Patent Publication Number: US-8534655-B2

Title: Quick action woodworking vise

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
     This application claims priority to Provisional Patent Application No. 61/396,221, filed May 24, 2010, the entire disclosure of which is hereby incorporated by reference and relied upon. 
    
    
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     A work holder including two or more jaws movable with respect to each other, and more particularly a screw-less, quick-action vise assembly. 
     2. Related Art 
     Woodworking workbenches have traditionally employed a vise or vises for gripping workpieces. The vises utilized have taken many different forms which suit a wide array of woodworking tasks. Face vises, mounted on the front or long face of the workbench may be in the form of a twin screw face vise with the screws coupled by a chain or where the screws are independent. They also take the form of cast iron Emmert style vises which have pivoting jaws to accept tapered or irregular shaped work or the quick action Record style of vise which typically have a central screw combined with two laterally displaced guide rods. Another form of face vise is the leg vise which utilizes a screw mounted in one of the workbench legs with a vertically displaced fulcrum arm which accepts a peg installed in a hole to match the thickness of the work being secured. Face vises may also be in the form of the Scandinavian style shoulder vise which has a vise screw installed in a bench block mounted at the end of the bench and typically supported by an additional leg. The vise jaw is open to three sides so it has the ability to clamp work that would be difficult to clamp in the other style of vises. 
     Vises may also be found mounted to the end of the bench in the form of a tail vise. Typically the tail vise includes a dog which may be used to clamp work flat on the bench top between a corresponding bench dog mounted in various holes in the top of the bench. Many of the previously described face vises may be mounted on the end of the bench to function as a tail vise. The twin screw vise for example may be mounted on the end of the bench and be the same width as the bench top. If provisions are made in the vise jaw to accept bench dogs then the vise can function as a tail vise and still operate as a face vise mounted in the end or tail vise position. 
     All of the aforementioned vises excel at some tasks and have deficiencies which have to be overcome. Twin screw vises offer drop through clamping of large objects without racking since pressure is applied on both sides of the workpiece. The chain operated twin screw vise may have an external chain which detracts from the aesthetics of the work bench. The chain operated twin screw vises do not have quick action and have to be laboriously cranked in and out. The screws also require grease to work freely which may soil the workpiece if contacted. Independent operated twin screw vises also do not have quick action and require each screw to be operated while maintaining a grasp on the workpiece with the operators other hand. The iron style face vises may have quick action and are easy to install but the central screw and guide rods prevent drop through clamping. The vise jaws may rack if the work is not centered and the quick action nut may clog with dirt and sawdust preventing proper action. Some vises require the actuation of a lever to enable quick action which makes them difficult to operate and the screw requires grease which may soil the workpiece. Leg vises excel at clamping work to the front face of the bench and have great holding power due to the long fulcrum arm. They do not have quick action and a peg must be moved in the fulcrum arm each time a different thickness workpiece is clamped. The fulcrum arm is very near the floor and requires considerable bending to change. The Scandinavian style shoulder vise requires the vise to be designed into the bench since it requires an additional leg. They do not have quick action and the bench block and vise screw extending outward from the front of the bench can be awkward to move around. Traditional tail vises are aesthetically pleasing and work well but they are very difficult to install, do not have rapid action and may sag when extended. 
     Typically, all screw actuated vises operate with clockwise rotation of the clamp handle which ergonomically speaking may not be ideal for all operators. Left-handed people in particular may find that clockwise operation is not the best direction of rotation for them. 
     Screw-less, or so-called clutch-type, vises have been proposed as alternatives to the aforementioned traditional screw-type vise. Screw-less vises are, by nature, quick-acting in that the vise jaws can be quickly opened and closed with a pushing or pulling force on the vise handle. These type of vises commonly utilize one or more clutch plates that smoothly slide along an elongated clamp shaft when held in a perpendicular orientation. Partial rotation of the vise handle turns a helical ramp that is positioned to interact with the clutch plate. Relative movement between the helical ramp and clutch plate causes the clutch plate to tip away from perpendicular and grip the clamp shaft. Continued rotation of the vise handle then draws the vise jaws together into engagement with a work piece. Examples of screw-less vises may be seen in U.S. Pat. Nos. 831,919 to Abernathy, 1,283,192 to Hughes, 1,439,822 to Johnson, 2,415,303 to Moore, and 4,057,239 to Hopf et al. In all of these examples, the clutch plate is fashioned as a non-circular member constrained to a particular orientation relative to the shaft. As a result, the clutch plate and shaft do not rotate relative to one another, thus causing the clutch and/or shaft to wear unevenly over time. Furthermore, the helical ramp feature common to the prior art screw-less vises is relatively expensive to manufacture, limits the clamping direction to a single direction (typically CW), and makes the vise assembly relatively unsuitable for use in multi-shaft, i.e., ganged, scenarios found in many woodworking vise applications. 
     SUMMARY OF THE INVENTION 
     According to a first aspect of this invention, a screw-less vise assembly is provided of the type for clamping a workpiece between opposing jaws. The assembly comprises a housing and a pair of jaws. At least one of the jaws is moveable relative to the housing and moveable relative to the other the jaw. An elongated clamp shaft defined a long axis and is slideably carried by the moveable jaw and the housing. The clamp shaft includes a clamp hub that is engagable with the moveable jaw. A locking element is supported by the housing and has a generally planar body. The locking element includes also a central hole in the body through which the clamp shaft slideably extends. A wedge is supported relative to the housing. A bridge is operatively disposed between the wedge and the locking element for reciprocating linear movement in a plane generally parallel to and offset from the axis of the clamp shaft in response to rotation of the clamp shaft. The bridge is configured to angularly displace the locking element into canted frictional engagement with the clamp shaft and then, with continued rotation of the clamp shaft, to axially displace the clamp shaft thereby forcibly drawing the moveable jaw toward the housing and the other the jaw. 
     The reciprocating linear bridge of this invention provides several advantages over prior art designs that lead to a more robust, more easily manufactured, and more versatile vise assembly. 
     According to another aspect of this invention, a twin shaft vise assembly if provided for clamping a workpiece between opposing jaws. The assembly comprises a pair of jaws and first and second clamping sub-assemblies. At least one of the jaws is moveable relative to the other the jaw. The first clamping sub-assembly comprises a first housing and an elongated first clamp shaft defining a long axis. The first clamp shaft is slideably carried by the moveable jaw and the first housing. A first locking element is supported by the housing. The first locking element has a generally planar body and a central hole in the body through which the first clamp shaft slideably extends. A first wedge is supported relative to the first housing. A first bridge is operatively disposed between the first wedge and the first locking element for reciprocating linear movement in a plane generally parallel to and offset from the axis of the first clamp shaft in response to rotation of the first clamp shaft. The first bridge is configured to angularly displace the first locking element into canted frictional engagement with the first clamp shaft and then, with continued rotation of the first clamp shaft, to axially displace the first clamp shaft thereby forcibly drawing the moveable jaw toward the other the jaw. The second clamping sub-assembly comprises a second housing and an elongated second clamp shaft defining a long axis. The second clamp shaft is supported parallel to the first clamp shaft. A second locking element is provided having a generally planar body and a central hole in the body through which the second clamp shaft slideably extends. A second wedge is supported relative to the second housing. A second bridge is operatively disposed between the second wedge and the second locking element for reciprocating linear movement. A motion transmitting member interconnects the first bridge and the second bridge for simultaneously displacing the first bridge and the second bridge in response to rotation of at least one of the first and second clamp shafts. 
     According to a still further aspect of this invention, a method is provided for clamping a workpiece between opposable jaws in a screw-less vise assembly. The method comprises the steps of providing a pair of jaws, at least one of the jaws being moveable relative to the other the jaw, and slideably and rotatably supporting an elongated clamp shaft through the moveable jaw. A locking element is slideably supported on the clamp shaft. A wedge is provided. A bridge is located between the wedge and the locking element. The method includes slideably supporting the bridge for reciprocating linear movement, and angularly displacing the locking element into canted frictional engagement with the clamp shaft in direct response to rotation of the clamp shaft. The method further includes axially displacing the clamp shaft with continued rotation of the clamp shaft thereby forcibly drawing the moveable jaw toward the other jaw. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       These and other features and advantages of the present invention will become more readily appreciated when considered in connection with the following detailed description and appended drawings, wherein: 
         FIG. 1  is a perspective view of a first embodiment showing the vise of the present invention configured as a face or end vise with two handles, with the workbench top, rear vise jaw and moveable front vise jaw shown in phantom for clarity. 
         FIG. 2  is a partial right section view of a first embodiment of the vise of the present invention taken along line  2 - 2  in  FIG. 1 . 
         FIG. 3  is a partial perspective exploded view of a first embodiment of the vise of the present invention showing the clamp shaft assembly to the clamp hub through the moveable front vise jaw shown in phantom for clarity. 
         FIG. 4  is a partial perspective exploded view of a first embodiment of the vise of the present invention showing the mechanism which provides clamping action. 
         FIG. 5  is a perspective illustrative view of a first embodiment of the vise of the present invention which shows the relationship of the locking element to the clamp shaft when the clamp shaft is rotated. 
         FIG. 6  is a perspective illustrative view of prior art locking elements which shows the relationship of the locking element to the clamp shaft when the clamp shaft is rotated. 
         FIG. 7  is a partial top plan view of a first embodiment showing the vise of the present invention in the unclamped state and configured for clamping by clockwise rotation of the clamp handle. 
         FIG. 8  is a partial top plan view of a first embodiment showing the vise of the present invention in the unclamped state and configured for clamping by counter-clockwise rotation of the clamp handle. 
         FIG. 9  is a partial rear illustrative view of a first embodiment showing the vise of the present invention and the relationship of applied handle force to the centerline of the clamp shaft. 
         FIG. 10  is a partial plan illustrative view of a first embodiment showing the vise of the present invention, with the bridge in the clamped position shown in phantom lines, which shows the direction of the clamping force, the angle of the wedge and bridge and the direction of motion during clamping. 
         FIG. 11  is a partial perspective exploded view of a second embodiment of the vise of the present invention configured as a single handle vise showing the clamp shaft assembly to the clamp hub through the moveable front vise jaw shown in phantom for clarity. 
         FIG. 12  is a partial perspective exploded view of a second embodiment of the vise of the present invention showing the mechanism which provides clamping action. 
         FIG. 13  is a perspective view showing a third embodiment of the vise of the present invention configured as a face or end vise with two handles and a swivel front jaw, with the workbench top, rear vise jaw and moveable front vise jaw shown in phantom for clarity. 
         FIG. 14  is a partial perspective exploded view of a third embodiment of the vise of the present invention showing the clamp shaft assembly to the clamp hub through the moveable front vise jaw. 
         FIG. 15  is a partial horizontal section view showing a third embodiment of the vise of the present invention and showing the moveable front vise jaw in a swiveled position. 
         FIG. 16  is a partial front illustrative view of a third embodiment of the present invention showing the swivel mechanism in the unlocked position. 
         FIG. 17  is a partial front illustrative view of a third embodiment of the present invention showing the swivel mechanism in the locked position. 
         FIG. 18  is a partial perspective exploded view of a fourth embodiment of the vise of the present invention configured as a single handle swivel jaw vise showing the clamp shaft assembly to the clamp hub through the moveable front vise jaw. 
         FIG. 19  is a perspective view of a fifth embodiment of the vise of the present invention configured as a leg vise with the moveable front vise jaw, bench leg and partial bench top shown in phantom for clarity. 
         FIG. 20  is a partial perspective exploded view of a fifth embodiment of the vise of the present invention showing the clamp shaft assembly to the clamp hub through the moveable front leg vise jaw shown in phantom for clarity. 
         FIG. 21  is a partial right side view showing a fifth embodiment of the vise of the present invention in the unclamped state and configured for clamping by clockwise rotation of the clamp handle. 
         FIG. 22  is a partial right side view showing a fifth embodiment of the vise of the present invention in the unclamped state and configured for clamping by counter-clockwise rotation of the clamp handle. 
         FIG. 23  is a perspective view showing a sixth embodiment of the vise of the present invention configured as a shoulder vise with the moveable front shoulder vise jaw, fixed rear vise jaw and partial bench top shown in phantom for clarity. 
         FIG. 24  is a partial perspective exploded view of a sixth embodiment of the vise of the present invention showing the clamp shaft assembly to the clamp hub through the moveable front shoulder vise jaw and rear fixed vise jaw shown in phantom for clarity. 
         FIG. 25  is a partial top plan view showing a sixth embodiment of the vise of the present invention in the unclamped state and configured for clamping by clockwise rotation of the clamp handle. 
         FIG. 26  is a partial top plan view showing a sixth embodiment of the vise of the present invention in the unclamped state and configured for clamping by counter-clockwise rotation of the clamp handle. 
         FIG. 27  is a perspective view showing a seventh embodiment of the vise of the present invention configured as an enclosed tail vise. 
         FIG. 28  is a partial perspective view showing a seventh embodiment of the vise of the present invention with the partial bench top and apron shown in phantom for clarity. 
         FIG. 29  is a partial perspective exploded view showing a seventh embodiment of the vise of the present invention. 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     Referring to the figures wherein like numerals indicate like or corresponding parts throughout the several views, with reference to  FIGS. 1-4 , the vise  10  of the present invention is shown in a preferred twin-shaft variation comprising first and second clamping sub-assemblies working in tandem. Among the several of the described embodiments utilizing twin shafts, components of the second clamping sub-assembly can be distinguished from components of the first clamping sub-assembly either by the use of prime designations or by the introduction of new reference numbers. It should be understood, however, that the invention may be practiced in single-shaft applications, and well as three-shaft (or more) applications due to its novel modular construction. One exemplary single-shaft embodiment is shown in  FIGS. 27-29 , with many other alternative expressions of a single-shaft design possible. Three-shaft (or more) applications will be appreciated by those skilled in the art in view of the following detailed descriptions. 
     Returning to  FIGS. 1-4 , the twin-shaft vise  10  includes two clamp shafts  12  and  12 ′ which are parallel to one another and have a keyway along most of their length and slide freely through the flanged plain bearings  47  and  47 ′ located in front holes in housings  11  and  11 ′ and through pinions  16  and  16 ′, locking elements  17  and  17 ′, through springs  20  and  20 ′, through washers  43  and  43 ′ and through flanged plain bearing  47  and  47 ′ located in the rear holes of housings  11  and  11 ′. Flanged plain bearings  47  and  47 ′ may, for example, be constructed of an ultra high molecular weight polyethylene material to provide low friction to prevent stick-slip and provide good durability. The flanged plain bearings  47  and  47 ′ may alternatively be made of Acetal, Polytetrafluoroethylene, Bronze or any other suitable material depending on the application. Generally speaking the further apart the clamp shafts  12  and  12 ′ are spaced the lower the friction coefficient must be for the material used in flanged plain bearings  47  and  47 ′ in order to avoid binding. Clamp shafts  12  and  12 ′ are prevented from being pulled out of housings  11  and  11 ′ by retaining rings  24  and  24 ′ which are housed in grooves machined near the ends of clamp shafts  12  and  12 ′. Clamp shafts  12  and  12 ′ are preferably constructed of mild carbon steel and are case hardened to provide a wear resistant surface, eliminate the need for oil lubrication and allow locking elements  17  and  17 ′ to securely grab clamp shafts  12  and  12 ′ as described later. 
     Housings  11  and  11 ′ are securely and distally mounted to the underside of a typical workbench top  46  using lag screws (not shown) or other appropriate fasteners, fastened through the mounting holes and slots provided in housings  11  an  11 ′. Housings  11  and  11 ′ may be constructed of ductile cast iron to provide strength, and may be formed as a unitary structure rather than as separate members in cases where the spacing between shafts  12 ,  12 ′ is predetermined. Pins  28  and  28 ′ are preferably press fit into corresponding holes in transfer bar  18  and pins  28  and  28 ′ fit freely into suitable holes in racks  15  and  15 ′ thus allowing racks  15  and  15 ′ to freely rotate about pins  28  and  28 ′. Racks  15  and  15 ′ engage pinions  16  and  16 ′ through rectangular holes in bridges  13  and  13 ′. Transfer bar  18  is allowed to freely move while being constrained between the workbench top  46  and the housings  11  and  11 ′. 
     The transfer bar  18  is depicted here in a preferred embodiment in the form of a solid member constructed of sturdy bar stock. However, other configurations are certainly possible in order to achieve a motion transmitting member that interconnects the first  13  and second  13 ′ bridges for simultaneously displacing these bridges  13 ,  13 ′ in response to rotation of either the first clamp shaft  12  or the second clamp shaft  12 ′. For example, the transfer bar  18  could be replaced with a flexible motion transmitting core element that is slideably supported in a flexible conduit. Such an alternative construction would enable custom spacing between clamp shafts  12 ,  12 ′ without changing the length of the motion transmitting member. Of course, many other variations are also possible. 
     With reference to  FIGS. 1 ,  2  and  3 , clamp shaft  12  passes through a clearance hole in fixed rear vise jaw  45 , wave spring  21  and washer  43  and through a circular hole and horizontal slot each bored part way through moveable front vise jaw  44  and into a close fitting bored hole in clamp hub  36 . Retaining ring  24  is installed in a groove machined in clamp shaft  12  and retains wave spring  21  against clamp shaft  12 . Clamp shaft  12  is securely affixed to clamp hub  36  by split pin  25  installed through a hole perpendicular to the close fitting bored hole in clamp hub  36  and into the cross hole in clamp shaft  12 . Washer  43  fits tightly into the bored hole and has enough clearance to clamp shaft  12  to allow clamp shaft  12  to swivel slightly (approximately 2° for example) within the close fitting slot. Thus washer  43  locates moveable front vise jaw  44  laterally but allows moveable front vise jaw  44  to swivel slightly to accept slightly tapered work. Similarly, clamp shaft  12 ′ passes through a clearance hole in fixed rear vise jaw  45 , wave spring  21 ′ and washer  43 ′ and through a large circular hole and horizontal slot each bored part way through moveable front vise jaw  44  and into a close fitting axially bored hole in clamp hub  36 ′. Retaining ring  24 ′ is installed in a groove machined in clamp shaft  12 ′ and retains wave spring  21 ′ against clamp shaft  12 ′. The horizontal slot in moveable front vise jaw  44  is very close fitting in the vertical direction to help stabilize moveable front vise jaw  44  when a workpiece is clamped high in the moveable front vise jaw  44  or dogs are utilized in moveable front vise jaw  44  for clamping work on the bench top. Wave springs  21  and  21 ′ apply spring pressure between retaining rings  24  and  24 ′ installed in grooves in clamp shafts  12  and  12 ′ and through washers  43  and  43 ′ and into the rear face of moveable front vise jaw  44  pulling clamps hubs close to the front face of moveable front vise jaw  44 . 
     The combination of the horizontal slot in moveable front vise jaw and the spring action from wave springs  21  and  21 ′ give compliance in the moveable front vise jaw  44  to allow moveable front vise jaw  44  to swivel slightly (approximately 2° for example) so that slightly tapered or irregular workpieces may be effectively secured. In addition, this compliance allows for wood movement in the bench top  46 , especially if vise  10  is located in the end position which would typically have higher expansion and contraction due to cross grain. Further, the compliance in moveable front vise jaw  44  allows for clamps shafts that are not perfectly parallel and also takes up tolerance between the clamp hubs  36  and  36 ′ so all clamping action is directed towards clamping, creating quicker clamping action (generally within 45° of handle movement). Clamp shaft  12 ′ is securely affixed to clamp hub  36 ′ by split pin  25 ′ installed through a hole perpendicular to the close fitting bored hole in clamp hub  36 ′ and into the cross hole in clamp shaft  12 ′. Handles  34  and  34 ′ slide within each clamp hub  36  and  36 ′ perpendicular to the longitudinal axes of clamp shafts  12  and  12 ′ and retained by knobs  35  and  35 ′. 
     To facilitate ease of construction of moveable front vise jaw  44  and fixed rear vise jaw  45 , a centrally located hole is provided in the end of clamp shafts  12  and  12 ′ to allow the use of blind hole spotter  33  as shown in  FIG. 2 . With the blind hole spotter  33  installed in the centrally located hole of clamp shaft  12  or  12 ′, the clamp shaft  12  or  12 ′ may be slid forward to mark the clamp shaft  12  or  12 ′ center location into moveable front vise jaw  44  and fixed rear vise jaw  45 , greatly simplifying the hole and slot locations and simplifying construction of vise  10 . 
     With reference to  FIGS. 2 and 4 , keys  26  and  26 ′ slide freely in keyways in shafts  12  and  12 ′ and in corresponding keyways in pinions  16  and  16 ′ and transmit rotational movement of shafts  12  and  12 ′ into pinions  16  and  16 ′ while allowing translational movement of shafts  12  and  12 ′ into and out of housings  11  and  11 ′. Bridges  13  and  13 ′ have a centrally located rectangular hole which fits freely around pinions  16  and  16 ′ and racks  15  and  15 ′ and have one working edge which is perpendicular to the longitudinal axes of clamp shafts  12  and  12 ′ and an opposite working edge which is skewed at a slight angle relative to the straight working edge. The angled working edges of each bridge  13  and  13 ′ are in contact with the identically angled edges of wedges  14  and  14 ′ which are free to move longitudinally in pockets in housings  11  and  11 ′ but are constrained from moving laterally. The edges of bridge  13  and  13 ′ that are perpendicular to clamp shafts  12  and  12 ′ are in contact with locking elements  17  and  17 ′. 
     Racks  15  and  15 ′ freely fit into the rectangular hole of bridges  13  and  13 ′ and engage pinions  16  and  16 ′. Racks  15  and  15 ′ may be machined with a very small lip on each end to better locate racks  15  and  15 ′ vertically in the rectangular hole in bridges  13  and  13 ′, otherwise racks  15  and  15 ′ are held in vertical location by pinions  16  and  16 ′ and the close lateral fit of racks  15  and  15 ′ within the rectangular hole of bridges  13  and  13 ′. The rectangular hole in bridges  13  and  13 ′ keep pinions  16  and  16 ′ in alignment with racks  15  and  15 ′ by nesting pinions  16  and  16 ′ and racks  15  and  15 ′ within the rectangular hole and converts the lateral motion of racks  15  and  15 ′ into longitudinal motion by means of the wedging action created by the angled edges of wedges  14  and  14 ′ acting against the corresponding angled edges of bridges  13  and  13 ′. Bridges  13  and  13 ′ also function to limit the rotation of pinions  16  and  16 ′ in order to prevent pinions  16  and  16 ′ from running off the end of racks  15  and  15 ′ by contacting the pinions  16  and  16 ′ teeth at the end of travel. Bridges  13  and  13 ′ may be constructed of low carbon steel and case hardened to eliminate galling between bridges  13  and  13 ′ and wedges  14  and  14 ′ and between bridges  13  and  13 ′ and locking elements  17  and  17 ′. In one contemplated but not illustrated embodiment, the bridges  13 ,  13 ′ could be integrated with their respective racks  15 ,  15 ′, however there is some advantage to manufacturing them as loose piece components. The pinions  16 ,  16 ′ are shown in a preferred, fully formed design. However those of skill will appreciate that each pinion could be formed with as few as one tooth or cam that interacts between a single pair of teeth or a slot in the racks  15 ,  15 ′. Alternatively still, the clamp shafts  12 ,  12 ′ and bridges  13 ,  13 ′ could be mechanically joined through a pivoting linkage or some other form of operative connection. 
     In this embodiment, rotary motion from clamp shaft  12  is transferred to pinion  16  through key  26  and is converted to translational motion by means of rack  15  which is engaged with pinion  16 . The translational motion of rack  15  is transferred to rack  15 ′ through pins  28  and  28 ′ which are press fit into transfer bar  18 . The translational motion from rack  15 ′ is converted back to rotary motion by means of pinion  16 ′ which is engaged with rack  15 ′. The rotary motion from pinion  16 ′ is transferred to clamp shaft  12 ′ through key  26 ′. In this way, clamp shafts  12  and  12 ′ are thus allowed to operate in unison when clamping and the motion of all elements contained in housings  11  and  11 ′ occur simultaneously and in synchronicity. 
     Transfer bar  18  may be fashioned to any specific length to give the desired center to center distance of clamp shafts  12  and  12 ′ and correspondingly any desired length of moveable front vise jaw  44 . It will be apparent to those skilled in the art that transfer bar  18  may also be constructed so as to be adjustable in length by use of bolted connections, multiple mounting holes or other suitable means. 
     In the unclamped state, bridges  13  and  13 ′ are positioned by racks  15  and  15 ′ at their shortest longitudinal width against wedges  14  and  14 ′ at their shortest longitudinal width allowing locking elements  17  and  17 ′ to contact release adjusting screws  23  and  23 ′ by means of spring pressure from springs  20  and  20 ′ bearing against housing  11  and  11 ′ and locking elements  17  and  17 ′. The springs  20 ,  20 ′ act as biasing members urging the body of the locking elements  17 ,  17 ′ each toward a generally perpendicular orientation relative to the axes of their respective clamp shafts  12 ,  12 ′. In alternative embodiments, the springs  20 ,  20 ′ could be replaced with other types of biasing members, such as Belleville washers, leaf springs, extension springs, torsion springs, or any other suitable devices. As can be seen in  FIG. 4 , the locking elements  17 ,  17 ′ each have a generally planar body and a central hole in their body through which the respective clamp shaft  12 ,  12 ′ slideably extends. Locking elements  17  and  17 ′ are thus held perpendicular to clamp shafts  12  and  12 ′ allowing clamp shafts  12  and  12 ′ to freely pass through locking elements  17  and  17 ′ and therefore moveable front vise jaw  44 , which is fixed to clamp shafts  12  and  12 ′, is free to be positioned against the workpiece whether square or slightly tapered. 
     Once moveable front vise jaw  44  is positioned against a workpiece, clamping begins as follows: rotation of handle  34  is transferred through clamp hub  36  into split pin  25  and into clamp shaft  12  and again transferred to pinion  16  through key  26  and its corresponding keyway in pinion  16  and clamp shaft  12 . Rotation of pinion  16  is transferred into linear motion by engaging rack  15  which causes bridge  13  to translate identically. As the angled edge of bridge  13  translates against the corresponding angled edge of wedge  14  it is forced rearward against locking element  17  on a line which is radially displaced from the center of locking element  17  thus creating a moment about the center of locking element  17  and causing it to lock onto clamp shaft  12 . Further rotation of handle  34  and thus clamp shaft  12  causes clamp shaft  12  to displace rearward to enable clamping. The motion transfer from transfer bar  18 , previously described, causes identical clamping action to occur in clamp shaft  12 ′ through identical movements of rack  15 ′, pinion  16 ′, bridge  13 ′ and locking element  17 ′. Clamping may be initiated by rotation of either clamp handle  34  or  34 ′. 
     Locking elements  17  and  17 ′ translate longitudinally with their respective shaft  12 ,  12 ′ while maintaining a planar relationship with bridges  13  and  13 ′ by rotating about shafts  12  and  12 ′ while locking elements  17  and  17 ′ are simultaneously locking against shafts  12  and  12 ′ as depicted in  FIG. 5 . The use of soft low carbon steel in locking elements  17  and  17 ′ combined with case hardened steel in clamp shafts  12  and  12 ′ allow locking elements  17  and  17 ′ to securely grip clamp shafts  12  and  12 ′ even though there is relative movement between clamp shafts  12  and  12 ′ and locking elements  17  and  17 ′. 
     The unique motion and combination of case hardened steel in clamp shafts  12  and  12 ′ and soft low carbon steel in locking elements  17  and  17 ′ of the current invention allows the locking elements  17  and  17 ′ to transmit the rotational clamping force and the translational clamping motion without being keyed to the shaft and without requiring a helical ramp or other complicated means used in prior art. The motion of locking elements  17  and  17 ′ allow the centrally located hole and the periphery of locking elements  17  and  17 ′ to be circular, greatly simplifying construction. Since locking elements  17  and  17 ′ rotate freely about clamp shafts  12  and  12 ′, locking elements  17  and  17 ′ wear evenly about the entire circumference of the hole in locking elements  17  and  17 ′ thereby increasing the durability of the part significantly. In contrast, prior art locking elements do not have relative motion between the locking element and the shaft. Instead, they typically require flats or other suitable means machined into the shaft and locking element so that the locking element and shaft turn in unison. 
     Synchronization and fine tune adjustment of the clamping action between the corresponding clamp shafts  12  and  12 ′ is accomplished by means of clamp adjusting screws  22  and  22 ′ which are threaded into housings  11  and  11 ′ and bear against wedges  14  and  14 ′. By threading the clamp adjusting screws  12  and  12 ′ in or out, wedges  14  and  14 ′ are advanced or retracted against bridges  13  and  13 ′ which in turn are advanced or retracted against locking elements  17  and  17 ′. This adjustment causes the clamping action to be respectively advanced or delayed which allows the two clamp shafts to be precisely and simply synchronized. The clamp adjusting screws  22  and  22 ′ also allows compensation for wear and tolerances in manufacturing. An additional benefit of clamp adjusting screws  22  and  22 ′ is that by retracting the screws significantly the maximum clamping force may be reduced to allow clamping of delicate or fragile workpieces. When clamp adjusting screws  22  and  22 ′ are advanced or retracted, locking elements  17  and  17 ′ may not release from clamp shafts  12  and  12 ′ properly due to the altered angular relationship of locking element  17  and  17 ′ to clamp shafts  12  and  12 ′. 
     A generally perpendicular relationship of locking elements  17  and  17 ′ to clamp shafts  12  and  12 ′ is required to unlock locking elements  17  and  17 ′ from clamp shafts  12  and  12 ′. To allow for proper release of locking elements  17  and  17 ′, release adjusting screws  23  and  23 ′ are threaded into housings  11  and  11 ′ and contact locking elements  17  and  17 ′ at their periphery. Release adjusting screws  23  and  23 ′ are advanced against locking elements  17  and  17 ′ when in the unclamped state until locking elements  17  and  17 ′, with the aid of spring pressure from springs  20  and  20 ′, release from clamp shafts  12  and  12 ′ by attaining a perpendicular relationship to clamp shafts  12  and  12 ′. Jam nuts  32  and  32 ′ are tightened against housings  11  and  11 ′ to prevent release adjusting screws  23  and  23 ′ from inadvertently moving after they are adjusted. 
     Vise  10  can be configured to clamp with clockwise rotation of clamp handles  34  and  34 ′ or with counter-clockwise rotation of clamp handles  34  and  34 ′. When bridges  13  and  13 ′ and wedges  14  and  14 ′ are oriented as shown in  FIG. 7 , clockwise (CW) rotation R 1  or R 2  of clamp handle  34  or  34 ′ enables clamping forces F 1  and F 2  to be applied to clamp shafts  12  and  12 ′ and translational force F 3  to be applied through transfer bar  18 . To configure vise  10  to clamp with counter-clockwise (CCW) rotation of clamp handles  34  and  34 ′, bridges  13  and  13 ′ and wedges  14  and  14 ′ are simply removed from housings  11  and  11 ′ rotated 180° about a longitudinal axis and re-installed into housings  11  and  11 ′ as depicted in  FIG. 8 . Counter-clockwise (CCW) rotation R 3  or R 4  of clamp handle  34  or  34 ′ enables clamping forces F 3  and F 4  to be applied to clamp shafts  12  and  12 ′ and translational force F 5  applied through transfer bar  18 . In other words, the bridges  13 ,  13 ′ are preferably selectively invertible relative to their respective racks  15 ,  15 ′. This simple inversion process allows the entire vise assembly  10  to be changed from a CW closing to a CCW closing configuration (and vice versa) which could be helpful for right-handed vs. left-handed operators or depending up in the set-up of the vise  10  for particular operations. Similarly, the bridges  13 ,  13 ′ and cooperating wedges  14 ,  14 ′ can be re-oriented to the opposite side of the housings  11 ,  11 ′ to cause the jaws to operate with a spreading motion rather than a clamping motion in response to continued rotation of the clamp shafts  12 ,  12 ′. 
     With reference to  FIGS. 9 and 10 , the clamping force C, handle force F, and total clamp travel T, may be changed in vise  10  by changing the angle α of the contacting surfaces between bridges  13  and  13 ′ and wedges  14  and  14 ′ and by changing the number of teeth on racks  15  and  15 ′. The clamp force C and total clamp travel T for angle α of wedges  14  and  14 ′ and bridges  13  and  13 ′ and for number of rack teeth Nr of racks  15  and  15 ′ may be determined from the following formulas: 
             C   =       (     Fd   p     )     ⁢   COTAN   ⁢           ⁢   α           
and:
 
             T   =       β   ⁡     (       π   ⁢           ⁢   r     180     )       ⁢   TAN   ⁢           ⁢   α           
where:
 
     C=Clamping force applied through clamp shafts  12  and  12 ′ and moveable front vise jaw  44  to clamp workpiece. 
     F=Handle force applied at distance d from clamp shafts  12  or  12 ′ centerline to point of force application on Handle  34  or  34 ′. 
     d=Distance from clamp shafts  12  or  12 ′ centerline to point where handle force F is applied on handle  34  or  34 ′. 
     p=Pitch line radius of pinions  16  and  16 ′. 
     α=Angle of contacting surfaces of bridges  13  and  13 ′ and wedges  14  and  14 ′ relative to a perpendicular line to the longitudinal axes of shafts  12  and  12 ′. 
     T=Total clamp travel distance of clamp shafts  12  and  12 ′ when clamp handle  34  or  34 ′ is rotated through the maximum allowed angular rotation β. 
     β=Maximum angular rotation of clamp handle  34  or  34 ′. The maximum rotation of clamp handle  34  or  34 ′ is limited by the number of teeth on racks  15  and  15 ′ and the number of teeth on pinions  16  and  16 ′ and may be calculated from the following formula: 
             β   =       [       (       N   r     -   1     )     ⁢     (     360     N   p       )       ]     -       COS     -   1       ⁡     (       r   -   0.049     r     )               
where:
 
     N r =Number of teeth on racks  15  and  15 ′ 
     N p =Number of teeth on pinions  16  and  16 ′ 
     r=Outside radius of pinions  16  and  16 ′ 
     Assuming handle force F remains constant, as angle α is decreased clamp force C increases and total clamp travel T decreases. Correspondingly as angle α is increased, clamp force C decreases and total clamp travel T increases. Assuming handle force F remains constant, vise  10  can thereby be configured, by increasing angle α on bridges  13  and  13 ′ and wedges  14  and  14 ′, to clamp highly compressible materials with more total clamp travel T and less clamp force C applied to moveable front vise jaw  44  and thus less clamp force applied to the workpiece being clamped. Vise  10  may also be configured, by decreasing angle α on bridges  13  and  13 ′ and wedges  14  and  14 ′, to clamp highly dense materials with less total clamp travel T and more clamp force C applied to moveable front vise jaw  44 . Total clamp travel T may be increased by adding teeth to racks  15  and  15 ′ effectively lengthening racks  15  and  15 ′. Adding teeth to racks  15  and  15 ′ increases the maximum angular rotation of clamp handles  34  and  34 ′ and thus increases total clamp travel T. Total clamp travel T may be decreased by subtracting teeth from racks  15  and  15 ′ effectively shortening racks  15  and  15 ′. Subtracting teeth from racks  15  and  15 ′ decreases the maximum angular rotation of clamp handles  34  and  34 ′ and thus decreases total clamp travel T. 
     The structure of a second embodiment shown in  FIGS. 11-12  is functionally similar to that of  FIGS. 1-10 . Reference numerals for functionally identical structure carry suffix “a” in  FIGS. 11-12 . 
     In this arrangement, a single clamp handle  34   a , clamp hub  36   a  and knobs  35   a  is utilized. This configuration may be necessary when the center to center distance of clamp shafts  12   a  and  50  are close enough in proximity to interfere with each other and hinder operation of vise  10 . All structure associated with clamp shaft  12   a  is substantially identical to structure detailed previously in the first embodiment. Since a single handle only is used in this embodiment, clamp shaft  50  is constructed without a keyway or a cross hole and has two distally spaced grooves machined into the forward most area of clamp shaft  50 . The rearmost groove of clamp shaft  50  accepts retaining ring  24   a ′. Wave spring  21   a ′ bears against retaining ring  24   a ′ and applies spring pressure through washer  43   a ′ and against the rear face of compliance ring  49 . Clamp shaft  50  protrudes slightly through compliance ring  49  and is retained with retaining ring  24   a ′ installed in the forward most groove machined in clamp shaft  50 , bearing against the forward most washer  43   a ′. Compliance ring  49  is installed into a circular pocket milled into single handle moveable front vise jaw  60  and secured with wood screws  48 . A decorative cover plate  61  may be fastened to single handle moveable front vise jaw  60  with wood screws  48  to provide an attractive appearance. Compliance ring  49  allows the high clamping forces of vise  10  to be applied directly to single handle moveable front vise jaw  60  and not through screws or other means which may fail under load. The slot milled into compliance ring  49  also provides compliance to single handle moveable front vise jaw  60  in the same manner as described in the first embodiment. 
     With reference to  FIG. 12 , clamp shaft  50  does not rotate and thus does not require a pinion  16 , key  26 , or rack  15  as described in the first embodiment. Spacer  75  is installed on shaft  50  between front flanged plain bearing  47   a ′ and locking element  17   a ′ to retain front flanged plain bearing  47   a ′. Spacer  75  may be constructed of plastic such as Polyvinyl chloride and with a sliding clearance to allow rotation and translation. Since a rack  15  as described in the first embodiment is not required with clamp shaft  50 , bridge  59  is constructed with a reamed hole to accept pin  28   a ′ instead of a rectangular hole. Bridge  59  is allowed to freely rotate about pin  28   a ′. in all other aspects, bridge  59  is similar to bridge  13   a . All rotational clamping motion is applied through clamp shaft  12   a ; the motion of clamp shaft  50  is translational only. All clamping and release functions are identical to the first embodiment. Clamp shaft  50 , clamp hub  36   a , handle  34   a  and knobs  35   a  may be positioned on the right or left side of single handle moveable front vise jaw  60 . 
     The structure of a third embodiment shown in  FIGS. 13-17  is functionally identical to that of  FIGS. 1-10 . Reference numerals for functionally identical structure carry suffix “b” in  FIGS. 13-17 . 
     In this configuration, moveable front vise jaw  72  is able to swivel to enable tapered objects or irregular shaped objects such as carvings or guitars while maintaining good contact between clamp hubs  36  and  36 ′ and moveable front vise jaw  72 . With reference to  FIGS. 13 ,  14  and  15 , clamp shaft  12   b  passes through a clearance hole in moveable front vise jaw  72  and through swivel base  38 , wave spring  21   b , lock ring  37  and swivel ring  39  and into clamp hub  36   b . Similarly, clamp shaft  12   b ′ passes through a clearance hole in moveable front vise jaw  72  and through compensator base  40 , wave spring  21   b , washer  43   b  and compensator ring  41  and into clamp hub  36   b ′. Compensator base  40  and swivel base  38  are rigidly mounted within circular pockets in moveable front vise jaw  72  using wood screws  27  and  27 ′. When mounted, compensator base  40  and swivel base  38  are flush with the outer surface of moveable front vise jaw  72 . Each clamp hub  36   b  and  36   b ′ is fixed on the end of its respective clamp shaft  12   b  and  12   b ′ with spring pins  25   b  and  25   b ′ or other appropriate means. Handles  34   b  and  34   b ′ slide within each clamp hub  36   b  and  36   b ′ perpendicular to the longitudinal axes of clamp shafts  12   b  and  12   b ′ and retained by knobs  35   b  and  35   b′.    
     Clamp shaft  12   b  passes through a circular hole in swivel ring  39  and is allowed to freely rotate. Lock ring  37  is held in firm contact with swivel ring  39  by spring force from wave spring  21   b  acting against retaining ring  24   b  which is housed within a groove in clamp shaft  12   b . Clamp hub  36   b  is allowed to freely rotate against swivel ring  39  and is kept in close contact by spring force from wave spring  21   b . Two pivot pins  42 , coaxially located on either side of clamp shaft  12   b , pass through holes in swivel ring  39  and swivel base  38 . Pivot pins  42  are retained on the outside by the circular pocket in moveable front vise jaw  44  and on the inside by clamp shaft  12 . Once mounted swivel ring  39  stands proud of the front face of moveable front vise jaw  44  so that when moveable front vise jaw  72  is swiveled a prescribed arc in either direction, clamp hub  36   b  does not contact the front face of moveable front vise jaw  72  as depicted in  FIG. 15 . 
     With reference to  FIG. 16 , when lock ring  37  is rotated until stop tab  2  contacts horizontal member of swivel base  38 , openings in lock ring  37  align with swivel stops  4  on swivel base  38  allowing swivel base  38  and moveable front vise jaw  72 , since it is firmly affixed to swivel base  38 , to freely swivel about pivot pins  42  in either direction. The swivel angle is limited (for example, to 10° arc) by swivel stops  4  on swivel base  38  contacting the bottom of machined pockets in swivel ring  39 . 
     With reference to  FIG. 17 , when lock ring  37  is rotated until stop tab  3  contacts the horizontal member of swivel base  38 , the openings in lock ring  37  are not aligned with swivel stops  4  on swivel base  38  thus preventing swivel base  38  and moveable front vise jaw  72  from swiveling. Thus moveable front vise jaw  72  is held essentially parallel to fixed rear vise jaw  45  to allow more control when clamping square work. Moveable front vise jaw  72  is not held firmly parallel to fixed rear vise jaw  45  and is allowed a small degree of movement (for example, 1° arc) so that slightly tapered work may be clamped firmly without the need to rotate lock ring  37  to the unlocked free swivel position. It may be apparent to those skilled in the art that swivel stops  4  could be replaced with set screws threaded into holes in swivel base  38  thus allowing adjustment of movement of moveable front vise jaw  72  when lock ring  37  is rotated to prevent swiveling of moveable front vise jaw  72  as described previously. 
     With reference to  FIGS. 13 ,  14  and  15 , clamp shaft  12   b ′ passes through a slot in compensator ring  41  and is allowed to freely rotate and translate laterally within the confines of the aforementioned slot. Compensator ring  41  is held in firm contact with clamp hub  36   b ′ by spring force from wave spring  21   b ′ acting against retaining ring  24   b ′ which is housed within a groove in clamp shaft  12   b ′. Two pivot pins  42 ′, coaxially located on either side of clamp shaft  12   b ′, pass through holes in compensator ring  41  and compensator base  40 . Pivot pins  42 ′ are retained by press fit into appropriately sized holes in compensator ring  41 . Once mounted, compensator ring  41  stands proud of the front face of moveable front vise jaw  72  so that when moveable front vise jaw  72  is swiveled an arc limited by contact of swivel ring  39  to swivel base  38  as described previously, clamp hub  36   b ′ does not contact the front face of moveable front vise jaw  72 . When moveable front vise jaw  72  is swiveled in either direction about pivot pins  42 , clamp shaft  12   b ′ is allowed to translate within the slot in compensator ring  41  thus allowing for the arc created by moveable front vise jaw  72 . The slot in compensator ring  41  also allows for any variation in distance between housings  11   b  and  11   b ′ caused by any seasonal wood movement in bench top  46 . 
     The structure of a fourth embodiment shown in  FIG. 18  is functionally identical to that of  FIGS. 1-10 . Reference numerals for functionally identical structure carry suffix “c” in  FIG. 18 . 
     In this configuration, moveable front vise jaw  72  is able to swivel identically to the previous embodiment of  FIGS. 13-17  and a single clamp handle  34   c , clamp hub  36   c  and knobs  35   c  is utilized. This configuration may be necessary when the center to center distance of clamp shafts  12   c  and  50   c  are close enough in proximity to interfere with each other and hinder operation of vise  10 . All structure associated with clamp shaft  12   c  is identical to structure detailed previously in the previous embodiment of  FIGS. 13-17 . Since a single handle only is used in this embodiment, clamp shaft  50   c  is constructed without a keyway or a cross hole and has two distally spaced grooves machined into the forward most area of clamp shaft  50   c  as previously described in the second embodiment of  FIGS. 11-12 . Clamp shaft  50   c  passes through a clearance hole in moveable front vise jaw  72   c  and through compensator base  40   c , wave spring  21   c ′, washer  43   c ′ and single handle compensator ring  76 . The rear most groove of clamp shaft  50   c  accepts retaining ring  24   c ′. Wave spring  21   c ′ bears against retaining ring  24   c ′ and applies spring pressure through washer  43   c ′ and against the rear face of single handle compensator ring  76 . Clamp shaft  50   c  protrudes slightly through single handle compensator ring  76  and is retained with retaining ring  24   c ′ installed in the forward most groove machined in clamp shaft  50   c , bearing against washer  43   c ′. Compensator base  40   c  is rigidly mounted within a circular pocket in moveable front vise jaw  72   c  using wood screws  27   c ′. When mounted, compensator base  40   c  is slightly lower than the outer surface of moveable front vise jaw  72   c.    
     Clamp shaft  50   c ′ passes through a slot in single handle compensator ring  76  and is allowed to freely rotate and translate laterally within the confines of the aforementioned slot. Single handle compensator ring  76  is held in firm contact with washer  43   c ′ by spring force from wave spring  21   c ′ acting against front retaining ring  24   c ′ which is housed within a groove in clamp shaft  50   c . Two pivot pins  42   c ′, coaxially located on either side of clamp shaft  12   c ′, pass through holes compensator base  40   c  and into holes in single handle compensator ring  76 . Pivot pins  42   c ′ are retained by a press fit into the appropriately sized holes in single handle compensator ring  76 . Once mounted, single handle compensator ring  76  remains within the front face of moveable front vise jaw  72  whether swiveled fully or not, so that the entire assembly may be concealed by decorative cover plate  61  mounted to moveable front vise jaw  72   c  with wood screws  27   c . When moveable front vise jaw  72   c  is swiveled in either direction about pivot pins  42   c ′, clamp shaft  50   c  is allowed to translate within the slot in single handle compensator ring  76  thus allowing for the arc created by moveable front vise jaw  72   c . The slot in single handle compensator ring  76  also allows for any variation in distance between housings  11   c  and  11   c ′ (not shown) caused by any seasonal wood movement in bench top  46 . 
     The structure of a fifth embodiment shown in  FIGS. 19-22  is functionally identical to that of  FIGS. 1-10 . Reference numerals for functionally identical structure carry suffix “d” in  FIGS. 19-22 . 
     In this configuration, vise  10  is constructed as a leg vise where clamping of the workpiece is done above clamp shaft  12   d . In a typical leg vise the lower fulcrum arm is held immobile by a pin inserted in a hole in the fulcrum arm and pressed against the workbench leg while the upper vise screw is tightened causing the upper portion of the vise jaw to secure the workpiece. In this arrangement vise  10  is mounted vertically as show in  FIG. 19  and the lower housing  11   d ′ is rotated 180° relative to the upper housing  11   d . In this way, the upper clamp shaft  12   d  will pull moveable leg vise jaw  53  inward toward workbench leg  58  while clamp shaft  50   d  will push moveable leg vise jaw  53  outward from workbench leg  58  when handle  34   d  is rotated, thus creating a net inward force applied above clamp shaft  12   d  to effect clamping. 
     With respect to  FIG. 19  the elements contained in housings  11   d  and  11   d ′ are identical to the elements previously described in  FIG. 12  for a single handle vise with the only difference being that housing  11   d ′ is rotated 180° relative to housing  12   d . Both housings  11   d  and  11   d ′ are firmly mounted to the inside face of bench leg  58  with bolts, screws or other suitable fasteners (not shown). Workbench leg  58  is constructed of suitably sized wood securely fastened together in the form of a “U” section to provide needed stiffness and to conceal housings  11   d  and  11   d ′ for aesthetic reasons. Transfer bar  18   d  and elements contained within housings  11   d  and  11   d ′ are contained on one side by the rightmost inner side of workbench leg  58  in a similar fashion as previously described in the configuration of  FIGS. 1-10 . The upper clamp shaft  12   d  protrudes through a clearance hole in the front member of workbench leg  58  and lower clamp shaft  50   d  also protrudes through a clearance hole in the front member of workbench leg  58 . 
     With reference to  FIG. 20  upper clamp shaft  12   d  passes through moveable leg vise jaw  53  and is secured to clamp hub  36   d  with split pin  25   d  installed through cross hole in clamp hub  36   d  and upper clamp shaft  12   d . Clamp hub  36   d , handle  34   d , knobs  35   d , washer  43   d , wave spring  21   d  and retainer  24   d  function identically to the first embodiment previously described in  FIG. 3 . Lower clamp shaft  50   d  passes through compliance ring  49   d , washer  21   d  and wave spring  43   d  with retaining ring  24   d ′ installed in the forward most groove machined in lower clamp shaft  50   d  to retain compliance ring  49   d  from coming off the end of lower clamp shaft  50   d . Compliance ring  49   d  is retained on the other side by washer  21   d ′ and retaining ring  24   d ′ installed in a second groove slightly rearward of the forward most groove. Compliance ring  49   d  is securely installed, with the slot oriented vertically, in a circular pocket machined in moveable leg vise jaw  53  with wood screws  48   d . The use of compliance ring  49   d  allows for easy assembly and preserves the appearance of the front face of moveable leg vise jaw  53  since all mounting hardware is hidden on the rear side of moveable leg vise jaw  53 . Compliance ring  49   d  also provides compliance to moveable leg vise jaw  53  in an identical fashion to the first embodiment described in  FIGS. 1-10 . Contained in a pocket and very near the floor, in the lower most portion of moveable leg vise jaw  53  is a wheel  56  mounted on axle  55 . Springs  54  mounted in holes on both sides of wheel  56  apply downward pressure on axle  55  which is retained from falling out of moveable leg vise jaw  53  by split pins  57  installed in holes under axle  55 . Spring pressure from springs  54  push against axle  55  and thus cause wheel  56  to apply pressure against the floor which counteracts the weight of moveable leg vise jaw  53  so moveable leg vise jaw  53  is easy to move in and out when in the unclamped state. 
     As mentioned above, vise  10  can be configured to clamp with clockwise rotation of clamp handle  34   d  or with counter-clockwise rotation of clamp handle  34   d . When bridges  13   d  and  59   d  and wedges  14   d  and  14   d ′ are oriented as shown in  FIG. 21 , CW rotation R 1  of clamp shaft  12   d  enables clamping force F 1  to pull upper clamp shaft  12   d  in toward workbench leg  58 , creating translational force F 2  to be applied through transfer bar  18   d  which creates fulcrum arm force F 3  to push lower clamp shaft  50   d  away from workbench leg  58 . Transfer bar  18   d  rotates slightly about pins  28   d  and  28   d ′ since the movements of clamp shafts  12   d  and  50   d  are 180° out of phase. To configure vise  10  to clamp with CCW rotation of clamp handle  34   d , bridges  13   d  and  59   d  and wedges  14   d  and  14   d ′ are simply removed from housings  11   d  and  11   d ′ rotated 180° about a longitudinal axis and re-installed into housings  11   d  and  11   d ′ as depicted in  FIG. 22 . Counter-clockwise rotation R 2  of clamp shaft  12   d  enables clamping force F 4  to pull upper clamp shaft  12   d  in toward workbench leg  58 , creating translational force F 5  to be applied through transfer bar  18   d  which creates fulcrum arm force F 6  to push lower clamp shaft  50   d  away from workbench leg  58 . Transfer bar  18   d  rotates slightly about pins  28   d  and  28   d ′ since the movements of clamp shafts  12   d  and  50   d  are 180° out of phase. 
     The structure of a sixth embodiment shown in  FIGS. 23-26  is functionally identical to that of  FIGS. 1-10 . Reference numerals for functionally identical structure carry suffix “e” in  FIGS. 23-26 . 
     In this arrangement, vise  10  is constructed as an adaptation of a Scandinavian shoulder vise where clamping of the workpiece is done to the right of clamp shaft  12   e . In a typical Scandinavian shoulder vise the vise screw is held in a cantilevered arm mounted to a vise block which is firmly attached to the workbench top. In this arrangement vise  10  is mounted horizontally under bench top  46   e  as show in  FIGS. 23 and 24  and the left most housing  11   e ′ is rotated 180° relative to the right most housing  11   e . In this way, the right most clamp shaft  12   e  will pull moveable shoulder vise jaw  51  inward toward fixed rear shoulder vise jaw  52  while left most clamp shaft  50   e  will push moveable shoulder vise jaw  51  outward from rear fixed shoulder vise jaw  52  when handle  34   e  is rotated, thus creating a net inward force applied to the right of clamp shaft  12   e  to effect clamping. The operation and function of this configuration is identical to that of the arrangement of  FIGS. 19-20  except vise  10  is mounted horizontally under workbench top  46   e , clamp shafts  12   e  and  50   e  protrude through clearance holes in rear fixed shoulder vise jaw  52  and the workpiece is clamped to the right of right clamp shaft  12   e . It will be apparent to those skilled in the art that vise  10  may also be mounted to the right end of workbench top  46   e  with clamp shaft  12   e  to the left of clamp shaft  50   e  and the workpiece clamped to the left of clamp shaft  12   e.    
     As in previous embodiments, the vise  10  can be configured to clamp with CW rotation of clamp handle  34   e  or with CCW rotation of clamp handle  34   e . When bridges  13   e  and  59   e  and wedges  14   e  and  14   e ′ are oriented as shown in  FIG. 25 , CW rotation R 1  of clamp shaft  12   e  enables clamping force F 1  to pull right most clamp shaft  12   e  in toward rear fixed shoulder vise jaw  52 , creating translational force F 2  to be applied through transfer bar  18   e  which creates fulcrum arm force F 3  to push left most clamp shaft  50   e  away from fixed rear shoulder vise jaw  52 . Transfer bar  18   e  rotates slightly about pins  28   e  and  28   e ′ since the movements of clamp shafts  12   e  and  50   e  are 180° out of phase. To configure vise  10  to clamp with CCW rotation of clamp handles  34   e , bridges  13   e  and  59   e  and wedges  14   e  and  14   e ′ are simply removed from housings  11   e  and  11   e ′ rotated 180° about a longitudinal axis and re-installed into housings  11   e  and  11   e ′ as depicted in  FIG. 22 . Counter-clockwise rotation R 2  of clamp shaft  12   e  enables clamping force F 4  to pull right most clamp shaft  12   e  in toward rear fixed shoulder vise jaw  52 , creating translational force F 5  to be applied through transfer bar  18   e  which creates fulcrum arm force F 6  to push left most clamp shaft  50   e  away from fixed rear shoulder vise jaw  52 . Transfer bar  18   e  rotates slightly about pins  28   e  and  28   e ′ since the movements of clamp shafts  12   e  and  50   e  are 180° out of phase. In an alternative implementation of this sixth embodiment, not shown in the drawings, the counter-acting movement of the first and second clamping sub-assemblies that work to angularly displace the jaws  51 ,  52  could be employed in a portable hand-screw clamp type of device with similar effectiveness. 
     The structure of a seventh embodiment shown in  FIGS. 27-29  is functionally identical to that of  FIGS. 1-10 . Reference numerals for functionally identical structure carry suffix “f” in  FIGS. 27-29 . 
     In this configuration, vise  10  is constructed in a shingle-shaft design as an adaptation of a tail vise where clamping of the workpiece is done on top of workbench top  74  between jaws in the form of a workbench dog  69  and moveable tail vise dog  64  as shown in  FIG. 27 . Tail vise dog  64  slides on a dovetail machined into dog block  63  allowing tail vise dog  64  to slide up and down to accommodate different thicknesses of work and can be fully retracted below the surface of workbench top  74  when not in use. Tail vise dog  64  and dog block  63  are located within a narrow slot machined through workbench top  74 . Workbench dog  69  may be installed in spaced holes to accept varying lengths of work clamped between workbench dog  69  and tail vise dog  64 . Movement of dog block  63  and tail vise dog  64  to effect clamping is accomplished by rotating handle  34   f  with associated knobs  35   f  which causes rotation of clamp hub  36   f  which is located outside of tail vise apron  70  which is firmly affixed to workbench top  74 . 
     With respect to  FIGS. 28 and 29 , clamp shaft  12   f  is held at one end by a close fit clearance hole in pillow block bearing  67  which is securely mounted to the underside of workbench top  74  with screws or other appropriate fasteners (not shown). The other end of clamp shaft  12   f  is contained within a close fitting clearance hole bored into tail vise apron  70 . Clamp shaft  12   f  is thus allowed to freely rotate within the confines of the close fitting clearance holes in pillow block bearing  67  and tail vise apron  70 . Clamp shaft  12   f  is prevented from sliding laterally to the left by clamp hub  36   f  which is secured to clamp shaft  12   f  by split pin  25   f  installed in cross holes machined in the end of clamp shaft  12   f . Clamp shaft  12   f  is prevented from sliding laterally to the right by shaft collar  68  which is firmly clamped to clamp shaft  12   f  and is located on the inboard side of tail vise apron  70  with a slight clearance to allow suitable retention while allowing free rotation. 
     Plate  62  is mounted to housing  11   f  by flat head machine screws  65  and nuts  66  installed in mounting holes and slots on housing  11   f . Dog block  63  is fastened to the top side of plate  62  using flat head machine screws  65  installed in tapped holes in the bottom of dog block  63 . Plate  62  retains the elements found within housing  11   f  and transfers motion to dog block  63 . Housing  11   f  is free to translate along shaft  12   f  when in the unclamped state thus allowing tail vise dog  64  to be quickly positioned against the workpiece to be secured. Plate  62  is located with a small amount of clearance from the underside of workbench top  74  so housing  1  if is free to move laterally while being restrained from rotation about clamp shaft  12   f  by the protrusion of dog block  63  into the slot machined through workbench top  74 . Dog block  63  is kept slightly below the top surface of workbench top  74  and has a dovetail machined at a slight forward angle on one side (2 to 4 degrees for example). A corresponding dovetail machined into tail vise dog  64  allows tail vise dog  64  to slide freely on dog block  63  with spring force from spring plunger  71  installed in threaded hole in dog block  63  providing frictional retaining force so tail vise dog  64  remains at any height setting the operator desires. The slight forward angle of dog block  63  similarly angles tail vise dog  64  so that a component of clamping force is directed downward toward the workbench top  74  thus keeping the workpiece to be clamped in firm contact with workbench top  74 . 
     The structure located within housing  11   f  function in a similar manner to the first embodiment of  FIGS. 1-10 . Tail vise transfer bar  73  does not connect to any other elements and is only long enough to cover the rectangular hole in bridge  13   f . Transfer bar  73  is kept from rotating about pin  28   f  by use of liquid retaining compound commonly used for retention purposes or alternatively pin  28   f  could also be press fit into suitable holes in transfer bar  73  and rack  15   f.    
     Clamping of a workpiece is accomplished as follows: Tail vise dog  64  is adjusted vertically to accommodate the thickness of the workpiece to be clamped and one side of the workpiece is placed against bench dog  69 . With the vise in the unclamped state tail vise dog  64  is slid within the slot in workbench top  74  until it contacts the workpiece on the opposite side from bench dog  69 . Counter-clockwise rotation of handle  34   f  causes similar rotation in clamp shaft  12   f  which creates relative motion between shaft  12   f  and housing  11   f  as previously described in the first embodiment of  FIGS. 1-10 . Since clamp shaft  12   f  is retained from moving laterally as previously described, housing  11   f , plate  62 , dog block  63  and tail vise dog  64  translate toward bench dog  69  thus clamping workpiece between bench dog  69  and tail vise dog  64 . Clamping can be accomplished with CW rotation of handle  34   f  by simply removing bridge  14   f  and wedge  13   f  from housing  11   f  and rotating 180° about a longitudinal axis and re-installing into housing  11   f  as described in the first embodiment of  FIGS. 1-10 . 
     It will be understood that each of the elements described above, or two or more together, may also find a useful application in other types of structures differing from the types described above. 
     The present invention improves prior art vises by providing a vise mechanism which is very versatile and can be configured into any of the vise forms previously described. Additionally the vise of the present invention has quick release that occurs automatically when unclamped and utilizes clamp shafts which can be designed so as not to require any lubrication for operation. The twin clamp shafts of certain embodiments allow work to be clamped anywhere in the vise jaws without racking and the vise may be simply configured to clamp with CW or CCW rotation of the clamp handle to suit the operator. It may be constructed to appear as a traditional 18th century twin screw vise with wooden vise jaws, handles and clamp hubs or as a traditional leg vise with a single wooden vise handle and wooden jaw. It may also be configured into a quick action shoulder style vise having a certain aesthetic appeal and streamlined appearance utilizing a single wooden handle and clamp hub. The invention may also be designed as a single shaft vise in a variety of configurations including but not limited to a tail vise like that shown in  FIGS. 27-29 . Alternatively still, the scaled version of the vise may be liberated from a stationary bench application and used in a portable hand clamping application, such as to replicate a traditional hand screw clamps using the arrangement principles of the design shown in  FIG. 23 . 
     The present invention vise operates smoothly and precisely without sagging or screw “chatter” common on quick action screw operated vises. It is simple and easy to install and adjust and clamping force can be limited for delicate work. The vise may be configured in any width desired and utilize one or two clamping handles. The vise jaw may be designed to allow a small amount of skew (approximately 2 degrees in either direction for example) which accommodates slightly out of square work to be clamped. The front vise jaw may be configured to allow it to swivel considerably (up to 10 degrees in either direction for example) for tapered or irregular objects to be firmly clamped. The vise may also be configured, using a single clamp shaft, into an enclosed tail vise with quick action and simple installation. The tail vise is visually appealing with a very narrow slot in the bench top and a wooden clamp hub and handle. 
     In accordance with the teachings of the present invention, a vise is provided which includes a pair of spaced housings secured to the underside of the workbench top. A pair of parallel clamp shafts is received in holes in the respective housings and is free to slide in and out of the housings. The clamp shafts pass through holes in the laterally-extending rear vise jaw which is secured to the workbench top. The clamp shafts further pass through holes in the movable front vise jaw and are fixed to clamp hubs which transfer motion from the clamp handles into the clamp shafts. Means may be provided to allow the front vise jaw to swivel and allow tapered objects to be clamped. 
     Pinions, which freely slide on the clamp shafts, are contained within the housings and convert rotational movement from the clamp shafts into linear movement by means of a corresponding rack. The linear motion actuates a bridge which slides against a laterally fixed wedge causing the bridge to displace a locking element which clutches and moves the clamp shafts to affect clamping. The linear motion from one clamp shaft is transferred through a rack and pinion to the other clamp shaft through a transfer bar and to the corresponding rack and pinion in the other housing. In this way, either clamp handle can be used to actuate the vise and both clamp shafts operate in unison when clamping. The vise may also be configured to utilize only one clamp hub and handle if desired, or more that two clamp shafts. 
     Adjustment screws located in each housing allow the clamping action of each clamp shaft to be quickly and easily synchronized. The wedge and bridge pair can be reversed to allow clamping to occur with a clockwise rotation of the clamp handle or a counter-clockwise rotation of the clamp handle. In alternative embodiments, the wedge and bridge pair can be re-oriented to cause the jaws to spread apart rather than draw together. When the clamp handle is in the un-clamped position, the clamp shafts are free to move in and out of the housing, independent from one another, thus allowing the front vise jaw to be quickly positioned against the workpiece, whether straight or tapered, with one hand while the other hand is free to actuate the clamp handle and secure the workpiece. 
     In twin shaft applications, one of the housings may be rotated 180° relative to the other to provide outward clamping force on one clamp shaft and inward clamping force on the other clamp shaft to allow clamping of a workpiece outside of (i.e., not in-between) the two clamp shafts. This allows the vise to be utilized as a leg or shoulder vise. 
     While the invention has been illustrated and described as embodied in woodworking settings, it is not intended to be limited to the details shown or exemplary applications mentioned, since various modifications and structural changes may be made without departing in any way from the spirit of the present invention.