PUFFER-TYPE GAS-BLAST CIRCUIT-INTERRUPTER HAVING VARIABLE-AREA STATIONARY COMPOSITE PISTON STRUCTURE

摘要

45,674PUFFER-TYPE GAS-BLAST CIRCUIT-INTERRUPTER HAVING VARIABLE-AREASTATIONARY COMPOSITE PISTON STRUCTUREABSTRACT OF THE DISCLOSUREA puffer-type gas-blast circuit-interrupter isprovided having an operating cylinder movable over a fixedcomposite piston structure, the fixed composite pistonstructure providing a variable cross-sectional area by meansof a secondary piston area, preferably annular in configuration,which is releasably latched in a fixed forward position,and, subsequently, during the opening operation of thebreaker, collapsed to a retracted position.The composite piston arrangement may be such thatupon collapse of the secondary "fixed" piston, the diameterof the surrounding movable operating cylinder may be such asto closely surround the central area of the primary fixedpiston structure to retain high-pressure gas within thepiston-compression chamber without loss.There results, by the utilization of the variable-area fixed composite piston structure, an improved inter-rupting performance of the circuit-interrupter by givingvery high gas pressures early in the opening stroke of thecircuit-interrupter, as compared to prior-art conventionalstructures, which proved such high gas pressure only at alater time in the opening stroke by conventional pistonmeans.