GB860042A - Improvements in time switches for controlling electric circuits - Google Patents

Abstract

860,042. Control of motors; controllers; actuation of switches. FRACHON, M. Aug. 6, 1958 [Aug. 13, 1957], No. 25148/58. Classes 38 (3) and 38 (5). A time-switch comprises an electric motor 1 driving a cam 3 which engages a spring-biased roller 4 carried by a micro-switch unit 5 pivoted at point 6, the actuating button 7 of the switch being adapted to abut an adjustable cam 8 when the cam 3 permits lowering of the switch at the position of rest of the apparatus. The switch 5 then engages contact 10, whereby actuation of push-button 17 energizes relay-coil 14 to close contacts 14a, 14b, and the motor is started whilst the relay is held closed through contact 10. After a predetermined period, the actuating button 7 leaves the cam 8 and the switch 5 is moved to the contact 9. The relay is deenergized, but the motor continues to operate until the roller 4 falls from the highest point of cam 3 and the switch 5 re-engages the cam 8. An external circuit controlled by the switch may be connected to lines 13, 18, or the circuit may be closed by relay-contact 14c. In another arrangement, which dispenses with a relay, the motor drives an additional cam for stopping the motor after one revolution of the cam 3, Fig. 4 (not shown). In a further embodiment, the motor operates at a higher speed during the idle period between the de-energization of the relay and stoppage of the motor, Fig. 8 (not shown). The motor may be reversible, the motor being started in one direction at a position of rest of the cam 3 to move the micro-switch 5 until its actuating-button engages a fixed abutment. The motor is then reversed until the cam is returned to its position of rest. A further cam closes an external circuit substantially as soon as the motor is started, and opens the circuit when the motor stops, Fig. 10 (not shown). Specification 858,552 is referred to.