Abstract: A condition responsive control is disclosed which includes a support housing, a snap switch supported by the housing having first and second control conditions for governing operation of a condition altering device, a condition responsive actuator system supported by the housing remote from the switch and a lever system coacting between the switch and the actuator for enabling operation of the switch between its conditions.The actuator coacts with the lever system via a lost motion mechanism which enables the establishment of a differential between the sensed condition levels at which the switch is operated. The lost motion mechanism is adjustable to alter the sensed condition levels at which the switch is operated throughout a relatively wide range and is also adjustable to permit the extent of the differential to be changed.

Abstract: There is disclosed a thermally responsive actuator useful for solenoids of electromagnetic valves and the like that includes a thermally responsive assembly of first and second metallic members that function as a thermocouple to generate an electrical voltage and also as a bimetallic operator for a switch carried within a housing of the device and operative to make and break the thermocouple circuit.

Abstract: There is disclosed a thermally responsive switch that is ideally suited for responding to the ignition and extinguishment of a flame. The switch is provided with two switch poles, one that is biased normally open and the other that is biased normally closed. The response of the switch to the presence of a flame is very sensitive and precise to open the normally closed contact within a few seconds after ignition of a flame and, shortly thereafter within another controlled time period, to close the normally open contact. Upon extinguishment of the flame, the switch reverses its movement, opening the normally open contact within a short time interval, and, thereafter, closing the normally closed contact. The switch mechanism employs a thermally responsive, tube-in-tube member with the inner tube connected to a push rod which resiliently carries a switch lever.