Abstract: The present invention provides, in a preferred embodiment, a thermostatic switch having a bimetal blade connected, at one end, to a terminal arm by means of a fastener. In accordance with the present invention, a weld electrically connects the one end of the blade to the terminal arm. The weld is located so that the fastener is located between the weld and a central, flexing portion of the bimetal blade. As a result of the placement of the weld and the fastener, weakening of the central flexing portion of the blade does not occur as is the case of a prior art connection in which the blade is welded to terminal arm.

Abstract: A thermostat, operating on the basis of current generated heat, rather than ambient temperature, operates as an equivalent of a snap-action thermostat, though without the necessity for provision of a snap-action dimple, by use of two bimetallic arms, the motion of one being restricted by the casing and a calibration dimple in or on the casing. The two bimetallic arms move, as in a creep action thermostat, upon current generation, with separation of the arms being accomplished when the restricted arm can no longer move to follow the unrestricted arm. Such thermostats are particularly valuable where a high initial inrush of current is experienced, as with an incandescent lamp fixture, when initial opening of the device, on the high current inrush, is not desired.

Abstract: A standard thermostatic switch, particularly one enclosed within a metallic casing, is provided with an insulating material, in the form of a sleeve, between the contacts or bimetallic elements and the metallic casing of the thermostat to aid in sealing the internal elements. The material is an aramide, particularly a copolymer of metaphenylenediamine and isophthaloyl chloride, particularly one marketed under the trademark "Nomex" by E. I. duPont deNemours & Co.