Gas-blast switch

摘要

A stationary contact element and a movable contact element are coupled to a drive unit. The movable contact element is surrounded by a co-movable blast nozzle which has an inlet flow communicating with a pump chamber surrounded by a pump cylinder. The pump cylinder is conjointly movable with the blast nozzle and the pump chamber contains an extinguishing gas which is pressurizable during a cut-off stroke. The pump chamber is bounded by the blast nozzle at one of its ends and by a spring-biased pump piston at its opposite end which is displaceable to a limited extent when the pressure in the pump chamber increases. A shock absorber is operatively associated with the spring-biased pump piston. To effectively attenuate the high-frequency pressure peaks generated by the switching arc and retroacting into the pump chamber the shock absorber and the spring biasing or supporting the pump piston are arranged such that the shock absorber only responds at the end of the stroke of the spring supporting the pump piston.