Abstract: A temperature responsive switch includes a housing, electrical contacts, an actuator arm, a rotatable shaft, and a cam assembly to open and close an electrical power circuit in response to environmental conditions. The cam assembly includes a cam and a cam follower attached to the actuator arm with a bias spring and contacting a cam surface. The cam surface has a first portion for adjusting the temperature calibration of the switch, and a second portion for positioning the cam follower in an OFF position that reduces the load on the bias spring. Thus, spring losses are avoided when the cam follower is in the OFF position, and the switch may be more accurately calibrated and adjusted when the switch is returned from the OFF position.

Abstract: A refrigeration apparatus containing a thermostat, adapted for use in a food storage compartment potentially containing a flammable gas, includes a thermostat and an enclosure forming a chamber configured to house the thermostat. The enclosure has two umbrella-type check valves configured to permit gas to pass into the chamber or out of the chamber when a predetermined pressure differential exists between the chamber and the food storage compartment. The enclosure forms a seal with the thermostat so that gas only passes through the check valves.