Abstract: A thermostat includes a case assembly with two terminals and movable contacts, one of which is on a resilient blade to open and close a circuit through the terminals. A bimetal disc actuates the blade by heating to open the contacts. A base defines an interface with the case assembly and supports the disc; the interface being deformed or crushed sufficiently to position the blade to define the threshold temperature and to couple the base and case assembly together. The deformable interface is preferably formed by upstanding, curved projections on the base and mating with the case assembly. When deformed, the projections are substantially perpendicular to the bottom panel of the base so that the disc is centered, but is freely movable. Bendable legs secure a cap in position and lock the case assembly and the base together.
Abstract: A thermostat includes a case assembly with two terminals and movable contacts, one of which is on a resilient blade to open and close a circuit through the terminals. A bimetal disc actuates the blade by heating to open the contacts. A base defines an interface with the case assembly and supports the disc; the interface being deformed or crushed sufficiently to position the blade to define the threshold temperature and to couple the base and case assembly together. The deformable interface is preferably formed by upstanding, curved projections on the base and mating with the case assembly. When deformed, the projections are substantially perpendicular to the bottom panel of the base so that the disc is centered, but is freely movable. Bendable legs secure a cap in position and lock the case assembly and the base together.
Abstract: A tuning element for a temperature responsive switch includes a bimetal assembly in the form of an elongated, relatively flat bimetal strip with bending action and including integral tuning webs for adjusting the thermodynamic properties of the element. Multiple apertures are punched in a predetermined pattern in the bimetal strip to form the webs. Each of the webs is also bent in alternate directions to form ribs that reinforce the element. The bimetal strip is formed from a bimetal base portion and extension portion butt welded together; the webs being formed in the strip adjacent the weld joint. The base portion of the strip bends to open the contacts and the extension portion bends to bring the contacts back closer together, thereby controlling overshoot and providing consistent operation within a relatively narrow temperature range.