Protected refrigerator compressor motor systems

Claim 2

A motor protector according to claim 1 wherein the base comprises a thermally and electrically insulating body having a recess open at one end, the heater means and thermostat metal member are arranged in closely spaced relation to each other within the recess to achieve said selected thermal coupling between the member and the heater means, the first contact means comprises a resilient electrically-conductive movable contact arm electrically connected in series to the heater means to be at the same polarity as the heater means in open and closed circuit positions, the arm having one end secured to the body at one side of the recess and having its opposite end extending across the open recess end to an opposite side of the recess, and the complementary contact means is mounted on the body at said apposite side of the recess to normally engage the movable contact arm for closing the motor circuit, the complementary contact means being mounted outside the recess to assure provision of proper electrical spacing from the heater means when the complementary contact means are of opposite polarity to the heater means while the Claim 2 continued motor circuit is open, the arm being disposed in selected close relation to the thermostat metal member in the recess so that the arm extending across the recess is positively moved to open circuit position when the member moves with snap action to its inverted dished configuration in response to being heated to its predetermined actuating temperature.

Claim 3

A motor protector according to claim 2 wherein the heater means comprises an electrical resistance heater element having terminal means at opposite ends thereof for connecting the element to the movable contact arm and to the motor circuit respectively, the heater means being arranged in a loop within the recess to extend around the recess to provide substantial heating capacity in the recess in closely spaced heat-transfer relation to the thermostat metal member.

Claim 4

A motor protector according to claim 3 wherein the recess has a bottom and side wall means and the heater element comprises a wire of metal material of selected electrical resistance properties wound in a helical coil of selected length, the coil being arranged in a loop within the recess extending around the recess bottom for accommodating the heater element with said substantial heading capacity in the recess in said closely spaced heat-transfer relation to the thermostat metal member.

Claim 5

A motor protector according to claim 2 wherein the thermally and electrically insulating body is molded with the recess therein opening at one side of the body, the recess having a bottom and a side wall and having a shoulder in the side wall facing toward the open end of the recess, and the body has first and second reference surfaces molded in said one body side at said one side and said opposite side respectively of the body recess, the heater means being mounted in selected position in the recess on the recess bottom, the thermostat metal member being disposed on the shoulder to extend over the heater means with said selected thermal coupling to the heater means, and the first and complementary contact means are mounted on said first and second reference surfaces respectively in predetermined relation to each other and to the thermostat metal member in the body recess.

Claim 6

A motor protector according to claim 3 having a thermally and electrically insulating cover secured to the body over the recess for improving thermal coupling of the heater means and the thermostat metal member to each other within the recess, at least one of said heater terminal means having resilient means for gripping a lead frcm a winding of the electrical motor for securing the thermostat metal member in the recess in selected thermal coupling to the electrical motor via that terminal means.

Claim 7

A motor protector according to claim 6 wherein extending cf the movable contact arm across the open recess end normally retains the thermostat metal member in the body recess substantially free of externally applied forces to position the thermostat metal member in said selected thermal coupling to the heater means in the recess.

Claim 8

A motor protector comprising a molded, thermally and electrically insulating bcdy having a recess open at one side of the body, the recess having a bottom and a side wall and having a shoulder in the side wall'facing the open recess end, an electrical resistance heater arranged in a loop in the recess located against the recess bottom extending around a circumference of the recess to be connected in a motor circuit to carry the motor current, a round, dished thermostat metal disc adapted to move from an original dished configuration to an inverted dished configuration with snap acticn when heated to an actuating temperature and to return to its original dished configuration with snap action when subsequently cooled to a relatively lower reset temperature, the member being disposed in the recess on the shoulder over the heater with selected thermal coupling to the heater, a first contact mounted on the body at one side of the recess to be connected in the motor circuit, and a resilient movable electrically conductive spring contact arm electrically connected to the heater to be electrically connected in the motor circuit to be at the same polarity as the heater in that circuit, the arm having one end mounted on the body at an opposite side of the recess to extend across the open recess end to normally engage an opposite end of the arm with first contact for energizing the motor during normal motor operation, to be moved to disengage the first contact and interrupt motor operation when the disc is heated to said actuating temperature by occurrence of either of short time trip and ultimate trip motor fault currents in the heater, and to reengage the first contact for reenergizing the motor when the disc cools to said reset temperature, characterized in that the body has a boss of body material upstanding from the center of the recess bottom inside the heater loop to be heated by the heater means during motor operation and for transferring heat to the thermostat metal disc after interruption of motor operation to extend the reset time of the protector.

Claim 9

A motor protector comprising a molded, thermally and electrically insulating bcdy having a recess open at one side of the body, the recess having a bottom and a side wall and having a shoulder in the side wall'facing the open recess end, an electrical resistance heater arranged in a loop in the recess located against the recess bottom extending around a circumference of the recess to be connected in a motor circuit to carry the motor current, a round, dished thermostat metal disc adapted to move from an original dished configuration to an inverted dished configuration with snap acticn when heated to an actuating temperature and to return to its original dished configuration with snap action when subsequently cooled to a relatively lower reset temperature, the member being disposed in the recess on the shoulder over the heater with selected thermal coupling to the heater, a first contact mounted on the body at one side of the recess to be connected in the motor circuit, and a resilient movable electrically conductive spring contact arm electrically connected to the heater to be electrically connected in the motor circuit to be at the same polarity as the heater in that circuit, the arm having one end mounted on the body at an opposite side of the recess to extend across the open recess end to normally engage an opposite end of the arm with first contact for energizing the motor during normal motor operation, to be moved to disengage the first contact and interrupt motor operation when the disc is heated to said actuating temperature by occurrence of either of short time trip and ultimate trip motor fault currents in the heater, and to reengage the first contact for reenergizing the motor when the disc cools to said reset temperature, characterized in that the body has a boss of body material upstanding from the center of the recess bottom inside the heater loop to be heated by the heater means during motor operation and for transferring heat to the thermostat metal disc after interruption of motor operation to extend the reset time of the protector.

Claim 10

A motor protector according to claim 8 further characterized in that the boss is proportioned with respect to the heater loop to extend snugly within the loop for retaining the heater loop in selected position on the recess bottom.

Claim 11

A motor protector comprising a molded, thermally and electrically insulating body having a recess open at one side of the body, the recess having a bottom and a side wall and having a shoulder in the side wall facing the open recess end, the body having reference surfaces on said one body side outside the recess at respective opposite sides of the recess, an electrical resistance heater arranged in the recess located against the recess bottom extending around a circumference of the recess to be connected in a motor circuit to carry the motor current, a round, dished, thermostat metal disc adapted to move with snap action to an inverted dished configuration when heated to a precisely predetermined actuating temperature while, being free of externally applied forces, the member being disposed on the recess shoulder over the heater unattached to any support and free of electrical connection an any circuit with selected thermal coupling to the heater adapted to be arranged in predetermined thermal coupling to the motor by mcunting of the protector on the motor, thereby to be heated to said actuating temperature in response to the cccurrence of either of short time trip and ultimate trip motor fault currents in the heater, a first contact mounted on one of the reference surfaces cutside the recess at one side of the recess to be connected in the motor circuit, and a resilient movable electrically conductive spring contact arm electrically connected to the heater to be electrically connected in the motor circuit and to be at the same polarity as the heater in that circuit, that arm having one end mounted on the other of said reference surfaces at an opposite side of the body to extend across the open recess end to normally engage the first contact outside the recess at said one recess side for energizing the motor during normal motor operation, the spring arm having a selected location relative to the thermostat disc in the recess and having a selected relatively low spring rate characteristic to be moved and disengaged from the first contact to interrupt motor operation by movement of the disc to its inverted dished configuration when the disc is heated to its actuating temperature by occurrence of either of short time trip and ultimate trip motor fault currents in the heater.

Claim 12

A motor protector comprising a molded, thermally and electrically insulating body having a recess open at one side of the body, the recess having a bottom and a side wall and having a shoulder in the side wall facing the open recess end, the body having reference surfaces on said one body side outside the recess at respective opposite sides of the recess, an electrical resistance heater arranged in the recess located against the recess bottom extending around a circumference of the recess to be connected in a motor circuit to carry the motor current, a round, dished, thermostat metal disc adapted to move with snap action to an inverted dished configuration when heated to a precisely predetermined actuating temperature while, being free of externally applied forces, the member being disposed on the recess shoulder over the heater unattached to any support and free of electrical connection an any circuit with selected thermal coupling to the heater adapted to be arranged in predetermined thermal coupling to the motor by mcunting of the protector on the motor, thereby to be heated to said actuating temperature in response to the cccurrence of either of short time trip and ultimate trip motor fault currents in the heater, a first contact mounted on one of the reference surfaces cutside the recess at one side of the recess to be connected in the motor circuit, and a resilient movable electrically conductive spring contact arm electrically connected to the heater to be electrically connected in the motor circuit and to be at the same polarity as the heater in that circuit, that arm having one end mounted on the other of said reference surfaces at an opposite side of the body to extend across the open recess end to normally engage the first contact outside the recess at said one recess side for energizing the motor during normal motor operation, the spring arm having a selected location relative to the thermostat disc in the recess and having a selected relatively low spring rate characteristic to be moved and disengaged from the first contact to interrupt motor operation by movement of the disc to its inverted dished configuration when the disc is heated to its actuating temperature by occurrence of either of short time trip and ultimate trip motor fault currents in the heater.

Claim 13

A current and temperature responsive motor protector for providing short time trip and ultimate trip protection for a refrigerator compressor motor, the protector comprising a base, contact means mounted on the base for relative movement between positions opening and closing the motor circuit, thermostat metal means adapted to move from an original dished configuration to an inverted dished configuration with snap action when heated to a selected actuation temperature and to return to its original dished configuration with snap action when subsequently cooled to a relatively lower reset temperature, the thermostat metal means being mounted on the base to be thermally coupled in selected heat-transfer relation to a refrigerator compressor motor to move the contact means between said circuit positions in response to movement of the thermostat metal means between said configurations, and electrical resistance heater means responsive to motor circuit current to heat the thermostat metal means for cooperating With said thermal coupling to the motor to provide both short time trip and ultimate trip protection for the motor, characterized in that, the base comprises a body of an electrical insulating material of relatively low thermal conductivity having a recess therein, the heater means is disposed in the recess, the thermostat metal means comprises a round, dished thermostat metal disc which is movable with snap action from an original dished configuration to an inverted dished configuration when heated to a precisely predetermined actuating temperature while Claim 11 continued being substantially free of externally applied forces, the disc being disposed in the recess over the heater means in close thermal coupling to the heater means to be normally free of substantially all externally applied forces, the contact means comprises first contact means mounted on the body and a resilient, movable contact arm extending across the recess to normally retain the disc in the recess substantially free of externally applied forces and to normally engage the first contact means for closing the circuit, the arm being movable by the disc to disengage the fixed contact means and open the motor circuit when the disc moves with snap action to its inverted dished configuration and to return to circuit closing position when the disc is subsequently cooled and returns with snap action to its original dished configuration, and the heater means has selected heating capacity and thermal coupling to the thermostat metal disc in the recess to cooperate with said selected thermal coupling to the motor to provide the protector with a ratio of short time trip current to ultimate trip current for a short time trip of 10 seconds in the range from 2.5 to 4.5 where the effective protector ambient is 65 0 C.

Claim 14

A motor protector as set forth in claim 11 wherein the thermal capacity of the protector is regulated with respect to said thermal coupling of the protector to the motor to provide the protector with a reset time following tripping in response to the occurrence of short time trip motor fault current in the heater of at least about 150 seconds.

Claim 15

A series of motor protectors to be externally mounted on selected, respective hermetically sealed refrigerator compressor systems for home refrigerator appliances to provide short time trip and ultimate trip protection for motors in the systems as specified in Table I, each projector having a thermally and electrically insulating base with a recess therein, having an electrical resistance heater arranged in the recess to carry the motor current of a protected motor, having a thermostat metal member movable from an original to an inverted dished configuration with snap action when heated to a precisely predetermined actuating temperature while fee of externally applied forces and adapted to return to its original configuration with snap action when subsequently cooled to a relatively lower reset temperature, the member being arranged in the recess over the heater unattached to any support and free of electrical connection in any circuit to have a selected thermal coupling to the heater to be heated to said actuating temperature in response to the occurrence of short time trip and ultimate trip motor currents respectively in the heater, and motor the member being. arranged to be normally free of substantially all externally applied forces in the recess and adapted to be disposed in predetermined thermal coupling to said motor by mounting of the protector on the system incorporating the motor, having a first contact mounted on the base to be connected in the circuit of said motor, and having a resilient movable electrically-conductive contact arm electrically connected to the heater to be connected in said motor circuit, the arm being mounted on the base to extend over the thermostat metal member in the recess to normally engage the first contact for energizing the motor and having a selected location relative to the Claim 13 continued member to be moved to disengage the first contact for interrupting motor operation when the member is heated to its actuating temperature by short time trip and ultimate trip motor currents respectively in the heater and motor, the heaters in the series protectors having current ratings in the range frcm 1 to 10 amperes wherein the current ratings of the respective series protectors are separated from each other by increments corresponding to about five percent of the heater current rating of the protector with the next lowest heater current rating in the series for carrying overload currents in selected motors likely to be encountered without risk of heater burnout, the thermostat metal member in the respective series protectors having actuating temperatures separated in increments of about 5°C. in the temperature range from 90 to 160 o C. to meet the requirements of selected motors likely to be encountered, and the heaters have selected capacities and couplings to the thermostat metal member in the protectors to provide each protector with a ratio of short tine trip current to ultimate trip current for a short trip time of 10 seconds in the range from 2.5 to 4.5 where the effective protector ambient is 65°C.

Claim 16

A series of motor protectors as set forth in claim 13 wherein the recess is formed at one side of the base and has an open end at said one base side, the recess having a bottom and a side wall and having a shoulder in the side wall facing the open recess end, the heater is located against the recess bottom electrically connected to the arm extending over the recess to be at the same polarity as the arm, the thermostat metal member is disposed on the shoulder extending over the heater in selected spaced relation to the heater to achieve said selected thermal coupling to the heater, and the thermal capacity of the protectors are regulated with respect to such thermal coupling to provide the protectors in the series with reset times following tripping in response to short time trip motor fault currents in the heaters in the range from 30 to at least about 150 seconds.

Claim 17

A series of motor protectors as set forth in claim 14 particularly adapted for use with selected motor starter means having selected starter reset times wherein the thermal capacity of each protector is regulated with respect to said starter means reset time so that said reset time of the protector is greater than said selected motor starter reset time.

Claim 18

A series of motor protectors as set forth in claim 15 particularly adapted for use with motor starter means comprising resistance switching means of positive temperature coefficient of resistivity having reset times of durations up to 150 seconds wherein the thermal capacity of each protector in the series is regulated so that said protector reset times exceed 150 seconds.

Claim 19

A motor protector to be externally mounted on an hermetically sealed refrigerator compressor system for home refrigerator appliances to provide short time trip and ultimate trip projection for the motor in the system as specified in Table I, the protector having a thermally and electrically insulating base with a recess therein, having an electrical resistance heater arranged in the recess to carry the motor current of a protected motor, having a thermostat meal member movable from an original to an inverted dished configuration with snap action when heated to a precisely predetermined actuating temperature while free of externally applied forces and adapted to return to its original configuration with snap action when subsequently cooled to a Claim 17 continued relatively lower reset temperature, the member being arranged in the recess over the heater unattached to any support and free of electrical connection in any circuit to have a selected thermal coupling to the heater to be heated to said actuating temperature in response to the occurrence of short time trip and ultimate trip motor currents respectively in the heater, the member being arranged to be normally free of substantially all externally applied forces in the recess and adapted to be disposed in predetermined thermal coupling to said motor by mounting of the protector on the system incorporating the motor, having a first contact mounted on the base to be connected in the circuit of said motor, and having a resilient movable electrically-conductive contact arm electrically connected to the heater to be connected in said motor circuit, the arm being mounted on the base to extend over the thermostat metal member in the recess to normally engage the first contact for energizing the motor and having a selected location relative to the member to be moved to disengage the first contact for interrupting motor operation when the member is heated to its actuating temperature by short time trip and ultimate trip motor currents respectively in the heater, the heater having a selected current rating in the range from 1 to 10 amperes for carrying overload currents in such a refrigerator compressor motor likely to be encountered without risk of heater burnout, the thermostat metal member having an actuating temperature in the temperature range from 90 to 160°C. to meet the requirements of such a refrigerator compressor motor likely to be encountered, and the heater has a selected capacity and coupling to the thermostat metal Claim 17 continued member to provide the protector with a ratio of short time trip current to ultimate trip current for a short trip time of 10 seconds in the range from 2.5 to 4.5 where the effective protector ambient is 65°C. and with a reset time after short time trip of at least about 150 seconds.

Claim 20

A protected refrigerator compressor motor system for home refrigerator appliance comprising an electrical motor and a refrigerator compressor operated by the motor hermetically sealed in a common shell, and a current and temperature responsive motor protector for providing short time trip and ultimate trip protection for the motor, the protector comprising a base, contact means mounted on the base for relative movement between positions opening and closing the motor circuit, thermostat metal means adapted to move from an original dished configuration to an inverted dished configuration with snap action when heated to, a selected actuation temperature and to return to its original dished configuration with snap action when subsequently cooled to a relatively lower reset temperature, the thermostat metal means being mounted on the base thermally coupled in selected heat-transfer relation to the motor within the shell to move the contact means between said circuit positions in response to movement of the thermostat metal means between said configurations, and Claim 18 continued electrical resistance heater means responsive to motor circuit current to heat the thermostat metal means for cooperating with said thermal coupling to the motor to provide both short time trip and ultimate trip protection for the motor, characterized in that, the base comprises a body of an electrical insulating material of relatively low thermal conductivity having a recess therein, the heater means is disposed in the recess, the thermostat metal means comprises a round thermostat metal disc which is movable with snap action frcm said original dished configuration to an inverted dished configuration when heated to a precisely predetermined actuating temperature while being substantially free of externally applied forces, the disc being disposed in the recess over the heater means in close thermal coupling to the heater means to be normally free of substantially all externally applied forces, and the contact means comprises first contact means mounted on the body and a resilient, movable contact arm extending across the recess to normally retain the disc in the recess substantially free of externally applied forces and to normally engage the first contact means for closing the circuit, the arm being movable by the disc to disengage the fixed contact means and open the motor circuit when the disc moves with snap action to its inverted dished configuration and to return to circuit closing position when the disc is subsequently cooled and returns with snap action to its original dished Claim 18 continued configuration, the heater means having selected heating capacity and thermal coupling to the thermostat metal disc to provide the protector with a ratio cf short time trip current to ultimate trip current for a short trip time of 10 seconds in the range from 2.5 to 4.5 where the effective protector ambient is 71°C.

Claim 21

A protected refrigerator compressor motor system for hone refrigerator appliance comprising an electrical motor and a refrigerator compressor operated by the motor hermetically sealed in a common shell, a motor starter comprising resistance switching means of positive temperature coefficient of resistivity having a reset time of a duration up to 150 seconds arranged for starting the motor, and a current and temperature responsive motor protector for providing short time trip and ultimate trip protection for the motor, the protector comprising a base, contact means mounted on the base for relative movement between positions opening and closing the motor circuit, thermostat metal means adapted to move from an original dished configuration to an inverted dished configuration with snap action when heated to a selected actuation temperature and to return to its original dished configuration with snap action when subsequently cooled to a relatively lower reset temperature, the thermostat metal means being mounted on the base thermally Claim 19 continued coupled in selected heat-transfer relation to the motor within the shell to move the contact means between said circuit positions in response to movement of the thermostat metal means between said dished configurations, and electrical resistance heater means responsive to motor circuit current to heat the thermostat metal means for cooperating with said thermal coupling to the motor to provide both short time trip and ultimate trip protection for the motor, characterized in that, the base comprises a body of an electrical insulating material of relatively lcw thermal conductivity having a recess therein, the heater means is disposed in the recess, the thermostat metal means comprises a round thermostat metal disc which is movable with snap action from said original. dished configuration to said inverted dished configuration when heated to a precisely predetermined actuating temperature while being substantially free of externally applied forces, the disc being disposed in the recess over the heater means in close thermal coupling to the heater means to be normally free of substantially all externally applied forces, and the contact means comprises first contact means mounted on the body and a resilient, movable contact arm extending across the recess to normally retain the disc in the recess substantially free of externally applied forces and to normally engage the first contact Claim 19 continued means for closing the circuit, the arm being movable by the disc to disengage the fixed contact means and open the motor circuit when the disc moves with snap action to its inverted dished configuration and to return to circuit closing position when the disc is subsequently cooled and returns with snap action to its original dished configuration, the heater means having selected heating capacity and thermal coupling to the thermostat metal disc to provide the protector with a ratio of short time trip current to ultimate trip current for a short trip time of 10 seconds in the range from 3.5 to 4.5 where the effective protector ambient is 65°C. and with a reset time of a duration longer than 150 seconds.

Claim 22

A current and temperature responsive motor protector to be mounted in a selected manner on an electrical motor for providing both short time trip and ultimate trip protection for the motor . comprising a base, first contact means on the base normally engaging complementary contact means to close a motor circuit, the first contact means being movable to disengage the complementary contact means to open the circuit, thermostat metal means mounted on the base to be disposed in selected thermal coupling to the motor when the protector is mounted on the motor in said manner, the thermostat metal means being actuatable when heated to a selected temperature to move the first contact means to open the circuit, and electrical resistance heater means responsive to increases in motor current on the occurrence of either short time trip or ultimate trip fault conditions in the motor for heating the thermostat metal means to said selected temperature, characterized in that the electrical resistance heater means is formed of a material having a positive temperature coefficient of resistivity arranged to carry the motor current, the material of the heater means being selected to display a first electrical resistance in response to normal motor currents in the heater means, a second relatively higher electrical resistance in response to ultimate trip motor current in the heater means, and a third substantially higher electrical resistance in response to short time trip motor current in Claim zu continued the heater means, the heater means being proportioned and arranged with selected thermal coupling to the thermostat metal means to cooperate with the positive temperature coefficient of resistivity and the thermal coupling of the thermostat metal means to the motor to display said first resistance and permit normal running operation of the motor in response to normal motor currents in the heater means, to display said second resistance and heat the thermostat metal means to said selected temperature in response to ultimate trip currents in the heater means, and to display said third resistance and heat the thermostat metal means to said selected temperature in response to short time trip current in the heater means.

Claim 23

A current and temperature responsive motor protector to be mounted in a selected manner on an electrical motor for providing both short time trip and ultimate trip protection for the motor comprising a base, first contact means on the base normally engaging complementary contact means to close a motor circuit, the first contact means being movable to disengage the complementary contact means to open the circuit, thermostat metal means mounted on the base to be disposed in selected thermal coupling to the motor when the protector is mounted on the motor in said manner, the thermostat metal means being actuatable when heated to a selected temperature to move the first Claim 21 continued contact means to open the circuit, and electrical resistance heater means responsive to increases in motor current on the occurrence of either short time trip or ultimate trip fault conditions in the motor for heating the thermostat metal means to said selected temperature, characterized in that the thermostat metal means comprises a dished thermostat metal member movable with snap action from an original dished configuration to an inverted dished configuration when heated to a precisely predetermined actuating temperature while substantially free of externally applied fcrces, the member being mounted on the base unattached to any support to be substantially free of such externally applied forces to move the first contact means to open the circuit as the member moves when heated to said precisely predetermined actuating temperature, the member being mounted out of the motor circuit so motor current does not pass through the member, and separate electrical resistance heater means are arranged with selected thermal coupling to the thermostat metal member, the electrical resistance heater means being formed of a material having a a positive temperature coefficiept of resistivity arranged to carry the motor current, the material of the heater means being selected to display a first electrical resistance in response to normal motor currents in the heater means, a second relatively higher electrical resistance in response to ultimate trip motor current in the heater means, and a third substantially higher electrical resistance in response to short time trip motor current in the heater means, the Claim 21 continued header means being proportioned and arranged with selected thermal coupling to the thermostat metal means to cooperate with the positive - temperature coefficient of resistivity and the thermal coupling of the thermostat metal means to the motor to display said first resistance and permit normal running operation of the motor in response to normal motor currents in the heater means, to display said second resistance and heat the thermostat metal means to said selected temperature in response to ultimate trip currents in the heater means, and to display said third resistance and heat the thermostat metal means to said selected temperature in response to short time trip current in the heater means.

Claim 24

A motor protector according to claim 21 wherein the base comprises a thermally and electrically insulating body having a recess open at one end, the heater means and thermostat metal member are arranged in closely spaced relation to each other within the recess to achieve said selected thermal coupling between the member and the heater means, the first contact means comprises a resilient electrically-conductive movable contact arm electrically connected in series to the heater means to be at the same polarity as the heater means in open and closed circuit positions, the arm having one end secured to the body at one side of the recess and having its opposite end extending across the open recess end to an opposite side of the recess, and the complementary contact means is mounted on the body Claim 22 continued at said opposite side of the recess to normally engage the movable contact arm for closing the motor circuit, the complementary contact means being mounted outside the recess to assure provision of proper electrical spacing from the heater means when the complementary contact means are of opposite polarity to the heater means while the motor circuit is open, the arm being disposed in selected closely spaced relation to the thermostat metal member in the recess so that the arm extending across the recess is positively moved to open circuit position when the member moves with snap action to its inverted dished configuration in response to being heated to its predetermined actuating temperature, further characterized in that the heater means comprises an electrical resistance heater element arranged in a loop within the recess to extend around the recess to provide a substantial heating capacity in the recess in closely spaced, heat-transfer relation to the thermostat metal member in the recess, the heater means having selected heating capacity and thermal coupling to the thermostat metal disc to provide the protector with a ratio of short time trip current to ultimate trip current for a short trip time of 10 seconds in the range from 2.5 to 3.5 where the effective protector ambient is 65 0 C.

Claim 25

A motor protector according to claim 22 wherein the thermostat metal member is adapted to return to its original dished configuration with snap action when subsequently cooled to a relatively lower reset temperature for permitting the first contact means to reengage the complementary contact means to reclose the Claim 23 continued the motor circuit, further characterized in that the thermal capacity of the protector is regulated with respect to thermal coupling of the thermostat metal member to said heater means to provide the protector with short trip times in the range from 3 to 10 seconds in response to short time trip motor fault currents in the heater element in selected motor applications.

Claim 26

A motor protector according to claim 20 wherein the heater means comprises a flat sheet of electrical resistance material blanked to provide a serpentine length of the resistance material, the heater sheet being disposed with a flat side thereof extending over the bottom of the body recess in precisely predetermined electrical spacing to the thermostat metal member arranged in the recess.

Claim 27

A protected refrigerator compressor motor system for a home refrigerator appliance comprising an electrical motor and a refrigerator compressor operated by the motor hermetically sealed in a common shell, a motor starter, and a current and temperature responsive motor protector for providing short time trip and ultimate trip protection for the motor, wherein the system incorporates a motor protector according to claim 23.

Claim 28

A motor protector comprising a molded-thermally and electrically insulating body having a recess open at one side of the bcdy, the recess having a bottom an a side wall and having a shoulder in the side wall facing the open recess end, an electrical resistance heater arranged in a loop in the recess located against the recess bottom extending around a circumference of the recess to be connected in a motor circuit to carry the motor current, a round, dished thermostat metal disc adapted to move from an original dished configuration to an inverted dished configuration with snap action when heated to an actuating temperature and to return to its original dished configuration with snap action when subsequently cooled to a relatively lower reset temperature, the claim 26 continued member being disposed in the recess on the shoulder over the heater with selected thermal coupling to the heater, a first contact mounted on the body at one side of the recess to be connected in the motor circuit, and a resilient movable electrically conductive spring contact arm electrically connected to the heater to be electrically connected in the motor circuit to be at the same polarity as the heater in that circuit, the arm having one end mounted on the body at an opposite side of the recess to extend across the open recess end to normally engage an opposite end with first contact for energizing the motor during normal motor operation, to be moved to disengage the first contact and interrupt motor operation when the disc is heated to said actuating temperature by occurrence of either of short time trip and ultimate trip motor fault currents in the heater, and to reengage the first contact for reenergizing the motor when the disc cools to said reset temperature, characterized in that the body recess has an opening in the side wall thereof, a first electrical conductor member is mounted on the body having one end disposed adjacent the recess side wall opening and having an opposite terminal end extending from the body to be connected in the motor circuit, a second electrical conductor member is mounted on the body having one end disposed adjacent the recess side wall opening spaced from the first conductor member and having an opposite end connected to one end oE the contact arm at said opposite side of the recess, and a third electrical conductor member is mounted on the Claim 26 continued body having one end connected to the first contact at said one side of the recess and having an opposite terminal end extending from the body to be connected in the motor circuit, the heater disposed in the recess having opposite ends thereof extending through said recess side wall opening and respectively connected to said one end of the first and second conductor members for electrically connecting the heater, the conductors, the movable contact arm, and the first contact in series relation with each other.

Claim 29

A motor protector according to claim 26 further characterized in that said one ends of the first and second electrical conductor members are electrically connected to respective opposite ends of the heater by laser welds.

Claim 30

A motor protector according to claim 26 further characterized in that the first and second electrical conductor members are mounted on the body with said one ends thereof extending over respective body openings to be accessible from both sides of the protector bcdy, and said opposite heater ends are welded to said respective conductor members ends at the location of said openings.

Claim 31

A motor protector according to claim 28 further characterized in that resistance weld projections are provided on said one ends of the first and second electrical conductor members at the location of said body openings and the opposite ends of the Claim 29 continued heater are arranged to engage such weld projections over the body openings, said one conductor member ends being electrically connected to said respective heater ends by resistance welds at said body openings.

Claim 32

A motor protector according to claim 26 further characterized in that grooves are provided in said one body side for receiving and locating the respective electrical conductor members in predetermined location relative to the heater and to each other, each cf the conductor members has a staking tab portion extending into a corresponding staking opening in the body and bent within the staking opening for securing the conductor members in said predetermined locations, the first contact means is mounted in predetermined location on said third contact member, and the contact arm has said che end thereof mounted in predetermined location on said second conductor member so the arm normally extends in predetermined location over the recess to engage the first contact, the body having an adjusting opening located beneath a portion of said second conductor member for permitting the second member to be bent for adjusting contact pressure between the contact arm and said first contact.

Claim 33

A motor protector according to claim 30 further characterized in that the contact arm has a protuberance formed therein intermediate its ends to be engaged by the thermostat metal disc for moving the arm to open circuit position when the disc moves to its inverted dished configuration in response to heating its actuating temperature, and the arm has a stiffening rib upstanding therefrom between the protuberance and the opposite arm end for a limiting flexing of the spring arm.

Claim 34

A motor protector according to claim 31 wherein the first and third conductor members are formed of cold rolled steel, . one of said conductor members has a cross sectional size selected for providing selected thermal coupling of the thermostat metal member to the motor through said one conductor member, and the other of said members has a portion of selected, relatively smaller cross sectional size located in its respective groove intermediate member end for limiting heat transfer away from the thermostat metal member through said other conductor member.

Claim 35

A motor protector according to claim 24 further characterized in that a cover of thermally and electrically insulating material is secured to the body to extend over the body recess and said movable contact arm, the cover having a protuberance depending toward said opposite arm end to be in selected spaced relation to the opposite arm end when engaged with the first contact and to engage the opposite arm end for limiting arm movement when disengaged from the first contact, thereby to limit bouncing movement of the opposite arm end.

Claim 36

A motor protector comprising a molded, thermally and electrically insulating body having a recess open at one side of the body, the recess having a bottcm an a side wall and having a shoulder in the side wall facing the open recess end, an electrical resistance heater arranged in the recess located against the recess bottom extending around the recess to be connected in a motor circuit to carry the motor current, a round, dished thermostat metal disc adapted to move from an original dished configuration to an inverted dished configuration a resilient movable electrically conductive spring contact arm electrically connected to the heater to be electrically connected in the motor circuit to be at the same polarity as the heater in that circuit, the arm having one end mounted on the body at an opposite side of the recess to extend across the open recess end to normally engage an opposite end of the arm with the first contact for energizing the motor during normal motor operation, to be moved to disengage the first contact and interrupt motor operation when the disc is heated to said actuating temperature by occurrence of either of short time trip and ultimate trip motor fault currents in the heater, and to reen g age the first contact for reenergizing the motor when the disc cools to said reset temperature, characterized in that a cover of thermally and electrically insulating material is secured to the body to extend over said recess and over said movable contact arm, the cover having a pair of protuberances depending therefrom into the body recess on respective opposite sides cf the contact arm to be disposed adjacent respective peripheral portions of the thermostat metal disc to securely retain the disc in said selected thermal coupling in the heater in the body recess.

Claim 37

A motor protector comprising a molded, thermally and electrically insulating body having a recess open at one side of the body, the recess having a bottcm an a side wall and having a shoulder in the side wall facing the open recess end, an electrical resistance heater arranged in the recess located against the recess bottom extending around the recess to be connected in a motor circuit to carry the motor current, a round, dished thermostat metal disc adapted to move from an original dished configuration to an inverted dished configuration a resilient movable electrically conductive spring contact arm electrically connected to the heater to be electrically connected in the motor circuit to be at the same polarity as the heater in that circuit, the arm having one end mounted on the body at an opposite side of the recess to extend across the open recess end to normally engage an opposite end of the arm with the first contact for energizing the motor during normal motor operation, to be moved to disengage the first contact and interrupt motor operation when the disc is heated to said actuating temperature by occurrence of either of short time trip and ultimate trip motor fault currents in the heater, and to reen g age the first contact for reenergizing the motor when the disc cools to said reset temperature, characterized in that a cover of thermally and electrically insulating material is secured to the body to extend over said recess and over said movable contact arm, the cover having a pair of protuberances depending therefrom into the body recess on respective opposite sides cf the contact arm to be disposed adjacent respective peripheral portions of the thermostat metal disc to securely retain the disc in said selected thermal coupling in the heater in the body recess.

Claim 38

A motor protector for use with a compressor having a shell with three triangularly disposed thermally and electrically conductive pins electrically separated from each other and the shell . extending through the shell and electrically connected to to windings of an electrical motor in the shell, the protector being adapted to be mounted on cne of the pins and to permit motor starting means to be mounted on the ether two pins to dispose the protector in selected thermally coupled relation to the motor throuch the one pin while thermally separating the protector from the motor starting means and the shell, the protector comprising a housing, current and temperature responsive switch means in the housing, a terminal for connecting the switch means in a power circuit, and a resilient, pin-receiving female clip terminal adapted to be pushed onto the one pin in pin-gripping relation thereto for thermally and electrically connecting the switch means to the motor, characterized in that the pin-receiving female terminal has an opening for axially receiving the one pin and is disposed on one side of the protector housing with he axis of the opening extending in a direction from the bottom to the top of the housing, the housing is formed of a thermally and electrically insulating material, and of hold-down locating tab means extend frcm said one side of the housing bottom to slidably engage each of the other two pins for locating the housing in a precisely predetermined position relative to the pins, the tab means being relatively thin for permitting motor starting means on the other two pins to be accommodated over the tab means for retaining the protector in its selected location.

Claim 39

A motor protector for use with a compressor having a shell with three triangularly disposed thermally and electrically conductive pins electrically separated from each other and the shell . extending through the shell and electrically connected to to windings of an electrical motor in the shell, the protector being adapted to be mounted on cne of the pins and to permit motor starting means to be mounted on the ether two pins to dispose the protector in selected thermally coupled relation to the motor throuch the one pin while thermally separating the protector from the motor starting means and the shell, the protector comprising a housing, current and temperature responsive switch means in the housing, a terminal for connecting the switch means in a power circuit, and a resilient, pin-receiving female clip terminal adapted to be pushed onto the one pin in pin-gripping relation thereto for thermally and electrically connecting the switch means to the motor, characterized in that the pin-receiving female terminal has an opening for axially receiving the one pin and is disposed on one side of the protector housing with he axis of the opening extending in a direction from the bottom to the top of the housing, the housing is formed of a thermally and electrically insulating material, and of hold-down locating tab means extend frcm said one side of the housing bottom to slidably engage each of the other two pins for locating the housing in a precisely predetermined position relative to the pins, the tab means being relatively thin for permitting motor starting means on the other two pins to be accommodated over the tab means for retaining the protector in its selected location.

Claim 40

A motor protector according to claim 34 wherein the tab means comprise a pair of tabs extending from the housing adjacent opposite ends of the housing to respectively engage said two pins for preventing rotation of the protector on said one pin.

Claim 41

A motor protector according to claim 36 wherein the female clip terminal is arranged for disposing the protector housing at the side of said one pin facing away from said two pins to be thermally isolated from motor starter means mounted on said two pins.

Claim 42

A motor protector according to claim 35 wherein the pair of tabs have respective grooves at the distal ends thereof disposed in facing relation to each other facing generally away from the housing adapted to slidably engage said two pieces for guiding the female clip terminal into pin-gripping relation to said one pin.

Claim 43

A motor protector according to claim 37 having a first terminal extending from one end of said housing and having an exterior terminal electrically connected to said one terminal extending along the protector housing to support said female clip terminal intermediate opposite ends of the housing for supporting the protector on said one pin.

Claim 44

A motor protector according to claim 39 having ridge means formed on said housing extending along sides of said exterior terminal for positioning, supporting and thermally isolating the exterior terminal on the housing.

Claim 45

A motor protector according to claim 40 wherein the housing includes base and cover means for enclosing said switch means, and wherein said ridges and tab means are provided on the . housing cover, the cover having rod means thereon fitted into openings in the base means for securing the base and cover means securely together.

Claim 46

A refrigerator compressor motor system comprising an electrical motor and a refrigerator compressor operated by the motor hermetically sealed within a shell having three lead-through pins extending in sealed electrically insulated relation to each other and to the shell through the shell for electrically connecting the motor in an electrical circuit, motor protector means mounted on one of said lead-through pins with selected thermal coupling to the motor through said pin, and motor starting means mounted on said other two pins for starting the motor, characterized in that the motor protector comprises a motor protector according to claim 6 and the motor starting means is mounted on said two pins over said tab means for securing the protector on said one pin.