US2169586A - Circuit breaker - Google Patents

Description

Aug. 15, 1939. M, G. LEONARD anBY :Z/

ATTORNE AU8- 15, 1939. M. G. LEONARD 2,169,586

CIRCUIT BREAKER Filed June 26, 1936 3 Sheets-Sheet 2 IN VENTOR A gwX/famQ/d BY 2/ I,/{TTORNEY 8 15, 1939. M. G. LEONARD 2,169,586

CIRCUIT BREAKER Filed June 26, 1936 3 Sheets-Sheet 5 WITNESSES: INVENTOR l f fr0" mier. M@ i Y Y @y d ATTORNE Patented Aug. 15, 1939 lUNITED STATES 2,169,586 CIRCUIT BREAKER Merrill G. Leonard, Sharon, Pa., assigner to Westinghouse Electric & Manufacturing Company, East Pittsburgh, Pa.,A a corporation of APennsylvania.

Application June 26, 1936, serial No. 87,351

2v claims. (m200- 116) This invention relates to circuit breakers and more particularly to overload trip mechanisms therefor. The circuit breaker of -my invention is particularly adapted to function as a protective device for apparatus subjected to overload conditions of considerable time duration. A distribution transformer is an example of such apparatus. Heretofore it has been the usual practice to provide protection for distribution transformlo ers against secondary overload and short circuits and winding faults by means of fused cut-outs in the primary circuits, but so many service interruptions were experienced that it became the usual practice to select high voltage fuses which 1:; will give protection only against short circuits across the customers line. In Patent No. 2,066,935 of John K. Hodnette, issued January 5, 1937, and assigned tothe assignee of this application. it is proposed to eliminate the high voltage fuse entirely and rely upon a thermal responsive circuit interrupter in the secondary circuit of the transformer to give protection not only against dead short circuits across the customers service lines but also against cumulative overload vconditions of these lines which causes the transformer to be disconnected only when thecumulative effects of overload are sufficient to raise the transformer insulation temperature to a value at which the insulation is about to fail.

It has been found desirable in the interest of maintaining continuity of service in distribution systems to provide means for indicating the condition of load upon aparticular transformer, which meansare visible to an observer from the ground. .H.) Thus periodic observations will reveal whether the transformer has been subjected to such frequent cr continued overloads that ultimate failure is likely to result. It the indicating means show a critical condition of overload; the transformer can be replaced by one of greater capacity with- -out subjectingthe customer to a loss of service which would result from transformer failure. Such a system for indicating the load conditions' on a distribution transformer is shown and described in an application of H. V. Putman, Serial No. 91.654, led July 2l, 1936, and assigned to the assignee of this application.

The instant invention is directed specifically to the structural features of al circuit breaker no adapted for operation in a system as described in the above named Putman application, or for a similar service. I-have discovered that by apprcpriately arranging the operating and tripA mechanisms of a thermally controlled circuit 5 breaker, a control. mechanism operated by the same current responsive element which trips the breaker on overload may be incorporated therewith for actuating an indicating mechanism. This indicating mechanism may be either of a 60 purely mechanical type or may utilize mechanical movements in conjunction with an electrical circuit. In the present embodiment of my invention, I propose to utilize the mechanical movement of a device controlled by the trip vmechanism of the breaker for controlling an electrical indicating circuit.

It is an object of my invention to provide a `circuit breaker having an overload trip mechanism controlled by an element responsivev to predetermined cnditions and which element is also employed to control an indicator for indicating certain predetermined conditions.

` A further object of my invention is to provide a circuit breaker having an overload tripping device and a current indicating tripping device controlled by a single current responsive element and which tripping devices are capable of .being reset to an inactive .position by actuating the breaker operating means.

Another object of the invention is to provide a circuit breaker having an overload trip mechanism controlled by a bi-metallic element which also controls an indicating trip device and means 'so correlated with the operating mechanism of the breaker that'J the indicating trip device may be reset by actuation of the operating mechanism without disturbing the breaker contact position.

Other objects and advantages relate to details of the breaker structure and the relation of the various parts thereof, all of which will appear more fully in the following description, taken in connection with the accompanying drawings, in which:

Figure i is a side elevational view of the circuit breaker of my invention showing the contacts in the open position and the operating mechanism in a position for resetting the tripping mechanisms.

Fig. 2 is a side elevational view of the circuit breaker of my invention showing the contacts in the closed position and the trip mechanisms in their inactive position.

Fig. 3 is a side elevational view of the breaker of my invention showing the operating and tripping mechanisms in the tripped position.

Fig. 4 is a'vertical cross sectional view of the breaker taken along line IV'-IV oi Fig. l.

Fig. 5 is a rear elevational View of the breaker with the cover removed. showing the bimetallic elements and the adjusting means therefor.

Fig. v6 is an exploded perspective view of the trip mechanisms of the breaker.

Fig. 7 is an enlarged perspective view of one of the bimetallic elements of the breaker.

Fig. 8 is a plan view partially in cross section showing the contact arrangement of the breaker and the operating linkage therefor.

Fig.v 9 is a perspective view of the indicating trip mechanism shown apart from the breaker contact tripping mechanism.

Fig.l10 is a side elevational view showingthe' indicating trip mechanism of Fig. 9 and the resetting means therefor.

Fig. 11 isa perspective view of the breaker contact tripping mechanism shown apart from the indicating trip mechanism, and

Fig. 12 is a side elevational View of the breaker contact tripping mechanism of Fig. 11 and the resetting means therefor.

Referring more particularly to the drawings, the reference character I designates a support preferably molded of insulating material and having a horizontally extending base portion 2- and a back portion 3. The breaker structure to be hereinafter fully described is of two-pole construction and comprises two stationary contacts 5', one for each pole mounted respectively upon conductor strips 6 (Fig. 8) secured to the base portion 2. A pair of cooperating movable contacts 8 are secured to support arms l0 which in turn are mounted for pivotal movement at I2 with respect to main contact arms'B. A coil spring I4 positioned between the arms 9 and IU in conjunction with the pivotal connectionbetween the respective arms insures self-alignment and equalization of pressure between the cooperating movable and fixed contacts. The contact arms 9 are insulatingly mounted in spaced relation upon. a tie bar I I. The tie bar I I is centrally supported by a movable actuating arm I3 which in this instance is pivotally mounted for rocking movement about a shaft l5 journalled in a frame' II. The actuating arm I3 has a forked end I9 to which a pair of toggle links 23 is connected by means of a pin 2l. The toggle links 23 are pivotedv at 2li (Fig. 3) to another 4pair of toggle links 25 which, in turn, are pivoted by means of pin 21 to a cradle or carrier 29. The cradle 29 ls pivcted at one end to the frame I'I. by means of pin 3|. The other end of the cradle or carrier 29 has a latch portion 33 adapted to register with an aperture 35 of a latching arm 36 forming part of the trip mechanism and which will be hereinafter more fully described.

The Icontacts 8 are adapted to be operated into and out of engagement with the fixed contacts 5 by an operating lever 38, one end of which is pivoted by means of stub pins 39 nested in U- shaped recesses 40 in the frame Il. An overcenter actuating spring 5I is connected at its upper end to the operating lever 38 and'at its lower end to theconnecting pin 2li joining the two pairs of toggle links 23 and 25.

As shownin Fig. l, the contacts 3 are in the open position. In this position the operating lever 38 is at the left hand limit o Aits movement. The togge links 23 and 25 are in a collapsed I position and retained inA that'position by the bia-sing action ci the spring 5I, thereby maintaining the actuating arm I3Ain the raised' position and consequently the contact arms 9 in 4the open position. The contacts 8 are closed by moving the actuating lever 38 to the right, as shown in Fig. 2. During the movement of lever 38 to the position shown in Fig. 2, the overcenter spring 4I acting upon the knee or thev pivotal connection 24 between the links 23 and 25 will straighten out these links thereby forcing the portion I9 of the actuating arm I3 downwardly with a snap action which eiects closing the contacts by the simultaneous movement of the contact arms 9. In the event of a predetermined overload condition existing in the circuit in which the breaker is connected, the carrier 29 will be automatically released in a manner which will be hereinafter aieacsc 25 carrying the actuating arm I9 upwardly and thereby rotate the contact carrying arms 9 to open the breaker.

The latching mechanism for the carrier 29 is more clearly shown in Figs. 6 and il. As heretofore mentioned, the carrier 29 has a latch portion 33 adapted for latching engagement with an aperture 35 in the latch arm 36. The latch arm 36 is adapted for pivotal mounting between the brackets 43 upon a pin M secured to a supporting plate 45 which, in turn, is mounted to the back portion 3 of the support I. The latch arm 36 is biased in a clockwise direction about the pivotal axis 44 in a'latching engagement with the latch 33 by means of a spring''I interposed between the latch arm 36 and the supporting plate 45. The upper end of the latch arm 3S has two laterally extending oiset projections 48.

' Each of the projections 158 is adaptedior operatending outwardly irom the supporting plate 45. lThe trip members 5I also have a latching surface 59 for engaging a catch member 6I preferably moulded in a block of insulating material 63 secured to the upper end of a bimetallic element 65 (Fig. 7). The method of pivotally mountingthe bimetallic elements 65 will be hereinafter more fully described. At this point of the description it will be sufficient 'to indicate that the upper portion of the bimetallic elements and their insulating head portions 63. are movable with respect to the trip members 5I. Under normal load conditions, the bimetallic element 65 will be in a-position so that the catch 5I overlaps the latching surface 59 of the trip member 5I a considerable amount. The trip members 5i are maintained in engagement with the catch 6i by means of biasing springs 6l, the upper ends of which are secured to upstanding projections 69 of the tripmembers 5I while the lower ends of the spring 67 are anchored in an aperture to the brackets ll of the suppoing plate 45. Thus, as the bimetallic elements 55 are deflected to thc left a distance suicient so that the catch 5I clears the latching surface 59, the biasing spring 6l will rotate the trip member 5i in a clockwise direction thereby causing the iinger 33 to engage the projection 43 of the latch arm 36, rotating the latter in a counter-clockwise direction about the pivotal axis 53 to cause the release of the latch portion 33 of the carrier 29. The release of the carrier 29 causes the overcenter actuating spring 4I to open the contacts in accordance with the method above described.

It will be noted that the end portions of the trip members 5I adjacent the catch 6I have an arcuate'suriace 'I3 against which the catch 5I kmay have bearing engagement when the trip member 5I is in the tripped position. Thus, as the bimetallic element 65 cools or, in other words, attempts to resume a normal position-the catch 6I will be brought with a slight pressure engagezov 59 clears the catch 6I, the latter will again move 75 into overlapping relation with the surface 59 and hold the trip member 5i in the inactive position.

It will be noted that the upstanding projections 69 of the trip members 5I are disposed so as to make a small acute angle with respect to the line of action of the biasing springs 61 when the trip members are in latching engagement with Athe catch 6i. Consequently, the line of action of the springs B1 when the trip members 5i are in the latched position will be immediately adjacent the shaft 55 about which the trip members 5l are adapted to pivot, to thereby produce a relatively low moment-arm and a resultant low latching pressure between the trip members 5i and their respective catch members 6|. When either of the trip members 5l is released, the moment-arm produced by the pull of the spring 61 upon the projection 68, whereby the trip member 5|,is caused to rotate clockwise, is increased due to the fact that the line of action of the spring V(i1 is carried away from the-shaft 55. The projections 48 of the latch arm 36 are so correlated with respect to the actuating fingers 4S of the trip members 5l that considerable rotation of the latter is permitted'from their latched p0- sitions before the fingers 49 engage the projections 48. Thus, a high tripping force is obtmned for moving the latch arm 36 to the tripped position. The springs 61 are of long deiiection construction so that the increase in moment-arm more than compensates for the decrease in spring tension as the trip members 5I are rotated to the tripped position. Y

The means for resetting the trip members 5l comprises an angular reset bar 15 (Fig. 6) having a downwardly extending U-shaped portion 16 for pivotal mounting upon the shaft 55. The reset bar 15 is adapted to engage the upstanding projections B9 of the trip members 5i. It is-thus seen that any rotational movement of the reset bar 15 in a counter-clockwise direction about the shaft 55 will rotate the trip members 5i in a counter-clockwise direction to their reset position. This rotative movement of the reset bar 'i5 is secured by an actuating bar 11 having sliding engagement with the bar 15through an aperture 18 contained therein. The actuating bar 11 is provided with a shoulder 19, which is more clearly shown in Fig. 12, which is adapted to engage the upper wall of the aperture 13. The actuating bar 11 has pivotal connection with the operating lever 38 at 8D. The operating lever 38 and the actuating bar 11 with its shoulder 18 .are so correlated with respect to the resetting bar 'i5 that when the operating lever is inthe full open position, the actuating bar 11 will have moved or rotated the trip members 5i to their latching or reset position.

The operating lever 38 is also provided with a U-shaped lateral projection 8i (Figs. l, 2 and 3) the closed end of which is adapted to engage the shoulder 83 of the carrier 29 so that upon movement of the operating lever 38 following tripping of the breaker contacts by releasing the carrier 29 through the action of the trip member 5i, to the open position, the carrier 29 will be rotated in a counter-clockwise direction about its pivotal axis 3l until the latch portion 33 makes latchmg engagement with the aperture 35 in the latch arm 36. At the same time, as above described,

. the actuating arm 11 actuates the reset arm 15 for resetting the trip members 5l to their normal or inactive position. 4

As previously indicated, the bimetais 65 Aare secured at their lower end to a U-shaped bracket 85 adapted for pivotal connection through the means of a pin 8'! to a support bracket 88 secured to the back of the portion 3 of the support i, the bimetal 65 and bracket 85 which are also rigidly secured to an adjusting arm 9i by means of rivets 92 extending therethrough, or by other suitable fastening means. The upper end of the adjusting arm 9| is provided with an aperture through which a stud bolt 93 extends. The bolt 83 has one end anchored in the back portion 3 and has its other end screw threaded for threaded engagement with a knurled adjusting member S5. A compression spring 91 'encircling the bolt 93 and interposed between the adjusting arm 9i and a washer 88 in engagement with the back portion 3, biases the adjusting arm 8i against the adjustable member 95. It will 'be apparent that .as the adjusting member 95 is rotated in either clockwise or counter-clockwise direction, the ad justing arm 9| will bemoved either toward or away trom the back portion 3 thereby movingr the' catch member BI with respect to the trip members 5i for adjusting the amount of overlap of the catch member 6i with respect to the latching surface 58. By means of the two adjusting members 95, the two bimetallic elements S5 may be adjusted so that the deflection of each element for a predetermined temperature condition will cause the release of the trip members 5 IA to thereby effect opening of the breaker contacts. A suitable spring 88 is positioned between the brackets 85 and 89 in order to avoid back-lash error during bimetal adjustments, which error may result from any looseness of the pivotal pin 81 within its bearings in the respective brackets.

Current connections to the bimetallic element 65 are had from the movable contact 3 by means of a exible connection 99 connected to a terminal iB secured to the upper end of the bimetal 65.' The lower end of the bimetal is provided with a terminal ii preferably held in clamping engagement between the bimetal and the, adjusting arm 9i. The terminal itl is connected by a iiexible conductor 62 to a terminal member l03 secured to the back portion 3 oi the support i and from which tern-iinalconneotion to the line may be made. The insulating head S3 is essential for effectively insulating the two poles oi" the breaker from each other since a conductive connection is had from one of the catchmembers Si through its corresponding trip member 5i, the shaft 55, the other trip member 5i and its corresponding catch il i.

.retain the trip member and catch in engagement until a predetermined temperature condition is obtained, is known. Then, in order to mechanically calibrate the bimetals, it is merely necessary to rotate each hand adjusting member 95 ina direction so as to cause the catch 6i to move away from the trip member 5i and continue rotation until the trip member 5i is just released. The adjusting members 95 are then rotated in the opposite direction a given number of turns corresponding to the amount of overlap required between the catch 6i and the trip member 5l. Although this mechanical method of adjusting the `bimetallic elements produces relatively uniform results, in practice the settings are checked by a more accurate method which consists in measuring the current trip time. Since the latter method involves considerable time, it is highly desirable in the interest of quantity production, to obtain a tentative mechanical setting prior to nal adjustment, which requires a minimum expenditure of time and which is reasonably accurate.

The foregoing description has dealt primarily with the actuating mechanism for 'operating the breaker contacts to open and closed position and the trip mechanism whereby the contacts of the breaker are operated from the closed to the open position upon the occurrence of predetermined overload current and temperature conditions. In order to provide means for indicating a partial overloaded co-ndition which is not of magnitude sufcient to cause the breaker contacts to be opened by the trip mechanism but which showsI that the circuit is-approaching overload conditions, the cumulative eiiects of which may become dangerous, it is desirable to incorporate a second trip mechanism controlled by the bimeiallic catch element 6| foractuating an indicator.

In order to carry out the objects of my invention, any suitable form of indicating means may he employed which may be actuated by the same bimetallic element which controls the overload release of. the breaker contacts. The indicating device proper may comprise solely mechanical means such as a lever or semaphore actuated by suitable linkage through a trip mechanism released by the bimetal. In the instant case I have selected an electrical system of indication which may comprise an indicating lamp circuit, ci which only the controlling switch contacts are slown. The fixed contact in this instance comprises a spring member |05 (Figs. 6 andv9) secured by any suitable means to the back portion 3 of the support lI'he spring member |05 has a contact |06 adapted to be engaged by a cooperating contact |07 carried by a movable contact arm |09. The contact arm |09 has pivotal connection at its lowerend with the shaft 04 upon which latch arm 36 is also pivoted. The contact. arm |09 is mounted directly in front of the latch arm 36 and is provided with a Ue shaped notch ||0 through which the latch portion 33 of the carrier 29 may project. Each of the upstanding portions on either side of the notch H0 also has a U-shaped notch I through which the laterally projecting iingers 4B oi the latch arm 36 may project. It will be apparent that the yU-shaped notches and the intermediate U-shaped notch ||0 provide upstanding fingers ||3 and H4, respectively.l

The outermost fingers ||3 are adapted to be engaged by fingers H6 of the trip members |I'l. It will be noted'that theftrip members are similar in configuration to the trip -members 5| and are also adapted to make latching engagement with the catches 6| of their respective bimetallic elements 65. The 'trip members |1 also have upstanding projections ||9 to which are secured one end of a biasing spring 2|, the other end of the spring being secured to the bracket H adjacent the biasing spring 61. The radial length of the trip members Il, that is, the distance from the shaft 55 to the arcuate surface |23 is somewhat less than the corresponding radial length of the trip members 5I. It will, therefore, be apparent that the trip members are disengaged from the catches-6| at a preaicase determined temperature value less than that required to disengage the trip members 5|.

When the bimetallic elements have moved a distance suiicient to release the trip members 1, but have not moved far enough to release the trip members 5|, the biasing springs |2| will rotate the trip members ||'l in a clockwise direction so as to bring the fingers I5 in engagement with the fingers I3 of the contact arm |09, thus causing this contact arm to be rotated in a counter-clockwise direction until the contact |07 engages the contact |06, thereby closing an indicating circuit which, in this instance, is indicated by a lead wire |25 connected to the contact member |05 and another lead Wire |26 connected to the contact arm |09. For example. if this indicating circuit includes a lamp, the engagement of the contacts |06- and |01 will energize the indicating circuit and light a lamp which will be visible so as to indicate that the apparatus, such as a distribution transformer, is beingoverloaded. The indicating circuit will remain energized as long as the contact arm |09 is allowed to remain in the closed position regardless of the subsequent cooling of the bimetallic elements 65.

From the foregoing description it follows that sin'ce the con'guration of the trip members i is Cil similar to that of the trip members 5| and the biasing springs |2| are disposed so that their lines of action are likewise similar to that of the springs 6l, the advantages of low latch pressure between the members and the catches 6i and a high tripping force are alsoobtained in connection with the trip structure for actuating the indicating mechanism,

In order to separate the contacts |06 and 01, I have provided a reset bar |28 having end members |29 mounted for pivotal movement about the shaft 55 and having projecting fingers |30 for engaging the fingers H0 of the contact member |09, which reset bar is adapted to be rotated in a counterclockwise direction so as to rotate the contact arm-|09 clockwise until the contacts |06 and |01 separate. to be actuated by the cam surface i3! provided on the lower side of the actuating bar i7. The end of the actuating bar 'VI adjacent the cam surface |3| is guided in its movement by an aperture |32 in the supporting plate 05, The earn surface r |3| is positioned along the bar il so that engagement is had with the reset bar |28 during the initial movement of the operating lever 38 from the closed to the open position. The cam surface |3| is also so correlated with the configuration i ofthe reset bar |28 so that only a small longitudinal movement vof the actuating bar Ti is required to reset the contact arm |09. This small movement of the actuating bar 'il to a position between open and closed positions is not sumcient to actuate the main contacts 8 of the breaker to the openV position. Therefore, after the Contact arm |09 has been moved to` the open circuit or set position, the operating lever 38 may be moved back to the full closed position.

From the above description it is apparent that I have provided a circuit breaker embodying a tripping mechanism controlled by a thermally rcsponsive element for opening the breaker contacts .under certain overload current or temperature I conditions. I have also utilized the same thermally responsive element for controlling another trip mechanism for the purpose of actuating an indicating mechanism, this indicating mechanism being useful for indicating a condition of overload The reset bar. |28 is adapted or temperature less severe than that required to actually trip the breaker. The particular arrangement of the two trip mechanisms embody a correlation of parts such that sequential operation is obtained, that is, the indicating mechanism being tripped and moved into the indicating position at a predetermined current or temperature of value less than that required to trip the contacts of the breaker to the open position;

The breaker structure above described also provides for the actuation of the indicating and mainV breaker trip mechanisms in response to predetermined conditions affecting either oi the poles of the breaker independently of the other. Although a two pole structure has been shown it is apparent that a similar arrangement of parts may be embodied in a three or higher multi-pole construction.

From the foregoing it will also be apparent that I have provided a simple yet efficient mechanism controlled entirely by the movement of the operating lever of the breaker for resetting the various latches and trip members. In the event that the breaker has been trippediby overload conditions a single operation of the operating lever from the tripped position to the open circuit 'position resets not -only any or all vlatches and trip members for a given pole, to the normal position, but for all poles. The operating lever may then be moved to the closed position to close,

the breaker contacts without eiecting further movement of the trip mechanisms. In the event that the trip mechanism of the overload indicator has been actuated and it is desired to reset the same, it merely'becomes necessary to move the operating lever a short distance toward the open circuit position whereby the indicating trip mechanism is reset, thus allowing the operating lever to be moved back to the full closed position without effecting the operation of the main breaker contacts from the closed to the open position.

Although I have shown and described a particular circuit breaker embodying specific trip mechanisms, it is to be understood that the same is for the purpose of illustration and that changes and modications may be made by those skilled in the art without departing lrom the spirit and scope of the appended claims.

I claim as my invention:

1. In a circuit breaker having contact means operable to open and closed positions, auxiliary means operable upon the occurrence of a predetermined condition, a plurality Aof independently movable elements, a control element responsive to predetermined conditions, at least one of said movable elements being operative upon movement of said control element to actuate said auxiliary means and at least one other of said movable elements being operative upon movement of the same said control element to cause actuation of said contact means from the closed to the open position, and means for resetting the control element moved first without causing actuation of the means actuated by the other control element.

2. In a circuit breaker having a contact member operable to open and closed positions, means for indicating a predetermined current condition in said contact member, a plurality of movable elements, means including a control element for releasably retaining said movable elements in a normal position, at least one of said movable elements being operative when released by said means to actuate said indicating means and at least one other of said movable elements being operative when released by said means to actuate said contact member from the closed to the open position, said last named movable element being releasable subsequent to the release of -ber operable toopen and closed positions,'means .for indicating a predetermined condition, a plurality of movable elements, means including a control element responsive to predetermined conditions for releasably retaining said movable elements in a normal position, at least one of said movable elements being operative when released by said means to actuate said indicating means, and at least one other of said movable elements being operative when released by saidv means to actuate said contact member from the closed to the open position, and operating means for the Contact member operable to restore said movable elements to their respective normal positions, said operating means having at least three positions including a rst position in which said contact member is closed, a second position in which said contact member is open and a third position for restoring said movable element which actuates the indicating means, and said operating means being movable from said first position to said third position without movement to said second position.

4. In a circuit breaker having a contact member, actuating means including a manually operable control member for moving said contact member to open Vand closed circuit positions, a

contact opening member, an auxiliary device operable upon the occurrence of a predetermined condition, and a control element responsive to predetermined conditions for actuating said ecntact opening member and said auxiliary device, said control element being operable to actuate said auxiliary device prior to actuating said contact opening member, said manually operable member having at least three positions including a rst position in which said contact member is closed, a second position in which said contact member is open and a third position in which said auxiliary device is reset, and said manually operable member being movable from said first position to said third position without movement to said second position.

5. In a circuit breaker having a contact member, means to operate said contact member to open and- -closed positions, a contact opening member movable from a normal to a tripped posit'ion, indicating meansoperable from a normal to an indicating position for indicating a predetermined condition, and means including a control element for releaeably retaining said contact opening member and said indicating means in their respective normal positions, said means being operable to release said indicating means prior to releasing said contact opening member. and means actuated by said means for operating said contact member to-open and closed positions for restoring both said contact opening member and said indicating vmeans to their respective normal positions when both have been released and for restoring said indicating means to normal position without movement of said contact member when only said indicating means has been released.

6. In combination, a circuit breaker having a contact member, means for operating saidl contact member to open and closed positions, a contact opening member, means responsive to predetermined conditions for releasably retaining said 75 mined conditions, said last named means being operable yto release said indicating member for movement to the indicating position prior to releasing said contact opening member, and means for returning said indicating member to normal position independently of opening movement of said contact member.

7. In a circuit breaker, a movable contact member, an operating mechanism including a contact opening member movable from a normal to a tripped position for operating said contact member from the closed to the open position, a movable control element responsive to predetermined conditions, latching means releasably interconnecting said control element and said contact opening member for retaining the latter in its normal position, an auxiliary member movable from a normal to a predetermined position, a second latching means releasably interconnecting said control element and said auxiliary member for retaining the latter in its normal position, said last named'latching means being adapted when released to actuate said auxiliary member to the predetermined position, and means for resetting said second latching means without opening movement of said movable contact member.

Ail. In a circuit breaker, a movable 'contact member, an operating mechanism including a contact opening member movable from a normal to a tripped position for operating said contact member from the closed to the open position, a movable current responsive element, latching means releasably interconnecting said current responsive element and said contact opening member for retaining the latter in its normal position, an auxiliary member movable from a nor- 'mal to a predetermined position, a second latching means releasably interconnecting s'aid current responsive element and said auxiliary member for retainingthe latter in its normal position, said/second latching means being adapted when released to actuate said auxiliary member to the predetermined position, and means actuated by said operating mechanism for returning said contact opening member and said auxiliary member to their normal positions and for restoring the latching engagement of -both said latching means with said current responsive element when both of'said latching means have been released, andfor returning said auxiliary member and restoring the latching engagement of said second latching means without opening of said movable contact member when only said second latching means has been released.

9. In a circuit breaker having a movable contact member, an actuating mechanism including an operating lever for operating said contact member to open and closed positions, a carrer for said actuating mechanism movable from a normal to a tripped position for operating said Contact member from the closed to the open position, a latch member for releasably retaining said carrier in the nonmal position, a control element movable in response to predetermined conditions, a pivoted trip member biased to the tripped position and held in the normal position by said control element,l saiiiv latch member bcing movable by said trip member to release said carrier, an indicating member movable from a norzmal to an indicating position, a second pivoted trip member biased to the trlpped position and held in the normal position by said control element, said indicating member being movable by said second trip member to the indicating position prior to the release of said rst trip member.

10. In a circuit breaker having a movable contact member, an actuating mechanism including an operating lever for operating said contact member to open and closed positions. a carrier for said actuating mechanism movable from a normal to a tripped position for operating said contact member from the closed vto the open position, a latch member for releasably retaining said carrier in the normal position, a movable bimetallic element, a pivoted trip member biased to the tripped position and held in the normal position by said bimetallic element, said latch member'being movable by said trip member to release said carrier, an indicating member movable from a normal to an indicating position, a second pivoted trip member biased to the tripped position and held in the normal position by said bimetallic element, said indicating member being movable by said second trip member to the indicating position in response to a predetermined current of value less than that required to release said rst trip member, means actuated by said operating lever for resetting said carrier to normal position and further means actuated by said operating leverior resetting said trip members and for actuating said indicating member to itsVnon-'indicating position.

11. In a circuitbreaker, an operating member for opening and closing the contacts of said breaker, means for opening said contacts irrespectiveof lthe position of said operating member including retaining means for holding the contacts from being tripped to the open position, a

control element responsive to predetermined conditions, a pivoted trip member biased to the tripped position and held in the non-tripping position by said control element, a latch element movable by said trip member to release said retaining means to open the contacts of said breaker, a second pivoted trip memberv biased'to the tripped position and held i'n a non-tripping position by said controlelement, and an auxiliary member movable by said secondtrip member from a normal to a predetermined position in response to a predetermined condition occurring prior to that condition required to release said retaining means.

l2. In a circuit breaker, an operating member for opening and closing the contacts of said breaker, means for -opening said contacts irrespective of the position of said operating member including retaining means for holding the contacts from being tripped to theopen position, a movable current responsive element, a pivoted trip member biased to the tripped position and held in the non-tripping position vby said current responsive element, a latch element movable by said trip member to release said retaining means toopen the contacts of said breaker, a second pivoted trip member biased to the tripped position and held in a non-tripping position by said current responsive element, an indicating member movable by said second trip member from a normal to an indicating position in response to a predetermined current vof value less than that required to release said retaining means, and means for resetting each of said trip members to their normal position, the means for resetting said second trip member 'being operable irrespective of the position of the contacts oi said breaker.

13. ln a circuit breaker, an operating member movable between predetermined positions 'for opening and closing the contacts of said breaker, means for opening said contacts irrespective of the position of said operating member including retaining means for holding the contacts from being tripped to the open position, a movable bimetallic element, a pivoted trip member biased to the tripped position and heid in the non-tripping position by said bimetallic element, a latch element movable by said trip member to release said retaining means to open the contacts of said breaker, a second pivoted trip memper biased to the tripped position and held in a non-tripping position bysaid bimetallic element, an indicating member movable by said second trip member from a normal to an indicating position in response to a predetermined current of value less than that required to release said retaining means, and means actuated by said operating member during a predetermined initial movement thereof from the closed to the open position for resetting said second trip member and for returning said indicating member to the normal position, said predetermined initial movement of said operating member being insufficient for actuating the contacts to the open position;

14. A trip mechanism for a 'circuit breaker hav ing means for retaining the contacts of the breaker in the closed position, said retaining means including a latch biased to latched position and movable to permit opening of said contacts,'a pair of pivoted trip members biased to lmove to the tripped position, a movable current responsive element in circuit with said contacts for engaging and holding both oi said trip members, one of said trip members being released upon movement of said current responsive element and then moving due to its bias to move said latch against its bias to open said contacts, an auxiliary contact member, a cooperating contact therefor, said auxiliary contact member being movable upon movement of the other of said trip members into engagement with said cooperating contact for closing an auxiliary circuit, said second trip member being released in response to a predetermined current of magnitude less than that required to release said first trip member.

15. A trip mechanism for a circuit breaker having'rneans for retaining the contacts of the breakeran the closed position, said retaining means being releasable to open said contacts, a pair of pivoted trip members biased to the tripped position, la movable current responsive element in circuit with said contacts for releasably holding said trip members in an inactive position, a latch member movable by one of said trip members for releasing said retaining means to open said contacts, an auxiliary contact member, a cooperating contact therefor, said auxiliary contact member being movable by the other of said trip members into engagement with said cooperating contact for closing an auxiliary circuit, said second trip member being releasable in response to a predetermined current of magnitude less thanthat required to trip said first trip member, and means lor resetting each of said trip members to their respective inactive positions.

16. A trip mechanism for a circuit breaker having means for retaining the contacts oi' the breaker in the closed position, said retaining means being releasable to open said contacts, an independently movable pivoted trip member, spring means engaging said trip member for biasu ing said trip member to the tripped position, n holding element movable in response to a predetermined condition for releasably holding said trip member in an inactive position, said biasing means being disposed with respect to said trip member so that the resultant moment arm producing the biasing action increases with the movement of said trip member when the latter is released, and a iatching member movable by said trip member for releasing said retaining means to open said contacts.

17. A trip mechanism for a circuit breaker having means foretaining the` contacts of the breaker in the closed position, said retaining means being releasable to open said contacts, an independently movable pivoted trip member. spring means engaging said trip member for biasing saidtrip member to the tripped position, Aa holding element movable in response to a pree determined condition for releasably holding said trip member in an inactive position, and a latch member movable by said trip member for releasing said retaining means to open said con tacts, said biasing means being disposed with breaker in the closed position, said retaining means being releasable to open said contacts, a p-ivoted trip member biased to the tripped position, a bimetallie element mounted for rotation about a xed pivot, a catch member mounted on said bimetallic element for releasably holding said trip member in an inactive position, a latch member movable by said trip member io'r re leasing said retaining means to open said contacts, means for adjusting the angular position of said bimetallic element with respect to said xed pivotl for determining the amount of overlapping between said catch member and said trip member, and spring means associated with thepivotal mounting of said bimetallic element for eliminating any back lash between said bimetallic element and its xed pivot.

19. In a circuit breaker having a movable circuit controlling member, and actuating means for moving said circuit controlling member to open or to closed circuit position, in combination, an auxiliary device, a plurality oi tripping members independently movabie from a normal position to an operative position, means biasing said tripping members to operative position, trip means for normally restraining said tripping members in their normal position, and operable in response to predetermined conditions to release said members, at least one of said tripping members being operative when released to eect actuation of said device and at least one other of said tripping members being operative when rcleased to cause said actuating means to move d circuit controlling member from the closed to the open circuit position. and said actuating means including a portion movable to return said tripping member for said device to restrained position while said circuit controlling member remains lin closed position.

20. In a circuit breaker having a contact member operable to open or to closed circuit position, in combination, an auxiliary device, a plurality of trip members independently movable from a normal position to an operative position, means biasing said members to operative position, means for releasably restraining said members in their normal position, an electro-responsive trip element operable in response to a predetermined condition to release said trip members, at least one of said trip members being operable when released to eiect actuation of said auxiliary device and at least one other of said members being operable when released to cause actuation of said contact member from the closed to the open circuit position, and means for returning said trip member for actuating the trip device from released to restrained position without causing opening movement of said Contact member.

and in response to an overload of different predetermined magnitude to cause said actuating mechanism to move said switch member to open circuit position, and means movable to return said auxiliary device to its original condition prior to any movement of said switch member to open circuit position.

22. In a circuit breaker having a switch member and actuating mechanism including a movable manually operable control member for moving said switch member to open or to closed circuit position, in combination, an auxiliary device, trip means including a trip element movable in response to a predetermined overload condition to effect actuation of said device, and in response to a different predetermined overload condition to cause said actuating mechanism to move said switch member to open circuit position irrespective of the position of said control member, and said control member being movable to return said auxiliary device to its original condition without causing movement of said switch member to open circuit position.

23. In a circuit breaker having a movable switch member, actuatingmeans for moving said switch member to open or to closed circuit position to opener to close the circuit, in combination, an auxiliary device, a lplurality of members independently movable from a normal position to an operating position, at least one of said members when moved being operative to actuate said device, at least one other ofv said members when moved being operative to cause said actuating means to move said switch member from the closed to the open circuit position, an electroresponsive control element movable in response to a predetermined condition to effect movement of said one member for actuating said device, and further movable to yeiect movement of said other member for causing said actuating means to move said switch member from the closed to the open position, and means for resetting said ene member without moving said switch member from closed circuit position.

24. In a circuit breaker having a movable switch member, actuating means for moving said switch member to open or to closed circuit position to open or to close the circuit, in combination, an auxiliary device, a plurality of members independently movable from a normal position to an aieasse operativev position, at least one oi said members when moved being operative to actuate'said dcvice, at least one other of said members when moved being operative to cause said actuating means to move said switch member` from the closed to the open circuit position, an electroresponsive control element movable in response to a predetermined condition to effect movement of said one member for actuating said device, and further movable to efect movement of said other member for causingsaid actuating means to move said switch member from the closed to 'the open position, said actuating means including means for resetting said one member without moving said switch member from closed circuit position.l

25. In a circuit breaker having a `movable switch member. actuating means .including a movable operating member for normally moving said switch member to open or to closed circuit position to open or to close the circuit, in combination, an auxiliary device, a plurality of members movable from a normal position to an operative position, atleast one of said members when -moved being operative to actuate said device, at

least one other of said members'when moved being operative to cause said actuating means to move said switch member from the closed to the open circuit position, an electro-responsive control element movable in response to a predetermined condition to effect movement of said one member for actuating lsaid device, and further movable to. eiect movement of said other member for causing said actuating means to move said switch member from the closed to the open circuit position, said Amovable-operating member being operable to restore said one member to its normal position without moving said switch member from closed circuit position.

26. In a circuit breaker having a switch member, operating mechanism including an operating member for moving said switch member to open and to closed circuit position, and a member releasable from a normal positionto effect movement of said switch member to open circuit position, in combination, an auxiliary device. trip means including a trip element movable in response to overloads ofv predetermined magnitude vto effect actuation of said auxiliary device and in response to overloads of different predetermined magnitude to eiect release of said releasable membei' to open the circuit, and means-operable by said operating member ior resetting said auxiliary device and said releasable member, said resetting means being operable by said operating member to reset said auxiliary device prior to release of said releasable member and while said switch member remains in closed circuit position. 27. In a trip mechanism for a circuitA breaker having means for retaining the contacts of the breaker in the closed position, said retaining means beingrelcasable to open said contacts, a pivoted trip member movable to the tripped position, a bimetallic element mounted for rotation about a fixed pivot, said trip member being movable upon movement of said bimetallic'element for releasing said retaining means to open said contacts, a spring for biasing said bimetallic element to move about said xed pivot for determining its relation to said trip member. and a second spring associated with the pivotal mounting of said bimetallic element for taking up any looseness between said bimetallic element and its iixed pivot.

MERRILL G. LEONARD.

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