Abstract: A circuit breaker is disclosed in which a compressed quenching medium, heated by an arc, is rapidly removed from a main duct in such a manner that the arc is effectively blown by axially opposing flows of quenching medium. The circuit breaker includes a nozzle made of an insulating substance and having the main duct. A first contact piece is slidingly accommodated in the main duct, and a second contact piece is fixedly connected to the nozzle. The nozzle includes a first blow duct having a first blow orifice, and an exhaust duct having an exhaust orifice. A second blow duct having a second blow orifice is included between the nozzle and the second contact piece. The first and second blow orifices are axially spaced from each other, and the exhaust orifice is located between the first and second blow orifices.

Abstract: A sliding seal assembly is provided to admit an operating shaft into the sealed high pressure housing of the interrupter of a high voltage circuit breaker. A heater is contained in the assembly and is coupled to the seals by heat conductive members to maintain the seals at a high enough temperature to ensure their integrity even when the external temperature falls below -55.degree. C.

Abstract: A gastight seal arrangement for an actuating rod that passes through a wall of a gas-filled enclosure is described. The actuating rod includes a pair of flanges that are spaced longitudinally of the rod and are positioned on opposite sides of the wall of the enclosure. Impact seals on the interior and exterior of the wall surround the actuating rod and are engaged by the respective flanges corresponding to the position of the rod. Additional seal members are provided in the interior of the wall to prevent leakage along the surface of the actuating rod.