Abstract: A pressure responsive electric switch is described having an elongated base containing an electrical switch and terminals. The base is attached to a sensor assembly which actuates and de-actuates the electric switch in response to pressure to be measured. The sensor assembly has a composite actuator member comprising a plurality of stacked snap-acting disc members which includes at least one snap-acting disc member of a chosen low coefficient of thermal expansion and at least one snap-acting disc member of chosen high coefficient of thermal expansion material so as to provide precise pressure activation/deactivation points over a wide temperature range. In a second embodiment, the composite actuator member includes a thermal adjustment member.

Abstract: A pressure responsive electric switch is described having an elongated base containing an electrical switch and terminals. The base is attached to a sensor assembly which actuates and de-actuates the electric switch in response to pressure to be measured. The sensor assembly has a composite actuator member comprising a plurality of stacked snap-acting disc members which includes at least one snap-acting disc member of a chosen low coefficient of thermal expansion and at least one snap-acting disc member of chosen high coefficient of thermal expansion material so as to provide precise pressure activation/deactivation points over a wide temperature range. In a second embodiment, the composite actuator member includes a thermal adjustment member.

Abstract: An electric switch is shown which is responsive separately to two different conditions, i.e. temperature and pressure. The switch includes a temperature sensing disc and a pressure sensing disc both coupled through several alternate motion transfer arrangements to the movable electrical contact of the switch. Several structures are shown for mounting a switch on a surface so that the pressure sensing disc is exposed to fluid pressure and the temperature sensing disc is thermally coupled to the surface.