GB1240175A - Drilling jig - Google Patents

Abstract

1,240,175. Drill jig. VIKTOR CHO. 25 Oct., 1968 [28 Oct., 1967], No. 50882/68. Heading B3C. A drill jig comprises adjustable supports 5, which releasably support holders 8 of drill bushes of different sizes. The base-plate 1 of the jig has secured thereto a fixed work-locating angle 2, and a tiltable work-clamping angle 3, which is also adjustable along base-plate 1. Rails 17, 18 are supported on replaceable pillars 21, and have screw-threaded holes 20 to which supports 5 are secured at 13. Screws 14 for the supports have heads 14 which co-operate with a groove 15 in rails 17, 18 and the latter can be located at various heights by providing pillars 21 of different heights. The workpiece is clamped by a bar 29 located in one of the grooves in angle 3, when the latter is tilted against springs 27, by tightening a screw 28. A vernier or like gauge 45, 46, Fig. 3, carries a plunger 52 which locates a drill bush, after the plunger is set in the required position. When drilling holes in the periphery of shafts a protractor 60, Fig. 5, is provided, and has a pointer 70 which is secured to the end of the shaft by a permanent magnet 69, or is secured on the periphery of the shaft by a vee-block. As the centre of any diameter shaft being drilled lies on the line 63, the protractor is adapted to be moved along a scale 65 to a position according to the diameter of the shaft and the pointer then indicates the angle through, which the shaft is rotated. The jig is located on a ball-bearing support 33 for easy movement, and the balls 35 are retracted by a handle 39, when the jig is in the drilling position.