BACKGROUND OF THE INVENTION
1. Technical Field
The present invention relates to a precision tooling fixture for accurately clamping multiple workpieces on a worktable for machining. More specifically, the invention is directed to a compact, two-station fixture vise wherein the workpieces are clamped against oppositely facing features of a common center-mounted fixed vise jaw. A plurality of such vises can be arranged in a precision mechanical array in order to accurately and repeatably present numerous workpieces to a machine tool.
2. Related Background Art
A tooling fixture is used to hold a workpiece during intricate machining such as computer numerically controlled (CNC) machining. CNC milling and drilling machines are flexible in that they can be programmed to automatically select and install one of a plurality of machine tools from a tool magazine, thereby allowing a wide variety of machining operations to be executed in a single preprogrammed sequence. Thus, if a number, N, of workpieces are to be machined, it can be economical to present an array of workpieces to the CNC machine in a single machining event as compared to N sequential individual machining events. To the extent that all pertinent workpieces can be sequentially machined using each selected tool, then approximately (N−1) tool change intervals can be saved compared to machining individual workpieces.
The fixture used in the CNC array must hold each workpiece securely and precisely. Vises capable of clamping two workpieces and having a fixed center block and movable jaws that move toward the center block are known in the art. But, these Prior Art vises are directed to mounting large and heavy workpieces and are themselves too large and bulky to be arranged into a dense array.
DISCLOSURE OF THE INVENTION
A tooling fixture that provides a compact, multi-station fixture vise is described. The individual workpieces are clamped by separate movable vise jaws against oppositely facing features of a common central fixed vise jaw solidly attached to a baseplate. The movable vise jaws slide on metal support rods that are press fit into the central fixed vise jaw. The movable vise jaws are drawn together toward the central fixed vise jaw by means of a vise screw that passes through the first movable vise jaw and the central fixed vise jaw and is threaded into the second movable vise jaw. Compression springs mounted on the vise screw provide a bias force that causes the movable vise jaws to be drawn simultaneously towards and away from the fixed central vise jaw as the vise screw is rotated.
BRIEF DESCRIPTION OF THE DRAWINGS
Features are numbered equivalently through all drawings.
FIG. 1 is a line drawing of an embodiment of the tooling fixture.
FIG. 2 is an exploded view of the embodiment of FIG. 1.
FIG. 3 illustrates the movement of the vise jaws in the embodiment of FIG. 1.
FIG. 4 shows a three unit array of the embodiment of FIG. 1.
FIG. 5 is a line drawing of a second embodiment of the tooling fixture.
FIG. 6 is an exploded view of the embodiment of FIG. 5.
FIG. 7 is a line drawing of a third embodiment of the tooling fixture.
FIG. 8 is an exploded view of the embodiment of FIG. 7.
FIG. 9 illustrates the movement of the vise jaws in the embodiment of FIG. 7.
FIG. 10 shows a three unit array of the embodiment of FIG. 7.
FIG. 11 is a line drawing of a fourth embodiment of the tooling fixture.
MODES FOR CARRYING OUT THE INVENTION
Referring to FIG. 1, a tooling fixture 100 is shown. The tooling fixture 100 comprises central vise jaw 101 and right and left movable vise jaws 102 and 103, respectively. The movable vise jaws 102 and 103 slide on support rods 104 that are press fit into the central vise jaw 101. Alternatively, support rods 104 may be inserted into clearance holes drilled in central vise jaw 101 and secured using optional set screws, such as 110. The movable vise jaws 102 and 103 are drawn together toward the central fixed vise jaw 101 by means of a vise screw 106 that is threaded along the distal third of its length. The upper part of the vise screw 106 is milled to clear the threads in the right movable vise jaw 102 and the central fixed vise jaw 101 while the distal third is threaded into the left movable vise jaw 103. Thus, in this embodiment the right movable vise jaw 102 and the left movable vise jaw 103 are identical. The central vise jaw 101 and right and left movable vise jaws 102 and 103, respectively, are shown as incorporating dovetail features 105 to firmly clamp the workpieces that incorporate complementary features. Right and left compression springs 107 and 108, respectively, are mounted on the vise screw 106 to provide a bias force that causes the movable vise jaws to be drawn simultaneously towards and away from the fixed central vise jaw 101. The central vise jaw 101 includes holes 109 for the insertion of screws to mount the fixture to a baseplate or to a work table.
Note that if the stiffness of the left compression spring 108 is larger than the stiffness of the right compression spring 107, then the right movable vise jaw 102 will approach the central fixed vise jaw 101 at a higher rate rate per turn of the vise screw 106 than will the left movable vise jaw 103. Therefore, a workpiece mounted between the right movable vise jaw 102 and the central fixed vise jaw 101 can be loosely clamped into position while the gap between the left movable vise jaw 103 and the fixed central vise jaw 101 caused by the larger stiffness if the left compression spring 108 allows a similar part to be introduced and clamped with subsequent further tightening of the vise screw 106.
Referring to FIG. 2, the same tooling fixture 100 as seen in FIG. 1 is shown in an exploded view. Features with the same numbers as those in FIG. 1 have already been described. Note in this view the upper end 201 and the lower end 202 of the screw 106 having diameters 203 and 204, respectively, are visible showing that the upper end is milled with a smaller diameter 203 than the diameter of the lower end 204 in order to clear threads (not visible) within the vise jaw 102.
FIG. 3 illustrates the movement of the vise jaws 102 and 103. FIG. 3a shows the fully open tooling fixture 100 as shown previously in FIG. 1. FIG. 3b shows how the movable vise jaws 102 and 103 have moved toward the fixed central vise jaw 101 because of advancement of the vise screw 106. In this example the stiffnesses of the right and left compression springs 107 and 108, respectively, are assumed to be approximately equal as the gaps 301, 302 are equivalent upon compression of the springs 107, 108.
FIG. 4 shows an array of three tooling fixtures 100 mounted on a base plate 401. The tooling fixtures 100 are attached to the baseplate 401 by machine screws 402 mounted in mounting holes 109 in the fixed central vise jaws 101. The mounting holes 109 and vice jaws 101 are shown in FIGS. 1 and 2. The baseplate 401 can be attached to a worktable using screws (not shown) inserted through screw holes 403 in the baseplate 401.
FIG. 5 shows a tooling fixture 500 in an alternate embodiment. The tooling fixture 500 comprises central vise jaw 501 and right and left movable vise jaws 502 and 503, respectively. The movable vise jaws 502 and 503 slide on support rods 504 that are press fit into the central vise jaw 501. The movable vise jaws 502 and 503 are drawn together toward the central fixed vise jaw 501 by means of a vise screw 506 that is threaded along its entire length. The right movable vise jaw 502 and the central fixed vise jaw 501 are drilled to clear the threads of vise screw 506 while the left movable vise jaw 503 is tapped to accept the threads of the vise screw 506. Thus, in this embodiment the right movable vise jaw 502 and the left movable vise jaw 503 are different. The central vise jaw 501 and right and left movable vise jaws 502 and 503, respectively, are shown as incorporating dovetail features 505 to firmly clamp the workpieces that incorporate complementary features. Right and left compression springs 507 and 508, respectively, are mounted on the vise screw 506 to provide a bias force that causes the movable vise jaws to be drawn simultaneously towards and away from the fixed central vise jaw 501. The central vise jaw 501 includes holes 509 for the insertion of screws to mount the fixture to a baseplate or to a work table.
Referring to FIG. 6, the same tooling fixture 500 as seen in FIG. 5 is shown in an exploded view. Features with the same numbers as those in FIG. 5 have already been described. The holes 601, 602 are milled to clear the screw 506. In this view the screw 506 is seen to be threaded along its entire length.
FIG. 7 shows a tooling fixture 700 in another alternate embodiment. The tooling fixture 700 comprises central vise jaw 701 and right and left movable vise jaws 702 and 703, respectively. The movable vise jaws 702 and 703 slide on support rods 704 that are press fit into the central vise jaw 701. The movable vise jaws 702 and 703 are drawn together toward the central fixed vise jaw 701 by means of a vise screw 706 that is threaded along at least a portion of its length. The right movable vise jaw 702 and the central fixed vise jaw 701 are drilled to clear the threads of vise screw 706 while the left movable vise jaw 703 is tapped to accept the threads of the vise screw 706. Thus, in this embodiment the right movable vise jaw 702 and the left movable vise jaw 703 are different. The central vise jaw 701 and right and left movable vise jaws 702 and 703, respectively, are manufactured using aluminum or light steel that can be machined to provide custom clamping surfaces for secondary machining of specific workpieces. Right and left compression springs are not shown in this view. The central vise jaw 701 includes holes 709 for the insertion of screws to mount the fixture to a baseplate or to a work table.
Referring to FIG. 8 the same tooling fixture 700 as seen in FIG. 7 is shown in an exploded view. Features with the same numbers as those in FIG. 7 have already been described. Right and left compression springs 707 and 708, respectively, are shown in this view. In this view, vise screw 706 is shown to include an upper end 801 and a lower end 802, which is threaded. The diameter 803 of the upper end 801 is nominally the same as the outer diameter 804 of the lower end 802. Also shown is helical insert 710 to provide robust tapping to match the threads of the vise screw 706 in the softer metal of the machinable left movable vise jaw 703. The figure also shows plastic covers 711 for the mounting holes in the fixed central vise jaw 701 and a washer 712 to prevent the head of the vise screw 706 from scoring the soft metal of the machinable right movable vise jaw 702.
FIG. 9 illustrates the movement of the vise jaws 702 and 703. FIG. 9a shows the fully open tooling fixture 700 as shown previously in FIG. 7. FIG. 9b shows how the movable vise jaws 702 and 703 have moved toward the fixed central vise jaw 701 because of advancement of the vise screw 706. In this example the stiffnesses of the right and left compression springs 707 and 708, respectively, are assumed to be approximately equal as the gaps 901, 902 are equivalent.
FIG. 10 shows an array of three tooling fixtures 700 mounted on a base plate 1001. The tooling fixtures 700 are attached to the baseplate 1001 by machine screws 1002 mounted in mounting holes 709 in the fixed central vise jaw 701. The baseplate 401 can be attached to a worktable using screws (not shown) inserted through screw holes 1003 in the baseplate 1001.
FIG. 11 shows a tooling fixture 1100 in yet another embodiment. This version is the same as the fixtures shown earlier in FIG. 1 and FIG. 5, except that the fixed central vise jaw has been eliminated and replaced with a fixed central platform 1101 having the same height 1104 as the base of the dovetail features 1105 in the left and right movable vice jaws 1102 and 1103, respectively. Thus, this embodiment serves as a single-station fixture vise for oversized workpieces.
SUMMARY
A tooling fixture that provides a compact, multi-station fixture vise is described. The design provides a compact, robust tooling fixture that is easily assembled into multi-unit arrays for machining of large volumes of workpieces.
Those skilled in the art will appreciate that various adaptations and modifications of the preferred embodiments can be configured without departing from the scope and spirit of the invention. Therefore, it is to be understood that the invention may be practiced other than as specifically described herein, within the scope of the appended claims.
Patent Application
20160214235
