Patent Publication Number: US-8540225-B2

Title: Quick change vise jaw system

Description:
BACKGROUND OF THE INVENTION 
     I. Field of the Invention 
     This invention relates generally to an improvement in engineers&#39; vises or the like, and more particularly to master jaw assemblies for the quick removal and attachment of hard and soft jaws. 
     II. Discussion of the Prior Art 
     An engineer&#39;s vise is used in metalworking applications. An engineer&#39;s vise, like a woodworking vise, is used to hold a work piece. Vises have one fixed jaw and another parallel jaw which is moved towards or away from the fixed jaw by a screw. In an engineer&#39;s vise, jaws are made either of hard or soft metal. Hard jaws are available with either a coarse gripping surface or are ground flat and smooth. Hard jaws can lead to deformation and error of the finished work piece if the vise is over-tightened, or if the operator is unskilled or negligent in his handling of the work piece around hard jaws. Soft jaws, in contrast, are usually made of a soft metal such as aluminum, plastic or wood. Soft jaws are used to hold delicate work pieces, and can be cut to hold specially shaped work pieces. Soft jaws are typically discarded or recycled after multiple uses. 
     Because soft jaws are consumable items, it is desirable that they be susceptible to rapid changeover. This requires that soft and hard jaws be prepared for attachment to both the parallel movable jaw and the fixed jaw of the vise. In the prior art, attachable jaws were typically attached to the parallel movable jaw by bolts, requiring holes be drilled into each detachable jaw. U.S. Pat. No. 4,251,066 (“the &#39;066 patent”) teaches providing a master jaw assembly including a locking jaw having a means providing a dovetail groove along an inner side for receiving a dovetail of approximately the same cross-section on the outer side of a detachable jaw. The detachable jaw is fastened to the locking jaw by providing a weakened section of the locking jaw, such as a slot, extending along the base of the groove intermediate of the tapers. One or more pins connect the tapers on opposite sides of the weakened section for movement toward and away from one another. When the dovetail is inserted into the groove, the detachable jaw is attached to the locking jaw. 
     The approach of fastening the detachable jaw to the locking jaw after attachment in the &#39;066 patent has manifest problems. First, the assembly of the &#39;066 patent is incapable of front loading the detachable jaw and requires that the detachable jaw be inserted from the side. Second, it weakens the structural integrity of the locking jaw. After repeated use of moving the tapers back and forth, the locking jaw will distort and weaken so as to be unusable for its intended purpose. Third, because the locking jaw is made of a metal of greater strength than a soft detachable jaw, a great deal of force is required to pull the tapers toward each other to securely capture the dovetail of the detachable jaw. This will strain the operator and add to the time necessary to change out the detachable jaw. Fourth, the fastening approach of the &#39;066 patent will still allow the detachable jaw to slip inside the dovetail groove if the pins do not adequately tighten the locking jaw to pull the tapers toward one another. Fifth, because the pins are placed on either side of the weakened segment of the locking jaw, the tapers will bow in the middle so that the groove will not conform to the cross-section of the dovetail. 
     It is accordingly a principal object of the present invention to provide a vise where the detachable jaws can be more easily fastened or clamped to locking jaw. 
     Another object of this invention is to provide a vise where the detachable jaws are comparatively inexpensive. 
     An additional object of the present invention is to provide a vise where the detachable jaw may be front loaded into the locking jaw. 
     Another object of this invention is to provide a vise where the detachable jaw may be releasably attached to the locking jaw with less time and effort. 
     Still another object of this invention is to provide a vise where the detachable jaw may be securely attached to the locking jaw. 
     A further object of this invention is to provide a vise in which a soft detachable jaw need not be provided in standard lengths, but instead may be cut from stock of the length required to mount a particular work piece. 
     A further object is to provide an attachment for converting an existing vise of this type to a vise adapted to accomplish one or more of the above noted objects. 
     SUMMARY OF THE INVENTION 
     These and other objects are accomplished, in accordance with the illustrated embodiment of the present invention, by providing a master jaw assembly used in a vise that comprises a locking jaw having a groove extending along an inner side of the hard jaw between a top surface and a bottom surface. The groove has a base and is defined by first and second opposing edges. The first edge is flat and the second edge is tapered toward the inward and downward base. The master jaw assembly further includes a detachable jaw with a dovetail protrusion along one side surface thereof. The protrusion is substantially the same width as the groove. A fastening device is disposed in the locking jaw along the first edge. 
     In accordance with the present invention, the fastening device includes a plurality of bores cut into the base of the locking jaw, a plurality of nut holes cut into a top surface and intersecting the first edge of the locking jaw. A plurality of studs is provided with a right-hand threaded segment, a left-hand threaded segment and an unthreaded segment separating the threaded segments. The right-hand threads are screwed into the bores in the base and a nut operatively engages the left-hand threads of the stud. The nuts further include a downwardly tapered edge. When the dovetail protrusion is inserted into the groove, one edge of the dovetail protrusion engages the tapered edge of the locking jaw, and the other edge of the dovetail protrusion engages the downwardly tapered edge of the nut. The detachable jaw is fastened to the locking jaw by torquing the studs further into the bores and the nuts are pulled through the nut holes and the tapered edges of the nuts engage the dovetail. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The foregoing features, aspects and advantages of the invention will become apparent to those skilled in the art from the following detailed description of an embodiment, especially when considered in conjunction with the accompanying drawings in which like numerals in the several views refer to corresponding parts: 
         FIG. 1  shows a side perspective view of a vise constructed in accordance with the present invention; 
         FIG. 2  is an end view of the locking jaw of the master jaw assembly; 
         FIG. 3  is a front view of the locking jaw; 
         FIG. 4  is a top view of the locking jaw; 
         FIG. 5  is a perspective view of the detachable jaw; and 
         FIG. 6  is a perspective view of the clamping means of the master jaw assembly. 
     
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENT 
     The following discussion is presented to enable a person skilled in the art to make and use the present teachings. Various modifications to the illustrated embodiments will be readily apparent to those skilled in the art, and the generic principles herein may be applied to other embodiments and applications without departing from the present teachings. Thus, the present teachings are not intended to be limited to the embodiments shown, but are to be accorded the widest scope consistent with the principals and features disclosed herein. 
       FIG. 1  shows the master jaw assembly  10  as used in a machinist&#39;s vise  12 . The vise  12  is a standard vise with a fixed jaw  14  and a parallel movable jaw  16 , in which the vise  12  is clamped together to hold a work piece  18 . The master jaw assembly  10  includes a locking jaw  20  coupled to a detachable jaw  22 . A locking jaw  20  is attached to both the fixed jaw  14  and the movable jaw  16  of the vise  12 . A detachable jaw  22  is coupled to each locking jaw  20 . The work piece  18  is sandwiched between the two detachable jaws  22 . 
       FIG. 2  is an end view of the locking jaw  20 . The locking jaw  20  includes a groove  24  extending across the inner side of the locking jaw  20  between its top edge  21  and its bottom edge  23 . The groove  24  has a base  26  and is defined by a first side edge  28  and a second side edge  30 . The first side edge  28  and the second side edge  30  are disposed on either side of the groove  24 . The first edge  28  has a flat bottom  32 . The second edge  30  includes a taper  34  sloping inward and downward toward base  26 . 
     As shown in  FIG. 3 , the locking jaw  20  further includes a plurality of nut holes  36  and a pair of countersunk holes  38 . The holes  38  are for accommodating threaded connection of the locking jaw  20  to either the fixed jaw  14  or movable jaw  16  by flat head socket bolts (not shown). When the locking jaws  20  are so attached to the fixed or movable jaws  14  and  16 , their outer side surfaces  42  are flush with the inner side surfaces of the fixed or movable jaws, and the lower ends  44  of the locking jaw  20  fit snugly against a top base  46  of the vise.  FIG. 4  shows that the upper surface  21  of the locking jaw  20  includes a plurality of the nut holes  36  with tapped bores  50  cut into the base thereof. 
       FIG. 5  shows that the detachable soft jaw  22  includes a dovetail protrusion  52  along one side surface thereof. The dovetail protrusion  52  is of substantially the same width as the groove  24  formed in the hard locking jaw  20 . The detachable jaw  22  may be made of plastic, aluminum, wood or the like. When the detachable jaw is made of plastic, aluminum or wood, the detachable jaw is a soft jaw. Conversely, the detachable jaw  28  may be made of hard metal and function as a hard jaw. 
     A clamping means is provided to securely fasten the locking jaw  20  to the detachable jaw  22 . The clamping means includes a specially shaped clamp-nut  54  having an inwardly and upwardly tapered edge  56  when viewed as in  FIG. 5 . The clamp-nut  54  operatively engages a double-ended stud  58 , where the stud has right-handed threaded segment  60  over one end portion  62  thereof and a left-handed threaded segment  64  extending over second end portion. An unthreaded segment  68  separates the threaded segments  60 ,  64 . The stud includes a socket at the upper end of segment  64  to accept an Allen wrench tool. The clamp-nut  54  operatively engages the left-hand threaded segment  64  of the stud  58 . The nut holes  36  are sized and shaped to receive the clamp-nuts  54 . The stud  58  can be screwed into the bores  50  by the right-handed threads  60 . When the clamp-nut  54  operatively engages the stud  58  by the left-handed threads  64  and the right-handed threads  60  are screwed clockwise into the bores  50  the nut is carried downward into the nut holes  36 . When torqued clockwise all the way down, the top surface  70  of the nut will be flush with the upper end  48  of the locking jaw  20 . Conversely, when the stud  58  is torqued counter-clockwise the clamp-nut  54  is raised out of the nut holes  36 . 
     When the dovetail protrusion  52  is inserted into the groove  24 , the inward and downward tapered edge  34  engages one side of the dovetail protrusion  52 . When screwed downward by torquing the studs  58  clockwise, the clamp-nuts are lowered into the nut holes  36  and the inwardly and downwardly tapered edges  56  thereof come into engagement with the opposing side of the dovetail protrusion  52 . Tightening the studs  58  further in a clockwise direction places a downward force on the protrusion  52  and securely clamps it between the inward/downward taper  34  and the inward/upward tapered edge  56  of the clamp-nuts  54 , and thus clamp the detachable jaw  22  to the locking jaw  20 . Turning the studs  58  in the opposite direction will raise the clamp-nuts  54  and permit the portions of the detachable jaw to be inserted or removed from the groove  24 . 
     This invention has been described herein in considerable detail in order to comply with the patent statutes and to provide those skilled in the art with the information needed to apply the novel principles and to construct and use such specialized components as are required. However, it is to be understood that the invention can be carried out by specifically different equipment and devices, and that various modifications, both as to the equipment and operating procedures, can be accomplished without departing from the scope of the invention itself.