Abstract: A molded case circuit breaker includes a generally "Z" shaped intermediate latch structure which has upper and lower substantially planar sections that are each bent at an angle with respect to a center pivot section. The upper portion of the intermediate latch includes one or two latch surfaces. One of these latch surfaces engages the cradle of the operating mechanism of the circuit breaker, to latch the operating mechanism when the circuit breaker is closed. The other latch surface engages a trip bar or an intermediate latch bar, which is rotated by the trip unit when an overcurrent condition occurs. The lower portion of the intermediate latch structure also includes a latch surface which may engage a trip bar. This latch surface is sloped such that when the latch surface of the trip bar is moved along this sloped latch surface, the trip bar rotates.

Abstract: A contact guide member extends transversely to the contact fingers on the contact carrier of electrical switching apparatus and has spaced openings through which the contact fingers extend and are held in spaced relation. The contact finger guide member is positioned to isolate the arc toes adjacent the free ends of the contact fingers from the main contacts and the contact springs in order to protect the latter items from the arc gases and debris generated during arcing. The openings in the contact finger guide member are elongated to permit differentially pivoting of the contact fingers, but not axial movement. The contact finger guide member slides in a pocket molded in the end face of the contact carrier and is captured by and moves with the contact fingers.

Abstract: A multipolar circuit breaker is provided for securely operating tripping sections of other poles when the tripping section of any pole operates. In the case of a first embodiment, a protrusion 5 for further moving a trigger plate in the tripping direction when a cradle 3 is tripped is provided for the cradle 3 of each pole so that the movement of the trigger plate 1 is securely transmitted to other poles connected by a trigger joint 2. Moreover, in the case of a second embodiment, a protrusion for further moving the trigger plate 1 in the tripping direction by pushing the cradle 3 when the cradle 3 is tripped is provided for the trigger plate of each pole to obtain the same above mentioned advantage.

Abstract: A solenoid type magnetic trip assembly for a molded case circuit breaker includes an armature biased against an adjustable stop by a tension spring to set the initial gap for the magnetic trip, so that the spring bias remains constant for the full range of the initial gap. The armature includes an elongated magnetically permeable member mounted by a frame to slide longitudinally along a pair of guide rails. The frame defines a trip surface axially aligned with the elongated magnetically permeable member which engages a trip arm on a trip bar to trip the circuit breaker in response to a predetermined level of overcurrent. A bimetal providing a thermal trip function is cantilevered from a support spaced from the trip bar by the armature, but has a terminal portion at the free end projecting toward the trip bar and through which the elongated magnetically permeable member of the armature extends.

Abstract: A miniature molded case circuit breaker is adapted for use with load conductors having ring lug terminations by extending the circuit breaker load terminal conductor through the terminal recess and beyond the molded housing. An adapter includes an insulative shield member having an open slot in which the load terminal conductor terminates for connection to the ring lug on a load conductor. The adapter further includes an insulator which seats snugly in the terminal recess of the housing and through which the load terminal conductor extends. A bifurcated neck on the insulator extends through an opening into the shield member. The shield member is secured to the circuit breaker by projections which snap into grooves in the neck portion of the insulator and a cantilevered resilient finger which engages a catch on the molded housing.

Abstract: A modular plastic trip bar assembly joins separate single pole molded case circuit breakers into a single multipole circuit breaker. The addition of the trip cam to the trip bar assembly allows four and five pole combinations to operate in unison.

Abstract: An interlock for first and second tandemly aligned circuit breaker switches which respectively have first and second external operating handles thereon oriented such that the operating handles are disposed away from each other when the switches are OFF and towards each other when the switches are ON. The interlock includes a linkage arrangement formed with at least one slot and having one end connected to the first operating handle and another end connected to the second operating handle such that pushing the first operating handle from an OFF to an ON position pushes the second operating handle from an ON to an OFF position.

Abstract: A multi-pole low-voltage power switch designed with several switching chambers per pole and a common switching shaft which acts for the pole units is formed by the switching chambers. The switching shaft is made up of shaft sections which correspond to the pole units. While the central shaft section has central pins and levers, the peripheral shaft sections are fitted with levers and have central apertures in which the pins engage. Bolts which pass through the levers are used to couple the shaft sections together. The pole units rest on a support which is dimensioned to accommodate the maximum width of the pole units and to allow for possible variations in their dimensions. Side walls of the correct dimensions for a pull-out rack enclosed the supporting framework of the power switch on each side.

Abstract: A circuit breaker comprises a container made of electrically insulating material, the container being constituted by a casing and a cover; a switching mechanism contained in the container; partition walls defining a recess in the casing, the recess being separated from an interior of the container by the partition walls; and a base made of electrically insulating material, on which an accessory which is in the form of a cassette is detachably mounted, the base being detachably mounted in the recess formed in the cover.

Abstract: An auxiliary switch, mounted in a compartment in the molded housing of a circuit breaker separate from the compartment in which the circuit breaker mechanism is mounted, is actuated, when the circuit breaker contacts are open, by cascaded actuating members, one of which engages, through a housing panel dividing the compartments, the latchable cradle of the circuit breaker mechanism to actuate the auxiliary switch when the circuit breaker is tripped, and the second of which is spring biased against a cam surface on an operating member incorporating the circuit breaker handle to actuate the auxiliary switch when the handle is in the off position.

Abstract: A current limiting circuit breaker including novel clutch arrangements between the contact arms of the circuit breaker and the crossbar. The clutch arrangements include cam surfaces formed on the crossbar from plastic and a cam follower attached to each contact arm. A cam surface is located on each side of each contact arm and each surface may be formed integrally with an insulating barrier. To reduce wear on the cam surfaces, each cam follower includes a roller which contacts the respective cam surface. The cam surfaces are configured to permit the contact arms to blow open under unacceptable fault conditions even though the crossbar remains stationary.

Abstract: A modular trip unit for automatically tripping a switch of a circuit breaker when the circuit breaker is being removed from its panel mounting when the circuit breaker has not been manually overridden. The modular trip unit is an integral part of the circuit breaker and includes a trip interlock assembly integrally mounted in the modular trip unit. The trip interlock assembly comprises a spring biased slider extending through and out of the housing of the trip unit, and an actuator in engagement with the slider. The actuator engages a first cam surface of a trip bar and a catching member of a latching assembly is engaged by a lip member on a second cam surface of the trip bar. When the circuit breaker is being mounted on the panel mounting, the slider is forced inwardly thereby compressing a spring associated with the slider, and the slider causes the actuator to rotate in a first direction.

Abstract: A molded insulator has a bottom wall, opposed sidewalls, and a transverse end wall extending between the sidewalls but spaced from the end of the bottom wall to define an opening in the bottom. A distribution lug is inserted from an open end of the insulator against the end wall, and under projections on inner surfaces of the sidewalls to trap the insulator against the end wall, and under projections on inner surfaces of the sidewalls to trap the insulator against up and down movement. The lug is attached to a circuit breaker terminal at the opening in the bottom to trap the end wall between the lug and the circuit breaker, blocking withdrawal of the insulator. A depending rib provides distal end support, while lateral ribs abut edges of barriers in the breaker housing to maintain the assembly properly aligned for electrical spacing.

Abstract: Each breaking module is formed by a parallelepipedic monoblock cartridge made of plastic material, housed in the corresponding compartment of the base plate, said cartridge housing at least a stationary contact, an arc extinguishing chamber, and a pair of connecting strips for connection to a terminal and to the trip module of the same pole. A mechanical actuation module constituted by the switching bar and mechanism assembly, is securedly united to the cover. The rotary trip bar is supported by clipping means, arranged on the bottom face of the cover. A plurality cf recesses and cutouts are arranged in the spacers of the base plate to act as first bearing surfaces respectively for the switching bar and trip bar when the first sub-assembly A composed of the base plate with the set of breaking modules and trip modules, is adjoined with the second sub-assembly B formed by the cover on which the mechanical actuation module, trip bar and latch are fitted.

Abstract: A multipole circuit breaker having a movable contact for each pole, the movable contact being biased by a spirally-wound spring including a feeler part which slides on a bearing surface of the movable contact to modify the application point of a pressure force P in a second active repulsion position, resulting in a decrease of the restoring torque before operation of the mechanism. The movable contact is forked-shaped and is articulated on an eccentric spindle parallel to the rotation axis of the bar. The spirally-wound spring is mounted to float in the recess of the bar, and comprises two helicoidal wire windings.

Abstract: A molded case circuit breaker unit having an accessory compartment within the circuit breaker cover, contains a field-replaceable fuse within the compartment for protecting an electric motor without tripping upon motor current reversal. Upon the occurrence of a short circuit within the protected circuit, the fuse operates to isolate the protected equipment and is conveniently replaced without disassembling the circuit breaker components.

Abstract: The breaker mechanism for power circuit breakers is the energy storage link between the handle and the contact systems. Known breaker mechanisms are generally too expensive to manufacture. When contact welding occurs, there is also the risk that, in spite of the tripping of the breaker mechanism, the contact system will not open. The new breaker mechanism reliably opens the contact system and consists of fewer and technologically simpler individual parts. It is inserted between two symmetrical breaker plates held in a die cast housing, and in which a connecting piece is mounted. Two toggle levers are connected at a distance from one another by means of a connecting shaft engaged in crossbar cam slots. A toggle lever spring is engaged between the connecting piece and the connecting shaft. A bracing lever which can be driven by the connecting piece is friction locked in the breaker plates, and the toggle levers in the bracing lever.

Abstract: A molded case multi-pole circuit breaker having an electronic trip unit to determine overcurrent conditions connects with a corresponding current transformer within each pole to sample circuit current. Upon the occurrence of an overcurrent condition, a trip actuator is energized to interrupt the circuit current. A current transformer adapter unit supports the trip actuator wire conductors and pin connectors while at the same time shielding the current transformers from the circuit breaker exhaust gases.

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: A modular low voltage multipole circuit breaker, including a plurality of identical single-pole breaking units each including a parallelipipedic insulating box having two opposite parallel large side faces and two opposite parallel small side faces, two terminals located at respective opposite parallel small side faces, a stationary contact electrically connected to one of the terminals, a movable contact cooperable between a first position contacting the stationary contact and a second position separated from the stationary contact and a molded case for housing the single-pole breaking units. The molded case has two opposite parallel side walls having the same thickness, the single-pole breaking units being sequentially arranged and parallel to each other and parallel to the side walls such that adjacent single-pole breaking units are spaced apart a distance equal to twice the thickness of the side walls, the single-pole breaking units being spaced apart at a constant pitch.

Abstract: A modular crossbar arrangement for molded case circuit breakers allows a plurality of contact arm assemblies to be interconnected from a single modular unit. To provide increased acceleration to the movable contact arms a contact arm accelerator lever interfaces with the contact arm and crossbar assembly. To promote further acceleration of the movable contact arms to their closed positions, the movable contact arms in a multi-pole circuit breaker are staggered with respect to their rotational alignment within each pole on the crossbar assembly.

Abstract: An overcurrent relay device is provided for monitoring current in a multi-phase current system including separate conductors each carrying a respective one of the current phases between a multi-phase current source and a load. The current system includes a system switch having a displaceable contact for switching the multi-phase current on and off. A plurality of electromagnets are provided, each including a magnetic core having a core pole and being associated with a respective one of the conductors for generating a magnetic attraction force in the vicinity of the core pole. The core poles all face in the same direction. An armature is rotatably mounted adjacent to the core poles and gaps are defined between the armature and the respective core poles so that the magnitude of a magnetic attraction moment on the armature generated by each electromagnet is the same for a given magnitude of the multi-phase current.

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: A modular crossbar arrangement for molded case circuit breakers allows a plurality of contact arm assemblies to be interconnected from a single modular unit. To provide increased acceleration to the movable contact arms a contact arm accelerator lever interfaces with the contact arm and crossbar assembly. To promote further acceleration of the movable contact arms to their closed positions, the movable contact arms in a multi-pole circuit breaker are staggered with respect to their rotational alignment within each pole on the crossbar assembly.

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: An arc gas controller-insert is used with molded case circuit breaker covers to direct the flow of arc gases that occur during intense overcurrent circuit interruption. The gas controller-insert provides access to the line and load terminal lugs for connection with and disconnection from an associated electrical power distribution system while controlling the egress of the arc gases.

Abstract: A circuit breaker comprises a housing (1) having a first face and an opposed second face, accessible electrical contacts (105, 106, 108, 115) exposed on each of the faces. An electrical connection is provided between at least one of the contacts (105) and an associated contact (106) on the second face. At least one further contact (108, 115) on the second face is engageable with the at least one contact (105, 112) on the first face of an adjacent circuit breaker.

Abstract: A new single pole circuit breaker, intended for use in a multipole circuit breaker, is disclosed. Among other distinctions, upon being tripped, a relatively large torque is imparted to the trip lever of the single pole circuit breaker. This is achieved by interacting the contact bar stop pin on the contact bar of the single pole circuit breaker with a camming surface on the trip lever. In addition, when pivotal motion is imparted to the trip lever by an external agent, the trip lever directly engages the toggle mechanism of the circuit breaker, to collapse the toggle mechanism and produce tripping. Moreover, the trip lever has a configuration which permits convenient pivotal mounting to a frame.

Abstract: Single pole circuit breakers are connected in a modular array to provide up to four poles by means of a handle tie bar assembly. The circuit breaker operating handles are grooved to receive a metal interlocking pin and a plastic tie bar to cause the circuit breakers to move in unison. A locking clip arranged between one of the operating handle slots and the tie bar assembly prevents the circuit breakers from being turned from their OFF-to-ON or ON-to-OFF conditions.

Abstract: A crossbar assembly is formed from an elongated metal bar. A pair of contact arm carriers are slid onto the metal bar and welded in place. Molded electrically insulated sleeves are sliding received at each of the crossbar. The insulated sleeves can be either molded directly on the crossbar or molded separately, in which case, the sleeves are glued with epoxy and pinned to the crossbar to prevent axial movement of the sleeves with respect to the crossbar. The insulated sleeves are formed with a pair of plates disposed at each end. A pair of oppositely disposed slots formed in the plates is used to receive the ends of a cam roll pin assembly. Since the crossbar in accordance with the present invention does not require wrapping with insulating paper, the possibility of dielectric failure due to cracking of the insulating paper is eliminated.

Abstract: The present invention is directed toward a circuit breaker having an open-and-close shaft; holding member coupled to the open-and-close shaft; at least one movable contactor coupled to the holding member; support member for rotatably supporting the open-and-close shaft; and stopper member coupled with the support member so as to restrict an open-and-separation position of the movable contactor, wherein the circuit breaker is disposed within a case, the stopper member are formed on side faces of between-phase partitions of the case and a portion of the holding member contacts the stopper member. Thereby, it is possible to improve an insulation function and to lessen the impact between the holding member and the stopper member.

Abstract: A high-current multipole circuit breaker is made up of standard poles juxtaposed in a molded case. At least two adjacent poles are twinned, that is to say electrically arranged in parallel and connected to a common connecting strip. The connecting strips of the other poles are widened, so as to partially overlap the immediately adjacent twinned pole. In this way, the circuit breaker rating is higher than that of the individual poles which make it up.

Abstract: A contactor which includes a contact bridge holder for opening and closing a first plurality of contacts of an electric circuit, a second plurality of additional contacts for each electrical phase and a coil connection of an associated magnetic system, respectively; the magnetic system including thermo trippers and magnetic trippers for selectively operating the first plurality of contacts, three actuation members each mounted for pivoting movement, the first of the actuation members being connected to a slider which is in turn connected to the second plurality of contacts, the second actuation member being operative by the magnetic tripper, the third actuation member being operative by the thermal tripper, the first and second actuation members having end portions which are normally in engagement when the trippers are not actuated and the second plurality of contacts are open, and the normally engaging end portions of the first and second actuating members are moved out of engagement upon the operation of ei

Abstract: A circuit breaker operating mechanism employs a multi-latch arrangement for controlling the automatic opening of the circuit breaker contacts upon predetermined overcurrent conditions. The multi-latch assembly is robotically assembled to the operating mechanism and is retained thereon by means of a retainer tab. The circuit breaker case and cover contain integrally formed steps which receive extensions formed on the operating mechanism assembly. The operating mechanism assembly becomes wedged between the circuit breaker cover and case when the cover is later fastened to the case.

Abstract: A molded case circuit breaker is provided with rubber stop assemblies disposed between the contact assemblies adjacent the outside poles and the cover portion of the housing. The rubber stop assemblies are disposed such that they prevent the contact assemblies from damaging the cover. The stop assemblies include a dual purpose U-shaped bracket having two parallel sets of arms. One set of arms is provided with aligned apertures at the free ends for receiving a pin which defines a pivot point for the crossbar assembly. The other set of arms is also provided with aligned apertures at the free end for receiving a metal pin for carrying a cylindrical shock absorber assembly. The shock absorber assembly is mounted adjacent outside poles above the contact carrier but spaced away from the inside of the cover of the circuit breaker. Thus, when the contact arm is opened, it will stop against the shock absorber and not damage the circuit breaker cover.

Abstract: A circuit breaker is constructed to maximize the range of current over which it may operate, and to enhance its safety of operation in both single-pole and multipole embodiments. Improved operating means are disclosed for both the manual and automatic modes of operation in single-pole or multipole embodiments.

Abstract: A multi-pole circuit interrupter comprising an electrically insulating housing having two side walls and at least two partition walls defining therebetween a central compartment and at least two side compartments. A central pole unit is disposed within the central compartment and a side pole unit is disposed within each of two side compartments. Each of the units includes a stationary contact element, a movable contact arm, an arc extinguisher and terminals for the external connection. The distance between a center line passing through the centers of the stationary contact element, the movable contact arm and the arc extinguisher of each of the pole units is smaller than the distance between the center lines passing through the terminals of each pole unit, so that the thickness of the housing side wall can be increased without increasing the overall width dimension of the housing.

Abstract: A crossbar spanning the poles of a multiple pole circuit breaker. The crossbar is formed from a structural member such as beam having an I-shaped cross-section, wherein an insulating material such as plastic is molded to the beam. The shape of the structural member is such that it provides a high strength to weight ratio. The plastic is molded such that it includes means for inhibiting arcing between the poles of the circuit breaker.

Abstract: A circuit breaker for breaking current conduction between line and load connectors in response to tripping of a bimetallic thermal element as a result of an over-current condition is disclosed. According to the invention, a trip crossbar is permitted to translate as well as rotate to relieve stress on the thermal element.

Abstract: A multipolar circuit breaker having a lower case portion with side frame plates and a central frame plate facing the side frame plates on its two major sides, the central frame plate having a deep central groove which forms two flexible central frame plate arms each facing one of the side frame plates to form a nacelle sized to receive one of the switching mechanisms, each of the side frame plates and the arms of the central frame plate having, proximate to its free end, at-least-one inwardly facing protrusion, each of which is in a position opposed to the corresponding protrusion on the companion plate forming the nacelle and, after the respective switching mechanisms are installed, overlapping the side plates of each of the switching mechanisms, the arms of the central frame plate having been deflected to permit insertion of each switching mechanism, deflection in testing or use being prevented by inserting a high dielectric strength plastic stiffener in the groove separating the arms in the central frame p

Abstract: A multipole low-voltage circuit breaker with an insulating material housing and arc quenching chambers. By a new mechanical design, the installation of the arc quenching devices is to be facilitated. All arc quenching chambers of a switchgear are arranged in a quenching chamber housing which is subdivided by partitions and is fastened to the insulating material housing of a circuit breaker. The quenching baffles are fastened directly to the walls of the arc quenching chambers. A low-voltage circuit breaker with an insulating material housing of compact design is thus provided.

Abstract: Warping and twisting of the armature of a polyphase alternating current air break contactor is reduced by mounting the operating coil near the middle of the armature. A polyphase alternating current air break contactor has a frame, an armature having two ends, the ends being rotatably mounted within the frame so that the armature may rotate within the frame, at least three movable contacts and at least three stationary contacts forming a contact pair of each phase of the polyphase alternating current, and the contactor has an operating coil for the armature mounted in the frame substantially midway between the two ends of the armature.

Abstract: A two pole circuit breaker has a central opening to receive the single actuator provided for setting and resetting the two breaker mechanisms. These mechanisms are compactly housed in two chambers that are defined by half sections which are in turn provided inside an outer shell that defines the top opening. In one version the actuator is a pushbutton that is coupled to both breaker mechanisms. In other versions the actuator is in the form of a toggle or a rocker with coupling means to both breaker mechanisms. In a preferred embodiment the half sections that define the breaker mechanism chambers include a center section of I-shape that defines the adjacent chambers and also accommodates a lamp to light the rocker/actuator and/or a well to receive a light switch that can be wired to provide remote indication of switch condition.

Abstract: A circuit breaker has a metal frame (10) disposed on a base of a housing. A trip-bar (6) made of molded plastic of like material is rotatably held on the frame (10) by insertion of a trip-bar pin (15) into a center through-hole provided on the trip-bar, and pinchers (14,14) of the trip-bar (6) pinch the trip-bar pin by elasticity of the plastic material to hold the same in place with very little lateral play.

Abstract: A multi-phase circuit breaker characterized by a plurality of phase compartments separated by spaced barriers, a circuit breaker structure within compartment and having separable contacts, manually operable handle within one compartment and including a crossbar extending laterally through the compartments and barriers and each barrier having a removable portion that is retained in place by an overlying portion of a handle.

Abstract: A circuit breaker for high-speed current-limiting breaking of a three-phase current in the event of a short-circuit condition. The breaker has three pairs of fixed and movable contactors, the latter being arranged for pivoting movement on a common shaft. The center movable contactor is biased against an opposing holder, such that in the event of a short-circuit, the bias is overcome and the movable contactors separate in unison from the fixed contactors.

Abstract: By articulating the neutral-pole switching element in a multi-pole circuit breaker, providing spring biasing to urge the two elements into a pre-determined position approximating alignment, advancing the neutral pole switching element with respect to the other switching elements and providing fixed contact elements which frictionally engage opposite sides of the neutral-pole switching contact in the closed position, the closing of the neutral circuit precedes the closing of the live circuits and the opening of the neutral circuit lags the opening of the live circuits, thus preventing arcing and transient damage to loads on the circuit.

Abstract: A ganged, multiple pole circuit breaker in which the multiple poles of each circuit breaker are mechanically related to a single operating point on the associated breaker. Their single operating points are pivotally related to a first common pivot point, which is fixed in relation to a common frame which supports both circuit breakers. Their single operating pivot points are additionally pivotally related to a second common pivot point. A guide arrangement, fixed to the common frame, guides the second common pivot point in a predetermined rectilinear path when actuated by an operating mechanism which includes a shaft arranged to extend through a transformer tank wall to a master operating handle. The guide arrangement prevents any motion of the second common pivot point in a direction lateral to the rectilinear path.

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: An electric switch assembly is split into two mating units one of which contains the mechanical control component parts, the accessories and display means, the other unit containing the fixed contacts and the tripping means for the switch. Further seats can be provided to make arc-quenching chambers.