Abstract: An electric motor control apparatus includes an electrical current control apparatus which is operable to limit current to an electric motor. When the electric motor is a three-phase motor, three current limiting switch assemblies are provided in the electric current control apparatus. A single stack of laminations concentrates magnetic fields emanating from conductors in all three current limiting switch assemblies. Each of the current limiting switch assemblies includes two movable contacts which are mounted on contact arms. The contact arms are movable in slots in the stack of laminations. A first series of splitter plates is disposed in an array along a path of movement of the contact on the first movable contact arm and a second series of splitter plates is disposed along a path of movement of the contact on the second contact arm for each of the current limiting switch assemblies. A short circuit splitter plate conducts electrical current between the two series of splitter 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: In a molded case circuit breaker with an interchangeable thermalmagnetic trip unit, the C-shaped heater transformer core is permanently held in place in the casing by a load bus strap with the gap in the core facing the trip unit. When the interchangeable trip unit is inserted into the molded casing, a magnetically permeable member mounted in the trip unit is aligned in the gap in the heater transformer core. The bimetal of the trip unit is fixed at one end to an electrically conductive sleeve surrounding the magnetically permeable member and forming the secondary of the heater transformer. The length of the magnetically permeable member is selected to establish the current conditions at which the bimetal trips the circuit breaker.

Abstract: A subframe is coaxially pivotally mounted with a movable frame of the operating mechanism of a molded case circuit breaker and is locked to the frame by a bell crank pawl which is pivotally mounted on the subframe. A leaf spring assembly rigidly attached to the subframe overlies the movable contact finger to engage the same in the circuit ON condition of the circuit breaker to provide desired contact force. The bell crank pawl is released upon an incrementally small amount of initial movement of the movable contact arm in response to blow-open magnetic repulsion forces to release the movable contact finger for pivotal opening movement relative to the movable frame of the circuit breaker operating mechanism.

Abstract: Molded insulating shell halves are secured together around a blowout coil, stationary and movable contacts to pivotally trap an armature assembly therebetween. Windows are provided in the shell halves to ventilate the electromagnet coil during operation. The electromagnet is removable through the window without disassembly of the contactor. Contact and armature adjustment is accomplished through additional window openings. An arc chute having left and right-hand arc extinguishing chambers each sub-divided into upper and front chambers splits the arc into four series segments and increases the overall length of the arc significantly over similar prior art devices.

Abstract: A two-pole switch for DC current has a housing formed by a pair of open shells abutting each other to enclose components of the apparatus. Each shell rigidly holds a stationary contact, and an actuator is pivotally coupled to the shells. A pair of movable contacts are pivotally attached to the actuator so that each movable contact touches one stationary contact when the actuator is in a first position and the contacts are separated when the actuator is in a second position. A spine plate is between the shells and electrically separates the two stationary contacts and arc extinguishing chambers. A solenoid is within the housing aligned with the contacts and drives the actuator between the second and first positions to close the contacts.

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: An electrical contractor device (80) for controlling the flow of electrical power from a source of electrical power to an electrical device according to a command signal from a controller utilizing a rotary disc assembly (90) rotated by an actuator (169) where the rotary disc assembly (90) is comprised of a rotary disc (100) supporting a disc conductor (102) having a pair of contact pads (106, 108) joined by a pair of conductor legs (109, 113) and a center section (111) where the conductor legs (109, 113) are parallel and offset one from the other straddling an axis of rotation (103) where high flow of electrical current through the disc conductor (102) generates an electro-magnetic torque in the rotary disc assembly (90).

Abstract: Molded case circuit breaker having collapsible toggle linkage with rectangular cross section knee pin non-rotatably held within open rectangular slots in upper link, bifurcated movable contact fingers loosely guided for pivotal movement about fixed pin to break contact welds, helical compression springs biasing bifurcations against faces of a stationary connector, trapezoidal cross section shaft biasing shaft against a fixed corner of clamping strap and frame, increasing clamping force and increasing tool clearance, operating handle which changes pivot point moving to RESET position, reducing lateral force component of operating springs for reliable return of handle to OFF position, dual stops for movable contact fingers to spread impact forces along fingers, greater contact separation in poles not containing operating mechanism, slot motor laminations providing metal reinforcement to separate arc chamber housing which is cooperatively interlocked with base to distribute structural strength, terminal cover wi

Abstract: Molded case circuit breaker having collapsible toggle linkage with rectangular cross section knee pin non-rotatably held within open rectangular slots in upper link, bifurcated movable contact fingers loosely guided for pivotal movement about fixed pin to break contact welds, helical compression springs biasing bifurcations against faces of a stationary connector, trapezoidal cross section shaft biasing shaft against a fixed corner of clamping strap and frame, increasing clamping force and increasing tool clearance, operating handle which changes pivot point moving to RESET position, reducing lateral force component of operating springs for reliable return of handle to OFF position, dual stops for movable contact fingers to spread impact forces along fingers, greater contact separation in poles not containing operating mechanism, slot motor laminations providing metal reinforcement to separate arc chamber housing which is cooperatively interlocked with base to distribute structural strength, terminal cover wi

Abstract: Molded case circuit breaker having collapsible toggle linkage with rectangular cross section knee pin non-rotatably held within open rectangular slots in upper link, bifurcated movable contact fingers loosely guided for pivotal movement about fixed pin to break contact welds, helical compression springs biasing bifurcations against faces of a stationary connector, trapezoidal cross section shaft biasing shaft against a fixed corner of clamping strap and frame, increasing clamping force and increasing tool clearance, operating handle which changes pivot point moving to RESET position, reducing lateral force component of operating springs for reliable return of handle to OFF position, dual stops for movable contact fingers to spread impact forces along fingers, greater contact separation in poles not containing operating mechanism, slot motor laminations providing metal reinforcement to separate arc chamber housing which is cooperatively interlocked with base to distribute structural strength, terminal cover wi

Abstract: Molded case circuit breaker having collapsible toggle linkage with rectangular cross section knee pin non-rotatably held within open rectangular slots in upper link, bifurcated movable contact fingers loosely guided for pivotal movement about fixed pin to break contact welds, helical compression springs biasing bifurcations against faces of a stationary connector, trapezoidal cross section shaft biasing shaft against a fixed corner of clamping strap and frame, increasing clamping force and increasing tool clearance, operating handle which changes pivot point moving to RESET position, reducing lateral force component of operating springs for reliable return of handle to OFF position, dual stops for movable contact fingers to spread impact forces along fingers, greater contact separation in poles not containing operating mechanism, slot motor laminations providing metal reinforcement to separate arc chamber housing which is cooperatively interlocked with base to distribute structural strength, terminal cover wi

Abstract: Direct current switching apparatus having front and rear arc extinguishing chambers substantially coextensive, the rear chamber being separated into two laterally spaced arc extinguishing chambers, each arc extinguishing chamber comprising rows of non-magnetic parallel splitter plates, a pair of spaced conductors each having a stationary contact element spanning both the front and rear arc extinguishing chambers, power supply terminals connected to the respective spaced conductors, magnetic plates disposed in front of the front chamber and in back of the back chamber having magnetic means providing a magnetic path externally around the chambers, permanent magnets magnetically coupled to at least one of the magnetic plates providing a magnetic field across the respective chambers, a movable contact movable normal to a front to rear direction into and out of bridging engagement with the stationary contacts, and an electromagnetic drive motor disposed coextensive with said arc extinguishing chambers coupled at a

Abstract: Direct current switching apparatus having two arc extinguishing chambers each comprising a pair of spaced conductors providing cooperable arc runners divergent toward a row of non-ferromagnetic splitter plates and a stationary contact conductively mounted on one conductor, the stationary contacts of respective chambers being mounted on respectively opposite conductors, corresponding conductors in respective chambers being conductively connected to each other and to power terminals of the apparatus, permanent magnets applying a magnetic field across the respective chamber for moving an arc within the chamber, ferromagnetic plates providing flux return paths to optimize and maximize the magnetic field, a movable contact extending into each chamber bridging the stationary contacts and movable to separate from the stationary contacts, drawing an arc therebetween in each chamber, the arc in one chamber bridging the pair of conductors within that chamber establishing a circuit comprising the arc between the conduct

Abstract: A linear acting ball latch is released by a rotary latch release member in the form of a rotor for a high torque, short stroke rotary electric motor which is electrically energized through a capacitor discharge system to release the latched member for spring biased movement into engagement with a bridging contact, thereby forcing the contact open from stationary contacts. A clapper type armature drives the contacts between open and closed positions through tubes, one of which extends through the latch mechanism. The tubes have spring biased plungers connected with the movable contact member to provide a low gradient spring force to the contacts permitting separation by the latch tube assembly and providing contact pressure when the magnetic operator closes the contacts. A manually operable handle and reset cam are disposed over the rotary latch mechanism and have mechanical connection with the latch release rotor to provide for manual operation of the release and for manual resetting of the latch mechanism.

Abstract: A hybrid switch (2) having a solid state circuit (2a) including a thyristor (SCR) for closing and reopening a supply circuit (S,4,6) to a load (L) and contacts including an isolating contact (S1) for connecting power to and disconnecting power from the solid state circuit (2a), a control contact (S2) for initiating turn-on and turn-off of the thyristor (SCR), and a bypass contact (S3) for shunting the solid state circuit (2a) after the load has been energized. A zero voltage crossover circuit (ZVC) allows turn-on of the thyristor (SCR) only when the A.C. supply voltage is below a preset value to avoid arcing at the contacts on closing. The inherent zero current crossing turn-off characteristic of the thyristor (SCR) avoids arcing at the contacts on opening.

Abstract: Stationary contacts (12) of a multi-pole disconnect or safety switch are arranged to be engaged by one of a rotatably movable bridging contact (2) before engagement of the other end thereof with a second set of stationary contacts (10). Stationary contacts (12) of adjacent switch poles are positioned on alternate ends for increasing the phase-to-phase failure distance, and one stationary contact (10a) may be arranged to close one or two milliseconds late to produce single phasing for a short time under fault current conditions during which time current limiting fuses (14) begin to open the circuit.

Abstract: A residential or commercial circuit breaker of the narrow width type, typically having a width of 3/4 inch or 1 inch, is provided with a magnetically permeable slot motor 102 mounted within the case 2 and around both current carrying conductors 8 and 12 for concentrating magnetic repulsive force and boosting the contact separating force.

Abstract: A D.C. power controller for interrupting a high voltage high current D.C. power line supplying a load (L) from a D.C.

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).