Abstract: A thermal switch assembly includes a dielectric spacer and a switch blade member of shape memory metal sandwiched between a pair of flat metal plates. The spacer provides a cavity between the plates, and the switch blade member has a switch blade portion projecting into the cavity. The switch blade member has a mounting portion engaging one of the metal plates, and the switch blade portion normally is under bending stress in engagement with the other metal plate to provide a current path between the plates. At elevated temperatures, the switch blade portion of shape memory metal moves out of engagement with the other metal plate to interrupt the current path. Fasteners integral with the dielectric spacer cooperate with the metal plates and the switch blade member to hold the switch assembly together with the spacer and the mounting portion of the switch blade member compressively sandwiched between the metal plates.

Abstract: A novel shape memory alloy electrical switch is disclosed, including both momentary and especially a latching relay. The switch/relay disclosed is particularly useful in low power control of appliances, including i.a. refrigerators. Used with a microprocessor, microcontroller, or like device to control the shape memory alloy switch/relay, an adaptive control routine may be included which facilitates an especially low-power dissipation, highly effective appliance control module, especially suitable for refrigerators. The disclosed refrigerator control module can be manufactured at low cost with high reliability.

Abstract: A thermal switch assembly has a stiffener disc positioned against a support flange that extends inwardly from a peripheral wall of a plastic assembly grommet. An actuator member of shape memory metal is received in a recess in the stiffener disc, and an insulator ring lies against the disc and actuator member on the opposite side of the disc from the support flange. A cap member is positioned against the insulator on the opposite side thereof from the stiffener disc, and a resilient actuator blade on the actuator member extends through a central opening in the insulator into engagement with the cap member. The actuator blade normally completes a circuit between the stiffener disc and the cap member, and automatically disengages from the cap member at an elevated transition temperature to open the circuit.

Abstract: A novel shape memory alloy electrical switch is disclosed, including both momentary and especially a latching relay. The switch/relay disclosed is particularly useful in low power control of appliances, including i.a. refrigerators. Used with a microprocessor, microcontroller, or like device to control the shape memory alloy switch/relay, an adaptive control routine may be included which facilitates an especially low-power dissipation, highly effective appliance control module, especially suitable for refrigerators. The disclosed refrigerator control module can be manufactured at low cost with high reliability.

Abstract: A thermal switch assembly has a stiffener disc positioned against a support flange that extends inwardly from a peripheral wall of a plastic assembly grommet. An actuator member of shape memory metal is received in a recess in the stiffener disc, and an insulator ring lies against the disc and actuator member on the opposite side of the disc from the support flange. A cap member is positioned against the insulator on the opposite side thereof from the stiffener disc, and a resilient actuator blade on the actuator member extends through a central opening in the insulator into engagement with the cap member. The actuator blade normally completes a circuit between the stiffener disc and the cap member, and automatically disengages from the cap member at an elevated transition temperature to open the circuit.

Abstract: A novel shape memory alloy electrical switch is disclosed, including both momentary and especially a latching relay. The switch/relay disclosed is particularly useful in low power control of appliances, including i.a. refrigerators. Used with a microprocessor, microcontroller, or like device to control the shape memory alloy switch/relay, an adaptive control routine may be included which facilitates an especially low-power dissipation, highly effective appliance control module, especially suitable for refrigerators. The disclosed refrigerator control module can be manufactured at low cost with high reliability.

Abstract: A micromechanical memory sensor. The sensor comprises a latch member mechanically latching upon detection of a threshold value of a variable condition and circuitry for detecting such latching. A sensor further includes a resetting mechanism for electrically unlatching the latch member whereby the sensor latched purely mechanically is electrically reset for repeat use.

Abstract: The present invention relates to compositions for use in forming resettable electronic circuit protection devices or fuses, methods of forming resettable fuses using the compositions, and resettable fuses formed from the compositions. Resettable fuse compositions according to the present invention include a mixture of the reaction product of polyethylene glycol and a diepoxide having a molecular weight of at least 18,000, solvent, conductive particles, and optional solvent volatility adjusters. In a preferred embodiment, resettable fuses according to the present invention are formed by screen printing the compositions directly onto printed electric circuits to form fuses. During current overload conditions, the temperature of the resettable fuse material rapidly increases due to resistive heating generated by excessive current flow through the conductive particle chains or pathways.

Abstract: An flat casing (10) exhibiting a convex curvature to the outside on all sides, is slid onto the projection (1a) of a base (1). The casing (10) protects a contact device anchored in the base (1). The base (1) protrudes with the peripheral brackets (1b), formed on two sides of the base (1), beyond the projection (1a) into the casing (10) and supports the casing (10) from the insides A U-shaped carrier plate (4) is anchored with its arms (4a) in the brackets (1b). The carrier plate (4) is furnished with longitudinal edges (6), which are bent off at right angles outside of the anchoring, and the longitudinal edges (6) rest force-matchingly at the interior wall of the casing (10).

Abstract: An electrical apparatus comprising first and second PTC elements composed of a polymer composition with conductive particles dispersed therein, an insulating body, and first and second conductive terminals. Flexible conductive members having a first end that can be electrically connected to a source of electrical power and a second end that is adapted to receive and make electrical contact with the apparatus are provided. The PTC element and the insulating body are positioned between the first and second conductive terminals so that when the apparatus is inserted between the flexible conductive members, the members exert a pressure on the insulating body.

Abstract: A thermally activated short-circuit switch for connection in parallel with a battery cell has first and second contact elements (6; 3) which are distinct from the electrodes of a diode, and thermally activatable means (45) for short-circuiting the first and second contact elements (6; 3). The first and second contact elements have respective first and second regions (6; 3) facing each other, and said thermally activatable means (45) is mechanically linked to the first contact element (6).

Abstract: A small-size high-performance electronic protective device (10) is provided for use in protecting communication equipment including an exchange servicing module against application of abnormal surge current due to accidental shorts between adjacent ones of power feed lines in a communications system. The protective device (10) includes positive thermistors (3a, 3b) connected between communication link input terminals (1a, 1b) and output terminals (1c, 1d) coupled to an associative equipment being protected. The protective device (10) also includes thick-film resistive elements (5a, 5b), which are connected in parallel with the thermistors (3a, 3b), respectively.

Abstract: A thermal switch assembly includes a dielectric spacer and a switch blade member of shape memory metal sandwiched between a pair of flat metal plates. The spacer provides a cavity between the plates, and the switch blade member has a switch blade portion projecting into the cavity. The switch blade member has a mounting portion engaging one of the metal plates, and the switch blade portion normally is under bending stress in engagement with the other metal plate to provide a current path between the plates. At elevated temperatures, the switch blade portion of shape memory metal moves out of engagement with the other metal plate to interrupt the current path. Fasteners integral with the dielectric spacer cooperate with the metal plates and the switch blade member to hold the switch assembly together with the spacer and the mounting portion of the switch blade member compressively sandwiched between the metal plates.

Abstract: An electrical apparatus comprising first and second PTC elements composed of a polymer composition with conductive particles dispersed therein, an insulating body, and first and second conductive terminals. Flexible conductive members having a first end that can be electrically connected to a source of electrical power and a second end that is adapted to receive and make electrical contact with the apparatus are provided. The PTC element and the insulating body are positioned between the first and second conductive terminals so that when the apparatus is inserted between the flexible conductive members, the members exert a pressure on the insulating body.

Abstract: A thermally expandable wax composition and its use in polymer-based actuators is disclosed and claimed. The compositions are wax-based and include conductive filler as well as a viscosity modifier to stabilize the composition against segregation. Optionally included are thermoxidative stabilizers.

Abstract: A symmetrical adsorption pump/compressor system having a pair of mirror image legs and a Joule Thomson expander 40, or valve, interposed between the legs thereof for providing a new, efficient refrigeration cycle. The system further includes a plurality of gas operational heat switches 48a, 48b, 48c, and 48d adapted selectively to transfer thereto heat from a thermal load 44 and to transfer or discharge heat therefrom through a heat projector 46, such as a radiator or the like. The heat switches comprise gas pressurizable chambers adapted for alternate pressurization in response to adsorption and desorption of a pressurizing gas confined therein.

Abstract: Disclosed is a relay for high current equipment, such as, for example, an electric range. The relay provides the interface between the solid state electronics and the high wattage electric heating elements. The relay is comprised of a frame having a non-electrically conductive, flexible substrate, such as a plastic substrate supported at its ends with a shallow V cross section. The substrate has conductive heater elements formed thereon with heater terminals connected to said elements. The plastic substrate has a high coefficient of thermal expansion. A biasing member in contact with the apex of the plastic substrate transmits forces between the substrate and a switch assembly, either creep or snap acting. The upper switch arm preloads or couples a force between the biasing element and the plastic substrate causing a shallow V to be formed in the substrate. When current is applied to the heater terminals and heats the heater element, the substrate expands.

Abstract: A heat-triggered, mechanically-actuated apparatus comprising a heating and conducting linkage connected in parallel with an automatically resetting safety control switch across the power supply of electrical equipment, an initial opening of the control switch being indicated by the steps of heating of a heat-softenable rigid rod by the power supply passing through the heating and conducting linkage supported thereby, and breaking the linkage by a spring biasing the heat-softened rod to collapse and release a frictional connector in the linkage, and oppositely biasing an indicator, normally concealed a part of the linkage, into view.

Abstract: High voltage control devices are provided comprising a housing, an aprotic liquid contained within said housing, means for effecting heat exchange with said liquid, at least two spaced electrodes contained within said liquid and each of said electrodes extending from said housing. These devices find utility as variable resistors, circuit breakers, thermostats, optical triggering devices, acoustic pulse generators and the like.