GB587448A - Improvements relating to the design and construction of jigs and fixtures - Google Patents

Abstract

587,448. Work-holders. WHARTON, W., and WHARTON, J. Nov. 9, 1943, No. 18631. [Class 83 (iii)] A jig is built up from a multiplicity of interchangeable standard elements each furnished with one or more T-slots, or tenon slots or tenons or any combination of T-slots, tenon slots or tenons adapted to locate and secure the elements relatively to one another and to a base or to a frame or frames attached to the base, on which they are mounted and secured to form a complete unitary structure. Fig. 1 shows a number of elements 1, 2, 3 and 4 of various forms and heights which may be assembled together on a base to form a structure of given height. The elements have T-slots 8 on their surfaces which co-operate with interlocking tenons 9. A laterally extending element 8x is mounted on a side face of the element 1. Elements may be provided with variable tenons comprising parts 5 and 6, Fig. 1a, adjustable by screws 7 in order to fit tenon slots of different widths. Vertical and horizontal bolt holes may be formed through the elements. The element shown in Fig. 4 comprises upper and lower members 13, 13x having internal cams 19, 20, the cam 20 being fixed and the cam 19 being rotatable relatively to the member 13 by means of screws 21 passing through arcuate slots. Movement of the cam 19 varies the height of the element which is preferably provided with a vernier scale. A further form of adjustable height element comprises upper and lower members with inclined co-operating faces. Elements may be provided with holes to receive the dowels of cylindrical.members mounted on the elements to serve as location pins. Fig. 8 shows elements arranged to form a sine-bar structure, an element 50 carrying two setting V-blocks 52, 53 and the upper element 55 carrying cylindrical bars 56 attached to its underside by screws. The parts are secured together 'by a pivotally mounted screw and a spherical nut element 58. A standard element may be rotatably mounted, by a spigot and socket, on a base element provided with a graduated scale. The table base element shown in Fig. 13 comprises angularly adjustable members 70, 71 having peripheral slots 75, 76 which may serve to locate setting- elements 77, 78. Another form of circular base element comprises a face plate 86, Fig. 15, having a number of radial T- slots 87 in which are mounted slides 89 carrying clamping members 90 or stop members 91. Rough adjustment and clamping of the slides is provided by serrations 88 on the upper surface of the plate and the lower surface of the slides, fine adjustment being effected by screws 92.