Gas-blast circuit breaker

摘要

A gas-blast breaker with two contact members which are movable relative to one another. Each contact member is provided with a respective sparking contact. The contacts communicate with a cylindrical compression chamber whose volume varies as a function of the movement of the contact members and which is filled pressurized gas. A channel leading into a quenching zone between the sparking contacts extends into a first one of the two end faces of the compression chamber. A second one of the two end faces is bounded by a piston which is displaceable along the cylinder axis of the compression chamber and which is subjected to the action of a tensioned spring. The circuit breaker is suited for reliably interrupting both small and large currents, with a comparatively weak and simple drive mechanism for the movable contact member. The piston interacts with a fixed stop which is arranged such that the movement of the piston which is subjected to the action of the tensioned spring is blocked, below a predetermined first gas pressure in the compression chamber, against the movement of one of the contact members which is moved upon the occurrence of a breaking operation in the circuit breaker.