GB656391A - Improvements in or relating to manually operated switches - Google Patents

Abstract

656,391. Controllers ; snap-action switches; mechanical switches. O'DELL, A. E. (Sauter Akt.-Ges. Fabrik Elektr. Apparate, F.). July 5, 1945, No. 17181. Classes 38(iii) and 38(v)] A manually-operated selector switch which may be used for controlling a threephase machine-tool motor, permitting of two forward speeds and two speeds in reverse, comprises a shaft 1 carrying a series of cams 2 which operate selector contacts 3 for the motor circuit, and an auxiliary cam 4 which operates a contactor 5 controlling a circuit breaker 12 in series with the selector contacts, the circuit being made by the auxiliary device after the selector contacts engage, and broken before the selector contacts separate. The operating handle 6 is of the type which can be swung into the positions shown in Fig. 2, and the camshaft 1 which it rotates is hollow and of square cross-section to receive a rod 7 which can be moved longitudinally by rocking the handle 6 in the direction of the axis of the shaft, thereby controlling the movement of a spring- biassed lever 8 which operates to open or close contacts 9, 10 in the circuit of the energizing coil 11 of the circuit' breaker. A pair of spring-pressed rollers engaging a toothed disc 20 on the shaft 1 serve to hold the shaft in any position to which it is rotated. The annular cam 4 opens the auxiliary contact 5 when the lever 6 is in the position O 2 of Fig. 2 or in positions between the other stops designated thereon, and closes the contact 5 when the lever is in any of the operative positions V 1 , V 2 , R 1 , R 2 . The motor is started by swinging the lever 6 arcuately into the desired position and then rocking it into position E to move the rod 7 to allow the auxiliary contact 9 to close and thereby closing the circuit of the circuit breaker coil 11 over contacts 5 and 10. The motor is switched off by rocking the lever 6 into position. A Remote control may be provided by pushbuttons 21, 22.