Abstract: The gas blast switch of the invention has an insulating housing which is divided into an arcing enclosure for an auxiliary arc intended to build up the pressure, a storage enclosure for storing fresh quenching gas, a quenching enclosure meant for the quenching of the main arc, and an expansion enclosure. An axially movable insulating follower piston is provided within the fixed contact piece. During switching-on, it is pushed into its resting position through the action of the movable contact piece and against the force of a spring. During switching-off, it will follow the movable contact piece until the latter leaves the dividing wall, whereupon the piston stops, thus closing the aperture in the dividing wall which connects arcing and quenching enclosures. An electrically conductive ring forms the mouth of the aperture and acts as an arcing electrode between the auxiliary arc and the main arc.

Abstract: In the cut-on position of the protective switch a movable contact element engages with a stationary contact element and at the same time is exposed to the action of a force displacing such movable contact element into a cut-off position. The movable contact element is arrestable in the cut-on position by means of a locking device which can be activated by an excess current. In order to reduce the number of movable parts to a minimum as well as to avoid parts which generate heat due to appreciable thermal losses, such locking device is provided with a substantially U-shaped locking element formed of a soft magnetic material. This locking element surrounds the movable contact element with play or clearance and is displaceably mounted transversely with respect to the flow of current in such movable contact element. At least one free leg end of the locking element is provided with a stop which in the cut-on position cooperates with a stop nose which is movable together with the movable contact element.

Abstract: A fixed contact element and a movable contact element can be brought into and out of engagement with one another within a switching chamber. The switching chamber flow communicates, on the one hand, by means of a blast nozzle, closed by the movable contact element in the cut-on position of the gas-blast switch, with an expansion chamber and, on the other hand, flow communicates by means of a check or a non-return valve which opens in the direction of the switching chamber, with the pressure side of a pump cylinder arranged in the expansion chamber. Operatively associated with the pump cylinder is a movable pump piston which pressurizes the pump cylinder during a cut-off stroke with a time-delay.

Abstract: A travelling switching block for a metallic encapsulated high-voltage switching installation wherein at or in a switching block housing there are assembled together into a metallic encapsulated insulated and transportable structural unit at least one input duct or throughpassage and one output duct or throughpassage as well as power- and/or disconnector switches and possibly additional quick grounders, voltage converters, current converters and work grounders. At least each duct or throughpassage which extends upwardly in operating position is pivotable by means of an insulating medium tight pivoting mechanism into a transport position producing a smaller transverse profile.