Siemens Aktiengesellschaft

Albert Warnest

Friedrich Ebnet

A tripping device for a thermal protection relay, particularly a bimetal relay, has a pivoted U-shaped support bracket for a tripping lever, can be adjusted by means of an adjusting dog, and acts on a set of contacts. The U-shaped support bracket has a crosspiece which carries one end of U-shaped temperature compensation strip. The other end of the strip rests against the adjusting dog. The support bracket has support points for the support bracket and the tripping lever lying one behind another in the longitudinal direction of the bracket legs, starting at the crosspiece. This relay design results in reduced cost of assembly and in reduced overall relay size. Also, a heretofore required contact pressure spring for the temperature compensation strip is dispensed with.

Tripping device for a thermal protection relay

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.degree.. 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.

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Freudenberg, Germany

Albert Warnest