Abstract: A circuit breaker electromagnetic tripping device in which the contact between the movable contacts and the stationary contacts is stable and well, and the tripping does not tend to fail is disclosed. In one embodiment, the circuit breaker device comprises a casing, a tripping armature and a tripping armature spring which are disposed transversely within the casing, and a tripping coil fitted over the casing corresponding to tripping armature. The device also includes a moveable support which is disposed longitudinally within the casing and moveable inside the casing and a lower end of the moveable support can be engaged with or disengaged from a front end of the tripping armature, and an attracting armature and an attracting armature spring which are disposed longitudinally at a center of the moveable support.

Abstract: An automatic turn-off switch responsive to displacement of a movable element placed on a seat which resides on the top of a chute located with an opening at the bottom immediately adjacent to a pivotal lever. A spring-loaded latch is normally biased in a contracted condition. An automatic release is cooperatively carried between the spring latch and the lever whereby displacement of the mechanical movable element causes the release to disconnect from the contracted latch, whereby the latch is released for forcible engagement with a conventional on/off switch in a circuit breaker box. When the circuit breaker switch is in the “on” position, the released latch engages the switch and causes the switch to move to its “off” position, terminating all electrical communication with the main power source.

Abstract: An apparatus for indicating a condition of a molded case circuit breaker, with the circuit breaker defining an accessory pocket in communication with an operating mechanism and a trip unit of the circuit breaker, including a mount member operatively coupled to one of the operating mechanism and trip unit in the accessory pocket. A housing coupled to the mount member, with the housing defining a compartment. A magnetic latch device disposed in the compartment and operatively coupled to the mount member. A switch disposed in the compartment and operatively coupled to the mount member. Wherein a condition of the circuit breaker is indicated by a condition of one of the switch and magnetic latch, and the condition of the circuit breaker is operatively transmitted via the apparatus to a remote location.

Abstract: An apparatus and method for circuit interruption, with auto-power on and fault memory. The interrupter includes first and second locks in series with one another, and in series between the circuit driving source and load. The first lock is in communication with the circuit driving source. Control circuitry may be disposed between the circuit driving source and the first lock. When either lock is open the circuit is open; with both locks closed the circuit is closed. Actuating one lock does not change the state of the other lock. While closing input such as a power signal is applied to the first lock it is closed, and while the closing input is not applied it is open. When an opening input such as a fault signal is applied the second lock opens, and when a closing input such as a reset signal is applied the second lock closes.

Abstract: An intermediate latch for a telecommunication system circuit breaker trip device is provided. The trip device has a spring biased trip bar with a latch extension. The circuit breaker has an operating mechanism with a spring biased cradle. The intermediate latch has a body with a central portion, an extending trip bar latch member, a cradle guide, and at least one axle member. The at least one axle member has a partial hub and a cylindrical member. The partial hub has a thicker, axial base portion and a thinner edge portion. The cylindrical member extends from the partial hub base portion.

Abstract: An accessory for providing mechanical communication between a rotatable latching shaft and an actuation device of an electrical circuit breaker includes a lever, a working surface, and a snap fitting. The lever includes an engagement orifice. The engagement orifice is receptive to the rotatable latching shaft. The working surface is in mechanical communication with the actuation device. The snap fitting is securely mated with the rotatable latching shaft.

Abstract: A supply device (1) for an electronic protection device to be used in a low-voltage circuit breaker. The supply device basically comprises a primary conductor (11), a secondary winding (12), a first magnetic circuit (10), and at least one second magnetic circuit (20). The first magnetic circuit (10) is such as to surround said primary conductor (11), which is related to a phase protected by the protection device; at the same time, the first magnetic circuit (10) constitutes the core of said secondary winding (12) that is used for supply of the protection device. The second magnetic circuit (20) is structurally separated from the first magnetic circuit (10), but is operatively connected thereto for subtracting part of the first magnetic flux generated within it by the current circulating in the primary conductor (11).

Abstract: A support structure for a circuit interrupter latch member includes a first side plate having a first opening, and a second side plate having a second opening. A first hardened bushing includes a first opening and a first perimeter. The first opening of the first hardened bushing is adapted to pivotally mount a first tab of the latch member. The first perimeter is coupled to the first side plate at the first opening thereof. A second hardened bushing includes a second opening and a second perimeter. The second opening of the second hardened bushing is adapted to pivotally mount a second tab of the latch member. The second perimeter is coupled to the second side plate at the second opening thereof. The hardened material of the first and second side plates is harder than the unhardened material of the first and second side plates.

Abstract: A breaker includes a housing (10) having two terminals (11, 12), two bars (17, 18) electrically coupled to the terminals (11, 12), an arm (30) supported in the housing (10) and movable to engage with the bars (17, 18) to electrically couple the terminals (11, 12) together. A control device (4) may control the arm (30) to engage with the bars (17, 18), and includes a lever (50) to maintain the arm (30) in engagement with the bars (17, 18). A spring (33) may bias the arm (30) away from the bars (17, 18), and another spring (53) may be engaged with the lever (50) to bias and disengage the lever (50) from the arm (30).

Abstract: A double-lever mechanism is for the trip actuator of a circuit breaker having a housing, separable contacts and an operating member for opening and closing the contacts. A trip bar opens the separable contacts in response to a trip condition, such as an overcurrent condition. The trip actuator assembly is a self-contained unit including an actuation subassembly comprising the double-lever mechanism and a coil and a plunger housed within an enclosure. First and second trip levers of the double-lever mechanism are pivotally coupled to first and second ends of the enclosure, respectively. In response to the trip condition, the plunger extends, pivoting the first trip lever which engages and pivots the second trip lever in order to actuate the trip bar. The double-lever mechanism provides a mechanical advantage by reducing actuating forces and plunger travel.

Abstract: An electrical switching device for fault-current, overcurrent and short-circuit current protection, has a contact point in a current path and a switching mechanism for permanently opening the contact point. The switching device further has a configuration for detecting the fault current, the overcurrent and the short-circuit current, and contains two permanent magnets and a core. The core is disposed between the like poles of the permanent magnets which point toward one another and one of which is fixed and the other is guided such that it can move. The permanent magnets are at least partially surrounded by a coil through which a fault, an overcurrent or a short-circuit current flows. When a current flow occurs in the coil, the magnetic field is changed causing a relative movement of the moving part, and the movement is transmitted to the contact point.

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: Resettable circuit interrupting devices, such as GFCI devices, that include reverse wiring protection, and optionally an independent trip portions and/or a reset lockout portion are provided. The reverse wiring protection operates at both the line and load sides of the device so that in the event line side wiring to the device is improperly connected to the load side, fault protection for the device remains. The trip portion operates independently of a circuit interrupting portion used to break the electrical continuity in one or more conductive paths in the device. The reset lockout portion prevents the reestablishing of electrical continuity in open conductive paths if the circuit interrupting portion is non-operational, if an open neutral condition exists or if the device is reverse wired. Methods for ensuring a reset lock out state before shipment are provided.

Abstract: Described herein is a low-voltage circuit-breaker, which comprises at least one mobile contact and a corresponding fixed contact, and a positive-opening-operation device. The positive-opening-operation device in turn comprises: a moving element associated to the mobile contact; a first kinematic chain, operatively associated to said mobile contact and to an actuating device; and a second kinematic chain, associated to said moving element and to said first kinematic chain. A first lever is associated to the first kinematic chain and a second lever is associated to the second kinematic chain, said first and second levers interacting with one another during the opening operation and being equipped with blocking devices in the event of welding of the contacts together.

Abstract: A latching mechanism is for locking an actuating shaft of an electrical switch, which can be transferred from an OFF position into an ON position by a drive train counter to the force of at least one first spring, in its ON position. The latching mechanism includes a first lever, which is pivotably coupled to the drive train of the actuating shaft and is supported against a stop held in a locking position. For accelerated release of the actuating shaft, also provided is a second lever, which has a working surface assigned to the stop. In this case, the second lever is held in a first stop position against the first lever by way of a second spring. When the second lever pivots under the action of an initiating force, which opposes the force of the second spring, the working surface acts in such a way on the stop that the stop is transferred into a release position.

Abstract: A circuit breaker includes a housing including a primary cover and a secondary cover having a tab; separable contacts; and an operating mechanism adapted to open and close the separable contacts. The operating mechanism includes a cradle pivotally mounted within the housing, the cradle including a latch, and a latch mechanism within the housing. The latch mechanism is adapted to capture the latch of the cradle when the separable contacts are closed. The operating mechanism also includes a rotary interlock pivotally mounted within the housing and cooperating with the latch mechanism and the tab of the secondary cover to release the latch of the cradle and to trip open the separable contacts when the secondary cover is removed from the primary cover.

Abstract: A circuit breaker having a set of electrical contacts, a first actuator in fluid communication with the set of electrical contacts, a second actuator in operable communication with the first actuator, and an operating mechanism in operable communication with the set of electrical contacts and the second actuator is disclosed. Pressurized gas created by separation of the set of electrical contacts acts on and drives the first actuator, which acts on and drives the second actuator, which effectuates tripping of the operating mechanism.

Abstract: A circuit breaker includes a crank for coupling a rotary arm breaker mechanism to the cradle. The crank has a protrusion which cooperates with a handle yoke to restrict movement of the operating handle when the contacts of the circuit breaker are welded. The crank protrusion is arranged such that it does not interfere with the handle under normal operating conditions.

Abstract: A trip system for a circuit breaker having a support frame, a trip unit, a crossbar, and a trip bar, is disclosed. The trip unit is responsive to an electric current for generating a trip force, the crossbar is directly coupled to the trip unit and to the support frame, and the trip bar is directly coupled to the support frame. The electric current at the trip unit generates a trip force that acts upon the trip bar to trip the circuit breaker. The crossbar remains substantially stationary during the tripping action.

Abstract: A circuit breaker includes a movable contact, a fixed contact, a switching device, a switching operation handle, and an over-current tripping device. The switching device has a switching lever connected to the handle, a toggle linkage having an upper link and a lower link for connecting to the movable contact, a tripping mechanism for activating the toggle linkage in response to over-current, and an operation spring tightly stretched between the switching lever and the toggle linkage. A locking member is provided in the switching device for interconnecting the toggle linkage and the switching lever and for restricting a movement range of the switching lever according to an operational position of the toggle linkage. When main-circuit contact points are stuck, the locking member restricts the movement of the switching lever and prevents the handle from moving to the OFF position.

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 switching chamber enclosure includes a number of enclosure parts with specific functional subdivision, in which switching elements are arranged. The enclosure of the switching device is formed at least by one lower shell and one upper shell, which are separated from one another by a horizontal separating joint. In addition, one or more intermediate shells may provided, which are likewise separated from the lower shell, from the upper shell and from one another by horizontal separating joints.

Abstract: A combined current and voltage sensor includes: a combined sensor shell; a current sensor located in the combined sensor shell, the current sensor disposed proximate to said first load strap; and a first voltage sensor located in the combined sensor shell, the first voltage sensor disposed proximate to the first load strap. A circuit breaker includes: a first load strap in electrical communication with an electronic trip unit; a breaker in electrical communication with the electronic trip unit; a current sensor disposed at the first load strap; and a first voltage sensor disposed proximate the current sensor.

Abstract: In order to prevent a mistrip caused by a closing operation of a toggle link mechanism, a trip lever is not mounted on a fixed frame of an opening/closing mechanism, but is mounted on a yoke of a disengaging device serving as a support base for the trip lever. The opening/closing mechanism and the disengaging device are held in a common casing. As a result, an impact force, produced at the time of closing the contact between two contacts by the toggle link mechanism, is transmitted through the casing, so that such a mistrip can be prevented.

Abstract: A microprocessor-based circuit breaker includes a removable chip that defines the current rating or ground fault current for the breaker. The breaker includes mechanical components that trip to disconnect the load terminal from the line input. The mechanical components include a floating breaker arm, trigger and tripper lever that cooperate to control the tripping of the breaker. A spring between the breaker arm and trigger, together with cam surfaces defined in the breaker switch cooperate to form a floating linkage to control the position of the breaker arm during on/off activation and current fault conditions. The circuit breaker also includes multiple indicia to provide a visual indication of the type of fault condition sensed by the breaker.

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 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 applies a force to an elongated member for manipulating the circuit interruption mechanisms. The mechanism applies a 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: 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 manual tripping device for a magnetic operating mechanism is provided with a connecting body which is connected with an operating rod of the magnetic operating mechanism at the time of manual operation for the switches, a spring compressing shaft one end of which is movably engaged to the connecting body to compress spring means, and a rotating shaft which is engaged to the other end of the spring compressing shaft with the spring compressing shaft being movable within the given range, and which is rotated with a handle.

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: A Residual Current Device is provided with a reset lockout mechanism.

Abstract: A tripping device used for protective circuit breakers. In the event that tripping is required, a detection unit drives a tripping element which is able to engage with the latching part of a protective circuit-breaker device. The tripping element is positioned and mounted in such a way that it is interchangeable and can be replaced with differently shaped tripping elements.

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 trip unit includes a housing, a rotary plunger mounted in the housing and a pivotal trip bar also mounted therein. The trip bar latches the plunger in an on position, releases the plunger to a tripped position and re-latches the plunger. A set of springs biases the plunger to the tripped position. A rotary trip lever is pivotally mounted in the housing. A trip solenoid includes a linear plunger, which resets the solenoid when retracted, and which engages and rotates the trip lever when extended, in order to rotate the trip bar and release the rotary plunger. The rotary plunger engages the rotary trip lever when reset and rotates the same in an opposite direction, in order to retract the linear plunger and reset the solenoid. During that reset operation, the rotary plunger also cams the trip bar, in order to re-latch the rotary plunger in the on position.

Abstract: Drive devices for switchgear interrupter units, having movable contact pieces that can be controlled by solenoid drives are described. The drives of the movable contact pieces being controllable by linear motor drives. The interrupter units are realized by vacuum circuit breakers, and the linear motor drives are realized by three-phase AC linear motors. Each of these can be influenced by a control unit that optimizes the switching operations and that is provided with a mains connection. The three-phase AC linear motors are composed of individual components that determine thrust and range of motion. The individual components together constitute the drive of the movable contact parts. The individual components are determined by the number of motor coils and/or by the number of parallel motor modules.

Abstract: A trip unit includes a housing, a rotary plunger, and a pivotally mounted trip bar, which latches the plunger in an on position and releases the plunger to a tripped position. A first plunger portion is biased outside the housing in a tripped position by a spring mechanism. A pivotally mounted rotary trip lever includes an elastic arm. A second plunger portion is inside the housing in a reset position and engages the elastic arm. When a trip solenoid is energized, its linear plunger rotates the rotary trip lever, in order to engage and rotate the trip bar and release the rotary plunger. The rotary trip lever rotates in an opposite direction in response to the rotary plunger reset position and engages the trip solenoid linear plunger, in order to reset the same. The elastic arm flexes after the linear plunger is reset and accommodates overtravel of the rotary plunger.

Abstract: An operating mechanism assembly for a circuit breaker that includes a frame assembly, a metal pivot structure, and a trip device. The trip device has a cradle member structured to pivot about a pivot point and a trip assembly. The trip assembly is coupled to the frame assembly. The cradle member is pivotally disposed on the metal pivot structure.

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 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: An apparatus for interrupting an electrical short circuit current in an electrical distribution system having a plurality of phases is disclosed. The apparatus includes a housing, a plurality of separable conduction paths, an operating mechanism in operable communication with the plurality of conduction paths, an electronic trip unit in signal communication with each of the plurality of conduction paths and in operable communication with the operating mechanism, and an electromagnetic trip unit in signal communication with each of the plurality of conduction paths and in operable communication with the operating mechanism. The electromagnetic trip unit is configured to be operably responsive to a first half-cycle waveform of the short circuit current prior to the electronic trip unit being operably responsive to a second multi-cycle waveform of the short circuit current.

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: An assembly for interacting with a circuit breaker operating mechanism of a circuit breaker including a housing and a pair of contacts within the housing, the operating mechanism arranged to separate the pair of contacts upon the occurrence of a trip event is disclosed. The assembly includes a plurality of linkages arranged to transmit mechanical energy from the operating mechanism to a plunger of an accessory device for changing a state thereof. The system of linkages is configured to compensate for any over-travel resulting from possible tolerance variations.

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 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: 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 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 magnetic trip unit for actuating a latching mechanism to trip a circuit breaker upon an overcurrent condition, the magnetic trip unit includes: a flux return component in electromagnetic communication with an electrically conductive strap; a tube disposed within the flux return component; a stator disposed at a first end of the tube and connected to the flux return component, the stator having a stator surface at one end; and a plunger slidably extending from a second end of the tube, the plunger comprises a plunger surface at one end facing the stator surface, the plunger further includes another end adapted to operably interact with the latching mechanism, the plunger is biased to a predetermined gap position.

Abstract: An assembly for interacting with a circuit breaker operating mechanism of a circuit breaker including a housing and a pair of contacts within the housing, the operating mechanism arranged to separate the pair of contacts upon the occurrence of a trip event is disclosed. The assembly includes a plurality of linkages arranged to transmit mechanical energy from the operating mechanism to a plunger of an accessory device for changing a state thereof. The system of linkages is configured to compensate for any over-travel resulting from possible tolerance variations.

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: In order to provide a bearing for an already prepositioned switching shaft, fitted with coupling levers, of a low-voltage circuit breaker in the region where the switching forces act, a bearing assembly is provided. The bearing assembly includes a bearing body which is mounted on the housing front wall of the switch pole, surrounding the switching shaft in the form of a half shell. The bearing body includes a subregion which projects between two coupling levers, which are at a distance from one another and are connected to a movable switching contact. It thus forms side guide surfaces for the coupling levers. Such a bearing assembly can be arranged in both the end regions of the switching shaft in multipole circuit breakers.