US Patent 7307505 Safety switches

A switch includes a push rod which extends from an underside of a switch member and the push rod selectively pivots an action member in “ON” and “OFF” positions. A bi-metallic contact plate has a first end fixed to one of two terminals and a contact portion splits from the contact plate. A first contact point is connected to an underside of the contact portion so as to contact a second contact point on the other terminal when in “ON” position. A free end of the contact portion is connected with a free end of a spring member which is fixed on the contact plate. There is a sufficient space for the upward movement of the action member when overloaded.