Electromagnetic relay with pivotable armature

Abstract

A relay has a contact assembly and an electromagnet with a L-shaped pivotable armature rockable with its inside angle supported against a complementary yoke edge. A base mounting the electromagnet and the contact assembly is formed with a retainer rib which is opposed to the yoke edge so as to loosely engage the angled portion of the armature therebetween but to prevent the inside angle of the armature from departing beyond an allowable distance from the yoke edge. A movable spring included in the contact assembly is operatively connected to a first leg of the L-shaped armature so as to be driven thereby to close the contacts in response to the energization of the electromagnet. The armature in the reset position has its free end rest on a fulcrum projection on the base and receives a return bias from the movable spring at a point inwardly of the fulcrum projection such that the return bias of the movable spring acts as a torque which causes the armature within the allowable distance from the yoke edge to pivot about the fulcrum in a direction of urging the inside angle of the armature toward the yoke edge to such an extent that, upon energization of the electromagnet, the inside angle of the armature can be firstly attracted to the yoke edge into exact coincidence therewith, ensuring an accurate pivotal movement about the yoke edge without requiring a conventional retainer spring which constantly urges the inside angle to the yoke edge.