GB911080A - Improvements in electrical remote control systems, more particularly for actuators - Google Patents

Abstract

911,080. Control of motors. RATORCK ENGINEERING CO. Ltd. April 6, 1961 [March 17, 1960], No. 9512/60. Class 38 (3). Relates to a remote control system for a valve which is actuated by an electric motor having reversing contactors 10, 11, associated with limit switches 15, 16. When switch 28 is in its " closed " position, current passes through resistors 26, 27, and relays R1, R2, this current being only sufficient to operate relay R2. The circuit of contactor 10 is completed through normally closed contacts 19 of relay R1, the energization of relay R2 being used to open switch 29 in series with signal lamp 31. If the line is open-circuited beyond terminals 1, 2, the relay R2 will drop out to energize lamp 31. To open the valve, switch 28 is operated to by-pass the resistor 26, the increased current being sufficient to actuate relay R1 which closes contacts 20 to energize contactor 11. The limit switch 16 is opened when the valve reaches its extreme opening position. If the control line is opencircuited beyond terminals 1, 2, and relay R1 is de-energized to re-close the valve and the signal lamp is energized. In a modification the remote control circuit is broken when the valve is moved away from either of its extreme positions, the circuit being re-made just before the limit switch is actuated. The valve-position is indicated by additional signal lamps. A further relay is used to indicate a short-circuit, Fig. 2 (not shown). In another embodiment, the control is provided from three remote points by means of push-buttons. A relay in shunt with the supply to the control circuit controls the resistor 26 and signal lamps for indicating the open or closed position of the valve. This relay is dropped in the event of a short-circuit. Specifications 842,581 and 865,565 are referred to.