Abstract: A metal-encapsulated, gas-insulated high-voltage circuit-breaker includes a fixed contact configuration which is accommodated in its own fixed contact housing, and a moving contact piece configuration which is driven by a first drive and is accommodated in a contact housing that is connected to the moving contact piece configuration or can move with said contact piece configuration during a switching operation. The contact configurations may have contact pieces for a rated current and for guiding and extinguishing an arc. At the same time, a device is provided for producing a gas flow. The device includes a dielectric nozzle in which the arc burns and is blown and which is guided in a sealed manner in the fixed contact housing throughout an entire switching operation.

Abstract: A circuit breaker, in particular a high-voltage circuit breaker employing SF.sub.6 gas, possesses a fixed contact part, and a movable switching piece which is provided with a blast nozzle and can be actuated by a drive. During the process of tripping out, a compression space is rendered smaller to generate a flow of gas towards the blast nozzle and an arc produced during switching out by movement of a movable cylinder over a stationary piston head. In order to reduce the drive power, the compression space is surrounded by a coil for generating a magnetic field. The coil is capable of being switched into the current path in such a manner that, during the process of tripping out, current does not flow through the coil until disconnection has been effected at the main contact point. An auxiliary piston is located in the compression space. The auxiliary piston is capable of being driven by the magnetic field toward the contact point in order to render the compression space smaller.

Abstract: 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.