Trip free/reset free manual reset

Abstract

A thermostat having an electrically insulating housing and a push button extending therein through a bottom wall thereof. Two normally closed contacts, one fixed and the other on a movable carrier with a projection are disposed within the housing. A spring member pivotable about its center portion has an end resting against the push button and an opposite end resting against the movable contact carrier. An electrically insulating sheet is disposed over an open end of the housing with a convex outwardly bimetallic disc over and external to the insulating sheet and a cap disposed over the disc to enclose the disc within the housing. In an alarm status, the disc becomes convex inwardly and pushes against the projection on the movable contact carrier to separate the contacts. To reset, the push button is moved toward the disc and rotates the spring member about its pivot, thereby resetting the disc and pushing the end portion of the spring member against the carrier of the movable contact to maintain the contacts open. The contacts remain open until the push button is released to allow the spring member to rotate away from the carrier for the movable contact and allow the contacts to close, the disc now being in the non-alarm state. In any position of the disc, the spring member holds the contacts open if the pushbutton is pushed in sufficiently to interfere with the normal operation of the disc and contacts.