Abstract: The undervoltage tripping device has an electromagnet with a magnet winding (3), a core (10) and an armature (20) and a tripping member (50) able to perform a tripping movement. In the ready-to-trip state the armature is in an attracted position on the core, is spring loaded in the dropping direction, but is prevented from dropping from the core by the magnetic force of attraction produced by the electromagnet. The tripping member is also spring loaded in this state, but is prevented from performing the tripping movement by the attracted armature. The electromagnet is a d.c. magnet. A rectifier is provided for rectifying the current flowing through magnet winding. Mechanical aids are provided for feeding the armature into the attracted position. The tripping member is latched in self-release manner in the ready-to-trip state. The latching effect is released when the armature drops.

Abstract: A novel fixing element (5) is proposed which extends over the entire housing base (2) of the switching device (1) and, with the housing base (2), forms a locking mechanism. Provided in the housing base (2) is a rectangular recess (3) which is substantially wider than the width of the profiled rail (4) and forms a nose (24) which grips round the profiled rail (4). The locking mechanism is formed by one end of the fixing element (5), and the other end has a second nose (23) which grips round the profiled rail (4). The fixing element (5) can subsequently be attached to the riveted or screwed-together switching device (1).

Abstract: A tripping device (1) for circuit breakers comprising a thermally influenceable wire-shaped tripping element (4) is presented, one end of which is attached to a rotatably supported tripping lever (3) which is under spring force and the other end of which is fixed in location. The thermally influenced lateral movement at one end of the tripping element (4) causes the unlatching of the circuit breaker. At the free end of the tripping lever (3), a locking element (11) is provided which engages a cam (10) of a contact lever (2) which is under spring force, in such a manner that the circuit breaker is switched off both with contraction and with expansion of the tripping element (4).