GB613844A - Improvements in or relating to gas-blast electric circuit-breakers - Google Patents

Abstract

613,844. Gas-blast switches. NAAMLOOZE VENNOOTSCHAP FABRIEK VAN ELECTRISCHE APPARATEN VOORHEEN F. HAZEMEIJER & CO. Nov. 16, 1945, Nos. 30738 and 30739. Convention dates, April 15, 1943, and Feb. 12, 1944. [Class 38 (v)] In a pneumatically-actuated, gas-blast circuitbreaker, compressed air supplied via a conduit 14 and a connection-box 19 to the annularspace between insulating-tubes 1, 2, acts on a spring-biassed piston 5 which descends and opens the contacts 3, 4, the air-blast exhausting to atmosphere through the open end of the tube 2. The piston 5 also carries a contact-pin 8, slidable in the socket 9 of an end-cap 10 carrying a fixed isolator-contact 12, the movable-contact 13 being operable by a rod 21 and piston, the cylinder 20 of which opens into the box 19. As shown, a plurality of tubes may be arranged in a metal-tank 22 filled with an insulating-medium having a dielectricstrength greater than atmospheric-air, such as compressed-air, oil, or insulating-compound. When the insulating-medium is solid, the isolator must be movable inside the tubes, or alternatively the breaker contacts must themselves provide an isolating-gap. In a threephase totally-enclosed arrangement, Fig. 3, the annular-spaces 35 between insulating-tubes 49, 50 terminate in a connection-box 53, which is connected to a supply-tank 31 through an electromagnetic control-valve 32, and extensions 39 of the tubes 50 pass through metaltubes 38 which reinforce the tank 31. The movable isolator-contacts are carried by a bridge 43, and are operable by a rod 44 connected to a pneumatic-mechanism 45. Specifications 611,229 and 613,433 are referred to. The invention is also applicable to the switch described in " Electrical Engineering," dated September, 1940, on pages 504-506.