Puffer piston circuit breaker

摘要

A puffer piston circuit breaker has a stationary contact and a movable contact, of which at least the movable contact is tubular in shape. A piston-cylinder puffer assembly is fixedly connected with the movable contact for providing a flow of gas to extinguish the arc when the cylinder and the piston are displaced with respect to each other. In order to reduce the driving force required to actuate the moving parts to effect a flow of gas, a supplemental piston-cylinder assembly is also provided, the compression space of which is compressed by a helical spring device actuated by the current during a switching operation, such that additional quenching gas is supplied to the extinguishing flow. At least part of the current is commutated onto the spring during a switching action. The helical spring is securely clamped on one end and on the other end is fixedly connected with a movable piston of the supplemental piston-cylinder assembly. When current is flowing through the helical spring, the windings contract so that the movable piston is urged against a stationary piston member at one end of the supplemental piston-cylinder assembly.