GB643202A - Improvements in and relating to fluid operated electric circuit breakers - Google Patents

Abstract

643,202. Fluid-break switches. BRITISH THOMPSON-HOUSTON CO., Ltd. Nov. 2, 1945, No. 29151. Convention date, Nov. 7, 1944. [Class 38(v)] The movable contact 3 of a fluid-blast circuit-breaker is operated by two pistons 19, 20 working in cylinders 22, 23 and interconnected by a rack 21 engaging a pinion 24 on a shaft 25 to which the contact 3 is connected by a link 43 and an arm 41. Upon operation of a valve 26, fluid, e.g. air, is supplied to cylinder 22 and pistons 19, 20 move to the left, thereby rotating the shaft 25 through about 180 degrees with toggle 41, 43" overset. Simultaneously, a cam 46 on shaft 25 opens a blast valve 14 to cause a blast of fluid across the contacts. The circuit-breaker is closed by opening a valve 28 and passing air into cylinder 23, whereupon the reverse movement of the parts takes place. The movement of the pistons 19, 20, is retarded by pistons 30, 31 coupled by a rack 32 engaging the pinion 24 and working in cylinders communicating by check valves 35, 37, with cylinders 22. 23. In Figs. 3, 4 (not shown), the shaft 25 operates all poles of a threephase circuit-breaker and a manual operating-lever can be put on the shaft 25 and interlocked with a valve which prevents application of the lever unless the valve is opened to exhaust the pressure gas to atmosphere. Specification 544,017, [Group VIII], is referred to. The Specification as open to inspection under Sect. 91 states that the pistons 30 and 31 may be dispensed with and that the pistons 19 and 20 may alternately function as the operating and retarding pistons. This subject-matter does not appear in the Specification as accepted.