GB572418A - Improvements in or relating to machines for profile cutting or finishing - Google Patents

Abstract

572,418. Grinding profiled work. STEVENS, A. H. (Weldon Tool Co.). June 16, 1943, No. 9666. [Class 60] In the production of profiled turning tools, gauges &c., wherein an optical system is used to project, during formation, an enlarged shadow of the work on to a screen for comparison with an enlarged scale drawing of the required form, a face of the work-piece is placed perpendicular to the optical axis of the optical system whilst the cutting-tool, described as a grinding-wheel, is operated to remove material from another face to form the profiled edge ; the grinding- wheel and the work-holder are linearly and angularly adjustable and the grinding-wheel is given a working reciprocation by fluid-pressure or electrical means. The machine comprises a hollow bed 1, Fig. 1, having a laterally-projecting arm 2 supporting the outer end of a table 3 carried on struts 4 ; the table carries the work-holder and the optical system. Bridged by the table is a saddle 6 movablehorizontally on transverse ways 7 by a hand wheel 8, and mounted on the saddle 6 is a hollow vertical slide 9, Fig. 4, moving in a chamber 10 of the bed 1 and operated through gearing 14 ... 16 by a hand wheel 12. The top of the slide 9 has therein an opening to receive rotatably a boss 21, Fig. 5, on a member 22 held in position by a ring 29 and having upward extensions on which is pivoted, by trunnions 24 a rock frame 23 held in adjusted position by slots 26 and a bolt 25; the member 22 is held in adjusted angular position by bolts 27 passing through slots 28. Mounted on the frame 23 is a toolslide 31 carrying, in a casing 32, the shaft 33 of a. grinding-wheel 34 driven by an electric motor mounted in the casing 32. The slide 31 is reciprocated by fluid pressure means comprising a cylinder 40 for a piston 41<1> and a cylinder 41 for valves 49 carried by the frame 23 within the member 22, and a cylinder 46 for master valves 50 mounted outside the frame 23 ; fluid is supplied by a pump 85 mounted in the slide 9 through a pipe-line 90 and exhausted to a tank 88 by a pipe-line 96. The pipes are led to the cylinders by flexible pipes passing through the boss 21 and reversal of movement of the slide is effected by fingers 61, 62 adjustably mounted on the slide 31 and adapted to operate a lever 53 connected to valves 50. The optical system comprises a light source 105 in a casing 106, with an extension 107, a condenser lens 108, and, spaced therefrom, objective lenses and prisms, for example, as shown at 111, 112 and 113 in Figs. 11 and 12 ; the magnified shadow is received by a mirror 115, angularly-adjustable on the table 3, and reflected on to a screen 116. The screen consists of a ground glass holder 117 carried by a ring 118 rotatably mounted by rollers 119 in a support frame 122 attached to an arm on the table 3 ; the screen also carries the enlarged drawing 120. The work-holder is arranged between the two parts of the optical system and comprises a base 130 bolted in grooves in the table 3 and having thereon a guide 131 for a slide 132 movable parallel to the optical axis by a screw 133. The slide 132 carries a cross-slide'135 operable by a screw 138 and the slide 135 carries a vertically movable slide adjusted by crank and gears 140, Fig. 10, and on the slide 137 is pivoted, on a horizontal bolt 143, an L-shaped fixture 142 carrying a magnetic chuck 145 ; a pneumatic chuck or other work-holder may be employed in place of the magnetic chuck. Figs. 13 and 14 show the machine in operation on a cutting-tool with a cutting face 150 of the work held perpendicular to the optical axis 35 and the work cut to shape along lines making the rake-angle of the work with the face 150. Circular tools may be formed on the machine, and for this purpose a block 160, Fig. 19, is provided having rotatable in bushes 162 therein a shaft 161, one end of which has a screwed stub shaft extension 167 to carry the tool 169, the other end 170 being connected to a flexible shaft whereby the work is rotated. The position of the work in relation to the grinding-wheel is shown in Fig. 21, and to hold the work thus the block 160 is mounted on the work-holder fixture 142 or attached by a flange to the vertical face of the slide 137.