sprungantriebsvorrichtung for an electrical switchgear, in particular for a medium voltage load break switches

摘要

A snap-action drive device for an electrical switching apparatus has a rotation spring (3) which is supported on a spring carrier (4) with built-in prestressing. When a drive shaft (1) rotates, one of the ends (35, 36) of the rotation spring (3) is driven by driver elements (43, 44) on the drive shaft (1) in the sense of increasing the stress of the rotation spring (3), while the spring carrier (4) is initially still held firmly together with the switching shaft (2) by means of a locking device (10). In the course of the rotational movement of the drive shaft (1), before reaching a rotation angle which corresponds to the switching angle, the locking device (10) is released by a tripping device (23), so that the spring carrier (4) suddenly lags the drive shaft (1) under the force of the more strongly stressed rotation spring (3) and at the same time drives the switching shaft (2). Since the rotation spring (3) is held on the spring carrier (4) by built-in prestressing, which is never undershot, springing back of the switching contacts (for example in the event of switching on into a short-circuit) is always reliably trapped by a force corresponding to the built-in prestressing, and the switching shaft (2) is thus reliably pressed into the respective switching limit position with the switching contacts, and there automatically latches once again, by means of the locking device (10). IMAGE