Abstract: A thermal magnetic circuit interrupter with instantaneous short circuit current response utilizes a hook-shaped contact arm pivotally mounted on the operating mechanism at the end of the contact arm most distant from the contact. A saddle-type torsion spring proximate the pivot end of the contact arm provides adequate contact pressure while allowing the contact to immediately respond to magnetic forces generated under short circuit conditions. The immediate separation of the contacts reduces the current let-through the operating mechanisms while the tripping mechanism operates to trip the breaker.

Abstract: An electric circuit breaker includes an insulated latch and cradle mechanism to prevent deleterious arc formation between their points of separation when the circuit breaker contacts are opened under short circuit conditions. One embodiment employs an insulated latch mounted on the breaker armature.

Abstract: A movable contact arm for circuit breakers allows the contact opening characteristics to be determined over an entire range of breaker ratings. The contact arm is provided with a camming surface with the contact closure spring arranged as a cam follower. Under short circuit conditions, the contact repulsion force is sufficient to overcome the bias provided by the contact closure spring and to drive the cam follower along the camming surface so that the resulting spring torque rapidly changes from a high initial torque on the contact arm to zero torque in a very short period of time. The contact arm is linked with the contact operating mechanism to open upon current overload in response to the trip mechanism.

Abstract: Electromagnetic relay with a housing consisting of two parts (1, 2) which are bonded to one another, with a circumferential groove (5) being provided for in one bottom part (1), which is filled with an adhesive (6) in which the cap-shaped housing member (2) immerses after having been placed into position. The groove (5) is arranged within the area in which the electric terminals (3) are led through the bottom part (1), so that simultaneously, the adhesive (6) also effects a sealing of the lead-through points (4) of the terminals (3).

Abstract: A circuit breaker having an automatically adjusting magnetic armature is provided. The magnetic armature includes a spring-biasing means to automatically maintain one end of the armature in the contact with the electromagnet and the other end away from an adjacent electromagnet. The magnetic armature includes a pair of slightly curved arms which are disposed about a pivot guide post. When current through the circuit breaker exceeds a predetermined amount, the end of the armature normally biased away from the adjacent electromagnet is suddenly attracted to the electromagnet. The force from the spring-biasing means is overcome, and the slightly curved arms of the armature pivot about the pivot guide post so that the armature contacts the adjacent electromagnet. A latch holder at the end of the armature becomes disengaged from a latch means to cause the circuit breaker to open.

Abstract: An electromagnetic actuator is provided by a single armature plunger that reciprocally shuttles between two magnetic paths provided by a pair of coils. Undesired retarding-flux is cancelled in overlapping linkage paths through the plunger, yielding increased net magnetic force in the intended direction of movement and faster plunger operation. When either coil is energized, a primary flux path is created around that coil through the plunger, and a secondary flux path is created around both coils through the plunger. The primary path attracts the plunger to close a magnetic air gap. The secondary path holds the plunger in place. Current to the ON coil is also supplied through a limiting resistor to the OFF coil to generate reverse polarity flux in the latter cancelling secondary flux from the ON coil.

Abstract: An actuator for selectively actuating a circular array of electric switches. The actuator includes a molded plastic rotor part that contains particles of magnetic material. One portion of the rotor is magnetized to provide a permanent magnet that is effective to attract a switch actuating arm that is pivoted to the rotor. Another tubular portion of the rotor is magnetized to provide the rotor of an electric stepper motor. The stepper motor rotates the rotor to various positions. The arm can be attracted by an electromagnet and pivoted to a position in which it operates one of the circular array of switches.

Abstract: A compact, flexible relay with plunger-type armature is provided. Relay configurations ranging from single-pole, single throw to double-pole, double-throw may be provided on the same base, using standardized components. A plurality of the relay terminals are placed in a stacked arrangement, including intermediate insulators, for minimizing the use of space transverse to the plunger armature. The terminals are integrally formed to include a plate portion for positioning parallel to the base and a depending blade portion extending transversely thereto for external electrical connections. Some of the terminals are included in the electromagnetic circuit. In a particular configuration, a double-pole, double-throw relay suited for dynamic braking of a motor is conveniently provided employing the stacked arrangement of terminals and several standardized components.

Abstract: A polarized electromagnetic relay has two L-shaped yokes with a permanent magnet disposed therebetween. Each yoke has a long leg and a short leg with a coil wound around the long legs of the yokes. The long leg of a similarly L-shaped armature is also disposed between the long legs of the yokes and the armature is pivotally mounted at its short leg so that the free end of the long leg of the armature executes switching movements between the short yoke legs and forms a rectangle in combination with the yoke arrangement. The armature may be mounted centrally or single-sided with respect to the yoke legs for monostable or bistable switching behavior of the relay. The compact arrangement of the yokes and armature permits a number of contact elements to be disposed beneath the coil at both sides of the long armature leg, with the armature causing movement of spaced spring contact elements for making and breaking with corresponding fixed contact elements.

Abstract: A relay with plunger-type armature includes a resilient contact support, such as a conductive leaf spring, supported by a terminal in a manner affording substantial attenuation of contact bounce when engaged by an armature-mounted contact. Provision is made for insuring separation of the contacts upon reverse displacement of the armature. Specifically, a leaf spring may be fixed at one end to the base of a channel formed in the surface of a terminal plate. An overlying apertured insulator preflexes the spring and limits its displacement in the reverse direction. In a double-throw relay, the other "stationary" contact may be mounted on a resilient support, such as another leaf spring, for providing contact bounce suppression there as well.

Abstract: A contactor apparatus is provided comprising automatic opening means and a local control member.This apparatus uses a transmission piece (40) associated with a sudden tripping mechanism (46) which is released by a bolt (29) held in position by means of a lever (24) which may be struck by a magnetizable part and adapted to maintain a power contact (13) open, this part assuming, after the appearance of a fault, visible positions so as to inform the user about the state of the apparatus.This apparatus is usable in installations where it is desired to protect the lines and the loads.

Abstract: A circuit breaker having a contact opening and closing mechanism including a contact actuator member which is moved between a first position and a second position to close and open the contacts. The movable contact is mounted on one end of a contact carrier which is pivotally mounted at its central region to the contact actuator member. A leaf spring is positioned between the other end of the contact carrier and the circuit breaker case. When the contact actuator member is in the first position, the leaf spring produces a torque on the contact carrier in one direction about the pivot forcing the contacts closed. When the contact actuator member moves from the first position toward the second, the leaf spring becomes ineffective and a torsion spring which engages the contact carrier and the contact actuator arm produces a torque pivoting the contact carrier in the opposite direction thus enhancing the contact opening process.

Abstract: A circuit breaker having an overload mechanism including a support member mounted in the circuit breaker housing. One end of an elongated bimetallic element is fixed to one end of the support member. An armature element is mounted at one end to the one end of the bimetallic element and its other end has a latching surface engaging a trip arm to hold it in a set position. The support member has a reference surface adjacent to its other end and the trip arm is biased against it. An overload current causes the other end of the bimetallic element to deflect, moving the other end of the armature element with it and disengaging its latching surface from the trip arm. The released trip arm pivots to a tripped position causing the breaker contacts to open. The dimensional relationships between the reference surface and the latching surface determine the tripping characteristics of the circuit breaker.

Abstract: A threshold coupling device for releasing the mobile contacts of circuit breakers when short circuits appear. A rectangular section blade (13) with longitudinal faces (13', 13") associated with a contact holder (10) is provided with balls (29, 30) which cooperate with a resilient clip (33) for providing a threshold mechanical connection between the contact (6) and an operating member (1, 2) which carries this clip. This coupling is advantageously used in circuit-breaker limiters.

Abstract: A mechanically controlled power switch with automatic opening is provided for limiting short circuits. A switch (13), a breaking chamber (30) which is associated therewith, a coil (50), a striker (51) cooperating therewith, and a lock (53) for holding the power switch in open position S after the appearance of a short circuit are placed in a removable cartridge (23) provided with connection terminals (37, 55). This switch cartridge is advantageously used in mechanically controlled protection apparatus or in electromagnetic contactor apparatus having their own protection.

Abstract: A contact structure (40, 44; 62, 63) is arranged to provide oppositely directed parallel current paths within a closed loop magnetic flux amplifier (46) to be directly separable under high overload current conditions, the flux amplifier (46) functioning to arrest the movable contact (62, 63) momentum. Manufacturing economies are realized by subassembling the stationary contact structure (40, 42, 44) and flux amplifier (46) and subsequently trapping one end (42a) of that assembly within the base (4a) and securing the other end with a single screw (68). The movable contact arm (62) comprises a plurality of blanked laminations assembled to provide improved contact (63) mounting and bearing (62d) surfaces. The molded case sidewalls are strengthened in the contact separation area by offsetting the parting line (PL) between cover (6) and base (4) closer to the bottom of base (4) and overlapping the thinner base sidewalls with thicker cover sidewalls at the offset (4e, 6e).

Abstract: The present invention relates to a disconnectable connection between a trip unit and circuit breaker. The disconnectable connections between the removable trip unit and the circuit breaker unit include inclined connection lugs so as to provide access to the set-screws of the connections on the narrow side face of the circuit breaker casing.

Abstract: An adapter assembly is provided for use with circuit breakers having automatic charge and employing undervoltage release accessory. The adapter is inserted between the undervoltage release tripping mechanism and the circuit breaker operating mechanism to prevent the circuit breaker from tripping from a charged position when the circuit breaker contacts are open. The adapter assembly interferes with the undervoltage tripping lever when the circuit breaker contacts are open to prevent the undervoltage release tripping mechanism from tripping the breaker under conditions of undervoltage or power outage, thus providing a true stored energy device regardless of undervoltage conditions.

Abstract: The present invention relates to a multi-pole circuit breaker with an interchangeable magneto-thermal tripping unit electrically and mechanically connected to the breaker unit by means of connecting screws. The connecting lugs of the breaker unit are positioned with vertical play in transverse slots in the breaker unit casing and are electrically connected to the movable contacts by flexible connections. When the connecting screws are tightened the breaker unit connecting lugs are shifted to bear on the associated tripping unit lugs irrespective of any positioning defects. A reset spring of the electro-magnetic tripping device is anchored on one end on the armature and on the other end to the tripping device adjusting bar.

Abstract: In an electric switch having a bridging contact movable into and out of engagement with a pair of fixed contacts, at least one of the terminal elements supporting the fixed contacts comprises a strip of sheet metal folded back upon itself to provide a loop shaped current path with first and second conductive sections extending generally parallel to the bridging contact on opposite sides thereof in close proximity thereto. Attractive forces electrodynamically developed between the bridging contact and the first conductive section of the one terminal element are additive to repulsive forces electrodynamically developed between the bridging contact and the second conductive section of the one terminal element for increasing contact pressure between the bridging contact and the fixed contacts under excessive current conditions.