A thermostat has a switch, a temperature sensor, a lever, a spring, and a control plate. The sensor generates a force to operate switch in response to the ambient temperature. The lever having an arm turns with the force from the sensor to open/close contacts of the switch. The first end of the spring is hooked to the lever to bias a force to the lever in the direction opposite to the force from the sensor. The control plate is hooked to the second end of the spring and is disposed on the lever, allowing a force for turning the lever to increase or to decrease due to turning of the control plate. The control plate turns the arm to perform the forced switch-off operation.

A temperature responsive switch includes a housing, an actuator arm for movement in response to temperature conditions, a movable contact, and an adjustable contact connected to a defrost terminal for completing a defrost circuit on demand without requiring a separate switch. The movable contact engages and disengages the defrost contact to cycle a defroster on and off in response to temperature changes in an evaporator tube, and also engages a stationary contact to complete a compressor circuit and cycle a compressor on and off in response to changes in an evaporator tube.

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.

A temperature responsive switch includes a housing, an actuator arm for movement in response to temperature conditions, a movable contact, and an adjustable contact connected to a auxiliary terminal for completing an auxiliary circuit. The movable contact engages and disengages the auxiliary contact to cycle a first element on and off in response to exceedingly large temperature swings a specified location, and also engages a stationary contact to complete a main circuit and cycle a different electrical element on and off in response to relatively modest changes in temperature changes at the same specified location.

A condition-responsive electric switch mechanism having a snap-acting bistable spring switch element carrying a movable contact, and an actuator movable in response to a detected condition to operate the bistable spring switch element. The spring switch element is capable of snapping between a circuit open position in which the movable contact is spaced from a fixed contact and a circuit closed position in which the movable contact engages the fixed contact. The spring switch element has a head mounting the movable contact thereon, and a pair of arms extending outwardly from the head being formed free of connection to one another at their distal ends opposite the head. The arms are fixed to a first terminal blade at their distal ends in a configuration deflected from the relaxed position so as to stress the switch element making it capable of snapping between the circuit open and circuit closed positions for a wide variety of preset contact gaps. The spring switch element is also capable of maintaining high contact force around the switch point.