Eaton Corporation

Other

Cutler-hammer, Inc.

Donald A Link

Michael R Larsen

Peter J Theisen

Edward Louis Wellner

John A Swessel, Jr

Dean A Hubbard

David S Hunter

Walter M Zoller

Richard G Smith

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. The bus strap has an off-set section forming a first shoulder against which one wall of the housing of the interchangeable trip unit seats, and a second shoulder against which a pole piece backed by the heater transformer core seats to fix a gap between the pole piece and the armature in the interchangeable trip unit providing the instantaneous magnetic trip function.

Molded case circuit breaker with interchangeable trip unit having

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.

Molded case circuit breaker having movable contact finger releasably

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.

Circuit breaker with distribution lug terminal having trapped insulator

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.

Molded case circuit breaker having rectangular knee pin non-rotatably

Molded case circuit breaker having changing pivot locations for the

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 with arc vent extension angled downwardly, extended lug cover with second arc vent extension interlocked to terminal cover and arc chamber housing for no-fastener securement, trip unit armature pivoted in crested surface of molded pocket and connected to trip bar by wire bail for space-efficient location of parts, and accessory devices supported on and secured to trip unit housing have throw-away pin locking.

Molded case circuit breaker having trapezoidally shaped shaft

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 with arc vent extension angled downwardly, extended lug cover with second arc vent extension interlocked to terminal cover and arc chamber housing for no-fastener securement, trip unit armature pivoted in crested surface of molded pocket and connected to trip bar by wire bail for space-efficient location of parts, and accessory devices supported on and secured to trip unit housing have throw-away pin locking operator lever in correct position during installation.

Molded case circuit breaker having housing elements

Molded case circuit breaker

Case circuit breaker having improved attachment means for accessory

Molded case circuit breaker having improved trip unit

Rejection of a twin circuit breaker at panelboard mounting positions not designated to receive a twin breaker is achieved by extending the hook of the twin breaker outwardly beyond the panelboard rail to prevent anchoring the outboard end of the twin breaker at non-designated positions, thereby indicating obviously improper installation. The rail is provided with outward extensions at designated mounting positions which do engage with the twin breaker hook to anchor the outboard end, such extension in a preferred embodiment being part of an adapter attached to the panelboard.

Panel rejection feature for twin circuit breaker

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.

Twin unit circuit breaker with improved magnet structure

A flat plastic retainer having a loop at one end rotatably receiving a threaded fastener and a tongue and outboard fingers unidirectionally extending from the loop to engage an essentially upright leg of a terminal of a circuit breaker, has lateral projections on the tongue which are compressed when the tongue is inserted through an opening in the leg of the terminal and expand when the projections pass beyond the opposite side of the terminal to resist pull-out of the retainer from the terminal. The outboard fingers are deflected along the terminal to bias the fastener into engagement with an associated leg of the terminal having an opening through which one portion of a threaded fastener pair projects to engage the other portion.

Bolt-in circuit breaker with improved terminal fastener retainer

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).

Molded case circuit breaker with improved high fault current

An arc extinguishing structure for a circuit breaker (2) wherein an arc chute is provided with a pair of transverse barrier plates (38) spaced apart to provide a centrally located opening (40) and spaced away from an upstanding wall (4a) of the breaker housing (4) so as to direct ionized gases associated with an electric arc drawn between separating contacts (8,20) through the arc plates (36) and central opening (40) against the upstanding wall (4a) thereby to be redirected along the wall (4a) and exhausted to the atmosphere through unrestricted openings (6a,4b) provided at opposite upper and lower ends of the wall. The barriers (38) project into the areas of the passageways (6a,4b) to prevent direct access to the switch contacts (8,20) through the passageways and to increase the length of the exhaust path for the arc gases.

Growing community of inventors

Hubertus, WI, United States of America

Donald A Link