Thermal trip device for electrical switchgear

The invention relates to a thermal trip device for electrical switchgear, such as, in particular, circuit-breakers, motor-protecting switches and relays, consisting of bimetallic strips (1a to 1c) which are assigned to each current path and react to temperature fluctuations, a trip bridge (2) which acts as a transmission element, a compensation strip (4) and a setting device (5, 6). Arranged in parallel with the trip bridge (2) is a slide (7) which can be moved relative to said bridge. Mounted on the slide (7) are a latch (32) and a gripping lever (33), which can be prestressed by means of a tension spring. The gripping lever (33) is operationally connected to the breaker mechanism of the item of switchgear, while the trip bridge (2) acts to trip a latching pin (321) of the latch (32), and the gripping lever (33), which is subject to the action of the tension spring (34), trips the breaker mechanism. Compensation of the ambient temperature and setting of the current for the tripping current are performed by means of the compensation strip (4), which on the one hand is connected in a self-closed fashion to the slide (7), and on the other hand is connected in a self-closed or force-closed fashion to the setting device.