Two-temperature thermally responsive fast idle control switch

Abstract

A thermally responsive electrical switch for a fast idle control in an automotive engine has two thermally responsive snap acting discs disposed in an open-ended well in a thermally conducting housing. A switch means having contacts movable between open and closed circuit positions is disposed in the open end of the well and the discs are arranged to snap at respective first and second temperatures. Resilient conductors are mounted on the switch means and are electrically connected to the respective contacts. A terminal member which completes the low cost assembly is secured to the housing to press terminals of different selected types against the resilient conductors to electrically connect the terminals to the respective switch contacts and to resiliently hold the switch means in place in the housing. The switch terminals are connected to a power source and to an electronic control for fast idle means and the switch housing is disposed in heat-transfer relation to the automotive engine to provide digital signals for regulating the control to actuate the fast idle means below the first temperature during engine warm-up, to deactuate the fast idle means when the engine heats above the first temperature during normal engine running, and to reactuate the fast idle means if the engine heats above the second temperature during extended standing or idling operation of the engine.