Abstract: A rotor spring insulator assembly comprises a base member having a D-shaped opening therein and a connecting rod of a D-shaped cross section dimensioned to be received in the D-shaped opening of the base member. The flat edge of the D-shaped connecting rod faces a spring of a rotor thereby maximizing the distance and the amount of insulative material between the connecting rod and the spring to minimize the chance that arcing will occur between the connecting rod and the spring.

Abstract: A high voltage disconnector comprising a fixed contact and a movable contact to the latter to produce an electrical connection between a first conductor and a second conductor, the movable contact and the fixed contact forming, when they are in contact with one another, a connector that is at an angle with respect to the first and/or second conductor, such that when the contacts are in contact with one another during operation a Lorentz force prevails which pulls the fixed and movable contacts apart and is transverse to the first or second conductor. The movable contact and the fixed contact are provided with locking devices which, when the contacts are in contact with one another, engage in one another and act in a direction parallel to the Lorentz force which is pulling the fixed and movable contacts apart and is transverse to the first or second contact.

Abstract: A current limiting device for protecting electrical circuits has a case and a pair of separable electrodes disposed within the case. Each electrode has a plurality of openings with an ablative member abutting the openings at an outer surface of the electrode. A spring is disposed between each ablative member and the case for urging the electrodes together. When the electrical current exceeds a predetermined setpoint the electrodes separate and an arc is created between the electrodes. The arc heats the ablative member causing expulsion of gasses which further increase the gap resistance and cool the arc to thereby quenching the arc. In a second embodiment of the current limiting device, one of the electrodes is a fixed electrode. The ablative member is disposed about a surface of the moveable electrode with a plurality of legs passing through a plurality of openings of the moveable electrode and in contact with an inner surface of the fixed electrode.

Abstract: An electrical circuit breaker includes a moveable contact piece connected to an actuating means and provided with a contact face arranged to make contact with a contact face of a second contact piece by movement of the moveable contact piece generally in a first direction. The circuit breaker further includes an electrical connector for conveying current to the moveable contact piece which includes at least two adjacent limbs adapted to convey the current in opposing directions so as to generate an electromagnetic force repelling the adjacent limbs from one another, which force is used to assist in maintaining the contact faces in abutment.

Abstract: A U-shaped magnetic plate is positioned on the side of a movable contact shoe opposite to a fixed contact shoe, and the tips of the respective legs of the magnetic plate face via a gap the movable contact shoe in a closed condition of the movable contact shoe. A magnetic plate is attached to the surface of the movable contact shoe at the side of the fixed contact, so that the magnetic plates form a closed magnetic circuit surrounding the movable contact shoe. If a high current, such as short circuit current, flows, a magnetic flux passing through the closed magnetic circuit induces an attractive force between the upper end surfaces of the U-shaper magnetic plate and the end surface of the magnetic plate. Accordingly, the movable contact shoe is rapidly opened to quickly interrupt the current, before a signal from an overcurrent trip apparatus operates an opening and closing mechanism. The opening speed of the movable contact shoe is increased when high current flows.

Abstract: A tester for an arc fault circuit breaker plugs into a socket in the protected branch circuit. An actuator includes a first spring biasing a moveable contact carried by a pivoted contact arm away from a fixed contact and a momentary closer for momentarily closing the contacts. The momentary closer includes a push button and a second spring coupling the push button to the pivoted contact arm to close the contacts when actuated. Closing of the contacts completes a circuit across the branch circuit resulting in a current producing a magnetic repulsion force which blows the contacts open thereby striking an arc. The arc, which should trip the arc fault circuit breaker is visible through a translucent or transparent section of the molded tester housing. A fuse interrupts any overcurrent and a test light verifies initial energization of the protected circuit and operation of the arc fault circuit breaker.

Abstract: An electrical switching device prevents moving contacts from welding to stationary contacts in a switching device. This is achieved using an auxiliary magnet system in the main current path, which system produces a contact pressure force corresponding to the excitation current so that no arcs are produce between the contacts when overcurrents and short-circuit currents occur. The moving iron core of the auxiliary magnet system is for this purpose connected to the contact link mounting via which the contacts are switched on and off.

Abstract: The outside poles of a three pole circuit breaker are each provided with a blow open latch which includes a latch hook having an open slot forming jaws pivotally mounted on the contact arm. A torsion spring biases the jaws to a cocked position in which they are aligned for engagement with a fixed stop member toward which the contact arm rotates as it blows open in response to the magnetic repulsion forces generated by a short circuit. As the jaws engage the stop member, the latch hook is rotated to mechanically latch the latch hook on the stop member thereby preventing rebound and reclosing of the contacts. A leaf spring mounted on the crossbar holds the latch hook in mechanical engagement with the stop member. As the circuit breaker responds to the overcurrent condition and rotates the crossbar, the leaf spring disengages from the latch hook so that the torsion spring can rotate the latch hook back to the cocked position for disengagement from the stop member upon reclosing of the circuit breaker.

Abstract: A molded case circuit breaker has a moving conductor assembly which includes a modular carrier assembly incorporating a plurality of spring biased contact cam members each of which engages contact pressure lobes on a pair of contact arm laminations to provide contact pressure. In response to the magnetic repulsion forces generated by a short circuit, the springs compress allowing the cam members to pivot and side step the contact pressure lobes so that the contact arm blows-open with little resistance. The cam members and springs are preassembled in a transverse channel in the carrier body and laterally retained in place by side plates for easier pivotal attachment of the contact arm laminations to the lobes on the side plates. The side plate lobes raise the contact arm relative to the mass of the carrier to reduce eddy current heating and provide a positive off indication for welded contacts by restricting movement of lower toggle links of the operating mechanism which are coplanar with the side plates.

Abstract: A thick solid steel slot motor is disposed adjacent a movable conductor to apply a contact closing force on the conductor, augmenting the contact pressure spring, under steady state current conditions, and to reduce the force under high rate of current rise conditions to enhance dynamic separation of the movable conductor from a stationary conductor, reducing the strength requirement of the contact pressure spring.

Abstract: A circuit breaker includes a first section and a second section with independently operating pairs of contact assemblies in each respective section. In the first section, at least one of the contact assemblies is constructed and arranged to interrupt the current by moving from a normally closed position to a blown-open position and latching with the contact assemblies separated. The second section has a biasing extension spring for biasing the contact assemblies of the second section so as to permit interruption of the current in response to a blow-open force, which causes the contacts to separate only momentarily and then return to a normally closed position. The first and second pairs of contact assemblies separate substantially simultaneously in response to the blow-open force, and only the first section reacts to lower-level over-current conditions. In addition to the contact assemblies, the second section of the circuit breaker is designed to operate using only a spring which is "Z-axis" mountable.

Abstract: A magnetic type power switch includes a base, a battery received in the base, a body detachably covering the base and the battery, a slider movably received in the body, and a magnetic element. The body has a first hollow pin which has a wire soldered therein and is in contact with a negative end of the battery, a contact ring coupled to the body by a second hollow pin having another wire soldered therein, a spring disposed on the ring and in contact with the slider. When the magnetic element approaches the base of the power switch, the slider is induced to move downward to contact a positive end of the battery thereby turning on the power. When the magnetic element is moved away, the slider is biased to move upward to disconnect the battery and thereby turning off the power.

Abstract: A switch having at least one power switching pole includes a contact bridge cooperating with fixed contacts and adapted to be maneuvered either by mobile parts of a solenoid or by a tripping mechanism. The contact bridge is rotatable and the mobile parts of the solenoid operate the contact bridge through the intermediary of a transmission mechanism.

Abstract: A vacuum switch has a vacuum interrupter which can be actuated by a drive device using a lever arrangement. A two-armed drive lever is mounted in a pivotable fashion on the displaceable connection bolt of the vacuum interrupter and interacts with a stop face against which the drive lever can be rested by a contact spring. In order to compensate contact-breaking forces, a loop-shaped, flexible strip conductor is used which is arranged between the two legs of the drive lever in such a way that one leg of the strip conductor rests on a central part of the drive lever while the other leg is supported in a fixed manner. The current-loop and lever assembly is suitable for the construction of compact power switches.

Abstract: An improved circuit breaker with moving line and load contacts is disclosed herein. The circuit breaker includes an enclosure for the operational components thereof including a line contact arm and associated contact for each phase of the circuit breaker, and an operating mechanism supported within the enclosure to move the contact arm(s) between open and closed positions. The circuit breaker also includes a terminal for each phase pivotally supported within the enclosure, and a load contact arm and associated contact for each phase pivotally connected to the terminal. The contact arms are supported so the contacts are engaged when the line contact arms are in the closed positions. The pivoted load terminal(s) allow the use of multiple connector types with the terminal(s), and the pivoting connection between the load contact arm and associated terminal facilitates a reduction in circuit breaker size for a given rating.

Abstract: A stationary contact strap for a circuit breaker, with an electrically conductive body portion having a plurality of discrete apertures arrayed in a pattern which define at least two input portions for splitting transient current input into the contact strap into generally parallel pathways which are also in the same general direction as transient current flow in the circuit breaker movable contact arm; and an output portion electrically coupled to the input portions and the fixed stationary main contact, wherein the output portion is oriented so that transient current flow therethrough is in a direction generally opposite to transient current flow in the movable arm.

Abstract: A contact arrangement for a circuit breaker utilizes magnetic attraction between parallel conductors in the movable contacts to open the contacts during a short circuit, high current condition. An elongated, pivotable, main contact arm includes a movable main contact at a first end that engages a fixed main contact in a closed circuit position. An elongated, arcing contact arm, pivotable in the same plane as the main contact arm, includes a movable arcing contact at a first end that engages a fixed main contact in a closed circuit position. The contact arms are spring biased in the closed circuit position such that a gap is defined between the arms. An attractive electromagnetic force tends to keep the first end of the arcing contact arm in contact with the fixed arcing contact until after the main contact arm has lifted. A hinge assembly for the main contact arm and the arcing contact arm assists in opening the contacts during the high current condition.

Abstract: A circuit breaker includes a first section and a second section with substantially independently operating pairs of contact assemblies in each respective section. In the first section, at least one of the contact assemblies is constructed and arranged to interrupt the current by moving from a normally closed position to a blown-open position and latching with the contact assemblies separated. The second section has a biasing extension spring for biasing the contact assemblies of the second section so as to permit interruption of the current in response to a blow-open force, which causes the contacts to separate only momentarily and then return to a normally closed position. The first and second pairs of contact assemblies separate substantially simultaneously in response to the blow-open force, and only the first section reacts to lower-level over-current conditions.

Abstract: A blow-off terminal includes a flat conductive tang, a flat conductive input section, and a flat conductive output section. The input section includes a pair of generally parallel U-shaped strips. Each of the pair of strips includes first and second end portions and a center portion bridging the first and second end portions. The first and second end portions and the center portion of each of the pair of strips are generally co-planar, and the tang and the output section are generally co-planar. The output section is elongated and includes first and second ends, the first end being disposed closer to the tang than the second end. The first end portions of the strips are connected perpendicular to opposite sides of the tang, and the second end portions are connected perpendicular to opposite sides of the second end of the output section. A stationary contact is mounted to the surface of the output section.

Abstract: A molded case circuit breaker movable contact arm electrically connects with the circuit breaker load terminal requiring only a small diameter auxiliary electrical braid conductor by pivotally arranging the contact arm within its support. The braid conductor is electrically connected with the movable contact arm and is contained within the contact arm support posts. The contact spring and the terminal screw retainer are formed from a single plate of spring steel. The contact arm support posts are capable of supporting movable contact arms of various thickness.

Abstract: An electrical power switching device employing a rotary disc driven by an actuation means whose position is selected by a control means where disc contacts engage and disengage stationary contacts where the stationary contacts are deflected away from the disc contacts by separation ramps thereby opening the current path and an arc plate is used on the disc to control arc energy. A pair of interrupter contacts are placed in series with the rotary disc contacts where abnormally high currents cause the interrupter contacts to separate and open the current path where slot motors and/or arc plates are used to dissipate the damaging electrical arcs as the contacts make and break.

Abstract: A power circuit breaker having movable and relatively stationary contact assemblies operable between open and closed positions. The contact assemblies respectively include pivotally mounted first and second conductive members. The first and second conductive members are disposed in spaced relation in the closed position of the circuit breaker, to provide a first current loop having first and second legs defined by said first and second conductive members. A pivotable mounting arrangement for the second conductive member provides a second current loop defined by the second leg portion of the first loop and a third leg portion. The magnetic forces in the first current loop, which tend to pivot the second leg portion towards the third leg portion, are opposed by magnetic forces in the second current loop. Compression spacers provide parallel current paths which reduce the magnitude of current flowing through a pivotable joint of the relatively stationary contact assembly.

Abstract: A pivoting lower contact arm arrangement and a circuit breaker including the arrangement. The pivoting lower contact arm arrangement includes a pivoting lower contact arm and a biasing arrangement. The biasing arrangement maintains the contact arm in an operating position with a first force and biases the arm from a blown-open position toward the operating position with a second force. The first force is greater than the second force to provide increased separating speed when the pivoting lower contact arm blows apart from a pivoting upper contact arm of the circuit breaker and moves from its operating position. The biasing arrangement also variously provides magnetic shielding and coupling between the pivoting lower contact arm and other current carrying components of the circuit breaker. The magnetic shielding enhances the blow-apart forces between the pivoting upper contact arm and the pivoting lower contact arm.

Abstract: A circuit breaker having at least one phase or pole including a first movable arm having a first contact and a second movable arm having a second contact. The first arm is driven by a switching gear. The second arm is disposed opposite to the first movable arm such that the second contact contacts the first contact when a normal current flows. The first arm exerts an electromagnetic repulsive force in such a direction that the first and second arms repel each other to open the first second contacts when a current exceeds a predetermined value. The second arm is pivotally supported by a support angle fixed on a housing and is electrically connected via a flexible lead with a terminal also fixed on the housing. The support angle and the terminal are fitted to an insulator such that the support angles, the terminal and insulator are assembled in a unitary construction.

Abstract: A repulsion type circuit breaker movable contact device comprising a first movable contact, an opening/closing mechanism which drives the first movable contact for opening and closing, a second movable contact for contacting the first movable contact, the second movable contact being freely pivotable and adapted to receive an electromagnetic repulsion force from said first movable contact, and a contact spring comprising a twisted coil spring disposed with its twisting fulcrum displaced from the rotational pivot of the second movable contact, the contact spring urging the second movable contact into contact with the first movable contact, whereby upon flow of a predetermined amount of electric current through the first and second movable contacts, the electromagnetic repulsion force moves the second movable contact apart from the first movable contact.

Abstract: An automatic cutout or a power circuit breaker with high current-limiting capacity contains no conductor connections of any kind, has only two weld or solder joints and requires no adjustment. This automatic cutout can be assembled progressively and purely mechanically from a minimum number of piece parts, without inconvenient connecting wires and without additional adjustment. Welding is prevented because the spark is discharge swiftly at the contacts and pressure of the movable contact in its bearing is guaranteed. As flexible connecting wires are dispensed with, fewer movable parts are necessary, and hence contact opening is more rapid. The excess-current trigger or the overcurrent trip is already calibrated and therefore the protective switch requires no adjustment. The excess-current trigger remains calibrated even after numerous disconnections.

Abstract: An apparatus for protecting the fault current intolerant elements of a motor starter circuit or the like is comprised of a protective shunt which bypasses the fault current intolerant elements in response to the detection of high fault currents. The protective shunt is formed of a "U" shaped conductor which flexes in response to the magnetic field created by the flow of the high fault currents through the "U" shaped conductor. Electrical contacts place on one leg of the "U" shaped conductor and on a stationary conductor form a shunting switch which conducts high fault currents around the starter circuitry. In a second embodiment, the stationary conductor is replaced with a flexible conductor which carries an armature. The magnetic armature is attracted by a focussed magnetic field from a magnetic yoke positioned around one leg of the "U" shaped conductor.

Abstract: A high voltage ground blade assembly which has a folding member to aid in breaking ice and lowering the force to operate the blade assembly in combination with an electric coil which creates an electromagnetic force to prevent the folding member from moving when the blade assembly is in closed position and the blade assembly is conducting very high short-circuit current.

Abstract: A laminated contact assembly formed from a plurality of contact arm subassemblies includes a contact arm portion, for carrying a movable main or arcing contact, and a stationary conductor portion. A flexible shunt, form wound from a flat electrical conductor, is used to connect the contact arm portion to the stationary conductor portion. The flexible shunt is formed into a V-shape defining two depending legs. The free ends of the shunt defining bulb portions are inserted into keyholes formed in the contact arm portion and the stationary conductor portion. A pin is inserted into a central portion of the bulb portion to exert radially outward forces against the interior surface of the keyhole to increase the contact force between the bulb portions and the keyholes to form joints having a lower electrical resistance. The pin may be inserted into the central portion of the bulb portion by orbital riveting.

Abstract: The invention relates to a contact arrangement, particularly intended for current-limiting low-voltage circuit breakers, with a double-break movable contact arm, the central part of which is attached to an insulating shaft which is rotatably journalled in elongated holes in stand parts on each side of the contact arm. In the closed position of the arrangement, the movable contact arm is pressed against two U-shaped fixed contact arms with the aid of two torsion springs. The contact arms have flat shape and are arranged with their broad sides facing each other. The shaft consists of two sleeve-formed holders surrounding the torsion springs. One holder exhibits a stop face for a latching member for arresting the movable contact arm in the open position.

Abstract: A limiting circuit breaker comprises an electrodynamic repulsion contact system, and an electromagnetic latch arranged in the vicinity of the contact system, and electrically insulated from the latter. Actuation of the latch to the active position results from the action of the electromagnetic field due to a short-circuit current flowing in the pole, so as to temporarily keep the movable contact open after repulsion. The latch is equipped with a pair of ferromagnetic brackets, and with a spring blade to return to an inactive position.

Abstract: A circuit breaker contact operating structure characterized by a circuit breaker operating mechanism having separable contacts of which one is mounted on a contact carrying arm. The arm being mounted on a one leg of a U-shaped flexible conductor. A guide link is pivotally mounted and connected to the arm to maintain the contacts in alignment during their separation. The operating mechanism having a latch for latching the arm in the closed-contact position of the arm and having a trip device for unlatching the latch in response to an overcurrent condition. The mechanism link is so placed on the contact arm structure as to effect a blow-on force on the contact structure during the duration of high overcurrent. At a preset current level, the mechanism link is prevented from applying the balancing force to the contact structure, thus allowing the blow-off forces due to the current in the contact structure to separate the contacts rapidly, and to effect current limitation and subsequent circuit interruption.

Abstract: A low voltage electrical power circuit breaker in which an actuator in the form of a pushrod controls the separation of arcing contacts by an actuating mechanism, a force-actuated mechanical latching assembly is interposed between the pushrod and the actuating mechanism. Under fault current conditions, the current-induced force tending to open the contacts exerts sufficient force on the latch assembly to unlatch it, thereby permitting the contacts to open freely on their own, without waiting for the operation of the actuating mechanism.

Abstract: A molded case circuit breaker is provided with a quick change current transformer assembly. The current transformer is used to sense overcurrent conditions and apply a signal to an electronic trip unit to trip the circuit breaker. The quick change assembly includes an insulated removable plate located adjacent an open cavity in the housing in which the current transformer is located. The current transformer is donut-type disposed about a load-side conductor located in a cavity in the housing rigidly fastened to the circuit breaker frame. In order to replace a current transformer, the insulated backplate is removed. Next the load-side conductor is unfastened and removed from the circuit breaker housing. The current transformer is then removed from the circuit breaker housing. In order to install a new current transformer, the steps are reversed. A force transmitting spacer is disposed adjacent a bight portion of a shunt, connected between a pivotally mounted contact arm and a load-side conductor.

Abstract: A compact, high capacity circuit breaker includes two breaking portions mounted in a single casing, with movable contacts for each portion disposed in series with one another and supported by a common switching shaft. Both portions of the breaker are tripped by either an overcurrent condition or manual operation, and the positioning of the common switching shaft maintains both breaking portions in the open state.

Abstract: A circuit breaker having a movable upper blade with a free floating pivot end. The operating mechanism is solidly connected to the upper blade. The contact force is generated by a contact spring which exerts an upward force on the lower blade. No other resilient force acts directly upon the upper blade. As the contacts separate, the force exerted on the upper blade is virtually eliminated, reducing substantially the resistance at the pivot end of the upper blade. The load terminal and pivot end of the upper blade provide a current path parallel to that of the load side flexible connector.

Abstract: A current limiting circuit interrupter consisting of a modular unit housed in an insulating case and provided with two fixed contact arms and two movable contact arms. The movable contact arms can be actuated automatically by means of a rod coupled to an operating mechanism as well as by means of an electromagnetic actuator. The operating mechanism includes a lever and a rotating bracket arranged to hold the movable contacts in an open condition when the electromagnet within the electromagnetic actuator is de-energized.

Abstract: A breaking device for a low voltage circuit breaker comprises in each pole a switching bar, a pair of stationary contacts connected to the connection terminals, a double-break rotary contact extending in a housing of the bar, and two arc chutes disposed on each side of the bar. Two contact pressure springs ensure elastic positioning of the rotary contact along the longitudinal direction of the pole. Pivoting of the rotary contact takes place around a fictitious axis mounted floating with respect to the fixed rotation axis of the bar.

Abstract: An electronic circuit breaker having withstand capability. When the fault current exceeds the required withstand level, the mechanism force trips the circuit breaker. The forces generated by a blow-on contact loop are exerted on the various components of the operating mechanism, including the quick trip latch and secondary latch. As the fault current exceeds the required withstand level, the forces on the operating mechanism exceed the spring force holding together the quick trip latch and secondary latch. These two components rotate as one assembly during a trip operation initiated by energizing the trip coil. In the force trip operation, these two components separate unlatching the mechanism and opening the circuit breaker contacts.

Abstract: A laminated contact assembly is formed from a number of individual contact assemblies. Each individual contact assembly includes a contact arm portion, which carries a movable main or arcing contact and a stationary conductor portion. A flexible shunt is used to connect the contact arm portion to the stationary conductor portion. Intermediate individual contact assemblies are provided with T-shaped slots for receiving square-headed fasteners. These square-headed fasteners are captured by adjacent assemblies once the laminated contact assembly is complete. By providing such an arrangement, the need to drill and tap holes in the base of the laminated contact arm assembly is obviated. Since all of the individual contact arm assemblies are fastened together, the possibility of the square-headed fasteners disposed in T-shaped slots in intermediate individual contact arm assemblies is greatly reduced.

Abstract: A contactor device for a circuit breaker includes a stationary contactor having a stationary contact, and a stationary conductor secured with the stationary contact and constituting an electricity path extending from an external terminal to the stationary contact, and a movable contactor having a movable contact movable to detachably touch the stationary contact, and a movable conductor secured with the movable contact and constituting an electricity path extending from the movable contact to another external terminal.

Abstract: A contactor device of a circuit breaker has a movable contactor to be raised or opened upon the occurrence of a short circuit current. One end portion of the movable contactor is bifurcated to form parallel claw members that engage a rotatable trip latch. When the movable contactor is raised due to a magnetic repelling force generated in the movable contactor and a fixed contactor during a short-circuit condition, the claw portions of the movable contactor are deformed due to a magnetic attractive force and are disengaged from the trip latch. The rotation of the movable contactor is restricted and it returns to the original positional relationship in which the claw members are engaged with the trip latch.

Abstract: A switch has contacts constructed so that an electro-dynamic force is created by the current flowing through the switch which tends to maintain the switch in a closed state. This force counteracts other electro-dynamic forces which tend to open the switch. The contact design is particularly adapted from use in a single pole-double throw switch having a contact arm that is movable between two fixed contacts. The electro-dynamic force compensation exists between the contact arm and whichever one of the fixed contacts the contact arm is against. The fixed contacts also include arc runners so that any arc that develops as the contacts separate eliminates electro-dynamic force which tends to maintain the switch in a closed state.

Abstract: A circuit breaker of a current-limiting type, which is able to open quickly by using a magnetic repulsive force generated when currents of opposite direction flow through a fixed contactor and a movable contactor which are arranged in parallel to each other. The movable contactor opens or rotates around a supporting shaft. Then, a guide pin, secured at the base portion of the movable contactor, slides into a guiding longish opening and passes over a turning point formed in the longish opening. As a result, the line of action of a compressed spring force changes its direction in order to push up the movable contactor to the full open position.

Abstract: A contact arrangement of a low-voltage circuit breakeer with electrodynamic breaking or opening. In contact arrangements which contain a compression spring for pretensioning a contact lever into the make position or after a dead center position is passed, the assembly is to be simplified and the use of an assembly fixture is to be made unnecessary. The pivot bearing of a contact lever at a contact lever carrier is formed by a pan-like depression of the contact lever carrier as well as an extension of the contact lever engaging the depression. Furthermore, a stop surface for the open position of the contact lever is arranged at the contact lever carrier. A brief application of force is sufficient for connecting the contact lever to the contact lever carrier. A current-limiting low-voltage circuit breaker of compact design is thus provided.

Abstract: A circuit breaker comprises a housing; a stationary contact mounted in the housing; an operating shaft disposed in the housing and rotatable about a first axis of rotation; and a movable contact including a contact arm pivotally held in the operating shaft for rotation about a second axis of rotation from an on position into a tripped position. By rotating the operating shaft about the first axis of rotation, the contact arm is movable into and out of the on position and an off position. The contact arm further has a terminus including a rounded corner and an adjoining rounded engagement face. There is further provided a structural unit stationarily supported in the housing and comprising a spring having a stationarily supported first end and a second end and a transfer lever having an end pivotally supported for rotation about a third axis of rotation.

Abstract: A current limiting assembly through which current may flow includes a stationary contact member, a movable contact member positioned in relation to the stationary contact member so that current flow through and from the stationary contact member into and through the movable contact member generates electromagnetic forces which create a repulsive force tending to force the movable contact member away from the stationary contact member, and a magnetic flux intensifying structure mechanically staked to said stationary contact member.

Abstract: A circuit breaker device has a chamber in which is disposed a single break contact system using low contact resistance material mounted on movable and stationary supports arranged in a loop configuration in order to direct arcs between the contacts through an arc chute into a remote portion of the chamber. A push-button is connected through a kinematic linkage which transfers motion using minimal frictional engagement to a movable contact to bring the movable contact into and out of engagement with a stationary contact and to latch the contacts in engagement during normal operation. A cantilevered current carrying bimetal transfers motion caused by I.sup.2 R heating of the bimetal to an ambient compensating bimetal connected to the latch mechanism. The kinematic linkage includes a latch surface which engages a rollable cylindrical reaction surface of the latch mechanism to cause the movable contact to come into engagement with the stationary contact upon depression of the push-button.

Abstract: A molded case circuit breaker includes a movable upper electrical contact having a base portion formed at one longitudinal end thereof with an elongated stop pin fixedly secured thereto and outwardly projecting therefrom for engaging one or more elongated upper spring arms of one or more torsion springs. A lower spring arm of each torsion spring is disposed in contact with a cross bar of an operating mechanism of the circuit breaker. During normal operation, the stop pin loads the upper spring arm with a force at a distance relatively close to the fulcrum of each torsion spring to cause the movement of the upper electrical contact in unison with the cross bar.

Abstract: A molded case circuit breaker crossbar assembly allows the movable contact carrier, contact spring and contact carrier operating cam to be preassembled prior to insertion within the circuit breaker case. The crossbar is fabricated from a plastic molding composition having slots thereon for supporting the movable contact carrier and for retaining the charged contact operating spring. The contact carrier operating cam engages a roller carried by the operating mechanism link to couple the crossbar assembly to the circuit breaker operating mechanism.