Circuit breaker with means for producing a flow of arc-extinguishing gas

摘要

A puffer type circuit breaker is provided with a pump means consisting of a piston and a cylinder for producing a blast of arc-extinguishing gas. The piston is axially displaceable against a spring force, and the cylinder is joined to the movable contact of the circuit breaker and arranged, during a breaking operation, to compress the gas in the cylinder space of the pump means to achieve a blast of extinguishing gas towards the contact area. A spring holds the piston pressed against a stop in the closed as well as the open position of the circuit breaker. The spring has such a high pre-stress that the piston only moves upon breaking of short-circuit currents.