GB878658A - Improvements in and relating to gas blast circuit breakers - Google Patents

Abstract

878,658. Gas-blast switches. SOC. GENERALE DE CONSTRUCTIONS ELECTRIQUES ET MECANIQUES (ALSTHOM). March 12, 1958 [March 19, 1957; July 4, 1957; July 22, 1957], No. 7985/58. Class 38 (5). A gas-blast circuit-breaker with a pressure chamber and a discharge chamber connected by the contact gap when the contacts separate, has a blast value in the wall of the discharge chamber and lever linkage in the discharge chamber connecting the moving contact to a power drive. In Fig. 1 pressure gas from the reservoir 9 passes through passages 13 to the pressure chamber 1, 19. When a coil 10a operates a valve 10 gas passes to a piston 7 driving a rod 5 to the right against a bias spring 6. The rod 5 moves a pivoted lever 4 having a lost-motion connection with the contact 3 and coupled to the valve 15 by linkage 17 including links a, b which are moved over-centre by a lever d to allow the valve 15 to reclose at the end of the contact travel when the lever d engages a stop f. Alternatively, the linkage may be moved over-centre by pneumatic means (Figs. 5 to 7, not shown). In Fig. 8 (not shown), the blast valve also controls gas from auxiliary contacts in series with a parallel switching resistor. The valve may also control the gasblast from two sets of series contacts (Figs. 9 and 10, not shown). In Fig. 11 the valve 110 opens and drives the extension 109a of a contact actuating rod 109 which can also be driven by a piston 117 fed with pressure gas through a narrow pipe 115. The contacts 3 are operated by means of an over-centre spring 114 and closing movement is effected by the admission of pressure gas to a pipe 118.