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AssigneeWestinghouse Electric Corp.
InventorJoseph R. Rostron
Estimating the term…
A puffer-type gas-blast circuit-interrupter is provided having an operating cylinder movable over a fixed composite piston structure, the fixed composite piston structure providing a variable cross-sectional area by means of a secondary piston area, preferably annular in configuration, which is releasably latched in a fixed forward position, and, subsequently, during the opening operation of the breaker, collapsed to a retracted position. The composite piston arrangement may be such that upon collapse of the secondary "fixed" piston, the diameter of the surrounding movable operating cylinder may be such as to closely surround the central area of the primary fixed piston structure to retain high-pressure gas within the piston-compression chamber without loss. There results, by the utilization of the variable-area fixed composite piston structure, an improved interrupting performance of the circuit-interrupter by giving very high gas pressures early in the opening stroke of the circuit-interrupter, as compared to prior-art conventional structures, which provide such high gas pressure only at a later time in the opening stroke by conventional piston means.
A puffer-type compressed-gas circuit-interrupter including means defining a relatively stationary contact structure, means defining a cooperable movable contact structure, operating means including a movable operating piston-cylinder carrying said movable contact structure and slidable over a composite piston structure, said composite piston structure being within said operating cylinder and comprising a centrally-disposed primary relatively fixed piston and a surrounding annularly-shaped secondary movable piston structure, means releasably latching said secondary annular movable piston structure in a forward position towards the stationary contact structure during the initial portion of the opening operation of the circuit-interrupter, means effecting a collapse and a retracting movement of said secondary annular movable piston structure at an intermediate point during the opening operation of the circuit-interrupter, whereby the cross-sectional area of the composite piston structure is variable to thereby bring about a fast attainment of high-pressure gas in a piston compression chamber on one side of the composite piston structure during the initial portion of the opening stroke.
A compressed-gas type of circuit-interrupter including means defining a composite piston structure including a fixed primary portion and a movable secondary portion, a movable operating piston cylinder containig said composite piston structure and having two effective diameter portions, said operating piston cylinder carrying a movable contact and a movable insulating orifice slidable over said composite piston structure, means defining a relatively stationary contact, means releasably latching the secondary portion of the composite piston structure in a forward position in a direction toward the stationary contact, means effecting a reduction of the cross-sectional area of the composite piston structure during an intermediate portion of the opening operation by releasing said latching means, whereby the smaller diameter portion of the operating cylinder slides over the fixed primary portion of the composite piston structure, and means including said operating piston cylinder for trapping high-pressure gas on one side of the composite piston structure following collapse of the secondary movable piston portion.
Dependencies are inferred from the claim text.