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US 4,213,020 AGranted
Pneumatic operating mechanism for a circuit-breaker
AssigneeWestinghouse Electric Corp.
InventorWillie B. Freeman
Life of this patent
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AssigneeWestinghouse Electric Corp.
InventorWillie B. Freeman
Estimating the term…
The present invention relates to the utilization of a surge tank in the pneumatic line interconnecting the high-pressure reservoir with the pneumatic control valve controlling the operation of a driving, or operating piston reciprocally operable within a surrounding operating cylinder to operate a circuit-breaker. Preferably, the volume of the surge tank is roughly of the order of the piston-displacement volume traveled by the driving piston in its opening tripping movement of the circuit-breaker, when the mechanism is used to open the circuit-breaker. However, the mechanism may also be used, if desired, to effect closing of the circuit-breaker. Also, preferably, the inlet connection to the surge tank is somewhat restricted in diameter, so as to limit the gas volume exited from the main high-pressure reservoir, yet, however, nevertheless supplying a desirable biasing air pressure to counteract bouncing back, or return movement of the movable circuit-breaker parts at the end of the opening tripping operation of the associated circuit-breaker when the breaker contacts are fully open.
A circuit-interrupter including a pair of cooperable separable contacts, at least one of which is movable, a pneumatic operating mechanism for effecting opening and closing motions of said one movable contact, said pneumatic operating mechanism including a main high-pressure gas-reservoir tank (32) and an inlet control valve (36), a movable driving piston reciprocally operable within a stationary operating cylinder, linkage means interconnecting said movable driving piston to said one movable contact, said inlet control valve controlling the admission of high-pressure operating gas from said main high-pressure gas-reservoir tank (32) to the driving side of the movabe driving piston for effecting the operation thereof, a separate surge tank (34) of appreciable volume interposed in the pneumatic operating mechanism extending between the main high-pressure gas-reservoir tank and the inlet control valve for increasing the initial high-pressure gas supplied to the driving piston, and there being no valve in said mechanism between said tanks, whereby pressure in the surge tank is substantially equal to that in said main tank to effect operation of the piston when the inlet control valve is opened.
A compressed-gas puffer-type circuit-interrupter of the type involving two interrupting breaks and including an outer grounded metallic tank and a pair of terminal-bushings supported by said grounded metallic tank, a pneumatic operating mechanism (3) including a main gas high-pressure reservoir storage tank (32), an inlet control valve (36) and a driving piston (25) reciprocally operable within a stationary operating cylinder (26), the improvement which comprises the interposition of a surge tank (34) in the pneumatic operating mechanism between the main high-pressure gas-reservoir tank (32) and the inlet control valve (36), there being no valve in said mechanism between said main tank and the surge tank, wherein the volume "V" of the surge tank (34) is approximately the same volume "V" as the driving piston (25) displacement volume.
A circuit-interrupter including a pair of cooperable separable contacts, at least one of which is movable, a pneumatic operating closing mechanism for effecting the closing operation of said one movable contact, biasing means for effecting opening of said one movable contact, said pneumatic operating closing mechanism including a main high-pressure gas-reservoir tank (32) and an inlet-control valve (36), a movable driving closing piston reciprocally operable within a stationary operating closing cylinder, linkage means interconnecting said movable driving closing piston to said one movable contact, said inlet control valve controlling admission of high-pressure operating closing gas from said main high-pressure gas-reservoir tank (32) to a closing, driving side of the movable driving closing piston for effecting thereby a closing operation of the circuit-interrupter, a separate surge tank (34) of appreciable volume interposed in the pneumatic operating closing mechanism extending between the main high-pressure gas-reservoir tank (32) and the inlet control valve (36) for increasing an initial high-pressure closing gas supplied to the closing driving piston, and said mechanism having no valve between said reservoir tank and said surge tank.
Dependencies are inferred from the claim text.