Drain devices in hydraulic control circuits
OwnerJean Louis Gratzmullerinventor
Life of this patent
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Abstract
The invention relates to drain devices in hydraulic control circuits, particularly for hydraulic ultrarapid release control of a circuit breaker. In order to enable rapid decompression and draining of high pressure fluid in an hydraulic jack which controls the circuit breaker, a plurality of drain valves are mounted directly on the jack in a cascade arrangement. The valves are hydraulically controlled by oil pressure on pilot jacks and are of progressively increasing cross-sectional areas. All the valves in cascade are physically coupled to one another and the setting to drain of the valve with the smallest cross-section is controlled by an electrovalve.
Claims14
A valve device for draining high pressure liquid from an enclosure, comprising a body defining at least two aligned cylinders of successively increasing internal diameter, a piston slidably disposed in each cylinder and dividing the same into a discharge chamber and a pressure chamber, each discharge chamber having an outlet port and an inlet port forming a valve seat, a valve element carried by each piston for closing against said valve seat, the inlet port of the largest diameter discharge chamber communicating with said enclosure and the inlet port of any smaller diameter discharge chamber communicating with the pressure chamber of the adjacent larger cylinder, means for supplying liquid under pressure to all the pressure chambers whereby to move each valve element through the related piston towards its valve seat and maintain it in the seated position, and means for discharging the pressure liquid from the smallest diameter pressure chamber in response to a drain signal.
Dependencies are inferred from the claim text.