Abstract: Motor protection for air conditioning and refrigeration compressors includes in a first embodiment a cluster block (22) having a seat for a hermetic motor protector (24, 24') and mounting a combination terminal/fusible link (26/26d, 26d') in which the motor protector and combination terminal/fusible link can be exposed to cooling fluid contained in the compressor container and the cluster block is mounted on a lead-through pin (18a) of a header (18) in the container wall. In a second embodiment the cluster block (30) is mounted on all three pins (18a, 18b, 18c) of header (18) with pin connectors received in parallel extending channels (30a, 30b, 30c) of the cluster block. In another embodiment the cluster block (40) is irregular in configuration in order to accommodate available space in certain compressor containers and has a lid (40g) to enclose the motor protector.

Abstract: A motor protector having a thermostat metal element thermally coupled to an electrical motor in a refrigerator compressor motor system has a heater responsive to motor current thermally coupled to the thermostat metal element and has an improved component arrangement to provide locked rotor and ultimate trip protection for the motor without requiring calibration of the operating temperature for the protector after assembly or after incorporation in the motor system.

Abstract: A miniature thermostatic switch of the type that can be inserted into the windings of electrical devices in order to sense the temperature of the windings is disclosed having an improved liquid tight seal to prevent seepage into the switch of varnish or other liquids to which the windings are subjected during assembly. The switch has a two part metallic housing with lips of one part clamped to the other part with an electrically insulating gasket interposed between the two parts. After assembly of the switch the gasket material is softened and the lip is subjected to a force to deform the gasket material, wetting the housing contiguous to the gasket and forming fillets therebetween to completely fill in any voids between the gasket and the contiguous housing.

Abstract: A snap-acting thermostatic electric switch in which a snap-acting thermostatic disc is physically attached to a heater plate which in turn mounts movable contacts. A stepped rivet loosely mounts the disc and is headed over to tightly mount any one of a series of heater plates having different thicknesses. The heater plate is shaped to allow unimpeded snap motion of the disc yet provide improved heat conduction to the disc. The disc and plate are mounted on a spider support which is adjustably positioned within the switch compartment by means of a combination rivet and screw received in a threaded bore of the base of the switch. An insulator is loosely received on the base and is biased thereagainst by a spring which also biases the spider upwardly to provide positional stability. Another spring is placed between the spider and the heater plate to optimize contact opening.

Abstract: An electrical lighting fixture adapted for recessed mounting has structure for mounting and energizing a lamp and has an insulation detecting protector device adapted to interrupt operation of the lamp to prevent overheating of the fixture if thermal insulation is disposed around the fixture in such a way as to excessively block heat dissipation from the fixture. The protector device has structure for mounting the device on the fixture to be subject to representative fixture conditions, has a thermally responsive switch which is actuatable in response to heating to a selected temperature for interrupting operation of the lamp, and has an electrical resistance heater which is thermally coupled to the switch for actuating the switch if thermal insulation excessively blocks dissipation of heat from the protector device.

Abstract: A miniature, solid state motor protector has a metallic housing with two hingedly connected recessed portions with a wafer of positive temperature coefficient (PTC) of resistivity material disposed in each recess in electrical connection with the housing and a center spring contact located intermediate the two PTC wafers and in electrical connection therewith so that the wafers are electrically connected in parallel relation.

Abstract: A current interrupting device having improved contact life includes a hermetically sealed housing in which a thermostatic member is adapted to cause electrical contacts to move into and out of engagement depending on the temperature of the thermostatic member. The atmosphere within the housing is a gas having a dielectric strength slightly over the impressed voltage.

Abstract: A current interrupting device having improved contact life incorporates a thermostatic member adapted to cause electrical contacts to move into and out of engagement depending on the temperature of the thermostatic member. The device is evacuated and back-filled with a mixture of argon and helium and then hermetically sealed.

Abstract: A motor protector characterized by low cost, by improved service life and by improved cycling properties has a bimetallic element mounted in a metal housing to move a first contact along a selected axis to engage and disengage a complementary contact in response to changes in element temperature. An electrical resistance heater coil, preferably with less than one full coil convolution, is oriented and secured externally of the housing so that the axis of the magnetic field established by the heater coil is coincident with the axis of movement of the first contact.

Abstract: A motor protector for use in motors having a high operating temperature employs a snap-acting composite thermostat element to actuate the protector wherein the multilayer thermostatic material embodied in the element has an electrical resistivity value from 20 ohms/c.m.f. to 400 ohms/c.m.f. and a flexivity value from 90 .times. 10.sup.-.sup.7 inches per inch per degree Fahrenheit to 110 .times. 10.sup.-.sup.7 inches per inch per degree Fahrenheit to provide for better calibration, longer life, and better space control in the protector for use in motors having higher operating temperatures.