Abstract:
A fixturing tool has an elongate body with a polygon cross section so as to define a plurality of sides. At least one annular groove extends around the circumference of the body thereby dividing each of the sides into a plurality of segments. At least one longitudinal groove extends across the plurality of segments which comprise one of the sides of the fixturing tool for retaining a work piece therein.

Description:
The present invention relates to fixturing tools used to retain and position objects in the machining industry and, in particular, to a fixturing tool sized to retain and position small and intricate objects. 
     BACKGROUND OF THE INVENTION 
     The tool and die industry involves the machining of both large and small parts and frequently it is necessary to work a very small object on a machine designed to accept a much larger workpiece. Such machines have vises and clamps sized to retain the largest work piece that the machine is intended to receive, however such vises and clamps are unsuitable for retaining miniaturized workpieces. To adapt such machines to receive very small workpieces, a fixturing tool is employed which has a mounting portion for fitting within the jaws of the vise or clamp of the machine and a retaining portion, often configured as a “V”, for retaining a miniature workpieces. 
     While small objects may be considered as constituting a single group, in reality, there are substantial differences of scale between sizes of such objects and, therefore, it is common to provide a plurality of sizes of fixturing tools to receive the many different sizes of small parts which can be machined. A tool and die maker, therefore, must maintain a multiplicity of sizes of fixturing tools for the machines which may be employed to accept small parts. It would be desirable, therefore, to provide a single fixturing tool which could be retained in the vise of a machine and could hold a multiplicity of sizes of small parts. It would also be desirable to have a fixturing tool that would be useable in conjunction with products such as V-blocks, and with angle plates, inspection equipment, integrated tooling, or as a standing alone retainer. 
     SUMMARY OF THE INVENTION 
     Briefly, the present invention is embodied in a fixturing tool having an elongate body with a principle longitudinal axis and a polygon cross sectional shape so as to define a plurality of sides. The outer surface of the body has at least one annular groove extending radially therein that divides each of the sides thereof into a plurality of segments. The groove defines a plane perpendicular to the principle longitudinal axis of the fixturing tool body, and the grove defines a first face and an opposing second face parallel to the first face with a distance between them. At least one longitudinal groove extends across a plurality of segments of one of the sides of the fixturing tool body. 
     The fixturing tool is used in conjunction with a clamp and a bridge. The clamp has a generally rectangular shape with parallel sides, an outer end, a clamp end and a generally rectangular central opening. The parallel sides are spaced a distance which is a little greater than the distance between parallel sides of the fixturing tool body, and the outer end is spaced from the clamp end a distance substantially greater than the distance between parallel sides of the fixturing tool body. In the preferred embodiment, the sides and outer end of the clamp have a thickness which is a little less than the distance between the parallel faces. The clamp end has a threaded bore therein through which a thumb screw is fitted, with the screw directed generally towards the center of the rectangular central opening. 
     The bridge has a body with a central portion and parallel legs, the end surfaces of which are angled to rest upon sides of the elongate body of the fixturing tool. The bridge may be used in conjunction with the fixturing tool to hold an elongate workpiece by retaining the fixturing tool in a vise between the jaws of the machine with the length of the workpiece extending between legs of the bridge. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     A better and more complete understanding of the present invention will be had after a reading of the following detailed description taken in conjunction with the drawings wherein: 
     FIG. 1 is an isometric view of a fixturing tool in accordance with the present invention; 
     FIG. 2 is a side elevational view of the fixturing tool shown in FIG. 1 with a bridge at one end thereof and a clamp at the other end thereof; 
     FIG. 3 is an enlarged cross sectional view of the fixturing tool and bridge shown in FIG. 2 taken through line  3 — 3  thereof; 
     FIG. 4 is an isometric view of a second embodiment of the fixturing tool; 
     FIG. 5 is a front elevational view of the bridge shown in FIGS. 2 and 3; 
     FIG. 6 is a cross sectional view of the fixturing tool shown in FIG. 2 showing a front elevational view of the clamp attached thereto; 
     FIG. 7 is a side elevational view of the clamp shown in FIG. 6; and 
     FIG. 8 is a isometric view of the clamp of FIG. 6 with the inner portions thereof shown in broken lines. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     Referring to FIGS. 1,  2 , and  3 , a fixturing tool for retaining a plurality of sizes of small workpieces has an elongate body  10  with a polygon cross section with a longitudinal axis  12 . In the preferred embodiment the cross sectional shape of a fixturing tool body  10  is that of an octagon with sides bearing indicia numbers  14  through  21 . As best shown in FIGS. 2 and 3, the sides  14 - 21  of the body  10  are broken into segments by a plurality of inwardly extending radial grooves  24 ,  26 ,  28 ,  30 . 
     As best shown in FIGS. 1 and 3, extending across all of the segments of one side  14  is a small V-shaped groove  32 , the sides of which are parallel to sides  17  and  19  of the block body  10 . Extending longitudinally across the segments of side  18  is a second, somewhat larger, groove  34 . Extending longitudinally across the segments of side  20  is an even larger groove  36 , and in similar fashion, extending across the segments of side  16  is the largest groove  38 . Finally, extending longitudinally into the surfaces of the segments of side  15  is a fifth groove  40  with a rectangular cross section with opposing parallel sides parallel to sides  17  and  21  and bottom parallel to sides  15  and  19 . 
     In the preferred embodiment, the block body  10  has an overall length of approximately 2¾″ and a width across opposing sides (for example sides  14  and  18 ) of the octagon of ⅞″. The faces defining the sides of each of the groves  24 ,  26 ,  28 ,  30  are spaced a distance of ¼″ from each other and the depth of each groove, from the flat of an associated side  14 - 21  to the cylindrical surface defining the bottom thereof, is approximately {fraction (3/16)}″. The bottom of the groves  24 ,  26 ,  28 ,  30  define a cylinder with a diameter of ½ inches. 
     Referring to FIGS. 2,  6 ,  7  and  8 , the fixturing tool is used in conjunction with a clamp  50 , the body of which defines the perimeter of an open rectangle, the body having side portions  52 ,  54 , an end portion  56 , and a head portion  58 . The inner surfaces of the side portions  52 ,  54  are spaced a distance a little greater than the distance between parallel sides of the fixturing tool body  10  so that the clamp is slideable over the sides  14 - 21  of the block body  10 . The head portion  58  is spaced from the end portion  56  a distance to enable a workpiece to be fitted between the head portion  58  and a side of the block body  10  when clamp  50  is fitted around the fixturing tool as best shown in FIG.  6 . Extending through the head portion  58  are a plurality of threaded holes  60 ,  62 ,  64  into which a thumb screw  66  can be threaded with the distal end thereof directed towards the rectangular central opening to retain a workpiece fitted between the head portion  58  of the clamp and the block body  10 . 
     As best shown in FIG. 7, in the preferred embodiment the clamp  50  has a thickness  70  which is a little less than the spacing between the opposing faces of the grooves  24 ,  26 ,  28 ,  30 . The clamp  50  will, therefore, fit into the groves  24 ,  26 ,  28 ,  30  so that it may be turned as needed to bring the desired groove  32 ,  34 ,  36 ,  38 ,  40  to engage a workpiece and be retained therein by on of the thumb screw  66  as shown in FIG.  6 . 
     As shown in FIGS. 2,  3  and  5 , to accommodate a long work piece, the fixturing tool is useable in conjunction with a bridge  74 . The bridge  74  is generally U-shaped, with a central portion  76  with opposing legs  78 ,  80  extending from opposite sides thereof. At the distal end of the legs  78 ,  80  are angled flats  82 ,  84  and the central portion has a third flat  86 . In the preferred embodiment, where the fixturing tool has an octagon cross section, the central flat  86  is perpendicular to the direction of the legs  78 ,  80  and the angled flats  82 ,  84  are at right angles to each other and define a 45° angle with the plane of the central flat  86 . The angled flats  82 ,  84  are spaced so they will rest upon angled sides  14 - 21  of the fixturing tool as shown in FIGS. 3 and 5. The fixturing tool can be retained between the jaws of a vice with one jaw compressed upon the central flat  86  of the bridge  70  and the other jaw compressed against the opposing surface  19  of the fixturing tool. An elongate workpiece  90  can be retained in a grove  34  by the clamp  50 , and the elongate end of the workpiece  90  can extend along the associated groove  34  and through the legs  78 ,  80  of the bridge  74  as best shown in FIG.  5 . 
     Referring to FIG.  4 . The fixturing tool  10  may also be adapted for use with integrated tooling systems by providing at one end thereof an axially aligned cylindrical stud  87  having a diameter of 20 mm. The tool  10  may also be used with inspection equipment and other work holding fixtures such as V-blocks, or it may be free standing. As a free standing body the fixturing tool  10  can retain a workpiece while the fixturing tool body  10  rests on one of the unused flat surfaces thereof or on one of the ends. The octagon cross section of the tool offers eight surfaces  14 - 2 l each of which can be formed to hold parts. The rectangularly shaped groove  40 , for example, may have been custom sized to receive a specific object. Customized grooves may similarly be cut into any of the remaining unused surfaces  17 ,  19  and  21 . 
     While the present invention is described with respect to two embodiments, it will be appreciated that many modifications and variations may be made without departing from the true spirit and scope of the invention. It is, therefore, the intent of the appended claims to cover all such modifications and variations which fall within the true spirit and scope of the invention.