Abstract: A pressure-resistent locking mechanism for locking a door of a switch cell accommodating a switching device includes two pivotable locking bars positioned in hollows formed by U-shaped door edges and U-shaped portions of the wall of the switch cell at a hinge side of the door and a closing side of the door. The locking bars are pivoted between a locked position and a released position by pivoting levers against the forces of respective springs. The springs always urge the locking bars to the rest position.

Abstract: A pressure-resistant locking mechanism for locking a door of a switch cell accommodating a switching device includes two pivotable locking bars positioned in hollows formed by U-shaped door edges and U-shaped portions of the wall of the switch cell at a hinge side of the door and a closing side of the door. The locking bars are pivoted between a locked position and a released position by pivoting levers against the forces of respective springs. The springs always urge the locking bars to the rest position.

Abstract: In an arc quenching device a quenching chamber filled with sulfur hexafluoride is provided with a plurality of superimposed overlapping ascending quenching plates having openings defining arc inlets. A movable contact cooperating with a stationary contact is insertable via the arc inlets into the quenching chamber.

Abstract: An HRC-fuse as an insulating body surrounding a main fusible conductor and an auxiliary fusible conductor connected to a spring biased impact pin. A conductive cap serving as a terminal for the fusible conductors is arranged on the insulating body and is provided with an outlet opening opposite the impact pin. A tripping hollow pin or sleeve coaxially surrounds at least a part of the impact pin and passes through the outlet opening. A bimetal release pawl is arranged in the one cap parallel to the pin and being electrically connected to the fusible conductors. The pawl engages a rest on the tripping sleeve to counteract a biasing spring. The impact pin and the tripping sleeve are triggered independently one from the other either by a short-circuit current melting the auxiliary conductor, or by an overload which heats up the bimetal release and triggers the sleeve. Both the tripping sleeve and the impact pin act on a load interruptor arranged opposite the outlet opening.