US2362257A - Circuit breaker - Google Patents

Description

Nov. 7, 1944. I FAVRE 2,362,257

CIRCUIT BREAKER Filed Nov. 4, i942 Invnb or: John A.F'avr=eq ls Aotorne g.

Patented Nov. 7, 1944 cmoorr nan/men John A. Fayre, Drexel Hill, Pm, assignor to General Electric Company, a corporation or New York- Appllcatlon November 4, 1942, Serial No. 464,466

14 Claims.

My invention relates to circuit breakers, more particularly to manually operated thermal cur rent responsive circuit breakers, and has for its object a reliable and efilcient operating mechanism which is not aiiected by shocks.

In carrying out my invention in one form, I provide a toggle for operating the switch arm, one link of which is normally secured to a plate sector member having two notches defining circult breaker open and closed positions, together with a handle provided with a plate cam for freeing the plate sector thereby to provide for move ment of the circuit breaker to the other position. I also provide spring operating means between the handle and the sector member which is wound up upon movement of the handle to provide a snap action. Likewise, I provide a releasable connection between the link of the operating toggle and the plate sector member operated by a thermal current responsive member to effect the auto matic opening of the circuit breaker independ ently of the handle.

Another feature is the movement, in response to overload trippin operation, of the detent or latch means for holding the sector member so that upon overload tripping operation the handle is moved to a central position thereby to indicate this tripped open condition.

Another and important feature in connection with the freedom from operation of the device by shocks is an over-travel movement of the handle in effecting the opening and. closing operations whereby the handle is returned by the spring slightly toward its other position thereby positively to lock the sector member and thereby lock the toggle. This efiectively prevents operation oi the switch in response to shocks from either position to the other.

For a more complete understanding oi? my invention, reference should be had to the accompanying drawing, Fig. l of which is a side elevation view of a circuit breaker embodying my in vention with the parts in the manual circuit open position; Fig. 2 is a view similar to Fig. 1 but showing the circuit breaker in its closed circuit position; Fig. 3 is a view similar to Figs. 1 and 2 but showing the circuit breaker in its open position in response to excessive current; Fig. 4 is an exploded view in perspective of the circuit breaker in its closed circuit position with the parts simplified for purposes of clarity; Fig. 5 is a diagrammatic view showing the electric circuits through the circuit breaker; while Fig. 6 is a fragmentary view partly in section showing tietails of the construction.

Referring to the drawing, particularly Fig. 4, I have shown my invention in one form as applied to a circuit breaker provided with a switch con tact operating arm i0 pivctally mounted at H on a base it and, movable pivotaily between open and closed circuit positions by means of a toggle comprising links 13 and his. The lower end of the toggle is connected by a pivot i l to the arm ill while the upper end oi the toggle, i. e., the upper end of the link i3, is connected to a stationary pivot i5 mounted on supporting side plates l6 and IT.

This toggle comprising links it and [3a is on erated between its made and broken positions to operate the contact arm ill by means of an inve "i u shaped operating member it having its arms pivoted on the stationary pivot 15. The connection between this operating member 18 and the toggle is effected by means oi two spaced apart members l9 and 20 carried by the operating member l 8 between which two members is the cooperating upper end of the link l3 extending above the pivot l5. Thus, as seen in Fig. 4. the two members iii and 20 extend downward in spaced relation on opposite sides oi a laterally extending portion ii on the upper end of the link i3. More specifically, as seen in Figs. 4 and 6, the member H has a projection 19a which is on the 1eft-hand side of the portion 2!, while the member 20 is a pin secured to the member l8 and extending downward on the right-hand side of the portion 2 i Thus when the operating member i8 is moved on the pivot i5, one or the other of the members i9 and 20 carried by the member l8 engages the portion ill on the link 18, depending on the direction of movement of the member l8, thereby to swing link it about the pivot l5 and move the toggle between its made and broken positions. As shown in Figs. 2 and 6, the member it has been swung clockwise about the pivot IE to its closed circuit position and, by engagement of the projection Illa with the portion 2|, has likewise swung the link i3 clockwise about the pivot l5 to its toggle made position whereby the contact arm Ill is moved downward to its closed circuit position. When the member i8 is moved. counterclockwise from the position shown in Fig. 6, the member 20. after a small movement, engages the portion 2i and, upon continued move ment of the member l8, swings the link l3 counterclockwise to its toggle broken or open circuit position.

The member (9 is, moreover, loosely secured to the member it by means of a loose rivet 2la to provide for movement of the member I! relative to the member ll in response to an overload current thereby to open the circuit breaker. Thus, as shown in Fig. 6, the rivet 2Ia has its lower headed end spaced below the member I8 a distance considerably greater than the width of the member I9, while the hole in the member I9 for the rivet is enlarged to provide for a limited amount 01' tilting of the member I! on the lower head of the rivet in the plane of the drawing. Normally, as shown, the member I9 is tilted clockwise to one extreme position on the member I8 by a helical tension biasing spring 2Ib having its lower end connected to the floating pivot 35 of the toggle.

Furthermore, as will be described later in detail, the member I9 is tilted by the overload responsive trip member 22, when this trip member is released in response to an excessive current, in a counterclockwise direction about the lower head of the rivet 2Ia far enough to move the portion I90; downward below the portion 2I out of disengagement with the portion 2i, as shown in Fig. 3. The portion 2| is then free to move counterclockwise about the pivot I5 in response to the force applied by the biasing spring 2lb independently of the operating member I8 with corresponding movement of the link I3 to its toggle broken open circuit position. This eifects the independent overloading responsive opening of the circuit breaker.

It will be understood from the drawing that, for purposes of greater strength, the toggle links I3 and I3a actually each consist of two parallel links and, as shown, the operating arm I 0 consists of two parallel arms secured together.

For the purpose of securing positively the member I8, and hence the toggle, in its open or closed position, one of the parallel arms of the member is is extended in the form of a plate sector member 23 having an arcuate portion provided with two circumferentially spaced locking notches 2i and to receive a stop pin 26. This pin 25 in turn is moved radially into and out of the notches 24 and 25 by means or a manually operated plate cam 21 secured to one arm 01' a second inverted U-shaped member 28 which is mounted on the pivot I5 outside of the member I8 and is provided at its top with an operating handle 28a. For the locking and movement of the stop pin 28 the cam 21 is provided with a slot having a central arcuate locking portion 29 whose center is the pivot I 5 and outwardly extending operating portions 30 and 30a at its ends. The central portion 29 is so positioned from the pivot I5 that in order that the pin 26 may lie in it the pin must also be in one or the other of the locking notches 24 and 25. Also, movement of the handle to bring the walls of an operating portion 30 or 30a into engagement with the stop pin forces the pin outward out of the particular notch in which it lies at that time. Reverse movement of the handle moves the stop pin into one or the other of the slots depending upon the position of the mechanism.

Snap action is obtained by means of a helical spring 3| surrounding the pivot pin I5 and having its opposite ends 3Ia and 2lb bent upward, as seen in the drawing, and biased toward each other on opposite sides of the parallel top cross portions of the two members I8 and 28. Thus movement of the member 28 in either direction independently of the member I8, which is held by the stop pin 26, moves one or the other end of the spring, depending on the direction of movement of the handle, and winds up the spring 2| for subsequent snap action 0! the member II in the same direction. Thus the spring 3| yieldably holds the parts I I and 22, and hence the parts 22 and 21, in a predetermined angular relation with respect to each other.

Beginning with the parts in the open circuit position, as shown in Fig. 1 ofthe drawing, it will be observed that the pin 2' lies in the notch 24 thereby locking the sector member 22 and the toggle in these positions. Also, this locking is assured by the fact that the handle has assumed an intermediate position in which the stop lies in the intermediate arcuate portion 25 of the slot. To close the switch, the handle is moved in a clockwise direction to its extreme position in which the walls of the slot 30a engage the stop pin 26 and move it out of the notch 24. Thereupon, the spring 3| snaps the member I8 in a clockwise follow-up direction, also carrying with it the toggle link I3 and straightening the toggle to move the switch arm II) to its closed circuit position, as seen in Fig. 2.

It will be observed, however, that the arcuate distance between the notches 24 and 25 is substantially the same as the length of the arcuate slot portion 29. Consequently, the handle and plate cam 21 must be moved angularly farther than the resulting movement of the plate sector 23 in order to move the stop 28 out of the slots. This means that when the sector member snaps to its opposite position, it is brought to rest by engagement of its end stop projection 32 adjacent the slot 25 with the stop 25. The spring II still is wound up and when the handle is released, the spring moves the plate cam 21 back in a counterclockwise direction to the position shown in Fig, 2 in which the stop 25 is in the slot portion 29, whereby the pin 25 is locked in the notch 25.

For opening movement of the switch, the handle is moved in a counterclockwise direction from the position of Fig. 2, to its opposite extreme position thereby to move the stop pin 26 into the slot 25 after which the parts snap back to the open position 01' Fig. 1 with the opposite stop projection 32a on the plate sector 23 brought to rest against the stop 25, as will be understood from the preceding description. It will be noted that the stop projections 22 and 32a define the closed and open circuit positions of the plate sector 22.

To effect the automatic current responsive opening of the switch arm I0 independently of the member I 8, the projection I9 is displaced in response to an excessive current, whereby the toggle link I2 is released from the member II for independent collapse of the toggle and opening of the switch arm It to the position shown in Fig. 3. As previously stated, the stop I! is secured loosely to the member It by means or a rivet 2Ia, and a helical tension spring 2lb is provided for pulling its right-hand end downward, the opposite end of the spring being connected to the knee pivot 25 01' the toggle II, Ila. Thus by moving the projection Ila downward, which movement is provided by the looseness of the rivet 2Ia, the projection Ha is moved downward out 01' the path of the projection 2| and the toggle released. This pivotal movement or the latch I9 is effected by the trip member or lever 22 which has a projection. extending over a horizontal portion of the member I 9 along the side of the projection Ila. When its opposite end 38 is released by the bimetallic thermal element 40, the trip member is moved clockwise from its normal position, as seen in Fig. 2, about its fixed pivot 4| by a spring 42 thereby to depress the projection Na and release the tog e. The spring 2) then moves the toggle to its broken open circuit position shown in Fig. 3.

Also, at. the same time, during this automatic opening the stop pin 26 is moved thereby to carry the interlocked parts 23 and 21 and hence the handle back to an intermediate indication position, as shown in Fig. 3. This i effected by an extension arm 43 on the trip member 22. This extension 43 is provided with an inverted V- shaped slot 44 in which is a floating pivot 45 of a toggle consisting of a link 46 on the outer end of which the pin 26 is mounted and a. link 41 mounted on a stationary pivot 48. Normally the pin 45 lies in the left-hand portion of the slot 44, as seen in Fig. 4, the release member 22 then being held by the thermostat 40 whereby the pin 45 is secured in this position. When the trip member 22 is released in response to an excessive current, however, the portion 43 moves downward about the pivot 4| thereby carrying the pivot 45 downward to break the toggle formed by the links H 46 and 41 and thus move the stop pin 26 toward the fixed pivot 48 to the position shown'in Fig. 3. This action results in the movement of the handle counterclockwise to its central position, as shown in Fig. 3. It .is efiected by the spring 42.

The slot 44 is given an inverted V shape for the purpose of more firmly securing the stop pin 28 in its normal position shown in Figs. 1, 2 and 4. In other words, the left-hand leg of the slot is a latching notch for the pin 45 about which the stop 26 is movable on the link 46. Little, it any, movement is given to the pivot 45 until the pivot 45 moves out of this left-hand portion and into the right-hand portion whereupon the pivot is moved downward in the position of Fig. 3.

With the mechanism in the overload automatic open position oi Fig. 3, the parts are restored to the positions of Fig. 1 by movin the handle in a counterclockwise direction to its extreme counterclockwise position. The plate cam 21 during this movement engages an upwardly extending projection 49 on the link 41 whereby the link is turned clockwise about its pivot 48 and the to gle 46, 41 straightened to bring the pivot back in the left-hand leg of the slot 44. This also, by the engagement of the pivot 45 with the slot. moves the trip member 22 in a counterclockwise direction about its pivot 4! until its left-hand end is in position to be re-engaged and held by the thermostat when the thermostat has cooled suiiiciently. However, this resetting of the trip member 22 is assured by a resetting projection 50 on the handle which engages a projection 51 on the trip member.

As shown in Fig. 5, the thermostat 40 is heated by a heating resistor 52 connected, as shown, in the electric circuit leading through the contacts of the circuit breaker. I contemplate, however, that any suitable current responsive device can be used to latch and release or control the latching and release of the member 22. It will be understood that when heated to a predetermined temperature in response to an excessive current the thermostat flexes whereby its upper end moves toward the left hand out of engagement with the end 39 of the trip member whereby the trip member is released.

While I have shown a particular embodiment of my invention, it will be understood, of course, that I do not wish to be limited thereto since many modifications may be made, and I therefore contemplate by the appended claims to cover any such modifications as fall within the true spirit and scope of my invention.

What I claim as new and desire to secure by Letters Patent oi the United States is:

1. A circuit breaker comprising a movable operating member provided with a pair of stop means spaced apart to define open circuit and closed circuit positions, a stop member cooperating with said stop means thereby to hold said operating member in one or the other 01' said positions, a manually movable member for moving said operating member from one position to the other and for locking said operating member to said stop member in each of said positions, spring means for maintaining said manually movable member in a predetermined angular relation with saidoperating member, switching means operated by said operating member, and current responsive means for releasing said switching means from said operating member for independent opening of said switching means.

2. A circuit breaker comprising a movable operating member provided with a pair of stop means spaced apart a predetermined distance from each other so as to define open circuit and closed circuit positions, a stop member cooperating with said stop means thereby to hold said operating member in one or the other of said positions, a manually movable member provided with means for locking said operating member to said stop member over a range of movement of said manually movable member substantially the same as said predetermined distance and for unlocking said operating member when moved beyond said range in either direction, spring means connecting said manually movable member to said operating member and normally maintaining said members in a predetermined positional relation with respect to each other, said spring means being stressed upon movement of said manually movable member to release said operating member whereupon said operating member when released is moved by said spring to its other position and said manually movable member when released is moved by said spring to said predetermined positional relation with said operating member thereby to lock said operating member to said stop member, and switching means operated by said operating member.

3. A circuit breaker comprising a movable operating member provided with a pair of stop means spaced apart a predetermined distance from each other so as to define open circuit and closed circuit positions, a stop member cooperating with said stop means thereby to hold said operating member in one or the other of said positions, a manually movable member provided with means for locking said operating member to said stop member over a range of movement of said manually movable member substantially the same as said predetermined distance and for unlocking said operating member when moved beyond said range in either direction, spring means connecting said manually movable member to said operating member and normally maintaining said members in a predetermined positional relation with respect to each other, said spring means being stressed upon movement of said manually movable member to release said operating member whereupon said operating member when released is moved by said spring to its other position and said manually movable member when released is moved by said spring to said predetermined positional relation with said operating member thereby to lock said operating member to said stop member, switching means operated by said operating member, a releasable operating connection between said switching means and said operating member, and current responsive means for eiiecting the release or said connection for independent operation of said switching means to its open circuit position.

4. A circuit breaker comprising a movable operating member provided with a pair oi stop means spaced apart a predetermined distance from each other so as to define open circuit and closed circuit positions, a stop member cooperating with said stop means thereby to hold said operating member in one or the other of said positions, a manually movable member provided with means for locking said operating member to said stop member over a range of movement of said manually movable member substantially the same as said predetermined distance and for unlocking said operating member when moved beyond said range in either direction, spring means connecting said manually movable member to said operating member and normally maintaining said members in apredetermined positional relation with respect to each other, said spring means being stressed upon movement or said manually movable member to release said operating member whereupon said operating member when released is moved by said spring to its other position and said manually movable member when released is moved by said spring to said predetermined positional relation with said operating member thereby to lock said operating member to said stop member, switching means operated by said operating member, a releasable operating connection between said switching means and said operating member, a trip arm movable to a tripped position to release said connection for independent movement of said switching means to its open circuit position, a spring for biasing said trip arm to said trip position, current responsive latching means for holding said trip arm in a normal position against the tension of said spring, supporting means for said stop member normally held by said trip arm but moved upon movement of said trip arm to said tripped position so as to move said stop member and said manually movable member to an intermediate position.

5. A circuit breaker comprising an operating member mounted on a pivot provided with stop means spaced apart to define open circuit and closed circuit positions, a stop member engaged by one or the other of said stop means thereby to stop said operating member in one or the other of said positions, switching means operated by said operating member, locking means spaced apart on said operating member arranged to be engaged by said stop member thereby to lock said operating member, a cam member mounted on said pivot adjacent said operating member for moving said stop member into and out of locking engagement with said locking means and for holding said stop member in said locking engagement, and a resilient connection between said cam member and said operating member for effecting a follow-up movement of said operating member to its other position when said cam member is moved to release said operating member.

6. A circuit breaker comprising an arcuate member mounted on a pivot provided on its periphery with a pair of projections spaced apart to define open circuit and closed circuit positions, a stop member engaged by one or the other or said projections thereby to stop said arcuate member in one or the other of said positions, switching means operated by said arcuate member, locking means spaced apart on said arcuate member arranged to be engaged by said stop member thereby to lock said arcuate member, a cam member mounted on said pivot adjacent said arcuate member for moving said stop member into and out 0! locking engagement with said locking means at each limit of its movement and for holding said stop member in said locking position over an intermediate range of movement between said limits, and a resilient connection between said cam member and said arcuate member for biasing said members into a predetermined angular relation with each other and (or effecting a follow-up movement 01' said arcuate member to its other position when said arcuate member is released by said cam member, said intermediate range of movement of said cam member being substantially coextensive with the spacing of said projections so that said cam member is biased by said resilient connection to an intermediate locking position after operation of said arcuate member to another position.

7. A circuit breaker comprising an arcuate member mounted on a pivot provided on its periphery with a pair of projections spaced apart to define open circuit and closed circuit positions, a stop member engaged by one or the other of said projections thereby to stop said arcuate member in one or the other of said positions, switching means operated by said arcuate member, locking means spaced apart on said arcuate member arranged to be engaged by said stop member thereby to lock said arcuate member, a cam member mounted on said pivot adjacent said arcuate member for moving said stop member into and out of locking engagement with said locking means at each limit of its movement and for holding said stop member in said locking position over an intermediate range of movement between said limits, a resilient connection between said cam member and said arcuate member for biasing said members into a predetermined angular relation with each other and for eflecting a follow-up movement of said arcuate member to its other position when said arcuate member is released by said cam member, said intermediate range of movement of said cam member being substantially coextensive with the spacing of said projections so that said cam member is biased by said resilient connection to an intermediate locking P sition after operation 0! said arcuate member to another position, a releasable connection between said arcuate member and said switching means, and current responsive means for releasing said connection to eflect opening movement or said switching means independently of said arcuate member.

8. A circuit breaker comprising an arcuate member mounted on a pivot provided on its periphery with a pair of projections spaced apart to define open circuit and closed circuit positions, a radially movable stop member engaged by one or the other of said projections thereby to stop said arcuate member in one or the other of said positions, switching means operated by said arcuate member, locking means on said arcuate member arranged to be engaged by said stop member upon radial movement of said stop member thereby to lock said arcuate member, a cam member mounted on said pivot adjacent said arcuate member for moving said stop member radially into and out of locking engagement with said locking means at each limit of its movement and for holding said stop member in said locking position over movement between said limits, and a resilient connection between said cam member and said arcuate member for efiecting a followup movement or said arcuate member when said arcuate member is released by said cam member.

9. A circuit breaker comprising an. arcuate member mounted on a fixed pivot provided on its periphery with a pair of projections and a pair of notches spaced apart to define open circuit and closed circuit positions, a stop member engaged by said projections mounted for movement into one or the other of said slots thereby to lock said arcuate member in one or theother of said positions, switching means operated by said arcuate member, a cam member mounted on said pivot adjacent said arcuate member cooperating with said stop member to effect the movement of said stop member into and out of locking engagement with one or the other of said slots upon movement of said cam member about said pivot, and a resilient connection between said arcuate member and said cam member for eliecting a follow-up movement of said arcuate member when said arcuate member is released by said cam member.

10. A circuit breaker comprising a plate sector provided with a pivot, switching'means operated by sai dplate sector, a pair of stop projections on said plate sector spaced apart to define open circuit and closed circuit positions of said plate sector, said plate sector being provided with a looking means on its periphery adjacent each of said stop projections, a stop member engaged by said stop projections when said plate sector is moved from one to the other of said positions, means movably mounting said stop member for engagement with one or the other of said locking means, a plate cam member mounted on said pivot adjacent said plate sector provided with a cam slot into which said stop member extends for maintaining said stop member in engagement with one or the other or said locking means during a predetermined intermediate movement of said plate cam and for moving said stop member into and out of engagement with said locking means, a resilient connection between said plate cam and said plate sector for biasing them to a predetermined angular relation with respect to each other whereby movement of said plate cam to move said stop member to release said plate sector effects a follow-up movement of said plate sector to its other position after which said plate cam when released is returned by said spring to said predetermined angular relation with said plate sector thereby to move said stop member into engagement with the other of said locking means to lock said plate sector.

11. A circuit breaker comprising switch operating means provided with a pivot, a. plate sector mounted on said pivot, a driving connection between said plate sector and said switch operating means, a pair of stop projections on the periphery of said plate sector and spaced apart to define open circuit and closed circuit positions of said plate sector, said plate sector being provided with a locking notch on its periphery adjacent each of said stop projections, a stop member engaged by said stop projections when said plate sector is moved from one to the other oi? said positions, means movably mounting said stop member for radial movement into one or the other of said slots, a plate cam member mounted on said pivot adjacent said P $801901 Provided. with a cam slot into which said stop member extends, said slot being provided with intermediate arcuate walls for maintaining said stop member in one or the other of said slots during a predetermined intermediate movement of said plate cam and outwardly extending walls ateach end of said intermediate walls for moving said stop member into and out of said slots upon movement of said plate cam, a resilient connection between said plate cam and said plate sector for biasing them to a predetermined angular relation with respect to each other whereby movement of said plate cam to an extreme position moves said stop member to release said plate sector and effects a follow-up movement of said plate sector to its other position after which said plate cam when released is returned by said spring to said predetermined angular relation with said plate sector thereby to move said stop member into the other of said slots to lock said plate sector.

12. A circuit breaker comprising an operating member mounted on a pivot provided with a pair of projections spaced apart to define open circuit and closed circuit positions, a stop member cooperating with said projections thereby to hold said operating member in one or the other of said positions, a manually movable member for moving said operating member from one position to the other and for locking said operating member to said stop member in each of said positions, and current responsive means for releasing said switching means from said operating member for independent opening of said switching means and for effecting movement of said stop member thereby to move said operating member to a predetermined position.

13. A circuit breaker comprising an operating member mounted on a pivot provided with a pair of projections spaced apart to define open circuit and closed circuit positions, a. stop member cooperating with said projections thereby to hold said operating member in one or the other of said positions, a manually movable member for moving said operating member from one position to the other and for locking said operating member to said stop member in each of said positions, a spring driving connection between said manually movable member and said operating member arranged to maintain said manually movable member in a predetermined angular relation with said operating member in which said operating member is locked to said stop member, switching means operated by said operating member, and current responsive means for releasing said switching means from said operating member for independent opening of said switching means and for effecting movement of said stop member thereby to move said manually operated member to an indicating position.

14. A circuit breaker comprising switch operating means provided with a pivot, an arcuate member mounted on said pivot provided with a pair of spaced projections to define open and closed circuit positions and with a pair of spaced locking notches, a first latch means forming a driving connection between said arcuate member and said switch operating means, a stop member movably mounted for movement into said notches thereby to lock said arcuate member, a cammember mounted on said pivot for moving said stop member into and out of said notches, a spring a predetermined angular relation with each other whereby movement or said cam member to move said stop member out of a notch produces a follow-up movement of said arcuate member to its other position, a trip arm mounted on a fixed pivot and having one end movable to a tripped position to operate said first latch means and release said switch means tor independent operation to an open circuit position, a spring for biasing said trip arm to said tripped position, a second latch means for holding said trip arm against the tension of said spring in a normal position, current responsive means for moving said second for biasing said'arcuate and cam members into latch means to release said trip am. an arm on said trip arm provided with a slot, and a toggle provided with a nxed pivot at one end and having a central floating pivot extending into said slot, said stop member being secured on the other movable end of said toggle so as to be plvotally movable about said floating pivot and said floating pivot being moved by the walls of said slot upon movement of said trip member 'to a tripped position so as to move said stop member and thereb move said interlocked sector and cam members to an intermediate position.

JOHN I FAVRE.

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