Circuit Breaker With Trip Indicator

Abstract

The circuit breaker includes a contact making and breaking assemblage mounted in a housing and having a trip mechanism with a trip lever carrying a indicator. The housing has an opening through which the handle of a manual operator extends. The handle has a dust shield which underlies the opening and which has a window with a lens therein. The lens is exposed for viewing from the exterior of the housing when the operator handle is in ON and TRIPPED positions, respectively. Upon tripping of the trip mechanism, the trip lever is moved so as to dispose the indicator close to, and in alignment with, the lens and window for indicating the tripped condition. The lens and operator are suitably notched for permitting passage of the indicator into and out of alignment with the window.

Description

This invention relates to a circuit breaker and trip indicator combination, and particularly to an improvement in the trip indicator and its interrelation with a moving part of the circuit breaker.

For purposes of illustration, the invention is shown as embodied in a circuit breaker such as disclosed in U.S. Letters Pat. No. 3,222,475, issued Dec. 7, 1965, and entitled Operating Mechanism for MultiPole Electrical Circuit Breaker.

A principal feature of the present invention is to provide in an exteriorly exposed part of a manual operator of the contact making and breaking assemblage a window which is exposed for viewing when the handle is out of the OFF position, and to provide a trip lever of the trip mechanism in such relation to the window that an indicating means on the lever is exposed for viewing through the exposed window in the tripped position of the breaker while the manual operator is in the TRIPPED position.

More specific objects are to provide the window for the indicator in the dust shield of the external operating handle, and to provide suitable clearance slots in the lens and operator for passage of the indicator as the trip lever is moved to released position so that a more compact circuit breaker and trip indicator structure results.

Other specific objects of the invention will become apparent from the following description wherein reference is made to the drawings, in which:

FIG. 1 is a top plan view of a circuit breaker and indicator embodying the principles of the present invention, part of the circuit breaker housing being broken away for clearness illustration.

FIG. 2 is a fragmentary vertical sectional view taken on the line 2-2 of FIG. 1, showing the circuit breaker latched in the contact making position by the trip mechanism and the manual operator in ON position;

FIG. 3 is a view similar to FIG. 2 showing the relative position of the parts of the circuit breaker, trip mechanism, operator and indicator in the tripped condition with the circuit breaker in contact breaking position;

FIG. 4 is a top plan view of the trip lever of the circuit breaker;

5 IS A FRONT ELEVATION OF THE TRIP LEVER ILLUSTRATED IN FIG. 4;

FIG. 6 is a top plan view of the supporting yoke of the manual operator, showing the notching thereof for affording proper relative movement between the operator and the trip indicator.

FIG. 7 is a cross-sectional view of the yoke, taken on the line 7-7 in FIG. 6;

FIG. 8 is a right end elevation of the yoke illustrated in FIGS. 6 and 7;

FIG. 9 is a top plan view of the lens of the indicator;

FIG. 10 is a front elevation of the lens illustrated in FIG. 9; and

FIG. 11 is a right side elevation of the lens illustrated in FIGS. 9 and 10, showing the notching thereof.

The specific circuit breaker shown and described herein for purposes of illustration and the manner of operation thereof are fully disclosed in the above-identified patent. Accordingly, the circuit breaker structure itself is described herein only briefly, inasmuch as its specific details form no part of the present invention which resides in the combination of a circuit breaker and its trip mechanism with a trip indicator.

Referring first to FIGs. 1 and 2, the breaker comprises a housing, indicated generally at 1, in which is mounted a circuit breaker mechanism. This circuit breaker mechanism comprises generally suitable brackets 3 to which various operating levers and linkages are pivotally connected. The circuit breaker has stationary contacts 4, and movable contacts 5 which are carried by a contact blade 6 pivotally mounted by a pivot 7 in the brackets 3. Connected to the blade 6 is a crossbar carrier 8 which is rockable with the blade 6 about the axis of the pivot 7.

A lower link 9 is pivotally connected at one end by a pivot 10 to the carrier 8 and blade 6 and is pivotally connected at the other end by a pivot 11 to the lower end of an upper link 12. The upper link 12 is pivotally connected by a pivot 13 to a trip lever 14.

A manual operator is provided and comprises a yoke 16 having dependent parallel arms 16a connected by a base portion 16b . The arms 16a have at their lower ends connecting portions 16c , respectively, which are received in suitable notches in the brackets 3 and are rockable therein about a fixed axis parallel to the axis of the pivots 7, 10, and 11, and thereby support the yoke 16 for rocking about the fixed axis.

Suitable springs 17 are connected at their upper ends to the base portion 16b of the yoke and at their lower ends to the pivot 11. The springs 17 urge the yoke 16 downwardly so that its lower end portions 16c are held in the notches in the brackets 3.

The trip lever 14 is connected to the brackets 3 by a pivot 20, parallel to the pivots heretofore described.

Mounted on the base 16b of the yoke is a manual operator handle 21 having a dust shield 22. The upper face of the shield 22 preferably is upwardly convex and arcuate about the rocking axis of the yoke arms 16a .

The yoke 16 is so arranged that when the handle 21 is moved to the right from the ON position, shown in FIG. 2, to the OFF position in which the handle is in its extreme right hand position, the line of action of the springs 17 is shifted to the right across the axis of the pivot 13, and the springs thereby rotate the pivot 11 counterclockwise about the axis of the pivot 13. This breaks and shifts the links 9 and 12 and causes pivot 10, blade 6 and carrier 8 to rock clockwise about the axis of the pivot 7 to OFF or contact breaking position.

When from its OFF position, the handle 21 is moved to the left to the ON position shown in FIG. 2, the line of action of the springs 17 is shifted to the left across the axis of the pivot 13 and the springs 17, thereupon, rotate the pivot 11 clockwise about the axis of the pivot 13 thereby extending the links 9 and 12 and rocking the pivot 10, the blade 6 and carrier 8 counterclockwise about the pivot 7 to the ON position. Thus the contacts can be opened and closed manually by operation of the handle 21.

As illustrated in FIG. 3, the handle 21 is moved by the yoke 16 and springs to a third, or TRIPPED position, intermediate the ON and OFF positions, when the latch mechanism releases.

A pin 23 is carried on the arms 16a which engages a latch shoulder 24 on the trip lever 14 at all times except when the handle 21 is in the ON position.

As the yoke 16 and handle 21 are rocked toward OFF position from the TRIPPED position illustrated in FIG. 3, the lever 14 is rocked clockwise about the pivot 20 by the pin 23 and extends the links, and is moved from the tripped position illustrated in FIG. 3 to the latching position illustrated in FIG. 2 wherein the links 9 and 12 are extended. When the lever 14 is moved to the latching position, and before the handle 21 is moved to ON position, the outer end 25 of the lever 14 is locked in position by a latch member 26 which is biased to rotate clockwise about a pivot 27 by a spring 28. At its upper end the member 26 has a latching shoulder 29 which engages the outer end of the trip lever 14 when the handle 21 is moved to the right for resetting, so as to retain the trip lever in fixed position, thereby latching the contact making and breaking assembly in contact making position when the handle 21 is in the ON position.

However, during this same movement, the lower end of the latch 26 is engaged by a latch 30 which, while in operating position, holds the latch 26 in latching engagement with the latch lever 14. During the resetting of the tripped mechanism, the trip lever 14, being locked against rocking counterclockwise by the pin 23, bears down on the upper end of the latch 26, swinging it counterclockwise against the bias of the spring 27 into a position where it can be engaged and latched by the latch 30. The latch 30 is supported by a pivot 30a for rocking into and out of latching position with respect to the latch 26. The latch 30 is connected to a trip bar 31 which is biased in a clockwise direction about the pivot 30a by a spring 32.

During the latching operation, since the free end 25 of the trip lever 14 engages beneath the latch yoke portion 26a of the latch 26, the lever 14 is held thereby in the position illustrated in FIG. 2 while permitting the contacts to be opened and closed by swinging the handle 21 to ON and OFF positions.

An armature 34 is mounted in the housing 1 and is rocked by a core 35 in case of excessive overloads, in a counterclockwise direction about a pivotal axis 36. The armature 34 is biased clockwise by a spring 37 and carries an adjustable screw 38, as shown in FIG. 1, which, when the armature is swung counterclockwise, engages and moves the trip bar 31 so as to release the latch 29 and thereby the latch 26. Thereupon the springs 17 break the linkage of links 9 and 12, as illustrated in FIG. 3, thus opening the contacts 4 and 5 while the operating handle 21 is in the ON position. Upon this happening, the handle 21 and arms 16a swing slightly clockwise, and the trip lever 14 is released and swung counterclockwise by the action of the links 9 and 12 and springs 17 so that its outer end 25 is moved toward the handle 21 to the position illustrated in FIG. 3.

The trip lever 14 may be released also in the event of a long sustained overload, and for this purpose, as illustrated in FIGS. 1 and 2, a bimetal release element 39 is provided and carries an adjustable abutment 40. The bimetal is so arranged that when it is heated by long sustained overload currents, it moves to the left in FIGS. 1 and 2 and engages the bar 31 and releases the latch 29 which, in turn, releases the latch 26 which thereupon releases the trip lever 14.

Thus, due to heating by sustained overload, or when there is a sudden surge of current, the latch member 30 is released. The latching member 26 then pivots under the influence of its biasing spring 28 and releases the lever 14. Upon release, the trip lever 14 pivots counterclockwise about the axis of the pivot 20 under the influence of the spring 17 acting through the pivot 11, links 9 and 12, and pivot 13 to the position illustrated in FIG. 3. The pivot 13 is thereby carried across the line of action of the springs 17 from a position to the right thereof illustrated in FIG. 2 to a position to the left thereof, illustrated in FIG. 3 so that the springs 17 operate to swing the pivot 11 counterclockwise about the axis of the pivot 13 thereby breaking the links 9 and 12 and swinging the pivot 10, blade 6, and carrier 8 clockwise about the pivot 7 to tripped contact breaking position, as illustrated in FIG. 3. Rotation of the pivot 11 counterclockwise about the axis of the pivot 7 shifts the line of action of the springs 17 across the pivotal axis of the arms 16a whereupon the springs 17 pivot the handle 21 to the tripped position slightly to the right of its extreme left position as illustrated in FIG. 3.

The structure thus far described and more fully described in the above patent of itself forms no part of the present invention.

As mentioned, it is desirable to indicate when the trip assemblage is in the tripped condition illustrated in FIG. 3, and for this purpose the trip lever 14 is made as shown in FIGS. 4 and 5. As there illustrated, it comprises a metal plate having near its free end portion 25 a projection 42 which on its upper face, as indicated at 43, is coated with suitable indicating indicia, such as fluorescent red paint or letters, or the like.

The dust shield 22 of the operating handle 21 has, as mentioned, an outer face which is arcuate about the rotational axis of the yoke 16 and which travels closely alongside the innerface of the housing 1 when the handle is operated. The housing top wall 2, at this location, is provided with a slot 44 through which the operating handle 21 extends to the outside. The inner face of the housing adjacent the slot passage 44 is shaped so that the shield lies closely adjacent thereto in all rocked positions of the handle 21. The shield 22 has a window 45 in which is mounted the upper end of a lens 46. The lens 46 as best illustrated in FIGS. 9 through 11, comprise a body portion 47 receivable in the window 45 and an inwardly extending bifurcated portion 48 providing a slot 49 into and out of which the flag projection 42 of the rock lever 14 can pass as the lever moves from tripped to untripped positions relative to the handle and shield. Furthermore, the base portion 16b of the yoke is provided with a slot 50 through which the indicating flat or projection 42 can pass during rocking of the lever 14 relative to the handle 21.

The window 45 is positioned so that it is concealed in the OFF position of the handle by the top wall 22 of the housing 1, but is exposed through the opening 44 in the top wall 2 when the handle 21 is in the ON position and when it is in the TRIPPED position.

Thus, when the handle 21 is in the ON position and the contact making and breaking assemblage is untripped, nothing is visible through the window 45 and lens 46 due to the dark interior of the housing. When the circuit breaker is tripped, the handle 21 is moved to tripped position of FIG. 3 and the lever 14 is moved so that the upper face 43 of the flag or projection 42 passes through the slots 49 and 50 to a position wherein it is exposed directly beneath and close to the lens and, therefore, is readily visible through the window 45 and lens 46 for indicating the tripped condition while the handle is in TRIPPED position.

Claims

Having thus described my invention, I claim:

1. In a circuit breaker and trip indicator combination:

a housing;

a contact making and breaking assembly in the housing which is settable in contact making position and which includes a trip mechanism settable for holding the assemblage in contact making position and for manual operation to ON and OFF positions;

means to return the assemblage to contact breaking position when the trip mechanism is released;

current responsive means operative under normal current conditions to latch the trip mechanism in its set position and operative under abnormal current conditions to release the trip mechanism, and thereby the assemblage for return of the assemblage to contact breaking position;

an operator having a manually operable handle and connected to the assemblage for setting the assemblage and the trip mechanism;

said operator being movable by the handle to and from an OFF position, selectively, for operating the assemblage to make and break contact, respectively, while the trip mechanism remains in its set position;

said housing having a passage through which the handle extends to the outside of the housing; and

indicating means within the housing and operated by the trip mechanism when the trip mechanism is released and the assemblage is returned to contact breaking position to move to an indicating position;

characterized in that the operator has a window therein, and movable therewith, and exposed to view through said passage when the operator is out of its OFF position; and

the indicating means includes an element pivotally mounted in the housing for rocking about an axis fixed in position relative to the housing, said element is rocked to an indicating position when the trip mechanism is released, and out of indicating position by setting of the trip mechanism;

an indicator is connected to said element so as to be moved thereby into alignment with the window in the operator when the element is rocked about its axis to its indicating position, and so as to be offset from the window when the trip mechanism is in its set position.

2. The structure according to claim 1 wherein the operator is arranged so that the window is unexposed when the operator is in OFF position.

3. The structure according to claim 1 wherein said element is the trip lever of the trip mechanism and the indicator is carried by the lever.

4. The structure according to claim 3 wherein a first pivot pivotally supports the operator for swinging about a fixed axis;

a second pivot supports the lever for swinging about said fixed axis and said fixed axis is parallel to, and offset from, said first axis; and

the indicator is an outwardly extending projection on the lever and faces toward the operator and is moved into alignment with the window by the trip lever.

5. The structure according to claim 4 wherein the operator includes a yoke having a base and supporting arms extending from the base and connected to said first pivot;

the manually operable handle is connected to the base of the yoke;

a leans is mounted in said window and has a portion extending into the housing; and

said yoke and lens portion have aligned slots therein in which said projection passes when the indicating means moves to indicating position.

6. In a circuit breaker and trip indicator combination:

a housing;

a contact making and breaking assembly in the housing which is settable in contact making position and which includes a trip mechanism settable for holding the assemblage in contact making position and for manual operation to ON and OFF positions;

means to return the assemblage to contact breaking position when the trip mechanism is released;

current responsive means operative under normal current conditions to latch the trip mechanism in its set position and operative under abnormal current conditions to release the trip mechanism, and thereby the assemblage, for return of the assemblage to contact breaking position;

an operator having a manually operable handle and connected to the assemblage for setting the assemblage and the trip mechanism;

said operator being movable by the handle to ON and OFF position, selectively, for operating the assemblage to make and break contact, respectively, while the trip mechanism remains in its set position;

said housing having a passage through which the handle extends to the outside of the housing; and

indicating means within the housing operative when the trip mechanism is released and the assemblage is returned to contact breaking position to move to an indicating position;

characterized in that the circuit breaker has a window;

the indicating means includes an indicator which is mounted in fixed position on one of the movable operating parts of the trip mechanism.

7. The structure according to claim 6 wherein said one part is the trip lever of the trip mechanism.

8. The structure according to claim 1 wherein the assemblage and operator move the handle to a TRIPPED position when the trip mechanism is released; and said window is exposed to view through said passage when the handle is in said TRIPPED position.