Abstract: A combined bell alarm and lock-out accessory is connected with the electronic trip unit that controls a high ampere rated circuit breaker. The accessory interacts with the circuit breaker operating mechanism to activate the bell alarm upon circuit interruption and to prevent the closing of the circuit breaker contacts until the accessory is manually reset.

Abstract: This invention relates to a high ampere-rated circuit breaker which meets the electrical code requirements of the world market. The powerful operating springs controlling the circuit breaker contacts are restrained by the interaction of a cradle operator and a two stage latching assembly. The latching assembly includes a primary and a secondary latch to insure against nuisance tripping.

Abstract: A split case magnetic circuit breaker has a bracket secured to the front of the breaker housing similar to that used to provide a rocker for operating the breaker manually and for resetting the breaker when tripped. The bracket is formed with a small access window so that the rocker can be reset, but cannot be manually switched off.

Abstract: A molded plastic current limiting circuit breaker includes an interrupter assembly that includes an over-molded magnet, arc stack, baffle stack, and a chamber liner in which a trip unit is described.

Abstract: A circuit breaker-includes: a casing having a base and a main cover secured to the base, the casing accommodating a circuit breaking mechanism; a recesses formed in one surface of the main cover, the opposite surface of which is on the side of the base, the recess being adapted to receive an auxiliary device of the circuit breaking mechanism; and an auxiliary cover mounted on the main cover in such a manner as to close the recess. The circuit breaker is automatically tripped when the auxiliary cover is opened, thus permitting installation of the auxiliary device thereon with high security.

Abstract: An operating mechanism of a multipole circuit breaker comprises a toggle associated with an automatic tripping hook and an operating handle cooperating with a pivoting locking lever arranged to block the handle in an intermediate position in case of welding of the contacts. When normal opening of the contacts takes place, the locking lever comprises a radiating bearing surface cooperating with a protuberance of the bar to keep holding the locking lever in the first active position of the stop, during a first part of the opening travel of the movable contact of each pole, and a notch for receiving said protuberance causing unblocking of the locking lever to release the base close to the end of opening travel of the movable contact.

Abstract: A molded plastic current limiting circuit breaker includes an interrupter assembly that includes an over-molded magnet, arc stack, baffle stack, and a chamber liner in which a trip unit is described.

Abstract: The present invention provides a mechanism for controlling the incremental release and subsequent resetting of a charging mechanism to slowly close an electrical contact operating mechanism of a circuit breaker. The slow close mechanism includes a frame defined by a pair of spaced, generally parallel sideplates connected together and terminating with support legs. The support legs have guide slots to receive a shaft of the charging mechanism. A support block rotatably connects between the sideplates and supports the shaft along the length of the guide slots as the support block rotates. An elongated arm slidingly couples to one of the support legs and has a flange at one end for manual operation. The opposite arm end rotatably couples to a crank arm extending through the one support leg to connect with the support block so that pulling the flange slides the arm and rotates the crank arm and the support block to control the travel of the shaft of the charging mechanism down the guide slots.

Abstract: An electrical switching device such as a low voltage power circuit breaker, can have a cover with a slot-like opening for providing access to a switch lever of the switching device. The cover can extend to cover over any chambers for shunt releases and/or auxiliary switches etc. which chambers can be located on both sides of the switch lever within the enclosure. The cover can also have fastening devices for attachment of a mechanical rotary actuator or a motor drive. The cover is connected to the enclosure in a manner which provides for a simple opening and closing of the cover, and essentially eliminates the danger of losing and mixing up such covers. The cover is designed with bearing legs which are bent at an angle of 90 degrees in relation to the cover plane. The bearing legs are preferably parallel to one another and laterally overlap the enclosure. The cover is mounted to the enclosure by means of the bearing legs and pivot bearing with coaxially interlocking pivots and pivot bearing openings.

Abstract: The present invention relates to a fusible switch for use in a multiphase circuit. The switch includes an operating mechanism which is secured to the enclosure of the switch and provides for a handle to operate the opening and closing of switch contacts. Movement of the handle stores energy in the operating mechanism which is subsequently released in a quick motion just as the switch contact is to be opened or closed. The switch also provides for heat sinks and means for venting the enclosure to dissipate the heat created from the higher voltage and greater current density carried by this improved switch.

Abstract: A molded case circuit breaker having an operating mechanism including a collapsible toggle linkage, an operating handle and a movable frame. The collapsible toggle linkage includes a rectangular cross section knee pin non-rotatably held within an open rectangular slot in an upper link of the linkage. The operating handle pivots about a first pivot point when moving between ON, OFF and TRIPPED positions. The operating handle pivots about a second pivot point when moving to a RESET position thereby reducing the lateral force component of the operating springs of the operating mechanism for reliable return of the handle to the OFF position. Also, bifurcated movable contact fingers are provided for pivotal movement about a fixed pin to break contact welds and a trapezoidal cross section shaft interconnects the movable contact fingers.

Abstract: A molded case circuit breaker having an operating mechanism including a collapsible toggle linkage, an operating handle and a movable frame. The collapsible toggle linkage includes a rectangular cross section knee pin non-rotatably held within an open rectangular slot in an upper link of the linkage. The operating handle pivots about a first pivot point when moving between ON, OFF and TRIPPED positions. The operating handle pivots about a second pivot point when moving to a RESET position thereby reducing the lateral force component of the operating springs of the operating mechanism for reliable return of the handle to the OFF position. Also, bifurcated movable contact fingers are provided for pivotal movement about a fixed pin to break contact welds and a trapezoidal cross section shaft interconnects the movable contact fingers.

Abstract: A molded case circuit breaker includes an interlock which prevents the operating handle from being moved from the on position after the main contacts have been welded together. By preventing the operating handle from being moved from the on position during such a condition, the operating handle will indicate the correct status of the main contacts and the operator will be made aware that the main contacts are welded together.

Abstract: A compact molded case circuit breaker operating mechanism crossbar assembly allows a unitary crossbar design to be used within a wide range of circuit breaker ampere ratings. A common phenolic crossbar and a metal staple are used for the higher ratings. An L-shaped filler in combination with the crossbar and staple are used to adapt the crossbar to the staple for the lower ratings.

Abstract: An improved miniature circuit breaker is provided which is adapted to improved automatic assembly of all components thereof. Key components of the breaker are individually and collectively designed to be susceptible to total Z-axis assembly. In particular, the circuit breaker operating mechanism which operates the contacts thereof to make or break the electric circuit is formed of elements designed to interact in a Z-axis assemblable fashion. The movable contact is defined on a contact carrier or blade assembly which is adapted for Z-axis assembly and also provides increased arc erosion resistance and improved opening of the breaker contacts.

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 molded case circuit breaker of the type containing an electronic trip unit to control an operating mechanism for automatically turning the circuit breaker contacts between ON and OFF conditions under overload conditions and a handle operator for same under quiescent conditions is designed for operation with a motor operator unit. The operating mechanism unit is structured to resist the high impact forces translated to the mechanism by the motor operator unit.

Abstract: A positive off mechanism for a circuit breaker includes a pair of positive off levers slideable in slots in the side plates and extendable into the path of the operating handle to prevent movement of the handle to the off position when the contacts are welded closed. The positive off levers are actuated by positive off links pivotally mounted to the side plates and coupled to the positive off levers by "dog bone" connections. The positive off links in turn are actuated by the toggle mechanism of the circuit breaker which collapses to open the contacts during normal circuit breaker operation, but which remains erect when the contacts are welded closed.

Abstract: A circuit breaker is disclosed having a toggle mechanism in which a desired overlap between the cam link and the sear pin is conveniently, and automatically, achieved. The toggle mechanism also exhibits a relatively small eccentricity, resulting in a circuit breaker which is significantly more sensitive to overcurrents than previous such circuit breakers.

Abstract: A pair of lock links straddling and pivoted on the same pin as the latchable cradle of a circuit breaker follow the toggle device of the breaker either by riding on the toggle knee pin or through a pin which bears against the edges of the toggle arms. The lock links have extensions which engage the handle yoke to prevent the handle from being moved to the off position when the circuit breaker contacts are welded closed causing the toggle device to remain erected.

Abstract: A circuit breaker device, convertible from break-after-make operation to break-during-make operation for response to break commands received during circuit breaker setting operation is provided having a driving lever rotated by the energy of an energizing spring released by an energization suppressing mechanism. A closing shaft is further provided for closing and opening a movable contact via a coupling device coupled to the driving lever. The coupling device being effective for transmitting energy from the driving lever to the closing shaft to close the moveable contact and to dampen the energy applied from the driving lever to the closing shaft when a trip-free command is asserted by a trip lever in order to keep the movable contact in an open position.

Abstract: A molded plastic current limiting circuit breaker includes an interrupter assembly that includes an over-molded magnet, arc stack, baffle stack, and a chamber liner in which a trip unit is described.

Abstract: A molded case circuit breaker includes an interlock which prevents the operating handle from being placed in the off position after the main contacts have been welded together. By preventing the operating handle from being placed in an off position during such a condition, the operating handle will indicate the correct status of the main contacts and the operator will be made aware that the main contacts are welded together.

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 circuit interrupter manually opens and closes its contacts by use of a manually rotatable handle which acts through a collapsible linkage rotatably connected to a crank extension of the handle and rotatably connected to a rotatably movable contact support. The rotatable contact support is urged away from closed contact position by a main spring and in moving from one contact position to the other the axis of the rotatable connection between the handle crank passes over a center line defined by the center of rotation of the handle and the rotatable connection between the linkage and the movable contact support providing a toggle action to hold the movable contact in selected open or closed position. Upon overload, the mechanism causes collapse of the collapsible linkage allowing the movable contact support to move and open the contacts.

Abstract: A molded case circuit breaker having current limiting capabilities is dimensionally optimized for relatively smaller frame size circuit breakers. The handle yoke is supported with rollers thereby allowing the crossbar to be disposed in the space normally utilized for the handle yoke pivot axis. A clinch joint arcer assembly with a plurality of arcing contact arms, each pivotally connected by a clinch joint to a pivotally mounted main contact arm permits additional main contact arms to be provided in the same space normally occupied by the arcing contact arms alone. Additionally, arcing contact spring housings protect the arcing contact springs from deterioration due to corrosive ionizing gases generated during interruption. A positive off link assembly prevents the operating handle from being placed on an OFF position when the main contacts are welded together and transfers the force applied to the operating handle to the upper link to allow the weld to be broken.

Abstract: A circuit breaker having a contact movable between open and closed positions, includes a closing spring assembly having a closing spring and first and second brackets. The closing spring assembly is chargeable when in a reset position in which the first bracket is hooked by a first hook. The closing spring is charged, manually or electrically, with support of the second bracket being transferred to a second hook. The closing spring is discharged to close the circuit breaker, with the closing spring assembly moving from the reset position to a discharged position in the process. The closing spring assembly is then moved as an integral unit, back to the reset position, with the closing spring again being charged, enabling the circuit breaker to immediately reclose in the event of a trip due to a transient condition. An improved breaker operating mechanism and power operated charging mechanism, are also disclosed.

Abstract: A screw retainer is fabricated from a thin sheet of spring steel and is comprised of three sections: a screw support section, a leg support section and a leg section. The screw support section contains a through-hole for receiving a support screw. The leg support section is bounded by the screw-support section and the leg section. The leg section is angulated with respect to the leg support section and has a degree of spring action that allows it to be compressed so as to allow it and the leg support section to be inserted between the respective lower portions of integrally-formed upstanding support arms of a support base. Once the screw retainer is completely inserted between the respective lower portions of the integrally-formed upstanding support arms, the leg section springs back to its normal position thereby preventing the screw retainer from becoming dislodged from its position.

Abstract: A pair of lock links straddling and pivoted on the same pin as the latchable cradle of a circuit breaker follow the toggle device of the breaker either by riding on the toggle knee pin or through a pin which bears against the edges of the toggle arms. The lock links have extensions which engage the handle yoke to prevent the handle from being moved to the off position when the circuit breaker contacts are welded closed causing the toggle device to remain erected.

Abstract: Apparatus is provided for an electrical circuit breaker for preventing the handle thereof from being moved to the OFF position when the electrical contacts of the circuit breaker are welded closed. This apparatus mechanically limits the travel of the operating handle so that it may not be moved to the OFF position when the electrical contacts are closed. This restrictor apparatus as it is called is mechanically connected to, but out of direct contact with the handle arm of the circuit breaker. The mechanical linkage between the operating handle and the contact arm of the circuit breaker includes a projection. During the foregoing condition, the projection will interact with a crossbar assembly for the contact arm of the circuit breaker.

Abstract: The handle of a circuit breaker is blocked from movement to the off positiion, when the contacts are welded closed, thereby preventing rotation of the common cross-bar on which contact arms carrying the movable contacts are mounted, by an interlock which includes radial extensions on the arms of a pivoted handle yoke which radially engage projections on the cross-bar.

Abstract: A circuit breaker includes an interlock which prevents movement of the handle to the off position when the contacts are welded closed. The interlock includes a pair of floating links which jam between slots in arms of the yoke of a spring powered operating mechanism which carries the handle, and recesses in the rotatable cross-bar carrying the movable contact arms. The recesses are offset from the rotational axis of cross-bar so that an attempt to move the switch to the off position generates a moment which will break open lightly welded contacts.

Abstract: A molded case circuit breaker includes an interlock which prevents the operating handle from being placed in the off position after the main contacts have been welded together. By preventing the operating handle from being placed in an off position during such a condition, the operating handle will indicate the correct status of the main contacts and the operator will be made aware that the main contacts are welded together.

Abstract: A two-link, trip-free operating mechanism assembly for a switch includes a first pivotally-mounted link comprising a switch lever arm. One end of the switch lever arm is coupled to the switch and a second end of the switch lever arm has a roller mounted thereto. A second link assembly includes a pivotable support member to which a cam member is mounted for rotation. The pivotable support member is selectively fixed during the closing of the contacts, or movable between a contact-closed position and an overriding open position. The cam member controls the state of the switch. In the tripped condition, the cam member and the roller are disengaged and the switch assumes a tripped, or open, state. A first spring arrangement applies a force to the link arrangement to cause the links to close from an open position. For trip-free operation, a second set of springs forces the switch arm link to immediately move to a switch-open position.

Abstract: A circuit breaker including a contact operating mechanism configured to prevent the switch handle of the circuit breaker from being placed in an OFF position when the contacts are not separable. In addition to the switch handle, the mechanism is operable with a tripping circuit which actuates the mechanism to urge the contacts apart when the current flowing through the circuit breaker exceeds the preset limits of the circuit breaker. When the contacts are not separable and the tripping circuit actuates the mechanism, the operating handle is restricted from being placed in the OFF position, thereby avoiding the possibility of indicating an incorrect position of the contacts.

Abstract: A molded case circuit breaker having a pair of movable contact arms arranged within each pole of a multi-pole arrangement utilizes a shunt clip between the movable contact arms to insure electrical continuity between the contact arms and the contact arm support base. The movable contact arms and the support base are both accurately positioned within the circuit breaker case by means of an interference-fit between the outside edges of the support base and the interior sidewall surfaces of the circuit breaker case.

Abstract: In a circuit breaker switching mechanism in which when a latch is released by setting a handle lever at the "on" position, a toggle link unit made up of upper and lower links with a center pin therebetween is elastically reversed thereby to trip the circuit breaker, an interfering stopper is held in contact with the periphery of the upper link to limit the operation of the latter thereby to cause the center pin to move straightly when tripped, whereby the period of time required for opening the circuit breaker is minimized.

Abstract: A circuit protector employs molded resinous parts including a base and a support frame structure. Advantageously the circuit protector support frame structure may include a medial plane frame providing space for two circuit protectors, one on each side of the frame and a common back plane mutually perpendicular to the medial frame and the base along one edge of the base. A cover fits over the support frame and base and snugly accommodates the base at its terminal edges except immediately along the back plane. The back plane is provided with a slot through the back plane in the vicinity of each pair of contacts which communicates to a space between the cover and the back plane of the base permitting venting of gases generated by arcing. Grooves are supplied in the medial plane frame and the back plane to accommodate edge flanges of an arc suppressing grid to hold the grid in place to bracket the contacts.

Abstract: A switching mechanism in a circuit breaker having a latch being locked from moving when the circuit breaker is in a normal "on" state, a toggle link having a striking part being coupled to the latch and elastically urged with an elastic force by a switching spring at times when the circuit breaker is in the normal state and released from said urge at times when the circuit breaker is tripped or changed from the normal state to a tripped "off" state, and a stopper disposed adjacent the striking part of the toggle link in that when the circuit breaker is tripped, the latch is released to cause the striking part of the toggle link strike the stopper intermediate in the tripping action so that the time required for completing the tripping of the circuit is reduced.

Abstract: A mechanism for accumulating and storing mechanical energy, wherein the energy is used to close the primary contacts of a circuit breaker. The energy can be input to the mechanism manually or by means of a motor. The mechanism includes a series of linkages which function to utilize the energy to close the primary contacts. These linkages also function to maintain the closing force upon the primary contacts, while also functioning to allow rapid contact opening when desired.

Abstract: An accessory module (104) for use with a circuit breaker (10) is configured for mounting to the breaker, and has a rotor (142) which follows the movement of the circuit breaker blade (24) in the breaker by means of a coupling member (118) passing through a passage (110) in the circuit breaker wall. A portion of the rotor is configured as a cam (162) operating a switch (152) in the module, the switch thus giving a reliable indication of the position of the breaker blade. The breaker is preferably of the type which has a trip lever (50) carried on the breaker blade and mounted for slight movement thereon, and the rotor is preferably coupled to the trip lever. A solenoid (148) within the accessory module is disposed to rotate the rotor when energized, this rotation being coupled to trip the breaker to provide for remote tripping. Since the trip lever is carried with the breaker blade, the blade position is monitored by the switch.

Abstract: A molded case circuit breaker movable contact arm electrically connects with the circuit breaker load terminal requiring only a small diameter auxiliary electrical conducting braid by pivotally arranging the contact arm within its support. The contact arm is nickel-plated prior to attachment of the contact to insure high current circuit interruption withtout damage to the contact or the contact arm.

Abstract: An assembly frame having first and second frame plates secures the movable parts of a breaker assembly together for ready assembly of the breaker assembly in a housing. A pivot pin supports the trip lever between the frame plates. The movable contact carrying blade has an elongated hole through which the pivot pin passes, the elongated hole forming a floating point for the pivot pin.

Abstract: Apparatus which is mechanically connected to and out of direct contact of the handle arm of an electrical circuit breaker to prevent the operating lever of the circuit breaker from being moved to the off position when the contacts of the circuit breaker are closed, due to a weldment of the contacts or obstruction of the contact arm carriers. In particular, a two part toggle mechanism is provided for opening and closing contacts in conjuction with the movement of the operating lever. The lower toggle link has a protrusion thereon which abuts against the rotatable crossbar mechanism which carries the contact arm of the moveable contacts if the contacts have not separated as the operating lever is moved from the closed to open position. The abutments, however, will rotate free of the crossbar if the contact arm moves in conjunction with the movement of the crossbar as the lever is moved from the open to closed position.

Abstract: An operation mechanism of a circuit breaker which allows either automatic or manual operation of the circuit breaker. The mechanism includes a moving contact lever, a hook lever, a handle, a pair of toggle links connecting the hook lever and the moving contact lever, an operation lever linked to the handle, and a spring connected between the operation lever and a joint of the toggle links. The operation mechanism may also include opening and closing delay latches which preclude movement of the toggle links until the handle has been fully turned to either one of two positions.

Abstract: A switchgear operating mechanism is disclosed which includes two helical springs which are stretched to store energy to close and then open circuit breaker contacts. A mechanism is provided for stretching the springs in response to reciprocating movement of a hook stick. A single operating handle is provided with a spring biased detent arrangement such that the handle may be moved from a predetermined reset position to a closed position to close the circuit breaker contacts using energy from the charged springs. The handle is returned to the reset position by the spring biased detent arrangement and may be moved from that position to an open position to open the circuit breaker contacts using energy from the charged springs. The handle is preferably operable by a shot gun type hook stick.

Abstract: A drive lever of an auxiliary handle operator is pivotally mounted alongside a molded case circuit breaker to move in a plane parallel with a plane of movement of a constituent handle of the circuit breaker. A superstructure attached to the top of the circuit breaker carries a slide disposed over the constituent handle for linear reciprocal movement. The slide has a projection which is disposed in a hollow shaft of a roller bearing structure carried by the drive lever for limited translation perpendicular to slide movement with a limited amount of free play between the corresponding parts.

Abstract: A circuit breaker has a stationary contact arm (2) having a stationary contact (3), a first contact arm (107) having a contact (6) for contacting the stationary contact (3) and an extended terminal portion (107) for connecting a flexible wire (8) and a second contact arm (110) for pivoting the first contact arm, and a third contact arm (110a) that pivots about a common axis of the second contact arm and is provided with a flattened U-shaped aperture (114) thereon, and which is connected with an oblong aperture of the second contact arm by a connecting member (16).

Abstract: A circuit breaker having positive contact indication. Upon the circuit breaker tripping, the operating mechanism components unlatch, moving the cradle, upper link and lower link upwards and opening the contacts. Upon the circuit breaker being manually opened, no operating mechanism components move except the upper link and lower link which causes the contacts to open. Upon the occurrence of locked contacts and the operating mechanism receiving a trip signal, the operating mechanism components unlatch but move only slightly since the contacts cannot open. A shuttle, pivotally mounted on the cradle, moves upward slightly to catch its tail on a flipper spring. The shuttle rotates slightly to meet a tab positioned on the handle arm and to block and opening movement of the operating handle.

Abstract: An electric switch with a set of stationary contacts and a set of movable contacts situated on a contact bridge (30) between an IN-position and an OUT-position includes a forcibly guiding mechanism (32) for manual handling of the contact bridge (30) and an ejector mechanism (56) and a trip device (74) co-operating with the ejector mechanism, whereby the contact bridge (30) is automatically longitudinally displaced from its IN-position to its OUT-position when an overloading, a fault or a signal current is present. The forcibly guiding mechanism (32) and the contact bridge (30) are interconnected by means of a releasably blocking device in such a manner that the ejector mechanism (56) in the releasing state need only overcome frictional forces between the stationary and the movable contacts as the blocking device is released by means of the trip device (74).