Abstract: The invention relates to a trip assembly for use in an electro-mechanical device, such as a circuit breaker. The trip assembly is used for interrupting the flow of current upon the detection of excess current in a circuit breaker and comprises a trip bar, a stationary armature bracket, a movable armature, and a spring. The movable armature includes a first end coupled to a base portion of the armature bracket, and a trip-actuating surface being disposed proximate a trip finger of the trip bar. The spring is directly coupled at its respective ends to a spring-support portion of the armature bracket and to a spring tab of the movable armature.

Abstract: A conducting element for shunting an electric power supply from a main conductor to an accessory device operatively associated with a circuit breaker, whose particularity consists of the fact that it comprises a contoured body that is meant to be arranged in a seat on the body of the circuit breaker in which a terminal for connection to the main conductor is arranged, the contoured body comprising at least one first surface that is suitable to be rested against a wall of the seat on the circuit breaker body and a second surface that protrudes at right angles from the first surface and is suitable to operatively couple to an additional conducting component that can be connected electrically to the accessory device.

Abstract: A method and magnetic trip unit for actuating a latching mechanism to trip a circuit breaker upon an overcurrent condition, the magnetic trip unit including: a first electrically conductive strap configured to conduct an electrical current; a first magnet yoke disposed proximate to the first electrically conductive strap; and a first armature pivotally disposed proximate to the first magnetic yoke in operable communication with the latching mechanism; the first armature providing a magnetic path having a reluctance to magnetic flux; and the reluctance is adjusted to prevent saturation of the magnetic flux when the current through the strap is a first number times a rated current of the circuit breaker and the reluctance is adjusted to promote saturation of magnetic flux when the current through the strap is a second number times the rated current of the circuit breaker, wherein the first number is a number smaller than the second number.

Abstract: This invention discloses a low-voltage circuit breaker with a capability of tripping quickly. Its main feature is that at least one of the side faces of the contact device provides an open flange which has an internal through hole, and the bottom of a rotating shaft disposed on the bottom part provides a stressed member. The stressed member receives the over-pressure airflow escaping from the open flange of the contact device to generate a force. The force is passed to the activating member by the rotating shaft and is magnified, then hits the latch quickly and makes a trip. An intermediate step is bypassed due to the force produced earlier, the force which is produced by the electromagnetism part in the heat energy and electromagnetic system, so that the low-voltage breaker can open quickly and reduces opening time greatly and improve the breaking capability.

Abstract: A trip unit for a circuit breaker having a current carrying conductor that electrically communicates with a cable or a bus bar. The trip unit includes a current carrying strap, a magnet core, an armature and a magnetic barrier. The current carrying strap is adapted to be in electrical communication with the current carrying conductor. The magnet core is disposed at the current carrying strap. The armature is pivotally disposed in magnetic communication with the magnet core. The magnetic barrier is disposed to shield the armature from a magnetic flux generated in the current carrying conductor.

Abstract: An electrically isolated rotor assembly for a cassette assembly of a circuit breaker includes a rotor having a first side and an opposing second side, a first isolation cap disposed on the first side, a second isolation cap disposed on the second side. Each isolation cap preferably includes a centrally located knob with a bushing surrounding each knob, wherein the bushings are sized for securement within apertures within first and second cassette half pieces.

Abstract: An electromagnetic relay with adjustable tripping threshold for a low-voltage circuit breaker, comprising a magnetic circuit that has a fixed part,, which comprises a fixed element made of ferromagnetic material, a core, and at least one winding coil, and a moving part, which has a moving plate made of ferromagnetic material and arranged so as to face at least partially the fixed element with the coil interposed between the moving plate and the fixed element, the moving plate being functionally connected to means for adjusting the tripping threshold; its particularity consisting of the fact that the moving plate and/or the fixed element have a contoured body that allows, by acting on the adjustment means, to set the tripping threshold by simultaneously varying the gap between the moving plate and the fixed element and the magnetic coupling between the moving plate and the core.

Abstract: A circuit breaker includes a molded housing having a base and a cover forming a recess. A cylindrical steel pivot pin is disposed in the recess of the housing. Fixed and movable separable contacts are disposed within the molded housing. An operating mechanism is disposed within the molded housing for moving the separable contacts between an open position and a closed position. The operating mechanism includes a cradle having a latch portion and a generally U-shaped pivot portion which pivotally engages the cylindrical steel pivot pin. A trip mechanism cooperates with the operating mechanism to trip open the separable contacts. The trip mechanism includes a portion which engages the latch portion of the cradle when the separable contacts are in the closed position.

Abstract: A circuit breaker includes separable contacts and an operating mechanism having a cradle for opening and closing the separable contacts. A trip mechanism cooperates with the cradle of the operating mechanism to trip open the separable contacts. The trip mechanism includes a bimetal conductor, which is electrically connected in series with the separable contacts. The trip mechanism is responsive to a predetermined condition of current flowing in the bimetal conductor. The trip mechanism also includes a magnetic yoke coupled to the bimetal conductor, an armature pivotally mounted to the magnetic yoke, and a spring biasing the armature away from the magnetic yoke. The spring is set apart from the bimetal conductor. The spring is coupled to the armature and engages the magnetic member.

Abstract: A magnet assembly for actuating a trip latch in a circuit breaker. The magnet assembly includes a core and an armature. The core is disposed around a conductor forming a primary current path in the circuit breaker, and includes an end forming a pole face. The armature is biased by a force acting in a direction away from the pole face. The armature includes a generally planar surface and a projection extending from the generally planar surface toward the pole face. The generally planar surface is separated from the pole face by a first air gap, and the projection is separated from the pole face by a second air gap. The first air gap is larger than the second air gap.

Abstract: A unitary operating mechanism assembly for a circuit breaker that includes a frame assembly having a planar member with a first pivot point located thereon, a handle member rotatably attached to the frame assembly at the first pivot point and structured to move between a first, closed position, a second, open position having an intermediate position therebetween, and a third, reset position, an operating arm coupled to the handle member and structured to move between a first and second position, and a trip device attached to the frame assembly and structured to move the handle member between the first, closed position and the intermediate position upon the occurrence of a predefined condition. The trip device causes the handle member to rotate upon the occurrence of a predefined condition, such as an overcurrent, thereby causing the operating arm to rotate and wherein none of the components except the frame assembly is attached to the housing.

Abstract: A trip system for a circuit breaker includes a current sensor and a stop surface, the current sensor having a contact surface, a first end that is supported, and a second end with a degree of freedom. The current sensor, arranged for receiving an electric current, undergoes a first deflection in response to a first current and a second deflection in response to a second current, the first deflection resulting in clearance between the contact surface and the stop surface, and the second deflection resulting in contact between the contact surface and the stop surface.

Abstract: A heater element for use in a circuit breaker whose initial shape can be varied to achieve various trip ratings for different circuit breakers. The material composition of the heater element and the bimetal strip indirectly heated by the heater element are kept the same. The electrical resistance presented to current passed through the heater element is varied by varying the shape of the heater element. The shape of one heater element relative to another heater element varies according to one geometric parameter. The geometric parameter may be surface geometry, thickness, or cross-sectional area.

Abstract: An electrical device, such as a circuit breaker, for interrupting the flow of current, which includes a stationary contact, a blade having a movable contact, a releasably latchable trip lever, a bimetal, and a magnetic armature. The movable contact is movable into and out of engagement with the stationary contact. The trip lever is releasable from a latched position for movement to a tripped position to cause separation of the stationary and movable contacts. The bimetal causes the release of the trip lever from the latched position by having the armature drawn a predetermined distance in response to a predetermined short circuit current. The trip lever is held in the latched positioned by a hardened latch having a minimal surface area, which is positioned near an opening located in the armature. When the predetermined short circuit current flows through the bimetal, the trip lever moves to the tripped position.

Abstract: A shunt wire spacer provides for proper spacing between the shunt wires extending from the movable arm to the bimetal within a circuit breaker, thereby ensuring that the shunt wires do not come together during over-current conditions within the circuit breaker, and preventing the shunt wires from interfering with the movement of the trip bar.

Abstract: A switching mechanism for use in an electromechanical device, such as a circuit breaker, comprising a stationary contact, a blade assembly having a blade, which includes a movable contact, a frame guide having a guiding area, a trip lever, a tripping mechanism, a lower link, and an upper link. The trip lever is connected to the frame guide and causes the separation of the movable contact from the stationary contact, thus switching the device from an ON position to a TRIPPED position. The tripping mechanism is adapted for holding the trip lever in the ON position, and for releasing it to the TRIPPED position when a tripping condition occurs. The lower link is adapted for moving the blade between the ON and the TRIPPED positions. The upper link includes an interface area which is adapted to remain in continuous contact with the guiding area for accelerating the tripping action.

Abstract: A circuit breaker for interrupting the flow of current upon the detection of excess current or temperature is provided which comprises a housing, a trip armature plate, a trip armature frame, and a bias spring. The trip armature plate has at least two pivot tabs extending laterally on opposite edges that are inserted into a pivot elongated slot, which is located at an open end of the trip armature frame, and a pivot aperture, which is located at the opposite end of the trip armature frame, respectively. A bias spring is used for securing the pivot tabs into the pivot elongated slot and the pivot aperture, and for urging the trip armature plate pivotably outwardly about the pivot tabs away from the trip armature frame. The circuit breaker also comprises a trip cross bar having at least two fingers that are used to engage optional circuit breaker accessories and that are located asymmetrically to allow the interchangeability of the accessories.

Abstract: A circuit breaker includes separable contacts and an operating mechanism having a cradle for opening and closing the separable contacts. A trip mechanisms cooperates with the cradle of the operating mechanism to trip open the separable contacts. The trip mechanism includes a bimetal conductor, which is electrically connected in series with the separable contacts. The trip mechanism is responsive to a predetermined condition of current flowing in the bimetal conductor. The trip mechanism also includes a magnetic yoke coupled to the bimetal conductor, an armature pivotally mounted to the magnetic yoke, and a spring biasing the armature away from the magnetic yoke. The spring is set apart from the bimetal conductor. The spring is coupled to the armature and engages the magnetic member.

Abstract: A circuit breaker for a multi-pole electrical distribution circuit includes a cassette associated with each pole in the multi-pole electrical distribution circuit. Each cassette includes a housing, a pair of electrical contacts disposed in the housing, and a thermal and magnetic trip unit supported by the housing. The housing includes a first compartment having the electrical contacts disposed therein and a second compartment having at least a portion of the thermal and magnetic trip unit disposed therein. A wall separates the first and second compartments for isolating the second compartment from gasses generated by separation of the first and second contacts. A duct adjacent to the second compartment allows the gasses to pass to an exterior portion of the housing. The housing includes a pair of opposing slots formed therein for receiving edges of a load terminal.

Abstract: A motor protection trip unit for a circuit breaker includes an electrically conductive strap, a yoke including a body including a first side wall, a second side wall, a third side wall, and a fourth side wall. The third side wall extends between the first and second side walls, the fourth side wall extending from the first and second side walls and comprising a yoke gap extending therethrough. A motor protection trip unit for a circuit breaker also includes a flapper holder coupled to the strap, a flapper pivotally coupled to the flapper holder, and a biasing mechanism coupled between the flapper holder and the flapper. The biasing mechanism is configured to maintain the flapper a distance from the yoke such that a yoke-flapper gap is defined between the yoke and the flapper.

Abstract: A circuit breaker includes a housing; separable contacts mounted in the housing; and an operating mechanism for opening and closing the separable contacts. An overcurrent assembly is responsive to selected conditions of current flowing through the separable contacts and actuates the operating mechanism to trip open the separable contacts. A bonnet forms a U-shape which surrounds the separable contacts and which cools and splits an arc when the operating mechanism trips open the separable contacts. A first bonnet piece forms a first leg of the bonnet, and a second bonnet piece forms a second leg and a base of the bonnet.

Abstract: An electromagnetic circuit breaker is provided with a pair of magnets on opposing sides of the contacts in the open position. A magnetic field generated by the magnets combines with the magnetic field generated by the electrical arc created upon opening of the contacts during an overcurrent condition sensed by the breaker. The combined magnetic fields deflect the arc current, shifting the arc current away from the contact points and lengthening the path of the arc, thereby increasing the voltage rating of the breaker, by decreasing the intensity of an associated arc current.

Abstract: The circuit breaker current/time characteristic value at which the bimetal in a thermal trip assembly actuates a trip mechanism is adjusted by an adjustable coupler that includes first and second pivoted members separately rotatable about a common pivot axis. Deflection of the bimetal by an overload current causes rotation of the first pivoted member, which is coupled by a coupling member extending parallel to the common axis into the second pivoted member which rotates to actuate the trip mechanism. A positioner moves the coupling member toward and away from the common pivot axis to adjust the amount of deflection of the bimetal needed to actuate the trip mechanism.

Abstract: A shunt wire spacer provides for proper spacing between the shunt wires extending from the movable arm to the bimetal within a circuit breaker, thereby ensuring that the shunt wires do not come together during over-current conditions within the circuit breaker, and preventing the shunt wires from interfering with the movement of the trip bar.

Abstract: A signal accessory for a molded case circuit breaker, with the circuit breaker (10) having an operating mechanism (40) with a cradle pin (41b), a cross bar (55) and a trip bar (54) and a main breaker cover (20). The signal accessory (300) comprises a signal accessory mounting (301) having a bottom mount (308) and a top mount (306) coupled to the bottom mount (308) with the top mount configured to receive a switch (302, 304) and engage the breaker cover (20) in an accessory socket (22). A switch member (311) is rotably mounted on the bottom mount (308) with the switch member (311) having an actuator lever (322) in contact with the operating mechanism (40) of the circuit breaker (10) and an actuator pad (314) in contact with a switch mounted on the top mount (306).

Abstract: A circuit breaker comprises a line terminal, a middle terminal, and a load terminal, at least one of which is constructed from a positive temperature coefficient material and configured for introducing a predetermined resistance into the current path of the circuit breaker. The predetermined resistance is intended to limit current reaching a bi-metallic trip element as temperature rises so as to protect the bi-metallic trip element from excessive thermal stress, where the predetermined resistance increases with the increased temperature.

Abstract: A circuit interrupter including a housing, separable main contacts disposed in the housing, and an operating mechanism disposed in the housing and interconnected with the contacts. A trip mechanism is disposed in the housing and has an automatic trip assembly that generates a tripping operation. The automatic trip assembly includes an armature and a magnetic yoke having pivot supports. The armature includes a head portion having a first hook-like member and an oppositely facing second hook-like member. The first hook-like member has a first recess, and the second hook-like member has a second recess. The automatic trip assembly includes a pivot pin positioned on the pivot supports and extending through the first recess and the second recess to provide a rotatable disposition of the armature. The assembly also includes a biasing member applying a force to the armature in a direction to normally rotationally displace a bottom portion of the armature away from the magnetic yoke.

Abstract: A motor protection trip unit for a circuit breaker includes an electrically conductive strap, a yoke including a body including a first side wall, a second side wall, a third side wall, and a fourth side wall. The third side wall extends between the first and second side walls, the fourth side wall extending from the first and second side walls and comprising a yoke gap extending therethrough. A motor protection trip unit for a circuit breaker also includes a flapper holder coupled to the strap, a flapper pivotally coupled to the flapper holder, and a biasing mechanism coupled between the flapper holder and the flapper. The biasing mechanism is configured to maintain the flapper a distance from the yoke such that a yoke-flapper gap is defined between the yoke and the flapper.

Abstract: The invention relates to a circuit breaker having a crossbar (7) that is supported swingably onto a base (1B) to hold swingably movable contacts (4), and has the small reduction of overtravel in the elapsed years, and can reduce its size. The bending modulus of elasticity Eb, Ec of the base (1B) and the crossbar (7) at the ordinary temperature/ordinary humidity satisfy following relationships Eb+Ec≧17000 MPa  (1) 8000 MPa≦Eb  (2) 9000 MPa≦Ec  (3).

Abstract: A circuit breaker mechanism comprises a coil which surrounds a tube in which a magnetic core can move against the urging of a spring. An armature is located adjacent the coil and moves transversely relative to the axis of the coil, with a head portion of the armature being attracted towards a pole piece of the mechanism, while a foot portion of the armature is attracted to the magnetic core. The armature is pivoted to a magnetic frame at a point between the head and foot portions, so that the magnetic force between the head portion and the pole piece is counteracted to some extent by the magnetic force between the foot portion and the magnetic core. This in turn depends on the position of the magnetic core in the tube, and the setting of an adjuster mechanism which spaces the foot portion closer to or further away from the core in use. The adjuster mechanism allows the instantaneous tripping characteristic of the mechanism to be adjusted in use.

Abstract: A release unit for a circuit breaker is equipped with a magnet yoke and an armature collaborating with it for actuating a release device, in which case a nonmagnetic weight element that increases the inertia of the armature is applied to the armature.

Abstract: A circuit breaker includes separable contacts, an operating mechanism, a power supply, and a trip mechanism powered from a first power supply output. A power supply monitor circuit includes a terminal adapted for electrical connection to a ground, a first resistor electrically connected in series with a power supply regulator, a first transistor having an output and two inputs electrically connected in parallel with the first resistor, a first capacitor electrically connected between the first power supply output and the first transistor output, a second resistor electrically connected in series with the first capacitor between power supply outputs, a second transistor having a first input electrically interconnected with the first transistor output, a second input and an output, a diode electrically connected between the terminal and the second transistor second input, and an interface between the second transistor output and a trip mechanism input for disabling the tripping.

Abstract: A magnetic release is described for an electrical switching device, such as a circuit breaker, which has a coil, a core located inside the coil, and an armature in the form of a plunger-type armature which can move inside the coil or in the form of a hinged armature. The coil is stamped and bent from sheet metal composed of an electrically highly conductive material. It has first webs that are located at a distance from one another in a first plane and second webs that are likewise located at the same distance from one another in a second plane. The webs each run parallel to one another and are offset with respect to one another in such a manner that the webs are disposed with connecting webs in a helical shape around a center axis, and on the inside form a through-opening for accommodating at least one core.

Abstract: The high transient current sustained by arcing during opening of the main contacts of a miniature circuit breaker is commutated out of the bimetal by deflection of the bimetal in response to the overcurrent to close secondary contacts on the free end of the bimetal and on a low resistance by-pass conductor shunting the bimetal. The by-pass conductor can be extended toward the movable contact arm carrying the movable main contact to commutate some of the overcurrent into the by-pass conductor earlier in the opening sequence to reduce the energy input to the bimetal and reduce the force closing the secondary contacts.

Abstract: An auxiliary magnetic trip system for a circuit breaker, the auxiliary magnetic trip system includes a strap configured to conduct a first level of electrical current and a second level of electrical current; a u-shape collar with a first pole face, the u-shape collar disposed around the strap; a trip lever rotatably mounted on an axis; and a holdback system releasably coupled to the trip lever, wherein the holdback system prevents movement of the trip lever at the first level of electrical current and releases the trip lever at the second level of electrical current.

Abstract: A pair of shunt wire spacer pins provides for proper spacing between the shunt wires extending from the movable arm to the bimetal within a circuit breaker, thereby ensuring that the shunt wires do not come together during over-current conditions within the circuit breaker, and preventing the shunt wires from interfering with the movement of the trip bar.

Abstract: A molded case circuit breaker that includes a double headed calibration screw. The calibration screw has a first and second end with identical convex tip surfaces and screw driver engagement surfaces. The convex tip surface is suitable for engaging a bi-metal thermal overload element. The screw driver engagement surface is suitable for applying a screw driver to adjust the calibration screw position in order to adjust the deflection of the bimetal and calibrate the thermal overload protection. At least one calibration screw planar surface allows for improved sealant injection to permanently fix the screw position and associated calibration setting following adjustment.

Abstract: A circuit breaker includes main circuit contact shoes disposed in a circuit breaker case and urged by a contact spring, a contact opening and closing mechanism located above the contact shoes and including an opening and closing lever, a toggle link, an opening and closing handle and a latch, and an overcurrent tripping device located above the contact shoes. The toggle link includes a first link extending between the opening and closing lever and a toggle shaft located above, and a second link extending between the toggle shaft and the latch to overlap the first link in the V-form, and an opening and closing spring extends between the toggle shaft and a tip of a handle lever coupled to the opening and closing handle to extend downward. As a result, a space occupied by the contact opening and closing mechanism section in the height direction can be reduced to make the circuit breaker more compact.

Abstract: A thermal overload relay includes an inversion operation mechanism that is driven by a releasing lever to open or close a contact. The inversion operation mechanism includes a movable plate supported at one end so as to be inverted, and a tension spring for driving the movable plate for inversion. The releasing lever presses a middle of a wire of the tension spring to drive the movable plate for inversion. A projection is formed in the middle of the wire of the tension spring to contact with the releasing lever. Thus, a stable inversion operation can be made regardless of the positioning of an adjustment dial.

Abstract: A load conductor for use with a circuit breaker includes a load terminal and a conductive tang engaged with one another. The load terminal is manufactured out of a first material having a first electrical conductivity, and the tang is manufactured out of a second material having a second electrical conductivity. The first electrical conductivity of the first material is such that the load terminal remains at a desirably high temperature during operation of the circuit breaker to avoid interference with the function of a bimetallic strip mounted on the load terminal. The tang extends across a bend formed in the load terminal to avoid the bend from becoming undesirably hot during operation of the circuit breaker. The tang also provides additional conductive cross-section and a higher conductivity surface to reduce the temperature of the load terminal in the vicinity of the clamped joint between the load terminal and the load. The abstract shall not be used for interpreting the scope of the claims.

Abstract: A load conductor for use with a circuit breaker includes a load terminal and a conductive tang engaged with one another. The load terminal is manufactured out of a first material having a first electrical conductivity, and the tang is manufactured out of a second material having a second electrical conductivity. The first electrical conductivity of the first material is such that the load terminal remains at a desirably high temperature during operation of the circuit breaker to avoid interference with the function of a bimetallic strip mounted on the load terminal. The tang extends across a bend formed in the load terminal to avoid the bend from becoming undesirably hot during operation of the circuit breaker. The tang also provides additional conductive cross-section and a higher conductivity surface to reduce the temperature of the load terminal in the vicinity of the clamped joint between the load terminal and the load. The abstract shall not be used for interpreting the scope of the claims.

Abstract: A molded case circuit breaker that includes a double headed calibration screw. The calibration screw has a first and second end with identical convex tip surfaces and screw driver engagement surfaces. The convex tip surface is suitable for engaging a bi-metal thermal overload element. The screw driver engagement surface is suitable for applying a screw driver to adjust the calibration screw position in order to adjust the deflection of the bimetal and calibrate the thermal overload protection. At least one calibration screw planar surface allows for improved sealant injection to permanently fix the screw position and associated calibration setting following adjustment.

Abstract: The circuit breaker (10) of the present invention is a molded case circuit breaker and includes a molded case (12) having a main cover (20), a first terminal (16) and a second terminal (16) mounted inside the case (12) with a stationary contact (44) electrically coupled to the first terminal (18) and a movable contact (42) electrically coupled to the second terminal (16). The movable contact (42) is coupled to an operating mechanism (40) which has a pivoting member (13) moveable between an ON position, an OFF position and a TRIPPED position. An intermediate latching mechanism (52) also is mounted in the housing (12) and is coupled to the operating mechanism (40). The intermediate latching mechanism (52) is selectively operated by a trip unit (60) which comprises a magnetic short circuit release and a thermal overload release.

Abstract: A switch includes a conductive region, a membrane, and a dielectric region. The dielectric region is formed from a dielectric material and is disposed between the membrane and the conductive region. When a sufficient voltage is applied between the conductive region and the membrane, a capacitive coupling between the membrane and the conductive region is effected. The dielectric material has a resistivity sufficiently low to inhibit charge accumulation in the dielectric region during operation of the switch.

Abstract: An apparatus and method for supplying power to a load circuit from main and alternate electric power sources involves actuating a signal-controlled selector inside a housing, at least a portion of which is received in a breaker receptacle of an electric power distribution panel such that a first conductor on the housing is operable to receive electric power from the electric power distribution panel and a second conductor on the housing is operable to receive electric power from an alternate electric power source, to selectively connect the load circuit to the first conductor on the housing or to a second conductor on the housing operable to receive electric power from an alternate electric power source, in response to a control signal.

Abstract: A circuit breaker for interrupting an electric circuit in detection of an overcurrent exceeding a rated value, said circuit breaker comprising: detection means for detecting the flow of an overcurrent exceeding a predetermined rated value in said electric circuit from the bending of a bimetal, and creating a detection signal; control means for sending an tripping signal in response to the detection signal from said detection means; and trip means being electro-magnetically operated in response to the tripping signal from said control means to interrupt said electric circuit. According to the circuit breaker, fabrication of the bimetal and the armature is easy and productivity in fabrication of the circuit breaker is increased. Also, a precise and rapid tripping can be carried out when overcurrents takes place. Furthermore, the time required for the time-lag tripping is reduced due to the rapid tripping and thus the degradation of the covering material can be reduced.

Abstract: A clapper armature system for a circuit breaker includes a heater having a heater element and a pair of electrical conductors. The heater element is electrically connected to and disposed between the conductors. The conductors are spaced from the heater element to provide a pair of slots between the conductors and the heater element. A heat sensitive strip having one end electrically connected to at least one conductor is disposed proximate the heater element. A yoke has a pair of arms with each arm passing through a respective slot of the heater. The heater element and heat sensitive strip are disposed between the arms and provide a plurality of current paths between the arms. A clapper is disposed pivotally proximate the arms. The clapper pivots to the arms of the yoke to open a pair of separable contacts of the circuit breaker in response to a predetermined current passing through the heater and heat sensitive strip.

Abstract: An electromagnetic actuator for a circuit breaker having a pair of relatively moveable contacts is disclosed. The actuator includes primary actuator coupled to at least one of the contacts by a link mechanism operable to provide closing and holding forces to the contacts of the circuit breaker and a secondary, faster acting actuator which, on tripping thereof, provides sufficient force to at least initiate opening of the contacts by the configuration of the link mechanism. The secondary actuator includes a stored energy latch which has a permanent magnet flux circuit for providing a holding force and a coil connected to receive a trigger signal to overcome the permanent magnet flux to trip the latch.

Abstract: A plug-in trip unit joint 900 for a molded case circuit breaker 10, with the circuit breaker 10 having an operating mechanism 40 with a movable contact arm 45 mounted on a cross-bar 55, a trip bar 618 and a line terminal mounted in a first housing and a trip unit 600 and a load terminal 16 mounted in a second housing. The plug-in trip unit joint 900 comprises a trip unit stab 910 coupled to the trip unit 600 and load terminal 16 and extends from the second housing and a movable contact arm clamp assembly 909 mounted in the first housing and aligned to selectively engage the trip unit stab 910 wherein the line terminal 18 and the load terminal 16 are electrically coupled together and with the trip unit in selective contact with the operating mechanism 40 of the circuit breaker 10.

Abstract: A circuit interrupter including a housing, separable main contacts disposed in the housing, and an operating mechanism disposed in the housing and interconnected with the contacts. A trip mechanism is disposed in the housing and has an automatic trip assembly that selectively generates a tripping operation which opens the contacts upon a predetermined current threshold. The automatic trip assembly includes a substantially planar bimetal, an electrical terminal, and a magnetic yoke. The bimetal has a first cutout region and a second cutout region on opposite sides thereof which form a neck portion and define a head portion. The head portion is connected to an end of the terminal. The magnetic yoke has a substantially planar portion and two arm portions. The bimetal is positioned substantially parallel with the planar portion with the neck portion positioned between the arm portions.