Thermostat with thermal insulator for protection against overheating

摘要

An electrical resistance heater is positioned adjacent to a bimetal disc in a thermostat for depressing the temperatures at which the disc snaps between oppositely bowed positions to open and close a switch. A thermal insulator interposed between the heater and the thermostat housing protects the housing against overheating and properly locates the heater relative to the disc. A dielectric film on the surface of the disc that faces toward the heater insures adequate electrical spacing between the heater and disc.