High-voltage circuit breaker with improved puffer means

摘要

Restoration of a gas-insulated type circuit breaker having a puffer assembly to "contact-closed" condition is achieved in a positive and reliable manner by providing the puffer cylinder with one or more apertures that relieve the back-pressure created by the rapid expansion of the puffer chamber during the contact-closing stroke of the arc-interrupter unit. The pressure-relieving aperture or apertures are so shaped and located that they are automatically opened and closed at the proper times by the movement of the puffer cylinder and movable contact relative to the stationary piston component. The gas-compression and puffer functions during the contact-opening operation and subsequent relief of the back-pressure condition during the contact-closing operation of the circuit breaker are thus provided without the need of check valves heretofore employed in the piston head to control the flow of the insulating gas into and out of the puffer chamber when the breaker is actuated through a full cycle of operations.