytic and therefore toxic activities (proteases, lipases etc.) this is of particular advantage. [0144] Expression vector and regulatory plasmid are compatible according to the invention and can preferably be replicated simultaneously in the host, e.g. in E. coli . Reading of the T7 promoter in E. coli requires expression of T7-polymerase, for example as in E. coli BL21(DE3). The ara promoter does not require any E. coli -foreign polymerase. [0145] Preferably the regulatory plasmid according to the invention comprises altogether at most 7000 bp, preferably at most 6500 bp, more preferably at most 6000 bp, and most preferably at most 5500 bp and in particular at most 5000 bp. [0146] Especially preferably the regulatory plasmid according to the invention has at least 70% homology to <SEQ ID NO: 2>. The homology is preferably determined by the algorithm according to Smith & Waterman (J Mol Biol, 1981, 147(1), 195-7), using the BLOSUM62 matrix and values of 11.0 for the opening of a gap, or 1.0 for the widening of a gap. [0147] Another aspect of the invention relates to a method of expression of DNA sequences using the expression vector or expression system described above comprising the steps (i) optionally transfecting or transforming a suitable host organism with the regulatory plasmid; (ii) cloning a DNA sequence or a DNA sequence mixture (library) into the expression vector between P 1 and P 2 ; (iii) optionally transfecting or transforming the host organism obtained in (i) with regulatory plasmid with the constructs obtained in step (ii); and (iv) inducing expression of the proteins encoded by the DNA sequences by adding the inductor I 1 and/or the inductor I 2 . [0152] The DNA sequence is preferably a constituent of a (meta)genome library. Genomic DNA sequences, extrachromosomal DNA sequences and cDNA sequences are included. [0153] In one embodiment the cloning into the expression vector takes place by subcloning from another vector. [0154] The terms “transfected” or “transformed” in the sense of the invention cover all methods of introducing nucleic acids into the host, e.g. including infection. The construct can be introduced in various ways, depending on the host used. Introduction of the construct into a prokaryotic host can for example take place by means of transformation, e.g. electroporation, transduction or transfection. Introduction of the construct into a eukaryotic host can, depending on the type of construct (expression vector), for example take place via calcium phosphate-DNA coprecipitation, DEAE-dextran-mediated transfection, polybrene-mediated transfection, electroporation, microinjection, liposome fusion, lipofection, viral infection, retroviral infection or ballistic methods. [0155] According to the invention, the regulatory vector or at least the parts that encode the repressor can also be introduced into the host by these methods. [0156] In one preferred embodiment of the method according to the invention, I 1 and I 2 are added successively. It was found, surprisingly, that in this way inhibition of the weaker promoter can be avoided. [0157] In another preferred embodiment of the method according to the invention, I 1 and I 2 are added to spatially separate partial cultures of the organisms obtained and therefore the two promoters are induced individually. It was found, surprisingly, that mutual inhibition of the promoters can also be avoided in this way. [0158] Therefore, according to the invention preferably spatially separate induction of reading of the same sequence takes place in different directions of reading, but not the successive or simultaneous induction of reading of different sequences. [0159] Especially preferably I 1 is the inductor for P 1 , but not for P 2 , and/or I 2 is the inductor for P 2 , but not for P 1 . [0160] Another aspect of the invention relates to a method of screening of DNA libraries using the expression vector or expression system described above comprising the method described above for expression of DNA sequences. [0161] Preferably screening is carried out with respect to catalytic activity of the expressed proteins. Preferably it is catalytic activity of one of the following enzyme classes: 1. Oxidoreductases, 2. Transferases, 3. Hydrolases, 4. Lyases, 5. Isomerases and 6. Ligases. Preferred oxidoreductases are selected from the EC group comprising 1.1, 1.2, 1.3, 1.4, 1.5, 1.6, 1.7, 1.8, 1.9, 1.10, 1.11, 1.12, 1.13, 1.14, 1.15, 1.16, 1.17, 1.18, 1.19 and 1.97. Preferred transferases are selected from the EC group comprising 2.1, 2.2, 2.3, 2.4, 2.5, 2.6, 2.7, 2.8 and 2.9. Preferred hydrolases are selected from the EC group comprising 3.1, 3.2, 3.3, 3.4, 3.5, 3.6, 3.7, 3.8, 3.9, 3.10, 3.11 and 3.12. Preferred lyases are selected from the EC group comprising 4.1, 4.2, 4.3, 4.4, 4.5, 4.6 and 4.99. Preferred isomerases are selected from the EC group comprising 5.1, 5.2, 5.3, 5.4, 5.5 and 5.99. Preferred ligases are selected from the EC group comprising 6.1, 6.2, 6.3, 6.4 and 6.5. The EC nomenclature introduced by the International Union of Biochemistry and Molecular Biology (IUBMB) is known by a person skilled in the art. Information about this can be found on the website of the IUBMB. [0162] Suitable assays for detecting a given catalytic activity are known by a person skilled in the art. They are preferably based on UV/VIS spectroscopy, fluorescence, luminescence or radioactivity. In this connection, reference may be made for example to J. L. Reymond, Enzyme Assays: High-throughput Screening, Genetic Selection and Fingerprinting, Wiley VCH, 2006 in its entirety. [0163] Alternatively, however, screening based on binding affinities is also possible. For example, this can be the binding affinity to an antibody or to some other binding partner (for example a protein or a nucleic acid or a carbohydrate). [0164] Screening based on functional assays that are suitable in each case, and known by persons skilled in the art, is also possible. [0165] In one embodiment the selected sequence is identified by sequencing the cloned sequence. [0166] In a special embodiment of the method, the host cell is multiplied and the expressed protein can be submitted to further steps such as purification and/or biochemical and/or functional characterization. [0167] In a special embodiment these steps take place using the tags linked to the expressed protein. As tags, it is possible for example to use a His tag, a Poly-His tag, a MAT tag, a streptavidin tag, a streptavidin-binding tag, a GST tag, an antibody-binding tag, a Myc tag, a Swa11 epitope or a FLAG tag or fluorescent tags such as a GFP tag, a BFP tag or an RFP tag. [0168] The preferred field of application of the expression vector according to the invention is as cloning and expression vector for the enzyme activity screening of genome and metagenome libraries. In fact, with (meta)genome libraries, high complexity (>10 6 clones) is necessary, so that already when they are being prepared, high cloning and transformation efficiency is decisive. Furthermore, the ideal screening vector must also enable efficient screening of large numbers of clones. In cluster screening, as in other screening assays, strong, controllable expression of the target proteins is essential. The expression vector according to the invention was specially developed for these requirements—high cloning efficiency combined with efficient, controllable expression. [0169] In contrast to the systems known from the prior art, the expression vector according to the invention has two strong, plasmid-located promoters, which moreover are still controllable, which offers advantages in screening for slightly toxic proteins. In the case of slightly toxic proteins, in fact, the host organism, e.g. E. coli , tolerates the presence of these proteins only for a relatively short time. In such cases, controllable promoters make it possible for the gene that codes for these slightly toxic proteins to be “switched off” at first, until the host organism has multiplied sufficiently. Then the controllable promoters enable the gene to be “switched on”, thus inducing production of the slightly toxic proteins for some time, before the expressed proteins exert their toxic action. In addition to the possible toxicity of a target protein, generally every additional expression of a recombinant protein represents a stress for the host organism (consumption of resources). Therefore as a rule it is always advantageous to switch on expression of the recombinant proteins only after reaching sufficiently strong multiplication. [0170] With the two convergent promoters in the expression vector according to the invention, it is possible to cover both potential orientations and thus double the usable information content of the cloned DNA. The ORFs can be expressed independently of orientation and therefore their gene products can be screened on the basis of activity. [0171] In addition to the great promoter strength, the separate induction of the two promoters is also advantageous, because in this way possible antisense RNA effects can be excluded. [0172] The separately inducible promoters of the expression vector according to the invention offer advantages. A decrease in promoter strength, or expression efficiency of the ORFs read can thus be avoided. [0173] Transcriptional interferences by convergent promoters had already been observed with eukaryotes. Thus, Callen et al. describe suppression of the weaker promoter by a factor of 5.6 with closely adjacent face-to-face promoters of different strength (Callen et al. (2004), Molecular Cell, 14, 647-56 B). Eszterhas et al. show that with a convergent promoter arrangement, the activity of two reporter genes is reduced almost to the background level (Eszterhas et al. (2002), Molecular and Cellular Biology 22, 469-79). This is sometimes attributed to disturbance of the binding properties in the promoter region. These results can be transferred to prokaryotes with limitations, taking into account that their transcription initiation differs from that of the eukaryotes. [0174] The expression system according to the invention combines the small size of a conventional cloning vector with the expression possibilities of controllable expression vectors. By using the two convergent promoters, the size of library that must be screened in order to cover a certain amount of DNA statistically, is halved. The separate induction of the promoters prevents possible transcriptional interference by antisense RNA, which is inevitably formed in simultaneous induction or a reduced transcription activity of the weaker promoter due to a higher transcription rate of the stronger promoter. [0175] A high, easily controllable promoter strength is of decisive advantage in the cluster screening method, as the strong signals against the background are detected better and accordingly greater complexities can be screened than previously. [0176] Therefore the expression system according to the invention is tailor-made for every kind of activity screening of banks with randomized fragmented (meta)genomic DNA, but in particular for cluster screening. [0177] This is a method of iterative deconvolution of variant libraries, which has considerable advantages over conventional deconvolution methods. [0178] In a preferred embodiment of such a method, shown schematically in FIG. 6 , a library, preferably a (meta)genome library, is prepared ( FIG. 6 , Step a.)(i)). The library contains the individual variants “A”, “B”, “C” and “D”. According to the invention, this library is transferred into a host ( FIG. 6 , Step a.) (ii)). [0179] In Step b.) the clones of one partial library are divided into a first compartment (variants “A” and “B” in FIG. 6 ) and the clones of another partial library into a second compartment (variants “C” and “D” in FIG. 6 ). [0180] During this dividing-up, it is not known which variants are put in which compartment. The compartments can for example be two adjacent wells on a first microtitre plate (“1st plate”). [0181] Now, in Step c.)(i), multiplication of the clones of the individual partial libraries takes place, preferably by growth of the organisms within the compartments on the 1st plate. [0182] In a preferred embodiment, next, in Step c.)(ii), an aliquot of the multiplied organisms is preserved, preferably retaining the compartment allocation. For retaining the compartment allocation, for example a second microtitre plate (“2nd plate”) can be used, wherein preferably the aliquot of the multiplied organisms, which is taken from the first compartment on the 1st plate, is transferred to the corresponding first compartment on the 2nd plate. [0183] With the unpreserved part of the multiplied organisms, in Step c.)(iii) biomolecules are produced, wherein clones that contain variant “A” produce biomolecules “a”; clones that contain variant “B” produce biomolecules “b”; and so on. Typically, the biomolecules are proteins, which are expressed by the organisms. The host organisms are macerated. A person skilled in the art knows various methods for this, for example cell lysis with suitable chemicals or cell lysis by osmotic shock or by the use of shearing forces such as the “French-press” method. The result is decoupling of phenotype and genotype. [0184] In Step c.)(iv), now in each case all of the biomolecules “a” and “b” contained in the first compartment and all of the biomolecules “c” and “d” contained in the second compartment are tested. This preferably takes place by screening for a particular biocatalytic activity (phenotype). In the example chosen, only all of the biomolecules contained in the first compartment “a” and “b” show the desired biocatalytic activity, which is shown symbolically with grey shading of the first compartment. From the observed phenotype, it is not possible to draw any direct conclusions about the genotype, as it is not outwardly apparent which of the biomolecules is responsible for the positive test, “a” or “b”, and moreover it is not known from which variants the totality of the partial library is composed (cf. explanation Step b.) above). [0185] The first compartment therefore contains biomolecules that fulfil the desired biocatalytic activity, and is selected in Step d.). [0186] The procedure now preferably does not start from the selected partial library in the first compartment as such, but from the preserved partial library in the corresponding first compartment on the 2nd plate (indicated by a dashed line). It is also possible to perform the preservation of the partial libraries directly in the 1st plate. In Step e.) the preserved partial library, which comprises the clones of variants “A” and “B”, is diluted and divided up. The clones of variants “A” and “B” are transferred respectively to different compartments. The compartments can for example be two wells on a third microtitre plate (“3rd plate”). [0187] Finally, in Step f.), Steps c.) to e.) are repeated until in each compartment only at most one variant of the gene sequence coding for the biomolecule is still contained. Under these preconditions, it is then possible to draw direct conclusions about the genotype from the observed phenotype, as all biomolecules contained in the compartment go back to an individual, separated clone. [0188] In a special embodiment of the method according to the invention for screening DNA libraries, the DNA library comprises 10 3 to 10 25 different sequences. The DNA library can for example comprise 10 3 to 10 5 , 10 5 to 10 10 , 10 10 to 10 15 , 10 15 to 10 20 or even 10 20 to 10 25 different sequences. [0189] According to the invention, Steps c.) to e.) can be repeated, and a person skilled in the art is able, taking into account the size of the library, to determine a number of repetitions appropriate to the particular circumstances. [0190] According to the invention, Steps c.) to e.) can for example be repeated at least 1×, preferably at least 2×, preferably at least 3×, more preferably at least 5×, more preferably at least 10× until individual sequences are individualized. [0191] In a preferred embodiment, after the first division of the library into compartments of the 1st plate, each compartment contains on average at least 10, preferably at least 20, more preferably at least 40, and most preferably at least 100 and in particular at least 1000 different variants. In one embodiment, the partial libraries therefore comprise, in the first round, preferably >10, more preferably >10 2 , even more preferably >10 3 sequences. [0192] The following examples serve for explanation of the invention, but are not intended to be limiting. [0193] In the following examples, pF2F4 was used, an expression vector for E. coli , in which two strong promoters flank the multiple cloning site (cf. FIG. 1 ). The promoters are convergent, i.e. their reading directions converge towards each other (face-to-face). The promoters that are inducible independently of one another are a T7 promoter and an arabinose promoter. DNA cloned into this vector can thus be transcribed from both sides, which halves the number of clones to be screened. The strong vector-supported transcription is independent of insert-coded promoters and thus increases the hit rate. Example 1 [0194] The promoter strength of the ara or T7 promoter in pF2F4 was investigated in various situations using a reporter gene. The data show that pF2F4, in conjunction with the regulatory plasmid pLacI+(cf. FIG. 2 ) is optimum for use as the expression plasmid. The reporter gene used was an alcohol dehydrogenase (ADH), which was inserted in both possible orientations. The gene was under the control of the ara promoter or of the T7 promoter, respectively. Only the combination of regulatory plasmid encoded Lad and AraC with the pF2F4 plasmid leads to maximum possible expression starting from the Ara promoter and from the T7 promoter ( FIG. 3 ). [0195] The ara promoter activity is lowered in the BL21 strain with simultaneous T7 induction to approx. 10% of the initial activity ( FIG. 4A ). The possibility of this effect being based on competitive inhibition of the regulator AraC by IPTG can be ruled out, as the inhibition is only observed in E. coli BL21(DE3). No significant decline in ara promoter activity is observed in an E. coli strain without chromosomal T7-polymerase (DH10B) ( FIG. 4B ). Here, the T7-activity is switched off to the greatest extent. The minimal activity still occurring is the basal activity of the T7 promoter, which even in E. coli without chromosomal T7-polymerase is recognized to a slight extent by the host organism's own polymerase ( FIG. 4 ). Example 2 Example of Application of pF2F4: Screening for Esterase/Lipase Activity in a Metagenome Bank [0196] A metagenome library set up in pF2F4 was screened for esterase/lipase-activity, using the cluster screening method (Greiner-Stoeffele, T., Struhalla, M., 2005, WO 2004/002386). The hit rate was compared with that of a metagenome bank cloned into the conventional pUC-vector. The target activity was an activity that is readily detectable with an established enzyme assay, and whose occurrence in metagenome banks has been described sufficiently in the literature. 1. Preparation of the Metagenome Bank [0197] For the metagenome banks used, metagenomic DNA (mgDNA) was isolated from the contents of a sheep's rumen by direct lysis (Zhou. J.; Bruns, M. A.; Tiedje, J. M. (1996): DNA recovery from soils of diverse composition. Appl. Environ. Microbiol; 62(2): 316-22). For preparing the metagenome bank in pF2F4, the mgDNA was then partially digested with the restriction enzyme AluI and ligated by standard methods into the vector pF2F4, blunt-end cut with Hindi and EcoRV and dephosphorylated (Sambrook, J., Fritsch, E. F., Maniatis, T., (1989). Molecular cloning: A laboratory manual. Cold Spring Laboratory Press 2nd Ed. Cold Spring Harbor, USA). [0198] For preparing the metagenome bank in pUCWhite, a pUC18 derivative, the mgDNA was digested with Bsp143I and also ligated by standard methods into the vector pUCWhite that had been cut with BamHI and dephosphorylated. [0199] For multiplying the libraries, electrocompetent E. coli DH10B cells were transformed with the libraries by electroporation. The pF2F4 library had an average insert size of 3.7 kb with inserts of 2.4-4.6 kb and a size of 2.9×10 6 individual clones. The pUC library had an average insert size of 3.5 kb with inserts of 1.9-5.9 kb and a size of 3.9×10 6 individual clones. After verification of quality, the libraries were isolated by preparation in the Midi-Scale (Qiagen, Hilden) from E. coli DH10B and electrocompetent cells of the expression strain E. coli BL21 (DE3) were transformed with 720 ng (pF2F4-rumen) or 200 ng (pUC-rumen) of the library. The expression strain transformed with the pF2F4 library additionally contained the regulatory plasmid pLacI+. 2. Cell Propagation [0200] Screening of the metagenome banks was performed using the cluster screening method (Greiner-Stoeffele, T., Struhalla, M., 2005, WO 2004/002386). In this high-throughput method, mixed cultures (clusters) of up to 1000 individual clones (here 300) are applied in the initial screenings. The clusters, to which the hits found in this first screening step relate, are diluted and screened again, until single clone level is reached. The single clones obtained are then characterized enzymatically and by methods of molecular biology. In this example of application, only the initial screening is carried out. All propagations were carried out in conditions optimized for the respective expression system. As the pF2F4 vector possesses two convergent vectors, and these were to be induced separately, from the pF2F4 library, two main cultures from a preculture were inoculated with standard media. 2.a Preculture [0201] Cultivation of the libraries in the expression strain was carried out in the 96-well format in deep-well plates. A preculture was grown first. Each well was inoculated with ˜300 individual clones of a metagenome bank, except that well A1 remained uninoculated as a control. At the same time, aliquots of the inoculated culture medium were plated out in order to verify the clone number. For the pF2F4-rumen bank, 278 individual clones/well were detected and for the pUC-rumen bank 300 individual clones/well. Preculture was carried out in 400 μl of medium. During preculture of the pUC library, 1% glucose and 100 μg/ml ampicillin were added to the medium. During preculture of the pF2F4 library, 0.5% glucose and 50 μg/ml kanamycin and 37 μg/ml chloramphenicol were added to the medium. Propagation took place overnight at 37° C. and 1000 rpm in a rotary shaker. 2.b Main Culture [0202] For the main culture of the pF2F4 library, two deep-well plates were inoculated in parallel, as the convergent promoters pAra and pT7 were to be induced separately. The main cultures of the pUC library and the part of the pF2F4 library to be induced later with IPTG were propagated in 1.2 ml of medium with 0.5% glucose and the corresponding antibiotics (ampicillin for the pUC library and kanamycin and chloramphenicol for the pF2F4 library). The part of the pF2F4 library to be induced with arabinose was propagated in the same medium without glucose. The main cultures were inoculated in each case with 30 μl of preculture, with well A1 remaining uninoculated as control. After incubation at 30° C. and 1000 rpm, the cultures were induced on reaching an OD of 0.7. For this, 1 mM IPTG was added to the pUC library and 0.5 mM IPTG or 0.2% L-arabinose was added to the two pF2F4 plates. Cultivation was continued overnight at 30° C. and 1000 rpm. 3. Cell Harvesting and Lysis [0203] The expression cultures grown overnight were centrifuged at 4000×g. The culture supernatant was removed, to be used additionally to the cell extract in the enzyme assay. The cell pellets were digested in CellLytic buffer to obtain the cell extract. For this, they were each resuspended in 200 μl CellLytic buffer and incubated for 30 min at 37° C. Then the cell debris was centrifuged at 4000×g for 15 min at 4° C. [0000] CellLytic buffer: [0204] 1 ml CellLytic B Cell Lysis Reagent (Sigma-Aldrich, Steinheim) [0205] 1 mg lysozyme (Applichem, Darmstadt) [0206] 1 μl benzonase (Sigma-Aldrich) [0207] to 10 ml 50 mM K-phosphate buffer pH 8. 4. Enzyme Activity Assay [0208] The activity assays were carried out with pNP-caprylate, an artificial substrate, for which a fatty acid consisting of 8 carbon atoms is derivativized via an ester bond with para-nitrophenol. During degradation, p-nitrophenolate is released, which can be detected at 405 nm. In each case 5 μl of cell extract or 5 μl of culture supernatant was mixed with 95 μl of assay buffer in flat-bottomed 96-well plates and incubated for up to 12 h at room temperature. If the background values were too high, the cell extracts were diluted 1:10 in KP8T buffer. Then the absorption at 405 nm was determined in a microplate reader (Infinite 200, Tecan, Crailsheim). [0000] Composition of assay buffer: [0209] 200 μl pNP-caprylate (Sigma-Aldrich) [0210] to 20 ml KP8T buffer [0211] KP8T buffer: [0212] 23.5 ml 1 M K2HPO4 [0213] 1.5 ml 1 M KH2PO4 [0214] 2.5 ml 20% Triton X-100 [0215] to 500.0 ml AquaMP [0216] pH 8.0. 5. Evaluation [0217] Wells were assessed as a hit for which the Z factor was >4, with Z defined as follows: [0000] Z =(absorption increase of the well−average of the absorption increase of the whole 96-well plate)/standard deviation of the average of the absorption increase of the whole 96-well plate. Results [0218] From the pF2F4-rumen library, ˜26400 clones with a total insert size of 97.7 Mb were screened for esterase/lipase activity. Both the culture supernatants and the cell extracts of both induction batches were examined. There were 10 non-redundant hits, which corresponds to a hit rate of 1 hit/9.8 Mb. Hits that appeared in several measurements were only included once in the overall balance. [0219] From the pUC-rumen library, 28500 clones with a total insert size of 99.8 Mb were screened for esterase/lipase activity. Both the culture supernatants and the cell extracts were examined. There was 1 hit, which corresponds to a hit rate of 1 hit/99.8 Mb. Therefore, for the metagenome library in pF2F4 there is a ˜10 times higher hit rate than for the pUC library. The hits are summarized in Table 1, and FIG. 5 shows the hit distribution in the cell lysis of the pF2F4 library induced with IPTG. [0000] TABLE 1 Esterase/lipase hits in the libraries after up to 24 h of incubation with pNP- caprylate pF2F4-rumen pUC-rumen (97 Mb screened) (95 Mb screened) Culture supernatants, 1 0 IPTG-induced Cell lysis, IPTG-induced 6 1 Culture supernatants, 0 — arabinose-induced Cell lysis, arabinose- 5 — induced Total 12 1 Total minus hits occurring 10 1 several times Hit Rate Comparison [0220] In order to show that the 2-promoter system in pF2F4 is superior to a simple lac promoter, a hit rate comparison was carried out. For this, a test screening for lipase/esterase activity was carried out with pNP-caprylate as substrate in cluster screening with ˜300 clones/well. The libraries used comprise fragmented metagenomic DNA, which was obtained from sheep rumen flora and was cloned both in pF2F4 and in pUCwhite, a pUC18 derivative. The average insert lengths were 3.5 kb (pUC-rumen) or 3.7 kb (pF2F4-rumen). In the comparative screening, 101 Mb or 99 Mb of cloned DNA was therefore covered. In this test screening it was found that by a combination of strong promoters and promoter convergence, with the same insert-DNA and screening method, a hit rate ( 1/9.7Mbp to 1/92 Mbp) higher by a factor of 9.5 can be achieved relative to a one-sided lac promoter system (pUC vector). As only double the hit rate would be expected from the convergent arrangement of the promoters, the rest of the increase in hit rate must be attributable to the promoter strength. [0221] The foregoing description and examples have been set forth merely to illustrate the invention and are not intended to be limiting. Since modifications of the disclosed embodiments incorporating the spirit and substance of the invention may occur to persons skilled in the art, the invention should be construed broadly to include all variations within the scope of the appended claims and equivalents thereof.	An expression vector including two separately inducible converging promoters P1 and P2, and expression system including such an expression vector and an additional regulator vector, a method of protein expression using such an expression system, and a method of investigating (meta)genome libraries using such an expression system.	2
CROSS-REFERENCE TO RELATED APPLICATIONS This application claims the priority of Chinese Patent Application No. 2013305988911, filed on Dec. 4, 2013 before the Chinese State Intellectual Property Office, the disclosure of which is incorporated herein in its entirety by reference. TECHNICAL FIELD The present invention relates to a tent, and more particularly, a tent having a retractable roof. BACKGROUND Tents have been widely used in nowadays, and as outdoor tents, tents having a retractable roof have been developed increasingly. But a conventional tent having a retractable roof has long non-foldable poles, which makes the package of the tent is big in size and thus is inconvenient to be transported. SUMMARY Accordingly, an objective of the present invention is to at least partially overcome the shortcomings of the prior art and to provide a tent having a retractable roof that can be easily folded so as to decrease the size of the package, thereby facilitating transportation of the tent. To achieve at least some of the objectives, the present invention provides a tent having a retractable roof, comprising a plurality of poles extending substantially perpendicular to the ground, a roof frame fastened to the plurality of poles and a tarpaulin attached on the roof frame. At least one of the plurality of poles comprises an upper pole and a lower pole, and the tent further comprises a connection mechanism detachably connecting the upper pole and the lower pole. Preferably, the connection mechanism comprises a connection plate, a plurality of bolts and a plurality of second through holes disposed on a lower end of the upper pole, a lower end of the connection plate is received in and fastened to an upper end of the lower pole, an upper end of the connection plate is received in the lower end of the upper pole, the connection plate has a plurality of first through holes, the plurality of bolts are inserted into the second through holes and the corresponding first through holes respectively so that the connection plate and the upper pole are fixedly connected. Preferably, the upper pole and the lower pole are formed in a shape of a hollow rectangular tube, and the connection plate is formed in a shape of a beam channel. The connection plate has a wall with a thickness being greater than a thickness of walls of the upper pole and a thickness of walls of the lower pole. Preferably, a sleeve is further disposed on the lower end of the upper pole, and the sleeve is formed in a shape of a tube adapted to slide along the upper pole. An inner diameter of an upper part of the sleeve is substantially the same as an outer diameter of the upper pole, and an inner diameter of a lower end of the sleeve is greater than an outer diameter of the upper pole. Preferably, a collar is further fixedly disposed on the upper end of the lower pole, the sleeve comprises a concave portion recessed inward at a lower end of an inner wall of the sleeve, the collar comprises a convex portion adapted to engage with the concave portion of the sleeve on an outer wall of the collar. Preferably, the collar further comprises a retainer ring on an inner wall of the collar, the retainer ring is protruded toward the center axis of the collar, a bottom surface of the retainer ring abuts a top surface of the lower pole, and a top surface of the retainer ring contacts and supports a bottom surface of the upper pole. Both of the sleeve and the collar are made of rubber or plastic material. Preferably, the lower end of the connection plate is fastened to the upper end of the lower pole through welding. The connection plate is made of metal. Alternatively, the connection mechanism comprises a plurality of first connection holes disposed on a lower end of the upper pole, a plurality of second connection holes disposed on an upper end of the lower pole and a plurality of bolts which are inserted into the first connection holes and the corresponding second connection holes respectively so that the upper pole and the lower pole are fixedly connected. Preferably, the roof frame comprises a front supporting rod, a rear supporting rod and a plurality of guiding rods, the number of the plurality of poles is four and each of the plurality of poles comprises an upper pole and a lower pole. The front supporting rod and the rear supporting rod are disposed to be extended along a first direction which is substantially parallel to the ground, both ends of the front supporting rod and both ends of the rear supporting rod are fixed to upper ends of the upper poles respectively, the plurality of guiding rods are disposed to be extended along a second direction which is substantially parallel to the ground and perpendicular to the first direction. Preferably, the number of the plurality of guiding rods is three, both ends of the outmost two guiding rods are fastened to the upper ends of the upper poles respectively, and both ends of the middle guiding rod is fastened to the front supporting rod and the rear supporting rod respectively. The middle guiding rod has the same interval to each of the outmost two guiding rods. Preferably, the roof frame further comprises a plurality of reinforcement rods extended along the second direction. The number of the plurality of reinforcement rods is two, each of the two reinforcement rods is disposed between adjacent guiding rods, with a same interval to the adjacent guiding rods. Preferably, the roof frame further comprises a plurality of sliding rods on which the tarpaulin is attached, wherein the plurality of sliding rods are disposed to be extended along the first direction. A plurality of sliding blocks may be further disposed on the plurality of sliding rods, and the guiding rods may have a plurality of sliding grooves extended in the second direction, the plurality of sliding blocks may be slidably received in the plurality of sliding grooves. Preferably, a plurality of feet attached on lower ends of the plurality of poles are further provided. According to the present invention, since at least one of the poles has two parts and a connection mechanism is provided between the two parts, the pole can be folded and thus the package is relatively small in size compared with the conventional tents having a retractable roof. Therefore, the tents according to the present invention are convenient to be transported. In addition, a sleeve and a collar may be further provided, so that the connection mechanism may be hidden in the sleeve, which makes the poles have a beautiful appearance. Further and other features of the invention will be apparent to those skilled in the art from the following detailed description of the embodiments thereof. BRIEF DESCRIPTION OF DRAWINGS Reference may now be made to the following detailed description taken together with the accompanying drawings in which: FIG. 1 is a schematic perspective view illustrating a tent according to a first embodiment of the present invention; FIG. 2 is a schematic partial cross-sectional view illustrating a pole of the tent according to the first embodiment of the present invention; FIG. 3 is an enlarged view of Part A shown in FIG. 2 ; FIG. 4 is an enlarged view of Part B shown in FIG. 2 ; FIG. 5 is a schematic partial perspective view illustrating a pole and a connection plate of the tent according to the first embodiment of the present invention; FIG. 6 is a schematic perspective view illustrating a collar and a sleeve of the tent according to the first embodiment of the present invention; FIG. 7 is a schematic partial perspective view illustrating a guiding rod of the tent according to the first embodiment of the present invention; and FIG. 8 is a schematic partial cross-sectional view illustrating a pole of the tent according to a second embodiment of the present invention. DETAILED DESCRIPTION Various embodiments of the present invention will be described hereinafter. The following description provides specific details for a thorough understanding and enabling description of these embodiments. Those skilled in the art will understand, however, that the present invention may be practiced without many of these details. Likewise, those skilled in the art will also understand that the present invention can include many other obvious features not described in detail herein. Additionally, some well-known structures or functions may not be shown or described in detail below, so as to avoid unnecessarily obscuring the relevant description. This invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein; rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art. Among other things, the present invention may be embodied as systems, methods or devices. The following detailed description should not to be taken in a limiting sense. Throughout the specification and claims, the following terms take the meanings explicitly associated herein, unless the context clearly dictates otherwise. The phrase “in one embodiment” as used herein does not necessarily refer to the same embodiment, though it may. Furthermore, the phrase “in another embodiment” as used herein does not necessarily refer to a different embodiment, although it may. Thus, as described below, various embodiments of the invention may be readily combined, without departing from the scope or spirit of the invention. In addition, as used herein, the term “or” is an inclusive “or” operator, and is equivalent to the term “and/or,” unless the context clearly dictates otherwise. The term “based on” is not exclusive and allows for being based on additional factors not described, unless the context clearly dictates otherwise. In addition, throughout the specification, the meaning of “a,” “an,” and “the” include plural references. The meaning of “in” includes “in” and “on”. Further reference may be made to an embodiment where a component is implemented and multiple like or identical components are implemented. While the embodiments make reference to certain events this is not intended to be a limitation of the embodiments of the present invention and such is equally applicable to any event where goods or services are offered to a consumer. The detail structures will be described to provide a thorough understanding of the present invention. Apparently, the implementation of the present invention is not limited by the specific details well known by those skilled in the art. A preferred embodiment will be described as follows; however, there are many other embodiments. The terminology used below is to be interpreted in its broadest reasonable manner, even though it is being used in conjunction with a detailed description of certain embodiments of the present invention. Indeed, certain terms may even be emphasized below; however, any terminology intended to be interpreted in any restricted manner will be overly and specifically defined as such in this Detailed Description section. FIG. 1 is a schematic perspective view illustrating a tent according to a first embodiment of the present invention. Referring to FIG. 1 , a tent according to the first embodiment of the present invention includes a plurality of poles 2 extending substantially perpendicular to the ground, a roof frame 3 fastened to the upper ends of the poles 2 and a tarpaulin 1 attached on the roof frame 3 . In this embodiment, the number of the poles 2 is four, but the prevent invention is not limited thereto. In addition, a plurality of feet 10 attached on lower ends of the poles 2 may be further provided to increase contact area with the ground. At least one of the poles 2 includes an upper pole 21 and a lower pole 22 . Preferably, each of the poles 2 includes an upper pole 21 and a lower pole 22 . The lower pole 22 is supported on the ground, for example, via the foot 10 . The roof frame 3 includes a front supporting rod 31 , a rear supporting rod 32 and a plurality of guiding rods 33 . In this embodiment, the number of the guiding rods 33 is three, but the present invention is not limited thereto. The front supporting rod 31 and the rear supporting rod 32 are disposed to be extended along a first direction which is substantially parallel to the ground, i.e., perpendicular to the direction in which the poles 2 are extended. Both ends of the front supporting rod 31 and both ends of the rear supporting rod 32 are fixed to the upper ends of the four upper poles 21 , respectively. The guiding rods 33 are disposed to be extended along a second direction which is substantially parallel to the ground and perpendicular to the first direction. Both ends of the outmost two guiding rods 33 are fastened to the upper ends of the upper poles 21 respectively, and both ends of the middle guiding rod 33 is fastened to the front supporting rod 31 and the rear supporting rod 32 respectively. Preferably, the middle guiding rod 33 has the same interval to each of the outmost two guiding rods 33 . The roof frame 3 may further include a plurality of reinforcement rods 34 extended along the second direction. The number of the reinforcement rods 34 may be two and each of the two reinforcement rods 34 may be disposed between adjacent guiding rods 33 , preferably with the same interval to the adjacent guiding rods 33 . The roof frame 3 may further include a plurality of sliding rods 4 on which the tarpaulin 1 is attached. The plurality of sliding rods 4 are disposed to be extended along the first direction. The guiding rods 33 have a plurality of sliding grooves 33 a (referring to FIG. 7 ) extended in the second direction, the plurality of sliding blocks 9 are slidably received in the plurality of sliding grooves 33 a so that the sliding rods 4 is adapted to slide along the guiding rods 33 . When lighting is needed, all of the sliding rods 4 can be slid to be together, thus the tarpaulin 1 is shrink, so that the roof frame 3 is opened and light can go into the tent. If an edge of the tarpaulin 1 is dragged to expand the tarpaulin 1 , the sliding rods 4 can be slid along the guiding rods 33 and can be stopped at any position, so that the area shaded by the tarpaulin 1 can be adjusted. When the tarpaulin 1 is fully expanded, the inside space of the tent is fully shaded. FIG. 2 is a schematic partial cross-sectional view illustrating a pole of the tent according to the first embodiment of the present invention. FIG. 5 is a schematic partial perspective view illustrating a pole and a connection plate of the tent according to the first embodiment of the present invention. FIG. 6 is a schematic perspective view illustrating a collar and a sleeve of the tent according to the first embodiment of the present invention. Referring to FIGS. 1 , 2 , 5 and 6 , the upper ends of the upper poles 21 are fastened to the roof frame 3 . For example, the upper ends of the upper holes 21 are fastened to the intersection points of the front supporting rods 31 and the guiding rods 33 and the intersection points of the rear supporting rods 32 and the guiding rods 33 respectively, but the present invention is not limited thereto. Hereinafter, one upper pole 21 and one corresponding lower pole 22 are taken as example. In this embodiment, the upper pole 21 and the lower pole 22 are formed in a shape of a hollow rectangular tube. The tent according to the first embodiment further includes a connection mechanism comprising a connection plate 5 , a plurality of bolts 6 and a plurality of second through holes 21 a disposed on lower end of the upper pole 21 . The connection plate 5 formed in a shape of a beam channel is disposed between the upper pole 21 and the lower pole 22 . The connection plate 5 extended vertically is disposed inside the upper pole 21 and the lower pole 22 . In detail, a lower end of the connection plate 5 is received in and fastened to, for example, through welding, an upper end of the lower pole 22 . An upper end of the connection plate 5 is received in a lower end of the upper pole 21 . The connection plate 5 has a plurality of first through holes 51 with the same number as the second through holes 21 a . The plurality of bolts 6 are inserted into the second through holes 21 a and the corresponding first through holes 51 respectively, so that the connection plate 5 and the upper pole 21 are fixedly connected. The connection plate 5 may be formed of metal and thus has a good strength, and may have a wall with a thickness being greater than a thickness of walls of the upper poles 21 and a thickness of walls of the lower poles 22 . Since the connection plate 5 is disposed between the upper pole 21 and the lower pole 22 , the robustness of the connection of the upper pole 21 and the lower pole 22 can be improved. FIG. 3 is an enlarged view of Part A shown in FIG. 2 . FIG. 4 is an enlarged view of Part B shown in FIG. 2 . Referring to FIGS. 2 , 3 , 4 and 6 , a sleeve 7 for covering the bolts 6 is disposed on the lower end of the upper pole 21 . The sleeve 7 is formed in a shape of a tube adapted to slide along the upper pole 21 . An inner diameter of an upper part of the sleeve 7 is substantially the same as an outer diameter of the upper pole 21 so that the sleeve 7 is radially supported by the upper pole 21 , and an inner diameter of a lower end of the sleeve 7 is greater than an outer diameter of the upper pole 21 so that a gap is formed there between. The sleeve 7 includes a concave portion 71 recessed inward at a lower end of an inner wall of the sleeve 7 . A collar 8 is fixedly disposed on the upper end of the lower pole 22 . The collar 8 includes a convex portion 81 which is adapted to engage with the concave portion 71 of the sleeve 7 on an outer wall of the collar 8 . In operation, the sleeve 7 can be slid in the first direction, and be stopped when the concave portion 71 of the sleeve 7 engages with the convex portion 81 of the collar 8 . The collar 8 may further include a retainer ring 82 on an inner wall of the collar 8 . The retainer ring 82 is protruded toward the center axis of the collar 8 . A bottom surface of the retainer ring 82 abuts a top surface of the lower pole 22 , and a top surface of the retainer ring 82 contacts and supports a bottom surface of the upper pole 21 . Both of the sleeve 7 and the collar 8 may be made of rubber or plastic material. In addition, since there is a gap between the lower end of the inner wall of the sleeve 7 and the outer wall of the upper pole 21 , the sliding of the sleeve 7 is not interfered by the heads of the bolts 6 . Such design enables the bolts 6 be hidden inside the sleeve 7 and makes the pole 2 have a beautiful appearance. In order to assemble the upper pole 21 and the lower pole 22 , the sleeve 7 is firstly mounted on the upper pole 21 , then the collar 8 is mounted to the connection plate 5 so that the bottom surface of the retainer ring 82 abuts the top surface of the lower pole 22 and the positions of the second through holes 21 a of the upper pole 21 correspond to those of the first through holes 51 . Next, the bolts 6 are inserted into the second through holes 21 a and the first through holes 51 respectively to fixedly connect the connection plate 5 and the upper pole 21 . At this point, the connection of the upper pole 21 and the lower pole 22 is completed. In an embodiment of the present invention, after the connection of the upper pole 21 and the lower pole 22 is completed, the sleeve 7 is further moved downward so that the concave portion 71 of the sleeve 7 engages with the convex portion 81 of the collar 8 . At this point, the sleeve 7 is fixed and the bolts 6 are hidden inside the sleeve 7 . FIG. 8 is a schematic partial cross-sectional view illustrating a pole of the tent according to a second embodiment of the present invention. The second embodiment is similar to the first embodiment and only different parts will be described hereinafter. Referring to FIG. 8 , unlike the connection plate 5 according to the first embodiment, the connection mechanism according to the second embodiment includes a plurality of first connection holes 11 , a plurality of second connection holes 12 and a plurality of bolts. In detail, the first connection holes 11 are disposed on a lower end of the upper pole 21 and the second connection holes 12 are disposed on an upper end of the lower pole 22 . And the positions of the first connection holes 11 correspond to those of the second connection holes 12 . The plurality of bolts are inserted into the first connection holes 11 and the corresponding second connection holes 12 respectively, so that the upper pole 21 and the lower pole 22 are fixedly connected. The connection manner of the front supporting rod 31 , the rear supporting rod 32 , the guiding rods 33 and the reinforcement rods 34 may be similar as that of the poles 2 . That is, each of the front supporting rod 31 , the rear supporting rod 32 , the guiding rods 33 and the reinforcement rods 34 may include two parts which may be connected by a connection mechanism according to the first embodiment or the second embodiment. The repeated description thereof will be omitted herein. Those skilled in the art can understand that even though there are a lot of terms, such as tarpaulin 1 , pole 2 , upper pole 21 , second through holes 21 a , lower pole 22 , a roof frame 3 , front supporting rod 31 , rear supporting rod 32 , guiding rod 33 , sliding grooves 33 a , reinforcement rods 34 , sliding rods 4 , connection plate 5 , first through holes 51 , bolt 6 , sleeve 7 , concave portion 71 , collar 8 , convex portion 81 , retainer ring 82 , sliding block 9 , feet 10 etc., other terms may also be used, and those terms are only used to describe and explain the nature of the invention, and should be used to limit the scope of the present invention. It should be understood that the above description just displays preferred embodiments of the present invention and is in no way intended to limit the scope of the present invention. Any modifications, equivalents, improvements and the like made within the spirit and principle of the present invention should be encompassed in the scope of the present invention.	The present invention provides a tent having a retractable roof. A plurality of poles extend substantially perpendicular to the ground. A roof frame is fastened to the plurality of poles and a tarpaulin is attached on the roof frame. At least one of the plurality of poles is divided into an upper pole and a lower pole, and a connection mechanism detachably connects the upper pole and the lower pole.	4
BACKGROUND OF THE INVENTION [0001] 1. Field of the Invention [0002] The present invention relates to a level shift circuit, and more particularly, to the level shift circuit that has a low power dissipation and is realized in a more simplified way. [0003] 2. Description of Related Art [0004] As shown in FIG. 1 , one integrated circuit (IC) could exist different supply voltages for different applications, a level shift circuit 100 is required between two circuitries with different supply voltages to adjust the level of logic signals so as to maintain the normal operation of the circuitry. FIG. 2 is a diagram showing the signal relation between an input signal S 1 and an output signal S 2 of the level shift circuit 100 in FIG. 1 . As shown in FIG. 2 , after the output signal S 2 passes the level shift circuit 100 , its logic value does not change, but its voltage level is different. The voltage level of V H1 is shifted to the voltage level of V H2 , and the voltage level of V L1 is shifted to the Voltage level of V L2 . [0005] In U.S. Pat. Nos. 5,057,721, 5,351,182, 6,362,679, 6,362,831 and 6,501,321, a level shift circuit making use of current and resistance to generate levels is disclosed. The level shift circuit using this method to generate levels will consume a large amount of power and require a complicated circuit to ensure the reliability and performance. [0006] Besides, U.S. Pat. No. 6,476,672 discloses a level shift circuit of low power dissipation, high reliability and high performance, but it needs to generate four complicated control signals to achieve the function of level shifting. SUMMARY OF THE INVENTION [0007] It is an object of the present invention to provide a level shift circuit of high performance, high reliability, low power dissipation, more simplified realization and low cost. [0008] It is an object of the present invention to provide a level shift circuit for driving an audio device. [0009] According to an exemplary embodiment of the claimed invention, a level shift circuit is disclosed. The level shift circuit comprises a first voltage level transfer unit, for transferring the voltage level of a first input signal from a first voltage level to a second voltage level and outputting a first level transferred control signal; a second voltage level transfer unit, for transferring the voltage level of a second input signal from the first voltage level to the second voltage level and outputting a second level transferred control signal; and a control block circuit coupled to the first voltage level transfer unit and the second voltage level transfer unit, for outputting an output signal according to the first level transferred control signal and the second level transferred control signal; wherein the first input signal and the second input signal are inversed. BRIEF DESCRIPTION OF THE DRAWINGS [0010] The various objects and advantages of the present invention will be more readily understood from the following detailed description when read in conjunction with the appended drawing, in which: [0011] FIG. 1 is a diagram showing the function of a level shift circuit; [0012] FIG. 2 is a clock diagram of a level shift circuit; [0013] FIG. 3 is a circuit diagram of a level shift circuit according to a first embodiment of the present invention; [0014] FIG. 4 is a timing diagram of all the signals in FIG. 3 ; [0015] FIG. 5 is a circuit diagram of the control block circuit in FIG. 3 according to an embodiment of the present invention; [0016] FIG. 6 is a circuit diagram of a level shift circuit according to a second embodiment of the present invention; [0017] FIG. 7 is a timing diagram of all the signals in FIG. 6 ; and [0018] FIG. 8 is a circuit diagram of the control block circuit in FIG. 6 according to an embodiment of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS [0019] FIG. 3 is a circuit diagram of a level shift circuit 300 according to a first embodiment of the present invention. The level shift circuit 300 comprises a first voltage level transfer unit 316 , a second voltage level transfer unit 318 , a control block circuit 310 , a first PMOS pull-up transistor 312 and a second PMOS pull-up transistor 314 . The first voltage level transfer unit 316 further comprises a NMOS transistor 302 and a PMOS transistor 304 , wherein the gate of NMOS transistor 302 receives a first input signal which is operated in first voltage level (Vdd and Vss), the source of the NMOS transistor 302 is coupled to the supply voltage Vss, and the drain and gate of PMOS transistor 304 are respectively coupled to the NMOS transistor 302 and supply voltage VL for outputting the level transferred control signal X 1 (operated in VH and VL level). On the other hand, the second voltage level transfer unit 318 comprises NMOS transistor 306 and PMOS transistor 308 , wherein the gate of NMOS transistor 306 receives a second input signal which operated in first voltage level (Vdd and Vss), the source of the NMOS transistor 306 is coupled to the supply voltage Vss, and the drain and gate of PMOS transistor 308 are respectively coupled to the NMOS 306 transistor and supply voltage VL for outputting the level transferred control signal X 2 (operated in VH and VL level). It is noticed that the first input signal In and the second input signal InB are inversed signal. Furthermore, the process of first voltage level transfer unit 316 and second voltage level transfer unit 318 are implemented by high-voltage process. [0020] The function of the level shift circuit 300 is to shift the voltage level of input signal In from first voltage level to second voltage level ((Vss and Vdd level) to (VL and VH level)). As shown in FIG. 3 , when the NMOS transistor 302 receives the first input signal In, the PMOS transistor 304 generates a level transferred control signal X 1 to the control block circuit 310 . On the other hand, when the NMOS transistor 306 receives the second input signal InB, the PMOS transistor 308 also generates a level transferred control signal X 2 to control block circuit 310 . It is obvious that the voltage level of the two control signals X 1 and X 2 have been shifted to the second voltage level (VH and VL) for controlling a control block circuit 310 , wherein the control block circuit 310 coupled between VH and VL. When the control block circuit 310 receives the first control signal X 1 and the second control signal X 2 , an output signal Out will be generated. The level of the output signal Out is the voltage between VH and VL, and the logic value of the output signal Out corresponds to the first input signal In. Additionally, after the control block circuit 310 receives the first control signal X 1 and the second control signal X 2 , two operation signals Y 1 and Y 2 will be generated, which is to adjust the voltage level of the first control signal X 1 and the second control signal X 2 through transistors 312 and 314 , respectively. [0021] FIG. 4 is a diagram of all the signals in FIG. 3 . As shown in FIG. 4 , when the first input signal In changes from 0 (Vss) to 1 (Vdd), the first control signal X 1 will be pulled down to 0 (VL). Since the control block circuit 310 detects the first control signal X 1 pulled down, it will set Y 2 to 0 (VL). At this time, the output signal Out will be set to 1 (VH) so as to make the output signal correspond to the first input signal with logic value (1). On the other hand, when Y 2 is pulled down to 0 (VL), the PMOS pull-up transistor 314 will pull up the second control signal X 2 . At this time, due to Y 1 is 1 (VH) and InB already becomes 0 (VL), only the parasitic capacitances of the transistors 302 , 304 , 306 and 308 are charged and discharged, hence having a very low power dissipation. When the second control signal X 2 is charged to 1 (VH), the control block circuit 310 will pull up Y 2 to 1 (VH) so as to stop the transistor 314 to pull up X 2 . On the contrary, when the first input signal In changes from 1 (Vdd) to 0 (Vss), the operations of the level shift circuit 300 are reversed to mentioned above, therefore the further detail description is omitted for brevity. [0022] FIG. 5 is a circuit diagram of the control block circuit 500 in FIG. 3 according to an embodiment of the present invention. As shown in FIG. 5 , when the first input signal In is 1 (Vdd), the signal st ought to be 1 (VH). When both the first control signal X 1 and the second control signal X 2 are 0 (VL), the signal rs is set to 1 (VH). One of st and stb is necessarily 1 (VH). If stb is 1 (VH), then Y 1 is 0 (VL), and X 1 is pulled up to 1 (VH). Subsequently, rst becomes 1 (VH) to set st to 1 (VH), and rs becomes 0 (VL). At this time, because In is 1 (Vdd), X 1 will be pulled down to 0 (VL) again, and rs will be set to 1 (VH) again, and Y 2 will be set to 0 (VL). After the second control signal X 2 is set to 1 (VH), Y 1 and Y 2 will become 1 (VH) again, waiting for the next time of change of In. At this time, the circuit is in the proper state. This shows that the circuit itself can restore to the correct state. [0023] FIG. 6 is a circuit diagram of a level shift circuit 600 according to a second embodiment of the present invention. The level shift circuit 600 comprises a first voltage level transfer unit 616 , a second voltage level transfer unit 618 , a control block circuit 610 , a first NMOS pull-down transistor 612 and a second NMOS pull-down transistor 614 . The first voltage level transfer unit 616 further comprises PMOS transistor 602 and NMOS transistor 604 , wherein the gate of PMOS transistor 602 receives a first input signal which is operated in first voltage level (Vdd and Vss), the source of the PMOS transistor 602 is coupled to the supply voltage Vdd, and the drain and gate of NMOS transistor 604 are respectively coupled to the PMOS transistor 602 and supply voltage VH for outputting the level transferred control signal X 1 (operated in VH and VL level). On the other hand, the second voltage level transfer unit 618 comprises PMOS transistor 606 and NMOS transistor 608 , wherein the gate of PMOS transistor 606 receives a second input signal which is operated in first voltage level (Vdd and Vss), the source of the PMOS transistor 606 is coupled to the supply voltage Vdd, and the drain and gate of NMOS transistor 608 are respectively coupled to the PMOS 606 transistor and supply voltage VH for outputting the level transferred control signal X 2 (operated in VH and VL level). It is noticed that the first input signal In and the second input signal InB are inversed signal. Furthermore, the process of first voltage level transfer unit 616 and second voltage level transfer unit 618 is implemented by high-voltage process. [0024] As the first embodiment, the function of the level shift circuit 600 is to shift the voltage level of input signal In from first voltage level to second voltage level ((Vss and Vdd level) to (VL and VH level)). As shown in FIG. 6 , when the PMOS transistor 602 receives the first input signal In, the NMOS transistor 604 generates a level transferred control signal X 1 to the control block circuit 610 . On the other hand, when the PMOS transistor 606 receives the second input signal InB, the PMOS transistor 608 also generates a level transferred control signal X 2 to control block circuit 610 . It is obvious that the voltage level of the two control signals X 1 and X 2 have been shifted to the second voltage level (VH and VL) for controlling a control block circuit 310 , wherein the control block circuit 610 is coupled between VH and VL. When the control block circuit 610 receives the first control signal X 1 and the second control signal X 2 , an output signal Out will be generated. The level of the output signal Out is also between VH and VL, and the logic value of the output signal Out corresponds to the first input signal In. Additionally, after the control block circuit 610 receives the first control signal X 1 and the second control signal X 2 , two operation signals Y 1 and Y 2 will be generated, which for adjusting the voltage level of the first control signal X 1 and the second control signal X 2 through transistors 612 and 614 , respectively. [0025] FIG. 7 is a timing diagram of all the signals in FIG. 6 . As shown in FIG. 7 , when the first input signal In changes from 1 (Vdd) to 0 (Vss), the first control signal X 1 will be pulled up to 1 (VH) by NMOS transistor 604 . Accordingly, after the control block circuit 610 detects that the first control signal X 1 being pulled up, the control block circuit 610 will set Y 2 to 1 (VH). At this time, the output signal Out will be set to 0 (VL) so as to make the output signal correspond to the first input signal with logic value (0). On the other hand, When Y 2 is pulled up to 1 (VH), the NMOS pull-down transistor 614 will pull down the second control signal X 2 . At this time, due to Y 1 is 0 (VL) and InB already becomes 1 (VH), only the parasitic capacitances of the transistors 602 , 604 , 606 and 608 are charged and discharged, hence having a very low power dissipation. When the second control signal X 2 is discharged to 0 (VL), the control block circuit 610 will pull down Y 2 to 0 (VL) so as to stop the transistor 614 to pull down X 2 . On the contrary, when the first input signal In changes from 0 (Vdd) to 1 (Vss), the operations of the level shift circuit 600 are reverse to mentioned above, therefore the further detail description is omitted for brevity. [0026] FIG. 8 is a circuit diagram of the control block circuit 800 in FIG. 6 according to an embodiment of the present invention. The control block circuit 800 can accomplish the functions of the signals in FIG. 7 . Besides, when the signal is at the initial state or is erroneous, the circuit also has the function of restoring to the correct state by itself. [0027] Although the present invention has been described with reference to the preferred embodiment thereof, it will be understood that the invention is not limited to the details thereof. Various substitutions and modifications have been suggested in the foregoing description, and other will occur to those of ordinary skill in the art. Therefore, all such substitutions and modifications are intended to be embraced within the scope of the invention as defined in the appended claims.	In many high voltage circuits, it often needs to shift the logic voltage level to keep the circuit normal operation. In the class-D amplifier circuitry, it needs to shift the voltage level of pulse width modulation (PWM) signal to control the connecting of different power switches. In other applications, such as a driver to drive amplifier of an audio device, it also needs a level shift circuit to maintain the circuitry in normal voltage operation. Therefore, this invention is to provide a novel level shift circuit with high performance, low cost and low power dissipation characteristics.	7
This application is a U.S. National Phase of International Application No. PCT/US2009/031004, filed Jan. 14, 2009, and which claims Priority to U.S. Provisional Application Nos. 61/006,447, 61/071,579, and 61/129,698 filed Jan. 14, 2008, May 7, 2008, and Jul. 14, 2008, respectively, the entire contents of which are hereby incorporated by reference. This invention was made with Government support of Grant No. 0507294 awarded by the National Science Foundation and of Grant No. FA9550-07-1-0264, awarded by the United States Air Force Office of Scientific Research. The Government has certain rights in this invention. BACKGROUND 1. Field of Invention The current invention relates to methods of producing graphene and devices and methods of producing the devices using graphene, and more particularly to high-throughput solution processing of graphene and devices and methods of producing the devices using the graphene. 2. Discussion of Related Art Since its experimental discovery in 2003, there has been a great amount of interest in single layer graphene for a variety of applications. Ballistic transport of electrons along the atomically thin layer, along with mobilities exceeding 15,000 cm 2 /Vs and an ambipolar field effect make graphene a particularly good candidate for the next round of semiconductor devices (Novoselov, K. S.; Geim, A. K.; Morozov, S. V.; Jiang, D.; Zhang, Y.; Dubonos, S. V.; Grigorieva, I. V.; Firsov, A. A.; Electric Field Effect in Atomically Thin Carbon films. Science 2004, 306 (5696), 666-9; Gusynin, V. P.; Sharapov, S. G.; Unconventional Integer Quantum Hall Effect in Graphene, Phys. Rev. Lett. 2005, 95(14), 146801; Zhang, Y.; Tan, Y. W.; Stormer, H. L.; Kim, P.; Experimental observation of the quantum Hall effect and Berry's phase in graphene. Nature 2005, 438(7065), 201-204; Novoselov, K. S.; McCann, E.; Morozov, S. V.; Fal'ko, V. I.; Katsnelson, M. I.; Zeitler, U.; Jiang, D.; Schedin, F.; Geim, A. K.; Unconventional quantum Hall effect and Berry's phase of 2pi in bilayer graphene. Nature Physics 2006, 2(3), 177-180; Novoselov, K. S.; Jiang, Z.; Zhang, Y.; Morozov, S. V.; Stormer, H. L.; Zeitler, U.; Boebinger, G. S.; Kim, P.; Geim, A. K.; Room-Temperature Quantum Hall Effect in Graphene. Science 2007, 315(5817), 1379; Novoselov, K. S.; Geim, A. K.; Morozov, S. V.; Jiang, D.; Katsnelson, M. I.; Grigorieva, I. V.; Dubonos, S. V.; Firsov, A. A.; Two-dimensional gas of massless Dirac fermions in graphene. Nature 2005, 438(7065), 197-200). Although similarities to carbon nanotubes and other conjugated systems help contribute to the theoretical understanding of graphene, experimental results have been less forthcoming due to the difficulty in producing single layer specimens. As with carbon nanotubes, the large aspect ratio of individual sheets, and strong Van der Waals forces holding them together, make isolating single sheets of graphene very challenging. Thus far only two methods have enjoyed reliable success; the Scotch tape or “drawing” method and by the reduction of silicon carbide (Novoselov, K. S.; Geim, A. K.; Morozov, S. V.; Jiang, D.; Katsnelson, M. I.; Grigorieva, I. V.; Dubonos, S. V.; Firsov, A. A.; Two-dimensional gas of massless Dirac fermions in graphene. Nature 2005, 438(7065), 197-200). The drawing method utilizes a piece of Scotch tape to draw a thin film from highly oriented pyrolytic graphite (HOPG). After repeated peeling from the thin film, it is ultimately stamped onto a substrate and the tape is carefully removed. The resulting deposition is a dense network of both single and multi-layered graphene, which must be scoured using an optical microscope and otherwise characterized before finally a single sheet may be reliably identified for further use. Alternatively, the reduction of silicon carbide (SiC) reliably produces small regions of graphitized carbon, but requires temperatures greater than 1000° C. (Berger, C.; Song, Z.; Li, T.; Li, X.; Ogbazghi, A. Y.; Feng, R.; Dai, Z.; Marchenkov, A. N.; Conrad, E. H.; First, P. N.; de Heer, W. A.; Ultrathin Epitaxial Graphite: 2D Electron Gas Properties and a Route toward Graphene-based Nanoelectronics. J. of Phys. Chem. B 2004, 108(52), 19912-19916; Berger, C.; Song, Z.; Li, X.; Wu, X.; Brown, N.; Naud, C.; Mayou, D.; Li, T.; Hass, J.; Marchenkov, A. N.; Conrad, E. H.; First, P. N.; de Heer, W. A.; Electronic confinement and coherence in patterned epitaxial graphene. Science 2006, 312(5777), 1191-1196). While these methods have provided adequate samples for preliminary experimental results, both present a number of drawbacks and neither is well suited for industrial applications. First and foremost, the yield of single sheets produced is exceedingly low. Furthermore, the location of those specimens is largely random, and certainly not controllable to the level required for mass fabrication techniques. Finally, neither the peeling method nor the reduction of silicon carbide is scalable or high-throughput. These necessary conditions for the ultimate goal of graphene electronics present formidable hurdles and will continue to motivate research. Chemists have recently proposed a third synthetic route through the oxidation and exfoliation of HOPG, which may provide a number of advantages (Viculis, L. M.; Mack, J. J.; Kaner, R. B.; A Chemical route to carbon nanoscrolls. Science 2003, 299(5611), 1361; Shioyama, H.; Akita, T.; A new route to carbon nanotubes. Carbon 2003, 41(1), 179-181; Stankovich, S.; Piner, R. D.; Nguyen, S. T.; Ruoff, R. S.; Synthesis and exfoliation of isocyanate-treated graphene oxide nanoplatelets. Carbon 2006, 44, 1558-1565; Stankovich, S.; Dikin, D. A.; Piner, R. D.; Kohlhaas, K. A.; Kleinhammes, A.; Jia, Y.; Wu, Y.; Nguyen, S. T.; Ruoff, R. S.; Synthesis of graphene-based nanosheets via chemical reduction of exfoliated graphite oxide Carbon. 2007, 45, 1558-1565; Gomez-Navarro, C.; Weitz, R. T., Bittner, A. M.; Scolari, M.; Mews, A.; Burghrd, M.; Kern, K. Electronic transport properties of individual chemically reduced graphene Oxide Sheets Nano lett. 2007, 7, 3499-3503). The resulting single sheets of oxidized graphite are stable as uniform aqueous dispersions. Although graphite oxide is itself an insulator, the sheets may be restored to semi-metallic graphene, and its planar structure, by chemical reduction or by thermal annealing. The technique has led to a number of functioning single sheet field-effect devices (Gilje, S.; Han, S.; Wang, M. S.; Wang, K. L.; Kaner, R. B.; A chemical route to graphene for device applications. Nano lett. 2007, 7, 3394-3398; Gomez-Navarro, C., Weitz R., Bittner, A. M., Scolari, M., Mews A., Burghard, M, and Kern, K. Electronic Transport Properties of Individual Chemically Reduced Graphene Oxide Sheets Nano lett. 2007, 7, 3499-3503). Fabrication typically includes air-brushing or spin-coating from water, followed by an electron-beam process to deposit electrodes, and in situ chemical reduction. Although graphite oxide dispersions facilitate some solution processing, the location of single sheets has been uncontrollable and individual sheets often aggregate due to the high surface tension of water (Stankovich, S.; Piner, R. D.; Nguyen, S. T.; Ruoff, R. S.; Synthesis and exfoliation of isocyanate-treated graphene oxide nanoplatelets. Carbon 2006, 44, 1558-1565). In addition, many of the resulting sheets are found to be wrinkled or folded when examined by atomic force microscopy (AFM). Also, cross-sectional step heights of more than 1 nm are often observed for a single sheet which is much larger than the theoretical value of 0.34 nm found in graphite. This increased thickness may be attributed to unreduced surface hydroxyl and epoxide groups. Such functionalities are detrimental to the electrical properties of graphene. Furthermore, aqueous dispersions are not ideal for deposition as the high surface tension of water leads to aggregation during the evaporation process. Finally, even if GO is perfectly deposited, reduction methods tend to neglect the area in direct contact with the substrate. Attempts have been made to complete the reduction stage in solution, but sheets tend to aggregate due to the attractive forces between layers and an overall decrease in hydrophilicity. Therefore, there remains a need for improved methods of producing graphene as well as device made using graphene. SUMMARY A method of producing carbon macro-molecular structures according to some embodiments of the current invention includes dissolving a graphitic material in a solvent to provide a suspension of carbon-based macro-molecular structures in the solvent, and obtaining a plurality of the carbon macro-molecular structures from the suspension. The plurality of carbon macro-molecular structures obtained from the suspension each consists essentially of carbon. A material according to some embodiments of the current invention is produced according to the method of producing carbon macro-molecular structures. An electrical, electronic or electro-optic device includes material produced according to the methods of the current invention. A composite material according to some embodiments of the current invention has carbon macro-molecular structures produced according to methods of producing carbon macro-molecular structures according to some embodiments of the current invention. A hydrogen storage device according to some embodiments of the current invention has carbon macro-molecular structures produced according to methods of producing carbon macro-molecular structures according to some embodiments of the current invention. An electrode according to some embodiments of the current invention has carbon macro-molecular structures produced according to methods of producing carbon macro-molecular structures according to some embodiments of the current invention. An electrode for an electrical, electronic or electro-optic device according to some embodiments of the current invention has a plurality substantially planar carbon macro-molecular structures, and a plurality of carbon nanotubes which are in electrical connection with at least two of the plurality of substantially planar carbon macro-molecular structures. The plurality of carbon nanotubes provide electrical connection between otherwise electrically isolated substantially planar carbon macro-molecular structures. An electrical, electronic or electro-optic device according to some embodiments of the current invention has an electrode that has a plurality substantially planar carbon macro-molecular structures, and a plurality of carbon nanotubes which are in electrical connection with at least two of the plurality of substantially planar carbon macro-molecular structures. The plurality of carbon nanotubes provide electrical connection between otherwise electrically isolated substantially planar carbon macro-molecular structures. A method of producing a device having patterned electrically conducting regions according to some embodiments of the current invention includes producing carbon macro-molecular structures, depositing the carbon macro-molecular structures on a first surface, providing a stamp having a pattern corresponding to a preselected pattern of electrically conducting regions of the device being produced, bringing the pattern of the stamp into contact with at least some of the carbon macro-molecular structures deposited on the first surface, and lifting the stamp from the first surface and bringing the pattern of the stamp into contact with a second surface to thereby transfer a pattern of electrically conducting regions of the carbon macro-molecular structures to the second surface. The producing of the carbon macro-molecular structures includes dissolving graphite oxide in a solvent to provide a suspension of carbon-based macro-molecular structures in the solvent, and obtaining a plurality of the carbon macro-molecular structures from the suspension, wherein the plurality of carbon macro-molecular structures obtained from the suspension consist essentially of carbon. BRIEF DESCRIPTION OF THE DRAWINGS Further objectives and advantages will become apparent from a consideration of the description, drawings, and examples. FIG. 1 is an SEM image of a large single graphene sheet (scale bar=10 μm). FIGS. 2 a and 2 b illustrate the preparation of graphene suspensions in an example according to an embodiment of the current invention. The photographs show ( FIG. 2 a ) 10 mg of graphite oxide (GO) paper in a glass vial and ( FIG. 2 b ) the resultant hydrazinium graphene (HG) dispersion after addition of hydrazine. Below each vial is a 3-D molecular model of GO and graphene, respectively, suggesting that removal of —OH and —COOH functionalities upon reduction restores a sheet structure. FIGS. 3 a - 3 d are results for an example graphene films according to an embodiment of the current invention. FIG. 3 a is an optical image of an evenly and continuously distributed graphene film under 500× magnification. FIG. 3 b is an AFM and FIG. 3 c is an SEM image of the same large single sheet of graphene. FIG. 3 d is a single cross-section (top) that indicates step heights of less than 0.6 nm as the AFM tip traverses the solid line in FIG. 3 b . A histogram (bottom of FIG. 3 d ) of height profiles collected over the entire area of the image confirms the average step height of under 0.6 nm. FIGS. 4 a and 4 b show an electronic device according to an embodiment of the current invention. Arrays of working graphene transistors were produced by spin-coating a well-dispersed graphene solution onto SiO 2 substrates, followed by registering gold source-drain electrodes on top of the single sheets. FIG. 4 a is a schematic illustration of a graphene field effect device. FIG. 4 b is a photograph, optical image, and SEM of a working device with a channel length of 7 μm according to an embodiment of the current invention. FIG. 5 a shows Current (I SD )—Voltage (V SD ) of reduced graphite oxide film devices according to an embodiment of the current invention. As the gate voltage is varied from 0 V to −50 V, the conductance of the device increases, indicative of a P-type semiconductor. The inset shows I-V G characteristic curve at V SD =0.1 V. FIG. 5 b shows that current (I SD ) —Voltage (V SD ) plots taken on graphite oxide films before and after reduction indicate a 10 8 fold decrease in sheet resistance according to an embodiment of the current invention. FIG. 6 is a schematic illustration of a method of producing carbon macro-molecular structures according to an embodiment of the current invention. FIGS. 7 a and 7 b illustrate the preparation of chemically converted graphene-CNT suspensions according to an embodiment of the current invention. FIG. 7 a shows a representative SEM image of G-CNT film. FIG. 7 b shows photographs of 1 mg of graphite oxide (GO) paper and 5 mg SWCNT dissolved in pure hydrazine (right) and in dichlorobenzene (DCB) (left), respectively. After 1 hr, G-CNT in DCB already precipitates out. FIG. 8 shows representative SEM and AFM images of G-CNT film, along with 3-D topographies of ( FIG. 8 a ) Chemically converted graphene. ( FIG. 8 b ) Single wall carbon nanotubes network. ( FIG. 8 c ) G-CNT hybrid film. Note that the dense network of G-CNT film exceeds the percolation threshold with average surface roughness of 5˜10 nm. Inset: phase diagram juxtapose the large sheet of chemically converted graphene and individual SWCNT. ( FIG. 8 d ) G-CNT film after surface optimization. Height profile (dark curve) taken along the white solid line shows the average surface roughness of 1.49 nm. FIG. 9 shows optical, electrical and mechanical characterization of G-CNT films according to an embodiment of the current invention. FIG. 9 a shows photographs of G-CNT film with increasing spin speed (from left to right), 1,050, 1,250, 1,500, 1,750 RPM, respectively. FIG. 9 b shows optical transmittance of G-CNT films as a function of different spin speed. FIG. 9 c shows sheet resistance versus different spin speed. Electrical measurements of G-CNT films before (left) and after (right) bending. I-V characteristics of ITO and G-CNT electrode on PET before ( FIG. 9 d ) and after ( FIG. 9 e ) bending at 60 degrees for 10 times. The ITO resistance increases three orders of magnitudes, while G-CNT hybrid electrode remains exceedingly low resistance. FIG. 10 shows representative SEM images of a variety patterns of G-CNT electrode and device structure along with current density-voltage (J-V) curves. FIG. 10 a shows SEM images of G-CNT patterns spin-coated on Si/SiO 2 substrates. FIG. 10 b shows a device configuration of G-CNT based organic solar cell, consisting of G-CNT (5 nm)/PEDOT (25 nm)/P3HT:PCBM (230 nm)/Ca:Al (80 nm) according to an embodiment of the current invention. FIG. 10 c shows current density vs. voltage (J-V) curves in the dark (upper, circles) and under simulated AM1.5G irradiation (100 mW cm −2 ) using a xenon-lamp-based solar simulator (lower, squares). FIG. 11 shows sheet resistance of G-CNT films before (squares) and after (circles) chemical doping. An exposure of 15 minutes to room temperature vapors resulted in a decrease in sheet resistance by a factor of 1.5 to 2 for all deposited films. FIG. 12 is an illustration of a method of producing graphene and/or G-CNT conducting patterns for device applications according to an embodiment of the current invention. A diagram (left) and optical microscope images (right) depict the PDMS transfer process according to an embodiment of the current invention. It begins by ( FIG. 12 a ) depositing materials on a glass substrate and ( FIG. 12 b ) carefully “inking” the pre-patterned PDMS stamp. In FIG. 12 c the inked stamp is contacted to a heated Si/SiO 2 substrate and ( FIG. 12 d ) peeled away to reveal deposited materials. FIG. 13 shows Micro Raman spectra that were collected inside and outside a rectangular region on ( FIG. 13 a ) glass and ( FIG. 13 b ) Si/SiO 2 according to an embodiment of the current invention. Raman intensity mapping of the G peak indicates that graphene has been completely removed from a section of the glass by the PDMS stamp and successfully deposited onto a Si/SiO 2 substrate. Representative spectra are provided for spots both inside and outside of the rectangular regions showing the G′ peak of graphitic carbon. FIG. 14 a Si 2p and FIG. 14 b C 1s spectra show the removal of residual PDMS upon thermal annealing to 400° C. for 1 hour. The peak shifts of nearly 1 eV for Si and SiO 2 are attributed to a charging effect from the thick insulating oxide. FIGS. 15 a and 15 b show optical images of the geometric layout of field effect devices according to an embodiment of the current invention. Gold electrodes are patterned via conventional photolithography to form top-contacts on the Si/SiO 2 substrate. In FIG. 15 c an SEM image verifies a single sheet of graphene (dark region) bridges the electrodes (top and bottom). FIG. 15 d is a schematic illustration showing the structure of the fabricated devices according to this embodiment of the current invention. FIG. 15 e shows I SD -V SD measurements and FIG. 15 f shows I SD -V G transfer curves indicating current modulation under negative gate bias in this example. FIG. 16 shows an atomic force microscope image and the corresponding line-scan that confirm a step height of less than 1 nm, indicative of single sheet graphene according to this embodiment of the current invention. DETAILED DESCRIPTION Some embodiments of the current invention are discussed in detail below. In describing embodiments, specific terminology is employed for the sake of clarity. However, the invention is not intended to be limited to the specific terminology so selected. A person skilled in the relevant art will recognize that other equivalent components can be employed and other methods developed without departing from the broad concepts of the current invention. All references cited herein are incorporated by reference as if each had been individually incorporated. According to some embodiments of the current invention we present a fundamentally new approach for producing large-scale single layer and few layer graphene ( FIG. 1 ) through a scalable solution process. According to an embodiment of the current invention, graphite oxide (GO) paper is dispersed in substantially pure hydrazine to create stable dispersions of hydrazinium graphene (HG) through the formation of counterions. However, the broad concepts of the current invention are not limited to only GO paper. More generally, one can disperse a graphitic material in hydrazine, GO paper being just one possible example of a graphitic material. These hydrazine colloids are readily deposited onto a variety of substrates, producing uniform films of single and/or few layer graphene. Graphene is an example of a carbon macro-molecular structure according to some embodiments of the current invention. A few-layer graphene structure may have less than ten layers of carbon molecular structures according to some embodiments of the current invention. A few-layer graphene structure may have less than three layers of carbon molecular structures according to some embodiments of the current invention. In some embodiments of the current invention, graphene structures may be single substantially planar layers consisting essentially of carbon. Photographs of GO paper and HG are presented in FIGS. 2 a and 2 b , respectively, along with 3-D molecular models of GO before and after reduction. By controlling the concentration and composition of these dispersions, films of a desired morphology and surface coverage may be produced. This non-destructive method preserves the scalability of graphite oxide, ultimately forming reduced sheets much larger than those previously reported (Stankovich, S.; Piner, R. D.; Nguyen, S. T.; Ruoff, R. S.; Carbon 2006, 44, 1558-1565; Stankovich, S.; Dikin, D. A.; Piner, R. D.; Kohlhaas, K. A.; Kleinhammes, A.; Jia, Y.; Wu, Y.; Nguyen, S. T.; Ruoff, R. S.; Carbon 2007, 45, 1558-1565; Gilje S.; Han S.; Wang M. S.; Wang K. L.; Kaner R. B.; Nano lett. 2007, ASAP; Gomez-Navarro C.; Weitz R. T., Bittner A. M.; Scolari M.; Mews A.; Burghrd M.; Kern K. Nano lett. 2007, ASAP). This increase in size vastly reduces the amount of effort necessary for electronic testing and renders characterization possible by a number of microscopic techniques. In fact, the scale of graphene produced allows one of the most comprehensive studies yet conducted on the characterization of graphene. Graphite oxide (GO) dispersions can be produced via a modified Hummers' method from graphite powder (Hummers, W. S., Jr.; Offeman, R. E.; J. Am. Chem. Soc. 1958, 80, 1339). Typical dispersions are 2% w/v GO in water and may be diluted to various concentrations for use. Uniformity of a given dispersion can be ensured by heating to 60° C. with repeated ultrasonication. In order to form GO paper, aqueous samples can be subjected to vacuum filtration through a 0.22 micron alumina membrane. This filtration process requires approximately 24 hours after which the resultant films are left to dry under ambient conditions. Each dry, matte black GO film is then carefully peeled from its membrane. While the reduction of GO by hydrazine vapors is well known (Stankovich, S.; Piner, R. D.; Nguyen, S. T.; Ruoff, R. S.; Carbon 2006, 44, 1558-1565; Gilje S.; Han S.; Wang M. S.; Wang K. L.; Kaner R. B.; Nano lett. 2007, ASAP; Stankovich, S.; Piner, R. D.; Chen, X.; Wu, N.; Nguyen, S. T.; Ruoff, R. S.; J. of Mat. Chem. 2006, 16(2), 55-158; Liu, P.; Gong, K.; Carbon 1999, 37, 706-707), here the GO films are dispersed directly into a 98% anhydrous hydrazine solution in a nitrogen filled dry box according to an embodiment of the current invention. Bubbles rapidly form along the film surface due to the reduction, likely producing NO 2 and N 2 . After several hours, no GO solid can be observed in solution and bubbling subsides, indicating complete dispersion and reduction, respectively. As an explanation for the new dispersions created, we suggest the formation of hydrazinium graphene (HG) comprised of a negatively charged, reduced graphene sheet surrounded by N 2 H 4 + counterions. Hydrazinium compounds readily disperse in hydrazine (Bourlinos, A. B.; Gournis, D.; Petridis, D.; Szabo, T.; Szeri, A.; Dékány, I.; Langmuir 2003, 19(15), 6050-6055). The resultant dispersions are stable for months with little aggregation. Purification of HG solutions can be carried out with various combinations of ultrasonication, dilution and centrifugation, for example. Briefly, dispersions of large (20 μm×20 μm) single sheets can be created by pelleting higher density multilayers via centrifugation. Such dispersions can be very useful for electronic applications due to the ease of making contact at the length scales of these relatively large single sheets. Alternatively, large sheets and aggregates may be fractured into uniform dispersions of smaller single sheets (e.g. 1 μm×1 μm) by repeated ultrasonication. These small sheets readily make continuous films upon deposition and can be useful as “transparent” conductors. Note that even these smaller sheets are large when compared to those prepared by either the peeling method or by chemical reduction of SiC, which have typically been no more than 0.2 μm 2 . HG suspensions can be spin-coated onto Si/SiO 2 substrates, for example, for characterization. After deposition, the films can be thermally annealed at 150° C. in order to remove all hydrazine and to return the HG samples to pristine graphene. Note that HG may also be dried and re-suspended in the organic solvent DMSO for deposition (Bourlinos, A. B.; Gournis, D.; Petridis, D.; Szabo, T.; Szeri, A.; Dékány, I.; Langmuir 2003, 19(15), 6050-6055). This approach has the advantage of avoiding spin-coating from a solvent of hydrazine's toxicity. The initial characterization of deposited samples is carried out by examination through an optical microscope, which was originally used to identify single layer graphene (Novoselov K. S.; Geim A. K.; Morozov S. V.; Jiang D.; Zhang Y.; Dubonos S. V.; Grigorieva I. V.; Firsov A. A.; Science 2004, 306 (5696), 666-9). Here, however, we use optical images primarily to observe the surface coverage of the depositions. For more detailed structural information, scanning electron microscope (SEM) images were collected, with a representative image of a large single sheet (˜40×25 μm) shown in FIG. 1 . SEM images were collected under a variety of accelerating voltages and probe currents in an attempt to improve contrast and resolution. Ultimately, a relatively small accelerating voltage (2-5 kV) and probe current (5-8 μA) proved most appropriate as they reduce the penetration depth of incident electrons and more directly probe surface species. With experience, single, double, triple and multilayer graphene may be differentiated by SEM. Although SEM images can be used to find single sheets of graphene, the images are representative of electronic structure, not topography. Hence, atomic force microcopy (AFM) is needed to establish the thickness and surface roughness of single sheets. For comparison, a representative AFM height image and its corresponding SEM image are shown in FIGS. 3 b and 3 c , respectively. Height profiles show steps from SiO 2 to graphene of ˜0.6 nm for a given cross-section ( FIG. 3 d ). The histogram provided represents height data over the entire area of the scan, confirming the 0.6 nm step value. A similar analysis of samples prepared by the peeling method has been performed in ultra-high vacuum (UHV), and also shows typical step heights for single layer graphene of 0.6 nm (Mitzi B. D.; Copel M.; Chey S. J.; Adv Mater. 2005, 17, 1289-1293). The apparent 0.3 nm discrepancy in thickness as compared with theoretical values suggests the presence of some nitrogen, oxygen, or water adsorbed onto the sheets (Novoselov K. S.; Geim A. K.; Morozov S. V.; Jiang D.; Zhang Y.; Dubonos S. V.; Grigorieva I. V.; Firsov A. A.; Science 2004, 306 (5696), 666-9). Never-the-less, the agreement between peeled samples and those measured here provides significant evidence that the planar structure of graphene has been largely reestablished upon reduction. Although reduced GO samples have been studied by AFM before, the size limitations of single sheets have not previously permitted such quantitative comparisons. In an investigation of graphene, the characterization of electrical properties and fabrication of electronic devices are of interest. Due to the size limitations of most graphene samples, e-beam lithography has been the only reliable method for producing patterns necessary for electrical testing. In a typical e-beam process, single sheet candidates are located by SEM, markers provided, and a polymethyl methacrylate photo-resist is selectively exposed. After removing the photo-resist, gold source and drain electrodes are then evaporated onto the surface to provide a top contact configuration for the graphene device. This method is laborious and requires a sophisticated lithographic setup, making it difficult to scale up. Moreover, this lithographic process can degrade device performance if the photo-resist is not entirely removed. Acrylic lithography resists have recently been reported to introduce unknown and unfavorable contamination (Schniepp C. H.; Li J. L.; McAllister J. M.; Sai h.; Herrera-Alonso M.; Adamson H. D.; Prud'homme K. R.; Car R.; Sacille A. D.; Aksay A. I. J. Phys. Chem. B 2006, 110, 8535-8539; Ishigami M.; Chen J. H.; Cullen W. G.; Fuhrer M. S.; Williams E. D.; Nano Lett. 2007, 7, 1643-1648). The size of the graphene sheets reported here, however, can provide far fewer constraints for the effective fabrication of devices. The large graphene sheets can instead be processed via conventional photolithography on silicon dioxide substrates to provide gold source-drain top contacts. FIG. 4 a provides a schematic of a field effect transistor (FET) according to an embodiment of the current invention. FIG. 4 b is a photograph, optical image, and SEM of an actual working device corresponding to FIG. 4 a . Electrode separation channel lengths of 7 μm can be used and no alignment is necessary in order to reliably produce single sheet devices. This is due to the nearly uniform and tunable distribution of single sheets over a large area of the wafer (˜1.5×1.5 cm). More than 50 devices were tested to confirm the electrical output performance with all measurements carried out under ambient conditions. P-type behavior is readily and reproducibly attained at gate voltages ranging from 0 to −60 V. FIG. 5 a shows the output and transfer characteristics of a typical field effect device according to an embodiment of the current invention. Output V SD -I SD curves show up to 6 mA at source-drain voltages of only −1 V. This represents a considerable improvement over previously reported values for reduced GO (25 μA at V SD equals to −5 V) (Gilje S.; Han S.; Wang M. S.; Wang K. L.; Kaner R. B.; Nano lett. 2007, ASAP) at considerably larger channel lengths (7 μm vs. 500 nm as previously reported). The results show current responses comparable to those of graphene produced by the peeling method (up to 100 μA at Vsd=10 mV and channel lengths of 0.5 μm) (Novoselov K. S.; Geim A. K.; Morozov S. V.; Jiang D.; Zhang Y.; Dubonos S. V.; Grigorieva I. V.; Firsov A. A.; Science 2004, 306 (5696), 666-9). FIG. 5 b shows output curves for parent GO and our reduced graphene, indicating a 10 8 fold decrease in sheet resistance. We attribute the increase in conductivity and mobility to more complete reduction of GO by anhydrous hydrazine. Graphene samples produced via the drawing method should be understood to represent the ultimate reduction limit of our devices. Several methods for the chemical modification of reduced samples to achieve n-type behavior of graphene according to some embodiments of the current invention have been devised. These include functionalization, e.g. alkylation, of parent GO materials before suspension in hydrazine. The large size of the graphene sheets produced according to some embodiments of the current invention can enable RAMAN spectroscopy to be carried out on a working FET. This can provide a non-destructive method for characterizing graphene (Matthew J. A.; Tran. H.; Tung C. V.; unpublished; Ferrari A. C.; Meyer J. C.; Scardaci V.; Casiraghi C.; Lazzeri M.; Mauri F.; Piscanec S.; Jiang D.; Novoselov K. S.; Roth S.; Geim A. K.; Phys. Rev. Lett. 2006, 97, 187401-187404; Tuinstra F.; Koenig J. L.; J. Chem. Phys. 1970, 53, 1126-1130; Reich S.; Thomsen C.; Phil. Trns. R. Soc. Lond . A 2004, 362, 2271-2288; Gupta A.; Chen G.; Joshi P.; Tadigadapa S.; Eklund P. C.; Nano Lett. 2006, 6, 2667-2673; Graf D.; Molitor F.; Ensslin K.; Stampfer C.; Jungen A.; Hierold C.; Wirtz L.; Nano Lett. 2007, 7, 238-242; Calizo I.; Balandin A.; Bao W.; Miao F.; Lau C. N.; Nano Lett . ASAP). D (1350 cm −1 ), G (1600 cm −1 ), 2D (2700 cm −1 ), and S3 (2950 cm −1 ) graphitic peaks are present in the spectra of the reduced samples. An increase of the D/G ratio upon reduction of GO is observed, indicating an increase in the total number of graphitic regions present. Residual sp 3 carbons likely contribute to the prominence of the D peak and suggest some unreduced regions. The chemically modified GO materials according to some embodiments of the current invention are the largest graphene samples produced to date and can be readily processed in a reliable, scalable method. This technique is extremely versatile and can be used to create a myriad of coatings and geometries necessary for device applications and a full range of characterization techniques. We believe that the large-scale of these single sheets represents a breakthrough in fabrication and could pave the way for new and innovative experiments on single layer graphene. In addition, the stability of the reduced dispersions can allow a new class of experiments and characterization to be performed in solution. The processing described here, along with current techniques in micro-patterning, makes possible the fabrication of a wide variety of graphene-based devices according to some embodiments of the current invention. The scalable solution process according to some embodiments of the current invention can be suitable for electronic applications, such as field-effect devices, non-volatile memory modules, and the circuits thereof. Electro-chemical applications can include use of graphene as large surface area carbon in (zinc-carbon) batteries, for example. Large area depositions may be immediately implemented as semi-transparent electrodes or anti-static coatings, for example. Graphene suspensions may be combined with a variety of structural polymers, producing composite materials that benefit from enhanced strength and improved electrical properties. Such composites can be especially appropriate for military applications as radar absorbent materials (RAMs), for example. Graphene's sensitivity to chemical environments lends itself naturally to applications in sensors, which could be mass-produced via this solution process. Particularly attractive may biological applications, such as a graphene based, in-situ glucose sensor, for example. Graphene-Carbon Nanotube Hybrid Transparent Conductors Printed transparent conductors using solution-based techniques for patterning and deposition are of great interest as they represent low cost, and high throughput alternatives to conventional thermal evaporation or sputtering. Nevertheless, conventional approaches have several drawbacks. First and foremost, synthesis of such materials typically involves multiple low yield steps. Second, the electrical conductivity is poor, as is chemical and thermal stability. Currently, indium tin oxide (ITO) represents the industry standard for transparent conductors, capable of delivering a sheet resistance of ˜40Ω/□ at 85-90% transmittance. However, several key issues will likely exclude ITO from meeting future challenges. First, the world's production of indium is limited, with recent increases in demand, especially for LCD manufacturing, resulting in a price increase of over ten-fold in just the past five years. The future demand for indium by the solar power industry at grid parity could be tremendous in scale and could readily overwhelm the supply. Second, ITO deposition is an expensive process to scale up because it includes sputtering directly under vacuum conditions. Third, ITO's physical properties are less than ideal, as it is a relatively brittle material and incompatible with the flexible substrates used in most roll-to-roll processes. According to some embodiments of the current invention we provide a facile synthesis of a surfactant free, nano-scale composite comprised of graphene and carbon nanotubes. Methods of production according to this embodiment of the current invention can be high throughput and without suffering the shortcomings of ITO. A feature of this embodiment of the current invention is the use of a single phase synthesis to reduce and disperse a homogenous solution of both chemically converted graphene (CCG) and carbon nanotubes (CNTs). Since their creation in bulk form in 1991, CNTs have delivered high axial carrier mobilities in small-scale devices, making them an obvious choice for use as transparent conductors. High aspect ratios lead to low percolation thresholds, meaning very little material is needed for conduction (Hu, L., Hecht, D. S. & Gruner, G. Percolation in transparent and conducting carbon nanotube networks. Nano Lett. 4, 2513-2517 (2004)). Thus far, CNTs are capable of delivering resistivities around 500Ω/□ at 80˜85% transmittance (Hu, L., Hecht, D. S. & Gruner, G. Percolation in transparent and conducting carbon nanotube networks. Nano Lett. 4, 2513-2517 (2004); Wu, Z. et al. Transparent conductive carbon nanotube film. Science, 305, 1273-1277 (2004); Hu, L., Gruner, G., Li, D., Kaner, R. B. & Cech, J. Patternable transparent carbon nanotube films for electrochromic devices. Journal of Applied Physics, 101, 016102-016104 (2007); Li, J., Hu, L., Wang, L., Zhou, Y., Gruner, G. & Marks, T. J. Organic light-emitting diodes having carbon nanotube anodes. Nano Lett. 6, 2472-2477 (2006); Zhang, D. et al. Transparent, conductive, and flexible carbon nanotube films and their application in organic light-emitting diodes. Nano Lett. 6, 1880-1886 (2006); Ago, H., Petritsch, K., Shaffer, M. S. P., Windle, A. H. & Friend. R. H. Composites of carbon nanotubes and conjugated polymers for photovoltaic devices. Adv. Mater. 11, 1281-1286 (1999); Rowell, M. W. et al. Organic solar cells with carbon nanotube network electrodes. Applied Phys. Lett. 88, 233506-233509 (2006); Pasquier, A. D., Unalan, H. E., Kanwal, A., Miller, S. & Chhowalla, M. Conducting and transparent single-wall carbon nanotube electrodes for polymer-fullerene solar cells. Applied. Phys. Lett. 87, 203511-203513 (2005)). Graphene, a single layer of carbon, has been touted for its potential as an excellent electrical conductor since its experimental discovery in 2004 (Novoselov, K. S. et al. Electric field effect in atomically thin carbon films. Science, 306, 666-669 (2004); Gusynin V. P. & Sharapov S. G. Unconventional integer quantum Hall effect in graphene. Phys. Rev. Lett. 95, 146801-146804 (2005); Zhang, Y., Tan, Y. W., Stormer, H. L. & Kim, P. Experimental observation of the quantum Hall effect and Berry's phase in graphene. Nature 438, 201-204 (2005); Novoselov, K. S. et al. Unconventional quantum Hall effect and Berry's phase of 2pi in bilayer graphene. Nature Physics 2, 177-180 (2006); Novoselov, K. S. et al. Room-temperature quantum Hall effect in graphene. Science 315, 1379 (2007)). Graphene can be conceptually viewed as a CNT cut along its axis and unrolled to lay flat. It can provide conduction pathways to a greater area per unit mass than CNTs, which should translate into improved conductivity at lower optical densities. The challenge has been in scaling up the mechanical cleavage of graphite. Single layer samples are most often the result of a laborious peeling method, which is neither scalable nor capable of producing uniform depositions Watcharotone, S. et al. Graphene-Silica composite thin films as transparent conductors. Nano Lett. 7, 1888-1892 (2007)). Recently, researchers have circumvented the problem of mechanical cleavage by using graphite oxide (GO), a layered compound that can be readily dispersed as individual sheets in a good solvent (I. Jung, D. A. Dikin, R. D. Piner, R. S. Ruoff, Nano Lett. 2008, DOI: 10.1021/n18019938.; Stankovich, S. et al. Synthesis of graphene-based nanosheets via chemical reduction of exfoliated graphite oxide. Carbon 45, 1558-1565 (2007); Hummers, W. S. & Offeman, R. E. Preparation of graphitic oxide. J. Am. Chem. Soc. 80, 1339 (1958); Gilje, S., Han, S., Wang, M. S., Wang, K. L. & Kaner, R. B. A chemical route to graphene for device applications. Nano lett. 7, 3394-3398 (2007); Gomez-Navarro, C. et al. Electronic transport properties of individual chemically reduced graphene Oxide Sheets. Nano lett. 7, 3499-3503 (2007); Li, X., Wang, X., Zhang, L., Lee, S. & Dai, H. Chemically derived, ultrasmooth graphene nanoribbon semiconductors. Science, 319, 1229-1232 (2008); Tung, V. C., Allen, M. J., Yang, Y. & Kaner, R. B. High throughput solution processing of large scale graphene. Nature Nanotech . doi:10.1038/nnano.2008.329; Li, D., Mueller, M. B., Gilje, S., Kaner, R. B. & Wallace, G. G. Processable aqueous dispersion of graphene nanosheets. Nature Nanotech. 3, 101-106 (2008); Hernandez, Y. et al. High-yield production of graphene by liquid-phase exfoliation of graphite. Nature Nanotech. 3, 563-568 (2008)). Although GO itself is not electrically conductive, the conjugated network may be restored upon reduction in hydrazine vapor or with high heat after deposition. However, both reduction methods have their drawbacks, as high temperatures are incompatible with flexible substrates (e.g. polyethylene terephthalate—PET) and hydrazine vapors are only able to access and reduce the outer surface of deposited films. Other reduction methods, such as NaBH 4 , phenyl hydrazine, and KOH in aqueous solution, have been suggested. However, incomplete reduction or large aggregates are often observed. Hence, the resulting graphitic regions are limited, which is detrimental to carrier transport and conductivity. Films of vapor phase reduced GO were reported recently and displayed poor conductivity i.e. 10 4 -10 5 Ω/□ at 80% transmittance (Li, X. et al. Highly conducting graphene sheets and Langmuir-Blodgett films. Nature Nanotech. 3, 538-542 (2008); Wang, X., Zhi, L. & Mullen, K. Transparent, conductive graphene electrodes for dye-sensitized solar cell. Nano Lett. 8, 323-327 (2008); Wang, X. et al. Transparent carbon films as electrodes in organic solar cells. Angew. Chem. Int. Ed. 47, 1-4 (2008); Eda, G., Fanchini, G. & Chhowalla, M. Large-area ultrathin films of reduced graphene oxide as a transparent and flexible electronic matrial. Nature Nanotech. 3, 270-274 (2008); Becerril, H. et al. Evaluation of solution-processed reduced graphene oxide films as transparent conductors. ACS Nano 2, 463-470 (2008); Wu, J. et al. Organic solar cells with solution-processed graphene transparent electrodes. Applied Phys. Lett. 92, 263302-263304 (2008)). Attempts to combine CNTs and CCG in a single layer have also been reported, but the resulting films were too thick for optical applications (Cai, D., Song, M. & Xu, C. Highly conductive carbon-nanotube/graphite oxide hybrid films. Adv. Mater. 20, 1706-1709 (2008); Yu, A. et al. Enhanced thermal conductivity in a hybrid graphite nanoplatelet-carbon nanotube filler for epoxy composites. Adv Mat, DOI: 10.1002/adma.200800401). By combining CNTs and CCG in a single layer, the conductivity compared to CNTs films can be enhanced, while sacrificing little in transparency, according to some embodiments of the current invention. Our approach according to some embodiments of the current invention uses hydrazine to disperse and reduce graphite oxide enabling the deposition of uniform films on almost any substrate by spin-coating, as described above. This method can produce more complete restoration of the graphitic network as compared to the analogous vapor phase process, which translates into more highly conductive films. Adding CNTs to our hydrazine suspensions of CCG now enables the deposition of thin and uniform layers of the hybrid material. To this end, graphite oxide was first synthesized and purified using Hummers method (see above). The resulting dry graphite oxide powders were dissolved in DI water with the assistance of ultrasonication. The stable dispersion was filtered through an alumina membrane and left to dry for several days. Once dried, the graphite oxide paper was carefully peeled from the filter and stored under ambient conditions. In order to enhance the solubility, CNTs were refluxed in a mixture of nitric acid and sulfuric acid to activate the surface with oxygen functionalities. As a result, most of the CNTs are terminated with hydroxyl and carboxylic moieties. After refluxing for 24 hrs, the resulting black dispersion was filtered and washed repeatedly with a combination of DI water and ethanol as shown in FIG. 6 . To produce hybrid suspensions of CCG and CNTs (referred to also as G-CNT), dry powders of GO and slightly oxidized CNTs were dispersed directly in anhydrous hydrazine and allowed to stir for 1 day. Hydrazine bubbles violently upon contact with the carbon powders, but soon forms a uniform dark-gray suspension with no visible solids remaining. A range of compositions were achieved following this protocol, with GO and CNT concentrations observed up to at least 1 mg/mL. A post-treatment process combining ultra-sonication and centrifugation can be used to vary the composition of the dispersions before deposition. To our knowledge this is the first report of dispersing CNTs in anhydrous hydrazine. This is an important observation as it provides a route to deposition that does not involve the use of surfactants, which typically degrade electrical performance. For the stable dispersion of CNTs in hydrazine, we suggest the formation of hydrazinium compounds comprised of negatively charged CNTs surrounded by N 2 H 4 + counter-ions. Such hydrazinium compounds are known to readily disperse in hydrazine (Mitzi, B. D., Copel, M. & Chey, S. J. Low-voltage transistor employing a high-mobility spin-coated chalcogenide semiconductor. Adv Mater. 17, 1289-1293 (2005)). The mechanism for hydrazine reduction of the CNTs is not entirely understood, but is consistent with our observations of gas evolution upon contact. Unlike CNTs suspensions in organic solvents, CNTs and G-CNT dispersions in hydrazine are stable for months with little aggregation as shown in FIG. 7 b . Moreover, UV/Vis spectra were carried out to characterize the dispersions. Solutions prepared using 1 mg graphene, 10 mg CNTs and a combination of the two were directly dispersed into anhydrous hydrazine. Prior to characterization, ultra-sonication was used to ensure a stable dispersion. Typically, CNTs exhibit a C m 1 to V m 1 absorption band at 650 nm within the van Hove singularities, whereas graphene displays a broad absorption band (Li, D., Mueller, M. B., Gilje, S., Kaner, R. B. & Wallace, G. G. Processable aqueous dispersion of graphene nanosheets. Nature Nanotech. 3, 101-106 (2008); Holzinger, M. et al. Fictionalization of single-walled carbon nanotubes with (R-) oxycarbonyl nitrenes. J. Am. Chem. Soc. 124, 8566-8580 (2003)). The spectra suggest that the electronic structures of both graphitic materials have been largely preserved due to the presence of the characteristic absorption bands. Note that the formation of covalent bonding could be detrimental to the intrinsic electronic conductivity. Nonetheless, the G-CNT composites showed red shifts in their absorbance spectra. The shift of the absorbance band can be attributed to strong π-π interactions between graphene and CNTs. If one wishes to avoid spin-coating from a solvent of hydrazine's toxicity, the hydrazinium complexes can also be dried and re-suspended in DMSO, DMF and THF before deposition (Tung, V. C., Allen, M. J., Yang, Y. & Kaner, R. B. High throughput solution processing of large scale graphene. Nature Nanotech. doi: 10.1038/nnano.2008.329). G-CNT dispersions were readily deposited onto a variety of substrates by spin-coating and subsequently heated to 150° C. to remove excess solvent. Note that the modest temperature of this post-treatment is fully compatible with flexible substrates, especially in contrast to previously explored procedures used for GO electrodes. The present synthesis is facile and can provide the following advantages according to some embodiments of the current invention: (i) one phase reaction without additional surfactants, (ii) the homogeneity and composition of films is simply determined by composition of the parent suspension, spin-coating parameters (speed and duration), and surface modification of the substrate, (iii) relatively inexpensive starting materials, and (iv) high throughput patterning over large area. The initial characterization of depositions was carried out by examination with a scanning electron microscope (SEM). FIG. 7 a provides an SEM image of one such deposited film according to an embodiment of the current invention. These images are used primarily to determine structural information for hybrid films, and to understand the effects of different coating conditions. We explored a myriad of spin speeds and durations as well as surface modification of substrates via an O 2 plasma treatment. The image presented shows the percolating network of intertwined graphene and CNTs common to most films according to this embodiment of the current invention. Good contrast in SEM can be difficult to obtain, with relatively low accelerating voltages (1.5-3.0 kV) and probe currents (5-8 μA) delivering the best results on 300 nm Si/SiO 2 substrates. Although SEM images can be used to understand generally the morphology of the films, they are not accurate representations of topography. Hence, we employed atomic force microscopy (AFM) to establish the thickness and surface roughness of the depositions. FIG. 8 shows representative AFM images for single component films, (a) CNTs and (b) graphene, as well as for the (c) hybrid. The hybrid film is approximately 5 nm thick, and exhibits a rough surface covered with CNT bundles/ropes. These bundles are problematic for device fabrication as they often protrude up through the active layers and cause shorting. In order to improve this roughness, G-CNT dispersions were sonicated for 90 minutes prior to deposition. This treatment was sufficient to break up the CNT bundles and remove the troublesome protrusions, reducing the r.m.s. surface roughness to ˜1.9 nm as shown in FIG. 8 d. Once we achieved the desired surface roughness, G-CNT films were deposited on glass substrates and further characterized by UV/Visible spectroscopy at normal incidence. Spin-speed had the most direct effect on transmittance, as evident in the photographs and spectra presented in FIG. 9 . As expected, higher spin-speeds delivered thinner films that were more optically transparent, with those deposited at 1,050, 1,250, 1,500 and 1,750 RPMs displaying optical transmittances of 58, 70, 87, and 92%, respectively. Note that compared with electrodes comprised of graphene only, the addition of CNTs does not appear to significantly increase the overall absorbance. Four-point sheet resistance measurements were made on the same devices after deposition of small gold fingers. FIG. 9 c shows the relationship between spin-speed and sheet resistance. Again the observed relationship is consistent with expectations, with higher spin-speeds delivering less material and hence fewer conduction pathways. As shown in the figures, the film deposited at 1,750 RPMs showed optical transmittance of 92% and a sheet resistance of only 636Ω/□. This sheet resistance is nearly 4 orders of magnitude lower than the analogous vapor reduced GO films reported previously (˜1 M Ω/□ and 80˜85% transmittance). Control experiments were also performed on single component CNTs and graphene films deposited from hydrazine, which reveal sheet resistances of 22 kΩ/□ and 980 kΩ/□, respectively. To explain the vast improvement in sheet resistance, we suggest the formation of an extended conjugated network with individual CNTs bridging the gaps between graphene sheets. The large graphene sheets cover the majority of the total surface area, while the CNTs act as wires connecting the large pads together. CNTs electrodes consistently outperform ITO on flexible substrates. The nanoscale architecture of intertwined CNTs is not significantly affected by bending on the macro-scale because the radius of curvature is so much larger than a single tube. In contrast, ITO's rigid inorganic crystal structure develops hairline fractures upon bending, which are quite detrimental to the overall electrical performance. To investigate the flexibility of G-CNT electrodes, hydrazine solutions were spin-coated directly on PET substrates. For the densest film, a resistance as low as 44Ω/□ was observed at 55% transmittance after chemical doping. The film's low transmittance is attributed to suboptimal surface morphology. FIGS. 9 d and 9 e presents the current-voltage characteristics before and after bending of the G-CNT film and a standard ITO on PET electrode for reference. After bending to 60 degrees more than ten times, resistance of the brittle ITO film increased by 3 orders of magnitude, while the G-CNT electrode remained nearly unchanged. Although G-CNT films perform well during electrical characterization, it is important to understand the feasibility of incorporating this new material in actual optical electronic devices. To this end, we used G-CNT films as a platform for the fabrication of P3HT:PCBM photovoltaic devices. To fabricate the devices, the pre-cleaned glass substrates were subjected to O 2 plasma to activate the surface. Subsequent to surface treatment, the hydrophilic substrates were brought into contact with PDMS stamps used for patterning the electrode area. A variety of electrode patterns can be achieved by PDMS with different relief structures as shown FIG. 10 a . Typically, a mixture of 1 mg/ml graphene and 10 mg/ml CNTs were used for spin-coating. The electrodes used were coated on glass and exhibited sheet resistances around 600Ω/□ at 87% transmittance. The device structure included a thin PEDOT:PSS buffer layer followed by a 2% 1:1 wt. ratio of P3HT:PCBM spin-coated and “slow-grown” from dichlorobenzene (Li, G. et al. High-efficiency solution processable polymer photovoltaic cells by self-organization of polymer blends. Nature Materials, 4, 864-868 (2005)). Finally, thermal evaporation of Al and Ca provided the reflective cathode. Similar devices have been reported using vapor reduced GO as the bottom electrode, but high resistivity was detrimental to solar cell performance, i.e. reduced short circuit current (Jsc) and fill factor (FF) resulted in a power conversion efficiency (PCE) of 0.2% (Eda, G., Fanchini, G. & Chhowalla, M. Large-area ultrathin films of reduced graphene oxide as a transparent and flexible electronic matrial. Nature Nanotech. 3, 270-274 (2008); Eda, G. et al. Transparent and conducting electrodes for organic electronics from reduced graphene oxide. Applied Phys. Lett. 92, 233305-233308 (2008)). The device structure and performance characteristics of our PV devices in this example are presented in FIG. 10 b . With a device area of 4 mm 2 , power conversion efficiency (PCE) of 0.85% was measured under illumination of 1.5 AM. The Jsc, Voc, and FF were 3.47 mA/cm 2 , 0.583 V, and 42.1% respectively. The low Jsc and FF are detrimental to PCE and likely due to poor contact at the interface between G-CNT and the polymer blend. Further engineering of the electrode morphology will likely improve the diode properties of these devices, and lead to higher PCEs. That said, the performance of these proof-of-concept devices far exceeds those previously reported and are encouraging the development of G-CNT electrodes. Chemical doping has been widely explored as an effective method for increasing the conductivity of CNT electrodes (Rowell, M. W. et al. Organic solar cells with carbon nanotube network electrodes. Applied Phys. Lett. 88, 233506-233509 (2006); Pasquier, A. D., Unalan, H. E., Kanwal, A., Miller, S. & Chhowalla, M. Conducting and transparent single-wall carbon nanotube electrodes for polymer-fullerene solar cells. Applied. Phys. Lett. 87, 203511-203513 (2005); Eda, G. et al. Transparent and conducting electrodes for organic electronics from reduced graphene oxide. Applied Phys. Lett. 92, 233305-233308 (2008); Dettleff-Weglikowska, U. et al. Effect of SOCl 2 treatment on electrical and mechanical property of single-wall carbon nanotube networks. J. Am. Chem. Soc 127, 5125-5131 (2005)). Simple treatment with SOCl 2 vapor is often employed as a means of anion doping and does not significantly affect the optical transmittance of CNT films. We used a similar method for this hybrid system by exposing as deposited G-CNT films to SOCl 2 vapors after spin-coating. The sheet resistance before and after treatment is recorded in FIG. 11 . An exposure of 15 minutes to room temperature SOCl 2 vapors resulted in a decrease in sheet resistance by a factor of 1.5 to 2 for all deposited films. The sheet resistance for the 1,750 RPM film was reduced from 636Ω/□ to 240Ω/□ after doping, while transmittance dropped only slightly from 92 to 91%. To confirm the mechanism of anion doping, similar experiments were performed using I 2 vapors and delivered comparable results. These initial doping experiments indicate that further improvements are likely. According to some embodiments of the current invention, we provide a competitive synthesis approach using a hybrid layer of carbon nanotubes and chemically converted graphene. This technology can be facile, inexpensive, and massively scalable and does not suffer from the shortcomings of ITO. We present conductivity and optical data according to some examples demonstrating comparable performance to the ITO used in flexible applications, 440Ω/□ at 87% transmittance, and also proof-of-principle application in a polymer solar cell with power conversion efficiency (PCE) of 0.85%. Chemical doping show that optimization of this material is not limited to improvements in layer morphology. This versatile material may provide an appropriate transparent electrode for optical electronics. Transfer Printing As described above, graphite oxide was isolated and subsequently dispersed directly in anhydrous hydrazine according to some embodiment of the current invention. Carbon nanotubes can also be added to the hydrazine according to some embodiments of the current invention. These methods utilize hydrazine both as a reducing agent and as a solvent according to some embodiment of the current invention. Suspensions in hydrazine have been shown to preserve the integrity of large sheets and tend not to aggregate according to some embodiment of the current invention. After modification by dilution, centrifugation, or ultrasonication, we are able to obtain a variety of controllable surface coverage, almost 95% single sheets in some examples. Prepared depositions were quite uniform, and allow for a range of both densities and sheet sizes. Subsequent to deposition, a transfer printing process enables us to selectively register regions of graphene to designated areas of another substrate. The non-destructive printing process is capable of defining small features and transfering depositions to precise positions on a wafer scale (Chabinyc, M. L.; Salleo, A.; Wu, Y.; Liu, P.; Ong, B. S.; Heeney, M.; McCulloch, I. Lamination Method for the Study of Interfaces in Polymeric Thin Film Transistors J. Am. Chem. Soc. 2004, 126, 13928-13929; Arias, A. C.; Ready, S. E.; Lujan, R.; Wong, W. S.; Paul, K. E.; Salleo, A.; Chabinyc, M. L.; Apte, R.; Street, R. A.; Wu, Y.; Liu, P.; Ong, B. All jet-printed polymer thin-film transistor active-matrix backplanes. Appl. Phys. Lett. 2004, 85, 3304-3306; Kawase, T.; Sirringhaus, H.; Friend, R. H.; Shimoda, T. Inkjet Printed Via-Hole Interconnections and Resistors for All-Polymer Transistor Circuits Adv. Mater. 2001, 13, 1601-1605; Lefenfeld, M.; Blanchet, G.; Rogers, J. High-Performance Contacts in Plastic Transistors and Logic Gates That Use Printed Electrodes of DNNSA-PANI Doped with Single-Walled Carbon Nanotubes Adv. Mater. 2003, 15, 1188-1191; Chabinyc, M. L.; Wong, W. S.; Salleo, A.; Kateri, E. P.; Street, R. A. Organic polymeric thin-film transistors fabricated by selective dewetting. Appl. Phys. Lett. 2002, 81, 4260-4262). Through this combination of control over hydrazine dispersions, deposition characteristics, and transfer printing, we here demonstrate the first wafer-scale patterning of graphene according to some embodiments of the current invention. The transfer mechanism according to some embodiments of the current invention is based on the differing strengths of non-covalent adhesion between the PDMS-graphene and graphene-substrate interfaces. For most materials, the PDMS interface is weaker than the substrate interface, due to the extremely low surface energy of PDMS (19.8 mJ/m 2 ) (Hur, S.-H.; Khang, D.-Y.; Kocabas, C.; Rogers A. J. Nanotranser printing by use of Noncovalent surface forces: applications to thin film transistors that us single walled carbon nanotube networks and semicondcting polymers. Appl. Phys. Lett. 2004, 85, 5730-5733). Transferring of single sheet specimens by a PDMS stamp is depicted in FIG. 12 . The process according to some embodiments of the current invention begins by spin-coating hydrazine suspensions onto an oxygen plasma treated glass substrate, followed by a thermal annealing process to remove solvent and hydrazinium cations. An optical image of the resulting deposition on glass is provided on the right-hand side of FIG. 12 a. Glass substrates were brought into contact with a patterned PDMS as shown in FIG. 12 b . In this case, the stamp was designed with three raised rectangles. Proper pressure was used to ensure intimate contact, which was maintained for 2 minutes for complete transfer. The hydrophobic surface of pristine PDMS interacts more strongly with graphene than does the initial glass substrate, which allows transfer to take place. Graphene registered PDMS stamps were then quickly peeled from the glass substrate. An optical image after peeling clearly shows that material has been removed in the rectangular areas of contact ( FIG. 12 b , right). “Inked” stamps were next carefully brought into contact with 300 nm Si/SiO 2 substrates ( FIG. 12 c ). A contact time of several days was necessary to fully transfer single sheets from PDMS to Si/SiO 2 substrates at room temperature. Transfer proceeds as low molecular weight oligomers are dissociated from the surface of the stamp over time, releasing the graphene sheets (Briseno, A. L.; Roberts, M.; Ling, M.-M.; Moon, H.; Nemanick, E. J.; Bao, Z. Patterning organic semiconductors using “dry” poly(dimethylsiloxane) elastomeric Stamps for thin film transistors. J. Am. Chem. Soc. 2004, 126, 13928-13929; Glasmastar, K.; Gold, J.; Andersson, A.; Sutheland, D. S.; Kasemo, B. Silicone Transfer during microcontact printing. Langmuir 2003, 19, 5475-5483; Li, X.-M.; Peter, M.; Huskens, J.; Reinhoudt, D. N. Catalytic microcontact printing without ink. Nano lett. 2003, 3, 1449-1453). With the assistance of heat, oligomers are more quickly dissociated from the PDMS stamp, allowing full transfer in 2h at 50° C. and 30 min at 75° C. Heating also facilitates reorientation and segmental motion, which further weakens the interface between graphene and PDMS. The stamp is finally removed from the Si/SiO 2 substrate, leaving behind the rectangular pattern of graphene as shown in bright-field ( FIG. 12 c , right) microscope images. Characterization of Transfer Although the initial characterization of a deposition was carried out optically, more sophisticated techniques are necessary to understand the extent to which transfer has taken place. FIG. 13 presents optical images and the corresponding G band Raman intensity maps of both the glass ( FIG. 13 a ) and Si/SiO 2 ( FIG. 13 b ) substrates used during the transfer process. The G band at 1584 cm −1 results from the E 2g vibrational mode in graphene and is not observed on a clean Si/SiO 2 surface (Ferrari, A. C.; Meyer, J. C.; Scardaci, V.; Casiraghi, C.; Lazzeri, M.; Mauri, F.; Piscanec, S.; Jiang, D.; Novoselov, K. S.; Roth S.; Geim, A. K.; Raman spectrum of Graphene and graphene layers. Phys. Rev. Lett. 2006, 97, 87401-187404; Tuinstra, F.; Koenig, J. L.; Raman spectrum of graphite. J. Chem. Phys. 1970, 53, 1126-1130; Gupta, A.; Chen, G.; Joshi, P.; Tadigadapa, S.; Eklundi, P. C.; Raman scattering from high-frequency phonons in supported n-graphene layer films. Nano Lett. 2006, 6, 2667-2673; Graf, D.; Molitor, F.; Ensslin, K.; Stampfer, C.; Jungen, A.; Hierold, C.; Wirtz, L.; Spatially Resolved raman spectroscopy of single- and few-layer graphene. Nano Lett. 2007, 7, 238-242). A G band intensity map for the glass substrate ( FIG. 13 a ) clearly shows that graphitic materials have been almost completely removed from the rectangular region that contacted the PDMS stamp. The removed region has well defined borders, including a nearly right angle at the upper right-hand side. A G band intensity map for the Si/SiO 2 substrate ( FIG. 13 b ) indicates a well-defined rectangular region of transferred graphitic material, closely resembling the PDMS stamp features. Removal of PDMS Residue Although they are not visible in the Raman spectra, our understanding of the PDMS transfer process suggests that there are likely dimethylsiloxane oligomers deposited along with graphene. This is often the case with transfer printing, but could represent a problem for subsequent fabrication techniques (Glasmastar, K.; Gold, J.; Andersson, A.; Sutheland, D. S.; Kasemo, B. Silicone Transfer during microcontact printing. Langmuir 2003, 19, 5475-5483; Li, X.-M.; Peter, M.; Huskens, J.; Reinhoudt, D. N. Catalytic microcontact printing without ink. Nano lett. 2003, 3, 1449-1453). In order to remove oligomers, we thermally annealed the deposited material at 400° C. for 1 hour. FIG. 14 shows Si 2p (top) and C 1s (bottom) XPS spectra from the deposited region both before and after annealing. The Si peak is predominately Si/SiO 2 , but displays a large shoulder consistent with dimethylsiloxane before the annealing process. The shoulder was nearly gone after heating at 100° C. and entirely removed after annealing at 400° C. for 1 hour, indicating complete removal of PDMS residue. The shift of peaks identified as SiO 2 at 104.4 eV and PDMS at 102.6 eV is attributed to a charging effect by the thick insulating layer of SiO 2 (300 nm) (Glasmastar, K.; Gold, J.; Andersson, A.; Sutheland, D. S.; Kasemo, B. Silicone Transfer during microcontact printing. Langmuir 2003, 19, 5475-5483). The carbon signal does not change before and after the process, an indication that annealing did not alter the deposited graphene. If anything, the heat treatment may increase the graphitization of single sheets, as has been indicated by other groups (Becerril, H.; Mao, J.; Liu, Z.; Stoltenberg, R.; Bao, Z.; and Chen, Y.; Evaluation of solution-processed reduced graphene oxide films as transparent conductors. Nano ASAP). Characterization of Single Sheets The electrical properties of deposited materials were confirmed by the fabrication of field-effect devices. Briefly, gold electrodes were patterned via a conventional photolithographic lift-off process, with electrode separation lengths of 7 microns. Optical images of the fabricated devices are provided at 10× and 20× magnification in FIGS. 15 a and 15 b , respectively. After evaporation, an SEM was used to identify single sheet devices as depicted in FIG. 15 c . Gate voltages were supplied via the Si substrate, providing I SD -V SD characteristics as depicted in FIG. 15 e . As shown in the figure, deposited graphene materials increase in conductivity under negative gating conditions, indicating p-type behavior. FIG. 15 f shows a transfer curve (I SD -V G ) collected at a V SD of 100 mV. These observations agree well with others of chemically derived graphene. Atomic force microscopy (AFM) was also used to confirm the edge step heights of graphene sheets. FIG. 16 shows an AFM image collected in tapping mode and a corresponding line-scan, which indicates a step height of less than 1 nm. Although the theoretical thickness of pristine graphene is 0.34 nm, measurements rarely approach this number even in ultra-high vacuum settings (Gomez-Navarro, C.; Weitz, R. T., Bittner, A. M.; Scolari, M.; Mews, A.; Burghrd, M.; Kern, K. Electronic transport properties of individual chemically reduced graphene Oxide Sheets Nano lett. 2007, 7, 3499-3503; Gilje, S.; Han, S.; Wang, M. S.; Wang, K. L.; Kaner, R. B.; A chemical route to graphene for device applications. Nano lett. 2007, 7, 3394-3398; Gomez-Navarro, C., Weitz R., Bittner, A. M., Scolari, M., Mews A., Burghard, M, and Kern, K. Electronic Transport Properties of Individual Chemically Reduced Graphene Oxide Sheets Nano lett. 2007, 7, 3499-3503). In our case, AFM images were collected under ambient conditions, where adsorbed water and gas molecules typically result in step heights around 1 nm for both pristine and chemically derived graphene. EXPERIMENTAL Preparation of Graphene Dispersions Graphite oxide (GO) was prepared from graphite powder via the Hummer's method. Resultant dispersions were 2% w/v in water and diluted to 1 mg/L for use. GO was then filtered through a 0.22 micron alumina membrane in order to create a thin film, which was allowed to dry for 24 hours under ambient conditions and then carefully peeled from the membrane. The GO film was matte black in color and physically robust. Elemental analysis was performed at this stage, yielding a C:O:N ratio of approximately 4:3:0. A small piece of the GO film (˜1 mg) was transferred into a nitrogen filled dry box, and added to 1 mL of anhydrous hydrazine for reduction and dispersion. Upon contact, a gaseous product was seen bubbling from the surface of the film, likely N 2 evolved during the reduction process. During this bubbling, the film could be seen breaking down and the hydrazine underwent a change from clear to a dark black color, indicating the dispersion of reduced graphite oxide. The hydrazine dispersions likely contain hydrazinium graphene (HG) due to the formation of a counter-ion pair during reduction (Mitzi B. D.; Copel M.; Chey S. J.; Low-Voltage Transistor Employing a High-mobility spin-coated chalcogenide semiconductor. Adv Mater. 2005, 17, 1289-1293). After 24 hours of stirring, no residual film could be observed. Elemental analysis of HG was performed by evaporating the solvent under streaming nitrogen, producing a dry, shiny black material that yielded a C:O:N ratio of approximately 8:1:1.5. HG dispersions were stable and allowed to stir for up to several months in a covered vial before deposition. Further treatment of HG suspensions was carried out just before spin-coating, and differed according to the desired level of surface coverage. A Heraeus Labofuge 400 was used for centrifugation, which removed any aggregates prior to spin-coating. Sonication was carried out using a VWR model 250D sonicator set at level 9 for 10 min. Preparation of Films Si/SiO 2 substrates were cleaned in piranha solution and pre-treated for 2 minutes by an oxygen plasma in order to ensure good wetting by hydrazine. Substrates were transferred into the dry box and spin-coated within 15 minutes of this pre-treatment. After deposition, films were baked to 115° C. to remove residual hydrazine and then to 350° C. in order to remove hydrazinium ions. Elemental analysis carried out on the final material produced a C:O:N ratio of 12:1:0.7, confirming the removal of nitrogen-containing species. In describing embodiments of the invention, specific terminology is employed for the sake of clarity. However, the invention is not intended to be limited to the specific terminology so selected. The above-described embodiments of the invention may be modified or varied, without departing from the invention, as appreciated by those skilled in the art in light of the above teachings. It is therefore to be understood that, within the scope of the claims and their equivalents, the invention may be practiced otherwise than as specifically described.	A method of producing carbon macro-molecular structures includes dissolving a graphitic material in a solvent to provide a suspension of carbon-based macro-molecular structures in the solvent, and obtaining a plurality of the carbon macro-molecular structures from the suspension. The plurality of carbon macro-molecular structures obtained from the suspension each consists essentially of carbon. A material according to some embodiments of the current invention is produced according to the method of producing carbon macro-molecular structures. An electrical, electronic or electro-optic device includes material produced according to the methods of the current invention. A composite material according to some embodiments of the current invention has carbon macro-molecular structures produced according to methods of producing carbon macro-molecular structures according to some embodiments of the current invention. A hydrogen storage device according to some embodiments of the current invention has carbon macro-molecular structures produced according to methods of producing carbon macro-molecular structures according to some embodiments of the current invention. An electrode according to some embodiments of the current invention has carbon macro-molecular structures produced according to methods of producing carbon macro-molecular structures according to some embodiments of the current invention.	2
PRIORITY CLAIM This application is a continuation of U.S. patent application Ser. No. 10/566,669 entitled “FREEWHEEL BEARING DEVICE WITH TORQUE LIMITER” filed on Oct. 23, 2006. BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to the field of bearings comprising a unidirectional clutch or freewheel, usually interposed between an inner element and an outer element. 2. Description of the Relevant Art The freewheel makes it possible to transmit a torque in one direction and to allow a relative rotation in the other direction. A bearing may also be interposed between the inner element and the outer element to support radial and, where necessary, axial loads. Document FR A 2 726 059 describes a device of this kind. Also known is document GB-A-2 259 962 which describes a torque limiter making it possible to limit the torque to different values depending on the direction of rotation of one race relative to the other race, by means of friction balls in one direction and a spring in the other direction. However, this torque limiter is structurally and functionally different from a freewheel, because the free rotation of one race relative to the other race is not possible. It would be beneficial to limit the torque transmitted by a freewheel when the freewheel is in a locked position, particularly to reduce the stresses sustained by other mobile elements, and reduce their fatigue. Document FR A 2 615 568 describes a freewheel starter drive comprising a torque limiter. Such a drive is however relatively bulky. SUMMARY OF THE INVENTION The freewheel bearing device described herein proposes to limit the torque transmitted by a freewheel in a simple and compact manner. Described herein is a freewheel device with torque limiter that is easy to transport and handle and incorporate into a mechanical assembly. The freewheel device, according to one embodiment, is of the type including an outer element, an inner element placed in the outer element, and a freewheel provided with at least one jamming element, placed between the inner element and the outer element to leave free a rotation movement in one direction between the outer element and the inner element and to transmit a torque in the other direction between the outer element and the inner element. The freewheel includes a race provided with an inner cylindrical surface and an outer cylindrical surface, substantially aligned on a radial plane perpendicular to the axis of rotation of the device, and a torque limiter member capable of limiting the torque transmitted by the freewheel, the torque limiter member being placed radially between said race and the outer element or the inner element in contact with said race and said element. A slipping raceway may be formed on the inner cylindrical surface or the outer cylindrical surface, the torque limiter member being placed in contact with the outer cylindrical surface or the inner cylindrical surface respectively. The freewheel and the torque limiter member are thus linked in a manner requiring little space. Any type of known freewheel with tilting cams, rollers, spring or pawl may be used. In one embodiment, the torque limiter member is mounted in series with the freewheel to limit the torque transmitted by the unidirectional engagement member in the torque transmission position. In one embodiment, the torque limiter member includes at least one friction element. The friction element may include a radial friction surface. The friction element may include an axial friction surface delimited by two radial planes. In one embodiment, the device includes a bearing allowing the outer element to rotate relative to the inner element. The bearing may be a rolling bearing. Raceways for the rolling elements of said bearing are arranged in the inner and outer elements. Alternatively, the raceways are arranged in inner and outer races fixedly attached to the inner and outer elements. In one embodiment, the torque limiter member is placed on an outer surface of the freewheel. In another embodiment, the torque limiter member is placed in a bore of the freewheel. In one embodiment, the torque limiter member includes an open elastic ring provided with an outer friction surface and an inner friction surface. The ring may be made of steel sheet and may have a U-channel provided with two axial flanges. In one embodiment, the torque limiter member includes a plurality of elastic friction tongues. In another embodiment, the torque limiter member includes an elastic ring made of synthetic material provided with an outer or inner friction surface and a respectively inner or outer attachment surface. In one embodiment, the torque limiter member includes at least one friction ring and an elastic washer for placing the friction ring bearing axially on a friction surface. The torque limiter member may include two friction rings between which said elastic washer is mounted. The friction rings may have radial friction surfaces. In one embodiment, the torque limiter member includes a body in the shape of an open ring. The race of the freewheel and the body of the torque limiter member may be a single element whose outer surface is in friction contact with the outer element in the case of angular rotation, and whose inner surface interacts with the jamming element, or whose inner surface is in friction contact with the inner element in the case of angular rotation, and whose outer surface interacts with the jamming element. In one embodiment, the torque limiter member also includes an elastic element for prestressing said body. The elastic element may be a ring of the circlip type. In one embodiment, the freewheel includes a spring provided with an end fixedly attached to the torque limiter member and coils in friction contact on the inner or outer element. In one embodiment, the jamming elements of the freewheel are cams, rollers or pawls. In one embodiment, the torque limiter member includes a friction element and an element for prestressing the friction element against said race and/or the outer element or the inner element. More particularly, the friction element may be prestressed between said race and the outer element, between said race and the inner element, between two surfaces fixedly attached to the outer element, or else between two surfaces fixedly attached to the inner element. The prestress element is advantageously a piece separate from the friction element. In one embodiment, the torque limiter member is prestressed between two separate pieces in opposite directions. More particularly, the torque limiter member may be prestressed radially outward against the outer element and radially inward against said race, radially outward against said race and radially inward against the inner element, or axially against two opposite surfaces fixedly attached to the outer element or the inner element. “Freewheel” as used herein refers to a device for transmitting a torque in one direction and a relative rotation in the other direction, with, where necessary, a negligible residual drag torque in normal operating conditions between an input element and an output element of the device. Advantages of the freewheel bearing devices described herein include that the space requirement of the device is limited and it has the shape of a compact, preassembled cartridge relatively well protected against the outer elements. The lifetime of the moving parts upstream and downstream of the freewheel is lengthened thanks to the smoothing of the torque peaks, hence more economical running and a reduced risk of breakage. BRIEF DESCRIPTION OF THE DRAWINGS The invention will be better understood on studying the detailed description of several embodiments taken as nonlimiting examples and illustrated by the appended drawings in which: FIG. 1 is a view in axial section of a freewheel device according to a first embodiment of the invention; FIG. 2 is a detail view of FIG. 1 ; FIG. 3 is a view in cross section along a plane passing through the jamming elements of the device of FIG. 1 ; FIG. 4 is a detail view of FIG. 3 ; FIG. 5 is a view in axial section of a freewheel device according to a second embodiment of the invention; FIG. 6 is a detail view of FIG. 5 ; FIG. 7 is a view in axial section of a freewheel device according to a third embodiment; FIG. 8 is a view in axial section of a freewheel device according to a fourth embodiment of the invention; FIG. 9 is a detail view of the freewheel device of FIG. 8 taken in cross section along a plane passing through the jamming elements; FIG. 10 is a detail view of FIG. 8 ; FIG. 11 is a view in axial section of a freewheel device according to a fifth embodiment of the invention; FIG. 12 is a detail view of the freewheel device of FIG. 11 taken in cross section along a plane passing through the jamming elements; FIG. 13 is a detail view of FIG. 11 ; FIG. 14 is a view in section along XIV-XIV of FIG. 15 of a freewheel device according to a sixth embodiment of the invention; FIG. 15 is a view in section along XV-XV of FIG. 14 ; and FIG. 16 is a detail view of FIG. 15 . While the invention is susceptible to various modifications and alternative forms, specific embodiments thereof are shown by way of example in the drawings and will herein be described in detail. It should be understood, however, that the drawing and detailed description thereto are not intended to limit the invention to the particular form disclosed, but on the contrary, the intention is to cover all modifications, equivalents and alternatives falling within the spirit and scope of the present invention as defined by the appended claims. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS As can be seen in FIGS. 1 to 4 , the freewheel device, reference number 1 in its entirety, includes a tubular sleeve 2 with its axis 3 , a rolling bearing 4 mounted on the sleeve 2 , an outer element 5 mounted on the rolling bearing 4 , a freewheel 6 mounted on the sleeve 2 and a friction element 7 mounted between the outer element 5 and the freewheel 6 . The sleeve 2 includes a bore 2 a , a transverse radial surface 2 b , an outer cylindrical surface 2 c extending over the major part of its length from the end radial surface 2 b , a radial surface 2 d extending toward the outside from the end of the outer cylindrical surface 2 c , a short axial surface 2 e extending from the free end of the radial portion 2 d , axially opposite the end radial surface 2 b , and an end radial surface 2 f opposite the end radial surface 2 b. The rolling bearing 4 may be of a standard type, with a low production cost and includes a solid inner race 8 provided with a bore mounted, for example by sleeve-fitting, onto the outer cylindrical surface 2 c of the sleeve 2 , and in contact with the radial portion 2 d , a solid outer race 9 , a row of rolling elements 10 , here balls, placed between a raceway of the inner race 8 and a raceway of the outer race 9 , a cage 11 for retaining the circumferential spacing of the rolling elements 10 and seals 12 and 13 fixedly attached to the outer race 9 and rubbing on a cylindrical bearing surface of the inner race 8 , placed on one side and the other of the row of rolling elements 10 to prevent foreign elements from intruding close to the rolling elements 10 and to retain a lubricant such as grease inside the rolling bearing and close to the rolling elements 10 . The outer race 9 is provided with an outer cylindrical surface 9 a , coaxial with the outer cylindrical surface 2 c of the sleeve 2 . The outer element 5 includes a central bore 5 a mounted, for example by sleeve-fitting, onto the outer cylindrical surface 9 a of the outer race 9 . The rolling bearing 4 thus provides the freedom of rotation of the outer element 5 relative to the sleeve 2 , and the acceptance of the radial forces. The outer element 5 also includes a bore 5 b , with a diameter very slightly greater than the central bore 5 a , and placed at the axial end of the outer element 5 situated opposite the support 4 . The rolling bearing 4 and the outer element 5 are symmetrical relative to a radial plane passing through the center of the rolling elements 10 . An annular radial surface 5 c is formed between the bores 5 a and 5 b. The freewheel 6 , mounted adjacent to the rolling bearing 4 , includes an outer race 14 , for example of the solid type, whose bore forms a slipping raceway 14 c, a row of jamming elements 15 , here cams, a cage 16 provided with windows in which are placed the jamming elements 15 in the form of cams and a spring 17 for the return of the jamming elements 15 keeping said jamming elements in permanent contact with the raceways. The jamming elements 15 are placed radially between the outer cylindrical surface 2 c of the sleeve 2 , axially between the rolling bearing 4 and the end radial surface 2 b of the sleeve 2 , and the raceway 14 c of the outer race 14 . Between the periphery of the outer race 14 and the bore 5 b of the outer element 5 , there is a radial space in which the friction element 7 is placed. More precisely, the outer race 14 includes two circular ribs 14 a , 14 b , directed radially outward. The ribs 14 a and 14 b are placed axially at the ends of the outer race 14 while being aligned with the end radial surfaces of the outer race 14 and surround an outer axial surface 14 d of the outer race 14 . The friction element 7 is placed between the ribs 14 a and 14 b and is thus fixedly attached axially to the outer race 14 . The friction element 7 has the shape of a ring open over a small angular sector, for example of the order of a few degrees. The friction element 7 is, in axial cross section, U-shaped with two axial flanges and may be made of rolled metal sheet, In other words, the friction element 7 , in axial section, includes a small diameter axial portion 7 a , a radial portion 7 b extending outward from one end of the axial portion 7 a , an axial portion 7 c extending opposite the axial section 7 a from the large diameter end of the radial portion 7 b , a radial portion 7 d extending inward from the free end of the axial portion 7 c and an axial portion 7 e extending opposite the axial portion 7 a from the small diameter end of the radial portion 7 b . The axial portions 7 a and 7 e have a substantially identical diameter and are in contact with the outer surface of the solid race 14 , the free end of the axial portion 7 a being placed close to the rib 14 a and the free end of the axial portion 7 e being placed close to the rib 14 b . The friction element 7 is symmetrical relative to a radial plane passing through the middle of the axial portion 7 c . The axial portion 7 c is in contact with the bore 9 b of the outer element 5 . The friction element 7 may be provided with a local or general coating to improve its friction or anti-corrosion properties. The operation of the device will be better understood with reference to FIG. 3 . When the outer element 5 rotates in the counterclockwise direction relative to the sleeve 2 , the freewheel 6 is in the freewheeling position with the jamming elements 15 in the tilted position, rubbing on the outer cylindrical surface 2 c of the sleeve 2 and/or on the raceway 14 c of the outer race 14 . The sleeve 2 is only subjected to the drag torque of the rolling bearing 4 and of the freewheel 6 . The friction element 7 drives the outer race 14 at the same speed as the outer element 5 . When the outer element 5 rotates in the clockwise direction relative to the sleeve 2 , the freewheel 6 is placed in the locking position, the jamming cams 15 pressing on the outer cylindrical surface 2 c of the sleeve 2 and on the raceway 14 c of the solid race 14 . The sleeve 2 is therefore subjected to a torque that may be high and which tends to make it rotate in the clockwise direction. However, when the torque transmitted from the outer element 5 to the friction element 7 , from the friction element 7 to the freewheel 6 and from the freewheel 6 to the sleeve 2 , exceeds a predetermined threshold, the friction element 7 begins to slip, relative to the solid race 14 and/or relative to the outer element 5 , and thus smoothes the torque peaks transmitted to the outer element 5 . The predetermined torque threshold may be chosen on assembly and depends on the features of the friction element and of the surfaces with which said friction element is in contact. By analogy with an electric system, the assembly formed by the freewheel 6 and the torque limiter friction element 7 may be seen as a Zener diode which allows free passage of the electric current in one direction and prevents it in the other until a certain voltage is reached, a voltage beyond which the current may again pass freely. Thus, placing the friction element 7 and the freewheel 6 in series makes it possible, on the one hand, to allow a free rotation in one direction, and to prevent rotation in the opposite direction up to the limit of a maximum torque beyond which the rotation is again allowed with, in addition, losses through friction of the friction element 7 on the outer race 14 and on the bore 5 b of the outer element 5 . The embodiment illustrated in FIGS. 5 and 6 is similar to the foregoing embodiments, except that the relative dispositions of the freewheel 6 and the friction element 7 are inverted, the friction element 7 is placed between the outer cylindrical surface 2 c of the sleeve 2 and the inner solid race 14 of the freewheel 6 . The jamming elements 15 are placed between the raceway 14 c formed on the outer cylindrical surface of the solid race 14 and the bore 5 b of the outer element 5 . The operation is similar, except that the freewheel 6 , in the jamming position, is fixedly attached to the outer element 5 and can move angularly relative to the sleeve 2 by slipping of the friction element 7 . The embodiment illustrated in FIG. 7 is comparable with that illustrated in FIGS. 1 to 4 , except that the friction element 7 is replaced by a circumferentially continuous friction element 18 attached, for example by overmolding, to the outer race 14 of the freewheel 6 between the ribs 14 a and 14 b and radially protruding outward. The friction element 18 is made of synthetic material. The choice of the material and the radial prestress of the friction element 18 between the solid race 14 and the bore 5 b of the outer element 5 determine the friction torque and therefore the maximum torque that can be transmitted between the outer element 5 and the sleeve 2 . Raceways for the rolling elements 10 are made directly on the sleeve 2 and on the outer element 5 , respectively from the surfaces 2 e and 5 a . The axial surface 2 e has an axial length greater than the preceding embodiments. In other words, the rolling races are of a single piece with the sleeve 2 and the outer element 5 respectively. The embodiment illustrated in FIGS. 8 to 10 is similar to that illustrated in FIGS. 1 to 4 , except that the friction element 7 is replaced by a friction element 19 having the shape of a metal sheet ring comprising radially elastic tongues 19 a originating from the body 19 b of the ring. The ring may be circumferentially continuous or have the shape of a band cut to the correct length and rolled on itself with its two ends abutting. The body 19 b of the friction element 19 is placed in contact with the solid race 14 between the ribs 14 a and 14 b , while the tongues 19 a , protruding radially outward, are in contact with the bore 9 b of the outer element 5 . In the embodiment illustrated in FIGS. 11 and 12 , the friction element 7 is replaced by an axial-action friction device 20 . The solid race 14 of the freewheel 6 has a reduced radial thickness to leave a greater space to the torque limiter device 20 and is provided with an axial outer surface. In addition, a groove 21 is formed in the bore 5 b of the outer element 5 so that a circlip 22 can be housed therein, close to the free end of the bore 5 b. The torque limiter device 20 which surrounds the solid race 14 includes two friction rings 23 comprising a friction portion 23 a made of synthetic material and a support portion 23 b , for example in the shape of a flat metal washer. The friction portions 23 a are fixedly attached to the support portion 23 b for example by bonding or overmolding. The friction rings 23 are fixedly attached in rotation to the outer race 14 of the freewheel 6 by means such as axial splines 24 interacting with the bore of the support portions 23 b of matching shape. The friction rings 23 may move axially relative to the solid race 14 . Between the two friction rings 23 is placed an axial-action washer 25 , of the Belleville washer type or else of the corrugated type. The torque limiter device 20 also includes a ring 27 in the shape of an L-section dish, sleeve-fitted into the bore 5 b of the outer element 5 and axially in abutment contact against the circlip 22 placed in the groove 21 . The ring 27 includes a radial friction surface 27 a. The friction portions 23 a of the friction rings 23 have radial friction surfaces 23 c , one in contact with the ring 27 , and the other in contact with a radial surface 5 c of the outer element 5 forming a shoulder between the bores 5 a and 5 b . The friction rings 23 are therefore pressing elastically against the corresponding friction surfaces of the outer element 5 and of the ring 27 fixedly attached to the outer element 5 . The choice of the material of the friction rings 23 and of the axial prestress of the rings by the washer 25 determines the friction torque and the maximum transmissible torque threshold. Naturally, a variant could be provided comprising two washers 25 or else a single ring 23 and a single washer 25 . The embodiment illustrated in FIGS. 14 to 16 is close to that illustrated in FIGS. 1 to 4 , except that the freewheel 6 includes a spring 28 provided with coils 29 in contact with the outer surface 2 c of the sleeve 2 and with one end 30 protruding outward. The friction element 7 includes a body 31 in the shape of an open ring made of synthetic material and provided with an axial outer surface 31 a in contact with the bore 5 b of the outer element 5 , a radial surface 31 b connecting to the axial surface 31 a , directed inward and in contact with the shoulder 5 c of the outer element 5 and with a transverse radial surface of the outer race 9 of the rolling bearing 4 , an axial bore surface 31 c adjusted on the outer surface 2 c of the sleeve 2 and a radial surface 31 d placed opposite the radial surface 31 b and joining the inner axial surface 31 c and outer axial surface 31 a . Seen in cross section, the body 31 has a generally rectangular shape. However, in the inner axial surface 31 c , an annular housing 32 is made, placed substantially in the center of the body 31 in the axial direction. Also, a notch 33 occupying a small angular sector is made between the housing 32 and the radial surface 31 b in contact with the rolling bearing 4 . The notch 33 opens onto a transverse radial surface of the inner race 8 of the rolling bearing 4 . The coils 29 of the spring 28 are housed in the annular housing 32 while the outward protruding end 30 is housed in the notch 33 . Thus, one of the free ends of the spring 28 is fixedly attached in rotation to the body 31 while the coils 29 are in friction contact on the outer axial surface 2 c of the sleeve 2 . The result is that, in one direction of relative rotation between the sleeve 2 and the body 31 , the spring tends to tighten and angularly connects said sleeve 2 and said body 31 . On the other hand, in the opposite direction of relative rotation, the coils 29 tend to loosen; The sleeve 2 and the body 31 may rotate freely relative to one another in said direction of relative rotation with a slight friction of the coils 29 on the outer axial surface 2 c of the sleeve 2 . The body 31 also includes another annular groove 34 made from the radial surface 31 d placed opposite the rolling bearing 4 and having a bottom slightly more extended radially than the entrance of said groove 34 . A circlip 35 is placed in the bottom of the groove 34 while being temporarily radially restricted when it is mounted. The groove 34 is dimensioned so that, when the circlip 35 is in place in the bottom of the groove 34 , said circlip 35 exerts on the body 31 a radially outward force. The body 31 being radially deformable due to the material used and due to said body 31 being an open ring, the outer surface 31 a of the body 31 is prestressed radially on the bore 5 b of the outer element 5 which ensures that the body 31 is fixedly attached to the outer element 5 up to a certain torque which may be determined by the dimensions of the outer element 5 , the body 31 and the circlip 35 and by their component materials. In other words, the body 31 forms a single element forming part of both the freewheel 6 and the friction element 7 . Specifically, the annular housing 32 and the notch 33 interact with the spring 28 , and the outer axial surface 31 a is in contact with the bore 5 b of the outer element 5 with the possibility of slipping angularly relative to said bore 5 b in the event of excess torque. Thus, in torque take-up operation, beyond a certain torque value, the body 31 of the friction element 7 begins to rotate relative to the outer element 5 , thus limiting the transmitted torque to the predetermined value. The illustrated embodiments relate to freewheels whose jamming elements are cams or a spring. Naturally the invention could also operate with a freewheel whose jamming element or elements are one or more pawls interacting with a serrated raceway. Thanks to the invention, the longevity of the freewheel and the mechanical members mounted upstream and downstream is increased by the filtering of the torque peaks by the friction member. The race of the freewheel interacts also with the friction member thus giving a particularly compact assembly that is easy to transport, handle and install in a mechanical assembly, for example between a cylindrical housing and a shaft. Further modifications and alternative embodiments of various aspects of the invention may be apparent to those skilled in the art in view of this description. Accordingly, this description is to be construed as illustrative only and is for the purpose of teaching those skilled in the art the general manner of carrying out the invention. It is to be understood that the forms of the invention shown and described herein are to be taken as the presently preferred embodiments. Elements and materials may be substituted for those illustrated and described herein, parts and processes may be reversed, and certain features of the invention may be utilized independently, all as would be apparent to one skilled in the art after having the benefit of this description to the invention. Changes may be made in the elements described herein without departing from the spirit and scope of the invention as described in the following claims. In addition, it is to be understood that features described herein independently may, in certain embodiments, be combined.	The invention concerns a freewheel bearing device including an outer element and inner element arranged inside the outer element, and a free wheel provided with at least a wedging element, arranged between the inner element and the outer element to allow a free rotational movement in one direction between the outer element and the inner element and for transmission of a torque in the other direction between the outer element and the inner element, the free wheel including a ring provided with a cylindrical inner surface and a cylindrical outer surface, substantially aligned on a radial plane perpendicular to the axis of rotation of the device, and a torque limiting member adapted to limit the torque transmitted by the free wheel, the torque limiting member being arranged radially between said ring and the outer element or the inner element in contact with said ring and said element.	5
STATEMENT OF GOVERNMENT INTEREST The Government may have certain non-exclusive rights to this invention for Government purposes. CROSS REFERENCE TO RELATED APPLICATION This is a divisional application of application Ser. No. 08/647,496, filed May 14, 1996, now U.S. Pat. No. 5,873,182. FIELD AND BACKGROUND OF THE INVENTION The present invention relates in general to the control of kilns used for drying wood, and in particular to a new and useful method and apparatus for controlling a wood drying kiln which is based on changes of the shrinkage rate in one or more boards of the lumber charge. In accordance with the invention, this information is used to determine internal stress levels in the board which in turn can be used to identify the occurrence of peak stress, stress reversal and reduced shrinkage as the drying rate is reduced after an initial increase of the drying rate during each advancement of the kiln schedule. Kilns have long been used to dry lumber, in particular hardwood, but also some softwoods, with multiple step schedules. It is also known to periodically change the internal conditions of temperature and humidity in a kiln, according to a manual or automated schedule for the purpose of maximizing the drying while minimizing damage to the lumber in case the moisture content is reduced too quickly. This balancing of maximum drying rate and the need to avoid damage to the wood, is the subject of several patents and articles. Presently kiln controls are based on a number of parameters such as electrical resistance of the lumber (U.S. Pat. No. 3,744,144), weight of the lumber (U.S. Pat. Nos. 1,593,890; 4,176,464; 5,226,241; 5,325,604), internal temperature of the lumber, air temperature decrease across the stack of lumber, or length of drying time. All are used to indicate the moisture content of the lumber. This inferred moisture content is an indirect and poor indicator of the internal stresses which are ultimately the key to drying efficiently while providing quality lumber. Further, all of the above methods have weaknesses which reduce accuracy in determining the true moisture content of the load. Board shrinkage has also been examined by Fortin, et al. in 1994 for example, but it was stated that an abrupt change in slope in shrinkage curves that were used, were due to the occurrence of fiber saturation point (FSP). See Fortin, Y., M. Ilieva, A. Cloutier, and P. Laforest. 1994, "Potential use of a semi-ring extensiometer for continuous wood surface strain measurement during kiln drying." 4th IUFRO International Wood Drying Conference Aug. 9-13th, 1994 Roturua, New Zealand. Ed. by A. Haslett and F. Laytner, pages 329-336. The error in their conclusions were precipitated by the absence of any stress data collected and reliance on the traditional moisture content orientation of drying research. They also did not mention how the data could be used to automate the kiln process. Fiber point saturation is not meaningful when considering average moisture content. It refers to a time when a cell wall in the wood contains the maximum amount of water but has no free water in the cell lumen. Stress reversal has been recorded to occur an at any board average moisture content between 60% and 30% (percentages in this disclosure are all by oven dry weight). The reason it occurred at about 33% for the researchers mentioned above is that they were using a particular schedule on a species which generally causes stress reversal to occur at about 30%. They did not realize that the abrupt change in slope they observed is caused directly by stress reversal, not moisture content. For this reason, the work of Fortin, et al. 1994, has not helped to progress automated kiln control. Bello and Kubler (1975) developed a shrinkage verses fracture-strain theory based on the comparison of true surface shrinkage and fracture strain of the material. By knowing the experimentally determined average fracture strain of the material and temperature, a theoretical loss of moisture can be calculated whereby the shrinkage is less than the average fracture strain. When this moisture is lost, a new data set of moisture and temperature set points can be calculated to advance the schedule. A drawback to this theoretical system is that the kiln sample boards would still be used to monitor moisture loss. Another drawback to this method is the need to know beforehand the average fracture strain of the material which is variable from board to board, a reversion back to the traditional manual method. See Bello, E. and H. Kubler 1975 "Shrinkage-strain-control (S-S-C)--A new approach to the process of kiln-drying wood" Wood Science 7(3):191-197. A second point mentioned in the Bello and Kubler article is shrinkage referred to in a paper by McMillen (1969). In the original paper, McMillen labels his graphs as shrinkage but refers to them in the caption as plastic strain (which they actually are) and not shrinkage. The curves are for released plastic strain of individual layers from a board, not an entire board or gross shrinkage as is measured by the present invention. The destructive, time-consuming method of slicing the board and measuring the released strain was only conceived as a research tool to measure stress gradients within a board and was never intended as a monitoring method. Hill, in 1975, performed a study to measure "barreling" or "bulging" of the side edge of lumber to infer stress levels. He was never able to obtain repeatable results that could be used as a control device. See Hill, J., 1996, Personal communication, Apr. 26, 1995. Referring to the drawings, FIGS. 15, 16, 17, illustrate Hill's device. Hill also only sought to detection stress reversal, not peak stress nor reduced drying rates. Hill advocated a system which measures the moisture contain difference between the surface and center of the board to obtain a theoretical stress level. He assumed stresses develop after 30% moisture content has been reached. In contrast, shrinkage can develop as high as 60% moisture content. Hill's system thus is not an actual stress level monitoring device. In Hill's device, a frame 1 includes a centrally located feeler mechanism 2 having a probe tip 3 for contacting the side edge of a board. The frame is held to the edge of the board by screws 5 and the differential between the longitudinal position of feeler 3 and fixed reference plate pins 4 measures the relative amount of bulging or cupping of the board edge. Although Hill's system is a real-time system, the moisture stress gradient is based on moisture content and the differential shrinkage obtained by measuring the bulging and cupping at the edge of the board, is a strain measurement and does not reveal peak stress points in the board, which is a main consideration and preferred for the present invention. SUMMARY OF THE INVENTION The Invention is a method and apparatus for controlling a lumber drying kiln, based on detecting the slope of a long term shrinkage curve and the slope of a short term shrinkage curve. Upon detecting a crossing of these two curves, which indicates a stress-reversal, the kiln setting changed to the next drying stage. The shrinkage curves are generated using an apparatus which is attached to a board of the lumber charge, for detecting a change in the length or shape of the board. Accordingly, another object of the invention is to provide a real-time process and apparatus for controlling conditions in a lumber drying kiln, comprising measuring a selected characteristic of a sample of lumber in the kiln, over time, the selected characteristic being indicative of stress in the sample, such as shrinkage, and analyzing the measured characteristic to determine when a stress peak or stress reversal has occurred in the sample. The conditions in the kiln and changed when the stress peak or stress reversal has occurred, to advance the drying of the lumber. A further object of the present invention is to provide a method and apparatus for improving the advancement of a kiln schedule, which is simple in designed, rugged in construction and economical to manufacture. The various features of novelty which characterize the invention are pointed out with particularity in the claims annexed to and forming a part of this disclosure. For a better understanding of the invention, its operating advantages and specific objects attained by its uses, reference is made to the accompanying drawings and descriptive matter in which the preferred embodiments of the invention are illustrated. BRIEF DESCRIPTION OF THE DRAWINGS In the drawings: FIG. 1 is a perspective view of an apparatus of the present invention; FIG. 2 is a side elevational view of two elements of the apparatus. FIG. 3 is an end view of a bar for use in lining up the apparatus of the invention on a piece of lumber; FIG. 4 is a top plan view of the bar on the lumber; FIG. 5 is a side elevation view of a second embodiment of the apparatus of the present invention; FIG. 6 is a board edge view of the apparatus of FIG. 5; FIG. 7 is a top view of the apparatus of FIG. 5; FIG. 8 is a graph plotting average moisture content, shrinkage and equilibrium moisture content against time for various oak loads; FIG. 9 is a graph plotting released strain against time for the loads of FIG. 8; FIG. 10 is a graph plotting shrinkage and slope against time and illustrating the statistical decision making approach of the present invention; FIG. 11 is a graph similar to FIG. 8 but comparing the shrinkage of tangentially and radially oriented oak boards; FIG. 12 is a graph similar to FIG. 10 for a maple load; FIG. 13 is a graph similar to FIG. 9 for the maple load with schedule changes shown as #/#; FIG. 14 is a graph plotting shrinkage and slope against time for a representative pilot run, illustrating long-term and instantaneous (short-term) slopes used for decision making according to the present invention; FIG. 15 is a side view of a prior art device taken in the direction of arrow 15 in FIG. 17; FIG. 16 is a bottom view of the prior art device taken in the direction of arrow 16 in FIG. 17; and FIG. 17 is an edge of board view of the prior art device. DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention involves the detection of changes in internal stress in lumber during drying, by measuring changes in the external dimensions of one or more boards in the lumber load in a kiln. These changes are used to automatically advance the dry kiln schedule. The invention is a method and apparatus that measures material shrinkage by which internal stress level can be directly inferred. The following three events are determined: 1) occurrence of peak stress; 2) stress reversal; and 3) reduced shrinkage as the drying rate is reduced after initial increase of drying rate with each advancement of the kiln schedule. For the detection of these occurrences, the apparatus is connected to a computer with a simple program requiring minimal input by the kiln operator. Unlike typical schedules which advance the kiln settings based on moisture content, the present invention detects changes of slope in the shrinkage curve created from the electronic input data from the shrinkage device. Upon the occurrence of significant slope change, advancement of the kiln schedule proceeds. This early advancement saves time and energy and avoids human error in judgment. The apparatus is inexpensive and represents considerable savings for the typical kiln owner in time, energy and lumber damage. Theory of Operation The present invention has been verified by eight kiln loads, with different species, grain orientation, and position within the kiln. The examples disclosed here are representative. FIG. 8 shows the results of the average moisture content (MC) for boards monitored during drying. The shrinkage of two boards, Board 1 and Board 2 (Board 3 was identical to Board 2), and the equilibrium moisture content condition of the kiln (EMC) were all examined. The shrinkage curves represent data taken every hour during the full drying period and every twenty minutes during conditioning at the end of the drying cycle. FIG. 9 displays the level of strain at three points of the boards. The dotted line shows results at the board center, the dash line at the board sub-surface and the solid line at the board surface. As lumber dries, only the surface has potential to shrink, but it is restrained by the lumber core, resulting in a reduced observed shrinkage as displayed in FIG. 8. Therefore, a low rate of shrinkage occurs. This produces internal stress as shown in FIG. 9. When the core starts to shrink, the restrained potential surface shrinkage is released and the observed shrinkage rate increases. This occurs just before stress reversal at Point i, in FIGS. 8 and 9 (at about 28 days in the example given). To a lesser degree, another abrupt change in slope appears at Point ii, immediately after peak stress occurs (at about 15 days). This cannot be detected by visual observation of the shrinkage curve. A statistical analysis of the curve during drying is, however, can pick this point out and provide the necessary input to controls, as illustrated in FIG. 10. The detection of Point ii enables the operator or computer program to advance the kiln schedule at a much earlier time than is typical. After each advancement of the dry kiln schedule the shrinkage rate increases. See Point iii in FIG. 8. A typical schedule is shown in Table 1. TABLE 1______________________________________Typical dry kiln schedule showing multiple steps.Moisture Kiln ConditionsContent Dry-bulb Wet-bulbof the Wood Temperature Temperature______________________________________above 50% 110 F (43.5 C) 106 F (41 C)50-40% 110 F (43.5 C) 105 F (40.5 C)40-35% 110 F (43.5 C) 102 F (39 C)35-30% 110 F (43.5 C) 96 F (25.5 C)30-25% 120 F (49 C) 90 F (32 C)25-15% 135 F (57.2 C) 90 F (32 C)15-% 180 F (82 C) 130 F (54.5 C)Equalization 180 F (82 C) 140 F (66 C)Conditioning 180 F (82 C) 170 F (76.5 C)______________________________________ As the drying progresses, the rate of moisture loss decreases therefore shrinkage decreases. This decrease in shrinkage rate along with peak stress and stress reversal, not moisture loss, is detected by the present patent. Both of these occurrences allow advancement of the dry kiln schedule prior to such an advancement being indicated by the moisture content of the kiln sample; the traditional method of monitoring the lumber and advancing the schedule. With advancement of the schedule taking place sooner because of shrinkage rate data and its indication of peak stress and stress reversal, the resident time of the charge is reduced. With reduced resident time, energy consumption is reduced without degrading lumber quality. A computer program to be used with the invention for processing the shrinkage data, operates so that the length of the instantaneous short term slope will be reduced, as the kiln schedule is advanced. This accounts for the successively shorter periods in the schedule as illustrated in curve EMC of FIG. 8. Since some species take a shorter time to dry than others, the slope length will automatically be set according for each species. During eight test runs the following factors were shown to have no effect on the results; initial moisture content range of the boards within a test run; position within the kiln; and type of grains or temperature. Because fifty percent of the lumber dried in the United States is oak and oak is also the hardest domestic lumber to dry, the test species were predominately oak. Maple, being an easy species to dry, was also tested. It was shown to display the same characteristic shrinkage curve as oak did, indicating that both ring porous and diffuse porous species behaved similarly. See FIGS. 12 and 13. This is not surprising since all lumber dries in the same way, the surface first then the center. This sets up the same basic stress patterns during drying. Therefore the same shrinkage patterns develop in all species during drying. The present invention is based on measuring the material response resulting from drying stresses which are all based on the known fundamental behavior of lumber. The invention does not monitor the coincidental roughly parallel processes of moisture content reduction, as do moisture content based systems. A pilot study was conducted involving a control load and two other loads, one faster than the other and advanced using the shrinkage as the control parameter. This involved closely inspecting 3,000 BDFT (board-feet) of red oak lumber after drying for quality, using a nondestructive ultrasonic analysis. The statistical analysis of the pilot charges and the control showed that there was no significant increase of drying defects in the pilot charges. The first pilot run had reduced visual quality compared to the control run. For the second pilot run, the initial advancement was delayed one day and had markedly superior visual quality as compared to the control run. The drying times for the two pilot runs were reduced 27% and 36% respectively. This demonstrates that the present invention can reduce the drying time with no increase in defects. Three additional red oak charges, one hard maple and three red oak charges for the comparative pilot study were run. FIG. 11 shows a charge which displays the difference in the curves for tangentially-oriented grain and radially-oriented grain. Both curves display the same general characteristic pattern on which stress levels can be seen. FIGS. 12 and 13 show the same characteristics for hard maple. FIG. 14 displays a shrinkage curve for one pilot run with the long term and instantaneous or short term slopes used for decision making. Mechanical Parts The apparatus of the invention includes four main mechanical parts as shown in FIGS. 1 and 2. The apparatus includes a Linear Variable Differential Transformer (LVDT) 10 for converting mechanical movement into electrical signals to a computer 12. The LVDT 10 is of known design and is mounted into a mounting bracket 14 by a set screw 16. The LVDT has a core rod 18 which extends into the LVDT 10 and which is attached to a second mounting bracket 20. The core rod 18 is locked into position relative to the mounting bracket 20 by a locking nut 22 to maintain accuracy. It is the relative movement between the core rod 18 and the LVDT 10 which produces the strain measurements. Both mounting brackets 14, 20 have a penetrating leg 24 which is driven into the surface of the board to produce a positive contact between the lumber and the LVDT assembly. Both mounting brackets also contain an elongated screw slot and screw 26 to attach the mounting brackets to the lumber and allow for any shrinkage between the screw and penetrating leg without allowing the legs 24 to be pulled from the board. This hardware may be plastic to avoid harm to saw blades during later use of the wood. For the proper movement to occur, the mounting brackets must be aligned. To ensure such alignment a set-up bar was used. The bar, shown at 30 in FIGS. 3 and 4, has a pair of feet 32,32 which are held against the side edge of the lumber shown at 38, and then the bar is lightly hammered so that protrusions 36 and 34 are pressed into the lumber. The mounting brackets are correctly aligned because the screws 26 are placed in the holes left by protrusions 36 and the legs 24 are placed in the holes left by protrusions 34. Brackets 14 and 20 are set on an upper surface of the board with rod 18 extending across the board from one side edge of the board toward the other, and exactly perpendicular to the long edge of the board, at a location away from the ends of the board. Boards near the outer edge of the lumber charge in the kiln can be used with the shrinkage measuring apparatus, for convenience and accessibility. The LVDT 10 is by Trans-Tek and is referred to as the Displacement Transducer, with range 1 inch, DC--DC. Any accurate measurement of external dimension or shape would give the same information pertaining to the internal stresses. Thickness shrinkage is one alternative parameter, as well as "barreling" of the lumber edge. FIGS. 5-7 illustrate an alternative measuring device to obtain the same information. This would monitor the "barreling" or bulging of the edge. An LVDT 41 is held in a holder 42 by a set screw 43. The holder 42 is mounted onto the lumber by a flexible mounting bracket 44 to allow for thickness shrinkage. Springs 45 ensure that reference feet 46 are maintained in contact with the edge 50 of the lumber board 52. A spring 47 ensures that the LVDT core rod 48 maintains contact with the center of the side edge of the lumber. The relative movement between the reference feet 46 and core rod 48 results from the "barreling" shown schematically by lines 54 in FIG. 5, and is the input to the computer 12. Screws 49 hold bracket 44 to the face of the board. Statistical Analysis The shrinkage data is gathered every hour from the LVDT's. Because fan reversal in a kiln is every six hours and causes swelling for half the cycle, the data was averaged on a running 12 hour basis to smooth the shrinkage curve out. From this data, two slopes of the shrinkage curve are calculated. One is a long term slope which is calculated by taking the slope of a segment in the curve in which one end point of the segment is at a time when the drying was initiated, and the other end point is the point on the curve of interest. The second, short term slope is calculated by taking a shorter segment where one end point is located again at the point of interest, with the other end point a short time previously on the curve. The length of this long term segment depends on where in the drying schedule the point of interest is and the type of species. For example, for the first step in drying oak, the segment is five days long whereas after the first step it is 24 to 12 hours long. For maple, the long term segment would be shorter since it dries faster. One standard deviation is added to the long term slope data set and a second curve is constructed. One standard deviation is subtracted from the short term slope and a third curve is constructed. Any changes in slope of the curve is detected when the short term slope crosses and becomes greater than the long term slope. See points A, B and C in FIG. 14 for example. This is on the principle that the short term slope will react faster than the long term slope and becomes greater when the original curve has a sudden increased slope. This process will detect when the point of peak stress has been passed and stress reversal occurs. To detect when shrinkage has reduced sufficiently in succeeding steps, the standard deviation is subtracted from the long term slope and the corresponding standard deviation is added to the short term slope. Then, when the short term slope crosses and becomes less than the long term slope, the kiln drying schedule can be advanced. All this is easily developed into the computer program to automate the process. Features of the Invention 1) Peak stress level and stress reversal points are detected by an abrupt change in slope in the shrinkage curve. It is the stress level within the lumber which is the origin of drying defects and is the limiting factor in the rate of drying quality lumber, not moisture content as is presently used as the decision parameter. With the present invention, moisture content monitoring is not used. 2) With the stress level monitored, the present invention has the ability to advance the kiln schedule before moisture content methods would indicate, thereby saving time, energy, and material loss due to human error. 3) Quality is not sacrificed but improved in two ways. First, as demonstrated by the pilot study, the amount of surface checking and honeycomb produced is no more severe than moisture content controlled drying because the defect causing stresses are what is monitored and maintained below a critical level. Second, with the ability to monitor the stress level, stresses can be maintained high but just below the critical level. This allows for a scheduled step to be avoided to save time and maximize stress relief during equalization and condition. Stress relief occurs during equalization because the lumber is relatively cool compared to the kiln atmosphere, the EMC difference at the lumber surface is actually greater than 9%, promoting stress relief. 4) The statistical method is easily programmed using known computing techniques to automate the decision making and advance the kiln schedule. 5) Confidence. The invention does not rely on a poor indicator (moisture content) but on an actual material response to internal stresses as the control parameter. The LVDT is an appropriate instrument to use for the invention, however, any strain measuring instrument which can withstand the kiln environment can be used. The data obtained and how it is used are the essential features of the invention. While a specific embodiment of the invention has been shown and described in detail to illustrate the application of the principles of the invention, it will be understood that the invention may be embodied otherwise without departing from such principles.	A real-time process and apparatus for controlling conditions in a lumber drying kiln include measuring the shrinkage of a sample of the lumber across the longitudinal axis of the lumber and over time. A slope of the curve is analyzed and can be used to determine when a stress peak and stress reversal occurs in the lumber sample. The detection of the stress peak indicates that the drying schedule of the kiln should be incremented to the next drying step. According to the invention, the schedule is incremented in the fastest possible way without degrading the quality of the lumber.	5
CROSS REFERENCE TO RELATED APPLICATIONS This application claims priority to U.S. Provisional Application No. 60/610,692 filed on Sep. 17, 2004 entitled “Broadband Transmission Line Transformer” by Simon Y. London. BACKGROUND OF THE INVENTION 1. Field of the Invention This invention relates generally to broadband radio-frequency impedance transformers. More particularly, the invention relates to broadband transmission line transformers with non-integer turns ratio (fractional ratio transformers) and mostly for high power application. 2. General Description of the Prior Art A particular class of RF impedance transformers with maximum achievable bandwidth and low insertion losses is a class of transmission line transformers that plays an important role in various RF systems, from low power up to high power levels. The main frequency limitation factors of these transformers are shunt inductance at lower frequencies and electrical length of transmission lines at higher frequencies. These two contradictory factors determine the achievable bandwidth of transformers. Impedance transformers with diverse circuit models, having different interconnections of transmission lines and impedance transformation ratios, have different limitations influenced by these two factors. As result, greater or lower bandwidth can be achieved. Widely used impedance transformation ratios are 4:1, 9:1 and 16:1 (integer turns ratios), and 1.5:1, 2:1, 3:1 (fractional turn's ratios). The latter ones are more difficult to realize at wide bandwidths, especially for high power application. Various circuit diagrams of transmission line impedance transformers are presented in book of Jerry Sevick “Transmission Line Transformers.” Among the impedance transformers with non-integer turns ratios, the most necessary is 2:1 impedance transformer. A typical structure includes a two-way power combiner/divider, which consists of a combiner/divider itself and a 2:1 impedance transformer. All of these RF transformers have multi-octave bandwidth and use generally ferrite toroids or other ferrite configurations. Due to high magnetic permeability of ferrite transformers, shunt inductance is high enough and it is possible to realize multi-octave bandwidth with admissible electrical length of transmission lines. In high power transformers (5-100 kW), magnetic flux in ferrite is also high and introduces harmonics and intermodulation products. Furthermore, for these transformers, hysteresis losses (heat dissipation) limiting power handling capability may require a liquid cooling system. Such transformers are heavy, expensive and can not be used in certain environmental conditions. Many attempts to develop high power, broadband transformers without ferrite have been made. In this case the high-pass correction usually used for partly compensation of relatively small shunt inductance. In simplest case it may be one series connected capacitor at the input or at the output of transformer. In spite of this, for achieving multi-octave bandwidth, especially at high power, the electrical length of the transformer's transmission lines should be great and high frequency limitation occurs. Additional low-pass correction compensates this effect to some extent. All of these corrections make transformers more complicated and expensive. In addition, for transformers with fractional turn ratios, the impedance ratios in some practical cases are not close enough to integer numbers and, consequently, even if the transformer is ideal some mismatch occurs. For example, when typical turns ratio is 3/2, the corresponding impedance's ratio is 2.25, and with respect to required impedance transformation ratio equal to the calculated VSWR=1.125. Practically, in this case value of VSWR will be higher. Furthermore, in combining the power of several amplifiers, a two—or more stage combining system is usually used. If each stage inserts some particular VSWR, the overall VSWR in the worst case is a product of its individual values. To decrease the above-mentioned theoretical value, the turns ratio 7/5 instead of 3/2 may be used, for example. A corresponding transformer is too complicated, especially for high power application. Besides, admissible electrical length of its transmission lines should be relatively small and the highest operating frequency decreases. The factors discussed above are applicable to impedance transformers that are unbalanced, balanced and baluns (balanced-to-unbalanced). Frequently it is difficult to provide good balance for high power, broadband baluns, especially for fractional turns ratios. In a prior art balun with 2.25:1 impedance ratio (U.S. Pat. No. 5,767,754), an additional transformer winding is used to improve balance. This winding introduces capacitive shunt effect that increases mismatch. Besides, balance can not be perfect due principally to the asymmetry of circuit models and the influence of stray elements, especially for high power applications. Different longitudinal voltages on the windings also introduce additional difficulties at high power levels. Another approach is a chain connection of two transformers in different combinations (see books of Jerry Sevick: “Transmission Line Transformers” and “Building and Using Baluns and Ununs,” CQ Communications Inc., 1994). This approach is too complicate at high power levels and the balance is not good enough due to stray elements in real design. In view of the above, it is an object of the present invention to provide a more effective, high power broadband impedance transformer. It is another object of the present invention to provide a high frequency, high power transformer with unbalanced ports that is simple in construction and has a wide bandwidth without ferrite. It is still a further object of the present invention to provide an unbalanced impedance transformer without ferrite having a multi-octave bandwidth ratio up to 20:1. Still another object of the present invention is to provide a high power, broadband unbalanced transformer with a fractional turns ratio, and specifically to provide a 2:1 impedance transformation ratio. Yet another object of the present invention is to provide a broadband, unbalanced transformer with a simple correction. It is still a future object of the present invention to provide a broadband, unbalanced impedance transformer having very small mismatch with respect to standard nominal port impedances. It is another object of the present invention to provide a high frequency, high power transformer with balanced ports that is simple in construction and has wide bandwidth without ferrite. It is still a future object of the present invention to provide a broadband balanced-to-unbalanced impedance transformer (balun) having all above mentioned properties and good balance in entire frequency band. SUMMARY OF THE INVENTION According to the present invention, a significant increase in bandwidth and a simplifying, multi-octave impedance transformer are achieved. These results are obtained by combining two factors in one device: High admissible electrical length of transmission lines in a simple schematic model; and usage of a correcting capacitor as an internal component between interconnected transmission lines. This capacitor, together with shunt inductance of transmission lines, effectively decreases mismatch in the entire frequency band caused by 3/2 turn's ratio. The described effect takes place for unbalanced-to-unbalanced transformers, for balanced-to-balanced transformers and for balanced-to-unbalanced transformers (baluns). BRIEF DESCRIPTION OF DRAWINGS The above described features and advantages of the present invention will be more fully appreciated with reference to the detailed description and figures, in which: FIG. 1 illustrates the block diagram of a typical usage of a broadband impedance transformer having a preferable 2:1 impedance transformation ratio and incorporated with two-way power combiner/divider according to the prior art. FIG. 2 illustrates a 2.25:1 broadband impedance transformer constructed with coaxial cables according to the prior art. FIG. 3 illustrates a 2.25:1 broadband impedance transformer that consists of three-conductor transmission line according to the prior art. FIG. 4 illustrates a 2.25:1 ratio impedance transformer that consists of three matched transmission lines, and specifically coax cables according to the prior art. FIG. 5 illustrates a 2.25:1 ratio impedance transformer that consists of coaxial cables with identical characteristic impedances according to the prior art. FIG. 6 illustrates a 2.25:1 impedance ratio balanced-to-balanced impedance transformer according to the prior art. FIG. 7 illustrates the block diagram of a broadband impedance transformer with lumped correction elements according to the prior art. FIG. 8A illustrates 2:1 impedance ratio unbalanced transformer according to an embodiment of the present invention. FIG. 8B illustrates the version of FIG. 8A that consists of three-conductor line according to an embodiment of the present invention. FIG. 9A illustrates 2:1 impedance ratio balanced transformer according to an embodiment of the present invention. FIG. 9B illustrates the version of FIG. 9A that includes two identical three-conductor lines according to an embodiment of the present invention. FIG. 10 illustrates a balun transformer according to an embodiment of the present invention. FIG. 11 illustrates a balun transformer with correcting capacitors according to an embodiment of the present invention. FIG. 12 a,b illustrate an experimental VSWR characteristic of a two-way power combiner incorporated into a transformer according to an embodiment of the present invention. FIG. 13 is a graph of experimental insertion loss characteristics a of two-way power combiner incorporated into a transformer according to an embodiment of the present invention. DETAILED DESCRIPTION Referring to FIG. 1 , there is typical prior art arrangement 1 when a 2:1 impedance ratio transformer 2 is required. Widely used broadband power combiners/dividers 3 have, at common output/input port 4 , the parallel connection of two 50-Ohm transmission lines. Inside combiner/divider these lines (or frequently coaxial cables) may be interconnected in various ways, depending on the schematic of the device, but two inputs/outputs 5 and 6 still have nominal 50-Ohm impedance. By a 2:1 impedance ratio transformer 2 , the nominal impedance at port 7 will be also 50 Ohm. At high power and in a broadband application, where efficiency is an important factor, transmission line impedance transformers are the best in most cases of HF-VHF frequency bands. These transformers generally have a simple construction. Referring to FIG. 2 , there is electrical scheme of one of such transformer 10 , investigated in above-mentioned book of Jerry Sevick. This transformer consists of paired coax cables 14 and 17 with their inner conductors 15 and 18 correspondingly. Paired outer conductors 16 and 19 form the second turn of transformer. Conductors 15 and 18 form first and third turns correspondingly. The nominal impedance at port 11 with respect to common ground 13 is 2.25 times more than the nominal impedance at port 20 with respect to ground 13 . Consequently, this unbalanced transformer with fractional 3/2 turns ratio, even if ideal, implies VSWR=1.125. Shunt inductance increases this value at lower frequencies. Besides, this transformer can operate satisfactorily if electrical length each of its transmission line does not exceed ≈60 deg at upper operating frequency. Corresponding optimum characteristic impedances of two coax cables 14 and 17 are different and non-standard values. For equal or standard values of characteristic impedances maximum admissible electrical length decreased rapidly. Another electrical scheme of simple impedance transformer with the same impedance transformation ratio 2.25 and near the same achievable frequency characteristics is shown on FIG. 3 . The spacing between adjacent conductors 23 and 24 , as well as spacing between adjacent conductors 24 and 25 are critical parameters to obtain maximum high frequency response. Two ports 26 and 28 are unbalanced with respect to common ground 29 . The main distinction between transformers shown on FIG. 2 and FIG. 3 is a different mutual arrangement of conductors. Referring to FIG. 4 , there is an electrical schematic of another prior art 2.25:1 ratio unbalanced impedance transformer. It consists of three matched transmission lines 33 , 34 and 35 having equal characteristic impedances. This transformer is described in the article of S. E. London and S. V. Thomashevich, “Line Transformers with Fractional Transformation Factor,” Telecommunication and Radio Engineering, vol. 28/29, April 1974, pp. 129-131 and in the book of Jerry Sevick “Building and Using Baluns and Ununs,” CQ Communications Inc., 1994). Ideally, this transformer with unbalanced ports 31 and 32 with respect to common ground 36 is operable at an unlimited upper frequency. On the other hand, it consists of two separate shunt inductances, formed by outer conductors of lines 33 and 34 , and of three separate transmission lines. Implementation of this transformer in high power applications introduces stray inductances and capacitances that decrease the upper operating frequency. Moreover, at some electrical length, all transmission lines have a resonance cut-off frequency that may occur. As a result, these transformers are relatively complicated and operate also at limited electrical length of transmission lines. Another prior art transformer ( FIG. 5 ) is obtained from the transformer of FIG. 4 if the length of line 35 equals zero, and if two outer conductors of lines 33 and 34 are connected together at their equi-potential points. These lines can be paired as shown on FIG. 5 . This 2.25:1 ratio impedance transformer with two unbalanced ports 51 and 52 with respect to common ground 53 has the same characteristic impedance of both lines 54 and 57 . The line 54 with inner conductor 55 and outer conductor 56 corresponds to line 32 on FIG. 4 . The line 57 with inner conductor 58 and outer conductor 59 corresponds to line 36 . Line 35 on FIG. 4 is excluded. This transformer has features with respect to the transformers of FIG. 2 and FIG. 3 in mutual arrangement of conductors. This mutual arrangement provides satisfactory operation up to electrical length of each line ≈105 deg. (as described in the article in “Telecomm. and Radio Eng.”, 1974). Besides, the optimum characteristic impedances of lines 54 and 57 are equal and the same as transformer FIG. 4 . Referring to FIG. 6 , there is a prior art electrical schematic of a 2.25 ratio balanced to balanced impedance transformer 60 , which has practically the same frequency limitations as the transformer shown on FIG. 5 . The nominal impedance at balanced port 61 - 61 ′ is 2.25 times more than the nominal impedance at balanced port 62 - 62 ′. This transformer is symmetrical with respect to ground 63 . Two paired coax cables 64 and 65 are the same as cables 66 and 67 . Characteristic impedances of coax 64 and coax 66 are equal and two times less than characteristic impedances of coax cables 65 and 67 . All transformers shown on FIGS. 2-6 have low frequency limitations due to shunt inductances, which may be partly compensated (included in high-pass filter) by using additional components. Referring to FIG. 7 , there is a prior art block diagram of a broadband impedance transformer 70 , having unbalanced ports 73 and 74 with respect to common ground 77 . Compensating elements 72 , 75 and 76 are connected typically at the input and at the output of transformer 70 . Capacitor 72 provides lower frequency correction; it forms high-pass filter with the transformer's shunt inductance 71 . Inductance 76 and capacitor 75 provides high frequency correction (see U.S. Pat. No. 5,309,120). With this three-element correction, the transformers in U.S. Pat. No. 5,309,120 provide bandwidth ratio up to 5:1. They can operate satisfactorily at electrical length of lines significant less than 90 deg. Referring now to FIG. 8A , there is an electrical schematic of a 2:1 ratio impedance transformer 80 in accordance with the present invention. In this transformer having two unbalanced ports 81 and 82 with respect to common ground 90 , internal capacitor 83 plays two roles: Effectively compensates shunt inductance of paired outer conductors 86 and 89 , and Decreases inserted mismatch due to 3/2 turns ratio in a wide frequency band. The optimum characteristic impedance of each of the coax cables 84 and 87 is equal Z 0 √2, where Z 0 is nominal impedance at port 82 (lower impedance side). For transformers with a typical required 50:25 Ohm impedance transformation, the characteristic impedance of each coax, Z=35.35 Ohm, i.e., is practically 35 Ohm. Manufactured coax cable UT 141-35 has Z=35 Ohm. Capacitor 83 in this transformer is connected between the end of inner conductor 85 of the first line 84 and port 82 . On the other hand, this capacitor is connected inside the transformer and between the first turn 85 and the second turn 88 . The third turn is formed by connecting together outer conductors 86 and 89 of coax cables 84 and 87 . Capacitor 83 , together with the inductance of paired outer conductors 86 and 89 , forms a high-pass filter that also improves frequency response. As a result, this transformer has the following advantages: Simple in construction (includes paired coax that have equal characteristic impedances), Includes only one correcting element, Operates satisfactorily up to electrical length of each coax≈110 deg, and Provides low reflection by relatively low shunt inductance. The calculated value of reflection coefficient is \|S\| max ≈0.035 in cases of a 2:1 impedance transformation ratio. Referring to FIG. 8B , there is an electrical schematic of a 2:1 impedance transformer 91 according to the present invention, which is different from that shown in the FIG. 8A implementation of transmission lines. Instead of paired identical coax, there is a symmetrical three-conductor line with conductors 92 - 1 , 92 - 2 and 92 - 3 . The capacitor 93 plays the same role as in the transformer, according to FIG. 8A . Nominal impedances at ports 94 and 95 with respect to common ground 96 are also the same as for FIG. 8A . Therefore, the optimum characteristic impedance of the line formed by adjacent conductors 92 - 1 and 92 - 2 is the same as the characteristic impedance of line 84 in FIG. 8A . The optimum characteristic impedance of the line formed by adjacent conductors 92 - 2 and 92 - 3 is the same as the characteristic impedance of line 87 on FIG. 8A . In some practical cases this implementation of conductors is preferable for fabrication. Referring to FIG. 9A , there is an electrical schematic of a balanced-to-balanced 2:1 impedance transformer 100 according to an embodiment of the present invention. The nominal impedance at balanced port 101 - 101 ′ is twice more than nominal impedance at balanced port 102 - 102 ′. This transformer is symmetrical with respect to ground 109 . Paired coax cables 103 and 104 have the same characteristic impedances as cables 105 and 106 correspondingly. Characteristic impedances of coax 103 and coax 105 are equal and two times less than characteristic impedances of coax cables 104 and 106 . The optimum characteristic impedance of each coax cable 103 and 105 is equal to Z/√2, where Z is the nominal impedance at balanced port 102 - 102 ′ (lower impedance side). For a transformer with 100:50 Ohm impedance, the transformation characteristic impedance of each coax is equal Z=35.35 Ohm, i.e., practically 35 Ohm. Two capacitors 107 and 108 have identical values of capacitances. They compensate shunt inductance of two pairs of outer conductors of coax cables 103 - 104 and 105 - 106 . The calculated reflection coefficient with these capacitors and with relatively small shunt inductance is \|S\| max ≈0.03 in the case of a 2:1 impedance transformation ratio. Referring to FIG. 9B , there is an electrical schematic of a 2:1 impedance transformer 110 in accordance with the present invention. This transformer is different from that shown on FIG. 9A implementation of transmission lines. Instead of paired identical coax cables, there are two symmetrical three-conductor lines with conductors 111 - 1 , 111 - 2 , 111 - 3 and 112 - 1 , 112 - 2 , 112 - 3 correspondingly. The capacitors 113 and 114 play the same role as capacitors 107 and 108 in the transformer, according to FIG. 9A . Nominal impedances at balanced ports 115 - 115 ′ and 116 - 116 ′ with respect to common ground 117 are also the same as for transformer shown on FIG. 9A . Now referring to FIG. 10 , there is an electrical schematic of a 2.25:1 impedance ratio balun 210 according to an embodiment of the present invention. It consists of coax 211 that plays two roles. Its outer conductor (external surface) and conductors 212 , 213 , 214 and 215 form a balanced transformer with ports 218 - 218 ′ and 219 - 219 ′. The inner conductor and internal surface of the outer conductor (normally coax cable function) provide a balanced-to-unbalanced transition and form an unbalanced port 217 . This impedance transforming balun may be considered a result of an internal chain connection of simplest 1:1 balun and balanced-to-balanced impedance transformer (see S. London and S. Thomachevich, Pat. USSR, no 649,050, 1979). Due to this internal chain connection of two transformers, the overall design is simpler than direct chain connection, and balance is better. These two factors are especially important for high power applications. The mutual arrangement of conductors in scheme FIG. 10 is different with respect to that used in a balun according to , Pat. USSR, no 649,050, Now referring to FIG. 11 , there is an electrical schematic of a 2:1 impedance ratio transformer 310 accordance to an embodiment of the present invention. Coax cable 311 and conductors 312 , 313 , 314 and 315 operate exactly as coax cable 211 and conductors 212 - 215 in a balun transformer of FIG. 10 correspondingly. Only additional capacitors 320 and 321 introduce the difference with respect to the balun transformer of FIG. 10 . These two capacitors operate exactly as in balanced transformer shown on FIG. 9B , and electrical characteristics are the same as for the balanced transformers of FIG. 9A and FIG. 9B . Experimental 20 : 1 Bandwidth Ratio Transformer The laboratory prototype of an 50:25 Ohm impedance transformer was constructed without ferrite in accordance to FIG. 9A of present invention. It has been incorporated with two-way power combiner/divider as shown on FIG. 1 , because it is the main application of such transformer. Besides, it verifies the possibility of designing a full device. Each of paired coax 84 and 87 on FIG. 8 was produced from standard high power 50-Ohm coax FE 81 (15 kW@ f=500 MHz). To obtain a characteristic impedance equal ≈35 Ohm, three upper layers of PTFE tape were removed. The transformer consists of three turns of paired these coax cable with average diameter 13.5 cm. Capacitor 83 shown on FIG. 8 is formed as a parallel connection of six standard capacitors HEC HT-50 of 700 pF each. A two-way power combiner consists of two cables FE 81 connected in parallel at common port 4 ( FIG. 1 ) that gives nominal impedance 25 Ohm this port. Experimental graphs are shown on FIG. 10 and FIG. 11 . As we can see on FIG. 12 , the obtained VSWR max in an operating frequency band from 2 to 40 MHz is close to a calculated value VSWR max =(1+\|S\| max )/(1−\|S\| max )=1.074, when \|S\| max is equal ≈0.035, as pointed above. The calculated upper operating frequency is equal ≈43.5 MHz, i.e. enough close to an experimental result for a full device (transformer with combiner itself). Data on FIG. 13 showing that full insertion losses of transformer and combiner are low verifies the practical importance of embodiments of the present invention. While the devices and methods of this invention have been described in terms of specific embodiments, it will be apparent to those of skill in the art that variations may be applied to the devices without departing from the concept, spirit, and scope of the invention. Therefore, all such substitutions and modifications apparent to those skilled in the art are deemed to be within the spirit, scope, and concept of the invention as defined by the appended claims.	A broadband transmission line impedance transformer performs impedance transformation with improved frequency response and efficiency across a wide operational bandwidth. In particular, the bandwidth of a transmission line 2:1 impedance transformer may be significantly increased by adding an additional compensating capacitor as an internal component between interconnected transmission lines. This capacitor effectively improves low frequency response for a given length of transmission lines and decreases mismatch in an entire frequency range. The overall bandwidth ratio increases at least twice and mismatch decreases.	7
CROSS-REFERENCE TO RELATED APPLICATIONS [0001] This application is a continuation of previously filed and copending application Ser. No. 13/258,153, filed Sep. 21, 2011, which is the 371 national phase of International Application No. PCT/EP2010/052202, filed Feb. 22, 2010, which claims priority to German Application No. 1020090020667, filed Mar. 31, 2009, which applications are hereby incorporated herein by reference in their entireties. [0002] The present invention relates to a method for detecting accelerations along, and rates of rotation about, at least one, preferably two of three mutually perpendicular spatial axes x, y and z by means of a MEMS sensor, wherein at least one driving mass and at least one sensing mass are moveably arranged on a substrate, and the driving mass is moved at a driving frequency in an oscillating manner relative to the sensing mass, and also to a corresponding MEMS sensor with a substrate, with at least one driving mass which is arranged moveably and in oscillation parallel to the plane of the substrate in an x-y plane, with at least one sensing mass, with connection springs for connecting the at least one driving mass to the at least one sensing mass, and with at least one anchor and one anchor spring for connecting the at least one driving mass and/or the at least one sensing mass to the substrate, with drive elements for driving the driving mass/es in oscillation at a driving frequency relative to the sensing mass/es in order to subject them to Coriolis forces during a rotation of the substrate about an arbitrary spatial axis, and with sensing elements for detecting the accelerations and rotational movements of the substrate. [0003] MEMS sensors are known for example as micro-gyroscopes, which are used for determining rotational movements about one or more axes in an orthogonal x-y-z-coordinate system. In order to be able to detect rotational movements of the system about each of the three axes, in the simplest case three micro-gyroscopes are necessary, each of which determines the rotational movement about a single axis. More expensive micro-gyroscopes are constructed in such a way that they can detect rotational movements about multiple axes. Basically, these gyroscopes work according to the principle that during a rotational movement of the entire system about an axis perpendicular to the driving motion, an oscillating driving mass generates a Coriolis force in the third axial direction. Given an appropriate mounting of the driving mass, this Coriolis force causes a deflection of the driving mass and, where applicable, of a sensing mass coupled to it. To the sensing mass in particular, sensing elements are assigned, which are normally plate capacitors or comb electrodes, which when their separation changes generate an electrical signal which is proportional to the rotational movement. The corresponding rotational movement can be detected by means of this electrical signal. A microgyroscope of this kind for three axes is known, for example, from TW 286201 BB. [0004] US 2008/0053228 A1 discloses a sensor for detecting accelerations which can occur in three spatial axes. In this arrangement a sensing mass is moveably suspended in the space, and is deflected accordingly when accelerations of the sensor occur in one of the spatial axes. The deflection that occurred is determined in turn, by means of electrodes or by a deformation of the springs on which the sensing elements are suspended, and converted into an electrical signal. [0005] A disadvantage of the sensors of the prior art is that to detect accelerations and rotational movements of the sensor, either different specialized sensors must be used, which only give information about the movements of the entire sensor unit in combination, or that very complicated sensors are necessary, which are difficult to manufacture and can be correspondingly vulnerable in operation. Also common to all these solutions is the fact that they are very cost intensive in their manufacture. [0006] The problem addressed by the present invention therefore, is to create a sensor for detecting accelerations and rotational movements, which is relatively simple in construction and inexpensive to manufacture, and moreover has a high detection accuracy. [0007] The problem is solved by a method and a MEMS sensor with the features of the independent claims. [0008] The method according to the invention serves to detect accelerations along and rates of rotation about one, preferably two, of three mutually perpendicular spatial axes x, y and z by means of a MEMS sensor. At least one driving mass and at least one sensing mass are moveably arranged on a substrate. The at least one driving mass is moved in oscillation at a driving frequency relative to the at least one sensing mass. Driving mass/es and sensing mass/es are deflected in the event of an external acceleration of the sensor at an acceleration frequency and in the event of an external rotation rate of the sensor at a rotation rate frequency. The acceleration frequency and rotation rate frequency are different, which means that the acceleration frequency or rotation rate frequency occurring in response to an acceleration or rotation rate can be kept distinct, and therefore conclusions can be drawn as to the acceleration or rotation rate that has taken place. Due to the method according to the invention, it is possible that the same sensing elements can be used both for the acceleration and for the rotation rate of the sensor. The distinction is made as to whether the sensor was exposed to an acceleration or to a rotation solely by means of the frequency that occurred. [0009] In an advantageous embodiment the method according to the invention can also be used for detecting a third acceleration direction and a third rotation rate. For this purpose, at least one additional driving mass is provided which is moved in oscillation in a direction orthogonal to the at least one driving mass of the first two directions or rotation rates and relative to at least one sensing mass. This enables a sensor to be created, which can detect three acceleration directions as well as three rotation rate directions. Only a small number of moving parts are necessary. The production of the device is thereby simplified quite considerably and the manufacturing costs are kept relatively low. [0010] It is particularly advantageous if, in the event of an external acceleration of the sensor, the driving mass/es and the sensing mass/es are deflected at an acceleration frequency which is equal to the driving frequency, and in the event of an external rotation rate of the sensor, they are deflected at a rotation rate frequency which is double the driving frequency. This provides a clear distinction between acceleration and rotation rate, which means that it is simple to determine whether the sensor is being accelerated or rotated. [0011] Preferably, driving mass/es and sensing mass/es are deflected due to a torque when the sensor is accelerated. The torque arises, for example, due to the fact that the driving mass/es is/are arranged eccentrically on the substrate with respect to the mounting of driving and/or sensing mass/es. The oscillating driving mass/es, which eccentrically projects over the balanced central position alternately on one side and the other side, create torques during an acceleration that are transverse to this driving motion and which, given an appropriate mounting of the driving mass and sensing mass on the substrate, generate a rotational movement of these masses. This rotational motion is also oscillating, like the driving motion of the driving mass/es, which means that an oscillating rotational motion of the driving mass/es and sensing mass/es arises. This oscillating rotational movement, due to the torque of the repeatedly asymmetrically arranged driving mass/es, can be detected by means of sensing elements. [0012] To detect the rotation of the sensor, driving mass/es and sensing mass/es are advantageously deflected due to a torque and a Coriolis force. The Coriolis force arises due to the driving frequency of the driving mass/es perpendicular to the acceleration and driving direction. If the driving mass is arranged and mounted in such a way that during its oscillating driving motion it repeatedly projects asymmetrically over the mounting of the driving mass/es and sensing mass/es, then a torque additionally occurs, which is superimposed on the Coriolis force. In this case a typical rotation rate frequency occurs which differs from the driving frequency and also from the pure acceleration frequency. Due to this, the associated sensing elements generate a typical signal, which indicates the rotation of the sensor. The deflection generated here is also, like the driving frequency, oscillating. [0013] Acceleration frequency and rotation rate frequency are advantageously proportional to the acceleration and rotation rate produced, and can be measured and evaluated accordingly. [0014] A MEMS sensor according to the invention is used to determine accelerations along and rotational movements about at least one, preferably two of three mutually perpendicular spatial axes x, y and z. The MEMS sensor has a substrate and at least one driving mass, which is arranged moveably and in oscillation parallel to the plane of the substrate in an x-y plane. At least one sensing mass is connected with connecting springs to the at least one driving mass. The driving mass/es and/or the sensing mass/es are connected to the substrate with at least one anchor and one anchor spring. In addition, the MEMS sensor has driving elements for driving the driving mass/es in oscillation at a driving frequency relative to the sensing mass, in order to subject them to Coriolis forces when a rotation of the substrate occurs about an arbitrary spatial axis. Sensing elements are used for detecting the acceleration and rotational movements of the substrate. According to the invention, in the resting state of the sensor the driving mass/es and the sensing mass/es are arranged on the substrate, balanced by means of at least one of the anchors. In the driving mode the driving mass/es vibrate in oscillation about this at least one anchor and thus alternately generate an imbalance towards one side or the other. The driving mass/es are then alternately on one side and the other side of the center of gravity of the sensor in the resting state, and thus alternately generate an imbalance on one side and the other side of the anchor, or center of gravity, respectively. The sensing elements detect the deflections of the driving and sensing masses due to the torques generated and/or Coriolis forces with an acceleration frequency and/or a rotation rate frequency. [0015] Due to the oscillation of the driving mass/es about an equilibrium state according to the invention, the driving and sensing masses to be deflected are alternately increased and reduced respectively on one side and the other. This causes different mass distributions to occur, which in the event of a linear acceleration of the sensor, generate torques about the anchor point or anchor points of the driving mass/es and the sensing mass/es on the substrate. Given an appropriate mounting of the driving mass/es, or the sensing mass/es, these torques deflect the mass/es on the substrate around the anchor point and cause a rotation of the two masses about the anchor. This moving oscillatory torque generates a unique signal, which indicates the corresponding acceleration. By means of the first driving mass/es, which is/are driven in oscillation in the x-direction, when an acceleration occurs in the direction, torques are thereby generated about the z-axis. If the sensor by contrast is accelerated in the z-direction, then an oscillating torque is produced, which generates a tilting motion of the driving and sensing mass/es about the y-axis. It should be noted here that the driving or sensing mass respectively is suspended on the substrate using anchor springs, which allow these movements. The anchor spring must therefore be constructed in such a way that it allows a rotation about the z-axis for the detection of an acceleration in they-direction, while for indicating a z-acceleration it must allow pivoting of the sensing mass/es and driving mass/es about the y-axis. The connection springs for connecting the driving mass to the sensing mass, on the other hand, should be configured such that they are only elastic in the driving direction, or have a controlled compliance. In the other axial directions, by contrast, they are designed to be stiff, so that the driving mass/es and sensing mass/es in these directions are essentially rigidly coupled to one another. [0016] If the sensor is rotated about the z-axis, then a Coriolis force arises, which, under the combined influence of the torques due to the oscillating asymmetric mass distribution causes a rotation of the driving and sensing masses about the z-axis. In the case of a rotation of the sensor about the y-axis, a corresponding rotation occurs about the y-axis. Both rotations occur at a typical rotation rate frequency, which is different from the rotation frequency induced by a linear acceleration and which can be detected and evaluated. [0017] The at least one driving mass can be preferably linearly driven in oscillation along one of the three spatial axes. For the drive, driving electrodes, in particular comb electrodes, are used in a customary way, which alternatingly attract the driving mass/es in turn. The at least one driving mass thereby preferably moves in such a way that starting from an end position it is accelerated up to a central position and then decelerated back again to the other end position. Subsequently, the driving direction is reversed and the driving mass is again accelerated up to the central position and decelerated once again. [0018] In a particularly advantageous embodiment of the invention the sensor is designed to detect a third acceleration direction and a third rotation rate. For this purpose the sensor has at least one additional driving mass, which can be driven with driving elements in oscillation in a direction that is orthogonal to the first driving direction. This at least one second driving mass therefore moves at right angles to the first driving mass/es, which is/are responsible for the first two directions or rotation rates, respectively. The at least one second driving mass, moreover, moves relative to at least one sensing mass, which reacts to the corresponding forces. This sensing mass can advantageously be identical to the sensing mass for the first two directions or rotation rates, respectively. In this case it must be fixed to the anchor in such a way that it allows appropriate reactions, which means oscillating rotational movements about the x and the z-axis. The second driving mass in this case preferably moves in the direction. When an acceleration of the sensor occurs in the x direction the second driving mass with the sensing mass reacts by rotation about the z-axis. If a rotation rate about the x-axis occurs, then the second mass pivots about the x-axis. The reaction to an acceleration or a rotation rate in each case takes place by means of oscillating movements of the second driving mass together with the sensing mass at frequencies which differ from one another. Preferably, the rotation frequencies for accelerations in all axes are equal to the driving frequency of the affected driving masses, while the rotation frequencies for rotations of the sensor are twice as large as the corresponding driving frequencies. [0019] In one advantageous embodiment of the invention, at least one of the anchors, which bears the driving elements or the central elements, is a central anchor. The central anchor can also consist of multiple individual anchor parts, which are arranged close together. The anchor preferably forms the center of mass in the balanced state of the sensor. [0020] The sensing mass is preferably arranged on the central anchor. This facilitates a particularly simple embodiment of the invention, since only one sensing mass is necessary for a symmetrical construction of the sensor in the resting state. [0021] In one advantageous embodiment of the invention, the at least one sensing mass can be rotated and pivoted about an axis, in particular about the central anchor. For this purpose the sensing mass is fixed using appropriate anchor springs on the central anchor. In this arrangement the anchor springs are implemented in such a way that they allow a rotation and pivoting in the intended direction for the sensing mass/es. [0022] If the at least one driving mass can rotate and pivot about an axis, in particular about the central anchor, then multiple sensing masses can be provided. This certainly means that more space is needed for the sensor, but on the other hand, the detection of the motion of the sensing masses is simpler to implement. [0023] The driving mass/es and the sensing mass/es are preferably connected together with connection springs. These connection springs must be implemented in such a way that, in particular, they allow mobility of the driving masses in the driving direction. The at least one sensing mass itself is arranged on the substrate so that it is immobile in this direction. The sensing mass is accordingly only moved, when a corresponding acceleration or rotation rate occurs and generates a deflection of the driving mass/es, and the sensing mass is rigidly coupled to the driving mass. [0024] In order to detect the motion of the sensing mass/es and/or the driving mass/es as a reaction to an acceleration or rotation rate, sensing elements are assigned to the at least one sensing mass and/or the at least one driving mass, which correspond to sensing elements arranged in a fixed position on the substrate. Suitable devices for this purpose are plate capacitors or fork electrodes, which convert changes in separation into an electrical signal. [0025] In a particularly advantageous embodiment of the sensor, an analysis unit is assigned to the sensor, in order to distinguish between an acceleration frequency and a rotation rate frequency. Because the rotation rate frequency and the acceleration frequency are fundamentally different, due to the corresponding occurrence of such a frequency, a distinction can be made as to whether the sensor is being accelerated in an axial direction or rotated about an axis. BRIEF DESCRIPTION OF THE DRAWINGS [0026] Other advantages of the invention are described in subsequent embodiment examples. These show: [0027] FIG. 1 is a sensor according to the invention during an acceleration in the direction, [0028] FIG. 2 is a sensor according to the invention during a rotation about the z-axis, [0029] FIG. 3 is a further sensor according to the invention with one sensor mass, [0030] FIG. 4 is a sensor according to the invention with two sensing masses, [0031] FIG. 5 is a sensor according to the invention with two driving masses and [0032] FIG. 6 is a further sensor according to the invention with four driving masses. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS [0033] In FIG. 1 a sensor 1 according to the invention is schematically illustrated. The sensor 1 consists of a substrate 2 , which is arranged parallel to the plane of the drawing (x-y plane). Arranged on the substrate 2 is an anchor 3 , which supports a sensing mass 5 via four anchor springs 4 . The anchor springs 4 are arranged in an x-shape on the anchor 3 , and due to their corresponding spring stiffnesses in the x, y and z-direction they allow a torsion of the sensing mass 5 about the z-axis, which projects out of the plane of the drawing, and a torsion of the sensing mass 5 about the y-axis. About the x-axis and in the directions of the x, y and z the springs 4 are not compliant. [0034] A driving mass 6 is fixed on the sensing mass 5 by means of four connecting springs 7 . The connecting springs 7 have a spring stiffness which is relatively soft in the x direction, in order to allow a movement of the driving mass 6 relative to the sensing mass 5 in the x direction. With regard to a rotation about the y-axis or z-axis however, the connecting springs 7 are stiff, which means a coupling of the driving mass 6 to the sensing mass 5 is affected. If the driving mass 6 is correspondingly deflected, then this deflection is transmitted to the sensing mass 5 , which, owing to its mounting via the anchor springs 4 , yields to this deflection and therefore rotates the sensing mass 5 together with the driving mass about the y-axis or the z-axis. [0035] As can be seen from FIG. 1 a ) and FIG. 1 b ), the driving mass 6 oscillates back and forth in the x direction relative to the sensing mass 5 . In FIG. 1 a ) the driving mass 6 is located in its left end position, while in FIG. 1 b ) it is shown in its right end position. The connecting springs 7 are accordingly bent within the x/y-plane in the x-direction, first to the left and then to the right. The sensing mass 5 does not take part in this driving motion. With regard to the anchor point 3 , in the case of the driving motion in the x-direction, an imbalance of the masses arises alternatingly on the left-hand side ( FIG. 1 a )) and on the right-hand side ( FIG. 1 b )). If acceleration forces now occur in the direction, as illustrated in FIGS. 1 a ) and 1 b ), then due to the alternating imbalance, these cause a rotation of the sensing mass 5 and driving mass 6 about the anchor 3 counter-clockwise in FIG. 1 a ) and clockwise in FIG. 1 b ). The frequency of this oscillating rotational motion about the z-axis, called the acceleration frequency, corresponds to the frequency of the oscillating driving motion of the driving mass 6 . Just as illustrated in FIGS. 1 a ) and 1 b ), the sensing mass 5 and the driving mass 6 are alternately rotated in an oscillating manner about the y-axis, when an acceleration of the sensor 1 takes place in the z-direction. Here also an alternating imbalance is present on the left-hand side (−x axis) and on the right-hand side (+x axis). The acceleration in the z direction therefore also causes an oscillation of the sensing mass 5 and driving mass 6 about the y-axis at an acceleration frequency equal to the driving frequency. [0036] In the drawing of FIG. 1 , as in the following drawings, the driving device and the sensor device are not shown for reasons of clarity. These can be effected in a conventional manner, for example with fork electrodes, which alternately attract the driving mass 6 and therefore lead to an oscillating back and forth motion of the driving mass 6 . Sensing elements can also be, for example, fork electrodes or consist of capacitor plates. Parts of these electrodes or plates are arranged on the substrate 2 in a fixed manner, while other parts are located on the moveable elements, namely the sensing mass 5 and/or the driving mass 6 . A deflection of the sensing mass 5 or the driving mass 6 leads to changes in the spacing between the parts arranged on the sensing mass 5 , or driving mass 6 , and the parts that are fixed on the substrate 2 . This change in the spacing can be converted into electrical signals and evaluated. [0037] In FIG. 2 a )- i ) the response of the sensor 1 during a rotational movement about the z-axis projecting out of the plane of the drawing is shown schematically. The respective torsion is shown with an arrow, rather than with a graphically represented torsion of the sensing mass 5 and driving mass 6 , in order to make the mode of action easier to understand. In FIG. 2 a ) the driving mass 6 is located at its left turning point. The velocity of the driving mass at this position is zero, since it is coming from one direction of motion—in the −x direction—and is subsequently moved into a +x direction. The sensing mass 5 and driving mass 6 , in spite of a rotational motion of the sensor 1 about the z-axis, are in this position not subject to a Coriolis force, since the driving velocity of the driving mass 6 is zero. Coriolis forces only arise when the driving mass 6 is in motion. The Coriolis forces are then proportional to the driving motion of the driving mass 6 . [0038] In FIG. 2 b ), at a time t=T/8, the driving mass is moving in the +x direction to the right. The driving mass 6 therefore has a velocity greater than zero, which generates a Coriolis force in the −y direction. The mass 6 in this position is on the −x axis to a greater extent than on the +x-axis, which causes an imbalance to arise and the Coriolis force directed in the −y direction causes a rotation of the sensing mass 5 and driving mass 6 in a counter-clockwise direction. [0039] FIG. 2 c ) shows the driving element 6 at the time t=T/4. The driving element 6 is located in the equilibrium state with respect to the sensing mass 5 . Furthermore, at this position it has an approximately maximum velocity, which causes the Coriolis force at this position to also be a maximum. The Coriolis force is directed in the −y direction, owing to the driving mass 6 and sensing mass 5 being in equilibrium however, no torque is generated. The sensing mass 5 and driving mass 6 accordingly do not rotate. [0040] FIG. 2 d ) shows an imbalance of the masses at time t=3 T/8, now with the greater mass on the +x-axis side. The driving velocity of the driving mass 6 is greater than zero, which in turn generates a Coriolis force in the −y direction. The force is unbalanced, which generates a torque on the driving mass 6 and the sensing mass 5 in a clockwise direction. The sensing mass 5 and driving mass 6 rotate accordingly in a clockwise direction about the anchor 3 . At time t=T/2—according to FIG. 2 e )—the driving mass 6 is in its rightmost position. The driving velocity is again zero, because the driving mass 6 is located at its turning point. Owing to the absence of the driving velocity, no Coriolis force is generated either. The sensing mass 5 and driving mass 6 do not rotate about the z-axis. [0041] In FIG. 2 f ) the driving mass 6 is moved in the −x-direction. Due to this, a Coriolis force occurs in the +y-direction. The masses are unbalanced, which generates a counter-clockwise rotational movement about the z-axis. [0042] FIG. 2 g ) shows the driving mass 6 in its central position at time t=3 T/4. The driving velocity is essentially a maximum, and hence the Coriolis force is also a maximum. The masses, and therefore the forces, are in equilibrium, which means that in spite of the maximal Coriolis force occurring in the +y-direction, no rotational movement is generated on the sensing mass 5 and the driving mass 6 about the z-axis. [0043] In FIG. 2 h )—at time t=7 T/8—the driving mass 6 once again has a velocity in the −x-direction, which is greater than zero. Due to the imbalance to the left −x side, a corresponding Coriolis force in the +y-direction generates a rotation of the sensing mass 5 and driving mass 6 clockwise about the z-axis. [0044] FIG. 2 i ) corresponds again to FIG. 2 a at time t=T. The driving mass 6 has completed one period T and is again located at its left-hand turning point. The velocity of the driving mass 6 is zero, which also causes no Coriolis force to occur. The sensing mass 5 and driving mass 6 are located, in spite of their imbalance, in the position illustrated with respect to the x and y-axis. The individual drawings of FIG. 2 reveal that during a period T of the driving mass 6 , which has a frequency fd=1/T, the sensing element 5 together with the driving mass 6 experiences a frequency fs=2fd. In contrast to the acceleration according to FIG. 1 , in which the driving frequency fd is equal to the sensing frequency fs, by evaluation of the frequency fs it can be established whether the sensor is being linearly accelerated or rotated about an axis. If the sensing frequency fs is equal to the known driving frequency fd, then an acceleration of the sensor 1 (acceleration frequency) is present, whereas in the case of a sensing frequency fs, which is twice as large as the driving frequency fd, a rotational movement of the sensor 1 (rotation rate frequency) is involved. [0045] In the same way as in FIGS. 2 a ) to 2 i ), in which a rotational movement about the z-axis was shown, an evaluation is also possible for a rotational movement of the sensor 1 about the y-axis. Due to the Coriolis force occurring, this causes a rotational movement of the sensing mass 5 and the driving mass 6 about the y-axis. The sensing mass 5 and driving mass 6 therefore pivot out of the plane of the drawing x-y about the y-axis. Corresponding sensing elements detect the respective movements of the frequency fs about the z-axis or the y-axis and supply corresponding electrical signals, which can be analyzed. [0046] FIG. 3 shows another exemplary embodiment of the invention. The sensor 1 is constructed in a very similar way to the sensor 1 of FIGS. 1 and 2 . A difference is the arrangement of the connecting springs 7 on the sensing element 5 . The connecting springs 7 are arranged at only one point on the sensing element 5 . This is intended to illustrate clearly that the actual configuration of the sensing element is only of lesser importance to the principle of operation of the present invention. What is essential is that an imbalance is generated with respect to the mounting, here the anchor 3 , which enables a rotational motion of the sensing element 5 and driving element 6 about this mounting, when appropriate Coriolis forces or acceleration forces occur. In FIG. 3 a ) the driving mass 6 is shown at its left turning point. FIG. 3 b ) shows the driving mass 6 in its central position and FIG. 3 c ) at its right turning point. The mode of action and the corresponding responses to accelerations and rotational movements of the sensor 1 correspond to those described as in FIGS. 1 and 2 . [0047] FIG. 4 shows another exemplary embodiment of the invention. In this case the driving mass 6 is fixed directly on the anchor 3 by means of anchor springs 4 . The anchor springs 4 allows both the mobility of the driving mass 6 in the x direction and a rotation about the y-axis and the z-axis. With respect to a rotation about the x-axis or a displacement in they or z direction however, the anchor spring 4 is stiff. [0048] The present exemplary embodiment has two sensing elements 5 . The sensing elements 5 are arranged on both sides of the y-axis or of the anchor 3 . They are connected by means of connecting springs 7 to the driving mass 6 . The connecting springs 7 allow a relative mobility of the driving mass 6 in the x direction. This means, in the x-direction the connection springs 7 are constructed to be relatively soft, or with a controlled stiffness or compliance. If the driving mass 6 however is rotated about the z-axis or y-axis owing to acceleration forces or Coriolis forces that occur, and a corresponding imbalance with respect to the anchor 3 , then the connecting springs 7 have a corresponding stiffness, so that the sensing masses 5 together with the driving mass 6 are moved in this direction. The sensing masses 5 for their part are fixed on the substrate 2 by means of sensor springs 8 and sensor anchor 9 . The sensor springs 8 are configured in such a way that they are stiff in the x direction, but allow mobility of the sensing mass 5 about the y-axis or z-axis respectively. [0049] The principle of operation of the present exemplary embodiment is identical to the principle of the above cited exemplary embodiments. In FIG. 4 a )- c ) the oscillating motion of the driving mass 6 is shown, FIG. 4 a ) showing it at its left turning point, FIG. 4 b ) at its central position and FIG. 4 c ) at its right turning point. A rotation about the y-axis or z-axis, which in each case extends through the anchor 3 , takes place in the same manner as shown in FIGS. 1 and 2 . Here too, an imbalance is generated to the left or right of the anchor 3 , which causes torques to occur which effect corresponding rotations of the driving mass 6 , causing detectable displacements in the sensing masses 5 . [0050] FIG. 5 shows a further exemplary embodiment of the present invention which is capable of detecting accelerations in the x, y and z direction, and rotational movements around the x, y or z-axis. For this purpose a sensing mass 5 is connected to two driving masses 6 . 1 and 6 . 2 . The sensing mass 5 is fixed on the substrate 2 at an anchor 3 that is divided into four, with anchor springs 4 . Anchor 3 can naturally also be implemented differently than shown here, for example, it can be divided in two parts or also be implemented as a single part. However care must be taken that the driving mass 6 . 2 is not prevented from performing a driving motion in the direction. The sensing mass 5 and driving mass 6 . 1 along with connecting springs 7 . 1 correspond essentially to the structure of the embodiment according to FIGS. 1 and 2 , and 3 . In addition, a further driving mass 6 . 2 is arranged within the sensing mass 5 . This driving mass 6 . 2 is connected to the sensing mass 5 by means of connecting springs 7 . 2 . The driving mass 6 . 2 is not driven in the x direction like the driving mass 6 . 1 , but rather in the direction. The driving mass 6 . 2 generates a periodically alternating imbalance on the +y and −y-axis. While the sensing mass 5 and the drive element 6 . 1 respond to accelerations in they and z directions, and to rotation rates about the y and z-axis, the driving mass 6 . 2 produces a response to accelerations in the x direction and rotation rates about the x-axis. In doing so, when accelerations occur in the x direction at least the sensing mass 5 and the driving mass 6 . 2 are rotated at the same frequency as the driving frequency of the driving mass 6 . 2 . When a rotation rate occurs about the x-axis, due to the corresponding imbalances and Coriolis forces, a rotational movement about the z-axis occurs at double the driving frequency of the driving mass 6 . 2 . [0051] FIG. 6 finally shows a further basis drawing of a sensor 1 for detecting accelerations in the x, y and z direction and rotations about the x, y and z-axis. In this arrangement four driving masses 6 . 1 and 6 . 2 are arranged around the sensing mass 5 . The driving masses 6 . 1 move in the x direction, while the driving masses 6 . 2 are driven in the direction. As described previously, in each case imbalances arise due to this eccentric motion of the driving masses 6 . 1 and 6 . 2 . The torques generated by this, which in the case of a rotational movement of the sensor 1 are superimposed with Coriolis forces and in the case of accelerations act alone, generate a rotation of the driving masses 6 . 1 and 6 . 2 and the sensing mass 5 about the anchor 3 with different frequencies. These different rotation frequencies are evaluated and then indicate a corresponding rotation rate or acceleration. To detect and distinguish the responses from the driving masses 6 . 1 and 6 . 2 , the driving masses 6 . 1 and 6 . 2 can be driven at different frequencies or amplitudes. The corresponding acceleration or rotation rate frequency is then also different. [0052] The invention is not limited to the exemplary embodiments illustrated. Combinations of the illustrated embodiments among themselves, and other arrangements of the sensing masses and driving masses and the shapes of the anchors are possible within the scope of the claims. In the same way, the sensor can also be used solely for displaying a single rotation direction and acceleration direction, if the movements of the sensing masses for the corresponding other directions are suppressed or not measured.	The invention concerns a MEMS sensor and a method for detecting accelerations along, and rotation rates about, at least one, preferably two of three mutually perpendicular spatial axes x, y and z by means of a MEMS sensor ( 1 ), wherein at least one driving mass ( 6; 6.1, 6.2 ) and at least one sensor mass ( 5 ) are moveably arranged on a substrate ( 2 ) and the at least one driving mass ( 6; 6.1, 6.2 ) is moved relative to the at least one sensor mass ( 5 ) in oscillation at a driving frequency and when an external acceleration of the sensor occurs, driving mass/es ( 6; 6.1, 6.2 ) and sensor mass/es ( 5 ) are deflected at an acceleration frequency and, when an external rotation rate of the sensor ( 1 ) occurs, are deflected at a rotation rate frequency, and the acceleration frequency and rotation rate frequency are different. At the MEMS-sensor the driving mass/es ( 6; 6.1, 6.2 ) and sensor mass/es ( 5 ) are arranged on the substrate ( 2 ), and are balanced in the resting state by means of at least one of the anchors ( 3 ). In the driving mode the driving mass/es ( 6; 6.1, 6.2 ), when vibrating in oscillation about this at least one anchor ( 3 ), generate/s an imbalance of the driving mass/es ( 6; 6.1, 6.2 ) and the sensor mass/es ( 5 ) with respect to this at least one anchor ( 3 ), and the sensor elements detect deflections of the driving and sensor masses, due to torques and Coholis forces generated, with an acceleration frequency and/or a rotation rate frequency.	6
CROSS-REFERENCE TO RELATED APPLICATIONS This application is based upon and claims the benefit of priority from prior Japanese Patent Application No. 2003-339979, filed Sep. 30, 2003, the entire contents of which are incorporated herein by reference. BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to improvement of an information recording apparatus and information recording method for recording a stream such as image and sound and management information of the stream on a recording medium. 2. Description of the Related Art As is well known in the art, research and development of information high-density recording technology has recently been promoted, and an optical disk having a recording capacity as large as 4.7 GB in one layer on one side has been put into practical use. For example, the optical disk includes read-only type digital versatile disk-read only memory (DVD-ROM), rewritable type random access memory (DVD-RAM) and rewritable (DVD-RW), and write-once type recordable (DVD-R). In these optical disks, the management information is adapted to be created and recorded when the stream such as the image and the sound is recorded, and reproduction or search of the stream is performed based on the management information when the stream is reproduced. The stream and its management information are individually recorded as an independent file on the optical disk. Therefore, a user can capture only the stream from the optical disk into a personal computer (PC) or the like to perform editing and rewrite the post-edit stream onto the optical disk. In view of such usage, it is very difficult with the optical disk to always ensure consistency between two different files of the stream and its management information. That the consistency between the stream and its management information cannot be ensured is the same state as that the management information is lost and only the stream exists on the optical disk. Jpn. Pat. Appln. KOKAI Publication No. 2001-143439 discloses a configuration in which file management information is recovered or generated so as to access AV data which has been already recorded in the case where the file management information is broken or lost during the time the AV data is recorded on the recording medium. However, in Jpn. Pat. Appln. KOKAI Publication No. 2001-143439, the file management information is corrected or generated by reproducing the whole of the AV data recorded on the recording medium from a leading recording block, so that the operation is complicated and a long time is required. BRIEF SUMMARY OF THE INVENTION According to one aspect of the present invention, there is provided an information recording apparatus comprising: a reception unit configured to receive image signals; a stream generation unit configured to generate a stream formed by continuously arranging a plurality of pieces of VOBU adhering to a DVD-VR standard from the image signals received by the reception unit; a management information generation unit configured to generate management information of the stream generated by the stream generation unit; a control unit configured to arrange part of the management information generated by the management information generation unit in each reserve area in a plurality of pieces of VOBU constituting the stream; and a recording unit configured to record the stream in which part of the management information is arranged by the control unit and the management information in a recording medium. According to another aspect of the present invention, there is provided an information recording method comprising: receiving image signals; generating a stream formed by continuously arranging a plurality of pieces of VOBU adhering to a DVD-VR standard from the received image signals; generating management information of the generated stream; arranging part of the generated management information in each reserve area in a plurality of pieces of VOBU constituting the stream; and recording the stream in which part of the management information is arranged and the management information in a recording medium. BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING FIG. 1 is a perspective view showing an appearance of an optical disk apparatus in an embodiment of the invention; FIG. 2 is a block diagram showing a signal processing system of the optical disk apparatus in the embodiment; FIG. 3 shows a data structure of a part concerning M_VOBI in a DVD-VR standard; FIG. 4 shows a detail of TM_ENT in M_VOBI in the DVD-VR standard; FIG. 5 shows a detail of VOBU_ENT in M_VOBI in the DVD-VR standard; FIG. 6 shows a relationship between TM_ENT and VOBU_ENT in the DVD-VR standard; FIG. 7 shows a general structure of a stream in the DVD-VR standard; FIG. 8 shows contents of RDI_PCK in the stream in the embodiment; FIG. 9 is a flowchart showing an operation in which VOBU_ENT is arranged in RDI_PCK in the embodiment; FIG. 10 is a flowchart showing the operation in which TM_ENT is restored from the stream in the embodiment; and FIG. 11 is a flowchart showing the operation in which TM_ENT is generated from VOBU_ENT in the embodiment. DETAILED DESCRIPTION OF THE INVENTION Referring to the accompanying drawings, a preferred embodiment of the invention will be described in detail. FIG. 1 shows an appearance of an optical disk apparatus 11 described in the embodiment. The optical disk apparatus 11 has a cabinet 12 formed in a substantially thin box shape. A disk drive unit 14 is placed in the central portion of a front panel 13 of the cabinet 12 . The disk drive unit 14 is configured to be able to load and unload a later-mentioned optical disk. The disk drive unit 14 has a function of performing the recording and reproduction of information on and from the loaded optical disk. A power key 15 is placed in one end portion of the front panel 13 of the cabinet 12 . A display unit 16 for displaying an operating state, a setting state, and the like, an operation unit 17 for setting the optical disk apparatus 11 in a predetermined state or a stopped state, and the like are placed on the other end portion of the front panel 13 . FIG. 2 shows a signal processing system of the optical disk apparatus 11 . A television broadcast signal received by an antenna 18 is provided to a tuner unit 19 to select a television signal of a predetermined broadcast channel. The television signal selected by the tuner unit 19 is provided to an image analog-to-digital converter circuit 20 and a sound analog-to-digital converter circuit 21 , and an image signal and a sound signal are digitized respectively. The image signal and sound signal which are input from an external input terminal 22 are provided to the image analog-to-digital converter circuit 20 and sound analog-to-digital converter circuit 21 to be digitized respectively. The image signal and sound signal which have been digitized by the image analog-to-digital converter circuit 20 and sound analog-to-digital converter circuit 21 are provided to a moving picture experts group (MPEG) encoder 23 . While the MPEG encoder 23 converts the input image signal and sound signal into the stream in the form of an MPEG 2 format adhering to a video recording (DVD-VR) standard, the MPEG encoder 23 generates the management information of the stream. The stream and its management information which have been output from the MPEG encoder 23 are provided to a recording/reproduction control circuit 24 . The recording/reproduction control circuit 24 has the function of controlling a hard disk drive (HDD) unit 25 to record the stream and its management information in a hard disk 25 a. The recording/reproduction control circuit 24 also has the function of controlling the disk drive unit 14 to record the stream and its management information on an optical disk 26 such as DVD-RAM loaded in the disk drive unit 14 . In this case, the stream and management information which have been output from the MPEG encoder 23 can be selectively recorded only on the hard disk 25 a , only on the optical disk 26 , or on both the hard disk 25 a and the optical disk 26 . The recording/reproduction control circuit 24 has the function of controlling the HDD unit 25 to read the stream from the hard disk 25 a based on the management information. The recording/reproduction control circuit 24 also has the function of controlling the disk drive unit 14 to read the stream from the optical disk 26 based on the management information. In this case, the stream can be selectively read from either the hard disk 25 a or the optical disk 26 . The stream which has been read from the hard disk 25 a or the optical disk 26 is provided to an MPEG decoder 27 through the recording/reproduction control circuit 24 . The MPEG decoder 27 performs decode processing corresponding to the MPEG 2 format to the input stream and outputs the digitized image signal and sound signal. After the image signal is provided to an image encoder 28 and the predetermined encode processing is performed to the image signal, the image signal can be led to the outside through an image output terminal 29 . After the digital sound signal output from the MPEG decoder 27 is provided to a sound digital-to-analog converter circuit 30 to be changed to an analog format, the sound signal can be led to the outside through a sound output terminal 31 . The recording/reproduction control circuit 24 also has the function of controlling the HDD unit 25 and the disk drive unit 14 so as to read the information recorded in the hard disk 25 a to record the information on the optical disk 26 or so as to read the information recorded on the optical disk 26 to record the information on the hard disk 25 a. At this point, the above-described series of recording/reproducing operations is totally controlled by a central processing unit (CPU) 32 . The CPU 32 controls each circuit so as to reflect operational contents of the operation unit 17 based on a control program stored in a ROM 33 while using a RAM 34 as a work area. A timer 35 and an interface circuit 37 are connected to the CPU 32 . The timer 35 obtains time information for the purpose of a reserved recording function and the like, and the interface circuit 37 connects an external PC or the like to an input/output terminal 36 to perform data communication. FIG. 3 shows a data structure of a part concerning movie video object information (M_VOBI) in the DVD-VR standard. When the optical disk apparatus 11 performs the recording processing, the information on the stream to be recorded is retained in the information of M_VOBI in a management information file named VR_MANGR.IFO. M_VOBI includes movie video object general information (M_VOB_GI) on the whole of M_VOBI, seamless information (SMLI) necessary to perform seamless reproduction with the immediately preceding M_VOBI, audio gap information (AGAPI) which describes an audio gap, and time map information (TMAPI) of an area where a time map is retained. TMAPI includes time map general information (TMAP_GI), time entry information (TM_ENT) #1 to #m, and video object unit entry (VOBU_ENT) information #1 to #n. FIG. 4 shows a detail of the time entry information TM_ENT in the time map (TMAP) information. TM_ENT is the information which is provided in each 600 fields in the national television system committee (NTSC) system or in each 500 fields in the phase alternation by line (PAL) color television system. TM_ENT includes video object unit entry number (VOBU_ENTN) which describes the number of VOBU_ENT which exists in a position of TM_ENT, time difference (TM_DIFF) in which a shift from a leading end of VOBU to the position of TM_ENT is expressed by the number of fields, and video object unit address (VOBU_ADR) in which the position from the leading end of M_VOBI of VOBU is expressed by the number of logical blocks. FIG. 5 shows the detail of the VOBU entry information VOBU_ENT in the time map (TMAP) information. VOBU_ENT includes first reference size (1STREF_SZ) in which a size of an intra-coded (I) picture of an intra-frame coding frame of the leading end of VOBU is described by the number of logical blocks, video object unit playback time (VOBU_PB_TM) in which a reproduction time of VOBU is described by the number of fields, and video object unit size (VOBU_SZ) in which the size of VOBU is described by the number of logical blocks. VOBU_ENT is utilized as navigation information for searching the target I picture without analyzing the interior of the stream, when a special reproduction such as forward-direction skip reproduction or reverse reproduction is performed. FIG. 6 shows a relationship between TM_ENT and VOBU_ENT. The information TM_ENT can be worked out only by calculation when the information VOBU_ENT exists. Because an interval of TM_ENT is constant, VOBU_ENTN can be determined as the number of VOBU_ENT exceeding TMU by adding the pieces of VOBU_PB_TM in VOBU_ENT. TM_DIFF is difference in which a total value of VOBU_PB_TMs exceeds the value of TMU. VOBU_ADR can be calculated by adding VOBU_SZ from the leading end of M_VOBI. That is, the information TM_ENT can be worked out by the calculation when all the pieces of information VOBU_ENT are prepared. The information TMAP is the information for high-speed searching for the position where the I picture is located in the stream in the DVD-VR standard, and there should not be a mismatch between stream data and TMAP data. It is considered that the optical disk apparatus 11 and PC are coordinated with each other by connecting the PC to the input/output terminal 36 of the optical disk apparatus 11 . For example, it is considered that the stream data recorded on the hard disk 25 a or the optical disk 26 is transferred to the PC to edit the stream data and the original stream data recorded on the hard disk 25 a or the optical disk 26 is rewritten by the post-edit stream data. In this case, in order to adhere to the DVD-VR standard, it is necessary that not only the stream data but also the management information described in an IFO file are simultaneously transferred to the PC to perform the rewrite corresponding to the edit contents. However, in the case where the stream data can be transferred to the PC which is of the system having a higher degree of freedom for users, it is actually difficult to always surely hold consistency between the stream data and the management information. That is, it should be previously assumed that the stream data is inconsistent with its management information. When the stream data is returned from the PC to the optical disk apparatus 11 , it is necessary to prepare a mechanism which can generate the management information only from the stream data. FIG. 7 shows a general structure of the stream in the DVD-VR standard. In an example shown in FIG. 7 , the stream is configured by continuously arranging a plurality of pieces of unit information which is of VOBU including a predetermined amount of information. One VOBU includes one group of pictures (GOP), and one GOP includes 15 pictures. RDI_PCK is described at the leading end of VOBU, and subsequently a packet of the I picture is recorded. In addition, however, there are also a sound packet, a sub-image packet, and the like, those will be omitted for the sake of convenience. FIG. 7 shows parts expressed by each of 1STREF_SZ, VOBU_PB_TM, and VOBU_SZ which are included in VOBU_ENT shown in FIG. 5 . 1STREF_SZ is the information in which the size of the I picture is expressed by the number of logical blocks. VOBU_PB_TM is the information in which the reproduction time of 1VOBU (15 pictures) is expressed by the number of fields. In this case, VOBU_PB_TM becomes 30 fields. VOBU_SZ is the information in which the size of the one VOBU is expressed by the number of logical blocks. Each of 1STREF_SZ, VOBU_PB_TM, and VOBU_SZ can be generated when the interior of the stream is analyzed. However, to that end, it is necessary to read at least header portions of all the packets, and the processing is complicated and a long time is required. Therefore, in the embodiment, the management information of the stream, particularly the information VOBU_ENT is adapted to be able to be reproduced from the stream at high speed. For this purpose, when the MPEG encoder 23 performs the encode processing, 1STREF_SZ, VOBU_PB_TM, and VOBU_SZ are inserted into RDI_PCK. FIG. 8 shows the contents of RDI_PCK generated by the MPEG encoder 23 . As shown in remarks, the pieces of information from the leading end of RDI_PCK to DCI_CCI are the information provided in the DVD-VR standard. Manufacturer's information (MNFI) is a reserve area where the data can be arbitrarily written on the side of the optical disk apparatus 11 . The pieces of information from MNF_ID to PIC_LENGTH14 in the pieces of the information recorded in the reserve area, as shown in remarks, are the information proposed in Jpn. Pat. Appln. KOKAI Publication No. 2003-151215 by the same inventor as the subject application. As shown by “the embodiment” in remarks, 1STREF_SZ, VOBU_PB_TM, and VOBU_SZ which constitute VOBU_ENT follow these pieces of information from MNF_ID to PIC_LENGTH14. FIG. 9 is the flowchart showing the operation in which the MPEG encoder 23 arranges each of 1STREF_SZ, VOBU_PB_TM, and VOBU_SZ which constitute VOBU_ENT in RDI_PCK. When the process is started (Step S 1 ), the MPEG encoder 23 encodes 1GOP from the input image signal in Step S 2 , generates the information TM_ENT in Step S 3 , generates the information VOBU_ENT in Step S 4 , and generates the information RDI_PCK in Step S 5 . In Step S 6 , the MPEG encoder 23 arranges each of 1STREF_SZ, VOBU_PB_TM, and VOBU_SZ which constitute VOBU_ENT at the specified positions of RDI_PCK. In Step S 7 , the MPEG encoder 23 inserts RDI_PCK into the leading end of 1GOP. In Step S 8 , the MPEG encoder 23 decides whether the encode processing is finished or not. When the MPEG encoder 23 decides that the encode processing is not finished (NO), the process is returned to Step S 2 . When the MPEG encoder 23 decides that the encode processing is finished (YES), the process is ended (Step S 9 ). After the stream generated by the MPEG encoder 23 passes through the recording/reproduction control circuit 24 , the stream is recorded on the hard disk 25 a by the HDD unit 25 or recorded on the optical disk 26 by the disk drive unit 14 . In this case, the various types of pieces of management information such as TM_ENT and VOBU_ENT which are generated in the MPEG encoder 23 are also recorded in the management area of the hard disk 25 a or optical disk 26 in a similar manner. FIG. 10 is the flowchart showing the operation in which each of TM_ENT is restored from the stream recorded on the hard disk 25 a or optical disk 26 . When the process is started (Step S 10 ), the CPU 32 causes a file pointer to be sought at the leading end of the stream in Step S 11 . In Step S 12 , the CPU 32 reads the data of leading-end one sector (=one logical block=2048 bytes). In Step S 13 , the CPU 32 decides whether the read data is RDI_PCK or not. When the CPU 32 decides that the read data is not RDI_PCK (NO), the process of restoring TM_ENT is ended (Step S 19 ). When the MPEG encoder 23 decides that the read data is RDI_PCK (YES), the CPU 32 reads 1STREF_SZ, VOBU_PB_TM, and VOBU_SZ from RDI_PCK in Step S 14 and creates and retains VOBU_ENT in Step S 15 . In Step S 16 , the CPU 32 decides whether the stream is finished or not. When the CPU 32 decides that the stream is not finished (NO), since the subsequent RDI_PCK is located at the position of (VOBU_SZ+1) sector ahead of RDI_PCK, the CPU 32 causes the file to be sought by (VOBU_SZ+1) sector in Step S 17 and returns the process to Step S 12 . The whole pieces of VOBU_ENT in the stream can be read by repeating the operations from Step S 12 to Step S 17 until the stream is finished. When the CPU 32 decides that the stream is finished in Step S 16 (YES), the CPU 32 restores each of VOBU_ENTN, TM_DIFF, and VOBU_ADR which constitute TM_ENT from each of VOBU_ENT which has been already obtained by the calculation in Step S 18 , and the process is ended (Step S 19 ). Each of the restored management information such as VOBU_ENT and TM_ENT is recorded in the management area of the hard disk 25 a or optical disk 26 and utilized for the reproduction of the stream. For example, in the case where the stream recorded on the hard disk 25 a is transferred to the PC to edit the stream and the post-edit stream is recorded on the hard disk 25 a again, not only the post-edit stream is recorded in the data area of the hard disk 25 a , but also VOBU_ENT is read from the stream to restore the TM_ENT and VOBU_ENT and TM_ENT are recorded in the management area of the hard disk 25 a. In the case where special reproduction is performed to the stream re-recorded on the hard disk 25 a , the restored VOBU_ENT and TM_ENT which are recorded in the management area of the hard disk 25 a are utilized. FIG. 11 is the flowchart showing the operation in which TM_ENT is generated based on VOBU_ENT which has been read from RDI_PCK of the stream. When the process is started (Step S 20 ), in Step S 21 the CPU 32 creates TM_ENT #1, assuming that VOBU_ENTN=1, TM_DIFF=0, and VOBU_ADR=0. In Step S 22 , the CPU 32 adds +1 to n. In Step S 23 , while the CPU 32 performs cumulative addition of the pieces of VOBU_PB_TM of VOBU_ENT #n, the CPU 32 performs the cumulative addition VOBU_SZ. In Step S 24 , the CPU 32 decides whether the sum of the pieces of VOBU_PB_TM is not lower than 600 fields which are of the interval of TM_ENT in the NTSC system or not. When the CPU 32 decides that the sum of the pieces of VOBU_PB_TM is lower than 600 fields (NO), the CPU 32 returns the process to Step S 22 . When the CPU 32 decides that the sum of the pieces of VOBU_PB_TM is not lower than 600 fields in Step S 24 (YES), the CPU 32 adds +1 to m in Step S 25 and creates TM_ENT #m in Step S 26 . In this case, TM_ENT #m is calculated assuming that: VOBU_ENTN=n, TM_DIFF=(the sum of the pieces of VOBU_PB_TM)−600 Fields, and VOBU_ADR=the sum of the pieces of VOBU_SZ. In Step S 27 , the CPU 32 decides whether VOBU_ENT is finished or not. When the CPU 32 decides that VOBU_ENT is not finished (NO), the CPU returns the process to Step S 22 . When the CPU 32 decides that VOBU_ENT is finished (YES), the process is ended (Step S 28 ). In accordance with the above-described embodiment, each of the information 1STREF_SZ, the information VOBU_PB_TM, and the information VOBU_SZ which constitute VOBU_ENT is recorded in RDI_PCK of the stream, so that each of the information VOBU_ENTN, the information TM_DIFF, and the information VOBU_ADR which constitute TM_ENT from VOBU_ENT can be calculated without reading the header portions of all the packets of the stream and the management information of the stream can be easily restored from the stream. It is practical that the process of restoring TM_ENT is performed only when the management information recorded in the management area of the hard disk 25 a or optical disk 26 is inconsistent with the stream, i.e. only when the management information of the management area is lost. The invention is not limited to the embodiment. In the working stage of the invention, it is possible to realize the invention by deforming the constituents in various manners without departing from the spirit and scope of the invention. Further, various inventions can be formed by appropriately combining the plurality of constituents disclosed in the embodiment. For example, it is possible to delete some constituents from all the constituents shown in the embodiment.	An information recording apparatus comprises a reception unit configured to receive image signals, a stream generation unit configured to generate a stream formed by continuously arranging a plurality of pieces of VOBU adhering to a DVD-VR standard from the image signals received by the reception unit, a management information generation unit configured to generate management information of the stream generated by the stream generation unit, a control unit configured to arrange part of the management information generated by the management information generation unit in reserve areas in a plurality of pieces of VOBU constituting the stream respectively, and a recording unit configured to record the stream in which part of the management information is arranged by the control unit and the management information in a recording medium.	6
CROSS-REFERENCE TO RELATED APPLICATION This application is a continuation-in-part of U.S. application Ser. No. 08/227,025 filed Apr. 13, 1994 now abandoned. FIELD OF THE INVENTION The invention relates to manufacturing of decor sheets having high opacity and reduced resin uptake, and more particularly to decor laminates having high opacity as well as high gloss and surface durability. BACKGROUND OF THE INVENTION Decorative laminates are widely employed in the building industry for use as counter tops, kitchen and bathroom work surfaces, wall panelings, floors, cabinets, partitions and doors. Because they are generally more durable than wood and provide an attractive appearance, decorative laminates are also popular in the furniture industry, primarily as tops for furniture such as tables and desks. The extensive use of these decorative laminates is primarily due to their low cost, impact and abrasion resistance, durability, clarity, and their resistance to heat, ultraviolet light and mild chemicals. Decorative laminates are conventionally made from a core or body comprising a plurality of sheets of a fibrous material such as unbleached kraft paper which can be impregnated with a thermosetting resin. A decorative sheet also known as a decor sheet can be mounted on top of the core to hide or disguise the underlying core. The decor sheet typically comprises a fibrous sheet having either a design printed on it or it may have pigments dispersed therethrough to provide a solid color decor sheet. The decor sheet is generally made of high quality cellulosic fiber impregnated with a thermosetting condensation resin such as melamine-formaldehyde resin. Another sheet known as an overlay is commonly used as a protective covering for the decor sheet. Examples of such overlays are described in U.S. Pat. No. 4,505,974 and Canadian Patent No. 990,632. Typically the decor sheet is a single layer sheet which exhibits good hiding power, surface durability and gloss. Generally, these properties are achieved by adding an opacifying pigment such as titanium dioxide to the paper furnish for the decor sheet to provide a controlled level of opacity and saturating the decor sheet with appropriate amounts of resin to insure that adequate resin is available on the surface of the sheet to provide durability. The addition of pigment and resin to the decor sheet have opposing effects on the opacity of the sheet. Reducing the resin concentration in the decor sheet tends to improve the hiding power, but lowers the gloss and surface durability. Increasing the resin concentration has the effect of lowering the hiding power of the decor sheet while increasing gloss and surface durability. Thus, the addition of higher amounts of resin to improve durability may require that additional pigment such as TiO 2 be incorporated in the sheet to compensate for loss of opacity. Such a sheet does not efficiently utilize either TiO 2 or saturating resin. The large amounts of resin and TiO 2 employed in such decorative sheets are unattractive from an economic point of view particularly with respect to TiO 2 which is very expensive. Thus, it would be desirable to provide an economical decor sheet which employs reduced amounts of both resin and TiO 2 and which exhibits good hiding power without sacrificing desirable surface durability properties and gloss to decorative laminates. The present invention provides such a decor sheet. SUMMARY OF THE INVENTION A principal object of the invention is to provide a decor sheet having high opacity at either reduced filler (TiO 2 ) level or at reduced basis weight. Another object of this invention is to provide a decor sheet having a resin-starved bottom surface and a resin-rich top surface. Methods for providing such a gradient resin capacity include use of internal sizing and the use of different types of furnishes and papermaking techniques in the bottom and top portions of the decor sheet. For example, in a preferred method, a sizing agent is applied to the bottom surface of the decor sheet to prevent or reduce absorption of the resin into the fiber network of the sheet. It has now been discovered that decor sheets having enhanced opacity can be obtained by internally or surface sizing the decor sheet. The decor sheet may be uniformly sized in one embodiment, but in another embodiment, by sizing one surface of the decor sheet, when the sheet is saturated with the laminating resins, a resin gradient in the thickness or Z direction of the decor sheet is obtained wherein the amount of resin in the surface-sized portion of the decor sheet is less than the amount of resin in the unsized portion of the sheet. By placing the unsized surface at the top of the laminate and the sized surface adjacent the core, surface durability and good hiding power are achieved. By uniformly internally sizing the sheet overall resin reduction and enhanced opacity are achieved. The decor sheet of the invention not only provides the desired opacity and surface properties, but requires less opacifying agent and resin than conventional decor sheets. For example, the amount of an opacifying agent, such as TiO 2 , may be reduced by 30 to 35% or more in some cases. The resin-starved decor sheet and, more particularly the resin starved bottom layer of a dual layer decor sheet contains entrained air in the fiber matrix. The difference in the index of refraction of the resin and fiber as compared to the air results in increased reflectance and increased opacity. In a dual layer decor sheet, the resin-rich top layer of the sheet provides the gloss and durable surface properties desired in a decorative laminate. The decor sheet of the invention is prepared by internally sizing or surface sizing the sheet such that its capacity for the laminating resin is reduced. In one embodiment of the invention, a dual layer decor sheet may be formed from two intimately associated fibrous mats or strata to provide a dual layer sheet. Typically, the dual layer decor sheet is prepared by depositing a layer of fibrous furnish containing an internal sizing agent on a paper machine forming wire, and while the layer is in a wet state and still supported on the forming wire, depositing a second layer of fibrous furnish which is free of size to the base layer from a second headbox. The top layer may contain the same fibrous materials as the base layer but for the sizing agent. The Decor sheet may be formed in a conventional manner from a single furnish and the bottom surface of the decor sheet may be sized without sizing the top surface so that the bottom portion of the sheet absorbs less resin than the top portion. While in the preferred aspect, the top of the decor sheet contains no sizing agent, it is within the present invention for the top layer to contain a sizing agent in an amount less than the amount of sizing agent in the bottom layer or to contain a less effective sizing agent in terms of reducing resin capacity than is used in the bottom layer. Those skilled in the art will also appreciate that the sized and unsized furnish may be placed on the wire in any order. Thus, it is an object of the present invention to provide a decor sheet for use in a decorative laminate wherein the decor sheet is sized to reduce its resin capacity and is preferably differentially sized so as to provide more resin at one surface (e.g., the top) of the sheet where surface durability is required and less resin adjacent the core where opacity is desired to hide the core sheets. Another object of the present invention is to provide a decor sheet containing a reduced amount of opacifying agent such as titanium dioxide. Still another objective of the present invention is to provide a decorative laminate containing a decor sheet in accordance with the invention. Another aspect of the present invention provides a decorative laminate comprising a resin-impregnated decor sheet wherein the decor sheet is treated with a sizing agent to reduce its resin capacity. More particularly, a decorative laminate is provided in which at least one surface of the decor sheet is treated with a sizing agent such that the decor sheet exhibits a resin gradient in the thickness direction of said decor sheet to provide a resin-rich top layer and a resin-starved lower layer. Definitions The term "dual layer decor sheet" as used herein means a decor sheet having two layers wherein the top layer and the bottom layer of the sheet are sized differently, for example, one layer may be prepared from a furnish containing more size than the other layer or from a furnish sized differently so that it absorbs less saturating resin than the other. By "desired level of opacity," is meant that the opacity of the decor sheet is such that the brown color of the kraft core sheets is not seen through the resin-containing decor sheet of the invention. "Top surface" or "top portion" is the surface or portion of the decor sheet furthest removed from the core sheets in a decorative laminate. This is the surface facing the top of the laminate. "Bottom surface" or "bottom portion" is the surface or portion of the decor sheet adjacent the core sheets in a decorative laminate. This surface is not seen in a laminate. DETAILED DESCRIPTION OF THE INVENTION As stated above, the purpose of this invention is to improve the hiding power of the decor sheet and, in the preferred embodiment, to improve hiding power while also providing sufficient surface resin to insure good gloss and surface durability properties. In accordance with the present invention, the decor sheet can be designed to provide reduced resin capacity or a graduated resin concentration, which is higher at the top of the sheet than at the bottom of the sheet. In a dual layer decor sheet, the top surface is designed to hold sufficient resin to insure both good gloss and the desired surface properties while the bottom surface is designed to reduce resin absorption and provide better opacity. The sizing agents which may be employed in the present invention must be capable of repelling or reducing the laminating resin uptake so as to retain entrained air within the treated portion of the sheet. Useful sizing agents include alkenyl succinic anhydride (ASA), alkylketene dimer (AKD), dispersed rosin, aluminum stearate, copolyester, fluorochemicals, fortified rosin, gelatin, latexes, polyurethane, rosin soap, silanes, silicates, stearato chromic chloride, styrene maletic anhydride (SMA), wax emulsions, etc. The preferred sizing agent is alkenyl succinic anhydride (ASA), alkylketene dimer (AKD), or dispersed rosin. Particularly preferred is dispersed rosin such as that sold under the Trade Name Stafor available from Hercules. While the application makes reference to the above sizing agents, those skilled in the art will appreciate that other sizing agents may be used in place of or in combination with the preferred sizing agents provided that they prevent complete infiltration of the decor sheet by the laminating resin. The fibers used in the decor sheet of the invention are most typically cellulosic fibers and preferably a bleached kraft pulp. The pulp may consist of hardwoods or softwoods or a mixture of hardwood and softwoods. Higher alpha cellulose such as cotton may be added to enhance such characteristics as postformability. In addition to cellulose fibers, a wide variety of other fibers may be used alone or in combination with the cellulose fibers. For example, the decor sheet may be formed from cellulose fibers, synthetic fibers such as nylon, rayon, acrylic, olefinic, etc. or inorganic fibers such as glass. In accordance with this invention, reductions of up to 50% in the amount of resin in the decor sheet may be provided. However, in order to maintain the other physical properties of the sheet, such as strength, durability and hardness, the resin uptake generally should not be reduced more than about 20%. The amount of sizing agent can be controlled to adjust the resin uptake to the desired level. For example, while a conventional decor sheet may take up about 45 to 70% of resin based on the total weight of the resin impregnated sheet, the decor sheets of the present invention will take up about 30 to 65% and in many cases less than about 45% resin. In a dual layer decor sheet, the top portion of the sheet may take up 45 to 70% resin and the bottom portion may take up about 35 to 65% resin with the top portion of the sheet containing at least 10% more resin than the bottom portion (i.e., [resin top - resin bottom] ÷ resin bottom). The resin pick up will depend upon the basis weight of the sheet, filler levels, amount of sizing, nature of the fibers, etc. The amount of sizing agent necessary to provide this effect will vary depending on the nature of the size, the laminating resin used, and the fibers and whether the size is a surface size or internal size. Conventional surface sizes are generally applied to the bottom surface of the sheet in an amount of about 0.1 to 3% based on the dry weight of the sheet. Using an internal size, the internal size is generally incorporated into the decor sheet as a whole or in the bottom fibrous layer of a dual layer sheet in an amount of about 0.1 to 3%. Opacifying pigments useful in the present invention are those commonly used in the papermaking industry to provide opacity in decor sheets. While titanium dioxide is the preferred opacifying agent, those skilled in the art will appreciate that other opacifying pigments such as zinc oxide, carbon black, iron oxide, cobalt oxide, chromium, chromium oxide, clay, amorphous silia, etc. may be used in place of or in combination with titanium dioxide. Typically, the amount of opacifying agent found to be useful in the invention is in the range of about 5 to 50% and preferably about 10 to 40% based on the weight of the sheet. Opacifying extenders like silica, alumina, and clay can be used with the furnish. Additives conventionally used in decor sheets such as alum, alkali and the like may be added in conventional amounts to control certain characteristics such as postforming. Wet strength resins may be added for wet strength characteristics. A retention aide may also be added if desired. Selection of the resin useful in the present invention will largely be governed by the intended end use of the finished decorative laminate. Amnioplasts such as melamine formaldehyde resin, acrylics such as polyacrylonitrile, polyester resins such as diallylphthalate, phenolic resins, polyurethanes, and epoxy resins may be used. The decor sheets of the present invention can be employed in conjunction with other sheets conventionally used in decorative laminates. For example, the decor sheet of the present invention may be bonded to a plurality of fibrous cellulosic core or body sheets which, typically, are unbleached kraft paper sheets impregnated with a thermosetting resin such as a phenol-formaldehyde resin. In addition, the laminate may be overlayed with a transparent overlay sheet which is, typically, a sheet of cellulose impregnated with melamine-formaldehyde resin. Particles of silica or other abrasion resistant particles may be incorporated into the overlay sheet to give added abrasion resistance to the sheet. In order for the overlay to be clear, the fiber, impregnating resin and the abrasion resistant particles must have an index of refraction close to each other. Decorative laminates in accordance with the present invention may be provided with glossy, matted or satin finishes in a known manner. Furthermore, properties such as flame retardant characteristics, abrasion resistance can be introduced using technology which is readily available and known in the art. The present invention is further illustrated by the following nonlimiting example. EXAMPLE 1 (Control) A single layer decor sheet having a basis weight of 62.2 grams per square meter was manufactured on a Fourdrinier paper machine forming wire from a cellulosic furnish to provide a decor sheet containing 21.0 grams TiO 2 per square meter. EXAMPLE 2 A dual layer decor sheet consisting of a primary layer (67%) and a secondary layer (33%) was manufactured using a first furnish similar to that used in Example 1. The furnish for the top layer was supplied from a second headbox and a second furnish, which differed from the first furnish in that the second furnish additionally contained 3% Stafor dispersed rosin internal size, was supplied from a primary headbox to provide the bottom layer. The finished dual layer decor sheet contained a total of 14.8 grams TiO 2 per square meter and 53.9% resin. The results are shown in Table I. TABLE I______________________________________ Resin TiO.sub.2 Scat. BW Amount TiO.sub.2, Ash Laminate Coef.,Example g/m.sup.2 % g/m.sup.2 % Reflect. lc.sup.2 /g______________________________________1 62.2 60.5 21.0 33.9 76.0 1818(Control)2 65.4 53.9 14.8 29.0 78.6 2587______________________________________ The Examples show an 11% savings in the amount of resin used and a 42% improvement in the scattering coefficient for TiO 2 in the dual layer (Example 2) when compared to the single layer (Example 1-Control). As illustrated in Table 1, the single layer decor sheet of Example 1 containing 21 g/m 2 TiO 2 had a laminate reflectance of 76. The dual layer decor sheet of Example 2 exhibited a comparable laminate reflectance but contained only 14.8 g/m TiO 2 . This represents a 29.5% savings in titanium dioxide to achieve the same hiding power as the control single ply sheet. Having described the invention in detail and by references to the preferred embodiments thereof, it will be apparent that modifications and variations are possible without departing from the scope of the invention defined in the appended claims.	A decor sheet for use in decorative laminates wherein the sheet is treated with a sizing agent to reduce its capacity for a laminating resin and enhance its opacity; in a preferred embodiment, the resin-impregnated decor sheet exhibits a resin gradient in the thickness direction to provide a decor sheet having a resin-rich top layer and a resin-starved bottom layer; in accordance with a preferred embodiment, the resin gradient is achieved by differentially sizing the bottom versus the top surface of the decor sheet; a decorative laminate employing such decor sheets are described.	3
TECHNICAL FIELD Embodiments relate to memory operation. And particularly, but not exclusively, embodiments may relate to monitoring the operation of a memory. BACKGROUND In memories, operations such as read and/or write take place in response to an enable signal, for example, a write enable signal. The write enable signal may be driven by a system clock, with an operation taking place at an operable clock edge of the system clock. Memories may require timing for further operations associated with the read and/or write operations. For example, timing for control operations of the memory, such as a bit line precharge, a word line assertion, and/or a sense amplifier enable, etc. Self-timed memories may provide these control timings independently of the system clock. These self-time memories may include additional circuitry for the generation of self-time control signals. However, operating conditions of a memory may affect the timing required for the memory. For example, memory components may require more time to operate correctly under low power conditions. Additionally, different requirements for the memory performance, for example, a high speed or low power performance, may affect the timing of the self-timed operations. Some memories may have built-in-self-test BIST capabilities in order to test the functioning of the memory. Other memories may have a test mode of operation in order to test the functionality of the memories. The testing of the memory may involve the external monitoring of data written to and read from the memory, and typical may take a number of clock cycles to identify an error. SUMMARY According to an embodiment, there is provided a memory block including: at least one memory cell; a sense amplifier configured to carry out a sensing operation on the at least one memory cell and determine whether the sensing operation is valid. The sense amplifier may be further configured to provide an indication of whether the sensing operation is valid. An indication of whether a sensing operation is valid may be provided to error correction circuitry. The sensing operation may include sensing a value stored in the at least one memory cell. The at least one memory cell may be part of a column of memory cells. The memory block may further include: at least one further column of memory cells; and at least one further sense amplifier associated with a respective at least one further column of memory cells. The at least one further sense amplifier may be configured to carry out a sensing operation on a memory cell of the associated at least one further column of memory cells and determine whether the sensing operation is valid. The at least one further sense amplifier may be configured to provide an indication of whether the sensing operation is valid. The memory block may further include: a combination circuit configured to receive the indications from the sense amplifier and the at least one further sense amplifier and determine whether at least one of the respective sensing operations is not valid. The combination circuit may be configured to provide an invalid signal to error correction circuitry in response to the indications from the sense amplifier and the at least one further sense amplifier. The memory block may further include error correction circuitry configured to determine a parameter of the memory block in response to an indication that a sensing operation is not valid. The parameter may be at least one of a sense amplifier enable signal delay, a sense amplifier current, a memory block voltage, and clock frequency. The memory block may further include error correction circuitry configured to replace one of: the at least one memory cell; the sense amplifier; and a data path in the memory in response to an indication that a sensing operation is not valid. The sense amplifier may carry out the sensing operation in response to an enable signal and the error detection circuitry may be configured to determine a delay in the provision of the enable signal in response to the indication. The sense amplifier may include: sensing circuitry configured to carry out the sensing operation on the at least one memory cell; and error detection circuitry configured to determine whether the sensing operation is valid. The sensing circuitry may include first and second process and hold circuits, each configured to process a difference between a value on a bit line input received at a first node and a value on a compliment bit line input received at a second node and hold the respective first and second nodes at values corresponding to the difference. The error detection circuitry may be configured to compare the value held at one of the first and second node of the first process and hold circuits and the value held at the other one of the first and second node of the second process and hold circuits. The first process and hold circuit may be biased towards one of the input on the first node and the input on the second node and the second process and hold circuit may be biased toward the other one of the input on the second node and the input on the first node. The error detection circuitry may be configured to compare the values held at the respective one of the first and second nodes of the first process and hold circuit and the second process and hold circuit corresponding to the input not biased toward. For each of the first and second process and hold circuits, the value at one of the first and second node corresponding to the biased toward input may determine the value held at the other one of the first and second node. According to an embodiment, there may be provided a method including: carrying out a sensing operation on at least one memory cell by a sense amplifier; and determining by the sense amplifier whether the sensing operation is valid. The method may further include: processing a difference between a value on a bit line input received at a first node and a value on a complement bit line input received at a second node and hold the respective first and second nodes at values corresponding to the difference. According to an embodiment, there may be provided a sense amplifier including: sensing circuitry configured to carry out a sensing operation on at least one memory cell; and error detection circuitry configured to determine whether the sensing operation is valid. According to an embodiment, there may be provided a memory block including: memory means for storing a value; sensing means for carrying out a sensing operation on the memory means and for determining whether the sensing operation is valid. According to an embodiment, there may be provided a sense amplifier including: sensing means for carrying out a sensing operation on at least one memory cell; and error detection means for determining whether the sensing operation is valid. BRIEF DESCRIPTION OF THE DRAWINGS Embodiments will be described with the reference to the following figures in which: FIG. 1 shows an example of a memory architecture according to some embodiments; FIG. 2 shows and example of method carried out by some embodiments; FIG. 3 shows an embodiment of memory circuitry with an adjustable delay; FIG. 4 shows an embodiment of memory circuitry with an adjustable delay; and FIG. 5 shows an example of a sense amplifier according to some embodiments. DETAILED DESCRIPTION Embodiments may provide a memory with adaptable timing for memory operations. The operation of a memory may be affected by factors such as operating conditions, process variations, and system requirements. In some embodiments, timing of the memory may be adjusted directly by, for example, adjusting the provision of timing control signal such as a sense amplifier enable signal by introducing delay. In other embodiments the timing may be adjusted indirectly. For example, by adjusting memory power, the delay in the provision of a sense amplifier enable signal required for a correct operation of the memory may be reduced. In additional or alternative embodiments, the delay required in the provision of the sense amplifier enable signal may be reduced by replacing failure-prone memory cells. In embodiments, timing may be adapted in response to an indication from a sense amplifier. Embodiments may relate to the generation of a sense amplifier enable signal. A sense amplifier enable signal may be generated in some embodiments at a time when a differential voltage provided to a sense amplifier is greater than a minimum differential voltage required by the sense amplifier. Embodiments may also provide sense amplifier circuitry capable of indicating an error in a read operation. For example the sense amplifier may generate an output indicating that a differential voltage provided to the sense amplifier was not greater than a minimum differential voltage required by the sense amplifier. Alternatively or additionally, the sense amplifier may indicate that an error has occurred in a read operation. FIG. 1 shows an example of a memory architecture in accordance with an embodiment. FIG. 1 includes a memory cell array 100 . The memory cell array 100 may include an array of memory cells arranged in rows and columns. Each row of the memory cell array 100 may be coupled to a respective word line and each column of the memory cells may be coupled to a respective bit line 101 . In some embodiments, each respective bit line may be a differential pair, for example, a bit line and an inverted bit line. It will be appreciated that this is by way of example only, and the memory cell array 100 may be arranged or include any appropriate circuitry for implementing a memory cell array. It will also be appreciated that the circuitry of the memory cells themselves may differ with embodiments and may be any suitable circuitry for storing information. The memory cells of the memory cell array 100 of FIG. 1 may be configured to store information, for example, a data value such as a logic 1 or logic 0. The memory cells may be coupled to a word line in such a way that an active or asserted word line may address a row of memory cells. The memory of FIG. 1 may further include an address decoder 104 coupled to the memory cell array 100 via word line control lines 103 . The word line control lines 103 may correspond to respective word lines of the memory cell array 100 , and may be used to address rows of the memory cell array 100 corresponding to an asserted word line control line 103 . The memory may also include sense amplifiers 102 . The sense amplifiers 102 may be coupled to the memory cell array 100 via the bit lines 101 (for example the bit line and inverted bit line for each column). The sense amplifiers 102 may be configured to write to and/or read from a row of memory cells addressed by a word line. The sense amplifiers 102 may provide sense amplifier outputs 106 corresponding to the read information. It is appreciated that in some embodiments, where the sense amplifiers 102 may be used to write to the memory cell array 100 , the sense amplifier outputs 106 may also be used as inputs to provide information to the sense amplifiers 102 to be written to the memory cell array 100 . The memory of FIG. 1 may additionally include a memory control block 105 . The memory control block 105 may be coupled to one or more of the address decoder 104 , the memory cell array 100 , and the sense amplifiers 102 via control signals. For example, the memory control block 105 may be coupled to the sense amplifiers 102 via a control line(s) 108 . In embodiments, the control line may be a sense amplifier enable signal. In some embodiments, the memory control block 105 may provide a common or respective write and/or read enable signal to the address decoder 104 , sense amplifiers 102 , and/or the memory cell array 100 via the control lines. In some embodiments, the memory control block 105 may provide a read output 107 . The read output 107 may correspond to information read from the memory cell array 100 , and may be provided to further circuitry and/or a system bus. It is appreciated that this is by way of example only, and information read from the memory cell array 100 may be provided to any further circuitry via the sense amplifier outputs 106 . It is also appreciated that in some embodiments, the memory control block 105 may be coupled to the other circuitry of the memory via other signals (not shown). In operation, the memory of FIG. 1 may carry out a read or a write operation. In some embodiments, the memory control block 105 may control the operation of the memory during the read and/or write operation. Alternatively, in other embodiments, further control circuitry may be provided for controlling memory operation. It is appreciated that a read or write operation may take place in response to a read and/or write enable signal. In an embodiment, a write enable signal may go low, indicating that a read operation is to take place. The memory control block 105 may control a pre-charge circuit to pre-charge the bit lines. It is appreciated that the pre-charge circuit may form part of the memory cell array 100 , the sense amplifiers 102 , or may be separate circuitry. Once the bit lines have been pre-charged, the address decoder 104 may assert a word line corresponding to the word in the memory cell array 100 to be read from. In some embodiments, the address decoder 104 may receive an indication of the word to be read and assert the word line via control of the word line control lines 103 . The memory cells coupled to the word line may transfer some of their charge to their respective bit line and inverted bit line. It is appreciated that embodiments may relate to any type of memory using sense amplifiers or their equivalent. For example, embodiments may be applied to semiconductor memories in very-large-scale integration VLSI systems such as Dynamic Random Access Memory (DRAM) or Static Random Access Memory (SRAM). It is appreciated that the architecture of the memory cells and the mechanism of the transfer of charge may differ according to the type of memory; however, it is appreciated that embodiments may be applicable to different memory types. In some embodiments, a memory cell may actively drive a bit line and inverted bit line to a low and high value in dependence on the value stored in the memory cell. In other embodiments, a memory cell may cause a charge differential on the differential bit lines by transferring or absorbing charge from one or both of the differential bit line pair. A sense amplifier enable signal may then enable the sense amplifiers 102 corresponding to each bit line pair to amplify and hold a voltage difference between the bit line and inverted bit line of the bit line pair. The value of the bit line and inverted bit line may indicate the value stored by the memory cell. For example, a bit line value of ‘1’ and inverted bit line value of ‘0’ may indicate that a ‘1’ was stored in the memory cell. The sense amplifier 102 may then provide a logic 1 or 0 at the sense amplifier output 106 corresponding to the value stored in the respective memory cell. In order for information to be read from a memory cell correctly, enough charge should be transferred and/or absorbed from the memory cell differential bit line pair such that a corresponding sense amplifier may amplify and hold the difference. For example, if a sense amplifier is enabled before sufficient charge is transferred to the bit line pair, the difference between the bit line and the inverted bit line may be insufficient for the sense amplifier to successfully provide an output. For example, the sense amplifier may provide an incorrect output (e.g., 0 instead of a 1), or the sense amplifier may provide a default output of 1 or 0. The minimum differential voltage on a bit line pair required for a successful sensing of data stored in a memory cell may be V critical . V critical may be affected by various factors. For example, process voltage and temperate variations of the memory may affect the value of V critical . Memories may be subject to dynamic scaling techniques, for example, voltage and/or frequency scaling, in order to improve efficiency and/or increase speed of a memory. This scaling may affect the value of V critical for a sense amplifier. Additionally, the time taken for the differential voltage on a bit line pair to reach V critical may also be affected by such factors. Embodiments may control the sense amplifiers 102 in order to take factors such as these into account. In some embodiments, operation of a memory may be configured and errors, for example read errors, may be corrected. In some embodiments, a sense amplifier may be provided that provides an indication of whether a sensing operation carried out on a differential bit line pair is valid or not. In some embodiments, the output of a sense amplifier may be corrected. In some embodiments, errors may be corrected or addressed by determining parameters of the memory. These parameters may be, for example, the timing of the generation of an enable signal, a current supplied to a sense amplifier, a voltage provided to the memory cells, and/or sense amplifier and/or a system clock. It is appreciated that other parameters may be adjusted. Additionally or alternatively, in some embodiments, memory cells may be replaced in response to an error being detected. In some embodiments, an operation of a sense amplifier may be monitored, and a generation of sense amplifier enable signal may be controlled which may attempt to avoid sensing errors. In some embodiments, parameters of the memory may be controlled in order to decrease the time taken for the differential bit lines to reach V critical in a read operation. In some embodiments, the operation of a sense amplifier may be monitored to determine whether a column of memory cells associated with that sense amplifier should be replaced. In some embodiments, the memory control block 105 of FIG. 1 may control the generation of the sense amplifier enable signal in response to the behavior of at least one sense amplifier. Additionally, in some embodiments, the memory control block 105 may receive the sense amplifier outputs 106 and provide correction before providing the sense amplifier outputs to further circuitry, for example, a system bus. In operation, once the memory control block 105 receives an indication (from a sense amplifier or in the form of an invalid signal), the control block may control a correction of the read operation. For example, in some embodiments, the read operation may be carried out again with a longer time period between coupling the pre-charged bit lines to the memory cell and enabling the sense amplifiers. Alternatively or additionally, for example, a voltage supplied to the sense amplifier, the memory, and/or pre-charge of the differential bit lines may be adjusted. In some embodiments, the memory control block 105 may replace a column of memory cells that indicate an invalid operation with a back-up or redundant column of memory cells. A row and/or column of memory cells may be replaced. In some embodiments, a sense amplifier may be replaced. In other or additional embodiments, a data path in the memory may be replaced. Alternatively, no action may be taken in the memory in response to an invalid operation, and a controller for the memory may implement changes in other parts of system in which the memory is a part to address any error. FIG. 2 shows an example of a method carried out by embodiments. It is appreciated that in some embodiments, the method of FIG. 2 may be carried out in conjunction with the circuitry of FIG. 1 . For example, the method of FIG. 2 may be carried out by the memory control block 105 . At step 200 of FIG. 2 , the control circuitry, for example, the memory control block 105 , receives an indication from a sense amplifier whether or not a sensing operation is valid. The indication may indicate that a differential voltage on a bit line pair was sufficient for the sensing operation to take place without error. The indication may be an indication of whether or not an error in the sensing operation has been detected. In some embodiments, the control circuitry may receive an indication from each sense amplifier, a combined signal indicative of the indication from each sense amplifier, or an indication from only one or some of the sense amplifiers. The sense amplifiers may provide an indication of whether or not the differential voltage V diff input into the sense amplifier was greater than V critical . A determination is made at step 201 of whether the sensing operation was valid, for example, a determination of whether V diff was greater than V critical . If the sensing operation was valid (for example if V diff was greater than V critical ), then the time between the assertion of the word line and provision of the sense amplifier enable signal was long enough for enough charge to be transferred to satisfy V critical . In this case, the method returns to step 200 . In some embodiments, a delay of providing the sense amplifier enable signal may be decreased as shown by optional step 203 . It is appreciated that this may only be under certain conditions. For example, the delay may be decreased if no error occurs for a given delay in the provision of the sense amplifier enable signal. The detection of no delay may indicate that the speed of the memory may be increased without error. Alternatively, other parameters may be adjusted in response to the detection of a successful operation. For example a voltage supplied to the memory may be reduced until a fail is detected. If the sensing operation is determined to be invalid (for example, if V diff was not greater than V critical ), then the memory may require a longer time between the assertion of the word line and the provision of the sense amplifier enable signal to the sense amplifier for the transfer of charge. In this case, the method progresses to step 202 , where a delay in the provision of the sense amplifier enable signal to the sense amplifiers 102 is increased. The method may then return to step 200 , where indications of a next read operation are received. In embodiments, a delay is introduced in the enablement of the sense amplifiers in order to provide enough time for charge to be transferred from a memory cell to the bit lines. In the example of FIG. 2 , a delay in the provision of a sense amplifier enable signal is adjusted in response to an invalid indication. It is, however, appreciated that other responses to an invalid indication are possible. For example, a voltage supplied to the memory may be adjusted. The adjustment in voltage may affect, for example, the minimum time required for sufficient charge to be transferred to the pre-charged bit lines from a memory cell. In this case, although a delay in the provision of the sense amplifier enable signal is not adjusted, the sense amplifiers may not detect an invalid operation at the next read due to the voltage adjustment. It is appreciated that the memory control block 105 may implement dynamic voltage scaling based on this. Additionally or alternatively, other parameters may be adjusted. The parameters (for example, voltage, frequency, and/or delay) may be determined by performance requirements of a memory. For example, in a high speed memory, the delay may be minimized at the expense of power consumption, whereas in a low power memory, power consumption may be reduced at the expense of speed. FIG. 3 shows an embodiment of the memory control block 105 of FIG. 2 and part of the sense amplifiers 102 . It is appreciated that in some embodiments, FIG. 3 shows only part of the circuitry of the memory control block 105 of FIG. 1 , and the memory control block 105 may include further circuitry, for example, for the control of the address decoder 104 and provision of a write enable signal. FIG. 3 shows a dummy referencing block 300 . The dummy referencing block 300 may form part of the memory control block 105 in some embodiments. The dummy referencing block provides an output 108 to sense amplifiers 310 , 311 and 312 . It is appreciated that the sense amplifiers 310 , 311 , and 312 may form part of the sense amplifiers 102 of FIG. 1 . It is also appreciated that the output 108 may correspond to the sense amplifier enable signal 108 of FIG. 1 and may be provided to the sense amplifiers 102 . It is appreciated that more than the three sense amplifiers 310 , 311 , and 312 may be provided, and this is indicated by the dashed line. Each sense amplifier 310 , 311 , 312 may be coupled to a differential bit line pair and provide an output 314 . The outputs 314 may be an indication of whether a sensing operation is valid. For example, the indications 314 may correspond to whether or not the differential voltage on the bit line pair is greater than a critical voltage V critical for the sense amplifier. It is also appreciated that the sense amplifiers may have a further output corresponding to a sensed value stored in a respective memory cell. The indications 314 are input into an AND gate 320 . The AND gate 320 provides an output 321 to the dummy referencing block 300 . In one example, an indication 314 of a sense amplifier may be a logic ‘1’ if the differential voltage is greater than a critical voltage. The AND gate 320 may AND the indications 314 from each sense amplifier. If the differential voltage of one of the sense amplifiers is less than a critical voltage, then that sense amplifier indication 314 will be a logic ‘0’ and the AND gate 320 may output a logic ‘0’. The dummy referencing block 300 may include a dummy column 301 . The dummy column 301 may be a column of memory cells similar to the columns of memory cells in the memory cell array 100 . The dummy column 301 may be manufactured with the memory cell array 100 and may be subject to the same process variations as the memory cell array 100 . In some embodiments, the dummy column may be used as a feedback of behavior of the memory cell array 100 . This may be because the dummy column behaves similarly to the memory cell array 100 . The dummy column 301 may be used in the generation of self-timing signals for the memory. For example, the dummy column may be used to generate an initial sense amplifier enable signal according to memory self-timing. The dummy column may include a number of memory cells and may generate a reference signal by discharging a bit line of the dummy column 301 . The reference signal may be used to generate a sense amplifier enable signal, which may further be delayed in some embodiments. The dummy column 301 may provide a sense amplifier enable signal output to a number of delay lines 304 , 305 , 306 , and 307 . Each of the delay lines 304 , 305 , 306 , and 307 may correspond to a different delay. For example, the delay line 307 may provide no delay and the delay line 304 may provide a maximum delay. The delay lines 305 and 306 may provide delays between the maximum delay line 304 and the no delay line 307 . It is appreciated that while four delay lines are depicted in FIG. 3 , more or fewer lines may be implemented in embodiments. It is also appreciated that the delay lines may incorporate any circuitry capable of causing a delay, and may, in some embodiments, be programmable. The delay lines 304 , 305 , 306 , and 307 may form inputs to a multiplexor 303 . The multiplexor 303 may have a selection input coupled to the output of a counter 302 . A count value of the counter, provided on the counter output, may select one of the delay lines 304 , 305 , 306 , and 307 . The multiplexor 303 may provide the sense amplifier enable signal output delayed by the selected delay line 304 , 305 , 306 , or 307 . In operation, the sense amplifiers may provide an indication of a valid sensing operation, for example an indication of whether a voltage difference on a respective bit line pair satisfies the critical voltage requirement. If at least one of the sense amplifiers has insufficient differential voltage, the AND gate 320 provides a logic ‘0’ as the input the counter 302 . It is appreciated that this is by way of example only, and other logic gates or circuitry may be implemented to provide an indication that at least one sensing operation may be invalid. The logic ‘0’ from the AND gate 320 may cause the counter 302 to increment. In this embodiment, the counter may be a hot counter and may be implemented with a ring buffer. The count value from the counter 302 may be provided to the multiplexor 303 and used to select one of the delay lines 304 , 305 , 306 , and 307 . For example, a count value may correspond to a delay line input—if the count value is 0, then the delay line 307 may be selected, if the count value is 1, then the delay line 306 may be selected, etc. It is appreciated that any correspondence between the delay line and count value may be used. In this manner, a first error (corresponding to an invalid sensing operation) may increase a delay of the sense amplifier enable signal; the second error may increase the delay; etc. until a maximum delay is reached. When the sense amplifier enable signal is generated by the dummy column 301 , it is first delayed by the respective delay lines. The multiplexor may couple the selected delay line to the sense amplifier enable signal output 108 , and the sense amplifier enable signal will be output on the sense amplifier enable output 108 in accordance with the selected delay. In embodiments, the enablement of the sense amplifiers may be controlled in order to provide sufficient time for charge to be transferred from a memory cell. In some embodiments, the enablement of the sense amplifiers may be controlled to minimize power consumption. For example, a voltage of the memory may be lowered to conserve power, which may result in a longer delay being required for the sense amplifier enable signal. In other embodiments, an enablement of the sense amplifiers may be controlled to increase a memory speed. For example, the delay may be set to a minimum and other parameters, for example, a voltage of the memory may be adjusted for correct operation. It is appreciated that the memory control block may include other control circuitry for other parameters in the memory, such as a clock frequency or voltage level, which may be controlled in conjunction with the enablement of the sense amplifiers. In some embodiments, sensing operation validity signals may be monitored for each sense amplifier. Some embodiments may implement redundant or spare columns. If, for example, it is determined that one column of the memory array fails more often than the other columns, that column may be disconnected and replaced by a redundant column. FIG. 4 shows another embodiment of the memory. Alternatively to the embodiment of FIG. 3 , the signal 321 of FIG. 4 is generated by a sense amplifier 401 of a dummy column 400 . The dummy referencing block 300 of FIG. 4 is similar to that of FIG. 3 . The dummy referencing block 300 provides the sense amplifier enable signal 108 to the sense amplifiers 102 coupled to the memory cell array 100 via the bit line pairs 101 . The sense amplifiers 102 may provide sense amplifier outputs 106 . It is appreciated that this may be similar to the circuitry of FIG. 1 . The sense amplifier enable signal 108 of FIG. 4 may also be provided to a sense amplifier 401 of a dummy column 400 . In some embodiments, the dummy column 301 and the dummy column 400 may be the same column. In other embodiments, the dummy column 301 and the dummy column 400 may be different columns. Similar to dummy column 301 , the dummy column 400 and sense amplifier 401 may have been manufactured with the memory cell array 100 and sense amplifiers 102 , and may have been subjected to the same manufacture and process variations. The dummy column 400 and sense amplifier 401 may, therefore, provide a similar indication 321 of whether a differential voltage on a different bit line pair of the dummy column 400 is greater than a critical voltage. Alternatively or additionally, the dummy column 400 and sense amplifier 401 may be modified to be more likely to have an invalid sensing operation than the memory cell array 100 and sense amplifiers 102 . This may be done, for example, by modifying operating parameters of the dummy column 400 and the sense amplifier 401 , for example, by decreasing a power provided to the sense amplifier 401 and dummy column 400 . Alternatively or additionally, a mismatch of the components of the dummy column 400 and sense amplifier 401 may be increased. The indication 321 from the sense amplifier 401 may be provided to the dummy referencing block. It is appreciated that the dummy referencing block 300 of FIG. 4 operates similarly to that of FIG. 3 . In some embodiments, only one sense amplifier may provide an indication of an invalid operation, in other embodiments two or more sense amplifier may provide an indication. The capability of providing an indication may be selectable in some embodiments. For example, sense amplifiers for columns of memory cells that tend to fail may be enabled to provide an indication. For example, some of the memory cells may be affected by random dopant fluctuations and may require a longer period between coupling of the pre-charged bit lines and enablement of the sense amplifiers for successful operation under the same conditions as other memory columns. In some embodiments, these affected memory cells may be read via a delay path for the sense amplifier enable signal while the other memory cells may be read without the delay path. In some embodiments, the delayed sense enable signal may be provided to some of the sense amplifiers and a non-delayed signal to other sense amplifiers. FIG. 5 shows an example of a sense amplifier in accordance with embodiments. It is appreciated that the sense amplifier of FIG. 5 may be implemented as any sense amplifier in the foregoing configured to provide an indication such as indication 321 or indications 314 . As such, the sense amplifier block 102 may be implemented with the sense amplifier of FIG. 5 in some embodiments. In other embodiments, only one or some sense amplifiers may be implemented in accordance with the sense amplifier of FIG. 5 . A sense amplifier according to embodiments may be coupled to a bit line BL and an inverted bit line BLB. When a word line is asserted, an addressed memory cell may pull one of this bit line pair high and the other low, creating a differential voltage across the bit line pair. When the sense amplifier enable signal En having an active logic high value is provided to the sense amplifier, the sense amplifier may amplify and hold the difference between the lines, driving one of the sense-amplifier input/output nodes high and the other sense-amplifier input/output nodes low. When the differential voltage V diff created by the memory cell on the bit line pair is too low, the sense amplifier may not operate correctly, and thus may not drive the correct output nodes low and high, respectively. In embodiments, a validity of the sensing operation may be detected by providing the sense amplifier as two imbalanced differential amplifiers. The first differential amplifier may have a first node coupled to the inverted bit line BLB and a second node coupled to the bit line BL. The second differential amplifier may have a first node coupled to the bit line BL and a second node coupled to the inverted bit line BLB. The first and second differential amplifiers may be such that they are biased towards an input on either a bit line or compliment/inverted bit line input. The first and second differential amplifiers may be biased on opposite inputs. It is appreciated that the biased towards input may be considered a ‘stronger’ input as a value on the other input may be determined by a value on the biased towards input. For example, either the first nodes or the second nodes form the stronger or biased toward input to the amplifier. During a read operation, the value at the nodes corresponding to the weaker inputs, or not biased toward inputs, of the amplifiers are compared. If the weaker nodes hold the same value, a sensing operation is invalid. For example, the first and second amplifiers of FIG. 5 are imbalanced such that the second nodes are the stronger nodes. During a read operation, if V diff is greater than V critical , then the difference between the first and second nodes (from the bit line pair) will be large enough for the sense amplifier to sense correctly. If V diff is less than V critical , then the second node will be considered to be a default value (for example a high or a low) by the sense amplifier and invert the first node at both the first and second differential amplifiers. In this case, both the first nodes of the differential amplifiers will be same and the sensing operation will be indicated as invalid. It will be appreciated that the differential amplifier may be imbalanced (or be biased toward an input) in a variety of manners. For example, transistors in a differential amplifier may have different sizes and/or have different capacitances. Alternatively or additionally, charge may be injected into the circuit. FIG. 5 shows an example of circuitry for the implementation of a sense amplifier according to some embodiments. FIG. 5 includes a first differential amplifier 510 and a second differential amplifier 520 . An output from a first node X 1 of the first differential amplifier 510 and an output of a first node X 2 of the second differential amplifier 520 are provided via respective inverting delays 532 to an XOR gate 534 , which provides an output 535 . The first differential amplifier 510 includes a first p-channel transistor 511 having a gate terminal coupled to an enable signal En and a source terminal coupled to a bit line BL. A drain terminal of the first p-channel transistor 511 is coupled to the first node X 1 and further to respective drain terminals of a third p-channel transistor 512 and a first n-channel transistor 513 . The first differential amplifier 510 also includes a second p-channel transistor 517 having a gate terminal coupled to the enable signal En and a source terminal coupled to an inverted bit line BLB. A drain terminal of the second p-channel transistor 517 is coupled to a second node Y 1 and further to respective drain terminals of a fourth p-channel transistor 514 and a second n-channel transistor 515 . A respective source terminal of the third p-channel transistor 512 and the fourth p-channel transistor 514 are coupled to a power source for the sense amplifier. A respective source terminal of the first n-channel transistor 513 and the second n-channel transistor 515 are coupled to a drain terminal of a third n-channel transistor 516 . A source terminal of the third n-channel transistor 516 is coupled to ground, and a gate terminal of the third n-channel transistor is coupled to the enable signal En. A gate terminal of the third p-channel transistor 512 is coupled to a gate terminal of the first n-channel transistor 513 and coupled to the second node Y 1 . A gate terminal of the fourth p-channel transistor 514 is coupled to a gate terminal of the second n-channel transistor 515 and further coupled to the first node X 1 . The second differential amplifier 520 may have similar structure to the first differential amplifier 510 . The second differential amplifier 520 includes a first p-channel transistor 521 having a gate terminal coupled to the enable signal En and a source terminal coupled to the inverted bit line BLB. A drain terminal of the first p-channel transistor 521 is coupled to the first node X 2 and further to respective drain terminals of a third p-channel transistor 522 and a first n-channel transistor 523 . The second differential amplifier 520 also includes a second p-channel transistor 527 having a gate terminal coupled to the enable signal En and a source terminal coupled to the bit line. A drain terminal of the second p-channel transistor 527 is coupled to a second node Y 2 and further to respective drain terminals of a fourth p-channel transistor 524 and a second n-channel transistor 525 . A respective source terminal of the third p-channel transistor 522 and the fourth p-channel transistor 524 are coupled to a power source for the sense amplifier. A respective source terminal of the first n-channel transistor 523 and the second n-channel transistor 525 are coupled to a drain terminal of a third n-channel transistor 526 . A source terminal of the third n-channel transistor 526 is coupled to ground and a gate terminal of the third n-channel transistor is coupled to the enable signal En. A gate terminal of the third p-channel transistor 522 is coupled to a gate terminal of the first n-channel transistor 523 and coupled to the second node Y 2 . A gate terminal of the fourth p-channel transistor 524 is coupled to a gate terminal of the second n-channel transistor 525 and further coupled to the first node X 1 . The enable signal En at the gates of transistors 511 , 517 , 521 , 527 , 516 , and 526 may correspond to the sense amplifier enable signal in some embodiments, or may be a different signal derived from the sense amplifier enable signal in other embodiments. For example, the enable signal En may be a pass enable signal. In operation, during a read operation, the bit line BL and the inverted bit line BLB may be precharged before a word line is asserted for the addressed cells. The pre-charge may be carried out in response to a pre-charge enable signal. This precharge may correspond to a logic ‘1’ of the pre-charge enable signal in some embodiments. When the word line is asserted, the addressed memory cells may be coupled to the respective pre-charged bit line pairs corresponding to those cells. Furthermore, during the precharge period, the signal En has an inactive level (here a logic low level), so that the transistors 511 , 517 , 521 , and 527 are “on’, and the transistors 516 and 526 are “off”. Once coupled to the bit line pair while the corresponding word line is asserted, a memory cell may drive one line of the bit line pair toward high and the other toward low. This may be through discharging one of the bit lines. For example, if a memory cell is storing a ‘1’, when the bit line pair is coupled, the memory cell may start to discharge the inverted bit line BLB and drive the bit line BL high. If the memory cell is storing a ‘0’, the inverted bit line BLB may be driven high and the bit line BL may start to be discharged or pulled low. The sense amplifier of FIG. 5 may sense a voltage difference between the bit line BL and inverted bit line BL and amplify and hold this difference. The sense amplifier may drive one line of the bit line pair high and the other low, and output the value of the memory cell on the sense-amplifier outputs X 1 , X 2 , Y 1 , and Y 2 . For example, during a read operation, the bit line BL, inverted bit line BLB, and the nodes X 1 and Y 1 of FIG. 5 may be pre-charged while the signal En is inactive low. A word line corresponding to a word of memory cells to be read may then be asserted and the memory cell being read by the sense amplifier of FIG. 5 may start to pull one of the bit line pair high and the other low. The enable signal En may then be asserted active logic high, thus uncoupling the first node X 1 of the first differential amplifier 510 from the bit line BL and the second node Y 1 of the first differential amplifier 510 from the inverted bit line BLB, as well as coupling the respective sources of the first and second n-channel transistor 513 and 515 to ground via the on third n-channel transistor 516 . If the memory cell was storing a ‘1’, then the node X 1 would start to be pulled high and the node Y 1 would start to be pulled low. The higher value at the first node X 1 is coupled to the gates of the fourth p-channel transistor 514 , tending to turn it off, and to the gate of the second n-channel transistor 515 , tending to turn it on. The tending-toward-on second n-channel transistor 515 may pull the second node Y 1 toward low, which may pull the gate terminals of the third p-channel transistor 512 and the first n-channel transistor toward low, tending to turn the first n-channel transistor 513 off and the third p-channel transistor 512 on. The tending-toward-on third p-channel transistor 512 may pull the first node X 1 toward high while the tending-toward-on second n-channel transistor 515 pulls the second node Y 1 toward low. Thereafter, the first differential amplifier 510 pulls the node X 1 high and pulls the node Y 1 low; therefore, after En transitions to an active logic high, X 1 and Y 1 provide the read signal for a corresponding bit of the read data. The second differential amplifier may operate similarly except that the inverted bit line BLB is coupled to the first p-channel transistor 521 and pulls the first node X 2 toward low while the second node Y 2 is pulled toward high by the bit line BL. It can be seen that while the enable signal En is active high, the differential amplifier 510 may operate as an inverter, inverting the high value at node X 1 to a low value at node Y 1 , and inverting the low value at node Y 1 to a high value at node X 1 . The second node Y 1 may be a stronger inverting input. In other words, if the first node X 1 and the second node Y 1 were input the same value, for example ‘1’, the second node Y 1 would invert the first node X 1 as it is the stronger inverted node—for example Y 1 would be ‘1’ and X 1 would be inverted to ‘0’. In order for the first differential amplifier 510 to provide values at the first node X 1 and the second node Y 1 corresponding to the value stored in the memory cell, the voltage difference between the bit line BL and inverted bit line BLB must be greater than a voltage threshold for the operation of the first differential amplifier. In other words Vdiff>Vcritical. The second differential amplifier may be similar to the first differential amplifier except that the second node Y 2 , which is the stronger inverting input node, corresponds to the value of the bit line BL, and not the inverted bit line BLB, as in the first inverting amplifier. In other words, if Vdiff is insufficient, the high value induced by the inverted bit line BLB at node Y 1 will invert node X 1 to a low value after En transitions to an active logic high, and the high value induced by the bit line BL at node Y 2 will invert the node X 1 to a low value after En transitions to an active logic high. The XOR gate 534 receives the value of the first node X 1 of the first inverting amplifier 510 and the first node X 2 of the second inverting amplifier 520 and, after En transitions to an active logic high, provides an indication of whether these values at the nodes X 1 and X 2 are the same. If the values are the same, it may be determined that V diff was not >V crtitical . So in summary according to an embodiment, first, the bit line BL and inverted bit line BLB are precharged, e.g., to a logic 1, while En is inactive logic low. Next, a word line is activated so as to couple a memory cell to the precharged lines BL and BLB. Then, at some time after the word line is activated, En transitions to an active logic high. If Vdiff>Vcritical, then the voltage difference across BL and BLB is sufficient to drive nodes X 1 and Y 2 toward the logic level on BL, and to drive the nodes X 2 and Y 1 toward the logic level on BLB. Because En is an active logic high, it causes the transistors 511 , 517 , 521 , and 527 to deactivate and isolate the nodes X 1 , Y 2 and X 2 , Y 1 from BL and BLB, respectively, so that the sense amplifier fully drives nodes X 1 and Y 2 to the logic level previously on BL (while En was at a logic low) and fully drives nodes X 2 and Y 1 to the logic level previously on BLB. Because X 1 ≠X 2 , the gate 534 indicates that the data output by the sense amplifier on nodes X 1 , X 2 , Y 1 , and Y 2 is valid. In contrast, if Vdiff≦Vcritical, then the voltage difference across BL and BLB is insufficient to drive nodes X 1 and Y 2 toward the logic level on BL, and to drive the nodes X 2 and Y 1 toward the logic level on BLB. Because En is an active logic high, it causes the transistors 511 , 517 , 521 , and 527 to deactivate and isolate the nodes X 1 , Y 2 and X 2 , Y 1 from BL and BLB, respectively, so that the sense amplifier fully drives nodes X 1 and X 2 to a logic low level and fully drives nodes Y 1 and Y 2 to a logic high level, because the nodes Y 1 and Y 2 are the stronger inverting nodes (if X 1 and X 2 where the stronger inverting nodes, then the sense amplifier would fully drive nodes X 1 and X 2 to a logic high level and nodes Y 1 and Y 2 to a logic high level). Because X 1 =X 2 , the gate 534 indicates that the data output by the sense amplifier on nodes X 1 , X 2 , Y 1 , and Y 2 is invalid. It is appreciated that this is by way of example only, and the comparison may be made on the stronger inverting node of each differential amplifier. Additionally, the first node of each amplifier 510 and 520 may be made the stronger input. Moreover, the read output form the sense amplifier of FIG. 5 may be derived from X 1 -Y 1 , X 2 -Y 2 , or both X 1 -Y 1 and X 2 -Y 2 , when the output of the XOR gate 534 equals a logic 1. Although the foregoing has described transistors as being n-channel and p-channel MOSFETs, it is appreciated that other circuitry may be used. For example, other types of transistors may be used to implement circuitry, and the channel type of the transistors may change with subsequent modification to the circuitry. Although the foregoing has described a bit line and inverted bit line as forming part of a differential pair, it is appreciated that a compliment bit line and bit line may form the pair, the terms inverted bit line and compliment bit lines being interchangeable. It is appreciated that embodiments may be implemented in conjunction with multiplexed memories. For example, a sense amplifier may be associated with more than one column of memory cells and a column to be operated on may be selected. For example the sense amplifiers may be used to carry out a memory operation on one set of memory cells under a first condition (for example those memory cells being selected) and a second set of memory cells under a second condition (for example the second set of memory cells being selected). In some embodiments, the memory may be for example a mux-2 or mux-4 memory and a sense amplifier may be associated with 2 or 4 columns of memory cells, respectively. It is also be appreciated that a signal indicating an error in operation of the memory may be used by any appropriate circuitry within or additional to the memory. For example, such a signal may be provided to circuitry external to the memory and may be used to correct an error or compile information regarding the error. In some embodiments, for example, such a signal may be provided from a cache memory to a processor within a system in which the memory is implemented. It is also appreciated that the circuitry of the imbalanced differential amplifiers is by way of example only, and other circuitry may be used to implement the amplifiers. In addition, an embodiment of a memory, such as an embodiment of the memory of FIG. 1 , may be combined with one or more other integrated circuits, such as a controller, e.g., a processor, to form a system, where the memory and other integrated circuit(s) may be disposed on a same die (e.g., system on a chip) or on a different die. From the foregoing it will be appreciated that, although specific embodiments have been described herein for purposes of illustration, various modifications may be made without deviating from the spirit and scope of the disclosure. Furthermore, where an alternative is disclosed for a particular embodiment, this alternative may also apply to other embodiments even if not specifically stated.	An embodiment of a sense amplifier includes a sense circuit and a monitor circuit. The sense circuit is configured to convert a first signal that corresponds to data stored in a memory cell into a second signal that corresponds to the data, and the monitor circuit is configured to indicate a reliability of the second signal. The monitor circuit allows, for example, adjusting a parameter of a memory in which the memory cell is disposed to increase the read accuracy, and may also allow recognizing and correcting an error due to an invalid second signal.	6
CROSS REFERENCE TO RELATED APPLICATIONS Not Applicable STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT Not Applicable DESCRIPTION OF ATTACHED APPENDIX Not Applicable BACKGROUND OF THE INVENTION This invention relates generally to the field of surfactants and more specifically to novel ether sulfonate surfactants, a process for making same, and applications for their use. Surfactants are used for a wide variety of applications because their unique structures impart special properties to systems containing them. These properties include the ability to allow immiscible liquids such as oil and water to mix, to improve the wetting properties of a liquid on a solid, to allow solids to be suspended in liquids, and to foam liquids. It is for these reasons that surfactants find widespread use in many industries including, but not limited to, agriculture, adhesives, coatings, deinking, detergents, emulsion polymerization, laundry, lubricants, metal working, mining, oilfield, personal care, pharmaceuticals, and soil remediation. Surfactants can be divided into four main classes by the charges they carry. The four classes are (1) nonionic surfactants having no charge, (2) anionic surfactants having a negative charge, (3) cationic surfactants having a positive charge, and (4) amphoteric surfactants having positive, negative or no charge depending on the pH of the system in which the surfactant is contained. The properties associated with the different types of surfactants are described in many articles and books including Rosen, Surfactants and Interfacial Phenomena , (1978). A compilation of most of the surfactants available along with their properties and a list of their manufacturers is available from McCutcheon's Emulsifiers and Detergents (2001). Of the four classes of surfactants, anionic surfactants are found to have the most widespread uses and are produced in the largest volume. This is primarily due to their lower cost, better performance, and because of the applications where they are used such as laundry, personal care, household, institutional and industrial cleaning, agriculture and coatings, that tend to require large volumes of lower cost material made from readily available raw materials. The anionic surfactants are essentially various sulfates, sulfonates, phosphates, phosphonates, and carboxylates. The chemistry of these products is very well described in Anionic Surfactants - Organic Chemistry, Volume 56, Surfactant Science Series, Marcel Dekker (1995). Their physical properties are addressed in Anionic Surfactants - Physical Chemistry of Surfactant Action, Volume 11, Surfactant Science Series. Marcel Dekker (1981). The most common and widely used anionic surfactants are the sulfates and the sulfonates. These include alcohol sulfates, alcohol ether sulfates, glycerol sulfates, alkoxylated alkylphenol sulfates and sulfonates, alkylaryl sulfonates, alpha-olefin sulfonates, alkane sulfonates, and sulfosuccinates. Sulfonates are generally more thermally and hydrolytically stable then sulfates since the sulfur group is attached directly to a carbon. In sulfates, the sulfur group is attached to the carbon through an oxygen group. Thus sulfates can be considered esters of sulfuric acid and the hydrolysable ester bond makes them relative instability. This instability limits the conditions and applications where they can be used. Ether sulfates contain not only a sulfate ester but also various amounts of ethylene, propylene, or butylene oxide, or mixtures of two or more of these. Due to the presence of additional hydrophilic alkyl oxides, the ether sulfates in general are more tolerant to electrolytes and divalent metal ions and are therefore useful where hard waters are encountered. Unfortunately the ether sulfates are also hydrolytically unstable and their uses are limited where high temperature or extreme pH conditions (high or low) are encountered. One solution to this instability problem is to employ ether sulfonates. These surfactants are both salt tolerant and hydrolytically stable. Ether sulfonates have been reported to give excellent performance under conditions of high salinities, high temperatures and extreme pH conditions. Schwartz et al., Surface Active Agents and Detergents , Interscience Publishers, Vol. II p 74-75, refers to these desirable properties of ether sulfonates and discloses sulfonated polyethoxylated alkyl phenols and their method of preparation by reaction of an ethoxylated alkyl phenol with sodium ethanol sulfonate. In addition, Schwartz et al. discloses that ether-linked sulfonates may be prepared by the addition reaction of butane sultone with an alkyl phenol. The prior art on the production of ether sulfonates is summarized below in Table 1 where: R=alkyl, alkenyl, phenyl, alkenylphenyl, amine, R′=C 2 H 4 , C 3 H 6 or C 4 H 8 , or mixtures of 2 or more of these, R″=an alkenyl spacer M=alkali or alkaline metal, ammonium or an amine TABLE 1 R—O—(R′O) n —R″SO 3 M Reference n R″ U.S. Pat. No. 1 to 30 C 2 H 4 5,075,042 U.S. Pat. No. 0 C 8 H 16 to C 22 H 44 3,424,693 U.S. Pat. No. 1 to 10 C 3 H 6 or C 4 H 8 4,138,345 U.S. Pat. No. 1 to 13 C 2 H 4 , C 3 H 6 , C 4 H 8 , or CH 2 (CH(OH))CH 2 4,267,123 U.S. Pat. No. 2 to 20 C 2 H 4 4,293,428 U.S. Pat. No. 0 to 15 C 2 H 4 , C 3 H 6 , or CH 2 (CH(OH))CH 2 4,733,728 This Invention 1 to 30+ C 7 H 14 to C 30 H 60 U.S. Pat. No. 5,075,042 issue to Allison et al. on Dec. 24, 1991 describes the preparation of aliphatic poly(ethyleneoxy)sulfonates by the chlorination with thionyl chloride of an ethoxylated aliphatic alcohol and subsequent conversion of the resulting chloride to the sulfonate with sodium sulfite. This patent goes on to reveal that certain aliphatic poly(ethyleneoxy)sulfonates are commercially available as AVANEL® S Anionic Surfactants. BASF Corporation currently markets AVANEL® surfactants. Their literature describes alkyl ether sulfonates of C12-15 alkyl with 7 EO (AVANEL® S-70), with 15 EO (AVANEL® S-150 CG), and C8 alkyl with 3 EO (AVANEL® S-74) as “unique because the ethylene oxide gives certain nonionic characteristics to the products, and the sulfonate group provides certain anionic characteristics. These products are extremely stable over a wide range of pH and electrolyte concentrations.” The key features of the alkyl ether sulfonates, as pointed out by BASF, include excellent hard water tolerance, hydrolytic stability over the entire pH range, biodegradability, oxidative stability in hypochlorite and oxygen bleaches, thermal stability, high electrolyte tolerance, excellent rinsability, sheeting action, extreme mildness to the skin, good emulsification characteristics, and low critical micelle concentrations. U.S. Pat. Nos. 3,424,693 and 3,424,694 issued to Stein, et al. on Jan. 28, 1969 discloses the reaction of partially neutralized olefin sulfonic acids containing 8 to 22 carbon atoms with a sultone reactive product and the recovery of the resulting mixture of surface-active compounds. Both these patents claim yields of between 10 and 50 mole percent for the reaction product of the sultone and sultone reactive compound with the remainder being the neutralized salt of olefin sulfonic acid. Alkoxylated products are not disclosed as sultone reactive starting materials in this patent. Ether sulfonates of alkylamines have been prepared in the past. Williams in U.S. Pat. No. 4,138,345 issued on Feb. 6, 1979, discloses the reaction of the metallic salts of alkoxylated or dialkoxylated amines with propane or butane sultone. These give the corresponding mono and di sulfonates of the amines and these have been found useful alone or in combination with other surfactants in the recovery of oil. U.S. Pat. No. 4,267,123 issued to Chen et al. on May 12, 1981 states that “propane sulfonates of various amines and polyethoxylated alcohols are known surfactants. However, propane sulfonates of alcohols and thiols have only been prepared in the literature by reaction of alkali metal salts of alcohols and thiols with propane sultone. This is a convenient high yield laboratory synthesis but is not desirable on a large scale for several reasons. Foremost among them are the fact that (1) such a reaction requires multistep synthesis and purification of propane sultone, (2) propane sultone is expensive to purify and its overall yield of 80-90% limits the yield in the preparation of the propane sulfonates and (3) propane sultone is a known carcinogen.” U.S. Pat. No. 4,293,428 issued to Gale, et al. on Oct. 6, 1981 involves the synthesis and application of alcohol ether sulfonates for oil recovery. This patent states that it has been determined that “positioning ethylene oxide and/or propylene oxide adjacent to the sulfonate group of a given surfactant tends to give it more water solubility and increases its tolerance to high concentrations of mono and di-valent salts”. In addition the ether sulfonates were found to exhibit very good resistance to hydrolysis in high-temperature reservoirs. A thorough discussion of their application in oil recovery is given in Surfactants—Fundamentals and Applications in the Petroleum Industry , L. Schramm editor, Cambridge Press (2000) p 209-214. U.S. Pat. No. 4,733,728 to Morita, et al. Mar. 29, 1988 describes alkylether sulfonates prepared from alkoxylated alcohol or alkylphenol by reacting with sodium isethionate, propane sultone, or epichlorohydrin followed by reacting with sodium sulfite. Our invention differs from the prior art in several ways. The presence of a long hydrocarbon chain spacer between the last alkylene oxide and the terminal sulfonate group gives the products of our invention greater oil solubility and lower irritation properties. Stein, et al in U.S. Pat. Nos. 3,424,693 and 3,424,694 also uses a long chain hydrocarbon spacer that is also derived from an olefin sulfonic acid. Stein et al. however, does not use alkoxylates, as we do, and therefore these materials do not have the high electrolyte tolerance or hardness tolerance of our compositions. Also, our process of reacting an un-neutralized olefin sulfonic acid with the alkoxide of an alkoxylated alcohol, phenol or amine gives yields of >90% whereas Stein, et al. only get 10 to 50 mole percent. Finally, our invention and process does not require the use of toxic reactants such as epichlorohydrin, thionyl chloride, propane sultone or butane sultone that are used by the other reference cited from the prior art. These important differences will become apparent through the examples presented. BRIEF SUMMARY OF THE INVENTION The primary object of the present invention is to make new ether sulfonates. Another object of the present invention is to provide new ether sulfonates made from readily available and non-toxic materials. Another objective of the present invention is to provide a new process to make the new ether sulfonates from readily available, non-toxic raw materials. Another objective of the present invention is to provide new surfactants that have excellent surface tension lowering properties, interfacial tension lowering properties, low Critical Micelle Concentration (CMC), good wetting/foaming properties, and are thermally and hydrolytically stable. Another object of the present invention is to provide new ether sulfonates that can be used in oilfield, agricultural, personal care, paint, adhesives, metal treating, lubrication, emulsion polymerization, detergent and laundry applications. Other objects and advantages of the present invention will become apparent from the following descriptions, wherein, by way of illustration and example, an embodiment of the present invention is disclosed. In accordance with a preferred embodiment of the invention, there is disclosed novel compositions of matter comprising ether sulfonate surfactants of the formula: R 1 [—(O—(R 2 O) m —(R 3 O) n —(R 4 )] y where: R 1 =alkyl, alkenyl, amine, alkylamine, dialkylamine, trialkylamine, aromatic, polyaromatic, cycloalkane, cycloalkene, R 2 ═C 2 H 4 or C 3 H 6 or C 4 H 8 , R 3 ═C 2 H 4 or C 3 H 6 or C 4 H 8 , R 4 =linear or branched C 7 H 14 SO 3 X to C 30 H 60 SO 3 X when y=1, R 4 =linear or branched C 7 H 14 SO 3 X to C 30 H 60 SO 3 X or H when y>1 but at least one R 4 must be linear or branched C 7 H 14 SO 3 X to C 30 H 60 SO 3 X, m≧1, n≧0, n+m=1 to 30+, y≧1, X=alkali metal or alkaline earth metal or ammonium or amine. When y is greater than 1 as would be the case if the starting R 1 is, for example, trimethylol propane, pentaerythritol, a diethanolamine, or triethanolamine all the terminal groups can be C 7 H 14 SO 3 X to C 30 H 60 SO 3 X or some can be C 7 H 14 SO 3 X to C 30 H 60 SO 3 X and some can be H as long as at least one is C 7 H 14 SO 3 X to C 30 H 60 SO 3 X. In accordance with a preferred embodiment of the invention, there is disclosed a process for preparing novel ether sulfonates of the formula: R 1 [—(O—(R 2 O) m —(R 3 O) n —(R 4 )] y where R 1 , R 2 , R 3 , R 4 , m, n, y have the same meaning as described above. This product is made by reacting an olefin sulfonic acid with the metal alkoxide derivative of one or more from the group alkoxylated phenol, alkoxylated polyphenol, alkoxylated alkylphenol, alkoxylated polyalkylphenol, alkoxylated linear alcohol, alkoxylated branched alcohol, glycol, polyglycol, alkoxylated monoalkylamine, alkoxylated dialkylamine, monoalkanolamine, dialkanolamine, trialkanolamine. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Detailed descriptions of the preferred embodiment are provided herein. It is to be understood, however, that the present invention may be embodied in various forms. Therefore, specific details disclosed herein are not to be interpreted as limiting, but rather as a basis for the claims and as a representative basis for teaching one skilled in the art to employ the present invention in virtually any appropriately detailed system, structure or manner. In accordance with the present invention, novel ether sulfonate surfactants are produced from the reaction of an olefin sulfonic acid and a metal alkoxide. Any molecule that can be oxyalkylated can be used as the starting material to produce the metal alkoxide. Examples of such include phenol, alkylphenol, alkoxylated phenol, alkoxylated alkylphenol, linear alcohol, alkoxylated linear alcohol, branched alcohol, alkoxylated branched alcohol, cyclic alkane, cyclic alkene, polyaromatic, glycol, polyglycol, amine, alkylamine, alkoxylated alkylamine, dialkylamine, alkoxylated dialkylamine, monoalkanolamine, dialkanolamine, trialkanolamine. Olefin sulfonic acids can be linear or branched and from 7 carbons to over 30 carbons in length depending on the particular properties one wishes to impart to the final ether sulfonate. Longer chain length olefin sulfonic acids will give more hydrophobicity as will linear sulfonic acids compared to shorter and more branched olefin sulfonic acids. The preferred olefin sulfonic acid is C7 to C30+ olefin sulfonic acid prepared by the SO 3 sulfonation of a single alpha olefin or mixture of alpha-olefins containing from about 7 to 30 or more carbons. These sulfonic acids are commonly referred to as alpha-olefin sulfonic acids or AOS acids. The chemistry and procedures for producing AOS acid are well known to those familiar with the art. A comprehensive discussion of AOS chemistry can be found in Anionic Surfactants Part II, Surfactant Science Series, Marcel Dekker (1976), p 345-380. Reaction temperatures can be between about ambient to about 200° C., depending on the olefin sulfonic acid and the hydroxyl containing starting material. More preferably temperatures are between 50° C. and 150° C. and most preferably temperatures are between 90° and 140° C. The first step in the process is to start with or produce an oxyalkylated alcohol, amine, glycol, phenol, alkylphenol. The oxyalkylation reaction to produce the starting material is well known to those familiar with the art. After the oxyalkylate has been prepared or secured, it is converted to an alkali metal alkoxide. This is done by reacting the oxyalkylate with a strong base such as sodium hydroxide or potassium hydroxide, or a metal alcoholate such as potassium methylate or sodium methylate. When sodium or potassium hydroxide is used, the material is heated to remove water and form the sodium or potassium alkoxide. When sodium methylate or potassium methylate is used, the material is heated to remove methanol, again forming the sodium or potassium alkoxide. Other metal hydroxide and alcoholates may be used such as lithium hydroxide, magnesium hydroxide, calcium hydroxide or ethylates of the various metals however the hydroxides and methylates of sodium and potassium are preferred because of cost and availability. An example of the series of reactions leading to the final product are shown below in reaction sequence A, starting with the addition of alkyl oxide (1), followed by the conversion to the metal alkoxide (2), and finally the reaction with olefin sulfonic acid (3) resulting in the final ether sulfonate product. The catalyst used in step (1) may be sodium or potassium hydroxide, or sodium or potassium methylate. This particular example shows the final product of reaction (3) having all terminal OH groups capped by an alkyl sulfonate group. When y is greater than 1, products can be made that have less than all the terminal OH groups capped by an alkylsulfonate group, if desired, as long as at least one OH has been capped. Since sodium hydroxide, potassium hydroxide, and sodium methylate are commonly used as catalysts for oxyalkylation, these catalysts may be left un-neutralized after the completion of the initial oxyalkylation reaction and supplemented with additional sodium or potassium hydroxide or methylate to the required stoichiometric amount for the subsequent reaction with olefin sulfonic acid. High concentrations of basic alkali metal catalyst are known to produce narrow distribution alkoxylates as is taught in U.S. Pat. No. 5,069,817 issued to Schmid, et al. on Dec. 3, 1991. The problem with the use of high levels of catalyst is that large quantities of salts are produced upon neutralization of these catalysts in order to remove them after the oxyalkylation has been completed causing a sludge that is difficult to remove. Since our invention uses the un-neutralized product from the oxyalkylation reaction, quantities up to stoichiometric amounts of sodium or potassium hydroxide or sodium or potassium methylate catalyst can be used in the oxyalkylation reaction to produce narrow distribution alkoxylates as shown in Sequence B, reaction 1a. Once the oxyalkylation is completed, olefin sulfonic acid can be added directly to the reactor to make the final product as shown in Sequence B, reaction 2a. Narrow distribution alkoxylates are useful in producing narrow distribution ethersulfonates by the process of this invention. These narrow distribution ether sulfonates are useful in applications where a broad distribution may separate into its various homologues. An example is in recovering oil from a subterranean formation. The ethersulfonates having a broad distribution may chromatographically separate on the reservoir rock resulting in changes in performance as the surfactant propagates through the formation. Also narrow distribution products have been shown to have more defined solubilities since they contain less higher molecular weight material that may cause cloudiness as a result of reduced cloudpoints. Where: R 1 is aromatic, cycloalkene, cycloalkane, amine, alkanolamine, dialkanol amine, alkylamine, alkoxylated alkyl amine, branched or linear alkane, R 2 =C 2 H 4 , C 3 H 6 , C 4 H 8 , or mixtures of two or more of these, n=1 to 30+, y≧1, R 5 =linear or branched C 7 H1 4 to C 30 H 60 , and the catalyst used in step (1) is sodium or potassium hydroxide or sodium or potassium methylate. Since sodium hydroxide or potassium hydroxide or sodium methylate is usually used to convert the terminal alkoxy group to the corresponding sodium or potassium alkoxide, the final product will usually be in the sodium or potassium form. Exchanging the sodium or potassium with other mono, di or trivalent metals, ammonium or an amine can easily be accomplished and these techniques are well known to those familiar with the art. Example 1 Preparation of Alcohol Ether Sulfonates This example uses a C10-12 alcohol with 7 moles of Ethylene Oxide and 6 Moles of Propylene Oxide (Witconol™ 1206 from Akzo-Nobel), sodium methylate (Aldrich) and C12 AOS Acid (Bio-terge® AS-12 Acid from Stepan Company) to produce an alcohol ether sulfonate containing both Ethylene and Propylene Oxide groups. 92.6 (0.100 Mole) grams of C10-12 alcohol with 7 Moles EO and 6 Moles of PO are added to a 250 ml roundbottom flask equipped with a stirrer, temperature controller and reflux condenser. 21.6 (0.100 Mole) grams of sodium methylate (25% in methanol) is added and the mixture is heated to 130° C. while purging with a stream of Nitrogen. After all the methanol has been removed and collected (20.0 grams), 24.8 grams (0.100 Mole) of the C12 AOS Acid is added slowly to maintain the temperature at 130° C. and control the foaming of the reaction. The reaction is completed after 2 additional hours at 130° C. following the addition of the C12 AOS acid. The final product was then analyzed for anionic surfactant, nonionic surfactant, free sulfonic acid and sulfuric acid. The amount of anionic surfactant was measured using a surfactant electrode and found to be 0.80 me/g. The theoretical activity is 0.84 me/g based on the equivalent weight of 1195. No nonionic surfactant (free alcohol alkoxylate) was found by gravimetric analysis after passing through a strong cationic ion-exchange resin column. No free sulfonic or sulfuric acid was found by potentiometric titration with hexylamine in isopropanol. Example 2 Surface Properties of Alcohol Ether Sulfonate from Example 1 This example demonstrates the excellent surfactant properties of the compositions of the present invention. Various surface properties were determined for the product from Example 1 to determine its suitability as a surfactant. All measurements were done at 24° C. unless noted otherwise. The Draves wetting time of a 0.1% wt/wt distilled water solution of the product from Example 1 was found to be instantaneous. The Surface Tension of a 0.1% w/wt solution of the product from Example 1 was found to be 34.2 mN/m. The interfacial tension of a 0.1% in distilled water solution was measured against mineral oil and found to be 0.6 mN/m at 50° C. The Critical Micelle Concentration (CMC) of the product from Example 1 was found to be 0.00001 moles/liter. The foaming of a 0.5% w/w solution was measured by mixing 100 ml in a Waring Blender at high speed for 30 seconds and immediately pouring the resulting foam into a 1000 ml graduated cylinder. The initial foam height was 600 ml and the time for 50 ml of liquid to appear (half-life) was 3 minutes and 54 seconds. These results indicate the product from Example 1 has excellent surfactant properties for use as a wetting agent, in lowering surface tension and interfacial tension, in producing low CMCs and as a foaming agent. These excellent surfactant properties makes this and similar products defined by our invention suitable for applications as surfactants in agriculture, adhesives, coatings, deinking, detergents, emulsion polymerization, laundry, lubricants, metal working, mining, oilfield, personal care, pharmaceuticals, and soil remediation. Example 3 Preparation of a Nonylphenol Ethoxysulfonate 42.8 grams (0.108 Mole) of the 4 Mole ethoxylate of nonylphenol (Witconol™ NP-40 from Akzo-Nobel) were added to a 250 ml round bottom flask equipped with a stirrer, temperature controller and reflux condenser. 17.3 grams (0.108 Mole) of a 25% wt/wt solution of sodium hydroxide in methanol were added and the mixture heated to 130° C. while purging with Nitrogen to remove the methanol. After all the methanol was removed and collected (14.9 grams), 31.4 grams (0.108 Mole) of C14/16 AOS Acid (Akzo-Nobel) was added slowly to maintain the temperature and control the foaming. The reaction was continued for an additional 2 hours at 130° C. after completing the addition of the AOS Acid. Before removing the final product from the flask it was allowed to cool to below 90° C. and then diluted with an equal weight (76.7 grams) of water to give a 50% active solution by weight. The final product was then analyzed for anionic surfactant, nonionic surfactant, free sulfonic acid and sulfuric acid. The amount of anionic surfactant measured using a surfactant electrode was found to be 0.68 me/g compared to a theoretical 0.71 me/g for the 50% active product, based on an equivalent weight of 708. No nonionic surfactant (free ethoxylated nonylphenol) was found by gravimetric analysis after passing through a strong cationic ion-exchange resin column. No free sulfonic or sulfuric acid was found by potentiometric titration with hexylamine in isopropanol. Example 4 Preparation of Alkylamine Ether Di-Sulfonates 186.6 grams (0.200 Moles) of tallowamine ethoxylate with 15 Moles of EthyleneOxide (Crisomin™ T-15 from Clariant Corporation), were added to a 500-ml roundbottom flask equipped with a stirrer, temperature controller and reflux condenser. 86.4 grams (0.400 Moles) of a 25% by weight solution of sodium methylate in methanol were added and the mixture heated to 130° C. to remove and collect the methanol. After all the methanol (77.2 grams) was removed, 99.2 grams (0.400 Moles) of C12 AOS Acid (Bio-terge® AS-12 Acid from Stepan Company) was added slowly to maintain the temperature and control the foaming. The mixture was held at 130° C. for an additional 2 hours after the final addition of AOS Acid. The final product was then analyzed for anionic surfactant, nonionic surfactant, free sulfonic acid and sulfuric acid. The amount of anionic surfactant was found to be 1.30 me/g compared to a theoretical 1.35 me/g using an equivalent weight of 736 for the 100% active di-sulfonated monotallow ethoxylated amine. No nonionic surfactant (free tallow amine ethoxylate) was found by gravimetric analysis after passing through a strong cationic ion-exchange resin column. No free sulfonic or sulfuric acid was found by potentiometric titration with hexylamine in isopropanol. Example 5 Pesticidal Composition Having Improved Performance This example demonstrates the utility of the compositions of the present invention as non-irritating surfactants to enhance the efficacy of pesticidal formulations. U.S. Pat. Nos. 6,603,733 issued on May 16, 2000 and 6,121,200 issued on Sep. 19, 2000, both to Berger, et al., describe the use of polyoxyalkylene alkylamine surfactants having reduced eye irritation by the addition of an effective amount of a sulfated polyoxyalkylene alkylphenol, alcohol sulfate, polyoxyalkylene alcohol sulfate, mono- or di-alcohol phosphate mono- or di-(polyoxyalkylene alcohol) phosphate, mono- or di-(polyoxyalkylene alkylphenol) phosphate, polyoxyalkylene alkylphenol carboxylate or polyoxyalkylene alcohol carboxylate surfactant. Examples of these surfactants are combined with glyphosate to give herbicidal compositions having reduced eye irritation and effective weed-killing properties. Taking advantage of the excellent surfactant properties found in Example 2 above and the properties described in the literature for alkyl ether sulfonates in general, including excellent wetting, interfacial and surface tension lowering, extreme mildness to the skin, biodegradability and high electrolyte tolerance; the composition from Example 4 above was formulated into a glyphosate formulation as described in Example 16 of U.S. Pat. No. 6,121,200. The ethoxylated tallow amine ether sulfonate from Example 4 above was substituted for the combined polyethoxylated tallowamine and sulfated polyoxyethylene nonylphenol described in Example 16 of U.S. Pat. No. 6,121,200 to compare the performance of this single surfactant to the combined surfactant of U.S. Pat. No. 6,121,200. Thus test material E was prepared by mixing 69.3 grams of glyphosate concentrate with 10.0 grams of the material from Example 4 above and 20.7 water and compared to test materials A, B, C and D from U.S. Pat. No. 6,121,200 where A is glyphosate containing 15.47 weight percent ethoxylated tallowamine along with 69.3 weight percent glyphosate, the remainder being water; B contains 15.49 weight percent of total surfactant, 69.3 weight percent glyphosate, the remainder being water and the surfactant being a mixture of 13.1 grams of ethoxylated tallowamine and 2.3 grams of sulfated polyoxyethylene nonylphenol, C contains 12.7 weight percent of this surfactant mixture along with 69.3 weight percent glyphosate, the remainder being water, and D contained 10.0 weight percent of the surfactant mixture, 69.3 wt percent glyphosate and the remainder being water. Test material E was diluted with water to 0.5, 1.0, 2.0 and 4.0 weight percent glyphosate aqueous solutions and sprayed onto a test field containing rhizome Johnsongrass. Half the test plot was sprayed with water after 2 hours in order to tests the rainfastness of the formulation. The test plot was evaluated 7 and 14 days after treatment. Percent control of the Johnsongrass for test material E is shown below in Table 2 compared to the reported results for test material A, B, C, and D. An untreated check plot showed no control of the Johnsongrass. TABLE 2 0.5% 0.5% 1.0% 1.0% 2.0% 2.0% 4.0% 4.0% Test Material 7 days 14 days 7 days 14 days 7 days 14 days 7 days 14 days A 42 82 62 99 67 100 88 100 B 57 90 75 99 68 99 88 100 C 42 97 70 99 73 100 88 100 D 47 95 58 99 73 99 83 100 E 50 95 70 100 75 100 90 100 E Rainfast 48 95 65 100 75 100 85 100 Example 6 Composition for Oil Recovery This example demonstrates the utility of the compositions of the present invention as surfactants for oil recovery at high temperatures in the presence of high concentrations of electrolyte and divalent metal salts. Anionic surfactants and surfactant mixtures have been used to recover oil from sub-terranean reservoirs by reducing the interfacial tension between and injection fluid containing surfactant and the oil trapped within the microscopic pores of the reservoir rock. Gale, et al. in U.S. Pat. No. 4,293,428, referred to previously, describes the use of alkoxylated alcohol ether sulfonates as surfactants having tolerance to high concentrations of electrolytes and divalent cations. The inventors stress the need to have a narrow distribution surfactant in order to minimize the chromatographic separation of the mixture when propagating through the reservoir. An alkoxylated tridecanol was prepared by first reacting 6 moles (336 grams) of propylene oxide (PO) with 1 mole (200 grams) of branched tridecanol (Exxal® 13 from Exxon) using 1 mole (216 grams) of a 25% by weight methanolic solution of sodium methylate catalyst. The methanol from the catalyst (162 grams) was removed before the start of the propoxylation reaction. The propoxylation was followed by the addition of 6 moles (264 grams) of ethylene oxide (EO). After the ethoxylation was completed the nonionic was analyzed and found to have a Weight Average Molecular Weight (MW wa ) of 798 (800 theoretical). HPLC confirmed that the material had a narrow distribution. Using a Waters HPLC the Number Average Molecular Weight (MW na ) was found to be 791. This gave a Dispersity Factor D of 1.01 where D=MW wa /MW na . 400 grams (0.500 Moles) of the sodium alkoxylate of the narrow distribution propoxylated/ethoxylated tridecanol was reacted with 124 grams (0.500 Moles) of C12 alpha-olefin sulfonic acid (Bio-terge® AS-12 Acid from Stepan Company) for 2 hours at 130° C. The final product was found to contain no residual nonionic propoxylated/ethoxylated tridecanol and had an anionic equivalent weight of 1039 grams/equivalent (1048 theoretical). A solution of 0.10 weight percent of the final reaction product was prepared in a brine consisting of 10.0 wt percent NaCl, 2.00 weight percent CaCl 2 and 1.00 weight percent MgCl 2 . The interfacial tension against a crude oil having an API Gravity of 18 was measured at 95° C. using a University of Texas Model 500 spinning drop tensiometer. The Interfacial tension was found to be 0.0012 mN/m. Example 7 Evaluation of Alkyl Ether Sulfonates as Components of a Laundry Detergent This example demonstrates the utility of the compositions of the present invention as components of laundry detergents and cleaning compounds to replace mixtures of nonionic and anionic surfactants and also to replace aromatic anionic surfactants. The sodium salt of a 5-6 mole ethoxylated C12-14 alcohol ether sulfonate was prepared from C14/16 AOS Acid and Witconol™ SN-70, both obtained from Akzo-Nobel, according to the procedure described in Example 1. Liquid laundry detergents of the formulations shown in Table 3 were prepared. All values are expressed as weight percent. Witconate™ 1260 is a 60% active by weight sodium linear dodecylbenzene sulfonate. Witconol™ SN-70 is a C 12 to C 14 alcohol with approximately 5.4 Moles of ethylene oxide. TABLE 3 Formulation A Formulation B Witconate ™ 1260 Slurry 17.0 — Witconol ™ SN-70 40.0 — SN-70/C14-16 AOS — 60.0 Acid(50% Aqueous) Tinopal ™ CBS (Ciba) 0.1 0.1 Ethanol 7.0 — Triethanolamine 5.0 — Water 30.9 39.9 Detergency was measured by visually inspecting naturally soiled fabrics according to ASTM D 2960. Both formulations gave acceptable and comparable results on cotton, polyester and mixed cotton/polyester fabrics. While the invention has been described in connection with a preferred embodiment, it is not intended to limit the scope of the invention to the particular form set forth, but on the contrary, it is intended to cover such alternatives, modifications, and equivalents as may be included within the spirit and scope of the invention as defined by the appended claims.	Novel compositions of matter and the process of preparing these surfactants having the structure: R 1 [—(O—(R 2 O) m —(R 3 O) n —(R 4 )] y where: R 1 =alkyl, alkenyl, amine, alkylamine, dialkylamine, trialkylamine, aromatic, polyaromatic, cycloalkane, cycloalkene, R 2 =C 2 H 4 or C 3 H 6 or C 4 H 8 , R 3 =C 2 H 4 or C 3 H 6 or C 4 H 8 , R 4 =linear or branched C 7 H 14 SO 3 X to C 30 H 60 SO 3 X when y=1, R 4 =linear or branched C 7 H 14 SO 3 X to C 30 H 60 SO 3 X or H when y>1 but at least one R 4 must be linear or branched C 7 H 14 SO 3 X to C 30 H 60 SO 3 X, m≧1, n≧0, n+m=1 to 30+, y≧1, X=alkali metal or alkaline earth metal or ammonium or amine. These novel ether sulfonate surfactants have excellent surfactant properties making them suitable for a variety of applications as surfactants including agriculture, adhesives, coatings, deinking, detergents, emulsion polymerization, laundry, lubricants, metal working, mining, oilfield, personal care, pharmaceuticals, and soil remediation.	2
BACKGROUND OF THE INVENTION [0001] In appliances that are used to wash various fabrics, oftentimes different chemistries are added to the appliance during different treatment cycles or at different times during a given treatment cycle, depending on the treatment function to be performed, and depending on the item being treated, for example. It is known to provide different containers containing different chemistries, such that during operation of the appliance, the appropriate chemistries can be selected and introduced to the appliance. [0002] For example, in U.S. Pat. No. 6,691,536, a washing apparatus is provided with various tanks 19, 20, 27 and 28 that can contain selected chemistries for dispensing for different cycles or during different parts of a cycle. [0003] In published application US2006/0107705, a stand-alone dispensing device for laundry care composition is provided with a plurality of containers 40 for selected chemistry products. [0004] Various sensors are utilized to determine the condition of a wash load or wash liquor in disclosures such as US2001/0049846, U.S. Pat. No. 6,955,067, U.S. Pat. No. 7,114,209 and U.S. Pat. No. 7,113,280. [0005] It would be an improvement in the art if there were provided wash cycle that could accept a color of a fabric load and provide a proper selection of chemistries based on at least the color of the fabric load. SUMMARY OF THE INVENTION [0006] In an embodiment of the invention, a wash cycle is provided which includes the steps: [0007] loading a wash machine with a fabric load for cleaning, [0008] selecting a wash cycle based on at least a color of the fabric load, [0009] determining a load size and type, [0010] dispensing wash water or other aqueous or non-aqueous working fluid into the wash machine to form a wash liquor, [0011] sensing water quality of the wash water, [0012] determining an amount of detergent to add into the wash liquor and a length of time for the wash liquor to be presented to the wash load based on the previous selecting, determining and sensing steps, [0013] determining an amount of oxidizing agent to add into the wash liquor and a time for adding the oxidizing agent to the wash liquor based on the selecting, determining and sensing steps, and [0014] performing washing steps of flexing the fabric load in the presence of the wash liquor, rinsing the fabric load and extracting liquid from the fabric load, while dispensing the detergent and oxidizing agent in accordance with the determinations made. [0015] The various steps of loading, selecting, determining dispensing and sensing can occur in many different orders than the order listed. [0016] In an embodiment, the step of selecting a wash cycle based on at least a color of the fabric load includes a step of automatically sensing a color of the fabric load in the wash zone. [0017] In an embodiment, the step of automatically sensing a color of the fabric load includes lighting an interior of the wash zone once the fabric load has been loaded and capturing a digital image of the fabric load [0018] In an embodiment, the step of capturing a digital image includes translating pixels of the resultant image into specific red, green and blue components, determining an intensity of each component and combining the determined intensities. [0019] In an embodiment, the step of automatically sensing a color of the fabric load includes lighting an interior of the wash zone once the fabric load has been loaded and scanning the fabric load using selective light filtering. [0020] In an embodiment, a further a step of controlling a pH of the wash liquor during the performing step is included. [0021] In an embodiment, the step of sensing water quality of the wash water comprises sensing at least one of ORP, pH, temperature and turbidity of the wash water. In an embodiment, a further step of sensing quality of the wash liquor during each of the washing steps is included. [0022] In an embodiment, the step of sensing water quality of the wash water comprises sensing at least one of pH, Oxidation Reduction Potential, temperature and turbidity of the wash water. [0023] In an embodiment of the invention, a wash cycle includes the steps: [0024] loading a wash machine with a fabric load for cleaning, [0025] selecting a wash cycle based on at least a color of the fabric load, [0026] dispensing a wash liquor into the wash machine, [0027] determining an amount of detergent to add into the wash liquor and a length of time for the wash liquor to be presented to the wash load based on the selecting step, [0028] determining an amount of oxidizing agent to add into the wash liquor and a time for adding the oxidizing agent to the wash liquor based on the selecting step, [0029] performing washing steps of recirculating the wash liquor through the fabric load, rinsing the fabric load and extracting liquid from the fabric load, while dispensing the detergent and oxidizing agent in accordance with the determinations made. BRIEF DESCRIPTION OF THE DRAWING [0030] FIG. 1 is a flow chart diagram of a wash cycle embodying the principles of the present invention. [0031] FIG. 2 is a flow chart diagram of a method of selecting a wash cycle based on color, in accordance with the principles of the present invention. [0032] FIG. 3 is a schematic illustration of a wash zone of the wash machine with a digital optical device and an illumination device. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS [0033] In an embodiment of the invention, as shown in FIG. 1 , the present invention provides a wash cycle comprising a plurality of steps. [0034] A step 20 includes loading a wash zone 21 of a wash machine 23 with a fabric load 25 for cleaning. The wash zone 21 may be located in a rotatable drum 27 of a horizontal axis washer, a vertical axis washer, a cabinet, a washer dryer combo, a dryer or a hanging apparatus. [0035] A step 22 includes selecting a wash cycle based on at least a color of the fabric load. The selecting may occur manually, as in step 24 , by a user of the machine 23 , or it may occur automatically, as in step 26 , via components of the machine. For example, the fabric load 25 may include radio frequency identification (RFID) tags which can be read by the machine to distinguish fabric type, size, color and construction. There may be alternative arrangements for automatically determining a color of the fabric load in step 26 . One method of determining the color of the fabric load, as shown in FIGS. 2 and 3 , would be to illuminate (step 28 ) the wash zone 21 after the fabric load 25 has been loaded (step 20 ) with an illumination device 29 , such as an incandescent bulb or LEDs, and to capture a digital image (step 30 ) of the fabric load with a digital camera or other digital optical device 31 . The pixels of the resultant image can be translated to the specific red, green and blue components. For each component, the scale of intensity will vary from 0-1. An intensity of 1 would be the most intense. A purely white load would have a low resultant number. The combination of the three numbers can be used by the machine to make a decision on the amount of oxidizing agent or detergent to be added during the wash cycle. In a simple case, ranges from 0-0.25 (step 32 ), 0.25-0.5 (step 34 ), 0.5-0.75 (step 36 ) and 0.75-1.0 (step 38 ) can be used to determine an amount of chemistry to add or how aggressive the machine should wash in order to protect the fabric. A similar range can be set for the effective emissivity of the fabric material; this information can be coded in the RFID chip. [0036] Selective light filtering, as is used in color copiers, can be used in step 26 to decide the color of the fabric load. A scan is taken by shining light on the material with a filter for red, green and blue. Behind each filter is a sensor or device that can sense the presence or absence of the light. This can then be translated into an intensity or effective emissivity number for each color. Ranges similar to those described above can then be used to make a decision on chemistry dispensing. The system may use a weighted average to determine the overall intensity and emissivity of the load as garments are added. Based on this information the system could provide the user with feedback on the color of the load. The value of the intensity or effective emissivity may be communicated in consumer language such as lights, whites, brights, darks and blacks. [0037] When a white or light colored fabric load is detected, care can be taken, via the chemistries added or not added, to not add color through dye bleeding. Also, the color detection can be used to look for large items that weren't sorted properly, such as a light/dark mix, or the inclusion of certain specific fabric types that should be washed differently, such as wool. When a white or light fabric load is detected, the dosage of oxidizing agent used in the oxidizing agent wash liquor can be increased. For non-white color loads, the temperature of the wash liquor can be lowered and more anti-redeposition agents can be added to the wash liquor. When a wool fabric is detected, the oxidizing agents can be prevented from entering the wash liquor. As shown in FIG. 1 , a step 40 includes determining a load size and type. This can be accomplished via a user input on a user interface device on the machine. Alternatively, the machine may automatically determine the load size and type. This may be accomplished via motor sense detection or through specific fill algorithms, as is known in the art. [0038] A step 42 includes dispensing wash water or some other aqueous or non-aqueous working fluid into the wash machine to form a wash liquor in a fluid state, such as liquid, gas, vapor, foam, etc. In some embodiments, the working fluid is water, a non-aqueous wash liquor, a vapor, a foam, a structured liquid or a gel may be used, so this step would not always include the dispensing of water. Although water or wash fluid is used in most of the examples, it can be substituted for any of the working fluids or combination thereof. As the water is dispensed into the wash machine, a step 44 of sensing water quality will occur. Sensors located in the washing machine are used to detect water quality in terms of parameters such as turbidity, conductivity, pH, ORP, dissolved oxygen, metals ions and organics. One or more of these parameters may be used in making a determination in a later step of the amount of detergents and oxidizing agents to be added to the wash liquor. [0039] A step 46 of pre-rinsing the fabric load may be undertaken before any detergent chemistries are added to the water in some cycles. The pre-rinsing setting can be used to add a dye fixer in the case of a dark load or a black load. The dye fixer can be added to the pre-wash chamber in the current dispenser system or a unit dose added from an auto dose system or poured in the wash basket. Continued sensing of the type noted in step 44 could be conducted during this pre-rinsing step 46 as well. [0040] A step 48 includes determining a type and amount of detergent chemistry to add (if any) into the wash liquor and a length of time for the wash liquor to be presented to the wash load based on the selecting 22 , determining 40 and sensing steps 44 . The oxidizing agents to be added to the wash zone are active oxygen releasing compounds, e.g., peroxides (peroxygen compounds) such as perborate, percarbonates, perphosphates, persilicates, persulfates, their sodium, ammonium, potassium and lithium analogs, calcium peroxide, zinc peroxide, sodium peroxide, carbamide peroxide, hydrogen peroxide, and the like. These agents also include peroxy acids and organic peroxides and various mixtures thereof. [0041] A peroxy acid is an acid in which an acidic —OH group has been replaced by an —OOH group. They are formed chiefly by elements in groups 14, 15 and 16 of the periodic table, but boron and certain transition elements are also known to form peroxy acids. Sulfur and phosphorus form the largest range of peroxy acids, including some condensed forms such as peroxydiphosphoric acid, H 4 P 2 O 8 and peroxydisulfuric acid, H 2 S 2 O 8 . This term also includes compounds such as peroxy-carboxylic acids and meta-chloroperoxybenzoic-acid (mCPBA). [0042] Organic peroxides are organic compounds containing the peroxide functional group (ROOR′). If the R′ is hydrogen, the compound is called an organic hydroperoxide. Peresters have general structure RC(O)OOR. The O—O bond easily breaks and forms free radicals of the form RO—. This makes organic peroxides useful for cleaning purposes. [0043] There are four possible descriptions of the oxidizing agent product composition based on concentration. “Ultra concentrated” means that 80 to 100% of the bleach is active. “Concentrated” means that 40 to 79% of the bleach is active. “Bleach with additive” means that 20-40% of the bleach is active. “Cleaning product with bleach” means that less than 25% of the bleach is active. [0044] Oxidizing agents may be combined within a mixture that has a selection of other material, such as one or more of the following: builders, surfactants, enzymes, bleach activators, bleach catalysts, bleach boosters, alkalinity sources, antibacterial agents, colorants, perfumes, pro-perfumes, finishing aids, lime soap dispersants, composition malodor control agents, odor neutralizers, polymeric dye transfer inhibiting agents, crystal growth inhibitors, photobleaches, heavy metal ion sequestrants, anti-tarnishing agents, anti-microbial agents, anti-oxidants, linkers, anti-redeposition agents, electrolytes, pH modifiers, thickeners, abrasives, divalent or trivalent ions, metal ion salts, enzyme stabilizers, corrosion inhibitors, diamines or polyamines and/or their alkoxylates, suds stabilizing polymers, solvents, process aids, fabric softening agents, optical brighteners, hydrotropes, suds or foam suppressors, suds or foam boosters, fabric softeners, antistatic agents, dye fixatives, dye abrasion inhibitors, anti-crocking agents, wrinkle reduction agents, wrinkle resistance agents, soil release polymers, soil repellency agents, sunscreen agents, anti-fade agents, water soluble polymers, water swellable polymers and mixtures thereof. [0045] A particular oxidizing agent to be added to form the oxidizing agent wash liquor could comprise a combination of water with one or more of sodium carbonate, sodium percarbonate, surfactants and enzymes. [0046] The detergent chemistries to be selected from may include surfactants, emulsifiers, enzyme activated stain removers, sudsing agents, builders, anti-redeposition polymers and perfumes. These chemistries may be premixed, or may be provided from separate containers. In addition to the type of chemistries to be added, and the amounts, the timing of the dispensing (step 50 ) of the detergent chemistries and the length of time that these chemistries are to remain in contact with the fabric load can be determined. This determination may be made in advance, or may be determined as the wash process occurs, such as through the continuous sensing of the wash liquor, for example to determine if proteins are being removed from the fabric load via enzyme action. [0047] A step 52 includes determining an amount of oxidizing agent to add (if any) into the wash liquor and a time for adding ( 54 ) the oxidizing agent to the wash liquor based on the selecting 22 , determining 40 and sensing 44 steps. The oxidizing agent may be in the form of a premade powder or liquid, or the oxidizing agent may be generated by the machine, as is known, and added to the wash liquor upon generation. Again, the type and amount of oxidizing agent to add into the wash liquor can be determined based on the various parameters. The timing for when the oxidizing agent is added is also determined, which may be based on initial selected 22 , determined 40 or sensed 44 parameters, or may be based on parameters sensed 44 during the wash process. In some fabric loads, or stain or treatment conditions, the addition of an oxidizing agent too early might deactivate certain detergent chemistries, such as enzyme detergents, before the enzymes have had sufficient time to remove various stains. In other loads or conditions, it may be beneficial to have a longer contact period between the fabric load and the oxidizing agents, and the detergent chemistries may not be negatively affected by the introduction of the oxidizing agents. The amount of oxidizing agent added may be in the range of 0.1-40% hydrogen peroxide equivalent, preferably 0.1 to 20%, and most preferably 0.1 to 10%. However, if the load is white or heavily stained, the preferred level of oxidizing agent is in the range of 1 to 30% and most preferred 10-30% hydrogen peroxide equivalent. These ranges can also be measured using an ORP sensor that can be calibrated to these concentrations. If the sensor detects that the concentrations are out of range for a particular color range, then the system can undertake an action to correct the level. The correction can be a combination of dilution or neutralization. [0048] A step 56 includes performing washing steps of flexing the fabric load in the presence of the wash liquor, rinsing the fabric load (step 58 ) and extracting liquid (step 60 ) from the fabric load, while dispensing the detergent and oxidizing agent in accordance with the determinations made. Some of the washing steps may include contact between the fabric load and the wash liquor without flexing of the fabric load, perhaps with recirculation and reapplication of the wash liquor onto the fabric load. This may occur, for example, by rotating the drum defining the wash zone to urge the fabric load towards the drum, or even to hold the fabric load against the drum, collecting any wash liquor which is not retained in absorption by the fabric load, and reapplying the wash liquor to the fabric load, such as by spraying the wash liquor against the rotating fabric load. In other washing steps, the fabric load may be flexed via tumbling, agitating, or other known methods of flexing fabric. [0049] The washing steps may occur in different wash liquors at different times during the wash cycle, and the different wash liquors may be derived by successively adding chemistries to the wash liquor, or by draining one wash liquor and reintroducing a completely different wash liquor. [0050] During each of the steps of the wash cycle, from when the wash water is first added to the wash zone (step 42 ), and including each of the cycles or portions of a cycle while the fabric load is in contact with the wash liquor, sensing of the wash liquor can occur, in order to determine a current condition of one or more of the parameters of pH, temperature and turbidity of the wash liquor. Various adjustments to each of these parameters can be effected, such as by adjusting the pH of the wash liquor to keep in within a certain desired range for a given chemistry application, or within a certain temperature range to increase the effectiveness of a certain chemistry application. Also the turbidity of the wash liquor can be monitored to determine whether the wash liquor needs to be filtered or replaced with cleaner wash liquor. [0051] The dispensing of the chemistries for the detergent and the oxidizing agents can be done through automatic dispensing chambers, such as mini-bulk, bulk or cartridges, in the form of liquids, solids or gases or vapors. [0052] The pH of the wash liquor can be controlled in ranges from 0-7 and 7-14, and preferably in the ranges of 3-7 and 7-12. In some cycles, the pH range could be controlled to between 6-11. For a gentle cycle with wool or similar materials, the machine can be arranged to control the pH in the range of 6.5 to 7.5. The pH can be controlled by using electrolytic water, adding an acid or a base. The acid or alkali can be selected from the classes of organic and non-organic compounds. This can include glycolic acid, silicafluorides, hydrofluosilic acid, citric acid, acetic acid, and laundry sours. Laundry alkali can include but is not limited to bicarbonates, carbonates, silicates, metasilicates, polysilicates and hydroxides. The pH can also be used in the rinse, preferably the final rinse, to restore the initial color of the garment. The pH control, temperature control and color sensing can be used in combination with dispensing of oxidizing agents and detergent to optimize the wash. [0053] The data gathered about the color of the fabric load can also be used to control the drying step in machines that are washer/dryer combinations or machines that have the ability to communicate with one another. If the measuring system indicates that the load is dark or black, the drying temperature is selected such that the maximum garment temperature does not exceed 120 F, preferably 110 F and most preferably 100 F. [0054] The wash unit can have a special cycle that the consumer can select or de-select that is labeled “color care” or some similar wording covering this concept. [0055] Various features and steps of the wash cycle have been described which may be incorporated singly or in various combinations into a desired wash cycle, even though only certain combinations are described herein. The described combinations should not be viewed in a limiting way, but only as illustrative examples of particular possible combinations of features. [0056] As is apparent from the foregoing specification, the invention is susceptible of being embodied with various alterations and modifications which may differ particularly from those that have been described in the preceding specification and description. It should be understood that we wish to embody within the scope of the patent warranted hereon all such modifications as reasonably and properly come within the scope of our contribution to the art.	A substrate treating appliance utilizing a plurality of different chemistries for different cycles or different wash loads with a plurality of receptacles for receiving a plurality of cartridges containing the different chemistries. Each receptacle has one half of a lock and key connection arrangement providing a unique interconnection configuration at each receptacle, relative to the remaining receptacles, permitting only a selected type of chemistry cartridge to be accepted at a particular receptacle. A connection effected between the cartridge and the receptacle occurs by rotation of the cartridge relative to the receptacle between an insertion orientation and a locking orientation. Each receptacle is shaped to receive a cylindrical mouth wall of a particular type of chemistry cartridge. Each receptacle may also be uniquely sized, relative to the remaining receptacles, to accept only a selected type of chemistry cartridge. The plurality of receptacles may be arranged adjacent to one another with each cartridge having a configuration that prevents insertion of a cartridge into a receptacle unless every cartridge located in an adjacent receptacle is rotated to the locking orientation.	3
FIELD OF THE INVENTION The present invention relates to a seesaw type switch in which breaking and making of contacts are selectively changed over with seesaw movement of a lever. DESCRIPTION OF THE RELATED ARTS FIGS. 6 through 8 are explanatory views of the prior art; in which FIG. 6 is a perspective view of a power window switch unit, FIG. 7 is an explanatory view of a toggle switch built in the unit, and FIG. 8 is an explanatory view of a seesaw type switch built in the unit. As shown in FIG. 6, a power window switch unit 1 has three toggle switches 2 for opening and closing windows associated with respective seats of a motor vehicle, and a seesaw type switch 3 for controlling on/off operations of those three toggle switches 2. Principal actuating portions of the four switches 2, 3 are housed in a single case 4 and a cover 5. From the design standpoint of the unit, a knobs 2a of the toggle switches 2 are arranged on the same plane as the surface of the cover 5, but only a knob 3a of the seesaw type switch 3 is arranged at a one-step higher level, i.e., over a projecting portion 5a provided on the cover 5. As shown in FIG. 7, each toggle switch 2 has a lever 7 having opposite shafts 8 which are rotatably supported by a flanged portion 6 provided on the cover 5. A torsion coil spring 10 is wound around a projection 9 of the lever 7 in such a manner that a pair of its resilient arms 10a, 10b extends in opposite relation to the cover 5 while gradually getting toward the upper surface of the cover 5. Denoted by 11 is a cover fitted with the case 4 to enclose the lower open surface of the case 4 with an insulating board 12 held in the case 4. The lever 7 is extended downward while penetrating through a hole 13 of the case 4, and has a bulged portion 14 at its lower end engaged in a hole 15a of a slider 15 which is slidably arranged on the insulating board 12. Inside the slider 15, there is housed a movable contact 17 capable of moving into or out of contact with a stationary contact 16 on the insulating board 12. Note that 30 is a connector. On the other hand, as shown in FIG. 8, the seesaw type switch 3 has a lever 18 having opposite shafts 20 which are rotatably supported by a flanged portion 19 provided on the projecting portion 5a of the cover 5. As with the toggle switch 2, the lever 18 is also extended downward while penetrating through another corresponding hole 13 of the case 4, and has a bulged portion 14 at its lower end engaged in a hole 15a of another corresponding slider 15 which is slidably arranged on the insulating board 12. Inside the slider 15, there is similarly housed a movable contact 17 capable of moving into or out of contact with a stationary contact 16 on the insulating board 12. The toggle switch 2 of the power window switch unit 1 thus constructed is vertically positioned in a rest state of the knob 2a fixed to the upper end of the lever 7. By turning the knob 2a clockwise, for example, the bulged portion 14 of the lever 7 engaging the slider 15 is moved to the left over the insulating board 12. Upon the knob 2a being released from the depressing force exerted on the same, the resilient force of the torsion coil spring 10 causes the toggle switch 2 to restore to the original rest state. During this movement, the movable contact 17 is contacted with or separated from the stationary contact 16 for selective breaking or making of the contacts. Further, the seesaw type switch 3 is inclined clockwise with the knob 3a lowered at its right end and the bulged portion 21 displaced to the left, as shown in FIG. 8, in a rest state of the knob 3a fixed to the upper end of the lever 18. By depressing the left end of the knob 3a in that state, the bulged portion 21 of the lever 18 engaging the slider 15 is moved to the right over the insulating board 12. During this movement, the movable contact 17 is contacted with or separated from the stationary contact 16 for selective breaking or making of the contacts. In the above-explained unit, however, the distance t 2 from the insulating board 12 to a support point of the lever 18 of the seesaw type switch 3, i.e., the central axis of the shaft 20, is set to be larger than the distance t 1 from the insulating board 12 to a support point of the lever 7 of other each toggle switch 2, i.e., the central axis of the shaft 8. Accordingly, the amount of movement of the slider 15 is increased with respect to an angle of inclination of the lever 18 so as to make the area occupied by the seesaw type switch 3 greater than the other area, which eventually leads to the problem that a reduction in the entire configuration of the power window switch unit 1 is prevented. SUMMARY OF THE INVENTION With a view of solving the problem as mentioned above, an object of the present invention is to reduce the distance through which a slider is moved by a lever upon its seesaw motion even when the distance from an insulating board to a support point of the lever is set to be relatively large, thereby making the entire switch size smaller. The above object is achieved by a seesaw type switch of the present invention comprising an insulating board having a stationary contact, a slider having a movable contact, a first lever rotatably supported by a case and engaging said slider, and a second lever rotatably supported by a cover fitted with said case, wherein a driver rod is held by said second lever through a coil spring, said driver rod being slidable over the top surface of said first lever. With the seesaw type switch of the present invention, a lever is divided into the first lever and the second lever, and the first lever engaging the slider is rotatably supported by the case. Therefore, even when the height of the cover is increased to increase the distance between a support point of the second lever and the insulating board, the sliding distance of the slider is minimized, thereby minimizing the size of the seesaw type switch. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a view for explaining operation of a seesaw type switch of the present invention in a state where a switch knob is inclined in one direction. FIG. 2 is a view for explaining operation of the seesaw type switch of the present invention in a state during change-over. FIG. 3 is a view for explaining operation of the seesaw type switch of the present invention in a state after it has been changed over with the switch knob inclined in the other direction. FIG. 4 is an exploded perspective view mainly showing parts of a cover, a lever and a case of a power window switch unit in which the seesaw type switch of the present invention is built. FIG. 5 is an exploded perspective view mainly showing parts of the case, a slider, and an insulating board of the power window switch unit in which the seesaw type switch of the present invention is built. FIG. 6 is a perspective view of a power window switch unit of the prior art. FIG. 7 is an explanatory view of a toggle switch built in the power window switch unit of the prior art. FIG. 8 is an explanatory view of a seesaw type switch built in the power window switch unit of the prior art. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT Hereinafter, one preferred embodiment of the present invention will be described with reference to the drawings (FIGS. 1 through 5). In the attached drawings, FIG. 1 is a view for explaining operation of a seesaw type switch in a state where a switch knob is inclined in one direction, FIG. 2 is a view for explaining operation of the seesaw type switch in a state during change-over, FIG. 3 is a view for explaining operation of the seesaw type switch in a state after it has been changed over, and further FIGS. 4 and 5 are each an exploded perspective view of a power window switch unit in which the seesaw type switch of the present invention is incorporated. It is to be noted that the same parts in these figures as those in the prior art shown in FIGS. 6 through 8 are denoted by the same reference numerals. Referring to FIG. 1, denoted by 22 is a first lever having opposite shafts 23 which are rotatably supported by a flanged portion 6 (see FIG. 4) provided on a case 4. The lever 22 includes a (first) protruding portion 22a extending downward while penetrating through a hole 13 of the case 4, and has a bulged portion 24 at its lower end engaged in a hole 15a of a slider 15 which is slidably arranged on an insulating board 12. Inside the slider 15, there is housed a movable contact 17 capable of moving into or out of contact with a stationary contact 16 on the insulating board 12. Denoted by 25 is a second lever having opposite shafts23 which are rotatably supported by a flanged portion 19 provided on a projecting portion 5a of a cover 5. The second lever 25 includes a (second) protruding portion 25a having a hollow inner portion. A coil spring 27 and a drive rod 28 are disposed in the hollow inner portion in such a manner that the driver rod 28 is biased against and slidable over the top surface of a horizontal portion 29 of the first lever 22. It will be understood that, as shown in FIG. 4, each toggle switch 2 has a lever 7 of which opposite shafts 8 are rotatably supported by another pair of flanged portions 6 of the case 4, and has a bulged portion 14 at its lower end engaged in a hole 15a of another corresponding slider 15. Operation of the seesaw type switch of the present invention will be next described below. FIG. 1 shows a state where a knob 3a fixed to the second lever 25 is inclined counterclockwise such that the first lever 22 is in a first pivoted position and the second lever 25 is in a second pivoted position. In this state, the line X--X connecting a support point of the second lever 25, i.e., the central axis of the shaft 26, and the center of the bulged portion 24 at the lower end of the second lever 25 forms an angle in a vertical plane relative to the line Y--Y connecting a support point of the second lever 25, i.e., the central axis of the shaft 26, and the central axis of the driver rod 28. When the knob 3a is depressed downward at its right end under the above state to turn the knob 3a clockwise, the driver rod 28 is moved to the left over the top surface of the horizontal portion 29 of the first lever 22 and the angle at which the line X--X intersects the line Y--Y is narrowed, as shown in FIG. 2. However, the first lever 22 still remains the same state as FIG. 1. When the knob 3a is further turned clockwise from that state, the first and second levers 22, 25 soon pass the so-called dead point at which the line X--X is aligned with the line Y--Y, and the first lever 22 is turned counterclockwise while causing an operator to feel a click, followed by stopping at a position where the horizontal portion 29 of the first lever 22 is abutted at its left end against a frame 4a of the case 4 in a second pivoted position, and the second lever 25 is in a fourth pivoted position, as shown in FIG. 3. During the above process, the bulged portion 24 of the first lever 22 engaging the slider 15 is moved to the right and the movable contact 17 is also moved in the same direction over the insulating board 12 to cooperate with the stationary contact 16 for selective breaking or making of the contacts. Additionally, the toggle switch 2 is arranged such that by depressing its knob 2a, the lever 7 is turned with the flanged portions 6 of the case 4 serving as a fulcrum and upon the knob 2a being released from the depressing force, the resilient force of a torsion coil spring 10 causes the toggle switch 2 to restore to the original rest state. With the seesaw type switch 3 of the present invention constructed as explained above, as shown in FIG. 4, the opposite shafts 23 of the first lever 22 are rotatably supported by one pair of flanged portions 6 of the case 4 similarly to the lever 7 of the toggle switch 2, and the first lever 22 is brought into a seesaw motion via the driver rod 28 of the second lever 25 of which opposite shafts are rotatably supported on the projecting portion 5a of the cover 5 at a level higher than the toggle switch 2. Therefore, even when the distance between the support point of the second lever 25 and the insulating board 12 is as large as conventionally, the amount through which the slider 15 is moved by the first lever 22 upon the seesaw motion of the knob 3a can be held the same as the amount through which the slider 15 is moved upon operation of the toggle switch 2. Furthermore, as shown in FIG. 4, the case 4 is divided into two compartments 4a, 4b of the same configuration. The opposite shafts 8 of the levers 7 of the two toggle switches 2 are rotatably supported in one compartment 4a between respective pairs of the flanged portions 6, while in the other compartment 4b, the opposite shafts 8 of the lever 7 of the remaining toggle switch 2 is rotatably supported between one pair of the flanged portions 6 and the opposite shafts 23 of the first lever 22 of the seesaw type switch 3 are rotatably supported between the last pair of the flanged portions 6. Covers 5b and 5c are fitted over the compartments 4a, 4b, respectively, such that the two levers 7 are projecting through a hole in the upper surface of one cover 5c, and the lever 7 of the remaining toggle switch and the second lever 25 of the seesaw type switch 3 are projecting through a hole in the upper surface of the other cover 5b. Then, the opposite shafts 26 of the second lever 25 are rotatably supported by one pair of flanged portions 19 formed on the projecting portion 5a. When a power window switch unit 1 is built in the central portion of front seats of a motor vehicle, for example, the seesaw type switch 3 is located at either one of symmetrical positions depending on whether steering wheels of motor vehicles are on the left or right side; i.e., it is located on the left side of the unit 1 for those motor vehicles having steering wheels on the left side, while it is located on the right side of the unit 1 for those motor vehicles having steering wheels on the right side. With the above-mentioned arrangement, even such a modification in assembly can be easily dealt with by changing the position of the seesaw type switch 3 in the case 4b and fitting the cover 5c over the case 4 after changing an orientation of the cover 5c correspondingly, resulting in an advantage of high versatility. Another advantage is that many parts such as the case 4, the slider 15 and the movable contact 17 can be commonly used to achieve improvements in both part management and assembling efficiency, enabling an inexpensive power window switch unit. As has been described previously, according to the present invention, since the amount through which a slider is moved by a lever upon its seesaw motion can be held small even when the distance from an insulating board to a support point of the lever is set to be relatively large from the standpoint of design, a reduction in the entire switch size is not impeded. Further, when the seesaw type switch of the structure according to the present invention is assembled along with a plurality of toggle switches to constitute one power window switch unit, many parts can be commonly used, thus making it possible to provide the power window switch unit at the reduced cost.	A seesaw type switch having a first lever pivotably mounted to a case, and a second lever pivotably mounted over the first lever such that a protruding portion of the second lever abuts a top surface of the first lever. A protruding portion of the first lever positions a slider relative to a stationary contact connected to the case. The first lever is pivoted by manual actuation of a knob connected to the second lever.	4
This application is a divisional of U.S. application Ser. No. 08/975,858 filed Nov. 21, 1997, now U.S. Pat. No. 5,950,271. FIELD OF INVENTION The invention relates to a swab that is used to clean and plug pipe lines. BACKGROUND OF THE INVENTION In the course of maintaining and rehabilitating utility lines including pipe lines, it is sometimes necessary to clean or swab these lines in order to ascertain their condition. Debris can build up and collect on the interior walls of an existing pipe. This debris must be cleaned before any repairs or rehabilitation can be made. Additionally, it is sometimes necessary to plug these lines in order to perform inspections or repairs. However, many of these lines cannot remain blocked or out of service for very long. SUMMARY OF THE INVENTION A swab has been developed for use in cleaning utility lines. The swab can be made of a flexible, circular member such as a tire having a front side with a front lateral sidewall, a rear side with a rear lateral sidewall, an exterior surface, an interior cavity and a central orifice. A steel plate is concentrically mounted against each lateral sidewall of the tire. The steel plates are attached to each other by four connecting rods which engage both plates by extending through both the tire and the plates. A yoke attachment point fixed to each end of connecting rods and a flexible yoke is attached to each point. Two cable attachment points connect all of the yokes on each side of the tire. In one embodiment, a flow pipe with a valve and valve actuator extends through the central orifice of the tire. In alternative embodiments, the exterior surface of the tire could be smooth or a raised tread. Also, the interior cavity of the tire could be filled with a foam such as a low density foam. In another embodiment, three tires are aligned in a side by side arrangement to form a swab. Two steel plates are concentrically mounted against the front and rear sidewalls of the exterior tires in the arrangement. A method is claimed for cleaning a host pipe with both a single tire swab and a multi-tire swab. The steps include positioning the swab in the host pipe, connecting each cable attachment point to a cable, and pulling the swab through the host pipe. A pipe plug has been developed for use in plugging pipe lines. The pipe plug comprises a tire having a front side with a front lateral sidewall, a rear side with a rear lateral sidewall, an exterior surface, an interior cavity and a central orifice. A tire rim with an axle connector is mounted with the central orifice of the tire. A steel plate covers the axle connector. A valve stem extends from the tire through the tire rim. An air tube which provides air from a compressed air source is connected to the valve stem. Four connecting rods engage and extend through the tire rim. A yoke attachment point fixed to each end of connecting rods and a flexible yoke is attached to each point. Two cable attachment points connect all of the yokes on each side of the tire. In an alternative embodiment, the exterior surface f the tire could be smooth. A further embodiment includes bladder disposed in the interior orifice of the tire to old the compressed air. In another embodiment, two tires are used to form a dual-tire plug. A pipe which extends through the tire rims connects the two tires. A transfer tube connects the interior cavities of each tire so that a single source of compressed air may be used to inflate the plug. A flow orifice is located inside the tire rim of each tire and a valve with a valve actuator is located in the pipe which connects the tires. A method is claimed for using both the single tire plug and the multi-tire plug. The steps include positioning the plug within the host pipe, inflating the plug until the exterior surface of the plug contacts the host pipe, and deflating the plug when it is to be removed. BRIEF DESCRIPTION OF THE DRAWING FIG. 1 is a perspective view of a swab. FIG. 2 is a cut-away side view of a swab. FIG. 3 is a cut-away side view of a multi-member swab. FIG. 4 is a frontal view of a swab with a flow pipe. FIG. 5 is a cut-away side view of a swab with a flow pipe. FIG. 6 is a perspective view of a swab with a flow pipe, valve and valve actuator. FIG. 7 is a perspective view of an operation using a swab with a flow pipe. FIG. 8 is a perspective view of an operation using a swab with a flow pipe. FIG. 9 is a perspective view of an operation using a swab with a flow pipe. FIG. 10 is a cut-away side view of a plug. FIG. 11 is a frontal view of a plug. FIG. 12 is a cut-away side view of a multi-member plug. FIG. 13 is a perspective view of a multi-member plug with a valve actuator. FIG. 14 is a cut Away side view of a multi-member plug with a valve and valve actuator. FIG. 15 is a perspective view of an operation using a plug. FIG. 16 is a perspective view of an operation using a multi-member plug. FIG. 17 is a perspective view of an operation using a multi-member plug with a valve. FIG. 18 is a perspective view of an operation using a multi-member plug with a valve. FIG. 19 is a perspective view of an operation using a multi-member plugs and a transfer pipe. DESCRIPTION OF THE PREFERRED EMBODIMENTS The following is a description of the invention and figures. In different figures, the same elements are represented with the same numbers. FIG. 1 shows a detailed perspective view of a tire swab 10. The tire swab 10 includes a tire 12, a rigid plate 22a, four yoke attachment points 26a-d, four yokes 28a-d, and a cable attachment point 30a. The tire itself can be a new or used tire. The use of old tires is a key benefit of the claimed invention. Old tires which are no longer usable on vehicles present a significant environmental disposal problem. The use of recycled tires can be a significant economic benefit in manufacturing. Tires that are damaged from use as a swab can be easily and quickly replaced at a low cost. The tire 12 is selected for a size to fit within the diameter of the host pipe which will be cleaned. The tire 12 can compress when encountering an obstruction which would lodge a rigid swab. As shown, the exterior surface 14 of the tire 12 has a rough, raised tread. However, the exterior surface 14 may be smooth so that it contacts the wall of the host pipe more fully. The exterior surface 14 of the tire 12 may be made smooth and the outside diameter of the tire 12 can be augmented by any re-treading or re-capping process for used tires. In re-capping the tire, different types of materials may be used to produce a different type of texture on the exterior surface 14 of the tire 12. While embodiments which use tires are shown in the drawings, any suitable alternative could be used. Such an embodiment would have a circular shaped member to contact the walls of the host pipe to be cleaned. Furthermore, this member would also have the necessary flexibility to compress or deflect around obstacles in the same manner as a tire. The rigid plate 22a is concentrically mounted against the front lateral sidewall 18a of the tire covering its central orifice 20. Because the tire rim has been removed, the rigid plate 22a provides a support to the tire and an attachment point for the yokes 28a-d which will pull the tire swab 10 through the host pipe. The rigid plate 22a is normally made of steel, but it can be made of any material which provides sufficient strength to support the apparatus. The size of the rigid plate 22a is selected to allow the deflection necessary to avoid lodging the tire swab 10 on any obstructions. The yoke attachment points 26a-d serve to provide an attachment point between the yokes 28a-d and the tire swab 10. They are attached to the end of connecting rods 24a-d which connect the rigid plate 22a to the tire 12. While four are shown, the yoke attachment points may vary in number according to the number of yokes. Also, the location of the yoke attachment points may vary depending on the desired distribution of the pulling force on the tire swab 10. While the yoke attachment points 26a-d are shown as loops, they may be of any other suitable attachment means. The yokes 28a-d serve to distribute the pulling force of the cable 45 to the tire swab 10. They are made of any material capable of withstanding the applied pulling force, including materials of different degrees of flexibility. The number of yokes 28a-d may vary depending on how widely the pulling force is to be distributed on the tire swab 10. The yokes 28a-d are connected to the cable 45 by a cable connection point 30a. The cable connection point 30a pulls all of the yokes 28a-d together to a single point to transfer the pulling force applied by the cable 45. The cable connection point 30a is shown as a loop, but any other suitable attachment mechanism could be used. FIG. 2 shows a cut-away side view of a tire swab. A second rigid plate 22b is shown mounted on the rear lateral sidewall 18b of the tire 12. The interior of the tire swab 10 shows the connecting rods 24a-b (24c-d are not shown) and the interior cavity 16 of the tire 12 which is filled with a low density foam 32. Also shown is an arrangement of yoke attachment points 26e-f (26g-h are not shown), yokes 28e-f (26g-h are not shown), and a cable attachment point 30b. This arrangement is identical to the arrangement mounted on the rigid plate 22a in FIG. 1 described previously. The connecting rods 24a-b (24c-d are not shown) extend through the tire 12 and both rigid plates 22a and 22b. Each connecting rod 24a-b has a yoke attachment point 26a-b and 26e-f on each end. The interior cavity 16 of the tire is shown filled with a low density foam 32 to provide support to the tire 12. However, the tire 12 will be able to compress to a certain degree while it is pulled through the host pipe. While a low density foam 32 is shown, any material may be used to fill the tire 12 depending on its characteristics and the desired effect. For example, if additional weight is desired to stabilize the tire swab 10, sand may be used to fill the tire 12. Also, air could be used to provide better contact between the exterior surface 14 of the tire 12 and the wall of the host pipe. This provides a more efficient swabbing. The rigid plate 22b and the arrangement of yoke attachment points 26e-f, yokes 28e-f, and cable attachment point 30b shown in FIG. 2, are an alternative embodiment of the tire swab in FIG. 1. The tire swab as shown in FIG. 1, has a tendency to turn within the host pipe when it is being pulled due to the pressure of the flow in the host pipe. Attaching the tire swab 10 to another cable (not shown in FIG. 2) on the other side of the tire swab 10 provides additional stability and reduces the tendency to turn. Additionally, if the tire swab 10 becomes wedged in the host pipe, the direction of the swab can be reversed by the other cable. This will avoid a costly stoppage of work and possible excavation to retrieve the swab. An alternative embodiment consisting of a multi-tire swab 34 is shown in FIG. 3. The structure of the apparatus is essentially the same as shown in a single tire swab except that three tires 14 are used instead of just one. The tires 14 are identical to each other and are placed side by side with the connecting rods 26a-b (26c-d not shown) extending through each of them. While three tires are shown, any number could be used depending on the desired result. As discussed previously, a single tire swab 10 has a tendency to turn while being pulled within the host pipe. A multi-tire swab 34 will not turn in the host pipe because of the length of the apparatus. In some circumstances, it is necessary to use a multi-tire swab 34 so as not to impose too great a load on the wall of the host pipe when a turn or deflection is encountered. FIG. 4 shows another embodiment where a tire swab 10 that has a flow pipe 36 with an orifice 20 located in the center of the tire. A cut away side view is shown in FIG. 5. FIG. 6 shows a valve 38 located within the flow pipe 36 and a valve actuator 40 that is used to control the opening and closing of the valve. The other structures of the tire swab 10 shown in FIGS. 4, 5 and 6 are the same as shown in FIG. 1. The flow pipe allows the flow in the host pipe to pass through the orifice while the tire swab 10 is being pulled. This reduces the pressure on the swab and the tendency to turn within the pipe. Because the flow through the orifice 20 is moving at a greater velocity than through the host pipe, it can be used to create a jetting action to carry away the debris collected by tire swab 10. FIGS. 7, 8 and 9 show the tire swab 10 with a flow pipe 36 being used to clean a host pipe 50. In FIG. 7, the tire swab 10 is lowered into the excavated access area 48 by a winch 44 mounted on a vehicle 42a. Another vehicle 42b with a winch 44 is located at the far end of the segment to be cleaned. In this case, access to the host pipe 50 is provided via an existing manhole 46. Once the tire swab 10 is positioned within the host pipe 50, it is connected to each vehicle 42a and 42b and pulled through the pipe. As shown in FIG. 8, the debris 54 within the host pipe 50 is collected in front of the tire swab 10 and pushed toward the manhole 46. At the manhole 46, it is removed by a vacuum mechanism or other suitable means. The flow pipe 36 allows the host pipe to remain in service while being cleaned. The flow 52 in the host pipe 50 is able to pass through the flow pipe 36 in the tire swab 10 while the cleaning is in process. Another use of the claimed invention is as a plug to block the flow in a host pipe. FIG. 10 shows a cut-away side view of an embodiment of a single tire plug 56. The structure of the apparatus is essentially the same as the tire swab, except that a circular tire rim 58 is mounted within the tire 90 instead of rigid plates mounted against the sidewalls. The tire rim 58 is a conventional type rim for mounting the tire on a vehicle. It has an axle connector 62 for attachment to such a vehicle. An alternative embodiment uses a pre-fabricated rigid support in place of the tire rim. It should be made of a material of sufficient strength to fully support the tire 90. A valve stem 60 extends from the interior cavity 94 of the tire 90 through the tire rim 58. The interior cavity 94 is empty so that once the plug is positioned, it can be inflated with air until the exterior surface 92 of the tire 90 is in solid contact with the wall of the host pipe. The valve stem 60 is connected to an air tube 64 which uses a source of compressed air to inflate the tire 90. The valve stem 60 is also used to deflate the tire 90 when the plug is to be removed from the host pipe. An alternative embodiment uses a bladder which is located in the interior cavity 94 of the tire 90. The bladder holds the compressed air which is used to inflate the tire 90. In this embodiment, the valve stem 60 would extend into the bladder instead just the interior cavity 94. FIG. 11 shows a frontal view of the tire plug 56 with a rigid cover 66a attached over the axle connector 62 of the tire rim 58. This completes the seal of the apparatus and thus block the flow. The rigid cover 66a is normally made of steel, but it could be made of a material of sufficient strength to withstand the applied forces and maintain a seal. If a pre-fabricated support is used instead of a tire rim, the axle connector will not be present and so the rigid cover 66a will not be necessary. An alternative embodiment of a tire plug is shown in FIG. 12. A cut-away side view of a dual-tire plug 68 shows two single tire plugs as previously described, which are connected by a pipe 72 and a transfer air tube 70. While a pipe 72 is shown, any other suitable device to transfer the flow through the plug could be used. The dual-tire plug 68 uses a second tire as a back-up should the first tire leak. The transfer air tube 70 serves to transfer air pressure between the tires so that one source may be used to inflate both. While two tires are shown in FIG. 12, any number could be used as the circumstances require. Another embodiment of the dual-tire plug is shown in FIGS. 13 and 14. Two flow orifices 74a and 74b are located in each rigid support which allow the flow into the pipe 72 which connects the tires 92. The pipe 72 is separated into segments which are connected by a pair of flanges 76. The flanges 76 are attached to each other by flange connectors 78 which may be a nut and bolt, a rivet or other suitable connectors. A valve 108 and valve actuator 110 is located at the junction of the flanges 76. The valve 108, which is controlled by the valve actuator 110, opens and closes to pass or block the flow in the pipe 72. The valve 108 may be a "butterfly valve" or any other suitable type of valve which is sufficient to block the flow within the pipe 72. FIG. 15 shows a single tire plug 56 in use in a host pipe 122. The single tire plug 56 is placed upstream of an excavated access area 120. An air compressor 80 on the surface is used to inflate the tire plug 56 with an air tube 64. Once the flow 124 is blocked, the work may proceed in the excavated access area 120. FIG. 16 shows an identical installation using a dual tire plug 68. It this embodiment, the additional tire provides additional protection if the first tire should leak. FIGS. 17 and 18 show an installation with the dual tire plug 68 with the valve 108 to control the flow 52. In FIG. 17, the valve 68 is closed and the flow 124 is blocked so that work may be done in the excavated access area 120. Once the work is completed, the valve 68 can be opened and the flow 124 resumed in the host pipe 122. The flow 124 may be resumed while keeping the dual tire swab 68 in place. This has the advantage of shutting off the flow 124 at a later time without the expense of re-installing another plug. FIG. 19 shows another use of the dual tire plug 68. In this configuration, two dual tire plugs 68 are installed in the host pipe 122 on either side of the excavated access area 120. A transfer pipe 86 connects the tire plugs 68. This allows the work in the excavated access area to proceed while the host pipe 122 remains in service. The transfer pipe 86 can remain in place indefinitely while the work is continuing.	A method for cleaning a pipe using a swab that can be made of one or multiple tires connected to one or more cables and pulled through the host pipe during the cleaning process. The cables are attached to rigid plates mounted in the central opening of the tire. The method provides an effective and low cost method to remove debris and mud particularly from underground pipe.	1
CROSS-REFERENCE TO RELATED APPLICATIONS [0001] This application claims the benefit of U.S. Provisional Patent Application No. 61/236,075; filed Aug. 21, 2009 by Rick Meserini, the present applicant. The entirety of said Provisional Application is hereby included by reference herein. TECHNICAL FIELD OF THE INVENTION [0002] The present invention relates to prefabricated housing modules and, more particularly, to said modules that are adapted for simplified installation and removal as a temporary house addition. BACKGROUND OF THE INVENTION [0003] With the first “baby boomers” turning 65 years of age in 2009, there will be a dramatic increase in the number of elderly with physical limitations (at least partially disabled) but who will be living alone or with a family member in a residence that is multi-leveled such that occupants must negotiate stairs to access important living facilities such as a full bathroom with shower or bathtub, and/or a bedroom/sleeping quarters—which in many homes are located on a second floor level or a split level first floor, while the main living space (e.g., kitchen, living/dining room) is on a ground floor, i.e., the floor closest to ground level, and therefore the most accessible from outside the house. Additionally, in most of such houses laundry facilities are located in a basement or other such lower level that is down stairs from the ground level main living area. [0004] Note: The ground floor is generally referred to as the “first floor” (first level) in the US. The two terms “ground” and “first”, as well as “floor” and “level” are treated as equivalent and interchangeable in the present disclosure, in accord with common usage in the US. [0005] Typical age-related disabilities range from medium-term handicaps due to injuries (e.g., a bone broken in a fall) that take longer to heal than for younger people, to essentially permanent disabilities that degenerate from slow and painful walking and stair negotiation to use of a walker, to confinement in a wheelchair and/or a bed. The lack of accessibility to important living facilities increases dependence on others, including family or paid assistance, and increases safety risks such as falls. [0006] Today's elderly, particularly those in the baby boomer generation, are typically used to living independent, self-sufficient and active lives while residing in private residences, and thus strongly desire to continue a similar lifestyle as long as possible, rather than giving up their accustomed living spaces to move into “retirement” facilities for some form of assisted living. The problem is compounded by a culture wherein elderly persons can no longer expect to be able to live with, and be cared for, by younger family members. Typical residential housing is constructed for smaller and younger families. Those elderly who do try to live with extended family are likely to be moving into a relatively small residence that is not equipped to accommodate a person of limited abilities, and/or doesn't have a spare bedroom for them regardless of ability. [0007] Without access to ground floor living facilities, including at least a toilet (lavatory), and preferably also such facilities as a full bathroom with sink and walk-in shower, a laundry (washer and dryer), and/or a private bedroom—all of which can be negotiated with convenience by a disabled resident—it will be difficult to live independently without moving to another more suitably constructed place of residence. This often holds true even for limited ability elderly wishing to stay at home by using part time home health care services. [0008] Thus, there is a substantial, and increasing, need for house modifications suitable for addressing the living facility needs of elderly residents. A house with at least a main floor lavatory can be adapted or even slightly re-modeled for use by a person unable to take stairs, for relatively low cost. However, the space parameters required for adapting a typical residence for wheelchair access and indoor use can turn simple interior remodeling into an overly expensive major reconstruction project, and if the needed reconstruction is structurally impractical or unviable, then an addition to the house may be needed. [0009] Until very recently few, if any, residences were designed and constructed with the needs of disabled or handicapped residents in mind. Thus we have a preponderance of multi-level and split level homes, plus door types, door frame widths, and open spaces in rooms, for example, that do not accommodate wheelchair use. [0010] The Americans with Disabilities Act (“ADA”) enacted by the US Federal Government in 1990 provides detailed specifications that are required to make a building and its functional elements “ADA Compliant”. Although originally directed toward public-use buildings, the specifications have proved to be very practical and suitable for enabling a disabled person, particularly one who is wheelchair-bound, to move independently and relatively freely in any ADA compliant structure, and to simplify use of facilities therein. For example, specifications enabling wheelchair movement include: 36″ (inch) minimum lateral clearance in all but a short portion of passageways and hallways, and a five foot (5′) minimum turning radius of clear floor space to allow turning around. Short portions of a passageway, e.g., a doorway, may have a reduced width of 32″. For example, specifications enabling simplified facility use include: elevations for toilet seats and bathroom sinks, placement and design of grab bars and faucet handles, design of a “step-in” bathtub or shower, and so on. [0011] Typical additions to a house are custom built and permanent in nature, involving substantial modifications to at least one exterior wall, and often to a roof as well. Such house additions are expensive in general, and can be cost prohibitive given that the addition is only needed for a relatively short period of time relative to the usable lifetime of the house—over which time ownership will change a number of times. Because only a small fraction of potential home buyers will want an addition such as those contemplated in the present disclosure, the resale value of the house is generally reduced by the addition even though it added substantially to the basis cost of the house. [0012] The prior art discloses some concepts for lowering the cost of home modification to accommodate the special needs of disabled, handicapped, or partially-abled (limited ability) residents. [0013] For example, inventors have disclosed ways to convert a portion of an existing interior room of a residence into a bathroom to accommodate handicapped individuals. This provides a ground floor bathroom, which avoids negotiating steps, but is severely limited to use in houses that have enough disposable living space on the first floor to accommodate an intra-room, modular bathroom. [0014] U.S. Pat. No. 4,238,858 describes a walk-in ablution or toilet compartment formed from a few standardized construction elements which are light and can be transported into living rooms independently of the width of door openings, and can there be assembled together, and which can be provided with several desirable living facilities, e.g. for washing, for bathing, and for use of a toilet, while for each of the individual functions a separate space can if desired be provided within the compartment. [0015] U.S. Pat. No. 4,899,402 describes a modular handicap-accessible bath facility that is constructed within an existing interior space of a home or building. [0016] U.S. Pat. No. 5,652,976 provides a prefabricated and pre-plumbed modular invalid bathroom unit which has wheelchair access for installation in a first floor room for the invalid. The unit may be assembled in a first floor room and disassembled and removed when no longer needed. [0017] Modular prefabricated (factory built) rooms are well known, and can reduce cost of adding a room outside of an existing structure, or more commonly, for quickly building a new structure such as a dormitory or motel where a plurality of identical rooms are needed. [0018] For example, U.S. Pat. No. 3,110,907 (King, Nov. 19, 1963) discloses a fully unitized, prefabricated bathroom structure which may be shipped as a completed unit for on-site integration within the interior of a new building structure. Pre-installation of utilities (water, sewer, electric) enable simplified connection with main utility lines while requiring only a minimum of installation time and effort. [0019] For example, U.S. Pat. No. 4,788,802 (Wokas, Dec. 6, 1988) discloses a transportable prebuilt room-forming module for external attachment to the exterior of a building. The disclosure focuses on details of construction considered suitable for transport while reducing cost through use of standard lumber sizes, for example squeezing the floor plan into a 4 by 8 foot area to fit a single sheet of plywood. Rigid “sandwich” or “reinforced” floor and roof members interconnect the walls of the room to provide strength. However, the walls and roof member are constructed using 2×4 studs and joists, with the front wall being only 2″ thick. The module arrives at the point of installation with a plywood exterior. Final external construction is completed on site after it is placed on a permanent foundation. The front wall has a doorway for aligning with a doorframe installed in the house's exterior wall. The front wall is permanently attached along its entire width and height to the exterior house wall. A plumbing tree of sewage lines is preinstalled with a common outlet conduit projecting through a hole in the front of the floor member for connection to the house sewer system. [0020] In another example, U.S. Pat. No. 2,644,203 (Donahue, Jul. 7, 1953) discloses a prefabricated bathroom structure which can be connected to a building, such as a rural residence, not previously provided with a bathroom, easily, quickly and without the requirement of special skill or the incurring of great expense. A further object is to provide a novel structure for attaching a prefabricated building structure to an old building structure and for sealing the horizontal and vertical joints between said structures effectively against wind and weather (using trim strips, flashing, caulking and a flat bottom periphery for sealingly resting on a sill plate provided on a foundation wall). A further object is to provide a novel, prefabricated, single room structure adapted to be connected or attached to another building, and characterized by a strong, light weight, insulated construction, which can be transported or shipped conveniently as a unit (using light weight construction such as 2×4 stud walls), and which is further characterized by the incorporation therein of plumbing and electric service lines and plumbing and electric fixtures, so arranged as to be protected against damage during shipment and installation of the structure, insulated against freezing in cold weather, and readily connected with plumbing and electrical lines serving the building to which the structure is attached. To this end, the preinstalled plumbing and electric lines are connected to common connection points provided in a box-like structure that encloses an opening all the way through the floor structure to access the inside of the foundation crawl space from inside the bathroom. The crawl space is surrounded by a permanent foundation wall like that of the residence, through which a hole is cut to allow passage of plumbing and electric lines from the residence for connection to the bathroom structure's connection points. The front wall has a doorway for aligning with a doorframe installed in the residence's exterior wall. The front wall is permanently attached and sealed along its entire width and height to the exterior house wall. [0021] Thus there is an unmet need for a cost effective temporary addition to a residence (house) that provides missing living space and facilities on a ground floor level. Preferably the addition is ADA compliant. [0022] A particularly suitable addition will provide an elderly and/or physically disabled person with sufficient space and facilities including a full bathroom or bedroom, optionally with laundry facilities, for ground floor living and sleeping. An ADA compliant temporary house addition will provide the necessary wheelchair space that can be comfortably negotiated alone or with the assistance of a caregiver. BRIEF SUMMARY OF THE INVENTION [0023] For elderly, handicapped or partially-abled house residents, a lack of accessibility to a ground floor bathroom, shower, bedroom/sitting room and/or laundry designed to be negotiated by a person utilizing a walker or wheelchair increases their dependence on others as well as increases safety risks, such as falls while attempting to reach needed facilities on another floor level. [0024] The present invention relates to additional residential living space and facilities, and more specifically to a prefabricated, transportable, room addition, preferably ADA-compliant, for providing a private bedroom/living area or a full bathroom with a shower, sink and toilet; optionally including laundry facilities, that is quickly connectable to a user's house, providing ground floor access to living facilities for the elderly or those with physical limitations only as long as they need them. [0025] Additionally, a nominally 36 inch wide outside door may be provided to accommodate an attached wheelchair ramp for wheelchair access/egress in and out of the home through the attached room addition if existing outside doors in the home are not wide enough. The door can also be used to provide rear access to the house if an existing rear door is temporarily blocked by the addition. [0026] Important aspects of the inventive house addition are an attachment collar structure and corresponding methods for house attachment/installation. [0027] Advantageously, the prefabricated temporary house addition can be attached and detached (installed/removed) from the residence without major re-construction, due to the minimized attachment area of a connecting collar and preferably also due to a simple four-pier foundation, thereby enabling relatively quick, easy and cost effective modification of the residence followed by returning the residence to its original pre-modification state. [0028] In a preferred embodiment, the prefabricated addition is set on a temporary foundation of piers then connected to an existing home through the connecting collar. The connecting collar forms a bridge, by way of the smallest possible surface area, from the existing home to an ADA compliant addition. [0029] The addition is pre-plumbed and wired with access points at its base. The addition's utilities are connected through the existing home's basement or subfloor using conventional supply lines but releasable and reusable connectors/couplings. [0030] According to an embodiment of the invention a prefabricated house addition is provided for temporary removable attachment to a user's house in order to provide the user with living facilities on a ground floor level during a limited time period when the user cannot readily access said living facilities that are only available on another level of the user's house. The prefabricated house addition comprises a factory-built, substantially enclosed structure comprising: a room having a floor section, a front wall, a back wall, two side walls, and a roof section; all being interconnected and suitably constructed according to applicable building codes for an outdoor structure attached to a residential building; and a collar extending forward from the front wall and comprising: a hallway that passes through the front wall to define a passageway that is open at a distal forward collar end and is surrounded by a collar floor section extending the room's floor section forward, two collar side walls and a collar roof section; all being joined with the front wall to form suitable exterior corner joints and substantially right angle interior wall corners; outside collar dimensions of collar height OH and collar width OW that are minimized but limited by a hallway width W between interior surfaces of the collar side walls, and a flooring-to-ceiling hallway height H, that are no smaller than applicable residential building code minimum values for width and height of a passageway to be used by one adult at a time; and a marriage joint around the hallway at the distal forward collar end that provides a substantially planar, forward-facing surface on the collar side walls, floor section and roof section; thereby enabling simplified, removable temporary joining of the prefabricated house addition to a user's house wherein modification of the user's house is minimized. [0031] According to an embodiment of the invention the prefabricated house addition is a temporary room suitable for providing various living facilities as needed, including bathroom, laundry, bedroom, sitting room, and an entrance to the house with a wheelchair ramp. [0032] Preferably hallway height H and width W are approximately equal to ADA minimum values, thereby maintaining wheelchair access while minimizing collar dimensions. [0033] Preferably living space and facilities of the prefabricated house addition are structured according to ADA standards for use with a wheelchair. Further preferably an external door is provided passing through a side or rear wall, optionally having provisions for handicapped access features such as a ramp, elevator, low pitch steps, and the like. [0034] According to an embodiment of the invention the prefabricated house addition's collar has an outside length OL from outside of the front wall of the room to the marriage joint at the distal forward collar end such that the front wall is suitably spaced apart from the user's house and projecting features thereof. A collar extension may be provided to add to a standard prefabricated collar outside length OL. [0035] According to embodiments of the invention the prefabricated house addition provides a compressible sealing gasket at the marriage joint for sealing the joint between addition and house. Furthermore, lag bolts or screws (not nails) are used to removably join the addition to the user's house. [0036] According to an embodiment of the invention site preparation for installation of the prefabricated house addition includes constructing a mating surface for the marriage joint on an exterior house wall, wherein the mating surface surrounds a doorway built into the wall then framed by a header board above and a header-like mating board on either side—all secured with a broad face of the board secured against the inside of the house wall's sheathing to provide support and strengthening extra thickness for the marriage (attachment) of the collar and the house wall. Further preparation includes attaching a ledger on the house wall positioned suitably for supporting the collar by the bottom of its floor section to hold the collar flooring at an elevation above grade that matches the house ground floor's elevation. The room portion of the addition is similarly supported on a foundation structure provided under a perimeter of the room floor section. [0037] According to an embodiment of the invention the prefabricated house addition site preparation uses four corner posts for the foundation. Preferably, as allowed by applicable building codes, the foundation is four helical screw piles positioned at four corners of the room, thereby enabling a relatively inexpensive temporary foundation that is quickly installable and removable with a minimal impact on the installation site. [0038] According to an embodiment of the invention the prefabricated house addition is factory built using robust construction methods and materials, thereby providing a re-usable unitary structure capable of a plurality of transport, lifting, installation, short-to-medium term use, and removal cycles. Robust construction includes any combination of: 2×6 exterior wall studs with a double top plate, OSB sheathing for exterior wall sheathing, roof decking and floor decking (which is preferably also tongue and groove); doubled or LVL joist headers and stringers, flexible rubber membrane roofing material; engineered trusses in the roof section; and solid blocking of floor joists. [0039] According to an embodiment of the invention the prefabricated house addition has a welded metal frame affixed around the floor joist headers and stringers of both the room and the collar. Advantageously, fork lift channels, a metal sill, and/or pier end caps can be affixed to the metal frame. [0040] According to an embodiment of the invention the prefabricated house addition is pre-wired and pre-plumbed to supply utilities suitable for the facilities being provided by the addition. Advantageously, a localized utility connection point is inside the floor section near the front of the collar; and releasable and re-usable utility connectors/couplers are used. [0041] According to an embodiment of the invention the prefabricated house addition has insulation in the floor section protected by a bottom board, plus an insulated skirt (wall) around the area below the addition. [0042] According to an embodiment of the invention the prefabricated house addition includes a sewage pump if needed for waste water handling. [0043] According to an embodiment of the invention the prefabricated house addition is provided as a split unit in two or three sections longitudinally cut to align with the outside of a side wall of the collar, thereby enabling transport through narrow passages followed by on-site assembly. [0044] Other objects, features and advantages of the invention will become apparent in light of the following description thereof. BRIEF DESCRIPTION OF THE DRAWINGS [0045] Reference will be made in detail to preferred embodiments of the invention, examples of which are illustrated in the accompanying drawing figures. The figures are intended to be illustrative, not limiting. Although the invention is generally described in the context of these preferred embodiments, it should be understood that it is not intended to limit the spirit and scope of the invention to these particular embodiments. [0046] Certain elements in selected ones of the drawings may be illustrated not-to-scale, for illustrative clarity. The cross-sectional views, if any, presented herein may be in the form of “slices”, or “near-sighted” cross-sectional views, omitting certain background lines which would otherwise be visible in a true cross-sectional view, for illustrative clarity. [0047] Elements of the figures can be numbered such that similar (including identical) elements may be referred to with similar numbers in a single drawing. For example, each of a plurality of elements collectively referred to as 199 may be referred to individually as 199 a , 199 b , 199 c , etc. Or, related but modified elements may have the same number but are distinguished by primes. For example, 109 , 109 ′, and 109 ″ are three different elements which are similar or related in some way, but have significant modifications. Such relationships, if any, between similar elements in the same or different figures will become apparent throughout the specification, including, if applicable, in the claims and abstract. [0048] The structure, operation, and advantages of the present preferred embodiment of the invention will become further apparent upon consideration of the following description taken in conjunction with the accompanying drawings, wherein: [0049] FIGS. 1A , 1 B, and 1 C are elevation views of a first side wall, a second side wall, and a front, respectively, of a prefabricated temporary house addition according to the invention. [0050] FIG. 2 is a perspective side view of a prefabricated addition and portions thereof being transported according to the invention. [0051] FIGS. 3A , 3 B, and 3 C are plan views of three embodiments of a prefabricated addition according to the invention. [0052] FIGS. 4A , 4 B, and 4 C are a top cross-section, a front-to-back side cross-section, and a partial side-to-side cross-section, respectively, of representative embodiments of the prefabricated addition according to the invention. [0053] FIG. 5 is a perspective exploded view of a floor portion of an embodiment of the prefabricated addition according to the invention. [0054] FIG. 6 is a perspective view of a user's house (wall structure shown ghosted behind house sheathing and siding) showing site preparation for temporary installation of the prefabricated addition according to the invention. [0055] FIGS. 7A and 7B are a bottom view and a side cross-section of a portion of a metal framed embodiment of the prefabricated addition, showing attachment of a pile type of foundation according to the invention. [0056] FIGS. 7C , 7 D, and 7 E are side cross-section views of exemplary suitable foundations supporting a corner portion of the prefabricated addition according to the invention. [0057] FIG. 8 is a magnified horizontal cross-section top view taken along the line 8 - 8 in FIG. 6 showing a portion of the house wall prepared for installation, plus a marriage joint portion of the prefabricated addition that is longitudinally split to show before and after views of marrying the house and the addition according to the invention. [0058] FIG. 9 is a side cross-section view with cutouts of subfloor, basement and foundation portions of the prefabricated addition married to the user's house, showing on-site utility connections according to the invention. [0059] FIG. 10 is a raised perspective view of a finished installation of the prefabricated addition on a user's house according to the invention. DETAILED DESCRIPTION OF THE INVENTION [0060] Although adding a room to a house is not new, the present disclosure will describe embodiments of novel improvements incorporated in the design and method of installation of an inventive prefabricated temporary house addition (the addition 100 ). It can be seen that the addition 100 is particularly suited for satisfying a heretofore unmet need of handicapped, partly disabled, ill, or infirm house residents for a temporary addition providing needed living space and facilities, and that is easily installed and later removed with minimal impact on the house and yard and resultant property resale value. [0061] Therefor the inventive addition 100 is prefabricated to simplify installation, is constructed for transport to and from an existing residential house location, and incorporates features that enable re-use of a particular addition at a plurality of residential sites. [0062] Referring to FIGS. 1A-1C , 4 A- 4 C, 8 and 10 , the prefabricated house addition 100 is a factory-built, substantially enclosed structure including a room 102 having a floor section 104 underneath, a roof section 112 above, and surrounding front wall 106 , back wall 108 , and two side walls 110 ; all being interconnected and suitably constructed according to applicable building codes for an outdoor structure attached to a residential building (e.g., user's house 500 ). An important feature of the inventive addition 100 is a collar 120 that enables simplified, removable temporary joining of the prefabricated house addition 100 to a user's house 500 wherein modification of the house 500 is minimized while still providing easy access from the house 500 to a living space (room) 102 in the addition 100 . The collar 120 extends forward from the front wall 106 and comprises: a hallway 122 that passes through the front wall 106 to define a passageway that is open at a distal forward collar end 124 and is surrounded by a collar floor section 126 extending the room's floor section 104 forward, two collar side walls 128 and a collar roof section 130 , all being joined with the front wall 106 to form suitable exterior corner joints 132 and substantially right angle interior wall corners 134 . The collar has outside dimensions of collar height OH (from a bottom board 186 beneath a collar floor section 126 to roofing 182 on top of a collar roof section 130 ) and collar width OW (between exterior wall coverings 148 on two collar side walls 128 ) that are minimized but limited by a hallway width W between interior surfaces 136 of collar side walls 128 , and a flooring 138 -to-ceiling 140 hallway height H, that are no smaller than applicable residential building code minimum values for width and height of a passageway to be used by one adult at a time. In preferred embodiments, the hallway height H and width W are approximately equal to ADA minimum values for use by a person in a wheelchair. For example, the ADA minimum width for a hallway is 36 inches or 32 inches for a short portion, like a doorframe. [0063] The collar 120 has an outside collar length OL measured from a front wall 106 of the addition 100 to a distal forward collar end 124 , which presents a substantially planar, forward-facing surface 144 on the collar's side walls 128 , floor section 126 and roof section 130 . This planar surface is a marriage joint 142 for attaching the addition 100 to the house 500 by sealing against a site-prepared corresponding planar mating surface 525 ( FIGS. 6 and 8 ). Preferably a good seal is formed by a releasable sealing gasket 146 rather than caulking In a test unit we will use a “Barrier Seal” product that is specifically sold for use in “marriage joints” of factory built modular and double wide manufactured homes. Also known as “bulb seal”, the ITP sealing gasket 146 is a longitudinally extending strip with a P-shaped cross-section made of a “highly compressible, non-gassing, engineered polymer foam.” This embodiment of the sealing gasket 146 is available from Industrial Thermo Polymers Ltd. (ITP), of Brampton, Ontario, Canada. [0064] Also shown in FIG. 1A is an exterior door 194 that is shown with an optional wheelchair ramp 196 , this being but one example of a number of provisions that can be made for handicapped access such as a ramp, elevator, low pitch steps, and the like. The door 194 is nominally 36 inches wide and the ramp 196 is suitably made to accommodate wheelchair access/egress in and out of the home 500 through the attached room addition 100 if existing outside doors in the home are not wide enough. The door 194 can also be used to provide rear access to the house if an existing rear door is temporarily blocked by the addition 100 . [0065] Nevertheless, FIG. 10 shows that spacing the addition 100 apart from the house 500 by the collar length OL, and by only covering a minimized area (collar width OW by collar height OH) then very little of the house siding 511 is disturbed and functional presence of projecting house features 504 such as windows, doors and hose faucets, for example, are retained. A “shadow” drawn on the house 500 shows that without the collar 120 , attachment to the house 500 of the entire width RW and height RH of the front wall 106 of the addition would require removal or boarding up of the window feature 504 and removal or moving of the faucet feature 504 . [0066] FIG. 2 illustrates some aspects of the prefabricated temporary house addition 100 that enhance its portability and facilitate its re-use. The room width RW and room height RH are suitable for transport on truck beds (e.g., width RW of 9′-9″, and height RH of about 11′-9″). To accommodate a narrow residential driveway, a longitudinally split addition 100 can be prefabricated like a “double wide” house trailer. For example, FIG. 2 shows a split portion 116 that is separated from the nearest third of the addition along a line parallel to a collar side 128 . [0067] Preferably as shown, fork channels 174 are built into the addition 100 . These are heavy gauge structural metal channels (e.g., 5 gauge steel) that extend completely across the room width RW under the floor section 104 (see FIGS. 5 and 7 A-B), thereby spreading out the forces imposed by lifting the addition 100 on forklift truck forks. Furthermore, the fork channels 174 are sized and shaped to confine a forklift fork above and on both sides in order to minimize wobbling and shifting of the addition 100 while it is carried from truck bed to installation site and also while it is being precisely positioned against the house 500 and on a foundation 160 of the addition 100 that may comprise only four narrow posts 162 (see FIG. 6 ). [0068] An optional component for the addition 100 is a collar extension 118 that duplicates the collar 120 structure except for additionally having a rearward facing planar surface 144 ′ that is suitable for use like a house mating surface 525 for marrying with the forward facing marriage joint of the standard collar 120 . As with the house mating surface 525 , through holes 540 can be provided in the rear face 144 ′ for enabling the use of lag screws or lag bolts/nuts 150 to secure the collar extension 118 to the collar 120 . The collar extension may be provided in several standard collar lengths, or could be custom made for specific installations. [0069] FIGS. 3A-3C show floor plans for three examples of rooms 102 that can be provided by additions 100 to supply temporary living facilities to meet various needs. FIGS. 3A and 3B show two bathrooms 102 a and 102 b , the main difference being that the second bathroom 102 b also has a washer and dryer 180 d as an extra living facility 180 , in addition to a step-in shower 180 a , a lavatory/sink 180 b , and a toilet 180 c . In preferred embodiments the living facilities are all ADA compliant, and also the arrangement of facilities 180 in the room comply with ADA standards for movement in a wheelchair. For example, ADA3 indicates a 5 foot diameter circle for allowing a 360 degree turn. Likewise, ADA1 and ADA2 indicate minimum required open spaces for use of the shower and sink facilities. It can be seen that suitable handgrip bars are provided where needed. In FIG. 3B , ADA4 indicates the ADA compliant doorway width (nominal 36″, minimum 32″). The hallway 122 in the collar 120 has a width W that is substantially 36″ wide. [0070] It can be seen that by leaving out the laundry facilities 180 d , the room depth RD can be reduced from RD(b) to a smaller dimension RD(a), while still maintaining ADA compliance. FIG. 3C shows a multipurpose room 102 c which can be used as a bedroom and/or sitting room or otherwise private area. An air conditioner 214 and/or a window 198 may be provided. Likely facilities 180 e would include, at a minimum, properly spaced electrical outlets, for example. [0071] FIG. 5 illustrates an extra base framing for strength, portability: a metal support frame with addition “exploded” above it, lined up for assembly. [0072] FIG. 6 shows site preparation for installation: Perspective view—a doorframe installed in outside wall of house. Lap siding removed from wall around it and header/mating boards/ledger board installed around it. Three helical pier posts in place, one lying on ground. Hole in basement wall below ledger, with bundle of wires, two water lines, and a sewer line extending out from it. [0073] FIG. 7A-B show how a helical pile cap with mounting plate is welded to bottom of metal sill, (alternatives include pile cap to double wood rim joists/lag screws, and metal sill on wood frame) 7 C is a 6×6 wood post in buried cement bolted into inside corner of floor rim joists, D=standard cement block wall on buried poured foundation, E=concrete slab with joists resting on a single brick riser. [0074] FIG. 8 is marriage joint: top view of horizontal X-section, magnified to show portions of married (installed) collar end and house wall at doorframe. Shows P-seal flattened between flat collar end face and header above plus “mating boards” either side of door frame, flush with outside of house sheathing. Shows AZEK trim boards sealed against house siding. Shows bolts or lag screws removably holding joint together. [0075] FIG. 9 shows utility connections/foundation insulation: side Xsection view of installed addition, magnified to show collar floor and down to ground, hole in basement wall, and part of basement. Shows ledger board supporting end of collar floor, utility supply lines from basement thru hole, connections together under floor of collar. Identifies releasable reusable connections. Shows insulation in floor, bottom board, and optional ejection pump. [0076] Referring to FIGS. 4A-5 , The prefabricated house addition 100 is factory built using robust construction methods and materials, thereby providing a re-usable unitary structure capable of a plurality of transport, lifting, installation, short-to-medium term use, and removal cycles. Robust construction includes any combination of: 2×6 exterior wall studs 155 with a double top plate 157 , OSB sheathing for exterior wall sheathing 156 , roof decking 156 and floor decking 156 (which is preferably also tongue and groove); doubled or LVL joist headers and stringers 154 , flexible rubber membrane roofing material 182 ; engineered wood or metal trusses 158 in the roof section 112 ; and solid blocking 153 of floor joists 152 . Optionally the roof section 112 is constructed a 3-12 pitch shed roof, but could also be a peaked roof. The trusses as well as joists are secured both by nails and by hanger brackets. The roof may be finished with underlayment, asphalt shingles or metal-standing seam roofing. The roof is vented by conventional means, and the roof cavity is insulated with an extra thick layer of either batt or blown-in insulation 190 . [0077] The exterior walls are constructed using 2×6 wood or metal studs 155 secured 16 inches on center. Drywall or other suitable products cover the interior side of the exterior walls; wood sheathing 156 covers the exterior side of the walls. The exterior walls are insulated with either batt or blown-in insulation (not shown). The exterior walls are finished with moisture barrier and vinyl or other suitable products. [0078] The floor joists 152 are constructed with either 2×8 or (preferably) 2×10 wood or metal joists spaced 16 inches O/C. Open joists may be used in places to accommodate plumbing and the like. Insulation 190 preferably fills the space between the floor joists 152 , headers and stringers 154 . Wood decking 156 is applied to the top of the floor joists, then covered by finish flooring 138 such as vinyl or other suitable materials. [0079] Referring to FIGS. 9-10 , the underside of the floor joists 152 are covered with a suitable bottom board 186 . When the preferred foundation of piers or posts 162 is used, the resulting crawl space is enclosed by a complete skirt 192 with insulation 190 applied from the bottom of the floor joists to grade level and extending completely around the addition 100 and connecting collar 120 after the plumbing and electrical connections are completed. [0080] Two pre-plumbed ¾ inch copper or Pex tubing, plumbing lines run in the center of the addition between the floor joists. One supplies hot water to the sink, shower, and laundry, if present, and the second water line supplying cold water to the toilet, sink, shower, and laundry, if present. ½ inch hot and cold water supply lines branch off from the ¾ inch line at the point of termination into the bathroom fixtures. A third pre-plumbed 3 inch sanitary line runs next to the hot and cold water branches between the floor joists in the center of the addition. This 3 inch sanitary line has branches that are also 3 inch to pick up the sanitary waste from the toilet, sink, shower, and washer, if present. This 3 inch sanitary line has a 2 inch conventional venting loop from beginning to end that terminates through the roof. [0081] The utilities 200 : hot and cold water lines 207 , the sanitary line 209 and the electrical wiring 202 end at a connection point 201 under the collar 120 but protected within it. Corresponding utility lines 529 from the existing home's plumbing and electrical lines are extended through a hole 520 cut in the foundation wall 518 to the point of connection 201 . [0082] Advantageously, releasable and re-usable utility connectors/couplers are used. For example, a Fernco Coupling 210 will be used to connect the PVC sanity line 209 to the house sewer line 530 . Fernco couplings have earned a reputation for consistent, superior performance. The dimensional flexibility of Fernco couplings ensures leak-proof seals on virtually any pipe material: plastic, cast iron, asbestos cement, clay, concrete, steel, copper and ductile iron. The coupling is made of an elastomeric compound that meets the requirements of ASTM #D5926, C1173 and applicable portions of ASTM #C443, C425, C564, CSA B602 and D1869. It is leak-proof, root-proof and resistant to chemicals, ultraviolet rays, fungus growth, and normal sewer gases. Stainless steel clamps are corrosion-resistant and rust-proof. [0083] The water lines 207 and 532 are preferably PEX plumbing lines for hot (red plastic) and cold (blue) water being connected to the supply lines 532 from the home with SharkBite reusable push-fit fittings 208 . There is a SharkBite Disconnection tool that is used to disconnect the supply lines when the addition 100 is removed. Thus the fittings are re-usable (both water and sewer). SharkBite Couplings make fast and easy connections from PEX, copper, or CPVC with NO soldering, clamps, unions or glue required. SharkBite push-fit fittings are fittings that you can push the connector by hand onto the tube or pipe. Once pushed to the proper depth, you're done; no extra parts, soldering or tools are required. Watertight to 200 psi, approved for hidden use. [0084] There are three pre-wired electrical circuits that supply an exhaust fan and lighting, a GFI (ground fault interrupter) outlet next to the sink, and the radiant heater. The exhaust fan and lighting circuit could also be on a GFI circuit. All three circuits are of conventional amperage and wattage. Two additional pre-wired circuits of conventional amperage and wattage are provided with suitable receptacles for laundry facilities, if present. [0085] All pre-wired circuits are fed back to a junction box 204 between the floor joists of the connecting collar. Patch connections are made from the existing home's electrical panel to the junction box under the connecting collar to provide electricity. Standard wire nuts may be used as re-usable connectors. [0086] Viewed in FIG. 3A , an ADA compliant walk-in shower and that is 60 inches wide and 30 inches deep is pre-installed. The shower seat is located 17-19 inches from the shower floor per ADA guidelines and extends the full depth of the shower stall. The controls for the hot and cold water and the lowest adjustable point for the flexible shower hose with handle are located between 38 and 48 inches from the shower floor. The hot and cold water controls and the shower handle are located no farther than 27 inches from the corner of the wall with attached seat. 1¼ or 1½ inch grab bars and are pre-installed throughout at proper ADA height between 33 and 36 inches from the floor. and are the 36×60 inch ADA approaches for this shower. [0087] An ADA compliant raised toilet, is pre-installed with a seat height 17 to 19 inches from the floor. The flush control is located on the open side of the toilet. A 36 inch grab bar that is 1¼ or 1½ inches in diameter is pre-installed behind the toilet, and a 42 inch grab bar of the same diameter is pre-installed at the closed wall side of the toilet at proper ADA height between 33 and 36 inches from the floor and extends no farther than 54 inches from the wall behind the toilet. [0088] A sink is pre-installed and mounted with counter or rim no higher than 34 inches above finished floor. Knee clearance is provided that is at least 8 inches under the sink where the height clearance is 27 inches. 17 inches of toe clearance from the wall is provided with a minimum height of 9 inches. The pipes under the sink are covered to prevent contact. The sink shall be a maximum of 6½ inches deep, and the faucet will have paddle handles. A tilt mirror is mounted no higher than 40 inches above the finish floor. and illustrate the 30 inch approach area for the sink. [0089] The room 102 b with space and utility connections providing for a laundry area is meant to receive either a washer and dryer from the existing home's basement or a washer and dryer purchased for the occupants level of functioning, i.e., occupant uses a cane, walker, or wheelchair. is the 30×48 inch approach areas to the washer and dryer. [0090] A 5 foot turning radius is provided to comfortably make a 360 degree turn in a wheelchair. The entrance into the addition, connecting collar hallway, is 36 inches wide and. The width of the exit door and clear floor space to this exit door is 36 inches (somewhat reduced by trim and door hinge edge, but well over the minimum allowance of 32 inches). [0091] FIGS. 6 and 8 illustrate the marrying of collar to house. The brick or siding would be peeled away to make room for the door framing. Install a ledger board 524 on the home where the frame for the hallway will rest for support. [0092] The exterior will be finished with either AZEK trim for around doorway plus caulk or aluminum siding trim plus caulk. Azek is a moisture resistant trim board. From web page: [0093] The plumbing that connects to the home after a hole is bored through the basement block may have a box 536 built around it so that the heat from the basement will pass through the bored hole and fill the box connecting the floor joists and the basement block. The box could also contain additional insulation 190 . [0094] If needed, a sewage ejector pump 212 is provided when gravity draining won't work. [0095] Although the invention has been illustrated and described in detail in the drawings and foregoing description, the same is to be considered as illustrative and not restrictive in character—it being understood that only preferred embodiments have been shown and described, and that all changes and modifications that come within the spirit of the invention as claimed are desired to be protected. Undoubtedly, many other “variations” on the “themes” set forth hereinabove will occur to one having ordinary skill in the art to which the present invention most nearly pertains, and such variations are intended to be within the scope of the invention, as disclosed herein.	A prefabricated, transportable, ADA compliant, temporary addition, providing ADA accessible bathing, hygiene, and optional laundry facilities to the disabled occupants, eliminating the need to negotiate stairs to access a second floor bath or basement laundry. The addition is designed to be transported, lifted, connected and disconnected multiple times. The addition contains a walk-in shower with grab bars, ADA sink and sink base, tilt mirror, raised toilet with grab bars, egress door, light, heating unit, and exhaust fan. The addition is supported on a foundation of piers and attached to a ground floor room of an existing home by way of a connecting collar, minimizing the surface area connection to the house. The addition is pre-plumbed and wired with plumbing and electrical access points at the base of the addition that are connected to the existing home's utilities through a hole into the basement.	4
FIELD OF THE INVENTION [0001] The present subject matter relates generally to washing machine appliances and more particularly to washing machine appliances having a system for adding supplemental wash liquid. BACKGROUND OF THE INVENTION [0002] Washing machine appliances generally include a tub for containing water or wash liquid, e.g., water and detergent, bleach, and/or other wash additives. A basket is rotatably mounted within the tub and defines a wash chamber for receipt of articles for washing. During normal operation of such washing machine appliances, the wash liquid is directed into the tub and onto articles within the wash chamber of the basket. The basket or an agitation element can rotate at various speeds to agitate articles within the wash chamber, to wring wash fluid from articles within the wash chamber, etc. [0003] During operation of certain washing machine appliances, a volume of wash liquid is directed into the tub in order to wash and/or rinse articles within the wash chamber. One or more fluid additives may be added to the wash liquid to enhance the cleaning or other properties of the wash liquid. The fluid additives may be in powder or concentrated liquid form, and are generally added to a dispenser box of the washing machine appliance by, e.g., a user of the washing machine appliance. The dispenser box may contain various chambers for containing different additives, e.g., wash detergent and softener. Water may be directed into the chambers of the dispenser box through a plurality of water inlet valves to mix with the additives and the resulting wash liquid is then dispensed into the wash chamber. [0004] The volume of water or wash liquid needed may vary depending upon a variety of factors. For example, large loads can require a large volume of water relative to small loads that can require a small volume of water. A user may wish to have additional wash liquid dispensed in order to perform a specific task, e.g., prewash an article of clothing or add additional liquid to accommodate an extra large load. The ability to adjust the amount of water or wash liquid dispensed is a generally commercially desirable feature and increases the user's positive perception of the wash process generally. However, conventional washing machine appliances typically do not have water-on-demand features, and those that do require additional nozzles, hoses, clamps, and other hardware to perform such a function. [0005] Accordingly, a washing machine appliance that provides a user with more control over the water or wash liquid fill amount is desirable. In particular, a dispenser box having a simple, convenient, integrated system for dispensing an additional predetermined amount of wash liquid would be particularly beneficial. BRIEF DESCRIPTION OF THE INVENTION [0006] The present subject matter provides a washing machine having an integrated water-on-demand feature. More particularly, the present subject matter provides a washing machine appliance that allows a user to adjust the water or wash liquid fill amount of the washing machine appliance using an actuator integrated into or positioned nearby the dispenser box, thereby enabling a simple, convenient, and effective manner of adding wash liquid without requiring a substantial number of additional parts or assembly. Additional aspects and advantages of the invention will be set forth in part in the following description, or may be apparent from the description, or may be learned through practice of the invention. [0007] In one exemplary embodiment, a washing machine appliance defining a vertical, a lateral, and a transverse direction is provided. The washing machine appliance includes a cabinet; a tub positioned within the cabinet; and a wash basket rotatably mounted within the tub, the wash basket defining a wash chamber for receiving articles for washing. The washing machine appliance further includes an additive dispenser positioned within the cabinet and configured to provide wash liquid to the tub. The additive dispenser includes a mixing chamber configured to receive wash additive and a water valve configured to provide a flow of water to the mixing chamber from a water inlet. The additive dispenser further includes a user input button for adding supplemental water to the tub and a controller in operative communication with both the user input button and the water valve. The controller is configured to receive a user input to add a supplemental water fill amount to the tub and open the water valve to provide the tub with the supplemental water fill amount. [0008] In another exemplary embodiment, a dispensing assembly for a washing machine appliance having a tub positioned within a cabinet is provided. The dispensing assembly includes a water valve configured to provide a flow of water from a water inlet and a dispenser box positioned within the cabinet, the dispenser box comprising a mixing chamber configured to receive the flow of water and dispense the flow of water into the tub. The dispensing assembly further includes a user input button and a controller in operative communication with both the user input button and the water valve. The controller is configured to open the water valve to provide the tub with a supplemental water fill amount responsive to the user input button being pressed. [0009] These and other features, aspects and advantages of the present invention will become better understood with reference to the following description and appended claims. The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments of the invention and, together with the description, serve to explain the principles of the invention. BRIEF DESCRIPTION OF THE DRAWINGS [0010] A full and enabling disclosure of the present invention, including the best mode thereof, directed to one of ordinary skill in the art, is set forth in the specification, which makes reference to the appended figures. [0011] FIG. 1 provides a perspective view of a washing machine appliance according to an exemplary embodiment of the present subject matter with a door of the exemplary washing machine appliance shown in a closed position. [0012] FIG. 2 provides a perspective view of the exemplary washing machine appliance of FIG. 1 with the door of the exemplary washing machine appliance shown in an open position. [0013] FIG. 3 provides a front, perspective view of an exemplary dispenser box assembly installed in the exemplary washing machine appliance of FIG. 1 . [0014] FIG. 4 provides a front, perspective view of the exemplary dispenser box assembly of FIG. 3 . [0015] FIG. 5 provides a rear, perspective view of the exemplary dispenser box assembly of FIG. 3 . [0016] FIG. 6 provides a front, perspective view of a front portion of a dispenser box according to another exemplary embodiment of the present subject matter. DETAILED DESCRIPTION OF THE INVENTION [0017] Reference now will be made in detail to embodiments of the invention, one or more examples of which are illustrated in the drawings. Each example is provided by way of explanation of the invention, not limitation of the invention. In fact, it will be apparent to those skilled in the art that various modifications and variations can be made in the present invention without departing from the scope or spirit of the invention. For instance, features illustrated or described as part of one embodiment can be used with another embodiment to yield a still further embodiment. Thus, it is intended that the present invention covers such modifications and variations as come within the scope of the appended claims and their equivalents. [0018] FIGS. 1 and 2 illustrate an exemplary embodiment of a vertical axis washing machine appliance 100 . In FIG. 1 , a lid or door 130 is shown in a closed position. In FIG. 2 , door 130 is shown in an open position. Washing machine appliance 100 generally defines a vertical direction V, a lateral direction L, and a transverse direction T, each of which is mutually perpendicular, such that an orthogonal coordinate system is generally defined. [0019] While described in the context of a specific embodiment of vertical axis washing machine appliance 100 , using the teachings disclosed herein it will be understood that vertical axis washing machine appliance 100 is provided by way of example only. Other washing machine appliances having different configurations, different appearances, and/or different features may also be utilized with the present subject matter as well, e.g., horizontal axis washing machines. [0020] Washing machine appliance 100 has a cabinet 102 that extends between a top portion 103 and a bottom portion 104 along the vertical direction V. A wash basket 120 ( FIG. 2 ) is rotatably mounted within cabinet 102 . A motor (not shown) is in mechanical communication with wash basket 120 to selectively rotate wash basket 120 (e.g., during an agitation or a rinse cycle of washing machine appliance 100 ). Wash basket 120 is received within a wash tub or wash chamber 121 ( FIG. 2 ) and is configured for receipt of articles for washing. The wash tub 121 holds wash and rinse fluids for agitation in wash basket 120 within wash tub 121 . An agitator or impeller (not shown) extends into wash basket 120 and is also in mechanical communication with the motor. The impeller assists agitation of articles disposed within wash basket 120 during operation of washing machine appliance 100 . [0021] Cabinet 102 of washing machine appliance 100 has a top panel 140 . Top panel 140 defines an opening 105 ( FIG. 2 ) that permits user access to wash basket 120 of wash tub 121 . Door 130 , rotatably mounted to top panel 140 , permits selective access to opening 105 ; in particular, door 130 selectively rotates between the closed position shown in FIG. 1 and the open position shown in FIG. 2 . In the closed position, door 130 inhibits access to wash basket 120 . Conversely, in the open position, a user can access wash basket 120 . A window 136 in door 130 permits viewing of wash basket 120 when door 130 is in the closed position, e.g., during operation of washing machine appliance 100 . Door 130 also includes a handle 132 that, e.g., a user may pull and/or lift when opening and closing door 130 . Further, although door 130 is illustrated as mounted to top panel 140 , alternatively, door 130 may be mounted to cabinet 102 or any other suitable support. [0022] A control panel 110 with at least one input selector 112 ( FIG. 1 ) extends from top panel 140 . Control panel 110 and input selector 112 collectively form a user interface input for operator selection of machine cycles and features. A display 114 of control panel 110 indicates selected features, operation mode, a countdown timer, and/or other items of interest to appliance users regarding operation. [0023] Operation of washing machine appliance 100 is controlled by a controller or processing device 108 ( FIG. 1 ) that is operatively coupled to control panel 110 for user manipulation to select washing machine cycles and features. In response to user manipulation of control panel 110 , controller 108 operates the various components of washing machine appliance 100 to execute selected machine cycles and features. [0024] Controller 108 may include a memory and microprocessor, such as a general or special purpose microprocessor operable to execute programming instructions or micro-control code associated with a cleaning cycle. The memory may represent random access memory such as DRAM, or read only memory such as ROM or FLASH. In one embodiment, the processor executes programming instructions stored in memory. The memory may be a separate component from the processor or may be included onboard within the processor. Alternatively, controller 100 may be constructed without using a microprocessor, e.g., using a combination of discrete analog and/or digital logic circuitry (such as switches, amplifiers, integrators, comparators, flip-flops, AND gates, and the like) to perform control functionality instead of relying upon software. Control panel 110 and other components of washing machine appliance 100 may be in communication with controller 108 via one or more signal lines or shared communication busses. [0025] During operation of washing machine appliance 100 , laundry items are loaded into wash basket 120 through opening 105 , and washing operation is initiated through operator manipulation of input selectors 112 . Wash basket 120 is filled with water and detergent and/or other fluid additives via dispenser box assembly 200 , which will be described in detail below. One or more valves can be controlled by washing machine appliance 100 to provide for filling wash basket 120 to the appropriate level for the amount of articles being washed and/or rinsed. By way of example for a wash mode, once wash basket 120 is properly filled with fluid, the contents of wash basket 120 can be agitated (e.g., with an impeller as discussed previously) for washing of laundry items in wash basket 120 . [0026] After the agitation phase of the wash cycle is completed, wash basket 120 can be drained. Laundry articles can then be rinsed by again adding fluid to wash basket 120 depending on the specifics of the cleaning cycle selected by a user. The impeller may again provide agitation within wash basket 120 . One or more spin cycles also may be used. In particular, a spin cycle may be applied after the wash cycle and/or after the rinse cycle to wring wash fluid from the articles being washed. During a spin cycle, wash basket 120 is rotated at relatively high speeds. After articles disposed in wash basket 120 are cleaned and/or washed, the user can remove the articles from wash basket 120 , e.g., by reaching into wash basket 120 through opening 105 . [0027] Referring now generally to FIGS. 2 through 6 , dispenser box assembly 200 will be described in more detail. Although the discussion below refers to dispenser box assembly 200 , one skilled in the art will appreciate that the features and configurations described may be used for other additive dispensers in other washing machine appliances as well. For example, dispenser box assembly 200 may be positioned on a front of cabinet 102 , may have a different shape or chamber configuration, and may dispense water, detergent, or other additives. Other variations and modifications of the exemplary embodiment described below are possible, and such variations are contemplated as within the scope of the present subject matter. [0028] Dispenser box assembly 200 is a box having a substantially rectangular cross-section that defines a top 202 and a bottom 204 spaced apart along the vertical direction V. Dispenser box assembly 200 also defines a front side 206 and a back side 208 spaced apart along the transverse direction T. As best shown in FIGS. 2 and 3 , dispenser box assembly 200 may be mounted underneath top panel 140 of cabinet 102 such that front side 206 is visible inside opening 105 . More specifically, dispenser box assembly 200 may be mounted to top panel 140 using a plurality of mounting features 210 , which may, for example, be configured to receive mechanical fasteners. One skilled in the art will appreciate that dispenser box assembly 200 may be mounted in other locations and use other mounting means according to alternative exemplary embodiments. [0029] Dispenser box assembly 200 may define a mixing chamber 220 configured to receive one or more additive compartments. For example, according to the illustrated embodiment, mixing chamber 220 may be configured to slidably receive a detergent compartment 222 and a softener compartment 224 . Compartments 222 , 224 are slidably connected to the mixing chamber 220 using slides 226 and are connected to a front panel 228 of dispenser box assembly. In this manner, a user may pull on front panel 228 to slide compartments 222 , 224 along the transverse direction T. Once extended, detergent compartment 222 and softener compartment 224 may be conveniently filled with detergent and softener, respectively. Front panel 228 may be then be pushed back into mixing chamber 220 before a wash cycle begins. [0030] Although the illustrated embodiment shows detergent compartment 222 and softener compartment 224 slidably received in mixing chamber 220 for receiving wash additives, one skilled in the art will appreciate that different configurations are possible in alternative exemplary embodiments. For example, more compartments may be used and the compartments may be accessed by a lid instead of sliding out of mixing chamber 220 . Alternatively, mixing chamber 220 may draw wash additives from a separate storage container such that sliding compartments 222 , 224 are not needed. Other configurations of mixing chamber 220 and compartments 222 , 224 are also possible and within the scope of the present subject matter. [0031] Dispenser box assembly 200 may further include a plurality of valves configured to supply hot and cold water to mixing chamber 220 or directly to wash tub 121 . For example, according to the illustrated embodiment, a plurality of apertures may be defined on top 202 of mixing chamber 220 for receiving water. Each aperture (not shown) may be in fluid communication with a different portion of the mixing chamber. A plurality of valve seats may be positioned over top of each of those apertures to receive a valve that controls the flow of water through each aperture. [0032] For example, a first valve seat 234 may be in fluid communication with a first aperture for providing hot water into detergent compartment 222 . A second valve seat 236 may be in fluid communication with a second aperture for providing cold water into detergent compartment 222 . A third valve seat 238 may be in fluid communication with a third aperture for providing cold water into softener compartment 224 . A fourth valve seat 240 may be in fluid communication with a fourth aperture for providing cold water into mixing chamber 220 or directly into wash tub 121 . [0033] Water inlets may be placed in fluid communication with each of valve seats 234 , 236 , 238 , 240 . More specifically, a hot water inlet 244 may be connected to a hot water supply line (not shown) and a cold water inlet 246 may be connected to a cold water supply line (not shown). According to the illustrated embodiment, each water inlet 244 , 246 may include a threaded male adapter configured for receiving a threaded female adapter from a conventional water supply line. However, any other suitable manner of fluidly connecting a water supply line and water inlets 244 , 246 may be used. For example, each water supply line and water inlets 244 , 246 may have copper fittings that may be sweated together to create a permanent connection. [0034] Notably, hot water inlet 244 is in direct fluid communication with first valve seat 234 . However, because washing machine appliance 100 uses cold water for multiple purposes, cold water inlet is in fluid communication with a cold water manifold 248 . As best shown in FIG. 5 , cold water manifold 248 is a cylindrical pipe that extends along the lateral direction from second valve seat 236 to fourth valve seat 240 . In this manner, cold water manifold 248 places valve seats 236 , 238 , 240 in fluid communication with cold water inlet 246 . [0035] Each of valve seats 234 , 236 , 238 , 240 may be configured to receive a water valve 252 for controlling the flow of water through a corresponding aperture into mixing chamber 220 . Water valve 252 may be, for example, a solenoid valve that is electrically connected to controller 108 . However, any other suitable water valve may be used to control the flow of water. Controller 108 may selectively open and close water valves 252 to allow water to flow from hot water inlet 244 through first valve seat 234 and from cold water manifold 248 through one or more of second valve seat 236 , third valve seat 238 , and fourth valve seat 240 . [0036] Dispenser box assembly 200 may further include one or more nozzles (not shown) for directing wash fluid, such as water and/or a mixture of water and at least one fluid additive, e.g., detergent, fabric softener, and/or bleach into wash tub 121 from dispenser box assembly 200 . For example, when second valve seat 236 is open, water may flow from cold water inlet 246 through cold water manifold 248 and second valve seat 236 into detergent compartment 222 . Water may mix with detergent placed in detergent compartment 222 to create wash liquid to be dispensed into wash tub 121 . [0037] A nozzle (not shown) may be placed on the bottom of detergent compartment 222 or on the bottom of mixing chamber 220 to dispense the wash fluid into wash tub 121 . According to the illustrated embodiment, dispenser box assembly 200 may include four nozzles associated with valves seats 234 , 236 , 238 , 240 , respectively. However, it will be understood that different nozzle configurations may be used in alternative exemplary embodiments. For example, nozzles may be positioned on a bottom of mixing chamber 220 near wash tub 121 or directly on wash tub 121 , but could be positioned in other locations as well. [0038] In some situations, a user may wish to add additional water to wash tub 121 . For example, a user may wish to prewash one or more articles of clothing or may perceive that more water is needed to effectively wash a load. Accordingly, dispenser box assembly 200 may include a system for allowing a user to add water to wash tub 121 on demand, i.e., a water-on-demand feature. [0039] In this regard, dispenser box assembly 200 may include one or more buttons that are configured to control one or more of valves 252 . According to the exemplary embodiment illustrated in FIG. 3 , dispenser box assembly 200 includes a cold water button 260 and a hot water button 262 for controlling valves 252 on first valve seat 234 and fourth valve seat 240 , respectively. However, one skilled in the art will appreciate that additional buttons may be included and the buttons may control different valves 252 or any combination of valves 252 . For example, a third button may be configured to add a “soapy” mixture of hot and/or cold water with a wash additive. In addition, one skilled in the art will appreciate that any of these buttons can be turned on/off independently or together in any combination. [0040] Cold water button 260 and hot water button 262 may be any button or switch suitable for providing an indication to controller 108 that a particular action should be initiated. For example, buttons 260 , 262 may be push button switches, toggle switches, rocker switches, or any other suitable tactile switch, such as capacitive touch buttons. According to the illustrated embodiments, buttons 260 , 262 are momentary switches (sometimes referred to as mom-off-mom switches). In this regard, buttons 260 , 262 are biased switches that return to their unlatched or unpressed state when released, e.g., by spring force. [0041] According to the exemplary embodiment illustrated in FIG. 3 , cold water button 260 and hot water button 262 may be located on front panel 228 of dispenser box assembly 200 . According to an alternative exemplary embodiment illustrated in FIG. 6 , a cold water button 270 and a hot water button 272 may be placed on a bottom surface of top panel 140 adjacent to dispenser box assembly 200 . For example, cold water button 270 may be placed just to the right of mixing chamber 220 and hot water button 272 may be placed just to the left of mixing chamber 220 . In this manner, when a user desires additional water, the user may insert their finger between top panel 140 and wash basket 120 to actuate buttons 270 , 272 . [0042] According to other embodiments, buttons 260 , 262 may be placed in any other suitable location that is easy to access by a user. As illustrated for washing machine appliance 100 , buttons 260 , 262 , 270 , 272 are all positioned in front of control panel 110 . This may be advantageous because washing machine appliance 100 is a vertical axis, top load washing machine that has door 130 that pivots up, thereby blocking access to control panel 110 when door 130 is in the open position. Thus, buttons 260 , 262 , 270 , 272 are preferably located somewhere within wash tub 121 that is easily accessible when door 130 blocks access to control panel 110 . [0043] Notably, buttons 260 , 262 are positioned in a location of washing machine appliance 100 where they may be exposed to very humid, damp conditions, or where they may be directly sprayed with water. Therefore, it is desirable that buttons 260 , 262 operate at a low voltage in order to prevent the possibility of shocking the user. More particularly, buttons 260 , 262 may operate on an isolated Safety Extra Low Voltage (SELV) circuit. In this regard, buttons 260 , 262 may be sealed and rated for direct contact with water. Buttons 260 , 262 may be directly connected with controller 108 and may be configured for operation at a low voltage, e.g., 5 volts. When buttons 260 , 262 are pressed, controller 108 may control valves 252 at the required 120 volts. In this manner, buttons 260 , 262 are safe for the user to operate even in the damp conditions within wash tub 12 without the risk of shock. [0044] Notably, buttons 260 , 262 may be placed directly on dispenser box assembly 200 or in very close proximity to mixing chamber 220 . In addition, buttons 260 , 262 may control valves 252 that are already included on washing machine appliance 100 . This obviates the need for additional hardware required for an independent water delivery system, e.g., nozzles, high voltage circuits, mounting hardware, etc. As a result, the water-on-demand feature provides an inexpensive, reliable, simple, and intuitive system to deliver additional water to wash tub 121 when the user desires. Similarly, because valves 252 and water delivery system are integrated into an existing dispenser box assembly 200 , washing machine appliance 100 may have a more aesthetically pleasing appearance. [0045] Buttons 260 , 262 may be used by a user to deliver an additional amount of water to wash tub 121 on demand, e.g., during or prior to any wash cycle. The additional amount of water may be a specific volume of water or valves 252 may simply be opened for a specific amount of time. For example, according to an exemplary embodiment, pressing hot water button 262 will open valve 252 seated on first valve seat 234 and deliver hot water to detergent compartment 222 or mixing chamber 220 for 20 seconds. However, one skilled in the art will appreciate that water may be delivered for other time durations as controlled by the user, e.g., via settings on controller 108 , or as set by the manufacturer. Indeed, these values may be set by the manufacturer, determined by controller 108 based on the operating parameters selected, selected by the consumer, or set in any other suitable manner. [0046] One skilled in the art will appreciate that the amount of water added to wash tub 121 upon pressing buttons 260 , 262 may vary depending on the application or wash cycle. Similarly, the amount of water delivered may be preset (as described above) such that pressing buttons 260 , 262 delivers the predetermined amount of water. Alternatively, valves 252 may be configured to remain open at all times when corresponding buttons 260 , 262 are depressed. In this manner, a user may precisely control the amount of water added to wash tub 121 . In order to ensure that wash tub 121 is never overfilled, a maximum water level sensor may be included in the wash tub 121 . When water reaches the maximum level, controller 108 may automatically close all valves 252 or perform a drain cycle to prevent water from spilling out of wash tub 121 . [0047] This written description uses examples to disclose the invention, including the best mode, and also to enable any person skilled in the art to practice the invention, including making and using any devices or systems and performing any incorporated methods. The patentable scope of the invention is defined by the claims, and may include other examples that occur to those skilled in the art. Such other examples are intended to be within the scope of the claims if they include structural elements that do not differ from the literal language of the claims, or if they include equivalent structural elements with insubstantial differences from the literal languages of the claims.	A washing machine having an integrated water-on-demand feature is provided. The washing machine appliance allows a user to adjust the water or wash liquid fill amount of the washing machine appliance using an actuator integrated into or positioned nearby the dispenser box, thereby enabling a simple, convenient, and effective manner of adding wash liquid without requiring a substantial number of additional parts or assembly.	3
This is a continuation of application Ser. No. Ser. No. 08/250,646 filed May 27, 1994 which is a continuation of U.S. Ser. No. 07/903,829 filed Jun. 24, 1992 which is a CIP U.S. Ser. No. 07/810,412 filed Dec. 20, 1991 (abandoned), which is a CIP of U.S. Ser. No. 07/786,738 filed Nov. 1, 1991 (now abandoned) which is a CIP of U.S. Ser. No. 07/722,500 filed Jun. 28, 1991 (abandoned). TECHNICAL FIELD The present invention relates, in general, to a method of preventing or treating alopecia, and, in a specific embodiment, to a method of preventing or treating alopecia induced by chemotherapeutic agents. BACKGROUND Alopecia is a common and distressing side effect of many chemotherapeutic agents and for which there is currently no effective preventive measure. In a recent study, thirty-five of forty-six patients receiving chemotherapy ranked alopecia as more important than vomiting (Tierney et al, B. J. Cancer, 62:527-528, 1990). Recently, using the young rat model, Applicants demonstrated that ImuVert, a biologic response modifier prepared from the bacterium Serratia marcescens, protected the animals from alopecia induced by cytosine arabinoside or adriamycin (Hussein et al, Science 249: 1564-1566, 1990). In subsequent studies, similar protection from ARA-C-induced alopecia was observed from recombinant interleukin-1 (IL-1) beta (Jimenez et al FASEB J. 1991). The present invention provides an independent method of preventing and treating chemotherapy-induced alopecia. This method involves the use of a growth factor, such as epidermal growth factor (EGF) or fibroblast growth factor (FGF). It should be noted that, as far as Applicants are aware, ImuVert has not been shown to stimulate the production of EGF or FGF, nor has it been proposed to stimulate such production. The present invention also relates to the use of Vitamin D 3 , or a metabolite thereof, alone or in combination with EGF to prevent or treat alopecia. Vitamin D 3 is absorbed after ingestion of fish liver oils or irradiated yeast. Plants and animal sources contain only the inactive vitamin D precursors, 7-dehydrocholesterol or ergosterol. 7-Dehydrocholesterol is stored in the skin and can be converted by sunlight into vitamin D 3 . However, whether ingested or formed by ultraviolet irradiation in the skin, Vitamin D has to be transformed into active metabolites. Vitamin D 3 is converted to 25-hydroxycholecalciferol by liver enzymes. Then in the kidneys two compounds 1,25-dihydroxycholecalciferol and 24,25-dihydroxycholecalciferol are formed. The vitamin D active metabolites play an important role in the absorption of calcium from the intestinal tract, bone deposition and bone reabsorption. 1,25-Dihydroxyvitamin D 3 , an active metabolite of Vitamin D 3 , has been shown to increase EGF receptors on breast cancer cells (Falette et al, Molec. and Cell. Endocrinol., 63 (1-2):189-198, 1989) and on a cell line established from rat calvaria (Petkovich et al, J. Biol. Chem. 262 (28):13424-13428, 1987). However, as far as Applicants are aware, the effect of Vitamin D 3 or a metabolite thereof, on alopecia has not been shown or proposed. SUMMARY OF THE INVENTION It is a general object of the invention to provide a method of treating or preventing alopecia. It is a specific object of the invention to prevent or treat alopecia in patients undergoing treatment with chemotherapeutic agents, including cycle specific agents (such as cytosine arabinoside (ARA-C)) and non cycle specific agents (such as Cytoxan), individually or in combination. Further objects and advantages of the invention will be clear from the description that follows. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is an image of 10 rats from Experiment I, Table I (see below). All rats received ARA-C 50 mg/kg×7 days. Five rats on top received buffer solution s.c. Five rats on bottom received murine EGF 2 μg s.c. daily×7 days. FIG. 2 is an image of 6 rats from Experiment III, Table I (see below). All rats received ARA-C 50 mg/kg×7 days. Three rats on top received buffer solution S.C. Three rats on bottom received rHu-EGF 2 μg s.c. daily×7 days. FIG. 3 is an image of 4 rats from topical murine-EGF experiment (see below). All rats received ARA-C 50 mg/kg×7 days. Two rats on the left received murine EGF 10 μg in DMSO daily×7 days rubbed topically between the shoulder blades over an area of 1 cm 2 . Two rats on the right received buffer solution topically. FIG. 4 is an image of 12 rats from ARA-C-aFGF experiment (see below). All rats received ARA-C 50 mg/kg×7 days. Six rats on top received buffer solution s.c. Six rats on bottom received aFGF 2 μg s.c. daily×7 days. FIG. 5 is an image of 8 rats treated with combination chemotherapy Cytoxan and Adriamycin. Four rats on top treated in addition with murine EGF. Four rats on bottom treated with buffer solution. FIG. 6 is an image of 10 rats treated with VP-16. All rats received 1.5 mg/kg×3 days i.p. of VP-16. Five rats on top received buffer solution for four days prior to treatment. Five rats on bottom received Vitamin D 3 50 μg/day for 4 days for four days prior to treatment. FIG. 7 is an image of 6 rats treated with combination chemotherapy Cytoxan and Adriamycin (25 mg/kg i.p.×1 day and 2.5 mg/kg i.p.×3 days, respectively). Three rats on top received buffer solution for four days prior to treatment. Three rats on bottom received Vitamin D 3 50 μg/day for four days prior to treatment. FIGS. 8 (A-C). For each experiment, five day old rats were randomly divided into equal numbers. The experimental group of rats (top group) received 0.2 μg of 1,25-dihydroxyvitamin D 3 in 0.15 ml of absolute ethanol daily over the head and neck for 5 days. Control rats (bottom group) were similarly treated with 0.15 ml of absolute ethanol. One day after the last topical treatment, the rats from FIG. 8A were treated with Cytoxan (CTX), rate from FIG. 8B with the Etoposide (VP-16) regimen and rats from FIG. 8C with CTX+Adriamycin (ADM) regimen. FIG. 9 . Twenty 5-day old rats were randomly divided into two groups of 10 rats each. The experimental group of rats (top group) received 0.1 μg of 1,25(OH)2D 3 in 0.1 ml of absolute ethanol daily over the head only for 5 days. Control rats (bottom group) were similarly treated with 0.1 of absolute ethanol. One day after the last topical treatment, all rats were treated with the VP-16 regimen. FIG. 10 . Thirteen 9-day old rats were randomized into two groups. Experimental, 7 rats (top group), received 1 μg of RO 23-7553 in 0.2 ml absolute ethanol daily topically over the neck and back for 6 days. Control, 6 rats (bottom group), were similarly treated with 0.2 ml of absolute ethanol. One day after the last treatment all rats were treated with the VP-16 regimen. FIG. 11, shows the effect of 1,25-dihydroxyvitamin D 3 on hair growth. DETAILED DESCRIPTION OF THE INVENTION The present invention relates generally to a method of preventing or reducing alopecia, particularly in patients undergoing chemotherapy. Applicants have shown that a growth factor, such as EGF, and Vitamin D 3 appear to render the hair follicle resistant to the toxic effect of chemotherapeutic agents thus preventing hair lose. In one embodiment of the present method, a growth factor is administered to a patient undergoing chemotherapy in an amount sufficient to prevent or reduce the hair loss that normally accompanies this treatment regimen. Growth factors suitable for use in the present method include EGF, FGF, transforming growth factors (TGF), and platelet-derived growth factor (PDGF). The growth factors can be derived from natural sources (for example, human tissue or rodent tissue); however, recombinant production is preferred as large quantities can be produced at relatively low cost. Chemically synthesized factors can also be used. The use of portions or derivatives of growth factors, such as EGF and FGF, is also contemplated as long as those portions or derivatives can effect the same result observed with the factor itself. In another embodiment of the present invention, Vitamin D 3 or metabolite, analog, derivative or structural variant thereof (for example 1,25-dihydroxy-16-ene-23-yne-cholecalciferol; 1α-hydroxyvitamin D 3 ; 1α-24-dihydroxyvitamin D 3 , MC 903, etc.) is administered to a warm blooded animal, for example, a human, in an amount sufficient to prevent or reduce the hair loss or stimulate hair growth. Hair loss treatable or preventable using vitamin D 3 can be due to chemotherapy or other cause, including, but not limited to, male pattern baldness. Examples of Vitamin D 3 metabolites suitable for use in the present method include, but are not limited to, 1,25-dihydroxyvitamin D 3 and 1,25-dihydroxy-16-ene-23-yne cholecalciferol. Compositions suitable for use in the claimed method include as an active agent a growth factor, Vitamin D 3 (or a metabolite or analog thereof) or a combination of both. Such compositions can be formulated by combining an active agent together with a pharmaceutically acceptable vehicle (carrier, diluent or excipient), in an amount sufficient to effect the preventative effect when administered in accordance with an appropriately designed treatment protocol. The composition can be in dosage unit form. Though not limiting the present method to a particular mode of action, it is suggested that Vitamin D 3 protects against alopecia by increasing the receptors for EGF at the hair follicle level. Accordingly, administering a combination of a growth factor and Vitamin D 3 can be expected to provide for greater protection. Compositions suitable for use in the method to which the invention relates can be in a form suitable for topical administration. In that event, the composition can take the form of a solution, lotion, cream, gel or ointment. When the composition is to be administered by injection, it advantageously takes the form of a solution. The vehicle used, regardless of the form taken by the composition, can be inert or can itself possess a physiologically or pharmaceutically beneficial effect. Various additives can be included in the composition. In this regard, inclusion in the composition of an agent that stimulates production of the patients' own growth factor is contemplated. Inclusion in compositions suitable for topical administration of penetration enhancing agents, such as DMSO or ethanol, is preferred. Stabilizers that extend shelf life can also be included in the composition, regardless of the manner in which it is formulated. One skilled in the art will appreciate that various concentrations of growth factor and/or Vitamin D 3 can be used in the above-described composition. Optimum concentrations can be readily determined by one skilled in the art. As noted above, the method to which the invention relates can involve either topical application of the active agent (a growth factor and/or Vitamin D 3 or metabolite thereof) or administration by injection. The amount of the active agent and the frequency of administration can vary depending on the individual and can readily be optimized by one skilled in the art. As an example, however, a solution of 2-100 μg/ml of 1,25-dihydroxyvitamin D 3 in absolute ethanol can be prepared and 3-5 ml of that solution applied directly to the scalp at various points with a dropper followed by scalp message for 3-5 min to ensure even distribution. When chemotherapy is involved, this treatment is, advantageously, administered once or twice daily beginning 5-8 days prior to initiation of chemotherapy and continued through the course of chemotherapy. However, it is also contemplated that the active agent can be administered substantially simultaneously with, or subsequent to, the administration of the chemotherapeutic agent. The method to which the invention relates is shown in the Examples that follow to be effective when the cell cycle-specific drug, ARA-C, is the chemotherapeutic agent used and when the combination of Adriamycin (cell cycle specific) and Cytoxan (non cell cycle specific) is used. It is contemplated, however, that, using the present method, hair loss resulting from treatment with other chemotherapeutic agents can be prevented. In addition, it is contemplated that a growth factor and/or vitamin D 3 can be used to prevent or retard hair lose in male pattern baldness if it is used on a regular basis and, advantageously, at the first sign of baldness, for example, once daily or every other day to the predisposed area of the scalp. The alopecia preventative effect observed by Applicants was wholly unexpected. Growth factors, such as EGF, are presumed stimulants of skin cell growth. Accordingly, these agents would be expected to induce the hair follicle to enter the cell cycle thus rendering the follicle more susceptible to chemotherapeutic agents, particularly cell cycle specific drugs, such as ARA-C. Thus, administration of growth factors to patients receiving chemotherapy would have been expected to aggravate hair loss. The reverse effect, however, was achieved. It should be noted therefore that the observations recorded herein with EGF and FGF are novel and have not been proposed or described in the literature. Similarly, nothing about the role of Vitamin D 3 in the body suggested that the vitamin would provide such excellent protection against alopecia, chemotherapeutically induced or otherwise. The following non-limiting Examples describe certain aspects of the invention in greater detail. EXAMPLES The following experimental details relate to Examples I-IV set forth below. Sprague Dawley rats were purchased from Charles River Laboratories, Wilmington, Mass. Cytosar-U (ARA-C) was from the Upjohn Company, Kalamazoo, Mich. Receptor grade EGF from mouse submaxillary glands, human recombinant EGF, dimethyl sulfoxide (DMSO) and Vitamin D 3 were purchased from Sigma Chemical Co., St. Louis, Mo. aFGF was purchased from AMGEN Corp., Thousand Oaks, Calif. All rats from each experiment were treated with ARA-C 50 mg/kg intraperitoneally (i.p.) daily for 7 days. For subcutaneous (s.c.) injections, EGF and FGF were prepared in PBS 1% BSA. Alopecia was always recorded on day 12 of experiment, and scored as previously described (Hussein et al, Science, 249:1564-1566, 1990; Jimenez et al, FASEB J., 1991). For topical treatment, murine EGF was prepared as follows: One vial of EGF (100 μg) was dissolved in 0.2 ml of PBS 1% BSA and 0.12 ml of this solution was added to 0.48 of DMSO. Three hours prior to ARA-C injection, 0.1 ml of the EGF-DMSO mixture was applied to each rat over a 1 cm 2 area between the shoulders using a rubber tip applicator. Rats were then kept individually separated for a period of three hours, following which the treated area was carefully washed with soap and water and dried. Treatment was continued for 7 days. Control animals were similarly treated using DMSO without EGF. Example I Protective Effect of EGF Two separate experiments were conducted to test the ability of murine EGF to protect from ARA-C-induced alopecia. In Experiment I, twenty-two 7-day old rats were randomized in two groups of eleven rats each. In addition to ARA-C, Group I received 2 μg of mouse EGF s.c. in the back between the two hind legs 3 hours prior to ARA-C injections daily for 7 days. Group II, received buffer solution similarly and served as control. Ten of eleven rats in Group II developed virtually total body alopecia and one rat developed more than 50% hair loss. In contrast, in Group I, 5 rats had no detectable hair loss and 6 rats had mild hair loss (Table I, Experiment I (FIG. 1 )). In Experiment II, twelve 7-day old rats were randomized in two groups of 6 rats each. In addition to ARA-C, Group I received mouse EGF 1 μg s.c. daily for 7 days. Group II received buffer s.c. All 6 rats in Group II developed moderately severe to severe alopecia, whereas in Group I, one rat had no detectable hair loss and 5 rats developed only minimal hair loss (Table I, Experiment II). For the next experiment, rHu-EGF was used. Twelve 7-day old rats were randomized in two groups of six rats each. In addition to ARA-C, Group I received rHu-EGF 2 μg s.c. in the flank area daily for 7 days. Group II received buffer s.c. All 6 rats in Group II developed total body alopecia, whereas in Group I none of the rats had total body alopecia, one rat had no detectable hair loss, four rats had mild alopecia and one rat had moderate alopecia (Table I, Experiment III, (FIG. 2 )). TABLE I OCCURRENCE OF ALOPECIA IN RATS TREATED WITH ARA-C. EFFECT OF MURINE EGF AND rHU-EGF. Alopecia* 0 1+ 2+ 3+ Experiment I ARA-C 0 0 1 10 ARA-C + Murine EGF 2 μg 5 6 0 0 Experiment II ARA-C 0 0 3 3 ARA-C + Murine EGF 1 μg 1 5 0 0 Experiment III ARA-C 0 0 0 6 ARA-C + rHu-EGF 2 μg 1 4 1 0 Seven day old rats were used for all experiments. All rats received ARA-C 50 mg/kg × 7 days I.P. in 0.1 ml. Murine EGF and rHu-EGF in PBS 1% BSA were given 3 hours prior to ARA-C once daily in 0.1 ml s.c. × 7 days. Controls received PBS 1% BSA 0.1 ml s.c. × 7 days. Data recorded on day 12. NC detectable alopecia, 0; mild alopecia defined as less than 50% hair loss, 1+; moderately severe alopecia with more then 50% hair loss, 2+; and total or virtually total (>90%) hair loss, 3+. In the next experiment, twelve 7-day old rats were randomized in two groups of six rats each. Group I, in addition to ARA-C, received murine-EGF 10 μg in DMSO daily×7 days rubbed topically with a cotton tip applicator between the shoulder blades over an area of 1 cm 2 . Group II received control solution topically. In Group II, all six rats developed complete body alopecia. In Group I, all rats developed complete body alopecia except where the EGF was applied topically (FIG. 3 ). Example II Protective Effect of aFGF Fourteen 7-day old rats were randomized in two groups. All rats received ARA-C 50 mg/kg/day for seven days. In addition, Group I received aFGF 2 μg s.c. on back of head daily for seven days. Group II received buffer injections and served as controls. Alopecia was recorded on day 12 of experiment. All rats in Group II developed complete body alopecia. In contrast, all rats in Group I were protected locally at the site of injection (FIG. 4 ). Example III Protection from Cytoxan/Adriamycin-Induced Alopecia Eight 4-day old Sprague Dawley rats were randomized in two groups of 4 rats each. Group I, received EGF 2μ s.c. on the head daily for 7 days. Group II received buffer injections and served as controls. One day after stopping EGF or buffer injections all rats received Cytoxan 25 mg/kg i.p.×1 day and Adriamycin 2.5 mg/kg i.p.×3 days. In Group II, all rats had 3+ alopecia over head and neck area. In contrast, in Group I one rat had mild alopecia, one rat minimal alopecia, and two rats no detectable alopecia over head and neck. (FIG. 5 ). Imuvert when used under similar conditions did not protect from alopecia caused by the Cytoxan/Adriamycin combination. Example IV Protective Effect of Vitamin D 3 Twelve 7 day old rats were randomized in two groups. Group I was treated daily with buffer 0.1 ml s.c. for four days. The second Group was treated daily with Vitamin D 3 50 μg s.c. over head for four days. After stopping the buffer or Vitamin D 3 treatment, all rats received 1.5 mg/kg i.p. of VP-16 (Etoposide) daily for three days. All rats in Group I developed complete body alopecia while the rats in Group II were protected (FIG. 6 shows 4 rats from each group). In other experiments, rats pretreated with Vitamin D 3 demonstrated excellent protection against alopecia produced by Etoposide, Cytoxan, Cytarabine and the combination of Cytoxan and Adriamycin (FIG. 7 ). The results are set forth below in Table II. TABLE II PROTECTION FROM CHEMOTHERAPY-INDUCED ALOPECIA BY PRETREATMENT WITH VITAMIN D 3 . Atopecic Total No. of Total No. Protection drug tested experiments of animals from alopecia Etoposide (VP-16) 2 22 Yes Cytoxan (CTX) 7 89 Yes* Cytarabine (ARA-C) 1 8 Yes* Adriamycin + CTX 6 77 Yes* Combination Chemotherapeutic agents were given as follows: VP- 16 1.5 mg/kg i.p. daily for 3 days; Cytoxan 32.5 mg/kg as a single injection; ARA-C 50 mg/kg i.p. daily for 7 days; for combination (Adriamycin 2.5 mg/kg i.p. daily for 3 days plus Cytoxan 25 mg/kg as a single injection). Vitamin D 3 was given in 50 μg daily doses i.p. or s.c. for 4 days prior to chemotherapy. *In these experiments, protection from chemotherapy-induced alopecia was uniformly observed in all animals treated with Vitamin D 3 In other experiments, 1,25-dihydroxyvitamin D 3 applied topically (0.5 μg daily) in 50% ethanol or DMSO also protected rats from VP-16-induced alopecia. Example V Protective Effect of Vitamin D 3 Pretreatment Topical Application of 1,25-Dihydroxyvitamin D 3 1,25-Dihydroxyvitamin D 3 was dissolved in absolute ethanol and applied topically with an applicator. Control animals were similarly treated with the same amount of ethanol. Animals were then kept individually separated for a period of three hours following which the treated area was carefully washed with soap and water and dried. Treatment was given daily beginning on day 5 after birth and ending on day 10. Chemotherapy All chemotherapies were given I.P. and started at 11 days of age. CTX, 35 mg/kg, was given for one day only. VP-16, 1.5 mg/kg, was given for three days. For CTX and ADM combination, CTX, 25 mg/kg was given for one day and ADM, 2.5 mg/kg, for three days. At these doses neither CTX nor ADM alone will produce alopecia. Alopecia was recorded on the tenth day from beginning chemotherapy. A total of 4 experiments were carried out. In the first experiment, protection from Cytoxan-induced alopecia was examined. The experimental group was pretreated with 0.2 μg of 1,25-dihydroxyvitamin D 3 in 0.15 ml of absolute ethanol applied topically over the head and neck and the control group received 0.15 ml of alcohol. All 10 rats in the control group became totally alopecic. In contrast, all animals in the experimental group were protected (FIG. 8 A). The second experiment was carried out under similar conditions to examine protection from VP-16-induced alopecia. All 10 rats in the control group developed total body alopecia. In contrast, all rats in the experimental group were protected (FIG. 8 B). The third experiment was designed to examine protection from alopecia induced by Cytoxan-Adriamycin combination. There were 11 rats in each group. Six rats in the control group developed alopecia over the head and neck and 5 rats developed total body alopecia. In contrast, all rats in the experimental group were protected (FIG. 8 C). In the fourth experiment, protection from VP-16-induced alopecia was similarly examined except that the dose of 1,25-dihydroxyvitamin D 3 was reduced to 0.1 μg in 0.1 ml absolute ethanol applied topically over the head area only. All 10 rats in the control group became completely alopecic. In contrast, all rats in the experimental group were protected primarily at the site of 1,25-dihydroxyvitamin D 3 application (FIG. 9 ). It is noteworthy that protection from 0.2 μg 1,25-dihydroxyvitamin D 3 was not limited to the site of application but involved the entire body, suggesting systemic absorption. When the dose was reduced to 0.1 μg applied to the head area only, protection from VP-16-induced alopecia was less generalized and was more limited to the site of application. Example VI Protection from VP-16-Induced Alopecia by Topical Application of RO 23-7553 RO 23-7553 (1,25 dihydroxy-16-ene-23-yne-cholecalciferol) was dissolved in absolute ethanol and applied topically with an applicator. Control animals were similarly treated with the same amount of ethanol. Animals were then kept individually separated for a period of three hours following which the treated area was carefully washed with soap and water and dried. Treatment was given daily beginning on day 9 after birth and ending on day 14. On day 15 all animals received VP-16, 1.5 mg/kg i.p., for three days. Alopecia was recorded on day 25. Thirteen rats were randomized in two groups. Experimental group, 7 rats; control group, 6 rats. The experimental group was pretreated with 1 μg of RO 23-7553 in 0.2 ml absolute ethanol applied topically over the neck and back and the control group received 0.2 ml of absolute ethanol. All six rats in the control group became totally alopecic over the neck and back. In contrast, all animals in the experimental group were protected (FIG. 10 ). It should be noted that when the chemotherapy is started at the age of 14 days, the head area does not become alopecic. Example VII Stimulation of Hair Growth by Vitamin D 3 During the course of the above-described studies on the protection from chemotherapy-induced alopecia by Vitamin D 3 and its active analog, 1,25-dihydroxyvitamin D 3 , it was noted that rats treated with 1,25-dihydroxyvitamin D 3 not only were protected from chemotherapy-induced alopecia, but these rats had a better coat of hair and longer hair in the treated area. These observations prompted the following further experiments on the stimulation of hair growth by 1,25-dihydroxyvitamin D 3 . The backs of nineteen 25 day old Sprague Dawley rats were shaven and randomized in two groups. Group I (control 10 rats) received 0.1 ml of ethanol applied topically once daily to the shaven area for 14 days. Group II (Calcitriol 9 rats) received 50 ng of 1,25-dihydroxyvitamin D 3 in 0.1 ml of ethanol applied topically once daily to the shaven area for 14 days. On day 15 stimulation of hair regrowth was assessed by reshaving an area 6 cm×6 cm in diameter. The hair was collected and weighed. The difference between two groups was highly statistically significant. P. value 0.003 (see Table III and FIG. 11 ). TABLE III STIMULATION OF HAIR GROWTH BY CALCITRIOL IN RATS Hair Weight in Mg. Control Calcitriol 98 202 131 143 72 150 84 253 102 130 144 177 115 140 129 147 125 135 130 Mean S.E.M. Mean S.E.M. 113 ± 8 164 ± 13 Based on these data showing stimulation of hair growth by 1,23-dihydroxyvitamin D 3 administered topically in the rat, it is expected that 1,25-dihydroxyvitamin D 3 can be used as a stimulant of hair growth in cases of alopecia of any cause. Additionally, the data suggest that vitamin D 3 and its metabolites is/are necessary for optimal hair growth and therefore can be used to prevent hair loss from any cause, including male pattern baldness. Example VIII Formulations The following are four formulations that include 1,25-dihydroxyvitamin D 3 as active ingredient, and the methods of their manufacture. 1. Topical Solution Ingredients % (W/W) 1,25-Dihydroxyvitamin D 3 0.0002-0.10 Propylene Glycol 10.00 Propylene Glycol Dicarprylate/Dicaprate a 30.00 Butylated Hydroxytoluene (BHT) 0.05 Butylated Hydroxyanisole (BHA) 0.05 Ethyl Alcohol, Absolute q.s. to 100.00 a Can be substituted by the following materials (1) medium chain triglycerides; 2) dimethyl isosorbide; (3) polyethylene glycols; (4) ethoxydiglycol Manufacturing Procedure i. Weigh the appropriate amount of propylene glycol dicaprylate/dicaprate, ethyl alcohol, propylene glycol in a stainless steel container. ii. Dissolve BHT and BHA into the solution from step (i). iii. Add the 1,25-dihydroxyvitamin D 3 into the mixture from step (ii) and stir until dissolved. 2. Buffered Topical Solution Ingredients % (W/W) 1,25-Dihydroxyvitamin D 3 0.0002-0.10 Propylene Glycol 50.00 Hydroxypropyl cellulose (Klucel MF) 0.50 Methylparaben 0.20 Butylated Hydroxytoluene (BHT) 0.05 Butylated Hydroxyanisole (BHA) 0.05 Sodium Phosphate, Monobasic 0.43 Sodium Phosphate Dibasic 0.70 Sodium Hydroxide (q.s. to pH = 7) 0.04 Ethyl Alcohol, 95% Proof 30.00 Water q.s. to 100.00 Manufacturing Procedure i. Dissolve the sodium phosphate, monobasic, sodium phosphate, dibasic, and sodium hydroxide in the water in a stainless steel container. Measure the pH of the solution. The pH of the solution should be 7.0; if not adjust the pH. ii. Add the propylene glycol and ethyl alcohol to the solution from step (i). iii. Dissolve the 1,25-dihydroxyvitamin D 3 , methylparaben, BHT and BHA to the solution from step (ii). iv. Dissolve Klucel MF to the solution from step (iii). 3. Oil-In Water Buffered Topical Lotion Ingredients % (W/W) 1,25-dihydroxyvitamin D 3 0.0002-0.10 Cetyl Alcohol 0.25 Stearyl Alcohol 0.50 Sorbitan Monosterate 2.00 Glyceryl Monostearate and 4.00 Polyoxyethylene Stearate Blend (Arlacel 165) Polysorbate 60 1.00 Mineral Oil 4.00 Propylene Glycol 5.00 Butylated Hydroxyanisole 0.05 Propylparaben 0.05 Buffering Agent q.s. to pH 7.00 Sorbitol Solution 2.00 Edetate Disodium 0.10 Methylparaben 0.18 Water q.s. to 100.00 Manufacturing Procedure i. Prepare the buffer solution (pH 7.0) in a stainless steel container. ii. In a stainless steel vessel, at 70° C., melt the cetyl alcohol, stearyl alcohol, sorbitan monostearate, Arlacel 165, Polysorbate 60, mineral oil, butylated hydroxyanisole, propylparaben, and 50% propylene glycol together. iii. Add the sorbitol solution to step (i) and heat the solution to 70° C. iv. Add the edetate disodium and methylparaben to the solution from step (iii). v. Dissolve the 1,25-dihydroxyvitamin D 3 in approximately 40% propylene glycol in a beaker and add this to the material from step (ii) while mixing. Rinse the container from 10% propylene glycol and add this to the mixture from step (ii). vi. Add step (v) to step (iv) when both phases are at 70° C. and homogenize. Cool the emulsion to 200 m temperature. 4. Topical Gel Ingredients % (W/W) 1,25-dihydroxyvitamin D 3 0.0002-0.10 Butylated Hydroxytoluene (BHT) 0.05 Butylated Hydroxyanisole (BHA) 0.05 Hydroxypropyl Cellulose 3.00 Ethyl Alcohol, 95% Proof 50.00 Water q.s. to 100.00 Manufacturing Procedure i. Weigh the ethyl alcohol and water in a stainless steel container. ii. Dissolve the 1,25-dihydroxyvitamin D 3 , BHT and BHA to the solution from step (i). iii. Dissolve the hydroxypropyl cellulose to the solution from step (ii). The entire contents of all references cited above are incorporated herein by reference. While the present invention has been described in some detail for purposes of clarity and understanding, one skilled in the art will appreciate that various changes in form and detail can be made without departing from the true scope of the invention.	A method of preventing or reducing chemotherapy-induced alopecia is disclosed which comprises administering to a host subjected to chemotherapy which induces alopecia an effective amount of vitamin D 3 or derivative or analog or active metabolite thereof. The amount is sufficient to affect prevention or reduction of chemotherapy-induced alopecia.	0
CROSS REFERENCE TO RELATED APPLICATIONS [0001] This application is a continuation-in-part of U.S. application Ser. No. 08/949,388, filed Oct. 14, 1997, the contents of which are hereby incorporated by reference in their entirety. TECHNICAL FIELD [0002] The invention relates to certain nucleoside analogues, the use of these compounds as pharmaceuticals, pharmaceutical compositions containing the compounds and processes for preparing the compounds. BACKGROUND OF THE INVENTION [0003] Purine nucleoside phosphorylase (PNP) catalyses the phosphorolytic cleavage of ribo- and deoxyribonucleosides, for example, those of guanine and hypoxanthine to give the corresponding sugar-1-phosphate and guanine, hypoxanthine, or other purine bases. [0004] Humans deficient in purine nucleoside phosphorylase (PNP) suffer a specific T-cell immunodeficiency due to an accumulation of dGTP and its toxicity to stimulated T lymphocytes. Because of this, inhibitors against PNP are immunosuppressive, and are active against T-cell malignancies. Clinical trials are now in progress using 9-(3-pyridylmethyl)-9-deazaguanine in topical form against psoriasis and in oral form for T-cell lymphoma and immunosuppression (BioCryst Pharmaceuticals, Inc). The compound has an IC 50 of 35 nM for the enzyme. In animal studies, a 50 mg/kg oral dose is required for activity in a contact sensitivity ear swelling assay in mice. For human doses, this would mean approximately 3.5 grams for a 70 kg human. With this inhibitor, PNP is difficult to inhibit due to the relatively high activity of the enzyme in blood and mammalian tissues. [0005] Nucleoside and deoxynucleoside hydrolases catalyse the hydrolysis of nucleosides and deoxynucleosides. These enzymes are not found in mammals but are required for nucleoside salvage in some protozoan parasites. Purine phosphoribosyltransferases (PPRT) catalyze the transfer of purine bases to 5-phospho-α-D-ribose-1-pyrophosphate to form purine nucleotide 5′-phosphates. Protozoan and other parasites contain PPRT which are involved in essential purine salvage pathways. Malignant tissues also contain PPRT. Some protozoan parasites contain purine nucleoside phosphorylases which also function in purine salvage pathways. Inhibitors of nucleoside hydrolases, purine nucleoside phosphorylases and PPRT can be expected to interfere with the metabolism of parasites and therefore be usefully employed against protozoan parasites. Inhibitors of PNP and PPRT can be expected to interfere with purine metabolism in malignant tissues and therefore be usefully employed against malignant tissues. [0006] It is an object of the invention to provide pharmaceuticals which are very effective inhibitors of PNP, PPRT and/or nucleoside hydrolases. BRIEF DESCRIPTION OF THE FIGURES [0007] [0007]FIG. 1: FIG. 1 shows purine nucleoside phosphorylase activity with time at a range of concentrations of the product of Example 1 (Compound Ib). [0008] [0008]FIG. 2: FIG. 2 shows fitting of a purine nucleoside phosphorylase activity progress curve to the kinetic model. [0009] [0009]FIG. 3: FIG. 3 shows K i * determination by the curve fit method for Compound Ib inhibition of bovine purine nucleoside phosphorylase. [0010] [0010]FIG. 4: FIG. 4 shows a progress curve for bovine purine nucleoside phosphorylase showing slow-onset inhibition by Compound Ib. [0011] [0011]FIG. 5: FIG. 5 shows the effect of oral administration of Compound Ib on the PNP activity of mouse blood. [0012] [0012]FIG. 6: FIG. 6 shows the K i determination for Compound Ib with protozoan nucleoside hydrolase. [0013] [0013]FIG. 7: FIG. 7 shows the progress curve for purine phosphoribosyltransferase showing slow-onset inhibition by the 5′-phosphate of Compound Ib. Inhibition of the malaria enzyme. [0014] [0014]FIG. 8: FIG. 8 shows the K 1 * determination for the 5′-phosphate of Compound Ib inhibition of human purine phosphoribosyltransferase. DETAILED DESCRIPTION OF THE INVENTION [0015] In one aspect the invention provides compounds having the formula: [0016] wherein A is CH or N; B is chosen from OH, NH 2 , NHR, H or halogen; D is chosen from OH, NH 2 , NHR, H, halogen or SCH 3 ; R is an optionally substituted alkyl, aralkyl or aryl group; and X and Y are independently selected from H, OH or halogen except that when one of X and Y is hydroxy or halogen, the other is hydrogen; and Z is OH or, when X is hydroxy, Z is selected from hydrogen, halogen, hydroxy, SQ or OQ, Q is an optionally substituted alkyl, aralkyl or aryl group; or a tautomer thereof; or a pharmaceutically acceptable salt thereof; or an ester thereof; or a prodrug thereof. [0017] Preferably when either of B and/or D is NHR, then R is C 1 -C 4 alkyl. [0018] Preferably when one or more halogens are present they are chosen from chlorine and fluorine. [0019] Preferably when Z is SQ or OQ, Q is C 1 -C 5 alkyl or phenyl. [0020] Preferably D is H, or when D is other than H, B is OH. [0021] More preferably, B is OH, D is H, OH or NH 2 , X is OH or H, Y is H, most preferably with Z as OH, H or methylthio, especially OH. [0022] It will be appreciated that the representation of a compound of formula (I) wherein B and/or D is a hydroxy group used herein is of the enol-type tautomeric form of a corresponding amide, and this will largely exist in the amide form. The use of the enol-type tautomeric representation is simply to allow fewer structural formulae to represent the compounds of the invention. [0023] The present invention also provides compounds having the formula: [0024] wherein A, X, Y, Z and R are defined for compounds of formula (I) where first shown above; E is chosen from CO 2 H or a corresponding salt form, CO 2 R, CN, CONH 2 , CONHR or CONR 2 ; and G is chosen from NH 2 , NHCOR, NHCONHR or NHCSNHR; or a tautomer thereof, or a pharmaceutically acceptable salt thereof, or an ester thereof, or a prodrug thereof. [0025] Preferably E is CONH 2 and G is NH 2 . [0026] More preferably, E is CONH 2 , G is NH 2 , X is OH or H, is H, most preferable with Z as OH, H or methylthio, especially OH. [0027] Particularly preferred are the following compounds: [0028] 1. (1S)-1,4-dideoxy-1-C-(4-hydroxypyrrolo[3,2-d]pyrimidin-7-yl)-1,4-imino-D-ribitol [0029] 2. (1S)-1-C-(2-amino-4-hydroxypyrrolo[3,2-d]pyrimidin-7-yl)-1,4-dideoxy-1,4-imino-D-ribitol [0030] 3. (1R)-1-C-(4-hydroxypyrrolo[3,2-d]pyrimidin-7-yl)-1,4-imino-1,2,4-trideoxy-D-erythro-pentitol [0031] 4. (1S)-1-C-(4-hydroxypyrrolo[3,2-d]pyrimidin-7-yl)-1,4-imino-1,4,5-trideoxy-D-ribitol [0032] 5. (1S)-1,4-dideoxy-1-C-(4-hydroxypyrrolo[3,2-d]pyrimidin-7-yl)-1,4-imino-5-methylthio-D-ribitol [0033] 6. (1S)-1,4-dideoxy-1-C-(2,4-dihydroxypyrrolo[3,2-d]pyrimidin-7-yl)-1,4-imino-D-ribitol [0034] 7. (1R)-1-C-(2,4-dihydroxypyrrolo[3,2-d]pyrimidin-7-yl)-1,4-imino-1,2,4-trideoxy-D-erthro-pentitol [0035] 8. (1S)-1-C-(2,4-dihydroxypyrrolo[3,2-d]pyrimidin-7-yl)-1,4-imino-1,4,5-trideoxy-D-ribitol [0036] 9. (1S)-1,4-dideoxy-1-C-(2,4-dihydroxypyrrolo[3,2-d]pyrimidin-7-yl)-1,4-imino-5-ethylthio-D-ribitol [0037] 10. (1R)-1-C-(2-amino-4-hydroxypyrrolo[3,2-d]pyrimidin-7-yl)-1,4-imino-1,2,4-trideoxy-D-erythro-pentitol [0038] 11. (1S)-1-C-(2-amino-4-hydroxypyrrolo[3,2-d]pyrimidin-7-yl)-1,4-imino-1,4,5-trideoxy-D-ribitol [0039] 12. (1S)-1-C-(2-amino-4-hydroxypyrrolo[3,2-d]pyrimidin-7-yl)-1,4-dideoxy-1,4-imino-5-methylthio-D-ribitol [0040] 13. (1S)-1,4-dideoxy-1-C-(7-hydroxypyrazolo[4,3-d]pyrimidin-3-yl)-1,4-imino-D-ribitol [0041] 14. (1R)-1-C-(7-hydroxypyrazolo[4,3-d]pyrimidin-3-yl)-1,4-imino-1,2,4-trideoxy-D-erythro-pentitol [0042] 15. (1S)-1-C-(7-hydroxypyrazolo[4,3-d]pyrimidin-3-yl)-1,4-imino-1,4,5-trideoxy-D-ribitol [0043] 16. (1S)-1,4-dideoxy-1-C-(7-hydroxypyrazolo[4,3-d]pyrimidin-3-yl)-1,4-imino-5-ethylthio-D-ribitol [0044] 17. (1S)-1,4-dideoxy-1-C-(5,7-dihydroxypyrazolo[4,3-d]pyrimidin-3-yl)-1,4-imino-D-ribitol [0045] 18. (1R)-1-C-(5,7-dihydroxypyrazolo[4,3-d]pyrimidin-3-yl)-1,4-imino-1,2,4-trideoxy-D-erythro-pentitol [0046] 19. (1S)-1-C-(5,7-dihydroxypyrazolo[4,3-d]pyrimidin-3-yl)-1,4-imino-1,4,5-trideoxy-D-ribitol [0047] 20. (1S)-1,4-dideoxy-1-C-(5,7-dihydroxypyrazolo[4,3-d]pyrimidin-3-yl)-1,4-imino-5-methylthio-D-ribitol [0048] 21. (1S)-1-C-(5-amino-7-hydroxypyrazolo[4,3-d]pyrimidin-3-yl)-1,4-dideoxy-1,4-imino-D-ribitol [0049] 22. (1R)-1-C-(S-amino-7-hydroxypyrazolo[4,3-d]pyrimidin-3-yl)-1,4-imino-1,2,4-trideoxy-D-erythro-pentitol [0050] 23. (1S)-1-C-(5-amino-7-hydroxypyrazolo[4,3-d]pyrimidin-3-yl)-1,4-imino-1,4,5-trideoxy-D-ribitol [0051] 24. (1S)-1-C-(5-amino-7-hydroxypyrazolo[4,3-d]pyrimidin-3-yl)-1,4-dideoxy-1,4-imino-5-methylthio-D-ribitol [0052] 25. (1S)-1-C-(3-amino-2-carboxamido-4-pyrroly)-1,4-dideoxy-1,4-imino-D-ribitol. [0053] 26. (1S)-1,4-dideoxy-1-C-(4-hydroxypyrrolo[3,2-d]pyrimidin-7-yl)-1,4-imino-D-ribitol 5-phosphate [0054] 27. (1S)-1-C-(2-amino-4-hydroxypyrrolo[3,2-d]pyrimidin-7-yl)-1,4-imino-D-ribitol 5-phosphate [0055] 28. (1S)-1-C-(3-amino-2-carboxamido-4-pyrrolyl)-1,4-dideoxy-1,4-imino-D-ribitol [0056] Most preferred are compounds Ib and Ic, their tautomers and pharmaceutically acceptable salts. [0057] The biological availability of a compound of formula (I) or formula (Ia) can be enhanced by conversion into a pro-drug form. Such a pro-drug can have improved lipophilicity relative to the compound of formula (I) or formula (Ia), and this can result in enhanced membrane permeability. One particularly useful form of a pro-drug is an ester derivative. Its utility relies upon the action of one or more of the ubiquitous intracellular lipases to catalyse the hydrolysis of these ester group(s), to release the compound of formula (I) and formula (Ia) at or near its site of action. [0058] In one form of a prodrug, one or more of the hydroxy groups in a compound of formula (I) or formula (Ia) can be O-acylated, to make, for example a 5-O-butyrate or a 2,3-di-O-butyrate derivative. [0059] Prodrug forms of 5-phosphate ester derivative of a compounds of formula (I) or formula (Ia) can also be made and may be particularly useful, since the anionic nature of the 5-phosphate may limit its ability to cross cellular membranes. Conveniently, such a 5-phosphate derivative can be converted to an uncharged bis(acyloxymethyl) ester derivative. The utility of such a pro-drug relies upon the action of one or more of the ubiquitous intracellular lipases to catalyse the hydrolysis of these ester group(s), releasing a molecule of formaldehyde and the compound of formula (I) or formula (Ia) at or near its site of action. [0060] Specific examples of the utility of, and general methods for making, such acyloxymethyl ester pro-drug forms of phosphorylated carbohydrate derivatives have been described, e.g. Kang et al., Nucleosides Nucleotides 17 (1998) 1089; Jiang et al., J. Biol. Chem., 273 (1998) 11017; Li et al., Tetrahedron 53 (1997) 12017; and Kruppa et al., Bioorg. Med. Chem. Lett., 7 (1997) 945. [0061] According to another aspect of the invention, there is provided a pharmaceutical composition comprising a pharmaceutically effective amount of a compound of the first aspect of the invention. [0062] Preferably the pharmaceutical composition comprises a compound chosen from the preferred compounds of the first aspect of the invention; more preferably the compound is chosen from the more preferred compounds of the first aspect. Most preferably the compound is the compound of formula Ib or Ic. [0063] In another aspect the invention provides methods for treatment of diseases or conditions in which it is desirable to decrease the level of T lymphocyte activity. The methods comprise administering a pharmaceutically effective dose of a compound of the invention to a patient requiring treatment. [0064] The diseases include T-cell malignancies and autoimmune diseases including arthritis and lupus. This aspect of the invention also includes use of the compounds for immunosuppression for organ transplantation and for inflammatory disorders. The invention includes use of the compounds for manufacture of medicaments for these treatments. [0065] In another aspect the invention provides a method for treatment and/or prophylaxis of parasitic infections, particularly those caused by protozoan parasites. Included among the protozoan parasites are those of the genera Giardia, Trichomonas, Leishmania, Trypanosoma, Crithidia, Herpetomonas, Leptomonas, Histomonas, Eimeria, Isopora and Plasmodium. An example of a parasitic infection caused by Plasmoodium is malaria. The method can be advantageously applied with any parasite containing one or more nucleoside hydrolases inhibited by the compound of the invention when administered in an amount providing an effective concentration of the compound at the location of the enzyme. [0066] In another aspect, the invention provides a method of preparing the compounds of the first aspect of the invention. The method may include one or more of methods (A)-(Z) and (AA)-(AF). [0067] Method (A): (4-hydroxypyrrolo[3,2-d]pyrimidines and access to 5′-deoxy-, 5′-deoxy-5′-halogeno-, 5′-ether and 5′-thio-analogues) [0068] reacting a compound of formula (II) [0069] [wherein Z′ is a hydrogen or halogen atom, a group of formula SQ or OQ, or a trialkylsilyloxy, alkyldiarylsilyloxy or optionally substituted triarylmethoxy group and Q is an optionally substituted alkyl, aralkyl or aryl group,] (typically Z′ is a tert-butyldimethylsilyloxy, trityloxy or similar group) sequentially with N-chlorosuccinimide then a sterically hindered base (such as lithium tetramethylpiperadide) to form an imine, then with the anion of acetonitrile (typically made by treatment of acetonitrile with n-butyllithium) followed by di-tert-butyl dicarbonate. This generates a compound of formula (III) [0070] [wherein Z′ is as defined for formula (II) where first shown above] which is then elaborated following the approach used to prepare 9-deazainosine [Lim et al., J. Org. Chem. , 48 (1983) 780] in which a compound of formula (III) is condensed with (Me 2 N) 2 CHOBu t and hydrolyzed under weakly acidic conditions to a compound of formula (IV) [0071] [wherein Z′ is as defined for formula (II) where first shown above] which is then sequentially condensed with a simple ester of glycine (e.g. ethyl glycinate) under mildly basic conditions, cyclized by reaction with a simple ester of chloroformic acid (e.g. benzyl chloroformate or methyl chloroformate) and then deprotected on the pyrrole nitrogen by hydrogenolysi& n the presence of a noble metal catalyst (e.g. Pd/C) in the case of a benzyl group or under mildly basic conditions in the case of a simple alkyl group such as a methyl group, to give a compound of formula (V) [0072] [wherein Z′ is as defined for formula (II) where first shown above, and R is an alkyl group] (typically R is a methyl or ethyl group) which is then condensed with formamidine acetate to give a compound of formula (VI) [0073] [wherein Z′ is as defined for formula (II) where first shown above] which is then fully deprotected under acidic conditions, e.g. by treatment with trifluoroacetic acid. [0074] Methods for the preparation of a compound of formula (II) wherein Z′ is a tert-butyldimethylsilyloxy group are detailed in Furneaux et al, Tetrahedron 53 (1997) 2915 and references therein. [0075] A compound of formula (II) [wherein Z′ is a halogen atom], can be prepared from a compound of formula (II) [wherein Z′ is a hydroxy group], by selective N-alkyl- or aralkyl-oxycarbonylation (typically with di-tert-butyl dicarbonate, benzyl chloroformate, or methyl chloroformate and a base) or N-acylation (typically with trifluoroacetic anhydride and a base) to give a compound of formula (VII): [0076] [wherein R is an alkyl- or aralkyl-oxycarbonyl group or an optionally substituted alkyl- or aryl-carbonyl group and Z′ is a hydroxy group] which is then either: [0077] (i) 5-O-sulfonylated (typically with p-toluenesulfonyl chloride, methanesulfonyl chloride or trifluoromethanesulfonic anhydride and a base) to give a compound of formula (VII) [wherein R is an alkyl- or aralkyl-oxycarbonyl group or an optionally substituted alkyl- or aryl-carbonyl group and Z′ is an optionally substituted alkyl- or aryl-sulfonyloxy group], then subjected to a sulfonate displacement reaction with a reagent capable of providing a nucleophilic source of halide ion (typically sodium, lithium or a tetraalkylammonium fluoride, chloride, bromide, or iodide); or [0078] (ii) subjected to a reagent system capable of directly replacing a primary hydroxy group with a halogen atom, for example as in the Mitsunobu reaction (e.g. using triphenylphosphine, diethyl azodicarboxylate and a nucleophilic source of halide ion as above), by reaction with diethylaminosulfur trifluoride (DAST), or by reaction with methyltriphenoxyphosphonium iodide in dimethylformamide [see e.g. Stoeckler et al, Cancer Res., 46 (1986) 1774] or by reaction with thionyl chloride or bromide in a polar solvent such as hexamethylphosphoramide [Kitagawa and Ichino, Tetrahedron Lett., (1971) 87] to give a compound of formula (VII) [wherein R is an alkyl- or aralkyl-oxycarbonyl group or an optionally substituted alkyl- or aryl-carbonyl group and Z′ is a halogen atom], which is then selectively N-deprotected by acid- or alkali-catalyzed hydrolysis or alcoholysis or catalytic hydrogenolysis as required for the N-protecting group in use. [0079] A compound of formula (VII) [wherein R is an alkyl- or aralkyl-oxycarbonyl group or an optionally substituted alkyl- or aryl-carbonyl group and Z′ is a hydroxy group] can also be prepared from a compound of formula (II) [wherein Z′ is a trialkylsilyloxy, alkyldiarylsilyloxy or optionally substituted triarylmethoxy group], by N-alkyl- or aralkyl-carboxylation or N-acylation as above, then selective 5-O-deprotection by acid-catalyzed hydrolysis or alcoholysis, catalytic hydrogenolysis, or treatment with a source of fluoride ion (eg tetrabutylammonium fluoride) as required for the 5-O-protecting group in use. [0080] The compound of formula (II) [wherein Z′ is a hydrogen atom] can be prepared from either: [0081] (i) a 5-hydroxy compound of formula (VII) [wherein R is an alkyl- or aralkyl-oxycarbonyl group or an optionally substituted alkyl- or aryl-carbonyl group and Z′ is a hydroxy group], by formation and radical deoxygenation of a 5-O-thioacyl derivative; or [0082] (ii) a 5-deoxy-5-halogeno-compound of formula (VII) [wherein Z′ is a chlorine, bromine or iodine atom] by reduction, either using a hydride reagent such as tributyltin hydride under free radical conditions, or by catalytic hydrogenolysis, typically with hydrogen over a palladium catalyst; followed by selective N-deprotection by acid- or alkali-catalyzed hydrolysis or alcoholysis or catalytic hydrogenolysis as required for the N-protecting group in use. [0083] A compound of formula (II) [wherein Z′ is an optionally substituted alkylthio, aralkylthio or arylthio group] can be prepared by reaction of a 5-deoxy-5-halogeno or a 5-O-sulfonate derivative of formula (VII) [wherein R is an alkyl- or aralkyl-oxycarbonyl group or an optionally substituted alkyl- or aryl-carbonyl group and Z′ is a halogen atom or an optionally substituted alkyl- or aryl-sulfonyloxy group] mentioned above, with an alkali metal or tetraalkylammonium salt of the corresponding optionally substituted alkylthiol, aralkylthiol or arylthiol followed by selective N-deprotection by acid- or alkali-catalyzed hydrolysis or alcoholysis or catalytic hydrogenolysis as required for the N-protecting group in use [see e.g. Montgomery et al., J. Med. Chem., 17 (1974) 1197]. [0084] The compound of formula (II) (wherein Z′ is a group of formula OQ, and Q is an optionally substituted alkyl, aralkyl or aryl group] can be prepared from a 5-hydroxy compound of formula (VII) [wherein R is an alkyl- or aralkyl-oxycarbonyl group or an optionally substituted alkyl- or aryl-carbonyl group and Z is a hydroxy group], by [0085] (i) reaction with an alkyl or aralkyl halide in the presence of a base (e.g. methyl iodide and sodium hydride, or benzyl bromide and sodium hydride, in tetrahydrofuran as solvent); or [0086] (ii) sequential conversion to a 5-O-sulfonate derivative (as above) and reaction with an alkali metal or tetraalkylammonium salt of the desired phenol, followed by selective N-deprotection by acid- or alkali-catalyzed hydrolysis or alcoholysis or catalytic hydrogenolysis as required for the N-protecting group in use. [0087] It will be appreciated that the conversions above are conventional reactions employed in carbohydrate chemistry. Many alternative reagents and reaction conditions can be employed that will effect these conversions, and references to many of these can be found in the Specialist Periodical Reports “Carbohydrate Chemistry”, Volumes 1-28, published by the Royal Society of Chemistry, particularly in the chapters on Halogeno-sugars, Amino-sugars, Thio-sugars, Esters, Deoxy-sugars, and Nucleosides. [0088] Method (B): (2-amino-4-hydroxypyrrolo[3,2-d]pyrimidines) [0089] reacting a compound of formula (V) [wherein Z′ is as defined for formula (II) where first shown above, and R is an alkyl group] with benzoyl isothiocyanate then methyl iodide in the presence of a base (e.g. DBU or DBN) following the approach used to prepare 9-deazaguanosine and its derivatives [see e.g. Montgomery et al., J. Med. Chem. 36 (1993) 55, Lim et al., J. Org. Chem., 48 (1983) 780, and references therein] to give a compound of formula (VIII) [0090] [wherein Z′ is a trialkylsilyloxy, alkyldiarylsilyloxy or optionally substituted triarylmethoxy group, a hydrogen or halogen atom, SQ or OQ wherein Q is an optionally substituted alkyl, aralkyl or aryl group and R is an alkyl group] (typically Z′, when a protected hydroxy group, is a tert-butyldimethylsilyloxy, trityloxy or similar group, and R is a methyl or ethyl group) which is then cyclized in the presence of ammonia to give a separable mixture of compounds of formula (IX) [0091] [wherein D is an amino or methylthio group, and Z′ and R are as defined for formula (VIII) where first shown above, or Z′ i s a hydroxy group] (where for example a tert-butyldimethylsilyloxy group has been cleaved under the reaction conditions) and the product of formula (IX) [wherein D is an amino or methylthio group] is fully deprotected under acidic conditions by the procedures set out in Method (A). [0092] Method (C): (4-aminopyrrolo [3,2-d]pyrimidines) [0093] reacting a compound of formula (IV) [wherein Z′ is as defined for formula (II) where first shown above] with aminoacetonitrile under mildly basic conditions, cyclization of the product by reaction with a simple ester of chloroformic acid (typically benzyl chloroformate or methyl chloroformate) to give a compound of formula (X) [0094] [wherein Z′ is a trialkylsilyloxy, alkyldiarylsilyloxy- or optionally substituted triarylmethoxy group, a hydrogen or halogen atom, SQ or OQ wherein Q is an optionally substituted alkyl, aralkyl or aryl group and R is an aralkyl or alkyl group] (typically Z′, when a protected hydroxy group, is a tert-butyldimethylsilyloxy, trityloxy or similar group, and R is a benzyl or methyl group) which is then deprotected on the pyrrole nitrogen by hydrogenolysis in the presence of a noble metal catalyst (e.g. Pd/C) in the case of a benzyl group or under mildly basic conditions in the case of a simple alkyl group such as a methyl group, and processed as described above for the transformation (V)→(VI)→(I) or (V)→(VIII)→(IX)→(I). This method follows the approach used to prepare 9-deazaadenosine and its analogues [Lim and Klein, Tetrahedron Lett., 22 (1981) 25, and Xiang et al., Nucleosides Nucleotides 15 (1996) 1821]. [0095] Method (D): (7-hydroxypyrazolo[4,3-d]pyrimidines—Daves' Methodology) [0096] reacting a compound of formula (II) [as defined where first shown above] sequentially with N-chlorosuccinimide and a hindered base (such as lithium tetramethylpiperidide) to form an imine, then condensing this with the anion produced by abstraction of the bromine or iodine atom from a compound of formula (XIb) or (XIc) [0097] [wherein R 3 is a bromine or iodine atom and R 4 is a tetrahydropyran-2-yl group] typically using butyllithium or magnesium, to give a product which is then fully deprotected under acidic conditions (as in Method (A)). Methods for preparing compounds of formula (XIb) and (XIc) and mixtures thereof are described in Zhang and Daves, J. Org. Chem., 57 (1992) 4690, Stone et al., J. Org. Chem., 44 (1979) 505, and references therein. [0098] It will be appreciated that while the tetrahydropyran-2-yl group is favoured as the protecting group for this reaction, other O,N-protecting groups can be used, and that this method will also be applicable to the synthesis of analogous pyrazolo[4,3-d]pyrimidines bearing substituents at position-5 and/or -7 of the pyrazolo[4,3-d]pyrimidine ring independently chosen from a hydroxy group, an amino, alkylamino, or aralkylamino group or a hydrogen atom using analogues of compounds of formula (XIb) and (XIc) in which the ionizable hydrogen atoms of any hydroxy or amino groups have been replaced by a suitable protecting groups. [0099] Method (E): (7-hydroxypyrazolo[4,3-d]pyrimidines—Yokoyama Method) [0100] subjecting a 5-O-ether protected 2,3-O-isopropylidene-D-ribofuranose derivative, where the 5-ether substituent is typically a trialkylsilyl, alkyldiarylsilyl, an optionally substituted triarylmethyl or an optionally substituted aralkyl group, particularly a tert-butyldimethylsilyl, tert-butyldiphenylsilyl, triisopropylsilyl, trityl or benzyl group, to the following reaction sequence. [0101] (i) condensation with the anion produced by abstraction of the bromine or iodine atom from a compound of formula (XIb) or (XIc) from Method (D); [0102] (ii) oxidation of the resulting diol to a diketone, typically using a Swern oxidation or a variant thereof using a dimethylsulfoxide-based oxidant (e.g. using a dimethylsulfoxide and trifluoroacetic anhydride reagent combination in dichloromethane solution at low temperature, typically −78° C., followed by triethylamine and warming to room temperature); [0103] (iii) double reductive amination to form a 1,4-dideoxy-1,4-imino-D-ribitol moiety, typically with sodium cyanoborohydride and ammonium formate, ammonium acetate or benzhydrylamine in methanol; and [0104] (iv) removal of the protecting groups by acid-catalyzed hydrolysis (e.g. with 70% aqueous trifluoroacetic acid) and if required (as in the case of the product made with benzhydrylamine or where an optionally substituted aralkyl group has been used for protecting the primary hydroxyl group in the iminoribitol moiety) hydrogenolysis over a metal catalyst (typically a palladium catalyst) or if desired (as in the case of silyl ether protecting group) exposure to a reagent capable of acting as a source of fluoride ion, e.g. tetrabutylammonium fluoride in tetrahydrofuran or ammonium fluoride in methanol). Conditions suitable for effecting this sequence of reactions are reported in Yokoyama et al., J. Org. Chem., 61 (1996) 6079, and conditions for double reductive amination with ammonium acetate or benzhydrylamine can be found in Furneaux et al., Tetrahedron 42 (1993) 9605 and references therein. [0105] Method (F): (7-hydroxypyrazolo[4,3-d]pyrimidines—the Kalvoda Method) [0106] reacting a compound of formula (II) [as defined where first shown above] sequentially with N-chlorosuccinimide and a hindered base (such as lithium tetramethylpiperadide) to form an imine, then with a combination of trimethylsilyl cyanide and a Lewis acid (typically boron trifluoride diethyl etherate) followed by acid catalyzed hydrolysis to give a compound of formula (XII) [0107] [wherein Z′ is a hydrogen or halogen atom, a hydroxy group, or a group of formula SQ or OQ where Q is an optionally substituted alkyl, aralkyl or aryl group] which is then converted by sequential selective N-protection (typically with trifluoroacetic anhydride, di-tert-butyl dicarbonate, benzyl chloroformate, or methyl chloroformate and a base), and O-protection with an acyl chloride or anhydride and a base (typically acetic anhydride or benzoyl chloride in pyridine) to a suitably protected derivative of formula (XIII) [0108] [wherein R 1 is an alkyl- or aralkyl-oxycarbonyl group or an optionally substituted alkyl- or aryl-carbonyl group, Z′ is a hydrogen or a halogen atom, a group of formula SQ or OQ where Q is an optionally substituted alkyl, aralkyl or aryl group, or a group of formula R 2 O, and R 2 is an alkylcarbonyl or optionally substituted arylcarbonyl group] (typically R 1 will be a trifluoroacetyl, tert-butoxycarbonyl or benzyloxycarbonyl group, and R 2 will be an acetyl or benzoyl group). [0109] The carboxylic acid moiety in the resulting compound of formula (XIII) is then transformed into a pyrazolo[4,3-d]pyrimidin-7-one-3-yl moiety following the method described by Kalvoda [Collect. Czech. Chem. Commun., 43 (1978) 1431], by the following sequence of reactions: [0110] (i) chlorination of the carboxylic acid moiety to form an acyl chloride, typically with thionyl chloride with a catalytic amount of dimethylformamide in an inert solvent; [0111] (ii) use of the resulting acyl chloride to acylate hydrogen cyanide in the presence of tert-butoxycarbonyltriphenylphosphorane (i.e. Ph 3 P═CHCO 2 Bu t ) to give a 3-cyano-2-propenoate derivative; [0112] (iii) cycloaddition of this with diazoacetonitrile (which can be prepared from aminoacetonitrile hydrochloride and sodium nitrite) with concomitant elimination of hydrogen cyanide to give a pyrazole derivative; [0113] (iv) acid-catalyzed hydrolysis of the tert-butyl a ester in this pyrazole derivative to its equivalent carboxylic acid; [0114] (v) Curtius reaction, typically with phenylphosphoryl azide and 2,2,2-trichloroethanol in the presence of triethylamine, which converts the carboxylic acid moiety into a 2,2,2-trichloroethoxycarbonylamino group (i.e. the product is a carbamate); [0115] (vi) reductive cleavage of this trichloroethyl carbamate, typically with zinc dust in methanol containing ammonium chloride; [0116] (vii) condensation of the resulting ethyl 4-amino-3-substituted-1H-pyrazole-5-carboxylate with formamidine acetate to give a compound of formula (XIV) [0117] [wherein R 1 is an alkyl- or aralkyl-oxycarbonyl group or an optionally substituted alkyl- or aryl-carbonyl group, Z′ is a hydrogen or a halogen atom, SQ or OQ where Q is an optionally substituted alkyl, aralkyl or aryl group, or a group of formula R 2 O, and R 2 is an alkylcarbonyl or optionally substituted arylcarbonyl group, A is a nitrogen atom, B is a hydroxy group and D is a hydrogen atom] which is then—and O-deprotected by acid- or alkali-catalyzed hydrolysis or alcoholysis or catalytic hydrogenolysis as required for the O- and N-protecting groups in use. [0118] Method (G): (7-aminopyrazolo[4,3-d]pyrimidines—the Buchanan Method) [0119] reacting a compound of formula (II) [as defined where first shown above] sequentially with N-chlorosuccinimide and a hindered base (such as lithium tetramethylpiperadide) to form an imine, which is then transformed into a 7-amino-pyrazolo[4,3-d]pyrimidine derivative following the approach used to prepare formycin and its analogues by Buchanan and co-workers [J. Chem. Soc., Perkin Trans. I (1991) 1077 and references therein], by the following sequence of reactions: [0120] (i) addition of 3,3-diethoxyprop-1-ynylmagnesium bromide or 3,3-diethoxyprop-1-ynyllithium to the imine; [0121] (ii) N-protection, typically with trifluoroacetic anhydride, di-tert-butyl dicarbonate, benzyl chloroformate, or methyl chloroformate and a base; [0122] (iii) mild acid hydrolysis to remove the acid sensitive O-protecting groups and convert the diethyl acetal moiety into an aldehydic moiety; [0123] (iv) condensation with hydrazine to convert the 3-substituted prop-2-ynal derivative into a 3-substituted pyrazole derivative; [0124] (v) acylation, typically with acetic anhydride or benzoyl chloride in pyridine; [0125] (vi) nitration, typically with ammonium nitrate, trifluoroacetic anhydride and trifluoroacetic acid, to produce an 3-substituted 1,4-dinitopyrazole derivative; [0126] (vii) reaction with a reagent capable of delivering cyanide ion, typically sodium cyanide in aqueous ethanol to cause a cine-substitution of one of the two nitro-groups; [0127] (viii) reduction of the residual nitro-group, typically with sodium dithionite or by catalytic hydrogenation over a metal catalyst; [0128] (ix) condensation with formamidine acetate to give a compound of formula (XIV) [wherein R 1 is an alkyl- or aralkyl-oxycarbonyl group or an optionally substituted alkyl- or aryl-carbonyl group, Z′ is a hydrogen or a halogen atom, SQ or OQ where Q is an optionally substituted alkyl, aralkyl or aryl group, or a group of formula R 2 O wherein R 2 is an alkylcarbonyl or optionally substituted arylcarbonyl group, A is a nitrogen atom, B is an amino group and D is a hydrogen atom] which is then—and O-deprotected by acid- or alkali-catalyzed hydrolysis or alcoholysis or catalytic hydrogenolysis as required for the O- and N-protecting groups in use. [0129] Method (H): (2′-deoxy-analogues) [0130] effecting the overall 2′-deoxygenation of a compound of formula (I) [wherein X and Z are hydroxy groups, Y is a hydrogen atom, and A, B and D are as defined where this formula is first shown above] through sequential: [0131] (i) selective N-alkyl- or aralkyl-oxycarbonylation (typically with di-tert-butyl dicarbonate, benzyl chloroformate, or methyl chloroformate and a base) or N-acylation (typically with trifluoroacetic anhydride and a base) of the 1,4-dideoxy-1,4-iminoribitol moiety in such a compound of formula (I); and [0132] (ii) 3′,5′-O-protection of the resulting product y reaction with 1,3-dichloro-1,1,3,3-tetraisopropyldisiloxane and a base to give a compound of formula (XV): [0133] [wherein R 1 is an alkyl- or aralkyl-oxycarbonyl group or an optionally substituted alkyl- or aryl-carbonyl group, R 2 is either the same as R 1 or is a hydrogen atom, and A, B and D are as defined for formula (I) where first shown above] [0134] (iii) 2′-O-thioacylation of the resulting compound of formula (XV) (typically with phenoxythionocarbonyl chloride and a base; or sodium hydride, carbon disulfide and methyl iodide); [0135] (iv) Barton radical deoxygenation (typically with tributyltin hydride and a radical initiator); [0136] (v) cleavage of the silyl protecting group by a reagent capable of acting as a source of fluoride ion, e.g. tetrabutylammonium fluoride in tetrahydrofuran or ammonium fluoride in methanol; and [0137] (vi) cleavage of the residual N- and O-protecting groups by acid- or alkali-catalyzed hydrolysis or alcoholysis or catalytic hydrogenolysis as required for the protecting groups in use. [0138] Reagents and reaction conditions suitable for conducting the key steps in this transformation can be found in Robins et al., J. Am. Chem. Soc., 105 (1983) 4059; Solan and Rosowsky, Nucleosides Nucleotides 8 (1989) 1369; and Upadhya et al., Nucleic Acid Res., 14(1986) 1747. [0139] It will be appreciated that a compound of formula (I) has a nitrogen atom in its pyrrole or pyrazole ring capable of undergoing alkyl- or aralkyl-oxycarbonylation or acylation during step (i), or thioacylation during step (ii), depending upon the reaction conditions employed. Should such derivatives be formed, the pyrrole or pyrazole N-substituents in the resulting derivatives are either sufficiently labile that they can be removed by mild acid- or alkali-catalyzed hydrolysis or alcoholysis, or do not interfere with the subsequent chemistry in the imino-ribitol moiety, and can be removed during the final deprotection step(s). If desired, this approach can be applied to a compound of formula (XV) [as defined above, but additionally bearing N-protecting groups on the. pyrazolo- or pyrrolo-pyrimidine moiety]. Methods suitable for preparing such N-protected compounds can be found in Ciszewski et al., Nucleosides Nucleotides 12 (1993) 487; and Kambhampati et al., Nucleosides and Nucleotides 5 (1986) 539, as can methods to effect their 2′-deoxygenation, and conditions suitable for N-deprotection. [0140] Method (I): (2′-epi-analoques) [0141] effecting the overall C-2′ epimerization of a compound of formula (I), by oxidizing and then reducing a compound of formula (XV) [as defined where first shown above] to give compound of formula (XVI): [0142] [wherein R 1 , R 2 , A, B and D are as defined for formula (XV) where first shown above] which may be present in a mixture with the starting alcohol of formula (XV), and then fully deprotecting this compound of formula (XVI) as set out in steps (v) and (vi) of Method (H). [0143] Reagents and reaction conditions suitable for conducting the key steps in this transformation can be found in Robins et al., Tetrahedron 53 (1997) 447. [0144] Method (J): (2′-deoxy-2′-halogeno- and 2′-deoxy-2′-epi-2′-halogeno-analogues) [0145] reacting compound of formula (XV) or (XVI) [as defined where first shown above] by the methods set out in Method (A) for the preparation of a compound of formula (II) [wherein Z′ is a halogen atom] which involve either: [0146] (i) 2′-O-sulfonylation and sulfonate displacement with a halide ion; or [0147] (ii) direct replacement of the 2′-hydroxy group with a halogen atom, e.g by the Mitsunobu reaction or reaction with diethylaminosulfur trifluoride (DAST) to give a compound of inverted stereochemistry at C-2′, which is then fully deprotected as set out in steps (v) and (vi) of Method (H). [0148] It will be appreciated that a compound of formula (XV) or (XVI) has a nitrogen atom in its pyrrole or pyrazole ring capable of undergoing sulfonylation during step (i), depending upon the reaction conditions employed. Should such derivatives be formed, the pyrrole or pyrazole N-sulfonate substituents in the resulting derivatives are either sufficiently labile that they can be removed by mild acid- or alkali-catalyzed hydrolysis or alcoholysis, or do not interfere with the subsequent chemistry in the iminoribitol moiety, and can be removed during the final deprotection step(s). [0149] If desired, this approach can be applied to a compound of formula (XV) or (XVI) [as defined above, but additionally bearing N-protecting groups on the pyrazolo- or pyrrolo-pyrimidine moiety]. Methods suitable for preparing such N-protected compounds can be found in Ciszewski et al., Nucleosides Nucleotides 12 (1993) 487; and Kambhampati et al., Nucleosides and Nucleotides 5 (1986) 539, as can methods to effect 2′-O-triflate formation and displacement by halide ion with inversion, and conditions suitable for N-deprotection. [0150] Method (K): (5′-deoxy-, 5′-deoxy-5′-halogeno-, 5′-ether and 5′-thio-analogues) [0151] by applying the procedures described in Method (A) for converting a compound of formula (VII) [wherein R is an alkyl- or aralkyl-oxycarbonyl group or an optionally substituted alkyl- or aryl-carbonyl group and Z′ is a hydroxy group] into a compound of formula (II) [wherein Z′ is a halogen or hydrogen atom or SQ or OQ where Q is an optionally substituted alkyl, aralkyl or aryl group alkylthio group of one to five carbon atoms] to a compound of formula (XVII): [0152] [wherein R is an alkyl- or aralkyl-oxycarbonyl group or an optionally substituted alkyl- or aryl-carbonyl group, Z′ is a hydroxy group, and A, B and D are as defined for formula (I) where first shown above] which is then fully deprotected under acidic conditions, e.g. by treatment with aqueous trifluoroacetic acid. [0153] Such a compound of formula (XVII) can be prepared from a compound of formula (I) [wherein X and Z are both hydroxy groups, Y is a hydrogen atom and A, B, and D have the meanings defined for formula (I) where first shown above] in the following two reaction steps, which may be applied in either order: [0154] (i) selective N-alkyl- or aralkyl-oxycarbonylation (typically with di-tert-butyl dicarbonate, benzyl chloroformate, or methyl chloroformate and a base) or N-acylation (typically with trifluoroacetic anhydride and a base) of the 1,4-dideoxy-1,4-iminoribitol moiety; and [0155] (ii) 2′,3′-O-isopropylidenation, which may be effected with a variety of reagents, e.g. acetone and anhydrous copper sulfate with or without added sulfuric acid; acetone and sulfuric acid; 2,2-dimethoxypropane and an acid catalyst; or 2-methoxypropene and an acid catalyst. [0156] It will be appreciated that such a compound of formula (I) or formula (XVII) has a nitrogen atom in its pyrrole or pyrazole ring capable of undergoing sulfonylation, thioacylation, acylation or aralkyl-oxycarbonylation, depending upon the reaction conditions employed. Should such derivatives be formed, the pyrrole or pyrazole N-substituents in the resulting derivatives are either sufficiently labile that they can be removed by mild acid- or alkali-catalyzed hydrolysis or alcoholysis, or do not interfere with the subsequent chemistry in the iminoribitol moiety, and can be removed during the final deprotection step(s). [0157] Method (L): (2- and 4-aminopyrrolo[3,2-d]pyrimidine and 5-and 7-aminopyrazolo[4,3-d]pyrimidine analogues) [0158] chlorinating a compound of formula (XVIII) [0159] [wherein R 1 is an alkyl- or aralkyl-oxycarbonyl group or an optionally substituted alkyl- or aryl-carbonyl group, R 2 is an alkylcarbonyl or optionally substituted arylcarbonyl group, X and Y are independently chosen from a hydrogen or halogen atom, or a group of formula R 2 O, except that when one of X or Y is a halogen atom or a group of formula R 2 O, the other is a hydrogen atom, Z′ is a group of formula R 2 O or, when X is a group of formula R 2 O, Z′ is a hydrogen or halogen atom, a group of formula R 2 O or of formula OQ or SQ wherein Q is an optionally substituted alkyl, aralkyl or an aryl group, A is a nitrogen atom or a methane group, and one of B or D is a hydroxy group, and the other is a chlorine, bromine or hydrogen atom] with a chlorinating reagent, and then displacing the chlorine atom with a nitrogen nucleophile by one of the following methods: [0160] (i) ammoniolysis, typically using liquid ammonia, concentrated aqueous ammonia, or a solution of ammonia in an alcohol such as methanol; or [0161] (ii) conversion first to a triazole derivative, by addition of 4-chlorophenyl phosphorodichloridate to a solution of the chloride and 1,2,4-triazole in pyridine, and alkaline hydrolysis of both the tetrazole moiety and the ester protecting groups with ammonium hydroxide; [0162] (iii) reaction with a source of azide ion, e.g. an alkali metal azide or tetraalkylammonium azide, and reduction of the resulting product, typically by catalytic hydrogenation; or [0163] (iv) reaction with an alkylamine or aralkylamine, such as methylamine or benzylamine in methanol. [0164] These conditions are sufficiently basic that O-ester groups will generally be cleaved but any residual O- or N-protecting groups can then be removed by acid- or alkali-catalyzed hydrolysis or alcoholysis or catalytic hydrogenolysis as required for the protecting groups in use. [0165] Suitable chlorinating agents are thionyl chloride—dimethylformamide complex [Ikehara and Uno, Chem. Pharm. Bull., 13 (1965) 221], triphenylphosphine in carbon tetrachloride and dichloromethane with or without added 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU) [De Napoli et al., J. Chem. Soc., Perkin Trans.1 (1995) 15 and references therein], phosphoryl chloride [Imai, Chem. Pharm. Bull., 12 (1964) 1030], or phenylphosphoryl chloride and sodium hydride. [0166] Suitable conditions for such an ammoniolysis or a reaction with an alkylamine can be found in Ikehara and Uno, Chem. Pharm. Bull., 13 (1965) 221; Robins and Tripp, Biochemistry 12 (1973) 2179; Marumoto et al., Chem. Pharm. Bull., 23 (1975) 759; and Hutchinson et al., J. Med. Chem., 33 (1990) 1919]. [0167] Suitable conditions for conversion of a such a chloride to an amine via a tetrazole derivative can be found in Lin et al., Tetrahedron 51 (1995) 1055. [0168] Suitable conditions for reaction with azide ion followed by reduction can be found in Marumoto et al., Chem. Pharm. Bull., 23 (1975) 759. [0169] Such a compound of formula (XVIII) can be prepared from a compound of formula (I) by selective N-alkyl- or aralkyl-oxycarbonylation (typically with di-tert-butyl dicarbonate, benzyl chloroformate, or methyl chloroformate and a base) or N-acylation of the 1,4-dideoxy-1,4-iminoribitol moiety and then O-acylation (typically with acetic anhydride or benzoyl chloride in pyridine). It will be appreciated that such a compound of formula (I) has a nitrogen atom in its pyrrole or pyrazole ring capable of undergoing alkyl- or aralkyl-oxycarbonylation or acylation depending upon the reaction conditions employed. Should such derivatives be formed, the pyrrole or pyrazole N-substituents in the resulting derivatives are either sufficiently labile that they can be removed by mild acid- or alkali-catalyzed hydrolysis or alcoholysis, or do not interfere with the subsequent chemistry, and can be removed during the final deprotection step(s). [0170] The above chlorination—amination—deprotection sequence can also be applied to a compound of formula (XVI:) [wherein B is a hydroxy group, D is a hydrogen atom, Z′ is a hydrogen or halogen atom, or a group of formula R 2 O, R 2 is a trialkylsilyloxy or alkyldibrylsilyloxy group, or an optionally substituted triarylmethoxy, alkylcarbonyl or arylcarbonyl group, R and A are as defined for formula (XVII) where first shown above]. Suitable conditions for conducting this reaction sequence can be found in Ikehara et al., Chem. Pharm. Bull., 12 (1964) 267. [0171] Method (M): (2,4-dihydroxypyrrolo [3,2-d]pyrimidine and 5,7-dihydroxypyrazolo[4,3-d]pyrimidine analogues) [0172] oxidation of either: [0173] (i) a compound of formula (XVIII) [wherein R 2 is a hydrogen atom; X and Y are independently chosen from a hydrogen or halogen atom, or a hydroxy group, except that when one of X or Y is a halogen atom or a hydroxy group, the other is a hydrogen atom; Z′ is a hydroxy group or, when X is a hydroxy group, Z′ is a hydrogen or halogen atom, a hydroxy group, or OQ; Q is an optionally substituted alkyl, aralkyl or aryl group; B is a hydroxy group or an amino group; D is a hydrogen atom; and RI and A are as defined for formula (XVIII) where first shown above] with bromine in water; or [0174] (ii) a compound of formula (XVIII) [wherein Z′ is a hydrogen or a halogen atom, or a group of formula R 2 O, or OQ; Q is an optionally substituted alkyl, aralkyl or aryl group; B is a hydroxy group or an amino group, D is a hydrogen atom and R 1 , R 2 , X, Y and A are as defined for formula (XVIII) where first shown above], with bromine or potassium permanganate in water or in an aqueous solvent mixture containing an inert, water-miscible solvent to improve the solubility of the substrate, to give a related compound of formula (XVIII) [but wherein B and D are now hydroxy groups], and then removal of any O- and N-protecting groups by acid- or alkali-catalyzed hydrolysis or alcoholysis or catalytic hydrogenolysis as required for the protecting groups in use. [0175] Such a compound of formula (XVIII) required for step (i) above can be prepared from a compound of formula (I) [wherein Z is Z′, and X, Y, Z, A, B and D are as defined for the required compound of formula (XVIII)] by selective N-alkyl- or aralkyl-oxycarbonylation (typically with di-tert-butyl dicarbonate, benzyl chloroformate, or methyl chloroformate and a base) or N-acylation (typically with trifluoroacetic anhydride and a base) of the 1,4-dideoxy-1,4-iminoribitol moiety. This can then be converted to the corresponding compound of formula (XVIII) required for step (ii) above by O-acylation (typically with acetic anhydride or benzoyl chloride in pyridine). It will be appreciated that such a compound of formula (I) has a nitrogen atom in its pyrrole or pyrazole ring capable of undergoing alkyl- or aralkyl-oxycarbonylation or acylation depending upon the reaction conditions employed. Should such derivatives be formed, the pyrrole or pyrazole N-substituents in the resulting derivatives are either sufficiently labile that they can be removed by mild acid- or alkali-catalyzed hydrolysis or alcoholysis, or do not interfere with the subsequent chemistry, and can be removed during the final deprotection step(s). [0176] Method (N): (4-amino-2-chloropyrrolo[3,2-d]pyrimidine and 7-amino-5-chloropyrazolo[4,3-d]pyrimidine analogues) [0177] chlorinating a compound of formula (XVIII) [wherein B and D are hydroxy groups and R 1 , R 2 , X, Y, Z′ and A are as defined for formula (XVIII) where first shown above] to give a corresponding dichloro-derivative of formula (XVIII) [wherein B and D are chlorine atoms], typically with neat phosphorous oxychloride, and then displacing the more reactive chloro-substituent selectively by ammoniolysis, typically using anhydrous liquid ammonia in a pressure bomb or methanolic ammonia, which simultaneously cleaves the O-ester protecting groups. The residual N-protecting group is then removed by acid-catalyzed hydrolysis or alcoholysis or catalytic hydrogenolysis as required for the protecting groups in use, to give a compound of formula (I) [wherein B is an amino-group and D is a chlorine atom]. [0178] The above dichloro-derivative of formula (XVIII) can be converted into a compound of formula (I) [wherein B and D are chlorine atoms] by removal of the O- and N-protecting groups by acid- or alkali-catalyzed hydrolysis or alcoholysis as required for the protecting groups in use. It will be appreciated that one of the chlorine atoms in the aforementioned compound of formula (XVIII) or of formula (I) is quite reactive and that conditions chosen for deprotection must be mild enough that they limit unwanted reactions involving this atom. [0179] Suitable reaction conditions for the key steps in this method can be found in Upadhya et al., Nucleic Acid Res., 14 (1986) 1747 and Kitagawa et al., J. Med. Chem., 16 (1973) 1381. [0180] Method (O): (2-chloro-4-hydroxypyrrolo[3,2-d]pyrimidine and 5-chloro-7-hydroxypyrazolo[4,3-d]pyrimidine analogues from dichloro-compounds) [0181] hydrolysis of a compound of formula (XVIII) [wherein B and D are chlorine atoms] available as an intermediate from the first reaction of Method (N), typically with aqueous potassium hydroxide or sodium carbonate, in the presence of an inert, water-miscible solvent such as dioxane to enhance solubility as required, followed by removal of the residual N-protecting group by acid-catalyzed hydrolysis or alcoholysis or catalytic hydrogenolysis as required for the protecting groups in use, to give a compound of formula (I) [wherein B is a hydroxy group and D is a chlorine atom]. [0182] Method (P): (2-chloro-4-hydroxypyrrolo[3,2-d]pyrimidine and 5-chloro-7-hydroxypyrazolo[4,3-d]pyrimidine analogues from aminochloro-compounds) [0183] deamination of a compound of formula (XVIII) [wherein B is an amino group, D is a chlorine atom, R 1 is an alkyl- or aralkyl-oxycarbonyl group or an optionally substituted alkyl- or aryl-carbonyl group, R 2 is a hydrogen atom, Z′=Z and X, Y, Z and A are as defined for formula (I) where first shown above), available as an intermediate following the chlorination and ammonyolysis reactions of Method (N), by reaction with nitrosyl chloride, followed by removal of the protecting groups as set out in Method (N). Typical reaction conditions can be found in Sanghvi et al., Nucleosides Nucleotides 10 (1991) 1417. [0184] Method (Q): (4-halogenopyrrolo[3,2-d]pyrimidine and 7-halogenopyrazolo[4,3-d]pyrimidine analogues) [0185] reacting a compound of formula (XVIII) (wherein R 1 is tert-butoxycarbonyl group, B is a hydroxy group, D is a hydrogen atom and R 2 , X, Y, Z′ and A are as defined for formula (XVIII) where first shown above] by a method used to prepare halogeno-formycin analogues [Watanabe et al., J. Antibiotic, Ser. A 19 (1966) 93] which involves sequential treatment with: [0186] (i) phosphorous pentasulfide by heating in pyridine and water under reflux to give a mercapto-derivative; [0187] (ii) methyl iodide to give a methylthio-derivative; [0188] (iii) a base in a simple alcohol or an aqueous solution of a simple alcohol, e.g. sodium methoxide in methanol, to remove the O-protecting groups; and [0189] (iv) chlorine, bromine or iodine in absolute methanol to give a halogeno-derivative which is then N-deprotected by reaction with aqueous acid, typically a concentrated trifluoroacetic acid solution. [0190] Method (R): (pyrrolo[3,2-d]pyrimidine and pyrazolo[4,3-d]pyrimidine analogues) [0191] hydrogenolytic cleavage of the chloride intermediate resulting from the chlorination reaction used as the first reaction in Method (L), or the chloride intermediate resulting from the chlorination reaction step (iv) in Method (Q), or the compound of formula (I) produced by Method (Q), typically using hydrogen over palladium on charcoal as the catalyst, optionally with magnesium oxide present to neutralize released acid, followed by cleavage of any residual O- or N-protecting groups by acid- or alkali-catalyzed hydrolysis or alcoholysis as required for the protecting groups in use. [0192] Method (S): (N-alkylated 4-aminopyrrolo[3,2-d]pyrimidine and 7-aminopyrazolo[4,3-d]pyrimidine analogues) [0193] heating an O-deprotected methylthio-derivative produced by step (iii) of Method (Q) with an amine, e.g. methylamine, in absolute methanol in a sealed tube or bomb, and then removing the N-protecting group by reaction with aqueous acid, typically a concentrated trifluoroacetic acid solution. This method has been used to prepare N-alkylated-formycin analogues [Watanabe et al., J. Antibiotic, Ser. A 19 (1966) 93]; or reacting a compound of formula (I) [wherein either B or D is an amino group] with 1,2-bis[(dimethylamino)methylene]hydrazine and trimethylsilyl chloride in toluene to convert the amino group into a 1,3,4-triazole group, hydrolysis to cleave the O-silyl groups (e.g. with acetic acid in aqueous acetonitrile), and displacement of the 1,3,4-triazole group with an alkylamine in a polar solvent (e.g. water or aqueous pyridine). This method has been used to prepare N,N-dimethyl-formycin A [Miles et al., J. Am. Chem. Soc., 117 (1995) 5951]; or subjecting a compound of formula (I) [wherein either B or D is an amino group] to an exchange reaction by heating it with an excess of an alkylamine. This method has been used to prepare N-alkyl-formycin A derivatives [Hecht et al., J. Biol. Chem., 250 (1975) 7343]. [0194] Method T: (2-chloro-4-hydroxypyrrolo[3,2-d]pyrimidine and 5-chloro-7-hydroxypyrazolo[4,3-d]pyrimidine analogues) [0195] Selective chlorination of dihydroxy compound of formula (XVIII) [wherein B and D are hydroxy groups, and R 1 , R 2 , X, Y, Z′ and A are as defined for formula (XVIII) where first shown above], taking advantage of the greater reactivity of the 4-hydroxy group on a 2,4-dihydroxypyrrolo[3,2-d]pyrimidine derivative and the 7-hydroxy group on a 5,7-dihydroxypyrazolo[4,3-d]pyrimidine derivative, followed by removal of protecting groups, using the methods set out in Method (N). [0196] Method U: (2-halogeno-, 4-halogeno- and 2,4-dihalogeno-pyrrolo[3,2-d]pyrimidine and 5-halogeno-, 7-halogeno-, and 5,7-dihalogeno-pyrazolo[4,3-d]pyrimidine analogues) diazotization of a compound of formula (XVIII) [wherein one of B or D is an amino group, and the other is independently chosen from an amino group, or a halogeno or hydrogen atom, and R 1 , R 2 , X, Y, Z′ and A are as defined for formula (XVIII) where first shown above] and subsequent reaction using one of the following procedures: [0197] (i) with nitrous acid (made in situ from sodium nitrite) in the presence of a source of halide ion. For replacement of an amino-group with a fluorine atom, a concentrated aqueous solution of fluoroboric acid [Gerster and Robins, J. Org. Chem., 31 (1966) 3258; Montgomery and Hewson, J. Org. Chem., 33 (1968) 432] or hydrogen fluoride and pyridine at low temperature (e.g. −25 to −30° C.) [Secrist et al., J. Med. Chem., 29 (1986) 2069] can serve both as the mineral acid and the fluoride ion source; or [0198] (ii) with an alkyl nitrite, typically tert-butyl or n-butyl nitrite, in a non-aqueous solvent in the presence of a source of halide ion. For replacement of an amino-group with a chlorine atom, a combination of chlorine and cuprous chloride, or antimony trichloride can be used in chloroform as solvent [Niiya et al, J. Med. Chem., 35 (1992) 4557 and references therein]; or [0199] (iii) with an alkyl nitrite, typically tert-butyl or n-butyl nitrite, in a non-aqueous solvent coupled with photohalogenation. For replacement of an amino group with a chlorine, bromine or iodine atom, carbon tetrachloride, bromoform, or diiodomethane have been used as reagent and solvent and an incandescent light source (e.g. a 200 W bulb) has been used to effect photohalogenation [Ford et al., J. Med. Chem., 38 (1995) 1189; Driscoll et al., J. Med. Chem., 39 (1996) 1619; and references therein]; to give a corresponding compound of formula (XVIII) [wherein B is a halogen atom and B is either a halogen atom or an amino group], followed by removal of the protecting groups as set out in Method (N). [0200] The same transformations can be effected for a corresponding starting compound of formula (XVIII) [wherein one of B or D is an amino group, and the other is a hydroxy group] if the hydroxy group is first converted to a thiol group [Gerster and Robins, J. Org. Chem., 31 (1966) 3258]. This conversion can be effected by reaction with phosphorous pentasulfide by heating in pyridine and water under reflux (see Method (Q)). [0201] Method (V): (4-iodo-pyrazolo[3,2-d]pyrimidine and 7-iodopyrazolo[4,3-d]pyrimidine analogues) [0202] treatment of corresponding chloro-analogue of formula (I) [wherein B is a chlorine atom] with concentrated aqueous hydroiodic acid, following the method of Gerster et al., J. Org. Chem., 28 (1963) 945. [0203] Method (W): (5′-deoxy-5′-halogeno- and 5′-thio-analogues) [0204] by reacting a compound of formula (XVIII) [wherein R 2 is a hydrogen atom; X and Y are independently chosen from a hydrogen or halogen atom, or a hydroxy group, except that when one of X or Y is a halogen atom or a hydroxy group, the other is a hydrogen atom; Z is a hydroxy group; and R 1 , A, B and D are as defined for formula (XVIII) where first shown above] with either [0205] (i) a trisubstituted phosphine and a disulfide, e.g. tributylphosphine and diphenyl disulfide; or [0206] (ii) a trisubstituted phosphine (e.g. triphenylphosphine) and carbon tetrabromide; or [0207] (iii) thionyl chloride or bromide. [0208] and then removal of the N-protecting group by acid- or alkali-catalyzed hydrolysis or alcoholysis or catalytic hydrogenolysis as required for the protecting group in use. [0209] Conditions suitable for conducting such selective replacements of a 5′-hydroxy group with a thio group or a halogen atom can be found in Chern et al., J. Med. Chem., 36 (1993) 1024; and Chu et al., Nucleoside Nucleotides 5 (1986) 185. [0210] Method (X): (5′-phospho-pyrazolo[3,2-d]pyrimidine and 5′-phospho-pyrazolo[4,3-d]pyrimidine analogues) [0211] reacting a compound of formula (XVII) [wherein R, Z′, A, B and D are as defined where first shown) with [0212] (i) a phosphitylation agent, such as N,N-diethyl-1,5-dihydro-2,4,3-benzodioxaphosphepin-3-amine, then oxidizing the phosphite ester to a phosphate ester, e.g. with 3-chloroperbenzoic acid; or [0213] (ii) a phosphorylatiing agent, such as phosphoryl chloride or dibenzylchlorophosphate; and removing the protecting groups, e.g. by hydrogenolysis and treatment under acidic conditions as set out in Method (A). [0214] Method (Y): (3-aminopyrrole-2-carboxylic acid and 4-amino-1H-pyrazole-5-carboxylic acid analogues) [0215] fully deprotecting a compound of formula (V) as defined where first shown, or an intermediate ethyl 4-amino-3-substituted-1H-pyrazole-5-carboxylate produced by step (vi) in Method (F), by acid- or alkali-catalyzed hydrolysis or alcoholysis or catalytic hydrogenolysis as required for the O- and N-protecting groups in use. [0216] Method (Z): (3-amino-2-cyanopyrroles and 4-amino-5-cyano-1H-pyrazoles) [0217] fully deprotecting a compound of formula (X) as defined where first shown above, or a 4-amino-5-cyanopyrazole intermediate produced by step (viii) in Method (G), by acid-or alkali-catalyzed hydrolysis or alcoholysis or catalytic hydrogenolysis as required for the O- and N-protecting groups in use. [0218] Method (AA): (3-aminopyrrole-2-carboxamide and 4-amino-1H-pyrazole-5-carboxamide analogues) [0219] conversion of the cyano-group of a compound of formula (X) as defined where first shown above, or a 4-amino-5-cyano-1H-pyrazoles intermediate produced by step (viii) in Method (G), into a carboxamido-group, conveniently by reaction with hydrogen peroxide and potassium carbonate in dimethylsulfoxide, and then fully deprotecting the resulting product by acid- or alkali-catalyzed hydrolysis or alcoholysis or catalytic hydrogenolysis as required for the O- and N-protecting group in use. [0220] Method (AB): (3-(thio)carbamoylpyrroles and 4-thio)carbamoyl-1H-pyrazoles) [0221] reaction of a compound of formula (V) or formula (X) as defined where first shown above, or a protected carboxamido-intermediate as prepared in Method (AA), or an intermediate ethyl 4-amino-3-substituted-1H-pyrazole-5-carboxylate produced by step (vi) in Method (F), with an isocyanate or isothiocyanate of formula RNCO or RNCS, where R is as defined for compounds of formula (I) and then fully deprotecting the resulting product by acid- or alkali-catalyzed hydrolysis or alcoholysis or catalytic hydrogenolysis as required for the O- and N-protecting groups in use. [0222] Method (AC): (esters of 3-aminopyrrole-2-carboxylic acid and 4-amino-1H-pyrazole-5-carboxylic acid analogues) [0223] converting the carboxylic acid group of a compound of formula (Ia) wherein E is CO 2 H into an ester, which can be accomplished by a number of well known methods for esterification. Conveniently an ester can be made by reaction of the carboxylic acid in acidic solution of the alcohol, e.g., ethanolic hydrogen chloride. [0224] Method (AD): (3-acylaminopyrroles and 4-acylamino-1H-pyrazoles) [0225] reaction of a compound of formula (V) or (X) as defined where first shown above, or an intermediate ethyl 4-amino-3-substituted-1H-pyrazole-5-carboxylate produced by step (vi) in Method (F), with an acylating agent, e.g. an acyl chloride such as benzoyl chloride, acid anhydride such as acetic anhydride in the presence of a base, such as triethylamine, potassium carbonate or pyridine, and then fully deprotecting the resulting product acid- or alkali-catalyzed hydrolysis or alcoholysis or catalytic hydrogenolysis as required for the O- and N-protecting groups in use. [0226] Method (AE): (N-mono- and N,N-di-substituted 3-amino-pyrrole-2-carboxamide and 4-amino-1H-pyrazole-5-carboxamide analogues) [0227] converting the carboxylic acid group of a compound of formula (Ia) wherein E is CO 2 H into an amide. Conveniently an amide can be made by carbodiimide induced condensation (e.g. with N,N-dicylcohexylcarbodiimide) of the carboxylic acid with a primary or secondary amine. [0228] Method (AF): (N-mono- and N,N-di-substituted 3-amino-pyrrole-2-carboxamide and 4-amino-1H-pyrazole-5-carboxamide analogues) [0229] condensing a compound of formula (V) as defined where first shown, or an intermediate ethyl 4-amino-3-substituted-1H-pyrazole-5-carboxylate produced by step (vi) in Method (F), with a primary or secondary amine and fully deprotecting the resulting product by acid- or alkali-catalyzed hydrolysis or alcoholysis or catalytic hydrogenolysis as required for the O- and N-protecting groups in use. [0230] It will be appreciated that the approaches outlined in Methods (H), (I), (J), (K) and (W) are equally applicable to the synthesis of compounds of formula (Ia) to give analogous variations in the 1,4-imino-pentitol moiety. [0231] Method (AG): (Acyloxymethyl Ester Prodrugs) [0232] reacting a 5-phosphate ester of a compound of formula (I) or formula (Ia) with benzylchloroformate in the presence of a base, conveniently aqueous sodium bicarbonate, to form an N-benzyloxycarbonyl derivative, reacting this derivative with an acyloxymethyl halide of formula RCO 2 CH 2 X where R is an alkyl group such as methyl, ethyl, propyl or tert-butyl and X is chloride, bromide or iodide, in the presence of a base, to form the 5-phosphate bis(acyloxymethyl) ester. Suitable conditions for the formation of the acetoxymethyl esters, using acetoxymethyl bromide and diisopropylethylamine in dimethylformamide, can be found in Kruppa et al, Bioorg. Med. Chem. Lett., 7 (1997) 945. [0233] When desired, e.g. as when the aforementioned N-benzyloxycarbonyl derivative is not sufficiently soluble in the reaction solvent, this derivative may first be converted into the corresponding stannyl intermediates, e.g. the bis(tributylstannyl) phosphate derivative by reaction with tributyltin methoxide in methanol, prior to reaction with the acyloxymethyl halide in the presence of tetrabutylammonium bromide, following the method described by Kang et al., Nucleosides Nucleotides 17 (1998) 1089. [0234] It will be appreciated that the conversion of such a 5-phosphate group to the corresponding bis(acyloxymethyl) ester can be accomplished by utilizing O- and or N-protected derivatives of compounds of formula (I) or formula (Ia) if desired, so long as the protecting groups can subsequently be removed without the use of strongly acidic or strongly basic conditions. Typically this requires the use of hydrogenolysis conditions for deprotection, so that O- and N-benzyl, -benzyloxymethyl or -benzyloxycarbonyl groups are favoured. [0235] Further Methods [0236] Compounds of the invention may also be prepared by other methods as will be apparent to those skilled in the art. [0237] Further Aspects [0238] The compounds of the invention are useful both in free base form and in the form of salts. The term “pharmaceutically acceptable salts” is intended to apply to non-toxic salts derived from inorganic or organic acids including f or example salts derived from the following acids -hydrochloric, sulfuric, phosphoric, acetic, lactic, fumaric, succinic, tartaric, gluconic, citric, methanesulphonic and p-toluenesulphonic acids. [0239] The compounds of the invention are potent inhibitors of purine nucleoside phosphorylases, nucleoside hydrolases and/or phosphoribosyltransferases. For example, the IC 50 values for the compounds of formula (Ib) and formula (Ic) are less than 0.1 nM for both calf spleen PNP and human red blood cell PNP. The examples below provide further detail of the effectiveness of this inhibitor. Purine nucleoside phosphorylase inhibitory activity can be determined by the coupled xanthine oxidase method using inosine as the purine substrate (H. M. Kalckar, J.) Biol. Chem. 167 (1947) 429-443. Purine phosphoribosyltransferase activity is detected in the same assay using inosine 5′-phosphate as the substrate. Slow onset inhibitor binding can be determined using methods such as those described by Merkler et al., Biochemistry 29 (1990) 8358-64. Parasite nucleoside hydrolase activity may be measured inter alia by methods disclosed in published PCT international patent application W097/31008 and the references cited therein. [0240] The potency of the inhibitors of the invention provides important advantages over the prior art because of the relatively high activity of PNP in blood and mammalian tissue. As mentioned above the required dosage of 9-(3-pyridylmethyl)-9-deazaguanine may be of the order of 3.5 grams per dose for a human adult. The present invention provides the advantage that considerably lower quantities of the compounds are required. This allows cost saving and may also reduce unwanted side effects. [0241] The amount of active ingredient to be administered can vary widely according to the nature of the patients and the nature and extent of the disorder being treated. Typically the dosage for an adult human will be in the range less than 1 to 1000 milligrams, preferably 0.1 to 100 milligrams. The active compound can be administered with a conventional pharmaceutical carrier and may be administered orally, by injection or topically. [0242] The preferred route of administration is oral administration. For administration by this route the compounds can be formulated into solid or liquid preparations, eg tablets, capsules, powders, solutions, suspensions and dispersions. Such preparations are well known in the art as are other oral dosage forms not listed here. In a preferred embodiment the compounds of the invention are tableted with conventional tablet bases such as lactose, sucrose and corn starch together with a binder, a disintegration agent and a lubricant. These exipients are well known in the art. The binder may be for example corn starch or gelatin, the disintegrating agent may be potato starch or alginic acid and the lubricant may be magnesium stearate. Other components such as colouring agents and flavouring agents may be included. [0243] Liquid forms for use in the invention include carriers such as water and ethanol, with or without other agents such as a pharmaceutically acceptable surfactant or suspending agent. [0244] The compounds of the invention may also be administered by injection in a physiologically acceptable diluent such as water or saline. The diluent may comprise one or more of other ingredients such as ethanol, propylene glycol, an oil or a pharmaceutically acceptably surfactant. [0245] Compounds of the invention may be applied to skin or mucous membranes. They may be present as ingredients in creams, preferably including a pharmaceutically acceptable solvent to assist passage through the skin or mucous membranes. Suitable cream bases are well known to those skilled in the art. [0246] The compounds of the invention may be administered by means of sustained release systems for example they may be incorporated into a slowly dissolving tablet or capsule containing a solid or porous or matrix form from a natural or synthetic polymer. EXAMPLES [0247] The following examples further illustrate practice of the invention. Ratios of solvents are by volume. Example 1 Preparation of (1S)-1,4-dideoxy-1-C-(4-hydroxypyrrolo[3,2-d]pyrimidin-7-yl)-1,4-imino-D-ribitol Example 1.1. [0248] A solution of 5-O-tert-butyldimethylsilyl-1,4-dideoxy-1,4-imino-2,3-O-isopropylidene-D-ribitol (Furneaux et al, Tetrahedron 53 (1997) 2915 and references therein) (2.0 g) in pentane (40 ml) was stirred with N-chlorosuccinimide (1.2 g) for 1h. The solids and solvent were removed and the residue was dissolved in dry tetrahydrofuran (40 ml) and cooled to −78° C. A solution of lithium tetramethylpiperidide (25 ml, 0.4 M in tetrahydrofuran) was added slowly dropwise. The resulting solution was then added via cannula to a solution of lithiated acetonitrile [prepared by the dropwise addition of acetonitrile (2.08 ml, 40 mmol) to a solution of butyl lithium (29.8 ml, 41.8 mmol) in dry tetrahydrofuran (50 ml) at −78° C., followed by stirring for 45 min and then addition of tetramethylpiperidine (0.67 ml, 4 mmol)] at −78° C. The reaction mixture was stirred for 15 min then quenched with water and partitioned between water and chloroform. The organic phase was dried and concentrated, and then chromatography afforded (1S)-5-O-tert-butyldimethylsilyl-1-C-cyanomethyl-1,4-dideoxy-1,4-imino-2,3-O-isopropylidene-D-ribitol (1) (0.83 g). Example 1.2 [0249] A solution of the product from Example 1.1 (0.80 g) in dichloromethane (20 ml) containing di-tert-butyldicarbonate (0.59 g) was stirred at room temperature for 16 h. The solution was concentrated and then chromatography afforded (1S)-N-tert-butoxycarbonyl-5-O-tert-butyldimethylsilyl-1-C-cyanomethyl-1,4-dideoxy-1,4-imino-2,3-O-isopropylidene-D-ribitol (2) (0.89 g). Example 1.3 [0250] To a solution of the product from Example 1.2 (0.88 g) in N,N-dimethylformamide (5 ml) was added tert-butoxy bis(dimethylamine)methane (1.5 ml) and the solution was heated at 65-70° C. for 1 h. Toluene (20 ml) was added and the solution was washed (×3) with water, dried and concentrated to dryness. The residue was dissolved in tetrahydrofuran/acetic acid/water (1:1:1 v/v/v, 40 ml) at room temperature. After 1.5 h chloroform (50 ml) was added and the mixture was washed with water (×2), aqueous sodium bicarbonate, and then dried and evaporated to dryness. Chromatography of the residue gave (1S)-N-tert-butoxycarbonyl-5-O-tert-butyldimethylsilyl-1-C-(1-cyano-2-hydroxyethenyl)-1,4-dideoxy-1,4-imino-2,3-O-isopropylidene-D-ribitol (3) (0.68 g) Example 1.4 [0251] Glycine hydrochloride ethyl ester (0.76 g) and sodium acetate (0.9 g) were added to a stirred solution of the product from Example 1.3 (0.51 g) in methanol (10 ml). The mixture was stirred at room temperature for 16 h and then concentrated to dryness. Chromatography of the residue gave the (1S)-N-tert-butoxycarbonyl-5-O-tert-butyldimethylsilyl-1-C-[1-cyano-2-(ethoxycarbonylmethylamino) ethenyl -1,4-dideoxy-1,4-imino-2,3-O-isopropylidene-D-ribitol (4) (0.48) g as a diastereomeric mixture. Example 1.5 [0252] A solution of the product from Example 1.4 (0.28 g) in dry dichloromethane (12 ml) containing 1,8-diazabicyclo[5.4.0]undec-7-ene (1.5 ml) and benzyl chloroformate (0.74 ml) was heated under reflux for 8 h, then cooled and washed with dilute aqueous HCl, aqueous sodium bicarbonate, dried and concentrated. Chromatography of the residue afforded (1S)-1-C-[3-amino-1-N-benzyloxycarbonyl-2-ethoxycarbonyl-4-pyrrolyl]-N-tert-butoxycarbonyl-5-O-tert-butyldimethylsilyl-1,4-dideoxy-1,4-imino-2,3-O-isopropylidene-D-ribitol (5) (0.22 g). Example 1.6 [0253] A solution of the product from Example 1.5 (0.22 g) in ethanol (10 ml) was stirred with 10% Pd/C (50 mg) in an atmosphere of hydrogen for 3 h. The solids and solvent were removed and the residue was dissolved in ethanol (10 ml) containing formamidine acetate (0.40 g) and the solution was heated under reflux for 8 h. The solvent was removed and chromatography of the residue gave (1S)-N-tert-butoxycarbonyl-5-O-tert-butyldimethylsilyl-1,4-dideoxy-1-C-[4-hydroxypyrrolo[3,2-d]pyrimidin-7-yl]-1,4-imino-2,3-O-isopropylidene-D-ribitol (6) (156 mg). Example 1.7 [0254] A solution of the product from Example 1.6 (66 mg) in trifluoroacetic acid (3 ml) was allowed to stand at room temperature overnight. The solution was concentrated and a solution of the residue in water was washed (×2) with chloroform and then evaporated. The residue was dissolved in methanol and treated with Amberlyst A21 base resin until the solution was pH˜7. The solids and solvent were removed and the residue was dissolved in water, treated with excess aqueous HCl and then lyophilized. Trituration of the residue with ethanol gave (1S)-1,4-dideoxy-1-C-(4-hydroxypyrrolo[3,2-d]pyrimidin-7-yl)-1,4-imino-D-ribitol (7) hydrochloride salt as a white solid (25 mg). Recrystallised from 90% ethanol, the crystalline solid darkened but did not melt below 300° C. NMR (300 MHz, D 2 O with DC1, δ ppm): 13 C (relative to internal acetone at 33.2 ppm) 58.1 (C-1′), 61.4 (C-5′), 68.8 (C-4′), 73.3 (C-3′), 76.7 (C-2′), 107.5 (q), 121.4 (q), 133.5 (C-2), 135.0 (q), 148.0 (C-6) and 155.4 (q); 1 H (relative to internal acetone at 2.20 ppm), 3.90 (H-4′), 3.96 (m, H-5′,5″), 4.44 (dd, H-3′, J 2′,3′ 5.4 Hz, J 3′,4′ 3.2 Hz), 4.71 (dd, J 1′,2′ 9.0 Hz, H-2′), 5.00 (d, H-1′), 8.00 (s, H-6) and 9.04 (s, H-2) Example 2 Preparation of (1S)-1-C-(2-amino-4-hydroxypyrrolo[3,2-d]pyrimidin-7-yl)-1,4-dideoxy-1,4-imino-ribitol Example 2.1 [0255] A solution of (1S)-1-C-[3-amino-1-N-benzyloxycarbonyl-2-ethoxycarbonyl-4-pyrrolyl]-N-tert-butoxycarbonyl-5-O-tert-butyldimethylsilyl-1,4 dideoxy 1,4-imino-2,3-O-isopropylidene-D-ribitol (Example 1.5) (0.87 g) in ethanol was stirred with 10% Pd/C (100 mg) in an atmosphere of hydrogen for 1.5 h. The solids and solvent were removed to give a residue (0.61 g). To a solution of a portion of this residue (0.12 g) in dichloromethane (10 ml) at 0° C. was added a solution of benzoyl isothiocyanate in dichloromethane (31 mL in 1 ml). After 0.5 h the solution was warmed to room temperature and 1,8-diazabicyclo[5.4.0]undec-7-ene (80 mL) and methyl iodide (100 mL) were added. After another 0.5 h the reaction solution was applied directly to a silica gel column and elution afforded 0.16 g of (1S)-1-C-[3-(N-benzoyl-S-methylisothiocarbamoyl)amino-2-ethoxycarbonyl-4-pyrrolyl]-N-tert-butoxycarbonyl-5-O-tert-butyldimethylsilyl-1,4-dideoxy-1,4-imino-2,3-O-isopropylidene-D-ribitol. Example 2.2 [0256] A solution of this S-methylisothiocarbamoylamino derivative, (0.20 g) in methanol saturated with ammonia was heated in a sealed tube at 95° C. for 16 h. The solvent was removed and chromatography of the residue afforded (1S)-1-C-[2-amino-4-hydroxypyrrolo[3,2-d]pyrimidin-7-yl]-N-tert-butoxycarbonyl-1,4-dideoxy-1,4-imino-2,3-O-isopropylidene-D-ribitol. Example 2.3 [0257] A solution of this protected iminoribitol (64 mq) in trifluoroacetic acid was allowed to stand at room temperature for 16 h. The solvent was removed and a solution of the residue in aqueous methanol (1:1) was treated with Amberlyst A21 base resin until the pH of the solution was ˜7. The solids and solvent were removed and a solution of the residue in water was treated with excess HCl and then concentrated to dryness. Trituration with ethanol gave (1S)-1-C-(2-amino-4-hydroxypyrrolo[3,2-d]pyrimidin-7-yl)-1,4-dideoxy-1,4-imino-D-ribitol hydrochloride salt (24 mg), which darkened at ca. 260° C. but did not melt below 300° C. NMR (300 MHz, D 2 O with DCl, δ ppm): 13 C (relative to internal acetone at 33.1 ppm) 58.0 (C-1′), 61.4 (C-5′), 68.6 (C-4′), 73.3 (C-3′), 76.3 (C-2′), 105.2 (q), 114.8 (q), 132.1 (C-6), 135.3 (q), 153.4 (q) and 156.4 (q); 1 H (relative to internal acetone at 2.20 ppm) 3.87 (m, H-4′), 3.94 (m, H-5′,5″), 4.40 (dd, J 2′,3′ 5.0 Hz, J 3′,4′ 3.2 Hz, H-3′), 4.65 (dd, , J 1′,2′ 9.1 Hz, H-2′), 4.86 (d, H-1′) and 7.71 (s, H-6). Examples 3-24 [0258] The following compounds may be prepared according to methods disclosed in the general description: [0259] 3. (1R)-1-C-(4-hydroxypyrrolo[3,2-d]pyrimidin-7-yl)-1,4-imino-1,2,4-trideoxy-D-erythro-pentitol may be prepared from the product of Example 1 using Method (H) [0260] 4. (1S)-1-C-(4-hydroxypyrrolo[3,2-d]pyrimidin-7-yl)-1,4-imino-1,4,5-trideoxy-D-ribitol may be prepared from the product of Example 1 using Method (K). [0261] 5. (1S)-1,4-dideoxy-1-C-(4-hydroxypyrrolo[3,2-d]pyrimidin-7-yl)-1,4-imino-5-methylthio-D-ribitol may be prepared from the product of Example 1 using Method (K). [0262] 6. (1S)-1,4-dideoxy-1-C-(2,4-dihydroxypyrrolo[3,2-d]pyrimidin-7-yl)-1,4-imino-D-ribitol may be prepared from the product of Examples 1 or 2 using Method (M). [0263] 7. (1R)-1-C-(2,4-dihydroxypyrrolo[3,2-d]pyrimidin-7-yl)-1,4-imino-1,2,4-trideoxy-D-erythro-pentitol may be prepared from the product of Example 6 using Method (H). [0264] 8. (1S)-1-C-(2,4-dihydroxypyrrolo[3,2-d]pyrimidin-7-yl)-1,4-imino-1,4,5-trideoxy-D-ribitol may be prepared from the product of Example 6 using Method (K). [0265] 9. (1S)-1,4-dideoxy-1-C-(2,4-dihydroxypyrrolo[3,2-d]pyrimidin-7-yl)-1,4-imino-5-methylthio-D-ribitol may be prepared from the product of Example 6 using Method (K). [0266] 10. (1R)-1-C-(2-amino-4-hydroxypyrrolo[3,2-d]pyrimidin-7-yl)-1,4-imino-1,2,4-trideoxy-D-erythro-pentitol may be prepared from the product of Example 2 by Method (H). [0267] 11. (1S)-1-C-(2-amino-4-hydroxypyrrolo[3,2-d]pyrimidin-7-yl)-1,4-imino-1,4,5-trideoxy-D-ribitol may be prepared from the product of Example 2 by Method (K). [0268] 12. (1S)-1-C-(2-amino-4-hydroxypyrrolo[3,2-d]pyrimidin-7-yl)-1,4-dideoxy-1,4-imino-5-methylthio-D-ribitol may be prepared from the product of Example 2 using Method (K). [0269] 13. (1S)-1,4-dideoxy-1-C-(7-hydroxypyrazolo[4,3-d]pyrimidin-3-yl)-1,4-imino-D-ribitol may be prepared by Methods (D), (E) and (F). [0270] 14. (1R)-1-C-(7-hydroxypyrazolo[4,3-d]pyrimidin-3-yl)-1,4-imino-1,2,4-trideoxy-D-erythro-pentitol may be prepared from the product of Example 13 using Method (H). [0271] 15. (1S)-1-C-(7-hydroxypyrazolo[4,3-d]pyrimidin-3-yl)-1,4-imino-1,4,5-trideoxy-D-ribitol may be prepared from the product of Example 13 using Method (K). [0272] 16. (1S)-1,4-dideoxy-1-C-(7-hydroxypyrazolo[4,3-d]pyrimidin-3-yl)-1,4-imino-5-methylthio-D-ribitol may be prepared from the product of Example 13 using Method (K). [0273] 17. (1S)-1,4-dideoxy-1-C-(5,7-dihydroxypyrazolo[4,3-d]pyrimidin-3-yl)-1,4-imino-D-ribitol may be prepared from the product of Example 13 using Method (M). [0274] 18. (1R)-1-C-(5,7-dihydroxypyrazolo[4,3-d]pyrimidin-3-yl)-1,4-imino-1,2,4-trideoxy-D-erythro-pentiol may be prepared from the product of Example 17 using Method (H). [0275] 19. (1S)-1-C-(5,7-dihydroxypyrazolo(4,3-d]pyrimidin-3-yl)-1,4-imino-1,4,5-trideoxy-D-ribitol may be prepared from the product of Example 17 using Method (K). [0276] 20. (1S)-1,4-dideoxy-1-C-(5,7-dihydroxypyrazolo(4,3-d]pyrimidin-3-yl)-1,4-imino-5-methylthio-D-ribitol may be prepared from the product of Example 17 using Method (K). [0277] 21. (1S)-1-C-(5-amino-7-hydroxypyrazolo[4,3-d]pyrimidin-3-yl)-1,4-dideoxy-1,4-imino-D-ribitol may be prepared using a variation of Method (D) in which the compound of Formula XIb or XIc is replaced by a corresponding compound in which the hydrogen atom in position 5 is replaced by protected amino group. [0278] 22. (1R)-1-C-(5-amino-7-hydroxypyrazolo[4,3-d]pyrimidin-3-yl)-1,4-imino-1,2,4-trideoxy-D-erythro-pentitol may be prepared from the product of Example 21 using Method (H). [0279] 23. (1S)-1-C-(5-amino-7-hydroxypyrazolo[4,3-d]pyrimidin-3-yl)-1,4-imino-1,4,5-trideoxy-D-ribitol may be prepared from the product of Example 21 using Method (K). [0280] 24. (1S)-1-C-(5-amino-7-hydroxypyrazolo[4,3-d]pyrimidin-3-yl)-1,4-dideoxy-1,4-imino-5-methylthio-D-ribitol may be prepared from the product of Example 21 using Method (K) Example 25 Enzyme Inhibition Results Example 25.1 [0281] Inhibition of purine nucleoside phosphorylases. Enzyme assays were conducted to assess the effectiveness of the products of Examples 1 and 2 (compounds Ib and Ic respectively) as inhibitors of purine nucleoside phosphorylase. The assays used human RBC and calf spleen purine nucleoside phosphorylase (ex Sigma, 90% pure) with inosine as substrate, in the presence of phosphate buffer, with detection of released hypoxanthine using xanthine oxidase coupled reaction. [0282] Materials. Inosine was obtained from Sigma. Xanthine oxidase (EC 1.1.3.22, buttermilk), human erythrocyte (as a lyophilized powder) and bovine spleen (in 3.2 M ammonium sulfate) purine nucleoside phosphorylases (EC 2.4.2.1) were purchased from Sigma. Human purine nucleoside phosphorylases obtained as a powder was reconstituted in 100 mM sodium phosphate buffer (pH 7.4) and rapidly frozen and stored at −80° C. Kinetic experiments were performed on a Uvikon 933 double beam ultraviolet/visible spectrophotometer (Kontron Instruments, San Diego, Calif.). [0283] Protein Concentrations. Protein concentrations for both isozymes were determined based on the quantative ultraviolet absorbance, using E 1cm 1%=9.64 at 280 nm [Stoelkler et al, Biochemistry, 32 (1978) 278] and a monomer moleculer weight of 32,000 (Williams et al, Nucleic Acids Res. 12 (1984) 5779). [0284] Enzyme Assay. Enzymes were assayed spectrophotometrically using the coupled xanthine oxidase method [Kalckar, J. Biol. Chem. 167 (1947) 429; Kim et al, J. Biol. Chem., 243 (1968) 1763]. Formation of uric acid was monitored at 293 nm. A 40 mM inosine solution gave an absorbance change of 0.523 units at 293 m, upon complete conversion of inosine to uric acid and ribose 1-phosphate. Unless otherwise noted, the standard assay reaction contained: inosine (500 μM), potassium phosphate (50 mM, pH 7.5); xanthine oxidase (0.06 units) and purine nucleoside phosphorylase in a final volume of 1.0 mL. [0285] One-Third-the-Sites Inhibition. Reaction mixtures of 6.7 nM bovine purine nucleoside phosphorylase containing varying amounts of compound Ib were pre-incubated at 30° C. for 1 hour. Reactions were initiated by addition of substrate (40 μM inosine, 3 times the K m value) and assayed at 30° C. The reaction containing 0.6 nM inhibitor (concentration ratio of [compound Ib]/[purine nucleoside phosphorylase]=0.09) showed 29% inhibition, that containing 1 nM inhibitor ([compound Ib])/ [purine nucleoside phosphorylase]=0.15) showed 44%, whereas the reaction containing 3 nM inhibitor ([compound Ib]/purine nucleoside phosphorylase]=0.44) had a rate decrease of 96%, and that containing 6 nM inhibitor ([compound Ib])/[purine nucleoside phosphorylate]=87%) showed 99% inhibition. These interactions are shown in FIG. 1. [0286] Purine nucleoside phosphorylase is known to be a homotrimer with a catalytic site on each of the three protein subunits [Stoelkler et al, Biochemistry 32, (1978) 278]. When the concentration of enzyme subunits is 6.7 nM, 50% inhibition of purine nucleoside phosphorylase occurs at approximately 1.1 nM. This result demonstrates that compound Ib binds tightly and that binding of compound Ib to one site of the trimeric enzyme leads to complete inhibition. [0287] Activity Recovery from the Complex of Purine Nucleoside Phosphorylase with Compound Ib. Purine nucleoside phosphorylase (6.7 μM) and sufficient compound Ib (3 μM) to inhibit 96% of purine nucleoside phosphorylase activity were incubated at 30° C. for 1 hour. An aliquot of this solution was diluted 1000-fold into a buffered solution of 500 μM inosine containing xanthine oxidase (0.06 units). The production of uric acid was monitored over time and the progres curve was fit to the kinetic model of FIG. 2. [0288] Dilution of inhibited purine nucleoside phosphorylase into a large volume of solution without inhibitor provided the rate of release of compound Ib from inhibited purine nucleoside phosphorylase. Under conditions of the experiment in FIG. 2, the time to achieve the new enzyme-inhibitor equilibrium is 5000 sec, an indication of a slow, tight-binding inhibitor (Morrison and Walsh, Advances Enzymol. 61 (1988) 201]. The rate contant k 6 is an estimate of the apparent first-order rate constant for dissociation of the complex under these experimental conditions and is 2.9×10 −4 sec −1 in this example. [0289] Inhibitory Mechanism. Slow, tight-binding inhibitors generally follow the kinetic mechanism [Morrison and Walsh, Advances Enzymol. 61 (1988) 201]: [0290] where EI is a rapidly formed, initial collision complex of purine nucleoside phosphorylase (E) and compound Ib (I) that slowly isomerizes to a tighter complex EI. Product formation curves are described by the following integrated rate equation 1: P=v s t +( v o −v s ) (1− e −k t )/ k 1 [0291] where P is the amount of product hypoxanthine (observed as uric acid in the present assay system), t is time, v o is the initial rate, v s is the final steady-state rate and k is the overall (observed) rate constant given by equation 2: k=k 6 +k 5[( I/K i )/(1+( S/K m )+( I/K i ))] 2 [0292] where K m is the Michaelis complex for purine nucleoside phosphorylase, S is inosine concentration, I is the concentration of compound Ib and K i is as described below. The rate of formation of the tightly bound complex is k5 and the rate of its dissociation is k6. K i , the inhibition constant for standard competitive inhibition (which influences v o ) and K l , the overall inhibition constant (which influences v s ), are defined as: K i =k 4/ k 3 K i =K i [k 6 /( k 5 +k 6 )] [0293] Determination of K i . K i was determined by measuring v s for reactions at a range of inhibitor concentrations, plotting v s vs [I] and fitting the curve to the competive inhibition equation 3: v s =V max S/[K m ( l+I/K i )+ S] 3 [0294] where v max is the uninhibited reaction rate for purine nucleoside phosphorylase, and the remaining terms are described above. The result of this analysis indicates an overall effective inhibition constant (K i ) of 2.5±0.2×10 −11 M (25±2 pM) for compound Ib (FIG. 3). [0295] Approximation of K i , k 5 and k 6 . Calculation of K l directly from v o and the competitive inhibition equation (above) is difficult for compound Ib because v o changes very little as a function of I at inhibitor concentrations which cause complete inhibition following slow onset. This result establishes that the initial dissociation constant K l is much greater than the equilibrium dissociation constant K l . [0296] Approximations of k 5 and K i were calculated from k (values obtained from curve fits of equation 1, FIG. 4) by using equation 2. Using the knowledge that k 6 <<k 5 [(I/K i )/(1+(A/K m )+(I/K i )], equation 2 can be rearranged so that a double reciprocal plot of 1/k vs I/[I] gives a straight line with y intercept=1/k 5 and x intercept of −(1/k 5 )/[K i /k 5 )(A/K m ))]. Substitution of these values into equation 2 give an approximation for k 6 . FIG. 4 demonstrates the slow-onset, tight-binding inhibition which occurs when a small concentration of enzyme (0.8 nM) competes for 200 nM compound Ib in the presence of 500 μM inosine. Under these conditions the apparent first order rate constant for onset of inhibition in FIG. 4 was 26×10 −4 sec −1 . [0297] The result of FIG. 4 demonstrates that even at inosine concentrations over 100 times that present in human serum or tissues, compound Ib can give 99% inhibition of the enzyme after several minutes of slow-onset inhibition. Based on analyses of experiments of the type shown in FIGS. 1 - 4 , the experimentally estimated dissociation constants and rates for the bovine purine nucleoside phosphorylase with compound Ib are: K m =15 μM K i =19±4 nM K i =25±2 pM k 5 =1.4±0.2×10 −2 sec −1 k 6 =1.8±0.5×10 −5 sec−1 [0298] Inhibition of Human Purine Nucleoside Phosphorylase. Studies similar to those described above for the interaction of bovine purine nucleoside phosphorylase were conducted with purine nucleoside phosphorylase (PNP) from human erythrocytes. The values for the overall inhibition constant, K i , for the interaction of human and bovine PNP with compound Ib are: enzyme K i , compound Ib K i , compound Ic human PNP 72 ± 26 pM 29 ± 8 pM bovine PNP 23 ± 5 pM 30 ± 6 pM [0299] The compound Ic is a more efficient inhibitor for the human enzyme than compound Ib, but compound Ib is slightly more efficient at inhibiting the bovine enzyme. Compounds Ib and Ic are more efficient at inhibiting both PNP enzymes than previously reported compounds. [0300] Summary of Compounds Ib and Ic as Inhibitors of Purine Nucleoside Phosphorylases. Inhibitors usually function by binding at every catalytic site to cause functional inhibition in living organisms. The one-third-the-sites inhibition and the slow-onset tight-binding inhibition described above indicate that compounds Ib and Ic are very potent inhibitors of purine nucleoside phosphorylases able to function in the presence of a large excess of substrate. [0301] The methods for the determination of the kinetic constants are given in detail in Merkler, D. J., Brenowitz, M., and Schramm, V. L. Biochemistry R29 (1990) 8358-8364. Example 25.2 [0302] Oral Availability and in vivo Efficacy of Compound Ib as a PNP Inhibitor. A single oral dose of 10 −7 mole of Compound Ib (27 μg) was administered with food to a young adult male mouse. Blood samples were collected from the tail at times indicated in FIG. 5. Dilution of blood into saline containing 0.2% Triton X-100 (final concentration 0.15%) resulted in lysis of blood cells and release of enzyme. PNP activity was measured with inosine and phosphate as substrates as indicated above. The results establish that Compound Ib is absorbed into the blood and taken up by blood cells to cause PNP inhibition with a half-time (t ½ ) of 14 minutes. Blood samples were taken for an extended time and analyzed for PNP activity to determine the biological t ½ for Compound Ib for inhibitors of blood PNP. The activity of blood PNP recovered with a t ½ of 100 hours. These results establish that Compound Ib is orally available and has an extended period of biological effectiveness. These tests establish that the compounds described herein have favorable pharmacological lifetimes. [0303] Inhibition of Protozan Nucleoside Hydrolases by Compounds Ib and Ic. Protozan parasites use the hydrolysis of purine nucleosides such as inosine to provide purine bases such as hypoxanthine to provide essential precursors for RNA and DNA synthesis. Protozoan parasites are purine auxotrophs. Using inhibition methods similar to those described above, a nucleoside hydrolase from Crithidia fasciculata [Parkin, et al, J Biol, Chem. 266 (1991) 20658] and a nucleoside hydrolase from Trypanosoma brucei brucei [Parkin, J. Biol. Chem. (1996) 21713] were tested for inhibition by compounds Ib and Ic. The inhibition of nucleoside hydrolase from C. fasciculata by Compound Ib is exemplified in FIG. 6. Similar studies indicated that Coumpound Ib and Ic are nanamolar inhibitors for nucleoside hydrolases from C. fasciculata and from T. brucei brucei . Compound Ic (A═CH, B═NH 2 , D═H, X═OH, Y═H, Z═OH) is a nanamolar inhibitor of both enzymes and Compound Va (OR═NH 2 , z′═OH, CO 2 Bu═H or H 2 , and the isopropylidine group removed to form two hydroxyl groups) is also a nanamolar inhibitor of both enzymes. The results are summarised below. K i Values (nM) Compound Compound Compound Compound enzyme source Ia a Ib b Ic b Va b nucleoside 42 ± 2 nM 40 nM 7 nM 3 nM hydrolase C. fasciculata nuceloside 24 ± 3 nM 108 nM 0.9 nM 23 nM hydrolase T. brucei brucei [0304] The inhibitors bind in direct competition with substrate, therefore the K i inhibition constants are direct competitive inhibition values. The compounds provide sufficient inhibition to the purine nucleoside hydrolases to inhibit protozoan parasites at readily accessible pharmacological doses. [0305] The methods and materials used are as described in published PCT international application WO 97/31008 using p-nitrophenyl riboside as substrate. Example 25.3 [0306] Inhibition of Purine Phosphoribisyl Transferases (PPRT) by 5′-Phosphates of Compounds Ib and Ic. Protozoan parasites, human tissues and tumors use PPRT for salvage of purine bases. Interruption of PPRT activity is expected to disrupt purine metabolism in these systems. 5′-phosphorylated Compounds I and Ic were anlyzed for inhibition of PPRT from human and malarial origins. The slow-onset inhibition curve for the 5′-phosphate of Compound Ib with malaria PPRT is illustrated in FIG. 7. The K i * determination for the 5′-phosphate of Compound Ib with malarial PPRT is shown in FIG. 8. Analysis of both human and malarial enzymes with the 5′-phosphates of Compounds Ib and Ic are summarized below. enzyme Compound Ib-5′-phosphate Compound Ic-5′-phosphate source K i K i * K i K i * PPRT human 40 nM 3 nM 14 nM 8 nM PPRT 33 nM 3 nM 48 nM slow onset malaria not observed [0307] Full inhibition studies indicated that the inhibitors are competitive with IMP. The nanamolar inhibition constants for both inhibitors with both enzymes are readily accessible pharmacologic doses of these inhibitors. It is anticipated that the nucleoside kinase activities of human and/or parasitic organisms will convert one or more of the compounds described herein to the respective 5′-phosphates. These compounds thereby provide precursors for pharmacologic doses of the 5′-phosphates for intracellular interruption of PPRT activity. The cellular uptake of Compounds I and Ic have been documented with mice and with human red cells. Example 26 Tablet [0308] 4 grams of the product of Example 1 is mixed with 96 grams of lactose and 96 grams of starch. After screening and mixing with 2 grams of magnesium stearate, the mixture is compressed to give 250 milligram tablets. Example 27 Gelatin Capsule [0309] Ten grams of the product of Example 1 is finely ground and mixed with 5 grams of talc and 85 grams of finely ground lactose. The powder is filled into hard gelatin capsules. Example 28 Preparation of (1R)-1,2,4-trideoxy-1-C-(4-hydroxypyrrolo[3,2-d]pyrimidin-7-yl)-1,4-imino-D-erythro-pentitol Example 28.1 [0310] A solution of (1S)-5-O-tert-butyldimethylsilyl-1-C-cyanomethyl-1,4-dideoxy-1,4-imino-2,3-O-isopropylidene-D-ribitol (1.93 g) in trifluoroacetic acid (20 ml) was allowed to stand at room temperature overnight. The solution was concentrated and a solution of the residue in water was washed (×2) with chloroform and then evaporated to afford (1S)-1-C-cyanomethyl-1,4-dideoxy-1,4-imino-D-ribitol (1.0 g) as the trifluoroacetic acid salt. Example 28.2 [0311] A solution of the crude product from Example 3.1 (1.0 g) in methanol (20 ml) containing di-tert-butyldicarbonate (2.09 g) was adjusted to neutral pH by the addition of triethylamine and stirred at room temperature for 16 h. The solution was concentrated and then chromatography afforded (1S)-N-tert-butoxycarbonyl-1-C-cyanomethyl-1,4-dideoxy-1,4-imino-D-ribitol (0.80 g). Example 28.3 [0312] 1,3-Dichloro-1,1,3,3-tetraisopropyldisloxane (0.9 ml) was added dropwise to a solution of the product from Example 3.2 (0.8 g) and imidazole (0.70 g) in N,N-dimethylformamide (10 ml) at 0° C. The resulting solution was allowed to warm to room temperature, diluted with toluene, washed with water (×3), dried, concentrated and then chromatography afforded (1S)-N-tert-butoxycarbonyl-1-C-cyanomethyl-1,4-dideoxy-1,4-imino -3,5-O-(1,1,3,3-tetraisopropyldisiloxan-1,3-diyl)-D-erythro-pentitol (1.4 g). Example 28.4 [0313] A solution of the product from Example 3.3 (1.5 g) in toluene (20 ml) containing thiocarbonyldiimidazole (0.9 g) was stirred at 90° C. for 2 h. The solution was concentrated and then chromatography afforded (1S)-N-tert-butoxycarbonyl-1-C-cyanomethyl-1,4-dideoxy-2-O-[imidazole(thiocarbonyl)]-1,4-imino-3,5-O-(1,1,3,3-tetraisopropyldisiloxan-1,3-diyl)-D-erythro-pentitol (1.8 g). Example 28.5 [0314] To a solution of the product from Example 28.4 (1.8 g) in toluene (50 ml) was added tri-n-butyltin hydride (1.0 ml) and the solution was heated at 80° C. for 3 h. The solution was concentrated and then chromatography afforded (1S)-N-tert-butoxycarbonyl-1-C-cyanomethyl-1,2,4-trideoxy-1,4-imino-3,5-O-(1,1,3,3-tetraisopropyldisiloxan-1,3-diyl)-D-erythro-pentitol (0.74 g). Example 28.6 [0315] To a solution of the product from Example 3.5 (0.74 g) in N,N-dimethylformamide (10 ml) was added tert-butoxy-bis(dimethylamino)methane (1.5 ml) and the solution was heated at 65-70° C. for 1 h. Toluene (20 ml) was added and the solution was washed (×3) with water, dried and concentrated to dryness. The residue was dissolved in tetrahydrofuran/acetic acid/water (1:1:1 v/v/V, 40 ml) at room temperature. After 1.5 h, chloroform (50 ml) was added and the mixture was washed with water (×2), aqueous sodium bicarbonate, and then dried and evaporated to dryness. Chromatography of the residue gave (1R)-N-tert-butoxycarbonyl-1-C-(1-cyano-2-hydroxyethenyl)-1,2,4-trideoxy-1,4-imino-3,5-O-(1,1,3,3-tetraisopropyldisiloxan-1,3-diyl)-D-erythro-pentitol (0.68 g). Example 28.7 [0316] Glycine hydrochloride ethyl ester (0.90 g) and sodium acetate (1.0 g) were added to a stirred solution of the product from Example 3.6 (0.68 g) in methanol (10 ml). The mixture was stirred at room temperature for 16 h and then concentrated to dryness. Chromatography of the residue gave the (1R)-N-tert-butoxycarbonyl-1-C-[1-cyano-2-(ethoxycarbonylmethylamino)ethenyl]-1,2,4-trideoxy-1,4-imino-3,5-O-(1,1,3,3-tetraisopropyldisiloxan-1,3-diyl)-D-erythro-pentitol (0.80 g) as a diastereomeric mixture. Example 28.8 [0317] A solution of the product from Example 3.7 (0.80 g) in dry dichloromethane (20 ml) containing 1,8-diazabicyclo[5.4.0]undec-7-ene (3.6 ml) and benzyl chloroformate (1.7 ml) was heated under reflux overnight, then cooled and washed with dilute aqueous HCl and then aqueous sodium bicarbonate, dried and concentrated. Chromatography of the residue afforded (1R)-1-C-[3-amino-1-N-benzyloxycarbonyl-2-ethoxycarbonyl-4-pyrrolyl]-N-tert-butoxycarbonyl-1,2,4-trideoxy-1,4-imino-3,5-O-(1,1,3,3-tetraisopropyldisiloxan-1,3-diyl)-D-erythro-pentitol (0.70 g). Example 28.9 [0318] A solution of the product from Example 28.8 (0.28 g) in ethanol (10 ml) was stirred with formamidine acetate (0.50 g) under reflux for 8 h. The solvent was removed and chromatography of the residue gave (1R)-N-tert-butoxycarbonyl-1,2,4-trideoxy-1-C-(4-hydroxypyrrolo[3,2-d]pyrimidin-7-yl)-1,4-imino-3,5-O-(1,1,3,3-tetraisopropyldisiloxa-1,3-diyl)-D-erythro-pentitol (120 mg). Example 28.10 [0319] A solution of the product from Example 28.9 (120 mg) in trifluoroacetic acid (2 ml) was allowed to stand at room temperature overnight. The solution was concentrated and a solution of the residue in water was washed (×2) with chloroform and then evaporated. The residue was dissolved in tetrahydrofuran and treated with tetrabutylammonium fluoride trihydrate (200 mg) and stirred for 1 h. The solvent was evaporated and chromatography gave a residue which was redissolved in methanolic HCl. The resulting precipitate was filtered to afford (1R)-1,2,4-trideoxy-1-C-(4-hydroxypyrrolo[3,2-d]pyrimidin-7-yl)-1,4-imino-D-erythro-pentitol hydrochloride salt as a white solid (17 mg) which darkened but did not melt below 300° C. NMR (300 MHz, D 2 O, d ppm): 13 C 38.8 (C-2′), 53.4 (C-1′), 59.3 (C-5′), 69.1 (C-4′), 71.5 (C-3′), 107.6 (q), 118.6 (q), 130.4 (C-2), 135.9 (q), 144.6 (C-6), and 153.7 (q); 1 H 2.69 (dd, J 14.3 Hz, J 6.4 Hz, H-2′), 2.60 (ddd, J 14.3 Hz, J 12.2 Hz, J 5.7 Hz, H-2″), 3.87 (m, 3H, H-4′, H-5′, 4.57 (m, 1H, H-3′), 5.26 (dd, 1H, J 12.1 Hz, J 6.4 Hz, H-1′), 7.80 (s, H-6) and 8.65 (s, H-2). HRMS (MH + ) calc. for C 11 H 14 N 4 O 3 : 251.1144; found: 251.1143. Example 29 Preparation of (1R)-1-C-(2-amino-4-hydroxypyrrolo[3,2-d]pyrimidin-7-yl)-1,2,4-trideoxy-1,4-imino-D-erythro-pentitol Example 29.1 [0320] A solution of (1R)-1-C-[3-amino-1-N-benzyloxycarbonyl-2-ethoxycarbonyl-4-pyrrolyl]-N-tert-butoxycarbonyl-1,2,4-trideoxy-1,4-imino-3,5-O-(1,1,3,3-tetraisopropyldisiloxan-1,3-diyl)-D-erythro-pentitol (Example 28.8) (0.78 g) in ethanol (10 ml) was stirred with 10% Pd/C (100 mg) in an atmosphere of hydrogen for 1.5 h. The solids and solvent were removed to give a residue (0.62 g). To a solution of this residue in dichloromethane (10 ml) at 0° C. was added a solution (4.8 ml) of benzoyl isothiocyanate in dichloromethane (0.30 ml in 10 ml). After 0.5 h, the solution was warmed to room temperature and 1,8-diazabicyclo[5.4.0]undec-7-ene (0.32 ml) and methyl iodide (0.70 ml) were added. After another 0.5 h the reaction solution was applied directly to a silica gel column and elution afforded 0.67 g of (1R)-1-C-[3-(1-benzamido-1-methylthiomethyleneamino)-2-ethoxycarbonyl-4-pyrrolyl]-N-tert-butoxycarbonyl-1,2,4-trideoxy-1,4-imino-3,5-O-(1,1,3,3-tetraisopropyldisiloxan-1,3-diyl)-D-erythro-pentitol. Example 29.2 [0321] A solution of the product from Example 29.1 (0.67 g) in methanol saturated with ammonia (20 ml) was heated in a sealed tube at 105° C. for 16 h. The solvent was removed and chromatography of the residue afforded (1R)-1-C-(2-amino-4-hydroxypyrrolo[3,2-d]pyrimidin-7-yl)-N-tert-butoxycarbonyl-1,2,4-trideoxy-1,4-imino-3,5-O-(1,1,3,3-tetraisopropyldisiloxan-1,3-diyl)-D-erythro-pentitol (0.30 g). Example 29.3 [0322] A solution of the product from Example 29.2 (300 mg) in trifluoroacetic acid (5 ml) was allowed to stand at room temperature for 16 h. The solvent was removed and the residue was dissolved in tetrahydrofuran, treated with tetrabutylammonium fluoride trihydrate (200 mg) and stirred for 1 h. The solvent was removed and the residue was dissolved in methanol (5.0 ml) and acetyl chloride (0.75 ml) was added dropwise and the reaction allowed to stand at room temperature for 16 h. The reaction was diluted with ether (25 ml) and the resulting crystals were filtered to afford (1R)-1-C-(2-amino-4-hydroxypyrrolo[3,2-d]pyrimidin-7-yl)-1,2,4-trideoxy-1,4-imino-D-erythro-pentitol hydrochloride salt (89 mg), which did not melt below 300° C. NMR (300 MHz, D 2 O d ppm): 13 C 38.8 (C-2′), 53.4 (C-1′), 59.3 (C-5′), 69.1 (C-4′), 71.5 (C-3′), 107.6 (q), 118.6 (q), 130.4 (C-2), 135.9 (q), 144.6 (C-6), and 153.7 (q); 1 H 2.69 (dd, 1H, J 14.3.Hz, J 6.3 Hz, H-2′), 2.63 (ddd, 1H, J 14.1 Hz, J 12.3Hz, J 5.7 Hz, H-2″) 3.88 (m, 3H, H-4′, H-5′) 4.55 (m, 1H, H-3′), 5.14 (dd, 1H, J 12.2 Hz, J 6.3 Hz, H-1′), and 7.63 (s, H-6). Example 30 Preparation of (1S)-1,4,5-trideoxy-1-C-(4-hydroxypyrrolo[3,2-d]pyrimidin-7-yl)-1,4-imino-D-ribitol hydrochloride salt Example 30.1 [0323] A solution of the product from Example 1.5 (0.45 g) in dichloromethane (10 ml) was treated with triethylamine (0.45 ml), 4-dimethylaminopyridine (20 mg) and then methanesulfonyl chloride (0.1 ml). The solution was stirred for 1 h and then washed with 2M aq HCl, aq bicarbonate and processed conventionally. The crude product was dissolved in toluene (10 ml) containing tetrabutylammonium bromide (1.55 g) and the solution was heated at 100° C. for 2 h. The cooled solution was washed with water, and processed to give, after chromatography, (1S)-1-C-(3-amino-1-N-benzyloxycarbonyl-2-ethoxycarbonyl-4-pyrrolyl)-N-tert-butoxycarbonyl-5-bromo-1,4,5-trideoxy-1,4-imino-2,3-O-isopropylidene-D-ribitol (0.27 g). Example 30.2 [0324] A solution of the product from Example 30.1 (0.27 g) in ethanol (10 ml) containing triethylamine (0.19 ml) was stirred with 20% Pd(OH) 2 /C (0.1 g) in a hydrogen atmosphere for 16 h. The solids and solvent were removed and chromatography afforded (1S)-1-C-(3-amino-2-ethoxycarbonyl-4-pyrrolyl)-N-tert-butoxycarbonyl-1,4,5-trideoxy-1,4-imino-2,3-O-isopropylidene-D-ribitol (0.15 g). Example 30.3 [0325] A solution of the product from Example 30.2 (75 mg) in ethanol containing formamidine acetate (0.15 g) was heated under reflux for 4 h. The solvent was removed and chromatography afforded (1S)-N-tert-butoxycarbonyl-1,4,5-trideoxy-1-C-[4-hydroxypyrrolo[3,2-d]pyrimidin-7-yl]-1,4-imino-2,3-O-isopropylidene-D-ribitol (69 mg). Example 30.4 [0326] The product from Example 30.3 (69 mg) was dissolved in trifluoroacetic acid (5 ml) and the solution was allowed to stand at room temperature for 16 h. The solvent was removed and a solution of the residue in 50% aqueous ethanol (10 ml) was treated with Amberlyst A21 base resin until the pH was ˜7. The solids and solvent were removed and the residue was treated with excess aqueous HCl and lyophilized to give (1S)-1,4,5-trideoxy-1-C-(4-hydroxypyrrolo[3,2-d]pyrimidin-7-yl)-1,4-imino-D-ribitol hydrochloride salt (46 mg). 13 C NMR (75 MHz, D 2 O with DCl, d ppm): 155.6 (C), 147.1 (CH), 137.4 (C), 132.6 (CH), 121.0 (C), 108.2 (C), 76.5 (C-3), 75.6 (C-2), 63.2 (C-4), 58.2 (C-1), 18.1 (C-5). Example 31 Preparation of (1S)-1-C-(2-amino-4-hydroxypyrrolo[3,2-d]pyrimidin-7-yl)-1,4,5-trideoxy-1,4-imino-D-ribitol hydrochloride salt. Example 31.1 [0327] A solution of benzoyl isothiocyanate (0.33 ml of 0.4 ml in 5 ml of dichloromethane) was added to the product from Example 5.2 (75 mg) in dichloromethane (5 ml) at 0° C. After 1 h, 1,8-diazabicyclo[5.4.0]undec-7-ene (0.06 ml) and methyl iodide (0.1 ml) were added and the solution was stirred at room temperature for 1 h. Chromatography then afforded 1(S)-1-C-[3-(1-benzamido-1-methylthio-methyleneamino)-2-ethoxycarbonyl-4-pyrrolyl]-N-tert-butoxycarbonyl-1,4,5-trideoxy-1,4-imino-2,3-O-isopropylidene-D-ribitol (0.10 g). A solution of this material in methanol (5 ml) saturated with ammonia was heated in a sealed tube at 95° C. for 16 h and then evaporated. Chromatography afforded (1S)-1-C-(2-amino-4-hydroxypyrrolo[3,2-d]pyrimidin-7-yl)-N-tert-butoxycarbonyl-1,4,5-trideoxy-1,4-imino-2,3-O-isopropylidene-D-ribitol (28 mg). Example 31.2 [0328] The product from Example 31.1 (28 mg) was treated as for Example 30.4 above to give (1S)-1-C-(2-amino-4-hydroxypyrrolo[3,2-d]pyrimidin-7-yl)-1,4,5-trideoxy-1,4-imino-D-ribitol hydrochloride salt (16 mg). 13 C NMR (75 MHz, D 2 O with DCl, d ppm): 156.5 (C), 153.5 (C), 135.8 (C), 131.7 (CH), 114.9 (C), 105.6 (C), 76.7 (C-3), 75.7 (C-2), 63.4 (C-4), 58.1 (C-1), 18.4 (C-5). Example 32 Preparation of (1S)-1-C-(4-aminopyrrolo[3,2-d]pyrimidin-7-yl)-1,4-dideoxy-1,4-imino-D-ribitol hydrochloride salt Example 32.1 [0329] A solution of the product from Example 1.3 (0.15 g) in methanol (5 ml) containing amincacetonitrile (0.12 g) and sodium acetate (0.20 g) was heated under reflux for 4 h and then concentrated. Chromatography afforded 1(S)-N-tert-butoxycarbonyl-5-O-tert-butyldimethylsilyl-1-C-(1-cyano-2-cyanomethylamino-ethenyl]-1,4-dideoxy-1,4-imino-2,3-O-isopropylidene-D-ribitol (0.12 g) as a diastereomeric mixture. A solution of this material in dichloromethane (10 ml) containing 1,8-diazabicyclo[5.4.0]undec-7-ene (0.7 ml) and benzyl chloroformate (0.33 ml) was heated under reflux for 1 h. Conventional processing and chromatography afforded (1S)-1-C-(3-amino-1-N-benzyloxycarbonyl-2-cyano-4-pyrrolyl)-N-tert-butoxycarbonyl-5-O-tert-butyldimethylsilyl-1,4-dideoxy-1,4-imino-2,3-O-isopropylidene-D-ribitol (0.125 g). Example 32.2 [0330] A solution of the product from Example 32.1 (0.125 g) in ethanol (10 ml) was stirred in an atmosphere of hydrogen with 10% Pd/C (20 mg) for 0.5 h. The solids were removed, formamidine acetate (0.21 g) was added to the filtrate and the solution was heated under reflux for 16 h and then concentrated. Chromatography of the residue gave (1S)-1-C-(4-aminopyrrolo[3,2-d]pyrimidin-7-yl)-N-tert-butoxycarbonyl-5-O-tert-butyldimethylsilyl-1,4-dideoxy-1,4-imino-2,3-O-isopropylidene-D-ribitol (80 mg). Example 32.3 [0331] The product from Example 32.2 (80 mg) was treated as for Example 30.4 above to give (1S)-1-C-(4-aminopyrrolo[3,2-d]pyrimidin-7-yl)-1,4-dideoxy-1,4-imino-D-ribitol hydrochloride salt (35 mg). 13 C NMR (75 MHz, D 2 O with DCl, d ppm): 152.1 (C), 146.2 (CH), 140.7 (C), 135.3 (CH), 115.4 (C), 107.7 (C), 76.0 (C-2), 73.1 (C-3), 68.4 (C-4), 61.3 (C-5), 58.3 (C-1). Example 33 Preparation of (1S)-1-C-(2-amino-4-hydroxypyrrolo[3,2-d]pyrimidin-7-yl)-1,4-dideoxy-1,4-imino-D-ribitol 5-phosphate bis-ammonium salt [0332] The product from Example 2.2 (0.13 g) in dry acetonitrile (6 ml) containing tetrazole (0.105 g) was stirred at room temperature while N,N-diethyl-1,5-dihydro-2,4,3-benzodioxaphosphepin-3-amine was added slowly dropwise until t.l.c. indicated complete reaction, then meta-chloroperbenzoic acid (60 mg) was added followed by further small quantities of the oxidant until t.l.c. indicated the initial product was fully reacted. Chloroform was added and the solution was washed with aqueous sodium bicarbonate, dried and concentrated. Chromatography afforded the phosphate ester (190 mg) which was stirred in ethanol (10 ml) in an atmosphere of hydrogen with 10% Pd/C (80 mg) for 1 h. The solids and solvent were removed and the residue was dissolved in trifluoroacetic acid (5 ml) and allowed to stand at room temperature for 16 h. The solution was concentrated by evaporation and the residue in water was applied to a column of Amberlyst A15 acid resin. The column was washed with water and then with 2M aqueous ammonia to elute the product. Concentration and trituration of the residue with water afforded (1S)-1-C-(2-amino-4-hydroxypyrrolo[3,2-d]pyrimidin-7-yl)-1,4-dideoxy-1,4-imino-D-ribitol 5-phosphate bis-ammonium salt (50 mg), referred to as the 5′-phosphate of compound Ib. 13 C NMR (75 MHz, TFA-D, d ppm): 146.9 (C), 144.0 (C), 127.0 (C), 124.5 (CH), 105.1 (C), 95.6 (C), 66.3 (CH), 64.0 (CH), 59.2 (CH), 56.2 (CH 2 ), 50.2 (CH). Example 34 Preparation of (1S)-1,4,5-trideoxy-5-fluoro-1-C-(4-hydroxypyrrolo[3,2-d]pyrimidin-7-yl)-1,4-imino-D-ribitol hydrochloride salt Example 34.1 [0333] To a solution of the product from Example 1.2 (1.48 g) in tetrahydrofuran (10 ml) was added tetrabutylammonium fluoride (6 ml, 1M in THF). After 2 h the solution was evaporated and chromatography of the residue afforded (1S)-N-tert-butoxycarbonyl-1-C-cyanomethyl-1,4-dideoxy-1,4-imino-2,3-O-isopropylidene-D-ribitol (1.15 g). A solution of 0.84 g of this material in dichloromethane (20 ml) containing triethylamine (1.0 ml) was stirred while diethylaminosulfur trifluoride (0.36 ml) was added. After 2 h, methanol (1 ml) was added and the solution was evaporated. Chromatography gave (1S)-N-tert-butoxycarbonyl-1-C-cyanomethyl-1,4,5-trideoxy-5-fluoro-1,4-imino-2,3-O-isopropylidene-D-ribitol (0.36 g). Example 34.2 [0334] The product from Example 34.1 (0.36 g) was treated in the same manner as described for examples 1.3 and then 1.4 and 1.5 above to give (1S)-1-C-(3-amino-1-N-benzyloxycarbonyl-2-ethoxycarbonyl-4-pyrrolyl)-N-tert-butoxycarbonyl-1,4,5-trideoxy-5-fluoro-1,4-imino-2,3-O-isopropylidene-D-ribitol (0.23 g). Example 34.3 [0335] The product from Example 34.2 (0.12 g) was treated as described for examples 1.6 and then 1.7 above to give, after lypohilization, (1S)-1,4,5-trideoxy-5-fluoro-1-C-(4-hydroxypyrrolo[3,2-d]pyrimidin-7-yl)-1,4-imino-D-ribitol hydrochloride salt (43 mg). 13 C NMR (75 MHz, D 2 O with DCl, d ppm): 146.8 (CH), 132.6 (CH), 83.0 (J C,F 169 Hz, C-5), 76.1 (C-2), 72.7 (C-3), 66.4 (J C,F 18 Hz, C-4), 59.0 (C-1). Example 35 (1S)-1-C-(3-amino-2-carboxamido-4-pyrrolyl)-1,4-dideoxy-1,4-imino-D-ribitol Example 35.1 [0336] Hydrogen peroxide (0.5 ml) was added dropwise to a solution of the product from Example 32.1 (90 mg) and potassium carbonate (50 mg) in dimethylsulfoxide (1.0 ml). The reaction was stirred for 10 minutes, diluted with water (50 ml), extracted with ethyl acetate (3×20 ml), and the combined organic layers dried and concentrated. Chromatography of the resulting residue afforded (1S)-1-C-(3-amino-2-carboxamido-4-pyrrolyl)-N-tert-butoxycarbonyl-5-O-tert-butyldimethylsilyl-1,4-dideoxy-1,4-imino-2,3-O-isopropylidene-D-ribitol (20 mg). Example 35.2 [0337] A solution of the product from Example 35.1 (20 mg) in trifluoroacetic acid (1 ml) was allowed to stand at room temperature for 16 h. The solvent was removed and the residue in water (20 ml) was washed with dichloromethane (2×5 ml). The aqueous layer was evaporated and chromatography afforded (1S)-1-C-(3-amino-2-carboxamido-4-pyrrolyl)-1,4-dideoxy-1,4-imino-D-ribitol (10 mg). NMR (300 MHz, D 2 O): 13 C 59.3 (C-4′), 64.0 (C-5′), 67.7 (C-1′), 74.4 (C-3′), 77.6 (C-2′), 113.2 (q), 124.1 (C-5), 126.2 (q) 141.0 (q), and 168.7 (q). HRMS (MH + ) calc. for C 10 H 17 N 4 O 4 : 257.12498; found: 257.12535. Example 36 Preparation of (1S)-1,4-dideoxy-1-C-(2,4-dihydroxypyrrolo-[3,2-d]pyrimidin-7-yl)-1,4-imino-D-ribitol Example 36.1 [0338] 2,4-Dihydroxy-6-methyl-5-nitropyrimidine (G. N. Mitchell and R. L. McKee, J. Org. Chem., 1974, 39, 176-179) (20 g) was suspended in phosphoryl chloride (200 ml) containing N,N-diethylaniline (20 ml) and the mixture was heated under reflux for 2 h. The black solution was concentrated to dryness and the residue was partitioned between water (600 ml) and ether (150 ml). The aqueous phase was further extracted with ether (150 ml) and the combined organic phases were washed with aqueous sodium bicarbonate and processed conventionally to give 2,4-dichloro-6-methyl-5-nitropyrimidine (23.1 g). Example 36.2 [0339] To a solution of the product of Example 36.1 (17 g) in benzyl alcohol (80 ml) was added a 1.1 M solution of sodium benzylate in benzyl alcohol (199 ml). After 1 h at room temperature, ether (500 ml) was added and the solution was washed with water. The organic phase was dried and concentrated to dryness under high vacuum. The crude residue in dry N,N-dimethylformamide (100 ml) and N,N-dimethylformamide dimethyl acetal (25 ml) was heated at 100° C. for 3 h and then the solution was concentrated to dryness. Trituration of the residue with ethanol and filtration afforded 2,4-dibenzyloxy-6-(2-dimethylaminovinyl)-5-nitropyrimidine as an orange solid (24.5 g) Example 36.3 [0340] Zinc dust (30 g) was added to a solution of the product from Example 36.2 (20 g) in acetic acid (300 ml) with cooling to control the exotherm. The resulting mixture was then stirred for 2 h, filtered, and the filtrate was concentrated to dryness. The residue was partioned between chloroform and aqueous sodium bicarbonate, the organic layer was dried and then concentrated to dryness to give a solid residue of 2,4-dibenzyloxypyrrolo[3,2-d]pyrimidine (15.2 g) Example 36.4 [0341] Sodium hydride (0.5 g, 60% dispersion in oil) was added to a solution of the product from example 36.3 (2.0 g) in tetrahydrofuran (40 ml) followed by tert-butyldimethylsilyl chloride (1.37 g) and the mixture was stirred for 1 h. The reaction was quenched with dropwise addition of water and then partitioned between ether (100 ml) and water (150 ml). The organic phase was dried and concentrated to dryness. A solution of the residue in dichloromethane (40 ml) was stirred while N-bromosuccinimide added slowly poriton-wise until t.l.c. analysis indicated complete conversion to a less polar product. The solution was washed with water, aqueous sodium bicarbonate, dried and concentrated. Chromatography of the residue afforded 2,4-dibenzyloxy-7-bromo-9-N-tert-butyldimethylsilylpyrrolo[3,2-d]pyrimidine as a white solid (1.8 g). Example 36.5 [0342] An imine was prepared from 5-O-tert-butyldimethylsilyl-1,4-dideoxy-1,4-imino-2,3-O-isopropylidene-D-ribitol (0.30 g) by N-chlorination with N-chlorosuccinimide followed by elimination of hydrogen chloride with lithium tetramethylpiperidide as described in Example 1.1, but with the following modifications: (i) when addition of the solution of lithium tetramethylpiperidide was complete, petroleum ether was added and the solution was washed with water, dried and concentrated to dryness; (ii) the residue was chromatographed on silica gel eluted with 0.2% triethylamine and 30% ethyl acetate in hexanes to afford the pure imine (0.215 g). A solution of this imine in ether (2 ml) was added to a solution prepared by slow addition of butyllithium (1.4 M in hexanes) to a solution of the product from Example 36.4 (0.786 g) in anisole (20 ml) and ether (30 ml) at −70° C. until t.l.c. analysis indicated lithium exchange with the starting material was complete. The mixture was allowed to slowly warm to ˜15° C., and then was washed with water, dried and concentrated. Chromatography of the residue afforded (1S)-1-C-)2,4-dibenzyloxy-9-N-tert-butyldimethylsilylpyrrolo[3,2-d]pyrimidin-7-yl)-5-O-tert-butyldimethylsilyl-1,4-dideoxy-1,4-imino-2,3-O-isopropylidene-D-ribitol (0.225 g). Example 36.6 [0343] A solution of the product from Example 36.5 (0.10 g) in ethanol (5 ml) was stirred in a hydrogen atmosphere with 10% palladium on charcoal (0.05 g) for 2 h. The solids and solvent were removed and concentrated aqueous hydrochloric acid (1 ml) was added to a solution of the residue in methanol (5 ml). After standing overnight, the solution was concentrated to dryness and the residue was extracted with ether and then triturated with ethanol and filtered to give (1S)-1,4-dideoxy-1-C-)2,4-dihydroxypyrrolo[3,2-d][pyrimidin-7-yl)-1,4-imino-D-ribitol hydrochloride (0.025 g). 13 C NMR (D 2 O), δ (ppm): 159.8 (C), 155.8 (C), 137.1 (C), 131.4 (CH), 114.2 (C), 104.1 (C), 76.2 (CH), 73.7 (CH), 68.5 (CH) 61.6 (CH 2 ) and 58.5 (CH). Example 37 Preparation of 1,4-dideoxy-(1S)-1-C-(2,4-dihydroxypyrrolo-[3,2-d]pyrimidin-7-yl)-1,4-imino-D-ribitol 5-phosphate bis-ammonium salt Example 37.1 [0344] A solution tetrabutylammonium fluoride (1 M, 0.5 ml) was added to a solution of the bis-silylated product from Example 36.5 (110 mg) in tetrahydrofuran. After 2 h, the solution was diluted with toluene, washed with water (×2), dried, and evaporated to dryness. The resulting syrup was dissolved in methanol and tert-butoxycarbonic anhydride (65 mg) was added. After 30 min, the reaction mixture was concentrated to dryness and subjected to chromatography to give (1S)-1-C-(2,4-dibenzyloxypyrrolo[3,2-d]pyrimidin-7-yl)-N-tert-butoxycarbonyl-1,4-dideoxy-1,4-imino-2,3-O-isopropylidene-D-ribitol (64 mg). Example 37.2 [0345] The product for Example 37.2 (64 mg) was converted by the method detailed in Example 33 into, 1,4-dideoxy-(1S)-1-C-(2,4-dihydroxypyrrolo[3,2-d]pyrimidin-7-yl)-1,4-imino-D-ribitol 5-phosphate bis-ammonium salt (11 mg); 13 C-NMR (D 2 O), δ (ppm): 156.0 (C), 151.9 (C), 134.0 (C), 127.3 (CH), 110.9 (C), 102.8 (C), 75.1 (CH), 70.4 (CH), 65.1 (CH), 61.9 (CH 2 ), and 54.5 (CH). [0346] Aspects of the invention have been described by way of example only and it should be appreciated that modifications and additions thereto may be made without departing from the scope of the invention.	The present invention provides novel nucleoside-analogue compounds that are effective inhibitors of purine nucleoside phosphorylase (PNP), purine phosphoribosyltransferases (PPRT), and/or nucleoside hydrolases. Also provided are tautomers, esters, prodrugs, and pharmaceutically-acceptable salts of the compounds disclosed herein. The present invention further provides the use of these compounds as pharmaceuticals. The present invention also discloses pharmaceutical compositions containing these compounds. Finally, the present invention provides processes for preparing these compounds.	2
BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a lifting apparatus for use in assembling a building at an elevated spot, painting and the like at the elevated spot, lifting operators or materials upward for operation at the elevated spot or loading and unloading disused building materials at the building work, particularly to the lifting apparatus capable of lifting a platform to the elevated spot irrespective of the short length of a lifting mechanism at folding state and of preventing wires, chain for connecting each boom from being broken. 2. Prior Art There has been employed a lifting apparatus for assembling, painting, repairing a building, and the like at an elevated spot, which apparatus is capable of lifting or lowering for loading operators or building materials and the like thereon or unloading the disused materials therefrom. There has been employed a pantograph type telescopic mechanism, i.e. scissors type comprising a first pair of arms pivotally connected with each other at a central portion thereof and plural pairs of arms connected with the first pair of arms. In this apparatus, it was necessary to lengthen the length of the pairs for increasing the maximum height of the apparatus. Hence, if an apparatus capable of lifting upward as high as possible is-designed, it was necessary to employ a plurality of paired pantographs, which entails increasing the height of the apparatus when folded whereby it is more troublesome for an operator to get thereon or thereoff or to load materials thereon or unload materials therefrom. There have been various proposed arrangements to solve the problems set forth above, for example the one as disclosed in U.S. Pat. No. 3 820 631. In a mechanism as proposed by this patent, a lower boom and an upper boom are respectively capable of moving linearly into a middle boom, the lower boom is pivotally mounted on a chassis at the end thereof, the upper boom is pivotally mounted on a platform at the end thereof, and these booms are assembled to form an X-shape. In this mechanism, inasmuch as the length of the boom per se becomes long, the height of the platform when folded can be decreased and the platform can be raised to the elevated spot. However, in this known mechanism, inasmuch as the mechanism for extending the lower boom and upper boom from the middle boom comprises a screw and a thread for engaging with this screw, the telescopic moving speed of the lower and upper booms relative to the middle boom is slow, and hence the platform cannot be moved quickly. Furthermore, since the sliding motion of the lower boom and the upper boom is made by a bevel gear provided at the central portion of the middle boom, the entire length of the combination of the lower boom and the upper boom extending from the middle boom reaches a length only half as long as the middle boom, and hence the mechanism has such a structure that the platform cannot be raised as high as possible. There has also been proposed a mechanism wherein another boom is inserted into a boom to extend the length thereof so that the entire length thereof is lengthened. For example, in FIG. 4 of Japanese Patent Laid-Open Publication No. 53-19556, lower and upper booms respectively having small diameters are inserted into a middle boom having a large diameter so that the lower and upper booms inserted into the middle boom are pulled out to lengthen the entire length of the booms, whereby the platform is raised high. However, in this latter mechanism, there is no mechanism for synchronizing the amount of extension and contraction of the lower boom pulled out from the middle boom with that of the upper boom as also pulled out from the middle boom. The lower and the upper booms move individually relative to the middle boom. The amount of extension and contraction is restricted by a link mechanism comprising bars, and hence the complete synchronization of the lower and upper booms relative to the middle boom cannot be achieved. Accordingly, the lower and upper booms cannot be connected to the platform by a pin and the like and a non-synchronized error of the amount of the extension and contraction between the lower and upper booms relative to the middle boom can be absorbed by rollers contacting the chassis and the platform. Hence, the platform is liable to swing because of accumulation of jolt caused by many supporting fulcrums and reception of the rolling motion by the roller. As a result, the mechanism is liable to swing due to wind and the like and is unstable, thereby causing the operator to feel anxious. To solve the drawbacks set forth above, there has been proposed a mechanism as disclosed in Japanese Patent Application No. 56-41289. In this application, lower and upper booms are inserted into a middle boom while both the lower and upper booms are connected by coupling means at one end thereof and the movable direction of the coupling means can be turned by a turning means pivotally mounted on the middle boom. In this latter mechanism, inasmuch as the upper boom is pulled out from the middle boom at the same time when the lower boom is extracted from the middle boom and the movable amount of the lower and upper booms are restricted by the coupling means, the movable amount of the lower boom equals that of the upper boom, and hence a pair of middle booms supported by the lower and upper booms at the center thereof turns in an X-shape to thereby raise the platform vertically upward. In this mechanism, since the lower and upper booms are accommodated in the middle boom, it is possible to stretch the entire length of the booms about three times as long as the length of the middle boom when the lower and upper booms are respectively pulled out, hence the platform can be raised high. The above lifting apparatus is characterized in comprising a pair of X-shaped middle booms having upper and lower openings, upper and lower booms being pulled out from the middle boom through the upper and lower openings wherein the lower boom is connected to the chassis and the upper boom is connected with the platform. The mechanism has an X-shape if viewed from the side thereof. In this mechanism, it is possible to decrease the height of the mechanism when folded such as a scissors-type mechanism and secure the platform against swinging since the respective distal ends of the lower and upper booms are connected by the pins with the chassis and the platform, which enhances the safety. Furthermore, inasmuch as the lengths of the lower and upper booms can be substantially the same as the length of the middle boom, there are many advantages such as the platform can be raised high and the height for raising the platform can be increased compared with the entire lengths of the booms when folded. However, there occurred the following first problem. That is, the conventional X-type lifting apparatus has a structure to extend and contract in three stages since the lower and upper booms are inserted into the middle boom. To increase the height of the platform, it is necessary to design the length of the middle boom to be set to be longer. Thus, the platform can be raised high by lengthening the middle boom. However, the entire length of the chassis accommodating the middle boom is lengthened, which entails drastic change in the design of the lifting apparatus. Hence, the height of the lifting apparatus to be raised is determined by the length of the middle boom and the entire length of the chassis which are great obstacles. Accordingly, there is desired a development of the lifting apparatus capable of lifting the platform as high as possible while permitting the middle boom to have the same length as the conventional mechanism. Next, in the aforesaid apparatus, there occurred the following second problem. That is, it was necessary to connect the middle boom to the upper and lower booms by wires or chains or the like for synchronizing the upper and lower booms relative to the middle booms. The length of the lower boom pulled out from the middle boom is synchronous with the movable length of the upper boom by connecting the upper end of the lower boom and the lower end of the lower boom with the wires, chains and the like, whereby the lifting mechanism is always maintained to form the X-shape. Although it is very simple in this arrangement to synchronize with use of wires, chains and the like, it was necessary to set the safety load toward the tensile stress in view of preventing an accident. In setting the safety load, the safety load is insignificant when the ratio of height of the lifting mechanism when folded relative to that when raised at the maximum is small. However, if the same ratio is large, the design of the safety load becomes a very significant matter. That is, when the platform is raised to an elevated spot, the angle of inclination of the booms relative to the horizontal is large and a component of the force of the load applied to the platform is not large. Hence, the tensile strength applied to the wires for connecting the lower boom to the upper boom is not excessive. However, when the platform is lowered, the angle of inclination of the booms relative to the horizontal becomes small and the component of the force of the load applied to the platform becomes large. This component of the force of the load is applied directly to the wires or chains serving for synchronization, hence the tensile strength becomes very strong. Accordingly, if the safety factor of the load applied to the wires, chains or the like is set to be small, there is a likelihood of generating such an accident load that the wires, chains or the like are broken by the component of the force. When the wires, chains or the like for connecting the lower boom with the upper boom are broken, the platform lowers suddenly which can cause injury or damage. Accordingly, wires, chains or the like having low safety factor do not generate any problem when they are used for synchronization at the state where they are raised high but they become one of the reasons of generating accidents when the platform is lowered which increases the component of the force of the load, thereby possibly breaking the wires, chains or the like. To prevent generation of such accidents, it is preferable to increase the safety factor and set the safety load of the wires, chains or the like to a large value. If the wires, chains or the like becomes thick to increase the safety factor, the wires becomes too thick, in the worst case, to function as the lifting apparatus due to deterioration in flexibility thereof. SUMMARY OF THE INVENTION It is therefore an object according to a first aspect of the present invention to provide a lifting apparatus capable of obviating the first problem set forth above. A gist of the present invention is to extend and contract the telescopic boom in five stages while keeping the synchronization therebetween so that the platform can be raised to an elevated spot higher than that made possible by the conventional three stage booms. The platform when contracted and folded is low in its height and can be lowered to a height which is the same as that of a conventional platform, which thus facilitates loading and unloading of an operator as well as materials. It is also an object according to a second aspect of the present invention to provide the lifting apparatus with a kick or support mechanism employed for initial lifting of the lifting mechanism, which kick mechanism can support auxiliarily the load of the platform at the position where the platform is lowered halfway. When the platform lowers and the angle of inclination of the boom is small and the component of the force of the load is increased, the load can be decomposed by the kick mechanism. Accordingly, even if the platform lowers at a position adjacent to the lowest position where the component of the force is increased to the greater extent close to infinity, the drawing force to be applied to the wires does not increase, whereby the safety factor of the wires, chains or the like can be set relatively low. To achieve the object of the lifting apparatus according to the first aspect of the present invention, the lifting apparatus comprises a movable chassis, a platform disposed over the chassis and capable of raising and lowering, a lifting mechanism disposed between the chassis and the platform for raising the platform, a pair of X-shaped middle booms the centers of which are pivoted and capable of turning, lower middle booms slidably telescopically inserted into the middle booms along the longitudinal direction thereof from the lower end openings of the middle booms, lower booms slidably telescopically inserted into the lower middle booms from the lower end openings of the lower middle booms and connected to the chassis at the lower ends thereof, upper middle booms telescopically inserted into the middle booms along the longitudinal direction thereof from the upper end opening of the middle booms, and upper booms telescopically inserted into the upper middle booms from the upper end openings of the upper middle booms and connected with the lower surface of the platform at the upper ends thereof. To achieve the object of the lifting apparatus according to the second aspect of the present invention, the lifting apparatus comprises a movable chassis, a platform disposed over the chassis and capable of raising and lowering, a pair of X-shaped middle booms the centers of which are pivoted and capable of turning, lower booms movable along the longitudinal direction of the middle booms and connected to the chassis at the ends thereof, upper booms movable along the longitudinal direction of the middle booms and connected to the platform at the upper ends thereof, a kick or support mechanism fixed on the chassis for lifting the centers of the middle booms and a detecting means for detecting the contact between the middle booms and the kick mechanism, the kick mechanism lowers while supporting the load of the middle booms upon reception of a detecting signal issued when the detecting means detects that the middle booms contact the upper end of the kick mechanism. The above and other objects, features and advantages of the present invention will become more apparent from the following description taken in conjunction with the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a side view of a lifting apparatus according to a first embodiment of the present invention in which a platform is at its lowest position; FIG. 2 is a front view of the lifting apparatus in FIG. 1; FIG. 3 is a side view of the lifting apparatus in FIG. 1 in which the platform is raised to its uppermost position; FIG. 4 is a schematic perspective view to assist in explaining a stretch mechanism; FIG. 5 is a cross sectional view to assist in explaining the structure of the middle booms; FIG. 6 is a plan view to assist in explaining the arrangement of the middle booms in the lifting mechanism; FIG. 7 is a cross sectional view taken along the line 7--7 in FIG. 6; FIG. 8 is an exploded perspective view showing a structure of the bearing mechanism; FIG. 9 is a view to assist in explaining the synchronous mechanism in the stretchable boom assembly; FIG. 10 is a perspective partially cross sectional view to assist in explaining the structure of an operation mechanism; FIG. 11 is an exploded perspective view showing the relation between a kick mechanism and a kick receiver employed according to the present invention; FIG. 12 is a view showing a hydraulic control circuit in the stretch mechanism; FIG. 13 is a view showing an electric circuit for controlling solenoid valves in the hydraulic circuit in FIG. 12; FIG. 14 is a view showing a hydraulic control circuit according to a second embodiment of the present invention; and FIG. 15 is a view showing an electric circuit for controlling solenoid valves in the hydraulic circuit in FIG. 14. DESCRIPTION OF THE PREFERRED EMBODIMENT First Embodiment (FIG. 1 to FIG. 13) A lifting apparatus according to a first embodiment of the present invention will be described with reference to FIGS. 1 to 13. The lifting apparatus comprises a movable chassis 1 having front wheels 2 and rear wheels 3 supported thereon, a lifting mechanism 4 mounted on an upper surface of the chassis 1, and a platform 5 disposed over the lifting mechanism 4 and having a handrail 6 fixed thereon. Fixed to the upper surface of the chassis 1 is a kick mechanism 7 for effecting an initial lifting of the lifting mechanism 6. The lifting mechanism 4 comprises a pair of stretch boom assemblies each comprising two stretch booms 10. The stretch boom 10 comprises a middle boom 11, lower middle boom 12, lower boom 13, upper middle boom 14 and upper boom 15. One pair of middle booms 11 among the stretch boom assembly are pivoted together in an X-shape at the inner central position thereof so that the middle booms 11 can pivot relative to one another. The lower middle booms 12 are inserted into the middle booms 11 from the lower end openings of the middle booms 11 so that the lower middle booms 12 can telescopically move in the longitudinal direction of the middle booms 11, and the lower booms 13 are inserted into the lower middle booms 12 from the lower end openings thereof so that the lower booms 13 can telescopically move along the longitudinal direction thereof. There are fixed coupling members 16 at the lower ends of the lower booms 13 which are pivotally coupled to members 17 fixed to the chassis 1 at the front and rear portions thereof. The upper middle booms 14 are inserted into the middle booms 11 from upper end openings thereof so as to slide in the middle booms 11 in the longitudinal direction thereof. The upper booms 15 are inserted into the upper middle booms 14 from upper end openings thereof so as to telescopically move into the upper middle booms 14 in the longitudinal direction thereof. The upper booms 15 have coupling members 18 at the upper ends thereof which are pivotally coupled to members 19 which are fixed to the lower surface of the platform 5 at the front and rear portions thereof. The front-to-rear interval between the fixed members 17 is the same as the front-to-rear interval between the fixed members 19, whereby the platform 5 can rise upward while the chassis 1 and the platform 5 are maintained parallel with one another when the telescopic booms 10 turn to form the X-shape. There are provided operating mechanisms 20 between the fixed members 17 and the lower middle booms 12. The operating mechanisms comprise hydraulic cylinders or guide mechanisms, details of which will be described later. FIGS. 4 to 8 show the internal structure of the lifting mechanism 4, i.e. the internal structure or the combinations of the elements of the telescopic body or booms 10 which will be described in detail later. The middle booms 11, the lower middle booms 12, the lower booms 13, the upper middle booms 14 and the upper booms 15 respectively form the telescopic bodies 10 and are made from thin metal plate by folding thereof for forming long hollow tubes which are rectangular in cross section. The middle booms 11 are rectangular in cross section and have a partition plate 25 for dividing the interior into two interior spaces which extend along the longitudinal direction thereof. The lower middle boom 12 is slidably inserted in one of the inner spaces. The lower middle boom 12 is structured as a hollow tube which is substantially rectangular in cross section. The lower boom 13 is slidably inserted into the lower middle boom 12. The lower boom 13 is also structured as a hollow tube of substantially rectangular cross section. The upper middle boom 14 is slidably inserted into the other inner space of the middle boom 11. The upper middle boom 14 is a hollow tube of substantially rectangular cross section. The upper boom 15 is slidably inserted into the upper middle boom 14 and a hollow tube of substantially rectangular cross section. The telescopic booms comprising the combination of the booms are disposed to be parallel with each other as shown in FIG. 6. In the same figure, four telescopic booms 10 are arranged in which the inner middle booms 11-B and 11-C are spaced from each other at a relatively large interval and a kick receiver 26 is intervened between the inner middle booms 11-B and 11-C at the central portions thereof. The kick receiver 26 contacts the upper end of the kick mechanism 7. Reinforcing rods 27 and 28 are fixedly provided between the inner middle booms 11-B and 11-C at the upper and lower portions thereof. There is formed a lattice shaped structure by the middle booms 11-B, 11-C, the kick receiver 26, and the reinforcing rods 27 and 28. There is provided a bearing mechanism 29 between the middle booms 11-A and 11-B at the central portion thereof whereby the middle booms 11-A and 11-B can be freely turned relative to one another. Similarly, the middle booms 11-C and 11-D are also coupled with each other to be freely turned. There is provided a reinforcing rod 30 fixed between the pair of middle booms 12 adjacent the lower ends thereof, and a reinforcing rod 31 fixed between the pair of upper middle booms 14 adjacent the upper ends thereof. The lower middle booms 12 and the upper middle booms 14 are slidable in synchronization with each other. A reinforcing rod 32 is coupled between the middle booms 11-A and 11-D at the upper end portions thereof and extends under the middle booms 11-B and 11-C. A reinforcing rod 33 is fixed between the middle booms 11-A and 11-D at the upper end portions thereof and extends over the middle booms 11-B and 11-C. Hence, the middle booms 11-A and 11-D are assembled in the shape of a lattice intervening the reinforcing rods 32 and 33 at the both end portions thereof and the assembled body is formed as a rigid structure by the combination of the middle booms 11-A and 11-D and the reinforcing rods 32 and 33. A reinforcing rod 34 is fixed between the lower middle booms 12 telescopically extending from the middle booms 11-A and 11-D and extending under the middle booms 11-B and 11-C for reinforcing both the lower middle booms 12. A reinforcing rod 35 is fixed between the upper middle booms 14 telescopically extending from the middle booms 11-A and 11-D and extending under the middle booms 11-B and 11-C, and the upper middle booms 14 are reinforced by the reinforcing rod 35. FIG. 7 is a cross sectional view taken along the line X--X in FIG. 6 and showing the relation between each of the middle booms 11-A, 11-B, 11-C, 11-D and the bearing mechanism 29. FIG. 8 is an exploded perspective view showing an arrangement of the bearing mechanism 29. The bearing mechanism 29 permits the two middle booms 11-A and 11-B to turn or pivot relative to one another and includes a ring shaped bearing washer 40 which is brought into contact with an outer side surface of the middle booms 11-A and 11-B. The bearing washer 40 has a circular guide groove 41 defined in an inner peripheral wall thereof and a plurality of screw holes 42 defined on the peripheral surface thereof. The bearing washer 40 is disposed coaxially with the kick receiver 26 at the central axis thereof and brought into contact with the side surface of the middle boom 11-B and screwed thereto by inserting the screws 43 into the screw holes 42. There is fixed a ring-shaped washer plate 44 at the inner side surface of the middle boom 11-A at the central portion thereof, which seat plate 44 has a plurality of screw holes 45 defined at the peripheral surface thereof. A plurality of sliding retainer elements 46 are engaged in the guide groove 41 and have cylindrical hubs which are brought into alignment with the screw holes 45. The retainers 46 are fixed to the washer plate 44 by screws 47. Inasmuch as the retainers 46 are engaged in the peripheral guide groove 41 and are thereafter fixed to the washer plate 40 by the screws 47, the washer plate 44 and the bearing washer plate 40 are assembled so as to be rotatable relative to one another. FIG. 9 shows a mechanism for synchronizing the lower middle boom 12, the lower boom 13, the upper middle boom 14 and the upper boom 15 relative to the middle boom 11 in the telescopic boom body 10. According to the first embodiment of the present invention, the amount of telescopic movement of the lower middle boom 12 relative to the middle boom 11 shall be the same as that of the upper middle boom 14 relative to the middle boom 11. In the same way, the amount of telescopic movement of the lower boom 13 relative to the lower middle boom 12 shall be the same as that of the upper boom 15 relative to the upper middle boom 14. That is, it is indispensable that the platform 5 is raised vertically while the platform 5 is maintained in parallel with the ground as illustrated in FIG. 3. In FIG. 9, one of the four telescopic boom bodies 10 is exemplified but the other three telescopic booms 10 have same structures. FIG. 9 is, as set forth above, the positional relation between the lower boom 13 and the upper boom 15 but is slightly different from the actual mechanism. There is provided a pulley 50 rotatably supported in the inside of the upper portion of the middle boom 11. A wire 51 is wound around the pulley 50 for synchronizing the lower middle boom 12 and the lower boom 13 with the upper middle boom 14 and the upper boom 15 relative to the middle boom 11 and has one end coupled to an upper end of the lower middle boom 12 and the other end coupled to a lower end of the upper middle boom 14. In such a mechanism, the lower middle boom 12 and the upper middle boom 14 are respectively moved by the same amount of telescopic movement relative to the middle boom 11. There is provided a pulley 52 rotatably supported at the upper end side portion of the lower middle boom 12. A wire 53 is wound around the pulley 52 and has one end coupled to an upper end of the lower boom 13 and the other end coupled to a lower end of the middle boom 11. There is provided a pulley 54 rotatably supported at the upper end side portion of the upper middle boom 14. A wire 55 is wound around the pulley 54 and has one end coupled to an upper end of the middle boom 11 and the other end coupled to a lower end of the upper boom 15. FIG. 10 is a view showing in detail the operating mechanism 20 according to the first embodiment of the present invention. Four operation mechanisms 20 are provided, one being mounted on each of the four telescopic booms 10. A pair of guide rails 60 is fixed in a predetermined spaced interval at the lower surface of the middle boom 11 in the longitudinal direction thereof. The pair of guide rails 60 are U-shape in cross section and are disposed so as to oppose one another. The guide rails 60 are fixed to the middle boom 11 and extend along substantially the entire length thereof. Rollers 61 are movably inserted into the inner space between the guide rails 60 and supported by a bearing plate 62. The bearing plate 62 is fixed to an operating rod 63 which is maintained in parallel with the middle boom 11. The operating rod 63 at its lower end is fixed to an upper end of a guide body 64. The guide body 64 is formed in U-shape and defines a narrow and long space between the opposing two leg members and both ends are forked and are coupled to lower ends of the lower middle boom 12. With such an arrangement, the guide body 64 and the operating rod 63 move together with the lower middle boom 12 relative to the middle boom 11. The guide body 64 is, as mentioned above, formed in the U-shape and has guide grooves 65 each U-shape in cross section and provided on the opposing inner sides thereof. There are movable rollers 66 in the grooves 65 and supported by a shaft 67 which is supported by a pair of supporting plates 68. A pulley 69 is supported between the pair of supporting plates 68. The supporting plates 68 are fixed to the tip end of a cylinder rod 72 of a fluid pressure (i.e. hydraulic) cylinder 71. The hydraulic cylinder 71 is positioned inside the inner space of the guide body 64 for operating the cylinder rod 72. The hydraulic cylinder 71 is pivotally coupled with a fixing member 17 at the base thereof. A wire 66 is wound around the pulley 69 and has one end coupled to the lower end of the lower middle boom 12 and the other end coupled to an upper end of the hydraulic cylinder 71. FIG. 11 shows in detail the kick or support mechanism 7. The kick or support mechanism 7 is a hydraulic cylinder comprising a plurality of cylinder rods 75, 76, 77 which are telescopically coupled in three stages. The cylinder rod 77 has fixed at its upper end a kick or support body 78, which kick body 78 opens upward in V-shape. The kick body 78 contacts the outer periphery of the tubular kick receiver 26 and can raise the kick receiver 26 and has a limit switch 79 at the V-shaped bottom portion thereof for contacting the outer periphery of the kick receiver 26 and detecting the position of the kick receiver 26. FIG. 12 shows a part of a hydraulic control circuit according to the first embodiment of the present invention. The hydraulic control circuit in FIG. 12 relates to the one for raising the platform 5. A hydraulic pump 81 is driven by an engine 80 and has an input portion connected to an oil tank 82. The hydraulic pump 81 has an output portion connected to solenoid valves 83 and 84 each having a return oil passage connected to the oil tank 82. The solenoid valve 83 is connected serially to the hydraulic cylinders 71-A and 71-B while the solenoid valve 84 is connected to the kick mechanism 7. These two solenoid valves 83 and 84 can respectively be switched to a closed middle position, a forward position and a backward position. The solenoid valve 83 has coils K and L while the solenoid valve 84 has coils M and N. FIG. 13 shows an electric circuit according to the embodiment of the present invention. A control unit (not shown) is attached to the platform 5 and provided with a control switch 86 for raising and lowering the platform 5 by operating thereof by an operator. The control switch 86 includes a contact 87 for controlling a raising operation, a contact 88 for controlling a lowering operation, in which the contact 87 is connectable to a relay 89 while the contact 88 is connectable to a relay 90. The relay 89 controls a normally opened contact 91 connected in series to the coil K while the relay 90 controls a normally opened contact 92 connected in series to the coil L. The limit switch 79 is open when it does not contact the kick receiver 26, and is connected to a normally opened contact 93 openable by the relay 89 and having the coil M in series therewith. The limit switch 79 is also connected to a normally opened contact 94 openable by the coil 90 and having the coil N in series therewith. An operation of the first embodiment will be described hereinafter. When the engine 80 mounted on the chassis 1 is actuated to drive the hydraulic pump 81, the hydraulic pump 81 sucks up the oil under pressure from the oil tank 82 and supplies the thus sucked oil under pressure to the solenoid valves 83 and 84. With such operation, the lifting apparatus is ready for controlling the constituents thereof. Raising the Platform A state where the platform 5 is at the lowest position is illustrated in FIGS. 1 and 2. Described hereafter is a case where the lifting apparatus is raised from the lowest position. At the lowest position, the kick receiver 26 is kept in contact with the kick body 78 and the limit switch 79 contacts the outer periphery of the kick receiver 26, hence the limit switch 79 is closed. When the control switch 86 is operated, at the state when the limit switch 79 is closed, to close the contact 87 for raising the platform 5, the relay 87 is operated to close the normally opened contacts 91 and 93. Thereupon, the current is applied to both the coils K and M, thereby switching the solenoid valves 83 and 84 to the forward position. As a result, the oil under pressure is supplied to each of four hydraulic cylinders 71-A, 71-B, 71-C and 71-D and the kick mechanism. Thereupon, each of the hydraulic cylinders 71 extends in the longitudinal direction thereof so as to pull up each of the booms in the telescopic boom body 10. However, when the platform 5 is positioned at its lowest position (the state as illustrated in FIG. 1), the booms are respectively directed in a straight line and arranged in parallel with each other wherein the force is not decomposed in the direction to rotate in X-shape around the bearing mechanism 29, and hence the platform 5 does not rise. However, since the oil under pressure is at the same time supplied through the solenoid valve 84 to the kick mechanism 7, the cylinder rods 75, 76, 77 respectively extend upward and the kick body 78 pushes the kick receiver 26 upward. Accordingly, the middle boom bodies 11-A, 11-B, 11-C and 11-D are respectively raised slightly to form an X-shape. When the telescopic booms are raised by the kick mechanism 7 to slightly form the X-shape, each of the hydraulic cylinders 71 starts to operate. Firstly, when the hydraulic cylinder 71 is operated to push the cylinder rod 70, the pulley 69 is pushed out upward together with the supporting plate 68 so as to pull up the wire 66. Since the wire 66 is coupled to the upper end of the hydraulic cylinder 71 at one end thereof, the wire 66 operates so as to pull up the lower middle boom 12 when the pulley 69 is pushed out. Hence, each of the lower middle booms 12 starts to extend so as to pull out the lower boom 13 from its lower end. At this time, although the guide body 64 moves forward together with the lower middle boom 12 and with the operating rod 63, the distance between the guide body 64 and the middle boom 11 is varied. However, the tip end of the operating rod 63 moves within the guide rail 60 by rollers 61, the operating rod 63 and the guide body 64 respectively keep in parallel with the lower middle boom 12 and assist the hydraulic cylinder 71 so as to keep and move in parallel with the lower middle boom 12. In such manner, the lower middle boom 12 is pushed up by the hydraulic cylinder 71 and the lower boom 13 is pulled out from the lower end of the lower middle boom 12 so that the telescopic boom bodies 10 are interlocked with each other. The interlocking operation will be described with reference to FIG. 9. When the lower middle boom 12 is pushed up, the lower boom 13 is pulled out from the lower end of the lower middle boom 12. Since the pulley 52 is supported at the upper end portion of the lower middle boom 12, the lower boom 13 is positioned in the same position but the wire 53 is pulled up since the pulley 52 is raised, which causes the middle boom 11 to move relative to the lower middle boom 12. The distance of movement of the middle boom 11 relative to the lower middle boom 12 is set to be the same length as that of the lower boom 13 relative to the lower middle boom 12 when the former is pulled out from the latter. Hence, the lower middle boom 12 and the lower boom 13 are respectively pulled out for the same length relative to the middle boom 11. When the lower middle boom 12 is pulled out from the middle boom 11, the wire 51 is pulled out downward which is delivered to the upper middle boom 14 through the pulley 50 and the upper middle boom 14 is pulled out from the upper open end of the middle boom 11. The amount of movement of the upper middle boom 14 when it is pulled out from the middle boom 11 is the same as that of the lower middle boom 12 when it is pulled out from the middle boom 11. When the upper middle boom 14 is further pulled out from the middle boom 11, the pulley 54 supported by the upper middle boom 14 pulls the wire 55. Since one end of the wire 55 is fixed to the middle boom 11, the wire 55 is still positioned in the same position at one end thereof but the upper boom 15 to which the other end of the wire is fixed is pulled out from the upper middle boom 14. The amount of movement of the upper boom 15 when it is pulled out from the upper middle boom 14 is the same as that of the upper middle boom 14 when it is pulled out from the middle boom 11. With such an interlocking operation of the wires 51, 53 and 55, the lower middle boom 12, the lower boom 13, the upper middle boom 14 and the upper boom 15 are pulled out respectively relative to the middle boom 11, the amount of movement of the lower middle boom 12 when it is pulled out from the middle boom 11 is the same as that of the upper middle boom 14 when it is pulled out from the middle boom 11, the amount of movement of the lower boom 13 when it is pulled out from the lower middle boom 12 is the same as that of the upper boom 15 when it is pulled out from the upper middle boom 14, and hence each of the booms is synchronized for the same amount of movement. Although the interlocking operation is exemplified for the synchronous operation of one of the telescopic boom bodies 10, the same synchronous operation is effected for the other telescopic boom bodies 10. The amount of movements of all the booms of each of the telescopic boom bodies 10 forming the X-shape is the same, whereby the lifting mechanism 4 can extend to a large amount while the X-shape thereof is maintained but the upper and lower portions thereof are intermittently moved to keep the X-shapes analogous with one another. Accordingly, the platform 5 is raised vertically upward relative to the chassis 1 while it is kept horizontal relative to the ground. With such series of operations, namely, when the hydraulic cylinders 71 are operated to extend each of the booms of the telescopic boom bodies 10, the lifting apparatus can be raised to an elevated spot whereby the lifting apparatus is raised from the state illustrated in FIG. 1 to the state illustrated in FIG. 3 and the entire length of the telescopic boom bodies 10 when they are fully extended as shown in FIG. 3 becomes about five times as long as the length when they are contracted as shown in FIG. 1. When the lifting apparatus 4 is raised to a predetermined position and the supply of pressurized oil to the hydraulic cylinder 71 is stopped, the platform 5 is kept at the elevated spot whereby the operator can work at the elevated spot. In the telescopic movement of the pair of telescopic boom bodies 10, two middle booms 11-A, 11-B and 11-C, 11-D are rotated relative to each other by the bearing mechanism 29. In the bearing mechanism 29, since the sliding retainers 46 are engaged in the guide groove 41 of the bearing washer 40, the retainers slide and move along the inner periphery of the guide groove 41. As a result, the middle booms 11-A and 11-B can be rotated relatively in opposite directions without varying the left and right intervals thereof, whereby both the middle booms 11-A and 11-B can be maintained in the X-shape. When the bearing mechanism 29 is raised by each of the hydraulic cylinders 71, the kick receiver 26 rises by its own force and moves away from the upper surface of the kick body 78, so that the limit switch 79 is opened. Hence, no current is applied to the coil M so that the solenoid valve 84 is switched to the closed middle position. Thereafter, the platform 5 and the bearing mechanism 29 are respectively raised by the successive operations as set forth above while the cylinder rods 75, 76 and 77 of the kick mechanism 7 are kept stretched at maximum and stopped. Lowering the Platform The lowering operation of the platform 5 will now be described. The operator on the platform 5 operates the control switch 86 to close the contact 88 thereof, whereby the current is applied to the relay 90 to close the normally opened contacts 92 and 94. Hence, the current is applied to the coil L but no current is applied to the coil N since the limit switch 79 is opened. With the application of the current to the coil L, only the solenoid valve 83 is switched to the backward position so that the oil under pressure is supplied through the hydraulic pump 81 to each of the hydraulic cylinders 71 in the reversed direction. As a result, the length of each of the hydraulic cylinders 71 is contracted so that each of the cylinder rods contracts into the respective hydraulic cylinder 71. The lower middle boom 12 and the upper middle boom 14 move respectively, contrary to that as set forth above, toward the middle boom 11 while the lower boom 13 moves toward the lower middle boom 12 and the upper boom 15 moves toward the upper middle boom 14, so that the entire length of the telescopic boom 10 is contracted as a whole. This operation is reverse to the operation set forth above, whereby the platform 5 is gradually lowered. The middle boom 11 is lowered while it is rotated about the bearing mechanism 29 by which the middle booms 11 are supported to form the X-shape. When the kick receiver 26 of the bearing mechanism 29 lowers to contact the kick body 78, the kick receiver 26 is supported by the kick body 78. At the same time, the limit switch 79 contacts the kick receiver 26 so that the limit switch 79 is closed, thereby applying current to the coil N through the normally opened contact 94. Hence, the solenoid valve 84 is switched to the backward position so that the oil under pressure is supplied from the hydraulic pump 81 to the kick mechanism 7 in the reversed direction. Then, the kick body 78 contacts the kick receiver 26 and supports the load of the platform 5 as the kick mechanism 7 is gradually lowered. That is, the load of the platform 5 is hitherto received by each of the hydraulic cylinders 71, but a part of the load is received by the kick body 78 by switching the solenoid valve 84 to the backward position. Thus, a part of the load can be supported by the kick mechanism 7 while it is contracted. The tension force of the wires 53 and 55 operated by the hydraulic cylinder 71 is reduced. Accordingly, the angle of inclination of the middle boom 11 relative to the chassis is small, hence even if the component of the load to be applied to the platform 5 becomes great, the component of the force imposed on the wires 53 and 55 does not become great. Second Embodiment (FIGS. 14 and 15) A second embodiment of the present invention will be described with reference to FIGS. 14 and 15. According to the second embodiment, parts of the hydraulic control circuit and the electric control circuit are varied wherein the elements common to the first embodiment are denoted by the same numerals and the explanation thereof is omitted. FIG. 14 shows the hydraulic control circuit of the second embodiment. There are intervened throttle valves 95 and 96 between the solenoid valve 83 and the hydraulic cylinders 71-A and 71-B. There are connected solenoid valves 97 and 98 in parallel with each other for cutting off the hydraulic circuit at both sides of the throttle valves 95 and 96. There is connected a coil Q to the solenoid valves 97 for cutting off the oil passage while there is connected a coil R to the solenoid valve 98 for cutting off the oil passage. FIG. 15 shows the electric control circuit of the second embodiment wherein there are connected the coils Q and R to the coil N. When the platform 5 is raised according to the second embodiment, the contact 87 of the control switch 86 is closed in the same way as in the first embodiment. When the contact 87 is closed to actuate the relay 89 so that the normally opened contacts 91 and 93 are closed and the current is applied to the coils K and M, the solenoid valves 83 and 84 are switched to the forward position so that the oil under pressure is supplied to the kick mechanism 7 and the hydraulic cylinder 71 whereby the platform 5 is raised. The operations to be effected thereafter are the same as in the first embodiment. However, the case where the platform 5 is lowered is slightly different from the first embodiment as set forth above. That is, in the state where the platform 5 is positioned at an elevated spot before the kick receiver 26 contacts the kick body 78, the limit switch 79 is opened so that the platform 5 is lowered due to the amount of contraction of the hydraulic cylinders 71. When the platform 5 and the bearing mechanism 29 are respectively lowered so that the kick receiver 26 contacts the kick body 78, the limit switch 79 is closed whereby the current is applied to the coils N, Q and R through the contact 94 as already closed by the relay 90. Then, the solenoid valve 84 is switched to the backward position so that the oil under pressure is supplied from the hydraulic pump 81 to the kick mechanism 7 in the reversed direction, thereby gradually lowering the cylinder rods 75, 76 and 77 of the kick mechanism 7. At the same time, since the current is applied to the coils Q and R, the solenoid valves 97 and 98 are closed so that the direct connections between the solenoid valve 83 and the hydraulic cylinders 71-A and 71-B are stopped. Accordingly, there is supplied the oil under pressure which is reversed in the flow thereof through the throttle valves 95 and 96 into the hydraulic cylinders 71-A and 71-B at low speed. As a result, the hydraulic cylinders 71-A and 71-B are contracted at low speed so that the lowering speed of the kick mechanism 7 is increased, thereby operating following the operation of the kick mechanism 7. Hence, there is always applying the tensile force to the wires 53 and 55 pulled up by the hydraulic cylinder 71 and the wires 53 and 55 follow the operation of the kick mechanism 7. In this operation, differing from the first embodiment, the hydraulic cylinders 71-A and 71-B are directly connected to the solenoid valve 83 and kept contracted, thereby occurring the phenomenon that the contracting speed of the hydraulic cylinder 71 is greater than that of the kick mechanism 7, thereby generating looseness in the wires 53 and 55. As a result, the wires 53 and 55 are likely to hang loosely inside the telescopic boom body 10. It is possible to prevent the phenomena of dropping the pulleys 50, 52, 54 and 60 wound around the wires 53 and 55 out of the wires 53 and 55 and of the non-raising operation of the wires 53 and 55 which is likely to occur depending on the looseness of the wires 53 and 55. Although the telescopic boom body 10 is structured to be telescopically moved in five stages by slidably moving the respective lower middle boom 12, the lower boom 13, the upper middle boom 14 and the upper boom 15 into the middle boom 11, the present invention is not limited to the embodiment set forth above but can be varied such that the lower boom and the upper boom can be directly telescopically moved into the middle boom 11 at three stages, whereby the same effect as the first and second embodiments can be obtained. Furthermore, the provision of the kick mechanism enables the kick mechanism to receive most of the component of the fourth of the platform, thereby preventing the wire or chain for synchronizing the upper and the lower booms from receiving the load of the platform. The lifting apparatus can be light weight as a whole because the safety factor of the wires and chains can be reduced. Although the invention has been described in its preferred form with a certain degree of particularity, it is to be understood that many variations and changes are possible in the invention without departing from the scope thereof.	A lifting apparatus having a least one set of paired stretchable boom assemblies which extend and contract, preferably in five stages. The boom assemblies are disposed between a chassis and a platform for raising and lowering the platform in interlocking relation with an operating mechanism, a guiding mechanism and a synchronizing mechanism. The lifting apparatus further includes a kick mechanism for auxiliarily supporting the load on the platform at a position where the platform is lowered about halfway. The kick mechanism has one end fixed to the chassis and the other end provided with a kick body capable of supporting the centers of the boom assemblies and provided with a detecting means for detecting contact between the boom assemblies and the kick mechanism.	1
BACKGROUND OF THE INVENTION 1. Field of the Invention This invention relates to the system for locating well equipment within the tubing string of a well. Within the tubing string are positioned locating nipples, each of which has an internal recess of a selected configuration. A tool, having expandable keys, is run through the tubing string. The keys have an outer configuration designed to mate with the internal recess configuration of a selected locating nipple. 2. The Prior Art Frequently wells are designed so that one operation may be performed in any one of several locations therein. For example, a plurality of identical sliding sleeve valves may be positioned in the well. Frequently, it is desired to shift the sleeve of one such valve while not disturbing the sleeves of the other valves. To lessen the likelihood that the desired operation will be performed at the wrong location, selective locating systems for wells have been devised. Heretofore, selective locating systems have generally included a single series of locating nipples. Each nipple in the series has an internal recess of a different configuration. A locating tool, having locator keys, would be run through the tubing string. The locator keys have an outer configuration which mates with the internal recess of a selected one of the locating nipples. Such locating systems are disclosed in U.S. Pat. No. 2,673,614 and 2,862, 564. Deep wells require more locating positions than shallower wells. Well depth has graudally been increasing. Consequently, the number of desired locating positions within a well has also been increasing. Additionally, more and more wells ae being equipped for use with pump down equipment. A pump down tool train must pass through a loop or curved portion of tubing prior to entry into the well. Therefore, each tool section is short. The short length required for pump down tools has limited the number of possible configurations for a locator key. Presently, approximately 20 select positions can be arranged in a well. A single series of 20 locating nipples, each having an internal recess with a different configuration, can be positioned in the well. A locating tool is provided with 20 sets of keys. One specific set of locator keys will mate with the internal recess of a selected landing nipple. However, for some deep wells, 20 select positions is insufficient. More select locating positions are desired. Until this invention, an increased number of locating positions could not be obtained. OBJECTS OF THE INVENTION An object of this invention is to provide an increased number of obtainable locating positions within a well. Another object of this invention is to permit a plurality of identical series of locating nipples to be positioned within a well tubing string and thereby increase the number of select locating positions in the well. Another object of this invention is to provide a locating tool that can pass through at least one series of locating nipples and subsequently engage a select locating nipple upon passage through another series of locating nipples. These and other objects and features of advantage of this invention will be apparent from the drawings, detailed description, and the appended claims. BRIEF DESCRIPTION OF THE DRAWINGS In the figures, wherein like numerals indicate like parts, and wherein an illustrative embodiment of this invention is shown: FIGS. 1A, 1B, and 1C are continuation views, in section, of a well tubing string having a plurality of series of locating nipples positioned therein; FIG. 2 is a quarter-sectional view of a locating tool after having been run through at least one series of locating nipples and prior to being run through the series of locating nipples in which it will engage one selected nipple; FIG. 3 is a quarter-sectional view showing the locating tool of FIG. 2 engaging a locating nipple; FIG. 4 is a cross-sectional view taken along line 4--4 of FIG. 2; FIG. 5 is a cross-sectional view taken along line 5--5 of FIG. 3; FIG. 6 is a quarter-sectional view taken at right angles to the view in FIG. 3; and FIG. 7 is an enlarged partial sectional view taken along line 7--7 of FIG. 2. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT Many different well operations will be performed in the tubing string 10 of a well. Certain operations must be performed at a specific location within the tubing string 10. To positively locate a tool train as it is being run through the tubing string 10, a series of locating nipples 12a, 12b, 12c and 12d may be positioned within the tubing string 10 at known, spaced locations. Each locating nipple has an internal recess 14a, 14b, 14c and 14d, respectively, of a different configuration. The tool train is made up to include a locating tool. The locating tool engages the internal recess 14 of a selected locating nipple 12. The tool train is thereby positively located in the tubing string 10. In accordance with this invention, multiple series of locating nipples 12 may be positioned within the tubing string 10. Each series of locating nipples 12 may be identical. The different series would be spaced vertically in the tubing string 10. The number of positive, known locations in the tubing string 10 is thereby increased. The number of locations now equals the number of nipples in each series times the number of series utilized. In FIGS. 1A, 1B and 1C, three identical series 12a through 12d, 12a' through 12d' and 12a" through 12d" of locating nipples are illustrated positioned within the tubing string 10. Additional or fewer or series of locating nipples could be so positioned depending upon the well installation. In accordance with this invention, a locating tool of a tool train may pass through at least one series of locating nipples 12. Thereafter, the locating tool will be rendered effective to engage a selective locating nipple within another series of locating nipples. To selectively render the locating tool effective so that it may engage a select locating nipple within a select series of locating nipples, means 16, 16' and 16" for selectively activating the locating tool are provided between each series of locating nipples 12, 12' and 12". These selective activating means 16, 16' and 16" may comprise the graduated restrictions illustrated. The locating tool 18 is shown engaging the graduated restriction 16 in FIG. 2. The locating tool 18 comprises a tool mandrel 20, locator key means 22, and actuator means 24. Locator key means 22 will engage the internal recess 14 of a select locating nipple 12. Actuator means 24 prevents the locator key means 22 from engaging any of the recesses 14 as the locating tool 18 passes through at least one series of locating nipples 12. Thereafter, actuator means 24 coacts with one of the selective activating means 16 and actuates the locator key means 24. Upon passage of the locating tool 18 through the next series of locating nipples 12, the locator key means 22 will engage the internal recess 14 of a select locating nipple 12. The tool mandrel 20 comprises one short section of a pump down tool train. Tool mandrel 20 carries locator key means 22 and other components of the locating tool 18. As shown, connector means 26 and 28 may be provided at each end of the tool mandrel 20 for connecting the locating tool 18 to other tools 30 and 32 (indicated in dotted form) of the pump down tool train. The connector means 26 and 28 may be the ball and socket connections shown. Connector means 26 comprises ball member 34 having an upwardly extending stem portion 34a and a ball portion 34b. Surrounding the ball portion 34b is a socket 36 which is threaded to the tool mandrel 20. The upwardly extending stem portion 34a includes outer threads 34c for connection to another tool 30 (shown in dotted form) of the tool train. The lower connecting means 28 may comprise a ball 38 received within a socket 40. The socket 40 is connected to the tool housing 20. The ball 38 includes inner threads 38a to which are threaded an upwardly facing stem of another tool 32 of the tool train. Locator key means 22 are carried by the tool mandrel 20. The locator key means 22 have an outer configuration which is adapted to mate with the internal recess of a selected one locating nipple within one series of locating nipples. Therefore, in accordance with this invention, the outer configuration of the locator key means 22 may mate with the inner recess of a plurality of locating nipples in the well tubing string 10. Each of these locating nipples 12 with which the locator key means 22 could mate, would be positioned within a different series of locating nipples 12. Locator key means are adapted to move radially with respect to the tool mandrel 20. During running of the locating tool 18 through the tubing string 10, the locator key means 22 will assume three different positions. First, locator key means 22 will be held in a radially, retracted position on the tool mandrel 20 (see FIG. 2). In that radially, retracted position, locator key means 22 can not engage the recess 14 of any locating nipple 12 through which the locator tool 18 passes. Instead, all of the locating nipples 12 will be by-passed. In a second operative position, locator key means 22 is urged radially outwardly. Radial outward movement of locator key means 22 is limited by the engagement of the outer surface 42 of locator key means with the internal wall of the tubing string 10. As the locating tool 18 moves through the tubing string 10, locator key means 22 will by-pass those landing nipples 12 which have an internal recess 14 which does not mate with the external configuration of locator key means 22. However, when the locating tool 18 reaches the selected landing nipple 12, locator key means 22 will assume their third position. In their third position, locator key means 22 are expanded radially to their outermost position (see FIGS. 3 and 6). Their outer portion is received within the recess 14 of the selected landing nipple 12. Further movement of the locating tool 18 and tool train through the tubing string 10 is stopped. Mounting means, such as collars 44, mount the locator key means 22 on the tool mandrel 20. Mounting collar means 44 permit the outwardly radial movement of locator key means 22 with respect to the tool mandrel 20. If desired, the mounting collar means 44 may also restrict the axial movement of locator key means 22 with respect to the tool mandrel 20. For the locating tool 18 shown, two mounting means 44 are positioned on the tool mandrel 20. The two mounting collar means 44 each confine a different end of the locator key means 22. Each mounting collar means 44 includes two opposed cut-outs 46 and four slots 48. The cut-outs 46 receive the extreme longitudinal ends of the locator key means 22. The slots 48 receive a projecting ear 50 of the locator key means 22. The engagement of the ear 50 within the slots 48 permits the radial movement of the locator key means 22 with respect to the tool mandrel 20. Inherently resilient biasing means, such as spring 52, bias locator key means 22 radially outwardly with respect to the tool mandrel 20. However, in accordance with this invention, during movement of the tool train through a portion of the tubing string 10, the spring means 52 will be rendered ineffective. They will be unable to move locator key means 22 radially outward. However, after operation of the actuator means 24, spring means 52 will be rendered effective. Thereafter, locator key means 22 will be movable radially outwardly and will be permitted to engage that select locating nipple 12 which has an internal recess 14 which matches the outer configuration of locator key means 22. Actuator means 24 selectively renders spring means 52 ineffective and effective. While in a first, expanded position with respect to the tool mandrel 20, actuator means 24 confines locator key means 22 in their first radially retracted position (See FIG. 2). Spring means 52 can not move the locator key means 22 radially outwardly. While in a second, contracted position with respect to the tool mandrel 20, actuator means 24 permits radially outward movement of locator key means 22 (See FIG. 3). Spring means 52 is rendered effective to move the locator key means 22 radially outwardly. For confining key means 22 radially inwardly, actuator means 24 includes an inwardly facing lip portion 54. Lip 54 is designed to engage an outwardly facing shoulder 56 of locator key means 22. When the lip portion 54 and the shoulder 56 have engaged, and the actuator means 24 are in their first position (See FIG. 2), the locator key means 22 are radially retracted. When the lip portion 54 is disengaged from the shoulder 56 (See FIG. 3), the locator key means 22 are permitted to expand radially outwardly. The actuator means 24 moves between its first, expanded and second contracted positions with respect to the tool mandrel 20 upon engagement with a selective one of the tubing string activating means 16. The engagement of the tool actuator means 24 with the activating means 16 in the well, permits a downward movement of the tool mandrel 20 with respect to the tool actuator means 24. Once the tool mandrel 20 moves downwardly a short, but sufficient distance, tool actuator means 24 disengages from the locator key means 22, moves to its second contracted position, and disengages from the well's selective actuating means 16. While in their first, expanded position, actuator means 24 have their largest effective distance between their outermost extremities. In their second, collapsed position, actuator means 24 have their smallest effective distance between their outermost extremities. Coacting surfaces on the tool mandrel 20 and on actuator means 24 selectively co-engages to either maintain actuator means 24 in its first expanded position or permit contraction of actuator means 24 to its second contracted position. For engaging and maintaining actuator means 24 in its first, expanded position, the tool mandrel 20 includes outer cylindrical surfaces 58 and 60 (best seen in FIG. 6). The inwardly facing surfaces 62 and 64 of actuator means 24 engage the mandrel's cylindrical surfaces 58 and 60 when actuator means 24 is in its first expanded position. Between the mandrel's cylindrical surfaces 58 and 60, is a recess 66. Likewise, between the inwardly facing surfaces 62 and 64 of actuator means 24 is a recess 68. The recess 68 is designed to receive the inwardly facing surface 64 of actuator means 24 when actuator means 24 is in its second position. Likewise, the recess 68 is designed to receive the outwardly facing cylindrical surface 58 of the tool mandrel 20 when the actuator means 24 is in its second position. Therefore, when actuator means 24 are in their first position, movement of the tool mandrel 20 downwardly with respect to actuator means 24 permits actuator means 24 to collapse inwardly to their second contracted position. The longitudinal length of the surfaces 58 and 64 and the longitudinal length of the recesses 66 and 68 permits movement of the actuator means 24 from its first position to its second position upon minimal longitudinal movement of the tool mandrel 20. To collapse actuator means 24 inwardly, yieldable resilient urging means 70, such as snap ring 70, resiliently urges actuator means 24 radially inwardly. Actuator means 24 are releasably maintained in their first, expanded position on the tool mandrel 20. Releasable holding means 72, such as shear screws 72 (shown in dotted form on FIG. 4) releasably maintain actuator means in their first position. As illustrated, the releasable holding means 72 may extend through a curved wing portion 74 of actuator means 24 and the wall of the tool mandrel 20. The locator key means 22 have holes 76 positioned so that the shear screws 72 may be threaded into the curved actuator wing portion 74 and the tool mandrel 20. Tool actuator means 24 includes downwardly facing chamferred stop shoulder means 78 sized to engage one of the well's selective activating means 16. The tool actuator means 24 may pass through one or more well activating means 16 and engage another selective activating means 16 deeper in the well. Thereafter, the tool actuator means 24 would actuate the locating tool 18 and permit the locator key means to engage the next locating nipple 12 having an internal recess 14 which matches the key's outer configuration. One manner of designing the tool actuator means 24 and the well activating means 16 for this selective co-engagement and activation is to vary the inside diameters of the well activating means 16 and the outside diameters of the tool actuator means 24. For example, at increasing well depths, the well activating means 16 could have increasingly smaller inside diameters. Thus, in the Figures, the well activating means 16 has a first inside diameter, the well activating means 16' has a second inside diameter which is smaller than the first inside diameter, and the well activating means 16" has a third inside diameter which is smaller than the second inside diameter. The actuator means 24, when actuator means 24 is in its first position, would then be designed to engage a specific one of the well activating means 16. For example, if it was desired to engage the second well activating means 16', the downwardly facing stop means 78 would be sized to pass through the first activating means 16 and engage the second activating means 16'. In other words, the outermost extremity of actuator means 24, when in its first position, would be less than the distance across inside diameter of the first well activating means 16 but greater than the distance across inside diameter of the second well activating means 16. During the running of the locating tool 18 through the tubing string 10 prior to engagement with the well activating means 10, the tool actuator means 24 will most likely engage and pass through numerous obstructions. To prevent the tool actuator means 24 from inadvertently shifting due to its engagement with an obstruction, the tool actuator means 24 includes a downwardly depending leg means 80. The leg means 80 are designed to engage the inner wall of locator key means 22 when actuator means 24 are in their first position. They thereby prevent actuator means 24 from becoming misaligned. Any such misalignment could vary the distance across the radial most extremity of actuator means 24. If that distance was appreciably varied, the tool actuator means 24 could engage the wrong well activating means 16. Until actuation, it is desired that actuator means 24 be maintained properly aligned in its first, expanded position on the tool mandrel 20. Therefore, only when the opposed tool actuator means 24 both engage the properly sized selective well actuating means 16, is the tool actuator means 24 moved to its second position. In operation, the locating system of this invention permits a tool train to be positively located at a subsurface location in a well tubing. The well tubing string 10 would be made up to include a plurality of locating nipples 12a, 12b, 12c and 12d. In addition to the one series of locating nipples 12a through 12d, the tubing string would also include additional series 12' through 12d' and 12a" through 12d" of locating nipples. Between each series of locating nipples would be located tubing selective actuating means 16, 16' and 16". The tool train would be made up to include a locating tool 18. The locating tool 18 would be arranged so that the tool actuator means 24 are in their first expanded position and confine the locator key means 22 radially inwardly in their first retracted position. The tool train would be run through the tubing string 10. As long as the locator key means 22 are confined inwardly by the tool actuator means 24, the locating tool 18 by-passes locating nipples in the well tubing string 10. Depending upon the effective distance between the outermost extremities of actuator means 24, one or more series of locating nipples 12 may be bypassed in this manner. All during this downward movement of the tool train, the spring means 52 has been rendered ineffective. The locator key means 22 are held confined inwardly by the lip portion 54 of the actuator means 24 against the outwardly applied force of spring means 52. The actuator means 24 will engage one of the selective activating means 16 in the tubing string 10. Such engagement is illustrated in FIG. 2. A downward force is applied to the tool train until shear screws 72 shear. Continued downward movement of the tool train will move the tool mandrel 20 downwardly a short distance with respect to the tool actuator means 24. The actuator's inwardly facing surface 64 will become disposed opposite the mandrel's recess 66 and the mandrel's outer surface 58 will become disposed opposite the actuator's inner recess 68. Actuator means 24 is collapsed inwardly to its second position by the yieldable urging means 70. The distance between the outermost extremities of actuator means 24 is now less than the inside diameter of the selective actuating means 16. The locating tool 18 may pass through the activating means 16. The lip portion 54 of actuator means 24 has disengaged from the recess 56 of locator key means 22. Spring means 52 is rendered effective. The locator key means 22 expand radially outwardly. Downward movement through the tubing string of the tool train is continued. As the tool train passes through a locating nipple 12, the locator key means 22 would be urged outwardly into the recess 14. However, unless the internal configuration of the recess 14 matches the outer configuration of the locator key means 22, the locator key means 22 will not engage the recess 14. Therefore, the locating tool 18 and the tool train will pass through that locating nipple 12. The locating tool 18 will pass through all locating nipples in a series of locating nipples 16 until the select locating nipple is reached. When the select locating nipple 12 is reached, the locator key means 22 expand radially outwardly into the mating recess 14 (see FIGS. 3 and 6). Engagement of the locator key means 22 with the locating nipple 12 positively locates the tool train in the tubing string 10. Thereafter, any desired well operation may be performed. From the foregoing, it can be seen that the objects of this invention have been obtained. An increased number of positive locations within a well can now be selected. A plurality of series of locating nipples can be positioned within the well tubing string. Each locating nipple within the series can have an internal recess of a different configuration to provide one source of selectively locating positions within the well. Between each series of locating nipples is an activator. The well activator provides a second source of selective locating by permitting selection of that series of locating nipples in which a locating tool will be effective. The locating tool will include locator keys which can engage a locating nipple in each series of locating nipples. The locating tool will also include an actuator which permits selective actuation of the locator keys within one series of locating nipples. The multiplied number of positive locations thereby obtained permits the precise location of a tool train at the numerous points required for many different well operations. The foregoing disclosure and description of the invention are illustrative and explanatory thereof. Various changes in the size, shape, and materials, as well as the details of the illustrated construction, may be made within the scope of the appended claims without departing from the spirit of the invention.	Disclosed is a system for locating well equipment at preselected locations within a well's tubing string. Positioned within the tubing string are a plurality of series of locating nipples. A locating tool runs through the tubing string. The locating tool may pass through at least one entire series of locating nipples without engaging any one nipple and subsequently engage a selected locating nipple in another series of locating nipples. This abstract is neither intended to define the scope of the invention, which, of course, is measured by the claims, nor is it intended to be limiting in any way.	4
CROSS-REFERENCE TO RELATED APPLICATION Attention is directed to Applicant's co-pending application, Ser. No. 418,937, filed Nov. 26, 1973. SUMMARY OF THE INVENTION The present invention is directed to a loom and, more particularly, it concerns apparatus for providing automatic and synchronized operation of the drawing roller and warp beam of a loom. Such apparatus contributes a new concept both in the drive and in the control and adjustments relating to the fabric drawing means and to the unwinding of the warp beam. At the present time, all of the mechanisms used for the control and synchronization of the drawing roller and warp beam in a loom have independent adjustments and control devices for each of them, and, as a result, defects in precision occur and, further, the operator must handle both of the individually regulated members and other disadvantages arise from this arrangement. The primary object of the present invention is to incorporate a direct transmission between the drawing roller and the warp beam to obtain synchronized action between the two of them. Such operation is achieved by using a single operating member which automatically affords the desired synchronization without resort to any additional adjustment or regulation. The various features of novelty which characterize the invention are pointed out with particularity in the claims annexed to and forming a part of this disclosure. For a better understanding of the invention, its operating advantages and specific objects attained by its use, reference should be had to the accompanying drawings and desscriptive matter in which there is illustrated and described a preferred embodiment of the invention. BRIEF DESCRIPTION OF THE DRAWING In the Drawing FIG. 1 is a schematic representation, in a side elevational view, of the apparatus embodying the present invention; FIG. 2 is a schematic showing in a front elevational view of a portion of the apparatus illustrated in FIG. 1; FIG. 3 is a detailed showing in section of the variators and change mechanism; FIG. 4 is a sectional view taken along line A--A of FIG. 3; FIG. 5 is a sectional view taken along line B--B of FIG. 3 and shows in detail the heck and control for the heck; and FIG. 6 is a sectional view taken along line C--C of FIG. 3. DETAILED DESCRIPTION OF THE INVENTION In the drawing, apparatus is illustrated for the automatic and synchronized driving action between a drawing roller and a warp beam in a loom. A driving member 1 affords the principal driving action for the loom and through a pinion 2, it acts simultaneously on a loom movement synchronizing shaft 3 and a primary shaft 4 of a first conventional variator 5 (See FIG. 6). An intermediate pinion 6 transmits the action of the pinion 2 to the primary shaft 4. The first variator 5 includes a manual control device 7 for the density of the fabric and a driven shaft 8 on which is mounted a change mechanism 9 with a range of picks, which increases the possibilities of actuation of the loom. Through an idle pinion 10, the change mechanism 9 acts on a shaft 11, note the arrangement of the shaft 11 shown in FIG. 2. A coupling action is provided on the shaft 11 by a clutch member 12 and a disc or plate 13 mounted on the shaft and elastically biased by a spring 14. In addition, a pinion 15 is mounted on the shaft 11 and acts through a transmission arrangement on the primary shaft 16 of a second conventional variator 17 (See FIG. 4.). At one end, the shaft terminates in an automatic device for member 18 and at its other end in a reduction assembly 19, which is in operative engagement with the shaft 20 of a fabric drawing roller 21. The reduction assembly 19 transmits rotary motion to the drawing roller 21 through a toothed pinion 30 in engagement with a worm screw 40 attached to the end of shaft 11, and to a shaft 32 of the toothed pinion 30 rotating a gear 36 affixed to the shaft 20 of the drawing roller 21 via a worm screw 34. The second variator 17 includes an automatic control device 22, which may be either mechanical or electrical, which is in communication with a thread guide or compensating heck 23. Further, the second variator 17 has a driven shaft 24 which, by means of a suitable transmission through a second reducing assembly 25, drives the shaft 26 of a warp beam 27. The reducing assembly 25 transmits rotary motion to the warp beam 27 through a belt transmission 41 driven by shaft 24 which rotates a gear 39, a pinion 38 affixed to an end of the shaft of gear 39, a pinion 31 engaging the pinion 38 which rotates a shaft 33 having a worm screw 35 at one end engaging pinion 37 fixed on the shaft 26 of the warp beam 27. Based on the above arrangement of elements, the loom operates in the following manner: The principal driving member 1 simultaneously controls the movement of the batten and weft inserting mechanism on one hand and, on the other hand, through an intermediate pinion the first variator 5. With the variator 5 actuated, its operation can be altered by the manual control device 7 for the purpose of selectively and continuously fixing the density of picks of the weft per centimeter of fabric. At the exit or outlet end of the variator 5, the change mechanism 9 permits the changing of the range of picks per centimeter as needed. On the intermediate shaft 11, which is in communication with the change mechanism 9 through the idle pinion 10, a clutch member 12 and the remainder of the coupling system on the shaft permits the automatic device 18 to disconnect the synchronized mechanism corresponding to the heck 23 of the fabric and warp unwinder 27 from the rest of the loom so that variations in density can be made for effecting patterns or reliefs in the fabric or for weaving and weaving backward, manual pick adjustment, and the pass of new warps. Accordingly, it is clear from this operation that the intermediate shaft 11 simultaneously drives the reduction assembly 19 of the drawing roller 21 and through the second variator 17, the reduction assembly 25 of the warp beam 27, both in forward motion (weaving) and in reverse motion (backward weaving). The function of the second variator 17 is to correct the proper relation of synchronism of the kinematics involved, so that it is adapted to the diameter of the warp beam 27, with its regulation being provided through a mechanism which senses the tension of the warp and compares it, for example, with a system of weights or a spring system, so that it transforms any imbalance into a mechanical or electrical impulse which alters the position of the control device 22 of the variator, controlling its output speed to adapt it to the unwinding of thread which causes a constant fabric tension. Finally, the reducing assembly 25, driven from the exit or outlet end of the second variator 17, takes charge of driving the warp beam 27. The change mechanism 9 is of conventional type and has two parallel shafts with respective pinions thereon which can be coupled or uncoupled with pinion 10. This change mechanism 9 can best be seen in FIG. 6 where it is shown connected between the pinion 10 and variator 5. FIG. 5 shows part of the controls for the heck 23, and which forms no part of the present invention. This control is the subject matter of co-pending application, Ser. No. 418,937, filed Nov. 26, 1973. While a specific embodiment of the invention has been shown and described in detail to illustrate the application of the inventive principles, it will be understood that the invention may be embodied otherwise without departing from such principles.	To provide synchronization between the drawing roller and the warp beam of a loom, direct transmission is provided between the two members by means of an intermediate shaft which is independent of the speed of the loom. Any variation in the density of the fabric is transmitted to the intermediate shaft and an automatic adjustment is afforded in the drawing roller and the warp beam.	3
FIELD OF THE INVENTION [0001] This invention generally relates to power actuators for vehicle latches, as for example to a power actuator for releasing a trunk latch or a power actuator for moving a lock lever between a locking and unlocking position. BACKGROUND OF THE INVENTION [0002] Cost is an important factor for manufacturing vehicle accessories such as motorized latch release devices. The number of parts which compose a power actuator has a bearing on the cost of the product. Heretofore, known power actuators for automotive closure latches have more parts, and thus likely higher cost, than the present invention. SUMMARY OF THE INVENTION [0003] A power actuator for automotive closure latches according to the preferred embodiment of the invention has a reduced number of components in comparison to comparable devices currently on the market. [0004] According to one embodiment of the invention, a power actuator is provided which includes a housing; an electric motor mounted in the housing; a worm operatively coupled to the motor for driving rotation of the worm about an axis in a first rotational direction; a worm gear, in meshing engagement with the worm, and being mounted in the housing for rotation about an axis substantially orthogonal to the worm axis; a camshaft mounted on the worm gear and having a rotation axis coincident with the gear axis, the camshaft having a distal end; and an output arm affixed at the distal end of the camshaft. [0005] The power actuator may be employed as a latch release device. According to this embodiment, the latch release device includes a housing; an electric motor mounted in the housing; a worm operatively coupled to the motor for driving rotation of the worm about an axis in a first rotational direction; a worm gear, in meshing engagement with the worm, and being mounted in the housing for rotation about an axis substantially orthogonal to the worm axis; a camshaft mounted on the worm gear and having a rotation axis coincident with the gear axis, the camshaft having a distal end extending to the exterior of the housing; and a cam affixed at the exterior end of the camshaft, having a surface for engaging a said latch to move the latch from a closed position to a release position as the gear rotates in a first direction from a first position to a second position when driven by the motor. [0006] In a preferred embodiment of the latch release device, the worm has a small diameter worm, efficient for the overall size of the device. The combination of an output cam with a gear reduction stage results in high overall force output as well. [0007] In the preferred embodiment of the latch release device, the worm gear is biased against the rotation from the first position to the second position. The ability to implement a biasing return spring provides repeatable uni-directional force output, and without such a spring, bi-directional torque/force output. [0008] In a particular embodiment, the device includes electrically conductive contacts embedded into the housing as the housing is molded from plastic resin, to be in electrical contact with the motor and the same time extending to the exterior of the housing for connection to an electric power supply. The integration of an electrical connector is another example how further functionality without additional components or complexity can be obtained by means of the invention described herein. [0009] The housing of the latch release device can include an injection-molded closure plate, wherein a hollow portion of the housing and the plate have opposing walls shaped to abut a housing of the motor when the hollow portion and the plate are secured together, and the plate further includes protrusions which extend into the housing interior to abut sides of the motor housing to preclude movement therepast. [0010] In another preferred aspect, the closure plate and housing include a plurality of holes in communication with each other and located to permit simultaneous fastening of the housing and closure plate together and fastening of the device adjacent a latch with the cam in operable proximity thereto. This arrangement permits utilization of the same fasteners which mount the unit to a host latch or mechanism to also bind the housing components of the device together. The preferred embodiment thus provides a highly versatile, customizable, compact, low-cost mechanism for power release or locking. BRIEF DESCRIPTION OF THE DRAWINGS [0011] Detailed embodiments of the invention are described below with reference to the accompanying drawings in which: [0012] FIG. 1 a is a perspective view of a motorized latch release device of the present invention installed on an automobile, in a closed position; [0013] FIG. 1 b is similar to FIG. 1 a in which the motorized latch release device is in an open position; [0014] FIG. 2 is a partially exploded view taken from a vantage point similar to that of the previous figures, having the cover plate of the latch release device removed and partially exploded to reveal the electric motor and worm gear arrangement of the mechanism; [0015] FIG. 3 is a more fully exploded view taken from a vantage point similar to that of the previous figures, to reveal the inner housing, worm wheel and spring for biasing the worm wheel towards the closed position, and the seating area for the motor; [0016] FIG. 4 is a plan type of view of the housing, spring and worm wheel with the worm wheel in the closed position; [0017] FIG. 5 is similar to FIG. 4 , but with the worm wheel fully rotated into the open position shown in FIG. 1 ; [0018] FIG. 6 is a perspective view of the exterior of the housing opposite of that shown in FIG. 1 ; [0019] FIG. 7 is perspective view from a vantage point similar to that of FIG. 6 , partially exploded to show the motor and cover plate; [0020] FIG. 8 is a top plan view of the device, as oriented in FIG. 1 ; [0021] FIG. 9 is a bottom plan view of the device, as oriented in FIG. 1 ; [0022] FIG. 10 is a right end view elevation of the device, as oriented in FIG. 1 ; [0023] FIG. 11 is a left end view elevation of the device, as oriented in FIG. 1 ; [0024] FIG. 12 is a rear elevation of the device, as oriented in FIG. 1 ; [0025] FIG. 13 is a plan view of the worm wheel, as viewed from the left of FIG. 7 ; and [0026] FIG. 14 is a sectional elevation of the worm wheel showing the cam installed therewith. DETAILED DESCRIPTION OF THE INVENTION [0027] Turning to the drawings, a motorized latch release device 20 of the present invention is shown generally in FIGS. 1 a and 1 b . In the figures, the device is shown installed on an automobile to permit remote-controlled trunk release by a driver. As illustrated in FIG. 1 a , the trunk is in the closed and locked position. Latch 22 , part of a conventional trunk locking mechanism, is biased in the clockwise direction. Generally speaking, device 20 operates through rotation of an output cam 28 from a closed position shown in FIG. 1 a to an open position shown in FIG. 1 b . This counterclockwise rotation (as viewed in FIGS. 1 a and 1 b ) forces latch 22 rightward from its closed position into a release position, as illustrated by the latch positioned in FIG. 1 b . The output cam 28 automatically rotates back to the closed position of FIG. 1 a after reaching the fully open position. A detailed description of device 20 and its operation is given below. [0028] As shown in FIGS. 2 and 3 , the device includes a hollow housing 30 and a closure plate 32 . Each of these members is injection-molded as single piece of plastic in a one-step process. Integrally molded as part of the housing and affixed within the plastic are electrical connectors, described further below, for connecting an electrical motor 34 of the device to an external power supply. The housing and closure are composed of a suitable plastic, in this case a glass and mineral-reinforced nylon resin. The polymers are generally selected for high strength and stiffness, dimensional stability and resistance to temperature extremes. [0029] As can be seen in FIGS. 2 and 3 , the electric motor 34 includes an output shaft 36 which drives a worm 38 mounted to the external end of the shaft. The device includes a worm gear 40 in meshing engagement with the worm, a helical spring 42 , and a cam shaft 44 upon which the output cam 28 is mounted. As described in greater detail below, these components are arranged such that the spring biases the worm gear, and hence the output cam, in the counterclockwise direction (as viewed in FIGS. 1 a to 3 ), towards the closed position. The motor operates via the worm to drive the worm gear in the clockwise direction, i.e., towards the open position shown in FIG. 1 b. [0030] Electric motor 34 is a high-torque output, low cogging torque 200-series motor with integrated thermal protection, EMC protection and a knurled shaft. Such motors are available, for example, from Mabuchi Motor Co., Ltd. or Johnson Electric North American, Inc. The motor is mounted in a fixed position within the housing, being held in place by positive abutment with surfaces of the housing and closure plate. A cylindrical stub 48 (see FIG. 7 ) of the motor is seated against a concave surface 46 of the housing. The motor housing abuts directly against first and second surfaces 50 , 52 . On the inside of closure plate 32 are two rows of triangular protrusions 54 having facing surfaces 56 located and oriented so as to, with inner surface area 58 of the plate, abut against the motor housing. Cylindrical stub 60 is received between upstanding members 62 , 64 of the inner housing of the device, the side surfaces of each member being in abutment to help hold the shaft end of the motor from moving to the right or left, as oriented in FIG. 1 . The motor includes first and second openings 66 , 68 having electrical terminals disposed therein. Contact posts 70 , 72 are molded into the housing and received within the openings 66 , 68 of the motor each in abutting electrical contact with a terminal of the motor. [0031] The housing includes a socket 74 having first and second prongs 75 a , 75 b molded externally as part of the rear (as oriented in FIG. 1 ) of the housing. Each of the prongs is electrically connected by an embedded conductor to posts 70 , 72 . Preferably, the socket and prongs are designed to receive a standard plug for supplying electrical power to the motor of the latch release device. However, any suitable form of electrical connector will suffice. [0032] Turning back to the drive mechanism for the device, the drive end of the shaft 36 extends about 1.5 cm beyond the end of cylinder 60 in which it is suitably journaled. The free end of the shaft has knurled ridges (not illustrated), parallel to the lengthwise axis of the shaft, pressed into it for a length of about 7 mm. The worm 38 is tubular, having an inner diameter slightly less than the outer diameter of shaft 36 so that receipt of the worm onto the shaft results in a snug fit sufficiently tight for the expected life of the device. The ridges on the shaft are deformed radially inward slightly during assembly of the worm onto the shaft and the ridges help to ensure that the worm is rigidly affixed to the shaft so as not to rotate with respect to the shaft during operation of the device. [0033] Worm gear 40 is preferably injection molded in a single step of a homopolymer acetal selected for its low friction, high wear resistance and dimensional stability properties. Alternative materials are possible. The gear is molded to include a tubular mounting shaft 80 (see FIG. 7 ). The shaft 80 is received into the open end of a cylindrical mount 82 that is integrally molded in the housing 30 . Shaft 80 has an external diameter of about 1 cm. The diameter of the shaft 80 and the internal diameter of the cylindrical mount 82 are closely dimensioned to each other so that there is very little play between the two pieces, but at the same time the worm gear is free to rotate with respect to the cylindrical mount 82 . The abutting surfaces are very smooth, of circular cross-section, and present minimal frictional resistance to rotational movement of the gear about the central axis of the shafts. [0034] In the illustrated embodiment the outer diameter of worm gear 40 is about 2.7 cm, and the width of the wheel rim, i.e., the tooth bearing portion of the wheel, is about 1.1 cm, with the total height of wheel shaft 80 being about 1.6 cm. A stop 84 is molded as part of the worm gear. The stop 84 protrudes from the toothed rim a distance of about 4 mm and extends around the circumference of the rim a distance of about 45 degrees. This stop can be omitted in the case that full 360 degree output rotation is desired. A stop 86 , molded as part of the housing, is radially spaced from the center of mount 82 a slightly smaller distance than the radial distance between worm gear stop 84 and the center of shaft 80 . Housing stop 86 and wheel stop 84 together govern the rotational (angular) distance that the worm wheel is permitted to travel between the closed position ( FIG. 1 a ) and the open position ( FIG. 1 b ), the rotational distance being about 270°. The length of the arc on which housing stop 86 lies is about 45° and the length of the arc on which the worm wheel stop 84 lies is about 45° so that together the two stops together extend about 90° along the common circle on which they together lie. When worm gear 40 is properly mounted and occupying the closed position, abutment surface 90 of the gear stop and abutment surface 92 of the housing stop abut each other to preclude clockwise rotation of the gear. When the gear is rotated counterclockwise to the extreme open position (see FIG. 1 b ) abutment surfaces 94 and 96 of the gear stop and housing stop, respectively, come into abutment with each other so as to preclude further counterclockwise movement of the gear. Because the combined distance of the two stops is 90° of the common circle on which the two stops lie, the rotation of the gear between the closed position and the open position totals 270°. As will be seen further below this is the rotational (angular) distance traveled by cam 28 in operation of the device in releasing the latch. [0035] Worm gear 40 is biased towards the closed position by the helical spring 42 . Spring 42 is installed within the generally toroidal space located between inner surface 98 of wheel rim, the outer surface of gear shaft 80 and inner surface 100 of gear wall 102 . Located within the toroidal space is a protrusion 104 which stands out from the gear wall and serves as a catch for hooked end 106 of the spring. Protrusion 104 includes overhang 108 . By precluding axial movement of the hooked portion of the spring (as in the direction parallel to the central axis of the wheel and away from inner wall 102 ), overhang 108 aids in the installation of the spring during assembly of the device, and helps to ensure that hook 106 of the spring does not slip past the catch during operation of the device. Spring end 110 is in the shape of a hook to latch onto housing surface 96 . It is noted here that gear stop 84 is generally radially spaced outwardly of spring 42 , but that hook 110 protrudes radially outwardly from the remainder of the spring so as to latch onto surface 96 , which is itself radially located to abut surface 94 of the stop of the wheel. Clearance for travel of stop 84 past hook 110 as the wheel rotates into the closed position is provided by locating the hook in recess 112 which encircles cylindrical mount 82 and extends radially outwardly in the neighborhood of stop 86 , as illustrated in FIG. 3 . Hook 110 is thus axially spaced from stop 84 (toward the floor of the housing) to provide for travel of stop 84 past hook 110 . [0036] The spring 42 is installed so as to be under constant tension and is preferably made of spring steel or stainless steel. This results in the worm gear being constantly biased towards the closed position, i.e., in the clockwise direction as viewed in either of FIG. 1 a or 1 b , for example. As the gear is rotated under force provided by the motor through the worm (described in greater detail below), the tension on the spring increases. [0037] The motive force of motor 34 is transferred to worm gear 40 by worm 38 . Thread 76 of the worm engages teeth 114 , which have an axial pitch and lead designed to mesh with the axial pitch and lead of the worm thread. Thus activation of motor 34 results in clockwise rotation of worm 38 (as viewed from the left in FIG. 1 a ), which in turn causes rotation of worm gear 40 in the counterclockwise direction, as viewed in FIG. 1 a . Activation of motor 34 by application of appropriate electrical current can be instituted as by an appropriately wired button located for access by the driver, or by an activation circuit under remote control, etc. In the position of FIG. 4 , the torque on the worm wheel from the spring is about 330 Nmm, and the torque from the spring is about 380 Nmm when the worm wheel is in the position shown in FIG. 5 . [0038] Rotation of worm gear 40 will eventually be halted by abutment of stop surfaces 94 , 96 when the gear has rotated through an angle of about 270° to the fully open position, as previously described. Halting the gear rotation prevents the worm from turning, and hence causes motor 34 to stall. The power supplied to the motor is cut off and the stored energy in the coiled spring causes the worm gear to rotate back to the closed position. [0039] The worm gear 40 has a central aperture 116 which receives a shaft 44 attached to cam 28 . The cam and shaft are injected molded as a single piece of the same type of plastic as the worm gear. The exterior profile of the cross-section of shaft 44 matches the cross-section of central aperture 116 of the gear and the cross-sections are non-circular. Shaft 44 received into the aperture is thus fixed against rotation with respect to the axis of the worm gear. Installed shaft 44 is also centered on the central axis of the worm gear so that when the gear rotates about the axis so too does the cam shaft. It will further be noted that the engagement of surfaces of the shaft 44 and aperture serve to orient the cam for operation between the closed and open positions. [0040] Cam 28 is installed as part of the device after assembly of the closure and housing, described further below. This is accomplished through tabs 150 at the free end of shaft 44 . Each tab is located at the end of finger 152 , the fingers being radially spaced apart from each other on opposite sides of the central axis of shaft 44 . Each tab includes abutment surface 154 which opposes and abuts surface 156 surrounding the central aperture of worm wheel 40 . Opposing tab surfaces 154 is surface 158 of shaft 44 , surface 158 being in abutment with surface 160 of the worm gear. Thus, for installation, cam shaft 44 is inserted through aperture 162 and into worm wheel aperture 116 . Chamfered lead surfaces 164 of the tabs abut against inner surfaces of narrowed portion 117 of aperture 116 squeezing the resilient fingers together as they pass through the narrowed passage, eventually springing apart into the installed position shown in FIG. 14 in which surfaces 154 , 156 abut each other, and surfaces 158 , 160 abut each other, to affix the cam against axial movement with respect to the worm wheel. [0041] The cross-sectional profile of the cam surface is wing-shaped. Translation of the rotational motion of the cam shaft 44 through the cam surface to move latch 22 from the closed position to the release position is illustrated in FIGS. 1 a and 1 b . As shaft 44 rotates, the cam surface area generally designated as 118 contacts latch 22 . As this rotation occurs, the radial distance (from the center of shaft 44 ) of the contact portion of the cam surface with the latch is in contact increases resulting in forced movement of the latch from the closed position towards the release position. As described above, the worm gear and affixed cam rotate until the fully open position 28 a ( FIG. 1 b ) is reached and motor 34 stalls, which stall leads to the eventual return of the cam to the closed position. [0042] The cam profile converts the output torque to a linear force pushing against a movable lever, plate or other feature to which one desires a force to be applied. This cam functions as a further gear ratio for the system, where smaller distances pushed by the full rotation of the cam are seen to result in higher applied forces by the cam. [0043] It is possible that the installed device could be exposed to minor amounts of water from time to time, as when a trunk was opened during a rainstorm, etc. To lessen the possibility of damage from such exposure, a liquid flow path for such liquids is provided around the periphery of the plate closure edge. Ridge 120 , molded as part of housing 30 , and ridge 122 , molded as part of the closure plate 32 are thus shaped to abut against opposing surfaces (of the closure plate and housing, respectively) to provide a limited seal against ingress of water. Further, the ridges are spaced slightly inwardly from the extreme periphery so that a liquid flow passage 124 is defined around the periphery of the ridges. [0044] Housing 30 and closure plate 32 are conveniently assembled together during manufacture of device 20 through a single assembly screw 126 received through plate aperture 128 , the screw shaft being received into housing aperture 130 . Aperture 130 is of smaller cross-section than the shaft of the screw so that the threads of the screw become embedded in the plastic wall of the housing during assembly. [0045] The housing and plate have a further three pairs of communicating apertures 132 , 134 , 136 . These apertures are used during installation of the device onto the automobile latch by fasteners 138 , 140 , 142 . Areas 144 , 146 , 148 of the external plate surface surrounding the apertures are in positive abutting contact with surfaces of the automobile when installed. (This could equally apply to external areas of the housing surround the apertures.) In this way, when the device is installed with the remainder of the latch, compressive forces are further applied to the housing and closure by their being sandwiched between the heads of fasteners 138 , 140 , 142 and auto surfaces with which plate areas 144 , 146 , 148 are in positive abutting contact. [0046] Spring 42 of the illustrated device can be omitted, which of course would free the worm wheel from biasing. In such situation, the control circuitry for the device may be modified to drive the motor in first and second directions so as to move the cam from the first to the second (nominally open to the closed) positions illustrated in FIGS. 1 a and 1 b , respectively, and to move the cam from the second to the first positions. The device could thus alternatively be used, for example, to positively move a latch between first and second positions, e.g., a lock lever may be moved between locked and unlocked positions. It will be appreciated that the cam or other output arm may have a different profile for different applications. [0047] The illustrated embodiment has been described with particularity for the purposes of description. Those skilled in the art will appreciate that a variety of modifications may be made to the embodiment described herein without departing from the spirit of the invention.	A power actuator for automotive door latches. The actuator includes an electric motor mounted in a housing. A worm is operatively coupled to the motor for driving rotation of the worm about an axis in a first rotational direction. A worm gear, which meshes with the worm, is mounted in the housing for rotation about an axis substantially orthogonal to the worm axis. A camshaft is mounted on the worm gear and has a rotation axis coincident with the gear axis. An output arm is affixed to the distal end of the camshaft for engaging the lever of a latch. The power actuator uses a reduced number of components.	8
RELATED TO OTHER APPLICATIONS This application is a continuation-in-part of Ser. No. 734,800, filed Oct. 22, 1976, now abandoned. BACKGROUND OF THE INVENTION This invention relates to a suture package which permits direct dispensing of a sterile surgical suture with or without a needle attached. More specifically, to a suture package having a bell shaped configuration that can be torn from a tear notch across the lower portion of the bell shape to expose a looped end of the sterile surgical suture. A suture is a strand of material suitable for suturing, with or without an attached needle, used for ligating or other surgical procedures. The packaging of many commercial products is essential to the proper and use of the product and thus forms an integral part of the overall product design. The significance of packaging is most evident in the packaging of surgical sutures. It is essential that the package protect the product and maintain sterility throughout its period of potential use. Sutures may be stored in hospitals for several years, although the usual storage time is much shorter. It is essential that the package provide rapid and positive means of identification and release the product undamaged ready for use by the surgeon. There are many sizes of sutures, and many materials of construction such as catgut or polyglycolic acid for absorbables, silk, cotton, nylon, dacron, polyethylene, polypropylene, stainless steel, insulated stainless steel and other materials for use as non-absorbables. There are several different needle types in common use including pointed straight, pointed curved, three cornered straight, three cornered curved, curved both regular and reverse cutting, and needles with side cutting edges of various types. The variations and combinations of each of these to meet the preference of many surgeons for different operative procedures means that the suture manufacturer needs to supply different suture combinations running into the thousands. The importance of positive identification and efficient, economical packaging can thus be readily appreciated. It is also important to provide convenience to the use and limit the risk of accidently enclosing foreign items in the patient by limiting the number of extraneous packaging materials associated with use of the product in the operating theater. A count is often kept to ensure that each item is accounted for and removed from the operating field. Considering the ramifications of enclosing such material in the patient accidently during surgical procedures, it is obviously essential to minimize this hazard. It is also important that the surgical package properly present the suture suitably oriented within the package so that the user can rapidly and reliably have access to the suture end, either needled or non-needled, in the proper position for dispensing from the package. It is important also, to provide a standard packaging format for all multiple suture materials to limit confusion on the part of the user during surgical procedures. Over the years various package styles have evolved that have detracted from user convenience and operating room efficiency. For purposes of storage in the hospital as well as economy of manufacture, it is highly desirable that as many suture combinations as feasible be packaged in a minimum number of different package styles and shapes and storage units. It is quite common to package 3 dozen identical sutures in a box. It is convenient to have most of the boxes about the same size and shape, so that the hospital may store them most conveniently. It is also convenient from the manufacturers stand point to be able to reduce his inventory of box sizes and to be able to use the same components for the maximum number of suture combinations in the product line. It is essential that a package containing a needled surgical suture protect the suture from contact with the sharp point or cutting edge of the needle which could partially cut or fray the suture. These requirements are so rigorous and of such importance that many different package designs have been tried. Applicant is not aware of any prior art reference which, in his respective judgment as one skilled in the suture packaging art, would anticipate or render obvious the suture package of the instant invention; however, for the purpose of fully developing the background of the invention and establishing the state of the requisite art, the following references are set forth: U.S. Pat. Nos. 3,939,969; 3,357,550; 3,221,873; 3,202,273; and 2,949,181. These patents are incorporated herein by reference. Generally, these patents disclose a surgical suture packaged in an outer plastic or foil strippable envelope. Contained in the strippable envelope is an inner or pouch which is sterile. The suture strand has been formed into various retainers, labels, or reels, within the inner envelope. The suture is normally prepared for the surgeon by stripping the outer envelope and transferring the inner envelope by sterile forceps, or by projecting it across a sterile barrier, into the sterile areas of the operating room. The inner envelope is opened at the time of use. The inner envelope and suture retaining label of the present invention for a needled or non-needled suture have advantages over these prior art patents. After tearing the inner envelope of the present invention, the suture retaining label is used for direct dispensing of the suture without extracting the label from the inner envelope. Access to the suture is provided by a loop at the suture and which is pulled after tearing the inner envelope. The suture unwinds from its array within the package upon pulling the loop. Because the inner envelope, the torn portion of the inner envelope, and the suture retaining label remain together after opening, the proliferation of packaging materials within the immediate area of the operation or other surgical procedure is reduced. In most operations and surgical procedures, the materials used for the operation or surgical procedure are counted subsequent to the operation or surgical procedure. The label, the inner envelope and the torn portion of the inner envelope of the present invention provide a readily identifiable and countable package. Further, the size of the needle and the type of suture strand can be printed on the suture retaining label. This provides ready identification in a surgical procedure where more than one size and type of suture is used. Also, because the inner envelope is clear, the size and type of suture and needle can be confirmed visually before the suture is dispensed. Perhaps of most importance and the greatest advantage to the package of the invention is the bell shaped configuration of the top portion of the inner envelope. The bell shaped seal allows more surface area for grasping by the hand. When the inner envelope contains a liquid e.g., a conditioning liquid or softening solution, the bell shaped configuration eliminates or minimizes the squirting of the liquid or solution by hand pressure on the envelope. The bell shaped configuration also gives a "bottle effect" to the package. The wider seal gives more rigidity and support to the top of the package even after opening. This tends to keep the opening closed. Also, because there is a narrower opening, the flow of the liquid is restricted. Also, the narrower opening tends to retain the liquid within the larger end of the package after it is opened. The Bell shaped configuration is unusual in the heat sealing art generally and in suture packaging specifically. In the heat sealing art, a contoured shape can be more difficult to fabricate because of closer tolerances in the tool design of the sealer, and in sealing pressure applied. The usual configuration in suture packaging is rectangular with the remaining side being a chevron or "cathedral roof" configuration. See, e.g., U.S. Pat. Nos. 3,357,550; 3,256,981 and 2,949,181 which are incorporated herein by references. Perhaps of equal importance to the bell shaped configuration is the direct dispensing of the suture strand from the package of this invention. In the prior art, the suture strand has been contained in or on various retainers, labels, or reels. The suture is dispensed by opening the package, e.g. by tearing or peeling, pulling out the wrapped suture, and then unwinding or separating the suture from its wrapper. The package of this invention is direct dispensing. Upon opening the package, the suture is directly removed from the package without having to unwind or separate the suture from its retainer label. This has the advantage of saving time, which in a surgical procedure can be of extreme importance. Another advantage of the direct dispensing package of this invention is that the suture is directly dispensed from the end. The suture is thus readily available for immediate use, either by hand or by use of a needle holder. Still another advantage is that the suture retainer label is retained in the package after direct dispensing of the suture. This has the advantage of reducing the amount of loose packaging materials in the surgical area. Still another advantage is that, because an accounting is usually made after a surgical procedure, the inner envelope, the torn portion of the inner envelope, and the retainer label can be counted as one piece after direct dispensing of the surgical suture. Still another advantage of the package of this invention is the textured surface of the sealed area. This allows for a secure grip, for example, by the thumb and index finger. Also, because of the textured surface, the amount of hand pressure which would have to be applied to the sealed area during tearing may be reduced. SUMMARY OF THE INVENTION A direct dispensing suture package has been invented. By direct dispensing is meant that only the suture is removed from the sealed envelope, after the envelope is opened. This direct dispensing suture package comprises a transparent envelope which is heat sealed. On three sides of the envelope, the heat seal is adjacent the edge. On the remaining side, the heat seal is a bell shaped configuration. In the preferred embodiment, the package perimeter is rectangular. Adjacent the lower portion of the bell shaped configuration, and on the edge of the package is at least one notch. The lower portion of the bell shaped configuration is the widest part of the bell shape. In the preferred embodiment, two notches are adjacent the lower portion on opposite edges of the package. A textured surface for gripping by hand is adjacent the bell shaped configuration. The textured surface allows for a secure grip by the thumb and index finger of the user. The textured surface is of such a size as to prevent hand pressure on the bell shaped configuration by the user. A label is contained in the envelope and is larger than the bell shaped configuration. Thus when the suture is directly dispensed from the envelope, the label is retained in the package. In the preferred embodiment, the label is folded into about four equal parts. The geometry of the folds is not critical as long as a suture strand is held in the label and the suture is directly dispensed after the package is opened. In another embodiment, the label is folded into at least about two equal parts horizontally from the bottom. In yet another embodiment, the label is folded into at least about two equal parts vertically from one side. In another preferred embodiment, the label contains identifying information on the suture and/or the needle. Because the envelope is transparent, the identifying information can be contained on both sides of the label. A suture strand is held in the label described above. In the preferred embodiment, the end of the suture strand looped into the bell shaped configuration is needled. In another preferred embodiment, the envelope contains a conditioning liquid. In the most preferred embodiment, the envelope contains a conditioning liquid wherein the suture strand is catgut and the end of the suture strand is needled. In other embodiments, the suture strand held in the label described above is either nylon, dacron, polyethylene or polypropylene. The configuration of the suture strand in the label is not critical to the practice of this invention except that the configuration must allow for direct dispensing of the suture when the envelope is opened. In this regard, a figure eight and a serpentine configuration have been found to be effective. These configurations are therefore preferred. The end of the suture strand is looped into the bell shaped configuration. The end of the suture strand is available for visual identification without opening the package. The end of the suture strand, because it is looped into the bell shaped configuration, prevents the suture strand in the label from being damaged. This is especially important when the end of the suture strand is needled. The bell shaped configuration is opened from the notch to the opposite lower portion of the bell shape. The end of the suture strand is then pulled by hand or by a needle holder for direct dispensing from the package. The suture strand unwinds within the envelope. The label is left with the package and the bell shape configuration is left on the envelope. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a front view of the envelope describing the bell shaped seal, the notched edges and the textured surface at the smaller end of the envelope. FIG. 2 is a front view of the envelope illustrating the opening of the envelope by hand-tearing across the smaller end. The wide heat seal area tends to prevent hand pressure on the fluid and to eliminate squirting. FIG. 3 is a front view of the opened envelope illustrating the ease of grasping the loop of catgut suture situated in the smaller end of the enclosure. The torn portion is not detached from the envelope. FIG. 4 is a front view of the inner envelope illustrating the direct dispensing of catgut suture from the envelope. The label remains within the envelope. DESCRIPTION OF THE PREFERRED EMBODIMENT This invention relates to catgut sutures which are needled and non-needled. The envelope contains a conditioning liquid which is required for the preservation of catgut sutures. Conventional conditioning liquids include ethyl alcohol or a mixture of ethyl alcohol, isopropyl alcohol, and water. Conditioning liquids can also contain a germicidal agent, and/or a rust inhibitor to prevent rusting of needles which may be attached to the sutures. Although the bell shaped configuration of the package of this invention is particularly suited to envelopes containing a suture in a conditioning liquid, it is to be understood that other suture materials such as nylon, dacron, polyethylene and polypropylene could be directly dispensed from the package without the conditioning liquid. The invention is more fully described in the figures. Referring to FIG. 1, on envelope 12 has been contoured heat sealed 16 to form an enclosure 17 which is smaller at one end. The contoured bell shaped configuration provides an enclosure for a dispensing loop of the invention. The outer edge of the envelope 12 is notched 13 near the lower portion of the bell shape. The contoured heat sealed area around the bell shape is textured 10. As shown in FIG. 3, the envelope 12 is opened by hand-tearing, beginning at the notch 13, across the smaller enclosure. This exposes an extended loop 18 of the enclosed catgut suture. The amount of conditioning liquid 20 in the envelope is such that when the envelope is opened, the level of the liquid is below the torn portion 14 of the envelope. The torn portion 14 is not detached from the envelope 12. FIGS. 3 and 4 illustrate the direct dispensing of the catgut suture. In FIG. 3, the catgut suture and 18 is grasped for removal from the envelope. In FIG. 4 the suture is removed by direct dispensing of the catgut suture and 18, either by hand as described or by needle holder. The catgut suture is directly dispensed by unwinding within the package. The label 19 and the conditioning liquid 20 are retained within the larger end of the envelope. The envelope can be designed from two separate, flexible, transparent sheets. While other flexible transparent materials, such as polyamid (or nylon), may be used, it is preferred that the envelope consist of a laminate having an external surface of a polyester film, such as the polyester of theylene glycol and terephthalic acid, which is sold under the trademark "Mylar" with an interior polyethylene or The envelope can be formed by adhesively uniting the films. It is preferred, however, to heat seal the films on the inside. The suture is folded in the label and inserted into the envelope. In the preferred embodiment, the suture is folded in a figure eight or serpentine configuration in the label. The label can be made of any foldable sheet material, such as paper. The label retains the suture is a configuration for direct dispensing within the larger end of the inner envelope. The label also provides identifying information, e.g. as to the length, size, and type of the suture and the needle. The envelope can be sterilized by either radiation or by placing the envelope in a sterilizing chamber containing sterilizing gas, such as ethylene oxide. The description of this invention is for preferred embodiments only. Any modifications which are within the scope of the claims and which suggest themselves to those skilled in the art are within the scope of this invention.	A catgut suture package is disclosed which upon opening exposes the looped end of a catgut suture. The suture loop is directly dispensed from the package leaving the label intact within the envelope.	0
BACKGROUND OF THE INVENTION The present invention relates to liquid crystal compositions and, more particularly, to novel liquid crystal compositions having a terphenyl constituent mixed with a four-part cyclohexane constituent. Use of liquid crystal displays is desirable, due in part, to the relatively low operating power consumption thereof. Typical liquid crystal materials for use in such displays, and typically utilized as a host material for a guest dichroic dye in dichroic liquid crystal displays, have generally been unable to provide a working temperature range from a melting point of less than 0° C. to a clearing point (the nematic-to-isotropic transition temperature) of greater than 85° C. In many applications, this extended temperature range of 0° C. to +85° C. is required. For example, commercially available liquid crystals of the biphenyl type, found to be useful for display devices due to relatively good stability and electro-optic behavior, may be eutectic mixtures, such as are sold under the designations E-7 and E-8 by BDH Chemicals, of Great Britain; the nematic range of the E-7 mixture is about 0° C. to about +60° C., whereas the nematic range of the E-8 mixture is about -10° C. to about + 70° C. A eutectic mixture of three phenylcyclohexanes and one biphenylcyclohexane, commercially available as Merck 1132, from EM Laboratories, Darmstadt, West Germany, has a nematic range of -6° C. to +70° C. It is known that the operating temperature range of a liquid crystal composition may be broadened by adding another liquid crystal material which has a very high nematic-to-isotropic transition temperature material will raise the nematic-to-isotropic transisition temperature of the mixture, but, depending upon the interaction of the additive with the molecules of the original liquid crystal composition, the melting temperature (crystal-to-nematic transition temperature) may be increased and an incompatibility between the original and additive liquid crystal compositions may be found. There is, therefore, a very delicate balance of lateral and intermolecular attractions between molecules which allows a liquid crystal mixture to have a broad nematic range, while possessing stable structures, and which results are presently incapable of precise prediction when original and additive liquid crystal materials are mixed together to form a liquid crystal composition having a desired nematic temperature range. BRIEF SUMMARY OF THE INVENTION In accordance with the invention, nematic liquid crystal compositions having a broad operating temperature range from about 0° C. to about +85° C. are produced by mixing 75-90% by weight of a four-part liquid crystal composition of cyclohexane materials, with about 10% to about 25%, by weight, of a terphenyl liquid crystal material. In several preferred embodiments, the four-part cycloclohexane composition, comprised of about 24%, by weight, of trans-4-n-Propyl-(4-cyanophenyl)-cyclohexane; 36%, by weight, of trans-4-n-Pentyl-(4-cyanophenyl)-cyclohexane; 25%, by weight, of trans-4-n-Heptyl-(4-cyanophenyl)-cyclohexane; and 15%, by weight, of trans-4-n-Pentyl-(4'-cyanobiphenyl-4)-cyclohexane, is mixed with 4-n-Pentyl-4"cyano-p-terphenyl. In one presently preferred mixture, 10%, by weight, of the biphenyl cyclohexane is added to a mixture of 75% of the 4-part cyclohexane composition and 15%, by weight, of the terphenyl composition, to achieve a nematic liquid crystal composition having an unusually broad temperature range from approximately 0° C. to about +103° C. Accordingly it is one object of the present invention to provide liquid crystal compositions having broad nematic temperature ranges. This and other objects of the present invention will become apparent upon consideration of the following detailed description. DETAILED DESCRIPTION OF THE INVENTION Liquid crystal compositions having broad nematic temperature ranges, wherein the compositions are in the liquid crystal phase over the temperature range from about 0° C. to at least 85° C., are formulated by combining between 10% and 25%, by weight, of the terphenyl liquid crystal additive 4-n-pentyl-4"cyano-p-terphenyl, available as T-15 (from E. Merck Co.), having the chemical formula: ##STR1## with about 75-90%, by weight, of a 4-part cyclohexane liquid crystal mixture. The cyclohexane mixture, commercially available as Merck 1132 (from E. Merck, Darmstadt, West Germany) is a mixture of about 24%, by weight, of trans-4-n-Propyl-(4-cyanophenyl)-cyclohexane, having the chemical formula ##STR2## which constituent is available from E. Merck as Licristal® S1103; about 36%, by weight, of trans-4-n-Pentyl-(4-cyanophenyl)-cyclohexane, having the chemical formula ##STR3## available as Licristal® S1114; about 25%, by weight, of trans-4-n-Heptyl-(4-cyanophenyl)-cyclohexane, having a chemical formula ##STR4## available as Licristal® S1115; and about 15%, by weight, of trans-4-n-Pentyl-(4'-cyanobiphenyl-4)-cyclohexane, having a chemical formula ##STR5## and available as Licristal® S1131. In a first preferred liquid crystal composition, 10%, by weight, of the terphenyl additive (0.10 grams) is mixed with 90%, by weight, (0.90 grams) of the 4-part mixture, which may be formed of about 0.22 grams of the first constituent, about 0.32 grams of the second constituent, about 0.23 grams of the third constituent and about 0.14 grams of the fourth constituent thereof. The mixture is compatible at room temperature, showing a relatively low viscosity, and having a melting point temperature of about -10° C. and a nematic-to-isotropic transition (clearing point) temperature of about +87° C. In a second presently preferred composition, about 17%, by weight, of the terphenyl additive (0.17 grams) is mixed with about 83%, by weight, (0.33 grams) of the 4-part cyclohexane mixture (about 0.20 grams of the first constituent, about 0.30 grams of the second constituent, about 0.21 grams of the third constituent and about 0.12 grams of the fourth constituent). This mixture appears compatible at room temperature and has a melting point temperature of approximately 0° C. and a nematic-to-isotropic transition (clearing point) temperature of about +97° C. A third composition (composition 3) adds about 25% by weight, of the terphenyl additive (0.25 grams) to about 75%, by weight, (0.75 grams) of the 4-part cyclohexane mixture (with about 0.18 grams of the first constituent, about 0.27 grams of the second constituent, about 0.19 grams of the third constituent and, about 0.11 grams of the fourth constituent) to provide a compatible mixture having a melting point at about +18° C. and a nematic-to-isotropic (clearing point) temperature of +109° C. Another presently preferred liquid crystal composition (composition 4) is a mixture of 75%, by weight, (0.75 grams) of the 4-part mixture (with the first through fourth constituents being present, by weight, in respective proportions of about 0.18 grams, 0.27 grams, 0.19 grams and 0.11 gram), with an additional 10%, by weight, (0.10 grams) of the fourth constituent of trans-4-n-Pentyl-(4'-cyanobiphenyl-4)-cyclohexane, and 15%, by weight, (0.15 grams) of the terphenyl additive (0.15 grams). This mixture has a melting point temperature of approximately 0° C. and a clearing point temperature of approximately 103° C. The trans-4-n-Pentyl-(4'-cyanobiphenyl-4)-cyclohexane constituent itself has a nematic range of +94° C. to +219° C. Composition four was evaluated by the addition of about 0.03 grams of an optically-active biphenyl material, 4 act-amyl-4'-cyanobiphenyl, having the chemical formula ##STR6## which is commercially available as CB-15 from E. Merck Co. and the further addition of about 0.003 grams of the dichroic dye 4,4'-bis-(4-N,N-diethylamino-2-methyl-phenylazo) azobenzene, as disclosed in U.S. Pat. No. 4,128,497, issued Dec. 5, 1978 and incorporated herein by reference. The dichroic dye has an order parameter S=0.78 and a wavelength of maximum absorption of 570 nanometers, in the 4-part cyclohexane composition, with no additives. This cholesteric dichroic formulation was tested in a 12 micron cell with transparent conductive electrodes. Upon voltage application, the cholesteric helix unwound to the homeotropic nematic state with the optical appearance transitioning from an intense purple, in the no-voltage-applied condition, to substantially white in the voltage-applied condition. The threshold voltage was measured at about 5.8 volts, at 25° C., with a gradual decrease in threshold voltage as the temperature was increased, whereby, at 75° C., the threshold voltge was about 5.0 volts and at 95° C., the threshold voltage was about 4.5 volts. The cell displayed adequate contrast up to 95° C. with cessation of electro-optic effects occurring at about 103° C. as the liquid crystal composition entered the isotropic region. The first composition was further tested by the addition to another sample of approximately 0.06 grams of the abovespecified dichroic dye. The dichroic nematic liquid crystal material thus formed was placed within the cavity of a liquid crystal display having cell walls treated to give parallel boundary conditions. A single polarizer was positioned on the 12 micron cell such that linearly polarized light was absorbed by the aligned dichroic dye-liquid crystal host layer. The colored state was intensely purple by transmission and, upon voltage activation, the dye-host molecules were reoriented to give a clear transparent state. The order parameter S of this guest dye-host liquid crystal system was measured to be 0.78, at room temperature, with order parameter being measured at greater than 0.60 at 75° C. It has also been found that certain dyes will have superior alignment, and hence improved order parameter values, when dissolved in the first mixture. For example, a commercially available dichroic dye D-27 (available from E. Merck Co.) which is 1-hydroxy-4-(p-dimethylaminophenyl)-anthraquinone, having a chemical formula ##STR7## has order parameter S of about 0.62 in the commercially-available E-7 liquid crystal material, and order parameter S=0.64 in the Merck 1132 material, but has a higher order parameter S=0.67 when dissolved in composition 1. Accordingly, dichroic liquid crystal displays having improved contrast may be fabricated by use of certain known dichroic dyes dissolved in the first liquid crystal composition. While several preferred liquid crystal compositions have been set forth in detail hereinabove, many variations or modifications will now become apparent to those skilled in the art. For example, other chiral additives known in the art could be used to give a guest-host effect utilizing the cholesteric to nematic transition. Other terphenyls which would be of equal utility were published by G. W. Gray, K. J. Harrison and J. A. Nash, J. Chem. Soc. Chem. Commun., 431 (1974). ______________________________________ ClearingCompound M.P. Point______________________________________4-n-propyl-4"-cyano-p-terphenyl 182° C. 275.5° C.4-n-butyl-4"-cyano-p-terphenyl 154° C. 242° C.4-n-hexyl-4"-cyano-p-terphenyl 125° C. 228° C.4-n-heptyl-4"-cyano-p-terphenyl 134° C. 222° C.4-n-actyl-4"-cyano-p-terphenyl 127° C. 216° C.______________________________________ It is my intent, therefore, to be limited only by the scope of the appending claims and not by the specific details set forth herein.	Novel liquid crystal compositions having extended temperature ranges, without sacrifice of stability, are provided by mixing 10-25%, by weight, of a terphenyl liquid crystal material with 75-90%, by weight, of a four-component liquid crystal composition of cyclohexanes.	2
This is a divisional of copending application U.S. Ser. No. 08/425,989 filed Apr. 20, 1995, which is a continuation of U.S. Ser. No. 08/156,653 filed Nov. 22, 1993, now abandoned, which is a continuation of U.S. Ser. No. 08/005,204 filed Jan. 15, 1993, now abandoned, which is a continuation of U.S. Ser. No. 07/449,356 filed Dec. 21, 1989, now abandoned, which is a continuation-in-part of U.S. Ser. No., and a continuation-in-part of U.S. Ser. No. 07/445,951 filed Dec. 13, 1989, now abandoned, which is a continuation-in-part of U.S. Ser. No. 07/301,192 filed Jan. 24, 1989, which issued as U.S. Pat. No. 5,235,049 on Aug. 10, 1993. BACKGROUND OF THE INVENTION The present invention relates to a soluble form of intercellular adhesion molecule (sICAM-1) as well as the DNA sequence encoding sICAM-1. sICAM-1 and ICAM-1 have substantial similarity, in that they share the first 442 NH 2 -terminal amino acids of the extracellular domain. However, sICAM-1 differs from ICAM-1 at the C-terminus, and these changes confer solubility to sICAM-1. ICAM-1 is known to mediate adhesion of many cell types, including endothelial cells, to lymphocytes which express lymphocyte function-associated antigen-1 (LFA-1). ICAM-1 has the property of directly binding LFA-1. There is also evidence for LFA-1 mediated adhesion which is not via ICAM-1. Additionally, ICAM-1 has the ability to bind both LFA-1 and human rhinovirus. It has the property of inhibiting infection of rhinovirus and Coxsackie A viruses. It may be used to antagonize adhesion of cells mediated by ICAM-1 binding including ICAM-1/LFA-1 binding and thus be useful in treatment of inflammation, graft rejection, LFA-1 expressing tumors, and other processes involving cell adhesion. Based on the substantial similarity of the extracellular domains of ICAM-1 and sICAM-1, sICAM-1 has the properties identified for ICAM-1. The major Human Rhinovirus Receptor (HRR) has been transfected, identified, purified and reconstituted as described in co-pending U.S. patent applications Ser. No. 262570 and 262428 filed Oct. 25, 1988. This receptor has been shown to be identical to a previously described cell surface protein, ICAM-1. European Patent Application 0 289 949 describes a membrane associated cell adhesion molecule (ICAM-1) which mediates attachment of many cell types including endothelial cells to lymphocytes which contain LFA-1. This patent application provides a discussion of the present research in the field of intercellular adhesion molecules. It is important to note that the inventors specifically looked for an alternatively spliced mRNA for ICAM-1 and did not identify one. ICAM-1 was first identified based on its role in adhesion of leukocytes to T-cells (Rothlein, R. et al, J. Immunol. 137: 1270-1274 (1986)) which has been shown to be mediated by the heterotypic binding of ICAM-1 to LFA-1 (Marlin et al, Cell 51: 813-819 (1987)). The primary structure of ICAM-1 has revealed that it is homologous to the cellular adhesion molecules Neural Cell Adhesion Molecule (NCAM) and Mylein-Associated Glycoprotein (MAG), and has led to the proposal that it is a member of the immunoglobulin supergene family (Simmons et al, Nature 331: 624-627 (1988); Staunton et al, Cell 52: 925-933 (1988) The DNA sequence of cDNA clones are described in the above referenced papers by Simmons et al and Staunton et al, supra, from which the amino acid sequence of ICAM-1 can be deduced. The ICAM-1 molecule has a typical hydrophobic membrane spanning region containing 24 amino acids and a short cytoplasmic tail containing 28 amino acids. The ICAM-1 of the prior art is an insoluble molecule which is solubilized from cell membranes by lysing the cells in a non-ionic detergent. The solubilized ICAM-1 mixture in detergent is then passed through a column matrix material and then through a monoclonal antibody column matrix for purification. SUMMARY OF THE INVENTION The present invention provides an endogenous alternatively spliced molecular species of ICAM-1 designated sICAM-1 which displays an alternative mRNA sequence and which is soluble without the addition of a detergent. The present invention provides purified and isolated human soluble intercellular adhesion molecule (sICAM-1), or a functional derivative thereof, substantially free of natural contaminants. sICAM-1 can be obtained from HeLa, HE1 and primary transfectant cells thereof characterized by being soluble in the absence of nonionic detergents and being the translation product defined by a novel mRNA sequence. This natural product of human cells has the advantage of being secreted from cells in a soluble form and not being immunogenic. The natural soluble product differs from the natural insoluble product in that the soluble product contains a novel sequence of 11 amino acid residues at the C-terminus and does not contain the membrane spanning and cytoplasmic domains present in the insoluble form. The present invention provides a purified and isolated DNA sequence encoding sICAM-1 as well as a host cell encoding said sequence. The present invention provides a method of recovering soluble intercellular adhesion molecule in substantially pure form comprising the steps of: (a) removing the supernatant from unlysed cells, (b) introducing the supernatant to an affinity matrix containing immobilized antibody capable of binding to sICAM-1, (c) permitting said sICAM-1 to bind to said antibody of said matrix, (d) washing said matrix to remove unbound contaminants, and (e) recovering said sICAM-1 in substantially pure form by eluting said sICAM-1 from said matrix. Further purification utilizing a lectin or wheat germ agglutinin column may be used before or after the antibody matrix step. Other purification steps could include sizing chromatography, ion chromatography, and gel electrophoresis. Further purification by velocity sedimentation through sucrose gradients may be used. The antibody capable of binding to sICAM-1 could include antibodies against ICAM-1 or HRR. The present invention includes polyclonal antibodies against sICAM-1. The present invention further includes an antibody specific for sICAM-1, capable of binding to the sICAM-1 molecule and that is not capable of binding to ICAM-1. For a method for producing a peptide antisera see Green et al, Cell 28: 477-487 (1982). The invention also includes a hybridoma cell line capable of producing such an antibody. This invention further includes the therapeutic use of antibodies specifically directed to sICAM-1 to increase the adhesion of cells mediated by ICAM-1 and LFA-1. The invention further includes a method for producing an antibody which is capable of binding to sICAM-1 and not to ICAM-1 comprising the steps of (a) preparing a peptide-protein conjugate said peptide-protein conjugate specific to at least a portion of the unique 11 amino acid sequence present in sICAM-1, (b) immunizing an animal with said peptide-protein conjugate, (c) boosting the animals, and (d) obtaining the antisera. The antibodies would be capable of binding to sICAM-1 and not capable of binding to ICAM-1. The invention includes the hybridoma cell line which produces an antibody of the same specificity, the antibody produced by the hybridoma cell and the method of production. The invention further includes a method of inhibiting lymphocyte function associated antigen (LFA-1) and intercellular adhesion molecule-1 (ICAM-1) interaction comprising the step of contacting LFA-1 containing cells with sICAM-1 or a functional derivative thereof. This method of inhibition of ICAM-1 adhesion has application in such disease states as inflammation, graft rejection, and for LFA-1 expressing tumor cells. This invention further includes a method of diagnosis of the presence and location of an LFA-1 expressing tumor cell. This invention further includes a method for substantially reducing the infection of human rhinoviruses of the major receptor group comprising the step of contacting the virus with sICAM-1 or a functional derivative thereof. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1, parts A and B, shows the nucleotide and amino acid sequence of sICAM-1. FIG. 2 is a comparision of the C-terminal regions of sICAM-1 and ICAM-1. The nucleotide and deduced amino acid sequences of ICAM-1 and sICAM-1 are shown beginning at amino acid residue 435. Dashes in the sICAM-1 sequence indicate missing nucleotides. The positions of the stop codons in both proteins are indicated by an asterisk. FIGS. 3A and B are comparison of the structure of sICAM-1 and ICAM-1. The membrane spanning region of ICAM-1 is indicated by the stippled box and the cytoplasmic domain by the hatched box. The novel C-terminus of sICAM-1 is indicated by the solid box. The five predicted domains showing homology with immunoglobulin are numbered I to V. FIGS. 4A, B, and C show the ICAM-1 gene and its expression in HRR transfectants. FIG. 4A: Southern blot of HeLa (Lane 1), LTK- (Lane 2) and HE1 (Lane 3) DNA restricted with Eco R1 and probed with the oligonucleotide ICAM-1; FIG. 4B: Northern blot of HeLa (Lane 1), Lkt 31 (Lane 2), and HE1 (Lane 3). poly A+ RNA probed with the oligonucleotide ICAM-1; FIG. 4C: PCR amplification of cDNA prepared from HeLa (Lane 1), Ltk - (Lane 2) and HE1 (Lane 3) poly A+ RNA. The primers used were from the N-terminal and C-terminal coding regions of ICAM-1 having the sequence ggaattcATGGCTCCCAGCAGCCCCCGGCCC SEQ ID NO:1 and ggaattcTCAGGGAGGCGTGGCTTGTGTGTT SEQ ID NO:2. Upper case denotes ICAM-1 sequence, lower case restriction site linkers. Lanes 1 and 2, 72 hour exposure, Lane 3, 90 minute exposure. FIG. 5 is a gel showing the detection of the ICAM-1 and sICAM-1 mRNAs in HeLa and HE1 cells. PCR amplification was performed on 100ng single stranded cDNA using the primers PCR 5.4 (CTTGAGGGCACCTACCTCTGTCGG) SEQ ID NO:3 and PCR 3.4 (AGTGATGATGACAATCTCATACCG) SEQ ID NO:4. Extensions were performed at 72° C. for 25 cycles and one tenth of the product was analysed on a 1% agarose/3% NuSieve® gel FMC, Rockland, Me. Lane 1, HeLa cDNA; lane 2, HE1 cDNA; lane 3, LTK - cDNA; lane 4, ICAM-1 phage control;, lane 5, sICAM-1 phage control; lane 6, ICAM-1+sICAM-1 phage control. Specific amplification products of 105 bp and 86 bp are indicated by the arrows. FIG. 6 is a Western blot showing the synthesis of a soluble form of ICAM-1 protein by HeLa and HE1 cells. It demonstrates the existence of a protein species in the culture supernatant of HeLa and HE1 cells related to ICAM-1. Equivalent aliquots of-cell lysates and culture supernatants were separated by SDS-PAGE, blotted onto nitrocellulose, and probed with a rabbit polyclonal antisera to ICAM-1 followed by 125 I protein A; a species migrating close to the position of membrane-bound ICAM-1 is seen in both HeLa and HE1 culture supernatants. FIGS. 7A and 7B are a graphical representation of the cloned sICAM-1 and ICAM-1 plasmids. FIG. 7A pHRR3 is a full length cDNA encoding sICAM-1 obtained by PCR. Clones 19.1-3 and 4.5 are partial cDNA clones encoding sICAM-1 obtained from an HE1 cDNA library in lambda GT11. Beneath the clones is a schematic of the sICAM-1 molecule. S denotes the signal peptide and I to V the IgG homologous domains. The solid box indicates the unique 11 amino acid C-terminus. FIG. 7B pHRR1 and pHRR2 are full length ICAM-1 cDNA clones obtained by PCR. The remaining ICAM-1 clones were obtained from an HE1 cDNA library in lambda GT11. Beneath the clones is a schematic of the ICAM-1 molecule, showing the signal peptide (S), the five IgG homologous domains (I to V), the transmembrane region (TM) and the cytoplasmic domain (C). DESCRIPTION OF THE PREFERRED EMBODIMENTS One aspect of the present invention relates to the discovery of a soluble natural binding ligand to the receptor binding site of Human Rhinovirus (HRV) and which also binds to LFA-1. This soluble natural molecule is related to but distinct from the molecule designated "Intercellular Adhesion Molecule-1" or "ICAM-1" which is insoluble, bound to the cell membrane and possesses a typical hydrophobic membrane spanning region and a short cytoplasmic tail. The novel protein of the present invention has a DNA sequence which includes a significant difference from the published DNA sequence for ICAM-1. sICAM-1 contains most of the extracellular domain of ICAM-1, which includes the functional domains for multiple functions including HRV and LFA-1 binding, but lacks the membrane spanning and cytoplasmic domains. sICAM-1 retains the ability to bind HRV and LFA-1 and is secreted in a soluble form. The DNA sequence for sICAM-1 contains a deletion of 19 base pairs from nucleotide 1465 to 1483 according to the numbering of Staunton et al, supra (1988). The remainder of the sICAM-1 clone matches the published ICAM-1 sequence with the exception of a substitution of an A for G at nucleotide position 1462 which changes Glu 442 to Lys, as shown in FIG. 1. The sequence of amino acid residues in a peptide is designated in accordance with standard nomenclature such as Lehninger's Biochemistry, Worth Publishers, New York, N.Y. (1970). sICAM-1 is a natural product of HeLa and HE1 cells and other human cells which should have the property of binding to and inhibiting the infection of human rhinovirus and Coxsackie A viruses. It also has the property of binding to LFA-1 and may be used to antagonize adhesion of cells mediated by ICAM-1/LFA-1 binding and thus be useful as a therapeutic in treatment of inflammation, graft rejection, suppression of LFA-1 expressing tumor cells and other processes involving cell adhesion. Isolated and purified sICAM-1 protein as a therapeutic would not possess the immunogenic problems associated with foreign proteins. The secretion of a soluble naturally occurring protein eliminates the problems associated with production and purification of an insoluble, cell membrane bound protein, since cell lysis is not required and thus continuous culture can be employed as well as simplified procedures for purification and isolation of sICAM-1. Non-human mammalian cell lines which express the major human rhinovirus receptor gene have been previously identified and are the subject matter of copending U.S. patent application Ser. No. 262,570 and 262,428 filed Oct. 25, 1988, and include references to the ATCC deposits for the cell lines. The major human rhinovirus receptor was identified with monoclonal antibodies which inhibit rhinovirus infection. These monoclonal antibodies recognized a 95 kd cell surface glycoprotein on human cells and on mouse transfectants expressing a rhinovirus-binding phenotype. Purified 95 Kd protein binds to rhinovirus in vitro. Protein sequence from the 95 kd protein showed an identity with that of ICAM-1; a cDNA clone obtained from mouse transfectants expressing the rhinovirus receptor had the same sequence published for ICAM-1, except for the A for G change previously described. Thus it was determined that the major human rhinovirus receptor and ICAM-1 were the same protein. A transfected mouse L-cell line designated HE1 had been isolated which contained and expressed the HRR gene or ICAM-1 gene. The ICAM-1 terminology has been used although it is now recognized that HRR and ICAM-1 are interchangeable. A randomly primed cDNA library was prepared in lambda GT11 from HE1 polyA+ RNA. The library was screened in duplicate using two oligonucleotides derived from the published sequence of ICAM-1. Oligonucleotide ICAM-1 has the sequence GAGGTGTTCTCAAACAGCTCCAGCCCTTGGGGCCGCAGGTCCAGTTC SEQ ID NO:5 and oligonucleotide ICAM-3 has the sequence CGTTGGCAGGACAAAGGTCTGGAGCTGGTAGGGGGCCGAGGTGTTCT SEQ ID NO:6. Eight positive clones were obtained from one screen and three were selected for further study. DNA sequencing of two of the clones showed identity with the published ICAM-1 sequence. The sequence of the third clone, lambda 19.1-3 was significantly different from the other two clones in that there was a deletion of 19 bp from nucleotide 1465 to 1483 according to the numbering of Staunton et al. supra. The 19 bp deletion was present in a second cDNA, lambda HE1-4.5 and independently confirmed using polymerase chain reaction (PCR) generated cDNA. Analysis of the cDNA sequence predicted the existence of a secreted form of ICAM-1 that is generated by an alternative splicing mechanism. Western blot identification of sICAM-1 from culture supernatants of HE1 and HeLa cell lines confirm that the sICAM-1 mRNA sequence encodes a soluble form of ICAM-1 that does not associate with the cell surface but is released into the cell medium. An alternatively spliced mRNA generating a secreted form of another adhesion molecule (NCAM) has been identified (Glower et al, Cell 55:955-964 (1988)), although in NCAM an exon is incorporated into the mRNA while in the present invention an exon is deleted from the mRNA. No alternative mRNA sequence for ICAM-1 had previously been identified. (Staunton et al.) sICAM-1 cDNA Clones A randomly primed cDNA library was constructed in lambda GT11 from HE1 poly A+ by Clontech Laboratories, Palo Alto, Calif. The library was screened with two 47 mer oligonucleotide probes from the middle of the ICAM-1 coding sequence. A positive clone designated 19.1-3 was isolated which had an insert of 1.5 kb; a second cDNA clone designated 4.5 which has an insert of 1.25 kb was isolated; and an additional cDNA clone pHRR-3 was obtained by subcloning the products of PCR amplification into Bluescript® utilizing the Perkin-Elmer/Cetus DNA Amplification System, Perkin Elmer, Wellesley Mass., as shown in FIG. 4C, lane 3. These clones showed a significant difference from the published ICAM-1 sequence. They all contain a deletion of 19 base pairs from nucleotide 1465 to 1483 according to the numbering of Staunton et al, supra. In order to demonstrate directly that the s-ICAM mRNA is present in HE1 cells and HeLa cels, a PCR experiment was performed using primers which flank the 19 bp region which is absent from the s-ICAM mRNA (FIG. 8). Using these primers the product from the ICAM-1 mRNA is 105 bp while the s-ICAM-1 product is 19 bp shorter i.e. 86 bp. This experiment shows that both HE1 cells and HeLa cells contain both forms of the ICAM-1 mRNA while the control L-cells do not. A synthetic oligonucleotide designated PCR3.2 having the following sequence: ggaattcTCACTCATACCGGGGGGAGAGCACATT SEQ ID NO:7! was used to distinguish between cDNA clones containing the 19 bp deletion from clones not containing the 19 bp deletion. The synthetic oligonucleotide does not bind to cDNA clones which contain the 19 bp deletion. In addition, partial sequence of the cDNA 19.1-3 and PHRR-3 confirmed the 19 bp deletion. This data indicates that there are at least two different and distinct ICAM-1 species in HE1 cells. The insoluble ICAM-1 of the prior art and a novel soluble form as described in the present invention. The sequences of the deleted (sICAM-1) and the nondeleted (ICAM-1) forms of the Intercellular Adhesion Molecule-1 mRNA represented by the cDNA clones are shown in FIG. 2. The sequence at the point of deletion is AGGT consistent with an RNA splice junction. The removal of 19 bases from the mRNA shifts the reading frame and causes the two polypeptide sequences to diverge at amino acid residue 443. The deleted form (sICAM-1) contains an additional 11 residues followed by an in-frame termination codon. This molecule thus consists of 453 amino acids as compared to 505 amino acids for the nondeleted form. Beginning with the N-terminus of ICAM-1, sICAM-1 has 442 amino acids in common with ICAM-1. The deleted form (sICAM-1) contains a unique 11 amino acid C-terminus but lacks the membrane spanning (24 amino acids) and cytoplasmic tail 28 amino acids) domains of ICAm-1, as shown in FIG. 3. ICAM-1 cDNA Clones A plurality of methods may be used to clone genes. One method is to use two partially overlapping 47 mer oligonucleotide probes. These two probes termed oligonucleotide ICAM-1 and oligonucleotide ICAM-3 were synthesized from the published ICAM-1 sequence. The ICAM-1 oligonucleotide was labeled to high specific activity and hybridized to a Southern blot under high stringency conditions. As shown in FIG. 4A, a single band of 4.4 kb was detected in HeLa, HE1 and two primary HRR transfectant cell lines and was absent from Ltk - cells. This result confirms that the HRR transfectants contain the human ICAM-1 gene. The size of the fragment agrees with Simmons et al but differs from Staunton et al probably reflecting a restriction site polymorphism. The ICAM-1 oligonucleotide was used to probe a Northern blot of poly A+ RNA from the same cell lines. As shown in FIG. 4B, an mRNA of 3.3 kb was detected in HeLa, HE1, and primary transfectant cell lines but was absent from Ltk - cells. The signal in HE1 cells was many times stronger than the other cell lines indicating a much higher level of mRNA in HE1 cells. This is in agreement with the higher level of HRR (ICAM-1) expression in HE1 cells. A second 2.4 kb RNA was also detected in HE1 cells. These data confirm that the human ICAM-1 mRNA is expressed in HRR transfectants. See FIG. 4B. The human ICAM-1 gene was isolated from the HE1 transfectant using polymerase chain reaction (PCR) amplification utilizing the Perkin-Elmer/Cetus DNA Amplification System, Perkin Elmer, Wellesley Mass. PCR amplification was performed on single stranded cDNA made from HeLa, Ltd - and HE1 RNA. Primers were made from the 5' and 3' coding regions of the published ICAM-1 sequence. ICAM-1 specific amplification products were detected by hybridization of a Southern blot of the PCR reactions using the ICAM-1 oligonucleotide. As shown in FIG. 4C, a single band of approximately 1600 bp which matches the predicted size was amplified from HeLa cells and HE1 cells but was absent from Ltk - cells. The amplification product was cloned into Bluescript® (Strategene, San Diego, Calif.) and two independent clones designated PHRR1 and PHRR2 were obtained. The complete sequence of PHRR2 showed 100% identity with the published ICAM-1 coding sequence with the exception of a single G to A change previously described. A lambda GT11 library made from randomly primed HE1 cDNA was screened with the ICAM-1 and ICAM-3 probes and eight positive clones were isolated. Six clones as shown in FIG. 7 were selected for further study and were anlayzed by partial DNA sequencing. A total of approximately 1000 nucleotides of sequence derived from these clones showed identity with the ICAM-1 sequence. Purification and Isolation of Soluble Protein HeLa and HE1 cells are grown under standard conditions in DMEM (Dulbecco's Modified Essential Media) with 10% Fetal Bovine Serum. Conditioned media from these cells is harvested and centrifuged or filtered to remove cells or cellular debris. The cell-membrane bound ICAM-1 is not present in the supernatant. This media is then absorbed to a monoclonal antibody-sepharose resin (the monoclonal antibody c78.4A being an example) in which the monoclonal antibody is directed to ICAM-1 or sICAM-1 and the unabsorbed proteins are washed from the resin with a physiological saline buffer, such as phosphate-buffered saline. The bound sICAM-1 is then eluted under conditions that preserve the native conformation of the protein, as described in copending application Ser. No. 262428 filed Oct. 25, 1988. The sICAM-1 may be further purified by lectin affinity chromatography, ion exchange chromatography, or gel filtration. mRNA transcribed in vitro from cDNA encoding sICAM in the Bluescript® vector (Strategene) was translated in vitro. In the absence of microsomal membranes, an unglycosylated protein with an apparent MW of 52,000 daltons was obtained; in the presence of microsomal membranes, a glycosylated species of 72,400 daltons was obtained which was sequestered within the microsomal membrane, indicating that the sICAM polypeptide is correctly translocated, processed, and glycosylated by the microsomal membranes. cDNA's encoding tmICAM and sICAM in the CDM8 vector (See, B. and Aruffo, A. PNAS 84:3365 (1987) were transfected into COS cells and mouse L cells using the DEAE-dextran technique. AT 72 hr, the cells were analyzed by two methods: (1) FACS analysis with anti-ICAM Mab (c78.4) for cell membrane expression of ICAM species and (2) metabolic labeling followed by immunoabsorption with anti-ICAM Mab of cell supernatants and cell lysates. The results from the metabolic labelling indicated intracellular accumulation of a 68,000 dalton species in sICAM-transfected cells but no detectable secretion of sICAM into th supernatant. These data are consistent with sICAM being secreted through the "Regulated" secretory pathway (R. B. Kelly, Science 230:25 (1985)). Antibody probes specific for sICAM and for ICAM-1 were prepared. The synthetic peptides S-PEP, P P G M R L S S S L W (C) SEQ ID NO:8! derived from a unique 11 amino acid sequence at the C-terminus of sICAM, and P002, derived from the C-terminus of ICAM-1, G T P M K P N T Q A T P P (C) SEQ ID NO:9! was made and purified; the C-terminal C residues in parentheses were added to facilitate coupling of the peptides to protein carriers. The synthetic peptide was coupled to KLH (Keyhole Limpit Hemocyanin) by standard procedures and the conjugate injected into rabbits to product anti-peptide antisera were shown to specifically bind to their respective peptide immunogens. __________________________________________________________________________SEQUENCE LISTING(1) GENERAL INFORMATION:(iii) NUMBER OF SEQUENCES: 12(2) INFORMATION FOR SEQ ID NO:1:(i) SEQUENCE CHARACTERISTICS:(A) LENGTH: 31 bases(B) TYPE: nucleic acid(C) STRANDEDNESS: single(D) TOPOLOGY: linear(ii) MOLECULE TYPE: other nucleic acid(iii) HYPOTHETICAL: no(iv) ANTI-SENSE: no(ix) FEATURE:(A) NAME/KEY: PCR 5.1 (5'PCR primer)(B) LOCATION: 5'end of ICAM-1 coding sequence(D) OTHER INFORMATION: bp 1 = G; bp 2-7 = EcoRIsite; bp 8- 31 = 24 bases coding for the firsteight amino acid residues of hICAM-1(x) PUBLICATION INFORMATION:(A) AUTHORS: Greve, J.M., G. Davis, A.M. Meyer,C.P. Forte, S.C. Yost, C.W. Marlor, M.E.Kamarck, and A. McClelland(B) TITLE: The Major Human Rhinovirus Receptor isICAM-1(C) JOURNAL: Cell(D) VOLUME: 56(F) PAGES: 839-847(G) DATE: March 10, 1989(K) RELEVANT RESIDUES IN SEQ ID NO:1: FROM 1 TO31(xi) SEQUENCE DESCRIPTION: SEQ ID NO:1:GGAATTCATGGCTCCCAGCAGCCCCCGGCCC31MetAlaProSerSerProArgPro(2) INFORMATION FOR SEQ ID NO:2:(i) SEQUENCE CHARACTERISTICS:(A) LENGTH: 31 bases(B) TYPE: nucleic acid(C) STRANDEDNESS: single(D) TOPOLOGY: linear(ii) MOLECULE TYPE: other nucleic acid(iii) HYPOTHETICAL: no(iv) ANTI-SENSE: yes(ix) FEATURE:(A) NAME/KEY: PCR 3.1 (3'PCR primer)(B) LOCATION: 3'end of ICAM-1 coding sequence(D) OTHER INFORMATION: base 1 =G; base 2-7 =EcoRI site; base 8-31 = 24 basescomplementary to nucleic acid sequence codingfor last 8 amino acid residues of hICAM-1(x) PUBLICATION INFORMATION:(A) AUTHORS: Greve, J.M., G. Davis, A.M. Meyer,C.P. Forte, S.C. Yost, C.W. Marlor, M.E.Kamarck, and A. McClelland(B) TITLE: The Major Human Rhinovirus Receptor isICAM-1(C) JOURNAL: Cell(D) VOLUME: 56(F) PAGES: 839-847(G) DATE: March 10, 1989(K) RELEVANT RESIDUES IN SEQ ID NO:2: FROM 1 TO31(xi) SEQUENCE DESCRIPTION: SEQ ID NO:2:GGAATTCTCAGGGAGGCGTGGCTTGTGTGTT31(2) INFORMATION FOR SEQ ID NO:3:(i) SEQUENCE CHARACTERISTICS:(A) LENGTH: 24 bases(B) TYPE: nucleic acid(C) STRANDEDNESS: single(D) TOPOLOGY: linear(ii) MOLECULE TYPE: other nucleic acid(iii) HYPOTHETICAL: no(iv) ANTI-SENSE: no(ix) FEATURE:(A) NAME/KEY: PCR 5.4 (5'PCR primer)(B) LOCATION: nucleotides 1351 to 1374 of sICAM(xi) SEQUENCE DESCRIPTION: SEQ ID NO:3:CTTGAGGGCACCTACCTCTGTCGG24LeuGluGlyThrTyrLeuCysArg5(2) INFORMATION FOR SEQ ID NO:4:(i) SEQUENCE CHARACTERISTICS:(A) LENGTH: 24 bases(B) TYPE: nucleic acid(C) STRANDEDNESS: single(D) TOPOLOGY: linear(ii) MOLECULE TYPE: other nucleic acid(iii) HYPOTHETICAL: no(iv) ANTI-SENSE: yes(ix) FEATURE:(A) NAME/KEY: 3'PCR primer(B) LOCATION: complementary to nucleotides 1432 -1455 of sICAM(xi) SEQUENCE DESCRIPTION: SEQ ID NO:4:AGTGATGATGACAATCTCATACCG24(2) INFORMATION FOR SEQ ID NO:5:(i) SEQUENCE CHARACTERISTICS:(A) LENGTH: 47 bases(B) TYPE: nucleic acid(C) STRANDEDNESS: single(D) TOPOLOGY: linear(ii) MOLECULE TYPE: other nucleic acid(iii) HYPOTHETICAL: no(iv) ANTI-SENSE: yes(ix) FEATURE:(A) NAME/KEY: ICAM1 probe(B) LOCATION: complementary to nucleotides 565 to611 of ICAM- 1(x) PUBLICATION INFORMATION:(A) AUTHORS: Greve, J.M., G. Davis, A.M. Meyer,C.P. Forte, S.C. Yost, C.W. Marlor, M.E.Kamarck, and A. McClelland(B) TITLE: The Major Human Rhinovirus Receptor isICAM-1(C) JOURNAL: Cell(D) VOLUME: 56(F) PAGES: 839-847(G) DATE: March 10, 1989(K) RELEVANT RESIDUES IN SEQ ID NO:5: FROM 1 TO47(xi) SEQUENCE DESCRIPTION: SEQ ID NO:5:GAGGTGTTCTCAAACAGCTCCAGCCCTTGGGGCCGCAGGTCCAGTTC47(2) INFORMATION FOR SEQ ID NO:6:(i) SEQUENCE CHARACTERISTICS:(A) LENGTH: 47 bases(B) TYPE: nucleic acid(C) STRANDEDNESS: single(D) TOPOLOGY: linear(ii) MOLECULE TYPE: other nucleic acid(iii) HYPOTHETICAL: no(iv) ANTI-SENSE: yes(ix) FEATURE:(A) NAME/KEY: ICAM3 probe(B) LOCATION: complementary to nucleotides 602 to648 of human ICAM(x) PUBLICATION INFORMATION:(A) AUTHORS: Greve, J.M., G. Davis, A.M. Meyer,C.P. Forte, S.C. Yost, C.W. Marlor, M.E.Kamarck, and A. McClelland(B) TITLE: The Major Human Rhinovirus Receptor isICAM-1(C) JOURNAL: Cell(D) VOLUME: 56(F) PAGES: 839-847(G) DATE: March 10, 1989(K) RELEVANT RESIDUES IN SEQ ID NO:6: FROM 1 TO47(xi) SEQUENCE DESCRIPTION: SEQ ID NO:6:CGTTGGCAGGACAAAGGTCTGGAGCTGGTAGGGGGCCGAGGTGTTCT47(2) INFORMATION FOR SEQ ID NO:7:(i) SEQUENCE CHARACTERISTICS:(A) LENGTH: 34 bases(B) TYPE: nucleic acid(C) STRANDEDNESS: single(D) TOPOLOGY: linear(ii) MOLECULE TYPE: other nucleic acid(iii) HYPOTHETICAL: no(iv) ANTI-SENSE: yes(ix) FEATURE:(A) NAME/KEY: PCR 3.2 antisense(D) OTHER INFORMATION: base 1 =G; bases 2-7 =EcoR1 site; bases 8-10 = complementary to a stopcodon; bases 11-34 = 24 bases complementary tonucleotides 1474-1497 of ICAM-1, nucleotide 1 beingthe ATG(xi) SEQUENCE DESCRIPTION: SEQ ID NO:7:GGAATTCTCACTCATACCGGGGGGAGAGCACATT34(2) INFORMATION FOR SEQ ID NO:8:(i) SEQUENCE CHARACTERISTICS:(A) LENGTH: 12 amino acid residues(B) TYPE: amino acid(D) TOPOLOGY: linear(ii) MOLECULE TYPE:(A) DESCRIPTION: peptide(iii) HYPOTHETICAL: no(v) FRAGMENT TYPE: modified C-terminal fragment(ix) FEATURE:(A) NAME/KEY: modified sICAM fragment(B) LOCATION: C-terminus of sICAM(D) OTHER INFORMATION: first 11 amino acidscorrespond to C-terminus of sICAM; lastresidue (Cys) added to faciliate coupling(xi) SEQUENCE DESCRIPTION: SEQ ID NO:8:ProProGlyMetArgLeuSerSerSerLeuTrpCys510(2) INFORMATION FOR SEQ ID NO:9:(i) SEQUENCE CHARACTERISTICS:(A) LENGTH: 14 amino acid residues(B) TYPE: amino acid(D) TOPOLOGY: linear(ii) MOLECULE TYPE:(A) DESCRIPTION: peptide(iii) HYPOTHETICAL: no(v) FRAGMENT TYPE: C-terminal fragment(ix) FEATURE:(A) NAME/KEY: modified ICAM fragment(B) LOCATION: C-terminus(D) OTHER INFORMATION: first 11 amino acidresidues correspond to the C-terminus ofICAM; last residue (Cys) added to faciliatecoupling(xi) SEQUENCE DESCRIPTION: SEQ ID NO:9:GlyThrProMetLysProAsnThrGlnAlaThrProProCys510(2) INFORMATION FOR SEQ ID NO:10:(i) SEQUENCE CHARACTERISTICS:(A) LENGTH: 1443 bases(B) TYPE: nucleic acid(C) STRANDEDNESS: single(D) TOPOLOGY: linear(ii) MOLECULE TYPE: cDNA to mRNA(iii) HYPOTHETICAL: no(iv) ANTI-SENSE: no(vi) ORIGINAL SOURCE:(A) ORGANISM: human(G) CELL TYPE: epithelial(H) CELL LINE: HeLa(vii) IMMEDIATE SOURCE:(A) LIBRARY: cDNA library(ix) FEATURE:(A) NAME/KEY: human sICAM cDNA to mRNA sequence(B) LOCATION: nucleotides 1 to 1435 numberedbeginning at ATG coding for first Met ofhuman sICAM protein(xi) SEQUENCE DESCRIPTION: SEQ ID NO:10:ATGGCTCCCAGCAGCCCCCGGCCCGCGCTGCCCGCACTCCTGGTC45MetAlaProSerSerProArgProAlaLeuProAlaLeuLeuVal51015CTGCTCGGGGCTCTGTTCCCAGGACCTGGCAATGCCCAGACATCT90LeuLeuGlyAlaLeuPheProGlyProGlyAsnAlaGlnThrSer202530GTGTCCCCCTCAAAAGTCATCCTGCCCCGGGGAGGCTCCGTGCTG135ValSerProSerLysValIleLeuProArgGlyGlySerValLeu354045GTGACATGCAGCACCTCCTGTGACCAGCCCAAGTTGTTGGGCATA180ValThrCysSerThrSerCysAspGlnProLysLeuLeuGlyIle505560GAGACCCCGTTGCCTAAAAAGGAGTTGCTCCTGCCTGGGAACAAC225GluThrProLeuProLysLysGluLeuLeuLeuProGlyAsnAsn657075CGGAAGGTGTATGAACTGAGCAATGTGCAAGAAGATAGCCAACCA270ArgLysValTyrGluLeuSerAsnValGlnGluAspSerGlnPro808590ATGTGCTATTCAAACTGCCCTGATGGGCAGTCAACAGCTAAAACC315MetCysTyrSerAsnCysProAspGlyGlnSerThrAlaLysThr95100105TTCCTCACCGTGTACTGGACTCCAGAACGGGTGGAACTGGCACCC360PheLeuThrValTyrTrpThrProGluArgValGluLeuAlaPro110115120CTCCCCTCTTGGCAGCCAGTGGGCAAGAACCTTACCCTACGCTGC405LeuProSerTrpGlnProValGlyLysAsnLeuThrLeuArgCys125130135CAGGTGGAGGGTGGGGCACCCCGGGCCAACCTCACCGTGGTGCTG450GlnValGluGlyGlyAlaProArgAlaAsnLeuThrValValLeu140145150CTCCGTGGGGAGAAGGAGCTGAAACGGGAGCCAGCTGTGGGGGAG495LeuArgGlyGluLysGluLeuLysArgGluProAlaValGlyGlu155160165CCCGCTGAGGTCACGACCACGGTGCTGGTGAGGAGAGATCACCAT540ProAlaGluValThrThrThrValLeuValArgArgAspHisHis170175180GGAGCCAATTTCTCGTGCCGCACTGAACTGGACCTGCGGCCCCAA585GlyAlaAsnPheSerCysArgThrGluLeuAspLeuArgProGln185190195GGGCTGGAGCTGTTTGAGAACACCTCGGCCCCCTACCAGCTCCAG630GlyLeuGluLeuPheGluAsnThrSerAlaProTyrGlnLeuGln200205210ACCTTTGTCCTGCCAGCGACTCCCCCACAACTTGTCAGCCCCCGG675ThrPheValLeuProAlaThrProProGlnLeuValSerProArg215220225GTCCTAGAGGTGGACACGCAGGGGACCGTGGTCTGTTCCCTGGAC720ValLeuGluValAspThrGlnGlyThrValValCysSerLeuAsp230235240GGGCTGTTCCCAGTCTCGGAGGCCCAGGTCCACCTGGCACTGGGG765GlyLeuPheProValSerGluAlaGlnValHisLeuAlaLeuGly245250255GACCAGAGGTTGAACCCCACAGTCACCTATGGCAACGACTCCTTC810AspGlnArgLeuAsnProThrValThrTyrGlyAsnAspSerPhe260265270TCGGCCAAGGCCTCAGTCAGTGTGACCGCAGAGGACGAGGGCACC855SerAlaLysAlaSerValSerValThrAlaGluAspGluGlyThr275280285CAGCGGCTGACGTGTGCAGTAATACTGGGGAACCAGAGCCAGGAG900GlnArgLeuThrCysAlaValIleLeuGlyAsnGlnSerGlnGlu290295300ACACTGCAGACAGTGACCATCTACAGCTTTCCGGCGCCCAACGTG945ThrLeuGlnThrValThrIleTyrSerPheProAlaProAsnVal305310315ATTCTGACGAAGCCAGAGGTCTCAGAAGGGACCGAGGTGACAGTG990IleLeuThrLysProGluValSerGluGlyThrGluValThrVal320325330AAGTGTGAGGCCCACCCTAGAGCCAAGGTGACGCTGAATGGGGTT1035LysCysGluAlaHisProArgAlaLysValThrLeuAsnGlyVal335340345CCAGCCCAGCCACTGGGCCCGAGGGCCCAGCTCCTGCTGAAGGCC1080ProAlaGlnProLeuGlyProArgAlaGlnLeuLeuLeuLysAla350355360ACCCCAGAGGACAACGGGCGCAGCTTCTCCTGCTCTGCAACCCTG1125ThrProGluAspAsnGlyArgSerPheSerCysSerAlaThrLeu365370375GAGGTGGCCGGCCAGCTTATACACAAGAACCAGACCCGGGAGCTT1170GluValAlaGlyGlnLeuIleHisLysAsnGlnThrArgGluLeu380385390CGTGTCCTGTATGGCCCCCGACTGGACGAGAGGGATTGTCCGGGA1215ArgValLeuTyrGlyProArgLeuAspGluArgGluCysProGly395400405AACTGGACGTGGCCAGAAAATTCCCAGCAGACTCCAATGTGCCAG1260AsnTrpThrTrpProGluAsnSerGlnGlnThrProMetCysGln410415420GCTTGGGGGAACCCATTGCCCGAGCTCAAGTGTCTAAAGGATGGC1305AlaTrpGlyAsnProLeuProGluLeuLysCysLeuLysAspGly425430435ACTTTCCCACTGCCCATCGGGGAATCAGTGACTGTCACTCGAGAT1350ThrPheProLeuProIleGlyGluSerValThrValThrArgAsp440445450CTTGAGGGCACCTACCTCTGTCGGGCCAGGAGCACTCAAGGGGAG1395LeuGluGlyThrTyrLeuCysArgAlaArgSerThrGlnGlyGlu455460465GTCACCCGCAAGCCCCCCGGTATGAGATTGTCATCATCACTGTGG1440ValThrArgLysProProGlyMetArgLeuSerSerSerLeuTrp470475480TAG1443(2) INFORMATION FOR SEQ ID NO:11:(i) SEQUENCE CHARACTERISTICS:(A) LENGTH: 240 bases(B) TYPE: nucleic acid(C) STRANDEDNESS: single(D) TOPOLOGY: linear(ii) MOLECULE TYPE: cDNA to mRNA(iii) HYPOTHETICAL: no(iv) ANTI-SENSE: no(vi) ORIGINAL SOURCE:(A) ORGANISM: human(G) CELL TYPE: epithelial(H) CELL LINE: HeLa(vii) IMMEDIATE SOURCE:(A) LIBRARY: cDNA library(ix) FEATURE:(A) NAME/KEY: partial human ICAM cDNA to mRNAsequence(B) LOCATION: nucleotides 1384 to 1623 numberedbeginning at ATG coding for first Met ofhuman ICAM protein(x) PUBLICATION INFORMATION:(A) AUTHORS: Greve, J.M., G. Davis, A.M. Meyer,C.P. Forte, S.C. Yost, C.W. Marlor, M.E.Kamarck, and A. McClelland(B) TITLE: The Major Human Rhinovirus Receptor isICAM-1(C) JOURNAL: Cell(D) VOLUME: 56(F) PAGES: 839-847(G) DATE: March 10, 1989(K) RELEVANT RESIDUES IN SEQ ID NO:11: FROM 1 TO240(xi) SEQUENCE DESCRIPTION: SEQ ID NO:11:ACTCAAGGGGAGGTCACCCGCAAGGTGACCGTGAATGTGCTCTCC45ThrGlnGlyGluValThrArgLysValThrValAsnValLeuSer51015CCCCGGTATGAGATTGTCATCATCACTGTGGTAGCAGCCGCAGTC90ProArgTyrGluIleValIleIleThrValValAlaAlaAlaVal202530ATAATGGGCACTGCAGGCCTCAGCACGTACCTCTATAACCGCCAG135IleMetGlyThrAlaGlyLeuSerThrTyrLeuTyrAsnArgGln354045CGGAAGATCAAGAAATACAGACTACAACAGGCCCAAAAAGGGACC180ArgLysIleLysLysTyrArgLeuGlnGlnAlaGlnLysGlyThr505560CCCATGAAACCGAACACACAAGCCACGCCTCCCTGAACCTATC223ProMetLysProAsnThrGlnAlaThrProPro6570CCGGGACAGGGCCTCTT240(2) INFORMATION FOR SEQ ID NO:12:(i) SEQUENCE CHARACTERISTICS:(A) LENGTH: 221 bases(B) TYPE: nucleic acid(C) STRANDEDNESS: single(D) TOPOLOGY: linear(ii) MOLECULE TYPE: cDNA to mRNA(iii) HYPOTHETICAL: no(iv) ANTI-SENSE: no(vi) ORIGINAL SOURCE:(A) ORGANISM: human(G) CELL TYPE: epithelial(H) CELL LINE: HeLa(vii) IMMEDIATE SOURCE:(A) LIBRARY: cDNA library(ix) FEATURE:(A) NAME/KEY: partial human sICAM-1 cDNA to mRNAsequence(B) LOCATION: sequence from human sICAMcorresponding to nucleotides 1384 to 1623 ofhuman ICAM lacking bp 1407 to 1426,inclusive, of hICAM(xi) SEQUENCE DESCRIPTION: SEQ ID NO:12:ACTCAAGGGGAGGTCACCCGCAAGCCCCCCGGTATGAGATTGTCA45ThrGlnGlyGluValThrArgLysProProGlyMetArgLeuSer51015TCATCACTGTGGTAGCAGCCGCAGTCATAATGGGCACTGCAGGCCTCAGCAC97SerSerLeuTrpGTACCTCTATAACCGCCAGCGGAAGATCAAGAAATACAGACTACAACAGG147CCCAAAAAGGGACCCCCATGAAACCGAACACACAAGCCACGCCTCCCTGA197ACCTATCCCGGGACAGGGCCTCTT221__________________________________________________________________________	The present invention relates to a soluble form of-intercellular adhesion molecule (sICAM-1) and purified and isolated human sICAM-1. This invention also relates to a purified and isolated DNA sequence encoding sICAM-1. The extracellular domain of sICAM-1 and insoluble ICAM-1 are substantially the same. ICAM-1 is involved in the process through which lymphocytes attach to cellular substrates during inflammation and serves as the major human rhinovirus receptor (HRR). sICAM-1 therefore has both the property of reducing immune inflammation and inhibiting infection of rhinovirus and Coxsackie A virus.	0
[0001] This nonprovisional application claims priority under 35 U.S.C. § 119(a) on Patent Application No. 2003-413635 filed in Japan on Dec. 11, 2003, the entire contents of which are hereby incorporated by reference. BACKGROUND OF THE INVENTION [0002] 1. Field of the Invention [0003] The present invention relates to a 90-degree phase shifter, and more particularly to a 90-degree phase shifter that is built using a T flip-flop. [0004] 2. Description of Related Art [0005] An example of the configuration of a conventional 90-degree phase shifter is shown in FIG. 3 . The conventional 90-degree phase shifter shown in FIG. 3 is a 90-degree phase shifter built using a T flip-flop, and is composed of transistors Q 1 to Q 12 , resistors R 1 to R 4 , input terminals 1 and 2 , constant current sources 3 and 4 , a constant voltage source 5 , and output terminals 6 to 9 . [0006] When an input signal having a predetermine frequency and having a duty factor of 50% is fed in via the input terminal 1 , the input transistors Q 1 and Q 8 , of which the bases are connected to the input terminal 1 , repeatedly turn on and off according to the input signal. When a signal complementary to the input signal is fed in via the input terminal 2 , the input transistors Q 2 and Q 7 , of which the bases are connected to the input terminal 2 , repeatedly turn on and off with the timing opposite to that with which the input transistors Q 1 and Q 8 turn on and off. [0007] As a result, a first frequency-divided signal (0-degreee signal), which is a signal obtained by performing ½ frequency division on the input signal and of which the zero cross points are synchronous with the rising zero cross points of the input signal is fed out via the output terminal 6 , and a signal (180-degree signal) complementary to the first frequency-divided signal is fed out via the output terminal 7 . Moreover, a second frequency-divided signal (90-degreee signal), which is a signal obtained by performing ½ frequency division on the input signal and of which the zero cross points are synchronous with the trailing zero cross points of the input signal is fed out via the output terminal 8 , and a signal (270-degree signal) complementary to the second frequency-divided signal is fed out via the output terminal 9 . [0008] When the input signal is free of any DC offset or distortion, the input and output signals behave, for example, as shown in the time chart in FIGS. 4A to 4 C. In FIG. 4A , A indicates the input signal that is fed in via the input terminal 1 , A-bar (overscored A) indicates the input signal fed in via the input terminal 2 . In FIG. 4B , B indicates the output signal fed out via the output terminal 6 , and B-bar (overscored B) indicates the output signal fed out via the output terminal 7 . In FIG. 4C , C indicates the output signal fed out via the output terminal 8 , and C-bar (overscored C) indicates the output signal fed out via the output terminal 9 . When the T flip-flop operates in an ideal manner on an ideal input signal like the input signal A, the phase difference between the two output signals (the output signals B and C) is exactly 90 degrees. [0009] On the other hand, if the input signal contains any DC offset and/or distortion, or if the circuit elements that constitute the T flip-flop have variations in their characteristics among them, the phase difference between the two output signals, undesirably, deviates from 90 degrees. For example, if the input signal contains a DC offset, the input and output signals behave, for example, as shown in the time chart in FIGS. 5A to 5 C. In FIG. 5A , A′ indicates the input signal that is fed in via the input terminal 1 , A′-bar (overscored A′) indicates the input signal fed in via the input terminal 2 . In FIG. 5B , B′ indicates the output signal fed out via the output terminal 6 , and B′-bar (overscored B′) indicates the output signal fed out via the output terminal 7 . In FIG. 5C , C′ indicates the output signal fed out via the output terminal 8 , and C′-bar (overscored C′) indicates the output signal fed out via the output terminal 9 . Since the input signal A′ contains a DC offset, its duty factor is not exactly 50%, and this deviation causes the phase difference between the two output signals (the output signals B′ and C′) to deviate from 90 degrees. [0010] A 90-degree phase shifter designed to offer a solution to the above problem is proposed in Japanese Patent Application Laid-Open No. H8-237077. The 90-degree phase shifter proposed in this publication is configured as shown in FIG. 6 . In FIG. 6 , such circuit elements as find their counterparts in FIG. 3 are identified with common reference numerals or symbols. [0011] As compared with the conventional 90-degree phase shifter shown in FIG. 3 , the conventional 90-degree phase shifter shown in FIG. 6 is additionally provided with a 90-degree phase comparator 10 , a low-pass filter 11 , a DC amplifier 12 , and capacitors C 1 and C 2 . [0012] In the conventional 90-degree phase shifter shown in FIG. 6 , the 90-degree phase comparator 10 detects the phase deviation from 90 degrees. The low-pass filter 11 and the DC amplifier 12 extract, from the output of the 90-degree phase comparator 10 , the direct-current component that corresponds to the phase deviation, and then feed it back to the control terminal (base) of each of the input transistors Q 1 , Q 2 , Q 7 , and Q 8 . This permits a direct-current bias to be applied to the base of each of the input transistors Q 1 , Q 2 , Q 7 , and Q 8 in such a way as to correct the phase deviation from 90 degrees, eventually eliminating it. [0013] The conventional 90-degree phase shifter shown in FIG. 6 , however, has the following disadvantages. First, since the phase deviation from 90 degrees is fed back as a voltage, how it is fed back tends to be influenced by noise. Second, also since the phase deviation from 90 degrees is fed back as a voltage, how it is fed back tends to be influenced also by the voltage drop across the wiring resistance of the path by way of which it is fed back. Incidentally, since a 90-degree phase shifter is typically built into an integrated circuit, the just mentioned wiring resistance is usually comparatively high. [0014] Hence, under the influence of noise or of the voltage drop across the wiring resistance as described above, the conventional 90-degree phase shifter shown in FIG. 6 , inconveniently, does not always yield output signals with a phase difference of exactly 90 degrees. SUMMARY OF THE INVENTION [0015] An object of the present invention is to provide a 90-degree phase shifter that more surely yields output signals with a phase difference of exactly 90 degrees. [0016] To achieve the above object, according to the present invention, a 90-degree phase shifter is provided with: a T flip-flop including first and second input transistors that receive at the control terminals thereof an input signal, third and fourth input transistors that receive at the control terminals thereof a signal complementary to the input signal, and a dual differential circuit that operates according to the switching operation of the first to fourth input transistors; a first variable current source that is connected to the node between the first input transistor and the dual differential circuit; a second variable current source that is connected to the node between the second input transistor and the dual differential circuit; a third variable current source that is connected to the node between the third input transistor and the dual differential circuit; a fourth variable current source that is connected to the node between the fourth input transistor and the dual differential circuit; and a phase comparator that compares the phase differences between the signals outputted from the T flip-flop in order to output signals commensurate with the results of the comparison. Here, the first to fourth variable current sources are controlled by signals based on the signals outputted from the phase comparator. [0026] In this configuration, the deviations from 90 degrees of the phase differences between the signals outputted from the T flip-flop are fed back as the currents produced by the first to fourth variable current sources. Thus, even if the input signal, despite having a predetermined frequency, has a duty factor other than 50%, the phase differences between the signals outputted from the T flip-flop can be so adjusted as to be exactly 90 degrees. [0027] Moreover, feeding back the phase deviations from 90 degrees as the currents produced by the first to fourth variable current sources minimizes the susceptibility to noise. Furthermore, now that the phase deviations from 90 degrees are fed back as currents, by making as short as possible the wiring from the phase comparator to the first to fourth variable current sources, even if the wiring from the nodes between the first to fourth input transistors and the dual differential circuit to the first to fourth variable current sources is long, it is possible to minimize the susceptibility to the voltage drops across the wiring resistances of the paths by way of which the phase deviations from 90 degrees need to be fed back. In this way, it is possible to more surely yield output signals with a phase difference of exactly 90 degrees. [0028] In the 90-degree phase shifter configured as described above, a low-pass filter may be provided between the phase comparator and the first to fourth variable current sources. With this configuration, it is possible to eliminate the alternating-current component contained in the output signals of the phase comparator. This makes it possible to perform feedback control accurately according to the results of the phase comparison by the phase comparator. In this way, it is possible to yield output signals with a phase difference of more exactly 90 degrees. [0029] In any of the 90-degree phase shifters configured as described above, an amplifier may be provided between the phase comparator and the first to fourth variable current sources. With this configuration, it is possible to increase the loop gain of the feedback loop, and thus to perform feedback control with high accuracy. In this way, it is possible to yield output signals with a phase difference of more exactly 90 degrees. [0030] In any of the 90-degree phase shifters configured as described above, a limiter may be provided that limits the variable range of the first to fourth variable current sources. With this configuration, even if the circuit elements that constitute the T flip-flop have variations in their characteristics among them, the balance between the twin portions of the dual differential circuit is not seriously upset thereby. Thus, even at start-up, the T flip-flop surely performs ½ frequency division. Once the T flip-flop starts to perform ½ frequency division, it is possible, through feedback control, to yield output signals with a phase difference of exactly 90 degrees. BRIEF DESCRIPTION OF THE DRAWINGS [0031] FIG. 1 is a diagram showing the configuration of a 90-degree phase shifter according to the invention. [0032] FIGS. 2A to 2 C are diagrams showing an example of the time chart showing the behavior of the input and output signals as observed when the 90-degree phase shifter shown in FIG. 1 is fed with an input signal containing a DC offset. [0033] FIG. 3 is a diagram showing one configuration of a conventional 90-degree phase shifter. [0034] FIGS. 4A to 4 C are diagrams showing an example of the time chart showing the behavior of the input and output signals as observed when the 90-degree phase shifter shown in FIG. 3 is fed with an input signal containing no DC offset or distortion. [0035] FIGS. 5A to 5 C are diagrams showing an example of the time chart showing the behavior of the input and output signals as observed when the 90-degree phase shifter shown in FIG. 3 is fed with an input signal containing a DC offset. [0036] FIG. 6 is a diagram showing another configuration of a conventional 90-degree phase shifter. DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS [0037] Hereinafter, an embodiment of the present invention will be described with reference to the accompanying drawings. An example of the configuration of a 90-degree phase shifter according to the invention is shown in FIG. 1 . In FIG. 1 , such circuit elements as find their counterparts in FIG. 6 are identified with common reference numerals or symbols. [0038] As compared with the conventional 90-degree phase shifter shown in FIG. 3 , the 90-degree phase shifter according to the invention shown in FIG. 1 is additionally provided with a 90-degree phase comparator 10 , a low-pass filter 11 , a DC amplifier 12 , a limiter circuit 13 , and variable current sources 14 to 17 . [0039] NPN-type transistors Q 1 to Q 12 , input terminals 1 and 2 , constant current sources 3 and 4 , resistors R 1 to R 4 , a constant voltage source 5 , and output terminals 6 to 9 together constitute a T flip-flop that functions as a ½ frequency divider. The input terminal I is connected to the base of the input transistor Q 1 and to the base of the input transistor Q 8 , and the input terminal 2 is connected to the base of the input transistor Q 2 and to the base of the input transistor Q 7 . The emitter of the input transistor Q 1 and the emitter of the input transistor Q 2 are connected together, and are grounded through the constant current source 3 . The emitter of the input transistor Q 7 and the emitter of the input transistor Q 8 are connected together, and are grounded through the constant current source 4 . [0040] The collector of the input transistor Q 1 is connected to the node between the emitter of the transistor Q 3 and the emitter of the transistor Q 4 , and the collector of the input transistor Q 2 is connected to the node between the emitter of the transistor Q 5 and the emitter of the transistor Q 6 . [0041] The collector of the input transistor Q 7 is connected to the node between the emitter of the transistor Q 9 and the emitter of the transistor Q 10 , and the collector of the input transistor Q 8 is connected to the node between the emitter of the transistor Q 11 and the emitter of the transistor Q 12 . [0042] The base of the transistor Q 3 is connected to the base of the transistor Q 11 , to the output terminal 9 , to the collector of the transistor Q 10 , and to the collector of the transistor Q 12 , and is also connected through the resistor R 4 to the positive terminal of the constant voltage source 5 . The base of the transistor Q 5 is connected to the base of the transistor Q 10 , to the output terminal 7 , to the collector of the transistor Q 6 , and to the collector of the transistor Q 4 , and is also connected through the resistor R 2 to the positive terminal of the constant voltage source 5 . [0043] The base of the transistor Q 6 is connected to the base of the transistor Q 9 , to the output terminal 6 , to the collector of the transistor Q 3 , and to the collector of the transistor Q 5 , and is also connected through the resistor R 1 to the positive terminal of the constant voltage source 5 . The base of the transistor Q 4 is connected to the base of the transistor Q 12 , to the output terminal 8 , to the collector of the transistor Q 9 , and to the collector of the transistor Q 11 , and is also connected through the resistor R 3 to the positive terminal of the constant voltage source 5 . The negative terminal of the constant voltage source 5 is grounded. [0044] The outputs of the T flip-flop configured as described above and functioning as a ½ frequency divider are fed to the 90-degree phase comparator 10 , which detects the phase difference between the output signal fed out via the output terminal 6 and the output signal fed out via the output terminal 8 and outputs two-phase direct-current voltages the voltage difference between which is commensurate with the deviation of the detected phase difference from 90 degrees. The output signals of the 90-degree phase comparator 10 usually contain, in addition to the direct-current components that indicate the result of the phase comparison, alternating-current components having frequencies related to the frequency of the signals that the 90-degree phase comparator 10 receives. These alternating-current components, if left contained in the output signals of the 90-degree phase comparator 10 , make it impossible to perform feedback control accurately according to the result of the phase comparison. For this reason, in this embodiment, the low-pass filter 11 is provided in the stage succeeding the 90-degree phase comparator 10 . The low-pass filter 11 eliminates the alternating-current components from the output signals of the 90-degree phase comparator 10 . [0045] To perform feedback control with high accuracy, it is necessary that the feedback loop have a sufficiently high loop gain. For this reason, in this embodiment, the DC amplifier 12 is provided in the stage succeeding the low-pass filter 11 . The DC amplifier 12 amplifies the output signals of the low-pass filter 11 . [0046] Moreover, in this embodiment, the limiter circuit 13 is provided in the stage succeeding the low-pass filter 11 . When the output signals of the DC amplifier 12 are within a predetermined range, the limiter circuit 13 outputs them intact; when the output signals of the DC amplifier 12 are out of the predetermined range, the limiter circuit 13 outputs them after correcting them so that they are within the predetermined range. [0047] Of the two-phase direct-current voltages outputted from the limiter circuit 13 , one controls the currents produced by the variable current sources 14 and 17 , and the other controls the currents produced by the variable current sources 15 and 16 . [0048] The variable current source 14 extracts a current from the node among the collector of the input transistor Q 1 , the emitter of the transistor Q 3 , and the emitter of the transistor Q 4 . The variable current source 15 extracts a current from the node among the collector of the input transistor Q 2 , the emitter of the transistor Q 5 , and the emitter of the transistor Q 6 . The variable current source 16 extracts a current from the node among the collector of the input transistor Q 7 , the emitter of the transistor Q 9 , and the emitter of the transistor Q 10 . The variable current source 17 extracts a current from the node among the collector of the input transistor Q 8 , the emitter of the transistor Q 11 , and the emitter of the transistor Q 12 . [0049] Now, a description will be given of what happens when an input signal having a predetermined frequency and containing no DC offset or distortion and thus having a duty factor of 50% is fed in via the input terminal 1 , and a signal complementary to the input signal fed in via the input terminal 1 is fed in via the input terminal 2 . Since the input signal fed in via the input terminal 1 has a duty factor of 50%, the phase difference between the signal fed out via the output terminal 6 and the signal fed out via the output terminal 8 is exactly 90 degrees. [0050] Consequently, the two-phase direct-current voltages outputted from the 90-degree phase comparator 10 have the same level, and thus the variable current sources 14 and 17 and the variable current sources 15 and 16 all produce the same current (which can be zero). As a result of the variable current sources 14 to 17 producing the same current, the balance between the twin portions, composed of the transistors Q 3 to Q 6 and the transistors Q 9 to Q 12 , respectively, of the dual differential circuit is not upset, and thus the phase difference between the signal fed out via the output terminal 6 and the signal fed out via the output terminal 8 is kept accurately at 90 degrees. [0051] Next, a description will be given of what happens when an input signal having a predetermined frequency and containing a DC offset and thus having a duty factor other than 50% is fed in via the input terminal 1 , and a signal complementary to the input signal fed in via the input terminal 1 is fed in via the input terminal 2 . In this case, the time chart of the input and output signals is, for example, as shown in FIGS. 2A to 2 C. In FIG. 2A , A″ indicates the input signal that is fed in via the input terminal 1 , A″-bar (overscored A″) indicates the input signal fed in via the input terminal 2 . In FIG. 2B , B″ indicates the output signal fed out via the output terminal 6 , and B″-bar (overscored B″) indicates the output signal fed out via the output terminal 7 . In FIG. 2C , C″ indicates the output signal fed out via the output terminal 8 , and C″-bar (overscored C″) indicates the output signal fed out via the output terminal 9 . [0052] Since the input signal A″ contains a DC offset, its duty factor is not 50%. Thus, the phase difference between the signal fed out via the output terminal 6 and the signal fed out via the output terminal 8 deviates from 90 degrees. Since the duty factor of the input signal A″ is higher than 50%, the 90-degree phase comparator 10 outputs the two-phase direct-current voltages with a voltage difference between them. Thus, the variable current sources 14 and 17 produce larger currents than the variable current sources 15 and 16 , upsetting the balance between the twin portions, composed of the transistors Q 3 to Q 6 and the transistors Q 9 to Q 12 , respectively, of the dual differential circuit. As a result, as will be clear from FIGS. 2A to 2 C, the output signal B″ fed out via the output terminal 6 is a signal that is obtained by performing ½ frequency division on the input signal A″ and of which the zero cross points are a predetermined phase delayed relative to the rising zero cross points of the input signal A″, and the output signal B″-bar fed out via the output terminal 7 is a signal complementary to the output signal B″ fed out via the output terminal 6 . Moreover, the output signal C″ fed out via the output terminal 8 is a signal that is obtained by performing ½ frequency division on the input signal A″ and of which the zero cross points are the predetermined phase advanced relative to the trailing zero cross points of the input signal A″, and the output signal C″-bar fed out via the output terminal 9 is a signal complementary to the output signal C″ fed out via the output terminal 8 . [0053] Through the feedback control described above, even when an input signal having a predetermined frequency and containing a DC offset and thus having a duty factor other than 50% is fed in via the input terminal 1 , and a signal complementary to the signal fed in via the input terminal 1 is fed in via the input terminal 2 , the phase difference between the signal fed out via the output terminal 6 and the signal fed out via the output terminal 8 can be so adjusted as to be exactly 90 degrees. [0054] Incidentally, in a case where the input signal fed in via the input terminal 1 has a duty factor lower than 50%, the variable current sources 14 and 17 produce smaller currents than the variable current sources 15 and 16 . [0055] In the 90-degree phase shifter according to the present invention shown in FIG. 1 , the phase deviation from 90 degrees is fed back as the currents produced by the variable current sources 14 to 17 . This minimizes susceptibility to noise. Moreover, in the 90-degree phase shifter according to the present invention shown in FIG. 1 , since the phase deviation from 90 degrees is fed back as currents, by making as short as possible the wiring between the 90-degree phase comparator 10 and the variable current sources 14 to 17 , even if, for example, the wiring from the node among the collector of the input transistor Q 1 , the emitter of the transistor Q 3 , and the emitter of the transistor Q 4 to the variable current source 14 , or the wiring from the node among the collector of the input transistor Q 2 , the emitter of the transistor Q 5 , and the emitter of the transistor Q 6 to the variable current source 15 , or the wiring from the node among the collector of the input transistor Q 7 , the emitter of the transistor Q 9 , and the emitter of the transistor Q 10 to the variable current source 16 , or the wiring from the node among the collector of the input transistor Q 8 , the emitter of the transistor Q 11 , and the emitter of the transistor Q 12 to the variable current source 17 is long, it is possible to minimize the susceptibility to the voltage drops across the wiring resistances of the paths by way of which the phase deviation from 90 degrees need to be fed back. Consequently, the 90-degree phase shifter according to the present invention shown in FIG. 1 yields output signals with a phase difference of exactly 90 degrees, operating with higher reliability than the conventional 90-degree phase shifter shown in FIG. 6 . [0056] The above description deals only with a case where an input signal having a predetermined frequency and containing a DC offset and thus having a duty factor other than 50% is fed in via the input terminal 1 . Also when an input signal having a predetermined frequency and containing a distortion and thus having a duty factor other than 50% is fed in via the input terminal 1 , the 90-degree phase shifter according to the present invention shown in FIG. 1 operates in a similar manner. [0057] Next, a description will be given of the reason that the limiter circuit 13 is provided in this embodiment. When the output signals of the DC amplifier 12 are within a predetermined range, the limiter circuit 13 outputs them intact; when the output signals of the DC amplifier 12 are out of the predetermined range, the limiter circuit 13 outputs them after correcting them so that they are within the predetermined range. In this way, the limiter circuit 13 serves to limit the variable range of the variable current sources 14 to 17 within the range within which the T flip-flop operates normally as a ½ frequency divider. [0058] Now, to evaluate the benefit of limiting the variable range of the variable current sources 14 to 17 , consider how the T flip-flop operates when it starts to operate if the limiter circuit 13 is absent, i.e., if the variable range of the variable current sources 14 to 17 is not limited. Suppose that, because of variations in characteristics among the circuit elements that constitute the T flip-flop, the voltage difference (DC offset) between the two-phase direct-current voltages outputted from the 90-degree phase comparator 10 is great, and accordingly the currents produced by the variable current sources 14 to 17 vary greatly. This upsets the balance between the twin portions, composed of the transistors Q 3 to Q 6 and the transistors Q 9 to Q 12 , respectively, of the dual differential circuit to such an extent that, even though the input transistors Q 1 , Q 2 , Q 7 , and Q 8 perform switching operation according to the input signal or the signal complementary thereto, the T flip-flop no longer performs ½ frequency division. By contrast, when the limiter circuit 13 is provided and the variable range of the variable current sources 14 to 17 is limited within the range within which the T flip-flop operates normally, even if the circuit elements that constitute the T flip-flop have variations in their characteristics among them, the balance between the twin portions, composed of the transistors Q 3 to Q 6 and the transistors Q 9 to Q 12 , respectively, of the dual differential circuit is not seriously upset thereby. Thus, even at start-up, the T flip-flop surely performs ½ frequency division. Once the T flip-flop starts to perform ½ frequency division, it is possible, through feedback control, to yield output signals with a phase difference of exactly 90 degrees. [0059] In this embodiment, bipolar transistors are used to build the T flip-flop functioning as a ½ frequency divider. It is, however, also possible to use field-effect transistors instead.	The 90-degree phase shifter of the invention has: a T flip-flop including transistors Q 3 to Q 6 and Q 9 to Q 12 that together constitute a dual differential circuit, input transistors Q 1 and Q 2 that receive at their bases an input signal, and input transistors Q 7 and Q 8 that receive at their bases a signal complementary to the input signal; variable current sources 14 to 17 connected respectively to the nodes between the individual input transistors and the dual differential circuit; and a 90-degree phase comparator 10 that compares the phase differences between the signals outputted from the T flip-flop to output signals commensurate with the deviations of those phase differences from 90 degrees. The variable current sources 14 to 17 are controlled by signals based on the signals outputted from the 90-degree phase comparator 10 . This configuration more surely yields output signals with a phase difference of exactly 90 degrees.	7
BACKGROUND OF THE INVENTION This invention is concerned with transmitting control motion from a vibration isolated control platform for use on a vehicle to a controlled device carried on the frame structure of the vehicle. In particular a hydraulic control valve, mounted to the vehicle frame is actuated by a foot operated pedal carried on and operating through the vibration isolated floor panel of an operator's compartment of a tractor vehicle. Current developments in agricultural tractors, earth-working machines and other material and personnel handling equipment are concerned with providing a comfortable, quiet and vibration free cab in order to reduce the environment induced fatigue to the vehicle operator. By isolating the operator from outside disturbances his full attention can be directed to the task at hand thus improving his efficiency and allowing increased fatigue free time in the field or on the job. An area of development yielding good comfort improving results has been the isolation mounting of the operator's work station above the frame of the tractor vehicle. This has been accomplished through the use of resilient dampers, basically, elastic spacers, between the vehicle frame and the floor of the operator's work zone. Typically these dampers are engineered to reduce the transmission of vibration from the frame to the floor. Unfortunately the transmission of vibration and its attendant noise generating property, also enters the cab or work zone through a vehicle controlled device which cannot always be of a flexible enough structure to minimize the transmission of vibrations. Prime offenders are steering shafts, brake and clutch linkages, implement control linkages and other solid connections affiliated with specific implement options. The instant invention provides a linkage means that allows the operation of a remotely mounted operating cylinder through the use of an interrupted solid linkage. The expense and unreliability of a flexible control cable is not incurred. The subject invention allows free floating association between the operating means and the control valve means while assuming that proximate alignment is maintained at all times. SUMMARY OF THE INVENTION An operating rod comprising a foot pedal assembly including a shaft having a pedal pad at one end thereof and a concave cup at a second end thereof is carried in a rod guide affixed to the vibration isolated floor plate of a vehicle. A control means such as a hydraulic spool valve is mounted to a vehicle frame and is equipped with an insulator cap of a resilient material for non-fixed association with the concave cup of the operating rod. Axial motion induced in the operating rod is communicated to the control means such that operation of the control means is positive in respect to the induced motion of the operating rod. Lateral movement between the vibration isolated floor plate and the frame is not interrupted by the association of the cup and the insulator cap. Misalignment between the operating rod and the control means will not impair the operating ability between the rod and the control means. It is an object of this invention to provide an operating device that can be used to communicate operating input motion from a first movable component to a second component regardless of moderate misalignment between the components. Further, it is an object to minimize the transmission of vibration from the frame of a vehicle to the vibration isolated control platform of a vehicle through a valve operating control linkage. BRIEF DESCRIPTION OF THE DRAWINGS These and other objects, advantages and embodiments will be obvious from the following drawings taken in light of the following description wherein the drawings illustrate; FIG. 1 is a partially sectioned view of a free floating actuating link and its association with the control means; FIG. 2 is a second embodiment of the invention in a partially sectioned view. DETAILED DESCRIPTION OF THE INVENTION Looking first at FIG. 1 and one preferred embodiment, the details of the free floating actuating linkage, generally 10, are apparent. The device is mounted to a structure such as the floor portion or floor plate 12 of, for instance, an agricultural tractor by at least one fastener such as the bolt 14. The fastener 14 passes through an aperture in the floor plate 12 and into the rod guide 16 of the actuating linkage. The rod guide 16 is equipped with a central longitudinal bore 20 opened at both ends. The bore 20 has a counterbored portion 22 with an inside diameter greater than the diameter of the bore 20. As indicated earlier there may be at least one bore perpendicular to the central longitudinal bore 20 to accommodate at least one fastening bolt 14. A bushing 24 may be pressed or otherwise fitted into the central longitudinal bore 20 in order to provide a controlled surface. This bushing may be honed or otherwise machined to a controlled tolerance. Furthermore, the bushing is replaceable when necessary thus eliminating the need to replace the entire rod guide for want of a fresh bushing. Carried in the bushing 24 is a rod 26 having a machined first end including a reduced diameter pedal retention portion 30 providing a shoulder 32. A radial groove 34 is provided to accept a retaining fastener 36 such as the lock ring shown. Obviously other types of retainers such as snap rings or Belleville washers could be used. A pedal assembly is maintained in the rod 26 by the retaining fasteners 36. The assembly includes pedal 40 having a central aperture 42 closely accommodating the pedal retention portion 30 and a pedal pad 44. The pedal pad 44 may be of a traction improving elastomer and may further have embossed traction grooves such as the one shown as 46. At the second end of the rod 26 a concave cup 50 is affixed. This cup 50 may be a shallow cup having short sides and a curved interior surface 52 as shown. A spring 54 or similar biasing means may be carried on the rod 26 between the cup 50 and the top of the counterbored recess 22. This spring 54 tends to urge the cup portion of the rod away from the rod guide 16. An access plate 56 is installed to the floor portion 12 by means of at least one fastener such as bolt 60. A dust seal 62 is clamped between the access plate 56 and the rod guide body 16 discouraging the entry of foreign material into the rod guide 16. The dust seal may be of any elastic sealing material that will inhibit the passage of foreign material and vibrations. The free floating actuating linkage generally 10 is used to operate a control device such as the hydraulic valve 64 which may be affixed to a portion of the vehicle not directly attached to the floor portion 12. For instance in FIG. 1 the valve 64 is bolted by fasteners 66 to a portion of the main frame 70 as shown. It is important to understand that the floor portion 12 or the attached rod 26 and rod guide 16 will be supported independently of the frame 70 and this will on occasion result in misalignment between the rod 26 and the hydraulic valve 64. The control means or hydraulic valve 64 includes a spool portion 72 which may move into a valve body to affect the output of the valve. The spool 72 has a small diameter. portion 74 that accommodates an insulator cap 76. The insulator cap is an elastic component having a relatively thick bumper section 80 and an attached flange 82. A boot 84 is maintained on the spool portion of the hydraulic valve by the flange 82 on the cap 76. Only a portion of the boot is seen in the figures. As the host vehicle moves across terrain the floor portion 12 will be displaced relative to the main frame 70. The relationship between the operating pedal assembly and the hydraulic valve will be preserved to a degree allowing operative association. Thus when the need arises depressing the pedal will actuate the control valve even if they be axially misaligned a small amount. The operative relationship is apparent by looking at the drawings. The spring 54 will tend to keep the cup 50 and the cap 76 in contact even when the floor moves up and down relative to the spool valve. The edges of the cup tend to prohibit the cap from moving horizontally out of contact. Vibrations and noise will not be transmitted from the spool 72 to the cup 50 or rod 26 as vibrations will be absorbed by the bumper portion 80 of the cap 76. This is one aspect of the invention. The device shown as FIG. 2 includes most of the components shown in FIG. 1 with the exception being the spring 54. Reference characters identifying parts as shown in FIG. 1 including such components as the pedal rod 40, rod 26, rod guide 16, cup 50, insulator cap 76, and the spool portion 72 of the hydraulic valve 64. FIG. 2 shows an alternative embodiment whereby the return spring of the hydraulic valve (not shown) or residual or active pressure in the hydraulic valve is sufficient to maintain the rod 26 in a displaced condition not affecting the output of the valve. The advantage of this embodiment is that the cost of providing the spring 54 may be conserved. In operation, FIG. 2 provides the same advantages as the FIG. 1 embodiment, namely pedal operation of a control device without transmission of vibrations from one variable component to a second component not necessarily in ideal alignment therewith. Several other embodiments would be obvious in light of this disclosure. For instance the device could be mounted horizontally or in a deployment other than the vertical position as shown. Also, the control means shown as a hydraulic cylinder could be a mechanical operating solid rod equipped with the insulator cap 76. Various other mounting means could also be used to mount the rod guide 16, for instance it could be mounted to the access panel 56. Thus it is apparent that there has been provided in accordance with the invention a free floating actuating linkage that fully satisfies the objects, aims and advantages set forth above. While the invention has been described in conjunction with a specific embodiment thereof it is evident that many alternatives, modifications, and variations will be apparent to those skilled in the art in light of the foregoing description. Accordingly, it is intended to embrace all such alternatives, modifications and variations as fall within the spirit and broad scope of the appended claims.	An operating rod comprising a foot pedal assembly is carried on a first movable body and is maintained in vertical axial alignment with a control means grounded to a second movable body. The operating rod maintains operative association with the control means regardless of divergent movement between the first and the second movable body.	8
RELATED APPLICATION [0001] The present application claims the benefit of priority of pending patent application 60/432,664 filed on Dec. 12, 2002, the disclosure of which is hereby incorporated by reference. BACKGROUND OF THE INVENTION [0002] Hair dryers have existed for a number of years. Existing hair dryers used in the home are held by the hand and moved over the surface of a person's hair or skin to allow warm air exiting the dryer to dry the hair or skin. [0003] An aging population finds it increasingly difficult to hold anything by hand, much less in a way necessary to effectively dry hair or skin. That is, it is sometimes difficult to hold existing dryers steady for the period of time needed to dry the hair or skin. [0004] Regardless of age, it is many times inconvenient for someone who is dressing to use one or both hands to hold a hair dryer. For example, ladies desire to put on makeup and men desire to fix their ties, both of which may require two hands. [0005] Accordingly, it is desirable to provide a way to dry the hair or skin without the need to hold a hair dryer while a person is engaged in another action or activity. [0006] Hands-free, commercial dryers are available. However, these are too expensive for the average household and usually require a person to place her head under and/or into such a dryer while remaining relatively motionless. Motion, however, is just what occurs when a person rushes to get dressed. [0007] Accordingly, it is also desirable to provide a hands-free hair and body dryer which allows a person a wide range of motion yet still manages to dry the hair or skin. BRIEF DESCRIPTION OF THE DRAWINGS [0008] [0008]FIG. 1 depicts a simplified drawing of a dryer according to embodiments of the present invention. [0009] [0009]FIG. 2 depicts a simplified drawing of a dryer according to yet other embodiments of the present invention. DETAILED DESCRIPTION OF THE INVENTION [0010] Referring now to FIG. 1, there is shown a hair and body dryer 1 comprising elevation and securing means 4 (collectively referred to as “securing means”), first movement means 2 , second movement means 3 , power supply means 7 , control means 6 and air diffuser means 5 , among other elements. [0011] Advantageously, the first movement means 2 allows the dryer 1 , in particular the outer circumference 8 of the diffuser means 5 , to be moved left, right, up or down in order to position the diffuser 5 over different parts of the surface of a person's head or body. The first movement means 2 may comprise a pivoting mechanism 2 a or the like to move the dryer 1 to a desired position. [0012] To further position the diffuser 5 , second movement means 3 may also be incorporated. The second movement means 3 may also comprise a pivoting mechanism 3 a to further allow the dryer 1 and diffuser 5 to be positioned over different parts of the surface of the head and body. [0013] The first and second movement means 2 , 2 a , and 3 , 3 a are operable to move the dryer 1 over a wide range of angles, for example, 0 to 35 degrees, 0 to 90 degrees, 0 to 180 degrees or even 0 to 360 degrees. These ranges are by way of example only. Other ranges are also possible, e.g., some range that covers less than 0 to 35 degrees. With this wide range of angles, the dryer 1 is capable of drying the surface of the hair and skin of a person as that person moves through a wide range of angles as he or she, for example, is dressing or putting on makeup. In comparison, though some existing commercial hair dryers are capable of moving in a side-to-side or up and down direction, they are not capable of moving over a wide range of angles, as is the dryer 1 of the present invention. [0014] Though nothing prevents a user from touching both movement means 2 , 2 a and 3 , 3 a , in one embodiment of the invention the movement of these means (and therefore the position of the diffuser 5 ) is controlled without the need for such contact or access by a user (discussed below). [0015] The body and component parts of the dryer 1 may comprise a lightweight material making the overall weight of the dryer 1 capable of being held by hand if desirable by a user. [0016] [0016]FIG. 1 also shows removable securing means 4 for securing the dryer 1 to another object, such as a chair, pole, etc., for support. The securing means 4 may comprise a heavy-duty plastic clip, or a combination of a receptacle and main pole which allows the dryer 1 to move up and down in a vertical motion in order to raise the height of the dryer 1 , to name just a few examples. [0017] In an alternative embodiment, the base 4 a of the dryer 1 may be weighted to allow the dryer to stand independently (i.e., without the need to be attached to a pole, chair, etc.) while the dryer 1 oscillates through a wide range of angles. [0018] Also shown is control means 6 . Control means 6 may comprise a removable or built-in remote control for controlling the power on/off functions of the dryer 1 , and/or controlling the initiation, cessation and positioning of the movement means 2 , 2 a and 3 , 3 a . In more detail, control means 6 may comprise circuitry or the like which is programmed (or programmable) to send instructions to both movement means 2 , 2 a , 3 , 3 a that result in an associated movement of lower body 2 b of the dryer 1 or upper body 3 b of the dryer 1 through a wide range of angles. Each movement of lower or upper body 2 b , 3 b results in a new position of diffuser 5 over a person's head or body. [0019] In addition, the control means 6 may comprise an infrared or radio frequency transceiver for detecting the presence or absence of a user, i.e., whether a user remains close enough to the dryer 1 so that the dryer 1 remains on. For example, if a person walks a far enough distance away from the dryer 1 , the control means 6 may detect such movement and send a signal to the power source of the dryer 1 in order to shut the dryer off. [0020] In addition, the control means 6 may comprise a timer which, regardless of the movement of a user, will track the amount of time the dryer 1 has been operating and automatically shut the dryer off if it exceeds a certain threshold (e.g., 15 minutes). [0021] The dryer 1 may be operated with AC or DC power supplies which are a part of the power supply means 7 . The power supply means 7 may also comprise a retractable power cord which is capable of changing its length as the dryer 1 moves from side to side, or up or down as the case may be. It is also capable of retracting entirely if it is to be disconnected from its present power source and moved to a different location. [0022] Though not shown in FIG. 1, the dryer 1 may also comprise a mirror placed on its surface to allow a user to view the top, back or sides of the head or body (sometimes in conjunction with a second mirror). [0023] Referring now to FIG. 2, there is shown another embodiment of the present invention. The dryer 10 shown in FIG. 2 adds a muffling means 9 which may comprise a baffling structure 12 made of a heat tolerant or heat resistant material capable of withstanding the temperatures of the air which exits from the air diffuser 5 . This muffler means 9 is capable of being detached completely or switched into and out of the path of the air exiting the diffuser 5 by means of optional hinging means 11 or the like. The purpose of the baffling structure 12 is to reduce the noise which results from the air leaving the air diffuser 5 or from the motor (not shown in FIG. 2) used to operate the dryer 10 . Such noise may interfere with the ability of a user to hear a phone or doorbell ring. [0024] In yet an additional embodiment of the present invention, the muffler means 9 may be made of a heat sensitive material which is capable of changing color depending on the temperature of the material. For example, the material may change from a darker color to a lighter color when the temperature of the material reaches a certain threshold. This color change may act as a warning to a user of the dryer 10 that the temperature of the muffler 9 is reaching a dangerous level and should be removed. [0025] In still another embodiment of the present invention, the control means 6 contains sensors and appropriate circuitry to measure the internal temperature of the dryer 1 including the muffler 9 in order to determine whether to disconnect the dryer 1 from its power supply 7 in order to meet United Laboratories specifications or the like and to prevent the dryer 10 from malfunctioning or catching fire. [0026] The discussion above has presented some examples of the present invention. Modifications may be made without departing from the spirit and the scope of the present invention, the scope of which is more closely defined by the claims which follow.	A hands-free dryer moves over a wide range of angles in order to dry the surface of a person's hair or body. The position of the dryer is controlled by a preprogrammed or programmable control unit freeing a user to use their hands to complete other activities.	0
BACKGROUND OF INVENTION [0001] This invention relates to a system and method for monitoring brake applications, more particularly but not exclusively monitoring the application of the brakes of an aircraft, for example, to determine the condition of the brakes. The invention also relates to a system for operating a braking system maintenance program and to a system for charging a user of a braking system. [0002] Carbon-carbon brake discs are commonly used in aircraft brakes. The service life of a carbon-carbon brake is commonly quoted in terms of the number of landings the brake discs are expected to achieve before replacement, the number of landings being routinely logged for maintenance and airworthiness requirements. The expected number of landings is commonly used as a guarantee of minimum service life for heat packs that are sold or to calculate the cost per brake landing (CBL) where brake heat packs are leased to operators by the brake manufacturers. [0003] Aircraft brakes, especially those employing carbon-carbon composite materials as the friction discs in a multi-disc arrangement, may suffer damage that can affect the performance of the brake during service. Routine inspection of brakes between scheduled services includes inspecting the wear pin to ensure sufficient material is available to enable the heat pack to safely absorb the energy of a stop without overheating and damage to the heat pack and surrounding components. Inspection of the wear pin will only reveal when the heat pack is reaching the end of its wear life and will not show other problems that can adversely affect performance of the brake such as broken discs, missing drive tenons, oxidation, uneven disc wear, brake drag or contamination. [0004] It is desirable to have accurate information for determining the condition and predicting the life of carbon-carbon brake discs. This is important for safety as well as commercial reasons. For example, the high cost of carbon-carbon brake discs and delivery lead times in the order of six months makes provisioning of spares an important issue if inventory and hence working capital is to be minimized. [0005] In use aircraft brakes are applied in five situations: when landing, when taxiing, when stationary, during pre-retract braking and, very rarely, during a rejected take off. This is an important point, for example, because it has been realized that the rate of wear of a carbon brake is dependent to a major extent on the number of brake operations effected and not on the energy dissipated during the operation. Thus, the wear during a taxi snub on a cold carbon-carbon brake is similar to that of a full landing. [0006] The prior art relating to brake monitoring includes DE-A-3433236 which discloses a brake application monitoring device intended for use in vehicle or aircraft. This device comprises a chart recorder with traces driven by a transducer measuring the brake force, e.g. by sensing the hydraulic pressure applied, and an intertial sensor responsive to the actual deceleration of the vehicle or aircraft. However, there are several disadvantages with this proposal. For example, the brakes on an aircraft may require an applied pressure of approximately 150 psi (10 bar) simply to close the clearance in the brake before any braking effect is seen. However, a relatively small increase in that applied pressure may be all that is necessary to achieve the desired braking effect for a taxi snub. In many existing systems there is little or no sensing of brake pressure which means that modifications to those systems would be needed if brake pressure is to be used as a means of determining brake application. The use of an inertial sensor is not able to identify all kinds of braking operation carried out, for example check braking against engine thrust, and it might erroneously identify as a braking application a deceleration due to drag, wind effects or throttling back the engines as a braking application. [0007] In the context of a braking system such as an aircraft wheel brake, it is known to measure physical parameters associated with the braking effect during an operation of the system with a view to regulating that effect. [0008] For example, in a hydraulic servo operated aircraft brake system (autobrake) the extent to which the pilot has depressed the brake pedal, i.e. the brake demand, may be measured and the resulting hydraulic pressure applied to the brakes regulated to a value appropriate to the demand. In more complex examples, further parameters are measured. Thus, U.S. Pat. No. 4,790,606 to Reinecke discloses apparatus for measuring and/or regulating a braking force, which apparatus includes a deceleration sensor, a brake temperature sensor, a mass sensor and an evaluation means which uses the signals from these sensors to achieve the measurement and/or regulation. U.S. Pat. No. 4,592,213 to Rapoport discloses a braking system comprising temperature, friction and pressure sensors and means for comparing the signals from these sensors with predetermined values and automatically operating the braking system accordingly. U.S. Pat. No. 4,572,585 to Guichard and U.S. Pat. No. 4,043,607 to Signorelli et al also disclose systems of such a nature. [0009] In some cases, the existence of excessively inefficient braking is signaled, e.g. by a warning signal to the pilot of an aircraft. SUMMARY OF THE INVENTION [0010] According to the invention there is provided a brake condition monitoring system and method in accordance with the claims. [0011] The invention could be applied to an existing or new aircraft by the addition to the brake of a stand-alone unit with its own power supply or an external power supply from the aircraft systems. Alternatively, brake control hardware and/or software could be modified to incorporate the system into existing and new aircraft. [0012] Methods for data storage and downloading such stored information are well known. The information on brake usage could be downloaded at some convenient time such as during maintenance of the aircraft. Data could be read directly from a visual display or downloaded to a portable facility for analysis later. Alternatively the recording unit could be removed for analysis at another site. The information could also be stored, for example, on a memory card that would be easier to remove than the whole unit. [0013] The system of the invention could utilize the current anti-skid control unit (ASCU) by including extra algorithms within the current software, or a stand-alone box that could be positioned either on the brake or somewhere within the aircraft. Different parameters (hydraulic pressure, temperature, wheel speed, torque, pedal deflection, brake wear) could be used within algorithms to detect when an application has taken place and possibly what kind of application it was. The recorded information could be downloaded for analysis of the brake usage and the information could be used for maintenance, spares provisioning and/or charging purposes. [0014] Information downloaded from the system could be used to build a detailed picture over a period of time of brake usage for each airline operating an aircraft type. This information could then be used to accurately predict when maintenance will be required and when heat packs will need changing. This will allow more accurate provisioning of heat pack spares, reducing inventory of these expensive carbon discs at the airline and brake manufacturer and hence reducing operating costs. [0015] Information downloaded from the system could be used to give more reliable guarantees of brake service life by accounting for the wear due to different types of brake usage. The information could alternatively be used to extend a CBL payment scheme to charge for all brake applications, rather than only landings, with the charge for each brake application related to the type of usage and associated wear. [0016] The monitoring system could be an additional unit added to the aircraft or it could be incorporated into the existing brake management control system. [0017] Congestion at many airports results in a considerable number of brake applications during taxiing where relatively little energy is dissipated compared with that dissipated during a landing run. This high number of brake applications during taxi braking can considerably reduce the expected life of the carbon brake disc heat pack. This can result in additional cost for aircraft operators where expected brake life is not achieved. Where operators pay for brakes on a CBL basis, an airline that averages only two taxi snubs per landing sequence would be charged the same CBL rate as an airline that operated from busier airports and averaged 20 snubs per sequence. If information on the type of brake application could be recorded a more detailed picture of an aircraft's brake usage could be built up to assist stock control and develop a pricing scheme reflecting brake usage. A knowledge of the factors influencing brake life could also be used by airlines to educate pilots in brake techniques to extend brake life and reduce operating costs. [0018] When the aircraft is stationary there is no relative rotational movement of contacting friction surfaces and, as applications of the brakes will not generate wear of the carbon, it may be decided that it is not desirable to record these applications. The difference between applications of the brakes while stationary and applications where the aircraft is moving can be ascertained by a system that considers the aircraft speed at the moment the brake is applied to considers the conversion of kinetic energy to heat. If the aircraft speed, measured for example by the signal from a wheel speed transducer, is below a certain threshold value the aircraft can be considered to be stationary and the brake application will not be logged/recorded. If the aircraft speed is equal to or above the threshold value the application of the brake will be recorded to provide information on brake usage. [0019] During a brake application the braking energy is dissipated through the brake as heat. Therefore, it is theoretically possible to sense even the slightest brake application through the change in brake temperature. Temperature sensors are routinely incorporated in brake units so it is possible to sense brake applications within the system with no or limited modification to existing brakes. The brake temperature signal can be processed to give reliable indications of all brake applications. [0020] As noted, aircraft brakes may be applied in five different situations; when landing, when taxiing, when stationary, during pre-retract braking and, occasionally, during a rejected take-off. Each type of brake application is carried out within a respective range of inputs, for example brake fluid pressure, pilot pedal deflection or wheel speed and each type of brake application should produce a relatively predictable response from the brake in terms of outputs such as, for example, heat pack temperature rise or torque generated. [0021] The brake demand inputs are monitored and processed to predict expected brake outputs. The actual outputs are also monitored and compared with the expected or predicted outputs to derive information on the condition of the brake. Such information could be used to predict service life or detect problems that might lead to unscheduled maintenance or premature brake heat pack removal. [0022] Preferably the system will predict the expected brake outputs from the measured inputs and compare such expected outputs with the measured outputs. Where there is a variation between expected and measured outputs the system will determine whether the variation is the result of a defect in the condition of the brake actuator or brake heat pack. [0023] Such a system for monitoring the condition of the brakes could be carried out within the brake control system, with the addition of hardware or software as necessary. Alternatively, monitoring could be carried out within a dedicated condition-monitoring unit fitted to the aircraft and receiving signals from brake control system hardware components and additional hardware components if required. [0024] The system can include means to alert the pilot or ground personnel if a fault in the brake condition is detected to allow maintenance to be carried out at the earliest opportunity so as to minimize the risks to aircraft safety and increase aircraft dispatchability. For alerting the pilot to any fault a display could be provided in the cockpit. Personnel on the ground could be alerted to any detected faults by a display on or from the brake control system or dedicated condition monitoring system during pre-flight checks or by a signal to a ground base. [0025] Signals that could be monitored and processed to provide a brake “signature” from which information on brake condition can be derived include but are not limited to pilot pedal deflection, brake fluid pressure, wheel speed, anti-skid activity, brake temperature, brake torque, brake wear, number of brake applications, brake application time, vibration, brake chassis acceleration, acoustic signature, brake odor. In addition, information can be received from other aircraft systems such as, for example, aircraft weight. Some of these signals can be regarded as inputs to the brake and reflect the type of brake application that is called for by the pilot or auto-brake system, for example a landing or taxi snub. Such inputs include but are not limited to pilot pedal deflection or auto brake demand, brake fluid pressure, brake application time and wheel speed. Other monitored signals can be regarded as outputs resulting from the brake application and condition of the brake. Such outputs include but are not limited to brake torque, brake temperature, vibration, acoustic signature, acceleration and brake odor. [0026] Where a brake heat pack is in as new condition with full amount of wearable material available and all disc drive tenons in place the heat pack will have a maximum number of friction surfaces in operation during brake applications. In addition there will be a maximum heat pack mass available to absorb the heat generated during the brake application. From the processing of a combination of some or all measured inputs including but not limited to wheel speed, pilot brake pedal or auto-brake demand, brake fluid pressure and anti-skid activity a number of expected outputs can be determined. Such outputs or brake signature include but are not limited to brake torque, brake temperature, acoustic signal, vibration, acceleration and brake odor. [0027] As the condition of the heat pack changes the monitored output or signature described above will change for any given set of brake inputs. [0028] Such a system could also monitor other aspects of the undercarriage to detect problems related to the wheel and brake. This might involve monitoring for example the temperature of the wheel bearing, the temperature of the tire or the tire pressure. [0029] Looking at a simple and common scenario, if the heat pack is worn there will be less material available to absorb the energy dissipated by any given brake application. This will result in a greater rise in heat pack temperature than would be seen in a new heat pack. The greater the degree of wear, the greater will be the resulting rise in heat pack temperature. [0030] Considering a different scenario, if all the drive tenons on a single rotor disc are broken this will result in the loss of two friction surfaces. In such a case, when compared with a brake with all friction surfaces available, the same brake control system inputs of pilot brake demand, brake fluid pressure, brake application time, wheel speed and anti-skid activity will result in a lower brake torque being generated, less rapid deceleration and a lower increase in temperature. Alternatively, if a deceleration regulating autobrake is in operation, it will act to regulate deceleration for a given pilot demand by controlling the brake fluid pressure. Hence, the main effect of the drive tenons of a rotor disc becoming broken will be an increased brake fluid pressure. BRIEF DESCRIPTION OF THE DRAWINGS [0031] In order that the invention may be well understood, it will now be described by way of example only with reference to the accompanying diagrammatic drawings, in which: [0032] FIG. 1 is a simplified diagram of one embodiment of system of the invention; [0033] FIG. 2 is a simplified diagram of another embodiment of system of the invention; [0034] FIG. 3 is a graph relating to a first dynamometer test sequence on a particular aircraft carbon disc brake with temperature T degrees C as the ordinate and time S seconds as the abscissa and showing (A) temperature as represented by a signal from a temperature sensor incorporated in the brake and (B) the same signal after being filtered; [0035] FIG. 4 is a graph similar to FIG. 3 but only showing (c) the filtered signal and for a different dynamometer test sequence. [0036] FIG. 5 is a main graph of amplitude M versus time T for the signal of FIG. 4 after numeric processing using a computer, FIG. 5 also comprises three diagrams amplifying respective details of the main graph. [0037] FIG. 6 is a simplified circuit diagram of a brake condition monitoring system. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT [0038] The system shown in FIG. 1 is applied to one wheel 1 of an aircraft (not shown) having a carbon-carbon multi-disc brake assembly 2 with a hydraulic actuator mechanism 3 . Mechanism 3 is driven through line 5 by a hydraulic system of a type containing an ASCU and known in the art. A brake temperature sensing unit 4 , typically a thermocouple, is located adjacent the assembly. To record brake usage, the signal from the thermocouple is input to unit 10 via an interface 11 to processor 12 where the signal is processed by an algorithm in known manner to detect when a brake application has been made. The processor output is recorded in the Non-Volatile Memory (NVM) unit 13 from which information can be downloaded from a suitable access port (not shown) inside the unit 10 or on an external surface of the unit. [0039] In order for unit 10 to be able to function independent of other control systems on the aircraft there is provided within unit 10 battery means 14 for providing power to the unit. During the majority of the unit's life the aircraft will be stationary or in flight, therefore, in order to preserve battery power, and hence extend unit life, a tilt switch 16 and a motion sensor 15 are present. The tilt switch would break the power line from the battery to processor when the undercarriage is retracted and the motion sensor will be used to send the processor into sleep mode during periods of inactivity. [0040] Referring to FIG. 2 , outputs from the thermocouple 4 , brake pressure transducer 6 and wheel speed transducer 7 are taken from an aircraft wheel, brake and brake actuation system (not shown) of a type shown in FIG. 1 . These output signals are input to the processor 24 in unit 20 via signal conditioning interfaces 21 , 22 and 23 . The signals are processed by algorithms to detect when a brake application has been made and the type involved. The processor output is recorded in unit 25 from which information can be downloaded from a suitable access port (not shown) inside the unit 20 or on an external surface of the unit. Records downloaded from the unit will show not only the number of brake applications but also the type of brake application, for example distinguishing between taxi snubs and landings. [0041] A “wake-up” call 26 is again incorporated to preserve the life of the battery 27 and can incorporate functions such as a tilt switch and/or motion sensor as described for the system of FIG. 1 . [0042] The systems of FIG. 1 and FIG. 2 represent stand-alone units added to the aircraft to monitor the brake applications, but the processing of the signals to be detailed below can also be incorporated into existing brake control units by modification of hardware and/or software. [0043] In the systems described above a temperature signal at the Brake Temperature Monitor Sensor (BTMS) is shown at A in FIG. 3 for three taxi snubs performed on a dynamometer for a carbon brake from a regional jet aircraft. Temperature rises TR 1 , TR 2 and TR 3 in the order of 2.5° C. are shown but noise resulting from interference by other equipment makes the shape of the trace difficult to see. The system therefore includes means for filtering, differentiation and amplification of the signal. [0044] The signal B of FIG. 3 has been processed by a fourth order filter. Although the trace is now smooth the individual temperature rises caused by each brake application are not easily detected so the signal is processed further by differentiating twice and amplified. A suitable computer program performs the necessary numeric algorithm and makes a decision on whether or not a brake application has taken place, if so, the brake application can be recorded. FIG. 4 shows the output for a full dynamometer test sequence consisting of three taxi snubs, one full landing followed by three taxi snubs, a short rest period and then another three taxi snubs. FIG. 5 shows the same output after processing using the algorithm. Peaks above a predefined amplitude in the FIG. 5 output indicate brake applications. From FIG. 5 the peaks clearly identify all the individual brake applications of the dynamometer test program. This dynamometer test work has been found to read across to data taken in aircraft testing. It has been shown in testing with the processed temperature signal that a reliable indication of a brake application can be detected even where temperature changes of less than 1° C. are seen. [0045] Analysis of the output is more suited to some aircraft than others, depending on the positioning of the BTMS in the brake. The optimum position for temperature sensing will depend on the design of the brake in question. In some brakes the optimum position might be close to the center of the heat pack. Generally the closer the temperature sensor is to the optimum position in the brake the more sensitive will be the temperature detection during a brake application. For example, the sensitivity for temperature measured at the center of a four rotor brake might be several times greater than elsewhere within the brake. [0046] The processed temperature data can be recorded on its own to give an indication of the number of brake applications using apparatus such as is represented in the diagram of FIG. 1 , or combined with wheel speed and/or brake pressure to give a more detailed record of the type of brake application that has been made, i.e. taxi snub or landing using apparatus as shown in FIG. 2 . [0047] The invention is not limited to the embodiment shown. The signals may be derived from and processed by components in existing brake control units. The temperature may be sensed or measured using a device other than a thermocouple. [0048] The system shown in FIG. 6 incorporates an electronic brake management controller 101 of a type known in the art to manage all aspects of brake control including monitoring pilot braking demand and controlling the application of pressure to the brake in accordance with pilot demand and detected skid activity. Pilot brake demand inputs to the controller are provided by monitoring means 104 . These inputs include but are not limited to pedal deflection and pressure demand. The controller will also monitor signals from sensors in the wheel 103 and brake 102 including but not limited to wheel speed, temperature, pressure stator position, brake torque, brake fluid pressure. Signals from sensors in other areas of the undercarriage such as, for example the tire and axle could also be used to monitor the condition of a range of components and assemblies forming part of the aircraft landing gear. Also, information such as aircraft weight could be inputted to the controller from one or more other a/c systems (these are represented by block 107 in the drawings). [0049] The controller analyzes the signals relating to pilot demand and the brake to evaluate a brake performance signature indicative of how the brake is performing. This brake performance signature could be compared against the signature for a heat pack in as new condition. Alternatively, over a period of time a record of a brake's performance can be built up that will allow statistical analysis showing trends in the brake performance signature and allow the controller to predict an expected signature for a given brake application. Where deviations from the expected signature occur the controller would be able to identify potential brake problems that might have caused the variation. [0050] Problems identified could then be signaled to an on-board maintenance computer 105 capable of alerting the crew or ground maintenance staff. Alternatively, or additionally data from the controller could be downloaded from a data port by ground staff during routine maintenance or pre-flight inspection. Such a port 106 could also be accessed by the brake supplier for downloading information about brake service, including number of brake applications and type of brake application. This service information could be used on its own or in combination with condition monitoring data for brake life prediction and/or commercial purposes. [0051] Such a brake management controller could also manage the auto-braking function of the braking system. [0052] In the system of FIG. 6 , the extent of heat pack wear is estimated by monitoring pilot brake demand and signals from wheel speed, brake fluid pressure and brake heat pack temperature. For a given set of operating conditions, for example, brake demand and speed, the controller compares the measured temperature rise with an expected temperature rise. The difference between these values gives an indication of heat pack wear with a greater degree of wear resulting in a greater temperature rise. Additionally, the controller incorporates a threshold value of temperature difference for any braking requirement, the threshold value representing the difference between the temperature expected for a new heat pack and a fully worn heat pack. As this threshold value of temperature difference is approached, the flight crew or ground crew are alerted that the heat pack is approaching the wear limit. Alternatively, the controller or onboard maintenance computer could send a signal using known communications technology, such as for example via satellite link, to the aircraft operator's maintenance base or the brake supplier's base so that maintenance action may be planned and replacement parts provisioned. Such signals could be sent on a regular basis to allow external monitoring of brake condition or once only when the wear reaches a predetermined value to alert that maintenance and spares provisioning is required. The timing of such an alert signal could allow for the lead-time for supply of the parts thereby minimizing stock levels and hence reducing working capital of the brake supplier and aircraft operator. [0053] The heat pack might lose mass for reasons other than wear, for example, by oxidation of carbon friction material or loss of a number of drive tenons. Such loss of mass will result in a larger increase in temperature in the brake performance signature than would be seen if the fault were not present. [0054] Where the reduction of mass is caused by loss of a number of drives in the heat pack, this would result in a step increase in the temperature rise during a brake application when compared to the temperature rise predicted from statistical analysis of brake signature trends for a number of stops over a period of time. The size of the step increase in temperature during brake applications would be greater the more drives were removed from the discs in the heat pack. [0055] Estimates of heat pack mass can also be made from X ps and (delta)T (refer to Table 1). If these estimates of mass do not match this would suggest some form of damage such a broken drives or oxidation. [0056] A disc with all drives broken off is detected in the system of FIG. 6 by monitoring signals representing brake torque, brake temperature and the brake acoustic signature. If the drive tenons on a rotor disc or double stator disc are broken this will result in the brake having two less friction surfaces when the brake is applied. For a given brake demand, brake pressure, duration of brake application and wheel speed there will be a correspondingly lower torque generated because of the loss of the two friction faces and a resulting lower brake temperature than would be seen under the same brake application conditions with a heat pack where all friction surfaces are operational. The number of ineffective friction surfaces in a brake will depend on the extent of damage to the heat pack. The deviation in brake torque and temperature from expected values could be analyzed to determine how many friction faces were ineffective. [0057] In comparison, under auto-braking conditions, if the drives on a disc are broken the brake will be controlled to achieve a predetermined brake torque and the system will deliver an increased brake fluid pressure to achieve this required torque. Therefore, under auto-braking a pressure higher than expected would indicate a disc with broken drive tenons. The deviation in brake pressure from that expected could be analyzed to give an indication of how many friction surfaces were no longer effective, so providing an indication of the extent of damage. [0058] In a brake with broken drive tenons on a disc, the acoustic signature of the brake during brake applications will be different from the acoustic signature of a brake with the same amount of wear and all friction faces working effectively. The acoustic signature is detected by a microphone. The signal from the microphone is input to the brake management controller for analysis to detect variations from the expected signature. [0059] Other scenarios outlined in Table 1 could be detected and reported in a similar way to those scenarios described above. The scenarios outlined in Table 1 are to be considered as illustrative examples of brake conditions that could be detected and not an exhaustive list. [0060] References herein to brake odor, scent and olfactory sensing applies to the process using appropriate transducers of detecting the presence and/or level of certain gases or combinations thereof and/or of vapor or particulates in and around the brake apparatus. TABLE 1 Expected Change in Signature For Constant Pressure For Autobrake Failure Modes Demand (deceleration) demand Cracked High T B High T B Brake Disc and/or and/or ΔAcoustic ΔAcoustic Broken Drive Low τ High P and Low T B and/or ΔAcoustic Missing Large ΔX PS Large ΔX PS Brake Disc and and Low τ High P Residual Torque ΔT B Δ B and/or and/or Δτ Δ and and No ΔPedal/ΔX PS /ΔP No ΔPedal/ΔX PS /ΔP Excessive Low τ High P Oxidation and/or and High T B High T B Excessive Variation in T B Variation in T B Spline Friction across brake across brake Excessive ΔOlfactory ΔOlfactory Contamination Cracked ΔAcoustic ΔAcoustic Torque Tube Tyre Fuse Low P Tyre Low P Tyre Plug Leakage Wheel Bearing High T Bearing High T Bearing Fatigue Failure Note: Low/High refers to lower/higher than expected Possible sensor inputs: P 8 Brake Fluid Pressure ω Wheel Speed τ Brake Torque X Pedal Pedal Deflection t Time Acoustic Brake Acoustic Signature T B Brake Temperature, measured at various positions through brake X PS Pressure Stator Position α Acceleration Olfactory Scent T Bearing Wheel bearing Temperature T Tyre Tyre Temperature P Tyre Tyre Pressure Δ Change in	A system and method for monitoring the applications of carbon-carbon brakes of an aircraft to determine brake condition and operate a brake maintenance program or charge a brake system user. The system and method includes monitoring each actuation of the brakes and making a separate record of each actuation of the brakes in which there is relative movement of the facing friction surfaces that cause wear, and from that separate record determining brake usage. The monitoring may include measuring changes and processing the signals to distinguish between those which fall below and those which are above a threshold value. The method and system may comprise sensing a plurality of braking parameters having values dependent upon the wear in the system and different faults of the system, and identifying and recording wear and faults based on combinations of values of the parameters.	1
This is a continuation in part of currently co-pending application Ser. No. 09/590,586 filed on Jun. 8, 2000, to which this application claims priority and benefit, and which hereby is incorporated by reference. BACKGROUND OF THE INVENTION 1. Field of the Invention This invention relates generally to connections between lengths of pipe, or between pipes and fittings. More particularly, the invention is directed toward a device and method of connecting two lengths of pipe that maximizes the advantages of both restrained push-on joints as well as mechanical joints, as are known commonly in the art. The invention has application to long-run pipe lengths as well as fittings, appurtenances, and connections. 2. Description of Related Art Due to thrust forces, earth movement, and external mechanical forces exerted on pipes, the industry has focused substantial attention on the problem of maintaining connections between adjacent lengths of pipe after installation. The result of this attention is a library of differing solutions and approaches known in the art. The majority of these solutions can be categorized as either “push-on” joints or “mechanical joints.” References to “pipe” made by the inventor with respect to application or use of the present invention shall be understood to include fittings, connections, and any other appurtenances to pipes. The most common connection device used in the art for connection of straight-run lengths of pipe is a “push-on” pipe/bell configuration. These push-on solutions are exemplified by U.S. Pat. No. 2,953,398, and account for the majority of straight-run pipe connections. In a typical configuration, a spigot end of a pipe slides into a bell end of another pipe past a tightly fitted gasket. No follower ring, stuffing box, or other external compression means typically is present in a push-on joint. Additionally, the typical push-on joint does not include a restraining means, though such means as tie bars, concrete thrust blocks, screws, and additional ring attachments have been employed in some cases to effect restraining to the joints. Advancements in the art have led to innovations and modifications of push-on joints to include restraining means. Examples of such restrained push-on joints include U.S. Pat. Nos. 5,295,697; 5,464,228; and 5,067,751. The securement of the connection in such advancements may be effected by locking segments or wedges within the gasket that engage the spigot. The locking segments are oriented in such a manner as to allow entry of the spigot into the bell, but upon counterforces tending to effect removal of the spigot, the segments pivot toward a biting engagement with the spigot, stopping further removal. The effect is much like a child's “finger lock” toy, the stronger the attempt to remove the pipe, the greater the locking effect exerted by the inserts. These push-on type joints enjoy superior flexibility and resistance to both axial and para-axial separative forces. Meaningful difficulty has been experienced in the industry, however, in applying these connections to fittings, where it may be impracticable to secure the fitting sufficiently to exert the high installation pressures necessary initially to push the spigot into the bell in such configurations. A “mechanical joint” is a well-known standardized connection device widely employed in the pipe industry. Such a joint fluid-seals two lengths of pipe together by compressing a gasket around a spigot and within a bell at the intersection. Mechanical joints are characterized by an outwardly flanged bell of a receiving pipe, into which a spigot of a second pipe is inserted. The bell is adapted to seat a gasket that fits snugly about the circumference of the spigot of the second pipe, and further to receive a supporting compression ring or gland. In assembly, the spigot is fully advanced into the bell and the gasket is firmly seated within the bell and around the spigot. The gland is then forced against the gasket by fastening it securely to the bell flange through such means as fastening bolts tightened under relatively high torque. This configuration typically includes a lip about the inner diameter of the gland that upon securement extends axially within the bell. The configuration of the gland is such that as the lip is forced against the gasket, the gasket becomes compressed under pressures sufficient to deform the gasket. As the gasket is compressed between the bell and the gland, the gasket therefore is squeezed inwards toward and into sealing contact with both the exterior of the inserted pipe section and the interior of the bell. This deformation enhances the sealing effectiveness of the gasket beyond that which can be readily obtained in the absence of compression or high insertion forces The mechanical joint enjoys wide acceptance in the industry, and is the subject of national and international standards such as ANSI/AWWA C111/A21.11-95. Given the industry affinity for such joints and the embedded nature of these standards into specifications, any mechanical joint should conform to these specifications to gain optimal acceptance. Numerous attempts have been made to improve upon the standardized mechanical joint. These attempts are almost uniformly characterized by the inclusion of an additional mechanism or attachment, creating a mechanical connection resistive to separation of the pipes. Such attempts that require modification of the bell or gland (or both) are exemplified by U.S. Pat. No. 784,400 to Howe, which employs locking inserts recessed within the gland; U.S. Pat. No. 1,818,493, to McWane, which discloses a modified gland that relies upon specially modified bolts having toothed cams that both pivot on and bite into the spigot as the bolts are hooked under a modified lip of the bell and forced into grooves in the gland. Further solutions employ additional restraining devices or teeth interposed between the gasket and the gland, which are driven into the spigot as the gland is tightened. Included among these devices are U.S. Pat. No. 4,664,426, to Ueki; and U.S. Pat. No. 5,297,826, to Percebois, which each require the use of multiple additional locking devices in addition to the standard mechanical joint's simple bell-gasket-gland configuration. U.S. Pat. No. 4,878,698, to Gilchrist, U.S. Pat. No. 5,335,946, to Dent, et al, and U.S. Pat. No. 5,398,946, to Hunter, et al., appear susceptible to, possible early engagement of the biting teeth prior to full seating of the gland. U.S. Pat. No. 5,803,513, to Richardson and others attempt to solve this potential problem by use of sacrificial skid pads to prevent early engagement of the teeth. Additional solutions employ a bolting assembly attached to (or incorporated into) the bell, which assembly is oriented such that upon tightening of certain specially configured bolts, the bolts or a device actuated thereby are driven into the outer surface of the spigot. These bolting schemes are exemplified by devices sold by EBAA Iron, commonly known in the art under the trademark MEGALUG (Registration No. 1383971) Further examples of this type of solution include U.S. Pat. No. 4,647,083, to Hashimoto, which modifies the standard gland to include bolts that act upon locking wedges when tightened. When a pipe is installed in a ground-bedded environment, it is typically inconvenient to have multiple additional bolting requirements on the underside of the pipe as laid. Such underside boltings increase the cost and time of installation. If, however, the bolt-in locking scheme employs only a few bolt locations, the inward pressure of the bolts may in some conditions tend to deform the cross-sectional profile of the spigot. For example, employment of only three bolt locations in some circumstances may exhibit an undesirable possibility of deforming the spigot into a slightly triangular shape. It will be noted by those reasonably skilled in the art that each of these configurations also suffers from practical issues, such as the expense of manufacture of additional components and the fact that additional components increase the potential for unacceptable failure. Furthermore, each of these solutions may be considered a “static” connection. Although pipelines are traditionally considered to be rigid and immobile structures, a durable connection must allow for a certain amount of flexibility and “play” at joints. Such accommodation to movement is necessary because the environments in which pipelines lay are not truly static. Thrust forces may create non-longitudinal, or para-axial, loads that tend to drive a pipe length toward an angle from the longitudinal axis of the lengths to either side of such axis. As the pressures of the material being transported within the pipe vary, the forces will similarly vary. Additionally, locations in which pipes are run rarely are as stable as commonly believed. In fact, pipes may be run above ground, in which cases such pipes do not enjoy the benefit of any stability enhancing factors of bedding or trenched installation. Finally, even typical earth-bedded pipes must endure shifting due to sedimentation, erosion, compaction, mechanical forces (such as nearby construction), and earth movement (such as earthquakes). A variation of the push-on joint is evidenced by U.S. Pat. No. 2,201,372, to Miller, which employs a compression snap-ring fitted within a special lip of the bell, in order to exert pressure onto the locking segments and thus drive them into the spigot. Alternatives in Miller similarly drive locking segments into the spigot upon installation. U.S. Pat. No. 3,445,120, to Barr, likewise employs a gasket with stiffening segments completely encased therein that are generally disposed in a frustroconical arrangement. Such segments are stated to give the gasket a resistance to compression along the plane that includes both ends of the segment. When a spigot is subjected to withdrawing forces, the gasket rolls with the movement of the pipe. As the gasket rolls, it is intended to eventually encounter a position in which the stiffened plane needs to compress for further rolling. In optimal conditions, due to the stiffening, the gasket cannot compress and therefore cannot roll further. As the rolling stops, the gasket becomes a static friction-based lock between the spigot and the bell. Notably, among other distinctions, the arrangement taught by Barr remains a rubber-to-pipe frictional connection. OBJECTS OF THE INVENTION The following stated objects of the invention are alternative and exemplary objects only, and no one or any should be read as required for the practice of the invention, or as an exhaustive listing of objects accomplished. As suggested by the foregoing discussion, an an exemplary and non-exclusive alternative object of this invention is to provide a gasket interchangeable with gaskets of standard mechanical joints which allows for the transformation of the joint into a restrained joint without the need for any reconfiguration or adaptation of the bell, spigot, or gland of the mechanical joint involved. A further exemplary and non-exclusive alternative object is to provide a dynamic connection for pipes that does not require high insertion pressures. A further exemplary and non-exclusive alternative object of the invention is to provide for a cost effective manner and device of restraining a typically configured pipe joint. The above objects and advantages are neither exhaustive nor each individually critical to the spirit and practice of the invention, except as stated in the claims as issued. Other objects and advantages of the present invention will become apparent to those skilled in the art from the following description of the invention. BRIEF SUMMARY OF THE INVENTION The present invention may be described basically as a gasket for converting a standard mechanical joint into a restrained mechanical joint without the need for altered configuration of the bell, spigot, or gland of the joint, and without the need for additional fittings or devices. In the practice of the present invention, a standard mechanical joint's bell and gland configuration can be employed to connect a spigot end of one pipe length to the bell end of another pipe length in a restrained relationship (restraint being defined as resistance to axial separation of a mated bell and spigot), with the restraint based on forces superior to rubber-to-pipe friction. In more particular discussion of some of the embodiments taught, the invention includes forming the gasket to fit within the bell in such a manner that a void exists during rest, into which void the gasket deforms, which in turn influences the rotational motion of the segment. In this manner, the configuration of the gasket influences the timing and extent of rotation during the process of securing the gland to the bell. Overpenetration may be avoided, while at the same time ensuring sufficient penetration at the proper moment in time. Controlling the timing and extent of locking segment rotation influences gasket performance and is addressed by the described embodiments of this invention. The extent of segment rotation affects the application of restraint. Once restraint occurs, which typically is when the segment has rotated into an interference position between bell and spigot, further meaningfully helpful gasket compression typically no longer occurs. Rotating the segment too early yields insufficient gasket compression for adequate sealing. Rotating the segment too late may not sufficiently restrain the joint. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 shows an diagram of the typical mechanical joint, having a gasket in place. FIG. 2 depicts a cross-sectional view of an un-stressed gasket of the present invention in the initial phase, at a location in which the position and cross-section of the locking segment can be viewed. FIG. 3 demonstrates the cross-sectional view of an embodiment of the gasket. FIG. 4 is a depiction of the gasket and segment in the joint during the act of assembly, in the transition phase. FIG. 5 shows an embodiment of a locking segment configuration useful in the present invention. FIG. 6 shows the joint of the present invention following compression and in a locked state, restraining the joint. FIG. 7 is an alternative embodiment of the locking segment useful in a gasket of the current invention. FIG. 8 is a cross-sectional view of a gasket for use in the current invention, showing an alternate embodiment of the locking segment in place. DETAILED DESCRIPTION OF THE INVENTION The following is a detailed description of the invention. Those skilled in the art will understand that the specificity provided herein is intended for illustrative purposes with respect to the inventor's most preferred embodiment, and is not to be interpreted as limiting the scope of the invention. References to “pipe” herein shall be understood equally to refer to any pipe length, appurtenance, fitting, or any other connected device or element regardless of the method or material of manufacture. Turning now to the drawings, FIG. 1 presents a diagram of a typical mechanical joint. Assembly of the joint according to the current invention is practiced as known in the art. Particularly, but without limitation of the known variants which shall be as equally applicable to the present invention as they are to the known art, the joint contains the following elements in the following relationship. Compression ring or gland 11 is placed on spigot 10 , following which gasket 2 is placed around the exterior of spigot 10 . Spigot 10 is then advanced within bell 12 until the end 41 of spigot 10 is stopped by an annular shoulder 42 within bell 12 . Gasket 2 is advanced into bell 12 until it seats in the annular recess seat 43 , as shown. Gland 11 is then abutted against gasket 2 and is secured to bell 12 by securing devices 44 , which are presented for illustration here as bolts 45 passing through perforations 46 and engaged by nuts 47 . As is evident, upon drawing up or tightening of nuts 47 , gland 11 is compressed against gasket 2 , causing it to compress. Alternative securing means will be apparent to those in the industry, such as overcenter clamps, cam locks, ramped wedges, ramped annular rings, and rivets, and could include any mechanism that may be used to decrease the axial spacing between the gland 11 and the bell 12 . Due to the constraining presence of recess seat 43 and gland 11 , deforming of gasket 2 may be directed primarily radially inward toward and into sealing engagement with spigot 10 . The invention of the present disclosure builds upon this interrelationship and requires no changes to the spigot, bell, or gland, though such changes may be accommodated within the spirit of the invention if such modifications are otherwise desired. As will be known in the art, traditional understanding counsels that the profile of the gasket 2 in a resting state substantially match with the internal profile of the bell 12 at the location in which the gasket 2 is intended to reside in final assembly. The purpose of such matching profiles is to allow for tight mating of the gasket 2 into the bell 12 to enhance fluid seal. In the shown embodiment, this conventional wisdom would counsel for the radially outward profile of the gasket 2 to have approximately the same configuration as recess seat 43 of bell 12 . As shown in FIG. 1 , in a resting state the primary mating surfaces of a prior art gasket would mate smoothly with the internal surfaces of the bell 12 . Accordingly, in prior art gaskets, following assembly the profile of the gasket at these areas of sealing interface is substantially the same as the profile of the gasket in the resting state. As is depicted in FIGS. 2 and 8 , the locking segment 1 of the present invention may be constructed to fit within a gasket 2 that is configured to fit within any standard mechanical joint without necessitating changes to the configuration of the bell, gland, or spigot. Gasket 2 is an elastomeric or other resilient or deformable material, such as those in the art will understand may be used in the practice of a mechanical joint. A useful configuration of the gasket 2 , as shown in FIG. 3 , is an annular ring with a radially inner surface 4 that is adapted to be in contact with spigot 10 , a gland face 7 that is adapted to be compressed by a gland or compression ring 11 , a front face 61 that leads in axial insertion, and a radially outer surface, shown in the drawings as having a configuration that does not mate smoothly with the recess seat 43 in a resting state. Particularly, in the shown embodiment, the radially outer surface of the gasket 2 has a compression seat surface 9 at the leading portion of the gasket 2 near the front face 61 that is designed to mate with and seal against an area of the recess seat 43 . Also characterizing the shown embodiment is a distortion control surface 62 that in the resting state leads away from the recess seat 43 to form a radially depressed gutter 63 , before the profile of the gasket 2 extends once again radially outward to meet the bell 12 in the area of rear seal 64 . Accordingly, the radially outer surface in the shown configuration is the entire area between and including the compression seat surface 9 through rear seal 64 ; stated differently with reference to the drawings, the radially outer surface is in FIG. 3 the entire “upward” surfaces of the drawing combined. Although these surfaces are readily distinguishable in the drawings and as discussed herein, the transition among surfaces may not be as readily apparent in the uncompressed state as in the configuration shown. In the shown embodiments, gasket 2 conforms to all of the requirements of ANSI/AWWA C111/A21.11-95. In particular, for any given spigot 10 , gasket 2 may have a slightly smaller inner diameter than the outer diameter of the spigot 10 . Accordingly, placement of gasket 2 over the exterior of spigot 10 may require exertion of force to expand gasket 2 to fit around spigot 10 . Alternatively described, it will be noted that the gutter 63 , being an annular depression (radially speaking) is characterized by the fact that if gasket 2 is advanced into the bell 12 as fully as is possible in the resting state (e.g., prior to deformation), and rotated to contact the bell 12 in the area of the recess-seat 43 as much as possible without deformation, a void remains between the gasket 2 and the recess seat 43 ; such depression or void is the gutter 63 . As shown FIGS. 2 and 4 , in this embodiment a portion of the gutter 63 remains vacant of gasket material, even during some advanced stages of compression and assembly. It will be noted that the gutter 63 in other embodiments could be covered by a film of rubber or otherwise be a void below the radially outward surface of gasket 2 , and still be and operate as a gutter 63 in the spirit and scope of the invention. Without limiting the application of the structure, effects, or scope of the invention or other possible advantages of practice of the invention, the operational aspects of having this void are believed in the shown embodiment to confer at least two advantages, either of which alone would be an advance in the art. (It should be noted that applicant does not limit the invention by this discussion to only embodiments that possess one or more of these advantages. First, the compression of compression seat surface 9 , and separately of distortion control surface 62 , against recess seat 43 in different locations is believed to create two separate areas of sealing, with gradients of compression between the points of initial contact with the recess-seat 43 , such that sealing efficiency is enhanced. Also, rear seal 64 in compressive contact with gasket land 49 may create yet another area of sealing. This appears to create maximum pressure against at least one point in the area of the gasket 2 , which serves to resist high fluid escape pressures, while still taking advantage of the flexibility and other advantages of high surface-area, lower-pressure sealing. A second perceived benefit is an operational effect on the motion of the segment 1 , which is described in more detail, below. Gasket 2 incorporates at least one locking segment 1 , which may be configured as shown in FIG. 5 , also shown as embedded in the gasket 2 in FIG. 8 . In the usual practice of the invention, a number of locking segments 1 will be circumferentially dispersed about and within gasket 2 , and though preferable, the placement need not be precisely or even nearly symmetrical. The number of such segments 1 may be selected with reference to the expected separative forces to be encountered by the joint, with a higher force tending to recommend a larger number of segments 1 . The inventor prefers to use no fewer than three such segments 1 , but the invention is not so limited. For example, a preferred configuration of segments 1 for use with a pipe of eight inch diameter intended to carry fluids at pressures of 350 p.s.i. includes eight to ten segments 1 uniformly spaced around the spigot-facing circumference of gasket 2 (e.g., the radially inner surface 4 ). An alternative would allow a single segment 1 of a circumference appreciable to (at least one-half the size of) the circumference of gasket 2 . Separative forces (shown diagramatically as vectors 50 , 50 a and 50 b in FIG. 1 ) tend to extract spigot 10 from bell 12 . As indicated by directional arrow 50 , some separative forces follow in-line with the common axis of assembled pipe lengths. Other separative forces are para-axial, as shown by vectors 50 a and 50 b , which may be due to bedding shifting or non-uniform securement around the periphery of spigot 10 . Segment 1 is intended to grip spigot 10 and to translate separative forces into forces at least partially opposing bell 12 . To this end, segment 1 possesses teeth 6 that are adapted to protrude from inner surface 4 of gasket 2 , at least upon compression of gasket 2 by gland 11 . Teeth 6 are adapted to contact spigot 10 , and are most preferably fashioned of a substance that is harder than the material comprising the exterior of spigot 10 . In a particular embodiment, teeth 6 are, in the uncompressed state of gasket 2 , already exposed from the inner surface 4 as shown by FIG. 8 . This exposure may be by protrusion from the inner surface 4 , or by slight recessing beneath inner surface 4 in combination with the absence of gasket material covering the teeth, which is the embodiment shown in FIG. 3 and subsequent images. As shown in FIGS. 3 and 8 , the gasket 2 may be configured with a recess about teeth 6 to prevent interference with penetration of such teeth 6 into spigot 10 . An alternative preferred embodiment presents teeth 6 slightly recessed within gasket 2 , and covered by a membrane or thin layer of compressible or puncturable material. The inventors suggest that at least some of the area between teeth 6 or immediately adjacent to teeth 6 be free of rubber to allow penetration of the spigot 10 . An advantage of initial concealment is that it allows for greater advancement of gland 11 , and thus greater compression of gasket 2 , prior to substantial engagement of teeth 6 into spigot 10 . A greater sealing effectiveness therefore may be achieved. Preferably, segment 1 possesses a plurality of teeth 6 . In a tested configuration, the tips of teeth 6 are arranged in an arcuate relationship. The arcuate relationship enhances the ability of teeth 6 to bite into spigot 10 despite any variations in circumference of spigot 10 or the inner dimensions of bell 12 . This is because a larger gap (frequently due to manufacturing tolerances) between spigot 10 and the inner dimensions of bell 12 (particularly annular gasket recess seat 43 ) will cause segment 1 in assembly to be rotated upon compression of gasket 2 toward a steeper angle relative to spigot 10 than exists in the unstressed configuration as displayed in FIG. 2 . Given the arcuate relationship of teeth 6 , upon such rotation of segment 1 the most axially inner teeth rotate into contact with spigot 10 . The arcuate configuration further urges at least two teeth 6 to be in contact with spigot 10 , regardless of the rotation of segment 1 . This is because in the arcuate configuration, a straight line can be drawn between any two adjacent teeth 6 . Beneficially, the presence of additional teeth 6 to either side of any biting tooth 6 tends to assist in preventing overpenetration of the spigot 10 by segment 1 , due to the fact that these adjacent teeth will be pointed at an angle to spigot 10 such that they are not optimally positioned for biting; rather, adjacent teeth 6 will tend to contact spigot 10 at an angle substantially more parallel to spigot 10 than those teeth 6 that are biting into spigot 10 . Accordingly, because of the more-parallel angle, adjacent teeth 6 act as stops to further penetration. In a shown configuration as detailed in FIG. 5 , segment 1 in cross section has a toothed edge 16 , with teeth 6 extending therefrom in the arcuate pattern as above discussed; and a back face 13 , extending radially and axially along a slope towards protrusion 17 . Back face 13 as shown is adapted to be in a close proximity to, or even in direct contact with, gland 11 when the mechanical joint is assembled. Connecting protrusion 17 in the axially inner direction with toothed edge 16 , is a surface, or a series of surfaces, denoted compression faces 15 . In this embodiment, back face 13 is in close proximity to gland 11 when the joint is assembled, and upper protrusion 17 , being the most radially outer area of the segment, is in close proximity to gasket land 49 of the bell. A greater volume of elastomeric material of gasket 2 exists between compression seat surface 9 (particularly shoulder 8 ) and segment 1 than is present between back face 13 and gland 11 . Upon insertion of spigot 10 into gasket 2 , toothed edge 16 of segment 1 may be forced radially outwardly by the presence of spigot 10 , and may cause pivoting of segment 1 . The volume of compressible material present between the segment's compression faces 15 and recess seat 43 allows for such outward movement or pivoting without compromising the integrity of gasket 2 . Given the arcuate configuration of teeth 6 along toothed edge 16 , even when rotated radially outwardly, at least one tooth 6 will be poised for contact with spigot 10 upon compression (though the inventor recognizes within the spirit of the invention that any or all of teeth 6 may be removed from direct physical contact with spigot 10 due to teeth 6 of segment 1 being recessed in gasket 2 or the presence of a thin layer of elastomeric material, or other substance, so long as the material, or substance is not sufficient to interfere with the effective grip of at least one of teeth 6 into spigot 10 upon full compression of gasket 2 , as is described below). Spigot 10 may be advanced as in the prior art until stopped by annular shoulder 42 . Following such insertion of spigot 10 into bell 12 , gasket 2 will be in a position basically as represented in FIG. 2 , and the gasket 2 may be already in contact with recess-seat 43 at some point. In any event, substantial compression of gasket 2 , as in compression sufficient to effect the sealing and securement of the joint is not at this point effected. Further assembly is carried out by advancing of gland lip 71 against the gasket 2 gland face 7 , and into the bell 12 . As will be evident to those skilled in the art, this advance of gland 11 will by contact with gasket 2 force gasket 2 inwardly into contact or more forceful contact with recess seat 43 . As shown from FIG. 4 , gasket 2 , and in the shown embodiment specifically compression seat surface 9 , begins deformation against recess-seat 43 . Deformation of gasket 2 , particularly in the area of distortion control surface 62 , begins to occur in the shown embodiment prior to substantial rotation of segment 1 . This phase of the assembly operation is considered the initial phase and is characterized by substantially translational motion of the segment. The forces acting on the segment are principally balanced between gland 11 acting on the back face 13 of segment 1 and the compression energy stored in the gasket rubber trapped between segment 1 , spigot 10 and bell 12 . This compression energy acts on segment 1 at a location known as the “center of pressure” that is believed in the shown embodiments to be substantially in line with the force vector imparted by gland 11 acting on segment 1 . As gland 11 continues to advance into bell 12 beyond the point shown in FIG. 4 , segment 1 begins to rotate. This phase of the assembly operation is the transitional phase and is characterized by a relatively decreasing amount of translational motion of segment 1 and a relatively increasing amount of rotational motion of segment 1 . In other words, upper protrusion 17 advances into the bell at a faster rate than teeth 6 for a given input by gland 11 . This occurs because the center of pressure of the compression energy stored in the gasket moves closer to the teeth 6 of segment 1 and away from upper protrusion 17 as the gasket is compressed. Rotation of segment 1 at this point is influenced by the gutter 63 and is related to the movement of the center of pressure of the gasket toward teeth 6 . Because gutter 63 presents the area of least resistance to compression, and hence to deformation (it being known in the art that rubber tends to deform, in preference to compressing), the upper (as seen in the Figures) portion of the segment 1 rotates toward the gutter 63 , reducing the size of the gutter 63 as the gasket material deforms into the area. Rotation of segment 1 continues substantially in this manner as the gland 11 advances until the point at which segment 1 is in resistive contact with both spigot 10 and bell 12 . This phase of the assembly operation shall be known as the final phase and in the shown embodiment is characterized by a substantially rotational motion of segment 1 and a substantial collapse of gutter 63 . This segment and gasket orientation is depicted by FIG. 6 . The resistive contact in the shown embodiment is specifically between a tooth 6 and protrusion 17 of segment 1 and the corresponding joint surfaces of spigot 10 and bell 12 . Until the final phase of assembly is entered, if a tooth 6 is in resistive contact with spigot 10 , or protrusion 17 is in resistive contact with bell 12 it will be understood that this contact is of a sliding nature. Upon the substantial collapse of gutter 63 and the start of the final phase of assembly, further gasket deformation is extremely limited which effectively prevents further translation of segment 1 further in the axial direction. Any additional clamping force applied to the securing mechanism between gland 11 and bell 12 (e.g. the bolts 44 ) imparts a large rotational energy to the segment due to the imbalance between the force vector created by contact of gland 11 and segment 1 vs. the vector between the center of pressure of gasket 2 and segment 1 . Any further rotation of segment 1 now causes a penetration of segment 1 into spigot 10 by teeth 6 and a penetration of segment 1 into bell 12 by protrusion 17 via plastic deformation of spigot 10 and bell 12 . This penetration provides a mechanical lock between spigot 10 and bell 12 via segment 1 and thus joint restraint is obtained. Following installation, it will be evident from the foregoing description that at least one tooth 6 remains in gripping contact with spigot 10 and protrusion 17 remains in contact with bell 12 . Any attempt of the spigot 10 to move outwardly of bell 12 urges at least this one tooth 6 to move axially outwardly of bell 12 along with spigot 10 , but axial movement is not possible due to the resistive contact between back face 13 and lip 71 of the gland and a rotation of the locking segment in a direction that exerts axial resistance as well as radial pressure among the segment 1 , the bell 12 , and the spigot 10 . This axial resistance, or restraint, is caused by the segment rotating into a direction in which its length is greater than the distance between the spigot 10 and the bell 12 . The balance between the axial load and the radial load imparted to the bell and spigot affects the performance of the invention and may be influenced by the configuration of segment 1 . As the forces trying to separate bell 12 and spigot 10 increase so does the axial resistance imparted to bell 12 and spigot 10 by segment 1 . The radial load also imparted keeps teeth 6 and protrusion 17 of segment 1 engaged with spigot 10 and bell 12 respectively. If the radial component is too low, then the segment 1 will disengage spigot 10 or bell 12 . If the radial component is too high, then excessive deformation or penetration of spigot 10 by segment 1 may occur. The inventors note that this feature, like others shown in the embodiments, may exhibit particular advantages, but that the presence or absence of these features and advantages required of the scope of the invention only as limited in each particular claim. Except to the extent expressly included in a claim, the inventors do not consider these advantages, configurations, or possibilities to be limitations on the invention. Manufacturing tolerances for spigots and bells are not precise; accordingly, in some installations, the distance between spigot 10 and bell 12 , including features of bell 12 such as recess seat 43 , will be greater or less than such distance in other installations. Under the above described embodiment of segment 1 , where the gap between spigot 10 and recess seat 43 is as intended or smaller, upon securement of gland 11 at least on of teeth 6 of segment 1 is driven into spigot 10 and and upper protrusion 17 is driven into bell 12 . The inventor believes that due to the supportive pressures of the gasket material, segment 1 does not begin biting engagement with spigot 10 until a generally effective seal among bell 12 , spigot 10 and gasket 2 has been effected by compression. Accordingly, teeth 6 are unable to prematurely engage spigot 10 in a manner that may adversely affect the ability to obtain optimal compression of gasket 2 . This delayed engagement can be manipulated by the means discussed above; namely, the configuration of the gasket, notably the gutter 63 , compression seat surface 9 , distortion control surface 62 , elastomeric characteristics of the gasket 2 , shape of segment 1 , position of segment 1 in gasket 2 or various combinations of these features. Due to contact with bell 12 in addition to gland 11 , separative forces are transferred by segment 1 , not just against gland 11 but also against bell 12 . This is significant in that it reduces a potentially substantial force that is resisted by bolts 45 and gland 11 . Under high loads, bolts 44 and gland 11 may distort, reducing sealing effectiveness of gasket 2 ; the current invention's ability to transfer a significant portion of the magnitude of the separative vector directly to bell 12 via segment 1 therefore enhances the effectiveness of sealing. In contrast to situations as in the previous paragraph, in which the distance between spigot 10 and gasket recess seat 43 is relatively small, an exaggerated pivoting mechanism is believed to occur in segment 1 when the gap is larger, as follows: The condition that exists in a large gap situation (e.g. when the manufacturing tolerances and assembly conditions exist such that bell 12 dimensions are at a maximum diameter condition and spigot 10 dimensions are at a minimum diameter condition) is such that upon initial assembly, neither gasket 2 or segment 1 may be in contact with either one or both spigot 10 or bell 12 . During the transition phase gasket deformation will occur, as previously described, due to compressive forces acting on gasket 2 by spigot 10 , gland 11 and bell 12 forcing gasket 2 into contact with both spigot 10 and bell 12 . At this point however, segment 1 may still not be in contact with either spigot 10 or bell 12 . Approaching the end of the transitional phase of assembly, as gutter 63 of gasket 2 closes up due to elastic deformation of gasket 2 caused by compression of gasket 2 , a dramatic rotation of segment 1 will occur due to the previously described shift in the center of pressure of the compressed gasket and its relationship to segment 1 . This dramatic rotation allows segment 1 to bridge large gaps for which restraint would otherwise be impossible to provide. The final phase of assembly then proceeds as previously described with teeth 6 embedding in spigot 10 and protrusion 17 embedding in bell 12 . In an embodiment of segment 1 , upper protrusion 17 may be formed in an angular configuration. Such an angular configuration will cause such points to bite into bell 12 when sufficient pressure is exerted between segment 1 and bell 12 . Although such biting can occur in any event under appropriately high pressures, particularly in the small-gap situation addressed above, the propensity to bite can be controlled by adjusting the acuteness of the angle. The inventor notes that the more acute the angle at either given point, the earlier along a pressure curve the point will likely bite into bell 12 . Accordingly, it is possible to adjust the tendency toward desired points of final rotation of segment 1 by adjusting the acuteness of angle of the upper protrusion 17 , which will in turn adjust the maximum probable radially outward movement of upper protrusion 17 . It should be noted that at pressures sufficient to drive upper protrusion 17 into bell 12 , rotation of segment 1 will be substantially prevented and will occur under conditions of plastic deformation of either segment 1 , spigot 10 or bell 12 . This mechanism can be employed to balance the rotation of segment 1 -and control the point of engagement. Similarly, if upper protrusion 17 is configured in a radiused fashion, movement of segment 1 may be adjusted to allow axial movement of segment 1 until upper protrusion 17 obtains non-compressible abutment with bell 12 , at which point the axial and radial forces acting on segment 1 at upper protrusion 17 cause the pivot point to occur in its near vicinity. Variations of this allow further control of segment engagement and the balance of axial and radial loading distributed to all load carrying components of the invention. An alternative embodiment, as shown in FIG. 7 , may be to incorporate an elbow 3 into the back face of segment 1 . Elbow 3 will contact gland 11 during securement of the restraining devices 44 in the initial stages of the transitional assembly phase. The location and configuration of elbow 3 may be tailored to further alter the behavior of segment 1 during rotation, engagement and lockup. The location and configuration of elbow 3 may be further explained by addressing several characteristics of elbow 3 which may be modified to alter segment behavior. If elbow 3 is given a sharp radius, elbow 3 may be made to penetrate gland 11 at the contact point. This penetration will impart additional resistance to further rotation of segment 1 when the final assembly phase is complete thus relieving some of the reliance on the angle of the line of action segment 1 makes relative to spigot 10 and bell 12 when balancing the segments axial and radial load carrying distribution. Additionally, elbow 3 may be positioned radially outward or inward on segment 1 . Placing elbow 3 radially outward on the segment will increase the rotational tendency of the segment during the transitional phase of assembly promoting earlier engaement and lockup of segment 1 . Placing elbow 3 radially inward on segment 1 will have a correspondingly opposite effect. If elbow 3 is made such that it penetrates gland 11 while at the same time upper protrusion 17 penetrates into bell 12 , a situation may be created whereas both axial and radial loads transferred into bell 12 may be balanced along multiple load paths. Building upon the concept of altering the acuteness of elbow 3 and upper protrusion 17 , the transition between such points may be less pronounced than in FIG. 2 . In fact, the transition may be so smooth as to create a general curve that acts as both elbow 3 and upper protrusion 17 . A curve could be adapted to effect biting engagement, whether by altering the radius of curvature, or by including nubs or other points to operate as engagement points (which, for purposes of this invention could be considered to be elbow 3 or upper protrusion 17 ). Further alternative embodiments that may be included with the foregoing or otherwise substituted for gutter 63 or the area around gutter 63 include the strategic positioning of a secondary or tertiary elastomeric material having different deformation characteristics than the remainder of gasket 2 . Such strategic positioning may optimally include placement between frontal slope 15 of segment 1 in the vicinity of upper protrusion 17 . This placement would influence the potential of upper protrusion 17 to move toward annular recess seat 43 , thereby causing upper protrusion 17 to cease substantial rotation prior to biting into bell 12 . Similarly, such secondary or tertiary rubber may be placed radially outwardly of elbow 3 to influence the maximum ability of elbow 3 to move radially outwardly of spigot 10 . Although much of the foregoing is discussed in terms of initial installation of a mechanical joint, the inventor notes the value and applicability of use of the present invention to “retrofit” or repair existing mechanical joints. By simply rejoinably severing the ring of gasket 2 (preferably at an angle to the radius) the gasket 2 can be fit over an existing spigot, and moved into place after removal of the old gasket. The gland 11 can then be re-attached, completing retrofitting of a standard mechanical joint to a gasket-restrained mechanical joint. The foregoing represents certain exemplary embodiments of the invention selected to teach the principles and practice of the invention generally to those in the art so that they may use their standard skill in the art to make these embodiments or other and variable embodiments of the claimed invention, based on industry skill, while remaining within the scope and practice of the invention, as well as the inventive teaching of this disclosure. The inventor stresses that the invention has numerous particular embodiments, the scope of which shall not be restricted further than the claims as issued. Unless otherwise specifically stated, applicant does not by consistent use of any term in the detailed description in connection with an illustrative embodiment intend to limit the meaning of that term to a particular meaning more narrow than that understood for the term generally.	A gasket for converting a standard mechanical joint into a restrained mechanical joint without the need for altered configuration of the bell, spigot, or gland of the joint, and without the need for additional fittings or devices. In the practice of the present invention, a standard mechanical joint's bell and gland configuration can be employed to connect a spigot end of one pipe length to the bell end of another pipe length in a restrained relationship, with the restraint based on forces superior to rubber-to-pipe friction. In more particular discussion of the embodiments taught, the invention includes forming the gasket to fit within the bell in such a manner that a void, or gutter, exists during rest, into which void the gasket compresses, which in turn influences the rotational motion of the segment. In this manner, the configuration of the gasket influences the timing and extent of rotation throughout the process of securing the gland to the bell.	5
FIELD OF INVENTION This application relates to the field of hand-held vacuum and pressure pumps, particularly of the type disclosed in U.S. Pat. Nos. 3,612,722, 4,775,302, 4,806,084, 4,954,054, and 5,112,203 by the present inventor, the disclosures of which are incorporated by reference. BACKGROUND Hand-held vacuum and pressure pumps are generally useful whenever vacuum or pressure is desired. Vacuum or pressure can be created, for example, by compressing (i.e. squeezing) and releasing a handle of such a vacuum or pressure pump. Generally, such squeezing and releasing causes a piston to move in a cylinder of the pump thereby creating vacuum or pressure. Many types of vacuum pumps have been devised, but they often suffer from such drawbacks as complexity, expense, excessive bulk, inability to pull a suitable vacuum, and the like. The vacuum pump of the referenced patents has significantly solved the need for a vacuum pump which is simple, inexpensive, lightweight, compact, and portable, and one which can pull a useful vacuum. Such hand-held vacuum and pressure pumps are especially useful for various tasks such as aiding in performing vacuum extractions during childbirth, and are useful in various industries, such as the automotive industry, for liquid sampling and vacuum system testing and repair. Vacuum pumps manufactured according to the aforesaid patents have the ability to pull a vacuum of, for example, twenty-eight inches of mercury. In some applications, it is desirable to pull a preset or controlled vacuum, and one which is repeatable. Inasmuch as the hand-held vacuum pump is manually operated by hand and because the pump can quickly pull a relatively high vacuum, it is difficult to manually pull a given level of vacuum. One way to accomplish this is disclosed in U.S. Pat. No. 4,979,883. That patent discloses a vacuum limiter that uses two distinct valves, one to meter the vacuum pressure, and the second to hold the vacuum. Both of these valves are located on the source side of the vacuum pump, so the valves have to maintain the difference in pressure between the vacuum and the vacuum cylinder. This leads to problems with drawing an accurate vacuum and holding it. SUMMARY OF THE INVENTION The present invention provides an improvement on the aforesaid vacuum pumps by enabling a preset vacuum to be obtained in a simple manner, and lends the pump to a wider range of potential uses. Additionally, the present vacuum limiter improves on previous vacuum limiters by enhancing the accuracy of the preset settings and serving to hold the vacuum better. The preferred embodiment of the current invention combines a metering check valve to limit the vacuum, and an exhaust valve, both of which are connected to the outlet port of the pump's cylinder. Experimentation has shown that this configuration enhances the accuracy of the vacuum limiter. Furthermore, because the present invention utilizes only one valve to limit the vacuum, the cost and complexity of manufacturing are both reduced. Accordingly, it is an object of the present invention to provide an improved hand-held vacuum pump. Another object of this invention is to provide an improved vacuum limiter for a hand-held vacuum pump. Another object of this invention is to provide a vacuum limiter which can be used for retrofitting or attachment to a hand-held vacuum pump. BRIEF DESCRIPTION OF THE DRAWINGS These and other objects of the present invention will become better understood through a consideration of the following description taken in conjunction with the drawings in which: FIG. 1 is a side view showing a hand-held vacuum pump of the type shown and disclosed in the referenced patents, including an attached vacuum limiter according to the present invention; FIG. 2 is a top view of the vacuum limiter, taken along a line 2--2 in FIG. 1; FIG. 3 is a rear view of the vacuum limiter, taken along a line 3--3 in FIG. 2; FIG. 4 is a detailed cross-sectional view of the vacuum pump cylinder and the vacuum limiter. DETAILED DESCRIPTION Turning now to the drawings, FIG. 1 depicts a hand-held vacuum pump 10 of the type disclosed in the referenced patents. As more fully described in U.S. Pat. No. 4,806,084 and the other referenced patents, the pump 10 comprises fixed and movable handles 11, 12 which can be squeezed together to operate a piston 31 within a sealed cylinder 14. This motion of the piston causes air to be drawn from an inlet channel 17 into a chamber 30 inside the cylinder 14. A vacuum limiter 40 shown in FIGS. 1-4 includes a ball check valve 60 and a duckbill valve 42. The ball check valve 60 is adjustable and operates to limit the amount of vacuum pressure that the pump 10 can pull. The duckbill valve 42 operates to exhaust the air out of the pump when the piston moves toward an inlet port 37. FIG. 1 shows a manifold 18 attached to the vacuum pump 10, which can be used to attach different components. The components shown in FIG. 1 are a pressure gauge 19 and a vacuum release 20. A source port 21 is shown at the left side of the manifold. This port 21 can be attached to the apparatus for which a vacuum is desired. The basic parts of the vacuum pump 10 operate similarly to the pump disclosed in U.S. Pat. No. 4,806,084. As will be apparent to those skilled in the art, squeezing the fixed and movable handles 11 & 12 together causes the piston 31 to be reciprocated back and forth in the cylinder 14 under spring tension as more fully described in U.S. Pat. No. 4,806,084. This causes a vacuum to be drawn at the inlet port 37. The vacuum is drawn in the following manner. When the piston 31 is withdrawn from an inlet end 28 to an outer end 29 of the cylinder (FIG. 4 shows the piston near the inlet end 28), the air pressure in the chamber 30 decreases, thus causing a pressure differential between the air in the inlet channel 17 and the chamber 30. An umbrella valve 38 operates to allow air to flow from the inlet channel 17 to the chamber 30, but not in the opposite direction, as is well known in the art. As air flows from the inlet channel 17, a vacuum is created at the inlet channel 17 and any device (eg. a container) thereto because the pressure is lower than in the atmosphere. The vacuum limiter 40 operates by restricting the vacuum that can be drawn in the cylinder chamber 30 to a preset or adjustable level. By restricting the vacuum allowed in the cylinder chamber 30, the pressure differential between the chamber 30 and the inlet channel 17 is reduced, so that the resultant vacuum is restricted. The vacuum limiter 40 of the present invention is attached directly to the cylinder 14 with an open channel between the two. The open channel comprises an outlet port 39 opening in the cylinder 14 and a vacuum limiter port 52 opening in the wall of a housing 41 of the vacuum limiter 40. This channel is sealed using an o-ring 55 to prevent air leaks. The preferred embodiment of the vacuum limiter uses a ball check valve 60, as shown in FIG. 4. The ball check valve 60 generally includes a spring 43, a steel ball 44 and an o-ring 45, and operates in the following manner. The spring 43 holds the steel ball 44 in place against the o-ring 45, thus biasing the valve 60 to a closed position. The preferred embodiment shows a plug channel 50 through which the atmosphere contacts the steel ball 44. The contact between the steel ball 44 and the o-ring 45 provides a seal so that no air can enter the vacuum limiter when the pressure is approximately the same in the atmosphere and inside the vacuum limiter (note that the pressure inside the vacuum limiter 40 is equal to the pressure inside the chamber 30 because there is an unobstructed channel between the two 39 & 52). Therefore, when the piston 31 is withdrawn and the pressure inside the chamber 30 and vacuum limiter 40 is reduced, the pressure on the steel ball 44 is less on the inside of the vacuum limiter than on the area of the steel ball 44 exposed to the atmosphere. Because of this pressure differential, the spring 43 is compressed and the steel ball 44 is withdrawn from the o-ring 45, allowing air to enter the vacuum limiter 40 and the chamber 30. This limits the amount of a vacuum that the pump can pull. The ball check valve 60 can be preset or adjustable. A preset version (not shown) will allow a set pressure to be drawn, the actual amount of which will depend on the physical characteristics of the spring 43, the steel ball 44, and the size of the plug channel 50. A preferred adjustable valve 60 is shown in FIG. 4. The spring 43 is attached at one end to a coupler 53 that mounts directly over the duckbill valve 42. The other end is frictionally held in place by the steel ball 44, which contacts an adjustable plug 46 via an o-ring 45. The adjustable plug 46 has a plug channel 50 to allow air to contact the steel ball 44. The adjustable plug 46 has external threads 47 mating with internal threads 48 of the housing 41, and has a suitable slot 49 for allowing adjustment by a coin or screwdriver (also see FIG. 3). The slot 49 allows the plug 46 to be screwed in or out (to the left or right as seen in FIG. 4) so as to adjust the force applied to the spring 43 via the steel ball 44, and thus adjust the maximum level of vacuum that can be drawn through the limiter. An o-ring 56 provides a seal so that no air can escape between the plug 46 and the housing 41. In the preferred embodiment, the duckbill valve 42 is also housed in the vacuum limiter 40 assembly. It is not functionally necessary that the duckbill 42 be located here, but it is done in the preferred embodiment for simplicity and to reduce the number of parts. The duckbill valve 42 is used as an exhaust valve. When the piston 31 is moved to,the inlet end 28 of the chamber 30, the pressure inside the chamber increases because the volume decreases. The pressure differential causes the duckbill valve 42 to open to expel the excess air through a duckbill valve channel 51 in the housing 41, thereby equalizing the pressure inside and outside. Note that the coupler 53 has a channel 54 to allow air to pass to the duckbill valve 42. The ball check valve 60 and the umbrella valve 38 only allow air flow in one direction (into the vacuum limiter/chamber), so they are not involved in exhaust. While embodiments of the present invention have been shown and described, various modifications may be made without departing from the scope of the present invention, and all such modifications and equivalents are intended to be covered.	A hand-held vacuum pump with an attached vacuum limiter valve is disclosed. The pump includes a cylinder coupled with a handle, a piston in the cylinder coupled with another handle, along with a suitable valving assembly for allowing a vacuum to be drawn at an inlet of the pump. More particularly, there is also disclosed a vacuum limiter which can be attached to or form an integral part of the pump. The vacuum limiter includes a valve which is attached to the cylinder outlet port and which is adjustable for allowing the limit vacuum to be set.	5
BACKGROUND OF THE INVENTION This application claims the benefit of U.S. Provisional Application No. 60/015,342, filed Apr. 19, 1996 and is the National Stage of International Application No. PCT/US97/06639, filed Apr. 18, 1997. In the commercial production of glass containers by use of an I.S. machine, it is common to employ what is known in the industry as the "blow-and-blow" process for sequentially forming glass containers. A vertically-oriented plunger mechanism is used in combination with a blank mold to achieve initial shaping of a glass parison. The parison is a deformable gob of molten glass which is dropped, vertically downward, into the cavity of the blank mold whereupon pressurized air is applied downward onto the parison to cause it to conformably fill the lower portion of the blank mold cavity. The foregoing step in shaping the parison is commonly referred to as the "settle blow". At the lower end of the blank mold is a neck ring for shaping what will become the container lip end or neck. Immediately following the aforementioned settle blow, an upwardly directed pressurized air flow or "counter blow" is directed through the neck ring to cause the parison to fill out the blank mold cavity and assume the general shape of a glass container. During the initial downward insertion of the parison into the blank mold, a funnel is normally disposed at the upper end of the blank mold to facilitate entry of the parison into the mold, after which the funnel is replaced by a baffle to close off the upper end of the blank mold except for air channels through the baffle which direct the downward pressurized air flow during the settle blow step. The baffle remains in place during the upward counter blow, and the counter blow results in the full shaping of the parison. Following the counter blow step of the blow-and-blow process, a mechanical transfer of the formed parison occurs, moving it from the blank mold to an adjacent blow mold where reheating and final forming of the parison to the desired container shape, consistent with the blow mold cavity, occurs. An inherent problem in the use of the blow-and-blow process is the continued formation of glass particulate debris in the area of the neck ring. Such debris becomes entrained in the air flow and may become embedded in the parison or form a buildup in the air flow channel of the plunger mechanism. Another inherent problem in the blow-and-blow process, particularly in the production of narrow neck containers, is the inability to consistently produce glass containers free of settle wave and with uniform lightweight glass distribution in the container. This problem has usually been addressed in the industry by using equipment specifically designed to produce containers by a process known as "NNPB", or narrow neck press and blow. Obtaining the speed, efficiency, and product consistency of the NNPB process through an improved blow-and-blow process has continued to be a goal which has until now eluded glass container manufacturers. SUMMARY OF THE INVENTION The present invention addresses the foregoing problems and presents an improved blow-and-blow process for the initial molding of a parison in a blank mold wherein the settle blow step of the process is considerably more efficient, and the removal of particulate debris is constant and in a direction always away from the parison whereby the number of flawless containers formed in the operation of the I.S. machine is significantly increased. More specifically, the present invention provides for utilization of a vacuum within the throat or air flow tube structure of the plunger mechanism of the I.S. machine, during the sequential steps of the blow-and-blow process, whereby initial shaping of the parison in the blank mold is more positive and consistent and is accompanied by air sweep debris removal in a direction away from the parison. The vacuum step of the process herein disclosed is preferably practiced in combination with a plunger mechanism in an I.S. machine which has the improved internal tube structure as disclosed in U.S. Pat. No. 5,358,543. Such structure provides a relatively smooth air passage surface and eliminates interfering ledges and seals which in the prior art acted as entraining surfaces for particulate debris carried by the air flow. The means of creating a momentary negative pressure, or vacuum, on the down side of the parison during the blow-and-blow operation is facilitated by the use of a transducer device adapted to utilize pressurized air flow to create suction by aspiration from the central tube structure of the plunger mechanism at the appropriate instant in the blow-and-blow cycle. By use of the transducer, vacuum is induced at a location immediately adjacent the plunger mechanism, obviating the need for a remotely located suction pump, and the same compressed air source that is used currently to press the parison downward during the settle blow step of the bottle forming cycle and to impart the upward pressurized air flow during counter blow can be momentarily channeled through the transducer to evacuate the central tube structure of the plunger mechanism as a incident of the counter blow. The invention disclosed herein comprehends a unitized valve structure which serves as an air flow controller or converter and includes a transducer assembly or vacuum sleeve which acts to convert a positive air flow pressure to a negative air flow whereby a partial vacuum is drawn, in accordance with a timed sequence, in the throat or tube structure of the plunger mechanism of the I.S. machine. BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWINGS FIGS. 1-3 are illustrations of the initial delivery and forming of a glass parison in a blank mold. More specifically, FIG. 1 is a vertical sectional view illustrating the first step in forming a parison into a container; FIG. 2 is a view similar to FIG. 1 but illustrating a parison having undergone the settle blow in a blank mold; and FIG. 3 is a view similar to FIGS. 1 and 2 but illustrating the parison after it has undergone the counter blow of the blow-and-blow process. FIG. 4 is a view in vertical section illustrating the internal structure of certain glass container forming equipment commonly referred to as a "plunger mechanism" in accordance with the present invention; FIG. 5 is a fragmentary view in vertical section illustrating the upper end of a plunger mechanism as shown in FIG. 4 but in operative mated combination with a blank mold, and having the components positionally disposed as they appear during parison gob loading of the blank mold; FIG. 6 is a fragmentary vertical sectional view of the same components shown in FIG. 5 and illustrating a relative component positioning during the counter blow step in a blow-and-blow container forming operation; FIG. 7 is a view in vertical section illustrating a plunger mechanism of the type first shown in FIGS. 5 and 6 but providing greater detail of the structure and its mated blank mold, and a transducer in combination therewith for inducing a vacuum in the internal tubing structure of the plunger mechanism in accordance with the method of the present invention; FIG. 8 is a side elevational view of an air flow control device for use in practicing the process or method introduced by the present invention; FIG. 9 is an isometric view of the air flow controller device first shown in FIG. 8 but here shown on a smaller scale and taken from a viewpoint facing toward the hidden corner at the left end of the structure first shown in FIG. 8; FIG. 10 is a view in vertical section of a plunger mechanism of the type first shown in FIG. 4 in combination with an air flow control device of the type first shown in FIG. 8; FIG. 11 is a view in vertical section of the air flow control device of the present invention first shown in FIGS. 8-10 but here shown substantially in full scale; FIG. 12 is a view in vertical section of a transducer first show in FIG. 10 but here shown in comparatively larger scale; FIG. 13 is a chart lay-out setting forth the steps of the known glass container forming cycle commonly referred to as the blow-and-blow process; and FIG. 14 is a chart layout consistent with the new blow-and-blow process in the practice of the invention herein disclosed. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIGS. 1, 2, and 3 illustrate successive steps in the blow-and-blow cycle which is utilized to form a molten gob or parison into an initial glass container shape. Each of these figures shows a blank mold 10 having a vertically-oriented cavity 12. FIG. 1 shows a funnel 14 positioned at the upper end of the cavity 12 to receive and guide a parison 20 downward into the cavity 12. A neck ring 16 is disposed at the lower end of the cavity 12 and has a vertically-reciprocal plunger 18 projecting therein. FIG. 2 shows a baffle 22 which is positioned on the funnel 14 after the parison 20 is deposited into the cavity 12 as shown in FIG. 1. The baffle 22 has passages 24 enabling compressed air to be injected downward into the cavity 12 to cause the parison 20 to fill the lower end of the cavity 12. The applied air acts to "settle" the gob into the finish and form the container lip end or neck in conformance with the shape of the neck ring. On completion of the blank shape as shown in FIG. 2, the air flow is terminated. After sufficient settling time, the baffle 22 is removed to allow the funnel 14 to be withdrawn whereby the baffle is again positioned on the blank as shown in FIG. 3 where it serves to seal the upper end of the blank mold. The plunger 18, which was utilized in an upward stroke position to form the container throat, is moved downwardly as shown in FIG. 3, and air is blown upwardly into the parison to form the glass to the shape of the blank. After completion of the sequential steps shown in FIGS. 1-3, mechanical means is utilized to move and invert the parison from the blank mold to a blow mold (not shown) where the parison is finally formed to the finished container shape by the further application of compressed air into the parison. The entire forming operation, beginning with the parison as shown in FIG. 1 and ending with the formed container in the blow mold, is commonly referred to in the industry as the "blow-and-blow" process. Hence, FIGS. 1-3 are illustrative of the first "blow" cycle of the "blow-and-blow" process. FIG. 4 (and also FIG. 10) illustrates a plunger cycling mechanism 40 for an individual section glass container forming machine, having a cylinder casing 42 defining a chamber 46. The cylinder base or bottom is an end cap 44, and the upper end of the cylinder is defined by an intermediate cap 48. Extending axially upwardly through the chamber 46 is a piston having an annular lower end or base 54 and a rod portion 50. The piston is adapted for air driven linear vertical movement to cycle a plunger 18 (FIG. 1) in a glass container forming operation which utilizes a blank mold 10 positioned at the upper end of the plunger mechanism. A casing section 52 disposed above the cylinder 40 serves to contain the plunger and other elements. Not shown in FIG. 4 are seals and bearings which would be supported by the intermediate cap 48, about the rod portion 50, to facilitate its reciprocal operation. For details of such structure and for a more thorough understanding of the operation of an individual section machine generally, reference may be made to U.S. Pat. No. 1,911,119; 2,508,890; 2,702,444; or 2,755,597. FIG. 4 also illustrates air tube structure within the plunger mechanism 40, including a first tube or tubular member 58, the upper end of which is secured within the upper end of the rod portion 50 by a connecting member 56. Between the inside wall surface of the rod portion 50 and the tube 58 is an annular space 60, and contained within the annular space 60 is a second tube or tubular member 62 which projects separately from the inward surface of the end cap 44. FIGS. 5, 6, and 7 illustrate the various structural modifications of a plunger mechanism assembly which are consistent with the practice of the improved blow-and-blow process of the present invention. In all three figures, arrows are used to indicate air flow direction during the improved blow-and-blow process, as hereafter further explained. FIG. 5 corresponds generally to the parison insertion step shown in FIG. 1. Laterally-directed ports 68 are shown in the blank mold 10 in FIG. 5 to enable expulsion of air from the cavity 12 as the parison enters the cavity 12. Although such exhaust ports are commonly used in the prior art, provision is made in the structure of the present invention for the ports 68 to lead downwardly and communicate with air passages 70 provided in the body of the neck ring 16, leading to the central tube 58, as shown in FIG. 7. FIG. 7 also shows the provision of a transducer or venturi means 72 placed in air flow communication with the tube-within-a-tube structure (tubes 58 and 62) axially disposed within the plunger mechanism 40. Elements 74, 76, 78, and 80 represent valve means for reversing air flow direction to the tube structure of the plunger mechanism. It has been experimentally established that the vacuum effect which is critical to the practice of the disclosed process may be greatly enhanced without changing the diameter of the air flow piping by utilizing a pair of vacuum transducers placed in parallel disposition for creating the evacuation illustrated in FIG. 5. The process of the present invention relates to the utilization of vacuum-assist during the initial insertion of the parison into the blank mold cavity, and completing or eliminating the settle blow step of the blow-and-blow process by continued application of vacuum in combination with pressurized air to push the parison into the neck ring at the lower end of the blank mold, and then reversing the air flow to force the parison to conform to the blank mold cavity and assume the intial glass container shape. The foregoing is a sequential timed sequence of events which also includes vacuum cleaning of glass particulate debris and any other contaminants through the central tube structure of the plunger mechanism so that such debris is not embedded in the parison. In the preferred embodiment of the apparatus of the invention, the lateral ports or vents 70 which serve to permit evacuation of air from the cavity 12 become closed off by the parison as it moves into the lower end of the cavity 12, however, air passages are provided at the base of the plunger 18 to allow suction applied in the tube 58 to effectively increase the downward air pressure and force the parison firmly into the neck ring 16. FIGS. 5 and 7 illustrate the direction of air flow as the vacuum is drawn, and FIG. 6 illustrates the application of pressurized air during the counter blow step. It is also comtemplated that a central air passage or throat be provided through the plunger 18 as shown in FIG. 7. Further, construction of the plunger body or its outer surface may be of a ceramic material to retard heat transfer between the plunger and the parison whereby container formation becomes more uniform. The air flow controller device, or controller 84, shown in FIGS. 8-11, comprises a rigid main body portion 86, a secondary body portion 88, and a bottom cover portion 90. With reference to FIG. 11 it will be seen that the main body portion 86 defines an inner rectilinear chamber 92 in which a slide block member 94 is mounted for reciprocal movement along a linear pathway and between a first position shown in FIG. 10 and a second position shown in FIG. 11. Slidably mounted within the secondary body portion 88 is a piston 96 which serves to drive the slide block 94 to the position shown in FIG. 11 in response to a pressurized air flow directed into a piston chamber 98. Pressurized air is the main source of energization for forming system equipment. Suitable air lines and valves (not shown) are provided to direct compressed air to operate the plunger mechanism 40 and to direct an air stream into the mold 10 to accomplish the blow-and-blow process container forming operation. A mechanical or electronic timing system well known in the prior art (not shown) is used to operate the valves in a timed pre-selected sequence to cycle the equipment and form each container. Referring again to FIG. 11, an air hose (not shown) is coupled to a male coupler 100 which is in flow communication with an air passage 102 leading to the chamber 98. When a pressurized air flow is directed into the chamber 98, and the piston 96 is disposed in the position shown in FIG. 10, the piston 96 is caused to shift along a linear pathway to the left shown in FIG. 11 whereby it pushes slide block 94 from the position shown in FIG. 10 to its second position shown in FIG. 11. At the end of the slide block 94 opposite the piston 96, a compression spring 104 is mounted to be compressed by the movement of the slide block 94 so that, when the pressurized air flow to the chamber 98 is curtailed, the spring 104 will urge the slide block 94 and the piston 96 back to the first position as shown in FIG. 10. The slide block 94 of the controller 84 and the cover portion 90 are provided with internal air flow passageways 106, 108, 112, and 114. When the slide block 94 is disposed within the chamber 92 at its normal position as shown in FIG. 10, the oblique passageway 106 through the slide block 94 is in sealed alignment with air flow passages 112 and 110 whereby pressurized air may be conducted through the male coupler, 124 of the controller 84 and thence to the plunger mechanism 40 as also shown in FIG. 10. FIG. 10 illustrates a section box 36 of an I.S. machine wherein a plunger mechanism 40 is operationally mounted. The vertical throat of the plunger mechanism 40, comprising central air tube structure made up of tube 58 and tube 62, is interconnected through the base plate 44 with an air line 38 leading to male coupler 126 of the air flow controller device 84. The device 84 may be stationarily mounted on the side of the section box although it is not shown in that disposition in FIG. 10. The air flow controller 84, when it is sequentially triggered during the parison forming cycle, undergoes a shift of its slide block 94 from the position shown in FIG. 10 to that which is shown in FIG. 11 whereby the transverse passageway 108 in the slide block 94 moves into sealed communication between port or passageway 110 and the central bore of the transducer 120. The means of inducing the shift of the slide block 94 between its two positions may, alternatively, be an electrically energized solenoid installed in the second body portion 88 and adapted to drive the piston 96 at the appropriate instant during the blow-and-blow cycle. Details of the vacuum transducer are shown in FIG. 12. The transducer has an intake passage 130 leading directly to an outlet barrel 132. A pressurized air flow (preferably 80 pounds per square inch) is directed, during the blow-and-blow process, through entry passage 114 which is coupled to the air supply by proper connection of a female coupler to male coupler 122. The air flow enters an annular manifold-like chamber 134 which directs the flow through an annular restriction 136 whereby the air flow exhausts out through the barrel 132. A venturi effect is created by the increase of velocity of the air flow through restriction 136 whereby a vacuum is drawn within the intake 130. The slide block 94 is positioned between low friction slide plates 91, 93 in the rectilinear chamber of the flow controller. The vacuum which is created through the transducer measures 28.6" (726 mm) mercury by application of the preferred 80 pounds per square inch pressurized air flow to the transducer 120. Combining the effect of the air flow controller 84 with the tube-within-a-tube structure disclosed in aforementioned U.S. Pat. No. 5,358,543, results in an absolutely clean air passage for counter blow air during the parison forming cycle, preventing accumulation of tramp glass and other debris that plagues more conventional plunger mechanisms in the industry. Comparison of the conventional blow-and-blow process for glass container forming with the improved method provided by the use of the apparatus herein disclosed is provided by comparing FIG. 13 with FIG. 14. As illustrated in FIG. 13, the conventional blow-and-blow process may be conducted with or without the use of a funnel positioned on the blank mold prior to the settle blow step in the cycle. FIG. 14 shows, however, that the blow-and-blow process is significantly altered by shortening the container forming cycle and effectively eliminating the settle blow step. In the blow-and-blow process practiced in accordance with this invention, the container forming cycle may be described as comprising nine discrete steps as identified in FIG. 14 instead of the eleven steps required in the conventional blow-and-blow process wherein a funnel is utilized or the ten steps required with the same process without the funnel, as illustrated in FIG. 13. By application of the process in accordance with the steps shown in FIG. 14, high quality containers are produced with a new level of consistency and virtual absence of the settle wave effect that is all too familiar in the sidewall structure of containers produced by the conventional blow-and-blow process and without the use of the air flow controller device in combination with the internal tube structure of the plunger mechanism as herein disclosed. The present invention has been described and illustrated in connection with a presently preferred structural embodiment and the method for its use, however, it is to be understood that other modifications and variations may be resorted to without departing from the spirit and scope of the invention, as those skilled in the art will readily understand. Such modifications and variations are considered to be within the purview and scope of the invention and the appended claims.	A method and apparatus for forming a glass container in a blow-and-blow process. The apparatus includes an air flow controller having a housing defining a chamber, a piston disposed for reciprocal movement from a first position to a second position within the housing for moving a slide block therein, first and second passages extending through the slide block, a first port in the housing in flow communication with the second passage and a transducer when the piston is in its second position to create a negative air flow through the second passage and first port when a pressurized air flow is induced through the transducer to draw a vacuum beneath a gob in a blank mold to form a finish in the gob and sweep debris away from the gob and blank mold, and a second port in communication with the first passage and first port when the piston is in its first position to provide pressurized air to the gob.	2
The present invention is directed to measurement of radial characteristics of test objects such as train wheels, and more particularly to a method and apparatus for measuring train wheel wear as a function of radial dimensional characteristics of the wheel rim and/or wheel flange. BACKGROUND AND OBJECTS OF THE INVENTION There are a number of circumferential characteristics or parameters of train wheels that are important for maintenance and safety purposes. These characteristics include radius and diameter of the wheel rim on which the car or locomotive rides on the track, radius and diameter of the wheel flange that extends from the rim surface, out-of-roundness of the rim and flange, eccentricity of the rim surface with respect to the flange, flat spots in the rim or flange, and spalls and tread build-up on the rim surface. Dimensional characteristics of a train wheel rim and flange are currently measured using a device called a standard steel wheel finger gauge. This measurement technique achieves somewhat less than desired accuracy, and the time and tedium involved do not encourage measurement at the desired frequency. It has been proposed to provide an instrumented track or rail section having accelerometers for detecting flat spots in train wheels as an engine or car is driven over the track section. Although this technique has been helpful in identifying flat spots in the wheel rim, there remains a need for an automatic and non-contact method of measuring geometric characteristics such as radius, out-of-roundness and eccentricity. It is therefore a general object of the present invention to provide a technique for measuring one or more circumferential characteristics of a test object such as a train wheel that does not require physical contact with the test object, and that may be implemented electronically for enhanced accuracy and automation. Another and more specific object of the present invention is to provide a method and apparatus for measuring one or more circumferential characteristics of train wheels, such as wheel rim and/or flange radius, that may be implemented automatically while the train wheels carry train cars over an instrumented section of track. A further object of the present invention is to provide a method and apparatus of the described character that employ microwave technology for measuring train wheel rim and/or flange radius, and other circumferential characteristics associated with rim and flange radius such as diameter, wear, flat spots and eccentricity, automatically and at high speed as the train wheels pass in succession over an instrumented section of track. SUMMARY OF THE INVENTION A method of measuring radial characteristics of a test object in accordance with the present invention contemplates provision of a transceiver, preferably a microwave transceiver, oriented to transmit energy toward and receive energy reflected from a radially oriented surface of the test object. Relative motion between the test object and the transceiver while the transceiver is energized develops at the transceiver an electrical signal that varies as a function of interferences caused by reflections from the surface of the test object. Radial characteristics of the text object are determined as a function of such interference test. The interference pattern represented by the transceiver output signal comprises a sinusoidal pattern of peaks (alternating maxima and minima), and radial characteristics of the test object are determined as a function of separation between the peaks in units of distance traveled during relative motion between the transceiver and the test object. A method and apparatus for measuring circumferential characteristics of train wheels for potential indication of train wheel wear in accordance with the preferred implementation of the invention include at least one microwave transceiver disposed adjacent to a section of train track. The transceiver is oriented to transmit microwave energy toward and receive microwave energy reflected from a radially oriented surface of each train wheel that traverses the track section. Wheels are rolled along the track section in sequence while the transceiver is energized so as to transmit energy toward each wheel in turn, and to develop a varying interference pattern of peaks (alternating minima and maxima) caused by reflection from the radially oriented surface of each wheel. The transceiver provides an electrical signal that varies as a function of such interference pattern, and one or more desired radial characteristics of the wheel are determined as a function of such signal. In the preferred embodiment of the invention, train wheel radius is determined as a function of separation between peaks (either minima or maxima) in units of distance traveled by the wheel along the track section adjacent to the transceiver. This is accomplished in the preferred embodiment of the invention by sampling the transceiver output signal at equal time increments while causing each train wheel to roll along the instrumented track section at constant velocity. Alternatively, the transceiver output signal may be sampled at predetermined increments of distance traveled along the track section, or the transceiver output signal may be sampled at predetermined time increments while actual velocity of the wheel along the track is measured. In any event, radius of the test surface, which may be the load bearing surface of the wheel rim or the outer edge of the wheel flange, is determined in the preferred embodiment of the invention as a function of separation between adjacent or non-adjacent peaks of the interference signal in units of distance. A plurality of transceivers are spaced from each other along the track section in the preferred embodiment of the invention, and radial characteristics of each train wheel are determined independently based upon the output of each transceiver. The radial characteristics so determined may be averaged, or may be compared with each other to detect variations potentially indicative of wheel wear. For measurement of wheel flange radius, the transceiver(s) in the preferred embodiment of the invention is disposed laterally adjacent to the track section, and oriented to direct microwave energy upwardly onto the outer diameter of the wheel flange as a wheel rolls over the track section. For measurement of rim radius in the preferred embodiments of the invention, the transceiver is disposed to transmit microwave energy upwardly through the rail surface onto the load-bearing surface of a wheel rim as the wheel rolls over the track surface. The transceiver output signal is sampled by a digital processor. One or more proximity sensors are disposed adjacent to the track section for both initiating a data sampling sequence as a wheel passes over the transceiver(s) and measuring actual wheel velocity where needed for data translation purposes. BRIEF DESCRIPTION OF THE DRAWINGS The invention, together with additional objects, features and advantages thereof will be best understood from the following description, the appended claims and the accompanying drawings in which: FIG. 1 is a side elevational view of a train wheel on a track section having wheel measurement transceivers in accordance with one presently preferred embodiment of the invention; FIG. 2 is a fragmentary sectional view taken substantially along the line 2--2 in FIG. 1 with transceiver for measuring wheel flange radius; FIG. 3 is a sectional view similar to that of FIG. 2 but showing a transceiver for measuring wheel rim radius; FIG. 4 is a sectional view that illustrates a modification to the embodiment of FIG. 3; FIG. 5 is a functional block diagram of control electronics in accordance with a presently preferred embodiment of the invention; FIGS. 6A and 6B are graphic illustrations that facilitate explanation of operation of the invention; and FIG. 7 is a graphic illustration of transceiver detector output amplitude versus wheel position, and which is also useful in describing operation of the invention. DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS FIG. 1 illustrates a train wheel 10 mounted on an axle 12 for supporting a train car or locomotive (not shown) as wheel 10 rolls along a section of track rail 14. Wheel 10 has the usual axially extending and radially facing rim surface 16 for supporting and bearing the load of the wheel and car on the upper surface of rail 14, and a flange 18 radially extending from rim surface 16 at one side edge of wheel 10 for retaining the wheel on the rail. Three microwave transceivers 20 are illustrated in FIG. 1 spaced from each other lengthwise on track section 14 for measuring radial characteristics of wheel 10 as wheel 10 is rolled along track 14 in direction 21 past the transducers. FIG. 2 illustrates one embodiment 20a of transceivers 20 for measuring the outer radius of rim flange 18. Transceiver 20a includes a Gunn diode 22 for directing microwave energy through a horn 24 upwardly toward the radially facing surface of flange 18, and a detector 26 for receiving microwave energy reflected downwardly from flange 18 back to the transceiver. Transceiver 20a is mounted within an enclosure 28 for protection against the weather, and has an upper surface 30 that is sloped to prevent accumulation of water or debris. Enclosure 28 is mounted to the side of track section 14 beneath the side edge of the upper rail section for alignment with flange 18 as described. FIG. 3 illustrates another embodiment 20b of transceiver 20, again including a Gunn diode 22 for transmitting microwave energy to a waveguide-to-coax adapter 32 and a coax cable 34. Coax cable 34 terminates in an antenna 36 (about a quarter-wavelength) that radiates microwave energy into a waveguide cavity 46 at the upper edge of rail section 14. The microwave energy then travels through dielectric material 38 within cavity 46 onto the radially facing rim surface 16 of a train wheel 10 rolling over track section 14. Reflected energy travels back through dielectric material 38 within cavity 46, coax 34 and adapter 32 to detector 26. Once again, transceiver 20b is surrounded within a protective enclosure 40 affixed to the side of rail 14. In the modified embodiment of FIG. 4, transceiver 20c is mounted within an enclosure 42 beneath the foot of rail 14. Microwave energy is transmitted and reflected through a rectangular passage 46 within track 14, which effectively forms a rectangular waveguide, and through a protective dielectric filling or seal 38 onto rim surface 16 of wheel 10. In both the embodiments of FIGS. 3 and 4, the associated transceiver 20b, 20c thus directs microwave energy upwardly onto rim surface 16, and receives energy reflected from rim surface 16 as wheel 10 passes thereover. Also, in both embodiments, the waveguide opening may be flared outward slightly at the top of the track in order to emulate a horn antenna more closely, and thereby improve the impedance match to the region above the track. By way of example only, enclosures 28,40,42 may be of fiberglass/polyester construction manufactured by Hoffman Engineering Co.; transceiver 20a,20b,20c may comprise a model MA86652 horn antenna or a model MA86859 (24.15 Ghz) transceiver manufactured by M/A-COM Inc. FIG. 5 illustrates a preferred embodiment of control electronics 50 in accordance with the present invention. Microwave flange transceiver(s) 20a (FIG. 2) is connected to one input of a multiplexer 54 through associated signal conditioning circuitry 52. Similarly, microwave rim transceiver(s) 20b or 20c is connected to a second input of multiplexer 54 through associated signal conditioning circuitry 56. One or more proximity sensors 58 are positioned adjacent to track 14 and responsive to passage of a wheel 10 over measurement transceivers 20 (FIG. 1) for both initiating a data acquisition cycle through a data acquisition trigger 60 (FIG. 5), and for providing wheel speed and direction information to a third input of multiplexer 54 through a signal conditioning circuit 62. The output of multiplexer 54 is connected to a sample-and-hold and analog-to-digital conversion circuit 64, which receives a control input from data acquisition trigger 60 and a clock input from a time-based data acquisition clock 66. Multiplexer 54, data acquisition trigger 60, converter 64 and clock 66 thus form a data acquisition sub-system 68, which has an output connected to a control microprocessor 70, and which in turn is controlled by microprocessor 70. Microprocessor 70 is connected by a suitable bus to a supplemented digital memory 72 for storing blocks of wheel test data for later analysis, and to a suitable display mechanism 74 such as a screen or printer. By way of example, data acquisition subsystem 68 may comprise a DT2839 analog and digital I/O board manufactured by Data Translation, Inc., and microprocessor 70 may comprise any suitable personal computer. In operation, data acquisition sub-system 68 is activated by proximity sensor(s) 58 to initiate a data sampling and data conversion operation via multiplexer 54 and one or all of the transceivers 20a,20b and 20c. The incoming data from the transceiver(s) is suitably conditioned, sampled at fixed time intervals under control of clock 66, converted to digital format, and fed to microprocessor 70 for storage in memory 72. Where velocity information is desired, signal information from proximity sensors 58 is also suitably conditioned at 62, sampled and converted to digital format at 64, and stored in memory 72 by microprocessor 70. Each transceiver 20a,20b,20c emits a continuous microwave signal toward the wheel flange or rim as it passes over the transceiver location on track section 14. As the wheel passes over each transceiver, an interference pattern caused by reflections from the radially oriented surface of the flange or rim causes the transceiver detector output to form a sinusoidal pattern of varying frequency, as illustrated in FIG. 7. That is, as the wheel approaches each transceiver, the output of the transceiver detector assumes a pattern 80 as illustrated in FIG. 7 in the form of a series of peaks consisting of alternating maxima and minima. The interference effect that gives rise to these signal peaks can be visualized in FIG. 6A. With wheel 10 traveling in direction 21 from left to right, the total distance (h+h 3 ) between transceiver 20 and the opposing point 10 3 on the wheel is such that a first interference peak 80 3 (FIG. 7) is created. As wheel 10 continues to move to the right, the distance between transceiver 20 and the opposing point 10 2 has decreased to a total distance (h+h 2 ), again giving rise to a interference peak 80 2 (FIG. 7). Continued motion of wheel 10 to the right in FIG. 6 brings another point 101 into opposition with transceiver 20 at a distance (h+h1) creating a third interference pattern 80 1 (FIG. 7). Three interference peaks are required for measuring wheel radius r in accordance with the technique to be described in connection with FIG. 6B, and for this reason three specific points 10 1 , 10 2 and 10 3 are illustrated in FIG. 6. It will be appreciated, however, that a multiplicity of additional interference peaks 80 4 -80 6 (FIG. 7) are also created at wheel positions prior to those shown in FIG. 6. Likewise, as the wheel makes contact with rail 14 immediately above transceiver 20, and then continues motion away from transceiver 20, a second series of interference peaks will be generated nominally as the mirror image of pattern 80 illustrated in FIG. 7. Signals 80 generated by all of the transceivers 20 are sampled and stored in memory 72 as wheel 14 passes over the transceiver. It will be noted in FIG. 7 that transceiver amplitude data is represented in units of distance of wheel travel along track 14 over the transceiver. In order to perform the calculations to be described in connection with FIG. 6B, it is necessary that the interference information be either stored or accessible in units of distance of wheel travel, as distinguished from units of time. This is accomplished in accordance with the preferred embodiment of the invention by driving the train over track section 14 at constant velocity, so that each sample time increment automatically represents a corresponding fixed increment of wheel travel. For example, if the train speed is 60 miles per hour and the sampling period of clock 66 (FIG. 5) is twenty-five microseconds, each sample increment automatically represents a distance of 0.0264 inches of wheel travel. Alternatively, if train speed is unknown or variable, proximity sensors 58 at predetermined fixed spacing may be employed in conjunction with clock 66 to determine speed of wheel travel over the measurement transceivers, and the fixed sampling intervals of clock 66 may be related to distance of wheel travel by multiplying the sampling intervals by measured wheel speed. As a third alternative, the train may be instrumented to provide a sampling signal at fixed increments of distance, thereby replacing time-based clock 66 with data sampling in the spatial domain. In any event, the resulting data stored in memory 72 is exemplified by FIG. 7, in which normalized transceiver detector output amplitude (simulated) is illustrated as varying as a function of wheel travel distance. In FIG. 6B, the data points of FIG. 6A have been transformed to reflect a fixed wheel position 10, and both horizontal and vertical separation between the wheel rim data points. It can be shown that radius r in FIG. 6A is given by the equation: ##EQU1## where j 12 is separation in units of wheel travel between peaks 80 1 and 80 2 in FIG. 7, j 13 is separation in units of wheel travel between peaks 80 1 and 80 3 in FIG. 7, and h 12 and h 13 are related to the specific peaks selected for measurement purposes, peaks 80 1 , 80 2 and 80 3 in this particular example. Specifically, both h 12 and h 13 are equal to nλ/2, where λ is the wavelength of the microwave signal and n is the number plus 1 of peaks between the peaks selected for measurement purposes. Thus, h 12 in this particular example is equal to λ/2, and h 13 is equal to λ. At an exemplary transceiver frequency of 24.15 GHz, h 12 in this example would be equal to 0.244535 inches, and h 13 would be equal to 0.489069 inches. In the particular example illustrated in FIG. 7, j 12 is equal to 1.6600 inches, and j 13 is equal to 2.6727 inches. Thus, in the above equation, all of the h and j variables are known, and radius r may be calculated. In the example, radius r is equal to 15.0 inches. It will be appreciated that the equation for radius r is sensitive to changes in the h and j variables, and that values for these variables should therefore be rendered and controlled with a high degree of accuracy. The foregoing example discussed in connection with FIGS. 6A, 6B and 7 applies to both wheel rim and wheel flange radius measurements. When employing transceivers 20 as illustrated in FIG. 1, a total of six measurements can be made, one as the wheel approaches and one as the wheel leaves each of the three transducers. It will also be noted that multiple measurements can be made from a single set of data illustrated graphically at 80 in FIG. 7 employing different peaks--i.e., peaks other than 80 1 , 80 2 and 80 3 . It will also be appreciated that the minima peaks may also be employed. Thus, any number of radius measurements may be obtained from a single passage of wheel 10 over one or more transceivers, and may be averaged or compared to each other for indicating a measured radius variance potentially indicative of a flat spot, another sign of wheel wear or defective data from the transceiver. Averaging a number of radius measurements can significantly reduce the effect of system noise and imperfect transceiver data. It will also be noted that the amplitude of the signal 80 in FIG. 7 at either the maximum or minimum peak is of no consequence to the radius measurement. However, amplitude information can be employed for identifying characteristics that affect reflectivity, such as spalls or tread formation on the wheel rim surface. Radius and diameter measurements of the wheel rim and flange can be correlated to determine eccentricity between the rim and flange centers, and to locate excessive flange wear that could lead to derailment in use. There is thus provided in accordance with the disclosed embodiments of the invention a fully automatic apparatus for non-contact measurement of train wheel rim and flange radial characteristics employing microwave technology. An entire train may be driven over a section of track instrumented on both sides in accordance with the present invention, and wheel measurement data may be rapidly collected for later analysis to identify wheels having excessive wear or undesirable surface characteristics at the rim and/or flange. The rate of data acquisition depends upon factors such as maximum expected train speed and the desired degree of measurement accuracy. For a maximum train speed of sixty miles per hour, the data acquisition rate may be on the order of thirty to one hundred thousand samples per second per data channel. Software data enhancement techniques, such as the use of interpolation for better resolution of maxima or minima, can be employed to improve measurement accuracy. Frequency stability of the transceiver(s) can be improved through the use of thermostatically controlled heating elements to reduce temperature variation. The instrumented rail section may be part of a long section of track with a slight curvature to reduce side-to-side oscillatory motion during measurement cycles.	A method and apparatus for measuring circumferential characteristics of train wheels for potential indication of train wheel wear that includes at least one microwave transceiver disposed adjacent to a section of train track and oriented to transmit microwave energy toward and receive microwave energy reflected from a radially oriented surface of a train wheel that traverses the track section. Wheels are rolled along the track section in sequence while the transceiver is energized so as to transmit energy toward the wheel and develop a varying interference pattern of peaks (alternating minima and maxima) caused by reflection from the radially oriented surface of the wheel. The transceiver provides an electrical signal that varies as a function of such interference pattern, and one or more desired radial characteristics of the wheel are determined as a function of such signal.	1
[0001] This application is a continuation of U.S. patent application Ser. No. 11/217,688, filed Sep. 2, 2005, which is a continuation in part of U.S. patent application Ser. No. 10/430,298, filed on May 7, 2003 (now U.S. Pat. No. 6,973,756), both of which are incorporated herein by reference in their entirety. FIELD OF THE INVENTION [0002] This invention relates to a connector for securing veneer to back-up walls. BACKGROUND OF THE INVENTION [0003] Many construction techniques have been developed for commercial buildings utilizing a back-up wall and a set of thin walled veneer panels that are supported on the back-up wall. Typically, there is a cavity between the veneer panels and the back-up wall to allow for the insertion of insulation and other materials. The veneer panels are connected to the back up wall using any of several different styles of connectors that are currently available. In addition to supporting the veneer panels, these connectors typically withstand various other loads, such as shear and wind loads. [0004] Typically prior art connectors are relatively expensive to manufacture, and offer relatively poor load-bearing capacity for their weight and cost. One such prior art connector consists of an L-shaped member, and a veneer connector plate. The vertical portion of the L-shaped member is mounted to the back-up wall, and the horizontal portion extends outwardly therefrom. The horizontal portion typically includes slotted holes therethrough, for the mounting of the veneer connector plate thereon. The veneer connector plate extends outwards and supports at its outwardmost edge, a portion of a veneer panel. [0005] For several reasons, these connectors are typically relatively expensive, and can add to the overall cost of erecting a building. One reason for their cost is that, to support the required loads during use, such connectors are typically required to be made from relatively thick materials. For example, for some applications, the L-shaped member is made from angle having a ⅜″ wall thickness. Furthermore, many building codes require such connectors to be made from stainless steel, to resist corrosion and subsequent weakening or failure. Because of this materials requirement, the cost of the L-shaped member is increased substantially. [0006] Furthermore, in order to cut ⅜″ thick angle when making the L-shaped member, a sophisticated cutting device may be required, such as, for example, a plasma cutter. Plasma cutters are typically more expensive to operate than other cutting devices, and also, plasma cutter operators are more expensive than other cutting machine operators due to their relatively uncommon expertise. [0007] A further issue driving the cost of prior art connectors is that, typically, they include at least two stainless steel bolts in their assembly, for example, to attach the veneer connector to the L-shaped piece. Stainless steel bolts are relatively expensive and can add significantly to the overall cost of the connector. [0008] Accordingly, there is a need for a connector that is relatively inexpensive to manufacture, for use in supporting veneer panels. SUMMARY OF THE INVENTION [0009] According to one aspect, a connector for retaining at least one veneer panel on a back up wall is provided. The veneer panel may have a top edge and a bottom edge. The connector comprises a veneer connector and a support member. The support member comprises a mounting flange adapted for securing the support member to the back-up wall, and first and second support member side walls extending outwardly from the mounting flange. The first and second support member side walls define at least one generally horizontal surface when the support member is secured to the back-up wall. The veneer connector is securable to the horizontal surface by a mechanical fastener and is adapted to support a generally horizontal edge of the at least one veneer panel when the support member is secured to the back-up wall and when the veneer connected is supported by the generally horizontal surface. The connector is mountable on the back up wall such that the veneer connector supports one of the top and bottom edges of the at least one veneer panel. [0010] The mounting flange may have an adjustment aperture therethrough. The adjustment aperture may be elongate and may be adapted to adjustably receive a fastener therethrough for mounting the support member to the back-up wall. The adjustment aperture may be generally vertical. [0011] The generally horizontal surface may be provided by an upper surface of the first and second support member side walls. [0012] The connector may further comprise a separate fastener for securing the veneer connector to the generally horizontally extending surface. [0013] The veneer connector may comprise a section that abuts the veneer panel and is adapted to receive fasteners that engage the veneer panel. [0014] According to another aspect, a connector for coupling a veneer panel to a back-up wall is provided. The connector comprises a support member comprising a mounting flange adapted for securing the support member to said back-up wall, and first and second support member side walls extending outwardly from the mounting flange. The first and second support member side walls define at least one generally horizontal slot when the support member is secured to the back-up wall. The connector further comprises a veneer connector configured for non-rotational sliding receipt in the generally horizontal slot and adapted to support a generally horizontal edge of said veneer panel when the veneer connector is received in the generally horizontal slot and when the support member is secured to the back-up wall. [0015] The veneer connector may have a load transfer region for supporting the veneer panel, and the first and second support member side walls may extend outward from the mounting flange sufficiently to support the veneer connector proximate the load transfer region. [0016] The veneer connector may have at least one veneer connector side wall. The veneer connector side wall may be generally vertical and may extend at least along a portion of the veneer connector that is unsupported by the support member. [0017] The veneer connector may have a generally horizontal load transfer region for mounting to a horizontal edge of the veneer panel. [0018] The generally horizontal slot may comprise a generally horizontal lower surface. [0019] The mounting flange may comprise a first mounting flange portion and a second mounting flange portion. Each may have an aperture therethrough for mounting the support member to the back-up wall. At least one of the apertures may be positioned above the slot. [0020] An elongate veneer connector adjustment aperture may be defined in the veneer connector. An elongate support member adjustment aperture may be defined in the support member. The support member adjustment aperture and the veneer connector adjustment aperture may extend generally perpendicularly to each other. [0021] A veneer connector aperture may be defined in the veneer connector. A support member aperture may be defined in the support member. The support member aperture and the veneer connector aperture may be alignable with respect to each other for the pass through of a single mechanical fastener for securing the veneer connector to the support member. [0022] The first and second side walls may be connected to each other by a side wall connecting portion. The first and second side walls may be joined together by a horizontal load support wall. The horizontal load support wall may be positioned at the top of the side walls. [0023] The veneer connector may comprise a section that abuts the veneer panel and is adapted to receive fasteners that engage the veneer panel. BRIEF DESCRIPTION OF THE DRAWINGS [0024] For a better understanding of the present invention and to show clearly how it may be carried into effect, reference will now be made, by way of example, to the accompanying drawings, in which: [0025] FIG. 1 is a perspective view of a system of connectors in accordance with a first embodiment of the present invention, supporting panels of veneer on a back up wall; [0026] FIG. 2 is a magnified plan view of a veneer connector shown in FIG. 1 ; [0027] FIG. 2 a is a plan view of a variant of the veneer connector shown in FIG. 2 ; [0028] FIG. 3 is a perspective view of a portion of the veneer connector shown in FIG. 2 , supporting a panel of veneer; [0029] FIG. 4 is a magnified perspective view of a support member shown in FIG. 1 ; [0030] FIG. 5 is a magnified perspective view of the connector shown in FIG. 1 ; [0031] FIG. 5 a is an end view of the connector shown in FIG. 5 , partially sectioned for greater clarity, with a variant to the fastener shown in FIG. 5 ; [0032] FIG. 6 a is a magnified plan view of the support member shown in FIG. 1 , in a partial state of manufacture; [0033] FIG. 6 b is a perspective view of the support member shown in FIG. 6 a in a further state of manufacture; [0034] FIG. 7 is a magnified perspective view of an alternative veneer connector to that which is shown in FIG. 1 ; [0035] FIG. 8 is a perspective view of a variant of the support member shown in FIG. 4 ; [0036] FIG. 8 a is an end view the support member variant shown in FIG. 8 , supporting a veneer panel; [0037] FIG. 9 is an end view of another variant of the support member shown in FIG. 4 ; [0038] FIG. 10 is an end view of yet another variant of the support member shown in FIG. 4 ; [0039] FIG. 11 is a plan view of a work piece that is in a partial state of manufacture, which can be made into either of the support members shown in FIGS. 9 and 10 ; [0040] FIGS. 12 a and 12 b are perspective views of the work piece shown in FIG. 11 , in a further state of manufacture; [0041] FIG. 13 is a plan view of a system, made up of the connectors shown in FIGS. 9 and 10 , supporting veneer panels to a back-up wall; [0042] FIG. 14 is a top view of a variant of the support member shown in [0043] FIG. 4 ; [0044] FIG. 15 is an front view of another variant of the support member shown in FIG. 4 ; [0045] FIG. 16 is a perspective view of a connector in accordance with another embodiment of the present invention; [0046] FIG. 17 is a front view of the connector shown is FIG. 16 ; [0047] FIG. 18 is a perspective view of another variant of the support member shown in FIG. 4 ; and [0048] FIG. 19 is a perspective view of another variant of the support member shown in FIG. 4 . DETAILED DESCRIPTION OF THE INVENTION [0049] Reference is made to FIG. 1 , which shows a system of connectors 10 in accordance with a preferred embodiment of the present invention. Each connector 10 includes a veneer connector 12 for connecting with a veneer panel 14 , and a support member 16 adapted for receiving the veneer connector 12 and for securement to a back-up wall 18 . The connectors 10 may be made of any suitable material, such as 10 or 11 gauge stainless steel. The connectors 10 are preferably free of welds and formed from a single sheet of metal manufactured into the desired shape. The veneer panel 14 is may be a natural stone material, such as marble or granite. The veneer panel 14 may be a thin-walled panel, which is typically known as a thin masonry veneer panel, which many building codes require to be individually supported (i.e., each panel must be supported individually). It will be noted that the mortar that would typically exist between adjacent veneer panels 14 has been removed from the Figures for greater clarity. [0050] The back-up wall 18 may be of form-poured concrete construction. Alternatively, the back-up wall 18 may be constructed of any suitable material, such as, for example, metallic studs, or block masonry. The veneer panels 14 may be spaced from the back-up wall 18 to provide a cavity 20 therebetween. Optionally, an insulation material 24 and a vapor barrier 26 may be installed in the cavity 20 . [0051] Reference is made to FIG. 2 , which shows the veneer connector 12 in plan view. The veneer connector 12 may have a generally rectangular shape and has a first edge 28 and a second edge 30 . An adjustment aperture 32 may be positioned adjacent the first edge 28 . Referring to FIG. 5 , the adjustment aperture 32 is used to receive a fastener 65 to join the veneer connector 12 to the support member 16 . Referring to FIG. 2 , the adjustment aperture 32 may be generally elongate to permit adjustment of the position of the veneer connector 12 within the support member 16 , as will be discussed further below. [0052] The veneer connector 12 includes a plurality of veneer connection apertures 34 , which may be positioned proximate the second edge 30 . The veneer connector 12 may include any suitable number of veneer connection apertures 34 , such as, for example, three apertures 34 , as shown in FIG. 2 . Referring to FIG. 3 , the veneer connection apertures 34 permit the pass-through of fastening ties 36 that extend from the edge of the veneer panel 14 . The veneer connection apertures 34 may be generally circular, and may be sized to permit easy pass-through of the fastening ties 36 , but are not required to be so large as to facilitate substantial adjustment of the veneer 14 relative to the veneer connector 12 . [0053] The veneer connection apertures 34 are positioned proximate the second edge 30 of the veneer connector 12 to prevent the unwanted protrusion of the second edge 30 past the outer face of the veneer 14 . Thus, the second edge 30 can be buried in the mortar between vertically adjacent panels of veneer 14 . [0054] Referring to FIG. 2 a , an alternative veneer connector 12 ′ is shown, which has a plurality of veneer connection apertures 34 ′ which are elongate to provide further adjustability of the veneer connector 12 with respect to the fastening ties 36 . [0055] Referring to FIG. 3 , a securing means 40 prevents veneer 14 from disengaging from veneer connector 12 . Securing means 40 may be any suitable means, such as, for example, a mechanical fastener or a weld. [0056] The veneer connector 12 supports the veneer panel 14 ( FIG. 1 ) during use generally in the region of the veneer connection apertures 34 . The load imparted to the veneer connector 12 from the weight of the veneer panel 14 is shown at F. [0057] Reference is made to FIG. 4 , which shows the support member 16 in more detail. The support member 16 includes a mounting flange 42 and a support portion 44 . The mounting flange 42 is adapted for mounting the support member 16 to the back-up wall 18 ( FIG. 1 ). As shown, the mounting flange 42 is formed by a first mounting flange and a second mounting flange 48 (shown in FIG. 4 ) [0058] The mounting flange 42 has an adjustment aperture 50 therethrough, which is adapted to receive a fastener 52 , for fastening the support member 16 to the back-up wall 18 ( FIG. 1 ). The adjustment aperture 50 may be generally elongate, as shown in FIG. 4 , to permit adjustment of the support member 16 in the vertical direction. Such vertical adjustment capability facilitates aligning the support members 16 in a row on the back-up wall 18 ( FIG. 1 ). [0059] The mounting flange 42 also includes a securing aperture 54 therethrough, may be positioned on the second mounting flange 48 , generally opposite the adjustment aperture 50 . The securing aperture 54 is adapted for receiving a fastener 56 therethrough to further retain the support member 16 on the back-up wall 18 ( FIG. 1 ), and to fix the position of the support member 16 therewith. Once the desired adjustment to the position of the support member 16 has been made using the fastener 52 and the adjustment aperture 50 , the fastener 56 may be passed through the aperture 54 and into the back up wall 18 ( FIG. 1 ), to fix the position of the support member 16 . [0060] Reference is made to FIG. 5 , which shows the support portion 44 of the support member 16 more clearly. The support portion 44 extends from the mounting flange 42 , and specifically, extends from the first mounting flange 46 and the second mounting flange 48 , in a generally vertical plane denoted by the axes (y) and (z), and joins the first mounting flange 46 and second mounting flange 48 along two generally vertical lines which extend generally in the vertical (y) direction. By extending in a generally vertical plane, the support portion 44 is provided with a generally greater resistance to vertical bending forces, which result from the load F, that arise when the connector 10 supports a veneer panel 14 ( FIG. 1 ). In other words, the configuration of the support portion 44 provides the support member 16 with a relatively high moment of inertia in the vertical (y) direction, compared to a typical L-shaped member used in connectors of the prior art. [0061] The support portion 44 is made up of two spaced apart side walls 58 , which are connected at their respective upper ends by a top portion 59 . The top portion 59 and the spaced configuration of the side walls 58 provide resistance to bending loads that can occur in the lateral (x) direction during use. It is expected that any lateral loads will be smaller than the vertical loads incurred from the weight of the veneer 14 ( FIG. 1 ). As a result, the moment of inertia in the lateral (x) direction may be smaller than that in the vertical (y) direction. [0062] The top portion 59 can thus be referred to as a horizontal load support wall 59 . As such it is not necessary for the horizontal load support wall 59 to be positioned at the top of the support member 16 . For example, referring to FIG. 18 , a support member 16 ″″″ is shown, having a horizontal load support wall 132 positioned at the bottom of the two side walls 58 . The support member 16 ″″″ may otherwise be similar to the support member 16 ( FIG. 5 ). [0063] In the embodiments in FIG. 5 , the horizontal load support wall 59 may be made contiguous such that the adjustment aperture 62 is not provided thereon. Instead the opposing end (ie. the bottom end) of the side walls 58 , which is not covered, may act as the adjustment aperture in the Z direction. Thus, the fastener 65 could mount between the open bottom end of the side walls 58 and the veneer connector 14 . Similarly, in the embodiment in FIG. 18 , horizontal support wall 132 may be made contiguous such that the adjustment aperture 62 is not provided thereon. Instead the opposing end (ie. the top end) of the side walls 58 , which is not covered, may act as the adjustment aperture in the Z direction. Thus, the fastener 65 (not shown in FIG. 18 ) 65 could mount between the open top end of the side walls 58 and the veneer connector 14 . [0064] Referring to FIG. 5 , the side walls 58 are advantageously joined together by the horizontal load support wall 59 . However, the horizontal load support wall 59 could be omitted, as shown in the embodiment shown FIG. 19 . FIG. 19 shows a support member 16 ″″″ that has a contiguous flange portion 136 . The side walls 138 extend outwards from the flange portion 136 and are joined to the flange portion along generally vertical, spaced apart lines. The side walls 138 could be joined to the flange portion by any suitable means, such as, for example, welding. [0065] Referring to FIG. 5 , the side walls 58 together define a slot portion 60 , which may extend in a generally horizontal (x-z) plane, for receiving and supporting the veneer connector 12 . The slot 60 permits the lateral adjustment of the veneer connector 12 in both the (x) direction and in the z direction. The slot 60 is made sufficiently deep so that the veneer connector 12 is supported along a substantial portion of its length. More particularly, the support portion 44 extends outwards to support the veneer connector 12 proximate its load supporting region, ie. the region about the apertures 34 where the load F is imparted to the veneer connector 12 by the veneer panel 14 ( FIG. 1 ). This reduces bending stresses on the veneer connector 12 in use when supporting a veneer panel 14 ( FIG. 1 ). [0066] The slot 60 is preferably positioned proximate the upper ends of the side walls 58 , to reduce its impact on the overall moment of inertia of the support portion 44 in the vertical (y) direction. It will be noted that the slot 60 may extend in a plane that is other than horizontal. For example the slot 60 may be angled generally downwards towards its blind end, so that the veneer connector 12 may be retained in place temporarily without the use of a fastener. [0067] An adjustment aperture 62 may be defined in the upper portion 59 , for receiving the fastener 65 therethrough. The fastener 65 may pass through the adjustment aperture 62 and the adjustment aperture 32 in the veneer connector 12 for fixedly retaining the veneer connector 12 in place in the support member 16 . The adjustment aperture 62 may be generally elongate, and may extend in a direction that is generally perpendicular the aperture 32 in the veneer connector 12 . In this way, the apertures 62 and 32 cooperate to provide adjustment for the veneer connector 12 within the slot 60 in both the (x) and (z) directions. [0068] The fastener 65 may be any suitable type of fastener. For example, the fastener 65 may be made up of a stainless steel hex-head bolt 65 a , a washer 65 b , and a nut 65 c . The hex head bolt 65 a extends upwards from under the veneer connector 12 , and is sized so that the side walls 58 capture the head of the bolt 65 a and prevent it from rotating. The threaded end of the bolt 65 a passes up and through the adjustment aperture 62 on the support member 16 . The washer 65 b and nut 65 c are positioned on the exposed end of the bolt 65 a and are tightened to provide a secure connection between the support member 16 and the veneer connector 12 . By having captured the bolt 65 a between the side walls 58 , the task of installing the fastener 65 is facilitated. It will be noted that other types of bolts and other types of fasteners altogether could alternatively be used to connect the support member 16 and the veneer connector 12 . [0069] Reference is made to FIG. 5 a , which shows an alternative washer 65 b ′ that can be used as part of the connector 65 . The washer 65 b ′ may have a generally arcuate shape in side view and extends downwards to capture the side walls 58 of the support member 16 . When the nut 65 c is tightened, the washer 65 b ′ captures and pushes together the side walls 58 , further strengthening their capture of the head of the bolt 65 a . Thus, as the tightening force on the nut 65 c is increased, the capturing force of the side walls 58 on the bolt 65 a is increased, inhibiting the bolt 65 a from rotating as a result of the increased tightening force. [0070] It will be noted that the washer 65 b ′ may have any suitable shape for pushing the side walls 58 together. For example, the washer 65 b ′ may alternatively have an inverted V-shape in side view instead of an arcuate shape. Furthermore, the washer 65 b ′ may have any shape in plan view. For example, the washer 65 b ′ may have a generally circular shape or may alternatively have a rectangular shape so that it better captures the side walls 58 . [0071] Reference is made to FIG. 6 a , which shows a plate 70 which may be used to manufacture the support member 16 ( FIG. 1 ). The plate 70 may be machined with a plurality of apertures and slots which will ultimately form the slot 60 , the aperture 62 and the mounting apertures 50 and 54 . Furthermore, a slot 72 may be machined into the plates 70 , to remove unnecessary material. Once the plate 70 is machined with the appropriate slots and apertures, it may be bent into the shape of the support member 16 by two primary bending operations. The first bending operation bends the two tabs shown at 74 and 76 along a bend line 78 , resulting in the structure 79 shown in FIG. 6 b . The tabs 74 and 76 will ultimately form the mounting flange 42 ( FIG. 4 ). The second bending operation involves folding the plate 70 generally about a fold line. The folding of the plate 70 may be performed on a radiused surface thereby forming the upper portion 59 and the spaced apart side walls 58 . Manufacturing the support member 16 in this way saves cost and manufacturing time while providing a relatively strong resulting structure. It will be noted that the order of operations described is preferable, but may alternatively be rearranged in any suitable way. [0072] By making the support member 16 by appropriately machining and by applying two simple bends to the single, integral plate 70 , the cost of manufacture for the support member 16 are reduced, relative to complex structures of the prior art which are made from multiple pieces which are welded together. [0073] Reference is made to FIG. 1 , which shows the connector 10 in use. In use, a plurality of connectors 10 are used to support a plurality of panels of veneer 14 in a spaced relationship from the back up wall 18 of a structure such as an office tower. The support members 16 are mounted to the back-up wall, and may be spaced from each other in a generally horizontally and vertically extending array. The veneer connectors 12 are positioned in the slots 60 ( FIG. 5 ), and extend therefrom to support the veneer panels 14 . The fastening ties 36 ( FIG. 3 ) extend between vertically adjacent veneer panels 14 and pass through the veneer connection apertures 34 , which retain the panels 14 in place. Furthermore, mortar may be used to close any air gap adjacent veneer panels 14 , and to assist in retaining the panels 14 in place. The vertical load F that results from the weight of the veneer panels 14 is supported by the veneer connectors 12 , and in turn, by the support members 16 . Because the support members 16 have generally high moments of inertia in the vertical direction, they are able to be made with relatively thin gauge material for supporting the load imposed thereon by the veneer panels 14 . It will be noted that while two connectors 10 are shown along the top edge of each veneer panel 14 , any suitable number of connectors 10 may be used to support each veneer panel 14 , depending on the nature of the specific application. [0074] Reference is made to FIG. 7 , which shows a veneer connector 12 ′″, which may be used alternatively to the veneer connector 12 . The veneer connector 12 ′″ may be similar to the veneer connector 12 ( FIG. 2 ), or the veneer connector 12 ′ ( FIG. 2 a ), except that the veneer connector 12 ′″ has a pair of side webs 84 that extend vertically from the side edges of the veneer connector 12 ′″. The side webs 84 may extend generally along substantially the entire length of the veneer connector 12 ′″, except for the portion 86 of the veneer connector 12 ′″ that will be embedded within the gap between adjacent veneer panels 14 ( FIG. 1 ). The side webs 84 provide increased bending resistance to the veneer connector 12 ′″, relative to the veneer connector 12 ( FIG. 2 ), because the side webs 84 generally increase the moment of inertia of the veneer connector 12 ′″. [0075] Reference is made to FIG. 8 , which shows a support member 16 ′ that maybe used as an alternative to the support member 16 ( FIG. 4 ). The support member 16 ′ may be similar to the support member 16 , except that the support member 16 ′ has a slot 90 that positioned closer to the bottom of the support member 16 ′, relative to the slot 60 on the support member 16 ( FIG. 4 ). The slot 90 may otherwise be similar to the slot 60 , and is for receiving and retaining the veneer connector 12 or 12 ′″ ( FIGS. 2 and 2 a ). Referring to FIG. 8 a , the slot 90 is positioned sufficiently low, so that, when the support member 16 ′ is being mounted to the back-up wall 18 proximate the top edge of a veneer panel 14 , the veneer panel 14 does not completely obstruct access to the adjustment aperture and the securing aperture, which are shown at 92 and 94 respectively. Thus, the relatively lower position of the slot 90 facilitates the mounting of the support member 16 ′. [0076] Reference is made to FIG. 9 , which shows a support member 16 ″, which is another alternative to the support member 16 . The support member 16 ″ may be similar to the support member 16 , except that the support member 16 ″ has an adjustment aperture 98 that is elongate along an angle A from the vertical. The adjustment aperture 98 in the embodiment shown in FIG. 9 provides vertical adjustability for the support member 16 ″, in a similar way to the adjustment aperture 50 on the support member 16 ( FIG. 4 ). During vertical adjustment of the support member 16 ″, however, the support member 16 ″ will be shifted by a certain amount horizontally. Preferably, the angle A from the vertical is small, to reduce the horizontal shift that occurs during vertical adjustment of the support member 16 ″. Referring to FIG. 10 , a support member 16 ′″ may also be made which has an adjustment aperture 98 ′ that is a mirror image of the adjustment aperture 98 ( FIG. 9 ). [0077] The support member 16 , as shown in FIG. 5 , has a support portion 44 that extends generally orthogonally outwards from the plane of the mounting flange 42 . It is, however, possible for the support portion 44 to extend outwards from the mounting flange 42 , at an angle such that it is not orthogonal to the mounting flange 42 , as shown in FIG. 14 . In the support member 16 ″ of the variant shown in FIG. 14 , the side walls 58 of the support portion 44 are supported along generally vertical lines by the mounting flange 42 and thus have a greater resistance to bending under a vertical load imposed thereupon, relative to a typical L-shaped member used in connectors of the prior art. This is true even though the side walls 58 extend outward from the mounting flange 42 at an angle such that they are not orthogonal to the mounting flange 42 . [0078] The side walls 58 of the support portion 44 are shown in FIG. 5 as being supported along vertical lines by the mounting flange 42 . It is not necessary that the support be provide along strictly vertical lines however. Referring to FIG. 15 , the support member 16 ″″ is advantageous relative to L-shaped members of the prior art, even though the side walls 58 are not strictly vertical, and are supported by the mounting flange 42 along lines that are off of vertical by some small amount. Throughout this disclosure and the accompanying claims, the term “generally vertical” is meant to include lines or planes that are strictly vertical and those that are off of vertical within a selected range. While the selected range is preferably small so that the side walls 58 are relatively close to vertical, the range could alternatively be relatively large while still providing a structure that is advantageous relative to L-shaped connectors of the prior art. For example, the range could be as large as 45 degrees off of vertical in each direction. [0079] Reference is made to FIG. 16 , which shows a connector 110 , in accordance with another embodiment of the present invention. The connector 110 includes a support member 16 ′″″ and a veneer connector 12 ″. The support member 16 ′″″ may be similar to the support member 16 ( FIG. 4 ), except that the support member 16 ″″″ supports the veneer connector on its upper surface, shown at 116 , instead of supporting the veneer connector 12 ″ in a slot. [0080] The upper support wall 116 may be made generally planer to assist in supporting and stabilizing the veneer connector 12 ″. The adjustment aperture 62 is provided in the upper support wall 116 . The upper support wall 116 extends between the two spaced apart side walls 118 . The side walls 118 may be similar to the side walls 58 , shown in the support member 16 , shown in FIG. 5 . The upper support wall 116 , thus acts as the horizontal support for the side walls 118 . [0081] The veneer connector 12 ″ rests on top of the upper support wall 116 . The veneer connector 12 ″ has the adjustment aperture 32 which is alignable with the adjustment aperture 62 on the support member 16 ′″″ when the veneer connector is positioned on the upper support wall 116 . The adjustment aperture 32 is generally perpendicular to the adjustment aperture 62 in order to provide adjustability for the veneer connector 12 ″ on the support member 16 ′″″ in two orthogonal directions in a horizontal plane. [0082] Referring to FIG. 17 , the fastener 65 may be provided for joining the veneer connector 12 ″ to the support member 16 ″′″. The fastener 65 may include the hex head bolt 65 a , the washer 65 b , the nut 65 c , and a washer 65 d. [0083] The washers 65 b and 65 d are provided to inhibit the pulling through of the bolt 65 a or nut 65 c through the adjustment apertures 62 and 32 during assembly and use of the connector 110 . [0084] Referring to FIG. 16 , the veneer connector 12 ″ includes the veneer connection apertures 34 , positioned proximate its second, or outside, edge 30 . The veneer connection apertures 34 may include a centre aperture 34 a and two outer apertures 34 b . The centre aperture 34 a may be generally circular while the outer apertures 34 b may be slotted to provide flexibility in receiving imperfectly positioned fastening ties 36 ( FIG. 3 ) on the veneer panels 14 ( FIG. 3 ). [0085] The veneer connector 12 ″ may include a pair of side webs 120 , which may be similar to the side webs 84 on the veneer connector 12 ′″, as shown in FIG. 7 . [0086] The veneer connector 12 ″ may include one or more strengthening ribs 121 on its upper surface 122 . The strengthening ribs 121 provide additional vertical bending resistance for the central region of the veneer connector 12 ″ which is spaced relatively far away from the side webs 120 . By positioning the strengthening ribs 121 on the upper surface 122 , they do not create an interference hazard when mounting the veneer connector 12 ″ on the support member 16 ″′″. Like the side webs 120 , the strengthening ribs 121 must be positioned so as not to obstruct the connection of the veneer connector 12 ″ with the veneer panel 14 that will ultimately sit above it (see FIG. 3 ). [0087] Referring to FIG. 11 , the support members 16 ″ and 16 ′″ may be manufactured from a common plate 100 . The common plate 100 may be similar to the plate 70 ( FIG. 6 a ), except that the common plate 100 has an aperture therein, that will ultimately become the adjustment aperture 98 ( FIG. 9 ), or the adjustment aperture 98 ′ ( FIG. 10 ), depending on which way the plate 100 is folded during manufacture. For example, referring to FIG. 12 a , the tabs on the plate 100 , which are shown at 104 may be folded in a first direction, so that the plate 100 will ultimately form the support member 16 ″. However, referring to FIG. 12 b , the tabs 104 may be folded in a second direction that is opposite the first direction, so that the plate 100 ultimately forms the support member 16 ′″. [0088] Reference is made to FIG. 13 , which shows a system of connectors 106 and 108 , which cooperate in pairs to support veneer panels 14 . The connectors 106 and 108 may be similar to the connector 10 ( FIG. 1 ), and include a suitable veneer connector, such as the veneer connector 12 . However, the connectors 106 and 108 include the support members 16 ″ and 16 ′″ respectively, instead of the support member 16 ( FIG. 1 ). [0089] The top and bottom edges of the panel 14 are supported by at least one of each connector 106 and 108 . As a result, the weight of the panel 14 is prevented from dragging the connectors 106 and 108 down the wall 18 , because the adjustment apertures extend in different directions. Thus, because the adjustment apertures 98 and 98 ′ are not parallel to each other when the connectors 106 and 108 are installed on the back-up wall and are in use, the adjustment apertures 98 and 98 ′ cooperate with their respective fasteners and with each other to prevent the connectors 106 and 108 from being dragged down from their supported load. [0090] It will be noted that more than one of each connector 106 and 108 may be used to support an edge of the veneer panel 14 . For example, several of one type of connector, eg. connector 106 and one or two of the other type of connector, eg. connector 108 , may be used to support an edge of the veneer panel 14 . At least one of each connector 106 and 108 is used, however. [0091] It will be noted that the features shown in the support members disclosed herein may all be combined into a support member in accordance with the present invention in any desired way. For example, a support member may be provided that includes the basic structure of support member 16 , but that has a low-positioned slot, similar to the slot 90 of support member 16 ′ ( FIG. 8 ), and that also has a slanted adjustment aperture, similar to the adjustment aperture 98 or 98 ′ of support members 16 ″ and 16 ′″ ( FIGS. 9 and 10 ). Similarly, the features shown in the veneer connectors disclosed herein may all be combined into a veneer connector in accordance with the present invention in any desired way. [0092] In the embodiments described above, the side walls of the support members have been described and shown as extending outwardly from the mounting flanges along vertical planes. It will be noted that the vertical planes need not be strictly vertical, but are at least generally vertical. In another alternative, the side walls of the support members need not be strictly planar, and may instead be curved or may have further folds, which are preferably generally vertical. [0093] In the embodiments described above, the veneer connector mounts to the support member using a single fastener, such as a bolt. Using a single fastener instead of a plurality of fasteners can provide a significant cost savings in the overall cost of the connector, particularly in jurisdictions which require the use of stainless steel for connectors supporting veneer panels in a cavity wall. [0094] The connectors of the present invention are able to support the same loads as the L-shaped connectors of the prior art, but can be manufactured from thinner material, with fewer fasteners. As a result the connectors of the present invention can be less expensive than the L-shaped connectors of the prior art. [0095] While what has been shown and described herein constitutes the preferred embodiments of the subject invention, it will be understood that various modifications and adaptations of such embodiments can be made without departing from the present invention, the scope of which is defined in the appended claims.	A connector for coupling a veneer panel to a back-up comprises a support member comprising a mounting flange adapted for securing the support member to said back-up wall, and first and second support member side walls extending outwardly from the mounting flange. The first and second support member side walls define at least one generally horizontal slot when the support member is secured to the back-up wall. The connector further comprises a veneer connector configured for non-rotational sliding receipt in the generally horizontal slot and adapted to support a generally horizontal edge of said veneer panel when the veneer connector is received in the generally horizontal slot and when the support member is secured to the back-up wall.	8
STATEMENT OF GOVERNMENT INTEREST The invention described herein may be manufactured and used by or for the Government of the United States of America for governmental purposes without the payment of any royalties thereon or therefor. CROSS-REFERENCE TO RELATED PATENT APPLICATIONS This continuation-in-part application claims the benefit of co-pending U.S. Patent Application Ser. No. 09/814,487 entitled “Instrumented Fiber Optic Tow Cable” filed on Mar. 20, 2001 by Anthony A. Ruffa who is the same and sole applicant of this application. BACKGROUND OF THE INVENTION (1) Field of the Invention The present invention relates to arrays towed through the water by vessels and more particularly to an improved tow cable for the arrays in which the temperature at various radii of the tow cable is measurable thereby self-calibrating the tow cable to account for the heat-dissipation of the tow cable in order to measure the temperature of the water surrounding the tow cable. (2) Description of the Prior Art In naval operations, an array is towed behind a vessel for gathering information, such as the location of enemy vessels or the depth of the ocean. A typical array comprises an exterior hose wall fabricated from rugged, insulated material, and a plurality of information gathering wires communicating with acoustical sensors disposed within the protective hose wall. The conducting wires or optical fibers of the towed array transmit information via the tow cable to a microprocessor within the vessel for a readout of gathered data. In addition to transmitting information, the tow cable also powers the array. Since the conducted power generates heat, the conducted power impacts the temperature of the cable and the water surrounding the cable. Further measurements that rely on the surrounding water temperature such as a sound velocity profile, can therefore be impacted by temperature variances along the length of the tow cable. Since no segment of the tow cable or only a minimal portion of the tow cable can be accessed on surface vessels, an accurate temperature measurement at different points along the length of the tow cable is difficult to discern after the tow cable is deployed or “let out” from the winch of the array handling system. In the art, various methods and devices are employed to measure the temperature of the tow cable and the surrounding water column. In Seaman et al. (U.S. Pat. No. 6,147,931), an apparatus for providing a temperature profile of a towed sonar array is disclosed. In the cited reference, the tow cable for the array comprises a central cable and a protective outer jacket. Thermistors are disposed at spaced positions along the outer jacket and connect to conductors embedded in the outer jacket. The conductors terminate onboard ship to provide continuous signals representing temperatures at various ocean depths. While thermistors can be positioned along the length of the tow cable to determine the temperature of the water, this use of thermistors is limited in its practical application. In a first example, using a high number of thermistors is impractical for a tow cable that can be as long as 8000 feet. Since each thermistor requires its own pair of conductors, the high number of thermistors can significantly increase the tow cable diameter over the length of the tow cable. In a second example, the technology of the cited reference is not easily transferable to the tow cable because of the strain encountered by the tow cable at the curvature of the cable to the winch of the towed array handling system. A separate protective band for the thermistor, as disclosed by the cited reference, is susceptible to detachment during repeated use of the tow cable such that the thermistor is easily exposed to these strains with the result of inaccurate information gathering if the thermistors are damaged. In Yamaguchi et al. (U.S. Pat. No. 5,198,662), a measuring system measures temperature distribution in water using an optical fiber. In the cited reference, the optical fiber is positioned in a central pipe sealed by filler material. Although, the optical fiber positioned in this manner can determine the temperature of the proximate water column, the positioning of optical fibers as temperature sensors can be improved. An improvement to the positioning of sensors for measuring temperature would be the ability to gather measurements at varying radii of the cable rather than only at the center of the cable. Gathering measurements at varying radii along a common vector from the center of the tow cable increases the accuracy of temperature measurements of the surrounding water column. SUMMARY OF THE INVENTION Accordingly, it is a general purpose and primary object of the present invention to provide a tow cable in which temperature measurements at various radii of the tow cable are attainable thereby self-calibrating the tow cable to account and correct for the heat-flow in the radial direction in order to measure the temperature of the water surrounding the tow cable. It is a further object of the present invention to provide a tow cable in which temperature measurements at various radii of the tow cable and along a common vector extending from a center of the tow cable are attainable. It is a still further object of the present invention to provide a tow cable which compensates for the strain encountered by the tow cable especially at the winch of the towed array handling system. To attain the objects described, there is provided a tow cable in which the temperature of the tow cable is measured by the use of multiplexing capability intrinsic to optical fibers in which the optical fibers are positioned at the center of the tow cable and separately wound as part of two layers of surrounding strength wires. During measurement, light signals are emitted from a multiplexer aboard the towing vessel to positions along the optical fibers in which the positions are intersections of a vector extending radially from a longitudinal axis to an outer surface of the tow cable. The returning light signals from the positions provide measurements that in conjunction with a data processor further provide measurement of the outer boundary temperature of the tow cable. The outer boundary temperature of the tow cable is determinant of the surrounding water column temperature. Sound velocity profiles are easily derived from the water column temperature by methods known to those skilled in the art. In the manufacture of the tow cable, a steel strength member wire is substituted in one armored layer of the tow cable and another steel strength member wire is substituted in another armored layer. The steel strength member wires are substituted with armored optical fibers or bendable stainless steel tubing encompassing an optical fiber. In an additional manufacturing step, an optical fiber is positioned within stainless steel tubing as the center of the tow cable. The above and other features of the invention, including various and novel details of construction and combinations of parts will now be more particularly described with reference to the accompanying drawings and pointed out in the claims. It will be understood that the particular devices embodying the invention are shown by way of illustration only and not as the limitations of the invention. The principles and features of this invention may be employed in various and numerous embodiments without departing from the scope of the invention. BRIEF DESCRIPTION OF THE DRAWINGS A more complete understanding of the invention and many of the attendant advantages thereto will be readily appreciated as the same becomes better understood by reference to the following detailed description when considered in conjunction with the accompanying drawings wherein: FIG. 1 depicts an arrangement view of the tow cable of the present invention secured to a towing vessel and a sensor array; FIG. 2 depicts a cross-sectional view of the location of the optical fibers in the tow cable of the present invention with a number of strength and conducting wires of the tow cable removed for purposes of clarification and with the view taken from reference line 2 – 2 of FIG. 1 ; FIG. 3 depicts a cross-sectional view of the location of the optical fibers in the tow cable of the present invention with a number of strength and conducting wires of the tow cable removed for purposes of clarification and with the view taken from reference line 3 — 3 of FIG. 1 ; FIG. 4 depicts a cross-sectional view of the intersecting radial location of the optical fibers with the strength wires and conducting wires of the tow cable removed for purposes of clarification and with the view taken from reference line 4 — 4 of FIG. 1 ; and FIG. 5 depicts a perspective view of the tow cable of the present invention in which the optical fibers are wound at a helical angle with the strength wires and conducting wires of the tow cable removed for purposes of clarification. DESCRIPTION OF THE PREFERRED EMBODIMENT Referring now to the drawings wherein like numerals refer to like elements throughout the several views, one sees that FIG. 1 depicts an arrangement view including the tow cable 10 of the present invention let out from a winch 12 of a vessel 14 in which the tow cable tows an acoustic sensor array 16 through the ocean 18 . The tow cable 10 powers the sensor array 16 and transmits measurement data from the sensor array to a multiplexer/demultiplexer 20 with data processing capability or transmits measurement data to other data processors known to those skilled in the art. As shown in the cross-sectional view of FIG. 2 , the double-armored tow cable 10 includes a centrally located section 30 , including at least one optical fiber 32 contained in a stainless steel tube surrounded by electrical conductors 34 (for transmitting power and signals). The optical fiber 32 preferably extends along a longitudinal axis of the tow cable 10 ; however, the optical fiber may extend parallel and helical to the longitudinal axis of the tow cable. Surrounding the central section 30 are two armored layers 36 and 38 of strength wires 39 . An optical fiber 40 encompassed by another stainless steel tube 41 or an armored optical fiber 42 of FIG. 3 replaces one of the strength wires 39 helixed around the section 30 as the first armored layer 36 . An optical fiber 46 of FIG. 2 encompassed by another stainless steel tube 48 or an armored optical fiber 50 of FIG. 3 replaces another of the strength wires 39 helixed around the first armored layer 36 as the second armored layer 38 . The number of steel strength wires 39 are shown in FIG. 2 and FIG. 3 for comparison and illustrative purposes wherein the actual number would be much larger and arrangement of the steel strength wires would vary. As shown in FIG. 4 , each of the armored optical fibers 42 and 50 intersects a vector 52 extending from the optical fiber 32 of the central section 30 . The vector 52 extends radially from a longitudinal axis 54 of the tow cable 10 such that the measurements derived from the group of optical fibers 32 , 42 and 50 are localized. The armored optical fibers 42 and 50 also intersect additional vectors extending similar to the vector 52 with the additional vectors at various lengths of the tow cable 10 such that the temperature of the water column at various points along the tow cable is measurable. Measurements are derived from the group of optical fibers 32 , 40 and 46 in a similar manner as the optical fibers of FIG. 4 with a similar positioning of the optical fibers 32 , 40 and 46 as the optical fibers of FIG. 4 . Furthermore, the armored optical fibers 42 and 50 replace strength wires 39 that are wound around the longitudinal axis 54 at a helical angle 0 depicted in FIG. 5 . The optical fibers 40 and 46 are similarly wound around the longitudinal axis 54 as the optical fibers 42 and 50 shown in FIG. 5 . The helical angle θ is approximately 20 degrees; however, the helical angle is based upon manufacturer's specifications (i.e.: the helical angle may decrease for larger tow cables). The placement of the armored optical fibers 42 and 50 at the helical angle θ to the longitudinal axis 54 is chosen to reduce the strain of the tow cable 10 at the large bending of the tow cable 10 encountered at the winch 12 . In a data-gathering operation during the towing of the array 16 , the multiplexer/demultiplexer 20 emits optical pulses of light through the optical fibers 32 , 42 and 50 of FIG. 3 as an example. The multiplexer/demultiplexer 20 also receives backward scattered light from the optical fibers 32 , 42 and 50 resulting from the emitted optical pulses of light. The back-scattered light has a component not shifted in frequency (due to Rayleigh scattering) and a component shifted in frequency (due to Raman scattering). In terms of the wavelength distribution, the back-scattered light includes Rayleigh scattered light having the same wavelength (λ 0 ) and the Raman scattered light deviated 6Δλ from the incident light. The Raman scattered light deviated +Δλ from λ 0 is referred to as Stokes light while the Raman scattered light deviated −Δλ from λ 0 is referred to as anti-Stokes light. The location of detection data is obtained from the tow cable 10 by denoting the relation between the time (t) elapsed from the incidence of optical pulses emitted and the intensity of light detected by the multiplexer/demultiplexer 20 . The data denoting the detected light intensity is inputted in a data processing portion of the multiplexer/demultiplexer 20 . Since the velocity of light in optical fibers is known, the time (t) that elapsed from the incidence of the optical pulses to the detection of a signal represents the distance from the end of the optical fibers. The Raman scattering effects can be used to derive the temperature (T); this is well-known to one skilled in the art. The time of arrival processing described above (and also well-known in the art) determines the location of each temperature on the optical fiber. Since the distance of emitted light can be obtained as stated above, the vector 52 of FIGS. 4 and 5 can also be established at a distance from the end of the tow cable 10 . Because of the helixing of the optical fibers 42 and 50 along the-tow cable 10 , the distances of emitted light for these optical fibers is slightly higher at the vector 52 and therefore the measurements based on these distances should be compressed multiplexer/demultiplexer 20 with data processing capability and accounted for at the vector 52 . For example, the distance of emitted light at the optical fiber 32 would be five hundred feet while the distances at the optical fibers 42 and 50 may be five hundred and twenty-five feet and five hundred and fifty feet respectively, depending on the helix angle. Once a distance is established and a temperature is measurable at the optical fibers 32 , 42 and 50 , the boundary condition of the tow cable 10 is measurable with a substantial degree of accuracy. The water temperature T 0 at the water column (of the ocean 18 or other surrounding fluid condition) is at or proximal to the boundary condition. Specifically, the heat going into the surface, q, at the radius r 3 of the tow cable 10 is resolved by the equation: q = KA ⁢ ∂ T ∂ r ⁢ ( r 3 ) ≅ KA ⁡ ( T 3 - T 2 r 3 - r 2 ) assuming that ∇ 2 T=0 in the second armored layer 38 . In the equation, the thermal conductivity is K; A is the circumferential area at the radius r 1 and ∂ T ∂ r represents the temperature gradient measured at the radius r 2 and the radius r 3 (r 3 =0) of FIG. 4 . Solving for Laplace's equation for heat conduction using the cylindrical coordinates intrinsic to the tow cable 10 and assuming axisymetric temperature distribution: ∇ 2 ⁢ T = [ ∂ 2 ⁢ T ∂ r 2 + 1 r ⁢ ∂ T ∂ r + ∂ 2 ⁢ T ∂ z 2 ] = 0 the temperature T of the surrounding water column at a length z of the tow cable 10 is resolvable. The water temperature T is reflected by example as T 0 in FIGS. 2 and 3 . It is found by fitting the solution to the temperatures: T 1 at the optical fiber 50 (alternatively the optical fiber 46 in FIG. 2 ); T 2 at the optical fiber 42 (alternatively the optical fiber 40 ) and T 3 at the optical fiber 32 . If the temperature is measured at three radial locations and if the temperature is assumed axisymmetric in nature, the temperature of the tow cable 10 can be determined by solving Laplaces's equation with T 0 and T 3 as boundary conditions with an effective conductance representing the cable material. Since T 0 is unknown, the problem is solved for a range of values of T 0 , and then the value of T 0 is chosen that best fits the measured temperatures T 1 and T 2 . Since the problem is linear, a look-up table can be pre-computed and stored so that Laplace's equation does not have to be solved in real time. As a result, the temperature T 0 of the surrounding water column at a length z along the tow cable 10 is resolved. Fitting to two temperatures T 1 and T 2 in a least squares sense minimizes error compared to fitting to only one interior temperature. Also, this accounts for cable heating in the center, which is reflected by the temperature T 3 . Thus by the present invention its objects and advantages are realized and although preferred embodiments have been disclosed and described in detail herein, its scope should be determined by that of the appended claims.	A tow cable in which the temperature of the cable is measurable by the use of multiplexing capability intrinsic to optical fibers in which the optical fibers are positioned at the center of the tow cable and wound as part of two layers of surrounding strength wires. The optical fibers of the two layers intersect a vector extending radially from the optical fiber at the center to an outer surface of the tow cable. Light signals emitted from a multiplexer to positions along the optical fibers, in which the positions intersect the vector, return light signals from the positions to provide measurements that in conjunction with a data processor further provide temperature measurement of the outer boundary of the tow cable.	6
CROSS-REFERENCE [0001] This application claims priority to U.S. application Ser. No. 15/636,073, filed Jun. 28, 2017, which in turn claims priority to Provisional Application No. 62/355,507, filed Jun. 28, 2016, both of which are incorporated herein by reference in their entirety, as if set forth in full in this application for all purposes. OVERVIEW [0002] A non-invasive multi-sensor eco-system tracks and monitors critical human physiological parameters, including those covered by the term “vital signs,” to detect and predict health conditions. The system may be operated in an adaptive mode. The physiological parameters are extracted from a plurality of sensors using novel algorithms. The parameters measured by one embodiment may include blood pressure, heart rate, oxygen saturation (SpO2), respiratory rate, blood glucose level, body temperature and physical activity measured as step count. [0003] The eco-system consists of multiple components wirelessly communicating with each other: (1) wearable sensors, which may include signal processing functionality as well as wireless inter-sensor communication and short-term data storage; (2) a portable computing device hosting a mobile application which enables reception of the processed sensed data, transmission of that data to a cloud platform for analysis, display of push notifications determined by the processed sensed data, reception of analysis results fed back from the cloud platform, and visualization of the processed sensed data and of the cloud analytics data; and (3) the cloud platform itself, allowing long-term data storage as well as analysis of the measurement data to obtain short and long-term health trends and future health predictions. In some embodiments the eco-system also includes a linked healthcare provider, for professional review and action as and when necessary or appropriate. [0004] The eco-system operates to (a) analyze the physiological parameters derived from data provided by two or more sensors, positioned at different locations over the subject's body; (b) compare them against their respective normal, critical and life-threatening bounds as defined by the clinical community; and (c) provide feedback, alerts, push notifications and/or 911 calls depending on the criticality of the results of the comparison. Machine learning algorithms may be employed to carry out various aspects of the analysis, at the cloud platform level. BACKGROUND [0005] With the increase in the size of the elderly population, as well as the emergence of chronic diseases on a broader population segment, largely influenced by changes in modern lifestyle, coupled with rapid increase in healthcare costs, there has been a significant need to monitor the health status and overall wellbeing of individuals in their daily routine to prevent serious health disorders. Alongside, we observe an increase in thirst for quantification of one's own health on a continuous basis. The adoption of mobile healthcare technology promises to enhance the quality of life for chronic disease patients and the elderly, as well as healthy individuals. Furthermore, it offers the potential to alter the modality of the current healthcare system by enhancing the scope of out-patient care and by reducing the need for hospitalizations and other cost-intensive healthcare needs. [0006] Some solutions have been proposed to address issues in this area, but none of them has provided a closed and comprehensive eco-system as envisaged by the present invention. [0007] There is, therefore, a need for systems and methods that allow for continuous non-invasive health monitoring technology—a disruptive technology, in the sense that it would alter the perspective of healthcare from reactive to proactive. The eco-system would ideally be closed-loop and comprehensive, covering a spectrum of actions, from automatically collecting physiological parameters from each of a plurality of users, getting a full understanding of the parameter profile for each individual user, and recording their long-term health trends and conditions, to providing guidance toward attaining a healthier lifestyle for individual users, groups and the community as a whole. BRIEF DESCRIPTION OF THE DRAWINGS [0008] FIG. 1 illustrates a high level view of an eco-system according to one embodiment of the invention. [0009] FIG. 2 schematically illustrates the functioning of an eco-system according to one embodiment of the invention. [0010] FIG. 3 illustrates examples of sensors that may be worn in various embodiments of the invention. [0011] FIG. 4 illustrates two examples of subjects wearing sensors according to embodiments of the invention. [0012] FIG. 5 illustrates the computational flow of data through some embodiments of the invention. [0013] FIG. 6 illustrates low power connectivity between hardware elements in some embodiments of the invention. DETAILED DESCRIPTION [0014] The manner in which the present invention provides its advantages over systems in current use can be more easily understood with reference to FIGS. 1 through 4 . It should be noted that throughout this disclosure, the words “user”, “patient”, and “subject” are used interchangeably. [0015] FIG. 1 is a high level view of an eco-system 100 of the present invention, illustrating relationships between four major elements—sensors 110 (central sensor 110 A and just one remote sensor 110 B are shown in this example for simplicity, but in other embodiments, there may be additional remote sensors), a cloud platform 130 hosting AI-based analytics, and a mobile or portable device 105 . Device 105 has a user interface enabling communication with the sensors, the platform, and with an entity 120 , typically comprising a healthcare entity, which may, for example, be a physician, a clinic, or an emergency care unit. Entity 120 may also include a user chosen sub-community of people such as family members. These various elements make up a closed or self-contained, independently functioning eco-system, which in this embodiment includes entity 120 . In some embodiments, entity 120 may be considered to lie outside the eco-system, but to be in communication with it. In the embodiment shown in FIG. 1 , a single healthcare entity 120 A is communicatively coupled to mobile device 105 and directly or indirectly to cloud platform 130 . In another embodiment, not shown, there may be two or more different healthcare entities, one in communication with the cloud platform and the other in communication with the mobile device. [0016] FIG. 1 indicates how a system of continuous and adaptive vital data monitoring with clinical accuracy may result in a healthier lifestyle and peace of mind. [0017] FIG. 2 illustrates the functioning of elements of an eco-system 200 according to the present invention, showing a finer granularity level than FIG. 1 , and illustrating some of the steps performed by components of the closed-loop ecosystem. [0018] One element or category is a plurality of wearable sensors ( 110 in FIG. 1 ), including one central sensor and one or more auxiliary or remote sensors worn by a user. Each sensor is configured to monitor one of the user's physiological parameters. Examples of typical parameters of interest are listed in Table 1. [0000] TABLE 1 1. Heart Rate 2. Pulse Rate 3. Heart Rate Variability 4. Cardiac Index 5. Blood Pressure 6. Blood Glucose 7. Respiratory Rate 8. Oxygen Saturation (SpO2) 9. Desaturation Index 10. Apnea Hypopnea Index 11. Body Temperature 12. Electrocardiograph Activity 13. Electro Dermal Activity [0019] As shown in FIG. 2 , measurements of one or more of these parameters may be initiated at step 240 , as and when desired by the user, using an interface of an application on a convenient portable device easily accessed by the subject, such as a smart-phone ( 105 in FIG. 1 ). Alternately, the parameters may be automatically measured as programmed in such an application. Components of device 105 include receiver 106 , transmitter 107 , processor 108 , and display screen 109 . [0020] The central sensor is typically worn on the wrist; typical locations for other sensors include the forehead, chest, fingertip, earlobe and leg. Examples of measurement technologies used include photoplethysmography (PPG), electrocardiography (ECG), 3-axis accelerometry, temperature measurement using thermistors, and electrodermal activity monitoring. Some of the sensors (often those at the forehead, earlobe and fingertip) may be used primarily or solely to provide calibration signals for other sensors. [0021] FIG. 3 shows close up views of examples of sensors at their envisaged body locations. Sensor 310 A is a wrist-mounted sensor, typically the central sensor of the system. Sensors 310 B, 310 C, 310 D, 310 E, and 310 F are examples of sensors designed to be worn on “remote” locations such as a finger tip, earlobe, around the chest, head, or ankle respectively. [0022] FIG. 4 illustrates how such sensors may be worn by two subjects at different stages of life. The wireless communication of data between the central sensor and each remote sensor may be carried out using Bluetooth or other well-known and established wireless technologies. The placement of sensors 310 A-F is shown on the youthful figure on the left, while the corresponding physiological parameters that may be measured using those sensors are shown on the elderly figure on the right. In different embodiments of the invention, a subset of the sensors shown may be used, with as few as one remote sensor present in addition to one central sensor. [0023] In some embodiments, a single sensor may provide data indicative of more than one physiological parameter of interest. One example of this is a photoplethysmographic (PPG) sensor, which essentially monitors blood volume, but from which data indicative of SpO2, glucose, heart rate, blood pressure, and respiratory rate may be derived. Sensors may be operated to monitor the wearer's vital parameters continuously and automatically over long periods of time. [0024] Returning to FIG. 2 , once the measurement instructions are issued at step 240 and received by the central sensor at step 242 , central sensor selects at step 244 which sensor or sensors are required to perform the desired measurement or measurements. If necessary, the request is transmitted to a remote sensor at step 246 . Each designated sensor (central or remote) performs the measurements of the corresponding parameter or parameters at steps 248 and/or 250 respectively. Any measurements performed by remote sensors (such as a leg sensor for example) are wirelessly sent to the central sensor (typically the sensor worn on the subject's wrist), with that central sensor taking responsibility for aggregating the other sensors' data as and when necessary, processing them at step 252 , as will be described in greater detail below, and transmitting the results to the user interface on the mobile device, typically a smart-phone. [0025] Calibration plays an important role in attaining clinical-grade accuracy for all measurements of physiological parameters. Two methods may be used to address the calibration issue: [0026] 1. Static calibration: Measurement of a parameter using the proposed apparatus is compared against the gold standard (clinical setting measurement) and repeated for a large and diverse set of individuals. The measurement error computed is used to determine the calibration coefficients for the given parameter. The calibration coefficients thus obtained are applied to every apparatus manufactured. The calibration coefficients do not change for the lifetime of operation for a given apparatus. [0027] 2. Dynamic AI-based calibration: The calibration coefficients of a given parameter are dynamically computed on cloud platform based on data from a large population bucketed according to age, sex, race, skin color, skin thickness etc. As new data points get added into a specific population bucket, the calibration coefficients get recomputed and adjusted into the settings of a given apparatus used by an individual. The calibration coefficients in this method get constantly adjusted and improved over the lifetime of the apparatus or device performing the parameter measurement of interest. [0028] The second method, dynamic calibration, clearly provides some significant advantages in terms of specificity for the individual, and long term reliability. In the present invention, both static calibration—the current standard practice—and dynamic calibration may be used, to provide a desirable combination of accuracy, convenience, specificity and reliability. [0029] Returning to FIG. 2 , at step 252 , as noted above, the central sensor processes (filters, calibrates, scales, etc) the raw data received to generate physiological parameter data with accuracies sufficient to render the parameter data clinically meaningful. Specially developed hardware-embedded algorithms may be used to achieve real-time signal processing. FIG. 5 schematically illustrates the computational flow of data gathered by various sensors, and processed by hardware-embedded algorithms according to some embodiments of the present invention, to yield data of clinical significance. The central sensor then compares those processed data values to values defining ranges of interest (normal, critical and life-threatening) for each corresponding parameter, at step 254 . The measured and processed data may be stored for the short term in the memory of the central sensor, at step 256 . Depending on the results of the comparisons, the central sensor may wirelessly send push notifications to the smart-phone (or similar portable device). These notifications may be normal text, or in some embodiments, simple symbols or easily appreciated codes. For example, at step 258 , a blue code, or a predetermined symbol such as a smiley face may be sent to indicate to the subject that a parameter is within normal bounds, an orange code may be sent at stip 260 to indicate that the parameter is outside normal bounds but within critical bounds, or a red code may be sent at step 262 to indicate life-threatening bounds have been exceeded. In some embodiments, audible alerts may be issued as well as or instead of visible ones. In the case of a life-threatening situation (red alert), the smart-phone may automatically initiate a 911 call. [0030] In some embodiments, not shown in this figure, alerts may be sent to medical professionals such as the user's personal physician, or to health centers or emergency services. In less serious cases, alerts may be sent just to the user, accompanied by recommendations on relevant corrective actions. [0031] One advantage of the present invention is that the data processing and transmission burdens of the entire group of sensors is carried by just the central sensor, easing the power consumption and size, weight, complexity and cost demands on the remote sensors. [0032] FIG. 6 schematically illustrates one embodiment in which ultra short range (0.5 m to 1 m), ultra low power (1 to 10 microwatt range) Bluetooth wireless connections are provided between central sensor 610 A and five remote sensors 610 B-F, and a slightly longer range (1.5 m) low power (100 microwatt to 300 microwatt) Bluetooth connection is provided between central sensor 610 A and mobile (in this case hand-held) device 605 . In other embodiments, other similar low and ultra low power protocols may be used. Reduced power consumption results in longer battery lifetime and reduced device heating, so better reliability. [0033] At step 264 , the smart-phone (or other portable device) then uses the standard internet service (e.g. 4G, LTE, WiFi etc) to securely send the processed data to the cloud for long-term storage and analytics as will be described further below. It should be noted that the use of just one device—the smart-phone or similar device—to handle the transmission of processed data to the cloud significantly simplifies system design and power consumption relative to the situations common today, where each sensor of a plurality worn by a subject independently processes and transmits data to distant receivers. In the present invention, the remote sensors only have to transmit data over very short distances to reach the central sensor, which then sends processed data to the smart-phone, which in turn transmits them to the cloud, and receives other data (such as trend data discussed below) back. The display screen on the smart-phone (or PDA or tablet) allows the subject to receive push alerts and easily visualized displays of the results of the cloud-based analytics. [0034] The cloud provides long term storage of the data received from the smart-phone, and carries out analysis using conventional and/or machine learning algorithms. The machine learning algorithms may be especially useful when applied to the stored physiological parameter data to provide information on long-term trends, and to yield personalized measurement data that are wirelessly sent back to the smart-phone. [0035] The machine learning algorithms may also use the received and stored data regarding one or a combination of the parameters measured to determine health conditions or clinical insights (examples of which are listed below in Table 2) relevant to the individual subject. Predictions regarding future health may be made. [0000] TABLE 2 1. COPD (Chronic Obstructive Pulmonary Disease) 2. Congestive Heart Failure (CHF) 3. Cardiovascular diseases 4. Cardiac Arrhythmia a. Atrial Fibrillation (from ECG) b. Ventricular Tachycardia (leading to Ventricular Fibrillation) 5. Stress Level 6. Sleep Apnea and Hypopnea 7. Personalized Meal Recommendation 8. Bodyweight Regulation 9. Pre-diabetic/Diabetic Stages 10. Hypothermia and Fever 11. Involuntary Fall and Seizure 12. Cholesterol Level 13. Hypertension 14. Dehydration [0036] Specialized, in some cases unique, algorithms may be used to provide the determinations, insights, and predictions. Table 3 lists examples of some of the types of specialized algorithms envisaged. In some embodiments, the “normal” parameter ranges relative to which the wearer's parameters are compared may be customized according to sex, race, weight, height, and/or other characteristics. Data may be analyzed over time and presented in a way that a user can monitor the progress of his/her health status for a given set of parameters. [0000] TABLE 3 SpO2 extraction algorithm Heart rate extraction algorithm Heart rate variability extraction algorithm Blood pressure extraction algorithm Respiratory rate extraction algorithm Blood glucose level extraction algorithm Desaturation index computation algorithm Cardiac index computation algorithm Apnea Hypopnea index computation algorithm [0037] As indicated by step 266 in FIG. 2 , the processed parameter data, trend data and clinical insights data (or some subset of such data) may be sent from the cloud directly or indirectly to a physician at a medical facility authorized by the subject to receive them. Upon reviewing the data, the physician may provide advice, guidance, education, and/or prescriptions to the patient (user). Prescriptions from the patient's doctor may then be wirelessly and securely sent via the cloud to a pharmacy pre-selected by the subject as part of his or her personal profile, the profile having been previously created by the subject at a secure website, accessed via the smart-phone or other computing device. Users can also update their profiles directly from a smart-phone. [0038] As indicated by step 268 , some or all of the processed data may be sent from the cloud directly or indirectly to family members of the user, pre-authorized to receive such data. [0039] The user's physician, other selected health professionals, family members, and others, make up a specific user-defined community, authorized to access data provided by the cloud platform relating to that user. [0040] Analytics performed in the cloud can also provide long-term trends for vital parameters and clinical insights to a subject. These long-term trends consist of vital parameters measured over the course of many months or event years that is displayed in a receiver like a smart-phone, a tablet, or a computer. [0041] As indicated by step 272 , the analytics carried out at the cloud may result in suggestions, transmitted back to the user via the smart-phone, for adjusting the sequence and/or frequency of measurements of particular parameters. The system may even request additional measurements of the same or other parameters if the previous measurements deviate from the predefined user specific range. For instance, an elevated temperature can trigger the automatic measurement of blood pressure, ECG, oxygen saturation, etc. [0042] In this way and others discussed above or readily envisaged in the light of this disclosure, the eco-system can be adaptive, responding to current measurement data in the light of past data from the same subject and/or other comparable subjects, whether to appropriately instigate future measurements, inform the subject of trends, or to add to the physician's knowledge base enabling more effective guidance and treatment. ADDITIONAL EXAMPLES AND DETAILS (1) Hardware Embedded Algorithms for Real-Time Vital Signal Processing [0043] Unique mathematical algorithms will process the raw PPG signal generated by the LED/Photo-Diode/AFE SpO2 extraction algorithm Heart rate extraction algorithm Heart rate variability extraction algorithm Blood pressure extraction algorithm Respiratory rate extraction algorithm Blood glucose level extraction algorithm Desaturation index computation algorithm Cardiac index computation algorithm Apnea Hypopnea index computation algorithm (2) Application for Smart Phone, Tablets, Laptop as User Interface, Data and Alerts Display Alert System [0000] The alert system has different severity level visualized by different colors Color green means a specific vital parameter is within the normal range Color yellow means that a specific vital parameter has exceeded the normal bounds but within a critical range Color orange means that a specific vital parameter has exceeded the critical bounds but still below the life-threatening range Color red means a specific vital parameter has exceeded the life-threatening bounds and an emergency call (such as, the 911 call in US) is automatically initiated. [0058] A red alert is automatically issued for any life-threatening situation. In this case, a central monitoring facility first tries to establish a contact with the user, and upon no response, an emergency call (such as the 911 in US) is issued with a message about the location of the patient and the specific body parameter(s) in question. This will ensure the correct paramedic team with the correct equipment arrive at the scene on time and well prepared to save the life of the patient. The red alert is handled in an automatic way to address cases where a patient is unconscious and cannot make an emergency call (such as, 911) or even express him/herself. The user can also issue a red alert if a vital parameter is in a life-threatening range and the system has not yet issued a 911 call. User Interface [0059] User can enter personal information called user profile [0060] User can request instant measurement of specific vital parameter [0061] User can request to view trend data (3) Analytics: Software and Machine Learning Algorithms for Data Pattern and Trend Analysis [0062] The cloud-based analytics platform allows for the secured collection and long-term hosting of all personalized vital parameter data. It allows for The creation of new multi-parameter machine learning algorithms to automatically derive the current state of various physiological vital parameters [002] and related health conditions for an individual user Automatic derivation of deviations from the baseline for each of these parameters Automatic derivation of a long-term trend for each of the vital parameters Automated alerts that go out from the cloud back to the users, family and medical support staff Derivation of gradual changes in baselines only observed over long periods of time Prediction of future health-critical events for an individual user based on her own health data points and a population of health data (from a population bucket of individuals similar to the user in context) annotated with respective health-critical events Special software algorithms developed to use the incoming vital sign data or combination of multiple vital signs data to provide long-term trends and insights for various health conditions. Personalized subject vital sign monitoring: Other embedded algorithms will study a subject body to adjust the sequence or frequency of measurements of vital parameters. This specific data is personalized to a subject's health status. Derivation of secondary health insights (such as body weight, body hydration level) from the primary vital parameters. Creation of a personalized scoring and recommendation of food items based on their impact on various vital parameters. Derivation of functioning status and health of major organs (such as liver, pancreas, and kidney) from the primary vital parameters measured. For liver health, enzyme levels in the blood critical for proper functioning of this organ can be detected, the parameters to track are Aspartate Aminotransferase (AST), Alanine Aminotransferase (ALT), alkaline phosphatase, bilirubin, albumin and total protein. For kidney health, the parameters to track are Blood Urea Nitrogen (BUN), creatinine, estimated glomerular filtration rate, and for the pancreas health, the important parameters are Amylase, Lipase and Calcium. Derivation of various vitamin levels in blood from the primary vital parameters measured. Derivation of blood parameters possibly indicating an elevated risk of presence of some form of cancer cells on the body from primary vital parameters measured. Some specific blood parameters include alkaline phosphatase, Lactate dehydrogenase (LDH), carcinoembryonic antigen (CEA), and prostate-specific antigen (PSA). Derivation of other blood parameters, such as blood albumin level, amount and changes in Flavin, which can be useful in determining changes in different enzymatic levels, blood pH levels and anemic conditions. Changes in lipid levels will be used to show the trend of arterial blockages. (4) Personalized Health Monitoring System Adaptive to Individual Physique and Lifestyle (PHMSYSTEM): [0077] An individual is many ways different physically compared to every other person and also the lifestyle choices of that person over a period of time and the changes thereof reflect on all vital health parameters measured instantaneously and/or over a time period. The apparatus described in this patent when used by an individual, “learns” about the user's unique physique and lifestyle choices over a period of time and adjusts its pattern of measurement of vital parameters. These changes in measurement patterns over time affect the overall operating efficiency of the apparatus (such as battery power consumption and heating). These changes help the apparatus become more adaptive to an individual with the continuous use of it and “blends” into the unique patterns of life of that individual. The enhancement of the quality of life of any given individual is a key outcome of the individual adaptive nature of this system. The apparatus is capable of being set into different operating modes such as an adaptive mode (as described above), a traditional mode where every measurement occurs at certain frequency, and a continuous mode where the apparatus keeps taking measurements on a continuous basis. [0000] (5) Individualized Food and Nutrition with the Help of Adaptive Personal Health Monitoring [0078] Food and nutrition are keys to status of health of an individual. An individually adaptive personalized health monitoring system is at the center of personalization and individualization of nutrition. The proposed apparatus starts to “learn” about the effects of various food items on the measured vital health parameters of an individual as soon as the individual starts to use it. Over a period of time the apparatus acquires adequate “knowledge” of impact of various food items on the individual's overall wellbeing and estimates trend of health based on the eating habit and recommendations on how to improve it. (6) Continuous and Adaptive Health Monitoring as a Service (CAHMaaS) [0079] While most healthy people do not monitor their vital data at all between yearly medical checkups and various medical appointments, those suffering from non-life threatening chronic disease requiring continuous monitoring are not as consistent in doing so as recommended by medical professionals. CAHMaaS® offer the possibility to continuously monitor one's vital data through the use of a wearable device that measures vital data and saves them in a secured cloud server. The collected data are then analyzed through advanced analytics to offer the users real time clinical insights, adapted to the specific conditions of each user through the use of machine learning algorithms. The use of CAHMaaS® requires monthly and/or yearly subscription as well as the ownership of a device providing the required measurements. CAHMaaS® is in the context of Internet-of-life or an embodiment of Internet-of-life. The service based health monitoring system is at the heart of individual adaptiveness of the device to every user's unique physique and lifestyle over a period of time. The individualized adaptive system would help create a tailored ecosystem for individual consumer, the ecosystem might comprise of many things like personal wellness program, customized nutrition etc, the “tailored ecosystem” as one key application as a direct result of CAHMaas. (7) Sensors Central Device at Wrist (PPG) [0080] (1) LED (optical signal transmitter) [0081] (2) Photodiode (optical signal receiver) [0082] (3) Analog Module (signal amplification and A/D conversion) [0083] (4) MicroProcessing Unit (finite state machine, integer/FP units, data path) [0084] (5) Memory [0085] (6) Host Controller Interface (HCI) [0086] (7) Low-power Bluetooth Interface [0087] (8) Three-axis Accelerometer (3D positioning) [0088] (9) Thermistor/Thermopile [0089] (10) Battery and charger unit Remote Device at Chest (ECG) [0000] The chest apparatus collects ECG signals that will be wirelessly sent to the central apparatus for further processing and storage. Remote Device at Earlobe [0000] The earlobe apparatus is used to collect data that gets wirelessly sent to the central apparatus to calibrate other vital signs for better accuracy. Remote Device at Finger Tip [0000] The finger tip apparatus is used to collect data that gets wirelessly sent to the central apparatus to calibrate other vital signs for better accuracy. Remote Device at Leg [0000] The three-axis accelerometer is strapped at the bottom leg part to monitor the leg movements to process a 3-dimentional position of the user that is wirelessly communicated to the central apparatus Remote Device at Forehead [0000] The forehead apparatus is used to collect data that is wirelessly sent to the central apparatus to calibrate other vital signs for better accuracy. [0095] The above-described embodiments should be considered as examples of the present invention, rather than as limiting the scope of the invention. Various modifications of the above-described embodiments of the present invention will become apparent to those skilled in the art from the foregoing description and accompanying drawings.	A power-optimized eco-system for tracking a user's health comprises: one or more wearable remote sensors, each wirelessly communicating only with one wearable central sensor; a portable device readily accessible to the user; and a cloud platform. Each sensor is configured to measure data indicative of one or more physiological parameters. The central sensor is configured to receive and subsequently process data measured by each remote sensor, to process data measured by the central sensor, and to generate corresponding instructions. The portable device comprises: a receiver wirelessly receiving the processed data and instructions from the central sensor; a processor running a mobile application handling the processed data and instructions; and a transmitter. The cloud platform is configured to: receive the processed data from the transmitter; analyze the received processed data; and transmit the results of the analysis to at least one of the portable device and an authorized healthcare entity.	0
CROSS-REFERENCE TO RELATED APPLICATIONS [0001] This application is a continuation in part of, and claims priority to, Utility patent Ser. No. 13/451,852 filed Apr. 20, 2012 which claims priority to U.S. Provisional Patent Application No. 61/541,943 filed Sep. 30, 2011, all of which are incorporated by reference herein in their entirety. STATEMENT OF GOVERNMENT INTEREST [0002] The U.S. Government claims certain rights in this invention pursuant to Contract No. DE-AC02-06CH11357 between the U.S. Department of Energy and UChicago Argonne, LLC, representing Argonne National Laboratory. FIELD OF THE INVENTION [0003] The present invention relates generally to thin film electrocatalysts and more particularly relates to thin film electrocatalysts having tunable compositions and controllable surface phases and crystalline morphology for improved catalytic performance. BACKGROUND OF THE INVENTION [0004] This section is intended to provide a background or content to the invention that is recited in the claims. This description herein may include concepts that could be pursued, but are not necessarily ones that have been previously conceived or pursued. Therefore, unless otherwise indicated herein, the concepts described in this section are not prior art to the description and claims in this application and are not admitted to be prior art by inclusion in this section. [0005] Over the past decades, extensive research has been devoted to the development of technologies that can effectively convert energy and become economically viable for use by the general public. Great expectations are held for technologies such as fuel cells and lithium—air batteries that rely on electrochemical processes. In both cases, satisfactory energy density can be attained; however, a major challenge lies in the insufficient activity and durability of the materials that are employed at present as cathode catalysts for electrochemical reduction of oxygen. These limitations inevitably lead to a lower operating efficiency of the devices, which highlights the need for the development of more active and durable oxygen reduction reaction (hereinafter “ORR”) catalysts. In the case of fuel cells, most of the research centers on platinum, the best monometallic catalyst for the ORR. At the present state of development, an approximately fivefold reduction in Pt content is necessary to meet cost requirements for large-scale automotive applications. Pt-based alloys have already made an impact in fuel-cell catalyst design by decreasing the amount of platinum while improving activity and durability, which places these materials at the focus of intensive fundamental and applied research on both extended (bulk)' and nanoscale systems. The main challenge in that effort is linked to the possibility of achieving the unique structural and compositional profile of Pt 3 Ni(111) alloys, which was established from single-crystal studies. This profile was obtained on extended surfaces by thermal annealing that facilitates thermodynamically driven segregation of Pt to form a pure ordered surface layer, denoted as Pt(111)-skin. The electronic structure of Pt(111)-skin is altered by the subsurface layer of PtNi (in 1:1 ratio) and is responsible for the extreme ORR activity, which is nearly two orders of magnitude higher than the state-of-the-art Pt/C catalyst. Consequently, the ability to mimic the compositional profile and structure of Pt-skin in high-surface-area catalysts would bring unprecedented benefits to technologies that rely on the ORR. However, despite numerous attempts, this goal has not been achieved yet for practical catalysts. SUMMARY OF THE INVENTION [0006] Various aspects of the invention are directed to compositions and methods for preparing platinum-based alloys to provide mesostructured thin films as electrocatalysts. These compositions represent an improved class of materials based on mesostructured multimetallic thin films with adjustable structure and composition, which have been tailored to emulate the distinctive properties of a Pt(111)-skin, to be employed in electrochemical devices and other applications. These catalysts can bridge the world of extended surfaces with superior activity and nanoscale systems with high specific surface area in order to harvest maximal utilization of precious metals such as, but not limited to, Pt based alloys. These principals can be applied to other such Pt group metal systems, like Pd and Rh. Such synergy is foreseen to be present at the mesoscale, which implies not only a specific length scale, but rather a principle of operating in between different physical regimes that exhibit distinct functional behaviour. In particular, for electrocatalytic materials, most previous work has emphasized either achievement of high surface area through small particle size, or the attainment of a better understanding of fundamental properties through the use of extended surfaces. From such studies, it is well known that there are substantial differences in catalytic properties between nanoscale and bulk materials. The benefits of targeting mesoscale architectures between these extremes have not been adequately explored, especially in the sense of transferring superior characteristics from extended surfaces to practical materials. In view of that, instead of using discrete nanoparticles (3-5 nm) supported on high-surface-area carbon, continuous Pt and Pt-alloy nanostructured thin films (hereinafter “NSTF”) were most preferably disposed over an oriented array of molecular solid whiskers by physical vapor deposition. Specifically, planar magnetron sputter deposition was most preferably used to deposit thin metal films with a wide range in composition. Such NSTF catalysts provide good surface area utilization and eliminate issues related to carbon-support corrosion and contact resistance at the carbon/metal interface that would lead to poor utilization and degradation of the catalyst. In a most preferred embodiment, the capability to control the deposition rate, as well as the combination and order of constituents, makes sputter deposition an effective tool to form thin films with desirable thickness, composition profile and surface roughness. A thorough examination of thin-film properties was performed on extended, flat, non-crystalline and chemically inert substrates such as a mirror-polished glassy carbon surface. These methods enable an extra level of control in terms of defined geometric surface area and surface roughness factor that is unattainable in the case of nanoscale substrates. [0007] These and other features of the invention, together with the organization and manner of operation thereof, will become apparent from the following detailed description when taken in conjunction with the accompanying drawings, wherein like elements have like numerals throughout the several drawings described hereinbelow. BRIEF DESCRIPTION OF THE DRAWINGS [0008] FIG. 1 a illustrates cyclic voltammograms (hereinafter “CV”) and STM images of Pt 20 nm thin layers as deposited and (111) films deposited on a glossy carbon substrate; FIG. 1 b illustrates CV and STM images of annealed Pt film and Pt(111); FIG. 1 c shows a CV profile of as deposited PtNi (“b”) film, annealed PtNi film (“r”) and Pt 3 Ni (111) skin and FIG. 1 d shows specific activities measured by RDE in 0.1M HClO 4 with 1600 rpm, 20 mVs −1 at 0.95V with corresponding improvement factors versus polycrystalline Pt; [0009] FIG. 2 a ( 1 ) illustrates schematically a starting substrate, FIG. 2 a ( 2 ) shows a schematic of physical vapor deposition, FIG. 2 a ( 3 ) shows a resulting HSREM snapshot (corresponding to FIG. 2 a ( 2 )) of a group of whiskers including length, shape and alignment after deposition of the thin films and FIG. 2 a ( 4 ) shows a schematic corresponding to FIG. 2 a ( 3 ); FIG. 2 b shows an HRSEM image close-up of an intentionally broken single whisker demonstrating thickness of the metallic film over a perylene red substrate; FIG. 2 c shows an HRTEM close-up of a single whisker side showing whiskerette (sub-whiskers on each whisker) growth along the whisker; FIG. 2 d shows on HRTEM image close-up of a whisker surface with a close packed formation of whiskerette tips of 5 nm diameter which provides a highly corrugated morphology; and FIG. 2 e shows a TEM micrograph of a whisker side that confirms grain texture of the sputtered thin film and shows representative diameters of the whiskerettes; [0010] FIG. 3 a ( 1 ) shows a side schematic view and HRSEM image of whiskers of a nanostructure thin film at the beginning of an anneal cycle; FIG. 3 a ( 2 ) shows an HRTEM low magnification image of one of the whiskers before annealing and FIG. 3 a ( 3 ) shows that same image but at higher magnification; FIG. 3 b ( 1 ) shows a side schematic view and an HRSEM image of whiskers after annealing at 400° C. has started and showing surface modification and evaporation, FIG. 3 b ( 2 ) shows an HRTEM low magnification image of one of the whiskers after annealing has started and FIG. 3 b ( 3 ) shows a higher magnification view of FIG. 3 b ( 2 ) showing flattening and smoothing of the surface morphology; and FIG. 3 c ( 1 ) shows after annealing has completed for a side schematic view and HRSEM image of whiskers to form mesostructured thin films on the whiskers; FIG. 3 c ( 2 ) shows an HRTEM low magnification image of one of the whiskers after annealing with clearly observable grain morphology and a smoother/flatter surface texture; and FIG. 3 c ( 3 ) shows a higher magnification HRTEM image of FIG. 3 c ( 2 ); [0011] FIG. 4 a shows CV plots for Pt-NSTF, PtNi-NSTF and PtNi-Meso-TF; FIG. 4 b shows ORR polarized curves for the materials of FIG. 4 a ; FIG. 4 c shows corresponding Tafel plots for two materials wherein Tafel slopes are determined at potentials higher than half-wave potential (E 1/2 : potential and which l=1/2 l diff ) to avoid diffusion and solution resistance induced errors; and FIG. 4 d shows specific activities measured at 0.95V and an improvement factor versus Pt-poly (and Pt-NTSF); and [0012] FIG. 5 illustrates an activity map for ORR obtained for different classes of Pt-based materials with improvement factors given on the basis of activities compared with values for polycrystalline Pt and state of art Pt/C catalyst systems established by RDS measurements in 0.1 MHClO 4 at 0.95V. DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS [0013] In a preferred method of the invention, various Pt based materials were processed to provide a mesostructured thin film. In a first step, a deposition was performed of a pure Pt thin film onto an ultrahigh-vacuum-cleaned glassy carbon substrate, which was followed by thermal annealing in a reductive atmosphere. The details of several examples of preferred methods of processing and analyzing are provided hereinafter in the Examples section. The morphology of the Pt film was validated by scanning tunneling microscopy (STM) as shown in FIGS. 1 a and 1 b . The difference between as-deposited versus annealed Pt films indicates a substantial change in the thin-film surface morphology due to rearrangement of the Pt topmost atoms towards the (111) structure with a minimum surface energy. The as-deposited Pt film has a corrugated nanostructured three-dimensional surface morphology with an average grain size of ˜5 nm, whereas the morphology of the annealed thin film has been transformed into a smooth two-dimensional surface with large 20×100 nm hexagonal (111) facets. In accordance with the STM results, the characteristic surface features are also confirmed by electrochemical cyclic voltammetry (CV). FIG. 1 a reveals that the CV profile of the as-deposited thin-film surface matches the one established for bulk polycrystalline Pt. On the other hand, FIG. 1 b shows that the CV profile of the annealed Pt thin film underwent extensive transformation from typical polycrystalline into Pt(111)-like with characteristic fingerprint features between 0.5 and 0.9 V; the so-called butterfly region that corresponds to adsorption/desorption processes of 0H ad on Pt(111) facets. Therefore, it is evident from both STM and CV that the annealed, extended thin film consists of predominantly (111) facets encompassing the entire surface. In fact, the degree of resemblance in electrochemical signature between the annealed thin-film surface and single-crystal Pt confirms that the (111) facets are both large and interconnected. The synergy between the surface structure, domain size and functionality establishes that the thin-film surface has a distinct mesostructured morphology. These findings clearly demonstrate the feasibility of controlling surface ordering of extended Pt based thin films deposited over a non-crystalline substrate, that is, without the use of templates for epitaxial growth. Instead of building the crystal lattice from a seed or underlying crystalline substrate, individual randomly oriented nanoscale grains coalesce and form large well-ordered (111) facets. These features greatly expand the potential for utilization of thin-film materials and enables particular types of thermal annealing in a controlled atmosphere as a useful tool in the fine tuning of a thin film's structure and hence electrocatalytic properties. [0014] In the following described preferred preparation steps a bimetallic PtNi thin film is prepared with the same thickness to mimic the composition profile of the Pt 3 Ni(111) single crystal system and to replicate its catalytic properties. The results from the electrochemical measurements in FIGS. 1 c and 1 d confirm that as for monometallic Pt, the polycrystalline nature of the as-deposited alloy thin film is predominantly transformed into a Pt(111)-skin-like surface. This is clear from both the CV profile of the annealed alloy thin film that substantially resembles the one obtained on Pt 3 Ni(111) and results in superior catalytic activity for the ORR, which was up to now obtained exclusively on the Pt 3 Ni(111)-skin surface. The combination of the Pt(111)-skin like voltammetry and the marked increase in the ORR activity proves that surface ordering from randomly oriented towards (111) is indeed feasible for bimetallic thin films. This also demonstrates that the catalytic improvement follows the same basic mechanism as previously reported for Pt-bimetallic single-crystal surfaces; that is, electronic modification of the topmost Pt layer leads to greatly improved catalytic enhancement solely for the (111) type of orientation. Therefore, the ORR-specific activity, which equals about 70% of the value established for the most active catalyst, Pt 3 Ni(111)-skin, serves as an indicator that (111)-skin facets are dominating on the annealed thin-film surface. Together this demonstrates the advantageous features of controlled annealing in facilitating the formation of the mesostructured Pt based alloy thin film morphology, characterized by both an energetically more favorable surface state rich in (111) facets, and a desired compositional profile. [0015] These results indicate the substantial advantages towards achieving mesostructured corresponding thin-film-based high-surface-area materials from the Pt group metals having greatly improved catalytic properties. In one illustrative example of a preferred embodiment, Pt-alloy NSTF catalyst is deposited by magnetron sputtering over an array of molecular solid whiskers, composed of an organic pigment N, N-di(3,5-xylyl)perylene-3,4:9,10 bis(dicarboximide); hereinafter denoted as perylene red. FIGS. 2 a ( 1 )- 2 e illustrate a step-by-step deposition process and analytical results for the thin metal films deposited and processed onto a perylene red support. Also shown are high-resolution scanning electron microscopy (HRSEM) and transmission electron microscopy (TEM) micrographs of the NSTF whiskers. These images reveal insight into critical parameters of the NSTF such as metallic film thickness, length, shape and surface morphology. A single whisker measures on average about 800 nm in length, and the film thickness is about 5-20 nm. In FIGS. 2 c - 2 e, the sides of a single whisker are quite clearly shown, smaller metal alloy whiskerettes are formed on each of the whiskers and have a diameter of ˜5 nm ( FIG. 2 c ), and a close-up of a broken whisker ( FIG. 2 e ) illustrates the metallic film/shell that surrounds the perylene red substrate. Surface-specific HRSEM in FIGS. 2 b - 2 e shows that the side walls along the whisker have a very rough surface morphology, consisting mainly of whiskerette tips bonded closely to each other to produce densely packed corncob-like features, providing the validity of terming this material a NSTF. It is important to note that the highly grained texture of the NSTF side walls made of closely packed whiskerettes is also confirmed in the TEM micrograph in FIG. 2 e . Such structural parameters and morphologies greatly affect the functional properties of the NSTF, and therefore the ability to control and tune them along with the near-surface compositional profile can lead towards a substantial gain in catalytic performance. [0016] In the following description a preferred methodology is combined with the knowledge related to highly active well-defined single crystalline and extended thin-film surfaces to develop mesostructured thin-film electrocatalysts with advanced properties. In situ HRSEM and TEM are simultaneously employed during NSTF annealing in a controlled atmosphere. This allows us to visualize real-time structural changes at and near the atomic level and to follow rearrangements of the surface and sub-surface morphology of thin-film materials. This insight is invaluable in the fine-tuning of the materials' properties. FIGS. 3 a ( 1 )- 3 c ( 3 ) show in situ results obtained during thermal annealing of a single PtNi-NSTF whisker. The NSTF catalyst is mounted onto the HRTEM heating stage and is introduced to a reductive atmosphere of argon and hydrogen gases. As the specimen is initially heated, no change in surface morphology is observed as depicted in FIG. 3 a ( 1 )- 3 a ( 3 ). These images show the initial stage and a close-up of the grained highly corrugated whisker side wall and its surface. Once the temperature reaches about 300° C., real-time restructuring occurs for the thin film's morphology. FIGS. 3 b ( 1 )- 3 b ( 3 ) capture the onset of the surface transformation, which appears as a smoothening of the near-surface regions. The steady-state structure is achieved after only about 30 minutes and is shown in FIGS. 3 c ( 1 )- 3 c ( 3 ). These images illustrate that the densely packed organization with the initial three-dimensional surface morphology is being rapidly transformed into a more homogeneous, flat and ordered two-dimensional thin-film material with clearly observable crystalline morphological features present in its exterior surface walls. This thermodynamically driven transition releases stress and strain of the as-deposited thin film and leads towards a state with minimum surface energy without compromising the overall shape and dimension of the whisker. As for Pt thin films on glassy carbon, the initial nanostructured surface morphology that originated from the closely bonded whiskerettes' tips is transformed into a smooth continuous film with large crystalline domains (about 20-40 nm). Specifically, randomly oriented nanoscale grains coalesce and give rise to a mesostructured thin film with unique physicochemical properties; therefore, the materials after this treatment will be referred to as mesostructured thin films (Meso-TF). Close inspection of the HRTEM micrographs of FIGS. 3 c ( 2 ) and 3 c ( 3 ), after applied thermal treatment, confirms that emerged facets have a (111) structure and prevail on the surface whereas under coordinated sites are diminished, which also has important implications towards improved stability. As a side effect, the perylene red substrate is removed during this procedure. In addition to HRTEM/SEM studies, X-ray diffraction measurements, which show enhanced alloying and an increase in the number of (111)-oriented domains on the Meso-TF, are presented in the Supplementary Information. [0017] The final step in the characterization is to obtain the electrochemical signature and compare adsorption and catalytic properties between different classes of thin-film materials and the state-of-the-art Pt/C catalyst by rotating-disc electrode (RDE) (see Example I). As expected, from the CV profile depicted in FIGS. 4 a - 4 d the smooth morphology of the Meso-TF slightly lowers the electrochemically active surface area (ECSA), from ˜11 m 2 g −1 for the NSTF to ˜9 m 2 g Pt −1 for the Meso-TF. This implies that most of the inner portion of the whiskers, which has been vacated by the perylene red, is not electrochemically active, presumably owing to lack of penetration of the electrolyte into the hollow of the whisker (see closed whisker ends in FIGS. 3 a ( 1 ) to 3 a ( 3 )). As shown in FIG. 4 a , the CV profile of PtNi NSTF whiskers exhibits similar behaviour to monometallic Pt NSTF with clearly visible polycrystalline Pt features due to the adsorption—desorption processes of underpotentially deposited hydrogen (H upd ). However, the H up region of PtNi Meso-TF is significantly different with a characteristic flat plateau (see FIG. 4 a ), which confirms that the surface has a relatively large contribution of (111) facets compared with the highly corrugated sputtered thin film that is rich in low-coordinated Pt sites. This is also in good agreement with HRTEM and X-ray diffraction results. Moreover, the onset of surface oxide formation is shifted positively in the following order: Pt-NSTF<PtNi-NSTF<PtNi Meso-TF. Accordingly, the ORR polarization curves, shown in FIG. 4 b , follow the same trend in activity. FIGS. 4 c and 4 d summarize the kinetic current densities (specific activities per ECSA of Pt) as Tafel plots and a bar graph, respectively. Specific activity is a fundamental property of a material that reflects its intrinsic catalytic performance, as opposed to mass activity, which emphasizes the optimized dispersion of a material. Consequently, the focus has been placed on boosting specific activity. This approach leads to a higher turnover frequency (the measure of activity per active site), which should result in better utilization of Pt, culminating in higher mass activity. Considering the large increase in specific activity, values are measured at 0.95 V to avoid diffusion-induced errors in kinetic current densities. The order of specific activity becomes apparent, with Pt/C being the least active, followed by Pt-NSTF and polycrystalline Pt. One can observe a significant increase in activity for PtNi Meso-TF, accompanied by a decrease in Tafel slope from ˜70 mV dec −1 for monometallic Pt to ˜ 40 mV dec −1 . This value is considerably lower than those commonly reported for Pt-based catalysts in the literature, but it is in line with the value obtained on Pt 3 Ni( )-skin′ The activity of PtNi Meso-TF exhibits an improvement factor of over 8 versus Pt-poly and Pt-NSTF. Furthermore, when compared with the state-of-the-art conventional Pt/C catalyst, the specific activity of the PtNi Meso-TF achieves an unprecedented 20-fold enhancement. The measured improvement expressed in A/mgp, corresponds to a mass activity that is already three times higher than the US Department of Energy technical target t 2 . Together, the flat voltammetric curves, the trend in specific activity, the low Tafel slope and the structural characterizations indicate that the annealed PtNi Meso-TF has a Pt-skin-type near-surface structure. [0018] As shown in FIG. 5 , the findings on thin-film-based mesostructured catalysts are merged into the same chart with nanoscale systems and bulk materials. In FIG. 5 , the ORR activity map is shown for different classes of Pt alloys, that is, from nanoparticles dispersed on high-surface-area carbon, to polycrystalline bulk materials and to single-crystalline alloys of Pt 3 Ni(hkl) surfaces'. This map shows a huge span in intrinsic specific activities among materials of the same bulk elemental composition that differ in form and surface structure. It also demonstrates the importance of controlling fundamental properties that determine catalytic performance. Specifically, the ability to alter physical parameters such as particle size, near-surface composition profile, morphology and surface structure can lead to substantial improvements in functional properties of real commercial catalysts. Notably, a number of NSTF catalysts with different compositions are summarized in FIG. 5 ; however, for the sake of brevity investigated only the results for the PtNi are shown in detail; but it is understood that the principals described herein can be applied to Pt group based alloys (such as Pd and Rh) combined with transition metals M, which are known to form desired alloys readily with Pt group metals. The activity values are thus given for exemplary Pt alloys with different example transition metals associated with the atomic number (Z). The main features in FIG. 5 are designated activity regions for different classes of materials. Metallic nanoparticles of Pt and Pt alloys dispersed on a high-surface-area carbon support exhibit profoundly lower activities compared with their polycrystalline bulk counterparts. The assigned region that reflects the activity range of metallic nanoparticles is based on the literature data reported for Pt-alloys obtained by conventional impregnation methods. The next level in activity is reserved for extended bulk polycrystalline systems, where the specific activity of Pt 3 M-alloys can be improved by a factor of three versus Pt-poly. As mentioned above, the capability to control the surface structure leads to an extra boost in activity, and hence the highest ORR activity ever measured was obtained for the Pt 3 Ni(111)-skin surface. [0019] On the basis of the values depicted in FIG. 5 , the NSTF catalysts can successfully mimic the catalytic behaviour of polycrystalline bulk materials, while Pt-alloy mesostructured thin films exceed the range designated for polycrystalline systems. This is the first practical catalyst alloy system and preparation method which can approach the levels of activity previously reserved only for bulk single-crystalline surfaces, owing to the formation of a surface and near-surface structure similar to that of the ideal Pt,Ni(111)-skin. These bimetallic Meso-TF materials preserve sufficiently high specific surface area, which enables better utilization of precious metals. Moreover, Pt-based catalysts with mesoscale features also avoid the activity losses that are caused by the higher fraction of low-coordinated surface atoms that are present in nanoscale catalysts. Consequently, thin-film electrocatalysts are hampered neither by the stability issues that accompany the use of high-surface-area carbon support, nor by the loss of active surface area due to particle agglomeration. The mesostructured thin films, therefore, unite the beneficial properties of both the nanoscale and the extended bulk systems, and lead to new design rules for producing highly active and durable electrocatalysts. These compositions and methods provide the ability to tailor the composition, morphology and structure of the thin-film-based Pt group metals at the mesoscale which allows the harvesting of maximal performance from the employed constituents. [0020] The compositions and methods are a new class of mesostructured catalysts based on thin films with an adjustable composition profile and surface morphology. These materials are in the form of metallic thin Pt group metal films with properties that have been tailored to improve the activity for the ORR. The obtained ORR activity is the highest ever measured on non-bulk catalysts owing to the beneficial near-surface compositional profile and its highly crystalline surface morphology. The exceptional properties of this Meso-TF are comparable to extended single-crystalline surfaces and improvement factors in kinetic activity of 8 versus polycrystalline Pt and 20 versus Pt/C are observed. The substantial advances in catalytic performance are obtained through structural mesoscale ordering of the thin film induced by thermal annealing in a reductive atmosphere. The approach as developed can be applied to generate a wide range of (electro)catalysts with tailored structure/composition, ultralow precious metal content and superior functional properties such as activity and durability. [0021] The following non-limiting examples illustrates various aspects of the composition and methods of the invention. EXAMPLE I [0022] Thin metal films were deposited by planar magnetron sputter deposition on the ultrahigh-vacuum-cleaned surface of a mirror-polished glassy carbon substrate of 6 mm in diameter (base vacuum 1×10 −10 torr). The deposition rate was set to 0.3 A by a quartz-crystal microbalance and an exposure of 7 s was calibrated for the nominal thickness of 2.2˜2.3 A for a monolayer of Pt. The film thickness was derived from the exposure time of computer-controlled shutters during deposition. The thickness of all thin films in this example was 20 nm. In the case of NSTF catalysts, consecutive layers of platinum and the transition metal, M, of choice were deposited onto the NSTF layer of oriented organic pigment (perylene red). Whiskers were also deposited by planar magnetron sputter deposition in vacuum. The deposition process covered each of the perylene red whiskers with a thin metallic film. Both the monometallic Pt and the Pt-alloy catalyst were obtained by this method. The Meso-TF were obtained by thermal annealing of NSTF at about 400° C. in a hydrogen-rich atmosphere. The temperature was increased in increments of 20° C. per 5 minutes, and the whole process lasted about 2 h. EXAMPLE II [0023] An Autolab PGSTAT 30 with FI20, ECD, ADC and SCAN GEN modules was used for electrochemical measurements. Perchloric acid diluted with MilliQ water to 0.1 M was the electrolyte in all cases. The gases used were research grade (5N5+) argon and oxygen. In all experiments, a silver-silver chloride was the reference electrode. However, all potentials referred to in this paper are converted to the pH-independent reversible hydrogen electrode scale. All experiments were repeated 8 times to confirm reproducibility, and to improve the accuracy in the determination of kinetic activities. Kinetic current densities were obtained from the measured ORR polarization curves in accordance with the Koutecky-Levich equation: [0000] I ORR −1 I kinetic −1 +I diffustion −1 [0000] The ECSA of the nanocatalysts was determined by integrating both the H 85 part of the CV profile, and the polarization curve obtained by oxidation of a monolayer of adsorbed carbon monoxide to avoid underestimation of the surface area due to altered hydrogen adsorption properties. All catalysts were deposited on a RDE made of glassy carbon, and the loading of the nanoscale thin-film catalysts was adjusted to be 60 μg, cm disc −2 , whereas the loading for Pt/C obtained from TKK was 12 μg Pt cm. Kinetic current densities as reported are normalized by ECSA in all cases. EXAMPLE III [0024] A Hitachi H-9500 environmental transmission electron microscope operated at 300 kV was used to perform the microstructural characterization and in situ heating TEM study. Powder samples were attached to the heating zone of a Hitachi gas-injection-heating holder. Images of nanoparticles were first recorded at room temperature, followed by heating of the specimen inside the microscope chamber with a vacuum level of about 10 −4 Pa. A CCD (charged-coupled device) camera was used to monitor the microstructural evolution and record images and videos. Each heating temperature was held for at least 10 mM for detailed structural characterization, including morphology and atomic structure. A Hitachi SU70 high-resolution field-emission SEM was used for routine nanoparticle sample inspection. For the detailed surface morphology study at the nanometre scale, a Hitachi S-5500 ultrahigh-resolution cold field-emission SEM delivered a much higher resolution power (0.4 nm secondary electron image resolution at 30 kV) than normal SEM because of the specially designed objective lens. On both SU70 and S-5500, secondary electron images were taken at 15 kV or 30 kV to reveal the surface morphology of both the as-deposited, as well as the annealed nanoparticles. [0025] The foregoing description of embodiments of the present invention have been presented for purposes of illustration and description. It is not intended to be exhaustive or to limit the present invention to the precise form disclosed, and modifications and variations are possible in light of the above teachings or may be acquired from practice of the present invention. The embodiments were chosen and described in order to explain the principles of the present invention and its practical application to enable one skilled in the art to utilize the present invention in various embodiments, and with various modifications, as are suited to the particular use contemplated.	A composition of matter and method of manufacturing as thin film electrocatalyst. The method uses physical vapor deposition to deposit a thin film of PtM (Ma transition metal) to form a Pt based alloy and annealing the thin film to achieve a (111) hexagonal faceted grain structure having catalytic activity approaching Pt 3 Ni (111) skin.	7
BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to systems for generating tension in the endless track of a tracked work machine. 2. Description of Related Art Tracked work machines are a staple in the military, construction, agriculture, mining, lumber, and other heavy industries. Tracked work machines range in shape and size from tanks and bulldozers to backhoes, mobile cranes, snowmobiles, and robots. These machines are prized for their superior maneuverability over rough terrain, enabled primarily by their tracked means of movement. Such work machines generally comprise a main frame or chassis, an engine or motor, a drive mechanism, and a tension management system. The frame or chassis is the main frame of the machine, upon which the other components are directly or indirectly mounted. For example, the engine or motor is mounted to the main frame. The drive mechanism comprises a drive mechanism frame coupled to the main frame, a drive wheel, an endless track, and a set of rollers or wheels. Two drive mechanisms are typically employed in a tracked work machine, one on each side of the machine. The drive wheel is driven by the engine or motor. The drive wheel is in operative communication with an endless track. Further, the rollers or wheels are distributed along the drive mechanism frame over which the endless track passes. The rollers and drive wheel are distributed to define the path for the endless track to follow. The engine or motor generates rotation of the drive wheel, which in turn results in complimentary rotation of the endless track. Maintaining proper tension of the endless track is necessary for the proper operation of the work machine. If the tension is too low the endless track may buckle, slip off the drive wheel and rollers, jump between teeth on a sprocket drive wheel or roller, or not generate enough friction with the drive wheel to allow for rotation. Alternatively, if the tension is too high, premature wear may occur in components of the drive mechanism. It is also important for the tension to be readily adjustable to prevent damage caused by debris passing between the endless track, and drive wheels, and rollers. Proper tension is also necessary for maintaining balance and stability during uphill or downhill movement, and during digging or other operations. The tension management system of the tracked work machine maintains tension in the endless track of the drive mechanism. The tension management system comprises an idler wheel, a biasing element, and intermediary components for translating force from the biasing element to the idler wheel. The idler wheel is coupled to the drive mechanism frame in a manner that enables its position to be adjusted, which provides regulation for the tension in the endless track. The idler wheel is coupled to the biasing element, which generates force and adjusts the idler wheel's position. The biasing element presses the idler wheel against the endless track to increase tension in the endless track. The biasing element also actively or passively enables the idler wheel to ease away from the endless track to reduce tension in the track. The large size and heavy loads of work machines require relatively high tension in the endless tracks. The connection between the biasing element and the idler wheel of the tension management system in conventional tension management systems is directly linear. FIG. 1 illustrates such conventional systems wherein a biasing element 10 is directly connected to a swing link 20 . The force from the biasing element is translated in a linear manner. Examples of such arrangements of the idler wheel and biasing element in the prior art can be found in U.S. Pat. No. 7,172,257 to Tamaru et al. and U.S. Pat. No. 5,851,058 to Humbek et al. The biasing element in such conventional work machines is often a hydraulic or pneumatic pump or a set of powerful springs. Such elements are expensive and prone to frequent damage, necessitating repair or replacement due to the extreme forces being generated. Until now, there has existed a need for a tension management system that can maintain proper tension in an endless track using a lightweight, less expensive biasing element than currently known. It is to such a tension management system that the present invention is primarily directed. BRIEF SUMMARY OF THE INVENTION The present invention is a tension management system for the endless track of a work machine. The exemplary embodiments of the present invention provide a tension management system for an endless track of a work machine, wherein the required tension is regulated with a smaller force produced by the biasing element than in conventional systems by employing the mechanical advantage of a pivotal bracket linking the idler wheel and biasing element. An exemplary embodiment of a tension management system according to the present invention comprises an idler wheel, a swing link, an idler arm, a pivotal bracket, a biasing element, and a biasing arm. The components of the tensions management system are coupled to the drive mechanism frame. The biasing element generates force, which moves the biasing arm. The biasing arm is connected to the pivotal bracket. Movement of the biasing arm causes the pivotal bracket to pivot about its connection to the drive mechanism frame. The pivoting of the pivotal bracket translates the force from the biasing element into movement of the idler arm. The idler arm is mounted on the swing link. The swing link is pivotally connected to the drive mechanism frame. As the idler arm moves, it causes the swing link to pivot about its connection to the drive mechanism frame in a direction away from the biasing element. As the swing link pivots, the idler wheel presses against and exerts force on the endless track, generating tension. Conversely, the swing link may pivot toward the biasing element, causing the idler wheel to ease off the track, lessening the tension. In a further aspect of the invention, in the normal working position shown, the distance between the connection point of the pivotal bracket to the drive mechanism frame and connection point of the pivotal bracket to the biasing arm is greater than the distance between the connection point of the pivotal bracket to the drive mechanism frame and connection point of the pivotal bracket to the idler arm. Thus, the biasing arm has a greater moment arm than the idler arm about the connection of the pivotal bracket to the drive mechanism frame. As a result, force generated by the biasing element and exerted upon the pivotal bracket translates into a greater force in the idler arm. This allows for a greater force to be exerted on the swing link than is generated by the biasing element. In a further aspect of the invention, the biasing element may be an air spring. In conventional work machines, an air spring is not capable of generating sufficient force to produce the required tension in the endless track. However, the mechanical advantage of the different moment arms of the present invention's biasing arm and idler arm enable a greater force to be exerted against the swing link than is generated by the biasing element. This enables the use of biasing elements such as an air spring, which previously would not have been available due to their limited force generation capacity. These and other features as well as advantages, which characterize various exemplary embodiments of the present invention, will be apparent from a reading of the following detailed description and a review of the associated drawings. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 illustrates the prior art tension management system employed by tracked work machines. FIG. 2 illustrates an exemplary embodiment of a tension management system within a drive mechanism of a work machine. FIG. 3 a - c illustrate alternate views of an exemplary embodiment of a pivotal bracket of the tension management system. FIG. 4 illustrates an alternate view of an exemplary embodiment of the tension management system within a drive mechanism of a work machine. DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS The various exemplary embodiments of the present invention provide a tension management system for regulating tension in the endless track of a work machine. An exemplary embodiment of the tension management system includes a pivotal bracket that serves as a lever arm for generating a moment of force that is preferably translated into a force acting upon the idler wheel, to generate tension in the endless track. The pivotal bracket enables a greater force to be exerted on the idler wheel than is generated by the biasing element. An exemplary embodiment of a tension management system comprises an idler wheel, a swing link, an idler arm, a pivotal bracket, a biasing element, and a biasing arm. The biasing element generates force, which moves the biasing arm. The biasing arm is preferably connected to the pivotal bracket. Movement of the biasing arm causes the pivotal bracket to pivot about its connection to the drive mechanism frame. The pivotal bracket is preferably also connected to a swing link by an idler arm. As the pivotal bracket pivots, force is translated from the biasing element to the swing link. The idler wheel is preferably mounted on the swing link. The swing link is preferably pivotally connected to the drive mechanism frame. As the idler arm moves it causes the swing link to pivot about its connection to the drive mechanism frame. As the swing link pivots, the idler wheel exerts force against the endless track, generating tension. FIG. 2 illustrates an exemplary embodiment of the tension management system 200 as employed in cooperation with the drive mechanism 100 of a work machine. The drive mechanism 100 comprises the drive mechanism frame 110 , an endless track 120 , a drive wheel 130 , and rollers 140 . The drive mechanism frame 110 is preferably connected to the main chassis or frame (not shown) of the work machine. Elements of the drive mechanism 100 are either connected to the drive mechanism frame 110 or connected directly to the main chassis or frame. The engine or motor (not shown) of the work machine causes the drive wheel 130 to rotate. The drive wheel 130 is preferably in operative communication with the endless track 120 . Rotation of the drive wheel 130 causes the endless track 120 to rotate around the drive wheel 130 , and rollers 140 . The tension management system 200 comprises a biasing element 210 , a biasing arm 220 , a pivotal bracket 230 , an idler arm 240 , a swing link 250 , and an idler wheel 260 . The biasing element 210 is preferably connected to the frame 110 . The biasing element 210 is a mechanical structure that is capable of generating force that may be translated to another element. It is contemplated that the biasing element 210 could be connected to the frame 110 by telescoping rods. A biasing arm 220 communicates between the biasing element 210 and the pivotal bracket 230 at bracket bias connection 231 . The pivotal bracket 230 is preferably substantially flat and constructed from metal or another suitable material. The pivotal bracket 230 is preferably triangular having a top, bottom, and middle corner or portion. The pivotal bracket 230 is preferably connected to the frame at a bracket frame connection 232 . The idler arm 240 is preferably connected to the pivotal bracket 230 at a bracket idler connection 233 . In other contemplated embodiments, two coplanar pivotal brackets can be employed, and the biasing arm 220 , idler arm 240 , and portion of the drive mechanism frame 110 connected and partially disposed between the two pivotal brackets. The idler arm 240 is preferably also connected to the swing link 250 at an idler arm connection 251 . The swing link 250 preferably comprises a top, middle, and bottom portion. The idler arm connection 251 is preferably located at the top portion of the swing link 250 . The swing link 250 is preferably connected to the frame 110 at a swing frame connection 252 . The swing frame connection 252 is preferably located at the bottom portion of the swing link 250 . The idler wheel 260 is preferably connected to the swing link 250 at a wheel swing connection 253 . Preferably, the idler wheel 260 comprises a bore, and the swing link 250 can comprise a integral pin extending from the swing link 250 into the bore. The wheel swing connection 253 enables the idler wheel 260 to revolve relative to the swing link 250 . In other contemplated embodiments, the swing link 250 can comprise a bore, and the idler wheel 250 comprises an integral pin in communication with the bore. In further embodiments, the swing link 250 and idler wheel 250 can comprise coaxial bores, and a pin may span the two bores to enable rotatable communication. The connections 231 , 232 , 233 , 251 , 252 , and 253 are preferably pivotal or rotatable. Contemplated fastening means employed in connections 231 , 232 , 233 , 251 , 252 , and 253 are a pin, bolt, screw, moveable rivet, or other suitable fastener enabling pivotal communication. Other contemplated connection means include coaxial cylindrical bores in the respective elements and corresponding pins inserted through the bores. In other contemplated embodiments, one element may comprise one of more bores and the other element may comprise one or more integral pins in communication with the bores, enabling pivotal communication. The idler wheel 260 maintains contact with the endless track 120 , and its location relative to the drive mechanism defines the tension in the endless track 120 . Force from the biasing element 210 is preferably translated by the tension management system 200 to the idler wheel 260 . This force presses the idler wheel 260 against the endless track 120 , generating tension. The idler wheel's 260 connection to the swing link 250 enables the position of the idler wheel 260 to be adjusted relative to the components of the drive mechanism 100 as the swing link 250 pivots. The wheel swing connection 253 enables the idler wheel 260 to revolve as the endless track 120 passes over it. As the biasing element 210 generates force, the biasing arm 220 translates toward the pivotal bracket 230 . The movement of the biasing arm 220 exerts a force on the pivotal bracket 230 at the bracket bias connection 231 . This force causes the pivotal bracket 230 to pivot about the bracket frame connection 232 , generating a moment of force. Arrow A in FIG. 4 illustrates the pivoting of the pivotal bracket 230 . As the pivotal bracket 230 pivots, it exerts a force upon the idler arm 240 at the bracket idler connection 233 . The force causes the idler arm 240 to translate toward the swing link 250 . Movement of the idler arm 240 exerts a force on the swing link 250 at the swing link idler arm connection 251 . The force causes the swing link 250 to pivot about the swing frame connection 252 . Arrow B in FIG. 4 illustrates the pivoting of the swing link 250 . As the swing link 250 pivots, it causes the idler wheel 260 to press against and exert force upon the endless track 120 , generating tension. The movements described above are bidirectional. The description above demonstrates the biasing element generating force and translating the force to create tension in the endless track 120 . Should a rock or debris enter between the drive wheel 130 , rollers 140 , or idler wheel 260 , the tension would dramatically increase and damage to the endless track 120 could occur, unless the tension is relieved. To prevent such damage the idler wheel 260 is preferably capable of easing away from the endless track 120 . The swing link 250 , idler arm 240 , pivotal bracket 230 and biasing arm 220 would correspondingly move in the opposite direction from that described above. This movement is possible due to the compressible nature of the biasing element 210 . In the normal working position shown, the force exerted on the swing link 250 is preferably greater than the force generated by the biasing element 210 . The force generated by the biasing element 210 is preferably amplified through the mechanical advantage of the pivotal bracket 230 . The biasing element 210 generates force that is translated by the biasing arm 220 and exerted on the pivotal bracket at bracket bias connection 231 . Because pivotal bracket 230 is preferably pivotally connected to the frame at bracket frame connection 232 , the force exerted at bracket bias connection 231 causes the pivotal bracket 230 to pivot or rotate. This rotation results in moments of force at connections 231 and 233 . The moments of force are a function of the force exerted at the connection multiplied by the moment arm of the connection. Because the system is static, the moments of force are equal. The moment arm at bracket bias connection 231 is equal to the bias frame distance D BF , which is the minimum distance between bracket frame connection 232 and the bias arm central longitudinal axis 280 . D BF is inherently always defined by a line from the bracket frame connection 232 normal to the bias arm central longitudinal axis 280 . Similarly, the moment arm at bracket bias connection 231 is equal to idler frame distance D IF , which is the minimum distance between bracket frame connection 232 and the idler arm central longitudinal axis 290 . D IF is inherently always defined by a line from the bracket frame connection 232 normal to the idler arm central longitudinal axis 290 . Because the bias frame distance D BF is preferably greater than the idler frame distance D IF , the force at bracket bias connection 231 translates to a greater force at bracket idler connection 233 . The ratio of the force at bracket idler connection 233 to the force at bracket bias connection 231 is equal to the ratio of bias frame distance D BF to idler frame distance D IF . The bias frame distance D BF and the idler frame distance D IF both vary as the pivotal bracket 320 pivots. FIG. 3 a illustrates the distances D BF and D IF in a normal working position. FIG. 3 b illustrates the distances D BF and D IF wherein the pivotal bracket 230 has significantly pivoted counterclockwise. As a result, both D BF and D IF have decreased compared to the normal working position. FIG. 3 c illustrates the distances D BF and D IF wherein the pivotal bracket 230 has pivoted clockwise. As a result, D BF has decreased and D IF has increased compared to the normal working position. Since the moment arms of the pivotal bracket 230 change during operation, the mechanical advantage of the pivotal bracket 230 varies correspondingly. Therefore, the ratio of the force at bracket idler connection 233 to the force at bracket bias connection 231 , which equal to D BF /D IF , changes as well during operation. It is clear from FIGS. 3 a - c that while the distances D BF and D IF change, they remain defined by lines from the bracket frame connection 232 normal to the bias arm central longitudinal axis 280 and idler arm central longitudinal axis 290 , respectively. In an exemplary embodiment, the pivotal bracket 230 is preferably triangular in shape. The connections 231 , 232 , and 233 are preferably located at or near the corners of the triangle. In other contemplated embodiments, the pivotal bracket 230 may be a different shape other than a triangle. For example, the pivotal bracket may be circular, oblong, elliptical, rectangular, square, polygonal, or another suitable regular or irregular shape. In the contemplated embodiments, the bias frame distance D BF is preferably also greater than the idler frame distance D IF . In an exemplary embodiment, the components of the drive mechanism 100 and tension management system 200 are preferably metal, such as high tensile steel. Other contemplated embodiments could incorporate components constructed from other metals and alloys such as stainless steel, iron, titanium, glassy metal, amorphous noncrystalline metal, or other suitable materials. In an exemplary embodiment, the biasing element 210 is preferably an air spring. In conventional tension management systems, an air spring would not be capable of generating sufficient force to produce the necessary tension in the endless track. In the various exemplary embodiments of the present invention, the forced generated by the biasing element 210 is preferably magnified by the pivotal bracket 230 . Consequently, a smaller force generated by the biasing element 210 may be sufficient to generate the tension necessary in the endless track 120 . This allows for a smaller biasing element 210 , such as an air spring, to be employed in the tension management system 200 than was possible in conventional designs. A smaller biasing element is advantageous since it is less expensive, lighter, easier to repair, and less prone to damage since it is not subject to large work forces. The air pressure within an air spring can be adjusted to generate a desired spring rate and a corresponding force generated by the air spring. The force generated by the air spring is translated into tension in the endless track as described above. In other contemplated embodiments, the biasing element 210 may be a coiled steel spring, specialty rubber spring, hydraulic cylinder and accumulator combo, electric motor, air cylinder, pneumatic pump, or other element capable of generating force and/or resistance. In a further embodiment of the present invention, shields may be provided around the biasing element 210 to protect it and increase its reliability. In a further embodiment of the present invention, the pivotal bracket may be replaced with a cam mechanism. The embodiments of the present invention are readily ascertainable by one of ordinary skill in the art. Likewise, modifications, substitutions of equivalent parts, and various design choices are also ascertainable. Thus, the following claims are intended to cover the entire scope of the invention as interpreted by a person having ordinary skill in the art and not merely limit the invention to the verbatim incarnation described and illustrated above.	A tension management system for generating tension in an endless track of a tracked work machine. The tension management system comprises a biasing element, an idler wheel, a swing link, an idler arm, and a pivotal bracket linking the biasing element with the idler arm. The biasing element generates force that is translated via the biasing arm to the pivotal bracket. The pivotal bracket provides a mechanical advantage in the translation of the force that enables the force exerted upon the swing link to be greater than the force generated by the biasing element. The idler arm connects the pivotal bracket to the swing link and exerts force on the swing link causing it to pivot. The idler wheel is mounted on the swing link and exerts force, generating tension, in the endless track as the swing link pivots. The tension management system enables a greater force to be exerted on the swing link than is generated by the biasing element, allowing for the use of smaller biasing elements than previously possible in conventional designs.	1
CROSS REFERENCE TO RELATED APPLICATIONS This application is a Continuation application of PCT/IB01/00232 filed Feb. 21, 2001, which claimed priority of European Patent Application No. 00810150.3 filed Feb. 23, 2000, entitled “Method and Knitting Machine for Rectilinear Knitting to Form a Tubular Seamless Knitted Material” which are included in their entirety by reference made hereto. BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for forming a seamless tubular knit on a rectilinear knitting machine comprising two sections for guiding the knitting needles, means of selecting these knitting needles, carriages for displacing the selected knitting needles and members for guiding the knitting yarn, and to a rectilinear knitting machine for implementing this method. 2. Description of the Related Art Conventional rectilinear knitting machines could possibly knit seamless tubular articles, with a few modifications, especially articles formed from two tubular elements joined into a single tubular element, such as a pair of pants. However, they are not able to produce such articles with a sufficiently dense knit to make trouser fabric. Nor do they allow production under economically viable conditions, since the production rate would be so much smaller. Circular machines do not allow either the production of tubular elements side by side, or the production of tubular elements of variable diameters, or else elements which depend on the uniformity of the knit, by varying, for example, the tension of the yarn, the density of the stitches, etc. The aim of the present invention consists in producing a seamless tubular knit on a rectilinear knitting machine, capable of overcoming, at least in part, the aforementioned drawbacks. BRIEF SUMMARY OF THE INVENTION To this end, the object of the present invention is first of all a method of forming a seamless tubular knit on a rectilinear knitting machine of the aforementioned type, as defined by claim 1 . Preferably, this method relates to the formation of two tubular bodies then joined into a single tubular body, making it possible to produce a seamless pair of pants. The subject of this invention is also a knitting machine for implementing the knitting method, as defined in claim 3 , and a pair of pants, boxer shorts or tights obtained by implementing this method. This invention has the advantage of allowing the manufacture of a novel product under favorable economic conditions. A seamless pair of pants or boxer shorts, whatever the size, is in fact an unknown article, given that it is not yet known how to produce it. It should be noted that one of the advantages of the method which is the subject of the invention resides in the fact that the diameter of the tubular part or parts of this article may vary so as to give the latter the desired shape. In fact, as will be realized during the following description, the knitting method according to the invention cannot be implemented on a conventional rectilinear knitting machine, but requires a novel rectilinear machine concept, thus explaining that it is only by imagining a novel knitting concept, radically different from that usually implemented in rectilinear knitting machines, that the invention has been able to see the light of day. Indeed, it was necessary to create a concept making it possible to knit two different knitted webs, one on each section, while continually joining them by a transfer of the knitting yarn from one section to the other, thus allowing the formation of a seamless tubular element. Starting from this principle, it becomes possible to imagine the simultaneous production of two tubular elements side by side, which can then be joined into a single tubular element by selecting the needles separating the two tubular elements. The invention will be better understood on referring to the following description and to the appended drawings which illustrate, schematically and by way of example, two implementational modes of the method which is the subject of the present invention, relating to two embodiments of the machine which is also subject of this invention. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view of a knitting machine according to the first embodiment; FIG. 2 is a view in transverse section along the line II—II of FIG. 1; FIG. 3 is a view in side elevation of FIG. 1; FIG. 4 is a partial view on a larger scale of a detail of FIG. 1; FIG. 5 is a top view of FIG. 1, illustrating only the system for transferring the yarn guides; FIG. 5 a is an enlarged view of a detail of FIG. 5; FIG. 5 b is a perspective view of FIG. 5 a; FIG. 6 is an elevated view of FIG. 5; FIG. 6 a is a view of a detail of FIG. 6; FIG. 6 b is a top view of the detail of FIG. 6 a; FIG. 6 c is an enlarged view of a detail of FIG. 6; FIG. 7 is a partial top view of FIG. 1 showing only the members relating to adjusting the width of the tubular knit; FIG. 7 a is an enlarged view of a detail of FIG. 7; FIG. 8 is a partial top view of a detail of a carriage for controlling the knitting needles, showing a device for displacing this carriage with respect to its drive mechanism; FIG. 9 is a view in side elevation of the knitting machine according to the second embodiment; FIG. 10 is a view along X—X of FIG. 9; FIG. 11 is a top view of FIG. 9; FIG. 12 is a view along XII—XII of FIG. 9; FIG. 13 is a view along XIII—XIII of FIG. 12; FIG. 13 a is a top view of the enlarged portion of FIG. 13; FIG. 14 is a top view of FIG. 13; FIG. 15 is a view similar to FIG. 14 of a second yarn transfer station; FIG. 16 is an enlarged view of a yarn guide; FIG. 17 is a view of a variant of the yarn guide illustrated in FIG. 16 . DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The knitting machine illustrated in FIG. 1 is a rectilinear machine comprising two sections 1 , 2 , which form either two parallel planes or, as illustrated in this FIG. 1, the planes of these sections form an acute angle with each other such that the knitting needles 3 , in their normal knitting travel, do not cross, as illustrated in FIG. 2 . It is stated that only the parts of the machine needed for understanding the invention have been shown. The usual parts of this type of machine, well known to a person skilled in the art and which are not part of the present invention have therefore not been shown. This is especially the case for the knitting needle 3 selection mechanism, and the cam mechanisms for controlling the needles secured to the carriages. A plurality of carriages 4 are placed along the sections 1 , 2 . These carriages 4 are secured to a drive chain or belt 5 . This drive chain 5 forms a closed loop which rotates around two drive disks 6 , mounted so that they can rotate about two respective vertical shafts, one 7 of which is visible in FIG. 1 . The carriages, secured to this drive chain 5 , therefore always advance in the same direction. In the example described, this direction is that of the arrow F, such that these carriages 4 pass successively from one section 1 to the other section 2 and conversely. A guide rail 8 forms a closed loop whose plane is parallel and located above the closed loop, formed by the drive chain 5 . Sliding supports 9 , illustrated in more detail in FIGS. 6 a , 6 b , are engaged with the guide rail 8 and are capable of sliding freely along this rail. A yarn guide 10 is suspended on each sliding support 9 . To this end, the upper end of the yarn guide 10 is terminated by a semicircular catching element 10 c , while the sliding support 9 comprises a longitudinal catching groove 9 a open at its two ends, in order to allow the catching element 10 c to exit via the rear of this longitudinal groove 9 a and to re-enter via the front, with respect to the displacement direction of the sliding support 9 . Each carriage 4 bears a bracket 11 , the horizontal arm 11 a of which extends just under the guide rail 8 . This horizontal arm 11 a forms a slide in which two pushers, an upper pusher 12 and a lower pusher 13 , are mounted so that they can slide, each of these pushers being secured by a peg 12 a , 13 a , respectively. The role of these pushers 12 , 13 is to push the sliding supports 9 and the yarn guides 10 along the guide rail 8 . The upper pusher 12 is terminated by an oblique part 12 b intended to push the yarn guides during the operation of transferring the yarn guides, as will be seen below. The knitting machine further comprises members 14 for transferring the yarn guides 10 from a knitting needle 3 bed associated with one of the sections 1 , 2 to the knitting needle 3 bed associated with the other of these sections 1 , 2 . Each of the transfer members 14 comprises two parts 14 a , 14 b (FIG. 5 a ), together forming a guide groove 16 , each of the two parts being secured to an arm 15 a , 15 b of a suspension member 15 (FIG. 1 ). The exit end of the guide groove 16 is closed by a retractable flap 16 a , retained by a spring 16 b and serving to retain the yarn guide 10 when it is transferred from a knitting needle 3 bed of one of the sections to the knitting needle 3 bed of the other of the sections. The yarn guides 10 comprise, along their stem, a guide portion 10 a , the cross section of which is ovalized to facilitate guiding in the guide groove 16 . The top of this guide portion 10 a comprises a projection 10 b intended to come into contact with the upper face of the transfer member 14 , thus defining the vertical position of the yarn guide 10 . Advantageously, the upper face of the transfer member 14 is in the shape of a cam to lift the yarn guide 10 during the transfer and thus to place it out of the range of the knitting needles 3 and to bring it back to its initial level after the transfer. As can be noticed in FIG. 1, four transfer members 14 are placed along the sections 1 and 2 . The two transfer members 14 placed at the two ends are oriented so that the ends of their guide grooves 16 face inward, that is to say that they face each other. The suspension members 15 of the two other transfer members 14 located between the end members are both secured to a drive member 17 intended to orient them angularly, as will be seen below. As will also be seen in FIGS. 1, 6 and 7 , each of the suspension members 15 is also connected to an adjustment nut 18 a , 18 b , 18 c , 18 d engaged with a threaded rod 19 comprising four portions 19 a , 19 b , 19 c , 19 d , threaded with reverse pitches with respect to each other. One end of this threaded rod 19 is secured to an adjustment member 20 , which may advantageously be a stepper motor. The role of this adjustment member 20 is especially to adjust the distance between the transfer member 14 . The adjustment nuts 18 a , 18 d bear an arm 77 a , 77 d , respectively, while the adjustment nuts 18 b , 18 c each bear two arms 77 b , 77 c , respectively. Each arm 77 a , 77 d located at one of the ends of the sections 1 , 2 bears a cam 21 a , 21 b (FIGS. 1 and 7) intended to engage with a peg 13 a of the pusher 13 . Each arm 77 b , 77 c located in the middle part of the sections 1 , 2 is associated with two cams 21 c , 21 f or 21 e , 21 d , respectively intended to engage with the same peg 13 a , for a purpose which will be explained below. As shown in the enlarged view of FIG. 7 a , the cam 21 d , borne by the arm 77 c , is secured to the end of an arm 81 , hinged at the end of the arm 77 c . A transmission belt 78 connects a pulley 79 , secured to the shaft of the drive motor 17 , to a pulley 80 secured to the hinge pin of the arm 81 . Thus the cam 21 d borne by the arm 81 can be placed in two positions, an active position illustrated in dot-dash line in FIG. 7 a and an inactive position illustrated in solid line in this same FIG. 7 a . The other cams 21 a - 21 f are actuated in the same way as described above for the cam 21 d. Each end of the guide rail 8 is terminated by a highly enlarged part 8 a , 8 b . At the entrance and at the exit of each of these enlarged parts, two more or less superimposed cams 22 a , 22 b , 22 c , 22 d are arranged so as to engage with the pegs 12 a , 13 a of the pushers 12 and 13 . The role of the cams 22 a , 22 c located at the entrances of the respective enlarged parts 8 a , 8 b , is to separate the pushers 12 , 13 in order to release the center of each of these enlarged parts 8 a , 8 b in order to allow the yarn guides to be supplied with yarn from two sets of four reels 23 (in this example) each one borne by a rotating creel 24 secured to a shaft 25 . A bevel gear transmission connects this shaft 25 to the shaft 26 of a geared drive motor M located at each end of the machine and which, by means of two respective transmission belts 27 , also drive the shafts 7 of the disks 6 around which the drive chain 5 of the carriage 4 passes. Each of the pins 25 of the creels also bears a take-off 28 engaged with a transmission belt 29 . A transmission shaft 30 transmits the movement received by the belt 29 , using a transmission belt 31 , to a rotating yarn guide 32 . By virtue of this arrangement, the relative speeds of the creel 24 and of the rotating yarn guide 32 may be controlled so that the various yarns do not get entangled. FIG. 8 again illustrates a device for the relative movement between the carriage 4 and the drive chain 5 . To this end, the carriage 4 is connected to the drive chain 5 via a slide 33 secured to the carriage 4 and a slider 34 secured to the drive chain 5 . A servomotor 35 serves to make a worm 36 turn while engaged with the slider 34 in order to displace it along the slide 33 . The servomotor is supplied by a supply rail 37 with which a contact arm 38 comes into sliding contact. Given that the knitting needles 3 do not cross, it is necessary to provide members for holding the knit during knitting. Such members 39 are visible in FIG. 4 . It can be seen that they are constructed like a sort of comb allowing the knitting needles 3 and the knitting yarns to pass. Each of these holding members 39 rests on a support bar 39 b . As can be seen in FIG. 4, the parts 39 a of the holding members which extend above the respective upper edges of the sections 1 , 2 are thinned, thus leaving space for the formation of stitches of the knit when the knitting needles 3 descend into the guide grooves of the respective sections 1 , 2 . It is by virtue of these holding members 39 that it is possible to increase the clamping force on the stitches so as to produce a knit with denser stitches. FIG. 16 illustrates a detail of the guide parts of the yarn guide 10 , each of which comprises a free ring 10 e held between two annular stops 10 d . This free ring 10 e has a diameter which is substantially greater than that of the stem of the yarn guide 10 , but less than that of the two annular stops 10 d , such that it is free to move between these stops 10 d . By virtue of this arrangement, the yarn guide 10 may rotate with respect to the direction of the yarn 52 . Thus when the yarn guide 10 is transferred from one section to another by the transfer members 14 , it rotates through 180° but, by virtue of the free ring 10 e which holds the yarn 52 , the rotation of the yarn guide 10 has no effect on the yarn 52 which may rotate with respect to the yarn guide 10 in order to retain the same orientation defined by the position of the coil supplying the yarn. The embodiment of the knitting machine which has just been described is as follows: In order to explain this operation, we are going to follow yarn guided by a yarn guide 10 from the moment where the latter is at the exit end of the guide groove 16 of the transfer member 14 which is located at the right-hand end of the section 1 , with reference to FIG. 1 . At the exit end of this guide groove 16 , this yarn guide is retained by the flap 16 a . When a sliding support 9 , pushed on the guide rail 8 by the pushers 12 , 13 secured to the bracket 11 fastened to the carriage 4 , arrives directly above the exit of this guide groove 16 , it encounters the catching member 10 c of the yarn guide 10 retained at the exit of this guide groove 16 by the flap 16 a . This catching member 10 c enters through the front of the catching groove 9 a until it stops against the pushers 12 , 13 which drive the sliding support 9 along the guide rail 8 . From this moment, the yarn guide 10 advances with its yarn progressively with the movement of the carriage 4 with respect to the section 1 . During its movement, the knitting cams (not shown) of the carriage 4 engage with the needles 3 which follow one another along the section 1 , thus making these needles, which knit the yarn which is presented to them by the yarn guide 10 , rise and fall. When the yarn guide 10 arrives opposite the following transfer member 14 , that is to say, in the example chosen, the second of the four transfer members 14 starting from the one located at the right-hand end of the section 1 in FIG. 1, its guide portion 10 a encounters the entrance of the guide groove 16 of this second transfer member. Simultaneously, the peg 13 a encounters the cam 21 d (FIG. 7) which withdraws the pusher 13 slightly rearward, thus releasing the rear end of the catching groove 9 a of the sliding support 9 , only the pusher 12 remaining, by its sloped part 12 b , in contact with the yarn guide 10 . Since the guide portion 10 a of the yarn guide 10 is engaged in the guide groove 16 of the transfer member 14 , the yarn guide 10 changes direction, while the sliding support 9 , engaged with the rail 8 , continues to follow a path parallel to the section 1 . By virtue of its sloped face 13 b , the pusher 13 can thus give impetus to the yarn guide 10 as it exits from the catching groove 9 a of the sliding support 9 , by the rear thereof. This impetus from the sloped face 12 b of the pusher 12 has the effect of pushing the yarn guide 10 into the guide groove 16 of the transfer member 14 , until it stops against the retaining flap 16 a , where it waits to be taken up by another carriage 4 pushing another sliding support 9 . As to the carriage 4 and to the sliding support 9 , which become separated from the yarn guide 10 engaged in the transfer member 14 , it continues its movement along the section 1 in the direction of the arrow F. Immediately after having left the second transfer member 14 from the right-hand end of the section 1 (FIG. 1 ), the sliding support 9 driven by the carriage 4 passes by the third transfer member 14 , rotates through 180° around the suspension member 15 , such that the path of the guide groove 9 a of the sliding support 9 passes through the exit end of the guide groove 16 of the transfer member 14 , driving the yarn guide 10 waiting at this end into the passage. The same knitting process as that described above takes place until the yarn guide 10 encounters the entrance of the guide groove 16 of the fourth transfer member 14 which is located at the left-hand end in FIG. 1 of the section 1 . Simultaneously, the cam 21 a (FIG. 7) moves the pusher 13 away using the peg 13 a , and the sloped part 12 b of the pusher 12 gives the yarn guide 10 impetus in order to transfer it toward the section 2 . The carriage 4 then arrives at the left-hand end (FIG. 1) of the section 1 and it is now driven by the chain 5 toward section 2 by rotating around the disk 6 . As to the sliding support on the rail 8 , it approaches the widened part 8 a of the guide rail 8 . At the start of this widened part, the pegs 12 a , 13 a of the pushers 12 and 13 encounter two cams 22 a which withdraw these pushers 12 and 13 outward from the loop 8 a in order to release the center therefrom and allow passage of the knitting yarn passing from the rotating yarn guide 32 to the yarn guides 10 . Once the carriage 4 finishes its rotation, the pegs 12 a , 13 a encounter a cam 22 b (FIG. 7) which returns the pushers 12 and 13 into their initial position, such that when the catching groove 9 a of the sliding support 9 passes directly below the exit of the guide groove 16 , the catching member 10 c of the yarn guide 10 is inserted in this catching groove 9 a and is driven along the rail 8 , with the sliding support 9 , by the pushers 12 and 13 . Given that the knitting yarn is transferred without cutting this yarn, from a knitting needle 3 bed of one of the sections 1 , 2 to the knitting needle 3 bed of the other of these sections, while rotating constantly in the same direction, a tubular knit is formed and, as there are two pairs of transfer members 14 placed along the sections 1 and 2 , it is thus possible to form two tubular knit elements side by side, which may advantageously constitute the two legs of a seamless pair of pants, boxer shorts or tights. Once the length of the legs is reached, it is enough to select the knitting needles 3 which are between the two transfer members 14 , using conventional selection means which are not shown because they are not part of the present invention. At the same time as the aforementioned knitting needles 3 are selected, the two transfer members 14 are rotated through 90° using motors 17 , such that the yarn guides 10 can no longer engage in the guide grooves 16 and that only the transfer members 14 placed at the two ends of the sections 1 , 2 are still in service. Hence, the two tubular knit elements forming the legs of the pair of pants, the boxer shorts or the tights are joined into a single tubular element forming the top of the pair of pants, boxer shorts or tights. Simultaneously, given that, from this moment, each knitting yarn makes a complete rotation of the sections over their entire width rather than only over half of this width, the geared drive motors M will drive the creels 24 at half speed. Given that the speed at which the carriages 4 are driven by the endless drive chain 5 is constant, the servomotors 35 associated with each carriage 4 make it possible to reduce or increase the rate of movement of these carriages 4 in order to make it possible to synchronize them. This is because, in the example described, each creel 24 bears four reels 23 supplying knitting yarn, which corresponds to four yarns per knitted leg and to eight yarns when knitting the top of the pair of pants. Given the increases and decreases in the width of the knit, it may be necessary to modify the speed of the carriages 4 in order to take the yarn guides 10 to the exit of the transfer members 14 . However, before the carriage 4 starts to rotate around the drive disks 6 in order to operate with the opposite section, the servomotor 35 must put the carriage 4 back into the zero position, that is to say, in the position where it is neither advanced or retarded with respect to the reference spacing between the carriages 4 . When the knitting needles 3 are selected for the purpose of increasing or reducing the diameter of the tubular knitted element or elements, it is necessary to change the positions of the transfer members 14 so that they follow these changes in diameter. This adjustment is carried out by the worm 19 and the stepper motor 20 . Since the threads of the various portions 19 a , 19 b , 19 c , 19 d of the worm are reversed, when the two legs of the pants are knitted, depending on the direction of the rotation of the worm 19 , the paired transfer members 14 defining the two legs of the pants come together or move apart from each other. Similarly, when knitting a single tubular element forming the top of the pair of pants, where the two transfer members 14 located in the middle part of the sections 1 , 2 are taken out of service, as explained above, the two transfer members 14 located at the ends of these sections 1 , 2 come together or move apart from each other depending on the direction of rotation of the adjustment screw 19 . In a variant illustrated in FIG. 17, to prevent the yarn 52 winding around the rotating yarn guide, when the latter follows the tubular shape of the knit and thus changes orientation with respect to the portion of yarn located between the movable yarn guide 10 and the yarn guide 32 , it is also possible to use a tubular yarn guide 10 ′. The yarn 52 enters by one end of the tube of the yarn guide 10 ′ and exits by the other end. Such a yarn guide 10 ′ may therefore change orientation with respect to the stationary yarn guide 32 without the yarn becoming wound around it. Such a yarn guide 10 ′ may advantageously comprise two disks 10 ′ f and 10 ′ g , one 10 ′ f serving to support the yarn guide 10 ′ on a carriage (not shown) and the other to engage with a transfer arm (not shown). The second embodiment will now be described with reference to FIGS. 9 to 15 . Several of the changes described in relation to this embodiment may be used in the previous embodiment. Similarly, several of the elements described with respect to the first embodiment may be used in the second embodiment. The fundamental difference between these two embodiments resides in the fact that, instead of moving in a horizontal plane, the carriages 40 in the second embodiment move in two vertical planes, such that this embodiment requires twice as many carriages as the first embodiment. Another noticeable difference is seen in the creels for the reels supplying knitting yarn. FIG. 9 shows an endless drive chain 41 forming a closed loop around two wheels 42 with horizontal pivot pins. A second identical chain forms a second parallel loop, placed on the other side of the two vertical sections 43 , 44 , as can be seen in particular in FIG. 10 . The carriages 40 are each connected to one of the chains 41 by a pin 40 a transverse to this chain, enabling them to pivot. Each of these carriages 40 also bears two guide pegs 40 b , intended to engage with two guide rails 45 placed at the two ends of the closed loop described by the carriages 40 . These carriages 40 therefore have three guide points, the pin 40 a and the pegs 40 b , such that, by virtue of the guide rails 45 , they can move from the upper horizontal part of their path to the lower horizontal part, while constantly remaining in a horizontal position both when going from the top downward of their path and from the bottom upward. Unlike the previous embodiment where the transfer of the yarn from one section to the other is carried out by transferring the yarn guides, in this embodiment, only the yarn is transferred, the yarn guides 46 being secured to the carriages 40 . As illustrated in FIGS. 13, 13 a , and 14 , the yarn guide 46 is fastened to the carriage 40 by a post 47 around which a tubular body 48 pivots. This tubular body 48 is terminated by a pinion 49 at its lower end and by a yarn retaining element 50 consisting of a member provided with four radial notches 50 a reminiscent of a Maltese cross, at its upper end. The pinion 49 engages with a take-off 49 a mounted so that it can pivot on the carriage 40 . The upper end of the post 47 bears a member 51 for locking the knitting yarn 52 . This locking member 51 is mounted so that it can pivot on this post 47 and is normally applied against a stop 53 secured to an arm 53 a itself secured to the post 47 . A return spring 54 tends constantly to keep the locking member applied against the stop 53 . There are four transfer stations 55 (FIGS. 12, 13 , 14 and 15 ), equivalent to the transfer members 14 of the first embodiment, so that the knitting yarn can be transferred from one section to the other, at each end of the knitting travel, corresponding to half a portion of tubular knit. The two transfer stations 55 located in the middle part of the sections can be taken out of service to allow the top of the pair of pants to be knitted. As with the transfer members 14 , the transfer members 55 of the second embodiment are engaged with adjustment screws 19 ′, 19 ″, controlled by motors 20 ′, 20 ″, in order to vary the width of the knit. Each transfer station 55 comprises two racks 56 located on the respective paths of two take-offs 49 a . A release cam 57 is again placed on the path of a portion 51 a of the member 51 for locking the knitting yarn 52 , on the side where this yarn must be released from the yarn guide 46 in order to be transferred to the other section. In the example described, this release cam 57 is located to the left with reference to FIG. 13 . The frame of this transfer station 55 also comprises two transfer slides 58 , 59 , each one bearing two stops 58 a , 59 a , respectively, intended to limit their respective travels. Two actuating members 60 serve to actuate these slides from one stop to the other and vice versa. The free end of the transfer slide 58 is also secured to a pusher 58 b fitted with an opening for passage of the other slide 59 . The pusher 58 b may be moved by the transfer slide 58 up to a stop surface 55 a secured to the frame of the transfer station 55 . FIGS. 9 to 11 show another creel device intended to supply the knitting yarns by making them rotate always in the same direction, in this case, clockwise (FIG. 11 ), and by allowing the knitting yarns to rotate around the two respective rotating pins while knitting the legs of the pants, then around a single pin when knitting the top of the pair of pants. This creel device comprises vertical reel supports 61 , each one of which bears a reel 62 of knitting yarn 52 . Each vertical support 61 rests on a support surface 63 while it is guided upward by a guide rail 64 . This guide rail forms, as illustrated in FIG. 11, two small oval loops included within a large oval loop. The two small oval loops are intended to guide the reel supports 61 when knitting the trouser legs, while the large loop is intended to guide them when knitting the top of the pair of pants. Each vertical support 61 comprises a connection member 65 , mounted so that it can slide in a vertical groove 66 (FIG. 9 ). A slide 67 secured by guide pegs 67 a engaged with guide grooves 67 b and actuated by a crank mechanism 82 , serves to move the connection member 65 in this vertical groove 66 . The inner end of this connecting member 65 is shaped so as to engage selectively with flexible drive members 68 , 69 , 70 (FIGS. 9, 10 ), forming three endless loops, like the guide rail 64 , while passing round wheels 71 pivoted around vertical pins 72 , 73 , 74 , 75 . The pin 72 is connected to a geared motor 76 also connected to one of the wheels 42 for guiding and driving the chain 41 . This geared motor 76 makes it possible to vary the drive speed of the pin 72 , depending on whether the supports 61 rotate along the two small loops of the guide rail 64 or along the large loop, that is to say, whether they are engaged with the drive members 68 , 69 or with the drive member 70 . As in the previous embodiment, the carriages 40 are connected to the drive chains 41 by a servocontrol system as illustrated in FIG. 8, making it possible to vary the speed of the carriages with respect to that of the drive chains 41 . To explain the operation of this second embodiment, we will start with a carriage 40 moving in the direction of the arrow F 1 (FIG. 12) and arriving at the transfer station 55 which is located toward the left-hand end of the sections 43 , 44 . This part of the knitting machine is illustrated in more detail in FIGS. 13 and 14 to which reference may be made. The carriage 40 , which moves in the direction of the arrow F 1 , bearing the yarn guide 46 which drives the knitting yarn 52 , is at the point of arriving at the transfer station 55 , while the carriage 40 which is moving in the direction of the arrow F 2 bearing the yarn guide 46 empty of knitting yarn also arrives at the transfer station 55 . On arriving at this transfer station 55 , the take-off 49 a of the yarn guide 46 moving in the direction of the arrow F 1 encounters the rack 56 which makes the yarn retaining member 50 rotate in the direction of the arrow F 3 (FIG. 13 a ). Virtually simultaneously, the part 51 a of the locking member 51 of the knitting yarn 52 (FIGS. 13, 14 ) encounters the cam 57 which makes this locking member 51 rotate counter to the tensile force of the spring 54 , such that the locking member 51 rotates in the direction of the arrow F 3 (FIG. 13 a ), releasing the radial notch 50 a and thus freeing the knitting yarn 52 . As soon as it is freed, the knitting yarn 52 is then moved by the pusher 58 b against the stop surface 55 a and the slide 59 closes the space in which the knitting yarn is enclosed, as is shown in dotted line in FIG. 14 . The yarn is then positioned to be taken into a radial groove 50 a of the yarn retaining member 50 which is moved in the direction of the arrow F 2 , as illustrated in FIG. 14 . Virtually simultaneously, the rack 56 encounters the take-off 49 a which makes the retaining member 50 of the knitting yarn 52 rotate through 90° in the direction of the arrow F 3 , which is locked by the locking member 51 . The same transfer operation is then carried out in the reverse direction when the carriage 40 , which moves in the direction of the arrow F 2 , has reached the transfer station 55 ′, which is located in the middle part of sections 43 , 44 . The transfer station 55 ′ differs from the station 55 of FIG. 14 only in that, in order to transfer the knitting yarn 52 from the section 44 to the section 43 , it is the slide 59 ′ with an arm 59 ′ b at 90° which must take the yarn 52 ′ from right to left instead of pushing it from left to right as the pusher 58 b of FIG. 14 does. The rest of the operations are the same such that reference may be made to FIG. 14 . Symmetrical operations are carried out on the knitting yarns, knitted on the right half of the sections 43 , 44 . When the legs of the pants or tights are completed and when it is necessary to pass to the top of the pair of pants, the two transfer stations 55 , 55 ′ located in the middle of the sections 43 , 44 are taken out of service and the knitting yarns 52 are transferred only at the two ends of the sections 43 , 44 . The reels 62 are moved on the creel by following the movement of the yarn guides 46 driven by the carriages 40 . When knitting the trouser legs, the connection members 65 of the supports 61 for reels 62 are connected to the flexible drive members 67 , 68 , respectively, and are guided along the two small elongated loops formed by the guide rail 64 . When the top of the pair of pants are knitted, the connection members 65 are connected to the flexible drive member 70 by the actuating members 67 and then describe a single elongated path. In the two embodiments described above, each section is made as a single part. In a variant (not shown), it would be possible to use sections in two parts capable of being moved laterally one with respect to the other according to a system known in rectilinear knitting machines. By virtue of this type of section, after having knitted the two tubular parts, the two section parts could be joined to knit the common tubular part, corresponding to the top of the pair of pants.	The invention concerns a knitting machine comprising two needle beds for guiding knitting needles, means for selecting said knitting needles, carriages for moving the selected knitting needles and members guiding the knitting thread. The method consists in arranging the needle beds so that the needles of a needle bed in their normal knitting travel do not cross the needles of the other needle bed, in moving the carriage in one direction along each needle bed, the displacement directions of said carriages along their respective needle beds being opposite relative to each other and in transferring the thread from the needles of one needle bed to those of the other needle beds, each time said thread reaches the end of the selected needles.	3
BACKGROUND OF INVENTION The detection of microorganisms in samples is generally a time consuming and laborious clinical procedure. In ordinary practice, a small portion of the sample, called an inoculum, is placed onto a media conducive to microbial growth. The system is then incubated under appropriate conditions and, after an appropriate time, the results are read. Plates are inspected and scored every day. Depending upon the suspected type of organism and the kind of medium used, plates with no growth are generally not discarded for 4 to 8 days. For small volume samples with a fairly high concentration of organism, the procedure above works well. For case where a fairy large liquid sample is required due to a low concentration of viable microorganisms, the sample is diluted with a several fold greater volume of liquid media and the mixture incubated to detect growth. Normally sterile samples such as blood samples being tested for the presence of viable microorganisms may require from 1 to several days before growth can be detected. Bottles are inspected daily. Bottles with no growth are generally not discarded for 5 to 7 days. Thus, there exists a real need to reduce this incubation time. SUMMARY OF INVENTION The above is realized by the method of this invention. Briefly, in the method of this invention the sample container is divided into a plurality of discrete zones, each of which can be separately monitored for microbial presence. When a sample is placed into this container, detection is simplified as the volume monitored is low (as compared with the sample); since microbial detection is a concentration dependent phenomenon, the speed with which the presence of microbial contamination can be detected is increased. BRIEF DESCRIPTION OF THE DRAWINGS FIGS. 1(a) and 1(b) present preferred apparatus for the division of the sample into a plurality of regions by use of interlocking dividers; 1(a) shows the device through one face, 1(b) presents a side view, and 1(c) presents a detail of the interlocking dividers. DETAILED DESCRIPTION OF INVENTION This invention provides a convenient way of enhancing microbial detection, thereby decreasing the detection time required, by dividing the sample into discrete regions and analyzing each separately. Since detection is dependent upon the concentration of the bacteria in the system, analysis of each individual region will provide detection of the bacteria in the system more rapidly, and at a lower overall concentration than analysis of the entire mixture. By way of example, the BACTEC® blood culture analyzer system marketed by Becton, Dickinson and Company requires an approximate threshold concentration of 1×10 6 organisms/ml to yield a positive result. If an initial inoculum, diluted to 50 ml with culture media contained only 1 CFU (0.02 CFU/ml), it can be calculated that a total of 26 generations would be required to achieve this threshold concentration. One Organism would have to multiply to more than 5×10 7 organisms. At an average generation time of 30 minutes, this translates to a detection time of 13 hours (assuming no lag before growth starts). In a preferred embodiment of this invention, the 50 ml sample is divided into 100 regions of 0.5 ml each. To achieve an effective concentration of 1×10 6 CFU/ml, such a region would need an actual concentration of 5×10 5 CFU/ml. This would be achieved in 19 generations in the cell containing the organism or about 9.5 hours (assuming the same generation time and no time lag as above), translating to a 3.5 hour saving. Should the 50 ml sample be divided into 1000 regions of 0.05 ml each, then only 16 generations or 8 hours would be required for each organism to multiply to greater than 1×10 6 CFU/ml. It is easily recognized that the number of regions examined and the volume of these regions can be varied as particular applications or equipment restrictions dictate. Further the means of achieving this division is immaterial, so long as the regions are effectively isolated from each other. FIG. 1 shows a preferred apparatus for this division, comprising a culture bottle divided on one face into a plurality of regions by interlocking dividers. These form discrete regions in the form of parallelapipeds, each having an identical volume. In actual use the height of these dividers must be sufficient to fully contain the volume during incubation, including incubation on an agitating device such as a shaker, when used. In practice the inoculum is introduced into the bottle which is then laid on the face containing the divider to obtain the division of the sample into the separate regions. The bottle is then incubated and analyzed for growth by any convenient means. Preferred methods of analysis include colorimetric, fluorometric, radiometric, nephelometric, and infrared analyses. It is to be recognized that the shape and/or volume of the regions can be varied, although identical shapes and volumes for each region are preferred. In addition to rapid detection of microorganisms, this method has two other major advantages over the prior art. The first is that this method permits quantitation of the bacteremia or septicemia. The second is that the method is both compatible with polymicrobial specimens and the method will, under most circumstances, produce isolated cultures from mixed specimens as long as the initial level of organisms is low. The Isolator 7.5 Microbial Tube marketed by Wampole Laboratories is a device and a system for concentrating microorganisms from blood specimens by centrifugation. The method is very time and labor intensive, including over a 25 step procedure with a 30 minute centrifuge spin. This method has been widely accepted, in part because it is the only commercial method capable of estimating the number of organisms in the original blood sample. An evaluation of this method by Dorn et al. (J. Clin. Micro., 9, pp. 391-396) concluded "Quantitation, offered only by the centrifugation method, proved useful on several occasions in discriminating between an opportunistic infection versus a skin contaminant and in judging the efficacy of antimicrobial therapy." Sullivan et al (Pediatrics, 69, 699-702) have demonstrated that the magnitude of bacteremia in children is associated with the severity of clinical disease. In the method of this invention, the estimation of the number of microorganisms in the original sample is as easy as counting the number of regions which have shown growth. When the number of positive wells is small relative to the total number of wells then this estimate can be expected to be very accurate. As the number of positive wells increases, the accuracy and reliability of the estimate becomes worse. However, most specimen types that would most benefit from rapid detection, such as blood, generally have microorganism counts of less than 10 cfu/ml. After dilution with media less than 10% of the wells would be positive. Additionally, the presence of more than one type of microorganism in the original sample is a big problem for most systems. This is an important and frequent occurrence in blood culture. Polymicrobial bacteremia has been reported in as many as 18% of septic episodes and has been associated with higher mortality. In the case where the entire sample goes into one bottle, it is very early for rapidly growing organisms, such as E. coli, to outgrow any other organisms present. The other organism(s) is (are) either not detected or require an additional. 18-24 hours to grow isolated colonies for identification and susceptibility testing. In the methods of this invention, when small numbers of organisms are present, it is highly likely that each organism goes into a separate well. When several species are present, it can, thus, be expected that each positive well is the result of a single organism and is therefore a pure culture. If one species (such as E. coli) dominates the original sample, it would be expected to be the culture in most of positive wells; but would not affect or mask the growth of other species in the remaining positive wells. Thus the detection of multiple microorganisms is greatly simplified. Further, in cases where the generation time for the microorganism is long, e.g. mycobacteria such as those associated with tuberculosis, the detection time is greatly reduced. This permits quicker diagnoses and permits treatment to begin earlier. EXAMPLES The following examples present certain preferred embodiments of this invention, but are not intended to be illustrative of all embodiments. Example 1 To illustrate the advantage of the method of this invention, a series of calculations were performed to determine the time required to achieve a threshold concentration of 1×10 6 CFU/ml, for a 8 ml aliquot diluted to 80 ml in culture media, assuming a generation time of 20 or 30 minutes, and a time lag of 30 minutes (1 day in the 12 hour case). The results are presented in Table 1. TABLE I______________________________________ Total CFU Time to ThresholdGeneration In 8 ml Blood (Min)Time (CFU/ml) Con..sup.a Inv..sup.b Time Saved______________________________________20 minutes 1 (0.125) 560 420 140 min 2 (0.250) 546 420 120 min 8 (1.0) 500 420 80 min 16 (2.0) 480 420 60 min 32 (4.0) 460 420 40 min30 minutes 1 (0.125) 825 615 210 min 2 (0.250) 795 615 180 min 8 (1.0) 735 615 120 min 16 (2.0) 705 615 90 min 32 (4.0) 675 615 60 min Days Days12 hours + 1 (0.125) 14.25 10.75 3.5 days1 day lag 2 (0.250) 13.75 10.75 3 days 8 (1.0) 12.75 10.75 2 days 16 (2.0) 12.25 10.75 1.5 days 32 (4.0) 11.75 10.75 1 day______________________________________ Notes .sup.a Conventional system single measurement .sup.b Invention using apparatus comprising One hundred twenty (120) 0.66 ml compartments As shown, the system of this invention provides a significant savings in time, especially when the initial concentration of organism is dilute, or when the generation time is long. Example 2 To evaluate the comparative speed of the method of the instant invention with commercial bacterial detection systems, the system was reproduced by using a microtiter tray. The three systems used are described below. Fluorescent Microtiter Tray (Invention) Preparation of Tray The fluorescent compound tris 4,7-diphenyl-1,10-phenanthroline ruthenium (II) chloride (Ru(DPP) 3 Cl 2 ) was synthesized using the procedure of Watts and Crosby (J. Am. Chem. Soc. 93, 3184 (1971)). A total of 3.6 mg of the compound was dissolved in 2.0 ml dimethyl sulfoxide (D-5879, Sigma Chemical St. Louis Mo.) and the resultant solutions was then added slowly, with stirring, to 1300 ml silicone rubber forming solution (Water Based Emulsion #3-5024, Dow Corning Midland Mich.). A 35 microliter aliquot of the mixture was subsequently dispensed into each well of a 96 well, flat bottom, white microtiter tray (#011-010-7901, Dynatech Chantilly Va.), and the systems was subsequently cured overnight in a low humidity (less than 25% RH), 60° C. incubator. After curing, the trays were washed by either soaking or by filling and emptying each well several times with each of the following reagents; a) absolute ethanol, b) 0.1M phosphate buffer pH 7.2, c) hot distilled water (about 45° C.) and d) ambient temperature distilled water. Thirty ml of Vacutainer® TSB was inoculated with 5 ml of organism suspension. The broth suspension was then pipetted into a fluorescent tray with a plurality of 250 ul wells. The tray was covered with a lid and placed in a humidified 35° C. incubator. To measure fluorescent levels the tray was placed in a Fluoroskan II fluorometer (480-490 bandpass excitation filter/570 cut-on emission filter). A well was considered positive if it had greater than 50 fluorescent counts above the mean of the 96 wells. From each positive well, 100 ul was removed, diluted, and plated onto TSA plates to verify organism identification. Negative wells were sampled to verify no organisms were present. Radiometric (14C) BACTEC® 6B Blood Culture Bottle Without Sheep Blood Using a syringe the bottle containing 14C media, was inoculated with 5 ml of the organism suspension. The bottle was incubated at 37° C. on a shaker and read at intervals using a BACTEC® 460 reader. A bottle was considered positive if it had greater than 0.0075 microcuries of 14 CO 2 . This radiometric level corresponds with a Growth Index Number of 30. BACTEC® bottles were read until the Growth Index Number was above 30 or the change between two consecutive readings was greater than 10. Samples of 100 ul were removed from each bottle and plated to verify organism identification. Control bottles with no organisms were also incubated and sampled. Radiometric (14C) Bactec® 6B Blood Culture Bottle With Sheep Blood Using a syringe, 5 ml of defibrinated sheep blood was added to the same BACTEC® bottle as above and mixed. Five ml of the media/blood mixture was then removed and 5 ml of organism suspension was added to the bottle. The bottle was incubated at 37° C. on a shaker and read at intervals using a BACTEC® 460 reader. BACTEC® bottles were read until the Growth Index Number was above 30 or the change between two consecutive readings was greater than 10. Samples were removed from each bottle and plated to verify organism identification. Control bottles with no organism were also incubated and sampled. Each system was examined using two different organisms, Escherichia coli ATCC 25922 and Pseudomonas maltophila BBL #7301 (containing 8 ug/ml amikacin). The results are presented in Table II. TABLE 11______________________________________ BACTEC ® BACTEC ® Microtiter Bottle Bottle Wells w/o S.B. w/S.B.______________________________________E. COLI ATCC #25922# Positive Tests 11 5 2Avg. Detection 8.25 12 13Time (hrs.)Detection Time as 100% 145% 158%Percent of MicrotiterWells______________________________________PSEUDOMONAS MALTOPHILA BBL #7301with 8 ug/ml Amikacin# Positive Tests 2 4 4Avg. Detection 12 41.0 40.0Time (hrs.)Detection Time as 100% 342% 208%Percent of MicrotiterWells______________________________________ E. Coli Upon subsequent examination, all positive microtiter wells (threshold equals 50 fl. units above the mean) were found to contain pure cultures of E. coli. Sampling from various negative wells yielded no organisms. The positive BACTEC® bottles also had pure cultures. As shown, the time to detection for the microtiter wells is about 45-58% faster than the BACTEC® bottles. Pseudomonas Maltophila Upon subsequent examination, all positive microtiter wells (threshold equals 50 fl. units above the mean) were found to contain pure cultures of Pseudomonas. Sampling from various negative wells yielded no organisms. The positive BACTEC® bottle also had pure cultures. As shown, the Bactec® bottles time to detection was over 200% of the time for the invention. It is apparent that many modifications and variations of this invention as hereinabove set forth may be made without departing from the spirit and scope hereof. The specific embodiments described are given by way of example only and the invention is limited only by the terms of the appended claims.	This invention describes a method for the rapid identification of the presence of microorganisms in a sample. Briefly, in the method of this invention the sample container is divided into a plurality of discrete zones, each of which can be separately monitored for microbial presence. When a sample is placed into this container, detection is simplified as the volume monitored is low (as compared with the sample); since microbial detection is a concentration dependent phenomenon, the speed with which the presence of microbial contamination can be detected is increased.	8
CROSS REFERENCE TO RELATED APPLICATIONS [0001] The present application is a Continuation of U.S. application Ser. No. 11/635,489 filed Dec. 8, 2006, which is a Continuation of U.S. application Ser. No. 11/172,839 filed Jul. 5, 2005, now issued as U.S. Pat. No. 7,152,860 which is a Continuation of U.S. application Ser. No. 10/968,923, filed Oct. 21, 2004, now issued as U.S. Pat. No. 6,957,811, which is a Continuation of U.S. application Ser. No. 10/728,782 filed Dec. 8, 2003, now issued as U.S. Pat. No. 6,840,512 which is a Continuation of U.S. application Ser. No. 10/309,224 filed Dec. 4, 2002, now issued as U.S. Pat. No. 6,672,584 which is a Continuation of U.S. application Ser. No. 09/721,859 filed Nov. 25, 2000, now issued U.S. Pat. No. 6,631,897 all of which are herein incorporated by reference. FIELD OF THE INVENTION [0002] The following invention relates to a page binding device having a support tray with vibratory page alignment. More particularly, though not exclusively, the invention relates to a page binder that applies glue to pages and feeds them to the support tray at relatively high velocities. The support tray receives the pre-edge glued, uniformly sized printed pages and aligns them prior to pressing the pre-glued edges together. [0003] It is well known to print individual pages of a volume to be bound, then to place all of the printed pages into a stack, to then crop one or more edges of the stack and to then bind the pages together by applying a binding adhesive to an edge of the stack of pages. This is a time consuming and labour-intensive process. [0004] It would be more efficient to provide pre-cut, uniformly sized pages, to print one or both surfaces of each page and to provide a strip of binding adhesive to one or both surfaces of each page adjacent the edge to be bound, to accurately place the printed and pre-glued pages in a stack, and to press the pages adjacent the spine so that the adhesive binds the page edges together. [0005] It would also be desirable to provide a page binding device that can apply adhesive and bind pages fed from a printer at relatively high velocity. OBJECT OF THE INVENTION [0006] It is the object of the invention to provide a page binding device configured for quick and reliable operation. DISCLOSURE OF THE INVENTION [0007] According to a first aspect, the present invention provides a page binding device for binding printed pages, the device comprising: [0008] a support tray for receiving and stacking printed pages to form a bound document; [0009] an adhesive applicator for applying a two part adhesive to the printed pages, the two part adhesive having a first part and a second part, wherein the first part and the second part must contact each other to form an adhesive bond, the adhesive applicator adapted to apply the first part of the adhesive to one side of the printed pages and the second part of the adhesive is applied to the opposite side of the page; and, [0010] a page conveyor for sequentially feeding pages along a paper path from the adhesive applicator to the support tray; wherein during use, [0011] the printed pages are stacked in the support tray such that the first part of the adhesive on one page contacts the second part of the adhesive on the adjacent page in the adjacent page in the stack. [0012] Using a two part adhesive allows the adhesive applicator to be easily incorporated into a duplexed printhead assembly. As each side of the duplexed printhead would only eject one part of the two-part adhesive, the nozzle are far less prone to clogging. [0013] In some embodiments, the printhead assembly is a duplexed printhead assembly adapted to print on both sides of a page and the adhesive applicator is integrally incorporated into the duplexed printhead assembly. In a preferred embodiment, the pages are conveyed in a landscape orientation. Preferably the tray has a support surface having one corner that is lower than other portions of the support surface. In a further preferred form, the device has a vibrator interacting with the tray so as to induce vibration therein to assist in alignment of the pages of the stack. [0014] Preferably the tray has at least two side walls extending substantially perpendicularly to each other and against which perpendicular edges of the pages bear for alignment of the pages within the stack. [0015] Preferably vibration of the tray is dampened by dampers. [0016] Preferably the tray is supported by a frame. [0017] Preferably the tray is suspended from the frame. [0018] Preferably the dampers extend from the tray to the frame. [0019] Preferably the vibrator is a subsonic vibrator. [0020] Preferably means are provided to alter a level of the support surface of the tray so as to ensure that an upper page of the stack is situated at a predefined level for interaction with an edge-pressing device. [0021] According to a second aspect, the present invention provides a method of binding pages from a printer into a bound document, the method comprising: [0022] applying a two part adhesive to the printed pages, the two part adhesive having a first part and a second part, wherein the first part and the second part must contact each other to form an adhesive bond, wherein the first part of the adhesive is applied to one side of the printed pages and the second part of the adhesive is applied to the opposite side of the page; and, [0023] stacking the pages such that the first part of the adhesive on one page contacts the second part of the adhesive on the adjacent page in the adjacent page in the stack. BRIEF DESCRIPTION OF THE DRAWINGS [0024] Preferred forms of the present invention will now be described by way of example with reference to the accompanying drawings wherein: [0025] FIG. 1 is a schematic illustration of a page conveyed along a path and passing a pagewidth print head and an adhesive applicator; [0026] FIG. 2 is a schematic illustration of a page having an adhesive strip adjacent one edge thereof, [0027] FIG. 3 is a table, schematically illustrating the principles of five alternative adhesive application methods; [0028] FIG. 4 is a schematic elevational view of a number of pages with all but the top page having a strip of adhesive applied to an upper surface adjacent to an edge to be bound; [0029] FIG. 5 is a schematic elevational view of a stack of pages with all but the bottom page having a strip of adhesive applied to a lower surface thereof adjacent to an edge to be bound; [0030] FIG. 6 is a schematic elevational view of a stack of pages with a first part of a two-part adhesive applied to the upper surface of all but the top page and a second part of a two-part adhesive applied to the bottom surface of all but the bottom page, [0031] FIG. 7 is a schematic perspective view of a page binding support tray situated immediately down-line of the adhesive applicator, [0032] FIG. 8 is a schematic cross-sectional elevational view of the page binding support tray of FIG. 7 showing a first page having a strip of adhesive adjacent its edge at an upper surface en route thereto, [0033] FIG. 9 is a schematic cross-sectional elevational view of the page binding support tray and page of FIG. 8 , with the page closer to its rest position, [0034] FIG. 10 is a schematic cross-sectional elevational view of the page binding support tray and page of FIGS. 8 and 9 , with the page at rest thereon, [0035] FIGS. 11 , 12 and 13 are schematic cross-sectional elevational view of the page binding support tray showing a second page as it progresses to rest upon the first page, [0036] FIG. 14 is a schematic cross-sectional elevational view of the page binding support tray having a number of pages resting thereon to be bound, with all but the top page having an upwardly facing strip of adhesive adjacent an edge thereof, [0037] FIG. 15 shows the progression of a page-binding press toward the edge of the stacked pages, [0038] FIG. 16 shows the page binding support tray with pages bound along their edge by application of the binding press, [0039] FIG. 17 is a cross-sectional elevational view of the page binding support tray having a number of individual volumes resting thereon, with a top volume ready to be pressed, [0040] FIG. 18 is a schematic cross-sectional elevational view of the page binding support tray and volumes of FIG. 17 , with all volumes having been pressed, one upon another, [0041] FIG. 19 is a schematic perspective illustration of a number of volumes having been bound, [0042] FIG. 20 is schematic elevational view of a page binding support tray having an alternative press, [0043] FIGS. 21 and 22 are schematic perspective views of a portion of the alternative press of FIG. 20 , and [0044] FIG. 23 is a schematic elevational view of a page binding support tray having an alternative press at a trailing edge of a stack of pages to be bound. DESCRIPTION OF THE PREFERRED EMBODIMENTS [0045] In FIG. 1 of the accompanying drawings there is schematically depicted a path 10 of a page 11 passing through a printer incorporating an adhesive applicator. [0046] Page 11 is driven to the right at a driving station D. Driving station D might comprise a pair of opposed pinch rollers 12 as shown. The page 11 then passes a printing station P and then an adhesive application station A. As an alternative, the adhesive application station A might precede the printing station P, but it is preferred that the adhesive application station follow the printing station so that adhesive on the page 11 does not clog the print head or print heads at printing station P. [0047] For single sided page printing, the printing station P might comprise a single print head 13 . The print head 13 might be a pagewidth drop on demand ink jet print head. Alternatively, the print head might be that of a laser printer or other printing device. Where the page 11 is to be printed on both sides, a pair of opposed print heads 13 might be provided. [0048] Where the print heads 13 are ink jet print heads, wet ink 15 on page 11 might pass through the adhesive application station A. [0049] An air cushion 14 at either side of the page 11 as it passes printing station P can be provided by means of air passing through an air flow path provided in each print head 13 . [0050] The adhesive application station A can comprise an adhesive applicator 16 at one or both sides of the page 11 , depending upon which side or sides of the page to which adhesive is to be applied. [0051] As shown in FIG. 2 , a page 11 having matter printed thereon by printing station P also includes a strip 17 of adhesive as applied at adhesive application station A. [0052] As can be seen, the strip 17 can be applied adjacent to the leading edge 27 of page 11 . The application of strip 17 adjacent to the leading edge 27 is suitable for those situations where the adhesive applicator does not contact the page, or contacts the page at a velocity accurately matching that of the page 11 as it passes the adhesive application station A. Alternatively, the strip 17 could be applied adjacent to the trailing edge 28 of page 11 and this position might be more suited to adhesive applicators that make some form of physical contact with the page 11 as it passes adhesive application station A. [0053] A margin 29 of about 1 to 2.5 mm is desirable between the strip 17 and edge 27 or 28 of page 11 . [0054] Various methods of applying adhesive to the page 11 are envisaged, some of which are schematically depicted in FIG. 3 . [0055] Method 1 in FIG. 3 is a non-contact method of applying adhesive to the moving page 11 . In this method, a stationary adhesive applicator 16 sprays adhesive on one side of page 11 as it passes the applicator. The adhesive applicator might be formed integrally with the print head 13 or might be located upstream or after the print head. [0056] Method 2 also applies adhesive to one side of the moving page 11 , although this time using a contact method. An adhesive applicator 16 ′ is pivotally mounted about a fixed pivot point and is caused to move at a speed matching that at which the page 11 passes through the adhesive application station. A reaction roller 30 comes into contact with the underside of page 11 as the adhesive applicator 16 ′ applies adhesive to the page. [0057] Method 3 applies adhesive to both sides of a page 11 as it passes through the adhesive application station. A pair of pivotally mounted adhesive applicators 16 ″ move pivotally at a speed corresponding with that at which the page 11 passes through the adhesive application station. They both come into contact with the page 11 and mutually counteract each other's force component normal to the page 11 . [0058] Method 4 employs a pair of adhesive applicator rollers 16 ′″ spaced from either side of the page 11 until activated to apply adhesive whereupon they move toward and touch the page 11 , leaving a strip of adhesive 17 at either side of the page. The rollers would mutually counteract each other's force component normal to page 11 . [0059] Method 5 employs a pair of adhesive spray applicators 16 ′″, one at either side of page 11 . The applicators do not contact page 11 . Each applicator would apply one part of a two-part adhesive to a respective side of page 11 so as to apply strips 17 a and 17 b . Like Method 1 , Method 5 could employ an adhesive applicator formed integrally with the print head. That is, a channel for the flow of one part of a two-part adhesive might be provided in each print head. [0060] Also, the use of a two-part adhesive could be beneficial in situations where there might be some delay in the printing/binding operation. For example, if there were a computer software or hardware malfunction part-way through a printing/binding operation, the use of a two-part adhesive could provide sufficient time within which to rectify the problem and complete the binding process. [0061] FIG. 4 illustrates a stack of pages 11 with all but the top page provided with an adhesive strip 17 at an upper surface adjacent one edge to be bound. [0062] An alternative is depicted in FIG. 5 wherein all but the bottom page has an adhesive strip 17 applied to its bottom surface adjacent an edge to be bound. [0063] In FIG. 6 , a stack of pages is shown with part A of a two-part adhesive applied to the upper surface of all but the top page and the second part of the two-part adhesive applied to the bottom surface of all but the bottom page. [0064] When the stacks of pages of FIGS. 4 and 5 are pressed together, adhesion of the pages occurs once the adhesive 17 has dried. [0065] When the pages 11 of FIG. 6 are pressed together, the respective parts of the two-part adhesive in strips 17 a and 17 b combine so as to react and set. [0066] Where print head 13 is an ink jet print head, and non-contact adhesive application Methods 1 and 5 are employed, the adhesive strip 17 is applied to page 11 before ink on the page passing through the adhesive application station 10 has dried. Air passing through air gap 14 accelerates the drying process. That is, adhesive is applied to the page as it passes out of the print head 13 . The velocity of the page 11 does not change as a result of the application of adhesive strip 17 . [0067] Where the strip 17 is applied alongside the leading edge 27 of the page 11 , any alteration to the velocity of page 11 would adversely affect print quality. Hence application of adhesive strip 17 alongside the leading edge 27 is only possible without adversely affecting print quality using non-contact adhesive application methods or methods where the velocity of the adhesive applicator coming into contact with the page is very close to that of page 11 . [0068] Where the adhesive strip 17 is applied alongside the trailing edge 28 of page 11 , a non-contact method or method of very close speed matching is also desired. For example, if the speed of the adhesive applicator of Methods 2 to 4 was faster than that at which the page 11 was passing the print head, the page could buckle. [0069] A most desirable embodiment of the present invention would use a two-part adhesive and would incorporate the adhesive applicators within the print heads themselves. That is, a passage or passages for the flow of adhesive through the print head would be space and cost-effective. [0070] The likelihood of adhesive “gumming” and blocking such channels would be diminished where a two-part adhesive was employed. That is, only one part of the two-part adhesive would pass through any particular channel or channels of the print head. [0071] Where respective parts of a two-part adhesive are applied to opposed sides of pages 11 , those respective parts could pass through dedicated channels in the respective print head at either side of the page. This would greatly reduce the likelihood of adhesive blockages in the flow channels. [0072] The adhesive or respective parts of a two-part adhesive can be provided in a chamber of a replaceable ink cartridge providing ink to the print head. [0073] The print head 13 should be as close a possible to the pinch rollers 12 . This is because the rollers 12 provide a mechanical constraint upon the page 11 to enable accuracy of printing. [0074] The pinch rollers 12 , print heads 13 and adhesive applicator 16 are illustrated in FIG. 7 alongside a page support tray 18 . That is, the page support tray 18 receives pages 11 that exit the paper path 10 . The tray 18 is suspended from a frame 21 by means of respective dampers 22 at each corner. The dampers could be elastomeric dampers or small hydraulic or pneumatic cylinders for example. The floor of tray 11 is not level. It has a lower-most corner 23 beneath which there is provided a vibrator 19 . The vibrator 19 might be a subsonic vibrator (ie a vibrator having a frequency below 20 hz) or an out-of-balance electric motor for example. A binding press 20 is situated above the tray 18 over the at-rest position of the respective leading edge of the pages 11 . However, as an alternative, the binding press 20 could be provided so as to be situated over the trailing edge of the pages. [0075] In FIG. 8 a first page 11 is shown in its trajectory toward tray 18 . Page 11 has a strip of adhesive 17 on its upper surface adjacent the leading edge. The page 11 might tend to catch a pocket of air beneath it as it floats into position and the leading edge 28 might strike the vertical wall 31 as shown in FIG. 9 . The vibrations of the tray 18 as a result of the vibrator 19 will cause the page 11 to come to rest with edge 27 alongside the lower edge of wall 31 and with a right angled edge of the page touching the front wall 32 of tray 18 . [0076] In FIG. 11 , a second page 11 is shown in its trajectory toward tray 18 . In a motion similar to that of the first page, the second page comes to rest upon the first page in a position perfectly aligned therewith. The second page comes to rest into the position depicted in FIG. 13 . Where the pages have the adhesive strip 17 applied to the upper surface, the final page is provided without any adhesive and it comes to rest at the top of the stack as depicted in FIG. 14 . If, instead, the majority of pages 11 had the adhesive strip 17 applied to their bottom surface, the first page (ie the page at the bottom of the stack) would have no adhesive applied to it. This would be suitable for multiple binding compressions. [0077] As shown in FIG. 15 , the binding press 20 commences downward movement toward the stack of pages 11 over the aligned adhesive strips 17 . The stack is then compressed to a bound volume 24 as shown in FIG. 16 . [0078] It should be noted that no subsequent edge trimming of the bound volume is required so long as standard-sized pages 11 had initially been used. This is because the vibrator 19 has aligned the pages into the lower-most corner 23 of tray 18 as described earlier. [0079] In FIGS. 17 and 18 , multiple volume 24 are shown stacked on upon another with the upper-most volumes being progressively compressed by repeated application of press 20 . [0080] The binding press 20 is shown schematically in the Figures and could be pneumatically or hydraulically driven, or could be driven by other mechanical means such as rack and pinion, electrical solenoid or otherwise. An alternative embodiment as depicted in FIGS. 20 , 21 and 22 incorporates a plurality of semicircular disks 20 ′ each spaced apart, but fixedly mounted to a common rotatably driven shaft extending along an axis of rotation 26 . Each disk 20 could pass through a respective vertical slot 33 formed in the end wall 31 of tray 18 . That is, there would be as many vertical slots in wall 31 as there are disks 20 . The disks could commence in the orientation depicted in FIG. 21 and upon rotation of the shaft pivot to the orientation depicted in FIGS. 20 and 22 so as to press down upon the pages. [0081] The tray 18 might be provided with a floor of adjustable height so as to always present the top page in the tray closely to the pressing device. This would reduce noise levels by minimizing the stroke length of the binding press 20 . Furthermore, the binding press 20 could be fixed and the tray could be pushed upwardly toward it to press and bind the pages. [0082] The floor of tray 18 can be driven so as to move downwardly as each page 11 is delivered thereto. This would ensure that the upper-most page always resided at the same level. This could result in reduced noise of movement of the press bar 20 as it need not move very far to effectively bind the pages. [0083] Where the pages have applied thereto adhesive strips alongside the trailing edge 28 , the press would be provided to the left as shown in FIG. 23 . In this embodiment, a pressing bar 20 ″ is provided. Any pressing arrangement could however be provided.	Provided is a printing assembly for printing and binding pages. The assembly includes pinch rollers for feeding a sheet of paper into the assembly, and a printhead arrangement arranged after the rollers for printing on the paper. The assembly also includes an adhesive applicator arranged after the printhead for applying adhesive to the printed paper, as well as a binding press arranged after the applicator for binding printed sheets of paper together.	8
BACKGROUND OF THE INVENTION This invention relates to an accessory for a riding lawnmower, more particularly, a riding lawnmower outrigger that may be permanently or removably secured to a riding lawnmower to prevent tipping of the riding lawnmower when used on sloped surfaces. Riding lawnmowers have become a popular tool for both residential and commercial purposes as the use of riding lawnmowers has many advantages over the use of traditional push lawnmowers. First and most importantly, the amount of energy expended by a person is drastically reduced when comparing the use of a riding lawnmower to a traditional push mower. Second, the amount of time expended by the person to cut a predetermined amount of grass is greatly reduced, thereby permitting a person to cut a larger amount of grass in a shorter amount of time as compared to traditional push lawnmowers. Finally, most people find riding lawnmowers much easier to use than traditional push lawnmowers. However, there is a great risk associated with riding lawnmowers that is not associated traditional push lawnmowers. When a riding lawnmower is being used on a sloped surface, such as on a hillside, ditch or other inclined area, the riding lawnmower may tip-over. Because a user sits atop a riding lawnmower, the effects of the riding lawnmower tipping over may be catastrophic as the user may obtain serious bodily injury, such as gashes and broken bones, or even die. Thus, a need exists for an outrigger for a riding lawnmower that may be permanently or removably secured to a riding lawnmower to prevent tipping of the riding lawnmower when used on sloped surfaces. The relevant prior art includes the following references: U.S. Pat. No. (U.S. unless Issue/ stated otherwise) Inventor Publication Date 2,767,995 Stout Oct. 23, 1956 3,802,720 Ellis Apr. 09, 1974 4,206,580 Truax et al. Jun. 10, 1980 3,763,956 Ruff Oct. 09, 1973 2,986,295 Shaffer May 30, 1961 6,394,738 Springer May 28, 2002 4,707,971 Forpahl et al. Nov. 24, 1987 6,722,113 Atterbury et al. Apr. 20, 2004 SUMMARY OF THE INVENTION The primary object of the present invention is to provide a riding lawnmower outrigger that prevents tipping of a riding lawnmower when used on sloped ground surfaces. A further object of the present invention is to provide a riding lawnmower outrigger that may be permanently or removably secured to a riding lawnmower. An even further object of the present invention is to provide a riding lawnmower outrigger that is easy to use. Another object of the present invention is to provide a riding lawnmower outrigger that may be adjustable. An even further object of the present invention is to provide a riding lawnmower outrigger that may be used on one or both sides of a riding lawnmower. The present invention fulfills the above and other objects by providing a riding lawnmower outrigger having a hollow outer tube having a predetermined cross-sectional shape with a first end and a second end, a telescoping inner tube having a predetermined cross-sectional shape with a first end and a second end, a means for securing the outer tube to a riding lawnmower, a means for locking the inner tube within the outer tube, a vertical tube having a top end and a bottom end wherein the vertical tube is connected to the inner tube first end, at least one outrigger wheel housing secured to the vertical tube bottom end and at least one wheel secured between the outrigger wheel housing such that the wheel rolls in a predetermined direction along with the direction of the riding lawnmower. Alternate embodiments of the present invention permit rotation of the outrigger wheel housing in a manner similar to that of caster wheels and pivoting of the outrigger wheel so as to pivot upwards and downwards according to the topography of the ground surface. To use the present invention, a user first secures the outer tube to a riding lawnmower, preferably under the riding lawnmower base. Then, he or she adjusts the length of the inner tube to a desired position and locks the inner tube within the inner tube, preferably via a pin and apertures located in the inner and outer tubes. Thus, when the user is using the riding lawnmower on a ground surface having a slope, the riding lawnmower will not tip-over or rollover because the riding lawnmower outrigger acts as a supporting arm to balance the riding lawnmower and prevent tip-over thereof. The above and other objects, features and advantages of the present invention should become even more readily apparent to those skilled in the art upon a reading of the following detailed description in conjunction with the drawings wherein there is shown and described illustrative embodiments of the invention. BRIEF DESCRIPTION OF THE DRAWINGS In the following detailed description, reference will be made to the attached drawings in which: FIG. 1 is a side perspective view of the riding lawnmower outrigger of the present invention installed on a riding lawnmower; FIG. 2 is a front plan view of the riding lawnmower outrigger of the present invention; FIG. 3 is a side view of the embodiment of FIG. 2 ; FIG. 4 is front view of a pivotal wheel used on the riding lawnmower outrigger of the present invention; FIG. 5 is a side view of the embodiment of FIG. 4 ; FIG. 6 is a side plan view of an alternate embodiment of the riding lawnmower outrigger of the present invention; and FIG. 7 is a front view of the riding lawnmower outrigger of the present invention in use on a sloped ground surface. DESCRIPTION OF THE PREFERRED EMBODIMENTS For purposes of describing the preferred embodiment, the terminology used in reference to the numbered components in the drawings is as follows: 1. riding lawnmower outrigger, generally 2. riding lawnmower 3. riding lawnmower base 4. riding lawnmower tire 5. outer tube 6. inner tube 7. outrigger wheel 8. handle 9. knob 10. vertical tube threads 11. vertical tube 12. connection tube threads 13. connection tube 14. spring 15. vertical tube aperture 16. outrigger wheel housing 17. wheel fastening means 18. inner tube aperture 19. pin 20. outer tube aperture 21. bracket 22. clamp 23. bolt 24. outer tube first end 25. outer tube second end 26. inner tube first end 27. inner tube second end 28. first plate 29. pivotal retaining means 30. vertical tube plate 31. slope 32. ground surface 33. top end 34. bottom end 35. outrigger wheel housing first side 36. outrigger wheel housing second side 37. second plate 38. outrigger wheel housing top side 39. vertical tube plate aperture 40. locking means 41. securing means With reference to FIG. 1 , a side perspective view of the riding lawnmower outrigger of the present invention installed on a riding lawnmower is shown. The riding lawnmower outrigger, generally 1 includes an outer tube 5 secured to a riding lawnmower 2 , preferably beneath a riding lawnmower base 3 , an inner tube 6 which is telescopingly adjustable within the outer tube 5 , a vertical tube 11 connected to the inner tube 6 , a handle 8 connected at one end of the vertical tube 11 and an outrigger wheel 7 connected to an opposite end of the vertical tube 11 . A spring 14 may wrap around the vertical tube 11 at a location adjacent to the outrigger wheel 7 to act as a shock absorber when the riding lawnmower 2 is used on ground surfaces. The riding lawnmower outrigger 1 is preferably secured to a riding lawnmower 2 at a substantially perpendicular angle to the riding lawnmower 2 to provide maximum support when the riding lawnmower 2 is used on a ground surface 32 having a slope 31 (see FIG. 7 ). When the riding lawnmower tires 4 move in a predetermined direction, the outrigger wheel 7 also moves in the same predetermined direction. For instance, if the riding lawnmower 2 moves in a forward direction, then the outrigger wheel 7 also moves in a forward direction. Conversely, if the riding lawnmower 2 moves in a reverse direction, the outrigger wheel 7 also moves in a reverse direction. With respect to FIG. 2 , a front plan view of the riding lawnmower outrigger of the present invention is shown. The riding lawnmower outrigger 1 of the present invention includes an outer tube 5 having an outer tube first end 24 and an outer tube second end 25 , an inner tube 6 having an inner tube first end 26 and an inner tube second end 27 . The outer tube 5 is preferably hollow having a predetermined cross-sectional shape, which is preferably square but which also may be any other shape, and the inner tube 6 preferably has the same predetermined cross-sectional shape as the outer tube 5 . The outer tube 5 preferably includes at least one outer tube aperture 20 while the inner tube 6 preferably includes at least one inner tube aperture 18 . When the inner tube 6 is secured within the outer tube 5 , a locking means 40 , which is preferably a pin 19 , is used to lock the inner tube 6 at a predetermined position within the outer tube 5 . The pin 19 is simply inserted into the desired outer tube aperture 20 and desired inner tube aperture 18 to provide a user with a customized length of the riding lawnmower outrigger 1 . A vertical tube 11 is secured to the inner tube first end 26 , preferably via a connection tube 13 . The vertical tube 11 has a top end 33 and a bottom end 34 wherein a handle 8 is secured to the top end 33 and a outrigger wheel housing 16 is secured to the bottom end 34 . The handle 8 preferably includes a knob 9 for a user to easily grasp and hold the handle 8 . Vertical tube threads 10 are located on the vertical tube 11 and correspond with connection tube threads 12 located within the connection tube 13 to permit a user to adjust the height of the vertical tube 11 in order to accommodate a user's armlength. A spring 14 is preferably located on the vertical tube 11 beneath the connection tube 13 and above the outrigger wheel housing 16 to act as a shock absorber. The outrigger wheel housing 16 includes an outrigger housing first side 35 , an outrigger housing second side 36 and an outrigger housing top side 38 which preferably form a C-shape. The outrigger wheel 7 is secured within the outrigger wheel housing 16 by a wheel fastening means 17 . The outrigger wheel housing 16 is connected to the bottom end 34 of the vertical tube 11 in such a manner as to provide rotation of the outrigger wheel housing 16 when the handle 8 is manipulated. In the alternative, the outrigger wheel housing 16 may be secured to the vertical tube 11 in such a manner so as to create a caster wheel wherein the outrigger wheel 7 is freely rotational when the riding lawnmower outrigger 1 is used. Because the outrigger wheel housing 16 , and thus outrigger wheel 7 , is rotational, the outrigger wheel 7 is able to turn when the riding lawnmower 2 turns. To secure the outer tube 5 to the riding lawnmower 2 , a securing means 41 is provided. The securing means 41 is preferably two brackets 21 having an L-shape. The brackets 21 are secured on each side of the riding lawnmower base 3 via bolts 23 which extend through the brackets 21 and riding lawnmower base 3 . Clamps 22 , which are preferably C-shaped, hold the brackets 21 on the outer tube 5 and permit a user to easily adjust the brackets 21 along the outer tube 5 to create a space wide enough to accommodate the riding lawnmower base 3 . Next, FIG. 3 shows a side view of the embodiment of FIG. 2 . The outrigger wheel 7 moves in a predetermined direction, depending upon which direction a riding lawnmower is moving, the predetermined direction which may be forward or reverse. FIG. 4 shows front view of a pivotal wheel used on the riding lawnmower outrigger of the present invention. Similar to the outrigger wheel 7 and outrigger wheel housing 16 described above, the pivotal outrigger wheel 7 is secured between the outrigger wheel housing first side 35 and the outrigger wheel housing second side 36 . However, a first plate 28 is secured between the outrigger wheel housing first side 35 and the outrigger wheel 7 and a second plate 37 is secured between the outrigger wheel housing second side 36 and the outrigger wheel 7 by a pivotal retaining means 29 . A wheel fastening means 17 secures the outrigger wheel 7 between the first plate 28 and the second plate 37 . In FIG. 5 , a side view of the embodiment of FIG. 4 is shown. Because the outrigger wheel 7 is secured within the first plate 28 and second plate 37 (not shown) and the plates 28 and 37 are secured to the outrigger wheel housing 16 by a pivotal retaining means 29 , the plates 28 and 37 , and thus outrigger wheel 7 , are pivotal in an upward and downward direction. The pivotal movement of the outrigger wheel 7 permits a wider range of use of the riding lawnmower outrigger 1 on ground surfaces having various topographies. FIG. 6 shows a side plan view of an alternate embodiment of the riding lawnmower outrigger of the present invention. Similar to the aforementioned riding lawnmower outrigger 1 , this embodiment of the riding lawnmower outrigger 1 of the present invention includes an inner tube 6 and an outer tube 5 which is securable to a riding lawnmower 2 (not shown). However, this embodiment includes a plurality of vertical tube apertures 15 extending through the vertical tube 11 . In addition, as opposed to having a connection tube 13 as shown in FIGS. 1-3 , this embodiment of the present invention includes a vertical tube plate 30 having at least one vertical tube plate aperture 39 secured on the inner tube first end 26 . In this manner, a user may adjust the height of the vertical tube 11 by inserting a pin 19 into the vertical tube plate apertures 39 and the desired vertical tube apertures 15 . Finally, FIG. 7 shows a front view of the riding lawnmower outrigger of the present invention in use on a sloped surface. Because the riding lawnmower outrigger 1 extends a predetermined distance away from a riding lawnmower 2 , the riding lawnmower outrigger 1 acts as a support arm to balance the riding lawnmower 2 when used on a ground surface 32 having a slope 31 . The use of the present invention will prevent tipping of a riding lawnmower when used on sloped ground surfaces. It is to be understood that while a preferred embodiment of the invention is illustrated, it is not to be limited to the specific form or arrangement of parts herein described and shown. It will be apparent to those skilled in the art that various changes may be made without departing from the scope of the invention and the invention is not be considered limited to what is shown and described in the specification and drawings.	A riding lawnmower outrigger ( 1 ) having a hollow outer tube ( 5 ) secured to a riding lawnmower ( 2 ), a telescoping inner tube ( 6 ) which locks within the outer tube ( 5 ), a vertical tube ( 11 ) connected to the inner tube ( 6 ), an outrigger wheel housing ( 16 ) secured to the vertical tube ( 11 ) and a wheel ( 7 ) secured within the outrigger wheel housing ( 16 ). When utilizing the riding lawnmower outrigger ( 1 ) on a ground surface ( 32 ) having a slope ( 31 ), the riding lawnmower ( 2 ) will not tip-over or rollover because the riding lawnmower outrigger ( 1 ) acts as a supporting arm to balance the riding lawnmower ( 2 ) and prevent tip-over thereof.	1
BACKGROUND The present invention relates generally to staplers, and more specifically, to staple feeding apparatus for spring powered staplers. A key for a staple to have good penetration is its entry speed. A spring powered stapler uses a spring to store energy. Upon a release of the stored spring energy, a staple can be driven out at a great speed. In traditional staplers reloading a staple magazine can be performed by simply dropping the staple magazine into a top-open staple feeding track. However, spring powered staplers have relatively complicated spring and release components housed above a staple feeding track, therefore, a bottom-open staple feeding track is need. SUMMARY In view of the foregoing, the present invention provides. The construction and method of operation of the invention, however, together with additional objects and advantages thereof will be best understood from the following description of specific embodiments when read in connection with the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS The drawings accompanying and forming part of this specification are included to depict certain aspects of the invention. A clearer conception of the invention, and of the components and operation of systems provided with the invention, will become more readily apparent by referring to the exemplary, and FIG. 1 is a side partial sectional view of a spring powered stapler with a bottom-open staple feeding apparatus in a resting position according to one embodiment of the present invention. FIG. 2 is a perspective view of the bottom-open staple feeding apparatus of the spring powered stapler of FIG. 1 in a closed and locked position. FIG. 3 is a perspective view of the bottom-open staple feeding apparatus of FIG. 1 in an unlocked, yet still closed position. FIG. 4 is a perspective view of the bottom-open staple feeding apparatus of FIG. 1 in an unlocked and opened position. FIGS. 5A and 5B are cross-sectional views of the bottom-open staple feeding apparatus of FIG. 1 . FIG. 6 is a perspective view of a front end of a U-channel staple holder. DESCRIPTION FIG. 1 is a side partial sectional view of a resting spring powered stapler in a substantially horizontal orientation. A staple driving blade 65 and a staple exit slot 16 are located at a front end of a housing body 10 of the spring powered stapler. A handle 20 is on a top and hinged to a rear end of the housing body 10 . The present invention provides a bottom-open staple feeding apparatus 5 to the spring powered stapler. The staple feeding apparatus 5 is opened from the bottom of the housing body 10 . A staple retention panel 40 is pivotally attached to a rear end of the staple feeding apparatus 5 . When the staple feeding apparatus 5 slides forward, the staple retention panel 40 can be withheld by a holding plate 14 , so that a staple magazine will be retained in the staple feeding apparatus 5 . When the staple feeding apparatus 5 slides backward, the staple retention panel 40 swings to an open position and allows a staple magazine to be dropped in the staple feeding apparatus 5 when the spring powered stapler is held upside down. Referring again to FIG. 1 , the housing body 10 contains a power spring 60 engaging the staple driving blade 65 through a driving blade opening 67 thereon. In the resting position, a front end of the power spring 60 is locked by a lock plate 70 through a lock plate opening 72 thereon. When the handle 20 is pressed down, a push-down rod 22 of the handle 20 forces the power spring 60 to bend, thereby store energy therein. The bending of the power spring 60 causes the front end thereof to withdraw from the lock plate opening 72 . After disengaging the lock plate 70 , the power spring 60 forces the staple driving blade 60 to move forcefully downward and drive out a staple (not shown) from the staple feeding apparatus 5 . When the handle 20 is released. A return spring 63 placed underneath the power spring 60 pushes up the power spring 60 with the front end thereof slides into the lock plate opening 72 . The working of the power spring 60 as described hereinbefore is just one example of numerous ways of constructing a spring powered stapler. The working of the power spring 60 is largely independent of the staple feeding apparatus 5 which will be described in more detail hereinafter. FIG. 2 is a perspective view of the bottom-open staple feeding apparatus 5 of the spring powered stapler of FIG. 1 in a closed and locked position. As shown in FIG. 2 , the spring powered stapler is placed upside down. A rear end of the staple retention panel 40 is fastened to a shaft 42 , which is mounted to a rear end of a U-channel 50 . The U-channel 50 is an elongated U shaped channel for containing a staple magazine. The staple retention panel 40 may have approximately the same or slightly bigger width than the U-channel 50 . When the staple retention panel 40 is in the closed position, the U-channel 50 is covered by the staple retention panel 40 . The U-channel 50 is horizontally slidably contained in the bottom part of the housing body 10 . During normal operations, the staple retention panel 40 , along with the U-channel 50 , is pushed toward the front end of the housing body 10 , so that the holding plate 14 prevents the staple retention panel 40 from swinging open when the spring powered stapler is set in an upright position. In order to firmly engage the staple retention panel 40 with the housing body 10 , an elastic member 102 is formed on the staple retention panel 40 , and a tip of the elastic member 102 snaps into an opening 18 on the holding plate 14 . Therefore, the holding plate 14 holds the staple retention panel 40 to the closed position and the elastic member 102 locks the staple retention panel 40 to the closed position. A skilled artisan may realize that the opening 18 on the holding plate 14 may be replaced by a concave member on the inner surface of the holding plate 14 . Referring again to FIG. 2 , when the elastic member 102 is pressed down the tip of the elastic member 102 disengages the opening 18 , so that the staple retention panel 40 , along with the U-channel 50 , is free to slide out of the frontal position of the housing body 10 . FIG. 3 is a perspective view of the bottom-open staple feeding apparatus 5 of FIG. 1 in an unlocked, yet still closed position. The tip of the elastic member 102 disengages the holding plate 14 , so that the staple retention panel 40 along with the U-channel 50 can be pulled backward. A protruding member 108 on the staple retention panel 40 facilitates the pushing-in or pulling-out of the staple retention panel 40 . The staple retention panel 40 can be made of either plastic or sheet metal material. In one embodiment of the present invention, the elastic member 102 may be formed by a separate sheet material with a rear end thereof riveted to the staple retention panel 40 . In another embodiment of the present invention, the elastic member 102 may be formed in the same processing step and by the same material, such as plastic, that form the staple retention panel 40 . FIG. 4 is a perspective view of the bottom-open staple feeding apparatus 5 of FIG. 1 in an unlocked and opened position. The spring powered stapler is held upside down. With the staple retention panel 40 along with the U-channel 50 further slides backward, the holding plate 14 can no long hold the front end of the staple retention panel 40 . Then a push-up spring 105 pushes the front end of the retention panel 40 away from the U-channel 50 . Therefore the staple retention panel 40 can be pulled wide open with an inside thereof facing up as shown in FIG. 4 . The push-up spring 105 is formed on an elongated edge of the staple retention panel 40 . When the staple retention panel 40 is in the closed position, the push-up spring 105 is pressed against a sidewall of the U-channel 50 . A skilled artisan may realize that the push-up spring 105 can be formed on both elongated edges of the staple retention panel 40 . In fact, the push up spring 105 may even be formed on the sidewalls of the U-channel 50 instead, pushing up a flat staple retention panel 40 . Referring again to FIG. 4 , with the staple retention panel 40 swings to the open position, the U-channel 50 is exposed. The opening of the U-channel 50 is facing upward when the spring powered stapler is held upside down as shown in FIG. 4 . Then a magazine of staples can be dropped in the U-channel 50 through the opening thereof. There is a drag spring 45 having a first end 48 mounted on the front end of the staple retention panel 40 , and a second end 49 mounted on a sliding block 47 . The sliding block 47 is horizontally slidably contained by the U-channel 50 . When the staple retention panel 40 swings open, the sliding block 47 is pulled backward by the drag spring 45 , so that a large portion of the U-channel 50 is exposed and ready to accept staples. When the staple retention panel 40 swings to the closed position, the sliding block 47 is pulled forward by the drag spring 45 and pushes any staple in the U-channel 50 toward the front end of the housing body 10 . FIGS. 5A and 5B are cross-sectional views of the bottom-open staple feeding apparatus 5 of FIG. 1 . Referring back to FIG. 3 , FIG. 5A shows a cross-section made at a location A-A′, and FIG. 5B shows a cross-section made at a location B-B′. Referring to FIG. 5A , there is a protruding member 147 on an outside surface of each sidewall of the sliding block 47 . The protruding member 147 fits in a horizontal concave slot 52 formed on the inside surface of a sidewall of the U-channel 50 . The horizontal concave slot 52 runs substantially across the entire elongated length of the U-channel 50 . Therefore, the sliding block 47 is slidably contained by the U-channel 50 . At the same time of forming the concave slot 52 , a protruding bar 53 can be formed on the outside surface of the sidewall of the U-channel 50 . The protruding bar 53 fits in a concave channel 19 formed on the inside surface of a sidewall of the housing body 10 . Therefore, the U-channel 50 is slidably contained in the housing body 10 . The staple retention panel 40 is stopped by the sidewalls of the U-channel 50 and substantially covers the U-channel 50 . Referring to FIG. 5B , the staple retention panel 40 is further retained by the holding plate 14 . A skilled artisan may realize that the holding plate 14 does not need to extend from one sidewall to the other. If the middle section of the holding plate 14 is left open, the purpose of holding the staple retention panel 40 can still be achieved. Additionally, there is a substantial gap between the concave channel 19 and the protruding bar 53 at the location B-B′ of FIG. 3 , because the concave channel 19 at this location needs to accommodate a protruding block 55 (shown in FIG. 6 ) sticking out from the protruding bar 53 . The concave channel 19 is deeper at the location B-B′ than at the location A-A′. Shallower concave channel 19 will stop the U-channel 50 from sliding further backward. The deeper portion of the concave channel 19 extends to a predetermined location just to allow the front end of the staple retention panel 40 to slide out of the holding plate 14 so that the staple retention panel 40 can be freely swung open. FIG. 6 is a perspective view of a front end of the U-channel 50 . The protruding block 55 is conveniently formed on the very front of the U-channel 50 . The sidewalls of the U-channel 50 are slightly longer than a bottom panel 57 of the U-channel 50 as well as the staple retention panel 40 . Therefore, when the sidewalls of the U-channel 50 are pushed against an internal frontal wall of the housing body 10 , there are still gaps for a staple (not shown) to exit the U-channel 50 when being struck by the driving blade 65 . For this purpose, the sidewalls of the U-channel 50 need to be longer than both the bottom panel 57 of the U-channel and the staple retention panel 40 by at least a wire width of the staple. The above illustrations provide many different embodiments or embodiments for implementing different features of the invention. Specific embodiments of components and processes are described to help clarify the invention. These are, of course, merely embodiments and are not intended to limit the invention from that described in the claims. Although the invention is illustrated and described herein as embodied in one or more specific examples, it is nevertheless not intended to be limited to the details shown, since various modifications and structural changes may be made therein without departing from the spirit of the invention and within the scope and range of equivalents of the claims. Accordingly, it is appropriate that the appended claims be construed broadly and in a manner consistent with the scope of the invention, as set forth in the following claims.	This invention provides a safety apparatus for a stapler, the safety apparatus comprises a first plate having a hook and a first opening, wherein when the first plate is in a first position, the hook engages a driving blade for preventing the same from driving out a staple, a second plate substantially parallel to the first plate and having a second opening, a pin having a first and second end, and a first spring urging the pin downward with the first end of the pin protruding from a bottom of a housing body of the stapler and the second end of the pin below the second plate, wherein when the housing body is pressed against an object, the first end of the pin is pushed into the housing body, and the second end of the pin is inserted into both the first and second openings.	1
BACKGROUND OF THE INVENTION In recent years, the application of permanent magnet DC motors as prime movers for machine tool feed drives have almost completely replaced the hydraulic motor. As experience was gained with the DC motor for this application, it was discovered that the method used for overload protection was ultraconservative. For certain duty cycles, the overload protection would shut the drive motor off, even though the motor temperature was hardly above the ambient temperature. The reason for this is due to the difference in the dynamic thermal characteristics between the motor and the overload relay or heater. The motor has a much high thermal inertia than the heater. Therefore, the temperature rise time (thermal time constant) of the motor is much longer than that of the heater. As a result, when a current is applied to the motor and heater in excess of their continuous ratings, the heater temperature will rise rapidly in comparison to the motor, causing the motor circuit to open prematurely; long before the motor begins to get hot. SUMMARY OF THE INVENTION An overload device having an element responding to the current in a permanent magnet DC motor is combined with a motor temperature sensor. The overload device and temperature sensor when simultaneously operated condition other control circuit elements which in turn operate a power relay to disconnect the source of electrical energy from the motor. THE DRAWINGS FIG. 1 is a schematic wiring diagram of a DC motor control circuit and its operating elements. FIG. 2 is a ladder diagram control circuit for elements of the diagram of FIG. 1. FIG. 3 is a plot of motor operation showing the results of control by the circuits of FIGS. 1 and 2. DETAILED DESCRIPTION The direct current motor 10 in FIG. 1 is energized by electrical energy from the secondary 12 of a transformer. The alternating current energy in the secondary winding 12 is rectified by the two controlled rectifier circuits 14, 16. The electrical circuit through the motor 10 is completed through an overload relay 10L to the common point on the secondary winding 12. The relay 10L is of a conventional type which operates to open contacts 10L-1 (FIG. 2) in a control circuit. The overload relay 10L is a heating type, the temperature of which is dependent upon the current passing therethrough. The energizing circuit also includes conventional fuses 18,20, the function of these being primarily to protect the rectifier circuits 14,16 from excessive current, but secondarily these also protect the motor 10 from catastrophic energy levels. The motor 10, in an application in which this invention is intended to provide protection, is in a repetitive short duty cycle such as a drilling machine spindle. Such an application demands high energy for a short time with rest periods between duty cycles. Any other similar application might be equally well served by this invention and to simplify this disclosure, the specific mechanism driven by the motor 10 has not been shown since it is not included as an element in the basic invention herein. The energy input to the system is applied through a transformer primary winding 22 that is connectable across a source 24 of alternating current electrical energy. The primary winding 22 is energized from the source 24 when normally open relay contacts 1PC-1 and 1PC-2 are closed by operation of a control circuit such as shown in FIG. 2. One other important element is shown representatively in FIG. 1. This is the snap action thermostat 26 which is applied to the casing of the motor 10 to sense the temperature of this inclosure structure of the motor 10. The temperature of the motor casing lags the temperature of the armature of the motor 10 but nonetheless is proportional to the temperature of the armature at any time over which heating occurs. The thermostat 26 might be for example, the type obtained from Texas Instrument Corporation and sold with the trademark "Klixon." One type used in a drilling machine application and found satisfactory was a No. 20700L/L135-1.5 "Klixon" snap action thermostat. This thermostat opened contacts when heated to 135° F., ±5° and closed when returned to 120° F., ± 6°. The control circuit of FIG. 2 includes a control relay 1CR that is energized whenever the snap action thermostat 26 is below the temperature at which it snaps open, taking into account the relay hysterisis when once opened. When energized, the relay 1CR closes its contacts 1CR-1 and 1CR-2 in circuit with the relays 2CR and 3CR, respectively. The relay 2CR is energized when either the contacts 1CR-1 or normally closed contacts 10L-1 of the overload relay 10L are unoperated. The relay 3CR is initially energized when both the contacts 1CR-2 and 2CR-1 are closed, this occurring when both relays 1CR and 2CR are energized. A latch comprising the contacts 3CR-1 holds relay 3CR energized even if the relay 1CR thereafter deenergizes to open the contacts 1CR-2. A power control relay 1PC is first energized when a master start switch 1PB is closed and the contacts 3CR-2 are closed by energization of relay 3CR. A latch is provided around the switch 1PB through a serial circuit including a normally closed stop switch 2PB and contacts 1PC-3 closed when relay 1PC is energized. The contacts 1PC-1 and 1PC-2 are closed when relay 1PC is energized and therefore the source 24 is connected across the winding 22 (FIG. 1). From the preceding description it can be seen that the power control relay remains energized whenever the contacts 3CR-2 are closed and the switch 2PB is not operated. The relay 3CR in turn can only remain energized when relay 2CR is energized. The relay 2CR is energized when either of two conditions is fulfilled. First, the snap action theremostat 26 is not actuated to deenergize relay 1CR or second, the overload relay 10L has not reached its actuating temperature. Once deenergized, the relay 3CR can only be reenergized when both relays 1CR and 2CR are energized. To start the motor 10 and continue its operation by use of the circuit of FIG. 2, there is an "and" condition that must be met and this condition is dependent on the snap action thermostat 26 and the overload relay 10L. The effect of the circuits described is shown graphically in FIG. 3. The diagram is that obtained for operation of a Getty 20 direct current motor obtained from Getty Manufacturing Company and with use of the snap action thermostat 26 described previously herein. The relay 10L is a type 816 -COV16, with a N39 element, both obtained from the Allen-Bradley Company. The fuses 18,20 standard FRN30 fuses. The curve ABC illustrates the operating conditions of the overload relay 10L on a time versus motor current plot. The curve DE represents the operation of the fuses 18,20. The curve FEBG represents the operation of the snap action thermostat 26 when applied to the closing of the motor 10 as described herein. By including in the control circuit the AND condition of the overload relay 10L and the thermostat 26, an area of increased system performance represented by the shaded area bounded by curves AB, BE and ED is obtained, it being presently conventional to supply only the circuit overload such as provided by relay 10L. The AND condition further does not sacrifice protection performance beyond the cross-over point B which might be made should the thermostat 26 be relied upon alone. The shaded area between curves BC and BG represents the area in which sacrifice of performance would be made in relying on the thermostat 26 alone. The fuses 18, 20 continue to provide protection against a catastrophic failure in the rectifiers 14,16 but this would ordinarily be at a power level substantially higher than usual operating levels as indicated by the curve DE. This invention provides increased utility in short cycle operation by permitting the direct current motor 10 to operate in short cycles on a repetitive basis at instantaneous power ratings above what might be considered normal. Since protection against excessive heat is still provided, no harm to the motor occurs. In addition, conventional constant duty protection is also provided without sacrifice. The gain in motor utility is provided by taking advantage of the much higher thermal inertia of the motor 10 itself as compared to the overload relay heater 10L. While the invention has been described in the context of the apparatus specifically disclosed herein, it is understood that variation in exact arrangement of circuits and control elements can be made within the scope of the claims following.	There is shown and described herein a D.C. motor control circuit which provides both overheat protection and current overload protection. The circuit provides for continued motor operation in short-duty cycles while operating in a current overloaded condition so long as the temperature of the motor has not exceeded a predetermined level past which damage might be expected.	7
BACKGROUND OF THE INVENTION [0001] The current invention is at the field of infant and children healthcare and safety and, more specific, it aspires to ease the difficulties of the child during situations which he couldn't control or help himself, like falling asleep during traveling in the car or in front of the television, his body twisted and it's sometimes impossible to help him. [0002] It's a well known among the experts, the parents or others that a child that falls asleep can find himself in some distorted positions, which are neither natural nor comfortable. It's a well known fact that, in our time and era, the kids spend substantial part of the day in a day care or with a nanny that handle more then one kid at once, and one can find himself sleeping in front of a T.V or in a safety seat in the wrong position for a long time. His head will be leaning down or turn aside on his shoulder, in an unhealthy way. [0003] The describe situation takes place even if the parent or the nanny is solely responsible on one kid! A lot of moms, after giving birth, are mentally and physically depressed, or managing the house or not noticing the infant condition if he is not crying. [0004] A common situation is during a car journey when both parents sit in the front seats and the infant is in the back seat. There is no safe way to change the safety seat to the infant needs. [0005] The majority of the situations mentioned deals with kids from infant stage till 8-9 years old, when they are not capable of taking care of themselves and, most of the times, don't even recognize the problem. [0006] While driving the car, the situation is even more complex. Even if the adult noticed the problem, He can't handle it without full stop and the ages of the kids can go up to 9-10 years old (depend on the legal age of every state). [0007] After saying that, it is only appropriate to offer an answer to these problems. Offers of manually, semi-automatic or fully automatic devices of changing angles and positions for the adults or for a child sovereign enough to take care of himself. [0008] There's a foreseeable need for an invention which includes a system or device that shifts and changes the position and angle of the seat, bed or mattress in present time or in future times according to the expectations without the need of being near the device during the position changing. In addition, there's a need for appropriate solutions for a situations when the kid is old enough and independent. [0009] A possible solution, for the current invention, is the possibility of programming a future time, either mechanically or digitally or electronically way, that in a given time gives an order to change the angle of the device to a wanted position. [0010] Another possible solution, to the current invention, is a mechanic or digital or electric system which enables programming changing the angle and position, both for future time or immediately, by an adult or the child himself. SUMMARY OF THE INVENTION [0011] The main purpose of the invention is to enable, whether in a safety seat, a mattress or in an infant bed, a future or present plans and orders to angles and positions changes. [0012] The current invention enables a baby or a kid a seat, like moveable seat, that structured to be used both indoors and outdoors, or indoors only or outdoors only, that suitable for angle and position change, between 90 degrees to 180 degrees, according to the child needs. The system manages and remotes whether mechanically, digitally or electrically, as part of the whole system or as a wire or wireless remote control. [0013] The control and managing system of the angle and position can be used both in a future orders or in immediate ones, or combination of both orders from 90 degrees position to 180 degrees and vice versa. [0014] The mechanic or electric system that actually enables the positions changing could be a system which influence the front of the infant seat, and by doing so, pushes back the angle of the seat back rest, or a system that changes the angle of the back rest itself, or a system that, simultaneously, the two of them, front and back rest. The system could be an integral part of the seat or an attached part to the seat or a part which the seat attached to [0015] The forces of the system mentioned above could be from air blowup and emptying system, which change the extent of the surface area, whether if increasing or decreasing it, according to the needed position. The system could be of a motorized cog-wheel which enables, for example, the back rest shift and changing the angles toward horizontal or a sitting angle or any angle between them. [0016] The current invention also takes place when the whole device is controlled with an electric system and power source (as a recharged battery and a car battery). In this case the manual grip pole, function as a steering stick, can contain a wired controller which operates the system. A device that is also electrical and already includes electric energy method optionally could have a light measures, a vocal measures, a whistle, a music capabilities, a vocal recognition of the owner and plenty more options for the convenience and safety of the child. BRIEF DESCRIPTION OF THE DRAWINGS [0017] The added drawings in this patent request come in order to provide more visual understandings about the invention and are integral part of the request and the invention. The drawings describe different functions of the invention and, added to all the mentioned above, serve the purpose of explaining the principles and ways of operation and not, by any means, suppose to limit the invention solely to them. [0018] Draw no. 1 is a schematic description that shows an example, included in the current invention, of a moveable infant seat with a device in the front part of the seat and optional alternative, or second, system at the back part of the seat. [0019] Draw no. 2 is a schematic description that shows another function of the invention. A moveable infant safety seat that include manage and operation system of the seat and the angle's diversion of the back seat. [0020] Draw no. 3 is a schematic description that shows another function of the invention. It shows an external connector for an infant safety seat with the other mentioned functions. [0021] Draw no. 4 is another external connector as in draw no. 3 but in a different form and shape. [0022] Draw no. 5 is a schematic description that introducing another function of the invention as in external coordinator for an infant safety seat, including the possibility of angle's diversion of the seat. [0023] Draw no. 6 is a schematic description that shows a mechanic system for diversion of a defined part of the seat; including the option of swinging it for the baby's pleasure during the process. DESCRIPTION OF THE PREFERRED EMBODIMENTS [0024] Draw no. 1 of the current invention apply an example of a moveable infant and children safety seat 100 including systems 110 and 112 on the front part of the seat and, optionally, system 104 and 106 alternative or extra at the back seat 100 when the front system 110 and 112 enables, at the time when the baby sits in his place 114 , to adjust the device to a future time according to our predicted need. On the right time, the front system part 112 will open towards the floor or the flat place of the seat and push the front seat up and, respectively, the back part of the seat will move and come closer to a sleeping angle of an infant. After operating 112 by foot there's an option of the foot system 110 will get active and make a secondary push in order to come as close as possible to 180 degrees of the baby and the moveable seat 100 . Units 100 or 112 could be operated by foot, or alternatively options that create the same outcome. For example, system units which puff up on demand and increase the surface area and, by doing that, push the seat towards horizontal position and vice versa. The systems located in the back seat 102 , which are 104 and 106 , could be parallel systems which operates parallel to the front system or as independent systems, and then, while the gravity is towards the back of the seat, opening or closing of the 104 and 106 devices, will allow a change of position as needed. [0025] Draw no. 2 of the current invention presents other implementation of safety seat 120 include operating and managing system 134 and 132 of the seat and back of seat diverse angle systems. The seat base 122 is in a relative stable position of angle but capable of moving forward and backward relatively to the angle and position changes of the back of seat 124 , when the managing system 134 simulate a mechanic managing system that turn as a turning button towards future operating time. When the time arrives, the system, mechanic or electronic, moves the back of seat 124 to the already adjusted angle or formerly programmed and fed in the operate button 134 or other device. Operate system 132 simulate a digital managing system or electric, futuristic or simultaneously when ordered, of direct and change of angle and position states of seat as in 132 , 130 and 128 . 132 , 130 and 128 , themselves, could be part of a structure which works like a bellows, that enables at the opening between the surface of the back of the seat 124 to the lower space of part 128 , when a full opening will cause a sitting position and the closing of the gap to the minimum, will cause the part 124 come closer to the ground and to a horizontal position of the device 120 . Wire remote 136 , in the current implementation, is a controlling option of the system and device and, obviously, a managing system by remote control can be also possible under the current invention. [0026] Draw no. 3 of the current invention presents example 140 which shows external connector 142 for babies and children moveable seat 144 , including a possibility of diversion of angle, when the moveable external device 142 includes a diversion programming and timer 146 and connectors 150 and 148 , that become possible in the connection between the 142 part and the seat 144 in a way the connectors 150 and 148 has a shortening and lengthening capabilities 152 . Extending it, the seat 144 moves toward a “lying down” position and shortening it moves the seat 144 back into sitting position. Needless to say those connectors 150 and 148 are not the only possible ones and they only a suitable example to other connectors, like to a safety belt 152 , which exist in almost any type of a moveable infant safety seat. [0027] Draw no. 4 of the current invention 180 presents external connector 188 for safety seat 182 , includes a possibility of seat's angle diversion, when the part 188 includes diversion and timing managing system which enables, with the help of connector 190 , that acts as a mediator for the device system 192 , in a way of pulley block that enables pulling or releasing of connector 190 that attached to the back rest 186 . [0028] Draw no. 5 presents a schematic of another function within the contents of the invention. An external coordinator 200 which includes an option of attaching or placing the safety seat 220 to him, or of using him as a seat itself, and has, at least, two positioning angles, like surface units 212 and 210 and 208 at the back rest of the seat and, respectively, as a possible option, a front seat units like 206 , 204 , 202 , when the 200 device basis is unit 214 , that includes parts of programming managing system and operate of blowing up and emptying air of puff up components like samples 212 , 210 , 208 , 206 , 204 , 202 . The purpose is to change the seat angles and positions between sitting positions to lying down positions, optionally with an early programming or planning of the time and wanted angle and at the right time the system will automatically perform the order, or, respectively, as a tool for instant operation of the seat system if the baby falls asleep and we don't want to disturb him by doing things roughly. [0029] Draw no. 6 is a schematic description of another implementation, within the content of the current invent, that presents a mechanic system for diversion of specific part of the safety seat, includes the possibility of swinging during the process.	The current invention renews, in a system and device method, a needed answer to a situation when an infant or a child shift\change his, or her, position when awake or fell asleep. The purpose of the current invention is to offer a various solutions of safety seats, beds or mattresses adjustments, whether in an automatic way, semi automatic or manually, which deliver the right, and healthy, angle for the child (till full horizontal)	0
BACKGROUND OF THE INVENTION Field of the Invention This invention relates to soft, absorbent and bulky cellulosic fibrous webs which have been treated so that they impart a soothing or emollient effect to the human skin when used for wiping or drying while essentially retaining their water-absorbent property and strength. The agent used in the present invention is lauroamphoglycinate. HISTORY OF THE PRIOR ART It has heretofore been suggested to treat cellulosic fibrous webs with lanolin to impart a feeling of softness to the webs. See, for example, Wemyss, et al., U.S. Pat. No. 2,877,115 and Yang, U.S. Pat. No. 2,944,931 or with other fatty solids, see Britt, U.S. Pat. No. 3,305,392 However, such a treatment has the disadvantage that the water absorbency of the cellulosic web is dramatically reduced by the application of these fatty-type materials, so that the web can no longer satisfactorily perform a wiping or drying function in reference to moist skin. SUMMARY OF THE INVENTION The present invention has as its object rather than imparting the feeling of softness to cellulosic webs, the imparting to the human skin an emollient or soothing effect through wiping with a cellulosic web while retaining the drying and strength characteristics of the untreated web. In many environments such as hospitals and clinics, persons are required to frequently wash and dry their hands. This can produce skin irritation, particularly in cold weather. Also, persons suffering from the common cold must frequently apply facial tissues. Also people suffering from diarrhea must use large quantities of toilet tissue. Repeated wipings with treated toilet tissue has been found to condition the perineal region so that it maintains a non-irritating condition. likewise, a soft feeling is achieved after using facial treatment in the manner of this invention so that the nasal skin is left with a velvety soft feeling even after repeated wipes. The present inventors have found that the water absorbency can essentially be retained while imparting a skin smoothing character to webs for drying or wiping the skin by treating soft absorbent cellulosic webs with a formulation consisting of amphoteric lauroamphoglycinate containing a nonionic surfactant and phosphoric acid. Products made from such webs exhibit the ability to transfer chemicals from the cellulosic fibrous web to the skin generating emollient benefits while concomitantly successfully executing the primary function of the product which is to wipe or dry the skin. Webs treated with lanolin, by contrast, are markedly inferior in producing the desired benefits and are even perceived in some cases as irritating or to cause itching. This may be attributable, not only to the fact that some people are allergic to lanolin, but also as observed by Jacobi, et al., U.S. Pat. No. 3,231,472 dry skin is not caused by the loss of fat material in skin but by the loss of the water soluble constituents therein. In accordance with the present invention, lauroamphoglycinate is applied to a web of cellulosic fibers in an amount from 0.1 to 2% by weight of the web. Lauroamphoglycinate is the amphoteric organic compound that conforms generally to the formula: ##STR1## As will be readily appreciated, the fact that the polymers of the present invention are water-soluble totally distinguishes the treatment of the present invention from that of the lanolin treatments of the prior art. Indeed, insofar as the present inventors are aware, lauroamphoglycinate has not been recognized as a skin moisturizer. DETAILED DESCRIPTION For the purpose of illustrating the present invention, paper webs having a basis weight of 54 g/m 2 (32 pounds per ream of 2,880 square feet) were treated in the finishing process at a point after the paper has been unwound from the parent roll and embossed, but before the slitting, folding, cut off stacking and wrapping processes. The treating fluid, comprising the active ingredients dissolved in water, is applied at a rate to yield the addition of between 0.034 to 1.086 g/m 2 (0.02 to 0.64 pounds per ream) of lauroamphoglycinate or 0.1 to 2.0% by weight of the web. For toilet tissue such as Scott COTTONELLE or 2-ply facial, another example illustrating the present invention could be paper webs having basis weight of 27 g/m 2 (16 lbs. per ream) of 2,880 square feet were treated at location similar to that disclosed above. The treating fluid comprising the active ingredients dissolved in water is applied at a rate to yield an addition of between 0.017 to 0.543 g/m 2 (0.01 to 0.32 lbs./ream of the compound or 0.1 to 2% by weight of web. Any application technique known in the art which does not unduly compact the web and which evenly distributes the fluid at the desired rate onto the paper web may be employed. These application techniques include spraying, transfer roll coating and gravure printing. If compaction caused by gravure printing is considered too great to the finished product, this step may be carried out prior to the step of bulking by embossing. The amount of compaction which can be suffered is influenced by numerous variables much as the original bulk of the web, consumer expectations regarding bulk and the perceived need for patterned printing which can be achieved by gravure roll methods. The present inventors have found that the benefits perceived by users are best achieved by spraying the treating fluid onto the web. In the examples which follow present inventors employed a method described by them as a doctored kiss roll method. In this process, the path of the paper web is directed over an application roll which rotates in the same direction as the travel of the paper. This roll, which has a smooth surface, for example polished chrome, rotates partially submerged in a bath of the fluid to be applied. As the roll rotates, it picks up a layer of liquid on its surface. The thickness of this layer is determined by the viscosity of the fluid. This layer is then metered to the desired thickness by doctoring the excess off of the roll. The paper, moving faster than the surface of the roll, then wipes the doctored layer of fluid from the roll. The rate of application for a given paper speed and fluid is controlled by adjustment of the speed of rotation of the coating roll; the angle of wrap (contact with the roll) of the paper over the coating roll; and the type of and setting of the doctor. These adjustments are made as required to deliver the desired quantity of fluid to the web for a given web speed and fluid. A sheet was prepared as follows: To paper web having a basis weight of 32.8 pounds per ream of 2880 square feet (55.6 grams per square meter) was applied in the above described manner a quantity of alcolac DV-1995 containing principally lauroamphogylcinate with phosphoric acid and a nonionic surfactant to yield a lotionized sheet containing 0.64% lauroamphoglycinate by weight of web. This example illustrates the ability of people to discern differences and benefits from towels treated in accordance with this invention as compared to untreated towels and to appreciate that the functional properties of the treated towels remain unchanged. These products exhibit the ability to transfer chemicals from the cellulosic fibrous web to the skin generating emollient benefits while concomitantly successfully executing the primary function of the product which is to wipe or dry the skin. The methodology employed involved choosing a panel of normal, healthy individuals and observing whether this panel (which consisted of eleven members) would be able to perceive beneficial differences amongst treated towels and untreated Scott Brand 150 C-fold towels, the towels were presented to the panel with a code number so that the sample identifications were unknown to each panelist. The investigation was carried out privately by each panelist so that there was no interaction with other panelists. Each panelist was to wash their hands with luke warm tap water and a mild liquid soap and then their hands were dried with an untreated towel. The subjects knew specifically that these towels were normal untreated towels and that these towels were utilized as a reference standard. The subjects were then asked to rewash their hands using an identical procedure and this time they were asked to dry their hands with a coded unknown towel. Included amongst the coded samples was a placebo sample containing untreated towel. After the eleven panelists had completed their evaluation, the scores were totaled and are herein shown in the Table I. Each sample was rated on a scale of zero to ten so that the maximum score would have been 110. The panelists were asked to rate the treated and untreated sample with regard to skin benefit. Besides a subjective functional evaluation of treated verses untreated towel (especially with regard to the key towel properties of strength and absorbency) an objective laboratory test evaluation of the sample was undertaken. These results show that the treated towel remained essentially unchanged in physical properties when compared to the untreated control. TABLE 1______________________________________Evaluation of Treated TowelsSample Designation Rating______________________________________Untreated towel used as placebo 22Lauroamphoglycinate 46______________________________________ This sample clearly shows that the unknown placebo sample is rated significantly lower than either of the treated variants when consiered with respect to skin comfort and functionality.	Disclosed are soft, absorbent and bulky cellulosic fibrous webs which have been treated so that they impart a soothing or emollient effect to the human skin when used for wiping or drying while essentially retaining their water-absorbent property and strength. The agent used in the present invention is lauroamphoglycinate.	3
CLAIM OF PRIORITY [0001] This application relates to and claims priority to U.S. Provisional Patent Application entitled “Pulsed Air-Actuated Micro-Droplet on Demand Ink Jet” filed Aug. 25, 2010 and assigned U.S. Application Ser. No. 61/376,942; the entire disclosure of which is hereby herein incorporated by reference. TECHNICAL FIELD [0002] The exemplary teachings herein pertain to methods and systems for ink jet heads for ink jet printers or other liquid jetting devices, and in particular, to a pulsed air-actuated micro-droplet on demand ink jet head. Specifically, the present disclosure relates to an ink jet head using pulsed air to extract and propel micro-droplets from a needle-shaped orifice at high velocity, for jetting high viscosity liquids with drop-on-demand requirements. BACKGROUND [0003] As is known in the art, ink jet printers use one or more ink jet heads for projecting drops of ink onto a printing medium (such as paper) to generate text, graphical images or other indicia. Drops are projected from a minute external orifice in each head to the printing medium so as to form the text, graphical images or other indicia on the printing medium. A suitable control system synchronizes the generation of ink drops. It is important that the ink drops be of substantially uniform size, and also that the drops are applied consistently onto the printing medium so that printing is not distorted. [0004] Existing ink jet technology, whether it is thermal jet or piezo-jet, can only jet micro-droplets with low viscosity liquids (typically 2-15 centistokes), such as water based inks, and only for short printing distances. In such existing ink jet technology, a pressure pulse is applied to a fluid chamber with sufficient pressure to overcome surface tension forces, thereby forming and ejecting a droplet of fluid from the ink jet nozzle. However, for jetting higher viscosity liquids (greater than 100 centistokes) with drop-on-demand requirement, there is no known ink jetting method. [0005] In one basic type of ink jet head, ink drops are produced on demand, for example as disclosed in U.S. Pat. No. 4,106,032 issued to Miura, et al. on Aug. 8, 1978, the entire disclosure of which is herein incorporated by reference. In such drop-on-demand ink jet heads, ink in an ink chamber in the ink jet head, in response to a pressure wave generated from an electric pulse applied to a piezoelectric crystal, flows through an ink passageway in an ink chamber wall and forms an ink drop at an internal drop-forming orifice outlet located at the outer surface of the ink chamber wall. The ink drop passes from the drop-forming orifice outlet, through an air chamber, and toward a main external orifice of the ink jet head leading to the print medium. Continuous air under pressure is delivered to the air chamber and propels the ink drop through the air chamber and to the print medium. [0006] However, such prior art drop-on-demand ink jet heads suffer from numerous disadvantages, drawbacks and/or limitations, for example as discussed in U.S. Pat. No. 4,613,875 issued to Le et al. on Sep. 23, 1986, and in U.S. Pat. No. 4,728,969 issued to Le et al. on Mar. 1, 1988, the entire disclosures of these patents are herein incorporated by reference. In an attempt to improve upon such prior art drop-on-demand ink jet heads, Le et al. discloses in the '875 patent an ink chamber with an ink drop-forming orifice outlet from which ink drops are generated in response to pressure waves caused by a piezoelectric crystal. This internal orifice outlet is centered in a projecting structure which extends toward an external orifice. The projecting structure is of a frustoconical or mesa-like shape. As stated therein, air flowing past the top (orifice outlet) of the projection prevents ink from wetting anything but the top of the projection, resulting in highly uniform ink drop formation with a single uniform dot being produced on the printing medium in response to each pressure wave. [0007] Reproduced herein as FIG. 1 , for the purpose of illustration, is the prior art FIG. 2 from the '875 patent to Le et al. showing this projecting structure of Le et al. As can be seen therein, the projection extends a length “D” into an annular air chamber, almost completely to the external orifice, with only a small spacing “E” there between. Le et al. discloses that the length of the projection is in the range of 50-90 μm with a preferred distance of 60 μm. [0008] However, this configuration suffers from numerous disadvantages, drawbacks and/or limitations itself. For example, Le et al. uses continuous air flow to accelerate the ink drop. As such, if the velocity is too high, the continuous air flow will adversely affect the ink drop as it is propelled to the printing medium, resulting in a poor or failed printing result. If the velocity is too low, then the ink drop will not properly form and will not be propelled at a high enough velocity, again resulting in a poor or failed printing result. These limitations are particularly apparent with higher viscosity liquids. [0009] Therefore, a need exists for an improved air assisted drop-on-demand ink jet head which is directed toward overcoming these and other disadvantages of prior art devices. Accordingly, to address the above stated issues, a method and system for jetting high viscosity liquids to form micro-droplets and at high velocity for achieving increased print distances is needed. The exemplary teachings herein fulfill such a need. It is desired that the methods and systems for providing the above benefits be applicable to any instances or applications wherein micro-droplets of high viscosity liquid are to be dispensed. SUMMARY [0010] The exemplary technique(s), system(s) and method(s) presented herein relate to a pulsed air-actuated micro-droplet on demand ink/liquid jet, and in particular for jetting higher viscosity liquids with drop-on-demand requirement. The exemplary method and system include utilizing a needle extending from an ink chamber, the needle terminating in an ink drop-forming orifice outlet from which ink drops are generated, and at least two air jets directing a non-continuous or pulsed air flow at the ink drop-forming orifice outlet of the needle. The pulsed air is synchronized with the generation of a desired volume of ink at the orifice outlet to extract and propel a micro-droplet at high velocity for printing. [0011] In use, ink from an ink chamber is supplied through the needle to its ink drop-forming orifice outlet, and the desired volume is pushed by a suitable actuator to the exit of the orifice and exposed. At least two air jets on opposite side of the exposed ink at the exit of the orifice are used to extract the volume of ink to produce a micro-droplet. The air jets produce a timed pulse of high velocity air to break off the micro-droplet and propel it onto the printing medium. The air jets are turned on prior to or contemporaneously with the forming of the desired volume at the exit of the orifice outlet of the needle, and turned off after the micro-droplet had been produced. A suitable control system synchronizes both the generation of desired volume at the needle orifice and the timing of the pulse of high velocity of air from the air jets. In this manner, micro-droplets on demand can be produced for liquids in a wide range of viscosities, and for printing at greater print distances. [0012] Additional objects, advantages and novel features will be set forth in part in the description which follows, and in part will become apparent to those skilled in the art upon examination of the following and the accompanying drawings or may be learned by production or operation of the examples. BRIEF DESCRIPTION OF THE DRAWINGS [0013] The drawing figures depict one or more implementations in accord with the present teachings, by way of example only, not by way of limitation. In the drawing figures, like reference numerals refer to the same or similar elements. [0014] FIG. 1 is an illustration of a prior art air assisted drop-on-demand ink jet head; [0015] FIGS. 2A , 2 B, 2 C and 2 D are schematic depictions of the formation of a micro-droplet by the method and system of the present disclosure; and [0016] FIG. 3 is a schematic depiction of an exemplary embodiment of the needle extending from an ink chamber, and an actuator used to expose the desire volume of ink at the orifice outlet of the needle. DETAILED DESCRIPTION [0017] The following description refers to numerous specific details which are set forth by way of examples to provide a thorough understanding of the relevant teachings. It should be apparent to those skilled in the art that the present teachings may be practiced without such details. In other instances, well known methods, procedures, components, and circuitry have been described at a relatively high-level, without detail, in order to avoid unnecessarily obscuring aspects of the present teachings. While the description refers by way of example to ink and ink jet printing, is should be understood that the method(s) and system(s) described herein may be used for jetting any type of liquid of various viscosities, and for application to any type of substrate, for example, wood, metal, plastic, textiles, etc. [0018] The description now proceeds with a discussion of FIGS. 2A-2D , which depict by way of example the following: FIG. 2A illustrates the initial formation of the desired volume of ink at the orifice outlet of the needle, and the beginning of the timed pulse of air from the air jets. FIG. 2B illustrates the initial formation of the micro-droplet by the pulsed air from the air jets. FIG. 2C illustrates the breaking away of the micro-droplet from the supply of ink and the orifice outlet of the needle, and the acceleration of the micro-droplet toward the printing medium. FIG. 2D illustrates the completed micro-droplet exiting the external orifice of the ink jet head, and the ending of the timed pulse of air. [0019] Accordingly, FIGS. 2A-2D illustrate schematically a cross-sectional view of the ink drop-forming portion of an exemplary ink jet head of the system 10 of the present disclosure. As can be seen, the end of a needle 20 terminates in an orifice outlet 30 . A first air jet 40 and a second air jet 50 are positioned at opposite sides of the orifice outlet 30 for directing a timed pulse of air at the orifice outlet 30 . An external orifice 60 of the exemplary ink jet head is located under the orifice outlet 30 of needle 20 . The external orifice 60 is axially aligned with the needle 20 and its orifice outlet 30 . [0020] Turning now to FIG. 2A , an initial formation of the desired volume 70 of ink 80 is formed at the orifice outlet 30 of the needle 20 by a suitable actuator, such as a piezoelectric crystal, a piston, or any other suitable actuator capable of pulsing the ink from an ink chamber into and through the needle 20 . The actuator force need not be sufficient to fully eject a droplet from the needle outlet. The desired volume 70 is depicted as the generally semi-spherical projection of ink extending out from the orifice outlet 30 of the needle 20 . Prior to or simultaneously with the formation of the desired volume 70 , the first air jet 40 and the second air jet 50 are activated in concert to deliver a timed pulse of air at the desired volume 70 . [0021] As a result, the force of the pulsed air from the air jets 40 and 50 squeezes the desired volume 70 , as illustrated in FIG. 2B , until the desired volume 70 breaks free from the remainder of the ink 80 in the needle 20 , as illustrated in FIG. 2C , thus creating the micro-droplet 70 a . As illustrated in FIG. 2C , the force from of the pulsed air from the air jets 40 and 50 continues to accelerate the micro-droplet 70 a out of the external orifice 60 and towards the printing medium. [0022] Once the micro-droplet 70 a is formed and propelled out of the external orifice 60 , the air jets 40 and 50 are deactivated, as illustrated in FIG. 2D . By utilizing a timed pulse of air to create and accelerate the micro-droplet 70 a using the method described above, a micro-droplet smaller than the diameter of the orifice outlet 30 can be created and accelerated at a high enough velocity for proper jetting, and at longer print distances. This is true even for high viscosity liquids. Ending the timed pulse of air at the time illustrated in FIG. 2D ensures that the micro-droplet 70 a will maintain its integrity as it travels to the printing medium at high velocity. A continuous high velocity air flow will shear the ink drop, produce long “tails” of ink trailing the ink drop, or otherwise adversely affect the integrity of the ink drop and result in improper or otherwise flawed application to the printing medium. [0023] Referring now to FIG. 3 , an exemplary embodiment of the disclosed method and system is illustrated. A piston housing 100 is illustrated having an ink chamber 110 terminating in a piston housing orifice 120 having a diameter D o . A needle 20 is suitably attached to the piston housing orifice 120 . The needle 20 having the same or substantially the same diameter as the piston housing orifice D o . The needle 20 further defining a length or liquid length S o . A piston 130 is operatively positioned inside the piston housing 100 and is moveable therein at a piston stroke distance of S p . The piston 130 has a piston diameter of D. It should be understood that the piston 130 is moved via a suitable piston control system which actuates the piston 130 on demand, wherein the piston 130 travels the piston stroke distance S p to push a desired volume of ink out of the ink chamber 110 , into and through the needle 20 and out of the needle orifice outlet 30 , as illustrated in FIG. 2A . [0024] While the actuator in FIG. 3 is illustrated as a piston 130 , it should be understood that any suitable actuator may be used to push a desired volume of ink out of the needle 20 as shown in FIG. 2A . For example, a piezoelectric crystal may be used instead of a piston, as disclosed in the '875 patent referenced above. [0025] Numerous factors affect the size of the ink drop, i.e. droplet diameter, and the jetting of the ink drop to the print medium. Such factors include acceleration time Δ t , orifice area A o , piston area A p , piston acceleration a p , orifice diameter D o , piston diameter D P , force on piston F p , piston mass M p , liquid column length S o , piston stroke S p , average liquid velocity U o , liquid final velocity at orifice U o,f , liquid initial velocity at orifice U o,i , average piston velocity U p , piston final velocity U p,f , piston initial velocity U p,i , liquid density ρ, and surface tension σ. In accordance with the presently disclosed method and system, it has been determined that the size of the ink drop, or more specifically the diameter of the droplet D d , can be calculated using the following equation: [0000] D d = ( 6  σ ρ  M p F p  D o 3 D p 2 ) 1 3 = ( 6  σ ρ  M p F p  S p  D o D p 2 ) 1 3 [0026] It can thus be seen that droplet volume is proportional to the ratio of surface tension to liquid density. Droplet volume is inversely proportional to acceleration. Droplet volume is proportional to the ratio of the cube root of the orifice diameter or D o 3 to the square root of the piston diameter or D p 2 . It can also be seen that higher acceleration produces smaller droplet volume. To get higher acceleration, a longer stroke length is generally needed, otherwise a huge amount of energy must be supplied. However, a longer stroke generates a larger droplet volume. To get small droplet volume, a short stroke must be used, but then high acceleration cannot typically be obtained. The present method and system, however, is able to use a short stroke to produce a small droplet volume, while simultaneously achieving high droplet velocity. [0027] In the presently disclosed method and system, only a micro-volume of ink is needed to be present at the needle orifice outlet, and the timed pulse of air from the air jets is used to extract the micro-volume. The timed pulse of air from the air jets is able to accelerate the droplet up to 340 m/s (sound velocity). Accordingly, the timed pulse of air from the air jets supplies the energy needed to extract the micro-droplets from high viscosity liquids and accelerate them to high velocities. The timed pulse of air also keeps the orifice clean, keeps the drop straight as it travels to the print medium, and adds extra detachment force. [0028] By way of example, the embodiment illustrated in FIG. 3 was used to jet micro-droplets of 30W Motor Oil. In this example, the orifice diameter D o was 152 μm and the piston diameter D p was 850 μm. Using a piston stroke S p of 100 μm, the timed pulse of air from the air jets produced and accelerated at high velocity micro-droplets having a diameter D d less than the orifice diameter D o . While the above stated dimensions are illustrative of the operation of the exemplary method and system, it should be understood that various modifications may be made to these dimensions with departing from the teachings herein. [0029] While the foregoing discussion presents the teachings in an exemplary fashion with respect to the disclosed method and system for pulsed air-actuated, high velocity micro-droplets on demand for high viscosity liquids, it will be apparent to those skilled in the art that the teachings may apply to any type of device that produces and applies droplets of liquid to a substrate (e.g., painting, soldering, printing, etc.). Further, while the foregoing has described what are considered to be the best mode and/or other examples, it is understood that various modifications may be made therein and that the subject matter disclosed herein may be implemented in various forms and examples, and that the teachings may be applied in numerous applications, only some of which have been described herein.	The present subject matter relates to a method and system for pulsed air-actuated micro-droplet on demand jetting, especially for jetting high viscosity liquids. A needle extends from a liquid chamber and terminates in a drop-forming orifice outlet from which micro-droplets are generated. At least two air jets direct a timed pulse of air at the drop-forming orifice outlet of the needle. The pulsed air is synchronized with the formation of a desired volume of liquid at the orifice outlet to extract and propel a micro-droplet at high velocity to a substrate. The air jets are turned on prior to the forming of the desired volume at the orifice outlet of the needle, and turned off after the micro-droplet had been produced.	1
BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a parachute canopy of the type which comprises at least one steering or air passage aperture which is normally retained in a closed position by air pressure within the expanded canopy and which aperture is selectively opened to permit air passage therethrough by means of operating members such as pull lines which are controlled by a parachutist. 2. History of the Prior Art Conventional completely closed parachute canopies have no apertures therein to control the direction of descent of the parachute, however, such closed canopies have the advantages of being quickly activated or deployed as they are rapidly filled with and retain air. Such parachutes thus afford safe deployment and require little vertical drop before becoming operative. These parachutes, therefore, are usually used for rescue and paratroop purposes. In certain situations, it would be advantageous for the user of a parachute to be able to manipulate the chute or steer it during descent. The capability of maneuvering the parachute during descent makes it possible to avoid possible mid-air collisions with other parachutists as well as to avoid obstacles on the ground. In order to make parachutes more maneuverable, some conventional parachutes have been designed so that the shape of the parachute may be changed during descent to affect a steering of the chute. In other types of parachutes, steering is accomplished by altering the effective air pressures around the parachute by placing openings in the canopy which create a steering effect forcing the chute in a particular direction. In order to control the amount of air flow through such openings, prior art parachutes are provided with means for reducing the size of the openings during descent. Such reduction in the size of the openings is usually affected by the parachutist through the use of pull lines which extend from an area adjacent the opening to the parachute harness. A drawback encountered with the use of conventional parachutes having openings therein which are used to control steering of the parachute during descent is that often such parachutes descend at a faster rate. For inexperienced jumpers the use of parachutes having steering openings therein may present an increased safety risk as the user of the parachute may not be familiar nor comfortable with controlling the amount of air flow through such openings to affectuate the proper movement of the chute as it descends. In paratrooping operations, experience has taught that there are increased risks of collision between parachutists immediately after the jump is initiated when steerable parachutes of conventional design have been used as the chutes have a tendency to be driven against one another before control thereof is established by the paratroopers. In addition to the foregoing, there is increased risk of collision between parachutists using steerable parachutes when jumping in darkness as the parachutists have difficulty in seeing one another in time to make the appropriate adjustment to the chute to prevent a collision. SUMMARY OF THE INVENTION This invention is directed to a parachute canopy having openings therein to permit the passage of air to make it possible to steer the parachute during descent and wherein the openings extend generally radially with respect to the center of the canopy extending along a line between two gores. In one embodiment of the invention, a single radially extending slot provides the aperture through which air is selectively permitted to flow as the free end of one gore is pulled away from the adjacent gore. An air permeable material such as an open mesh cloth or netting is provided over the entire width of the gore which is movable to create the air passage opening and thereby serves as a retaining surface to prevent the free edge of the movable gore from extending outwardly of the parachute canopy. In another embodiment of the invention, the radially extending opening in the movable gore may be enlarged by cutting the gore at two spaced points in a direction perpendicularly with respect to the radial opening in the gore to thereby form a generally rectilinear flap which is hinged about the joint of the movable gore with the immediately adjacent gore. In both of the foregoing embodiments, control lines extend from the movable gore to the parachute harness whereby a vertical force may be exerted by the parachutist to cause the movable gore to be pulled away from the adjacent gore to increase the opening therebetween. It is a primary object of the present invention to provide a steerable parachute canopy having an opening therein wherein the opening is normally covered during initial deployment of the canopy so that the parachute functions essentially the same as an unsteerable parachute when initially deployed. It is another object of the present invention to provide a steerable parachute canopy which functions as a conventional canopy having no steering openings therein when initially deployed but which can be steered by selectively exposing openings therein by the actuation of the parachutist of lines which extend to movable gores which are vertically displaceable to make openings in the canopy. These and other objects of the invention are achieved in accordance with the following description and with reference to the drawings and subsequent claims. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a top plan view of a parachute canopy according to the present invention showing two steering aperatures placed in spaced and symmetrical relation in the parachute canopy. FIG. 2 is an enlarged cross-sectional view taken along lines II--II of FIG. 1. FIG. 3 is a front elevational view of the parachute canopy shown in FIG. 1 in which a single elongated slit in one of the gores is shown in dotted line. FIG. 4 is an enlarged view of the parachute harness as it is attached to the control and shroud lines of the parachute shown in FIG. 3. FIG. 5 is a front elevational view of the parachute canopy shown in FIG. 1 showing in dotted line both the spaced gores in an open position. DESCRIPTION OF THE PREFERRED EMBODIMENT The parachute of the present invention is shown in FIG. 1 including a round canopy 10 which is generally dome-shaped and which is constructed of a number of radially extending gores 12. As is shown in FIGS. 3 and 4, the parachute canopy 10 is connected in a conventional manner by a number of shroud lines 14 with fittings 16 which in turn are connected by straps or woven belts 18 with a harness (not shown) which is adapted to be worn by a parachutist. The parachute canopy made according to the invention has two steering apertures which are formed identically alike, therefore, only the aperature shown at the right in FIG. 1 will be described in detail. Each steering opening is formed by a slit or slot 20 which extends radially between two gores 12a and 12b. The slot 20 may itself constitute the steering aperture or, in addition, slots or slits 22 and 24 may be made in the gore 12a which slits extends generally perpendicularly from the slot 20 along the width of the gore to the joint or seam 26 between gore 12a and gore 12c thereby forming a flap 21. In this manner an enlarged opening is created in the gore 12a which is covered by the flap 21. The flap 21 is connected with the parachute canopy along the radial joint or seam 26 between the slots 22 and 24. The gore portion of the parachute canopy which includes the slot 20 and in some instances slots 22 and 24, will be hereinafter defined as a steering gore. The steering gore 12a is covered by an air-permeable material, such as open-meshed cloth, netting or ribbon 28, which is sewn onto the external side of the canopy and thereby prevents the steering gore from opening towards the upper side of the parachute canopy 10. The covering material 28 is shown in FIG. 2 with dash-dotted lines and extends from joint or seam 26 to gore 12b. Fixed to the exposed or free edge portion 30 of the steering gore 12a along the slot 20 is a pull line 32 wich extends down to the parachute fitting 16 shown in FIG. 4. The pull line 32 may be connected along the central area of the free edge portion 30. By pulling the pull line 32 in the direction indicated by the arrow in FIG. 4, the steering gore can be urged downwardly with respect to the adjacent gore 12b to a position indicated with broken lines in the FIGS. 2 and 3. Thereby the slot 20 or enlarged opening is uncovered permitting air to flow outwardly from the interior of the parachute canopy through the air-permeable material 28. The movement of the air through the slot or opening accomplishes a steering movement of the parachute. If the parachutist releases the operating line 32, the steering gore 12a will be closed by the air pressure as shown in FIG. 2 in full lines. Thereafter, the parachute works as a conventional non-apertured parachute having a closed canopy. The return movement of the steering gore 12a or flap 21 can be assisted by elastic straps 34 or the like attached between the edge of the adjacent parachute gore 12b and the steering gore 12a or flap 21. The straps 34 can be used also to limit the effective opening area of the aperture. Separate return and arresting straps may also be provided. The steering gores 12a' shown in the left of FIGS. 1, 3 and 5 are identical to the steering gores 12a, but reversed. The numbers shown in the drawings have been given the same designations with an "a" added. If the steering gores 12a and 12a', which are shown in the FIGS. 1 to 5, are positioned in the rear half of the parachute canopy 10, relatively to the direction which is faced by the jumper, and the right pull line 32 shown in FIGS. 3 and 4 is pulled downwardly, a turning movement is created to the left of the parachute. With a simultaneous downward movement of both the right and the left pull lines 32 and 32a, shown in FIG. 5, a driving movement forwardly is created. It is clear that positioning of the gores 12a and 12a' on the front half of the parachute canopy 10 results in an opposite effect. Also, the steering gores 12a and 12a' can be more in number than 2, such as 4, 6, etc., so long as such gores are uniformly placed on the opposite sides of the canopy. As is evident from the foregoing, a parachute has been designed which, under deployment as well as in situations of panic when the jumper may accidentally release the pull or control lines go, works as a paracute with totally closed canopy, whereas, at the same time, the canopy may be steered by suitable actuations of the pull lines 32 and 32a. Obviously, the invention is not limited to the shown and described embodiment but may be varied within the scope of the basic concept taught herein.	A parachute canopy having at least one steering aperture created in a gore, which aperture is generally closed by air pressure urging the material from which the gore is formed into a closed relationship with the parachute canopy but which is relatively exposed to permit air flow therethrough by the operation of pull lines which are attached to the gore and may be used to urge the gore inwardly of the canopy in order to control the direction of descent.	1
BACKGROUND [0001] The present invention relates to a support device for a work vehicle. For example, crane trucks are provided with such a support device that significantly increases the stability of the crane truck; the crane boom can absorb large operating loads that transfer, due to the lever arm, a correspondingly large moment to the crane truck. The support device prevents the tipping over of the crane truck under these operating loads. [0002] From DE 2208333 A, for example, a support device is known in which a support carrier can be moved transverse to the vehicle longitudinal axis and is provided with a support piston on its end facing away from the work vehicle. The support carrier absorbs tipping moments that act on the vehicle. The support piston is provided with a piston rod that is constructed as a lifting element and is provided with a support foot. The support foot can be supported on a support surface, for example, on a road surface. The support piston has a double-acting hydraulic cylinder as an actuating drive for actuating the piston rod. The hydraulic cylinder can be pressurized hydraulically by means of hydraulic lines, in order to actuate the lifting element. The work vehicle is typically equipped with hydraulic pumps that generate the necessary hydraulic pressure. [0003] When hydraulic cylinders are operating, leaks can occur between pistons and cylinders, wherein replacing defective seals can be associated with considerable expense. Furthermore, leaks can occur at the hydraulic lines that are laid from the hydraulic pump to the double-acting cylinder. SUMMARY [0004] The object of the invention is to disclose an improved support device. [0005] According to the invention, this objective is met by the support device. Therefore, because the actuating drive has a planetary roller screw drive, wherein planets arranged between the spindle nut of this drive and a threaded spindle are in rolling engagement with the threaded spindle and the spindle nut, wherein a relative rotation between the threaded spindle and the spindle nut is converted into a longitudinal displacement between the threaded spindle and the spindle nut along the lifting axis for a lifting movement of the lifting element, a more powerful mechanical actuating drive is provided. Hydraulic elements are eliminated without replacement. Such planetary roller screw drives can be driven in a simple way by means of small electric motors. Instead of complicated hydraulic lines and hydraulic pumps, only electrical lines are provided that can be connected to the already existing electrical 12 volt or 48 volt on-board power network of the work vehicle. [0006] In addition to the planetary roller screw drive, the actuating drive can have another gear unit that is connected to the planetary roller screw drive. Support devices according to the invention advantageously have an electric motor that drives the planetary roller screw drive as a direct drive. Alternatively, a speed-reducing gear unit can be arranged between the electric motor and the planetary roller screw drive, in order to reduce the rotational speed of the electric motor to the benefit of a higher drive moment on the driven shaft of the intermediate gear unit. [0007] The planetary roller screw drive can be designed so that it is self-locking. If the threaded spindle is arranged along a lifting axis and the full support load is supported by means of the planets, a low pitch of the screw-shaped external profile of the threaded spindle selected as a function of the spindle diameter provides for a self-locking effect. This means that under the external load, there is no relative rotation between the spindle nut and the threaded spindle and thus no lifting movement. The lifting element can selectively comprise the spindle nut or the threaded spindle, so that the spindle nut or the threaded spindle can perform the lifting movement. [0008] For support devices according to the invention, the support piston can be provided on the work vehicle. For example, the support piston can be attached to a typical support carrier of the work vehicle. The support carrier can be moved longitudinally along a support axis arranged transverse to the vehicle longitudinal axis, in order to enlarge the support distance between the vehicle longitudinal axis and the support piston. Instead of a longitudinal displacement, it can also be provided that the support carrier is arranged so that it can pivot about a pivot axis. In this case, the support distance can also be increased. [0009] Planetary roller screw drives are known in different designs and described and shown, for example, in DE 10 2006 060 681 B3, EP 0320621 B1, and DE 3739059 B1. For planetary roller screw drives, relative rotational movements between the threaded spindle and the spindle nut are converted into relative axial movements between the threaded spindle and spindle nut. The planets engage with a first profiling in an external profiling of the threaded spindle. The external profiling is formed by screw-shaped threaded grooves of the threaded spindle wound about the spindle axis, wherein a thread or several threads arranged one behind the other in the axial direction can be provided. The planets further engage with a second profiling in internal profiling on the nut side. [0010] The number of planets arranged distributed around the circumference can vary. The first and second profiles of the planets can have matching designs, so that the planets can be provided as cylinders with a plurality of grooves arranged one behind the other along the planet axis, wherein these grooves are arranged transverse to the planet axis. The grooves can have a ring-shaped form. The nut-side internal profiling can be formed by flanks or grooves that are arranged coaxial to the spindle axis. [0011] When the planetary roller screw drive is actuated, the planets roll both on the spindle nut and also on the threaded spindle. The planets rotate both about their planet axis and also about the spindle axis. The rotational speed of the planets about the spindle axis is less than the rotational speed of the driven threaded spindle, for example. Only after one complete revolution of all the planets is an advance between the threaded spindle and the spindle nut reached that corresponds to the pitch of the threaded spindle. The pitch indicates the axial progress of one complete winding of a thread of the threaded spindle. The total pitch of the planetary roller screw drive and the pitch of the threaded spindle are different. [0012] Relative rotation between the spindle nut and the threaded spindle produces an axial advance that is converted into a lifting of the lifting element. Advantageously, the axial advance is used directly for the lifting of the lifting element, wherein the threaded spindle can absorb the full lifting load. The lifting element can have the threaded spindle or the spindle nut. If, for example, the spindle nut is driven, the threaded spindle can perform the axial advance; in this case, the lifting element comprises the threaded spindle. If the threaded spindle is driven, the spindle nut can perform the axial advance; in this case, the lifting element comprises the spindle nut. In all cases, the planets can transfer the support load between the threaded spindle and the spindle nut. [0013] The support element can have a housing in which the threaded spindle and alternatively the spindle nut is supported so that it can rotate. [0014] Advantageously, planetary roller screw drives can be used whose threaded spindles are provided with very small pitches, so that these planetary roller screw drives can be self-locking. This means that, in this case, no additional precautionary measures are required that prevent an undesired retraction of the lifting element under the support load. The planets can transfer the support load between the threaded spindle and the spindle nut in that the flanks of the profiles of the planets are supported, on one side, on the flanks of the external profiling of the threaded spindle and, on the other side, on the flanks of the nut-side internal profiling. [0015] The small pitches also allow a lifting of larger loads. The gear-transmission ratio between the spindle nut and threaded spindle can be selected so that, on one hand, a lifting of larger loads for relatively small rotational moments of the driven threaded spindle or the driven spindle nut is enabled and, on the other hand, a self-locking effect can be ensured. [0016] Support devices according to the invention therefore can be provided with electric motors that generate the necessary actuating movements of the lifting element with low power. In particular, the 12-V or 48-V on-board power network of the work vehicle can provide sufficient electrical power. In particular, a multi-pole direct-current motor is suitable as the electric motor. [0017] Direct drives can be realized, wherein a rotor of the electric motor is arranged coaxial to the threaded spindle and drives either the threaded spindle or the spindle nut. [0018] Alternatively, the electric motor can be arranged on the post offset relative to the spindle axis and, if necessary, connected to the planetary roller screw drive by means of a gear unit. For example, a spur gear drive, a worm drive, or a traction mechanism drive is conceivable, with this drive being connected to the threaded spindle or to the spindle nut on the drive side. Traction mechanism drives have, as the traction mechanism, a chain or a belt. Favorably, the drive is constructed as a speed-reducing gear unit, so that a high rotational speed of the rotor of the electric motor is stepped down to the benefit of an improved rotational moment on the drive-side driven shaft. [0019] The lifting element has at least one lifting part that is connected, on one side, to the threaded spindle or to the spindle nut for a common lifting movement. This lifting part can have a tubular construction and thus can be lightweight. On the other hand, this lifting part can be provided with a support foot for supporting on the support surface. In the simplest case, the lifting part can be formed by the threaded spindle. [0020] Advantageously, the support piston has a receptacle for the lifting element and the lifting element can be inserted into this receptacle. The structural height of the support piston according to the invention can then correspond to approximately the height of the receptacle. It is also possible, however, to provide the receptacle with a lead-through for the lifting element along the lifting axis; then the receptacle can have a short construction along the lifting axis. [0021] If the threaded spindle is driven, that is, it is to be rotated, it can be supported in the radial and axial directions in the receptacle of the support piston, for example, by means of one or more anti-friction bearings that can be constructed as deep groove ball bearings or as needle bearings or roller bearings. [0022] Other forms of planetary roller screw drives can also be used in a support device according to the invention. For example, planets can be used that have only one uniform groove profile meshing with both the spindle nut and also with the threaded spindle. In each case, the planets are in rolling engagement both with the threaded spindle and also with the spindle nut, wherein, when the planetary roller screw drive is actuated, the planets rotate about their planet axis and roll both on the inner circumference of the spindle nut and also on the outer circumference of the threaded spindle. [0023] For support devices according to the invention, the threaded spindle can be arranged coaxial to the lifting axis of the lifting element. These support devices according to the invention make possible compact structural forms that allow simple storing on the work vehicle. BRIEF DESCRIPTION OF THE DRAWINGS [0024] The invention is explained in more detail below using four embodiments shown in a total of eleven figures. Shown are: [0025] FIGS. 1 and 2 a support device according to the invention in longitudinal section with retracted and extended support piston, [0026] FIGS. 3 and 4 another support device according to the invention in longitudinal section with retracted and extended support piston, [0027] FIGS. 5 and 6 a work vehicle with a support device according to the invention, [0028] FIGS. 7 and 8 another support device according to the invention in longitudinal section with retracted and extended support piston, [0029] FIGS. 9 and 10 another support device according to the invention in longitudinal section with retracted and extended support piston, and [0030] FIG. 11 a known planetary roller screw drive. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS [0031] FIG. 11 shows, in a longitudinal section, a known planetary roller screw drive 1 according to DE 10 2006 060 681 B3 for converting a rotational movement into an axial movement or vice versa. The planetary roller screw drive 1 comprises a threaded spindle 2 that has, on its lateral surface, an external profiling 3 in the form of grooves. The threaded spindle 2 thus forms a threaded spindle and can form the shaft of an electric motor. The threaded spindle 2 is surrounded by a spindle nut 4 , wherein the spindle nut 4 can rotate relative to the threaded spindle 2 . An internal profiling 5 in the form of grooves is provided on the inside of the spindle nut 4 . [0032] Between the hollow cylindrical spindle nut 4 and the threaded spindle 2 there is a specified number of planets 6 . The planets 6 are arranged offset in equidistant angular distances in the peripheral direction of the threaded spindle 2 , wherein the longitudinal axes of the planets 6 run parallel to the longitudinal axis L of the threaded spindle 2 . The longitudinal-side ends of the planets 6 are each supported in a spacer washer 7 so that it can rotate. The planets 6 each have a first profiling 6 a and a second profiling 6 b . The first profiling 6 a produces an axial non-positive fit of the planets 6 with the threaded spindle 2 , in that this profiling 6 a is guided into the external profiling 3 of the threaded spindle 2 . These first profiles 6 a form advance grooves. The second profiling 6 b produces an axial non-positive fit of the planets 6 with the spindle nut 4 , in that this profile 6 b is guided into the inner profiling 5 of the spindle nut 4 . These second profiles 6 b form guide grooves. [0033] The spacer washers 7 holding the longitudinal-side ends are used as spacers for the planets 6 . The identical spacer washers 7 have a circular disk-shaped form. In the center of each spacer washer 7 there is a drilled hole through which the threaded spindle 2 is guided. On the side facing the planets 6 of each spacer washer 7 there are receptacles 7 a for the ends of the roller body 6 . The planets 6 are supported in these receptacles 7 a so that they can rotate. The spacer washers 7 each lie at a distance to the spindle nut 4 and to the threaded spindle 2 . [0034] The profiles 6 a of the individual planets 6 are offset relative to each other. Here, the profiling 6 a of each planet 6 has a defined axial offset relative to the preceding planet 6 . The offset profiling structures of the planets 6 form a thread for the external profiling 3 of the threaded spindle 2 . For a relative movement of the threaded spindle 2 relative to the spindle nut 4 , the planets 6 roll with the profiles 6 a on the external profiling 3 , wherein, at the same time, the second profiles 6 b are guided into the internal profiling 5 of the spindle nut 4 . For a stationary spindle nut 4 and rotating threaded spindle 2 , the planets 6 supported in the spacer washers 7 rotate on the lateral surface of the threaded spindle 2 , wherein this movement is slower than the rotational movement of the threaded spindle 2 . The rotational movements are realized such that only after one complete revolution of the planets 6 about the spindle nut 4 , the threaded spindle 2 has shifted in the axial direction by the magnitude of the pitch of the external profiling 3 relative to the spindle nut 4 . [0035] As can be seen from FIG. 11 , means for sealing this spacer washer 7 relative to the spindle nut 4 and the threaded spindle 2 are provided on a spacer washer 7 . In general, such means for sealing can also be provided on both spacer washers 7 , wherein these preferably have an identical construction. [0036] FIG. 1 shows a support device according to the invention in longitudinal section. A support piston 8 is held on a support carrier 8 a that is only indicated here. The support carrier 8 a is supported on a work vehicle that is not shown here. The support piston 8 is provided with a hollow receptacle 9 that is formed from a tube 10 . A lifting element 11 is arranged in the receptacle 9 . An electric motor 12 that is constructed as a multi-pole direct-current motor and is connected to a planetary roller screw drive 14 by means of a spur gear drive 13 is also arranged on the support piston 8 a . The spur gear drive 13 is constructed as a speed-reducing gear with which high rotational speeds of the electric motor 12 is reduced to a relatively low rotational speed of a threaded spindle 15 of the planetary roller screw drive 14 . The support piston 8 has a housing 8 b in which the spur gear drive 13 is housed. [0037] This planetary roller screw drive 14 corresponds in its structural design to the planetary roller screw drive 1 described previously for FIG. 7 . Between the threaded spindle 15 and a spindle nut 16 there are planets 17 that are arranged distributed around the circumference and are in rolling engagement in the described way both with the threaded spindle 15 and also with the spindle nut 16 . While the planets 6 of the planetary roller screw drive 1 each have two sections with a profiling 6 a , the planets 17 of the planetary roller screw drive 14 have only one section with such a profiling 17 a for engagement with an external profiling 15 a of the threaded spindle 15 , wherein this external profiling 15 a is constructed as a screw-shaped thread groove. [0038] The threaded spindle 15 is provided on its end facing the spur gear drive 13 with a drive shaft 18 in axial extension on which a spur gear 19 of the spur gear drive 13 is locked in rotation. A spur gear 20 that meshes with the spur gear 19 is locked in rotation on a motor shaft 19 of the electric motor 12 . The drive shaft 18 can be provided with spline teeth and the spur gear 19 can be provided with internal contours adapted to the spline teeth, so that a preassembled unit—consisting of the lifting element 11 , planetary roller screw drive 15 , as well as tube 10 —can be inserted into the spur gear 19 already preassembled on the stator side. [0039] The threaded spindle 15 is supported in the radial and axial directions relative to the housing 8 b by means of an upper support bearing 21 constructed as a ball bearing. The threaded spindle 15 is supported by means of another axial bearing not shown here relative to the housing 8 b . Forces transmitted by the lifting element 11 are guided via the upper support bearing 21 and the not-shown axial bearing into the housing 8 b. [0040] The lifting element 11 has a tubular lifting part 27 that holds the spindle nut 16 of the planetary roller screw drive 14 that is held by means of retaining rings 29 in the axial direction on the lifting part 27 . The lifting part 27 is provided on its end facing away from the spur gear drive 13 with a support foot 30 that is provided for contact on a support surface. The lifting part 27 is supported on the tube 10 in the radial direction by means of a sliding bearing 33 . [0041] The threaded spindle 15 and the lifting part 27 are arranged coaxial relative to each other, wherein the threaded spindle 15 enters into the inner lifting part 27 in the retracted state of the lifting element 11 . [0042] FIG. 2 shows the support piston 8 in the extended state, wherein the lifting part 27 is extended out of the receptacle 9 of the housing 8 b. [0043] FIGS. 3 and 4 show an alternative support device according to the invention that differs from the support device shown in FIG. 1 essentially in that a direct drive is provided in order to drive the drive shaft 18 . FIG. 3 shows the support device with retracted lifting element 11 and FIG. 4 shows the support device with an extended lifting element 11 . [0044] An electric motor 34 is arranged coaxial to the threaded spindle 15 . A rotor 35 of the electric motor 34 is provided with coils. A ring 36 held in the housing 8 b of the support piston 8 forms a stator 37 . The drive shaft 18 is connected to the rotor 35 for transmitting rotational movements. This variant allows a gear unit between the drive shaft 18 and the electric motor 34 to be eliminated and therefore has an extremely space-saving design. [0045] The drive shaft 18 is supported by means of an upper support bearing 38 and also by means of a lower support bearing 39 relative to the housing 8 b . The upper support bearing 38 is constructed as an axial anti-friction bearing and the lower support bearing 39 is constructed as a radial anti-friction bearing. [0046] FIGS. 5 and 6 show a work vehicle with the support device according to the invention from FIGS. 3 and 4 . A total of four support pistons 8 are held on four support carriers 8 a . On the two longitudinal sides, two support pistons 8 and two support carriers 8 a are provided. [0047] Below, the mode of action of the support devices according to the invention described above is explained in more detail using FIGS. 3 , 4 , 5 , and 6 . The mode of action of the support device according to the invention from FIGS. 3 and 4 does not differ from that from FIGS. 1 and 2 only by the spur gear drive connected between the electric motor and the planetary roller screw drive. [0048] When the electric motor 34 is actuated, the threaded spindle 15 of the planetary roller screw drive 14 is set in rotation. The planets 17 roll with their first profiling 17 a on the screw-shaped external profiling 15 a of the threaded spindle 15 wound around the spindle axis. The planets 17 also roll with their second profiling 17 b on the internal profiling 16 a constructed on the inner circumference of the spindle nut 16 . Due to the described screw movement, the lifting element 11 is moved with the spindle nut 16 along the lifting axis from the receptacle 9 of the tube 10 , wherein the tubular lifting part 27 does not rotate. [0049] The lifting element 11 is extended until the support foot 30 contacts the support surface—e.g., the roadway. The four support pistons 8 allow a secure support of the work vehicle. The lifting elements 11 can be extended until the wheels of the work vehicle lift from the roadway. [0050] The pitch of the screw-shaped external profiling of the threaded spindle is selected as a function of the spindle diameter, so that the support piston 8 is self-locking. [0051] FIGS. 7 and 8 show another support device according to the invention that is provided with a direct drive just like the support device from FIGS. 3 and 4 . [0052] A support piston 46 provided in this embodiment has an electric motor 40 that is held in the housing 8 b and drives the spindle nut 16 of the planetary roller screw drive 14 , while the threaded spindle 15 is locked in rotation. [0053] The threaded spindle 15 with the connected support foot 43 here simultaneously forms a lifting element 15 b that can also be designated in the present document as a lifting part. The threaded spindle 15 can be supported in the radial direction on the housing 8 b by means of a radial bearing not shown here. [0054] The spindle nut 16 is locked in rotation with a rotor 40 a , while a stator 41 is locked in rotation in the housing 8 b . The spindle nut 16 is supported by means of two angular contact ball bearings 44 , 45 upright in an X-arrangement so that it can rotate in the housing 8 b. [0055] The housing 8 b is provided with a lead-through 42 for the threaded spindle 15 . On its lower end shown in FIGS. 7 and 8 , the threaded spindle 15 is provided with a support foot 43 . [0056] The support carrier 8 a is merely indicated. [0057] When the electric motor 40 is actuated, the spindle nut 16 of the planetary roller screw drive 14 rotates. The planets 17 roll, on one side, on the spindle nut 16 and, on the other side, on the threaded spindle 15 , wherein the threaded spindle 15 undergoes an axial advance. FIG. 8 shows the extended position of the self-locking support piston 46 . [0058] The support device according to the invention shown in FIGS. 9 and 10 differs from the support device shown in FIGS. 7 and 8 essentially in that an electric motor 47 is provided that drives the spindle nut 16 of the planetary roller screw drive 14 by means of a worm drive 48 . For this purpose, a worm 49 locked in rotation with the motor shaft of the electric motor 47 meshes with a worm gear 50 locked in rotation with the spindle nut 16 . Incidentally, the structure and mode of action of this support device according to the invention match that from FIGS. 7 and 8 . LIST OF REFERENCE NUMBERS [0000] 1 Planetary roller screw drive 2 Threaded spindle 3 External profiling 4 Spindle nut 5 Internal profiling 6 Planet 6 a First profiling 6 b Second profiling 7 Spacer 8 Support piston 8 a Support carrier 8 b Housing 9 Receptacle 10 Tube 11 Lifting element 12 Electric motor 13 Spur gear drive 14 Planetary roller screw drive 15 Threaded spindle 15 a External profiling 15 b Lifting element 16 Spindle nut 16 a Internal profiling 17 Planet 17 a First profiling 17 b Second profiling 18 Driveshaft 19 Motor shaft 20 Spur gear 21 Upper support bearing 22 23 24 25 26 27 Lifting part 28 29 Retaining ring 30 Support foot 31 32 33 Sliding bearing 34 Electric motor 35 Rotor 36 Ring 37 Stator 38 Upper support bearing 39 Lower support bearing 40 Electric motor 40 a Rotor 41 Stator 42 Lead-through 43 Support foot 44 Angular contact ball bearing 45 Angular contact ball bearing 46 Support piston 47 Electric motor 48 Worm drive 49 Worm 50 Worm gear	A support device for work vehicles, including a support post ( 8, 46 ) to be provided on the work vehicle, the lift element ( 11, 15 b ) thereof being displaceable along a lift axis for supporting on a support area, wherein the support post ( 8, 46 ) has an actuating drive for actuating the lift element ( 11, 15 b ), and the actuating drive is designed as a planetary roller screw drive ( 1, 14 ).	1
CROSS-REFERENCE TO RELATED APPLICATION This application claims priority to U.S. Provisional Patent Application No. 61/526,818 entitled “COLLABORATIVE, CONTEXTUAL ENTERPRISE SOCIAL FUNCTIONALITY,” filed on Aug. 24, 2011, and U.S. Provisional Patent Application No. 61/565,284 entitled “COLLABORATIVE, CONTEXTUAL ENTERPRISE SOCIAL FUNCTIONALITY,” filed on Nov. 30, 2011, both of which are incorporated herein by reference in their entirety. BACKGROUND It is advantageous for business employees to stay in contact among themselves and with outside resources, such as vendors, clients, partners, customers, fellow industry workers, etc. The use of media can be helpful in allowing people to stay connected and collaborate on projects. Current media implementations, however, can detract from business goals and waste time, as well as cause issues with confidentiality and privacy. SUMMARY Disclosed herein is an enterprise network allowing businesses to connect employees with one another, as well as with the businesses' outside resources. This enterprise network includes “subjects,” which provide a quick and easy way to discover and categorize information and allows users to quickly find the information they are looking for. There are various dimensions to the subject that provide for ways to categorize information associated with it—these dimensions can be associated either manually by the user or automatically generated—these dimensions include a. Ad-hoc (Opt-in or explicitly added) groups of people b. Organization structure or project teams c. Geographic location of their workplace or workers' current locations d. Specific data sources or applications from where information is being pulled from (e.g., CRM, ERP, Purchase Order type applications) e. Public, private, or invitation-only subjects For example, if a user wants to share confidential information with just company executives and not with the rest of the company, in embodiments disclosed herein the user may easily share that information with all of the executives by sending the information to an “executives” group, instead of having to send multiple emails and wait for multiple replies. The information reaches the right people, and all of the recipients can comment openly with one another on the enterprise network, without other users seeing their messages. This enterprise network allows for this connection between internal and external to be made in a work-productive way by adapting the applications to the user and their needs, as well as creating incentives to improve work, all while maintaining company privacy. The enterprise network communities provide a one-stop approach to create, manage, interact with, and monitor customers, partners, resellers, and vendors from one interface. Thus, through the disclosed embodiments as global enterprises look for more ways to create two-way dialogs with their stakeholders, they will have created internal communities behind the firewall, as well as external communities addressing partners, customers, and others. The disclosed enterprise network communities provide a single integrated approach to diminish the “enterprise sprawl” that would otherwise result from having multiple forms of creating secure communications channels. The disclosed enterprise network communities partition separate groups. These partitions allow for privacy by separating certain groups of users. In described embodiments, users will not be able to join or see any information that has been posted or exchanged between members of a community if they are not members of that community. This partitioning of groups into communities allows users to privately and securely send, share, and receive information within a defined community. For example, if a user wants to communicate confidential information to a supplier, an external resource, the user may do so without worrying about other groups he or she interacts with knowing. The user may also contact one of the sellers with comments and for dialog, instead of contacting all of the company's sellers. Other features of the enterprise network that allow for ease of communication and the sharing of ideas within communities and among subjects include profiles, microblogging, instant messaging, video conferencing, screen sharing, voice memos, event streaming, integration of external programs, life stream, and mobile availability. Profiles allow users to search for colleagues. Searching for colleagues offers users the chance to connect with colleagues they do not know directly. By getting in touch with colleagues outside of the user's general contacts, the user may be able to receive helpful feedback or advice from someone in a particular department. Microblogging allows users to post general questions or comments to various forums, such as the user's wall, someone else's wall, a subject, or a community. With this feature, the user may open a contextual dialogue on a particular topic of interest with other users in the company's enterprise network. Instant messaging allows users of the enterprise network to view who is currently online and open a direct line of communication with another user. This direct line of communication may result in rapid responses that help everyone complete their work more efficiently. Video conferencing allows the user to easily create face-to-face interaction between members of specific subjects. The enterprise network automatically can generate calendar invites and email notifications for all participants for conferences based on the users associated with the subject. While in a video conference, users may record the video conference and post the media on the wall of the specified group that was invited to video conference. The ability to post the recording to the selected group's wall may be very beneficial, especially to members of the group who were unable to attend. Users also have the option to create transcripts of the video conference, which may be posted on the appropriate group's wall as well. While in a video conference, users may share their screens with the other users in the video conference and show these other users what they are working on or what they are referencing. Voice memos allow users to post voice messages to specific communities or subjects from their phones. For example, in the case that a user is driving or unable to send a typed message for another reason, but needs to send a message to his or her team, rather then calling each individual member separately, the user may call and leave a message on the enterprise network to a group with all of the team members. With voice memos, users can save time in situations like this, as well as ensure that every member of the user's team receives the message that needs to be relayed. Event streams allow users of the enterprise network system to access business systems from within the enterprise network. For example, users may approve expense reports for employees without ever leaving the enterprise network. Integration of outside programs, such as SharePoint, allows users to search and work in the programs without having to leave the enterprise network. Users may also upload files from outside business systems to their subject's or community's wall. Other media like Facebook, LinkedIn, and Twitter may also be connected to a user's enterprise network. By connecting users to outside media, the user may always be connected, even while staying on the enterprise network. Another way users may stay connected at all times is through mobile applications that run on devices while the user is away from his or her computer. These features of the enterprise network may allow users to stay connected and work in various applications without leaving the enterprise network. The above collaborative elements of this network are provided in a unique contextual way, such that conversations can be built around subject and communities, and followers of subjects and members of communities can automatically and efficiently be brought into relevant, business-productive conversations and discussions. Another feature of the present application provides for networking gaming techniques in order to induce loyalty and to help modify consumer behavior. The enterprise network may optimize these techniques for the enterprise setting, thereby creating a platform for tracking employee behavior within the enterprise network as well as guiding employees to modify their behavior in a desired manner. A typical software application allows users to evaluate a product on a trial basis for a predetermined period of time (e.g., 15, 30, 60, or 90 days). While this evaluation period allows users to test the product for their specific needs, having a predetermined evaluation period may not properly encourage users to test all of the program's features. In addition, having a predetermined evaluation period may not encourage users to fully evaluate the program, thereby resulting in the application losing out on valuable evaluation feedback from end users. What is desired are a system and method to motivate and incentivize widespread adoption and evaluation of the program. To motivate widespread adoption and evaluation, the enterprise network introduces time-bound awards that allow continued evaluation of the application and/or additional add-on modules in exchange for invitation acceptance and user participation. Gaming techniques such as multidimensional leveling, leader boards, badges, status, recognition, appointment dynamics, guided outcome, intrinsic motivators, and extrinsic rewards may be used to encourage continued evaluation of the application. By encouraging and incentivizing users to evaluate the product and invite new users to evaluate the product in exchange for an increase in time that users are allowed to continue using the product and/or providing additional add-on modules, the application may receive greater evaluation feedback that it otherwise may not have received if the application had a predetermined evaluation period. In addition to receiving increased feedback, the application may also receive higher quality feedback, as the application may target specific users for feedback based on their positions within the organization, number of invitees, number of followers, etc. The enterprise network may also use tracking to map users' activity within the application in order to present each user with a tailored user interface. The application may map where each user clicks, who the user interacts with, what he or she comments on, and subjects the user finds interesting. The application may present a tailored user interface based on the organization, user's clicking history, level of awards, job descriptions, size of network, and even where the application wants each user to focus his or her future evaluations. For example, if a user is identified as a marketing employee of the organization, either through self-identification or identification by the application, the application may look broadly at how the collective group of marketing employees is utilizing the network and present the interface differently for marketing employees than for engineering employees. Marketing employees may be more inclined to browse through networking posts on colleagues' walls, while engineering employees may be more inclined to search for an answer to a specific inquiry using a search bar. As a result, the user interface for marketing employees may be more focused on wall posts, specific groups, subjects, and colleagues that marketing employees may be interested in. tracking may incentivize specific users to perform certain types of evaluations for specific types of behavior in order to return the highest quality and quantity of evaluations to the application. By using the information from the network with tracking, each user may become more intertwined within the enterprise network and as a result, may spend more time on it. By spending more time on the enterprise network, the user and/or organization may be able to extend their evaluation period to 30, 60, 90 days or more, for example, and therefore may become more inclined to purchase the full version of the application. Certain features that have been disclosed in this document are further described more specifically in a published “How-To Guide” that is attached hereto as Appendix A 1 to the present specification. This Appendix A is fully a part of the present application by virtue of it being an appendix hereto, and it further incorporated by reference herein. Attached aspects of elements of the present application are additionally described in a features of the inventions disclosed in the present application are further illustrated. One of ordinary skill in the art would readily understand how features described in Appendix A could be employed in the systems disclosed in the present application in conjunction with the other features shown and described herein. 1 Tibbr®, tibbr Service, tibbr Community, and tibbr Community Service, How-To Guide, Software Release, February 2012, at https://docs.tibco.com/pub/tibbr/3.5.-april-2012/doc/pdf/tib 13 tibbr_howto.pdf, included herein as Appendix A, which is incorporated herein by reference for all purposes. BRIEF DESCRIPTION OF DRAWINGS Reference is now made to the following detailed description of the preferred embodiments, taken in conjunction with the accompanying drawings. It is emphasized that various features may not be drawn to scale. In fact, the dimensions of various features may be arbitrarily increased or reduced for clarity of discussion. In addition, it is emphasized that some components be omitted in certain figures for clarity of discussion. Reference is now made to the following descriptions taken in conjunction with the accompanying drawings, in which: FIG. 1 is a screenshot of a user's homepage. The user's wall for a specific community is shown here. FIG. 2 shows the system architecture and how external elements, such as other websites or different views, are processed through the main machine. FIG. 2A offers a viewpoint from the inner workings of the system, and FIG. 2B shows the system architecture with emphasis on the transaction layers. FIG. 3 shows a video conference with multiple participants and the functions available for video conference users. FIG. 4 shows the enterprise network's smart widgets “floating” over an open window. The smart widget allows a user to provide feedback from his or her wall, without having to toggle between the feed on the wall and the window in which he or she is working. FIG. 5 shows the mapping of Salesforce feeds to the enterprise network's subjects, through the edit stream box shown in the webpage. FIG. 6 shows the enterprise network options users can have integrated with external programs. FIG. 7 shows the options for gadget configurations for integration of application content into the enterprise network. FIG. 8 shows the integration of a document management system and how it integrates functions into the enterprise network. FIG. 9 shows the advanced searching capabilities of the enterprise network by combining document management searching with contextual collaborative content searching. FIG. 10 shows how subjects can be based on not only business topics, but also locations that allow for collaboration over geolocation. FIG. 11 shows an optional view for a smartphone of the subject/location gate C 21 and how the creation of these subjects/locations can appear in relation to a user. FIG. 12 illustrates another way to view information related to a location-based subject. In this screenshot, the view is based off of comments made relating to the subject/location gate C 21 . FIG. 13 is a two-dimensional top view map of location/subjects as icons. FIG. 14 shows a two-dimensional top view map, but also of colleagues who are associated with a common subject, as well as their locations. FIG. 15 is an event feed screen showing “My Communities” and “Post to Community” options. FIG. 16 shows posting to a community from the event feed window. The community is listed in the first blank as “Admin.” FIG. 17 shows a screenshot of the “set up your profile” page when a user is setting up an account for a dynamic evaluation period. FIG. 18 shows a screenshot of the “What's Interesting” page when a user is setting up an account for the dynamic evaluation period. FIG. 19 shows a screenshot of the “Invite more people” page when a user is setting up an account for the dynamic evaluation period. FIG. 20 shows a screenshot of an exemplary email when someone from the enterprise network sends an invitation to join the enterprise network. FIG. 21 shows the “What's interesting” page of the setup to join the enterprise network if a new user is not the first member of their company to join the enterprise network. FIG. 22 is a screenshot of a new user's home screen showing the user's wall with helpful hints to orient the user in the enterprise network. FIG. 23 shows a status screen that may be presented to users upon logging in to the enterprise network. FIG. 24 shows a help screen available to users. These exemplary figures and embodiments below provide a written, detailed description of the inventions set forth by any claims that issue from the present application. These exemplary figures and embodiments should not be used to limit any claims that ultimately issue in a patent from the present application. DETAILED DESCRIPTION FIG. 1 shows what a user desktop may look like for a preferred embodiment of the present application. On the left side, the desktop shows for a particular user, proceeding from top to bottom, the user's followers 101 , following 102 , and number of messages 103 . It provides options to go to the user's wall 104 , posts 105 , private messages 106 , chat history 107 , notifications 108 , as well as generally popular posts 110 . Further, it includes various event streams 111 the user might be following, which for example might include machine interfaces such as from Oracle Express, Salesforce, SAP, RSS, Facebook, Twitter, and LinkedIn. Various sources for such machine interfaces are described in further detail below in FIG. 2 . Still referring to FIG. 1 , with event streams 111 , users can configure and receive events into the enterprise network from enterprise applications that users run day to day. The event streams 111 may be configured as plug-ins that integrate with specific enterprise applications. As will be described below, the event stream 111 operates as a daemon process that runs the configured event streams 111 from each connected external machine, with exemplary event streams 111 as follows: RSS—The enterprise network provides support for listening on RSS feeds and makes them available in a contextual way through the enterprise network subjects 116 . Users may configure RSS feeds from various sites to publish messages 103 to the enterprise network subjects 116 . The application may provide streamlining functionality such that the messages 103 are published only once on a stream window. Email—The email event stream 111 may offer integration with email clients by delivering the enterprise network messages 103 to the subjects 116 and people 117 as addressed. That way, users can receive, post, or reply to messages from email clients such as Outlook, iPhone, or BlackBerry. In the enterprise network, users may send and receive email in a secure mode as facilitated by the email server. Salesforce—In the present example, the system may receive a Salesforce event stream 111 b by connecting to the Salesforce system and retrieving records according to user-specified preferences. Records may be published as private subjects 116 on the enterprise network. Of course, as with other exemplary event streams described here, Salesforce is an example of a current commercial CRM software/service. The implementation allows for any such integration with this or similar types of applications. SAP—In the present example, the enterprise network receives an SAP event stream 111 c , reading events from SAP and publishing them as messages 103 to a subject 116 . Again, the reference to SAP as an enterprise system is exemplary. Other enterprise-oriented systems and/or databases can be coordinated and/or synchronized with subjects 116 or communities 113 to provide such followers or members with timely and relevant updates therefrom. Oracle Expenses—The Oracle Expenses event stream 111 a enables a user to browse the details of expense reports and, if the user is a manager, approve the expense reports of others. Oracle Order Management—The Oracle Order Management event stream 111 may track the order fulfillment process and publish the status as messages 103 to a subject 116 . Oracle Expense and Oracle Order Management are merely two examples of business process related stream updates that can be coordinated and/or synchronized with subjects 116 and communities 113 Voice Memo—The Voice Memo event stream 111 enables the posting of voice messages in the form of audio files to the enterprise network. Also shown in FIG. 1 are the user's filters 112 , which may be used to define certain subsets of information to be included in an event stream 111 , with filtering in this example by colleagues or by news. The event streams 111 and filters 112 can be configured by the user through the “manage” icon 125 . Finally, on the left is “my communities,” 113 which in this instance defines partner 113 a , customer 113 b , reseller 113 c , and supplier 113 d segments; these may be used to limit the information accessed to or from a particular user depending on whether certain machine interactions or human interactions are within each of these community segments. Still referring to FIG. 1 , in the middle portion of the screen is a newsfeed 114 . In this particular instance the partner community 113 a is selected, so the newsfeed 114 reflected on the screen would be that which relates to the partner community 113 a . The general view indicated here is the home view 115 , which provides a generalized newsfeed 114 . As indicated by the various boxes at the top of the screen—subjects 116 , people 117 , my profile 118 , and event streams 119 —it is possible to present different views to the user in order to allow the user to receive news 115 , follow subjects 116 , follow people 117 , configure his or her personal profile 118 , or follow event streams 119 . To the right side of FIG. 1 , there is an informational help option for users who are new to the enterprise network 120 , one that allows a user to invite other colleagues 121 and to initiate a video conference 122 . Further provided is a “what's happening around you” window 123 , which includes news updates, as well as status updates by other users and colleagues who are relationally close to the user. Finally, there is a “most popular subjects” 124 box that shows currently active subjects in the reflected community. Consistent with the functionality reflected in FIG. 1 , the system architecture diagram is illustrated in FIG. 2A . At the center of the system architecture 201 is a network processor or network processing machine 207 that is operable to provide overall control, coordination and processing for the network system described in embodiments herein. Provided within the system 201 and in communication with the network processor 207 is a web server or web client interface 202 that provides an interface for external elements or client machines 203 such as a BlackBerry 203 a , various browsers (e.g., Facebook, Twitter, LinkedIn, and/or RSS) running on client devices 203 b , iPhone/iPad 203 c , Android 203 d , and an associated desktop client application 203 e. Also provided is an app runner interface or enterprise application interface 204 that connects to various external machines 205 such as Oracle 205 a , SAP 205 b , RSS Server 205 c , and Salesforce 205 d . This interface comprises the machine interface previously described with respect to the screen interface that allows the user to see updates fed from such machine applications associated with their communities 113 , followed subjects 116 , or other pertinent groupings. The app runner 204 accordingly provides an interface for the network processor 207 to receive and coordinate those feeds and make them available to users through the web server 202 (running the webUI interface 206 ) to the users' client machines 203 . With respect to the overall coordination of the network system operation, the network processor 207 is a computer processor operable to execute computer code on a computer-readable medium that would be attached to or embodied within the network processor 207 . This network processor 207 accordingly provides the logic for associating various subjects 116 and people 117 , including by interfacing with the LDAP server 208 to verify user logins and credential and the database 209 (e.g., MySQL/Oracle) which would provide profile data that the network processor would use to form the appropriate contextual relationships and provide appropriate feeds accordingly. The network processor 207 may be operable to directly provide user streams according to interests in the database 209 , or a separate stream server (see FIG. 2B ) in communication with the network processor 207 may be provided to specifically provide such user streams. The network processor 207 may further provide for search capability through the Solr search 210 . Finally, also provided is a worker's interface 211 that provides “push” notifications, such as through a notification server 212 , such as an Apple Push Notification Server 212 . FIG. 2A also indicates the types of connections made between the system elements and software operating on the various sub-machines 213 , such as Ruby/Rails 213 a , Java 213 b , C 213 c , Obj C 213 d , Lua 213 e , Ruby/Java 213 f , Adobe Air 213 g , CSS/HMU/JS 213 h . All of these system and software elements are operated through computer instructions stored on computer-readable media associated with processors associated with the system 201 . Further provided in FIG. 2A is an enrollment server 230 in communication with the web server 206 to receive new user enrollments and to communicate with a database within the system 201 , such as a database connected to the LDAP server 208 and/or with the database 209 to build user profiles into the system. Central coordination and control of the various servers and databases in the system 201 is provided by the network processor 207 . FIG. 2B provides another way of viewing the above-described architecture of FIG. 2A , more from a level of the various transaction layers—browser 214 , presentation 215 , application 216 , enterprise connectivity 217 . The elements shown in FIG. 2B were described previously in the context of FIG. 2A , and FIG. 2B merely provides a different view of the dataflow and elements described in FIG. 2A . The logical and physical connections are consistent as between these two figures and would be understood by one of ordinary skill in the art. The above-described architecture and framework provide users the abilities to start new conversations with other users within appropriate contexts. In particular as described herein, conversations and updates can be organized around subjects 116 , as reflected in the subject 116 organization illustrated in FIG. 1 . If this were a video conference 122 , for example, there would be a group of colleagues associated with a certain subject 116 . Within that subject 116 , a user can initiate a new video conference 122 , which might look like FIG. 3 , and the implementation of this new contextualized, collaborative video conference 122 initiated around an enterprise-defined subject 116 is further described below. In FIG. 3 , the user may have entered this subject-focused video conference from a subject 116 screen mentioned in the FIG. 1 desktop by clicking on the video conference 122 button. The colleagues associated with the selected subject 116 would accordingly be pulled up and/or invited to participate, and this could be effected contextually, without any particular action by the user to invite the other interested colleagues. As shown in FIG. 3 , a multiple thumbnail video interface 301 is presented, and the focus of the larger window may be adaptively switched 304 according to which of the colleagues is speaking at a given time. These users may have been from among the following group 302 indicated for this subject 116 in the upper right hand corner of the screen. Particularly when following a certain subject 116 , events occurring (notices received) within that subject 116 can be used to spur the subject-based, multiple-party video conferences 122 . The advantages of this approach are that it allows users to: Be spontaneous: Have impromptu white boarding sessions with simultaneous screen sharing 305 . Broadcast: Perform company-wide video broadcasts of key events and announcements. Save time: Automatically record 303 and store on relevant subject 116 walls for future playback and knowledge sharing. Get face time: Catch up with a colleague and get some face time—whenever and wherever. Accordingly, this video conference feature 122 is operable to combine video image sharing, desktop sharing 305 , and archiving into one seamless package, and it delivers this feature into the relevant context—right onto the user's wall 104 . With video conferencing 122 , the user can address issues as they arise, in a direct and personal way. For example, if a user sees a post that requires instant clarification or face-to-face collaboration, he or she can simply start a video conferencing 122 session and tune in the relevant people 117 to a live discussion. Video conferencing 122 allows switching to desktop sharing 305 , as well as automatic recording 303 and storing of the session to be posted afterward, fully searchable for those unable to attend. Furthermore, a recording 303 can be stored and contextualized, including with automatic voice transcription that maps the recording to the appropriate subjects 116 within the collaborative, contextualized system and thus facilitates further searching and browsing. Another feature of the described video conferencing 122 system is that it automatically employs security with respect to the communications that occur. When a video conference 122 is initiated within a discussion for a particular subject 116 , only those users who are permitted to be associated with the subject 116 have access to be invited to a related video conference 122 . With respect to FIG. 4 , smart widgets are provided as a connection to the contextual system described in the present application to allow for integration of the contextual features described with others of the user's enterprise applications, such as SAP, Oracle, Salesforce, or the like. This way, contextual interaction may be provided in an enterprise network window that can “float” above or next to the application software window such that a user may receive contextual feedback in connection with the subjects that are presented on the enterprise application window. Smart widgets allow users of the enterprise network to work in programs unrelated to the enterprise network while remaining connected to the enterprise network. Users may remain connected to the enterprise network by having relevant feeds from their wall or from specific subjects updated and visible to the user as the user works in other programs. The ability to view the relevant feeds lets the user receive feedback from other users as it pertains to what he or she is working on. For example, with further reference to FIG. 4 , if “Business Optimization” were a relevant subject open within an enterprise software application, the “Business Optimization” subject of the enterprise network contextual widget could be presented to the user on the right side of the screen and overlying the enterprise software window. Thus, a back-end synchronization of subjects between the enterprise application database and the enterprise network contextual application may exist in order to provide these contextual widget overlays. By activating this feature, users are able to continue working within the context of their enterprise applications while having contextual, collaborative messaging resources and other contextual features available to further facilitate their work. “Mapping” of enterprise application subjects to a user's wall 104 or subjects 116 is an approach for making the connections between those applications and subjects 116 . This type of mapping is further described below in the example of a mapping of Salesforce event streams 111 b to subjects 116 in FIG. 5 . Specifically, The web interface in FIG. 5 shows the exemplary mapping of Salesforce streams 111 b to subjects 116 through an “edit stream” box 501 . Mapping of context to applications can be done by the enterprise network gadget configuration as well. Taking SharePoint integration as an example, a SharePoint user can bring SharePoint content into the enterprise network by adding the enterprise network gadgets, as illustrated in FIG. 6 . The user may also bring the enterprise network content into SharePoint with the enterprise network widgets. FIG. 6 shows various enterprise network gadgets users may have on their screen when working on an integrated program such as SharePoint. The various subjects the user may use include the user's wall 601 , relevant subjects 602 , and relevant people 603 to the user and the integrated program he or she is working on while on the enterprise network. FIG. 7 illustrates that the enterprise network gadgets can then be further configured to specify the enterprise network context that is most relevant to the application context by using the gadget configuration settings 701 , such as by setting the “Base URL” that is used. The gadget configuration settings 701 also include ways to modify the “appearance,” “layout,” and “advanced settings,” where, for example, “advanced settings” might include security settings or other more sophisticated setup elements. It is further possible to provide searching within the enterprise application as shown by the query string feature shown—in this way enterprise application subjects can be easily found and mapped to subjects in the presently described enterprise network. To abstract these configurations, for enterprise application content integrated into the enterprise network, the enterprise network maintains a mapping of enterprise application content and the enterprise network context, so the enterprise application content is associated with the most relevant enterprise network context. For enterprise applications that integrate the enterprise network content into their context via the enterprise network gadgets, each enterprise network gadget is a self-configurable entity that maintains the mapping of application context and the enterprise network content. By using the enterprise network's gadgets, users may be able to integrate external programs into their enterprise network. Integrating external programs into one's enterprise network may let users stay within the enterprise network to work on documents from the integrated external programs or to utilize other functions of these programs. In addition to the contextual integration with the smart widget functionality, the present application provides for integration with enterprise storage and document management systems. In an example, the screen in FIG. 8 shows integration with the document management program SharePoint where the documents are organized under certain subjects and those subjects are in turn tied to contextual streams associated with the contextual functionality described in the present application. Through this approach, as a user navigates the enterprise documents 801 , relevant messages 802 and 803 and the like are presented to the user through the enterprise network features shown on the right-hand side of FIG. 8 . In the present example, what is shown on the right-hand side are conversation threads 802 and users associated with the subject 803 “Business Process Management.” Users may integrate external programs into the enterprise network, which allows them to access their files from the integrated programs while remaining within the enterprise network. Users also may be able to work on the external programs they have integrated into the enterprise network while in the enterprise network. By working on integrated programs within the enterprise network, users may receive feedback from those allowed access to such documents in their enterprise network. Users thus may be able to see comments from certain people 803 from particular groups or subjects 802 who help the user with his or her documents. By using subjects, users may also share their documents with relevant people without allowing other users who are not a part of the specified group to see. Through the contextual ties to the system and method described in the present application, users are able to find relevant context and initiate conversations/communications with other users or colleagues who are following the subjects encountered while navigating through the document management system. This generates efficient and effective teaming within that context. The above-described document management integration, in the context of an exemplary integration with SharePoint (a program sold under a registered trademark not associated with the present assignee), allows at least the following functionalities: Discovery: Search SharePoint subjects simultaneously with the enterprise network search to find the most relevant information and conversations. Bi-directional activity: The enterprise network users may directly post back into SharePoint repositories. Subject-level integration: Link documents in SharePoint to specific, granular subjects. SharePoint widget: The enterprise network may also be embedded in SharePoint as a widget, going beyond mere event streams to ensure that SharePoint users get the full context of people, application, and system-level updates relevant to their profile. As to the “Discovery” element described above, FIG. 9 provides an exemplary simultaneous search screen 901 . Notice how users may search SharePoint files 902 from within the enterprise network, providing for simultaneous searching of the contextual collaboration content as well as the document management system documents. Note that the sites/subjects 903 may be selected for more selective searching, still from the enterprise network. Note that the above description of the advantageous features of the present embodiments in the context of their integration and coordination with a SharePoint enterprise document management system is exemplary of how such features could be implemented with other document management systems and or other enterprise-based software and/or database implementations. The generality of such interaction is comprehended within the description herein, and the scope of any claims issuing from the present filing should not be limited in any way to the specific embodiments described here. The subject-area-focused collaborative features enable unique applications in the context of geolocation as well. For example, rather than thinking of subjects 116 as more classic business subjects, a subject 116 could be a site or location. The below example in the context of an airport provides an interesting application of the above-described techniques. In particular, the screenshot 1001 in FIG. 10 is built around a terminal gate—“C 21 ”: Thus, the geolocation-based subject essentially operates as a hotspot around which relevant contextual information can be collaboratively stored and updated and around which relevant users can automatically interact with each other. In addition to the features gained in the contexts described above, in that the system develops a contextual, collaborative framework for interaction with specified groups and around specified contexts, in the above described context there is a synergistic connection to geolocation. For example, a supervisor or other airport employee walking through a terminal with his or her personal communication device (e.g., smartphone) can quickly and intuitively focus on a subject 116 gate as illustrated in FIG. 11 —note the superimposed gate icons 1101 , which may be considered as references to relevant subjects 116 within this described system. Thus, a supervisor walking through the terminal with his or her personal communication device can be presented with discussions 1201 surrounding a particular gate by the users who are connected to that subject 1202 , as in FIG. 12 . Having discussions surrounding a location may allow users to stay updated on information pertaining to a particular location. As in FIG. 12 , the post by “Jake” 1201 a demonstrates the importance of being able to share information pertaining to particular locations in an efficient way that may reach everyone with one post. The location-based subjects may be accessed in other ways as shown in FIG. 13 and FIG. 14 , which are described in further detail below. In the example in FIG. 13 , the previously described subjects 1202 may be accessed through icons 1302 appearing on a two-dimensional top view map 1301 . The same type of conversation around that subject 1202 (such as shown in FIG. 12 ) could then appear to the user. Similarly, in the approach of FIG. 14 , the subjects may be presented in a two-dimensional top view map, along with indicated colleagues who follow the same subject. The colleagues are indicated by the orange, numbered teardrops 1402 ( 1 through 7 ). By using geolocation features within their mobile terminals in conjunction with the described embodiments herein, users may be able to react to ever-changing conditions on the job, especially when their workspace is a large public area. The geolocation feature may be helpful not only in airports, but also in sports arenas, concert venues, and other large, highly trafficked areas. In addition to the above described subject navigation, the system described in this application includes communities 113 , which provides an added level of control for developing collaborative communication. In particular, each user may be provided with a community 113 within which multiple of the above-described subjects 116 may be followed. For example, a user might be in a “product development” community 113 as well as an “admin” community 113 . These communities can be defined within the enterprise such that certain users belong to some communities 113 and not to others, and other users belong to different communities 113 . Thus, the communities 113 and subjects 116 provide a layered context for the user to interact with other users. The screenshot in FIG. 15 illustrates a user screen where the user can navigate to one of his or her communities 113 by clicking on the “my communities” 113 choices in the lower left hand corner of the screen. Navigating communities allows users to keep information separate, so as to only inform the intended communities without allowing other communities or groups to see the information shared between the user and the intended community. Additionally, even from the user's home 115 screen, a user can post relevant content from his or her wall 104 to selected communities 113 by clicking on the “post to community” 1501 option below the items shown there. In this way the user can cross-reference relevant content to one or more communities 113 without departing from the current view. An illustration of the functionality for this cross-referencing enabled by this feature is illustrated in FIG. 16 . Various options may be used for placing the addressed communities for the post and could be implemented to affect the functionality. In this instance, as shown in FIG. 16 , the content is about to be posted to the “Admin” community 1601 to which the user belongs. From this screen the user may be able to post to one or more of his or her communities to ensure that the correct information is delivered to the correct community securely, without any users other than the users of the recipient community viewing the content. In operation, a user may sign up for a profile for a dynamic evaluation period as shown in FIG. 17 . The user may enter his or her first name 1704 , last name 1705 , email address 1706 , password 1707 , department 1708 , and a brief description in the “about me” section 1709 . In the “about me” section 1709 , the user may include his or her job title, interests, and any other pertinent information for evaluation purposes. Once the user has entered all of this information, the user may click “next” 1710 and proceed to create a profile for a dynamic evaluation period, as shown in FIG. 18 . Certain assigned users, which might in some instances be the first person from his or her organization to create a profile, will become administrators for their organization's enterprise network 1801 . As an administrator, a user may be given the opportunity to follow certain subject areas 1802 , such as marketing, legal, or engineering, as shown in FIG. 18 . Administration functions are further described below. Once established as the administrator of the enterprise network, the user may invite colleagues 1901 to establish their own profiles for the dynamic evaluation period, as shown in FIG. 19 . The application may only allow the administrator to invite colleagues with verified email addresses from the same company 1902 to be a part of the company's network. For example, in the screenshot shown in FIG. 19 , the administrator is an employee of Example Company with an @examplecompany.com email address. As an employee of Example Company, the administrator may only invite those colleagues who also have an @examplecompany.com email address to be a part of the Example Company enterprise network. When inviting colleagues, the administrator may enter email addresses 1903 directly or may import his or her contacts 1904 from Outlook or any other network, such as Facebook, Twitter, and LinkedIn. In addition, the administrator may enter a personal message 1905 to be sent to the colleagues who the administrator chooses to invite to the company network. Once a colleague is invited to join the company network by the administrator, the colleague may receive an email invitation from the administrator to join the company network, as shown in FIG. 20 and described below. As shown in FIG. 20 , the email invitation from the administrator to a colleague may include a personal message 2001 from the administrator. The colleague may then join the company's enterprise network directly from the email by clicking on a hyperlink 2002 to the enterprise network. The email may also include helpful information 2004 and/or a brief description 2004 about the enterprise network. The helpful information 2004 section may include hyperlinks to download applications for iPhone, BlackBerry, or Android phones and a FAQ section. If the user is not the first person from his or her organization to create a profile, as in the case of receiving an email invitation from a colleague, this new user may be given the opportunity to follow colleagues 2101 within their organization who have already established profiles, as shown in FIG. 21 . As discussed earlier, all of the users from a specific organization may be partitioned behind a wall. In addition, the user may be given the opportunity to follow certain subject areas 2102 , such as marketing, engineering, legal, etc. By following certain subjects 2102 , the user may be connected to other users, both within the organization and outside the organization, who have similar interests. When choosing which colleagues 2101 and/or subjects 2102 to follow, the user may click a colleague's name to see a more detailed profile 2104 of the colleague, or on a subject to see some of the discussions in that subject 2105 . These approaches are described further below. For example, in FIG. 21 , a user may click on “Abby's” name icon 2101 a to see Abby's more detailed profile. Based on this profile information, the user may determine whether or not to follow 2103 Abby in his or her company's network. In FIG. 21 , a user may click on the “products” subject 2102 a to see the current discussion in the “products” subject area. At the next step of creating a profile for a dynamic evaluation period, as shown in FIG. 22 , once the user has created a profile, the user may be directed to the wall 104 for his or her personalized home page on the enterprise network. The first time the user views the user's own profile, a welcome message 2201 may be displayed. As described previously, the profile may include the user's followers 101 , who the user is following 102 , and messages 103 . The user's wall 104 may also include the options to post messages 2202 , go to other users' walls, send private messages 106 , edit notification settings 2203 , and view chat histories 107 and event streams 111 . Each organization may have their own enterprise network partitioned off and away from other organizations' enterprise networks. Members of an organization, whether a company, non-profit organization, educational institution, or group of professionals within the same profession, may only see their fellow members from the same organization. While users may invite people from outside their organizations to join the enterprise network, which process would be handled by the enrollment server 230 (see FIG. 2A ), the new users may be “on their own” behind a separate partition and may then invite new users from their own organizations to join the enterprise network. Behind each organization's partition, each new user may start out with a specific number of days for his or her evaluation period. For example, new users may initially be given 15 days to use, test, and evaluate the application. Based on the user's or organization's use of the application, one or more of the users' evaluation periods may be extended by incentivizing users to participate in the evaluation. For example, users may extend their evaluation periods by a week every time they invite ten new users to join the network or make ten posts on the enterprise network wall. Unlike networking sites such as Facebook, Twitter, and LinkedIn, which have few or no evaluation concepts tied to them, the present application may dynamically extend the period of time that a user uses the network based on the quantity and quality of evaluation feedback received from the users comprising an organization's enterprise network. The application may rely on gaming techniques to encourage increased participation through group dynamics. Awards may be given to users who invite the most colleagues to join their organization's enterprise network, to those who post the most entries on the network's walls, to those who post on specific subject matters, and to those who give the best feedback. All of the awards may be explicitly provided as a result of the user reaching a certain predetermined level, such as inviting ten people to join their enterprise network, or may be implicitly provided in order to surprise and excite users when they take an action that the application desires, such as when they provide feedback on a certain subject. By allowing users within an organization to see every other user's awards, the group dynamic may encourage and/or incentivize other users to strive to receive awards of their own. Awards may be depicted in the network by badges displayed on the user's profile or in a separate badge tray, for example. Levels or dimensions of awards may also be given based on a user's level of expertise within an organization. A first level of awards may be based on a user's level of participation within the enterprise network. For example, a user may be a beginner, intermediate, advanced, or expert user within the network based on their number of invites, number of wall posts, etc. A second level of awards may be based on the user's role within the organization. This level may be self-described or may be based on the subjects in which the user participates. For example, a user may be described as a sales specialist or a marketing expert based on the subjects in which the user participates. A third level of awards may be based on the user's level of participation within the enterprise network. For example, if a user repeatedly answers questions on his or her network, the user may be labeled a “problem solver,” whereas if a user repeatedly asks questions that start a chain of conversation, the user may be labeled a “conversation starter.” Each level of awards may be used in the organization or within the application to target specific employees who may be of value to the organization and/or application for evaluative purposes. Also shown in FIG. 22 , the user's profile may include additional functionality such as the date when the evaluation period is currently set to expire 2207 , the number of days in which the evaluation period is set to expire 2206 , the number of people who have recently joined the company's enterprise network 2204 , and the number of posts made to the enterprise network 2205 . In this example, the user's evaluation period is set to expire in 18 days 2206 on December 2, 2207 , there are 14 people who have recently joined the company's enterprise network 2204 , and there have been 207 posts to the company's enterprise network 2205 . The user may click on the number of people to see who has joined the network recently 2204 , the number of posts 2205 to see the most recent posts made, and the number of days in which the evaluation period is set to expire 2206 in order to see how many new colleagues the user needs to invite to join the enterprise network to extend his or her evaluation period. As can be seen in FIG. 22 , next to the date that the evaluation period is set to expire 2207 , the user may invite colleagues 2208 to join his or her organization's enterprise network. By inviting colleagues to join, the user may extend his or her, as well as the organization's, evaluation period by one or more days, which incentivizes users to invite their colleagues to join the enterprise network. As shown in FIG. 23 , when a user signs in to the application, a status screen 2301 may be presented to the user. For example, the status screen may state that while the user has been away from the application, the trial evaluation period has been extended to five days 2302 . In the screenshot shown in FIG. 23 , the trial evaluation period has been extended three additional days 2303 —two days because three additional people have joined the organization's enterprise network 2304 and one day because two new people have signed up for the enterprise network as a result of the user's email invitations 2305 . The user is also reminded that the organization's evaluation period may be extended by inviting more people to join the enterprise network 2306 . The application may also include a help feature 2405 , as shown in FIG. 24 . For example, the help feature 2405 may include tutorial videos 2401 , featured videos 2402 , a question and answer section 2403 , and an expandable frequently asked questions section 2404 . The user may click on each frequently asked question 2404 to see an answer to the question. The help section 2405 may also include a feature where a user may ask a customer support staff individual a specific question not already answered in the frequently asked questions section 2405 by clicking the “Contact Us” button 2406 . While not depicted, the application may be interoperable with other networks such as Facebook, Twitter, and LinkedIn. That is, each time a user in the enterprise network posts a new post on his or her wall 104 about a subject 116 , for example, the user's Facebook, Twitter, and LinkedIn accounts may also reflect that the user was active on the enterprise network. By updating the user's Facebook, Twitter, and LinkedIn accounts, the user's friends, followers, and connections, respectively, may desire to join the enterprise network. If the new user is a member of an organization that already has an enterprise network, that new user may be added to the existing network. If, on the other hand, the new user is not a member of an organization that has an enterprise network, that new user may become the administrator of a new enterprise network behind a separate partition. The application may also include a calendar feature (not shown). The calendar feature may depict on a calendar how many days are currently remaining in the evaluation period and how many days have been added to the evaluation period. The calendar feature may also include additional designations on specific dates that may become goals for the organization. For example, if the evaluation period is set to expire on December 1, December 3 may include a designation stating the user can extend their organization's evaluation period by two days if the user invites three more users to join the company's enterprise network. While various embodiments have been described above, it should be understood that they have been presented by way of example only, and not limitation. Thus, the breadth and scope of a preferred embodiment should not be limited by any of the above described exemplary embodiments, but should be defined only in accordance with the claims and their equivalents for any patent that issues claiming priority from the present application. For example, as referred to herein, a machine or engine may be a virtual machine, computer, node, instance, host, or machine in a networked computing environment. Also as referred to herein, a networked computing environment is a collection of machines connected by communication channels that facilitate communications between machines and allow machines to share resources. Also as referred to herein, a server is a machine deployed to execute a program operating as a socket listener and may include software instances. Resources may encompass any type of resource for running instances including hardware (such as servers, clients, mainframe computers, networks, network storage, data sources, memory, central processing unit time, scientific instruments, and other computing devices), as well as software, software licenses, available network services, and other non-hardware resources, or a combination thereof. A networked computing environment may include but is not limited to computing grid systems, distributed computing environments, cloud computing environment, etc. Such networked computing environments include hardware and software infrastructures configured to form a virtual organization comprised of multiple resources that may be in geographically disperse locations. While TCP/IP communication protocols may be described herein, the coverage of the present application and any patents issuing there from may extend to other communications protocols. Various terms used herein have special meanings within the present technical field. Whether a particular term should be construed as such a “term of art” depends on the context in which that term is used. “Connected to,” “in communication with,” “associated with,” or other similar terms should generally be construed broadly to include situations both where communications and connections are direct between referenced elements or through one or more intermediaries between the referenced elements, including through the Internet or some other communicating network. “Network,” “system,” “environment,” and other similar terms generally refer to networked computing systems that embody one or more aspects of the present disclosure. These and other terms are to be construed in light of the context in which they are used in the present disclosure and as one of ordinary skill in the art would understand those terms in the disclosed context. The above definitions are not exclusive of other meanings that might be imparted to those terms based on the disclosed context. Words of comparison, measurement, and timing such as “at the time,” “equivalent,” “during,” “complete,” and the like should be understood to mean “substantially at the time,” “substantially equivalent,” “substantially during,” “substantially complete,” etc., where “substantially” means that such comparisons, measurements, and timings are practicable to accomplish the implicitly or expressly stated desired result.	Described is an enterprise-based, contextual network system and method to keep employees connected with one another, as well as to external resources. Current media offers a great way to stay in touch with others but is not cohesive and contextual for businesses or generally productive for businesses. The enterprise media disclosed in this application presents a way for businesses to keep all of their employees and outside resources connected, but in a professional and efficient manner for the workplace. This enterprise media adapts to its users to create an interface that will help the user complete work, connect with others, and use various applications all in one place.	7
CROSS-REFERENCE TO RELATED APPLICATION This application is related to and claims priority to U.S. Provisional Patent Application Ser. No. 62/278,143, filed Jan. 13, 2016, entitled “ACOUSTIC CHAMBER WITH LOW FREQUENCY TRANSPARENCY”, the entirety of which is incorporated herein by reference. TECHNICAL FIELD The present disclosure relates to an acoustic chamber with low frequency outer wall transmissivity. BACKGROUND Anechoic and hemi-anechoic chambers are designed to mimic an acoustic free field inside of an enclosed environment. An acoustic free field is a region where there are no acoustically reflective surfaces or effects from such surfaces. Current and historical anechoic chambers have all been constructed in similar methods. FIG. 1 is an acoustic chamber 10 having a solid outer wall 12 constructed to isolate the acoustic environment 14 inside the chamber from that outside the chamber. The outer wall 12 is typically constructed using modular steel panel systems or by conventional techniques such as concrete, cinder blocks, or studs and drywall. The interior of the outer wall 12 is then lined with an acoustic absorber system 16 . The absorber system 16 absorbs nearly all of the acoustic energy within its frequency range of operation creating a free field. This absorber system 16 is typically a wedge or a tuned wedge/wall system where the wedges operate in conjunction with the wall panels. In a tuned wedge/wall system, the outer wall 12 of the chamber 10 is solid steel and the inner wall 20 is usually perforated steel. The inside of the wall enclosure 18 is filled with a variety of different materials depending on what the designer is trying to achieve. In a tuned wedge/wall system, where the inner wall is perforated steel, the outer wall 12 of the acoustic chamber 10 in this case is solid and can be steel or one of the other materials mentioned above. The solid outer wall 12 is reflective and impacts the free field performance of the chamber below the absorber cutoff frequency. At low acoustic frequencies, the acoustic energy is not totally absorbed by the absorber system 16 and some acoustic energy passes through the perforated inner wall 20 . Some of the acoustic energy passing through the inner wall 20 is absorbed by material of the wall enclosure 18 . However, some of the acoustic energy will reflect from the inner surface of the solid outer wall 12 and will propagate back toward the interior 14 of the acoustic chamber 10 . This is undesirable because it degrades the low frequency performance of the acoustic chamber 10 . In order to improve the low frequency performance of an anechoic chamber, conventional solutions call for the chamber size to increase and the depth of the absorber system 16 to increase. This greatly increases cost and size of these chambers and limits the ability of users to obtain a chamber that meets their low frequency requirements. SUMMARY The present embodiments advantageously provide an acoustic chamber with low frequency outer wall transmissivity. According to one aspect, an acoustic chamber has an inner wall encompassing an interior of the acoustic chamber and configured to allow acoustic energy to penetrate the inner wall. The acoustic chamber also has an outer wall configured to allow low frequency acoustic energy that penetrates the inner wall to penetrate the outer wall and leave the acoustic chamber. According to this aspect, in some embodiments, the acoustic chamber further includes an interior absorber system lining the inner wall and configured to absorb acoustic energy above a particular frequency. In some embodiments, the outer wall is made of perforated metal. In some embodiments, the size and density of the perforations determine a frequency response of the outer wall. In some embodiments, the outer wall is made of a porous fabric. In some embodiments, the outer wall is made of a skeletal structure. According to another aspect, a method of constructing an acoustic chamber is provided. The method includes constructing an inner wall configured to encompass an interior region of the acoustic chamber; the inner wall being at least partially acoustically penetrable. The method also includes constructing an outer wall in proximity to the inner wall, the outer wall being at least partially acoustically penetrable. According to this aspect, in some embodiments, the method further includes installing acoustic absorbing material between the inner wall and the outer wall. In some embodiments, the acoustic penetrability of the outer wall is frequency-dependent. In some embodiments, the acoustic penetrability of the inner wall is frequency-dependent. In some embodiments, the method includes the inner wall facing the interior region with an acoustic absorbing material configured to absorb acoustic energy above a particular frequency. In some embodiments, the inner wall and lining material are configured to substantially absorb acoustic energy above a particular frequency. In some embodiments, the outer wall is configured to pass acoustic energy below the particular frequency. In some embodiments, the method further includes installing acoustic absorbing material between the inner wall and the outer wall. In some embodiments, a frequency response associated with the outer wall has a low pass component. According to yet another aspect, a method of constructing a composite wall for an acoustic chamber is provided. The method includes constructing an inner wall having an acoustically penetrable surface. The method also includes constructing an outer wall having an acoustically penetrable surface, the outer wall being positioned in relation to the inner wall to form the composite wall. According to this aspect, in some embodiments, the outer wall is substantially parallel to the inner wall. In some embodiments, the method further includes selecting a thickness of the composite wall to achieve a particular low pass frequency response of the composite wall. BRIEF DESCRIPTION OF THE DRAWINGS A more complete understanding of the present embodiments, and the attendant advantages and features thereof, will be more readily understood by reference to the following detailed description when considered in conjunction with the accompanying drawings wherein: FIG. 1 is a cross sectional top view of a known acoustic chamber; FIG. 2 is a cross sectional side view of a wall of a known acoustic chamber; FIG. 3 is a cross sectional top view of an acoustic chamber having low frequency transparency; and FIG. 4 is a cross sectional side view of a wall of an acoustic chamber having low frequency transparency. DETAILED DESCRIPTION Before describing in detail exemplary embodiments, it is noted that the embodiments reside primarily in combinations of apparatus components and processing steps related to an acoustic chamber with low frequency transparency. Accordingly, components have been represented where appropriate by conventional symbols in the drawings, showing only those specific details that are pertinent to understanding the embodiments so as not to obscure the disclosure with details that will be readily apparent to those of ordinary skill in the art having the benefit of the description herein. As used herein, relational terms, such as “first” and “second,” “top” and “bottom,” and the like, may be used solely to distinguish one entity or element from another entity or element without necessarily requiring or implying any physical or logical relationship or order between such entities or elements. Conventional acoustic chambers have a solid outer surface. For example, the outer surface may be 16 gauge, 11 gauge or 3/16″ thick solid steel. While providing enhanced isolation, the solid outer surface acts like an acoustically reflective surface below the cutoff frequency of the absorber system. This creates a low frequency limit to the performance of the anechoic chamber and influences the overall size of the chamber. By changing the outer surface of the chamber to one that is more acoustically transparent through the use of a material such as perforated steel, the acoustically reflective outer surface is eliminated. Acoustic energy that is not absorbed by the absorber system is allowed to propagate through the absorber and outside of the enclosure. By allowing the energy to escape, the cut off frequency of the acoustic free field is lowered without increasing the size of the chamber or depth of the wedges. Thus, in some embodiments, the outer surface of the acoustic chamber could be made of perforated steel of 16 gauge, 11 gauge or 3/16″ thick. The density and/or size of the perforations can be chosen to achieve a desired frequency response. In alternative embodiments, the outer surface of the acoustic chamber can be fabric or other acoustically transparent material. In yet other embodiments, the outer surface of the acoustic chamber may be skeletal to provide support but leaving large open areas to be substantially acoustically transparent. FIG. 3 is an acoustic chamber 24 constructed according to principles discussed herein. The acoustic chamber 24 has an absorber system 16 in the interior 14 and lining the inner wall 20 , which may be perforated steel, as described above. The acoustic chamber 24 has an outer wall 26 that allows low frequency acoustic energy to escape the acoustic chamber 24 . This can be accomplished by constructing the outer wall 26 from perforated steel or by a flexible or rigid fabric, and/or a skeletal frame with openings. FIG. 4 shows a cross sectional view of the wall formed by the inner wall 20 and outer wall 26 enclosing absorber material 28 . The absorber system 16 absorbs acoustic energy but may have a cutoff frequency below which acoustic energy is not effectively absorbed. Low frequency acoustic energy may propagate through the absorber system 16 and penetrate the inner wall 20 which may be made of perforated steel. Some of the acoustic energy is absorbed by the absorber 28 within the wall of the acoustic chamber. Acoustic energy that is not absorbed by the absorber 28 penetrates the outer wall 26 and propagates into the space surrounding the acoustic chamber 24 . Some embodiment include a method of constructing an acoustic chamber. The method includes constructing an inner wall configured to encompass an interior region of the acoustic chamber; the inner wall being at least partially acoustically penetrable. The method also includes constructing an outer wall in proximity to the inner wall, the outer wall being at least partially acoustically penetrable. In some embodiments, the method further includes installing acoustic absorbing material between the inner wall and the outer wall. In some embodiments, the acoustic penetrability of the outer wall is frequency-dependent. In some embodiments, the acoustic penetrability of the inner wall is frequency-dependent. In some embodiments, the method includes the inner wall facing the interior region with an acoustic absorbing material configured to absorb acoustic energy above a particular frequency. In some embodiments, the inner wall and lining material are configured to substantially absorb acoustic energy above a particular frequency. In some embodiments, the outer wall is configured to pass acoustic energy below the particular frequency. The particular frequency can be adjusted as desired by adjusting the size and density of perforations in the inner wall and by adjusting a thickness and structure of the absorbing material lining the inner wall. In some embodiments, the method further includes installing acoustic absorbing material between the inner wall and the outer wall. In some embodiments, a frequency response associated with the outer wall has a high pass component. Some embodiments include a method of constructing a composite wall for an acoustic chamber. The method includes constructing an inner wall having an acoustically penetrable surface. The method also includes constructing an outer wall having an acoustically penetrable surface, the outer wall being positioned in relation to the inner wall to form the composite wall. In some embodiments, the outer wall is substantially parallel to the inner wall. In some embodiments, the method further includes selecting a thickness of the composite wall to achieve a particular high pass frequency response of the composite wall. Generally, the thicker the composite wall—that is, the greater the distance between the inner and outer wall, when this thickness is filled with absorber—the lower the cutoff frequency of the composite wall, the cutoff frequency being the lowest frequency at which energy is substantially reflected by the wall. It will be appreciated by persons skilled in the art that the present embodiments are not limited to what has been particularly shown and described herein above. In addition, unless mention was made above to the contrary, it should be noted that all of the accompanying drawings are not to scale. A variety of modifications and variations are possible in light of the above teachings without departing from the scope of the following claims.	An acoustic chamber with low frequency outer wall transmissivity is provided. According to one aspect, an acoustic chamber has an inner wall encompassing an interior of the acoustic chamber and configured to allow acoustic energy to penetrate the inner wall. The acoustic chamber also has an outer wall configured to allow low frequency acoustic energy that penetrates the inner wall to penetrate the outer wall and leave the acoustic chamber.	4
STATEMENT OF GOVERNMENT INTEREST The invention described herein may be manufactured and used by or for the Government for governmental purposes without the payment of any royalty thereon. BACKGROUND OF THE INVENTION The present invention related generally to aircraft and more specifically to an improved aircraft wheel and tire compressor system. Air Force military aircraft have their tires serviced in accordance with USAF Technical Orders 4T-1-3 the disclosure of which is incorporated by reference. Previously our aircraft wheel and tire assemblies were compressed by stepping on the wheel assembly, while placed on boards, or on top of workbench. Another method that was used was placing the wheel and tire assembly between two large pieces of wood in the bead breaker compressing the assembly by drawing the rings together and inserting the nuts and bolts. Before the compressor was implemented, O-rings were pinched causing air leaks resulting in having to take the assembly apart to repair. The tie bolts would not always come completely through the tie bolt holes and the individual standing on the wheel assembly would have to shift weight forward to the person installing the nut and bolt, or bounce up and down to insert a nut on the bolt. Quite often, trying to insert the nut to the bolt would result in having to aim the nut to the bold before the bolt receded back into the hole. Placing the wheel and tire assembly into the bead breaker on small wheels would require balancing the tire assembly on your knee between two boards and than compressing, often the bolts would catch on the other half and push back out (gravity angle), you would than have to push bolts back in and then install nuts. You're finger manipulation area was smaller and the assemblies very limited. SUMMARY OF THE INVENTION The present invention includes a modification to a military aircraft wheel assembly fixture used on servicing tires of F-16, T-38, F-15 and similar aircraft. In operation the wheel compressor has a spring loaded, shaft with a foot operated torque brace, that when stepped on moves the shaft down. The shaft has an ACME threaded collar welded to the inside that has a ACME bolt threaded T-bar that has a compressor wing that when inserted through the center axel of the wheel assembly threaded to the shaft compresses the wheel. The invention was tested on a F-16 main, T-38 main, F-16 Nose, and an Fl-15 Nose. We found that the compressor tool worked extremely well and that a job that took normally 2 people was reduced down to one person, also to unsafe procedures need be implemented, and no carrying the assembly from one area to another just to insert bolts. DESCRIPTION OF THE DRAWINGS FIGS. 1-3 illustrate the major elements of the tire compressor system of the present invention; and FIG. 4 illustrates the 4-step process of using the invention of FIGS. 1 - 3 . DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT The present invention includes an improved aircraft wheel and tire compressor system for use in servicing aircraft tires. To understand the improvements of the present invention it is necessary to describe the current practice of aircraft tire service. FIGS. 1-3 are illustrations of the major elements of the aircraft wheel assembly fixture used in the present invention. This unit is designed to hold a wheel under uniform compression for installation of bolts during wheel-tire build-up. It will handle practically every wheel-tire assembly in current use up to 1400 pounds. It will serve as a bead breaker for wheels with up to and including 19-inch rim diameters. In the process of the deflation, all aircraft tires must be completely deflated and the valve core removed before any attempts are made to dismount tires and disassemble the wheels. Failure to do so has resulted in fatal injury to personnel. Another concern is that aircraft tires, tubes, and wheels can be damaged beyond repair by improper dismounting procedures and use of unauthorized tools. Tubeless tire bead sealing surfaces and the relatively soft aluminum and magnesium alloy wheels are easily damaged. The present invention compresses aircraft evenly so that nuts may easily threaded onto bolts and O-ring will not be pinched, while utilizing one individual for a complete process. The elements of FIG. 1 are: a main frame 100 with a cap 160 and pivot point 151 ; an interior drive shaft 110 which has a threaded central surface 111 on its top and which goes down when the foot pedal 150 is depressed. The foot pedal 150 is held up by fixed springs 161 but drives downwards when the foot pedal is depressed. FIG. 1 is an illustration of the main tire compression frame, upon which a tire is compressed. FIG. 2 shows the “tee” handle, which has a central threaded shaft that screw into the foot of FIG. 3 and the threaded cap of the inner drive shaft as follows. When an aircraft tire is placed on the cap 160 of the frame 100 the “tee” of FIG. 2 and foot bar 300 of FIG. 3 act as described below. The present invention is an aircraft tire compression system that is hand operated to evenly compress the tire from the wheel rim. The reader's attention is directed towards FIG. 2 which shows a threaded adaptor 250 in which a tee 250 drive down the foot bar 300 along a threaded axis 251 , through the center of a wheel when the foot pedal 150 is pressed. FIG. 2 illustrates the threaded shaft and fixed tee handle of the present invention Where the tee handle is about 6 inches and the threaded shaft 14 inches long. FIG. 3 is the wheel press foot bar 300 of the present invention to compress a tire. In FIG. 4 the threaded tee 251 is inserted through the compression plate into the central axle hole of a wheel to a threaded nut on the other side of the wheel. In FIG. 4 the threaded tee 251 and the wheel press foot bar 300 press plate 300 is spinned down to the compression plate 400 . In FIG. 4 the wheel is uniformly compressed after the threaded tee 251 is turned by the mechanic and the foot bar is stepped on. FIG. 4 adds another structural element not shown in FIGS. 1-3 . More specifically, the tire is sandwiched between a pair of circular plates that have rims that fit over the rim of the tire and which uniformly squeeze the tire from the rim. These circular plates have a central aperture throw, which the shaft of the “tee” is inserted. The pair of plates used have a predetermined radius sized for the tire of interest and a projecting ½ inch rim that fits over the rim of the tire on each side of the tire rim. FIG. 4 is a side view of the present invention and the process for using it is as described above. The invention is usually fixed to an adjacent workbench to ensure it remains upright as the foot pedal is stepped on. Now, in order to understand the improvements the present invention offers, readers are reminded that at Edwards Air Force Base, part of the aircraft tire compression process currently used includes standing on the tire! The tire can be on a frame where someone is four feet above ground level, which presents a potential safety hazard from falls as well as inefficient tire compression. While the invention has been described in its presently preferred embodiment it is understood that the words, which have been used, are words of description rather than words of limitation and that changes within the purview of the appended claims may be made without departing from the scope and spirit of the invention in its broader aspects.	This new wheel compressor has a spring loaded, shaft with a foot operated torque brace, that when stepped on moves the shaft down. The shaft has an ACME threaded collar welded to the inside that has an ACME bolt threaded T-bar that has a compressor wing that when inserted through the center axel of the wheel threaded to the shaft compresses the wheel.	1
This application is a national stage application filed under 35.U.S.C.37/ of PT/FR95/00320 on Mar. 6, 1995. FIELD OF THE INVENTION The present invention relates to a friction material designed for fitting to a device using friction in a liquid medium, and the method of producing such a friction material and the device to which it is fitted. More particularly, such a friction material takes the form of a flat ring or a truncated cone and the device to which it is fitted is a clutch or brake disc, notably for an automatic gear box or associated therewith, operating in oil, or a synchronisation ring or cone for a manually-operated gearbox also operating in oil, such a device being installed in a vehicle. BACKGROUND OF THE INVENTION The friction materials used up to now for the aforementioned applications are of three types: materials of the paper type, sintered materials and graphite-containing moulded materials. The materials of the paper type consist essentially of cellulose fibres impregnated with resin. Such materials are obtained by a wet method using a normal paper-making process, that is to say by dispersing cellulose fibres in an aqueous solution containing a resin, then spinning and drying. Such a method necessarily involves using short fibres, with an average length below one millimeter. Materials of this type have the drawback of degrading very rapidly as soon as their temperature reaches 150° C., which is the case when the device that is equipped with the friction material must, within a small space, transmit or absorb high torques at speeds which, in practice, are growing ever higher. This situation now arises by virtue of, on the one hand, the increasing power of thermal engines and, on the other hand, the reduction in the size of the devices for transmitting engine torque, which make it necessary to increase the gripping pressure of the friction devices. Sintered materials do not exhibit the above described drawback but, unlike with materials of the paper type, the coefficients of friction obtained are low. Moreover, these materials generate damaging vibrations and noises. Materials of the graphite-containing moulded type have a relatively high cost and do not permit stable transmission of a torque. SUMMARY OF THE INVENTION The aim of the invention is to overcome the aforementioned drawbacks by proposing a friction material for a liquid medium which has in particular a high, stable coefficient of friction, a high resistance to heating at high working pressures, and good resistance to wear. A friction material for a liquid medium, according to the invention, is characterized in that it consists of a mat of fibres impregnated with a thermosetting resin, and in that the fibres have a length of at least 12 mm. According to other characteristics taken separately or in combination: the average length of the fibres is at most 120 mm; the fibres are chosen from amongst the group of fibres of glass, wool, cotton, ceramic, polyacrylonitrile, preoxidized polyacrylonitrile and aramid; fillers in powder form are incorporated into the mat, comprising all or some of the following elements or compounds: copper, rockwool, carbon (coke and/or reduced-powder carbon fibres, graphite), zirconium silicate, iron sulphide, alumina, rubber and diatoms; fillers in the form of pulps are incorporated into the mat, comprising all or some of the following compounds: pulps of glass, aramid, acrylic and phenolic fibres; the resin of the thermosetting type includes a polar solvent, preferably aqueous; the thermosetting resin has latex and/or fillers in powder form added to it which comprise all or some of the following elements or compounds: copper, rockwool, carbon (coke and/or reduced-powder carbon fibres, graphite), zirconium silicate, iron sulphide, alumina, rubber and diatoms. The method of producing the friction material according to the invention is characterized by the following steps: a) a mixture of fibres of the same nature or of different natures as defined above is produced in a mixer; b) the mixture is carded to form a card web; c) the card web is lapped; d) the lap thus formed is needled; e) the needled mat is impregnated with a thermosetting resin and; f) the impregnated mat is dried. According to other characteristics taken independently or in combination: between steps b) and c) above, fillers in powder form as defined above are sprinkled on the card web; before step e) the thermosetting resin has fillers as defined above added to it; step e) is preceded by an operation of impregnation of the needled mat by means of a dilution or dispersion in a liquid of the fillers as defined above; the carding is effected by means of a wool-type card; the needling operation is preceded by a preliminary needling operation; the resin impregnation is effected by soaking in a tank containing the resin in solution or dispersed in water; drying is preceded by a squeezing or hydroextraction operation; after or during drying, the mat is wound up. As a variant, the method is characterized by the following operations; a) a mixture of fibres of the same nature or of different natures, as defined above, is produced in a mixer; b) the mixture is carded to form a card web; c') fillers in powder form as defined above, and a resin in powder form, are sprinkled on the card web; d') the mat is pressed while being brought to an appropriate temperature to ensure the flow of the resin. In order to produce a device coated with friction material, the method according to the invention is as follows: g) a ring, or as a variant a plurality of sectors forming a ring, is cut out from the mat produced as indicated above; i) the ring or plurality of sectors forming a ring is placed in the bottom of a mould; j) a metal support is placed in the mould on the ring or on the plurality of sectors forming a ring; k) where appropriate, a second ring or a plurality of sectors forming a ring is placed on the metal support, opposite the ring or the said plurality of sectors forming a ring; l) the mould is closed, shims being disposed so as to control and limit the movement of a piston-closing the mould; m) heating under pressure is effected in the mould, thereby also ensuring the adhesion of the said ring, and where applicable of the said second ring, to the metal support; n) the mould is opened and the device covered with the friction material is cooled. As a variant, step g) is replaced by a step h) identical thereto, but conducted between steps d) and e) above. According to other characteristics of the invention, taken independently or in combination: the mould and piston have a flat bottom; the bottom of the mould is grooved; the mould and the piston are in the shape of a truncated cone; the shims limiting the movement of the piston are sized so that the porosity of the friction material is between 20% and 70%; the heating temperature is between 130° C. and 220° C. Other characteristics and advantages of the product and of the method will appear from a reading of the description that follows, of example embodiments and implementations of the invention, in relation to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a functional diagram of a first part of the installation designed for the implementation of the method according to the invention; FIG. 2 is a functional diagram of a second part of this installation; FIG. 3 is a diagram illustrating the cutting out of friction rings and sectors; FIG. 4 is a series of graphs summarizing the results of comparative tests. DESCRIPTION OF THE PREFERRED EMBODIMENTS Four fibre mats (examples A, B, C, D) are produced from the following compositions by weight of fibres: ______________________________________ EXAMPLESFIBRES A B C D______________________________________GLASS Parts 20 -- 20 --COTTON Parts -- 30 -- --CERAMIC Parts 10 10 10 --PAN (polyacrylonitrile or Parts 10 -- 10 20preoxidized)______________________________________ The average length of the fibres used is as follows: glass fibres: 50 mm; cotton fibres: 18 mm; ceramic fibres: 12 mm; PAN fibres: 42 mm. Referring to FIG. 1, the above fibres or mixtures of fibres, produced in a mixer, are introduced into the hopper 1 (FIG. 1) of a feed device 2 for a wool-type card 3 which has a feed chute 4. In examples Card D, filler in powder form are sprinkled at the discharge from the card 3, on the card web formed, by means of a sprinkling device 5. The fillers in powder form have the following composition (composition by weight referred to the parts by weight of the above fibres): ______________________________________ EXAMPLESFillers IN POWDER FORM A B C D______________________________________COPPER -- -- -- 10POWDERED ROCKWOOL -- -- -- 10GRAPHITE -- -- 10 --COKE -- -- 10 --______________________________________ The card web is then lapped by means of a lapper 6, and the lap thus formed undergoes a needling process in two phases: preliminary needling by a preliminary needler with rollers 7 and needling by a needler 8. The mat of needled nonwoven material thus produced is, in the example depicted, wound on a roll 9 at the discharge from the first part of the installation. The roll 9 is carried into a second part of the installation shown in FIG 2, and is paid out for the remainder of the process of producing a friction material. As a variant (not shown), the second part of the installation follows immediately on from the first part and the needled nonwoven mat is not wound up. The needled mat is fed into a cutting station 10 where rings 11 or sectors 12 as depicted in FIG. 3 or any other shape that the friction material is to take are cut out. The part of the mat that is not cut out, also called a skeleton, is directed to a winder 13, for subsequent recycling. The cut-out shapes 11 or 12 are conveyed into an impregnating bath 14 containing one or more resins of the thermosetting type in solution or dispersed in water. The impregnating bath 14 is of the following composition by weight, expressed in parts, in a manner consistent with the proportions indicated previously for fibres and fillers. ______________________________________ EXAMPLESIMPREGNATING BATH A B C D______________________________________WATER-BASED RESIN 60 60 -- --RESOL-BASED RESIN -- -- 40 60______________________________________ In general, the following types of resin can be used: phenolic plastic resins (resol or novolak); aminoaldehyde resins (urea formaldehyde, melamine formaldehyde or combinations thereof); epoxy (epoxide) resins; polyimide resins. At the end of impregnation, squeezing takes place, firstly in the bath (conveyor 16) and outside the bath (rollers 17). As a variant, not shown, the cut-out shapes 11, 12 undergo, after soaking in the impregnating bath, a hydroextraction operation. The cut-out shapes 11, 12 are then introduced into an infrared drying tunnel 18, and then packaged. As a variant, the operation of cutting out the shapes is carried out after impregnation, squeezing and/or hydroextraction and drying. In the latter case, the impregnated mat can be wound up in order to be transported to a cutting station as shown in FIG. 3. Each cut-out shape, a ring or plurality of sectors forming a ring, is placed in a mould which has, depending on the equipment for which the friction material is intended, a bottom which is flat or in the form of a truncated cone or any other shape, grooved or otherwise. A metal support is placed in the mould on the ring or plurality of sectors forming a ring. Where appropriate, a second ring or a plurality of sectors forming a ring is placed on the metal support, opposite the said ring or the plurality of sectors forming a ring. The mould is closed, shims being disposed so as to control and limit the movement of a piston closing the mould. Heating under pressure is effected in the mould, which moreover ensures the adhesion of the ring, and where applicable of the second ring, to the metal support. The mould is opened and the device coated with the friction material is cooled. Advantageously, the shims limiting the movement of the piston are sized so that the porosity of the friction material is between 20% and 70% and the heating temperature is between 130° C. and 220° C. In order to effect comparative tests with a known friction material of the paper type, two samples of friction material (clutch disc) are produced with the following composition by weight: cellulose fibres: 30% (length: 2 to 20 mm); phenolic resin: 31% diatoms: 23% aramid fibres: 10% (length: 6 to 20 mm) quartz: 5% sodium sulphate: 1% Four series of three clutch friction discs produced in accordance with the invention from the compositions of the above examples A, B, C and D and two series of three clutch friction discs of the paper type having the above compositions underwent endurance tests under the conditions indicated hereinafter. Three discs from the same series, corresponding to the same embodiment, were placed in a testing machine of the type defined by the standard SAE II (US standard). The test was effected in an oil bath brought to 114° C. A circulation of oil was also provided with a flow rate of between 2 and 3 liters per minute. The test included three series of cycles. Each cycle consisted of braking, until it stopped, a centrifugal mass previously launched at a rotation speed of 3600 revolutions per minute. After each cycle the centrifugal mass was relaunched at the speed indicated above. A 30 second time interval was provided between each cycle start. The first series comprised 50 cycles where the unit-area pressure of the gripping of the discs was 0.5 Mpa, the inertia being 0.213 m 2 .kg. The second series comprised 2400 cycles where the unit-area pressure of the gripping of the discs was 1.5 Mpa, the inertia being 0.501 m 2 .kg. The third series was identical to the first. The graphs in FIG. 4 represent the evolution of the dynamic friction coefficient of each of the six samples during the endurance cycles defined previously. It will be observed that at between 500 and 800 cycles, a paper lining is destroyed while the friction material according to the invention remains intact after 2500 cycles (end of tests). Furthermore, a remarkable stability will be observed in the coefficient of friction of the material according to the invention during the cycles, at a level very close to that of a paper-type material. Variant embodiments can be used. In particular, fillers in the form of pulps can be incorporated into the mat, notably pulps chosen from amongst the group of pulps of glass, aramid, acrylic and phenolic fibres. It is, moreover, entirely possible to incorporate the fillers into the liquid resin instead of, or in addition to, sprinkling them onto the mat. The fillers can also be diluted or dispersed in a suitable liquid constituting a first impregnating bath for the mat, a second impregnation then being provided so as to ensure the addition of resin. Furthermore, it is possible to use a solid resin, in the form of a powder, which is sprinkled onto the mat at the same time as the fillers. This mat is then pressed to the correct thickness at 60° C. for 2 secs; in this variant, there is no needling or impregnation.	A friction material for a liquid medium consists of a fibre mat impregnated with a thermosetting resin, the fibres having a length of at least 12 mm. The method of producing such a material includes the steps of providing a mixture of fibres, carding the mixture to form a card web, lapping the card web, needling the lapped card web for form a needled mat and impregnating the needled mat with a thermosetting resin.	3
CROSS-REFERENCE TO RELATED APPLICATIONS Not Applicable. STATEMENT REGARDING FEDERALLY-SPONSORED RESEARCH OR DEVELOPMENT Not Applicable. BACKGROUND OF THE INVENTION 1. Field of Invention The present invention relates generally to the field of seating and chairs including moveable and stackable seating. More specifically, this invention relates to stackable chairs having a flexible back support with an improved spring assembly. 2. Description of the Related Art Prior chairs having a flexible backrest frame have provided frame members with spring members connected internal of seat tube members for control of movement of the backrest frame of the chair. A typical flexible backrest is illustrated in U.S. Pat. No. 5,039,163, issued to Tolleson, which discloses a chair including depending leg members and a hollow support frame having members with open ends terminating beneath the seat assembly of the chair. The chair includes a pair of hollow backrest frame members having open frame ends extending beneath the seat assembly for alignment with respective open ends of the support frame members. Each open end of the respective frame members includes at least one flexible spring member inserted therein. Prior configurations of spring members allow insertion of opposed spring member ends into opposed and aligned open frame ends, with each spring member being aligned with the frame ends and extended to fill any gap between the respective back frame members and support frame members. Therefore, replacement of the spring member required full disassembly of the chair frame and removal of each inserted spring member end. In order to prevent each spring element from excessive flexing during reclining movements of the chair backrest, the spring member ends have been typically enclosed by pairs of U-shaped brackets of metal that limit the range of angular movement of each enclosed spring member, thereby limiting the reclining movements of the chair backrest. Additional pairs of spring members and U-shaped brackets have been required to be added for rigorous use. The additional pairs of spring members are typically positioned parallel to each first set of spring members with associated enclosure by U-shaped brackets of greater width or depth, thereby requiring an increased width or depth of the support frame members to accommodate the additional spring members and brackets. Another example of a prior art chair having a flexible backrest frame is illustrated in U.S. Pat. No. 6,896,327, issued to Barile, which discloses a stackable chair with a seat assembly and flexible back support having a seat spring system attached there between. The seat assembly includes seat sides having spaced apart rear portions. The back support includes lower ends curved forwardly and disposed in registry with and separated by right and left gaps from respective seat side rear portions. Right and left spring members are disposed inwardly adjacent to bridge each gap. Each spring member includes forward ends connected to respective right and left front support members extended inbound from respective seat sides, and includes rear ends connected to opposed ends of a frame rear cross-member. The spring members allow limited reclining movement of the back frame. A limit to excessive forward movement of the back support is provided by pairs of fixation plates positioned in aligned and abutting relationship on upper surfaces of each respective forward and rear ends of each spring member. The prior art leaf springs are securely fastened to the frame of the chair making replacement of the spring difficult and labor intensive. What is missing from the art is a stackable chair with a flexible back support frame employing a spring assembly attached directly to the rear cross support member of the seat assembly that allows for easily replacing the spring, or compression, member allowing for ease of adjustment of flex tension, thus eliminating elongated, or leaf, spring members and their attendant support members. BRIEF SUMMARY OF THE INVENTION The present invention provides an improved spring assembly for a chair frame for a stackable chair having a flexible back member. While described herein in terms of a stackable chair, it will be appreciated that the present invention has utility with non-stackable chairs as well. The chair frame comprises a seat support portion for supporting a chair seat, and a pair of leg assemblies oppositely disposed on either side of the seat support portion. Each leg assembly includes a front leg and a rear leg, and an upper support member. Each leg assembly also includes a stacking bar extending between the front leg and the rear leg, the stacking bar being disposed below, and being selectively spaced from the upper support member. The stacking bar of each leg assembly has a lower surface configured to closely engage at least a portion of the upper surface of the upper support member of another chair frame of the present invention to facilitate the stacking of the chair frame on such other chair frame. The back support frame includes frame lower ends curved forwardly and positioned in registry with and spaced apart by a gap separation from the rear portions of the seat assembly. Right and left spring can assemblies are carried by the rear cross support member. This improved spring can assembly dispenses with the need for the prior art elongated springs and their attendant support components that were previously required. During reclining movement of the back support frame, the back support frame member compresses the compression member downwardly to a compressed position. When reclining pressure is released from the back support frame member, the spring member biases the back support frame member to a non-reclined position, thereby returning the back support to a substantially upright position when not reclined by a seat occupant. BRIEF DESCRIPTION OF THE DRAWINGS The above-mentioned and additional features of the invention will become more clearly understood from the following detailed description of the invention read together with the drawings in which: FIG. 1 illustrates a perspective view of a chair constructed in accordance with the present invention. FIGS. 2A and 2B illustrate a partial rear elevation view of the chair illustrated in FIG. 1 . FIG. 3 illustrates an exploded view of the plunger, compression member, and plunger of the present invention. In FIGS. 3A and 3B , the compression member is illustrated as a helical coil spring. In FIG. 3C , the compression member is illustrated as a crest-to-crest wave spring. FIGS. 4A and 4B illustrates the hinge member of the present invention; FIG. 4A is an assembled perspective view; while FIG. 4B is an exploded perspective view. FIG. 5 is a partial perspective view of the chair illustrated in FIG. 1 . FIGS. 6A, 6B and 6C are partial elevation views showing the interaction of the back frame member and the spring assembly during assembly of the chair and during reclining of the back frame member. FIG. 7 is a side elevation view of the chair illustrated in FIG. 1 showing a seat cushion. DETAILED DESCRIPTION OF THE INVENTION A chair frame for a stackable chair incorporating various features of the present invention is illustrated generally at 10 in FIGS. 1-7 . While the chair frames 10 , constructed in accordance with the present invention may be stacked, one upon another, to facilitate the storage of a plurality of chairs, it will be appreciated that the present invention is not limited to stackable chairs but rather could be utilized with non-stacking chairs or other seating structures, such as benches, that include a back support frame. The chair frame 10 includes a seat support portion 15 which in the preferred illustrated embodiment defines a generally U-shaped frame portion 20 and a rear cross support member 25 which extends across, and is secured at its opposite ends to, the right and left leg assemblies 35 , 40 . The seat support portion 15 is used to support the seat portion of a chair utilizing the frame 10 , such as the seat cushion 30 . The right and left leg assemblies 35 and 40 are disposed on opposite sides of, and attached to, the seat support portion 15 . Each of the leg assemblies 35 and 40 includes a front leg 45 and a rear leg 50 . The leg assemblies 35 and 40 also include an upper support member 55 which is disposed between the upper ends of the front leg 45 and the rear leg 50 . As will be understood by those skilled in the art, the upper support members 55 serve to support another chair utilizing a chair frame 10 which is stacked above. In the preferred embodiment, the support members 55 extend between, and serve to support, the associated leg members 45 and 50 . Each of the leg assemblies 35 and 40 are also provided with a stacking bar 60 which extends between the front leg 45 and the rear leg 50 , and which is selectively spaced below the upper support member 55 . In the preferred embodiment the chair frame 10 also includes a back support frame member 65 for supporting a seat back member (not shown), which can be a cushion or a rigid member for supporting the back of an occupant of the chair. The back support frame member 65 includes an upper portion 70 joined at opposed ends to right and left frame side members 75 and 80 which are spaced apart by a sufficient width to accept a seat back member (not shown). Each frame side member 75 and 80 extends downwardly and is bent forwardly to form respective frame lower ends 75 ′, 80 ′ that extend forwardly to a generally horizontal orientation in aligned registry with and spaced apart from the seat member rear portions 90 and 95 . In order to facilitate the preferred hinged attachment of the frame lower ends 75 ′, and 80 ′ with the seat member rear portions 90 and 95 , a gap is preferably provided there between. As best illustrated in FIGS. 4A and 4B , the chair frame 10 includes hinge assembly 100 defined by cooperating hinge members 105 and 110 for connecting the lower ends 75 ′ and 80 ′ of the back support frame member 65 to the rear portions 90 and 95 of the seat assembly 15 respectively. In the preferred embodiment, each hinge member 105 and 110 includes at least one knuckle 115 which are connected hingedly by a pin 120 . In one embodiment, hinge member 105 defines a tenon which is releasably received by the tubular end of either of the lower ends 75 ′ and 80 ′, in mortise and tenon manner. Similarly, hinge member 110 defines a tenon which is releasably received by the tubular end of the rear portions 90 and 95 of the seat assembly 15 . Whereas the figures, specifically FIGS. 4A and 4B depict a tenon and mortise configuration for the knuckles 115 of the hinge members 105 and 110 , it will be appreciated by those skilled in the art, that the hinge members 105 could include a plurality of knuckles for receiving hinge pin 120 . It will be appreciated that the present invention does not intend to limit the number or configuration of the knuckles of hinge assembly 100 . Rather, it should be appreciated that, regardless of the configuration and number of knuckles of the hinge assembly 100 , hinge assembly 100 is configured so as to provide pivotal motion of the lower ends 75 ′ and 80 ′ with respect to rear portions 90 and 95 . Further, while one type of hinge member has been shown, those skilled in the art will appreciate that various types of hinge members could be utilized. Further, it will be recognized that frame lower ends 75 ′ and 80 ′ could be pivotally secured to a portion of the chair frame in a manner that allows for pivotal motion of the back frame support 65 and maintains the substantial horizontal plane alignment with the seat member rear portions 90 and 95 when the back fram support 65 is in the non-reclined position. In order to provide a back support frame 65 that repetitively reclines and rebounds to a generally vertical position relative to the seat assembly 15 , the rear cross support member 25 includes distal ends 125 which are secured to the rear legs 50 . A recess 130 is provided at each distal end 125 . Further, at least one compression member 140 is carried by at least one distal end 125 . In the preferred embodiment, a cylindrical can member 135 is carried by recess 130 . The compression member 140 is received within the can member 135 . Further, a plunger member 145 is received within the can member 135 and engages the compression member 140 such that the compression member biases the plunger 145 upward when the plunger 145 engages and compresses compression member 140 . In this regard, the can 135 is positioned such that the lower surface of each lower end 75 ′ and 80 ′ of the back support frame member 65 engages the plunger 145 . As a reclining force is applied to the back support frame member 65 by an occupant of the chair 10 , the lower ends 75 ′ and 80 ′ compress the plunger 145 against the biasing force of the compression member 140 . The can member 135 serves as a stop to limit the extent of reclining motion for the back support frame member. The fully reclined position is illustrated in FIG. 6C . The compression member 140 of the improved spring can assembly biases the back frame support member 65 to return to the non-reclined position shown in FIG. 6B , after the reclining force is released. Whereas in one embodiment, illustrated in FIGS. 3A and 3B , compression member 140 is defined by a helical coil spring, it will be appreciated that other compression members could be utilized. For instance, as illustrated in FIG. 3C , compression member 140 ′ could be defined by a crest-to-crest wave spring. Those skilled in the art will recognize that other known compression members could be utilized for biasing the plunger 145 upward upon release of the reclining pressure applied to the back support frame member 65 . In the preferred embodiment, the range of compression of the plunger member 145 and compression member 140 is limited to approximately ⅜″. Further, while the can member 135 is illustrated as being a separate component carried by recess 130 , it will be appreciated that the can member 135 and the recess 130 could be integrally formed. In one embodiment, as the chair 10 is being assembled, it will be appreciated that the frame members will be fully assembled prior to the attachment of either the seat cushion 30 or the supporting seat back member (not shown) are attached. With the back frame support member 65 tilted forward, as illustrated in FIG. 6A , compression member 140 and plunger member 145 are inserted within can 135 . The back frame support member 65 is then returned to a neutral, i.e. non-reclined position. The seat cushion 30 is then secured to the seat support 15 . The back portion of the seat cushion 30 extends over the frame lower ends 75 ′ and 80 ′. In this position, the frame lower ends 75 ′ and 80 ′ will engage the lower surface of the seat cushion 30 if the back frame support member is flexed substantially forward, thereby retaining compression member 140 and plunger 145 within the can member 135 . It will be appreciated by those skilled in the art that the spring can assembly of the present invention allows the compression member to be readily and easily changed, thus providing the ability to easily adjust the flex tension of the back support member. While the present invention has been illustrated by description of some embodiments, and while the illustrative embodiments have been described in detail, it is not the intention of the applicant to restrict or in any way limit the scope of the appended claims to such detail. Additional modifications will readily appear to those skilled in the art. The invention in its broader aspects is therefore not limited to the specific details, representative apparatus and methods, and illustrative examples shown and described. Accordingly, departures may be made from such details without departing from the spirit or scope of applicant's general inventive concept.	Disclosed is a chair containing a flexible back support frame mechanism that includes an improved spring assembly designed to allow reclining movement of a back support frame relative to a seat assembly. The spring can assembly of the present invention is, preferably, carried by a rear cross support member thereby eliminating the need for cumbersome elongated springs and their attendant support members. Further, the spring can assembly of the present invention allows the compression member to be readily and easily changed, thus providing the ability to easily adjust the flex tension of the back support member.	0
CROSS-REFERENCE TO RELATED APPLICATIONS [0001] This non-provisional application claims priority under 35 U.S.C. §119(a) on Patent Application No(s). 100110435 filed in Taiwan, R.O.C. on Mar. 25, 2011, the entire contents of which are hereby incorporated by reference. BACKGROUND [0002] 1. Technical Field [0003] The present disclosure relates to an optical lens assembly, and more particularly to a compact optical lens assembly. [0004] 2. Related Art [0005] In recent years, with the prosperity of photographing optical lens assemblies, the demand for compact photographing cameras increases exponentially. The photo-sensing device, e.g. a sensor, of an ordinary photographing camera is commonly selected from a charge coupled device (CCD) and a complementary metal-oxide semiconductor (CMOS) device. In addition, as the advanced semiconductor manufacturing technology enables the miniaturization of pixel size of sensors, the resolution of a compact optical lens assembly is gradually increased, so that there is an increasing demand for a compact optical lens assembly capable of generating better quality image. [0006] A conventional compact photographing lens used in a mobile electronic device usually consists of four lens elements, which is disclosed in U.S. Pat. No. 7,365,920. However, with the growing popularity of high technology mobile devices including Smart Phone, and PDA (Personal Digital Assistant), the demand for the compact photographing lens with better resolution and image quality increases exponentially. The conventional four lens assembly does not fulfill the specification of the high-level photographing lens assembly. With the electronic devices heading towards the direction of high functionality while being as small and light as possible, the inventors recognize that an optical imaging system capable of improving the image quality of mobile electronic devices as well as miniaturizing the overall size of the camera lens equipped therewith is urgently needed. SUMMARY [0007] According to an embodiment, a photographing optical lens assembly comprises, in order from an object side to an image side: a first lens element with positive refractive power having a convex object-side surface, a second lens element, a third lens element, a fourth lens element with at least one aspheric surface, a fifth lens element with at least one inflection point having a convex object-side surface and a concave image-side surface and a sixth lens element having an object side surface and a concave object-side surface. At least one of the object-side surface and the image-side surface of the fifth lens element is aspheric; at least one of the concave image-side surface and the object-side surface of the sixth lens element is aspheric. [0008] The photographing optical lens assembly satisfies the following condition: [0000] −0.3<( R 9 −R 10 )/( R 9 +R 10 )<0.6 (Condition 1): [0009] Wherein R 9 is the curvature radius of the object-side surface of the fifth lens element; R 10 is the curvature radius of the image-side surface of the fifth lens element. [0010] According to another embodiment, a photographing optical lens assembly comprises, in order from an object side to an image side: a first lens element with positive refractive power having a convex object-side surface; a second lens element; a third lens element; a fourth lens element having a concave object-side surface and a convex image-side surface, a fifth lens element having a convex object-side surface and a concave image-side surface and a sixth lens element having a convex object-side surface and a concave image-side surface. At least one of the object-side surface and the image-side surface of the fourth lens element is aspheric; at least one of the object-side surface and the image-side surface of the fifth lens element is aspheric; at least one of the object-side surface and the image-side surface of the sixth lens element is aspheric. The fifth lens element and the sixth lens element are made of plastic. BRIEF DESCRIPTION OF THE DRAWINGS [0011] The present disclosure will become more fully understood from the following detailed description when taken in connection with the accompanying drawings, which show, for purpose of illustrations only, and thus do not limit other possible embodiments derived from the spirit of the present disclosure, and wherein: [0012] FIG. 1A is a schematic structural view of a first embodiment of a photographing optical lens assembly; [0013] FIG. 1B is a schematic view of longitudinal spherical aberration curves when the lights having wavelengths of 486.1 nm, 587.6 nm, and 656.3 nm are respectively projected in the photographing optical lens assembly in FIG. 1A ; [0014] FIG. 1C is a schematic view of astigmatic field curves when the light having the wavelength of 587.6 nm is projected in the photographing optical lens assembly in FIG. 1A ; [0015] FIG. 1D is a schematic view of a distortion curve when the light having the wavelength of 587.6 nm is projected in the photographing optical lens assembly in FIG. 1A ; [0016] FIG. 2A is a schematic structural view of a second embodiment of a photographing optical lens assembly; [0017] FIG. 2B is a schematic view of longitudinal spherical aberration curves when the lights having wavelengths of 486.1 nm, 587.6 nm, and 656.3 nm are respectively projected in the photographing optical lens assembly in FIG. 2A ; [0018] FIG. 2C is a schematic view of astigmatic field curves when the light having the wavelength of 587.6 nm is projected in the photographing optical lens assembly in FIG. 2A ; [0019] FIG. 2D is a schematic view of a distortion curve when the light having the wavelength of 587.6 nm is projected in the photographing optical lens assembly; [0020] FIG. 3A is a schematic structural view of a third embodiment of an photographing optical lens assembly; [0021] FIG. 3B is a schematic view of longitudinal spherical aberration curves when the lights having wavelengths of 486.1 nm, 587.6 nm, and 656.3 nm are respectively projected in the photographing optical lens assembly in FIG. 3A ; [0022] FIG. 3C is a schematic view of astigmatic field curves when the light having the wavelength of 587.6 nm is projected in the photographing optical lens assembly in FIG. 3A ; [0023] FIG. 3D is a schematic view of a distortion curve when the light having the wavelength of 587.6 nm is projected in the photographing optical lens assembly in FIG. 3A ; [0024] FIG. 4A is a schematic structural view of a fourth embodiment of a photographing optical lens assembly; [0025] FIG. 4B is a schematic view of longitudinal spherical aberration curves when the lights having wavelengths of 486.1 nm, 587.6 nm, and 656.3 nm are respectively projected in the photographing optical lens assembly in FIG. 4A ; [0026] FIG. 4C is a schematic view of astigmatic field curves when the light having the wavelength of 587.6 nm is projected in the photographing optical lens assembly in FIG. 4A ; [0027] FIG. 4D is a schematic view of a distortion curve when the light having the wavelength of 587.6 nm is projected in the photographing optical lens assembly in FIG. 4A ; [0028] FIG. 5A is a schematic structural view of a fifth embodiment of a photographing optical lens assembly; [0029] FIG. 5B is a schematic view of longitudinal spherical aberration curves when the lights having wavelengths of 486.1 nm, 587.6 nm, and 656.3 nm are respectively projected in the photographing optical lens assembly in FIG. 5A ; [0030] FIG. 5C is a schematic view of astigmatic field curves when the light having the wavelength of 587.6 nm is projected in the photographing optical lens assembly in FIG. 5A ; [0031] FIG. 5D is a schematic view of a distortion curve when the light having the wavelength of 587.6 nm is projected in the photographing optical lens assembly in FIG. 5A ; [0032] FIG. 6A is a schematic structural view of a sixth embodiment of a photographing optical lens assembly; [0033] FIG. 6B is a schematic view of longitudinal spherical aberration curves when the lights having wavelengths of 486.1 nm, 587.6 nm, and 656.3 nm are respectively projected in the photographing optical lens assembly in FIG. 6A ; [0034] FIG. 6C is a schematic view of astigmatic field curves when the light having the wavelength of 587.6 nm is projected in the photographing optical lens assembly in FIG. 6A ; [0035] FIG. 6D is a schematic view of a distortion curve when the light having the wavelength of 587.6 nm is projected in the photographing optical lens assembly in FIG. 6A ; [0036] FIG. 7A is a schematic structural view of a seventh embodiment of a photographing optical lens assembly; [0037] FIG. 7B is a schematic view of longitudinal spherical aberration curves when the lights having wavelengths of 486.1 nm, 587.6 nm, and 656.3 nm are respectively projected in the photographing optical lens assembly in FIG. 7A ; [0038] FIG. 7C is a schematic view of astigmatic field curves when the light having the wavelength of 587.6 nm is projected in the photographing optical lens assembly in FIG. 7A ; [0039] FIG. 7D is a schematic view of a distortion curve when the light having the wavelength of 587.6 nm is projected in the photographing optical lens assembly in FIG. 7A ; [0040] FIG. 8A is a schematic structural view of an eighth embodiment of a photographing optical lens assembly; [0041] FIG. 8B is a schematic view of longitudinal spherical aberration curves when the lights having wavelengths of 486.1 nm, 587.6 nm, and 656.3 nm are respectively projected in the photographing optical lens assembly in FIG. 8A ; [0042] FIG. 8C is a schematic view of astigmatic field curves when the light having the wavelength of 587.6 nm is projected in the photographing optical lens assembly in FIG. 8A ; [0043] FIG. 8D is a schematic view of a distortion curve when the light having the wavelength of 587.6 nm is projected in the photographing optical lens assembly in FIG. 8A ; [0044] FIG. 9A is a schematic structural view of a ninth embodiment of a photographing optical lens assembly; [0045] FIG. 9B is a schematic view of longitudinal spherical aberration curves when the lights having wavelengths of 486.1 nm, 587.6 nm, and 656.3 nm are respectively projected in the photographing optical lens assembly in FIG. 9A ; [0046] FIG. 9C is a schematic view of astigmatic field curves when the light having the wavelength of 587.6 nm is projected in the photographing optical lens assembly in FIG. 9A ; and [0047] FIG. 9D is a schematic view of a distortion curve when the light having the wavelength of 587.6 nm is projected in the photographing optical lens assembly in FIG. 9 A. DETAILED DESCRIPTION [0048] The photographing optical lens assembly of the present disclosure is described with FIG. 1A as an example, to illustrate that the embodiments have similar lens combinations, configuration relationships, and the same conditions of the optical lens assembly. The differences are described in detail in the following embodiments other than the embodiment described in FIG. 1 . [0049] Taking FIG. 1A as an example, the photographing optical lens assembly 10 comprises, from an object side to an image side along an optical axis (from left to right in FIG. 1A ) in sequence, a first lens element 110 , a second lens element 120 , a third lens element 130 , a fourth lens element 140 , a fifth lens element 150 , and a sixth lens element 160 . [0050] The first lens element 110 with positive refractive power provides part of the refractive power needed by the photographing optical lens assembly 10 , and, therefore, helps reduce the total optical length of the photographing optical lens assembly 10 . The first lens element 110 comprises a convex object-side surface 111 and an image-side surface 112 . When the object-side surface 111 is convex, the positive refractive power of the first lens element 110 is increased which reduces the total optical length of the photographing optical lens assembly 10 . The first lens element 110 is made of plastic, and the object-side surface 111 and the image-side surface 112 are both aspheric. [0051] The second lens element 120 with negative refractive power corrects the aberration of the photographing optical lens assembly 10 . The second lens element 120 comprises an object-side surface 121 and an image-side surface 122 . The second lens element 120 is made of plastic, and the object-side surface 121 and the image-side surface 122 are both aspheric. [0052] The third lens element 130 with positive refractive power may reduce the sensitivity of the photographing optical lens assembly 10 . The third lens element 130 comprises an object-side surface 131 and an image-side surface 132 . The image-side surface 132 is concave for correcting the aberration. The third lens element 130 is made of plastic, and both the object-side surface 131 and the image-side surface 132 are aspheric. [0053] The fourth lens element 140 comprises a concave object-side surface 141 and a convex image-side surface 142 for correcting the aberration of the photographing optical lens assembly 10 . The fourth lens element 140 is made of plastic, and the object-side surface 141 and the image-side surface 142 are both aspheric. [0054] The fifth lens element 150 comprises a convex object-side surface 151 and a concave image-side surface 152 , thereby effectively adjusting the astigmatism of photographing optical lens assembly 10 . The fifth lens element 150 is made of plastic, and the object-side surface 151 and the image-side surface 152 are both aspheric. In addition, the fifth lens element 150 has at least one inflection point. For example, the fifth lens element 150 has an inflection point 153 for reducing the angle at which the light is projected onto the image plane 150 from the off-axis field and further correcting the off-axis aberrations. [0055] The sixth lens element 160 comprises a convex object-side surface 161 and a concave image-side surface 162 . When the image-side surface 162 of the sixth element 160 is concave, the principle point is moved toward the object side and, therefore, the total optical length of the photographing optical lens assembly 10 is reduced. When the object-side surface 161 is convex with the image-side surface 162 being concave, the distortion can be corrected. The sixth lens element 160 is made of plastic, and both the object-side surface 161 and the image-side surface 162 are aspheric. In addition, the sixth lens element 160 has at least one inflection point. For example, the sixth lens element 160 has an inflection point 163 that can reduce the angle at which the light is projected onto the image plane 150 from the off-axis field and further correct the off-axis aberrations. [0056] In the photographing optical lens assembly 10 , the first lens element 110 with positive refractive power provides part of the refractive power needed by the photographing optical lens assembly 10 for reducing the total optical length. When the first lens element 110 has the convex object-side surface 111 , the refractive power of the first lens element 110 can be further increased which reduces the total optical length of the photographing optical lens assembly 10 . When the fourth lens element 140 has the concave object-side surface 141 and the convex image-side surface 142 , the aberration and chromatism of the photographing optical lens assembly 10 are corrected. When the fifth lens element 150 has the convex object-side surface 151 and the concave image-side surface 152 , the astigmatism of the photographing optical lens assembly 10 can be corrected. When the sixth lens element 160 has the concave image-side surface 162 , the total optical length of the photographing optical lens assembly 10 can be effectively reduced. When the sixth lens element 160 has the convex object-side surface 161 and the concave image-side surface 162 , the distortion of the photographing optical lens assembly 10 can be corrected. [0057] Furthermore, when the fifth lens element 150 has at least one inflection point 153 , the angle at which the light is projected onto an image plane 180 from the off-axis field can be reduced to further correct the off-axis aberrations. When the fifth lens element 150 and the sixth lens element 160 are made of plastic, the manufacturing cost can be reduced. [0058] The photographing optical lens assembly 10 of the present disclosure satisfies the following condition: [0000] −0.3<( R 9 −R 10 )/( R 9 +R 10 )<0.6 (condition 1): [0059] Wherein R 9 is the curvature radius of the object-side surface 151 ; R 10 is the curvature radius of the image-side surface 152 . [0060] When the photographing optical lens assembly satisfies 10 Condition 1, the object-side surface 151 and the image-side surface 152 have the proper curvature radius which effectively corrects the high order aberration in the lens assembly. [0061] Moreover, the photographing optical lens assembly 10 further comprises an aperture stop 100 disposed in front of the second lens element 120 . That is, the aperture stop 100 is on the object side of the second lens element 120 . Also, the photographing optical lens assembly 10 comprises an infrared filter 170 and an image sensor 182 disposed on the image plane 180 . [0062] The photographing optical lens assembly 10 of the present disclosure may further satisfy at least one of the following conditions: [0000] 0.8 <f/f 1 <1.9 (condition 2): [0000] 0.75 <SD/TD< 1.10 (condition 3): [0000] 0.10 <BFL/TTL< 0.35 (condition 4): [0000] 0.1 <R 12 /f< 0.5 (condition 5): [0000] ( T 23 +T 45 )/ T 34 <1.0 (condition 6): [0000] TTL/ImgH< 2.5 (condition 7): [0000] \| f/f 4 \|+\|f/f 5 \|+\|f/f 6 \|<1.5 (condition 8): [0000] 0.05<( CT 2 +CT 3 )/ f< 0.19 (condition 9): [0000] −0.3<( R 7 −R 8 )/( R 7 +R 8 )<0.5 (condition 10): [0000] 23 <V 1 −V 2 <40 (condition 11): [0063] Wherein SD is the axial distance between the aperture stop 100 and the image-side surface 162 ; TD is the axial distance between the object-side surface 111 and the image-side surface 162 ; BFL is the axial distance between the image-side surface 162 and the image plane 180 ; TTL is the axial distance between the object-side surface 111 and the image plane 180 ; R 12 is the curvature radius of the image-side surface 162 ; T 23 is the axial distance between the image-side surface 122 and the object-side surface 131 ; T 34 is the axial distance between the image-side surface 132 and the object-side surface 141 ; T 45 is the axial distance between the image-side surface 142 and the object-side surface 151 ; CT 2 is the axial distance between the object-side surface 121 and the image-side surface 122 , i.e. the central thickness of the second lens element; CT 3 is the axial distance between the object-side surface 131 and the image-side surface 132 , i.e. the central thickness of the third lens element; R 7 is the curvature radius of the object-side surface 141 ; R 8 is the curvature radius of the image-side surface 142 ; ImgH is half of the diagonal length of the effective photosensitive area of the image sensor 182 ; f is the focal length of the photographing optical lens assembly 10 ; f 1 is the focal length of the first lens element 110 ; f 4 is the focal length of the fourth lens element 140 ; f 5 is the focal length of the fifth lens element 150 ; f 6 is the focal length of the sixth lens element 160 ; V 1 is the Abbe number of the first lens element 110 , and V 2 is the Abbe number of the second lens element 120 . [0064] When the photographing optical lens assembly 10 satisfies Condition 2, the refractive power of the first lens element 110 is appropriate which helps control the total optical length of the photographing optical lens assembly 10 . When the photographing optical lens assembly 10 satisfies Condition 3, the aperture stop 100 has a proper position that provides the telecentric effect to enhance the image quality. When the photographing optical lens assembly 10 satisfies Condition 4, the back focal length is appropriate so that there is enough room for fabricating and focusing. When the photographing optical lens assembly 10 satisfies Condition 5, the total optical length of the photographing optical lens assembly 10 can be reduced. When the photographing optical lens assembly 10 satisfies Condition 6, the aberration of the photographing optical lens assembly 10 is corrected. [0065] When the photographing optical lens assembly 10 satisfies Condition 7, the photographing optical lens assembly 10 is advantageous in miniaturization. When the photographing optical lens assembly 10 satisfies Condition 8, the refractive power of the fourth lens element 140 , the fifth lens element 150 , and the sixth lens element 160 are well balanced. The balanced refractive power benefits the correction of aberration and the reduction of the optical sensitivity of the photographing optical lens assembly 10 . When the photographing optical lens assembly 10 satisfies Condition 9, the total optical length of the photographing optical lens assembly 10 can be reduced. When the photographing optical lens assembly 10 satisfies Condition 10, the object-side surface 141 and the image-side surface 142 have the proper curvature radius so that the aberration of the photographing optical lens assembly 10 is not excessive. When the photographing optical lens assembly 10 satisfies Condition 11, the chromatism of the photographing optical lens assembly 10 can be corrected. [0066] Furthermore, the lenses of the photographing optical lens assembly 10 can be made of glass or plastic. If a lens is made of glass, there is more freedom in distributing the overall refractive power for the photographing optical lens assembly 10 . If a lens is made of plastic, the manufacturing cost can be reduced. In addition, the surfaces of the lenses can be aspheric. Aspheric profile allows more design parameter freedom for the aberration correction which can reduce the required number of lenses to produce high quality images in the optical lens assembly, so that the total optical length of the photographing optical lens assembly 10 can be reduced effectively. [0067] In the photographing optical lens assembly 10 , a convex surface means the surface at a paraxial site is convex. A concave surface means the surface at a paraxial site is concave. [0068] Furthermore, at least one stop (such as glare stops, field stops, or other types of stops) may be disposed within the photographing optical lens assembly 10 if necessary for eliminating the stray light, adjusting the field of view, or other improvements concerning the image quality. [0069] As for the optical lens assembly 10 , the specific schemes are further described with the following embodiments. Parameters in the embodiments are defined as follows. Fno is an f-number value of the photographing optical lens assembly, and HFOV is a half of maximal field of view in the photographing optical lens assembly 10 . The aspheric surface in the embodiments may be represented by, but not limited to, the following aspheric surface equation (Condition ASP): [0000] X  ( Y )  ( Y 2 / R ) / ( 1 + sqrt  ( 1 - ( 1 + k ) * ( Y / R ) ) 2 + ∑ i  ( Ai ) * ( Y i ) [0070] Wherein Y is the distance from the point on the curve of the aspheric surface to the optical axis, X is the height of a point on the aspheric surface at a distance Y from the optical axis relative to the tangential plane at the aspheric surface vertex, k is a conic factor, Ai is an i th order aspheric surface coefficient, and in the embodiments, i may be, but is not limited to, 4, 6, 8, 10, 12, 14 and 16. The First Embodiment (Embodiment 1) [0071] FIG. 1A is a schematic structural view of the first embodiment of the photographing optical lens assembly. [0072] In this embodiment, the first lens element 110 with positive refractive power comprises the convex object-side surface 111 . The second lens element 120 has negative refractive power. The third lens element 130 with positive refractive power comprises the concave image-side surface 132 . The fourth lens element 140 with positive refractive power comprises the concave object-side surface 141 and the convex image-side surface 142 . The fifth lens element 150 with negative refractive power comprises the convex object-side surface 151 , the concave image-side surface 152 , and the inflection points 153 . The sixth lens element 160 with negative refractive power comprises the convex object-side surface 161 , the concave image-side surface 162 , and the inflection points 163 . The aperture stop 100 can be disposed between the first lens element 110 and the second lens element 120 . [0073] The detailed data of the photographing optical lens assembly 10 is as shown in Table 1-1 below: [0000] TABLE 1-1 Embodiment 1 f = 4.07, Fno = 2.60, HFOV = 34.4 deg. Curvature Thickness Focal length Surface # Member radius (mm) (mm) Material Index Abbe # (mm) 0 Object Plano Infinity 1 Lens 1 1.688170(ASP) 0.566 Plastic 1.544 55.9 3.02 2 −54.436600(ASP) −0.026 3 Ape. Plano 0.187 4 Lens 2 −3.359800(ASP) 0.261 Plastic 1.632 23.4 −5.81 5 −40.436700(ASP) 0.113 6 Lens 3 2.277470(ASP) 0.266 Plastic 1.544 55.9 68.88 7 2.325000(ASP) 0.619 8 Lens 4 −1.676210(ASP) 0.491 Plastic 1.530 55.8 8.25 9 −1.334830(ASP) 0.057 10 Lens 5 2.822250(ASP) 0.338 Plastic 1.530 55.8 −12.05 11 1.876050(ASP) 0.375 12 Lens 6 1.300530(ASP) 0.464 Plastic 1.530 55.8 −57.20 13 1.092920(ASP) 0.700 14 Infrared Plano 0.300 Glass 1.517 64.2 — 15 Plano 0.290 16 Image Plano — Note: Reference wavelength is d-line 587.6 nm, ASP represents aspheric [0074] In Table 1-1, the first lens element 110 , the second lens element 120 , the third lens element 130 , the fourth lens element 140 , the fifth lens element 150 , and the sixth lens element 160 can all be aspheric, and the aspheric surfaces can satisfy Condition ASP, but are not limited thereto. As for the parameters of the aspheric surfaces, reference is made to Table 1-2 below: [0000] TABLE 1-2 Aspheric Coefficients Surface# 1 2 4 5 K −9.94728E−01 −1.00000E+00 −1.00000E+01 −1.00000E+00 A 4 1.59061E−03 −7.66451E−02 9.27752E−02 1.87048E−01 A 6 1.09469E−02 −7.01206E−02 −3.41956E−02 −3.04114E−02 A 8 −1.46547E−01 −5.69562E−02 1.13669E−01 2.87264E−02 A 10 3.00673E−01 6.34619E−01 −3.41332E−01 −1.58393E−02 A 12 −5.23152E−01 −1.07352E+00 2.19885E−01 −1.04721E−01 A 14 4.09767E−01 −3.41685E−01 2.09379E−01 1.36113E−01 A 16 −1.59312E−01 1.15796E+00 −1.66569E−01 −1.46176E−02 Surface# 6 7 8 9 K −1.00000E+00 −1.00000E+00 −3.61596E+00 −1.21410E+00 A 4 −5.38455E−02 −2.83211E−02 −1.06439E−01 −4.12421E−02 A 6 −3.44462E−02 −3.33608E−02 5.81821E−02 2.56195E−02 A 8 −2.14017E−02 −1.31147E−02 −1.07226E−01 −3.19532E−02 A 10 3.57584E−03 2.65328E−03 9.15270E−02 1.11242E−02 A 12 — — −1.17124E−03 8.02637E−03 A 14 — — −1.57509E−02 2.57108E−03 A 16 — — −4.87416E−03 −2.59621E−03 Surface# 10 11 12 13 K −5.67803E+00 −1.00000E+01 −7.59004E+00 −5.68534E+00 A 4 −2.86288E−02 −1.52934E−04 −6.31902E−02 −4.25796E−02 A 6 7.40712E−03 −7.81982E−03 7.22119E−03 2.01384E−03 A 8 −3.90295E−03 5.54585E−04 −1.85957E−04 −5.15087E−05 A 10 1.00887E−03 2.13520E−04 — — A 12 2.13454E−05 −6.99915E−07 — — A 14 −4.88672E−05 −1.21257E−05 — — A 16 4.74490E−06 1.09951E−06 — — [0075] In Table 1-1, the curvature radius, the thickness and the focal length are shown in millimeters (mm). Surface numbers 0-16 represent the surfaces sequentially arranged from the object-side to the image-side along the optical axis. “f” stands for the focal length, “Fno” is the f-number, and “HFOV” is the half field of view of this embodiment. In Table 1-2, k represents the conic coefficient of the equation of the aspheric surface profiles. A1-A16 represent the aspheric coefficients ranging from the 1st order to the 16th. All labels for Tables of the remaining embodiments share the same definitions as those in Table 1-1 and Table 1-2 of the first embodiment, and their definitions will not be stated again. [0000] The content of Table 1-3 may be deduced from Table 1-1: [0000] TABLE 3 Embodiment 1 f(mm) 4.07 (R 7 − R 8 )/(R 7 + R 8 ) 0.113 Fno 2.60 (R 9 − R 10 )/(R 9 + R 10 ) 0.201 HFOV(deg.) 34.4 f/f 1 1.35 V 1 − V 2 32.5 \|f/f 4 \| + \|f/f 5 \| + \|f/f 6 \| 0.90 (CT 2 + CT 3 )/f 0.13 SD/TD 0.85 (T 23 + T 45 )/T 34 0.27 BFL/TTL 0.24 R 12 /f 0.27 TTL/ImgH 1.73 [0076] It can be observed from Table 1-3 that (R 9 −R 10 )/(R 9 +R 10 ) satisfies Condition 1; f/f 1 satisfies Condition 2; SD/TD satisfies Condition 3; BFL/TTL satisfies Condition 4; R 12 /f satisfies Condition 5; (T 23 +T 45 )/T 34 satisfies Condition 6; TTL/ImgH satisfies Condition 7; \|f/f 4 \|+\|f/f 5 \|+\|f/f 6 \| satisfies Condition 8; (CT 2 +CT 3 )/f satisfies Condition 9; (R 7 −R 8 )/(R 7 +R 8 ) satisfies Condition 10, and V 1 −V 2 satisfies Condition 11. [0077] FIG. 1B is a schematic view of longitudinal spherical aberration curves when the lights having wavelengths of 486.1 nm, 587.6 nm, and 656.3 nm are respectively projected in the photographing optical lens assembly 10 in FIG. 1A . The longitudinal spherical aberration curve of the light having the wavelength of 486.1 nm in the photographing optical lens assembly 10 is indicated by a solid line L in FIG. 1B . The longitudinal spherical aberration curve of the light having the wavelength of 587.6 nm in the photographing optical lens assembly 10 is indicated by a dashed line M in FIG. 1B . The longitudinal spherical aberration curve of the light having the wavelength of 656.3 nm in the photographing optical lens assembly 10 is indicated by a dotted line N in FIG. 1B . Horizontal axis is the focus position (millimeter, mm), and vertical axis is the normalized entrance pupil or aperture value. In other words, the differences of the focus positions of the paraxial light (the longitudinal coordinate is close to 0) and the fringe light (the longitudinal coordinate is close to 1) on the image plane 180 can be seen from the longitudinal spherical aberration curves. It can be observed from FIG. 1B that the longitudinal spherical aberrations generated by the photographing optical lens assembly 10 are within a range of −0.025 mm to 0.040 mm. [0078] In the second embodiment to the ninth embodiment and the schematic views of the longitudinal spherical aberration curves in FIGS. 2B , 3 B, 4 B, 5 B, 6 B, 7 B, 8 B, and 9 B, the solid line L indicates the longitudinal spherical aberration curve of the light having the wavelength of 486.1 nm, the dashed line M indicates the longitudinal spherical aberration curve of the light having the wavelength of 587.6 nm, and the dotted line N indicates the longitudinal spherical aberration curve of the light having the wavelength of 656.3 nm, which will not be repeated herein for conciseness. [0079] FIG. 1C is a schematic view of astigmatic field curves when the light having the wavelength of 587.6 nm is projected in the photographing optical lens assembly 10 in FIG. 1A . An astigmatic field curve of a tangential plane is a dashed line T in FIG. 1C . An astigmatic field curve of a sagittal plane is a solid line S in FIG. 1C . Horizontal axis is the focus position (mm), and vertical axis is the image height (mm). It can be observed from FIG. 1C that the astigmatic field curvature of the tangential plane is within a range of −0.010 mm to 0.025 mm, and the astigmatic field curvature of the sagittal plane is within a range of −0.025 mm to 0.015 mm. [0080] In the second embodiment to the ninth embodiment and the schematic views of the astigmatic field curves in FIGS. 2C , 3 C, 4 C, 5 C, 6 C, 7 C, 8 C and 9 C, the solid line S indicates the astigmatic field curve of the sagittal plane, and the dashed line T indicates the astigmatic field curve of the tangential plane, which will not be repeated herein for conciseness. [0081] FIG. 1D is a schematic view of a distortion curve when the light having the wavelength of 587.6 nm is projected in the photographing optical lens assembly 10 in FIG. 1A . The horizontal axis is the distortion ratio (%), and the vertical axis is the image height (mm). It can be observed from FIG. 1D that the distortion ratio is within a range of 0% to 2.5%. As shown in FIGS. 1B to 1D , the photographing optical lens assembly 10 , designed according to the first embodiment, is capable of effectively correcting various aberrations. [0082] In the second embodiment to the ninth embodiment and the schematic views of the distortion curves in FIGS. 2D , 3 D, 4 D, 5 D, 6 D, 7 D, 8 D, and 9 D, the solid line G indicates the distortion curve of the light having the wavelength of 587.6 nm, which will not be repeated herein for conciseness. [0083] It should be noted that the distortion curves and the astigmatic field curves of the wavelength of 486.1 nm and 656.3 nm are highly similar to the distortion curve and the astigmatic field curves of the wavelength of 587.6 nm. In order to prevent the confusion of reading the curves in FIGS. 1C and 1D , the distortion curve and the astigmatic field curves of wavelengths of 486.1 nm and 656.3 nm are not shown in FIGS. 1C and 1D , and the same applies throughout the rest of the embodiments of this present disclosure. The Second Embodiment (Embodiment 2) [0084] FIG. 2A is a schematic structural view of the second embodiment of the photographing optical lens assembly. The specific implementation and elements of the second embodiment are substantially the same as those in the first embodiment. The element symbols in the second embodiment all begin with “2” which correspond to those in the first embodiment with the same function or structure. For conciseness, only the differences are illustrated below, and the similarities will not be repeated herein. [0085] In this embodiment, for example, the wavelength of the light received by the photographing optical lens assembly 20 is 587.6 nm, but this wavelength may be adjusted according to actual requirements, and is not limited to the wavelength value mentioned above. [0086] In this embodiment, a first lens element 210 with positive refractive power comprises a convex object-side surface 211 . A second lens element 220 has negative refractive power. A third lens element 230 with positive refractive power comprises a concave image-side surface 232 . A fourth lens element 240 with positive refractive power comprises a concave object-side surface 241 and a convex image-side surface 242 . A fifth lens element 250 with negative refractive power comprises a convex object-side surface 251 , a concave image-side surface 252 and two inflection points 253 . A sixth lens element 260 with negative refractive power comprises a convex object-side surface 261 , a concave image-side surface 262 and two inflection points 263 . An aperture stop 200 can be disposed between the first lens element 210 and the object. [0087] The detailed data of the photographing optical lens assembly 20 is as shown in Table 2-1 below: [0000] TABLE 2-1 Embodiment 2 f = 3.86, Fno = 2.80, HFOV = 35.9 deg. Curvature radius Thickness Surface # Member (mm) (mm) Material Index Abbe # Focal length 0 Object Plano Infinity 1 Ape. Plano −0.093 2 Lens 1 1.651590(ASP) 0.444 Plastic 1.544 55.9 3.38 3 14.723500(ASP) 0.136 4 Lens 2 −5.931600(ASP) 0.250 Plastic 1.634 23.8 −6.23 5 12.012100(ASP) 0.090 6 Lens 3 1.925990(ASP) 0.283 Plastic 1.544 55.9 17.72 7 2.282220(ASP) 0.633 8 Lens 4 −1.777020(ASP) 0.511 Plastic 1.530 55.8 5.25 9 −1.192140(ASP) 0.057 10 Lens 5 3.474500(ASP) 0.344 Plastic 1.583 30.2 −5.89 11 1.663960(ASP) 0.329 12 Lens 6 1.188600(ASP) 0.491 Plastic 1.530 55.8 321.46 13 1.025680(ASP) 0.800 14 Infrared Plano 0.300 Glass 1.517 64.2 — 15 Plano 0.151 16 Image Plano — Note: Reference wavelength is d-line 587.6 nm, ASP represents aspheric. [0088] In Table 2-1, from the first lens element 210 to the sixth lens element 260 , all lens elements can be aspheric, and the aspheric surfaces can satisfy Condition ASP, but are not limited thereto. As for the parameters of the aspheric surfaces, reference is made to Table 2-2 below. [0000] TABLE 2-2 Aspheric Coefficients Surface# 2 3 4 5 K −1.33270E+00 −1.00000E+00 −1.00000E+01 −1.00000E+00 A 4 −7.85373E−03 −1.28677E−01 1.04817E−01 1.65890E−01 A 6 7.31073E−03 −4.82706E−02 −9.02634E−02 −1.54308E−02 A 8 −2.20177E−01 −2.60324E−01 1.78923E−01 5.57066E−02 A 10 2.79474E−01 8.55972E−01 −2.59450E−01 1.04990E−02 A 12 −5.23152E−01 −1.07352E+00 2.19885E−01 −1.04721E−01 A 14 4.09850E−01 −3.41665E−01 2.09379E−01 1.36113E−01 A 16 −1.59291E−01 1.15796E+00 −1.66574E−01 −1.46176E−02 Surface# 6 7 8 9 K −1.29262E+00 −1.09322E+00 −1.75889E+00 −1.36744E+00 A 4 −8.17675E−02 −3.27659E−02 −9.75451E−02 −3.84290E−02 A 6 −1.81690E−02 −3.84875E−02 8.22654E−02 2.50924E−02 A 8 −1.07739E−02 −6.41439E−03 −1.12449E−01 −3.24423E−02 A 10 1.48959E−02 1.48897E−02 8.24219E−02 1.03709E−02 A 12 5.53488E−03 1.34841E−03 −7.49772E−03 7.64481E−03 A 14 −2.81837E−08 −1.52594E−03 −1.61432E−02 2.34446E−03 A 16 — — 2.49426E−03 −2.77081E−03 Surface# 10 11 12 13 K −4.37850E+00 −9.94436E+00 −7.49068E+00 −5.81520E+00 A 4 −2.95037E−02 −3.44326E−03 −6.32326E−02 −4.14803E−02 A 6 5.75210E−03 −5.53589E−03 7.84310E−03 1.96140E−03 A 8 −4.01662E−03 2.16183E−04 −2.20731E−04 −9.00605E−05 A 10 9.85076E−04 1.76276E−04 — — A 12 1.69675E−05 2.49445E−06 — — A 14 −4.99459E−05 −1.10618E−05 — — A 16 4.85710E−06 1.29914E−06 — — [0089] The content of Table 2-3 may be deduced from Table 2-1. [0000] TABLE 2-3 Embodiment 2 f(mm) 3.86 (R 7 − R 8 )/(R7 + R8) 0.197 Fno 2.80 (R 9 − R 10 )/(R 9 + R 10 ) 0.352 HFOV(deg.) 35.9 f/f 1 1.14 V 1 − V 2 32.1 \|f/f 4 \| + \|f/f 5 \| + \|f/f 6 \| 1.40 (CT 2 + CT 3 )/f 0.14 SD/TD 0.97 (T 23 + T 45 )/T 34 0.23 BFL/TTL 0.24 R 12 /f 0.27 TTL/ImgH 1.66 [0090] FIG. 2B is a schematic view of longitudinal spherical aberration curves of the photographing optical lens assembly 20 . It can be observed from FIG. 2B that the longitudinal spherical aberrations generated by the photographing optical lens assembly 20 are within a range of −0.010 mm to 0.025 mm. [0091] FIG. 2C is a schematic view of astigmatic field curves of the photographing optical lens assembly 20 . It can be observed from FIG. 2C that the astigmatic field curvature of the tangential plane is within a range of 0.00 mm to 0.025 mm, and the astigmatic field curvature of the sagittal plane is within a range of −0.025 mm to 0.015 mm. [0092] FIG. 2D is a schematic view of a distortion curve of the photographing optical lens assembly 20 . It can be observed from FIG. 2D that the distortion ratio is within a range of 0.0% to 2.5%. As shown in FIGS. 2B to 2D , the photographing optical lens assembly 20 , designed according to the second embodiment, is capable of effectively correcting various aberrations. The Third Embodiment (Embodiment 3) [0093] FIG. 3A is a schematic structural view of the third embodiment of the photographing optical lens assembly. The specific implementation and elements of the third embodiment are substantially the same as those in the first embodiment. The element symbols in the third embodiment all begin with “3” which correspond to those in the first embodiment with the same function or structure. For conciseness, only the differences are illustrated below, and the similarities will not be repeated herein. [0094] In this embodiment, for example, the wavelength of the light received by the photographing optical lens assembly 30 is 587.6 nm, but the wavelength may be adjusted according to actual requirements, and is not limited to the wavelength value mentioned above. [0095] In this embodiment, a first lens element 310 with positive refractive power comprises a convex object-side surface 311 . A second lens element 320 has negative refractive power. A third lens element 330 with positive refractive power comprises a concave image-side surface 332 . A fourth lens element 340 with negative refractive power comprises a concave object-side surface 341 and a convex image-side surface 342 . A fifth lens element 350 with negative refractive power comprises a convex object-side surface 351 , a concave image-side surface 352 , and two inflection points 353 . A sixth lens element 360 with positive refractive power comprises a convex object-side surface 361 , a concave image-side surface 362 , and two inflection points 363 . An aperture stop 300 can be disposed between the first lens element 310 and the second lens element 320 . [0096] The detailed data of the photographing optical lens assembly 30 is as shown in Table 3-1 below. [0000] TABLE 3-1 Embodiment 3 f = 4.46 mm, Fno = 2.60, HFOV = 32.5 deg. Curvature radius Thickness Surface # Member (mm) (mm) Material Index Abbe # Focal length 0 Object Plano Infinity 1 Lens 1 1.685240(ASP) 0.542 Plastic 1.544 55.9 3.16 2 76.290300(ASP) 0.008 3 Ape. Plano 0.075 4 Lens 2 3.495700(ASP) 0.250 Plastic 1.632 23.4 −5.96 5 1.763320(ASP) 0.199 6 Lens 3 3.387500(ASP) 0.302 Plastic 1.544 55.9 14.14 7 5.860500(ASP) 0.448 8 Lens 4 −1.881460(ASP) 0.472 Plastic 1.632 23.4 −14.62 9 −2.591980(ASP) 0.141 10 Lens 5 5.193800(ASP) 0.630 Plastic 1.544 55.9 −39.85 11 4.011100(ASP) 0.193 12 Lens 6 1.583190(ASP) 0.536 Plastic 1.544 55.9 25.02 13 1.577780(ASP) 0.700 14 IR-filter Plano 0.300 Glass 1.517 64.2 — 15 Plano 0.406 16 Image Plano — Note: Reference wavelength is d-line 587.6 nm, ASP represents aspheric [0097] In Table 3-1, from the first lens element 310 to the sixth lens element 360 , all lens elements can be aspheric, and the aspheric surfaces can satisfy Condition ASP, but are not limited thereto. As for the parameters of the aspheric surfaces, reference is made to Table 3-2 below. [0000] TABLE 3-2 Aspheric Coefficients Surface# 1 2 4 5 K −5.32817E−01 −1.00000E+00 −1.00000E+01 −2.81013E+00 A 4 −5.69598E−03 −5.26592E−02 −2.22636E−02 3.73435E−02 A 6 −2.46613E−02 2.74979E−03 9.05107E−02 3.98767E−02 A 8 3.58648E−03 −3.12279E−02 −5.80411E−02 1.10009E−01 A 10 −3.85316E−02 −1.31973E−02 1.64120E−02 −1.75759E−01 A 12 5.47527E−04 1.40366E−02 3.60695E−02 1.43017E−01 Surface# 6 7 8 9 K −1.00000E+00 −1.00000E+00 −4.09418E−01 2.34374E+00 A 4 −1.28260E−02 −6.41027E−03 −4.28663E−02 −6.88771E−02 A 6 −3.25173E−03 −1.67201E−02 1.78059E−02 7.75948E−02 A 8 9.28602E−03 2.22358E−03 −3.08921E−02 −2.04321E−02 A 10 3.55072E−02 1.38083E−02 3.57849E−02 8.85034E−03 A 12 −1.63569E−05 1.07848E−02 −2.63837E−02 −8.60488E−04 Surface# 10 11 12 13 K 2.34521E+00 0.00000E+00 −5.68341E+00 −5.03798E+00 A 4 −5.97523E−02 −4.17290E−02 −8.48349E−02 −7.29846E−02 A 6 1.52538E−03 −2.28651E−03 6.46958E−03 8.14468E−03 A 8 7.06467E−04 5.45892E−04 3.20023E−04 −1.41081E−03 A 10 −8.21833E−04 6.26931E−06 −3.00675E−05 7.09856E−05 A 12 −5.62729E−05 −3.30350E−05 5.48489E−06 2.07934E−05 A 14 — — — −1.66400E−06 [0098] The content of Table 3-3 may be deduced from Table 3-1. [0000] TABLE 3-3 Embodiment 3 f(mm) 4.46 (R 7 − R 8 )/(R 7 + R 8 ) −0.159 Fno 2.60 (R 9 − R 10 )/(R 9 + R 10 ) 0.128 HFOV(deg.) 32.5 f/f 1 1.41 V 1 − V 2 32.5 \|f/f 4 \| + \|f/f 5 \| + \|f/f 6 \| 0.60 (CT 2 + CT 3 )/f 0.12 SD/TD 0.86 (T 23 + T 45 )/T 34 0.76 BFL/TTL 0.26 R 12 /f 0.35 TTL/ImgH 1.79 [0099] FIG. 3B is a schematic view of longitudinal spherical aberration curves of the photographing optical lens assembly 30 . It can be observed from FIG. 3B that the longitudinal spherical aberrations generated by the photographing optical lens assembly 30 are within a range of −0.010 mm to 0.025 mm. [0100] FIG. 3C is a schematic view of astigmatic field curves of the photographing optical lens assembly 30 . It can be observed from FIG. 3C that the astigmatic field curvature of the tangential plane is within a range of 0.0 mm to 0.025 mm, and the astigmatic field curvature of the sagittal plane is within a range of −0.015 mm to 0.005 mm. [0101] FIG. 3D is a schematic view of a distortion curve of the photographing optical lens assembly 30 . It can be observed from FIG. 3D that the distortion ratio is within a range of −1.0% to 1.0%. As shown in FIGS. 3B to 3D , the photographing optical lens assembly 30 , designed according to the third embodiment, is capable of effectively correcting various aberrations. The Fourth Embodiment (Embodiment 4) [0102] FIG. 4A is a schematic structural view of the fourth embodiment of the photographing optical lens assembly. The specific implementation and elements of the fourth embodiment are substantially the same as those in the first embodiment. The element symbols in the fourth embodiment all begin with “4” which correspond to those in the first embodiment with the same function or structure. For conciseness, only the differences are illustrated below, and the similarities will not be repeated herein. [0103] In this embodiment, for example, the wavelength of the light received by the photographing optical lens assembly 40 is 587.6 nm, but the wavelength may be adjusted according to actual requirements, and is not limited to the wavelength value mentioned above. [0104] In this embodiment, a first lens element 410 with positive refractive power comprises a convex object-side surface 411 . A second lens element 420 has negative refractive power. A third lens element 430 with positive refractive power comprises a concave image-side surface 432 . A fourth lens element 440 with negative refractive power comprises a concave object-side surface 441 and a convex image-side surface 442 . A fifth lens element 450 with positive refractive power comprises a convex object-side surface 451 , a concave image-side surface 452 , and two inflection points 453 . A sixth lens element 460 with positive refractive power comprises a convex object-side surface 461 , a concave image-side surface 462 , and two inflection points 463 . An aperture stop 400 can be disposed between the first lens element 410 and the second lens element 420 . [0105] The detailed data of the photographing optical lens assembly 40 is as shown in Table 4-1 below. [0000] TABLE 4-1 Embodiment 4 f = 4.46 mm, Fno = 2.60, HFOV = 32.5 deg. Curvature radius Thickness Surface# Member (mm) (mm) Material Index Abbe # Focal length 0 Object Plano Infinity 1 Lens 1 1.834910(ASP) 0.570 Plastic 1.544 55.9 3.15 2 −23.488200(ASP) −0.049 3 Ape. Plano 0.180 4 Lens 2 −18.656700(ASP) 0.278 Plastic 1.632 23.4 −5.97 5 4.757800(ASP) 0.259 6 Lens 3 2.347300(ASP) 0.284 Plastic 1.544 55.9 16.03 7 3.074800(ASP) 0.470 8 Lens 4 −1.580330(ASP) 0.357 Plastic 1.632 23.4 −10.73 9 −2.240680(ASP) 0.065 10 Lens 5 3.406000(ASP) 0.627 Plastic 1.544 55.9 129.21 11 3.347200(ASP) 0.200 12 Lens 6 1.591620(ASP) 0.596 Plastic 1.544 55.9 22.48 13 1.588290(ASP) 0.700 14 IR-filter Plano 0.300 Glass 1.517 64.2 — 15 Plano 0.449 16 Image Plano — Note: Reference wavelength is d-line 587.6 nm [0106] In Table 4-1, from the first lens element 410 to the sixth lens element 460 , all lenses can be aspheric, and the aspheric surfaces can satisfy Condition ASP, but are not limited thereto. As for the parameters of the aspheric surfaces, reference is made to Table 4-2 below. [0000] TABLE 4-2 Aspheric Coefficients Surface# 1 2 4 5 K −6.59310E−01 −1.00000E+00 0.00000E+00 −1.92119E+01 A 4 −9.33154E−03 −5.99498E−02 3.56275E−04 2.01891E−02 A 6 −2.82703E−02 −1.04837E−02 1.07852E−01 5.59198E−02 A 8 −6.36889E−03 9.21343E−03 −4.23176E−02 1.28756E−01 A 10 −2.64375E−02 −3.54169E−02 −2.17657E−02 −2.55367E−01 A 12 5.55531E−04 1.40931E−02 3.60678E−02 1.43016E−01 Surface# 6 7 8 9 K −1.00000E+00 −1.00000E+00 −3.06731E+00 9.71501E−01 A 4 −9.76301E−02 −1.95864E−02 2.52984E−02 −8.07438E−03 A 6 −1.01631E−02 −5.59234E−02 4.11863E−02 8.44757E−02 A 8 −2.71467E−02 1.24840E−02 −3.81793E−02 −3.20353E−02 A 10 7.90390E−03 −1.65455E−02 2.45770E−02 6.68380E−03 A 12 −3.66838E−03 −6.26253E−04 −2.34361E−02 −2.64461E−04 Surface# 10 11 12 13 K −1.76892E+00 0.00000+00 −7.70613E+00 −6.69083E+00 A 4 −7.09127E−02 −5.46082E−02 −8.39249E−02 −6.76588E−02 A 6 2.70982E−03 2.71610E−03 9.14098E−03 9.24683E−03 A 8 6.68203E−04 −2.58205E−04 5.01978E−04 −1.51491E−03 A 10 −1.93334E−03 −1.85881E−04 −4.07349E−05 6.33452E−05 A 12 −2.43560E−04 2.15888E−05 −5.73868E−06 1.98123E−05 A 14 — — — −1.50566E−06 [0107] The content of Table 4-3 may be deduced from Table 4-1. [0000] TABLE 4-3 Embodiment 4 f(mm) 4.44 (R 7 − R 8 )/(R 7 + R 8 ) −0.173 Fno 2.40 (R 9 − R 10 )/(R 9 + R 10 ) 0.009 HFOV(deg.) 32.5 f/f 1 1.41 V 1 − V 2 32.5 \|f/f 4 \| + \|f/f 5 \| + \|f/f 6 \| 0.65 (CT 2 + CT 3 )/f 0.13 SD/TD 0.86 (T 23 + T 45 )/T 34 0.69 BFL/TTL 0.26 R 12 /f 0.36 TTL/ImgH 1.82 [0108] FIG. 4B is a schematic view of longitudinal spherical aberration curves of the photographing optical lens assembly 40 . It can be observed from FIG. 4B that the longitudinal spherical aberrations generated by the photographing optical lens assembly 40 are within a range of −0.005 mm to 0.050 mm. [0109] FIG. 4C is a schematic view of astigmatic field curves of the photographing optical lens assembly 40 . It can be observed from FIG. 4C that the astigmatic field curvature of the tangential plane is within a range of 0.0 mm to 0.040 mm, and the astigmatic field curvature of the sagittal plane is within a range of −0.005 mm to 0.015 mm. [0110] FIG. 4D is a schematic view of a distortion curve of the photographing optical lens assembly 40 . It can be observed from FIG. 4D that the distortion ratio is within a range of 0.0% to 2.0%. As shown in FIGS. 4B to 4D , the photographing optical lens assembly 40 , designed according to the fourth embodiment, is capable of effectively correcting various aberrations. The Fifth Embodiment (Embodiment 5) [0111] FIG. 5A is a schematic structural view of the fifth embodiment of the photographing optical lens assembly. The specific implementation and elements of the fifth embodiment are substantially the same as those in the first embodiment. The element symbols in the fifth embodiment all begin with “5” which correspond to those in the first embodiment with the same function or structure. For conciseness, only the differences are illustrated below, and the similarities will not be repeated herein. [0112] In this embodiment, for example, the wavelength of the light received by the photographing optical lens assembly 50 is 587.6 nm, but the wavelength may be adjusted according to actual requirements, and is not limited to the wavelength value mentioned above. [0113] In this embodiment, a first lens element 510 with positive refractive power comprises a convex object-side surface 511 . A second lens element 520 has negative refractive power. A third lens element 530 with positive refractive power comprises a concave image-side surface 532 . A fourth lens element 540 with negative refractive power comprises a concave object-side surface 541 and a convex image-side surface 542 . A fifth lens element 550 with positive refractive power comprises a convex object-side surface 551 , a concave image-side surface 552 , and two inflection points 553 . A sixth lens element 560 with positive refractive power comprises a convex object-side surface 561 , a concave image-side surface 562 , and two inflection points 563 . An aperture stop 500 can be disposed between the first lens element 510 and the object-side of the optical axis (Left side of FIG. 5A ). [0114] The detailed data of the photographing optical lens assembly 50 is as shown in Table 5-1 below. [0000] TABLE 5-1 Embodiment 5 f = 4.44 mm, Fno = 2.40, HFOV = 32.5 deg. Curvature Radius Thickness Surface# Member (mm) (mm) Material Index Abbe # Focal length 0 Object Plano Infinity 1 Ape. Plano −0.153 2 Lens 1 1.757050(ASP) 0.603 Plastic 1.544 55.9 3.13 3 −46.769700(ASP) 0.100 4 Lens 2 20.071600(ASP) 0.268 Plastic 1.634 23.8 −5.47 5 2.941720(ASP) 0.239 6 Lens 3 2.384770(ASP) 0.298 Plastic 1.544 55.9 13.55 7 3.370000(ASP) 0.448 8 Lens 4 −1.591540(ASP) 0.367 Plastic 1.634 23.8 −11.82 9 −2.201410(ASP) 0.050 10 Lens 5 3.669800(ASP) 0.632 Plastic 1.535 56.3 −125.11 11 3.270200(ASP) 0.180 12 Lens 6 1.482020(ASP) 0.598 Plastic 1.535 56.3 18.50 13 1.498180(ASP) 0.700 14 IR-filter Plano 0.300 Glass 1.517 64.2 — 15 Plano 0.424 16 Image Plano — Note: Reference wavelength is d-line 587.6 nm [0115] In Table 5-1, from the first lens element 510 to the sixth lens element 560 , all lenses can be aspheric, and the aspheric surfaces can satisfy Condition ASP, but are not limited thereto. As for the parameters of the aspheric surfaces, reference is made to Table 5-2 below. [0000] TABLE 5-2 Aspheric Coefficients Surface# 2 3 4 5 K −4.85962E−01 −1.00000E+00 0.00000E+00 −5.45107E+00 A 4 −4.63259E−03 −6.17626E−02 −1.59077E−02 1.75524E−02 A 6 −5.05585E−02 −4.40404E−02 8.33807E−02 6.82135E−02 A 8 4.05358E−02 2.23783E−02 −3.61055E−02 1.46519E−01 A 10 −7.01338E−02 −4.77831E−02 −2.61487E−02 −2.68630E−01 A 12 4.73320E−04 1.40268E−02 3.66720E−02 1.43013E−01 Surface# 6 7 8 9 K −1.00000E+00 −1.00000E+00 −3.15023E+00 8.80274E−01 A 4 −9.32067E−02 −1.49040E−02 2.75514E−02 −4.85834E−03 A 6 −9.50051E−03 −5.53285E−02 4.47192E−02 8.40273E−02 A 8 −2.15526E−02 1.50415E−02 −3.75321E−02 −3.24794E−02 A 10 1.18681E−02 −1.52880E−02 2.38437E−02 6.65014E−03 A 12 −1.63627E−03 −2.50960E−03 −2.24794E−02 −2.60572E−04 Surface# 10 11 12 13 K −9.77209E−01 0.00000E+00 −6.30485E+00 −5.82976E+00 A 4 −6.90338E−02 −5.62897E−02 −8.62534E−02 −6.89849E−02 A 6 1.35993E−03 2.87583E−03 9.10119E−03 9.04722E−03 A 8 −1.39334E−04 −2.88743E−04 4.78809E−04 −1.48731E−03 A 10 −1.94710E−03 −1.86205E−04 −3.94985E−05 6.59309E−05 A 12 −2.18586E−04 2.26306E−05 −4.55811E−06 1.98644E−05 A 14 — — — −1.53882E−06 [0116] The content of Table 5-3 may be deduced from Table 5-1. [0000] TABLE 5-3 Embodiment 5 f(mm) 4.38 (R 7 − R 8 )/(R 7 + R 8 ) −0.161 Fno 2.50 (R 9 − R 10 )/(R 9 + R 10 ) 0.058 HFOV(deg.) 32.8 f/f 1 1.40 V 1 − V 2 32.1 \|f/f 4 \| + \|f/f 5 \| + \|f/f 6 \| 0.64 (CT 2 + CT 3 )/f 0.13 SD/TD 0.96 (T 23 + T 45 )/T 34 0.65 BFL/TTL 0.26 R 12 /f 0.34 TTL/ImgH 1.79 [0117] FIG. 5B is a schematic view of longitudinal spherical aberration curves of the photographing optical lens assembly 50 . It can be observed from FIG. 5B that the longitudinal spherical aberrations generated by the photographing optical lens assembly 50 are within a range of 0.0 mm to 0.040 mm. [0118] FIG. 5C is a schematic view of astigmatic field curves of the photographing optical lens assembly 50 . It can be observed from FIG. 5C that the astigmatic field curvature of the tangential plane is within a range of 0.005 mm to 0.040 mm, and the astigmatic field curvature of the sagittal plane is within a range of 0.0 mm to 0.015 mm. [0119] FIG. 5D is a schematic view of a distortion curve of the photographing optical lens assembly 50 . It can be observed from FIG. 5D that the distortion ratio is within a range of 0.0% to 1.5%. As shown in FIGS. 5B to 5D , the photographing optical lens assembly 50 , designed according to the fifth embodiment, is capable of effectively correcting various aberrations. The Sixth Embodiment (Embodiment 6) [0120] FIG. 6A is a schematic structural view of the sixth embodiment of the photographing optical lens assembly. The specific implementation and elements of the sixth embodiment are substantially the same as those in the first embodiment. The element symbols in the sixth embodiment all begin with “6” which correspond to those in the first embodiment with the same function or structure. For conciseness, only the differences are illustrated below, and the similarities will not be repeated herein. [0121] In this embodiment, for example, the wavelength of the light received by the photographing optical lens assembly 60 is 587.6 nm, but the wavelength may be adjusted according to actual requirements, and is not limited to the wavelength value mentioned above. [0122] In this embodiment, a first lens element 610 with positive refractive power comprises a convex object-side surface 611 . A second lens element 620 has positive refractive power. A third lens element 630 with negative refractive power comprises a concave image-side surface 632 . A fourth lens element 640 with positive refractive power comprises a concave object-side surface 641 and a convex image-side surface 642 . A fifth lens element 650 with negative refractive power comprises a convex object-side surface 651 , a concave image-side surface 652 , and two inflection points 653 . A sixth lens element 660 with positive refractive power comprises a convex object-side surface 661 , a concave image-side surface 662 , and two inflection points 663 . An aperture stop 600 can be disposed between the first lens element 610 and the object-side of the optical axis (Left side of FIG. 6A ). [0123] The detailed data of the photographing optical lens assembly 60 is as shown in Table 6-1 below. [0000] TABLE 6-1 Embodiment 6 f = 4.75 mm, Fno = 3.00, HFOV = 30.8 deg. Curvature Radius Thickness Surface# Member (mm) (mm) Material Index Abbe # Focal length 0 Object Plano Infinity 1 Ape. Plano 0.100 2 Lens 1 2.152490(ASP) 0.617 Plastic 1.544 55.9 3.21 3 −8.328200(ASP) 0.100 4 Lens 2 −9.423200(ASP) 0.388 Plastic 1.632 23.4 171.31 5 −8.807200(ASP) 0.120 6 Lens 3 −17.167700(ASP) 0.300 Plastic 1.614 25.6 −4.85 7 3.625500(ASP) 0.899 8 Lens 4 −3.121100(ASP) 0.644 Plastic 1.530 55.8 77.93 9 −3.109200(ASP) 0.081 10 Lens 5 1.796700(ASP) 0.784 Plastic 1.530 55.8 −59.68 11 1.443150(ASP) 0.150 12 Lens 6 1.759260(ASP) 0.417 Plastic 1.544 55.9 18.59 13 1.951780(ASP) 0.700 14 IR-filter Plano 0.400 Glass 1.517 64.2 — 15 Plano 0.302 16 Image Plano — Note: Reference wavelength is d-line 587.6 nm [0124] In Table 6-1, from the first lens element 610 to the sixth lens element 660 , all lens elements can be aspheric, and the aspheric surfaces can satisfy Condition ASP, but are not limited thereto. As for the parameters of the aspheric surfaces, reference is made to Table 6-2 below. [0000] TABLE 6-2 Aspheric Coefficients Surface# 2 3 4 5 K −5.30262E−01 −3.35619E+01 −5.69788E+01 −1.59941E+00 A 4 −3.52973E−03 −1.50932E−02 −4.46232E−03 −1.83378E−03 A 6 −1.62487E−03 −2.91399E−02 −2.29821E−02 3.13611E−04 A 8 −1.93803E−02 −1.36497E−02 1.91527E−03 −7.18608E−04 A 10 −2.91580E−04 1.06037E−02 1.86133E−02 −1.63033E−04 A 12 — — −3.35756E−03 — Surface# 6 7 8 9 K 9.13723E+01 1.87261E+00 −3.03803E+01 3.62127E−01 A 4 −5.69047E−04 2.65235E−02 3.31423E−02 −1.44260E−02 A 6 −9.27822E−05 −3.18407E−02 −4.31940E−02 2.18114E−02 A 8 1.69487E−04 3.84778E−02 1.95554E−02 −4.20389E−03 A 10 −1.04122E−03 −1.88278E−02 −4.38054E−03 −5.80357E−04 A 12 — 4.71828E−03 −4.06202E−04 1.10720E−04 Surface# 10 11 12 13 K −9.77778E+00 −1.95351E+01 −3.05852E+01 −4.65636E+00 A 4 −5.99117E−02 −3.18215E−02 −1.19530E−02 −2.36748E−02 A 6 1.69295E−02 8.11310E−03 6.01147E−04 2.24707E−03 A 8 −4.09539E−04 −1.79669E−03 2.02782E−05 5.01172E−05 A 10 −8.62579E−04 1.31304E−04 7.63863E−06 −1.04778E−05 A 12 1.18682E−04 −4.93833E−06 1.02917E−06 −4.84331E−07 A 14 −2.47769E−06 — −2.61860E−07 5.75116E−09 [0125] The content of Table 6-3 may be deduced from Table 6-1. [0000] TABLE 6-3 Embodiment 6 f(mm) 4.75 (R 7 − R 8 )/(R 7 + R 8 ) 0.002 Fno 3.00 (R 9 − R 10 )/(R 9 + R 10 ) 0.109 HFOV(deg.) 30.8 f/f 1 1.48 V 1 − V 2 32.5 \|f/f 4 \| + \|f/f 5 \| + \|f/f 6 \| 0.40 (CT 2 + CT 3 )/f 0.14 SD/TD 1.02 (T 23 + T 45 )/T 34 0.22 BFL/TTL 0.22 R 12 /f 0.41 TTL/ImgH 2.02 [0126] FIG. 6B is a schematic view of longitudinal spherical aberration curves of the photographing optical lens assembly 60 . It can be observed from FIG. 6B that the longitudinal spherical aberrations generated by the photographing optical lens assembly 60 are within a range of −0.025 mm to 0.015 mm. [0127] FIG. 6C is a schematic view of astigmatic field curves of the photographing optical lens assembly 60 . It can be observed from FIG. 6C that the astigmatic field curvature of the tangential plane is within a range of −0.025 mm to 0.020 mm, and the astigmatic field curvature of the sagittal plane is within a range of −0.025 mm to 0.015 mm. [0128] FIG. 6D is a schematic view of a distortion curve of the photographing optical lens assembly 60 . It can be observed from FIG. 6D that the distortion ratio is within a range of 0.0% to 2.0%. As shown in FIGS. 6B to 6D , the photographing optical lens assembly 60 , designed according to the sixth embodiment, is capable of effectively correcting various aberrations. The Seventh Embodiment (Embodiment 7) [0129] FIG. 7A is a schematic structural view of the seventh embodiment of the photographing optical lens assembly. The specific implementation and elements of the seventh embodiment are substantially the same as those in the first embodiment. The element symbols in the seventh embodiment all begin with “7” which correspond to those in the first embodiment with the same function or structure. For conciseness, only the differences are illustrated below, and the similarities will not be repeated herein. [0130] In this embodiment, for example, the wavelength of the light received by the photographing optical lens assembly 70 is 587.6 nm, but the wavelength may be adjusted according to actual requirements, and is not limited to the wavelength value mentioned above. [0131] In this embodiment, a first lens element 710 with positive refractive power comprises a convex object-side surface 711 . A second lens element 720 has negative refractive power. A third lens element 730 with negative refractive power comprises a concave image-side surface 732 . A fourth lens element 740 with positive refractive power comprises a concave object-side surface 741 and a convex image-side surface 742 . A fifth lens element 750 with positive refractive power comprises a convex object-side surface 751 , a concave image-side surface 752 , and two inflection points 753 . A sixth lens element 760 with positive refractive power comprises a convex object-side surface 761 , a concave image-side surface 762 , and two inflection points 763 . An aperture stop 700 can be disposed between the first lens element 710 and the object-side of the optical axis (Left side of FIG. 7A ). [0132] The detailed data of the photographing optical lens assembly 70 is as shown in Table 7-1 below. [0000] TABLE 7-1 Embodiment 7 f = 4.68 mm, Fno = 3.00, HFOV = 31.1 deg. Curvature Radius Thickness Surface# Member (mm) (mm) Material Index Abbe # Focal length 0 Object Plano Infinity 1 Ape. Plano 0.100 2 Lens 1 2.225820(ASP) 0.604 Plastic 1.544 55.9 3.07 3 −6.077200(ASP) 0.100 4 Lens 2 −6.113100(ASP) 0.300 Plastic 1.583 30.2 −22.90 5 −11.473000(ASP) 0.120 6 Lens 3 −15.098400(ASP) 0.514 Plastic 1.614 25.6 −5.92 7 4.854000(ASP) 0.830 8 Lens 4 −3.152800(ASP) 0.653 Plastic 1.530 55.8 43.54 9 −2.972800(ASP) 0.070 10 Lens 5 1.769450(ASP) 0.760 Plastic 1.530 55.8 103.37 11 1.556470(ASP) 0.150 12 Lens 6 1.885080(ASP) 0.398 Plastic 1.544 55.9 120.22 13 1.796600(ASP) 0.700 14 IR-filter Plano 0.400 Glass 1.517 64.2 — 15 Plano 0.303 16 Image Plano — Note: Reference wavelength is d-line 587.6 nm [0133] In Table 7-1, from the first lens element 710 to the sixth lens element 760 , all lens elements can be aspheric, and the aspheric surfaces can satisfy Condition ASP, but are not limited thereto. As for the parameters of the aspheric surfaces, reference is made to Table 7-2 below. [0000] TABLE 3 Aspheric Coefficients Surface# 2 3 4 5 K −5.83973E−01 −2.98477E+01 −4.71281E+01 −2.03759E+01 A 4 −4.14624E−03 −1.70915E−02 −5.19255E−03 −6.53804E−04 A 6 −3.54169E−03 −3.32882E−02 −2.46471E−02 −2.06015E−03 A 8 −1.95943E−02 −1.34697E−02 −1.55784E−03 −3.34624E−03 A 10 −1.24628E−03 1.10383E−02 1.90500E−02 −4.31693E−03 A 12 — — −2.92656E−03 — Surface# 6 7 8 9 K 9.20000E+01 2.48916E+00 −3.70959E+01 2.35999E−01 A 4 −3.89573E−03 2.89390E−02 3.24609E−02 −1.38094E−02 A 6 7.30086E−04 −3.42085E−02 −4.24020E−02 2.17481E−02 A 8 −1.11769E−03 3.77118E−02 1.92455E−02 −4.02650E−03 A 10 −2.82471E−03 −1.88636E−02 −4.53275E−03 −4.99926E−04 A 12 — 4.80075E−03 −2.24030E−04 1.32531E−04 Surface# 10 11 12 13 K −1.00066E+01 −2.68667E+01 −4.45133E+01 −4.77362E+00 A 4 −6.13008E−02 −2.62884E−02 −1.34330E−02 −2.61490E−02 A 6 1.75182E−02 7.49911E−03 1.04975E−03 2.69538E−03 A 8 −5.06676E−04 −1.81117E−03 1.85372E−05 −9.63136E−06 A 10 −8.74977E−04 1.27930E−04 6.27454E−06 −7.02519E−06 A 12 1.18803E−04 −4.19196E−06 1.14756E−06 4.11247E−07 A 14 −2.30728E−06 — −2.61808E−07 −8.37336E−08 [0134] The content of Table 7-3 may be deduced from Table 7-1. [0000] TABLE 7-3 Embodiment 7 f(mm) 4.68 (R 7 − R 8 )/(R 7 + R 8 ) 0.029 Fno 3.00 (R 9 − R 10 )/(R 9 + R 10 ) 0.064 HFOV(deg.) 31.1 f/f 1 1.52 V 1 − V 2 25.7 \|f/f 4 \| + \|f/f 5 \| + \|f/f 6 \| 0.19 (CT 2 + CT 3 )/f 0.17 SD/TD 1.02 (T 23 + T 45 )/T 34 0.23 BFL/TTL 0.22 R 12 /f 0.38 TTL/ImgH 2.02 [0135] FIG. 7B is a schematic view of longitudinal spherical aberration curves of the photographing optical lens assembly 70 . It can be observed from FIG. 7B that the longitudinal spherical aberrations generated by the photographing optical lens assembly 70 are within a range of −0.025 mm to 0.010 mm. [0136] FIG. 7C is a schematic view of astigmatic field curves of the photographing optical lens assembly 70 . It can be observed from FIG. 7C that the astigmatic field curvature of the tangential plane is within a range of −0.025 mm to 0.020 mm, and the astigmatic field curvature of the sagittal plane is within a range of −0.025 mm to 0.015 mm. [0137] FIG. 7D is a schematic view of a distortion curve of the photographing optical lens assembly 70 . It can be observed from FIG. 7D that the distortion ratio is within a range of 0.0% to 1.5%. As shown in FIGS. 7B to 7D , the photographing optical lens assembly 70 , designed according to the seventh embodiment, is capable of effectively correcting various aberrations. The Eighth Embodiment (Embodiment 8) [0138] FIG. 8A is a schematic structural view of the eighth embodiment of the photographing optical lens assembly. The specific implementation and elements of the eighth embodiment are substantially the same as those in the first embodiment. The element symbols in the eighth embodiment all begin with “8” which correspond to those in the first embodiment with the same function or structure. For conciseness, only the differences are illustrated below, and the similarities will not be repeated herein. [0139] In this embodiment, for example, the wavelength of the light received by the photographing optical lens assembly 80 is 587.6 nm, but the wavelength may be adjusted according to actual requirements, and is not limited to the wavelength value mentioned above. [0140] In this embodiment, a first lens element 810 with positive refractive power comprises a convex object-side surface 811 . A second lens element 820 has negative refractive power. A third lens element 830 with negative refractive power comprises a concave image-side surface 832 . A fourth lens element 840 with positive refractive power comprises a concave object-side surface 841 and a convex image-side surface 842 . A fifth lens element 850 with positive refractive power comprises a convex object-side surface 851 , a concave image-side surface 852 , and two inflection points 853 . A sixth lens element 860 with negative refractive power comprises a convex object-side surface 861 , a concave image-side surface 862 , and two inflection points 863 . An aperture stop 800 can be disposed between the first lens element 810 and the object-side of the optical axis (Left side of FIG. 8A ). [0141] The detailed data of the photographing optical lens assembly 80 is as shown in Table 8-1 below. [0000] TABLE 8-1 Embodiment 8 f = 4.63 mm, Fno = 2.60, HFOV = 31.4 deg. Curvature Radius Thickness Surface# Member (mm) (mm) Material Index Abbe # Focal length 0 Object Plano Infinity 1 Ape. Plano 0.100 2 Lens 1 2.413420(ASP) 0.712 Glass 1.517 64.2 3.35 3 −5.521300(ASP) 0.123 4 Lens 2 −6.705100(ASP) 0.300 Plastic 1.583 30.2 −10.50 5 72.067600(ASP) 0.372 6 Lens 3 −19.230800(ASP) 0.300 Plastic 1.614 25.6 −13.77 7 15.190200(ASP) 0.735 8 Lens 4 −3.177700(ASP) 0.649 Plastic 1.530 55.8 27.47 9 −2.792840(ASP) 0.070 10 Lens 5 1.761540(ASP) 0.669 Plastic 1.530 55.8 10.71 11 2.218620(ASP) 0.150 12 Lens 6 2.766520(ASP) 0.420 Plastic 1.544 55.9 −7.51 13 1.561140(ASP) 0.700 14 IR-filter Plano 0.400 Glass 1.517 64.2 — 15 Plano 0.304 16 Image Plano — Note: Reference wavelength is d-line 587.6 nm [0142] In Table 8-1, from the first lens element 810 to the sixth lens element 860 , all lens elements can be aspheric, and the aspheric surfaces can satisfy Condition ASP, but are not limited thereto. As for the parameters of the aspheric surfaces, reference is made to Table 8-2 below. [0000] TABLE 8-2 Aspheric Coefficients Surface# 2 3 4 5 K −6.53053E−01 −1.74924E+01 −2.82346E+01 −7.70000E+01 A 4 −5.08112E−03 −2.16452E−02 −5.92365E−03 −5.68810E−04 A 6 −6.49710E−03 −2.96536E−02 −2.62580E−02 −5.40988E−03 A 8 −8.77555E−03 −5.28819E−03 −8.95736E−03 −1.16380E−03 A 10 −3.55531E−03 3.31555E−03 1.89195E−02 −3.62862E−03 A 12 — — −5.02605E−03 — Surface# 6 7 8 9 K −2.26614E+00 −2.09500E+00 −5.27329E+01 4.01796E−01 A 4 −3.90888E−03 2.90111E−02 2.53046E−02 −1.48295E−02 A 6 6.08392E−03 −3.70138E−02 −4.12241E−02 1.96023E−02 A 8 6.46792E−04 3.70935E−02 1.79116E−02 −3.93335E−03 A 10 −2.87004E−03 −1.79563E−02 −4.91104E−03 −3.37609E−04 A 12 — 3.82634E−03 8.39015E−05 1.69969E−04 Surface# 10 11 12 13 K −1.11632E+01 −7.23176E+01 −1.59273E+02 −4.85171E+00 A 4 −6.78877E−02 −1.67870E−02 −1.74539E−02 −3.08432E−02 A 6 1.85545E−02 5.16060E−03 1.80914E−03 3.86432E−03 A 8 −8.30713E−04 −1.85847E−03 4.36023E−05 −1.88848E−04 A 10 −9.31168E−04 1.43935E−04 8.57367E−06 −1.45262E−06 A 12 1.23587E−04 5.73756E−07 2.13791E−07 1.05762E−06 A 14 4.57693E−07 — −3.75526E−07 −1.46229E−07 [0143] The content of Table 8-3 may be deduced from Table 8-1. [0000] TABLE 8-3 Embodiment 8 f(mm) 4.63 (R 7 − R 8 )/(R 7 + R 8 ) 0.064 Fno 2.60 (R 9 − R 10 )/(R 9 + R 10 ) −0.115 HFOV(deg.) 31.4 f/f 1 1.38 V 1 − V 2 34.0 \|f/f 4 \| + \|f/f 5 \| + \|f/f 6 \| 1.22 (CT 2 + CT 3 )/f 0.13 SD/TD 1.02 (T 23 + T 45 )/T 34 0.60 BFL/TTL 0.22 R 12 /f 0.34 TTL/ImgH 2.02 [0144] FIG. 8B is a schematic view of longitudinal spherical aberration curves of the photographing optical lens assembly 80 . It can be observed from FIG. 8B that the longitudinal spherical aberrations generated by the photographing optical lens assembly 80 are within a range of −0.025 mm to 0.010 mm. [0145] FIG. 8C is a schematic view of astigmatic field curves of the photographing optical lens assembly 80 . It can be observed from FIG. 8C that the astigmatic field curvature of the tangential plane is within a range of −0.030 mm to 0.025 mm, and the astigmatic field curvature of the sagittal plane is within a range of −0.030 mm to 0.020 mm. [0146] FIG. 8D is a schematic view of a distortion curve of the photographing optical lens assembly 80 . It can be observed from FIG. 8D that the distortion ratio is within a range of 0.0% to 2.0%. As shown in FIGS. 8B to 8D , the photographing optical lens assembly 80 , designed according to the eighth embodiment, is capable of effectively correcting various aberrations. The Ninth Embodiment (Embodiment 9) [0147] FIG. 9A is a schematic structural view of the ninth embodiment of the photographing optical lens assembly. The specific implementation and elements of the ninth embodiment are substantially the same as those in the first embodiment. The element symbols in the ninth embodiment all begin with “9” which correspond to those in the first embodiment with the same function or structure. For conciseness, only the differences are illustrated below, and the similarities will not be repeated herein. [0148] In this embodiment, for example, the wavelength of the light received by the photographing optical lens assembly 90 is 587.6 nm, but the wavelength may be adjusted according to actual requirements, and is not limited to the wavelength value mentioned above. [0149] In this embodiment, a first lens element 910 with positive refractive power comprises a convex object-side surface 911 . A second lens element 920 has negative refractive power. A third lens element 930 with negative refractive power comprises a concave image-side surface 932 . A fourth lens element 940 with positive refractive power comprises a concave object-side surface 941 and a convex image-side surface 942 . A fifth lens element 950 with negative refractive power comprises a convex object-side surface 951 , a concave image-side surface 952 , and two inflection points 953 . A sixth lens element 960 with negative refractive power comprises a convex object-side surface 961 , a concave image-side surface 962 , and two inflection points 963 . An aperture stop 900 can be disposed between the first lens element 910 and the second lens element 920 . [0150] The detailed data of the photographing optical lens assembly 90 is as shown in Table 9-1 below. [0000] TABLE 9-1 Embodiment 9 f = 4.98 mm, Fno = 3.20, HFOV = 32.8 deg. Curvature Radius Thickness Surface# Member (mm) (mm) Material Index Abbe # Focal length 0 Object Plano Infinity 1 Lens 1 2.194430(ASP) 0.753 Plastic 1.544 55.9 3.22 2 −7.616400(ASP) 0.050 3 Ape. Plano 0.110 4 Lens 2 −26.096800(ASP) 0.321 Plastic 1.614 25.6 −6.29 5 4.556600(ASP) 0.651 6 Lens 3 −2.862130(ASP) 0.300 Plastic 1.614 25.6 −23.61 7 −3.708100(ASP) 0.278 8 Lens 4 −3.547700(ASP) 0.787 Plastic 1.583 30.2 3.39 9 −1.374130(ASP) 0.050 10 Lens 5 2.175410(ASP) 0.378 Plastic 1.632 23.4 −4.78 11 1.179760(ASP) 0.846 12 Lens 6 36.192500(ASP) 0.555 Plastic 1.632 23.4 −9.94 13 5.323000(ASP) 0.500 14 IR-filter Plano 0.300 Glass 1.517 64.2 — 15 Plano 0.251 16 Image Plano — Note: Reference wavelength is d-line 587.6 nm [0151] In Table 9-1, from the first lens element 910 to the sixth lens element 960 , all lens elements are aspheric, and the aspheric surfaces can satisfy Condition ASP, but are not limited thereto. As for the parameters of the aspheric surfaces, reference is made to Table 9-2 below. [0000] TABLE 9-2 Aspheric Coefficients Surface# 1 2 4 5 K −7.56384E−01 −4.58833E+01 −1.00000E+02 −1.31337E+01 A 4 −5.26461E−03 −4.82011E−02 2.71727E−03 4.98945E−02 A 6 −2.20417E−02 −3.45321E−02 −2.17170E−02 −3.34814E−03 A 8 1.24804E−02 1.28580E−02 2.95137E−02 4.92489E−03 A 10 −2.21777E−02 −3.06938E−03 1.31657E−03 1.00627E−02 A 12 — −3.25773E−04 −9.63819E−04 4.14908E−04 Surface# 6 7 8 9 K −6.82619E+00 9.64543E−02 1.20215E−02 −2.24868E+00 A 4 −5.91562E−02 −2.85195E−04 1.79641E−04 −2.18579E−02 A 6 −4.10717E−03 1.64971E−04 −7.43378E−04 −2.05121E−03 A 8 3.03064E−03 1.61449E−05 −4.50620E−04 −5.66288E−04 A 10 −3.03480E−03 −1.74200E−04 −1.84981E−05 4.08493E−04 A 12 4.13012E−04 — — 5.64212E−05 Surface# 10 11 12 13 K −1.41219E+01 −4.73865E+00 −1.00000E+00 1.49423E+00 A 4 −4.91395E−02 −3.67593E−02 −4.59986E−03 −3.19344E−02 A 6 3.65022E−03 6.12007E−03 9.37229E−04 2.51865E−03 A 8 4.63033E−04 −5.94934E−04 −7.38096E−06 7.15866E−05 A 10 −6.10779E−05 8.96944E−06 −1.21675E−05 −2.06759E−05 A 12 5.74835E−06 2.47353E−06 — −4.87548E−07 A 14 — — — 5.96384E−08 [0152] The content of Table 9-3 may be deduced from Table 9-1. [0000] TABLE 9-3 Embodiment 9 f(mm) 4.98 (R 7 − R 8 )/(R 7 + R 8 ) 0.442 Fno 3.20 (R 9 − R 10 )/(R 9 + R 10 ) 0.297 HFOV(deg.) 32.8 f/f 1 1.55 V 1 − V 2 30.3 \|f/f 4 \| + \|f/f 5 \| + \|f/f 6 \| 3.01 (CT 2 + CT 3 )/f 0.12 SD/TD 0.84 (T 23 + T 45 )/T 34 2.52 BFL/TTL 0.16 R 12 /f 1.07 TTL/ImgH 1.77 [0153] FIG. 9B is a schematic view of longitudinal spherical aberration curves of the photographing optical lens assembly 90 . It can be observed from FIG. 9B that the longitudinal spherical aberrations generated by the photographing optical lens assembly 90 are within a range of −0.025 mm to 0.035 mm. [0154] FIG. 9C is a schematic view of astigmatic field curves of the photographing optical lens assembly 90 . It can be observed from FIG. 9C that the astigmatic field curvature of the tangential plane is within a range of −0.015 mm to 0.100 mm, and the astigmatic field curvature of the sagittal plane is within a range of −0.025 mm to 0.015 mm. [0155] FIG. 9D is a schematic view of a distortion curve of the photographing optical lens assembly 90 . It can be observed from FIG. 9D that the distortion ratio is within a range of 0.0% to 6.0%. As shown in FIGS. 9B to 9D , the photographing optical lens assembly 90 , designed according to the ninth embodiment, is capable of effectively correcting various aberrations.	An photographing optical lens assembly includes, in order from an object side to an image side, a first lens element with positive refractive power having a convex object-side surface, a second lens element, a third lens element, a fourth lens element having at least one aspheric surface, a fifth lens element having a convex object-side surface and a concave image-side surface with at least one surface being aspheric and at least one inflection point being formed, and a sixth lens element having a concave image-side surface with at least one surface being aspheric. By adjusting the curvature radii of the fifth lens element, the photographing optical lens assembly can stay compact and correct the aberration while obtaining superior imaging quality.	6
BACKGROUND OF THE DISCLOSURE 1. Field of the Disclosure This invention relates to a cartridge case processing device for producing, preparing or refurbishing empty cartridge cases. 2. Description of the Related Art High levels of dimensional accuracy are demanded when preparing cartridge cases, in particular for precision ammunition. Firing a cartridge case leads to an increase in its diameter along its entire length as well as to a linear expansion of the cartridge case. A cartridge case deformed by firing the cartridge must be refurbished to a suitable shape to be reused. In view of the aforementioned prior art, it is the object of the present disclosure to provide a cartridge case processing device for producing, preparing and/or refurbishing empty cartridge cases that allows simple tool-free handling, while simultaneously facilitating precise tooling of the cartridge case. SUMMARY OF THE PRESENT DISCLOSURE According to the present disclosure, a trimming and sizing device to produce and prepare empty cartridge cases comprising a trimmer holder in which a die body is received in the lower section and in an upper section a bushing guided shaft is received on which a cutter, an expander die and a decapping pin are coaxially arranged is characterized by the integration of an adjusting nut coaxial with the shaft in an opening in the upper section of the trimmer holder, which when turned relative to the shaft leads to a relative movement of bushing relative to the upper section. The adjusting nut is accessible from the outside of the upper section. When the adjusting nut is turned relative to the shaft it leads to the position of the cutter being adjusted in an axial direction. The trimmer holder accommodates all of the components required to trim and calibrate a cartridge case. By turning the adjusting nut integrated in the trimmer holder in a clockwise or counterclockwise direction it is possible to finely adjust the position of the cutter without the need for any tools. The arrangement of the adjusting nut projecting partially above the trimmer holder in a radial direction allows easy access for its operation. Turning the adjusting nut results in a relative movement of the bushing relative to the trimmer holder so that the position of the shaft together with the cutter mounted on the shaft is altered in an axial direction to facilitate carrying out the trimming process with the greatest possible precision. In this manner it is possible to adjust the final position of the cutter simply, conveniently and at the same time with extreme precision. This design embodiment sees the adjusting nut joined to the bushing by means of the external thread of the bushing. The adjustment distance traveled by the bushing as a result of turning the adjusting nut is directly proportional to the lead of the external thread of the bushing or rather the corresponding internal thread of the adjusting nut. The axial position of the bushing relative to the upper section of the trimmer holder, which serves as an end stop for the axial movement of the cutter when trimming, is altered relative to the shaft. Consequently, it is easily possible to determine precisely the final position the cutter reaches when trimming the neck section of the cartridge case. The trimmer holder is connected to a loading press by means of the die body received in the lower section. The die body is partially screwed into the lower section of the trimmer holder. The die body is partially screwed into the loading press. It is in this manner that the loading press and the trimmer holder are joined together. A favorable aspect of the design embodiment is that it is possible for the adjusting nut to partially protrude out of the upper section of the trimmer holder in a radial direction. This makes it possible to manually operate the adjusting nut easily and surely. A further embodiment lies in the possibility of adjusting the adjusting nut step-by-step or infinitely variably. Adjusting the axial position of the cutter for fine adjustment purposes instead of infinitely variable adjustment simplifies the trimming process with reproducible settings, and prevents unintentional maladjustment of the position of the cutter that does not correspond to the length the cartridge case is to be shortened in accordance with the caliber. However, infinitely variable adjustability means it is possible to set the position of the cutter to any setting. In particular, a locking element is arranged in the upper section of the trimmer holder that can be form-lock engaged with the adjusting nut. The adjusting nut is held in the respective position by means of the locking element so that operating the trimming and sizing device does not alter the undertaken fine adjustment of the cutter when performing the trimming operation. This has the added advantage that the operating person is able to sense that a further step has been undertaken to finely adjust the cutter based on the form-locked engagement. In doing so, the locking element is applied with pressure induced by means of a spring element against a radially outward extending surface of the adjusting nut provided with recesses. As a consequence, when setting the cutter by turning the adjusting nut it is necessary to overcome a mechanical resistance. That prevents unintentional maladjustment on the one hand and better retains the individually undertaken steps to make settings on the other. Ideally, the recesses are interposed by intermediate, plane surfaces. Thus, when the adjusting nut is turned the locking element slides over the plane surface when moving from one recess to the next, which means an individual step can be heard and felt when the locking element again reaches a corresponding recess. The locking element is preferably provided with an at least partially curved surface with which the locking element can engage in one of the recesses. The locking element is preferably designed in the form of a ball. To press the ball against the underside of the adjusting nut with constant pressure, a dedicated spring element designed in the form of a coiled spring is assigned to the ball to apply a pressure force to the ball. For this purpose a blind hole has been sunk in the upper section of the trimmer holder parallel to the axis of the shaft, which serves to accommodate the spring element designed in the form of a coiled spring as well as the locking element designed in the form of a ball. In the following the invention is explained in more detail with reference to the accompanying drawings. The depicted examples of embodiment do not represent any limitation to the depicted versions, but serve solely to explain a principle of the invention. The same or similar components are indicated with the same reference numbers. In order to be able to illustrate the mode of operation according to the invention highly simplified schematic representations only are depicted in the figures, while no components are depicted that are of no essential significance to the invention. Nevertheless, that does not mean that such components are not present in a solution according to the invention. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 A sectional view of a trimming and sizing device FIG. 2 A detailed view II of an upper section of a trimmer holder of the trimming and sizing device as per FIG. 1 FIG. 3 Enlarged view of detailed view II as per FIG. 2 FIG. 4 A detailed view IV of an upper section of a trimmer holder of a second design embodiment of the trimming and sizing device as per FIG. 1 FIG. 5 A view from below of an adjusting nut of the trimming and sizing device FIG. 6 A partially sectional side view of the adjusting nut with locking element as per FIG. 5 . DETAILED DESCRIPTION A sectional view of a trimming and sizing device is depicted in FIG. 1 . A loading press, of which just a holder arm section is partially visible, is denoted by the reference numeral 4 . The loading press 4 serves to receive the trimming and sizing device, which includes a die body 14 and other components. The die body 14 has a hollow interior into which a cartridge case 2 can be inserted. The die body 14 is provided with an external thread with which it is possible to screw the die body 14 into a corresponding threaded section of the holder arm section of the loading press 4 . The base 16 of the cartridge case 2 is fixed in position by a case holder 1 into which it is possible to temporarily secure the cartridge case 2 . As indicated by the arrow P the case holder 1 can be moved in a vertical direction by means of a pressing ram 4 . 1 , which is part of the loading press 4 . The die body 14 is partially screwed into a lower, horizontally extending section 6 . 1 of an essentially C-shaped trimmer holder 6 . For this purpose the lower section 6 . 1 of the trimmer holder 6 has a through hole with an internal threaded section. A clamping screw 13 serves to squeeze together or loosen the slotted section 6 . 1 of the trimmer holder 6 so that the position of the die body 14 can be adjusted in the trim holder 6 by means of the external thread. The die body 14 joins the trimmer holder 6 to the loading press 4 . An upper section 6 . 2 , which is provided with a through hole, of the trimmer holder 6 extends parallel to the lower section 6 . 1 . The upper section 6 . 2 of the trimmer holder 6 serves to receive a threaded rod 5 that is at least in part provided with a thread, which in turn can be rotated by means of a crank handle 8 arranged on one end of the threaded rod 5 . The crank handle 8 is secured on the threaded rod 5 by means of lock nut 23 . Viewed in the direction of the die body 14 a cutter 12 is arranged coaxially with the threaded rod 5 and secured with a lock nut 7 . The cutter 12 is screwed onto the threaded rod 5 . Below the cutter 12 there is an expander die 3 to which a decapping pin 15 is attached. The expander die 3 and the decapping pin 15 can be designed as a single component. However, it is advantageous when the expander die 3 and the decapping pin 15 are implemented as separate components, so that it is easily possible to replace the decapping pin 15 when necessary. To achieve a coaxial arrangement on the threaded rod 5 the cutter 12 , the expander die 3 as well as the decapping pin 15 are screwed separately from one another onto a threaded section, not shown, of the threaded rod 5 . This arrangement results in the essential advantage that the individual production-related tolerances of the cutter 12 , expander die 3 as well as the decapping pin 15 do not stack up as is the case with elements screwed into one another. The crank handle 8 is arranged on the threaded rod 5 above the upper section 6 . 2 of the trimmer holder 6 . To provide rotatable support of the threaded rod 5 this is partially enclosed by a plain bush 10 . A lower part of the plain bush 10 that faces away from the crank handle 8 is received in a stop bushing 9 with a flange-shaped edge. The flange-shaped edge of the stop bushing 9 is supported on its underside of the upper section 6 . 2 of the trimmer holder 6 . An upper part of the plain bush 10 that faces towards the crank handle 8 is received in a bushing 25 provided with an external threaded section 31 . There is a lock nut, 11 and 24 , located at both respective ends of the plain bush 10 . In FIG. 2 there is a detailed view II depicting an upper section 6 . 2 of a trimmer holder 6 of the trimming and sizing device as per FIG. 1 . The drawing in FIG. 3 shows an enlarged view of the detailed view II as per FIG. 2 ; however, to achieve a better representation FIG. 3 dispenses with an illustration of the upper section 6 . 2 of the trimmer holder 6 . As can be seen in FIG. 2 and FIG. 3 , the upper bushing 25 is provided with an external threaded section 31 preferably designed as a fine thread. The bushing 25 provided with an external threaded section 31 is received by means of a corresponding internal thread 30 of an adjusting nut 26 that is coaxially arranged with the threaded rod 5 , as depicted in FIG. 6 , which is integrated in the upper section 6 . 2 of the trimmer holder 6 of the trimming and sizing device. In order to integrate the ring-shaped adjusting nut 26 in the trimmer holder 6 depicted in the embodiment, the upper section 6 . 2 is provided with a corresponding opening, in particular slot-shaped opening. The adjusting nut 26 protrudes partially above the upper section 6 . 2 of the trimmer holder 6 in a radial direction so that it is possible to access and turn the adjusting nut 26 from outside of the device. Alternatively, the adjusting nut 26 can for example be provided with a polyhedral external contour, preferably a hexagonal external contour, so that it can, for example, be operated using an open-ended wrench. At the same time, it is possible to design the dimensions of the adjusting nut 26 in such a manner that it does not protrude outside of the upper section 6 . 2 of the trimmer holder 6 . According to a further embodiment of the adjusting nut 26 , it is possible to provide this with drilled blind holes distributed evenly around its external circumference into which it is possible to insert a pin with which to turn the adjusting nut 26 . The bushing 25 is fixed in position in the upper section 6 . 2 of the trimmer 6 holder by means of a threaded pin 20 that extends vertically to the longitudinal axis of the threaded rod 5 , to prevent any rotational movement of the bushing 25 relative to the threaded rod 5 . For this purpose, the bushing 25 is provided with a groove 22 that extends parallel to the axis of the threaded rod 5 . The threaded pin 20 engages in this groove 22 . The freedom of the bushing 25 to move in a longitudinal direction along the threaded rod 5 is equally restricted by the threaded pin 20 . A tapped hole designed to receive the threaded pin 20 is preferably located on the side of the trimmer holder 6 facing that section of the adjusting nut 26 that protrudes above the upper section 6 . 2 of the trimmer holder 6 . Furthermore, a drilled blind hole 21 is provided in the upper section 6 . 2 of the trimmer holder 6 that is arranged parallel to the axis of the threaded rod 5 . Inside the drilled blind hole 21 there is a spring element 18 , for example a coiled spring, designed as a compression spring as well as a locking element designed in the form of a ball 19 . Instead of a ball, it is also possible to use a cylindrically shaped element with a curved end face as a locking element. For instance, it is also conceivable to use an essentially mushroom shaped locking element without impairing the function. Designed as a coiled spring the spring element 18 is supported at one end by the floor of the drilled blind hole 21 and presses the locking element designed as a ball 19 against the underside of the adjusting nut 26 with its other end. When ejecting a primer out of the base 16 of the cartridge case 2 , which leaves an opening 17 in the base 16 of the cartridge case 2 , the act of ejecting the primer by means of the decapping pin 15 briefly generates a pressure force. The cartridge case 2 is pressed into the die body 14 to size the cartridge case 2 . The pressure force generated when ejecting the primer is absorbed by the threaded rod 5 and the lock nut 11 , and transmitted to the flange-shaped edge of the stop bushing 9 . The stop bushing 9 is in turn supported via its flange-shaped edge by the upper section 6 . 2 of the trimmer holder 6 . This design embodiment prevents the forces being transmitted to the external threaded section 31 of the bushing 25 or rather the internal thread 30 of the adjusting nut 26 . The drawing in FIG. 4 shows a detailed view IV depicting an upper section 6 . 2 of the trimmer holder 6 of a second embodiment of the trimming and sizing device as per FIG. 1 . This embodiment differs from the first described embodiment as per FIG. 2 and FIG. 3 in as much that it does not require the stop bushing 9 with a flange-shaped edge. Instead, a bushing 25 . 1 coaxially arranged with the threaded rod 5 extends in an axial direction of the drilled blind hole at least as far as the total axial extension of the upper section 6 . 2 of the trimmer holder 6 . This bushing 25 . 1 receives the plain bush 10 , which encloses the threaded rod 5 . In the same manner as the bushing 25 described in the first embodiment example, the bushing 25 . 1 is also provided with groove 22 that extends parallel to the axis of the threaded rod 5 . The threaded pin 20 engages in this groove 22 so that the bushing 25 . 1 is secured to prevent it twisting. The freedom of the bushing 25 . 1 to move in a longitudinal direction along the threaded rod 5 is equally restricted by the threaded pin 20 . As described above, the bushing 25 . 1 is provided with an external thread 31 , which is engaged with the internal thread 30 of the adjusting nut 26 so as to facilitate achieving a fine adjustment of the axial position of the cutter 12 by turning the adjusting nut 26 . Turning the adjusting nut 26 effects a relative movement of the bushing 25 . 1 in relation to the upper section 6 . 2 of the trimmer holder 6 . Together with the bushing 25 . 1 the position of the plain bush 10 received in the bushing 25 . 1 as well as that of the threaded rod 5 also changes. When ejecting the primer out of the cartridge case 2 , the act of ejecting the primer by means of the decapping pin 15 briefly generates a pressure force. When ejecting the primer this pressure force is transmitted by the threaded rod 5 and the lock nut 11 to the bushing 25 . 1 or rather to its external thread 31 and the internal thread 30 of the adjusting nut 26 , which are in turn supported at the upper section 6 . 2 of the trimmer holder 6 . The drawings in FIG. 5 and FIG. 6 show the adjusting nut 26 when viewed from below as well as in a partially sectional view. As can be seen in the drawing in FIG. 5 the adjusting nut 26 is provided with recesses 27 arranged and distributed evenly on its underside in a circumferential direction that extend in a radial direction across the entire width of the underside. The adjacent recesses 27 are separated from one another by plane surfaces 28 on the underside of the adjusting nut 26 . The drawing in FIG. 6 shows how the coiled spring 18 presses the ball 19 into one of the recesses 27 by means of spring force to secure the adjusting nut 26 in position. Knurling 29 is provided on the outside circumference of the adjusting nut 26 to provide additional grip when operating the adjusting nut 26 . The fundamental mode of operation of sizing and trimming of this trimming and sizing device is known from the DE 10 2010 048 117 A1 or rather the corresponding Patent U.S. Pat. No. 8,408,112 B2, which are hereby incorporated by reference. However, the described trimming and sizing device according to the present disclosure differs from the device described in the DE 10 2010 048 117 A1 by the embodiment of a means to simplify the setting of the vertical position of the cutter 12 in combination at the same time with the highest accuracy when setting the required length to which the cartridge case 2 is to be shortened at the bullet end. Turning the adjusting nut 26 integrated in the trimming and sizing device in its circumferential direction to the left or right results in transposing the ball 19 from one recess 27 to an adjacent recess, into which it clearly perceptibly and audibly engages. This ensures the user is made aware of the individual steps when making settings, which in conjunction with the pitch of the internal thread of the adjusting nut 26 or rather of the external threaded section 31 of the bushing 25 or the bushing 25 . 1 , make it possible to precisely set the axial position of the cutter 12 . This embodiment makes it possible to make settings in steps within a range of hundredths of a millimeter (in a range of thousandths of an inch steps). The size of the setting step depends on the thread lead on the bushing 25 or rather 25 . 1 as well as the adjusting nut 26 . In addition, the size of the setting step is also influenced by the number of recesses 27 as well as the number of plane surfaces 28 between the recesses 27 , as shown in FIG. 5 . When performing the trimming operation by turning and simultaneously pressing down on the crank handle 8 the cartridge case 2 is shortened by the cutter 12 to the length appropriate to the corresponding caliber. The maximum depth the cutter 12 can achieve is restricted by the bushing 25 or rather the bushing 25 . 1 , which serves as an end stop for the crank handle 8 . In using the adjusting nut 26 it is possible to set the end position of the cutter 12 in relation to the base 16 of the cartridge case 2 that the cutter 12 reaches at the end of the trimming procedure; in other words, with the adjusting nut 26 it is possible to set the minutest of axial distances that the cutter 12 can travel in relation to the base 16 of the cartridge case 2 when trimming. According to the present disclosure, this embodiment guarantees precision, reproducible shortening of the cartridge case 2 . LIST OF REFERENCE SIGNS 1 Case holder 2 Cartridge case 3 Expander die 4 Loading press 4 . 1 Pressing ram 5 threaded rod 6 Trimmer holder 6 . 1 Lower section of the trimmer holder 6 6 . 2 Upper section of the trimmer holder 6 7 Lock nut of cutter 12 8 Crank handle 9 Stop bushing 10 Plain bush 11 Lock nut of plain bush 10 12 Cutter 13 Clamping screw 14 Die body 15 Decapping pin 16 Base of cartridge case 2 17 Opening in base 16 18 Coiled spring 19 Ball 20 Threaded pin 21 Drilled blind hole 22 Groove 23 Lock nut of crank handle 8 24 Lock nut of plain bush 10 25 Bushing 25 . 1 Bushing 26 Adjusting nut 27 Recess 28 Surface on underside of adjusting nut 26 29 Knurling 30 Internal thread of adjusting nut 26 31 External threaded section	The present disclosure relates to a cartridge case processing device to produce and prepare empty cartridge cases ( 2 ) comprising a trimmer holder ( 6 ) in which a die body ( 14 ) is received in the lower section ( 6.1 ) and in an upper section ( 6.2 ) a bushing ( 25, 25.1 ) guided shaft ( 5 ) is received on which a cutter ( 12 ), an expander die ( 3 ) and a decapping pin ( 15 ) are coaxially arranged characterized by the integration of an adjusting nut ( 26 ) coaxial with the shaft ( 5 ) in the upper section ( 6.2 ) of the trimmer holder ( 6 ), which when turned relative to the shaft ( 5 ) leads to the position of the cutter ( 12 ) being adjusted in an axial direction.	5
TECHNICAL FIELD The present invention relates to an image device such as: an image recording device that moves a recording portion facing an image forming face of a recording medium back and forth along a guide shaft; or an image reading device that moves a reading portion facing an image face of a document back and forth along a guide shaft. BACKGROUND ART Among image devices including image recording devices such as printers and image reading devices such as scanners, there are image devices in which a movable body is moved back and forth within a predetermined range in the apparatus. For example, in inkjet printers, which are image recording devices, an ink head and ink cartridge, which are recording portions, are loaded on a carriage, which is a movable body, and that carriage is moved back and forth in a direction perpendicular to the transport direction of a recording medium such as paper. The carriage moves back and forth in a range that the ink head faces the entire image forming face of the recording medium in the direction perpendicular to the transport direction. Thus, in the internal portion of the inkjet printer, a guide shaft is fixed whose longitudinal direction has been matched with the direction perpendicular to the transport direction of the recording medium. This guide shaft passes through a shaft bearing provided in the carriage. The movement direction of the carriage is prescribed to be the longitudinal direction of the guide shaft. Ordinarily, in the carriage, the shaft bearing that the guide shaft penetrates is disposed in a position biased upstream or downstream in the transport direction of the recording medium from the center of gravity of the carriage, such that the guide shaft does not interfere with the ink cartridge or ink head loaded on the center portion of the carriage. Thus, a rotational moment centered on the guide shaft acts on the carriage. Also, forces that raise one end of the carriage in the direction of movement due to inertial force when accelerating or decelerating, and that rotate the carriage in a horizontal plane including the guide shaft, act on the carriage, which moves along the guide shaft. When the carriage is displaced in a direction other than the direction of movement along the guide shaft due to the action of these forces, the interval between the ink head and the image forming face of the recording medium changes, not only generating noise and vibration when the carriage moves, but also leading to a decrease in image quality because the image forming state is not fixedly maintained. Consequently, in an ink jet printer, the carriage is fixed with respect to a direction of rotation centered on the guide shaft in order that rolling due to rotational moment in the carriage, and pitching and yawing due to inertial force when accelerating or decelerating, will not occur. As an example of a configuration for this purpose, there are ink jet printers in which two guide rails are disposed parallel to the guide shaft, and a pressing member and a rotation stopping member that slide on each guide rail are provided in the carriage. Due to the pressing member pressing against one of the guide rails with a predetermined pressing force, rotational force in one direction that is centered on the guide shaft acts on the carriage. Due to the rotation stopping member contacting the other guide rail in the direction of this rotational force, the position of the carriage is fixed with respect to the direction of rotation centered on the guide shaft. In this way, it is assumed that the guide shaft does not dislocate at the shaft bearing in a direction perpendicular to the direction of movement of the carriage, in order to reliably prevent carriage rotation centered around the guide shaft by putting the rotation stopping member and the pressing member in contact with the two guide rails. On the other hand, ink jet printers have been proposed in which, in order to make it unnecessary to strictly maintain machining accuracy with the guide shaft, as the shaft bearing provided in the carriage, at least two inclined faces that contact an arc portion that constitutes a cross-section of the guide shaft are provided that contact the guide shaft at only two points in the cross-section (for example, see Patent Document 1). In the configuration disclosed in Patent Document 1, by setting angles formed by a tangential direction and a perpendicular direction on the outer circumferential face of the guide shaft at the two contact points between the shaft bearing and the guide shaft such that frictional force generated between the guide shaft and the shaft bearing becomes larger than the force that attempts to slide the bearing shaft along the circumferential direction of the guide shaft during acceleration or deceleration of the carriage, the carriage is driven in a state in which a predetermined precision is maintained relative to the guide shaft. Thus, in the configuration disclosed in Patent Document 1, along with controlling rotation of the carriage around the guide shaft, a guide rail is further provided that guides the carriage such that it is driven back and forth in the direction of the intersecting direction, and the angles are set according to the weight of the carriage, the position of the center of gravity of the carriage relative to the guide shaft, the distance between shaft bearings respectively provided in approximately both end portions of the carriage, the coefficient of friction between the shaft bearing and the guide shaft, the position of a guide transmission portion of the carriage relative to the guide shaft, the position of the guide rail relative to the guide shaft, and the speed of acceleration or deceleration conferred on the carriage. Thus, the shaft bearing portion of the carriage is prevented from rising up from the guide shaft during acceleration or deceleration of the carriage, noise and vibration is suppressed when the carriage is accelerated or decelerated, and it is made possible to record an image quietly and with high precision. It is also described that of the angles mentioned above, by adopting a configuration in which the angle formed by a tangential direction and a perpendicular direction on the outer circumferential face of the guide shaft at the contact point of the downstream side of the transport direction of the recording medium is smaller than the angle formed by a tangential direction and a perpendicular direction on the outer circumferential face of the guide shaft at the contact point of the upstream side of the transport direction, because the sliding load between the guide shaft and the shaft bearing diminishes, the amount of friction at the contact point of the shaft bearing can be suppressed to a minimum limit, and it becomes possible to improve the durability of the recording device. However, according to the configuration disclosed in the aforementioned Patent Document 1, there is the problem that it is not possible to reliably control rolling, pitching, and yawing that is generated during acceleration and deceleration of the carriage that moves along the guide shaft. That is, with only the factors considered in the configuration disclosed in Patent Document 1, it is not possible to reliable determine the angle of the two inclined faces of the shaft bearing. Thus, vibration and noise are generated when the carriage moves, leading to a deterioration of the image forming state. This sort of problem occurs not only in image recording devices such as ink jet printers provided with a carriage that is loaded with an ink head and an ink cartridge and moves back and forth; it likewise also occurs in image reading devices such as scanners provided with a unit that is loaded with a lens and a light-receiving element and moves back and forth. It is an object of the present invention to provide an image apparatus in which, by considering all of the factors that operate on a movable member that moves along a guide shaft, it is possible to reliably control rolling, pitching, and yawing generated when accelerating or decelerating the movable member. Patent Document 1: JP 2002-137481A DISCLOSURE OF THE INVENTION This invention is provided with the following configurations as a means for solving the problems described above. (1) An image device includes a movable member, a guide shaft, and a shaft bearing. The movable member moves back and forth inside the device along a guide shaft when reading or recording image information. The guide shaft includes an arc portion in at least part of a cross-section. The shaft bearing is penetrated by the guide shaft at two locations in the movement direction that differ from the center of gravity in the movable member. The shaft bearing includes two inclined faces contacted by the arc portion of the guide shaft in the cross-section. The respective two inclined faces of the shaft bearing are at an angle θf (rad) and an angle θr (rad) with the perpendicular direction. The angle θf (rad) and the angle θr (rad) satisfy the following inequality: cos {π/2−(θ f+θr )}>0. As shown in FIG. 14 , with respect to a load F that acts on the guide shaft from one of the two inclined faces of the shaft bearing, for which the angles formed with the perpendicular direction are θf and θr, a component E parallel to the other inclined face is E=F ·cos {π/2−(θ f+θr )}. When the direction against which the guide shaft is pressed is made positive, when this parallel component E is a positive value, it becomes the direction that the guide shaft bites into the inclined face of the shaft bearing, and rising up of the movable member from the guide shaft does not occur. On the other hand, when the parallel component E is a negative value, it becomes the direction that the guide shaft separates from the inclined face of the shaft bearing, rising up of the movable member from the guide shaft occurs, and it becomes impossible to insure positional accuracy. In this configuration, the cosine of an angle obtained by subtracting the sum of the angles which the two respective inclined faces of the shaft bearings provided at two locations of the movable member form with the perpendicular direction from π/2 is made to be a positive value. Accordingly, when the direction that presses against the guide shaft has been made a positive value, because a load F that acts on the guide shaft from one of the inclined faces definitely becomes a positive value, the component E parallel to the other inclined face obtained by multiplying a positive cosine value by this value also definitely becomes a positive value, and this component becomes the direction that the guide shaft bites into the inclined faces of the shaft bearing. Thus, it is possible to reliably prevent the movable member from rising up from the guide shaft. (2) The image device further includes first and second guide rails disposed parallel to the guide shaft, a rotation stopping member that slides in the direction of rotation of the movable member with the guide shaft as a center and in contact with the first guide rail, and a pressing member that slides pressing against the second guide rail are provided in the movable member. The angle θf (rad) and the angle θr (rad) are determined such that the load Ff (gf) received by the inclined face of the side of the center of gravity of the movable member in the shaft bearing on the downstream side in the movement direction and the load Fr′ (gf) received by the inclined face opposite to the side of the center of gravity of the movable member in the shaft bearing on the upstream side in the movement direction become positive values when calculated when the mass of the movable member is made M, the acceleration that acts on the first guide rail from the movable member when accelerating is made G, the load that acts on the rotation stopping member is made W, the coefficient of friction between the rotation stopping member and the first guide rail is made μ, the pressing force that acts on the second guide rail from the pressing member is made P, the coefficient of friction between the rotation stopping member and the second guide rail is made μ′, the coefficient of friction between the shaft bearings and the guide shaft is made μ″, an angle formed with the direction perpendicular to the pressing force that acts on the second guide rail from the pressing member is made η, in the perpendicular direction, the distance from the contact position of the guide shaft and the shaft bearings to the point where movement force acts in the movable member is made z, the distance to the contact position of the first guide rail and the rotation stopper is made c, the distance to the center of gravity of the movable member is made j, the distance to the contact position of the second guide rail and the pressing member is made a, in the horizontal direction perpendicular to the movement direction of the movable member, the distance from the contact position of the guide shaft and the shaft bearing to the center of gravity of the movable member is made y, the distance to the contact position of the first guide rail and the rotation stopper is made d, the distance to the contact position of the second guide rail and the pressing member is made k, in the movement direction of the movable body, the spacing of the two shaft bearings is made b, and Ff={φ−ε−h ·tan θ r }·cos θ r /sin(θ f+θr )+2φ{(μ″· z )/ b }(cos θ r +cos θ f )·cos θ r /sin 2(θ f+θr ) Fr′={φ+ε−h ·tan θ f }·cos θ f /sin(θ f+θr )−2φ{(μ″· z )/ b }(cos θ r +cos θ f )·cos θ f /sin 2(θ f+θr ), Where +=( M/ 2)+ P ·cos η ε={ G·M ( j−z )+μ· W ( c−z )+2 μ′·P ( a−z )} /b h={G·M·y+ 2 μ″·P·d+μ·W·k}/b. In this configuration, the angles which the two inclined faces of the shaft bearing form with the perpendicular direction are determined taking into consideration all of the factors that affect the load that acts on the guide shaft from the inclined face of the side of the center of gravity of the movable member in the shaft bearing on the downstream side in the movement direction, and the load that acts on the guide shaft from the inclined face opposite to the side of the center of gravity of the movable member in the shaft bearing on the upstream side in the movement direction, when the movable member accelerates. Accordingly, the inclined faces of the shaft bearing do not separate from the guide shaft when the movable member accelerates due to the load that acts on the guide shaft from the inclined faces of the shaft bearing, and there is no occurrence of the movable member rising up. (3) The image device further includes first and second guide rails disposed parallel to the guide shaft, a rotation stopping member that slides in the direction of rotation of the movable member with the guide shaft as a center and in contact with the first guide rail, and a pressing member that slides pressing against the second guide rail, are provided in the movable member. The angle θf (rad) and the angle θr (rad) are determined such that the load Ff′ (gf) received by the inclined face opposite to the side of the center of gravity of the movable member in the shaft bearing on the down stream side in the movement direction and the load Fr (gf) received by the inclined face opposite to the side of the center of gravity of the movable member in the shaft bearing on the upstream side in the movement direction become positive values when calculated when the mass of the movable member is made M, the acceleration that acts on the movable member when accelerating is made G, the load that acts on the first guide rail from the rotation stopping member is made W, the coefficient of friction between the rotation stopping member and the first guide rail is made μ, the pressing force that acts on the second guide rail from the pressing member is made P, the coefficient of friction between the rotation stopping member and the second guide rail is made μ′, the coefficient of friction between the shaft bearings and the guide shaft is made μ″, an angle formed with the direction perpendicular to the pressing force that acts on the second guide rail from the pressing member is made η, in the perpendicular direction, the distance from the contact position of the guide shaft and the shaft bearings to the point where movement force acts in the movable member is made z, the distance to the contact position of the first guide rail and the rotation stopper is made c, the distance to the center of gravity of the movable member is made j, the distance to the contact position of the second guide rail and the pressing member is made a, in the horizontal direction perpendicular to the movement direction of the movable member, the distance from the contact position of the guide shaft and the shaft bearing to the center of gravity of the movable member is made y, the distance to the contact position of the first guide rail and the rotation stopper is made d, the distance to the contact position of the second guide rail and the pressing member is made k, in the movement direction of the movable body, the spacing of the two shaft bearings is made b, and Ff′={φ+ε+h ·tan θ r }·cos θ r /sin(θ f+θr )−2φ{(μ″· z )/ b }(cos θ r +cos θ f )·cos θ r /sin 2(θ f+θr ) Fr′={φ−ε+h ·tan θ r }·cos θ r /sin(θ f+θr )+2φ{(μ″· z )/ b }(cos θ r +cos θ f )·cos θ r /sin 2(θ f+θr ), Where φ=( M/ 2)+ P ·cos η ε={ G·M ( j−z )+μ· W ( c−z )+2 μ′·P ( a−z )} /b h={G·M·y+ 2 μ″·P·d+μ·W·k}/b. In this configuration, the angles which the two inclined faces of the shaft bearing form with the perpendicular direction are determined taking into consideration all of the factors that affect the load that acts on the guide shaft from the inclined face opposite to the side of the center of gravity of the movable member in the shaft bearing on the downstream side in the movement direction, and the load that acts on the guide shaft from the inclined face of the side of the center of gravity of the movable member in the shaft bearing on the upstream side in the movement direction, when the movable member decelerates. Thus, the inclined faces of the shaft bearing do not separate from the guide shaft when the movable member decelerates due to the load that acts on the guide shaft from the inclined faces of the shaft bearing, and there is no occurrence of the movable member rising up. (4) The maximum value of the moment that acts on the movable member when it moves due to disturbance is made Mm (gf), and the load Ff (gf) received by the inclined face of the side of the center of gravity of the movable member in the shaft bearing on the downstream side in the movement direction and the load Fr′ (gf) received by the inclined face opposite to the side of the center of gravity of the movable member in the shaft bearing on the upstream side in the movement direction are made Ff ·cos {π/2−(θ f+θr )}· b/ 2 >Mm Fr ′·cos {π/2−(θ f+θr )}· b/ 2 >Mm In this configuration, the angles which the two inclined faces of the shaft bearing form with the perpendicular direction are determined taking into consideration all of the factors that affect the load that acts on the guide shaft from the inclined face of the side of the center of gravity of the movable member in the shaft bearing on the downstream side in the movement direction, and the load that acts on the guide shaft from the inclined face opposite to the side of the center of gravity of the movable member in the shaft bearing on the upstream side in the movement direction, when the movable member accelerates. Thus, the inclined faces of the shaft bearing do not separate from the guide shaft when the movable member accelerates due to the load that acts on the guide shaft from the inclined faces of the shaft bearing, and there is no occurrence of the movable member rising up. (5) The maximum value of the moment that acts on the movable member when it moves due to disturbance is made Mm (gf·mm), and the load Ff′ (gf) received by the inclined face opposite to the side of the center of gravity of the movable member in the shaft bearing on the downstream side in the movement direction and the load Fr (gf) received by the inclined face of the center of gravity of the movable member in the shaft bearing on the upstream side in the movement direction are made Ff′ ·cos {π/2−(θ f+θr )}· b/ 2 >Mm Fr ·cos {π/2−(θ f+θr )}· b/ 2 >Mm In this configuration, the angles which the two inclined faces of the shaft bearing form with the perpendicular direction are determined taking into consideration all of the factors that affect the load that acts on the guide shaft from the inclined face of the side opposite to the center of gravity of the movable member in the shaft bearing on the downstream side in the movement direction, and the load that acts on the guide shaft from the inclined face of the side of the center of gravity of the movable member in the shaft bearing on the upstream side in the movement direction, when the movable member decelerates. Thus, the inclined faces of the shaft bearing do not separate from the guide shaft when the movable member decelerates due to the load that acts on the guide shaft from the inclined faces of the shaft bearing, and there is no occurrence of the movable member rising up. (6) The load Ff (gf) received by the inclined face of the side of the center of gravity of the movable member in the shaft bearing on the downstream side in the movement direction and the load Fr′ (gf) received by the inclined face opposite to the side of the center of gravity of the movable member in the shaft bearing on the upstream side in the movement direction are made approximately equal. In this configuration, the angles which the inclined faces of the shaft bearings form with the perpendicular direction are set such that the load that acts on the inclined face of the side of the center of gravity of the movable member in the shaft bearing on the downstream side in the movement direction and the load that acts on the inclined face opposite to the center of gravity of the movable member in the shaft bearing on the upstream side in the movement direction are made approximately equal when the movable member accelerates. Thus, an approximately equal moment is generated at the inclined faces of each shaft bearing when the movable member accelerates, and the movement of the movable member is stable. (7) The load Ff′ (gf) received by the inclined face opposite to the side of the center of gravity of the movable member in the shaft bearing on the downstream side in the movement direction and the load Fr (gf) received by the inclined face of the center of gravity of the movable member in the shaft bearing on the upstream side in the movement direction are made approximately equal. In this configuration, the angles which the inclined faces of the shaft bearings form with the perpendicular direction are set such that the load that acts on the guide shaft from the inclined face opposite to the side of the center of gravity of the movable member in the shaft bearing on the downstream side in the movement direction and the load that acts on the guide shaft from the inclined face of the center of gravity of the movable member in the shaft bearing on the upstream side in the movement direction are made approximately equal when the movable member decelerates. Thus, an approximately equal moment is generated at the inclined faces of each shaft bearing when the movable member decelerates, and the movement of the movable member is stable. (8) The angle θf (rad) and the angle θr (rad) which the two respective inclined faces of the shaft bearing form with the perpendicular direction are determined such that they satisfy abs [Δ(μ· W+ 2·μ′· P+μ″·T )/Δ{57.3·(θ f+θr )}]≦2. There is a relationship between the sum of the angles which the two inclined faces in the shaft bearing form with the perpendicular direction and the sliding resistance between the inclined faces and the guide shaft, as shown in FIG. 11 , and the value of sliding resistance becomes an approximately minimum value in a range where the ratio of the change in sliding resistance to the sum of the angles is not more than two. In this configuration, the angles of the inclined faces are determined such that the ratio of the change in sliding resistance to the sum of the angles is not more than two. Thus, the sliding resistance that occurs between the shaft bearings and the guide shaft when the movable member moves can be suppressed to a low value, and the movable member moves smoothly. (9) In the shaft bearings disposed in two locations in the movement direction of the movable member, the angle θf (rad) and the angle θr (rad) which the two respective inclined faces of the shaft bearing form with the perpendicular direction differ from each other. In this configuration, shaft bearings for which the inclination angles of the inclined faces differ are disposed at two locations in the movement direction of the movable member. Thus, the movable member moves back and forth in a stable state even when the movement speed of the movable member differs when moving forth and when moving back. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is an exterior view of an ink jet printer that is an image device according to an embodiment of this invention. FIG. 2 is a side view of relevant portions including a carriage in the aforementioned inkjet printer. FIG. 3 is a rear view of relevant portion including a carriage in the aforementioned inkjet printer. FIG. 4 is a side view that shows details of a shaft bearing provided in the aforementioned carriage. FIG. 5 is a front view that illustrates a calculation method for determining an angle that an inclined face of a shaft bearing forms with a perpendicular direction. FIG. 6 is a side view that illustrates the same calculation method. FIG. 7 is a front view that illustrates the same calculation method. FIG. 8 is a front view that illustrates the same calculation method. FIG. 9 is a front view that illustrates the same calculation method. FIG. 10 is a front view that illustrates the same calculation method. FIG. 11 is a side view of a shaft bearing that illustrates the same calculation method. FIG. 12 is a plan view that illustrates the same calculation method. FIG. 13 is a side view of a shaft bearing that illustrates the same calculation method. FIG. 14 is a side view of a shaft bearing that illustrates the same calculation method. FIG. 15 shows data values of an embodiment of this invention. FIG. 16 shows the relationship between the angle of one inclined face in the shaft bearing and the moment of a direction parallel to the other inclined face. FIG. 17 shows the relationship between the sum of the angles of the two inclined faces in the shaft bearing and sliding resistance. FIG. 18 is a view of the configuration of a carriage applied in an inkjet printer according to another embodiment of this invention. FIG. 19 shows data values of another embodiment of this invention. DESCRIPTION OF THE INVENTION FIG. 1 is an exterior view of an ink jet printer that is an image device according to an embodiment of this invention. An inkjet printer 1 is configured from a paper supply portion 1 a , a separation portion 1 b , a transport portion 1 c , a printing portion 1 d , and a discharge portion 1 e . The paper supply portion 1 a supplies paper P that is a recording medium when performing printing, and includes a paper supply tray 2 and a pickup roller 3 . The paper supply portion 1 a stores the paper P when printing is not performed. The separation portion 1 b supplies the paper P supplied from the paper supply portion 1 a to the transport portion 1 c page by page, and is constituted of a paper supply roller and a separation device that are not shown in the figures. The frictional force between a pad portion of the separation device (the portion that touches the paper P) and the paper P is greater than the frictional force between pages of the paper P. Also, the frictional force between the paper supply roller and the paper P is greater than the frictional force between the pad portion of the separation device and the paper P, and greater than the frictional force between pages of the paper P. Thus, even if a plurality of pages of the paper P are fed from the paper supply portion 1 a to the separation portion 1 b at the same time, these pages of paper P are separated by the paper supply roller and the separation device, and only the topmost page of paper P is guided to the transport portion 1 c. The transport portion 1 c is provided with a guide plate 4 and a transport roller 5 , and transports the paper P transported page by page from the separation portion 1 b to the printing portion 1 d . The transport roller 5 adjusts the transport speed and the transport start timing of the paper P when the paper P is fed between an ink head 6 and a platen 10 , such that ink discharged from the ink head 6 affixes to an appropriate position of the paper P. The printing portion 1 d prints an image to an image forming face of the paper P transported by the transport roller 5 of the transport portion 1 c , and includes the ink head 6 that discharges ink according to the image, an ink cartridge 7 storing ink to be supplied to the ink head, a carriage 8 on which the ink head 6 and the ink cartridge 7 are loaded and that moves back and forth, a guide shaft 9 that guides the movement direction of the carriage 8 , and a platen 10 that holds the paper P when printing. The discharge portion 1 e discharges paper P for which printing has been performed on an image forming face out of the ink jet printer 1 , and includes discharge rollers 11 and 12 , and a discharge tray 13 . Paper P that has passed the printing portion 1 d is discharged onto the discharge tray 13 by the discharge rollers 11 and 12 . In this configuration, the inkjet printer 1 performs printing according to the following operation. First, based on image information, a printing request is made to the ink jet printer 1 from a computer or the like not shown in the figures. The inkjet printer 1 , having received the request, dispatches the paper P on the paper supply tray 2 with the pickup roller 3 . Next, the dispatched paper P passes the separation portion 1 b and is fed to the transport portion 1 c page by page by the paper supply roller, and is further transported between the ink head 6 and the platen 10 of the printing portion id by the transport roller 5 of the transport portion 1 c. In the printing portion 1 d , ink is discharged from the ink head 6 to an image forming face of the paper P on the platen 10 corresponding to the image information. At this time the paper P is temporarily stopped on the platen 10 . As ink is discharged, the carriage 8 moves the amount of one line in a main scanning direction perpendicular to the paper transport direction along the guide shaft 9 . When the carriage 8 reaches one end of the movement range, the paper P is transported only a fixed width on the platen 10 in a secondary scanning direction, which is the paper transport direction. In the printing portion 1 d , an image is printed on the entire face of the paper P by repeatedly executing transport stoppage of the paper P, movement of the carriage 8 that accompanies driving of the ink head 6 , and transport of the paper P, corresponding to the image information. The paper P on which an image has been printed is discharged onto the discharge tray 13 by the discharge rollers 11 and 12 . FIGS. 2 and 3 are a side view and a rear view of relevant portions including the carriage in the above inkjet printer. The carriage 8 includes a rotation stopping member 81 , a pressing member 82 , a belt receiver 83 and a shaft bearing 84 . The rotation stopping member 81 abuts a first guide rail 31 . The pressing member 82 presses against a second guide rail 32 . The guide rails 31 and 32 are disposed parallel to the guide shaft 9 in the interior portion of the inkjet printer 1 . Part of a driving belt 33 is fixed to the belt receiver 83 . The guide shaft 9 penetrates the shaft bearing 84 . The driving belt 33 fixed to the belt receiver 83 is stretched between a driving pulley and a driven pulley that are not shown in the figures. The driving pulley is fixed to a rotating shaft of a driving motor that is not shown in the figures. Accordingly, rotation of the driving motor is transmitted to the carriage 8 via the driving belt 33 , and the carriage 8 moves back and forth along the guide shaft 9 . The shaft bearing 84 that the guide shaft 9 penetrates is disposed in the lower portion of the rear side of the carriage 8 , and is positioned lower in the rear side than a center of gravity C of the carriage 8 . Accordingly, the carriage 8 attempts to rotate in the direction of arrow A, with the guide shaft 9 as the center of rotation. In order to control this rotation, the rotation stopping member 81 provided in the upper portion of the carriage 8 abuts the first guide rail 31 toward the front side. Also, the carriage 8 can be thought to rotate in the direction of arrow B when vibration or shock have acted on the inkjet printer 1 . In order to control this rotation, the pressing member 82 provided in the upper portion of the carriage 8 presses against the second guide rail 32 in the diagonally upward direction of the rear side. As is clear in the rear view in FIG. 3 , the rotation stopping member 81 and the belt receiver 83 are provided in one location in of the center portion in the movement direction of the carriage 8 , and the pressing member 82 and the shaft bearing 84 are provided in two locations in the vicinity of both ends of the movement direction of the carriage 8 . FIG. 4 is a side view that shows details of the shaft bearing provided in the aforementioned carriage. A part of the inside circumferential face of the shaft bearing 84 is configured from a front side inclined face 84 a and a rear side inclined face 84 b . The shaft bearing 84 makes contact with the inclined faces 84 a and 84 b . Accordingly, it is not necessary to strictly control the inner diameter of the shaft bearing 84 considering the fit with the guide shaft 9 . Also, in order to support both sides of the circumferential face of the guide shaft 9 with the two inclined faces 84 a and 84 b , the angles θf and θr which the two respective inclined faces 84 a and 84 b form with the perpendicular direction necessarily are 0<(θ f+θr )<π and necessarily satisfy the relationship cos {π/2−(θ f+θr )}>0. In this manner, by setting the angles such that the cosine of an angle obtained by subtracting the sum of the angles which the two respective inclined faces 84 a and 84 b of the shaft bearing 84 that are provided in two locations of the carriage 8 form with the perpendicular direction from π/2, when the direction in which the guide shaft 9 is pressed against has been made a positive value, because the load that acts on the guide shaft 9 from the one inclined face 84 a definitely becomes a positive value, a component parallel to the other inclined face 84 b obtained by multiplying a positive cosine value by this value also definitely becomes a positive value, this component becomes the direction that the guide shaft 9 bites into the inclined faces 84 a and 84 b of the shaft bearing 84 , and it is possible to reliably prevent the carriage 8 from rising up from the guide shaft 9 . However, it is necessary to consider the moment that acts on the carriage 9 when determining the angles θf and θr. That is, a pitching moment that biases the front and rear ends in the movement direction upward or downward, a rolling moment around the guide shaft 9 , and a yawing moment that biases the front and rear ends in the movement direction to the front face side or the rear face side, act on the carriage 9 . Following is an explanation of a calculation method for determining the angles which the inclined faces of the shaft bearing form with the perpendicular direction with reference to FIGS. 5 to 14 . When the carriage 8 moves from the left side in FIG. 5 toward the right side, the mass of the carriage 8 is made M, the acceleration that acts on the carriage 8 when accelerating is made G, the load that acts on the rotation stopping member 81 is made W, the coefficient of friction between the rotation stopping member 81 and the first guide rail 31 is made μ, the pressing force of the pressing member 82 is made P, the coefficient of friction between the rotation stopping member 82 and the second guide rail 32 is made μ′, the vertical load component that acts on the shaft bearing 84 on the downstream side (right side) in the movement direction is made S, the horizontal load component that acts on the shaft bearing 84 on the downstream side in the movement direction is made h, the vertical load component that acts on a shaft bearing 84 ′ on the upstream side (left side) in the movement direction is made S′, the horizontal load component that acts on the shaft bearing 84 ′ of the upstream side of the movement direction is made h′, the coefficient of friction between the shaft bearings 84 and 84 ′ and the guide shaft 9 is made μ″, the angle formed with the perpendicular direction of the pressing force P that acts from the pressing member 82 on the second guide rail 32 is made η, in the perpendicular direction, the distance from the contact position of the guide shaft 9 and the shaft bearings 84 and 84 ′ to the point where movement force acts in the carriage 8 (the position where the driving belt 33 is fixed in the belt receiver 83 ) is made z, the distance to the contact position of the first guide rail 31 and the rotation stopping member 81 is made c, the distance to the center of gravity of the carriage 8 is made j, the distance to the contact position of the second guide rail 32 and the pressing member 82 is made a, in the horizontal direction perpendicular to the movement direction of the carriage 8 , the distance from the contact position of the guide shaft 9 and the shaft bearings 84 and 84 ′ to the center of gravity of the carriage 8 is made y, the distance to the contact position of the first guide rail 31 and the rotation stopping member 81 is made d, the distance to the contact position of the second guide rail 32 and the pressing member 82 is made k, and in the movement direction of the carriage 8 , the spacing of the two shaft bearings 84 and 84 ′ is made b. As shown in FIG. 5 , the pitching moment in this case is obtained from M+ 2 ·P ·cos η= S+S′. As shown in FIG. 6 , the rolling moment is obtained from W·c=M·y+P ·cos η· d+P ·sin η· a. Accordingly, the load W that acts on the rotation stopping member 81 is ∴ W =( M·y+P ·cos η· d+P ·sin η· a )/ c. Here, as shown in FIG. 7 , the inertial force α that acts on the carriage 8 is 2·α·( b/ 2)= G·M·e ∴α= G·M ·( j−z )/ b. As shown in FIG. 8 , the sliding resistance β of the rotation stopping member 81 is 2·β·( b/ 2)=μ· W ·( c−z ) ∴β=μ· W ·( c−z )/ b. Further, as shown in FIG. 9 , the sliding resistance γ of the pressing member 82 is 2·γ·( b/ 2)=2·μ′· P ( a−z ) ∴γ=2·μ′· P ( a−z )/ b. In addition, as shown in FIGS. 10 and 11 , making the loads that respectively act on the inclined face 84 a on the side of the position of the center of gravity (front face side) of the shaft bearing 84 on the downstream side in the movement direction of the carriage 8 and the inclined face 84 b on the side opposite to the center of gravity (rear face side) to be Ff and Fr, and making the loads that respectively act on the front inclined face 84 a ′ and the rear inclined face 84 b ′ of the shaft bearing 84 ′ on the upstream side in the movement direction of the carriage 8 to be Ff′ and Fr′, the sliding resistance δ of the guide shaft 9 is 2·δ·( b/ 2)=μ″·( Ff′+Fr′+Ff+Fr )· z ∴δ=μ″·( Ff′+Fr′+Ff+Fr )· z/b. Accordingly, the vertical loads S and S′ of the shaft bearings 84 and 84 ′ are S =( M/ 2)+ P ·cos η−α−β−γ+δ S ′=( M/ 2)+ P ·cos η+α+β+γ−δ. On the other hand, as shown in FIG. 12 , the yawing moment of the carriage 8 is obtained from 2 ·h ·( b/ 2)= G·M·y+ 2·μ″· P·d+μ·W·k and the horizontal load component h that acts on the shaft bearings 84 and 84 ′ is h=G·M·y/b+ 2·μ″· P·d/b+μ·W·k/b. From the above, as shown in FIGS. 13 and 14 , the vertical load component S and the horizontal load component h that act on the shaft bearing 84 on the downstream side in the movement direction, and the vertical load component S′ and the horizontal load component h that act on the shaft bearing 84 ′ on the upstream side in the movement direction, becomes S′=Ff ′·sin θ f+Fr ′·sin θ r Formula 1 h=Ff ′·cos θ f−Fr ′·cos θ r Formula 2 S=Ff ·sin θ f+Fr ·sin θ r Formula 3 h=−Ff ·cos θ f+Fr ·cos θ r Formula 4 Here, when making ( M/ 2)+ P ·cos η=φ and (α+β+γ)=ε, from formula 3, φ−ε+μ″( Ff′+Fr′+Ff+Fr )· z/b=Ff ·sin θ f+Fr ·sin θ r Formula 3′ and from formula 1, φ+ε−μ″( Ff′+Fr′+Ff+Fr )· z/b=Ff ′·sin θ f+Fr ′·sin θ r Formula 1′ Also, from (formula 2)-(formula 4), Ff ′=( Fr′+Fr )·cos θ r /cos θ f−Ff, from formula 2, Ff′=Fr ′·cos θ r /cos θ f+h /cos θ f, and from formula 4, Ff=Fr ·cos θ r /cos θ f+h /cos θ f. Substituting these into formula 3′ and arranging gives: Fr ′ ⁢ { ( 1 + cos ⁢ θ ⁢ ⁢ r ) / cos ⁢ θ ⁢ ⁢ f } · μ ′′ · z / b + Fr ⁢ { ( cos ⁢ θ ⁢ ⁢ f + cos ⁢ θ ⁢ ⁢ r ) / cos ⁢ ⁢ θ ⁢ ⁢ f } · μ ′′ · z / b - Fr · sin ⁡ ( θ ⁢ ⁢ f + θ ⁢ ⁢ r ) / cos ⁢ ⁢ θ ⁢ ⁢ f = - h · tan ⁢ ⁢ θ ⁢ ⁢ f - ϕ + ɛ . Further, extracting the second and third expressions on the left side gives: Fr·(1/cos θf)·{(cos θf+cos θr)·μ″·z/b−sin(θf+θr) Formula 5 and arranging Fr′ gives: Fr ′ = - Fr · { b / ( μ ′′ · z ) / ( cos ⁢ ⁢ θ ⁢ ⁢ r + cos ⁢ ⁢ θ ⁢ ⁢ f ) } · ɛ - h · b · sin ⁢ ⁢ θ ⁢ ⁢ f / { μ ′′ · z ⁡ ( cos ⁢ ⁢ θ ⁢ ⁢ f + cos ⁢ ⁢ θ ⁢ ⁢ r ) } - ϕ · b · cos ⁢ ⁢ θ ⁢ ⁢ f / { μ ′′ · z ⁡ ( cos ⁢ ⁢ θ ⁢ ⁢ f + cos ⁢ ⁢ θ ⁢ ⁢ r ) } + ɛ · b · cos ⁢ ⁢ θ ⁢ ⁢ f / { μ ′′ · z ⁡ ( cos ⁢ ⁢ θ ⁢ ⁢ f + cos ⁢ ⁢ θ ⁢ ⁢ r ) } . Here, the first expression on the right side becomes −Fr·{1−b·sin(θf+θr)/(μ″·z)/(cos θr+cos θf)} Formula 6 Also, from formula 1′ and formula 5, Fr ′{(μ″· z )/ b }·(cos θ r +cos θ f )/cos θ f +sin(θ f+θr )/cos (θ r )}+ Fr (μ″· z/b )(cos θ r +cos θ f )/cos θ f=φ+ε−h ·tan θ f Formula 7 and from this formula 7, Fr =(φ−ε+ h ·tan θ f )·cos θ f /sin(θ f+θr )+2φ(μ″· z/b )(cos θ r +cos θ f )·cos θ f /sin 2(θ f+θr ), Formula 8 and substituting this formula 8 in formula 4 and solving conditions Ff≧0 gives Ff =(φ−ε− h ·tan θ r )·cos θ r /sin(θ f+θr )+2·φ(μ″· z/b )(cos θ r +cos θ f )·cos θ r /sin 2(θ f+θr ) Formula 9 On the other hand, substituting formula 8 in formula 6 and solving conditions Fr′≧0 gives Fr ′=(− h ·tan θ f +φ+ε)·cos θ f /sin(θ f+θr )−2φ(μ″· z/b )(cos θ r +cos θ f )·cos θ f /sin 2(θ f+θr ). Formula 10 Further, substituting formula 10 in formula 2 gives Ff ′=(φ+ε+ h ·tan θ r )·cos θ r /sin(θ f+θr )−2φ(μ″· z/b )(cos θ r +cos θ f )·cos θ r /sin 2(θ f+θr ) Formula 11 FIG. 15 shows data values of an embodiment of this invention in which the angles θf and θr that form a perpendicular direction of the inclined faces 84 a and 84 b of the shaft bearing 84 have been calculated from the above calculation. By calculating in the above manner, angles formed with the perpendicular direction of the two respective inclined faces 84 a , 84 b , 84 a ′ and 84 b ′ of the shaft bearings 84 and 84 ′ are determined, taking into consideration all of the factors that affect the load that acts on the guide shaft 9 from the two respective inclined faces 84 a , 84 b , 84 a ′ and 84 b ′ of the shaft bearings 84 and 84 ′. Accordingly, the inclined faces 84 a , 84 b , 84 a ′ and 84 b ′ of the shaft bearings 84 and 84 ′ do not separate from the guide shaft 9 when the carriage 8 accelerates or decelerates, and it is possible to reliably prevent the carriage 8 from rising up. Making the maximum value of the moment that acts on the carriage 8 during movement due to disturbance to be Mm(gf·mm), the loads Ff, Fr, Ff′ and Fr′ that act on the guide shaft 9 from the two respective inclined faces 84 a , 84 b , 84 a ′ and 84 b ′ of the shaft bearings 84 and 84 ′ can be made Ff ·cos {π/2−(θ f+θr )}· b/ 2>Mm Fr ′·cos {π/2−(θ f+θr )}· b/ 2>Mm Ff ′·cos {π/2−(θ f+θr )}· b/ 2>Mm Ff ·cos {π/2−(θ f+θr )}· b/ 2>Mm Thus, it is possible to set the angles θf, θr, θf′, and θr′ such that the components in the direction parallel to the face that opposes the load that acts on the guide shat 9 from the inclined faces 84 a , 84 b , 84 a ′ and 84 b ′ of the shaft bearings 84 and 84 ′ are larger than the maximum value of the moment that acts on the carriage 8 during movement due to disturbance. Accordingly, even when disturbance such as vibration acts on the inkjet printer 1 , the inclined faces 84 a , 84 b , 84 a ′ and 84 b ′ of the shaft bearings 84 and 84 ′ do not separate from the guide shaft 9 , and it is possible to reliably prevent the carriage 8 from rising up. Also, based on the relationship between the angle of one inclined face and the moment of the direction parallel to the other inclined face shown in FIG. 16 , it is possible to make the load Ff (gf) that acts on the guide shaft 9 from the front side inclined face 84 a in the shaft bearing 84 on the downstream side in the movement direction and the load Fr′ (gf) that acts on the guide shaft 9 from the rear side inclined face 84 b ′ in the shaft bearing 84 ′ on the upstream side in the movement direction, and the load Ff′ (gf) that acts on the guide shaft 9 from the rear side inclined face 84 b in the shaft bearing 84 on the downstream side in the movement direction and the load Fr (gf) that acts on the guide shaft 9 from the front side inclined face 84 a ′ in the shaft bearing 84 ′ on the upstream side in the movement direction, approximately equal. Thus, an approximately equal moment is generated at the inclined faces 84 a , 84 b , 84 a ′ and 84 b ′ of the shaft bearings 84 and 84 ′ when the carriage 8 accelerates or decelerates, and it is possible to stably move the carriage 8 . Further, it is possible to determine the angles θf and θr which the two inclined faces of the shaft bearings 84 and 84 ′ respectively form with the perpendicular direction such that abs [Δ(μ· W+ 2 ·μ′·P+μ″·T )/Δ{57.3·(θ f+θr )}]≦2 (where 57.3 (=180/π) is a coefficient for converting from rad to deg) is satisfied. Thus, as shown in FIG. 17 , because the value of sliding resistance becomes an approximately minimum value in a range where the ratio of the change in sliding resistance to the sum of the angles which the two inclined faces in the shaft bearing 84 form with the perpendicular direction is not more than two, the sliding resistance that occurs between the shaft bearing 84 and the guide shaft 9 when the carriage 8 moves can be suppressed to a low value, and it is possible to smoothly move the carriage 8 . In addition, as shown in FIG. 18A , in the shaft bearings 84 and 84 ′ disposed at two locations in the movement direction of the carriage 8 , it is possible to allow the angles θf and θr which the two inclined faces respectively form with the perpendicular direction to differ from each other. In the example shown in FIG. 18 , the angle θr which the inclined face 84 b of the rear side of one shaft bearing 84 ( FIG. 8B ) forms with the perpendicular direction is made a positive value, and the angle θr′ which the inclined face 84 b ′ of the rear side of the other shaft bearing 84 ( FIG. 8C ) forms with the perpendicular direction is made a negative value. Thus, it is possible to move the carriage 8 back and forth in a stable state even when the movement speed of the carriage 8 differs when moving forth and when moving back. FIG. 19 shows data for an embodiment of a carriage in which the angles of the inclined faces in the left and right shaft bearings 84 and 84 ′ shown in FIG. 18 are different, and in which the pressing member 82 has been omitted. In this embodiment, the load from the pressing member 82 is made 0, and the angles of the inclined faces 84 a , 84 b , 84 a ′ and 84 b ′ of the shaft bearings 84 and 84 ′ are calculated according to the method described above. In the example shown in FIG. 19 , when the acceleration is 2 G, the angle of the front side inclined face 84 a in the shaft bearing 84 on the downstream side in the movement direction is 29°, and the angle of the rear side inclined face 84 b ′ in the shaft bearing 84 ′ on the upstream side in the movement direction is −8°. Also, when the acceleration is 0.8 G, the angle of the front side inclined face 84 a in the shaft bearing 84 on the downstream side in the movement direction is 41°, and the angle of the rear side inclined face 84 b ′ in the shaft bearing 84 ′ on the upstream side in the movement direction is 7°. Accordingly, when the carriage 8 moves right at 2 G of acceleration and moves left at 0.8 G of acceleration, the angle of the front side inclined face 84 a of the right side shaft bearing 84 is made 29° and the angle of the rear side inclined face 84 b is made 7°, and the angle of the front side inclined face 84 a ′ of the left side shaft bearing 84 ′ is made 41° and the angle of the rear side inclined face 84 b ′ is made −8°. Also, in the above description, an inkjet printer provided with a carriage that is a movable member was given as an example of the image device of this invention, but this invention may also be similarly embodied with respect to other image devices, such as an image reading device.	An image device includes a movable member, a guide shaft, and a shaft bearing. The movable member moves back and forth inside the device along a guide shaft when reading or recording image information. The guide shaft includes an arc portion in at least part of a cross-section. The shaft bearing is penetrated by the guide shaft at two locations in the movement direction that differ from the center of gravity in the movable member. The shaft bearing includes two inclined faces contacted by the arc portion of the guide shaft in the cross-section. The respective two inclined faces of the shaft bearing are at an angle θf (rad) and an angle θr (rad) with the perpendicular direction. The angle θf (rad) and the angle θr (rad) satisfy the following inequality: cos {π/2−(θ f+θr )}>0.	5
CLAIM TO PRIORITY OF PROVISIONAL APPLICATION [0001] This application claims priority under 35 U.S.C §119(e)(1) of provisional application No. 60/373,665, filed Apr. 18, 2002. TECHNICAL FIELD OF INVENTION [0002] This invention relates to the field of communications. More particularly, the invention relates to novel and improved pseudorandom noise generators for generating binary sequences with an arbitrary offset delay, where said sequences are periodic, but appear random within their period. BACKGROUND OF THE INVENTION [0003] Pseudo noise sequences or PN sequences have a wide range of applications including spread spectrum communications, cryptography, coding etc. One of the uses is in wideband code division multiple access (WCDMA) communication systems. [0004] These PN sequences are commonly generated by Linear Feedback Shift Registers (LFSR), also known as a Linear Sequence Shift Register. [0005] As shown on FIGS. 1 and 2, the LFSR is comprised of an N-stage shift register, with some intervening exclusive-OR gates to program a specific PN sequence. The location of the exclusive-OR gates is determined by the defining polynomial of the circuit which in turn, determines which one of the possible sequences will be generated. [0006] Present wideband code division multiple access (WCDMA) systems are characterized by simultaneous transmission of different data signals over a common channel by assigning each signal a unique code. This unique code is matched with a code of a selected receiver to determine the proper recipient of a data signal. Base stations in adjacent cells or transmit areas also have a unique pseudorandom noise (PN) code associated with transmitted data. This PN code or Long Code is typically generated by a Linear Feedback Shift Register (LFSR), and enables mobile stations within the cell to distinguish between intended signals and interference signals from other base stations. Identification of a PN code requires the mobile station to correctly identify an arbitrary part of the received PN sequence. The identification is frequently accomplished by a sliding window comparison of a locally generated PN sequence with the received part of the PN sequence. The sliding window algorithm often requires the mobile station to efficiently calculate multiple offsets from the LFSR to match the received sequence. [0007] In another application of an LFSR, the base station typically generates a PN sequence for the forward link by a combination of one or more LFSRs 100 , 120 as in FIG. 1. The mobile unit is also generates a PN sequence for the reverse link with LFSR circuits 200 , 220 as in FIG. 2. This PN sequence is used for quadrature phase shift keyed (QPSK) reverse link transmission. This transmission requires that the PN sequence be arbitrarily shifted by the number of chips equivalent to 250 microseconds for transmitting the in-phase component and the quadrature component. This arbitrary shift may vary with data rate. SUMMARY OF THE INVENTION [0008] The invention described herein presents a number of novel architectures for efficient pseudo noise sequence generators, with a variable offset. Based on the matrix vector based PN generators, three architectures are part of the invention. These are the look ahead PN generator, a higher radix implementation of the matrix-vector architecture, and one implementing the PN generator with polynomial multiplication replacing the matrix-vector design. BRIEF DESCRIPTION OF THE DRAWINGS [0009] These and other aspects of this invention are illustrated in the drawings, in which [0010] [0010]FIG. 1 is a simplified block diagram of a linear feedback shift register of the prior art; [0011] [0011]FIG. 2 is simplified block diagram of another linear feedback shift register of the prior art; [0012] [0012]FIG. 3A is a block diagram of a PN generator circuit of the present invention; [0013] [0013]FIG. 3B is a schematic diagram of an embodiment of a matrix multiplication circuit of FIG. 3A of the present invention; [0014] [0014]FIG. 4 is a block diagram of a state generator circuit of the present invention for producing a plurality of state matrices separated by a predetermined offset; [0015] [0015]FIG. 5 is a block diagram of another embodiment of a PN generator circuit of the present invention; and [0016] [0016]FIG. 6 is a block diagram of another embodiment of a PN generator circuit of the present invention. DETAILED DESCRIPTION OF THE INVENTION [0017] Referring to FIG. 3A, there is a block diagram of a PN generator circuit that may be used to generate an N-bit PN sequence corresponding to the LFSR 220 of FIG. 2. The N-stage PN generator circuit has 2 N −1 or approximately 2.2×10 12 states. The PN generator circuit includes plural matrix generator circuits connected in series. The first matrix generator circuit receives an input state matrix S 0 on bus 300 . The last matrix generator circuit in the series produces an output state matrix S n on bus 340 . Each matrix generator circuit, for example the first matrix generator circuit, includes a matrix multiplication circuit 302 and a multiplex circuit 306 . The matrix multiplication circuit is arranged to produce a matrix product of the respective input matrix and a respective stored matrix. The multiplex circuit produces one of the input state matrix and the matrix product in response to a respective count signal on lead 308 . [0018] In operation, the output state matrix S n on bus 340 of the PN generator circuit is a matrix multiplication product of the initial state matrix S 0 on bus 300 and a stored transition matrix. Alternatively, the stored transition matrix may be included in the matrix multiplication circuit as hard-wired combinatorial logic. This matrix multiplication is preferably a modulo-2 matrix multiplication for producing a state matrix or vector that is offset or delayed from the initial state matrix by the offset value. In general, this new state S n is determined by equation [1]. S n =M n S 0 [1] [0019] The state matrix S n is offset or delayed from initial state matrix S 0 by n states of the PN sequence. The transition matrix M n is an initial transition matrix M 1 raised to the power n. This transition matrix has a form determined by the PN sequence polynomial as will be explained in detail. A maximum length of the offset value is determined by a practical length of the total PN sequence as will be described in detail. The concept of the present invention, however, may be extended to any N-bit offset value for a corresponding N-stage LFSR. The offset value c on leads 308 , 318 , 328 and 338 may be represented in binary form as shown in equation [2] n=c n−1 2 n−1 +c n−2 2 n−2 + . . . +c 1 2 1 +c 0 2 0 [2] [0020] A transition matrix for producing an arbitrary offset n from initial state S 0 is then represented by equation [3]. M n =( M 2 n−1 ) c n−1 ×( M 2 n−2 ) c n−1 × . . . ×( M 2 2 ) c 1 ×( M 2 0 ) c 0 [3] [0021] Any transition matrix having an arbitrary n exponent, therefore, may be calculated by storing the matrices of equation [3] in memory circuits of matrix multiplication circuits 302 , 312 , 322 and 332 . Any zero-value bit of the offset value, for example bit c 0 on lead 308 , produces the input state matrix S 0 at the respective output bus 310 . Alternatively, a one-value bit c 0 of the delay value on lead 308 applies the matrix product on bus 304 of the respective transition matrix and the input matrix to the respective output matrix bus 310 . This selective matrix multiplication continues at each matrix generator stage in response to the value of each respective bit of the offset signal. The final state matrix S n at bus 340 may be any arbitrary offset with respect to the input state matrix S 0 in response to the offset value. [0022] This circuit will efficiently produce a state vector having an arbitrary offset with respect to an initial state vector. Memory requirements are greatly reduced by storing only exponentially weighted matrices rather than the matrices for each desired offset. Moreover, computation time and power are minimized by use of combinatorial logic for modulo-2 matrix multiplication. [0023] [0023]FIG. 3B is a matrix multiplication circuit of the present invention that may be used with the matrix generator circuits of FIG. 3A. The matrix multiplication circuit includes n logic circuits 370 - 374 corresponding to elements of the state vector s 11 -s 1n . Each logic circuit, for example logic circuit 370 , receives row elements m 11 -m 1n of a respective transition matrix and column elements s 01 -s 0n of a respective input state matrix. The matrix multiplication circuit includes a first logic circuit 380 - 383 that performs a logical AND of corresponding row and column elements of the transition and state matrices, respectively. A second logic circuit 390 produces a logical exclusive-OR (XOR) of the multi-bit logical AND signal for each respective state matrix element s 11 . The transition matrix may be stored in a memory circuit (not shown) as previously described, thereby providing programmability. [0024] Alternatively, each element of the state output matrix might be generated by Boolean minimization. For example, the 18-bit LFSR 100 of the prior art (FIG. 1) produces a PN polynomial as in equation [4] where offset value c 7 represents feedback tap 106 . G ( x )= x 18 +c 7 x 7 +1 [4] [0025] An initial transition matrix M 1 for this PN polynomial has the form of equation [5]. The left column of the initial transition matrix includes zero elements m 0,0 -m 17,0 and a one in element m 18,0 . The I of equation [5] indicates a 17×17 square identity matrix having ones from the upper-left m 0,1 element along the diagonal to the lower-right m 17,18 element and zeros elsewhere. The 18-element vector c corresponds to coefficients of the PN polynomial of equation [4] in elements m 18,1 -m 18,18 . Only element m 18,7 corresponding to coefficient c 7 , has a non-zero value. M  I = [ 0 I 1 c ] [ 5 ] [0026] Logic equations for each element of the matrix multiplication product of FIG. 3B have the general form of equation [6]. s ( k + n ) , j = ∑ i  ∑ j  r i , j  s k , j [ 6 ] [0027] The predetermined form of the sparse transition matrix of equation [5], therefore, provides an efficient matrix multiplication circuit. A first element of the offset state vector for the PN polynomial of equation [4], for example, is simply column element s 01 , since row element m 01 is the only non-zero element in the first row of the initial transition matrix. Other matrix products are also realized with minimal logic due to the relatively sparse characteristic of each transition matrix. Thus, transition matrix storage as a hard-wired combinatorial logic circuit offers significant advantages in speed and simplicity and eliminates the need for programmable memory. [0028] Turning now to FIG. 4, there is a block diagram of a state generator circuit of the present invention for producing a plurality of state matrices separated by a predetermined count or offset. The circuit includes a state matrix generator circuit as previously described in FIG. 3A. The state matrix generator circuit receives a state-input matrix S 0 on bus 402 and a count signal c ki+j on bus 404 . The state matrix generator circuit produces-a k-bit state matrix S n on bus 410 that is delayed from the state input matrix S 0 by a number of states in the count signal. A plurality of m transition matrix multiplication circuits 406 - 408 , similar to circuits 302 , 312 , 322 and 332 (FIG. 3A), are connected in series. Each matrix multiplication matrix circuit 406 - 408 includes a transition matrix multiplication circuit having a predetermined order n. Each matrix multiplication circuit 406 - 408 produces a respective state matrix delayed from a respective state input matrix by this predetermined order. [0029] In operation, the count signal c ki+j on bus 404 is initialized at a desired offset j. This initial count signal produces m output state matrices at buses 410 , 412 and 414 . Each output state matrix is delayed from the respective input state matrix by the predetermined order n of the transition matrix M n . Index i is incremented to produce a count signal that is incremented in multiples of k from the initial offset j, where k is less than n. Thus, a sequence of m sets of state matrices are produced in parallel, each set having a predetermined offset from an adjacent set according to the order of the transition matrix M n . Each set of the sequence further includes a sequence of k-bit state matrices. This circuit is highly advantageous in producing multiple PN sequences for matching with a received signal. Minimal logic is required and parallel sets are generated in a single clock cycle. [0030] It has been shown earlier that the logic delay incurred by a single matrix multiply could be as high as log(N) XOR gates and 1 AND gate. In order to circumvent this problem it is possible instead to limit the number of matrix multiplies and instead advance the initial state being fed to the PN generator. Instead of N stages of matrix-vector multiplication as in FIG. 3, L≦N stages are “collapsed” to generate 2 L initial states. L bits of the phase offset k can then be used to select one out of these 2 L initial states. The logic delay is then reduced by L log(N); the complexity however increases to (2 L +N−L)N 2 . [0031] The block diagram in FIG. 5 shows one embodiment of a PN generator of the present invention that demonstrates this approach. The PN generator circuit includes a series of matrix generator circuits including N stages having 2 N −1 unique states. Each matrix generator unit, with the exception of the first stage 500 - 510 is similar to those previously described in detail in FIG. 3A, and function in a similar manner. [0032] The first stage matrix generator circuit receives the input state matrix S 0 on bus 500 . This bus is connected to multiplex circuit 506 , and to multiple matrix multiplication circuits 502 , 503 and others. Bus 508 replaces control line 308 in FIG. 3A to act as select control for the multiplex circuit 506 . With the above exception, detailed operation of the generator is described with FIG. 3A. [0033] The state of an LFSR, at time k, with generator polynomial, P(x) and initial state polynomial S 0 (x) can be represented as: S k ( x )=( x k S 0 ( x )) modP ( x ) [0034] As was shown with the matrix approach k can again be represented in binary form as: k= 2 (0) .k 0 +2 (1) .k 1 +2 (2) .k 2 + . . . +2 (N−2) .k N−2 +2 (N−1) .k N−1 ; 0≦k≦2 N −1 [0035] Additionally since the polynomial field has a cardinality of 2 N we have: x 2 N =(1) modP ( x ) [0036] Hence, as an alternative to the matrix approach one may implement the state update of the LFSR as: S k ( x )=( x 2 (0) k 0 .x 2 (1) k 1 .x 2 (2) k 2 . . . x 2 (N−2) k N−2 .x 2 (N−1) k N−1 ) S 0 ( x )) modP ( x ) [0037] Denoting <x,m>=x 2 m modP(x) shows that if we pre-compute and store the polynomials, <x,0>, <x.1>, <x,2>, . . . , <x,N−2>, <x,N−1> then the state update can be computed using polynomial instead of matrix multiplication. The number of polynomial multiplications required is upper bounded by N+1 and by using a tree-structured multiplication algorithm the latency of this architecture is bounded by ceil(log(N+1)) polynomial multiplications. This contrasts with a worst case latency of N matrix multiplications in the traditional serial matrix based approach. [0038] The block diagram in FIG. 5 shows one embodiment of a PN generator of the present invention that demonstrates this approach. The PN generator circuit includes a series of matrix generator circuits including N stages having 2 N −1 unique states. Each matrix generator unit is similar to those previously described in detail with FIG. 3A, with the exception that a polynomial multiplier is substituted for the matrix multipliers, and function in a similar manner. The base of the polynomial used may be hard wired, or stored in an alterable memory. [0039] [0039]FIG. 6 shows another embodiment of a PN generator of the present invention that may be used where a minimum delay is desired. By the use of higher radix representations, the delay is reduced at the expense of circuit area. For a radix 4 implementation, the offset k is given by the following equation: k =( k 00 +2 k 10 )4 (0) +( k 01 +2 k 11 )4 (1) + . . . +( k 0L +k 1L )4 (L) , k ij ε(0,1); 0≦k≦2 N −1 (9) [0040] As FIG. 6 shows, the overall structure is again very similar to the embodiment shown on FIG. 3A. There are a plurality of matrix generator circuits, each consisting of multiple matrix multipliers circuits, and a multiplex circuit. In the case of Radix 4 shown on FIG. 7, there are 3 multiplier circuits in each matrix generator circuit. This is given as an example only, as the number of multipliers is selected as a trade off between reduced delay and increased circuit area. With the exception of having multiple multiplier circuits in each matrix generator, the operation is identical to the embodiment described in detail with FIG. 3A [0041] Although the invention has been described in detail with reference to its preferred embodiments, it is to be understood that this description is by way of example only and is not to be construed in a limiting sense. Furthermore, any of the previously described embodiments may be implemented in software by a digital processor as will be appreciated by those ordinarily skilled in the art. [0042] It is to be further understood that the inventive concepts of the present invention may be embodied in a mobile communication system as well as circuits within the mobile communication system. Moreover, numerous changes in the details of the embodiments of the invention will be apparent to persons of ordinary skill in the art having reference to this description. It is contemplated that such changes and additional embodiments are within the spirit and true scope of the invention as claimed below.	The invention solves the problem of efficiently generating pseudo noise sequences with an arbitrary offset delay. Novel and improved architectures are used, based on the matrix-vector pseudo noise generators.	6
This is a continuation application of U.S. patent application Ser. No. 08/343,716 filed Nov. 22, 1994 entitled THERMOPLASTIC STRUCTURAL PIECE CONTAINING INJECTION MOLDED PORTION, now abandoned. TECHNICAL FIELD The present invention is a thermoplastic panel or piece having a resilient injection molded portion. The panel or piece of the present invention may be used in a variety of applications such as to provide sealing ends on thermoplastic panels or to create resiliently closeable passages in thermoplastic panels through which wires and other objects may be passed while maintaining an even surface appearance of the baseboard panel. Other uses include attaching one or more thermoplastic pieces together. BACKGROUND The present invention pertains generally to the field of thermoplastic constructions such as those in office furnishing and equipment, hospital and clinic furnishings, cafeteria furnishings, office partitions, etc. Office furnishings and equipment, and the like, are often put into service in environments where there is exposure to impact and abrasion, such as through heavy foot traffic, hand contact, or exposure to things in motion, such as dollies, carts, tables and chairs, wheelchairs and hospital beds. Office furnishings and equipment, and the like, are often provided with baseboards, railings and other pieces to resist or absorb impacts and scuffing, as well as to present and maintain an even and neat appearance. It is also often the case that such furnishings use trim pieces, and the like, to provide a continuous covering or finish. However, such pieces must be produced so as to be securely incorporated into the balance of the furnishing piece, such as along the top or bottom of office partitions. Accordingly, it is desirable to be able to produce a furnishing piece or panel capable of secure incorporation into a furnishing piece. To achieve these ends, it is often desirable to be able to take advantage of two or more plastic materials having different flexion and appearance qualities by combining them into an integral part. This is complicated by the fact that attempts to incorporate different materials require a secondary adhesion operation involving specialized adhesives or the injection molding of different polymers under conditions that may not allow the two materials to sufficiently adhere and/or may mar the surface or other aesthetic qualities of the part (such as through the application of heat and/or pressure). Therefore, it is an object of the present invention to provide a method of integrating dissimilar polymers to one another. It is also often desirable to be able to produce plastic composites capable of being used as sight and/or light barriers, as well as to produce products that present and maintain desirable aesthetic qualities. Also, in many instances, these pieces must be made to allow the passage of various electrical and signal transmissive wires, fiber optic cables, and the like, which are often necessary to operate office equipment such as telephones, computers, copiers, projectors, lights, etc. To this end, panels normally have been provided with holes or gaps to allow wires and cables to be passed through. However, the various potential applications of baseboard panels, their arrangement and their working environments make it difficult to predict where wire/cable access will be needed, and the size and number of wires or cables to be passed through at a given location. One of the ways of constructing a gapped baseboard panel is to extrude a relatively rigid panel of material such as a rigid PVC. These panels are then cut to a desired length and a relatively flexible polymeric material, such as a flexible PVC material, is adhered to the relatively rigid material through use of an adhesive, such as a cyanoacrylate adhesive, in a secondary hand operation. There are several problems attendant to the use of such adhesives in hand operations. One problem is that of ventilation. The adhered pieces must normally be carefully stacked to provide sufficient curing of ventilation. Also, in the case of cyanoacrylate adhesives, the vapor issuing from the curing adhesive can form a white deposit on the finished pieces, often rendering them unacceptable to the manufacturing customer. Naturally, any gaseous emissions from curing adhesive may pose a health hazard to the operator. The use of liquid adhesives in hand operations are also inefficient. Liquid adhesive can be spilled, requiring cleanup, and hand operations, even when carefully done, can lead to gaps in the alignment between the rigid and flexible portions. It is therefore more difficult to manufacture such pieces within required tolerances. Finally, the use of liquid in hand operations must rely upon the operator to dispense the appropriate amount of adhesive uniformly to be sure that a strong bond is achieved. This is often difficult to do efficiently in repetitive operations. Accordingly, it is desirable to be able to produce a baseboard panel which can accommodate, alternatively, the throughput of a small or great number of wires (or wires of a small or great diameter) or remain unused, while maintaining an even appearance and without the use of separable parts. It is also desirable to be able to produce such a furnishing panel in a continuous process without the need for secondary, post-extrusion operations (that is, a piece or panel that can be produced in a continuous in-line process). It is further an object of the present invention to produce a furnishing panel with a strong and uniform bond across the interface between the rigid and flexible portions, while eliminating the environmental hazards, inefficiencies and product objections discussed above. It is also an object of the present invention to provide an aperture covering for a piece or panel which is durable and resists the impact and flexion often occurring in high traffic environments, and the like. In view of the present disclosure and/or through practice of the present invention, other advantages and the solutions to other problems may become apparent. SUMMARY OF THE INVENTION The present invention is a method of applying a relatively flexible polymeric material onto a surface of a relatively less flexible material, typically both thermoplastic materials. As used herein, the term "relatively flexible" may include, for instance, comparative references to the flexibility as between rigid and semi-rigid materials, rigid and flexible materials, semi-rigid materials and flexible materials, etc. In this regard, the relatively flexible materials may include ethyl vinyl acetate (EVA), urethanes (such as thermoplastic polyurethanes), PVC-urethane alloys (such as those commercially available from Alpha Chemical & Plastics Corporation), alloyed vinyls, thermoplastic rubbers (TPRs) and polyester elastomers, such as Hytrel® commercially available from DuPont®. Most preferred is the polytetramethylene glycol ether type polyurethane elastomers, such as Pellethane®, commercially available from Dow Chemical Company, of which grade 2103-70A is preferred. Pellethane® was found to bond extremely well when injection molded onto a PVC substrate and gave adhesion across the length of the applied piece. The relatively more flexible polymeric material may be selected from the group consisting of those preferably having a Shore A hardness in the range of from about 60 to about 95 according to ASTM method D-2240, most preferably in the range of from about 70 to about 80 according to ASTM method D-2240. The relatively rigid polymeric material may be any extrudable material, such as those selected from the group consisting of rigid or semi-rigid PVC. Such materials may have a Shore D hardness of at least about 50 according to ASTM method D-785, preferably in the range of from about 50 to about 90 according to ASTM method D-785, preferably in the range of from about 78 to about 82 according to ASTM method D-785. The method of the present invention also includes a method for sequentially attaching an injection molded portion onto each of a series of thermoplastic parts, described more fully herein. The present invention also includes a part such as that made in accordance with the subject method. Such a part generally comprises: (1) a relatively rigid piece (which may be adapted to be attached to a furnishing piece; typically a thermoplastic material), having an application surface; and (2) a portion of a material (also typically a thermoplastic material) being relatively more flexible than the relatively rigid material, and injection molded onto the application surface of said rigid piece. The present invention more specifically includes a polymeric extrudate member having at least one resiliently sealed gap, for use as a baseboard or trim piece and the like. The polymeric extrudate comprises: (1) a first extrusion half of a relatively rigid polymeric material (such as a polyvinylchloride material) having a substantially flat first surface having a first edge; and (2) a second extrusion half of a relatively rigid polymeric material (such as a polyvinylchloride material) having a substantially flat second surface having a second edge. The first and second extrusion halves are attached to one another so as to be positioned beside one another and aligned so that the first edge is aside the second edge forming a gap. The first and second halves have inner application surfaces and outer facing surfaces. These surfaces are to be attached to an injection molded sealing member of a relatively flexible material (such as a urethane material), which is relatively more flexible than the relatively rigid material injection molded directly onto each of said first and second surfaces so as to form a resiliently closing cover over the gap. This arrangement allows the formation of a baseboard member, having a resiliently closing passage, once the first and second extrusion halves are positioned next to one another. It is preferred that the polymeric extrudate be a semi-rigid or rigid material, preferably PVC, and most preferably having a Shore D hardness in the range of from about 78 to about 82. An example of such a material is PVC Formulation 87256, commercially available from Geon Corporation. An example of a urethane material which may be used in accordance with the present invention, and which is preferred, is Pellethane®, commercially available from Dow Chemical. An example of an ethylene-vinyl acetate copolymer which may be used in accordance with the present invention is ELVAX®, commercially available from Dow Chemical. The present invention also includes a polymeric extrudate member having a resilient attachment. Such a member in accordance with the present invention in broadest terms comprises: (a) a first extrusion half of a relatively rigid polymeric material (such as a polyvinylchloride material), the first half having an attachment surface having an edge; (b) a resilient attachment member of a flexible material injection molded onto the attachment surface so that the attachment member extends beyond the edge of the attachment surface; and (c) a second extrusion half of a relatively rigid polymeric material such as a polyvinylchloride material), the second extrusion half and the attachment member adapted to engage one another whereby the first and second extrusion halves are held together so as to form an integral member. The materials which may be used for the relatively rigid and relatively flexible portions may be as given above. The present invention also includes a method of producing a polymeric extrudate member having a resiliently closing passage. The method of the present invention comprises a first step comprising the alignment of (a) a first extrusion half of a relatively rigid material (such as a polyvinylchloride material) having a substantially flat first surface having a first edge; and (b) a second extrusion half of a polyvinylchloride material having a substantially flat second surface having a second edge; such that the first and second surfaces are positioned beside one another and aligned so that the first edge is aside the second edge so as to form a gap. The first and second surfaces define an application surface and an opposite facing surface. In the second step, sealing members of a relatively more flexible material are injection molded, respectively, directly onto each of the first and second application surfaces so as to form a panel or baseboard member having a resiliently closing passage, when the first and second panels are brought together to form a gap therebetween. DESCRIPTION OF THE DRAWINGS FIG. 1 is a sectioned perspective view of a thermoplastic panel designed for use as a baseboard panel of an office partition in accordance with one embodiment of the present invention; FIG. 2 is a sectioned elevational view of the reverse side of a thermoplastic panel designed for use as a baseboard panel of an office partition in accordance with one embodiment of the present invention; FIG. 3 is a sectioned elevational view of the facing side of a thermoplastic panel designed for use as a baseboard panel of an office partition in accordance with one embodiment of the present invention; FIG. 4 is a sectioned elevational view of the facing side of two thermoplastic panels forming a portion of a baseboard panel of an office partition in accordance with one embodiment of the present invention; FIG. 5 is a perspective view of an office partition in accordance with one embodiment of the present invention; FIG. 6 is a top plan view of a thermoplastic panel designed for use as a top portion of an office partition in accordance with one embodiment of the present invention; FIG. 6a is a perspective view of the underside of the thermoplastic panel shown in FIG. 6; FIG. 7 is a sectioned perspective view of an office partition in accordance with another embodiment of the present invention; FIG. 8 is an apparatus used to perform the sequential attachment method of the present invention; and FIG. 9 is a reverse side of a facia piece of the office portion shown in FIG. 7. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The following is a detailed description of the preferred embodiment of the proposed invention which is also considered to be the best mode. FIG. 1 is a perspective view of a baseboard panel 5 in accordance with one embodiment of the present invention, showing the reverse or non-facing side 6 of polymeric panel portion 7. Polymeric panel portion 7 is preferable of a rigid or semi-rigid polyvinylchloride (PVC) material. Affixed to polymeric panel portion 7 is flexible extension piece 8 which is preferably injection molded onto surface 6 and is preferable of a urethane material. FIG. 2 shows a back view of baseboard panel 5 while FIG. 3 shows a front view of a baseboard panel 5 showing front or exposed surface 9. As can be appreciated from FIGS. 1-3, flexible extension piece 8 preferably has a cross-section with a very slight step-down which allows that portion of flexible extension piece 8 extending from polymeric panel portion 7 to be substantially flush with front surface 9. FIG. 4 is a perspective view of two baseboard panels in accordance with one embodiment of the present invention, held at approximately 90 degrees to one another. Baseboard panel 15 comprises polymeric portion 17 and flexible extension portion 18. Baseboard panel 25 comprises polymeric panel portion 27 and flexible extension portion 28. Also shown are flexible attachment tabs 19 and 29 which are used to attach baseboard panels 15 and 25 along the bottom of for instance, an office partition unit as shown in the environmental view of FIG. 5. As can be seen in FIG. 4, baseboard panels 15 and 25 are attached in sufficiently close proximity to form a gap which is substantially covered by flexible extension pieces 18 and 28 (preferably overlapping). Flexible extension portions 18 and 28 thereby form a resiliently closable passage through the baseboard made up of baseboard panels 15 and 25. As is also shown in FIG. 4, this allows for the passage through the baseboard of one or more wires, cables, tubes, or fiber optic cables, etc. An example is electrical wire 20 shown in FIG. 4. The gap formed between baseboard panels 15 and 25, i.e. gap 30, may be any appropriate width depending upon the intended application. For typical office applications, this gap may be from about 1/2inch to about 2 inches. FIG. 5 shows baseboard panels 15 and 25 affixed along the bottom of office partition panels 31 and 32, respectively. To produce a baseboard panel such as is shown in FIG. 1-3, a semi-rigid or rigid PVC material is extruded to form an appropriately sized and shaped profile which has a reverse and facing surface such as surfaces 6 and 9, respectively. As the polymeric panel portion is moved along to the end of the extruder line where it is cured, individual sections of the polymeric material are cut to the desired length. Typical of lengths for use in office applications may be in the range of from about 1/2 foot to about 8 feet. The terminal end of the cut extrudate is then guided to a position where an injection mold is placed against reverse surface 6. Flexible extension portion 8 is then injection molded in place onto the terminal end of the polymeric panel 7. Once the leading edge of the first polymeric panel has been provided with a flexible extension portion, the next panel is moved into a position such that its leading edge, and the trailing edge of the first panel, can be provided with respective flexible extension portions simultaneously. This process can then be repeated for subsequent panels, making the injection molding process more efficient. As an alternative, the extension portions may be injection molded in place by using an injection molding clamp such as Model WDH-35-S Vertical Clamp, Horizontal Injection, Insert Molding Machine, commercially available from Autojectors, Inc. of Albion, Indiana. FIG. 6 shows a top trim piece 42 for an office partition. Trim piece 42 comprises thermoplastic portion 40 and end sealing thermoplastic portion 44 injection molded onto surface 41 (see FIG. 6a) and extending therefrom Thermoplastic portion 44 also has groove 43. FIG. 6a shows the underside 41 of thermoplastic portion 40 shown in FIG. 7. FIG. 7 shows office partition 50 having wall portion 53 and top trim piece 42 shown sectioned so as to show the position of flexible portion 44 injection molded onto the underside thereof Flexible portion 44 extends from top trim piece 42 so as to be able to engage side trim piece 45 (via groove 43) to form a trim perimeter and to help to hold the trim pieces together. By virtue of being flexible, portion 44 is able to engage side trim piece 45 by side trim piece 45 being slid vertically into place (note directional arrows in FIG. 7) so as to engage groove 43 in portion 44. This can be appreciated f farther by reference to FIG. 9 which shows side trim piece 45 having lip portion 46 which engages groove 43 when side trim piece 45 is slid vertically into place. The geometric arrangement of the panel show in FIG. 7 is in accordance with that of office partitions known in the art. As can be appreciated from the present disclosure, the panel and panel arrangements of the present invention may be used for any of a wide variety of uses, such as in baseboards, along the tops, sides and bottoms of office furniture, and even for household use. Producing panels and panel arrangements for a particular application will be a matter of selecting dimensions and shapes for the rigid and flexible portions, and is within the ability of one of ordinary skill in the art. The present invention also includes a method for sequentially applying flexible polymeric portions to the surfaces at either end of a series of thermoplastic extrudate members each having lead and trailing edges and surfaces adjacent thereto. The method in broadest terms comprises the steps of: (a) aligning a first rigid thermoplastic extrudate member so as to position its leading edge in an injection mold cavity; (b) injection molding a flexible polymeric portion onto the surface of the first rigid extrudate member adjacent its leading edge; (c) transporting the first rigid thermoplastic extrudate member so as to position its trailing edge in the injection mold cavity and transporting a second thermoplastic extrudate member so as to position its leading edge in the injection mold cavity; (d) injection molding substantially simultaneously (1) a flexible polymeric portion onto the surface of the first rigid thermoplastic extrudate member adjacent its trailing edge, and (2) a flexible polymeric portion onto the surface of the second rigid thermoplastic extrudate member adjacent its leading edge; (e) transporting the first rigid thermoplastic extrudate member from the injection mold cavity, transporting the second rigid thermoplastic extrudate member so as to position its trailing edge in the injection mold cavity, and transporting a third rigid thermoplastic extrudate member so as to position its leading edge in the injection mold cavity; and (f) repeating steps (d) and (e) for subsequent rigid thermoplastic extrudate members beyond the third rigid thermoplastic extrudate member and beginning with the third rigid thermoplastic extrudate member. FIG. 8 shows an apparatus used to perform the sequential attachment method of the present invention. FIG. 8 shows the downstream end of an assembly line 60 (such as an extrusion line) adapted to support and transport a series of rigid thermoplastic polymeric pieces 61, 62 and 63. First rigid thermoplastic polymeric piece 61 has a leading edge 61a and adjacent surface (beneath injection molded portion 61c), and trailing edge 61b (beneath injection molded portion 61d). Second rigid thermoplastic polymeric piece 62 has a leading edge 62a with adjacent surface (beneath injection molded portion 62c), and trailing edge 62b with adjacent surface 62d. Third rigid thermoplastic polymeric piece 63 has a leading edge 63a and adjacent surface 63c, and trailing edge 63b with adjacent surface 63d. The polymeric pieces are moved along the shown path in direction 64 and in sequential movements so as to first place leading edge 61a and its corresponding surface (beneath injection molded portion 61c) in the upstream side of mold cavity of injection mold 65 (which is adapted to place two injection molded portions, such as portion 8 of FIG. 1) onto each of two edge surfaces of respective adjacent polymeric pieces. After the mold is raised along direction 66, the next sequential movement transports first polymeric piece 61 to a position where its trailing edge 61b (beneath injection molded portion 61d) is disposed beneath the downstream side of mold cavity of injection mold 65 while second polymeric piece 62 is positioned such that its leading edge 62 (beneath already placed injection molded portion 62c) is in the upstream side of mold cavity of injection mold 65. Injection mold 65 is then able to place injection molded portions (such as 61d and 62c) simultaneously. The subsequent movements then place sequential sets of leading/trailing edges (and their adjacent surfaces), such as edge/surface 62b/62d and edge/surface 63a/63a into the mold cavity for subsequent application of injection molded portions in like-styled steps. In light of the foregoing disclosure, it will be within the ability of one skilled in the extrusion and injection molding arts to make modifications to the present invention, such as through the substitution of equivalent materials and parts and the arrangement of parts, or the application of equivalent process steps, without departing from the spirit of the invention.	The present invention is a thermoplastic panel or piece having a resilient injection molded portion. The panel or piece of the present invention may be used in a variety of applications such as to provide sealing ends on thermoplastic panels or to create resiliently closable passages in thermoplastic panels through which wires and other objects may be passed while maintaining an even surface appearance of the baseboard panel. Other uses include attaching one or more thermoplastic pieces together.	8
BACKGROUND OF THE INVENTION The present invention relates to the decoration of bottles and the like, and more particularly to decoration of bottles by means of heat transfer labelling. Decorating systems using heat transfer labels have received widespread commercial acceptance over the last decade. Such decorating systems are typically characterized by conveyors for feeding the objects to be labelled, usually bottles; turrets for sequentially positioning the bottles at a label station; a feed mechanism for transporting labels supported by a carrier web to the labelling station; and a device for placing a label against an adjacent bottle at the labelling station. Examples of such systems appear in U.S. Pat. Nos. 2,981,432; 3,036,624; 3,064,714; 3,208,897; 3,231,448; 3,261,734; 3,313,667; 3,709,755; and 3,861,896. A problem which poses great challenges in designing apparatus for heat transfer labelling is that of the variety of containers which may be encountered in such labelling applications. It is known in the prior art to adapt the labelling apparatus for decoration of containers of a particular shape. U.S. Pat. No. 2,981,433 discloses a machine for cylindrical bottles and U.S. Pat. No. 3,208,897 discloses a machine for bottles having oval cross-sections. Apparatus of these types suffer the limitation that they are not readily adaptable to a wide variety of bottle cross-sections. U.S. Pat. No. 3,540,968, assigned to the assignee of the present invention, discloses a mechanism of a similar type as that of the present invention, for decorating articles of a noncircular shape. The apparatus is designed to maintain at a constant value the peripheral velocity of the rotating article to match that of the carrier web. This apparatus also includes the feature of controlling the location of the article's axis. This apparatus represents an ingenious solution to the problems inherent in decoration of noncircular articles, but suffers the limitation that the transfer roll is frictionally driven by the rotating article, thereby creating a probability of undesirable distortion of the labels. The use of a sprocket or gear to control article rotation, as taught in this patent, will result in a "polygon effect," wherein the label transfer has an undesirable segmented appearance. Accordingly, it is a principal object of the invention to achieve apparatus for transferring labels from a carrier web to articles having a variety of cross-sections. A related object is the provision of decorating apparatus which may be easily adapted to the requirements of a particular use. Another object of the invention is the avoidance of labelling distortions when decorating articles of unusual shapes. A related object is the coordination of a label-bearing web with the motion of an article to be labelled. A further object of the invention is the achievement of apparatus which enables precise speed control over article motion in order to match the motion of a label-bearing web. A related object is an even, distortion-free appearance of the transferred label. SUMMARY OF THE INVENTION In accordance with the above and related objects, the invention provides apparatus for transferring labels from a carrier web to the periphery of bottles and other articles, such apparatus being adaptable to a variety of article cross-sections. The apparatus of the invention is designed to maintain contact between a portion of the article periphery and the carrier web, and to ensure that the article and carrier web are moving at the same linear velocity while in contact. In accordance with one aspect of the invention, the article to be decorated is mounted in a cup which is connected to a rotatable cam. In accordance with a related aspect, the article, cup, and cam are coaxially mounted. In accordance with a further related aspect, the cam has an identical horizontal cross-section to that of the article to be labelled. The cam and article are angularly oriented in phase synchronization. In the preferred embodiment, the apparatus includes means to preorient the article prior to depositing it in the cup. In an alternative embodiment, in the case of a tapered article, the cam is profiled and oriented to reflect an average article cross-section. In accordance with another aspect of the invention, the cam contacts a cam follower, the latter being mounted coaxially with the transfer roll. In accordance with a related aspect, the rotation of the cam is controlled by a flexible elongate member. Preferably, the flexible elongate member lies in the contact plane of the cam and cam follower. In accordance with a further related aspect, the flexible elongate member moves at the same linear velocity as the carrier web. In the preferred embodiment, the flexible elongate member comprises a cable. This manner of controlling the rotation of the cam ensures that the article periphery will move at the same linear velocity as the carrier web. In an alternative embodiment, the cam rotation is controlled by a flexible steel belt or band. BRIEF DESCRIPTION OF THE DRAWINGS The above and additional aspects of the invention are illustrated in the detailed description which follows, taken in conjunction with the drawings in which: FIG. 1 is a plan view of article decorating apparatus in accordance with a preferred embodiment of the invention. FIG. 2 is a sectional elevation view of the decorator cup, transfer roll, and associated drive mechanisms of the apparatus of FIG. 1; FIG. 2A is a sectional elevation view of the decorator cup, transfer roll, and associated drive mechanisms in accordance with an alternative embodiment of the invention; FIG. 3 is a perspective view of the decorating station of the apparatus of FIG. 1, as seen from above; and FIG. 4 is a schematic view of an illustrative drive linkage for the carrier web and drive mechanisms of FIG. 2. DETAILED DESCRIPTION Reference should now be had to FIGS. 1-4 for a detailed description of the apparatus of the invention for decorating bottles and like articles. FIG. 1 gives a plan view of decorating apparatus in accordance with the preferred embodiment of the invention. Decorating apparatus 10 includes a carrier web transport 20 for advancing a label bearing carrier web 25, and for transferring labels from the carrier web 25 to articles B as disclosed, for example, in U.S. Pat. Nos. 2,990,311, 2,862,832 and 2,989,413. The apparatus additionally includes a turret assembly 30 for conveying articles to a decorating station where they are rotated into contact with the carrier web 25 in order to receive a label. The general construction and mode of operation of the labelling apparatus of the invention is similar to that of the patents cited above and, being well known, need only be outlined as follows. The carrier web 25 is fed from unwind spool 21 through a series of dancer and idler rolls to the labelling area, and is further transported therefrom to a takeup spool 23. The carrier web is fed past an applicator roller or transfer roller 27 which presses the web against the side of an article B to transfer a label from the web to the article. The carrier web transport further includes a metering roll 26, as well as a pair of shuttle rolls 28 and 29 which bracket the labelling area, utilizing the carrier web transport principle disclosed, for example, in U.S. Pat. No. 3,208,897. A drive mechanism for controlling the speed of the carrier web and commensurately controlling the rotation of articles to be labelled is discussed in detail within. Articles B are sequentially fed into turret assembly 30 from an infeed conveyor 40, which deposits each article into one of the pockets 31A-31D of the turret assembly. Once received, an article B is held between one of two gripper arms 33 and 34, which carries the article with the turret 35. A member 55 is used to push the article B into a decorator cup and to act as a centering device for the top of the article during decoration. In the case of plastic bottles the article is filled with air under pressure; this function may be effected by an inflation nozzle 55 which also acts as the centering device mentioned above. Suitable apparatus is disclosed in U.S. Pat. Nos. 3,064,714 and 3,261,734. The decorator cup 50 is molded in the same shape as the article, which may have any cross-section subject to certain limitations discussed herein. The decorator cup 50 is rotatably mounted in a swing arm assembly 60, which pivots toward and away from the transfer roll 27 in order to control the distance of the article axis from that of the transfer roll. Article B is maintained in an upright position, its axis parallel to that of transfer roll 27, in the case of articles B which have no vertical taper. In the case of tapered articles B, the housing for the carrier web transport 20 is advantageously adapted to tilt from a horizontal orientation in accordance with U.S. Pat. No. 3,139,368. In such case, the surface of the transfer roll 27 will be inclined in order to maintain contact with the inclined article surface (for example the surface of a conical article B). In this special circumstance the axes of transfer roll 27 and article B will not be parallel. The article B is pressed against the transfer roll with the carrier web 25 compressed therebetween, and the article B rotates in conjunction with decorator cup 50, its tangential velocity matching the advance of carrier web 25 during label transfer as more fully explained herein. After completion of label transfer, the article is released from the decorator cup 50 and removed on outfeed conveyor 45. FIG. 2 shows in section the decorator cup 50, transfer roll 27, and associated mechanisms for controlling their rotation as well as the location of the decorator cup. The decorator cup 50 is interconnected by a shaft 66 to a cam 70 which is coaxially mounted in order to rotate in conjunction therewith. The cam 70 has an identical horizontal cross-section to that of article B and the two should be angularly oriented in phase synchronization. With reference to FIG. 1, grippers 33 and 34 preorient articles B for this purpose prior to placing them in decorator cup 50. In the case of tapered articles B, such as conical articles of the type illustrated in U.S. Pat. No. 3,139,368, the profile and angular orientation of cam 70 preferably matches the horizontal cross-section of article B at the mean height of that portion of the articles which is to receive a label. This will result in a slight shrinking of that part of a label which is transferred to a narrower portion of the article, and slight stretching of that part of the label which is transferred to a broader article portion. Cam 70 contacts a cam follower 80, which is located directly below the transfer roll 27. Neither transfer roll 27 nor cam follower 80 are subject to translational motion. The rotation of cam 70 and cam follower 80 is regulated by a cable or series of cables 75. Cables 75 are placed so that their pitch lines will be located in the plane of the contact surface between cam 70 and cam follower 80. Cam 70 and cam follower 80 are advantageously recessed for this purpose. The peripheral velocity of the cam and cam follower therefore match the linear velocity of the cable; by this device, the peripheral velocity of the article, which has the identical cross-section to that of the cam, will match this instantaneous value. Preferably, article B has a convex periphery in order that cable 75 may effectively drive the cam 70 of identical cross-section. The advance of cable 75 is regulated in turn to correspond over time to the velocity of the carrier web 25 as further explained within. In the preferred embodiment, in which cable 75 has a constant linear velocity to match the constant speed of carrier web 25, cam 70 and article B will have a variable angular velocity. By this means, the decorator apparatus of the invention avoids the stretching or shrinking of transferred labels due to speed differentials. FIG. 2A depicts an alternative embodiment of the mechanism for controlling article rotation. In lieu of cables 75, the driving apparatus includes belts or bands 75', illustratively comprising flexible steel belts. FIG. 3 illustrates the preferred manner of mounting the decorator cup 50, wherein the cup is rotably mounted on a swing arm 60. Swing arm 60 is pivotally mounted at 61, so as to permit lateral movement of the decorator toward and away from the transfer roll 27, as shown by arcuate arrows A--A. In the preferred embodiment, swing arm 60 includes an assembly 55 for lowering a nozzle or top support into the article B. Advantageously, the nozzle of assembly 55 rotates in conjunction with article B during decoration. Swing arm 60 is attached to a spring 65 or similar tensioning member which exerts a pull toward the transfer roll and carrier web, thereby maintaining contact between cam 70 and cam follower 80. The tension created by spring 65 is advantageously combined with an adjustable setting of transfer roll 27 to cause the carrier web 25 to be compressed between transfer roll 27 and article B during labelling. The lateral movement of swing arm 60 is basically controlled by cam 70 (see FIG. 2). Due to the shape and orientation of cam 70, the axis of decorating cup 50 will be maintained over time at a distance from transfer roll 27 corresponding to the instantaneous radius of the article along the line between the axes of transfer roll 27 and article B. With reference to the schematic view of FIG. 4, the advance of cable 75 is controlled by a drive system which coordinates this advance with the means for regulating the advance of carrier web 25. Advantageously transfer roll 27 is internally driven by the carrier web drive apparatus so as to rotate at a peripheral velocity which matches the speed of carrier web 25. An illustrative drive system for cables 75 includes drum 100 coaxially mounted with drive pinion 105, driven by drive gear 110 and pinion 115, which is in turn driven by shuttle rack 120 (shown in part). Shuttle rack 120 provides a reciprocating motion C--C which matches the reciprocation of a slide 130 on which is mounted shuttle rolls 28 and 29 (see FIG. 1). During article decoration, reciprocating slide 130 provides a constant web speed and shuttle rack 120 provides an identical rate of advance of cable 75. Suitable carrier web transport apparatus is disclosed in the prior art, such as in U.S. Pat. No. 3,208,897. In this system, the shuttle roll in combination with metering roll 26 provides a constant web advance during the decorating portion of the machine cycle, with an intervening period of retarded motion or dwell in order to minimize wasted web motion. The drive system for cables 75 may be appropriately modified to reflect any changes in the carrier web transport. In an alternative embodiment of the invention, the above disclosed apparatus may be employed to provide a controlled stretching or shrinking of labels transferred from carrier web 25 to articles B. This would merely require modifying the drive apparatus of FIG. 4 to achieve a desired speed differential between cables 75 (and therefore the periphery of articles B) and carrier web 25. While various aspects of the invention have been set forth by the drawings and the specification, it is to be understood that the foregoing detailed description is for illustration only and that various changes in parts, as well as the substitution of equivalent constituents for those shown and described, may be made without departing from the spirit and scope of the invention as set forth in the appended claims.	Apparatus is disclosed for decorating the sides of bottles and similar articles having a variety of cross-sections, of the type in which a label is pressed onto the article from a carrier web while both the web and article are in motion. The apparatus includes a cam and cam follower mechanism wherein the cam is profiled in the cross-section of the article. The cam and cam follower are driven by a cable moving at the linear velocity of the carrier web in order to coordinate web advance with article rotation. The article is housed on a laterally movable swing arm during labelling to provide a variable axial location.	1
BACKGROUND OF THE INVENTION The present invention relates to air conditioning apparatus of the separated type, for cooling room air, and particularly to an air conditioning apparatus the main body of which can be simply manufactured, and the compressor and condenser of which can be easily mounted in a wall. Air conditioning apparatus for cooling room air is classified into separated and integral types, all of which include compressing means, condensing means and evaporating means. A typical example of an integral-type air conditioning apparatus is disclosed in U.S. Pat. No. 4,505,328. When a building or a house is built, an opening is made in an exteriorly facing wall of the building or the house. Air conditioning apparatus which comprises evaporating means, condensing means, compressing means, fan means and a motor is put in a cabinet, and the cabinet is mounted in the opening made in an exteriorly facing wall of the building or the house. However, air conditioning apparatus of the integral type is of great bulk and has a disadvantage in that the condensing means and motor are noisy. In order to obviate these problems of integral-type air conditioning apparatus in the prior art, air conditioning apparatus has been separated into a set of indoor apparatus components including evaporating means, and a set of outdoor apparatus components including condensing means. The indoor apparatus is installed in the room and the outdoor apparatus is installed out of the room. Even though such a separated type apparatus conventionally has reduced the bulk, the user still has had difficulty in installation and, because the outdoor apparatus components are installed out of the room, the outdoor apparatus components require a space in which to be installed, and furthermore, such external installation spoils the overall appearance of the house or the building. SUMMARY OF THE INVENTION In order to solve these problems, at least the condensing means of the compressing means and condensing means of an air conditioning apparatus is separated from the main body of the air conditioning apparatus, and mounted within an exteriorly facing wall, i.e., facing the outside. The main body of the air conditioning apparatus is connected with compressing means and condensing means mounted in the wall by connecting members and is mounted on the wall by hanging means and fixing means. Accordingly, it is an object of the present invention to prevent noise generated in compressing means of condensing means of a room air conditioner from being transferred to the interior of a room by separating these components from the main body of the air conditioner and mounting them in an exteriorly facing wall. It is another object of the invention to eliminate the requirement for mounting the outdoor apparatus components of a separated-type air conditioner, in the outdoors. It is another object of the present invention to make manufacturing and mounting of the main body of a separated-type air conditioner easy, by excluding condensing means and compressing means from it. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a longitudinal vertical cross-sectional view showing air conditioning apparatus according to a first embodiment of the present invention; FIG. 2 is a fragmentary cross-sectional view showing air conditioning apparatus according to a second embodiment of the present invention; FIG. 3 is a longitudinal vertical cross-sectional view showing air conditioning apparatus according to a third embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION A presently preferred embodiment of the invention will now be described in conjunction with the accompanying drawings. Air conditioning apparatus according to the invention is shown in FIG. 1. The apparatus includes a main body 1 which is mounted on the inside of a building wall 5, and the housing of the main body 1 has a rectangular form. An air discharging portion 11 is formed in the front face of the housing of the main body 1, and an air in-taking portion 12, for in-taking indoor air, is formed in the slanted bottom of the main body 1. Inside of the housing, an evaporating means 2 is installed behind the discharging portion 11, blowing means 7, e.g., a motor-operated fan, is installed behind the evaporating means 2, and a compressing means 3 is fixed on the horizontal bottom of the housing of the main body 1, e.g., by screws. The evaporating means 2 is connected to the compressing means 3 by piping, and the evaporator, compressor and piping together form a part of a refrigeration cycle. The opposite side of the evaporating means 2 is connected with an expansion means 10. The expansion means 10 and the compressing means 3 are extended to the outside of the main body 1 with piping, so they project a predetermined length from the upper backside of the housing of the main body 1. The projecting ends of this piping are capable of being connected with condensing means mounted in the wall, by the connecting members 6. Also, hanging means 8 for hanging the main body 1 on the inside of the wall 5 are mounted on the left and right upper corners of the back of the main body 1, and distance-holding members 9 are mounted on the left and right lower corners of the back of the main body 1. A condensing means 4 is embedded in the wall 5 and has screw-threaded fittings formed at its ends. These ends project out of the wall 5, on the indoor side, so that the condensing means can be connected via the connecting members 6, with the expansion means 10 and the compressing means 3. The condensing means 4 is made of pipe having a serpentine form. The condenser piping is laid parallel to the interior face 5" of the wall 5 and occupies a prescribed rectangular area behind the wall face 5". The laying interval between pipe runs is a predetermined length, and the pipe is embedded in the wall a distance that is 1.5 to 2.0 times the diameter of the pipe. The air conditioning apparatus according to the invention comprises expansion means 10, evaporating means 2, compressing means 3 which are mounted in main body 1, condensing means 4 which are mounted in wall 5, main body 1, and connecting members 6 by which the main body 1 is connected with the condensing means 4. The evaporating means 2, the compressing means 3, the condensing means 4 and the expansion means 10 are connected with one another, so they make refrigeration cycle. In the expansion means 10, coolant expands, so it changes to liquid of low temperature and high pressure. In the evaporating means 2, coolant absorbs heat, so it changes from liquid to gas. Coolant is supercooled and absorbs heat in the air surrounding the evaporating means 2, so the temperature of the air falls. Indoor air is in-taken in the inner side of the main body 1 by the blowing means 7 mounted on the backside of the evaporating means 2. The in-taken indoor air is heat-exchanged through the evaporating means 2, and then it is discharged to the room. As described above, the air conditioning apparatus according to the invention circulates and cools indoor air in a room with forced convention. The connecting members 6 comprise a pair of sockets 62 and nipples 61. The socket 62 is a nut having the form of a hexagon, and is coupled with the projected end of the condensing means 4 from wall face 5'. Because the nipple has a screw thread on the exterior face, which is coupled with socket 62, the socket 62 and the nipple 61 are coupled together by their own screw threads. The wall hanging member 8 is mounted on the backside of main body 1. The wall hanging member 8 is an angle bracket having the form of a "[". One side of the angle is fixed to the backside of the main body 1 by bolts; the other side of the angle has holes which are coupled with the hanging member 82 by nuts. One end of the hanging member 82 projects out of the indoor side of the wall 5 and other end of it is embedded in the wall 5. A distance-holding member 9 having the same thickness as the wall hanging member 8 is fixed to the backside of the main body 1 by bolts, and the gap between the wall 5 and the main body 1 is adjusted by tightening the bolts. In use, a gaseous coolant at high pressure and high temperature flows from the compressing means 3 to the condensing means 4, and radiates heat to the outdoor air during its passage through the condensing means 4, thereby becoming a liquid coolant at a lower temperature and high pressure. As described above, the condensing means 4 transfers heat to the wall 5, which, typically, is made of concrete, and the heat absorbed by the wall 5 is transferred in all directions along the wall 5. However, because wall surface 5' on the indoor side is preferably covered with an insulating member, heat is not transferred to the indoor side. Because heat conductivity of concrete is as low as 2×10 -4 kcal/sec.m.°C., the heat transferred to the wall is relatively small in amount and most of the heat is radiated to the atmosphere. Coolant, being gaseous in the evaporating means 2, flows to the compressing means 3 due to pumping of the compressor. In the compressing means 3, coolant is compressed by the compressing means 3, so it changes to gas in high temperature and high pressure. Gaseous coolant at high temperature and high pressure transfers heat to the wall 5, and the gaseous coolant changes to liquid at a lower temperature, and high pressure. The wall 5 radiates heat to atmosphere by radiation and convection. Refrigeration capacity of a normal air conditioning apparatus is 2,240 kcal/h. When the heat radiated per hour through the wall surface 5" in which the condensing means 4 is embedded is equal to the refrigeration capacity of conventional air conditioning apparatus, the wall area which the condensing means occupies is calculated as follows: The amount of heat radiated from the wall is related to pipe-embedding depth and pipe laying space. It is desired that pipe-embedding depth be 1.5 to 2.0 times the pipe's diameter, and pipe laying space be 3 cm, in the preferred embodiment. The equation obtained by experimentation is Q=KA(tp-t)kcal/h ##EQU1## wherein, tp=the surface temperature of the pipe, t=the temperature of exterior wall surface (normally, tp-t=5° C.), A=the area for radiating heat, a=the distance between the exterior wall surface and the exterior diameter of the pipe, b=the pipe laying space, and λ.sub.o =the heat conductivity of concrete (1.1 kcal/h). The external diameter of the pipe 5 is 1/2 inch, in the preferred embodiment. Solving the above equations on conventional air conditioning apparatus of 2,240 kcal/h, one obtains the following solution: ##EQU2## K=18.3 kcal/m.sup.2.h.°C. 2,240 kcal/h=(18.3 kcal/m.sup.2.h.°C.)A(5° C.) ∴A=25 m.sup.2 Therefore, when the air conditioning apparatus according to the invention has a refrigeration capacity of 2,240 kcal/h, its condensing means is installed in a way that it is 3 cm in depth, pipe laying space is 3 cm and it takes area 5 m in width and 5 m in length of wall surface. To improve heat radiation capacity of condensing means, the person of ordinary skill in the art related to the invention understands well that the condenser should be installed in an area that is larger than the area calculated above. As shown in FIG. 2, when the air conditioning apparatus of the invention is implemented with the pipe of condensing means 4 wound on other piping members (a water pipe, etc.), it has an improved heat efficiency, because it is then able to radiate heat through the other piping members. Another embodiment of the apparatus of the present invention is shown in FIG. 3. In the FIG. 3 embodiment, the compressing means 3 and the condensing means 4 are separated from the main body 1 and embedded in the wall 5. Because the compressing means 3 is as thick as the wall 5, it cannot be installed in the wall 5 in the same way as is the condensing means 4. Accordingly, an opening having a predetermined depth is made in the wall 5, which opening is closed towards the indoor side and open towards the outdoor side. The wall surface 5" is finished with a covering member which makes it look good. Two ends extended from the devices in the main body 1 project to a predetermined length in the backside of it. They each connect with the condensing means 4 and the compressing means 3. The air conditioning apparatus, according to the invention, has advantage in that, because compressing means and condensing means are separated from main body and mounted in a wall, its exposed volume is reduced, and the room is screened from noise generated by the compressing means and condensing means, by the wall, and the apparatus has a high heat efficiency.	In a room air conditioner, at least the condenser, and preferably both the compressor and the condenser, are separated from the main body of the air conditioning apparatus, and are mounted in an exteriorly facing wall, outside the room which is to be cooled. The main body of the air conditioning apparatus is connected with compressor and condensor mounted in the wall by connecting piping and fittings and is mounted on the wall by a hanging bracket and position-fixing spacer bracket.	5
This application is a continuation of application Ser. No. 07/996,988, filed Dec. 28, 1992, now abandoned. BACKGROUND OF THE INVENTION 1. Field of the Invention This invention relates to the elimination or reduction of appearance defects known as "measles", as defined hereinafter, in fluorescent lamps having a conductive starting aid layer or coating on the inner surface of the lamp tube or glass envelope. 2. Background of the Invention Rapid-start or similar fluorescent lamps including an internal conductive layer, such as a tin oxide or indium oxide layer, and mercury vapor as part of the discharge sustaining gas fill are subject to the formation of localized appearance defects referred to as "measles." Such defects comprise a dark spot surrounded by a concentric ring of discoloration usually on the order of one or two millimeters in diameter. Measles are believed to develop during lamp operation as a result of an interaction involving the conductive layer and the mercury in arc discharge. The mercury is presumed to penetrate the phosphor layer or coating leading to conditions which allow build-up of charge and subsequent discharge which results in the measle defect by disrupting the phosphor layer and generally forming a small crater in the glass tube. The occurrence of such appearance defects has been delayed in fluorescent lamps having a tin oxide conductive layer by varying the electrical resistance of the conductive layer along the axial length of the glass tube. More particularly, the electrical resistance profile of the conductive layer has been varied from a flat or constant value to a U-shaped or "bathtub" profile wherein a relatively low resistance value is provided at the center portion of the lamp and relatively high resistance values are provided at the end portions of the lamp. The bathtub resistance profile is difficult to control and to uniformly maintain in a commercially acceptable manner using existing production equipment and technology. The relative differences in electrical resistance along the axial length of the lamps achieved in this manner tend to decrease after about the first 500 hours of lamp operation. Moreover, the resulting variations in electrical resistance merely delay the occurrence of such defects from a time following the first 1000 hours of lamp operation to a later time after about 3000 to 4000 hours of lamp operation. This is a rather short improvement in the total life of the lamp life which is in the order of about 20,000 hours. Accordingly, this process technique does not provide a satisfactory solution to such measle defects. A variety of protective or barrier layers are known in the art for inhibiting or delaying other appearance defects characterized by darkened stains or a general discoloration of the phosphor layer and/or conductive layer. U.S. Pat. No. 3,624,444 discloses the use of a protective layer over a tin oxide conductive layer in a low pressure mercury vapor discharge lamp to inhibit black stains formed on the inner side of the glass tube. The protective layer is formed of oxides of elements of the secondary groups in columns 4 and 5 of the periodic table of elements, preferably titanium dioxide and zirconium dioxide. In U.S. Pat. No. 4,338,544, an aluminum oxide protective or barrier coating is taught to inhibit a "blackening" phenomenon on the tin oxide coating attributed to its reaction with mercury. U.S. Pat. No. 3,967,153 discloses a fluorescent lamp having an alumina layer deposited by application of a suspension of aluminum oxide over the tin or indium oxide conductive coating, with a layer of phosphor covering the alumina. U.S. Pat. No. 4,338,544 discloses a similar protective coating in a fluorescent lamp which further comprises an inert gas, such as krypton, neon or xenon, used together with mercury as the gas fill in the lamp. U.S. Pat. No. 4,363,998 likewise discloses the use of an alumina coating applied over the tin oxide coating, but also comprises the use of antimony oxide mixed with the alumina, the antimony oxide acting to improve the performance of a zinc silicate phosphor applied over the alumina-antimony oxide layer. Thus it is known in the art to employ a layer of alumina, or certain other metal oxides, as a protective layer or precoat over the layer of conductive material to prevent its discoloration and/or that of the subsequently applied phosphor materials. However, such precoats of metal oxides have not effectively prevented or reduced the occurrence of measle defects. SUMMARY OF THE INVENTION The present invention provides an improved fluorescent lamp having a protective layer or precoat comprising a particulate coating over a layer of conductive material, wherein the protective layer comprises ceria, yttria, silica or combinations thereof. The protective layer effectively prevents or reduces the occurrence of measles. These improvements are substantially maintained throughout the life of the fluorescent lamp with a lesser occurrence of measle defects irrespective of whether the resistance profile is flat or bathtub. Conductive layers presently known for use in fluorescent lamps include oxides of tin and indium. The protective layer may be used in combination with a bathtub electrical resistance profile to further enhance the improvements in suppression of measle defects. In such combinations, the improvements attributed to the bathtub profile itself are better maintained during the life of the fluorescent lamp. Presently, ceria and yttria are preferred metal oxides since they have been found to substantially suppress the occurrence of measles with or without the benefit of the bathtub resistance profile. A wide range of particle sizes may be used. Preferably, the particle is small enough to enable the formation of a particle suspension or dispersion in a fluid medium of a colloidal system for deposition onto a surface such as the internal conductive layer of the fluorescent lamp tube. Herein, such a particle is referred to as a colloidal particle. The presently preferred particle sizes have a major dimension in the range from about one nanometer to about 500 nanometers, and, more preferably in the range of from about one to about 100 nanometers, and, most preferably in the range of from one to about 50 nanometers or less. The protective layer may be applied directly to the conductive layer using conventional application techniques. Preferred application techniques involve deposition from a colloidal system wherein the particle is suspended or dispersed in an aqueous liquid medium. BRIEF DESCRIPTION OF THE DRAWING The drawing illustrates, in perspective view, a partially broken away section of a low pressure mercury discharge fluorescent lamp in accordance with the present invention. DETAILED DESCRIPTION Referring to the drawing, fluorescent lamp 1 comprises an elongate sealed glass envelope or tube 2 having an inner wall surface 2a, and having electrodes 3 at each end. The envelope 2 contains the known discharge sustaining fill comprising mercury and an inert, ionizable gas (not shown). Electrodes 3 are connected to lead wires 4 and 5 which extend through a glass seal 6 in a mount stem 7 to the electrical contacts of base 8 fixed at both ends of the sealed glass envelope and containing contact pins 11 and 12 which are electrically connected to leads 4 and 5. The inert gas will generally be argon or a mixture of argon and krypton and/or neon at a low pressure generally less than 5 or 10 torr. The inert gas acts as a buffer or means for limiting the arc current. The inner wall surface 2a is covered by a conductive layer or coating 14 which is a starting aid for the lamp 1. The conductive layer 14 is covered by a protective layer or precoat 15 which is preferably a continuous coating in order to adequately protect the conductive layer. The protective layer or precoat 15 is in turn covered by a phosphor layer or coating 16. These layers are described in greater detail below. The conductive layer 14 is preferably tin oxide, but may be formed of indium oxide or other electrically conductive materials known in the art to aid rapid starting and energy efficiency. The thickness of layer 14 may vary some along the axial length of the tube, but is generally uniform within the known technological capabilities for applying such coatings to the inner wall of glass tubes for fluorescent lamps. The thickness of the layer 14 is sufficient to provide the preselected parameters of startability and wattage consumption efficiency of the lamp. The protective layer 15 is a colloidal metal oxide which provides superior protection against measle defect formation as compared with known materials. As indicated above, the colloidal metal oxide forming the protective layer 15 comprises at least one oxide selected from the group consisting essentially of ceria, yttria, silica or a combination of these metal oxides. In a preferred embodiment, the metal oxide will be selected from the group consisting essentially of ceria, yttria or mixtures thereof. The thickness of layer 15 is within the range of thicknesses used commonly for alumina, e.g. corresponding with a bulb loading of from 20-60 mg of oxide per 48" lamp of 1 or 1.5" diameter, and is sufficient to allow only minimal defect formation in the lamp. In terms of weight per unit area, the protective layer 15 may be applied in an amount ranging from about 100 to about 750 mg/m 2 , and more preferably from about 125 to about 625 mg/m 2 . The protective layer 15 is covered with phosphor layer 16 comprising at least one phosphor material. Any phosphor known in the fluorescent lamp art is suitable for use with the present invention. The phosphor may be applied in one or more layers, and may comprise more than one phosphor as well as known phosphor performance enhancers. The coatings of the present invention may be applied by methods known in the art. Known methods for applying coatings to the inner wall 2a of envelopes 2 for fluorescent lamps include dipping in a liquid based colloidal dispersion, spraying, and by electrostatic methods. The thickness of each layer 14, 15, 16 may vary slightly over the axial length of the tube, but it is generally uniform within the known technological capabilities for applying such coatings. Each layer is applied to the full axial length of the tube. One means of applying layer 14 of conductive material is by spraying a solution of a tin oxide precursor onto the inner envelope wall surface. To that end, a spray head is inserted a small distance into one end of the tube, and from this position the entire axial length of the tube is coated with the conductive material. As a result of inherent limitations in using such spraying procedure, the conductive material layer 14 is generally slightly thicker at the end of the tube into which the spray head was inserted than at other portions of the tube. The protective layer 15 is applied by any of the known methods which can be sufficiently controlled to allow application over the conductive layer 14. Such methods include dipping, spraying, and application by electrostatic means. Preferred processes comprise flowing an aqueous colloidal suspension or dispersion of the particulate forming the layer or coating to be applied through the tube in a "down-flush" or an "up-flush" flow technique. This colloidal dispersion or suspension may be custom made, or may be obtained commercially, e.g. from Nyacol Products, Inc., Ashland, Mass., under the tradename "NYACOL". The quantity of colloidal metal oxide layer 15 applied is preferably sufficient to achieve a continuous coating, as opposed to a discontinuous coating, in order to provide adequate protection and will generally be substantially the same as that of known compounds for protective coatings, e.g., alumina. The phosphor layer 16 may be applied over the layer 15 by any of the known methods of applying such materials. The phosphor material may be any such material known in the art. Upon completion of the application of layers 14, 15 and 16, the manufacture of the lamp 1 continues in a known conventional manner. The invention is further illustrated in the following non-limitative example. EXAMPLE The following experimental protocol was designed to follow closely the standard, conventional practices in the art of fluorescent lamp production. In a standard one inch diameter, four foot long glass tube used in the manufacture of fluorescent lamps, a layer of conductive tin oxide was deposited by the standard spraying method. Next, covering this layer, a layer of colloidal metal oxide particles was applied by the down-flush process over the first layer. The colloidal metal oxides used in this example are shown in the Table below. The colloidal metal oxide was applied at an approximate weight of 20-60 mg/bulb. Following the metal oxide layer, a layer of phosphor material was applied over the protective layer. The glass tube was then subjected to further conventional manufacturing processes used in production of fluorescent lamps. The lamps thus produced were tested by operating at standard conditions for the indicated time periods, with the results shown in the Table. As indicated, control lamps having an alumina protective layer and comparative lamps having a zirconia protective layer were included in the tests. TABLE______________________________________Precoat Particle Resistance Burn MeaslesMaterial Size (nm) Profile Time Rating______________________________________alumina 50-100 flat 3000 hr <5alumina 50-100 bathtub 5000 hr 5yttria 10 flat 5000 hr 8yttria 10 bathtub 5000 hr 10ceria 10 flat 3000 hr 10silica 50 flat 3000 hr 5silica 50 bathtub 3000 hr 9silica 20 flat 3000 hr 5silica 20 bathtub 3000 hr 9zirconia 50 flat 3000 hr <5zirconia 50 bathtub 3000 hr <5______________________________________ The "measles rating" ranges from 1 to 10, and it is based on a subjective evaluation of the population of the "measles" defects. A rating of 5 or lower is unacceptable, while a rating of 10 indicates no measles formation at all, for the indicated test period. A rating of at least 8 is desired to make the lamp commercially acceptable. The resistance profile, shown in the Table, refers to the variation in electrical resistance of the conductive tin oxide layer along the axial length of the lamp, and has been referred to as either "flat" or "bathtub" in the art. The flat resistance profile has no substantial variation in electrical resistance along the axial length of the lamp. In the bathtub profile, each of the end portions (e.g. axially outboard 12 inch lengths in a four foot long bulb) of the lamp has a much higher resistance than that of the center portion of the lamp. The bathtub profile is more resistant to measles formation than is the flat profile, but the bathtub is much more difficult to achieve in production. As shown by the test results, ceria, yttria and silica provide improved measle ratings as compared with alumina and zirconia. In addition, these metal oxides may be used in combination with a bathtub electrical resistance profile to further enhance the improvements in suppression of measle defects.	A protective layer or precoat of a metal oxide for an internal conductive layer in a rapid-start fluorescent lamp is formed of yttria, ceria or silica to suppress the occurrence of localized appearance defects referred to as measles. The protective layer may be used in combination with conductive layers having a uniformly flat profile or a U-shaped bathtub profile to further enhance the suppression of measle defects. The lamp retains the desirable qualities of good startability and energy efficiency while at the same time avoiding the undesirable measle appearance defects.	7

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