GB618863A - Improvements in or relating to electric motor and like controllers - Google Patents

Abstract

618,863. Control of A.C. motors; controllers ; rotary switches. IGRANIC ELECTRIC CO., Ltd. Dec. 4, 1945, No. 32744. Convention date, Dec. 4, 1944. [Classes 38 (iii) and 38 (v)] A cam-shaft electric motor or like controller comprises a frame, a shaft rotatably supported thereby, a plurality of switches supported by said frame in rows disposed in an arc about said shaft, and cams carried by said shaft, each of said rows of switches having associated therewith a common actuating element which is adapted to be actuated by said cams, by rotary movement of said shaft, and thereby is adapted to operate the switches of said row. A cam-shaft controller comprises switch blocks 1 mounted on arms 9 and 10 which are formed on the members 5 and 6. Each switch comprises a moving contact 14, which is biassed into engagement with a stationary contact 13 by means of a spring 24, and is movable to an open position by means of a plunger 25 the projecting portion 35 of which rests upon a rod 40. The rod carries rollers 41 which are moved by cams 60 and 61, the cams 60 being fixed to a shaft 2 and having a slot 62, and the cams 61 being rotatably mounted on the shaft and carrying a pin 63. The cams 60 and 61 raise the plungers 25 to open the switches except when the rollers are aligned with deep notches 65 and 66. When the shaft is turned from a position wherein the notches 65 and 66 are coincident, the cams 61 are delayed until the lost-motion between the cams has been taken up. Continued rotation of the shaft will not effect closure of any switch until the cams 61 are aligned with the rollers 41 and the shaft is reversed to re-align the notches 65 and 66. This return motion of the shaft may be made automatic on release thereof, such action being assisted by the rollers entering shallower notches in the cams. Lost-motion, equal to that between the cams, is provided between the controller handle 4 and a dial 75 so that the time position of the controller is indicated. The invention may be applied to the contro of a multi-speed alternating current motor, a cam 70 affording control of an electromagnetic main switch with no-volt release which is re-set by returning the controller handle to a position intermediate the " off " and first operative positions of the controller.