Abstract: A circuit breaker assembly includes first and second rotary contact assemblies mountable to a base member, a circuit breaker operating mechanism mounted to the first rotary contact assembly, and a trip bar in mechanical communication with the first rotary contact assembly and the circuit breaker operating mechanism. The rotary contact assemblies each include rotors rotatable about axes therethrough and movable contact arms pivotally mounted within the rotors. The circuit breaker operating mechanism serves to position the rotors to separate movable contacts thereon from fixed contacts. A trip override device includes spring links operably connected via springs to each of the rotors of the rotary contact assemblies and the trip bar. The trip bar comprises trip levers protruding radially therefrom and being in mechanical communication with the rotary contact assemblies.

Abstract: A draw out interlock mechanism comprises a draw out trip arm pivotally attached in a draw out circuit breaker and an interlock activating assembly attached to a the draw out circuit breaker. The draw out trip arm comprises a first extension on a first end and a second extension on a second end. The first extension is positioned to interact with a trip latch of the operating mechanism. The interlock activating assembly comprises an extended arm and a camming arm, which are pivotally attached to a pin supported by a mounting bracket attached to the draw out circuit breaker. The extended arm extends through an aperture in the draw out circuit breaker with an end thereof proximate to the second extension of the draw out trip arm.

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: The present invention relates to a switching device (14) which is arranged to switch a load (12) to a direct voltage circuit (13). The switching device (14) comprises a switching member (14a) consisting of at least three contacts (7, 8, 9), a control member (10) which controls the contacts (7, 8, 9) of the switching member (14a) and has the positions open [0] and closed [1], and one or more spring members (16a, 16b) which are tensioned by the control member (10) and control the contacts.

Abstract: An operating mechanism controls and trips a separable contact structure arranged in a protected circuit. The mechanism includes a frame, a drive member pivotally coupled to the frame, a spring pivotally connecting the drive member to a drive connector, an upper link pivotally seated on the drive connector, a lower link member pivotally coupled to the drive connector, a crank member pivotally coupled to the lower link member for interfacing the separable contact structure, and a cradle member pivotally secured to the frame and pivotally securing the upper link. The cradle member is configured for being releasably engaged by a latch assembly, which is displaced upon occurrence of a predetermined condition in the circuit such as a trip condition. The mechanism is movable between a tripped position, a reset position, an off position, and an on position. Spacers are operatively positioned between movable members, and protrusions are operatively formed on the enclosure of the contact structure.

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: In order to prevent a mistrip caused by a closing operation by a toggle mechanism, a trip lever 23 is not mounted on a fixed frame of a mechanism portion 8, but is mounted on a yoke 30 of a disengaging device 9 serving as a support base for this trip lever. The mechanism portion 8 and the disengaging device 9 are held on a common casing 10, and therefore an impact force, produced at the time of closing the contact between two contacts 2 and 3 by the toggle mechanism, is not completely prevented from being transmitted to the trip lever 23, while this impact force is transmitted through the casing 10, and therefore is far smaller as compared with the case where the trip lever 23 is supported on the fixed frame 13, so that such a mistrip can be prevented.

Abstract: An operating mechanism comprises an operating handle movable between on and off positions, the operating handle extending substantially up at a point between said on and off positions; a crank for controlling a contact arm of a circuit breaker to cause the contact arm to move between open and closed positions when the crank moved; mechanism springs connected between the operating handle and crank so that the crank moves when the mechanism springs are discharged and when the operating handle is moved between on and off positions; a trip latch restraining the mechanism springs from discharging unless moved; and a trip lever having a lever arm, the trip lever being biased by a tripping spring to cause the trip lever to extend substantially up from the operating mechanism and move the trip latch and discharge said mechanism springs unless the trip lever is prevented from rotating under the influence of said tripping spring.

Abstract: A pressure sensitive trip mechanism for actuating a circuit breaker operating mechanism to trip a circuit breaker includes a trip lever and a trip bar. The trip lever is rotatable about a first pivot. The trip bar is positioned proximate the trip lever. The trip bar is arranged to rotate about a second pivot in response to a predetermined level of pressurized gas created by separation of the pair of electrical contacts, thereby urging the trip lever to unlatch the circuit breaker operating mechanism. The pressure sensitive trip mechanism provides for very fast tripping of the circuit breaker in the event of a short circuit condition or an overcurrent fault condition within any one on the circuit breaker poles. In a multi-pole circuit breaker, the present invention provides for protection against single-phasing.

Abstract: A plunger assembly support structure for a molded case circuit breaker magnetic trip mechanism for aligning a trip mechanism plunger assembly. The plunger assembly support structure includes a base member assembly having a plurality of guide members, and a plunger carriage assembly slidably disposed adjacent to said base member assembly.

Abstract: The auxiliary switch (2) has a slide (5) with a gate (14) as an actuating element that engages with the reversing lever (13) acting upon the contact carrier (11). After a first actuation stage, in which the slide (5) pushes the contact carrier (11) into the ON position, the actuating element of a basic switching device (1) is actuated when pushing is continued.

Abstract: An operating mechanism controls and trips a separable contact structure arranged in a protected circuit. The mechanism includes a frame, a drive member pivotally coupled to the frame, a spring pivotally connecting the drive member to a drive connector, an upper link pivotally seated on the drive connector, a lower link member pivotally coupled to the drive connector, a crank member pivotally coupled to the lower link member for interfacing the separable contact structure, and a cradle member pivotally secured to the frame and pivotally securing the upper link. The cradle member is configured for being releasably engaged by a latch assembly, which is displaced upon occurrence of a predetermined condition in the circuit such as a trip condition. The mechanism is movable between a tripped position, a reset position, an off position, and an on position. Spacers are operatively positioned between movable members, and protrusions are operatively formed on the enclosure of the contact structure.

Abstract: An operating mechanism controls and trips a separable contact structure arranged in a protected circuit. The mechanism includes a frame, a drive member pivotally coupled to the frame, a spring pivotally connecting the drive member to a drive connector, an upper link pivotally seated on the drive connector, a lower link member pivotally coupled to the drive connector, a crank member pivotally coupled to the lower link member for interfacing the separable contact structure, and a cradle member pivotally secured to the frame and pivotally securing the upper link. The cradle member is configured for being releasably engaged by a latch assembly, which is displaced upon occurrence of a predetermined condition in the circuit such as a trip condition. The mechanism is movable between a tripped position, a reset position, an off position, and an on position. Spacers are operatively positioned between movable members, and protrusions are operatively formed on the enclosure of the contact structure.

Abstract: An operating mechanism controls and trips a separable contact structure arranged in a protected circuit. The mechanism includes a frame, a drive member pivotally coupled to the frame, a spring pivotally connecting the drive member to a drive connector, an upper link pivotally seated on the drive connector, a lower link member pivotally coupled to the drive connector, a crank member pivotally coupled to the lower link member for interfacing the separable contact structure, and a cradle member pivotally secured to the frame and pivotally securing the upper link. The cradle member is configured for being releasably engaged by a latch assembly, which is displaced upon occurrence of a predetermined condition in the circuit such as a trip condition. The mechanism is movable between a tripped position, a reset position, an off position, and an on position. Spacers are operatively positioned between movable members, and protrusions are operatively formed on the enclosure of the contact structure.

Abstract: The present invention provides a spring for a tripping mechanism in a circuit breaker for connection to a circuit. The tripping mechanism has a first component which is accelerated along a predetermined path of travel to a trip release velocity upon occurrence of a trip event in the circuit and a second component which is initially stationary prior to engaging the first component. The spring includes a body for decreasing the trip release velocity of the first component prior to engaging the second component. A tripbar for a tripping mechanism in a circuit breaker for connection to a circuit is also provided. The tripping mechanism has an armature which is accelerated along a predetermined path of travel to a trip release velocity upon occurrence of a trip event in the circuit while the tripbar is initially stationary prior to engaging the first component. The tripping mechanism further includes a spring having at least two ends.

Abstract: An operating mechanism controls and trips a separable contact structure arranged in a protected circuit. The mechanism includes a frame, a drive member pivotally coupled to the frame, a spring pivotally connecting the drive member to a drive connector, an upper link pivotally seated on the drive connector, a lower link member pivotally coupled to the drive connector, a crank member pivotally coupled to the lower link member for interfacing the separable contact structure, and a cradle member pivotally secured to the frame and pivotally securing the upper link. The cradle member is configured for being releasably engaged by a latch assembly, which is displaced upon occurrence of a predetermined condition in the circuit such as a trip condition. The mechanism is movable between a tripped position, a reset position, an off position, and an on position. Spacers are operatively positioned between movable members, and protrusions are operatively formed on the enclosure of the contact structure.

Abstract: A circuit breaker operating mechanism for separating a pair of electrical contacts within an electrical circuit breaker includes a lower link operatively connected to one of the electrical contacts. An upper link includes first and second legs extending from a central portion. The first leg is pivotally secured to the lower link, and the second leg includes a cam surface formed thereon. A roller is in intimate contact with the cam surface, and the cam surface is configured such that movement of the upper link relative to the roller causes the upper link to pivot about the central portion. Pivoting of the upper link about the central portion moves the lower link causing the second contact to move away from the first contact. A mechanism spring is configured to provide a force for separating the electrical contacts when the operating mechanism is tripped. A toggle handle includes a void disposed therein, and an end of the spring is secured to the operating handle within the void.

Abstract: A circuit breaker operating mechanism for separating a pair of electrical contacts within an electrical circuit breaker includes a lower link operatively connected to one of the electrical contacts. An upper link includes first and second legs extending from a central portion. The first leg is pivotally secured to the lower link, and the second leg includes a cam surface formed thereon. A roller is in intimate contact with the cam surface, and the cam surface is configured such that movement of the upper link relative to the roller causes the upper link to pivot about the central portion. Pivoting of the upper link about the central portion moves the lower link causing the second contact to move away from the first contact. An operating spring is configured to provide a force for separating the electrical contacts when the operating mechanism is tripped. An operating handle includes a void disposed therein, and an end of the spring is secured to the operating handle within the void.

Abstract: A pressure sensitive trip mechanism for actuating a circuit breaker operating mechanism to trip a circuit breaker includes a trip lever and a trip bar. The trip lever is rotatable about a first pivot. The trip bar is positioned proximate the trip lever. The trip bar is arranged to rotate about a second pivot in response to a predetermined level of pressurized gas created by separation of the pair of electrical contacts, thereby urging the trip lever to unlatch the circuit breaker operating mechanism. The pressure sensitive trip mechanism provides for very fast tripping of the circuit breaker in the event of a short circuit condition or an overcurrent fault condition within any one on the circuit breaker poles. In a multiple circuit breaker, the present invention provides for protection against single-phasing.

Abstract: A switchgear unit having a switching device which has a rotary operating mechanism (12) and a breaker mechanism and having a leading auxiliary switch (1) coupled to it is provided. The switching device has a gate guide (15) which is in operative connection with a projection (9) on the contact bridge carrier of the auxiliary switch (1).

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: A tripping device for a circuit breaker with contacts that are arranged in a housing and can be separated from one another by actuating a tripping shaft of a switchdevice contains a blowchannel that is arranged in the housing and assigned to the contacts. The tripping device also contains a rotatably arranged lever that is functionally connected to the tripping shaft. A magnet system that subjects the lever to an excursion in order to actuate the tripping shaft is able to act upon the lever. A baffle surface that is arranged on the lever and arranged in the blowchannel promotes the excursion of the lever due to the fact that it is subjected to a pressure impulse in the blowchannel.

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. The operating mechanism includes a handle having a base into which is formed a channel. The base includes a compressible protrusion that is disposed within the channel. The operating mechanism further includes a handle assembly having a platform that inserts into the channel of the base. The platform includes an indent that mates with the protrusion.

Abstract: A mechanism for operating a plurality of circuit interruption mechanisms of a circuit breaker, the mechanism applies a uniform force to the circuit interruption mechanisms. The mechanism applying a force to an elongated member for manipulating the circuit interruption mechanisms. The mechanism applying the force to the elongated member at a first position and a second position, the first position and the second position being intermediate to a center of the elongated member and the plurality of circuit interruption mechanisms.

Abstract: Circuit breaker mechanism comprising a manually controlled part 40a acted upon by a knob 42 and a part 40c with an electromagnetic overcurrent tripping device 41 and a trip spring 65. The parts 40b, 40c act on a common lever 43 through a connecting rod 62 and a control lever 66 respectively. The part 40b is coupled to a lever 64 onto which the spring 65 exerts a torque, and also applies an opening torque to lever 66.

Abstract: The toggle mechanism of a circuit breaker is connected at one end to the pivoted contact arm and at the other end to a pivoted latch lever which is engaged to latch the toggle mechanism by a latch member pivoted for movement in a plane perpendicular to the plane of the toggle mechanism. The latch member serves as an armature for a trip motor energized by a trip circuit responsive to an arc fault and/or a ground fault to unlatch the toggle mechanism and trip the circuit breaker open. The latch member is also tripped by a helical bimetal responsive to persistent overcurrents and coupled to the latch member through an ambient compensator bimetal cantilevered from the latch member. A flexible shunt connected between the helical bimetal and contact arm passes through an extension of the magnetic circuit of the trip motor to generate a magnetic field of sufficient strength to trip the latch member instantaneously in response to a short circuit.

Abstract: An adjusting ring includes a surface which is matched to the pitch of the winding wire. This adjusting ring is used in a device having a coil winding. As such, the coil winding can be positioned in its axial direction.

Abstract: A latching mechanism of a circuit breaker operating mechanism comprises a primary latch and a secondary latch. The primary latch is of a general H-shape and includes elongated leg members connected by a cross member and has notched portions thereon proximate the first ends of the elongated leg members, reset feet depending from the second ends of the elongated leg members, and tabs protruding from the elongated leg members at points intermediate the first and second ends and extending in the general direction of the reset feet. The elongated leg members of the primary latch are pivotally mounted on an axis that extends laterally through a cross member. The secondary latch is of a general inverted U-shape and includes elongated leg members connected by a base member and has notched portions thereon proximate first ends of the elongated leg members. The elongated leg members of the secondary latch are also pivotally mounted on pins that protrude from the base member.

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. The operating mechanism includes a cradle for moving from a first position to a second position in the event of a tripping operation and thereby causing the contacts to open. A trip mechanism is disposed in the housing and includes a rotatable trip bar assembly that, when selectively rotated, generates a tripping operation. The trip mechanism includes a rotatable latch that engages the trip bar assembly and the cradle and keeps the cradle in the first position when a tripping operation has not occurred. The trip mechanism further includes a tension member that is positioned to bias the latch in a first rotational direction.

Abstract: This mechanism comprises a fixed contact (3), a mobile contact (4) mounted in a support (5) pivoting on the casing (2), an operating knob (13) actuating a pivoting pawl (16) via a link rod (15), forming a toggle lever system, and a trip element (25) which can be actuated by electromagnetic and/or thermal circuit-breaking means.

Abstract: A circuit interrupter including a housing, separable main contacts disposed in the housing and rotatable between a contact open position and a contact closed position, and an operating mechanism disposed in the housing and interconnected with the contacts for rotating the contacts alternatively between the contact open position and the contact closed position. The operating mechanism includes a handle moveable by an operator between handle open and handle closed positions normally corresponding to and resulting in the contact open position and the contact closed position, with the handle including a protrusion. The operating mechanism further includes a crossbar assembly for rotating with the contacts as the contacts rotate between the contact open position and the contact closed position.

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.

Abstract: A shock resistant under-voltage release mechanism for a circuit breaker includes a magnetic tripping device resiliently mounted onto a mounting bracket with one or more resilient mounts. The magnetic tripping device includes a plunger that selectively engages a trip button of the circuit breaker when the voltage supplied to a coil of the magnetic tripping device drops below a given preset limit voltage. The resilient mounts each include first and second flanges, with a hub extending between the first and second flanges. The resilient mount is mounted on the mounting bracket of the under-voltage release mechanism such that the hub is disposed against a mounting hole formed in the mounting bracket, and the first and second flanges are disposed against the opposite faces of the mounting bracket. A fastener is slidingly received through an opening formed in each resilient mount and is attached onto an attachment hole formed on a coil frame of the magnetic tripping device.

Abstract: The circuit breaker of the present invention is a molded case circuit breaker 10 having a moving contact 42 and crossbar assembly comprising a crossbar 55 having a formation pivotally mounted in the circuit breaker housing 12 with the formation having two spaced apart sidewalls 842, with each sidewall 842 having a first cam surface 830, a cam node 832, a second cam surface 834 and a bearing surface 826. Mounted in the formation, between the sidewalls 842, is a moving contact arm assembly 811 that is mechanically coupled to the circuit breaker operating mechanism 40 and electrically coupled to the load terminal 16 of the circuit breaker 10. The moving contact and crossbar assembly 811 comprises a movable contact arm 45 coupled to a pivot pin 818 positioned between the sidewalls 842 and in rotational contact with a bearing surface 826 of each sidewall 842.

Abstract: A thermal-magnetic trip unit, suitable for use in a circuit breaker, for eliminating the requirement for latching surfaces while still providing the additional force and motion required to trip the breaker during a short circuit or an overcurrent trip event. The trip unit comprises a link that is biased based on the position of a trip bar. A spring biases the link in a first direction when the trip unit is in a reset condition and biases the link in a second direction when the trip bar is rotated about a pivot point. A trip unit further including an improved indication-of-trip system comprising a two-piece trip bar mechanism and flag system is described to discriminate between overcurrent and short circuit faults. In this embodiment of the invention, visual confirmation of the cause of the trip is provided.

Abstract: A circuit interrupter including separable main contacts, an operating mechanism interconnected with the contacts, and a housing in which the contacts and the operating mechanism are disposed. A trip mechanism is disposed in the housing and includes a trip bar assembly that, when selectively rotated in a first direction, generates a tripping operation causing the contacts to open. The trip bar assembly includes a groove in which sits a torsion spring for rotationally biasing the assembly in a second direction that is opposite the first direction.

Abstract: A molded case circuit breaker is taught with a housing base and a primary cover disposed on the housing base. The primary cover has a recess therein for an auxiliary module which is disposed in the recess. A secondary cover is disposed on the primary cover for covering the recess when the auxiliary module is disposed therein. A combination manual trip and secondary cover interlock is provided which is accessible from outside of the secondary cover for manually opening separable main contacts or for automatically opening separable main contacts when the secondary cover is removed. There is also provided on the back plane of the housing a single piece DIN rail attachment for securing the back plane to a DIN rail. There is provided an under voltage release mechanism for actuating the circuit breaker to trip on the occurrence of an under voltage condition of predetermined magnitude across the lines served by the circuit interrupter.

Abstract: This concerns a molded case circuit breaker having separable main contacts and an operating mechanism utilized to cause the separable main contacts to open and close. A trip unit is provided to actuate the operating mechanism in desirable circumstances. The aforementioned trip unit has disposed on an outside surface thereof, dials for adjustment of the thermal and magnetic tripping characteristics of the circuit breaker. The face of the trip unit also has a set of hinge regions disposed therein into which a plastic, transparent, hinged cover may be inserted. The top of the trip unit has a convenient ridge around the outside of the dial regions. The cover after insertion is rotated downward on to the face of the dial region and then moved transversely to abut one of the ridges. Both the cover and the surface of the dial region have bridged openings therein through which a single wire may be fed and locked in place with a solder lock at the ends of the wires.

Abstract: A thermomagnetic circuit breaker in a preformed housing comprises a display means for selective display of the reasons for tripping. Tripping bars, actuable independently of one another, include a release function as well as a display function. Alternatively, display may take place with additional trip levers. Combinations of independently actuable tripping bars and an operating handle provide a display means for display of an overload, momentary, ground fault or accessory trip condition.

Abstract: The toggle mechanism of a circuit breaker is connected at one end to the pivoted contact arm and at the other end to a pivoted latch lever which is engaged to latch the toggle mechanism by a latch member pivoted for movement in a plane perpendicular to the plane of the toggle mechanism. The latch member serves as an armature for a trip motor energized by a trip circuit responsive to an arc fault and/or a ground fault to unlatch the toggle mechanism and trip the circuit breaker open. The latch member is also tripped by a helical bimetal responsive to persistent overcurrents and coupled to the latch member through an ambient compensator bimetal cantilevered from the latch member. A flexible shunt connected between the helical bimetal and contact arm passes through an extension of the magnetic circuit of the trip motor to generate a magnetic field of sufficient strength to trip the latch member instantaneously in response to a short circuit.

Abstract: A trip device of a circuit breaker that operates speedily when an enormous abnormal current such as short-circuit current flows is provided. The trip device includes a pressure detection space having a wall portion formed of a repeatedly usable thin plate, an operating rod which protrudes from the pressure detection space when the pressure in the pressure detection space increases, and a return spring which returns the operating rod. The pressure detection space is arranged in the vicinity of switching contacts, and the operating rod is arranged to release a trip latch mechanism when it protrudes.

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 includes a rotatable trip bar assembly that, when selectively rotated, generates a tripping operation that causes the contacts to open. The trip mechanism further includes an automatic trip assembly for selectively rotating the trip bar assembly upon a predetermined current threshold. The automatic trip assembly includes a magnetic yoke having two arms with a pivot support on the top of each. Each of the pivot supports includes a pivot surface, and one of the pivot supports includes a rear retaining protrusion adjacent its pivot surface. The other of the pivot supports includes a front retaining member adjacent its pivot surface.

Abstract: A thermal-magnetic trip unit, suitable for use in a circuit breaker, for eliminating the requirement for latching surfaces while still providing the additional force and motion required to trip the breaker during a short circuit or an overcurrent trip event. The trip unit comprises a link that is biased based on the position of a trip bar. A spring biases the link in a first direction when the trip unit is in a reset condition and biases the link in a second direction when the trip bar is rotated about a pivot point. A trip unit further including an improved indication-of-trip system comprising a two-piece trip bar mechanism and flag system is described to discriminate between overcurrent and short circuit faults. In this embodiment of the invention, visual confirmation of the cause of the trip is provided.

Abstract: A thermal trip unit within a multi-pole circuit breaker includes a bimetal element having an off-set end to provide cam function during the calibration of the bimetal element. A calibration screw is threadingly engaged within the bimetal element and is adjusted at various calibration levels by means of a step motor driver element.

Abstract: A decreased mechanical trip time latching system for use in a molded case circuit breaker assembly. The latching system comprising a quick release primary latch having a first primary latching surface and a second primary latching surface. Where the second primary latching surface engages a first secondary latching surface located on an interactive secondary latch, to prevent the rotation of the quick release primary latch. The first primary latching surface engages a cradle latching surface, located on a cradle, to prevent the rotation of the cradle. Assembled to the interactive secondary latch is a trip bar. Activation of the trip bar rotates the secondary latch so that the first secondary latching surface moves out of contact with the second primary latching surface just prior to the interactive secondary latch making physical contact with the quick release primary latch.

Abstract: An adjustable magnetic trip unit for a circuit breaker (1) is equipped with a magnet yoke (16), an armature element (18) that works therewith to actuate a trip shaft (14), and an adjusting bar (23) that can be tilted about the axis (15) of the trip shaft (14) for adjusting the distance (L) between the magnet yoke (16) and the armature element (18). This magnetic trip unit can be used in a circuit breaker (1) having a plurality of breaker cassettes (30) arranged adjacent to one another wherein the adjusting bar (23) extends parallel to the axis (15) of the tripping shaft (14) and on which are arranged a plurality of adjusting arms (24) corresponding to the number of breaker cassettes (30).

Abstract: A flux transfer shunt trip actuator has an elongated seat member extending between the legs of a U-shaped magnetically permeable frame member. A plunger is magnetically latched against the seat formed by the seat member in a retracted position by permanent magnets positioned adjacent the seat. The field generated by permanent magnets produces a latching force which exceeds a bias force generated by a helical compression spring extending along the elongated seat member and biasing the plunger toward an actuated position spaced from the seat. A coil surrounding the elongated seat member and the spring, generates an electromagnetic field when energized which bucks the permanent magnet field so that the plunger is driven to the actuated position by the spring. Preload on the spring is adjusted by an adjusting member positioned along a threaded shaft coaxial with the spring and extending from the bight of the U-shaped frame in the opposite direction from the pair of legs of the frame.

Abstract: A shunt (heater strap) (36) for a bimetallic strip (34) is presented. The shunt (36) has a section of reduced thickness (70) for the generation of a localized hot spot. The bimetallic strip (34) is attached to the shunt (36) at the reduced thickness section (70).

Abstract: A trip actuator (66) includes a trip spring (106) to bias the trip arm (104) in a clockwise direction about trip arm pivot (120). In the latched and ready to operate state, the clockwise moment about the axis of the latch pivot (132) created by force “F” opposes the counterclockwise moment created about the axis of the latch pivot (132) created by the horizontal component “fx” of force “f”, to hold the latch (110) in the upright position against the force of the trip arm (104). When a trip (triggering) signal is provided to the flux shifter (102), the flux shifter (102) releases the plunger (130). With the force “F” removed, the trip arm (104) will drive the latch pin (134), causing the latch (110) to rotate counterclockwise about the latch pivot (132). As the latch (110) and trip arm (104) rotate, the latch pin (134) slides off the latch surface (126), fully releasing the trip arm (104) and allowing the trip paddle (96) to move the secondary latch tab (50).

Abstract: A circuit interrupter including a housing, separable main contacts within the housing, and an operating mechanism within the housing and interconnected with the contacts. A trip mechanism is disposed within the housing and includes a rotatable trip bar assembly that, when selectively rotated, generates a tripping operation. The trip bar assembly includes an attaching structure which interconnects with an accessory trip member. The accessory trip member causes the trip bar assembly to rotate and generate a tripping operation when the accessory trip member is moved in a first direction. The accessory trip member is configured to enable flexing of the accessory trip member in a second direction opposite of the first direction.