Abstract: Such switches have current connections for contacts. One contact may be a fixed contact and the other contact may be a mobile contact. A drive opens the mobile contact when a predetermined electric current intensity is exceeded. The electric drive is a thermoelectric drive. For that purpose, the contacts (2,3) are arranged in a closed housing (1) made of an insulating material and a disk-shaped resistive member (4) is arranged between the contacts (2,3). A switch of this type may also be advantageously designed as a bistable limiter.

Abstract: A remotely changeable thermostat for a refrigeration or air conditioning system and method and system employing same. The thermostat has a fluid filled capsule with a diaphragm movably responsive to fluid expansion and contraction for actuating, via lever means, a compressor power switch. The capsule senses temperature via a fluid filled capillary. A separate remote user activated switch energizes an electrical actuator for moving the fulcrum of the lever means to change the sensed temperature of the evaporator at which the power switch is actuated. The user activates a remote switch to energize an electrical heater coil for heating a bimetal strip which moves the fulcrum for the lever means between a high or low temperature setting for compressor power switch actuation in response to user opening or closing the remote heater switch.

Abstract: A control system and control device for controlling a heating unit and method of making the control device are provided, the control device having a rod and tube temperature sensing unit for providing linear motion of a part thereof along a substantially straight linear path in relation to the temperature being sensed by the temperature sensing unit and having a potentiometer unit provided with an electrical output producing unit operatively interconnected to the part of the temperature sensing unit so as to produce a variable electrical signal in relation to the temperature being sensed by the temperature sensing unit, the electrical output unit being movable along an arcuate linear path by the part of the temperature sensing unit. The potentiometer unit has a member provided with an arcuate surface, the electrical output unit being disposed in sliding engagement with the arcuate surface whereby the arcuate surface defines the arcuate path of movement of the electrical output unit.

Abstract: Temperature limit control having a normally closed contact switch secured to a formed cup with vacuum operated formed diaphragm seal to cup bottom, contacts open on reduced vacuum as by boiling thermal fluid in the linear capillary tube welded to the cup below the diaphragm or boiling of fluid in a sensor bulb welded to the capillary tube end for remote temperature control, with vacuum leakage within lower cup, diaphragm, capillary tube and, or, sensor bulb releasing diaphragm from its pulled down position against inward formed dimples between the cup side and central outlet likewise opening contacts providing fail safe operation.

Abstract: A thermostatic switch unit for controlling a freezer or, for example, refrigeration apparatus in automotive air conditioning, includes a switch (1) which is acted upon by a thermostat mechanism responsive to the working temperature of the evaporator so as to maintain this temperature within a normal working range which is presettable by means of a control knob (18) in a conventional manner. By depressing manually a push button (26) mounted centrally in the control knob a spring loaded trip lever (29) is rotated to release a spring loaded lever (35) into engagement with a switch operating plunger (2, 3), closing the associated switch contacts (21) and causing the compressor motor of the apparatus to run until a low temperature, below the preset working range of the equipment, is reached, when the latch mechanism (29, 35) is reset automatically by the temperature sensing bellows (8) acting through the operating lever (4) of the thermostat mechanism.

Abstract: A condition responsive electric switch system comprises switch means which includes at least one set of contact elements defining a preselected open position, a preselected closed position, and a preselected initial contact make-break position, disposed between the open and closed positions. Switch actuating means is movable in actuating relation with the switch means for operating the contact elements selectively into and out of the three preselected positions. Spring means and temperature responsive means are connected to and impart motion to switch actuating means, with the spring means and temperature responsive means creating opposing forces on the switch actuating means. The condition responsive electric switch system has both positive and negative spring gradients including a force producing means having maximum absolute positive gradient forces F.sub.1 and F.sub.2 in which F.sub.

Abstract: A condition responsive electrical switch construction having a frame carrying an electrical switch and a condition responsive device having a movable wall for causing movement of a lever that is pivotally carried by the frame and is operatively associated with the switch to operate the same as the lever is moved by the wall to a certain position in opposition to the force of a range spring also carried by the frame. A cradle-like member has a base operatively associated with the range spring so as to be held thereby against the wall to be moved in unison with the wall and has arms engaging the lever to cause the lever to move in relation to movement of the wall. The switch has a pair of movable contact members disposed on opposite sides of a fixed contact member and each is biased in a direction to tend to place the same in contact with the fixed contact member and each having an offset loop therein.

Abstract: A linear pull actuator converts working fluid such as halogenated hydrocarbons into vapor by electrical heating element housed inside a shell, generating a vapor pressure against a rolling membrane secured inside actuator so as to respond to the vapor pressure linearly delivering an end force to an integral first piston and tube assembly which is adaptable to axially move inside the housing proper against spring biasing means along with an externally mounted second piston of a piston and rod assembly secured thereto by a spring so as to have rod end passing centrally through the tube protrude a distance out of the shell end for a position change from a first rod end protruded when electrical heater is not energized electrically to a second rod end retracted position with work when pulled away by the pistons due to the vapor pressure of the working fluid when the electrical heater is energized electrically, de-energization of the electrical heating element electrically returns the rod end to the first protrude

Abstract: A temperature responsive control device is provided for controlling an electric oven. The device is comprised of a housing which contains an electrical switching means which is controlled by a temperature sensitive expansible member through a snap-acting spring mechanism. The expansible member consists of a hydraulic diaphragm, a fluid filled capillary tube and a temperature-sensing bulb. The hydraulic diaphragm is composed of two generally circularly shaped plates which are welded together at their edges. The top of the diaphragm contains a circular stud the top of which is conically shaped and is received into a conical bearing recessed into the shaft of a rotatable temperature setting means. One corner of the diaphragm is formed to fit into a notch in the interior of the housing. One end of the capillary tube is inserted directly into a small inwardly extending channel in the edge of the diaphragm and the other end contains the temperature-sensing bulb.

Abstract: The invention relates to an electric switch assembly of the type operated by a thermostatic bellows, for use on refrigerators. The operating bellows is part of a system having a liquid/vapor filling and the movement of the bellows operates a microswitch. A hinged arm which operates the microswitch is biased in a switch closing direction by the bellows and in a switch opening direction by a spring system which includes a main spring and a differential spring in series. The force displacement line of the spring system approximates the force displacement line of the bellows and has two segments with different slopes. The two segments are formed by arresting the movement of the differential spring to make it ineffective at an intermediate point in the displacement of the bellows. The first segment with a lesser slope represents the action of both springs in series while the other segment, of greater slope, represents only the main spring.