Gas-blast switch

Abstract

A gas-blast switch having a hollow support insulator, and and at least one switching chamber housing supported thereon and within which there is arranged a set of fixed contacts, surrounded by a blast chamber, and a set of movable contacts. A blast nozzle coacts with the movable contacts and is connected with a pump device having a pump cylinder surrounding a pump chamber and movable with the movable contacts. The pump cylinder is displaceably arranged upon a stationary piston. A check valve opens towards the pump chamber. During the cut-on stroke pressurized gas is sucked by the valve into the pump chamber. The latter is connected by the check valve with a supply compartment communicating via inlets with the blast chamber and the internal space of the support insulator. A further valve is responsive to the pressure increase in the blast chamber, which valve, when responsive, interrupts the connection between the internal space of the support insulator and the inlets. The supply compartment is preferably formed by a cylindrical hollow body whose one end face serves as the pump piston, whereas at the end region of the outer surface of the hollow body furthest from such piston there are formed the throughpassages or inlets as axially lengthwise extending slots. The valve may be a plate valve whose valve plate coacts with a valve seat affording access to the internal space of the support insulator and further, in its open position, subdivides the inlets into two sections, one opening into the supply compartment, the other by means of the valve seat into the internal space of the support insulator.