| 摘要 |
<p>A device for shifting a contact arrangement in a thermally operating protective relay having a make contact, a break contact, as well as a double-throw contact, provides for shifting the arrangement from self-locking to automatic resetting by shifting the make contact by means of a piston which can be locked. The self-locking condition provided can be cancelled by arranging the make contact for motion, in the closing direction, by the piston which is supported so as to be freely movable. The plunger has a resilient hook which can snap into undercuts in the housing of the relay which establish the end positions of the plunger. The undercuts are arranged in steps so that two different end positions for the plunger are obtained when the plunger is rotated approximately 90 DEG . One end position corresponds to the automatic resetting of the contact arrangement. The other end position makes it possible to move the plunger to cancel the self-locking condition. Using this structure, only one piston is needed, and the shift can be made with one hand.</p> |
