GB1253310A - Gas blast circuit-breaker - Google Patents

Abstract

1,253,310. Gas blast switches. COQ N.V. 10 Dec., 1969 [20 Dec., 1968], No. 60282/69. Heading H1N. In a gas blast switch, of the kind with two movable contacts which during an interruption initially move in the same direction until the trailing contact is arrested, each contact being mounted on an operating piston 7, 12 biased in the opposite direction by springs 10, 15 and a blast valve 16, 18 surrounding the contacts and being opened by the initial conjoint movement thereof, the underside of piston 7 is permanently subject to the high pressure gas in chamber 19 which tends to move the contacts in the opening direction, the contacts being held in the closed position by a latch 38. To cause an interruption a secondary latch 49 is withdrawn; high pressure gas drives a piston 40 carrying the latch 38 releasing the contacts. The pressure acting on piston 7 moves both contacts upwards opening the valve 16, 18. With the contacts still closed pressure in space 57 rises, acting on piston 12 to drive it upwards while piston 7 engages block 60 and the contacts separate. When the latch 38 is withdrawn a valve 46 is changed over. After a delay caused by a throttle 54 the high pressure gas drives a piston 37 to the right changing over a second valve 28 connecting the spaces 6b, 11b and 42b to the high pressure gas; the pressure is thus equalized on pistons 7, 12, 40 and they are returned to the position shown by respective springs 10, 15, 45 reclosing and relatching the contacts.