US2303492A - Circuit-breaker mechanism - Google Patents

Description

Uecl l, 1942.- g. J. A. PETERsoN ETAL V 2,303,492

'HcmUIT-BREAKR MECHANISM Fnednec. 29, 1959 ATTORNEY Patented Dec. 1, 1942 2,303,492 CIRCUIT-BREAKER MECHANISM Alfred J. A. Peterson and John B. MacNeill, Wilkinsburg, and Andrew H. Bakken, Pa., assignors to VVesti ufacturing Company,

Pittsburgh,

nghouse Electric & Man- East Pittsburgh, Pa., a

corporation of Pennsylvania Application December 29, 1939, Serial No. 311,652

(Cl. 200m-50) 23 Claims.

Our invention relates to a circuit-breaker linkage or operating-mechanism which has been specially designed for circuit-breakers comprising an arc-extinguishing switching-member, a serially connected disconnecting switching-member, and a relatively high-ourrent-capacity switchingmernber adapted to be connected in parallel-circuit relation to the two serially connected switching-members. Our invention was particularly designed for water breakers, or breakers in which the arc-extinguishing contact is broken in water, utilizing the water vapor and the gaseous products of water-dissociation to extinguish the arc, although our invention is applicable also to other types of breakers in which the arc-extinguishing function is performed in some medium other than water, such, for example, as in oil or compressed air.

Our invention has particular applicability to those breakers, in general, in which the arc-extinguishing function is performed in a medium or structure of such nature that it is desired to open a serially connected disconnect-switch after the arc-extinguishing contacts have been substantially fully opened, and in which it is desirable to close the arc-extinguishing contacts before the full line-voltage is applied thereto by the closure of the disconnect-switch. In this class of breakers, the nal opening of the disconnectswitch, as the last step in the opening of the breaker, serves to remove the line-voltage from ,the arcing chamber, thus making it possible to design said chamber in an economical manner having no relation to the necessity for constantly and continuously withstanding the full linevoltage with practically no current-leakage.

The operation of closing the arc-extinguishing contacts while the disconnect-switch is still open, that is. while no voltage is being applied to the terminals of the arc-extinguishing contacts, avoids the possibility of the premature striking of an arc across the arc-extinguishing contacts as they are approaching each other in the closingoperation. as such premature or temporary striking of an arc would produce very undesirable turbulence in the arc-quenching chamber, and would also very much weaken the efficacy of the arc-quenchincr properties of the breaker in the event that it should be necessary to immediately reopen the breaker, because of some faulty condition in the line in which the breaker is connected.

The parallel-connected by-passing-contact of high our. rit-capacity is desirable in many instances, notably in breakers of the higher current-ratings, in order to relieve the arc-extinguishing or current-interrupting contacts of all but temporary duty during the circuit-closing and circuit-opening operations, the major portion of the current being normally carried by the Icy-passing contacts.

The principal object of our invention is to provide an improved operating-mechanism linkage for operating a circuit breaker of the type just described.

A more specic object of our invention is to provide an air-break member or disconnectswitch which is operated, with a snap-action, from the operating-mechanism linkage of the circuit-breaker as a whole, either with a togglespring mechanism for opening or closing the disconnect-switch near the ends of the opening and closing operations of the linkage, respectively, or with holding-latches, or their equivalent, for holding the disconnect-switch in either or both of its open and closed positions, until such time as the holding-latches are released by the movement of the operating-mechanism linkage, the closed-disconnect latch being preferably a multinotched latch, or the equivalent, for holding the disconnect-switch in any one of a plurality of closed positions of diierent degrees of closure. The disconnect-switch may also have a positive thrust imparted to the same, either as an aid to, or as a substitute for, the toggle-spring mechanism, by means of rollers or bumpers carried by the operating-mechanism linkage, for opening cr closing the disconnect-switch near the latter part of the movement of the linkage in either the opening or closing direction, respectively.

A further object of our invention, in breakers which are provided with a parallel-connected main switch of heavy current-carrying capacity, is to provide a toggle-mechanism, or equivalent mechanical-motion means, between the operating mechanism and the linkage of our invention, whereby a relatively large movement of the operating mechanism is accompanied by a relatively small movement of the arc-extinguishing switching-member when the latter is in its fully closed position, so that the operating mechanism can continue to close, through a considerable distance of motion, after the arc-extinguishing contacts have closed, this nal closing movement of the mechanism being utilized to close the main contacts, and contrary-wise, during the opening movement of the mechanism, the initial movement of the mechanism being utilized to open the main contacts, while the arc extinguishing contacts scarcely move at all, and at first remain closed.

With the foregoing and other objects in view, our invention consists in the systems, combinations, mechanisms, parts and processes hereinafter described and claimed, and illustrated in the accompanying drawing, wherein:

Figure 1 is a diagrammatic view showing our improved breaker, and the operating mechanism and linkage therefor, in a diagrammatic manner, not to scale, but wi h a view to the illustration of the essential operative principles of the very complicated mechanism and linkage which is neces-- sary in any practical embodiment of our invention, as will be readily understood by those who are familial' with circuit-breaker' mechanisms. Fig. l shows the operating mechanism and the novel linkage of our invention, with the three different contact-members of the circuit-breaker in their closed positions, while Fig. 2 is a similar View of the linkage-part alone, showing the switchingmembers of the circuit breaker in their open posi-- tions.

We have illustrated our invention in connection with a circuit-breaker having three switchingmembers designated, in their entireties, at l, 2 and 3, respectively.

The switching-member i is the arc-extinguishing member of the combination, or the point at which the arc is ilnally extinguished, in the circuit-opening operation of the breaker as a whole. Although, as previously pointed out, we are not limited to any particular kind of arc-extinguishing switching-member I, we have diagrammatically illustra-ted this member, for the sake of fixing our ideas and showing something deilnite, as a water-break circuit-breaker in which the stationary contacts 4 are immersed in water 5 which is held within a suitable container the stationary contacts 4 being adapted to be bridged by a movable contact 'i'. There are, on the market, several different forms of switc ing-members utilizing water as the arc-extinguishing medium, and a number of these have been described in technical press, so that we have not deemedit necessary to illustrate and describe the precise details of any preferred form of water-break .p- .paratua but have merely diagrammatically designated such an apparatus in the drawing.

The switching-member 2 is .an open-air disconi nect-switch which is electrically connected in series with the arc-extinguishing switching member I Physically, the disconnecting switchingmember 2 comprises a pivoted switch-arm 8, plv-- oted at S, and terminatingin a contact-blade i i which cooperates with a bifurcated stationary contact-member i2.

The switching-member 3, when utilized, is the main Current-carrying member which is electrically connecte-d in shunt across the two seriallyconnected switching-members E and L. It is made of very massive parts, cr nrising a movable switch-arm i3 which is pivoted at i4, a bifurcated stationary contact-member 5.

Any suitable operating-mechanism may be utilized to operate our circuit-breaker. Although our invention not limited to any particular of operating mechanism, we have shown, by way of preference. a typical trip-free operating mechanism which may be described as comprising an operating-link il which joins the switch-arm I3 to one endof an outer lever 22 which is intermediately pivoted at The outer lever t2 has a second extending end 24, carrying a trippinglatch pin 'Mounted upon the same pivot-pin 23 as the outer lever 22, is an inner lever 2G, one end of which is connected to a retrieving` spring 2l, while the other end carries a latch-pivot Il?! which supports a tripping-latch 2S.- fcr engaging the latch-pin 25 carried by the outeri lever The tripping-latch 2S is provided with an ortwardly extendin arm cr tripping lever I. which is adapted to 'oe elevated, in order to trip the mechanism, as by means of a trip-coil and a cooperating armature o-r core 33 for rais pin 34 into engagement with the tripping The inner lever 2E is provided with a re pin 36 which is fastened to said inner lever $273 at a point intermediate between the pivotal point 2! and the latch-pivot 2S. The retrieving pin engages within an eye-bolt 3? which is carried by the armature or core 33 of a closing-magnet 39.

The inner lever 26 is also provided with a main latch-pin 4i which shown. in a position intermediate between the retrieving pin the latch-pivot The main latch-pin 4I is adapted to be engaged by a main latch which is tionarily pivoted at 43, and which is normally biased toward its latching position, as by means of a compressing-spring 44. The main latch 42 has 'an outwardly extending operating-arm 45 which is adapted to be actuated by an abutment or projection 45, which is carried by the outer lever 22, and which moves into engagement with the latch-arm 45 when the mechanism moves away from its closed position which is illustrated in Fig. l.

Our invention relates to a novel form of linkage for utilizing any suitable operating mechanism such as the mechanism 20 which has just been described, and which is diagrammatically indicated in Fig. l. In the illustrated form of embodiment of our invention, the operating link ZI of the operating mechanism is connected to the movable arm I3 of the main switching-member 3, being pivoted thereto at an intermediate point 5D thereof. The said movable arm I 3 of the main Vswitching-member 3 is also illustrated as being provided with a powerful opening-spring 5I.

In the illustrated embodiment of our invention, the pivoted arm I3 of the main switching member 3 is provided with a projecting extension 52 carrying apivot-pin 53 which is displaced out of the plane of the switching arm iS, so as to operate, in eiect, something like a bell-crank arm with respect to the pivot-point I4, as indicated by the dotted line 54. The bell-crank pivot-,pin 53 is connected, by a link 55, to a projecting arm 5S of a complicated lever-mechanism 5l' which is stationarily pivoted at 58. rlhe lever-mechanism 5'! has a second arm 59 which is pivoted, at SI to an intermediate point in a walking-beam 62 which operates to lift-rod 53 of the arc-extinguishing switching-member I, the lower end of the lift-rod 63 carrying the movable contact-member 1 of said switching-member.

The lever-mechanism 51 a third extending arm S5 is also provided with which terminates in a 4pin 65 to which is attached one end of a toggle- Yspring 6T, the other end of which is connected to an intermediate point 58 in the pivoted arm 8 of the disconnecting switching-member 2. The extending arm 65 of the lever-member 5T operates in what we call a toggle fashion, to swing the end 66 of the toggle-spring S! from one side, to the other, of the disconnect-arm 8, when the lever-member 51 is moved from its breaker-closed position to its breaker-open position, in a manner which will be more fully described hereinafter.

We also preferably provide our disconnect-arm 8 with a pair of latching-members 10 and 1|, which are stationarily pivoted at 12. When the disconnect-arm 8 is open, an intermediate pin 13, which is carried thereby, is engaged by the latch 10, to hold the disconnect-arm 8 open, while, when the disconnect-arm 8 is closed, its holdingpin 13 will be engaged by any one of a plurality of notches or detents I4 of the latching-member 1I, it being understood that the latching-members 10 and 1I are so offset that their latching I points can engage the holding-pin 13 of the disconnect-arm 8, while the latch-pivot I2 is out of the path of the holding-pin 13 so as not to interfere with the swinging movement 0f the disconnect-arm 8.

We usually prefer to provide a plurality of notches 14 on the closed-disconnect latchingmeans 1I so as to more effectively hold the disconnect-arm 8 against rebounding, either from the mechanical forces involved, or because of the electrical forces developed by the current owing through the disconnect-contacts I I and I2, and also for the more important purpose of holding the disconnect-arm 8 either fully closed, with its movable contact-member II fully inserted into the bifurcated stationary contact-member I2, as in the normal operation of the device, or only partially closed, in case a breaker-opening operation should be instantly initiated as soon as the movable disconnect-contact II began to touch ff.

the stationary disconnect-contact I2. This precaution is taken in order that these contacts |I and I2 will not possibly prematurely open, prior to the opening of the arc-extinguishing contacts 6 and 1, as will be subsequently described more .2."

fully.

` The latching members 18 and 1I are also provided with actuating arms 15 and 11, respectively, which are adapted to be engaged by an unlatching arm 18, which is carried by the lever-mechanism 51, so that the respective latches 18 and 1| are disengaged from the holding-pin 13 of the disconnect-arm 8, at an appropriate time during the operation of the lever-member 51, as will be subsequently described.

In accordance with our invention, we further prefer to equip the lever-mechanism 51 with thrust-members or rollers 8|) and 8| for cooperation with the disconnect-arm 8. The thrustroller 88 of the lever-member 51, which is a part of our operating-mechanism linkage, engages the disconnect arm 8, at an appropriate point in the closing-movement of the linkage, to supplement the action of the toggle-spring B1 by giving the disconnect-arm 8 a positive thrust in the closing direction, while the thrust roller 8| performs a similar function during the opening operation, as will be subsequently described.

In operation, assuming that the circuit-breaker is closed, as shown in Fig. l, it will be noted .y

that the main current is carried, say from the line 85. through the main contacts I5 and I3, to the line 86. Only a relatively small part of the total current is carried through the shunt-path through the disconnect-switch contacts I 2 and I I, and the arc-extinguishing contacts 1 and 4. In order to carry this current, a iiexible pigtail shunt 81 is preferably provided, to connect the disconneet-arm 8 and the lift-rod 63 of the arc-extinguishing switching-member I.

A circuit-opening operation is initiated by the elevation of the tripping-lever 3|, as by the energization of the trip-coil 32. This disengages the tripping latch 28 from the latch-pin 25 oi the outer lever 22, and leaves said outer lever free magnet 39.

-, at the beginning of the opening-stroke.

to swing clockwise, about its pivotal point 23, by y reason of the downward thrust of the operating link 2I as a result of the strong pull of the opening-spring 5|. For convenience in description, We shall first follow through the operation of the operating mechanism 20 and then go back and follow through the operation of our novel linkage which is associated with the main switcharm I3.

When the outer lever 22 of the operating mechanism swings open, in a clockwise direction, its latch-actuating projection 48 engages the actuating-arm of the main latch 42, disengaging said latch from the latch-pin 4| carried by the inner lever 25, and permitting said inner lever 2B to move, in a clockwise direction, about the pivot pin 23, under the influence of the retrieving spring 21. During this movement of the inner lever, the retrieving pin 36 is elevated, thus raising the armature-core 38 of the closing- When the inner lever 26 completes its clockwise movement, it relatches itself again, to the outer lever 22, through the operation of the tripping latch 29, so that the parts are now ready for a reclosing operation, which will be described later on.

Meanwhile, considering the operation of our novel linkage during the opening movement of the main switch-arm I3, it will be noted that, when the main switch-arm I3 is in its closed position, as shown in Fig. 1, the bell-crank arm 54 and the link 55 are almost in alignment with each other, in toggle fashion, so that a considera'ole swinging-movement oi the main switcharm I3 will be accompanied by only a slight rocking-movement of the lever-member 51 about its pivot-point 58. The object in this togglejoint disposition of the parts 51| and 55 is to permit the main contacts I5 and I3 to be well opened or separated before the rocking levermember 51 has moved far enough to raise the arc-extinguishing moving-contact 'I out of its bridging-relation with respect to the stationary conta-cts II of the arc-extinguishing switchingmember I. y

After the main switch-arm i3 is well separated from its stationary contact I5, the toggle 553-55 is broken suiiiciently so that the continued opening movement of the main switch-arm i3 rocks the lever-member 51 in a clockwise direction suiiiciently to elevate the lift-rod S3 far enough to break the arc-extinguishing contacts between the contact-members 1 and 4, thus arc which is extinguished in the water 5, or equivalent arc-extinguishing medium. opening movement of the mechanism continues until a point is reached at which the arc is eX- tinguished. or practically extinguished, in the arc-extinguishing switching-member I. Before this point has been reached, in the opening movement of the mechanism, the bottom end 58 of the rocking lever-mechanism 51 will have swung from the right-hand side to the left-hand side of the disconnect-arm 3. so that. whereas. the toggle-spring 61 tendedl to hold the disconnectarm closed, the bottom end of the toggle-sining` actuates the closed-disconnect latch or holdingrneans il, so as to permit the disconnect-arm 8 to begin to open, under the iniiuence of the toggle-spring el. Almost immediately thereafter, as the clockwise rotation of the lever-member 5'! continues, during the remainder of the ojo-eningz-movement of the mechanism, the thrustroller El engages the disconnect-arm 8 to supplement the toggle-spring operation by giving the disconnect-arm a positive thrust in the opening direction, thereby considerably facilitating this o1 eration. The nal opening-operation is thus completed, at the disconnecting switchingmember 2, the contacts of which open with a rapid and positive snap-action, thus insulating the arc-extinguishing chamber 5 from the voltage of the line -85. When the disconnectarrn 8 is fully opened, it is latched in. its open position, by means of the latch "lll, so that during the subsequent closing operation, the disconnectarm 8 will not prematurely close.

To close the circuit breaker, the closing-magnet Si) is energized, thus pulling,r down the retrieving pin 35 of the operating mechanism, and

since the inner and outer levers 26 and 22 are i latched together at 29, depression of the retrieving pin 36 causes both of the levers 2S and 22 to swing,T in a counter-clockwise direction about their common pivotal point 23. thus lifting the operatingT rod 2l, and closing the switch-arm i3.

Duringr the first portion of the lifting-movement of the main switch-arm .3. long before said arm comes into contact with its cooperating stationary contact-member l5, the link swings the lever-member 5l in a counter-clockwise direction, from the position shown in Fig. 2, the irst result of said suriname-movement being to close the arc-extinguishing contacts 'l and d, this operation being completed while the disconnecting switching member 2 is still open, and hence while the line-voltage is kept off of the arc-extinguishing switching-member I. thus premature disturbances within the arcishing chamber F3.

During this counter-clockwise swing-movement of the lever-member 51. the bottom end 65 of the toggle-spring 'Il is swung from the left-hand side of the disconnect-arm 8, past dead-center with respect to said arm, and over to the righthand of said disconnect-arm il, so that the toggle-spring M now tends to close the disconnect-arm 3, but arm is latcbed in its open. position, as shown in Fig. f2, by means of the latch it?. 'When the moving Contact 'l oF the arc-extinguishing switching-member l into contact with its cooperatin y stationary contacts or when it is just about to come into Contact theV the latch-actuating projection 'IS the counter-clockwise swinging lever-inember 5l engages the open-disconnect latch 'll and disengages the same from the latching pin .'3 of the disconnect-arm S, permitting seid arm to begin to close, onder the iniluence of the toggle-spring El. Almost irnmediatel;Y thereafter. however, the thrust-roller Si) of the counter-clockwise swinging lever-member 51 engages the left-hand side of the disconnect-arm 8 and forcibly thrusts it in a closing direction, to ite the closing-movement of the disconneet-arm 8, with a positive snap-action.

. t this point, in the closing operation, when the moving Contact l of the arc-extinguishing switching member I has just begun to move in between the stationary contacts 4, the closing operation of the circuit-breaker mechanism 20 is not yet completed, but the bell-crank arm 54 of the mechanism 13--52 is nearly -1n alignment, Vtoggle-fashion, with the link 55, so that the continued swinging movement of the closing switcharm I3 of the main switching-member 3 results in a relatively small, continued wiping-movement of the moving contact l, as it continues to move, in the closing direction, between the two stationary contacts 4 of the arc-extinguishing switching-member I. As a result of this toggle-action 541-55, when the arc-extinguishing switchingmember l is in its fully closed position, We make it possible for the main contact-arm I3 to be well separated from its stationary contact-member I5 at the time when the arc-extinguishing contacts 'I and close and when the disconnecting contact-arm 8 snaps closed, so that the final movement of the closing-operation will nally close the main contacts i3 and I 5, thus bypassing the temporary-duty contacts 4, T, II and I2 of the serially-connected switching-members I and 2.

While we have illustrated our invention in a preferred form of embodiment, and have explained its mode of operation, particularly in connection with a water-dielectric circuit-breaker, we wish. to be understook that it is not necessary, in practicing our invention, to utilize all of the described features at the same time, in any given apparatus, and we wish it to be further understood that various changes, by way of substitutions and additions` may be uti without departing from the essential spirit of our invention, particularly in its broader aspects. We further wish it to be understood that the illustrated embodiment is only dia grammaticallv shown, and that the necessary clearances will be provided so that the various moving parts will clear each other, or Contact with each other, as the occasion requires, and as hereinbove described. We desire, accordingly, that the appended claims shall be given the broadest interpretation consistent with their language.

We claim as our invention:

l. A circuit-breaker comprising an arc-extinguishing switching-member, a serially connected disconnectinsT switching-member, an operatingmechanism for opening and closing said yarc-extinauishincr switchingy member, a shiftable togglespring support carried by said mechanism, a spring operatively connected between said disconnecting switching-member and said toggle-spring support, and opening and closing means for operating said mechanism, said toggle-spring support being so disposed as to be so shifted, during the operation of said mechanism, that said spring tends to close said disconnecting switching-member when said toggle-spring support is past a dead-center in the closing movement of said mechanism, and said spring tends to open said disconnecting switching-member when said togglespring is past a dead-center in the opening movement of said mechanism.

2. A circuit-breaker comprising an arc-extinguishing switching-member, a serially connected disconnectin-7 switching-member, an operatingmechanism for opening and closing said arc-extinguishing switching-member, a disconnectopening spring-inea operable, when said arcextinguishing switching ibcr is open, to tend to open said disconnecting switching-member, releasable closed-disconnect holding-means for holding said disconnecting switching-member closed against the bias of said disconnect-opening spring-means, means operable during the opening movement of said mechanism, when said arc-extinguishing switching-member has opened by a predetermined amount, to release said disconnecting switching-member from said closed-disconnect holding-means, and means responsive to the closing movement of said mechanism for causing said disconnecting switching-member to close after the closure of said arc-extinguishing switching-member during the closing movement of said mechanism.

3. A circuit-breaker comprising an arc-extinguishing switching-member, a serially connected disconnecting switching-member, an operatingmechanism for opening and closing said arc-extinguishing switching-member, disconnect-opening spring-means o-perable, when said arc-extinguishing switching-member is open, to tend to open said disconnecting switching-member, releasable closed-disconnect holding-means for holding said disconnecting switching-member closed, in any one of a plurality of closed positions o diierent degrees of closure, against the bias of said disconnect-opening spring-means, means operable during the opening movement of said mechanism, when said arc-extinguishing switching-member has opened by a predetermined amount, to release said disconnecting switchingmember from said closed-disconnect holdingmeans, and means responsive to the closing movement of said mechanism for causing said disconnecting switching-member to close after the closure of said arc-extinguishing switching-member during the closing movement of said mechanism.

4. A circuit-breaker comprising an arc-extinguishing switching-member, a serially connected disconnecting switching-member, an operatingmechanism for opening and closing said arc-exiii) tinguishing switching-member, disconnect-closing :ai

spring-means operable, when said arc-extinguishing switching-member is closed, to tend to close said disconnecting switching-member, releasable open-disconnect holding-means for holding said disconnecting switching-member open against the bias of said disconnect-closing spring-means, means operable during the closing movement of said mechanism, when said arc-extinguishing switching-member has closed, to release said disconnecting switching-member from said opendisconnect holding-means, and means responsive to the opening movement of said mechanism for causing said disconnecting switching-member to open after the opening of said arc-extinguishing switching-member during the opening movement of said mechanism.

5. The invention as dei-ined in claim 1, in combination with releasable open-disconnect holding-means for holding said disconnecting switching-member open, releasable closed-disconnect holding-means for holding said disconnecting switching-member closed, means responsive to the closing movement of said mechanism to release said disconnecting switching-member` from said open-disconnect holding-means after said toggle-spring support has been moved past the dead-center in the closing movement of said mechanism, and means responsive to the opening movement of said mechanism to release said disconnecting switching-member from said closed-disconnect holding-means after said toggle-spring support has been moved past the deadcenter in the opening movement of said mechanism.

6. A circuit-breaker comprising an arc-extinguishing switching-member of a kind such that it is undesirable to leave the circuit-Voltage continuously applied thereto after its opening-operation and such that it is undesirable to have the circuit-voltage applied thereto when its switching-contacts are approaching each other during its closing-operation, a serially connected disconnecting switching-member, holding means for holding the disconnecting switching-member both in its open position and in its closed position,

respectively, an operating-mechanism for opening and closing said arc-extinguishing switchingmember, and means responsive to the movement oi said mechanism for operatively engaging the disconnecting switching-member With a sudden striking-movement and for nullifying the holding-action of the holding-means which had been effective on the disconnecting switching-member, when the mechanism is in an intermediate position, both in its closing movement and in its opening movement, whereby the disconnecting switching-member is forcibly moved from one position to the other.

7. A circuit-breaker comprising an arc-extinguishing switching-member of a kind such that it is undesirable to leave the circuit-voltage continuously applied thereto after its opening-operation and such that it is undesirable to have the circuit-voltage applied thereto when its switching-contacts are approaching each other during its closing-operation, a serially connected disconnecting switching-member, an operatingmechanism, means responsive to an early part of the opening movement of said mechanism for initiating a separation of the contacts of said arc-extinguishing switching-member, means responsive to an early part of the closing movement of said mechanism for beginning to close the contacts of said arc-extinguishing switchingmember, and lost-motion means responsive to the continued movement of said mechanism, with a lost-motion connection so that the mechanism must rst move a considerable distance, in either its opening movement or its closing movement, before said lost-motion means is set into motion, said lost-motion means thereupon belatedly responding to the continued movement of said mechanism for forcibly mechanically actuating the disconnecting switching-member from the mechanism with a delayed snap-action so that the disconnecting switching-member opens with a snap-action after the opening of the arc-extinguishing switching-member during the open-l` ing operation of the mechanism, and closes with a snap action after the closure of the arc-eX- tinguishing switching-member during the closing operation of the mechanism.

8. A circuit-breaker comprising an arc-extinguishing switching-member of a kind such that it is undesirable to leave the circuit-voltage continuously applied thereto after its opening-operation and such that it is undesirable to have the circuit-voltage applied thereto when its switching-contacts are approaching each other during its closing-operation, a serially connected disconnecting switching-member, an operating-mechanism, means responsive to an early part of the opening movement of saidpmechanism for initiating a separation of the contacts of said arcextinguishing switching-member, means responsive to an early part of the closing movement of said mechanism for beginning to close the contacts of said arc-extinguishing switchingmember, and lost-motion means responsive to the continued movement of said mechanism, With a lost-motion connection so that the mechanism must first move a considerable distance, in either its opening movement or its closing movement, before said lost-motion means is set into motion, said lost-motion means thereupon belatedly responding to the continued movement of said mechanism for forcibly mechanically actuating the disconnecting switching-member from the mechanism with a delayed snap-action so that the disconnecting switching-member opens with a snap-action after the opening of the arc-extinguishing switching-member during the opening operation of the mechanism, and closes with a snap-action after the closure of the arc-extinguishing switching-member during the closing operation of the mechanism, said lost-motion means including means responsive to the movement of said mechanism for engaging the disconnecting switching-member with a sudden striking-movement, so as to apply anl eitective operating-force thereto, when the mechanism is in an intermediate position during the actuating operation in at least one direction of travel of the mechanism.

9. A circuit-breaker comprising an arcextinguishing switching-member of a l'nd such that it is undesirable to leave the circuit-voltage continuously applied thereto after its opening-operation and such that it is undesirable to have the circuit-voltage applied thereto when its switching-contacts are approaching each other during its closing-operation, a serially connected disconnecting switching-member, an operating-mechanism, means responsive to an early part of the opening movement of said mechanism for initiating a separation of the contacts of said arcextinguishing switching-member, means responsive to an early part of the closing movement of said mechanism for beginning to close the contacts of said arc-extinguishing switchinggf opening movement or its closing movement, be-

fore said lost-motion means is set into motion, said lost-motion means thereupon belatedly responding to the continued movement of said mechanism for forcibly mechanically actuating the disconnecting switching-member from the I., mechanism with a delayed snap-action so that the disconnecting switching-member opens with a snap-action after the opening of the arc-extinguishing switching-member during the opening operation of the mechanism, and closes with a snap-action after the closure of the arc-extinguishing switching-member during the closing operation of the mechanism, and holding means for temporarily holding the disconnecting switching-member in at least one of its operative positions, said lost-motion means including means for nullifying the holding-action of said holdingmeans and for applying an elTective operatingforce to said disconnecting switching-member only after said delayed-action time when said lost-motion means becomes eiective to forcibly displace the disconnecting switching-member during an actuation of the mechanism.

10. A circuit-breaker comprising an arc-extinguishing switching-member of a kind such that y.;

it is undesirable to leave the circuit-voltage continuously applied thereto after its opening-operation and such that it is undesirable to have the circuit-voltage applied thereto when its switching-contacts are approaching each other during its closing-operation, a serially connected disconnecting switchng-member, an operatingmechanism, means responsive to an early part of the opening movement of Said mechanism for initiating a separation of the contacts of said arc-extinguishing switching-member, means responsive to an early part of the closing movement of said mechanism for beginning to close the contacts of said arc-extinguishing switching- 'i member, lost-motion means responsive to the` continued movement of said mechanism, with a lost-motion connection so that the mechanism must rst move a considerable distance, in either its opening movement or its closing movement, before said lost-motion means is set into motion, said lost-motion means thereupon belatedly responding to the continued movement of said echanism for forcibly mechanically actuating the disconnecting switching-membe;` from the mechanism with a delayed snap-action so that the disconnecting switching-member opens with a snap-action after the opening of the arc-extinguishing switching-member during the opening operation of the mechanism, and closes with a snap-action after the closure of the arc-extinguishing switching-member during the closing operation of the mechanism, and holding means for temporarily holding the disconnecting switching-member in any one of a plurality of closed i positions of different degrees of closure, said lostmotion means including means for nullifying the holding-action of said holding-means and for applying an effective operating-force to said disconnecting switching-member only after said delayed-action time when said lost-motion means becomes effective to forcibly displace the disconnecting switching-member during an opening operation of the mechanism.

l1. A circuit-breaker comprising an arc-extinguishing switching-member of a kind such that it is undesirable to have the circuit-voltage applied thereto when its switching-contacts are appreaching each other during its closing-operation, a serially connected disconnecting switching-member, an operating-mechanism, means responsive to an early part of the opening movement of said mechanism for initiating a separation of the contacts of said arc-extinguishing switching-member, means responsive to an early part of the closing movement of said mechanism for beginning to close the contacts of said arcextinguishing switching-member, lost-motion yieldable means responsive to the continued movement of said mechanism, with a lost-motion connection so that the mechanism must rst move a considerable distance, in either its opening movement or its closing movement, before said lost-motion means is set into motion, said lostmotion means thereupon belatediy responding to the continued movement of said mechanism for forcibly mechanically actuating the disconnecting switching-member from the mechanism with a delayed-action movement, and holding means for temporarily holding the disconnecting switching-member in its open position, said lost-motion means including means for nulliiying the holding-action of said holding-means and for applying an eiective operating-force to said disconnecting switching-member only after said delayed-action time when said lost-motion yieldable means becomes effective during the course of the closing operation of said mechanism, whereby said disconnecting switching-member closes after the closure of said arc-extinguishing switching-member.

12. A circuit-breaker comprising an arc-extinguishing switching-member, a serially connected disconnecting switching-member, an operatingmechanism, means responsive to an early part of the opening movement of said mechanism for initiating a separation of the contacts of said arc-extinguishing switching-member, means responsive to an early part of the closing movement of said mechanism for beginning to close the contacts of said arc-extinguishing switchingmember, lost-motion yieldable means responsive to the continued movement of said mechanism, with a lost-motion connection so that the mechanism must first move a considerable distance, in either its opening movement or its closing movement, before said lost-motion means is set into motion, said lost-motion means thereupon belatedly responding to the continued movement of said mechanism for mechanically actuating the disconnecting switching-member from the mechanism with a delayed-action movement, and holding means for temporarily holding the dis connecting switching-member in any one oi a plurality of closed positions of different degrees of closure, said lost-motion means including means for nulliying the holding-action of said holding-means and for applying an effective cperating-iorce to said disconnecting switchingmember only after said delayed-action time when said lost-motion yieldable means becomes effective during the course of the opening operation o said mechanism.

i3. A circuit-breaker comprising an arc-extinguishing switching-member of a kind such that it is undesirable to leave the circuit-voltage continuously applied thereto after its opening-operation and such that it is undesirable to have the circuit-voltage applied thereto when its switchingcontacts are approaching each other during its closing-operation, a serially connected disconnecting switching-member, an operating-mechanism, means responsive to an early part of the opening movement of said mechanism for initiating a separation of the contacts of said arcextinguishing switching-member, means responsive to an early part of the closing movement of said mechanism for beginning to close the contacts of said arc-extinguishing switching-member, lost-motion yieldable means responsive to the continued movement of said mechanism, with a lost-motion connection so that the mechanism must first move a considerable distance, in either its opening movement or its closing movement, before said lost-motion means is set into motion, said lost-motion means thereupon belatedly responding to the continued movement of said mechanism for mechanically actuating the disconnecting switching-member from the mechanism with a delayed-action movement, and holding means for temporarily holding the disconnecting switching-member both in its open position and in its closed position, said lost-motion means including means for nullifying the holding-action of said holding-means and for applying an eiectlve operating-force to said disconnecting switching-member only after said delayed-action times when said lost-motion yieldable means becomes effective during the operations of said mechanism.

14.. A circuit-breaker comprising an arc-eX- tinguishing switching-member, a serially connected disconnecting switching-member, an operating mechanism for opening and closing said arc-extinguishing switching-member, locking-means for positively holding said disconnecting switching-member in at least one of its operative positions, means responsive to the movement of said mechanism for disengaging said locking-means at a predetermined intermediate point in the travel of the mechanism from its position in which the disconnecting switchingmember was locked, and means responsive to the movement of said mechanism for subsequently giving said disconnecting switching-member a positive thrust away from its aforesaid locked position during the continued movement of the mechanism.

i5. A circuit-breaker comprising an arc-extinguishing switching-member, a serially connected disconnecting switching-member, a relatively high-current-capacity switching-member adapted to be connected in parallel-circuit relation to the two serially connected switchingmembers, an operating mechanism, means responsive to an early part of the opening movement of said mechanism for opening the highcurrent-capacity switching-member and initiating a separation of the contacts of said arcextinguishing switching-member, means responsive to an early part of the closing movement of said mechanism for beginning to close the contacts of said arc-extinguishing switching-member, lost-motion means responsive to the continued movement of said mechanism, with a lostmoton connection so that the mechanism must first move a considerable distance, in either its opening ovement or its closing movement, before said lost-motion means is set into motion, said lost-motion means thereupon belatedly responding to the continued movement of said mechanism for mechanically actuating the discon'necting switching-member from the mechanism with a delayed snap-action so that the disconnecting switching-member opens with a snap-action after the opening of the arc-extinguishing switching-member during the opening operation of the mechanism, and closes with a snap-action after the closure of the arc-extinguishing switching-member during the closing operation of the 5 mechanism, mechanical-motion means whereby a relatively large movement of said operating mechanism is accompanied by a relatively small movement of said aforesaid arc-extinguishing switching member when the latter is in its fully closed position, and means responsive to a nal part of the closing-movement of said mechanism for nally bringing together the contacts of the high-current-capacity switching-member, whereby the closing movement of said mechanism irst closes said arc-extinguishing switching-member and then closes said disconnecting switchingmember and finally closes said relatively highcurrent-capacity switching-member, and the opening movement of said mechanism first opens said relatively high-current-capacity switchingmember and then opens said arc-extinguishing switching-member and finally opens said disconnecting switching-member.

16. A circuit-breaker comprising an arc-extinguishing switching-member, a serially connected, non-arc-extinguishing disconnect-member, and operating-means therefor; characterized by said arc-extinguishing switching-member being of a kind such that it is undesirable to leave the circuit-voltage continuously applied thereto after its opening operation, and such that it is undesirable to have the circuit-voltage applied thereto when its switching-contacts are appro-aching each other during its closing-operation; and said operating-means having an opening-operation and a closing-operation, means for causing the opening-operation of the operating- ;neans to open the arc-extinguishing switchingmern er and to temporarily hold it open until the next closing-operation of the operatingroeans, means for causing a closing-operation of the operating-means to close the arc-extinguishing switching-member and to temporarily hold it closed until the next opening-operation of the operating-means, and lost-motion, snap-action means for automatically operating the non-arcextinguishing disconnect-member in response to the respective continued opening and closing movements of the aforesaid operating-means, said lost-motion, snap-action means responding at an intermediate point in the opening-movement of the operating-means, and thereupon operating t0 forcibly mechanically open the disconnect-member with a snap-action substantially independent of the remainder of the openingmovenient of the operating-means, and to thereafter temporarily hold the disconnect-member open until the next closing-operation of the lostmotion, snap-action means, the timing being such that the disconnect-member opens after the opening of the arc-extinguishing switchingmember, and said lost-motion, snap-action means responding at an intermediate point in the closing-movement of the operating-means, and

thereupon operating to forcibly mechanically close the disconnect-member with a snap-action substantially independent of the remainder of the closing-movement of the operating-means, and to thereafter temporarily hold the disconnect-member closed until the next openingoperation of the lost-motion, snap-action means, the timing being such that the disconnect-member closes after the closure of the arc-extinguishing switching-member.

f7. The invention as dened in claim 16, charaoterized by said lost-motion, snap-action means having a thrust-abutment for engaging the nonarc-extinguishing disconnect-member with a sudden striking-movement, so as to apply an effective operating-force thereto, during at least one direction of travel of the lost-motion, snap-action means.

18. The invention as :lenned in claim i6, in combination with an auxiliary holding-means for temporarily holding the non-arc-extinguishing disconnect-member in at least one of its operative positions, said lost-motion, snap-action means including means for nullifying the holding-action of said auxiliary holding-means when it applies an effective operating-force to said nonarc-extingushing disconnect-member.

19. The invention as donned in claim l5, in combination with an auxiliary holding-i -sans -for temporarily holdin the non-arc-extinguishing disconnect-member in any one of a plurality of closed positions cdifferent degrees of closure, said lost-motion, snap-action means including means for nullifying the holding-action of said auxiliary holding-means when it applies an effective operating-force to said non-arc--extinguishing disconnect-member during the next opening-operation.

20. The invention as dened in claim 16, in combination with an auxiliary holding-means for temporarily holding the non-arc-extinguishing disconnect-member in its open position, said lostmotion, snap-action means including means for nulliying the holding-action of said auxiliary holding-means when it applies an effective operating-force to said non-arc-extinguishing disconnect-member during the next closing-operation.

2l'. The invention as defined in claim l5, in combination with ai ary hold g-means for temporarily holding the nen-arcextinguishing disconnect-member both. in its open position and in its closed position, said lost-motion, snapaotion means including means for nulliiying the holding-action of said auxiliary l'iolding-means when it applies an effective operating-force to said non-ar -extinguishing disconnocta An'oer during the next operation of the circuit-breaker.

22. The invention as defined in claim 16, che acterized by said lost-motion, snanaction means being an over-center yieldable-spring means.

23. A circuit-breaker comprising an arc-extinguishing switching-member, a serially connected, non-arc-eatinguishing disconnect-member, a current-carrying shunt-contact adapted to be connected in parallel-circuit relation to the two serially connected members, and operatingmeans therefor; characterized by said arc-extinguishing switching-member being of a kind such that it is undesirable to leave the circuit- Voltage continuously applied thereto after its opening operation, and such that it is undesirable to have the circuit-voltage applied tiereto when its switching-contacts are approaching each other during its closing-operation; and said operating-means having an opening-operation and a closing-operation, means for causing the open-- ing-operation of the operating-means to open the shunt-contact and the arc-extinguishing switching-member and to temporarily hold both open until the next closing-operation of the operatingmeans, getting the shunt-contact open irst, means for causing a. closing-operation of the operating-means to close the arc-extinguishing switching-member and the shunt-contact and to temporarily hold both closed until the next opening-operation of the operating-means, and lostmotion, snap-action means for automatically operating the non-arc-extinguishing disconnectmember in response to th, respective continued opening and closing movements of the aforesaid operating-means, said lost-motion, snap-action means responding at an intermediate point in the opening-movement of the operating-means, and thereupon operating to forcibly mechanically open the disconnect-member with a snap-action substantially independent of the remainder of the opening-movement of the operating-means, and t0 thereafter temporarily hold the disconnect-member open until the next closing-operation of the lost-motion, snap-action means, the timing being such that the disconnect-member opens after the opening of the arc-extinguishing switching-member, and said lost-motion, snapaotion means responding at an intermediate point in the closing-movement of the operatingmeans, and thereupon operating to forcibly mechanically close the disconnect-member with a snap-action substantially independent of the remainder of the closing-movement of the operating-means, and to thereafter temporarily hold the disconnect-member closed until the next opening-operation of the lost-motion, snap-action means, the timing being such that the disconnect-member closes after the closure of the aro-extinguishing switching-member.

ALFRED J. A. PETERSON.

JOHN B. MACNEILL,

ANDREW H. BAKKEN.

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