Abstract: A thermal trip unit for a circuit breaker having a primary conductive path for conducting a load current is provided. The thermal trip unit comprises a shape memory alloy (SMA) member adapted to change from a first shape to a second shape at a predetermined thermal condition, a holding member coupled electrically in series with the circuit breaker primary conductive path, said holding member arranged to operatively support said SMA member, wherein said SMA member is configured and disposed within the circuit breaker to trigger a trip response of the circuit breaker at said predetermined thermal condition.

Abstract: A thermally responsive switch includes a hermetic container including a housing and a header plate hermetically secured to an open end of the housing, a conductive terminal pin inserted through the header plate, a conductive pin, a thermally responsive plate having one of two ends fixed to the terminal pin, a movable contact secured to the other end of the thermally responsive plate, and a fixed contact fixed via an electrical conductor to the terminal pin, the conductor having a fuse part and a heater. The fixed contact is fixed to a ceramic member disposed between the container and the fixed contact. The housing includes a bottom surface including both lengthwise ends between which the conductive pin is interposed. Both ends of the housing bottom surface are deformed axially relative to the conductive pin from an initial state, so that an operating temperature of the switch is calibratable.

Abstract: A thermal overload relay includes a main bimetal for detection of an overload current, a shifter associated with the main bimetal, a release lever working according to a displacement of the shifter, a contact reversing mechanism for changing-over contacts by reversing action caused by rotation of the release lever, and a manipulation structure for manipulating the release lever and the contact reversing mechanism. The manipulation structure includes a reset bar for returning the contact reversing mechanism to an initial state. The reset bar is arranged to change-over between a manual reset state in which the reset bar can be pushed-in and an automatic reset state in which the reset bar is pushed-in and turned from the manual reset state and held in that state.

Abstract: A thermal overload relay is provided with an external case, and an adjustment dial with a cam inserted into an adjustment dial insertion hole provided in the external case for adjusting a settling current. A press-fitting section is provided at one of the adjustment dial and the adjustment dial insertion hole, and a locking section is provided at the other of the adjustment dial and the adjustment dial insertion hole. The press-fitting section is press-fit and retained in the locking section.

Abstract: A concealed adjustable temperature switch includes a fixed plate, an adjusting block threadedly engaged with a screw hole of the fixed plate, a bimetal plate, and a metal plate. Mounted on the adjusting block are upper and lower positioning rings and a fixing ring between the positioning rings. The fixed ring includes a hole through which the adjusting block extends. The fixing ring includes a stop projecting toward the fixed plate. The stop includes two sides having a height greater than a thickness of the fixed plate. A distance between the stop and a center of the hole of the fixing ring is greater than that between a front edge of the fixed plate and a center of the screw hole of the fixed plate and than that between either one of two sides of the fixed plate to the center of the screw hole of the fixed plate.

Abstract: A motor protector (10) is shown having an elongated generally cup-shaped metallic housing (12) formed by a top wall (12a) and a side wall (12b) extending down from the perimeter of the top walls, the free end of which is welded to a header (14). The side and top wall have a rounded junction (12c) and a calibration rill (12e) is formed in the top wall from one end of the housing and through the rounded junction. An elongated thermostatic disc (16) is mounted in the housing and has a movable electrical contact (20) mounted at one end to be movable into and out of engagement with a stationary electrical contact (34) that is in turn mounted on a heater (26). A ceramic insulator plate (32) is interposed between the heater and the header.

Abstract: A switching element of a sheet of resilient metal having high and low heat-expansive sides, the switching element having a middle leg carrying an electric contact for making and breaking a circuit with a stationary contact on a substrate below, first and second outer legs each having one end connected to the same end of the middle leg, and an arm of width smaller than ⅓ of the width of said switching arm extended outwards from the connecting area between the middle leg and the outer legs in longitudinal alignment with the middle leg for pulling upwards/pushing downwards by an external force to reverse the middle leg.

Abstract: 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.

Abstract: A condition-responsive electric switch mechanism for use in controlling a compressor of a refrigeration appliance. The switch mechanism includes first, second and third terminals, an actuator movable as a function of a detected condition and a bistable spring switch element electrically connected to the first terminal. The spring switch element includes a movable contact and is adapted for snap-acting movement between an open and a closed position. In the open position, the movable contact of the spring switch element is spaced apart from a fixed contact mounted on the second terminal. In the closed position, the movable contact engages the fixed contact to electrically connect the first and second terminals. The spring switch element also includes a toggle blade operable by engagement with the actuator for motion through a first switch point. At the first switch point, the spring switch element snaps between the open and closed positions.

Abstract: An electrical switching device includes a switching device socket and terminals. The device also includes a snap-action switch with at least one catch spring. The catch spring carries at least one switching contact stud. The snap-action switch is trippable by a thermobimetal. For thermal influencing the thermobimetal, a heating device with a heating resistor mounted on a metal support is provided. The metal support can be made from a steel plate carrying an electrically insulating layer made from glass. An extensive heating resistor is provided on the insulating glass.

Abstract: An electric toaster comprising a heating element; and a combined user actuation and thermostat switch assembly connected to the heating element. The switch assembly comprises a thermostat having a bi-metal electrical contact blade and a snap-acting electrical contact blade, and a user actuated member for moving the snap-acting blade towards the bi-metal blade. The switch assembly provides an electrical path between the heating element and an electrical power supply cord without an additional separate user actuated power switch along the path.

Abstract: A thermal protector includes a header plate and a metal housing having an open end hermetically welded to an peripheral edge of the header plate. The housing is formed into a generally slender shape so as to be suited for mounting on end turns of a stator winding of a three-phase electric motor. A thermally responsive element includes a shallow curved portion at which the element changes states of curvature with snap action in response to different ambient temperatures. The thermally responsive element has two movable contacts secured to it to be disposed symmetrically about a center of the curved portion so that the movable contacts are engageable with and disengageable from fixed contacts respectively. A push piece is disposed in the housing to exert a pushing force on a normally convex side of the thermally responsive element. The pushing force is adjusted by deforming the outer surface portion of the housing for calibration of the operating temperature.

Abstract: A thermostat uses a bimetal plate carried by a rotating knob. Adjustment of the knob to select the thermostat's temperature setting displaces the entire bimetal plate towards or away from the electrical switch being activated. The bimetal plate is contained between protrusions from the knob and the coupling to the electrical switch.

Abstract: A thermostatic switch that utilizes a snap acting bimetal blade that deforms at an actuation temperature and returns to an undeformed state at a reset temperature. Actuation and reset projections, preferably in the form of dimples, are provided to calibrate the switch. The bimetal blade has a centrally located, cupped or dish-like snap acting depression. The reset dimple is spaced below the bimetal blade between the snap acting depression and the free end of the bimetal blade instead of substantially directly below the moveable contact as in the prior art. Accordingly, the thermostatic switch may be used in relatively high voltage settings of up to approximately 600 volts without the occurrence of arcing.

Abstract: 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.

Abstract: A thermostat includes a case assembly with two terminals and movable contacts, one of which is on a resilient blade to open and close a circuit through the terminals. A bimetal disc actuates the blade by heating to open the contacts. A base defines an interface with the case assembly and supports the disc; the interface being deformed or crushed sufficiently to position the blade to define the threshold temperature and to couple the base and case assembly together. The deformable interface is preferably formed by upstanding, curved projections on the base and mating with the case assembly. When deformed, the projections are substantially perpendicular to the bottom panel of the base so that the disc is centered, but is freely movable. Bendable legs secure a cap in position and lock the case assembly and the base together.

Abstract: A thermostatic switch construction including a housing having a switch arm mounted for movement inside. A bi-metallic snap disk is mounted in the housing and movable in response to temperature change with snap action between two positions of stability. A switch arm actuating plunger is slidably mounted in the housing with its lower end adapted for contact by and snap movement by the bi-metallic snap disk. A creep gap assembly is provided which includes a creep gap screw threadably mounted in the switch arm opposite the upper end of the plunger. Axes of the plunger and the gap set screw are in alignment. The creep space between the lower end of the set screw and the upper end of the plunger is adjustable by rotation of the set screw. A temperature setting adjustment is provided which includes a spring member mounted in the housing with one end of the spring member in direct contact with the bi-metallic snap disk to thereby exert pressure on the disk.

Abstract: A resettable circuit breaker for protecting an electrical circuit from prolonged overload current conditions. The resettable breaker opens upon prolonged overload current conditions. With an optional resistor, the resettable breaker remains open until the prolonged overload current is removed from the breaker. The breaker comprises a first stationary terminal having a first contact, and a movable terminal comprised of a single metal and having a second contact for engagement, under normal conditions, with the first contact. A shape memory alloy wire is positioned adjacent the movable terminal. The shape memory alloy wire is normally in a relaxed, non-contracted configuration. Upon prolonged overload current conditions, the shape memory alloy wire is heated and contracts to contact and shift the movable terminal and the second contact out of engagement with the first contact.

Abstract: Control device for at least two luminous condition indicating signals (30, 41) mounted on a domestic electrical appliance provided with a quick opening adjustable thermostat (2) which passes over center. An insulating support (13, 14, 15) receives a thermostat arm (11), a blade (16) forming a fixed contact, a movable blade (7) provided with a flexible tongue (20) on which bears an insulating plug (22) controlled by a rotatable screw (10) permitting obtaining a predetermined temperature, and another movable blade (8) fixed to the movable blade (7) and whose free end bears against the fixed contact as well as an insulating partition (9) fixed to the bimetal (6) and controlling the movable blades (7 and 8). The blade forming a fixed contact (16) and the movable blades (7 and 8) are fixed to the insulating support, connected respectively to electrical terminals by electrical connections (3, 4) and supply the two luminous signals (30, 41).

Abstract: A three-phase thermal protector includes a hermetic receptacle composed of an elliptic dome-shaped cover having an opening at one end and a header plate having two terminal pins extending through respective apertures formed in it, and a switch assembly mounted in the receptacle. Two fixed contacts are secured to the respective terminal pins. The switch assembly includes a metal operating temperature calibrating plate with one end welded to the cover, a bimetallic thermally responsive element having one end secured to the calibrating plate and the other end having a central dish-shaped portion, and a thermally-responsive-element support to which the supported end of the thermally responsive element is welded. The thermally responsive element carries two movable contacts symmetrical about the center line.

Abstract: A thermally responsive switch includes an elliptic dome-shaped metal receptacle, a header metal plate hermetically secured to the receptacle and having a through-aperture at one of two longitudinal ends, an electrical conductor inserted through the aperture of the header plate and secured with an electrically insulating material such as glass, a support having at one of two longitudinal ends a fixed portion secured to the end of the conductor in the receptacle and a supporting portion positioned away from its other end in the direction of the fixed portion, a bimetal secured at one of its two ends to the supporting portion of the support and carrying a movable contact at the other end, the bimetal having a central shallow dish-shaped portion reversing its curvature with a snap action in response to the temperature, a fixed contact secured to the header plate in the vicinity of its other longitudinal end, and a calibrator interposed between the inner wall of the receptacle and the other end of the support oppo

Abstract: A thermal motor protector includes a first support for supporting a thermally responsive element and a second support for supporting a fixed contact. The first and second supports are mounted on and insulated from a header plate. The thermally responsive element is secured to the first support through a fixing strip and has a central shallow dish-shaped portion and carries a movable contact at its distal end. A calibration mechanism includes a male screw, a hole formed in the first support and elastically slender clamping portions clamping the screw when it is screwed into the hole. The diameter of the hole is smaller than the outer diameter of the screw. The stiffness of the fixing strip is determined so that variations in the ratio of the current bypassed into the calibration mechanism to the current flowing through the fixing strip and thermally responsive element can be substantially ignored.

Abstract: A thermally responsive switch includes an elliptic dome-shaped receptacle, a support conductively secured at one of two ends to an inner surface of one of two ends of the receptacle in the direction of its length, a bimetallic thermally responsive element secured at one end to the other end of the support with the other end opposite to an inner surface of the other end of the receptacle in the direction of its length with a predetermined space interposed therebetween, the thermally responsive element carrying a movable contact on the other end, and a metallic lid secured to the open end of the receptacle so as to hermetically close the open end of the receptacle. The lid has a through-hole through which a terminal pin is disposed with an electrically insulative material charged in the through-hole. Alternatively, two terminal pins may be disposed through two through-holes respectively.

Abstract: A snap-action thermostatic switch, having a bimetallic member with a snap-action formed section bearing against a calibration dimple, has an insulative coating provided on the calibration dimple to prevent current flow through the dimple which could disrupt switch operation or cause damage to the bimetallic member.

Abstract: A thermostat for controlling the electrical heating element of an appliance has a user-activated control shaft for controlling the overall operation of the appliance. The thermostat includes a first switch controllable by a temperature sensing element for turning the heating element on and off. When the control shaft is turned to an off position, the shaft disables the operation of the first switch, maintaining it in an open condition. The thermostat also has a second switch which operates a pilot light for indicating when the appliance is on. The second switch is continuously open when the control shaft is in the off position and continuously closed when the control shaft is in an on position.

Abstract: A thermally responsive switch used in enclosed motor-compressors includes a supporter formed of a single metallic plate and including a support arm cantilever mounting a thermally responsive bimetallic or trimetallic element carrying a movable contact at one end, first and second beams disposed in a relation that the support arm is interposed between these beams, and an operative temperature calibration strip integrally extended from the first beam. The calibration strip is slidably inserted between the support arm and the second beam into a wedge structure in the state that the calibration strip is bent at the root portion. Consequently, when the calibration strip is bent with the slidable movement, the support arm is bent so that the contact pressure between the contacts is set, an amount of bending deformation of the support arm corresponding to an amount of bending deformation of the calibration strip.

Abstract: An electrical circuit breaker comprises a base with two terminals embedded in, and extending through, the base. The external plug-in portions of the terminals are centered on the base. The internal portions of the terminals are off to one side in order to accommodate a PMB bimetal mounted on said internal portions. A cover secured to the base encloses the PMB bimetal.

Abstract: A three phase hermetic protector for electrical apparatus has a pair of terminals extending through a header with first and second elongated heaters mounted on the terminals and extending away from the header. A rigid support is attached to the header between the terminals and extends away from the header and mounts a third elongated heater extending back toward the header. A snap acting disc is cantilever mounted on the free end of the third heater and mounts thereon a pair of movable contacts adapted to move into and out of the engagement with stationary contacts mounted at the free ends of the first and second heaters. The rigid support mounts a calibration screw beneath the free end of each of the first and second heaters to independently adjust the vertical position of the stationary contacts.

Abstract: This invention relates to a three-phase thermal protector having two pairs of fixed and movable contacts for opening and closing the neutral of wye-connected phase windings of a three-phase induction motor.

Abstract: The present invention provides an improved means of connecting the end of a bimetal blade, from which the bimetal flexes, to a planar member of a thermostatic switch. The bimetal blade, in response to temperature changes of the ambient, flexes to alternately establish circuit closed and open conditions of the switch. In a preferred embodiment, the planar member is a contact strip that overlies the basewall of a non-conducting case. The attachment provided by the present invention increases the cyclical life expectancy of the bimetal blade by locating a preloaded weld button against the one attached end of the bimetal blade in a press fit wherein a pressure, exerted by the weld button, prevents movement of the bimetal blade. A weld penetrates the planar member, the bimetal blade and the weld button to prevent relaxation of the pressure. In the connection of the present invention, the blade is held in place essentially by the pressure exerted by the weld button rather than by the weld itself.

Abstract: The present invention provides a method of forming a thermostatic switch having a calibrated operating temperature range that is defined by a calibrated actuation temperature and a calibrated reset temperature. In accordance with this method a snap action thermostatic switch is provided having a bimetal blade with a snap acting depression. The blade is formed to have a range of actuation temperatures above the desired actuation temperature and a range of reset temperatures below the desired reset temperature. The actuation temperature is calibrated in a heated temperature environment that has an initial temperature that is equal to the desired actuation temperature by a fulcrum-like calibration projection. The reset temperature is then calibrated in the heated temperature environment, after the temperature has been lowered to equal the desired reset temperature.

Abstract: A thermostatically controlled electric heater for aquariums includes within an electric waterproof envelope, a heating element and a working unit regulating the temperature, moving axially in order to vary the rest position of a bimetal strip which, depending on its deformation, opens and closes the supply circuit of the heating element. The regulation unit (3) is provided with a threaded pin (13), the end resting against the bimetal strip (7) and with a cylindrical body (11), provided on the side surface with a helical line (12) dividing the surface of the cylindrical body into two differently colored portions (12) covered by a screen (18) provided with a longitudinal slot (19) through which a short portion of said helical line (12) is visible. A grauated scale is provided along the slot and cooperates with the visible portion of the line to indicate the set operating temperature of the heater.

Abstract: A thermostat having heat anticipation uses a temperature responsive bimetallic element for effecting a thermostat contact closure during a heating operation controlled by the thermostat with an electrical contact carried by terminal strip positioned adjacent to the bimetallic element and formed from a high resistance stainless steel material. The resistance of the terminal strip is enhanced by lengthening the current path into a convoluted path utilizing notched out areas of the terminal strip. The resistance heat generated in the terminal strip by the current flow therein during the heating operation provides the desired heat anticipation for the operation of the thermostat by the bimetallic element by increasing the temperature sensed by the element.

Abstract: A bimetallic thermostat with dual temperature control has a first male/female screw unit, one of the elements of which is secured to the thermostat's supporting structure and the other to one of the elements of a second male/female screw unit the other element of which is operatively connected with a flexible lamina having a contact. Between the elements of at least one of the two male/female screw unit is a stop to fix the deflection of said flexible lamina affected by a bimetallic lamina of the thermostat.

Abstract: A thermostat equipped with a bimetallic element sensitive to a given temperature comprises a monolithic base open at one end in which two terminals connectable to an electric circuit are inserted and precisely located, each having one end bent at a right angle and each carrying a stationary contact, an element carrying movable contacts for connecting the stationary contacts with one another, a spring housed in a seat on said base biasing the movable contact element to engage the stationary contacts, a sliding element for moving and guiding said movable contact-carrying element, a bimetallic element suitably spaced from the said sliding element for initiating movement of the sliding element in response to temperature change, and a lid which fastens the said bimetallic element to the said base with said spacing from the sliding element.

Abstract: A tuning element for a temperature responsive switch includes a bimetal assembly in the form of an elongated, relatively flat bimetal strip with bending action and including integral tuning webs for adjusting the thermodynamic properties of the element. Multiple apertures are punched in a predetermined pattern in the bimetal strip to form the webs. Each of the webs is also bent in alternate directions to form ribs that reinforce the element. The bimetal strip is formed from a bimetal base portion and extension portion butt welded together; the webs being formed in the strip adjacent the weld joint. The base portion of the strip bends to open the contacts and the extension portion bends to bring the contacts back closer together, thereby controlling overshoot and providing consistent operation within a relatively narrow temperature range.

Abstract: A thermally responsive snap-acting switch consists of an elastic plate cantilever mounted at one end on a header, a thermally responsive element which includes a central dish-shaped portion for inducing snap action and one end of which is connected with the other end of the elastic plate in an opposed relation to the elastic plate, a support one end of which includes a portion receiving a connection between the elastic plate and the thermally responsive element so that it slides and is inclined on the receiving portion, and a projection which exerts a force on the dish-shaped portion of the thermally responsive element to calibrate the operative temperature of the thermally responsive element. The calibration is performed either by employing a screwed stud as the projection or by plastically deforming the receiving portion of the support.

Abstract: A circuit breaker formed of a PMB bimetal fastened to a post and arranged to face against a new contact that is disposed upon a U-shaped calibration bracket. A span is exposed in the U-shaped calibration bracket to enable a calibration probe to break the circuit breaker at a predetermined time to permanently bend it into a fixed position.

Abstract: A circuit breaker comprises a two piece metal enclosure, a cover and a base. Disposed within the enclosure is a PMB bimetal which is fastened to a step in the cover. The opening time of the circuit breaker can be adjusted by means of the step.

Abstract: A switch construction having a support carrying a pair of spaced apart first and second fixed contacts and a movable switch blade unit carrying a contact unit for being disposed in contact with the first fixed contact and out of contact with the second fixed contact when the switch blade unit is in a first position thereof and for being disposed in contact with the second fixed contact and out of contact with the first fixed contact when the switch blade unit is in a second position thereof.

Abstract: A condition responsive switching device has a cup-shaped case, a body secured in abutting assembled relationship to the case, the body and case defining a chamber, a switch mounted on the body in the chamber providing a fixed electrical contact and a cantilever mounted leaf spring, the free end of the leaf spring overlying the fixed contact and providing a mobile contact movable into and out of engagement with the fixed contact, a snap disc in the chamber on the side of the leaf spring remote from the body, the snap disc being movable between two positions of stability in response to two different predetermined environmental conditions, the central portion of the snap disc moving from each position of stability to the other position of stability first with a predetermined amount of creep movement followed by snap movement, the disc and spring arm being operably connected so that the switch is closed when the disc is in one position of stability and is open when the disc is in the other position of stability,

Abstract: A circuit breaker comprises a two piece metal enclosure, a cover and a base. Disposed within the enclosure is a PMB bimetal which is fastened to a step in the cover. The opening time of the circuit breaker can be adjusted by means of the step.

Abstract: A snap action type thermally responsive switch comprising a fixed contact secured to a stationary frame, a rectangular thermally responsive plate having a central dish-shaped portion and being secured at one lengthwise end to the stationary frame and carrying a movable contact, the plate being determined at the ratio of length to width to be more than two, a calibrator screw projecting toward the convex side of the dish-shaped portion to depress thereagainst at the normal temperature, the calibrator means being positioned to contact the dish-shaped portion within the region ranging from the central point to a point away from the central point that is equal to one-third of the width of the plate in the direction toward the secured end thereof.

Abstract: A temperature responsive switch has a bimetal-and-spring arrangement carrying a movable contact and having a first stable state urging the movable contact towards a stationary contact into an ON position and a second stable state urging the contacts away from one another into an OFF position; and a setting shaft setting the bimetal-and-spring arrangement to a desired temperature value at which the bimetal-and-spring arrangement displaces the movable contact from the ON position into the OFF position. The setting shaft has a relatively low temperature setting range and a relatively high temperature setting range. The switch further has a stopping mechanism having an operative and an inoperative state for preventing the bimetal-and-spring arrangement from assuming the second stable state in the operative state of the stopping mechanism and for allowing the bimetal-and-spring arrangement to assume the second stable state in the inoperative state of the stopping mechanism.

Abstract: In a hermetic type thermally responsive switch comprising a fixed contact support having a fixed contact at its end and cantilever disposed in a hermetically sealed vessel, a elongated support supporting a thermally responsive disk which has a movable contact and cantilever disposed in said vessel through a connecting means; said fixed contact support comprises laminated metallic sheets each having different elastic modulus, while a spacer means is interposed in electrically, thermally insulated relationship between said elongated support and said connecting means so as to calibrate the snap temperature of said disk.

Abstract: A unitary assembly includes a thermostatically controlled valve and an electric switch coupled for operation therewith. Both the valve and the electric switch are operated under the control of a thermostatic actuator which effectuates operation through a snap acting member movable between alternate stable positions. Neither the valve nor the electrical switch can dwell at the threshold of actuation, but rather are positively actuated to either an open or closed position when the snap acting member moves to one of its stable positions, and to an opposite condition when the snap acting member moves to its alternate stable position. The movement of the thermostatic actuator can be adjustably multiplied by a lever arrangement in the valve housing. The movement of the snap acting member can also be multiplied by an internal arrangement employing a lever ring with radially inwardly directed cantilevered lever arms.

Abstract: A thermally responsive electrical switch assembly is shown having a housing with a dielectric end portion through which is formed a passage an axial portion of which has an integrally molded thread which coacts with an externally formed thread of an electrically conductive terminal member extending through the passage; a resiliently deflectable elastomeric member, generally within the housing, frictionally engages the terminal member as to thereby mask any otherwise perceived looseness between the externally formed and integrally molded threads and, instead, cause the terminal member to exhibit an apparent smooth movement during threadable adjustment thereof.

Abstract: A thermally responsive switch comprises a housing enclosing a contact arm bearing a fixed contact and a thermally responsive snap-acting element designed to move and return with snap action depending upon the degree of switch self-generated heat or the ambient temperature. One end of the snap-acting element carries a movable contact and its other end is the supporting portion connected to a metallically elastic member mounted in the housing. To a stationary member integrated with the housing, an end support element and a central support element are respectively mounted. The end support element engages the supporting portion of the snap-acting element against the elastically urging force of the elastic member to push in one direction, while the central support element engages a middle portion of the snap-acting element to push in the opposite direction.

Abstract: A motor protector has a tubular metal housing with open and closed ends, has a contact welded to one inner side of the housing near the closed housing end spaced from an opposite inner side of the housing, has a terminal sealed in the open housing end, and has a bimetal member extending from the terminal into the housing along the housing axis in spaced insulated relation to the housing to move into and out of engagement with the contact in response to temperature change. The protector is compact and hermetically sealed and is calibratable by housing deformation without loss of hermetic sealing. In some embodiments first and/or second heaters connected to selected motor windings via sealed terminals are compactly accommodated in the housing along respective sides of the bimetal member.

Abstract: A thermal responsive electrical switching device provides an electrical connection between first and second electrical connectors when the temperature of the switching device is less than a first predetermined temperature level and terminates the electrical connection when the temperature of the device exceeds the first predetermined temperature level. The electrical connection is not re-established until after the temperature of the switching device has dropped below a second predetermined temperature level which is less than the first predetermined temperature level. The switching device includes an actuator means mounted on a bimetal blade which causes a snap contact blade to be snapped into first and second snap positions as a result of movement of the bimetal blade. The actuator means includes first and second actuators which are embedded in a curable material.