GB562967A - Improvements in or relating to fluid pressure operated electric circuit interrupters - Google Patents

Abstract

562,967. Actuation of switches. WESTINGHOUSE ELECTRIC INTERNATIONAL CO. April 7, 1943, No. 5575. Convention date, April 7, 1942. [Class 38 (v)] In a fluid-pressure actuated switch in which the fluid is exhausted in advance of the moving piston, a normally-closed valve is employed for throttling the exhaust a predetermined amount to cushion the movement and is adapted to be opened by operating fluid supplied to the cylinder and to remain open for a given time after the supply has ceased. The invention is described in its application to the switch of Specification 563,641 in which a disconnect contact 39 is mounted on a double-acting piston 105 in a cylinder 103 supplied at the ends with closing and opening fluid through pipes 183, 175, respectively leading to spaces 149, 153 which communicate with the cylinder through passages 151, 155. Normally these passages are closed by cup-shaped. valves 235 all but for one or more leak holes 243 which permit of a restricted exhaust of the fluid. When operating fluid is supplied, however, the valves are depressed against spring-action 239 so long as the pressure is sustained, but when the pressure is removed a bleed hole 240 permits slow return of the valve to throttling position. In cases where rapid automatic reclosure is desired,. therefore, the relatively-high opening .pressure can rapidly exhaust before the valve returns to its throttling position.