Abstract: A circuit breaker with improved magnetic trip assembly includes electrical contacts operable between a closed position in which a circuit is completed and an open position in which the circuit is interrupted, a latchable operating mechanism operable to open the electrical contacts when unlatched and a trip bar rotatable from a biased position to a trip position to unlatch the operating mechanism. The circuit breaker further includes a magnetic trip assembly comprising a stationary magnetic structure, a movable armature which is attracted to the stationary magnetic structure by an abnormal current through the conductor to rotate the trip bar to the trip position and a plate means mounted to the movable armature and disposed between the armature and the stationary magnetic structure. The plate means adjusts the amount of abnormal current required to attract the movable armature to the stationary magnetic structure and in turn rotate the trip bar.

Abstract: A molded case circuit breaker is provided with a magnetic trip device which allow for a relatively wide range of adjustment. The magnetic trip device allows the magnetic air gap to be varied as well as the spring force on the plunger. Additionally, the magnetic trip device allows the force required to rotate the trip bar to be varied. By providing a means for adjust the force required to rotate the trip bar, the adjustment range of the magnetic trip device can be substantially enhanced. The molded case circuit breaker includes at least one pair of separable main contacts. The separable main contacts are mounted on upper and lower contact arms. The lower contact arm may be rigidly mounted to a line side conductor, while the upper contact arm is pivotally mounted to a load side conductor. The upper contact arm is mechanically coupled to an operating mechanism. A pivotally mounted trip bar is operatively coupled to the operating mechanism.

Abstract: A circuit breaker is disclosed having a movable magnetic core provided in the magnetic trip assembly thereof adapted to lower the current levels at which the magnetic trip mechanism will operate. The magnetic trip assembly also includes a pivotally connected armature, a current carrying conductor, a fixed magnetic yoke and a latchable operating mechanism. A primary air gap exists between the armature and the fixed yoke. The movable core is designed to move into an extended position which reduces the primary air gap which in turn increases magnetic flux coupling which allows the magnetic force required for the armature to pivotally rotate to unlatch the operating mechanism and thereby trip the circuit breaker to be generated at a lower current level. This reduction in current is the desired effect of the new design.

Abstract: A twin unit circuit breaker has a V-shaped stainless steel combination armature pivot and bias spring, a central offset portion on the armature to increase the armature surface area that is substantially uniformly spaced to pole faces of a pole piece, a thin profile connection of an operating spring with a latch lever, and a preformed U-shaped conductor attachable in circuit between a bimetal and a flexible conductor and insertable over a pole piece from one end thereof.

Abstract: A mounting frame is provided for components of a circuit breaker. The frame is of metal and is designed so that it carries current and is not merely for supporting the components. The frame has a terminal portion, a field generating portion, pole piece defining portions, a reverse arc runner, a support post for a bi-metal strip, a latching projection for an armature, guide surfaces for the armature and a pivot pin for an operating handle. The invention further provides a circuit breaker which utilizes the frame and to a circuit breaker which uses a coil of varying resistance, in comparison with the constant resistance of a path between a terminal and a bi-metal strip, to vary the magnetic tripping characteristic of breaker.

Abstract: A magnetic trip unit for molded case circuit breakers includes a pair of U-shaped magnets opposedly arranged around a part of the circuit breaker load strap and the armature strap. Circuit current in excess of a threshold value displaces the armature strap, causing it to articulate the circuit breaker operating mechanism to interrupt the circuit current.

Abstract: A circuit breaker structure having a faster trip unit characterized by a circuit breaker operator and a trip unit comprising a coil, a core, and an armature, and a hold-back bracket extending from and retaining the armature in a spaced position from the core so as to cause the magnetic field lines to flow through the bracket and the armature.

Abstract: A circuit breaker structure having a faster trip unit characterized by a circuit breaker operator and a trip unit comprising a coil, a core, and an armature, a flux concentrating plate spaced from and on the side of the armature opposite the core and for concentrating the magnetic field between the core and the armature, and a hold-back bracket having extending from and retaining the armature in a spaced position from the core so as to cause the magnetic field lines to flow through the bracket and the armature.

Abstract: A magnet piece and armature are arranged around a circuit breaker load strap having a bimetal strip attached thereto. The magnet piece is formed in a U-shaped configuration and is attached to the load strap. A corresponding U-shaped armature is pivotally mounted to the magnet piece in a partially overlapping relation. The U-shape armature presents a larger magnet pole surface to the magnet piece for enhanced magnetic interaction.

Abstract: An electronically driven trip actuator for multipole industrial rated molded case circuit breakers is installed within a common housing with the circuit breaker operating mechanism. The trip actuator consists of a mechanical actuator cooperatively connected with a magnetic latch. The magentic latch arrangement holds the trip actuator against an actuating spring bias. Upon receiving an appropriate signal response, the magnetic latch releases, allowing the mechanical actuator to move into contact with the circuit breaker latch under the influence of the actuator spring. The arrangement of the mechanical actuator and actuator spring provides a low latching force to the magnetic latch, while providing a large trip force to the circuit breaker latch.

Abstract: An interchangeable operating mechanism assembly for molded case circuit breakers having a detachable movable contact arm and trip unit assembly allows the same mechanism assembly to be employed across a wide range of breaker ratings. A snap-on common trip bar attachment further allows multiple-pole facility off the common interrupter mechanism assembly. The mechanism assembly is designed to maintain the operating handle in the "on" position upon the occurrence of a welded contact and prevents the mechanism from being reset.

Abstract: A circuit breaker capable of breaking an associated circuit when an overcurrent higher than a rated current keeps flowing through the breaker or upon a short-circuit current. Electric power path in the breaker is partly inserted through an arm of a magnetic material and holding a movable contactor plate of make-and-break contact means, an armature means is provided as pivoted at one end to the holding arm, and a tension spring means is provided between the other end of the armature means and the movable contactor plate to provide a contact pressure. The overcurrent flowing through the path causes a magnetic force to be induced in the holding arm, whereby the armature means is rotated to change the direction in which the force of the tension spring means acts on the movable contactor plate and the latter breaks the contact means.

Abstract: A circuit breaker comprising an electrically insulating housing, an overcurrent sensor in the housing, a stationary and a movable contact in the housing, and a latch mechanism coupled to the movable contact. The latch mechanism is tripped in response to a sensed overcurrent; an overcenter spring is coupled to the movable contact for opening and closing the contacts with a snap action when the latch mechanism is tripped. An elongated handle member extends through a handle opening in the housing and is movable axially between a contacts open position and a contacts closed position. Handle link means couples the handle member to the latch mechanism and translates a longitudinal movement of the handle member into a rotational movement of the handle link to urge the latch mechanism into the contacts closed position.

Abstract: Current limiting switch for rapid circuit breaking, including at least one pair of contacts, one contact being mounted stationary and the other being mounted on a movable arm. The contact arm is rotatable about a fixed point upon surpassing a predetermined current threshold value, by means of an electromagnet energized by the current passing through the switch. The electromagnetic means comprise an electromagnet and a first and a second armature cooperating with the electromagnet, in which the first armature drives the movable contact in the direction of disengagement and the second armature releases a locking device, which blocks the movable contact in the direction of movement until the current threshold is reached.

Abstract: The common trip mechanism of a multi-pole circuit breaker is supplemented by individual breaker pole trip mechanisms operating independently of each other in response to fault current flowing in its breaker pole to unlatch the movable contact arm operating therein for uninhibited, independent opening movement from its closed circuit position to a tripped open position motivated by the electrodynamic forces associated with its breaker pole fault current.

Abstract: A low voltage circuit breaker has an insulating housing which is split along a parting line into an upper part and a lower part. Disposed in the housing is an electromagnetic tripping device which comprises a fixed magnet yoke and a movably disposed armature. By means of trunnion (pivot) pins of rectangular cross-section the armature is mounted in bearing openings designed in the form of pocket-like cutouts in the wall surfaces of the lower part which limit the pole channels of the circuit breaker. The bearing surface of the bearing openings associated with a narrow surface of each trunnion pin may be composed of two subsurfaces disposed at an angle to each other so that an edge-like bearing results. For the attachment of the magnet yoke there is provided on the lower part of the housing an island-like projection which is spaced from the wall surfaces and against which the central part of the magnet yoke is caused to rest by a spring element.

Abstract: A molded case current limiting circuit breaker includes separable contacts, an operating mechanism releasable to effect automatic separation of the contacts, and a high speed electromagnetic trip device operable upon overcurrent conditions to release the operating mechanism and separate the contacts. The trip device includes a U-shaped pole piece disposed about a conducting path through the circuit breaker and a movable laminated armature mechanically coupled to the operating mechanism and magnetically coupled to the pole piece. The thickness of the armature is substantially greater than the thickness of the pole piece. During extreme overcurrent conditions electrodynamic force is produced upon the armature by magnetic flux in the pole piece. Upon saturation of the pole piece, force upon the armature continues to increase with increasing current due to electrodynamic force produced between the armature and the conducting path.

Abstract: A high performance, manually and automatically operable, trip-free magnetic circuit breaker incorporates a collapsible linkage having selected elements of precision molded plastic cooperating in a dual latch system, the linkage being adapted to be accurately assembled and mounted in the breaker without requiring adjustment inside the breaker housing; incorporates a double break contact system to achieve longer life, more reliable operation and improved rupture capacity; and incorporates auxiliary switch means with improved actuator biasing to achieve more reliable breaker operation in auxiliary switch applications.

Abstract: A molded case multi-pole circuit breaker is provided with a solid state trip unit constructed to automatically open the breaker responsive to predetermined fault current conditions by actuating a permanent magnet latch. The latch and main conductors of the circuit breaker are constructed and arranged so that at very high short circuit currents, even if the solid state circuitry malfunctions, flux generated directly by current flow in the main conductors will buck the permanent magnet flux sufficiently to actuate the magnetic latch directly.

Abstract: A high performance, manually and automatically operable, trip-free magnetic circuit breaker incorporates a magnetic actuation system with improved core, clapper and coil mounting to achieve more accurate and consistent breaker operation; incorporates a modular structure permitting adaptation of the breaker for use in a variety of breaker applications while minimizing circuit breaker costs; and incorporates improved magnetic circuit means to achieve more reliable breaker operation in flux switch type breaker applications.

Abstract: A magnetic trip assembly for use in a device such as an electric circuit breaker. The magnetic trip assembly includes a magnet and an armature arranged with respect to the magnet to coact with a pole face of the magnetic member which is in a plane normal to the magnetic plane of the magnetic member. An electrical load conductor is coupled to the magnetic member and establishes together with the magnetic member a magnetic field for closure of the armature in response to specified, excessive values (short circuit or overload values) of current passing through the load conductor. When the armature is operated to its closed position, a first portion of an actuating and latch member abutting against the armature is caused to move, in turn causing a captive, generally-cylindrical portion of the actuating and latch member to rotate.

Abstract: A plurality of single pole circuit breakers stacked side-by-side are interconnected by a tie rod connecting the magnetic armatures of their respective instantaneous trip means. When one pole is caused to trip because of a fault condition a driving cam formation on the releasable cradle of the faulted pole engages the armature moving it in the tripping direction substantially beyond the point required for releasing the cradle latch in the faulted phase. Substantial movement beyond cradle release is permitted even though the magnetic air gap at the armature is small in that after this gap is closed the magnet is moved bodily in the tripping direction. This added movement assures that the tie rod shall transmit sufficient motion to all non-faulted poles to cause tripping thereof.

Abstract: A current limiting circuit breaker having for each pole, a pair of main contacts separable upon operation of a thermally and electromagnetically operable tripping device and a pair of auxiliary contacts for current limiting in series with the main contacts and in parallel with a transformable resistor having a positive temperature coefficient of resistance. The auxiliary contacts are separable when an electromagnet is energized by a fault current which simultaneously energizes a field magnet to produce a transverse magnetic field across the auxiliary contacts and the arc formed between them when separating. This simultaneous action of electromagnet and field magnet coacting for rapid contact separation and lengthening of the arc upon flow of a fault current serves to increase arc voltage almost instantaneously to that of the source, about which time the fault current is totally shunted into the resistor. An armature and armature pin are mounted for reciprocal movement when the electromagnet is energized.

Abstract: An excess current switching device having particular but not exclusive application in switching direct current power.The switching device comprises first and second excess current switches. The first switch comprises a break point and a thermal and/or electromagnetic tripping device(s) linked to a latching mechanism and the second switch comprises a break point and an electromagnetic tripping device having a high resistance coil linked to a latching mechanism. The break point of the first switch is connected in parallel with the tripping device of the second switch. When an excess current occurs, the break point of the first switch opens, leaving the tripping device of the second switch in curcuit and this opens the break point of the second switch.