| 摘要 |
A gas-blast switch having a housing composed of a hollow insulator body. Within such housing there are arranged a set of fixed contacts and a set of movable contacts surrounded by a blast chamber as well as a blast nozzle operatively associated with the set of movable contacts. The blast nozzle is connected with a pump device. This pump device comprises a pump cylinder movable in conjunction with the movable contact set. The pump cylinder coacts with a stationary pump piston. In the pump chamber or compartment defined by the pump cylinder there merges a nonreturn or check valve which opens towards such pump chamber. By means of such nonreturn valve there is sucked-up pressurized extinguishing gas during the course of the cut-on switching-on stroke of the gas-blast switch. The pump chamber is connected by means of this nonreturn valve with a supply compartment which, in turn, communicates by means of labyrinth-like extending flow paths with the blast chamber. The supply compartment is advantageously formed in a hollow body, for instance of cylindrical shape, the end face of which is structured as the pump piston. The access or communication between the blast chamber and the supply compartment is spaced as far as possible from the nonreturn valve which leads to the pump chamber. |
