Abstract: A high limit thermostat for gas furnace applications is shown having a molded base plate and an elongated housing formed integrally with the base plate which mounts a thermostat at a free end of the housing in order to be positioned within an air stream of a heat exchanger to sense temperature conditions of the air stream. An extended version is shown in which one end of a pair of elongated terminals are received in slots formed in the housing with the thermostat mounted on the opposites ends of the elongated terminals.

Abstract: Disclosed is a relay for high current equipment, such as, for example, an electric range. The relay provides the interface between the solid state electronics and the high wattage electric heating elements. The relay is comprised of a frame having a non-electrically conductive, flexible substrate, such as a plastic substrate supported at its ends with a shallow V cross section. The substrate has conductive heater elements formed thereon with heater terminals connected to said elements. The plastic substrate has a high coefficient of thermal expansion. A biasing member in contact with the apex of the plastic substrate transmits forces between the substrate and a switch assembly, either creep or snap acting. The upper switch arm preloads or couples a force between the biasing element and the plastic substrate causing a shallow V to be formed in the substrate. When current is applied to the heater terminals and heats the heater element, the substrate expands.

Abstract: A current sensing, self-heating device for protecting equipment against abnormal current levels which is automatically resettable under mild overcurrent conditions and nonresettable under severe overcurrent conditions. The device comprises a thermostat metal assembly with a temperature compensating portion and an actuating portion which is placed adjacent a nonresettable two-position snap-acting blade electrically connected to ground. During normal operation current flows from the line source through the actuating portion of the thermostat metal assembly to the equipment. However, if an overcurrent condition occurs the heat generated in the actuating portion of the assembly will bend the assembly and cause it to make contact with the blade shorting the current from the line source to ground.