Asea Aktiebolag

Samuel Berg

Carl E Solver

A puffer type circuit breaker is provided with a pump means consisting of a piston and a cylinder for producing a blast of arc-extinguishing gas. The movable arcing contact of the circuit breaker and the cylinder are connected to an operating device via a rod axially displaceable through an opening in the piston. In the piston there is arranged a check valve, which upon closing of the breaker opens for subsequent filling of the pump chamber with arc-extinguishing gas. The check valve comprises a guiding sleeve of a ductile material (e.g. polyetrafluoro ethylene), which sealingly surrounds the rod and is fixed with a certain axial mobility in the opening in the piston arranged for the rod. The sleeve controls (or is fixedly connected to) the movable valve means of the check valve and, in addition, serves as a seal and a bearing between the rod and the piston.

Circuit breaker with means for producing a flow of arc-extinguishing gas

The invention relates to an oil damping device intended to be used in operating mechanisms for puffer-type SF.sub.6 breakers where there is a risk that the contact movement is reversed during an opening operation with great current. The damping device comprises a piston which is attached to a piston rod and is movable in a damping cylinder. The damping device is double-acting and the movement is damped against the two end positions of the piston (corresponding to the closed and open position, respectively, of the circuit breaker) by forcing oil to flow out through restricted openings in the damping cylinder. The damping cylinder is movable inside an additional cylinder between a rest position and a lock position. Upon an opening operation, the damping cylinder is automatically brought to the lock position where it is temporarily retained by a latching member. With the damping cylinder in this position, the restricted openings arranged on the closed position side of the piston are closed, such that the piston is prevented from moving in the closing position. By providing the damping device with a nonreturn latching member, a higher breaking capacity of the circuit breaker can be achieved.

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Ludvika, Sweden

Samuel Berg