Patent Publication Number: US-8109494-B1

Title: Workholding apparatus having a movable jaw member

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     This application claims the benefit under 35 U.S.C. §119(e) of U.S. Provisional Patent Application Ser. No. 60/841,824, entitled WORKHOLDING APPARATUS, filed on Sep. 1, 2006, the entire disclosure of which is hereby incorporated by reference herein. 
    
    
     BACKGROUND 
     1. Field of the Invention 
     The present invention generally relates to devices for holding workpieces and, more particularly, to devices used in connection with high precision machining (CNC, etc.) operations. 
     2. Description of the Related Art 
     High precision machining operations often utilize workholding devices, such as vises, for example, for holding a workpiece in position while the workpiece is cut, milled, and/or polished. As is well known in the art, financially successful machining operations utilize vises which are quickly and easily adaptable to hold a workpiece in different positions and orientations during the machining operation. These vises typically include a rigid base, a fixed jaw member mounted to the base, and a movable jaw member. In use, the workpiece is often positioned between the fixed jaw member and the movable jaw member, wherein the movable jaw member is then positioned against the workpiece. In various embodiments, the movable jaw member can be moved via the interaction of a threaded rod with the base and the movable jaw. Often, the threaded rod must be rotated a significant amount of times before the movable jaw member is positioned against the workpiece. What is needed is an improvement over the foregoing. 
     SUMMARY 
     The present invention includes a device for holding a workpiece, the device comprising, in one form, a base, a first jaw member, a movable jaw member, and features which allow the movable jaw member to be moved in large increments relative to the first jaw member in addition to features which allow the movable jaw member to be moved in smaller increments. In various embodiments, the device can include a drive member operably engaged with the base and the movable jaw member such that the operation of the drive member can move the movable jaw member in small increments. In at least one embodiment, the movable jaw member can include at least one connection member, or claw, which can operatively engage the movable jaw member with the drive member. In such embodiments, the connection member can be moved between first and second positions to disengage the movable jaw member from the drive member such that the movable jaw member can be slid relative to the drive member, and the first jaw member, in large increments. In various embodiments, the connection member, or claw, can be rotated or pivoted between its first and second positions. As a result of the above, the movable jaw member can be accurately and precisely positioned relative to the workpiece and/or the first jaw member. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The above-mentioned and other features of this invention, and the manner of attaining them, will become more apparent and the invention itself will be better understood by reference to the following description of an embodiment of the invention taken in conjunction with the accompanying drawings, wherein: 
         FIG. 1  is an elevational view of an exemplary workholding device in accordance with an embodiment of the present invention; 
         FIG. 2  is an end view of the workholding device of  FIG. 1 ; 
         FIG. 3  is a top view of the workholding device of  FIG. 1 ; 
         FIG. 4  is a cross-sectional view of the workholding device of  FIG. 1  taken along line  4 - 4  in  FIG. 3 ; 
         FIG. 5  is a perspective view of the workholding device of  FIG. 1  illustrating a movable jaw member including a connection member engaged with an adjustment rack assembly; 
         FIG. 6  is a detail view of the movable jaw member of the workholding device of  FIG. 1  illustrating a portion of the connection member engaged with the rack assembly; 
         FIG. 7  is a cross-sectional view of the workholding device of  FIG. 1  taken along line  7 - 7  in  FIG. 3 ; 
         FIG. 8  is a detail view of a portion of the movable jaw member of  FIG. 7  illustrating a spring assembly configured to bias the connection member into an engaged position; 
         FIG. 9  is a perspective view of the connection member of  FIG. 5 ; 
         FIG. 10  is an elevational view of the connection member of  FIG. 5 ; 
         FIG. 11  is a cross-sectional view of the workholding device of  FIG. 1  taken along a line to illustrate a cam extending from the spring assembly of  FIG. 8  configured to cooperate with a base of the workholding device and bias the connection member into the engaged position; 
         FIG. 12  is a detail view of the cam of  FIG. 11 ; 
         FIG. 13  is a perspective view of a connection member of a movable jaw member in accordance with an alternative embodiment of the present invention; 
         FIG. 14  is an elevational view of the connection member of  FIG. 13 ; 
         FIG. 15  is a cross-sectional view of the connection member of  FIG. 13  taken along line  15 - 15  in  FIG. 14 ; and 
         FIG. 16  is a detail view of a spring assembly of the connection member of  FIG. 15  configured to bias the connection member into an engaged position. 
     
    
    
     Corresponding reference characters indicate corresponding parts throughout the several views. The exemplifications set out herein illustrate preferred embodiments of the invention, in one form, and such exemplifications are not to be construed as limiting the scope of the invention in any manner. 
     DESCRIPTION 
     Certain exemplary embodiments will now be described to provide an overall understanding of the principles of the structure, function, manufacture, and use of the devices and methods disclosed herein. One or more examples of these embodiments are illustrated in the accompanying drawings. Those of ordinary skill in the art will understand that the devices and methods specifically described herein and illustrated in the accompanying drawings are non-limiting exemplary embodiments and that the scope of the various embodiments of the present invention is defined solely by the claims. The features illustrated or described in connection with one exemplary embodiment may be combined with the features of other embodiments. Such modifications and variations are intended to be included within the scope of the present invention. 
     In various embodiments, referring to  FIG. 1 , workholding device  50  can include base  52 , first jaw member  54 , and second jaw member  56 . In use, a workpiece can be positioned on surface  53  of base  52  intermediate first jaw member  54  and second jaw member  56  wherein at least one of jaw members  54  and  56  can be positioned or moved against the workpiece to apply a clamping force thereto. In the illustrated embodiment, first jaw member  54  can be fixedly mounted to base  52  and, as described in greater detail below, second jaw member  56  can be movable relative to base  52 . In various alternative embodiments, although not illustrated, a workholding device can include two or move movable jaw members. A workholding device having two movable jaw members and a fixed jaw member is described and illustrated in U.S. Pat. No. 5,022,636, entitled WORKHOLDING APPARATUS, which issued on Jun. 11, 1991, the content of which is hereby incorporated by reference herein. In either event, in at least one embodiment, device  50  can further include work stop  58  which can be configured to control at least the transverse position of the workpiece within device  50 . More particularly, in at least one embodiment, work stop  58  can include a post which is adjustably threaded into base  52  and, in addition, a friction clamp configured to allow extension rod  60  to be rotated into any suitable orientation or extended into any suitable position. In various embodiments, work stop  58  can further include a threaded rod or set screw extending from extension rod  60  which can be adjusted to abut the workpiece and hold the workpiece in position. 
     As outlined above, second jaw member  56  can be moved relative to base  52 . In various embodiments, workholding device  50  can include features which can allow second jaw member  56  to be moved in large increments relative to base  52  and first jaw member  54  and, in addition, features which can allow jaw member  56  to be moved in small increments. In at least one embodiment, referring to  FIGS. 5 and 6 , second jaw member  56  can include body portion  64  and at least one connection member, or claw,  62  movably mounted to body portion  64 . In such embodiments, a connection member  62  can be selectively engaged with base  52 , for example, to retain jaw member  56  to base  52 . More particularly, connection member  62  can be positioned in a first position in which connection member  62  is engaged with base  52  and, as a result, second jaw member  56  can be fixed, or substantially fixed, relative to base  52 . In at least one embodiment, connection member  62  can be selectively moved into a second position in which it is not engaged with base  52  wherein, as a result, second jaw member  56  can be moved relative to base  52 . Stated another way, once connection member  62  is moved into a position in which it is not engaged with racks  66 , as described below, second jaw member  56  can be slid relative to base  52  along displacement axis  55  ( FIG. 3 ), for example, in large increments and placed against a workpiece positioned intermediate jaw members  54  and  56  as outlined above. In various alternative embodiments, although not illustrated, second jaw member  56  can be moved along a curved and/or curvilinear path. 
     In various embodiments, base  52  can include at least one rack  66 , wherein each rack  66  can include notches, or recesses,  68 . Recesses  68  can be configured to receive at least a portion of connection members  62  and secure second jaw member  56  relative to base  52  as outlined above. In at least one embodiment, referring to  FIGS. 5 ,  6  and  9 , each connection member  62  can include at least one projection  70  extending therefrom which can be configured to be received within recesses  68 . In various embodiments, referring to  FIG. 7 , each recess, or notch,  68  can include an arcuate or circular profile which can be configured to receive a projection  70  having a corresponding arcuate or circular profile, for example. In at least one embodiment, although not illustrated, recesses  68  can include a linear groove, or a groove having any other suitable profile, which can be configured to receive a projection having a corresponding or other suitable profile, similar to the above. In various embodiments, such recesses can be oriented in a vertical direction, for example, or any other suitable direction. In at least one embodiment, the recesses can be oriented at an approximately 20 degree angle from the vertical direction. 
     In order to remove projections  70  from recesses  68 , and thereby disengage second jaw member  56  from base  52 , connection members  62  can be moved such that projections  70  are displaced away from recesses  68 . In at least one embodiment, connection members  62  can be rotatably mounted to body portion  64 . More particularly, referring to  FIGS. 7 ,  9  and  10 , each connection member  62  can include a pivot  72  which can be pivotably mounted to body portion  64  by a pivot pin  73 , for example, wherein the cooperation of pivot  72  and pin  73  can define pivot axis  74  about which connection member  62  can be rotated. In various embodiments, axis  74  and axis  55  can extend in any suitable direction relative to each other. In the illustrated embodiment, axis  74  can be perpendicular, or at least substantially perpendicular, to axis  55  such that connection members  62  can be pivoted upwardly and/or downwardly relative to base  52  as described in greater detail below. In other various embodiments, although not illustrated, axes  74  and  55  can be transverse, skew, or parallel to each other. In such embodiments, connection members  62  can be pivoted outwardly away from racks  66 , for example. In at least one embodiment, at least one of axes  74  can be oriented at an approximately 20 degree angle with respect to the horizontal plane. In such embodiments, a connection member  62  can be configured to rotate in a plane which is neither parallel nor perpendicular to the horizontal or vertical planes. 
     In various embodiments, referring to  FIGS. 2 ,  3 , and  5 , connection members  62  can further include projections, or handles,  76  extending therefrom. In at least one embodiment, handles  76  can be configured such that they can be grasped by an operator to rotate connection members  62  between a first position in which connection members  62  are engaged with racks  66  and a second position in which connection members  62  are disengaged from racks  66 . In various embodiments, workholding device  50  can further include a biasing member such as a spring, for example, which can bias a connection member  62  into engagement with a rack  66 . In at least one such embodiment, referring to  FIGS. 7-10 , connection member  62  can include spring assembly  78  comprising spring  80 , drive pin  82 , and cam pin  84 . In various embodiments, spring  80  can be positioned within cavity  81  intermediate fastener  86  and head  83  of drive pin  82  wherein fastener  86  can be threaded into, or otherwise suitably retained in, cavity  81 . In various embodiments, spring  80  can be configured to bias drive pin  82  against cam pin  84  and apply a biasing force to cam pin  84 . As described in greater detail below, this biasing force can rotate connection member  62  about axis  74 , for example, such that projections  70  are biased into engagement with recesses  68 . 
     Further to the above, referring to  FIGS. 11 and 12 , cam pin  84  can include an eccentric, or lobe,  88  extending therefrom which can be configured to abut surface  51  of base  52 . In various embodiments, the biasing force applied to cam pin  84  by spring  80  as described above can bias lobe  88  into engagement with surface  51 . More particularly, end  79  ( FIG. 8 ) of drive pin  82  can fit within notch  85  of cam pin  84  such that spring  80  can cause cam pin  84  to rotate, or at least bias cam pin  84  to rotate, in a direction indicated by arrow  87 . As a result of the above, lobe  88  can be rotated, or biased to rotate, upwardly such that, owing to contact between lobe  88  and surface  51 , a downwardly-acting reaction force, F D  ( FIG. 10 ), can be transferred through cam pin  84  into connection member  62  causing connection member  62  to rotate in a direction indicated by arrow  89  and position projections  70  within recesses  68 . Stated another way, referring to  FIG. 10 , lobe  88  can be offset from axis  74  by a distance “X 1 ” such that the biasing force applied through lobe  88  can apply a moment, or torque, to connection member  62  thereby causing connection member  62  to rotate in a direction indicated by arrow  89  and move projections  70  upwardly into recesses  68 . In various embodiments, this moment, or torque, can cause projections  70  to abut recesses  68 . 
     In use, handles  76  can be lifted upwardly, i.e., in a direction opposite arrow  89 , to rotate projections  70  downwardly and out of engagement with recesses  68 . Such rotation of connection members  62  can move cam pin  84  upwardly toward surface  51  wherein lobe  88 , as a result, can rotate downwardly in order to accommodate the upward movement of cam pin  84 . Such rotation of lobe  88  can rotate cam pin  84  in a direction opposite of arrow  87  and, owing the interaction of end  79  of drive pin  82  and notch  85  of cam pin  84  as outlined above, cam pin  84  can displace drive pin  82  toward fastener  86  and compress spring  80 . In various embodiments, spring  80  can be configured to store potential energy therein when it is compressed. In various alternative embodiments, although not illustrated, spring  80  can be stretched to store potential energy therein. In either event, connection members  62  can thereafter be released and, as a result of the potential energy stored within spring  80 , spring  80  can move drive pin  82  toward cam pin  84 , rotate cam pin  84  in a direction indicated by arrow  87 , and rotate lobe  88  upwardly. Ultimately, as a result, the rotation of lobe  88  can rotate connection member  62  in a direction indicated by arrow  89  and projections  70  can be repositioned within recesses  68 . 
     In various embodiments, cam lobe  88  can be configured to abut surface  51  regardless of the orientation of workholding device  50 . More particularly, cam lobe  88  can be configured to remain in contact with surface  51  when axis  55  is positioned in either a horizontal direction or a vertical direction, for example. In either event, referring to  FIG. 7 , body portion  64  can include recess  65  which can be configured to receive at least a portion of connection member  62  therein and permit connection member  62  to rotate about pin  73  as described above. In at least one embodiment, recess  65  can include guide surface  63  against which a guide member of connection member  62 , such as projection  61 , for example, can abut, or slide thereagainst. In such embodiments, guide surface  63  can define a path for connection member  62  and/or support connection member  62  when a force is applied thereto. In various embodiments, although not illustrated, a workholding device can include a torsion spring having a first end engaged with body portion  64  and a second end engaged with connection member  62 . In at least one such embodiment, when connection member  62  is rotated between first and second positions as described above, the torsion spring can be configured to resist the rotational movement of connection member  62  and store potential energy therein such that the torsion spring can bias connection member  62  back into its first, or engaged, position, for example. 
     In various alternative embodiments, a workholding device can include the biasing assembly depicted in  FIGS. 13-16 . In at least one embodiment, biasing assembly  78 ′ can include spring  80 ′, pin  84 ′, and plunger  88 ′. When an operator lifts upwardly on handle  76  to disengage projections  70  from recesses  68  as outlined above, plunger  88 ′ can be lifted upwardly toward surface  51 . In at least one embodiment, plunger  88 ′ can contact surface  51  and compress spring  80 ′ within cavity  81 ′. Similar to the above, spring  80 ′ can be configured to store potential energy therein which can, after handles  76  have been released by the operator, release the potential energy to move connection member  62 ′ from its second, operably disengaged, position into its first, operably engaged, position. In various embodiments, plunger  88 ′ can include a flat, or at least substantially flat, surface  90 ′ which can be positioned flush against a flat, or at least substantially flat, portion of surface  51 , for example. In such embodiments, pin  84 ′ can be rotatably mounted within aperture  85 ′ ( FIG. 15 ) in connection member  62 ′ such that, when connection member  62 ′ is rotated as described above, pin  84 ′ can rotate relative to connection member  62 ′ and surface  90 ′ can remain positioned flush against surface  51 . In at least one embodiment, referring to  FIG. 16 , assembly  78 ′ can further include retaining ring  87 ′ which can be received within recess  89 ′ in pin  84 ′ such that translational movement between pin  84 ′ and connection member  62 ′ can be prevented, or at least inhibited. 
     In order to move second jaw member  56  in small increments relative to base  52  and/or first jaw member  54  as outlined above, workholding device  50  can include a drive system configured to displace second jaw member  56  when jaw member  56  is engaged with at least one of racks  66 . In at least one embodiment, referring to  FIG. 4 , the drive system can include drive member  92 , wherein drive member  92  can include first end  93  and second end  94 , and wherein second end  94  can be threadably engaged with at least one of base  52  and first jaw member  54 , for example. In at least one such embodiment, base  52  and/or first jaw member  54  can include a threaded aperture  57  configured to threadably receive second end  94  such that, when drive member  92  is rotated about an axis, drive member  92  can be translated relative to base  52  and first jaw member  54 . In various embodiments, the drive system can further include bushing, or crossbar,  100  mounted to drive member  92  wherein, when drive member  92  is rotated about its axis, crossbar  100  can be advanced toward and/or retracted away from first jaw member  54  along axis  55 , depending on the direction, i.e., clockwise or counter-clockwise, in which drive member  92  is rotated. In at least one embodiment, racks  66  can be operably engaged with crossbar  100  such that, when crossbar  100  is translated relative to first jaw member  54  by drive member  92 , racks  66  can be translated relative to first jaw member  54  by crossbar  100 . In at least one such embodiment, although not illustrated, crossbar  100  can include projections extending therefrom which can be configured to fit within slots in racks  66  such that the drive force created by drive member  92  can be transferred into racks  66 . 
     Further to the above, when second jaw member  56  is engaged with at least one of racks  66 , second jaw member  56  can be translated relative to base  52 , and first jaw member  54 , when racks  66  are translated by drive member  92  as described above. In such embodiments, a workpiece can be positioned between jaw member  54  and  56  wherein, when large adjustments to the position of second jaw member  56  are necessary, second jaw member  56  can be released from racks  66  and brought into close opposition to, or contact with, the workpiece. Thereafter, second jaw member  56  can be re-engaged with racks  66  such that second jaw member  56  can be moved in small increments by drive member  92  until jaw member  56  is positioned firmly against the workpiece and a clamping force can be applied thereto. In various embodiments, first end  93  can be operatively engaged with a handle (not illustrated) such that drive member  92  can be easily turned as described above. In at least one such embodiment, referring to  FIG. 4 , first end  93  can include socket  97  which can be configured to receive the handle therein. 
     In various embodiments, as outlined above, drive member  92  can be operably connected to first jaw member  54  and second jaw member  56 . In at least one such embodiment, the clamping force generated by drive member  92  can be directly transferred to a workpiece through jaw members  54  and  56  without having to flow through the base of the workholding device. More particularly, owing to the fact that first jaw member  54  can be threadably engaged with drive member  92  and second jaw member  56  can be releasably engaged with racks  66 , the rotation of drive member  92  can generate a clamping force which is directly applied to the workpiece through jaw members  54  and  56 . In various embodiments, referring to  FIG. 4 , the drive system can further include connection member  95  which can operably engage drive member  92  and first jaw member  54 . In order to fix the position of first jaw member  54 , jaw member  54  and base  52  can each include apertures therein configured to receive fasteners (not illustrated) which can secure jaw member  54  to base  52 . In addition, device  50  can further include at least one set screw  98  which can be threadably retained in base  52  wherein set screw  98  can abut, or be positioned against, connection member  95 , for example, to hold connection member  95  in position. In such embodiments, set screw  98  can prevent, or at least inhibit, unwanted movement or ‘backlash’ in connection member  95 . 
     In various embodiments, the incremental travel of racks  66  and/or drive member  92  may be physically limited by shoulders and/or stops in base  52 . In a further embodiment, although not illustrated, a detent mechanism, such as ball plunger, for example, may be used to provide an audio and/or tactile feedback to an operator indicating that racks  66  have reached the end of their desired or permitted stroke. In the event where the maximum stroke of racks  66  has been reached and further adjustment is still desired, connection members  62  may be released from racks  66  and then reengaged with an adjacent set of notches  68  such that the drive mechanism can be readjusted. 
     While this invention has been described as having exemplary designs, the present invention may be further modified within the spirit and scope of the disclosure. This application is therefore intended to cover any variations, uses, or adaptations of the invention using its general principles. Further, this application is intended to cover such departures from the present disclosure as come within known or customary practice in the art to which this invention pertains.