GB696742A - Intermittent and proportionate pattern control mechanism for machine tools - Google Patents

Abstract

696,742. Copying machines. SENECA FALLS MACHINE CO. Feb. 19, 1952. No. 4397/52. Class 40 (i). [Also in Group XXII]. A machine tool is equipped with pattern control mechanism comprising opposed torque motors and normally open or normally closed switches controlled by a rotating cam or eccentric. In the copying-lathe shown, Fig. 1 a spring-controlled stylus 31 pivots at 41 clockwise or anti-clockwise Fig. 2 from normal mid-position as it follows the contour of a templet 30 with traverse of cutting tool T lengthwise of work W and a cam or eccentric 72 continuously driven by a motor M2 Fig. 3 functions to open either switch 55 or 57 so that a corresponding torque motor M or M1 is released whereby the other motor operates to turn feedscrew 38 to move the guide plate 21 and thus the cutting tool T towards or away from the work W and also post 43 supporting the stylus assembly until with return of the stylus to midposition the switch 55 or 57 is closed and the opposing torque motors M, M1 again neutralize one another. The stylus 31 is mounted on a T shaped member 40 pivoted at 41 in a frame 42 supported by post 43 and the normally closed switches on this T-piece comprise rigid plates 50, 51 and flexible plates 52, 53 which latter extend upwards and are terminated by insulating pads 70, 71 normally spaced apart slightly less than twice the greatest radius of the cam or eccentric 72. With displacement of the stylus 31 the eccentric 72 during a part of each revolution encounters or engages one of the pads 70 or 71 to open the corresponding switch and the switch open period is dependent on the extent of the stylus displacement. In a modification Fig. 4 (not shown) the switches are normally open and as one or the other is closed by the rotating eccentric so a corresponding relay is operated to open the circuit of one of the motors.