US2538774A - Circuit interrupter - Google Patents

Description

23, 1951 R. E. FRIEDRICH EIAL 2,533,774

CIRCUIT INTERRUPTER Filed ma 2, 1947 2 Sheets-Sheet 1 qeldip j l Patented Jan. 23, 1951 PATENT OFF-ICE .e w ,NCIRCI II-T INTEBBUPTER R ert.E. Friedrich, Pittsbnrgh'Pa and Oswald M ehre'm'Lora'in, Ohio, assignors" to 'Westmghouse Electric CorporlitidiL'East' Pittsburgh,

raga' eorpora'tion of Pennsylvania This invention rel in' general, and, in guishihg str itftii therefor. ITheprincipaLobje t ofonr invention is to providean "ifiiidiovdfoir'uit rrupter of the highvolta e"ty 'ofe in wh oh "oh p'e ratingimechanism for" the inavmg co we is simplified.

Another, object cuitinterrii'pter having of pressure high-voltag establishef nether object is toprovidean improved circuit interrupter withian' improved" if t ing mechanism ftdes tablisha pressure ga serially rlafi edintellllptin g"Q5435.

Furtherfobjeots and"advantages will readily 3o become apparent updii aieading'of the fc11'6""ng specification, taknfincofijunction Withthed w r m ,7

" Figure 1 is aside elevational view of a circuit interrupter embodying our invention; -Fig'. 2 isan enlarged fragnientary side elevation'al view; partially in"section; ofzth'e circuit interrupter of -Fig; 1; the contact 'stru'tureibeing shown inthe'closed'oirouit position? Fig. W3 is an enlarged verticarsectional, View through the improved" arc extinguishing unit of Fig.3. 2, the contacts being shown inlthepartially open circuit position;

LFig. 1411's a,sctional viewi,oncafreduqed scale taken along the line IVIV.'of'Fig.c.3;

tFig; V5 is ga, secti nalwview .on; a reduced scale ctakenalon ith 1ine,Vv.V..0feFi 3rg and Erie-r6 is 2;. vertical sectional Mi'QW .ofm mmedifie type of. arceextin uishin ii i ,thetemact ebeine shown inthec losre l ircuit .po i cnbraced by di rally 2 @DlYJQEI EQQ QQ a,

99M 2, 1947;.sgr i111t0.i45,542

,S ClaimS. (01499- nd 9f h n leirpxl fi r r u ded?- nprtmee s e erell d si t lb the r numeral 4 which supports a circui'finterr generallydesignated by the reference m Referring mere barticularly toFigTFZ, itwll be observed that terminal bushing rx eans '6', instance including ahighvoltiage condenserb' i 1, ext i lisaileh he rq d u means 4 and is sllppoifted thereby. Theline rminal H is spo edatthe u ie cendfifih bil ing l and is shgwn more clearly in Fig l" W hav provid in ul tin c asin e era i nated .b th e e e nu ra 1 en n i dm th .su m tmeens "f e fif supported thereby. A base section; g enerally designated by the referencemnneral I3, is u ported in mpineirelatiq h w t thevlo er end of the easing means 52. The base s eption uppc scan ermextix e' in u iwrall fie na ed by the re renq n m lre vJ Pre rab cth insu atine cas nern i 1 2, pe dinsi omr e ppo ean W9 hoilowporcelam column i5, interiorlyof w q h ispositiqne n insulating eylindric al qasing l5. Thecasing leis clamped at its upperendto the p t form a perto the lioli v 1912? eans A. he QWer end o the fies ne 1L5 plamp d t en inwardly ex nd neplate pqrtien 2! of thelbase section {3. Thns,q the insulating cylinder 16 isl put under t ension, and the hollow porcelain column 15 is maintainedhin compression. A suitable ar c extinguishing fluid 20, v in this instance circuit breakeroil', fills the casin 16 to the 1evel22. I

The arc-extingnishingnnit or elongatedarcin v chamber M is supported above the'base sec on 1 183 by vmeans 0i upwardly extending supports 23, the latter resting against the baseplate ZA f the base section i31andsuibably fiured thereto as by welding.

Movable into andont of the arc-extinguishing unit 94 is an upper moyafole rod-shaped contact pally, the ,operating rneansfii includes an operating crank 32 which is pivotally nounted at 33 t0 a pair of fixed brackets only one of whichi'is shown in Fig. 2. Thebrackets 34 may beintleg ally r rn a with the plate ll Qf-f the 's' pp' irt means i. Suit min e bw may v ,v a t t mg iqn be emnloyed to e rota of the o rating cranh 32.

. Qe ai v v We t O th ie qnniie cceestrwilsm 3 herein disclosed are set forth and claimed in United States patent application, Serial No.

591,047, filed April 30, 1945, by Leon R. Ludwig and Benjamin P. Baker, now Patent No. 2,534,920, granted Dec. 19, 1950, and assigned to the same assignee as the instant application.

Referring to Fig. 3, which shows more clearly than does Fig. 2 the internal construction of the arc-extinguishing unit or arcing chamber I4, it Will be observed that the upper movable contact 25 in the closed circuit position makes contact with an intermediate or relatively stationary contact 35, the latter being fixedly mounted in place by the cooperation of three insulating plates 36, 3?, and 38. The insulating plate 31 has a recess 4| formed therein within which is positioned a flange portion 42 integrally formed with the intermediate contact 35. Also cooperable with the intermediate contact 35 is a lower movable rod-shaped contact assembly 43 including an operating rod 44 formed of conducting material and-having a pair of rod-shaped movable contacts 45, 46 operatively connected by an insulating rod portion 41. The rod portion 41 'formed of insulating material may be threadedly secured to the movable contacts 45, 46 so that the entire movable contact assembly 43 moves as a unit in response to vertical reciprocating motion of the operating or contact rod 44.

As more clearly shown in Fig. 2, the contact rod 44 is biased downwardly in the circuit opening direction by a compression spring the rod 44 has a slot 54 formed therein within which is slidably guided a pivot pin 55, the latter being extended through slots 56 formed in the leg portions 5'! of a bifurcated lever 61 mounted on a stationary pivot 62. The stationary pivot 52 is supported by a pair of brackets 63 extending up wardly from the base plate 24 of the housing or base section 13. Extending longitudinally of the arc-extinguishing unit i4 exteriorly thereof and positioned within the casing I6 is an insulating operating rod 54, the upper end of which is piv- -otally connected to the operating crank 32 by the pivot 28. The lower end of the operating rod 64 is bifurcated as at 65 and the two leg portions 5? thereof have slots 68 provided therein within which is slidably guided a pin 69 which extends transversely of the right-hand end of the lever 5|. A compression spring it surrounds the bifurcated portion 85 of the operating rod 64 being disposed between a flange l'l rigidly secured to the operating rod 54 and a movable washer 12 slidable about the leg portions 61 and making abutting engagement with the lever 61.

The upper movable contact 25 is telescopically guided by a conducting tube 14 which passes interiorly through the bushing l, the latter being clamped by a flange clamp 75 to the top plate I! of the interrupter. Disposed interiorly of the conducting tube 14 is a tension spring :6 which 4 sequently, the electrical circuit passes. from the conducting tube '54 through the contact assembly F8 to the contact rod 25 from whence the circuit passes through the intermediate contact 35, movable contact 45 of movable contact assembly 43, through a plurality of longitudinally extending stationary contact segments to the movable contact 46 of the movable contact assembly 43. The circuit then extends through the lower contact rod 44 to a pair of slider contacts 86 which bear inwardly upon the outer surface of the conducting operating rod 44. After passing through the slider contacts 86, the circuit passes through the conducting base plate 24 to the lower line terminal 8? of the interrupter.

During the opening operation, suitable means (not shown), which is responsive to either manual operation or to the presence of excessive current conditions existing in the circuit controlled by the interrupter, is operative to cause clockwise rotative motion of the operating crank 32 about the pivot 33. The clockwise motion of operating crank 32 simultaneously causes upward motion of both operating rods 2'1 and 54. The operating rod 2'1 being pivotally connected at 26 to the upper movable contact 25 causes upward separating motion of the same away from the intermediate contact 35 to draw an interrupting are 88, as shown more clearly in Fig. 3. The interrupting arc 85 is established within an interrupting chamber, generally designated by the reference numeral 89 and more fully described hereinafter.

The upward motion of the operating rod 64 causes counterclockwise rotation of the lever 6| to thereby permit the compression spring 5| to force the flange 53 and operating rod 44 downwardly. The downward motion of the contact rod 44 simultaneously establishes an interrupting arc 90 between the contacts 35, 45 and a pressure-generating arc 9| between the contacts 46, 85 within a pressure-generating chamber 92.

In other words, one or a first movable contact 45 of the movable contact assembly 43 separates from the first relatively stationary contact 35 to establish a first or an interrupting are 90. The other movable contact 46 of the movable contact assembly 43 separates from the other or second relatively stationary contact 85 to establish a second or a pressure-generating arc 9!. The third movable contact 25 separates from the first relatively stationary contact 35 to establish a third or an interrupting arc 85.

Since the unit [4 is immersed in oil, and consequently oil exists within the pressure-generating chamber 92, the arc 5i acting upon the oil within the pressure-generating chamber 92 will cause the oil under pressure to flow upwardly, as indicated by the arrows 93, to flow into the interrupting chamber 89 and also into the interrupting chamber 94. The oil flowing into the interrupting chambers 89, 94 extinguishes the interrupting arcs 88, 90.

It will be observed that a plurality of ringshaped plates formed of insulatingmaterial and designated by the reference numeral 95 form the pressure-generating chamber 92 in which the pressure-generating arc Si is established. Further, a plurality of insulating suitably configured plates form the interrupting chambers 89 and 94. The interrupting chambers 89, 94 assume a shape as more fully set forth in United States Patent 2,406,469, issued August 27, 1946 to Leon R. Ludwig, Winthrop M. Leeds andBenjamin P. Baker,

a a si ned -t9 tone: misus wo reception of 4a pluralitysoffiin this in a ce o r,

insulatineztie rods 99 which in cooperation with nuts I90 serve to hold the several insulating plates' fixedlyain position. fl he inlet plate 9 ;I- has a cutout portion I92 :formed therein which pr vides again of opposedinletlpassages; I;Il3 ;leading toward each zotheryfrom two-vertical flow passages generally designated by -:the reference numeral I'M -and'r lead-ing upwardly from the pressure-generating chamber 92. The second type of insulating plate is herein {termed an 1 fice insulating plate and .is des.ienat d y reierence :numeral I 05. --The configuration of the orifice plate I 05 :is Emore clearly shown in i I (It will be noted that the orifice insulating plate :.I 051=-h.as twoIzkidn yv-shaped peni 96 whigh tassist-55in f rmingjthevertical flow passages I9 he qlorific lplate vc 05 al o a e trally formed thereinean orifice I01 through which one ,of theginterrupting arcs 88, 99 is dr wn. Itwill be noted that an orifice insulating plate I05 is positioned on both sides of-each inlet fplatew; 9].

-The.:;thirdtypeof i1- 1sulating;plate employed in the :interrupting sections-is termed an insulating vent plate and is designated generally by the reference numeral --I 98. Theinsulating pfate I 08 =com posite and formed ;by,the cooperation of twoidentical halves indicatedby the reference num ralan own-more c ea y the cu -ar-way portions of Big. v l. Each of the halves 109 11. r eidlyyi p s t n by w insulating tie ;rods 99. Thecooperation of;the halves I89 form ,a, plurality f,;in this; instance ;tWo,-opposed event passages'designated by the reference nuere 1 41 ze eh-pfqilieh s "191$ fi m with akidney shaped; opening I 06 110 form upon alignment withthepther plates the vertical flow pass e Erom the foregoing descriptiomt referring to .Eig. 5 3, it will be-;apparent that upon the estab lishment of thepressure-generating arc 9| and .the interrupting arcs 88, 90 within the-interrupting chambers 89, 94, oil underpressure Will flow eupw rdly rou h th We ret na 9 as tlllt ras; desi na ed by th arr w t f --radia11y nwardly fliro hv th po e let oassages 193 to strilge interrupting ares 88, 90 and -pa.ss unwar y @an d wnwar l hrou the .7 or --fi s::l; pr vid d ,byihe L ins. fice plates 015- to e haust out in h i 44 thro the eppos flvent passa es' I 0. -,w, the app r n gthatibyz-thisinterrupting :construction, which is o ratin -rod lit-amin up r v li dr l nt ct 2.5 niinne ei e erm re upwersl rriu i sop n- Washer ,12 provides the requisite: conta et pr,

lower contact rod 49 eer-gnar able q ni e fl m re wa dl gn leie li l of the extinguishingunit I4 inthe o en c ircuit position of the interrupter to provide ins sap- :It will be n te a ih flan e! ngiq e etion, with the compression spring flil and "slidable in the closed circuit position of the as shown in Fig. 2. Thus, a certain overtravel of the 1 operating rod -64 r genera es lever; 6l is permitted by virtue oftherpre s nee of s ots 68. From the foregoing description it willbeapparent that w have provided an improved "I cuit interrupter of the type establishing simultaneously a pressure-generating arc and serially related interrupting arcs with effe flow conditions being achieved to bring about interruption of the interrupting,ares jiegfiii. The mechanism herein shownis Simple incon tion and provides the requisite contact p'r in the closed circuit position. it will he ohserved that the contact segments fiil provide-con means 1A6 which spans orparall l the r 7 rod portion 41 of the movable act ass y 43 when in the closed circuit pgsition." During :the opening operation the upper endsof the contact segments 85 bear against the n ovahie contact 45 of the movablecontact assembly qt la d the pressure-generating arc S l -is drawn between the contact portion lfi of the-operating-rodfdd and the lower ends of -the contact-segments-85. Referring to Fig.6, it will be notedj that lwe have provideda modified type of 7 arm-extinguishing unitor device generally designated bythe reference numeral H3 which may be used 'i'n place of theunit It of Fig.;2. An uppermovable rod-shaped contact 25 has an uppersquare portion I I4 anda lowercylindrical portion I I5. The

terru line of division between the square and cylinati-ng rods I24 fixedly to the yoke fi22 so t the dovvnward motion ofthe yoke igfi ias eg by engagement of the corner l'portions H1? Iof movable contact'25 with ring I18, wiilvcause downward motion of both the yoke I 22 fand the "two operating rods 12%.

Lever means I21, including levers -i28 rotativ-ely mounted at fixed pivots E29, are tally secured at I38 to the; lower ends of -the;two ,-operating rods I24. 'Iheinner ends of-the-levers J28 niake pivotal engagement at I34 to the lower movable contact assembly or,c ontai':t"I'neans 43.

The movable 7 contact assembly rages before, .has

- a pair of movable .-contacts 45, gets ciated therewith operatively connected by an wer Th in ul te li ri 9 4 an insulating tube I32,--the-lower vend oi To provide the requisite contact pressure in the closed circuit position of the interrupter, as shown in Fig. 6, we have provided a lost-motion connection between the insulating tube I32 and the upper movable contact 45 of the movable contact assembly 43. In other words, we have disposed a compression spring I34 between the upper interior end of the tubular movable contact 45 and the upper end of the insulating tube I32 to bias the two apart. We have provided a pin I35 which passes through the insulating tube I32 in fixed relation thereto. The pin I35 passes outwardly through slots I36 provided in the lower end of the movable tubular contact 45 of the contact assembly 43. This permits slight relative motion between the movable contact 45 of contact assembly 43 and the insulating tube I32.

Thus during the closing operation when the upper movable contact 25 strikes the yoke I22 thereby causing upward motion of the movable contact assembly 43, the two movable contacts 25, 45 may strike the stationary intermediate contact 35 and compress the spring I34 to provide the contact pressure between contacts 35, 45. This permits the movable ring-shaped pressure-generating contact 46 to strike the sta tionary contact segments 85 to make firm engagement therewith.

In the closed circuit position of the interrupter, as shown in Fig. 6, the electrical circuit therethrough includes upper movable contact rod 25, intermediate stationary contact 35, movable contact 45 of movable contact assembly 43, stationary contact segments 85, lower movable contact 46 of movable contact assembly 43, slider contacts I31 to the lower casting I38. The circuit extends from the lower casting 53a to suitable line terminal means 81 (Fig. 2).

During the opening operation, suitable mechanism (not shown) is operable in response to manual operation or to excessive current con ditions existing in the circuit controlled by the interrupter to cause upward opening motion of the upper movable contact 25. This permits the compression springs I39 to cause following upward movement of the yoke E22 and the two operating rods I24 in response to the initial upward motion of the movable contact 25.

The upward motion of the two operating rods I24 causes downward motion or" the movable contact assembly 43 to thereby establish a pressure-generating arc between the contacts 45, 85 and an interrupting are between the interrupting contacts 35, 45. The internal plate construction of the unit H3 is identical to that of the unit I4 previously described in connection with Figs. 1-5; consequently, a further description thereof appears unnecessary. It suffices to say in explanation of this embodiment of our invention, as shown in Fig. 6, that oil under pressure is forced upwardly through the vertical flow channels 1st: from the pressure-generating chamber 92 to cause radially inward flow of fluid within the inlet passages N33 to strike the two interrupting arcs (not shown) and pass through the orifices Ill! provided in the insulating orifice plates Hi5. After passing through the orifices till, the oil is forced out of the unit I i3 through the oppositely disposed vent passages IIil. Interruption soon occurs, and the continued upward motion of the upper movable contact 25 out of the unit H3 as indicated by the dotted lines I lt interposes an isolating gap in the circuit.

It will be observed that in this embodiment of our invention, we have provided an improved 8 contact construction and an improved operating mechanism of simplified type for operation of the same. The rod means I45, which we have provided, including the yoke I22 and the operating rods I24, has a portion H8 which abuts the contact rod 25 near the end of the closing stroke to thereby interconnect motion of the contact rod 25 and motion of the lever means I21. The contact structure is operable to establish a pressure-generating and two interrupting arcs, and fluid under pressure from the pressuregenerating arc causes rapid extinction of the interrupting arcs.

From the foregoing description it will be apparent that we have provided an improved arcextinguishingstructure forming a single pressure-generating break and two serially related interrupting breaks. Furthermore, we have disclosed a novel, simple mechanism for positively actuating the contact structure of the circuit interrupter to thereby provide a high speed type of circuit interrupter.

Although we have shown and described specific structures, it is to be clearly understood that the same were merely for the purpose of illustration, and that changes and modifications may readily be made therein by those skilled in the art without departing from the spirit and scope of the appended claims.

We claim as our invention:

In a circuit interrupter, a relatively stationary contact, a movable contact assembly movable linearly and including two movable contacts spaced along the direction of motion and operatively connected by an insulating portion, one movable contact separating from the relatively stationary contact to establish an arc, another relatively sta tionary contact electrically isolated from the first said relatively stationary contact, the other movable contact separating from the second said relatively stationary contact to establish a second arc and to have only the insulating portion therebetween in the open position, means electrically connecting the said other relatively stationary contact to the first said movable contact and paralleling the in sulating portion during and after the time of arc extinction so that the two arcs will be serially related and there will be a clear nonparalleled gap between the first said relatively stationary contact and the first said movable contact in the open position, and a third movable contact separable from the first said relatively stationary contact to establish a third serially related are.

2. In a circuit interrupter, means defining a pressure-generating chamber, means defining two interrupting chambers, a relatively stationary contact, another relatively stationary contact electrically isolated from the first said relatively stationary contact, a movable contact assembly movable linearly and including two movable contacts spaced along the direction of motion and operatively connected by an insulating portion, one movable contact separating from the first said relatively stationary contact to establish an interrupting are within one of the interrupting chambers, the other movable contact separating from the said other relatively stationary contact to establish a pressure-generating are within the pressure-generating chamber and to have only the insulating portion therebetween in the open position, means electrically connecting the said other relatively sta tionary contact to the first said movable contact gain paralleling th inisiilatmg games during" .3:-In' a"circuit interrupter," arelatively sta tionary contact, a movable contact assembly movable linearly and including two movable contacts spaced along the dir ti'oii 6f motion and operatively connected by a nsulatingpor tion', r

ti lybtti'ohary contact to establish other} relatively stationary cbfntact el is'ola-tedfromthefirst said relatively s a mnary contact, the other movable contact separating from the second said relatively stationary contact to establish a second arc and to have only the insulating portion therebetween in the open position, means electrically connecting the said other relatively stationary contact to the first said movable contact and paralleling the insulating portion during and after the time of arc extinction so that the two arcs will be serially related, a third movable contact separable from the first said relatively stationary contact to establish a third serially related are, an operating rod operatively connected to the movable contact assembly, another operating rod operatively connected t6 the third movable contact, and means for simultaneously causing the actuation of both operating rods.

4. In a circuit interrupter, means defining a pressure-generating chamber, means defining two interrupting chambers, a relatively stationary contact, another relatively stationary contact electrically isolated from the first said relatively stationary contact, a movable contact assembly movable linearly and including two movable contacts spaced along the direction of motion and operatively connected by an insulating portion, one movable contact separating from the first said relatively stationary contact toestablish an interrupting are within one of the interrupting chambers, the other movable contact separating from the said other relatively stationary contact to establish a pressure-generating are within the pressure-generating chamber, a third movable contact, means paralleling the insulating portion and electrically connecting the said other rela-,

tively stationary contact to the first said movable contact during and after the time of arc extinction, means causing the separation of the third movable contact from the first said relatively stationary contact to establish another interrupting are within the other interrupting chamber,

"e movable contact separatmg' fromgtherel'a are will be seriauy re portion, one movable- (seamen leling the"in'sulating portion and electrically con- 7 the said otlfer relatively stationary "corifirst said movable contact durifigand extinction" soqth'at' the two lated athird movable con"- tact separ-ablefrom the first said relativelyi'sta- J contact to establish a third serially re-- 12; e and bpei ating me'ans supported by:'the support means for simultaneously actuating the third movable contact and the movable contact assembly.

5.111 a circuit interrupter, grounded support means, terminal bushing means extending through the support means, insulating, casing means depending from the grounded support means, a base section supported by the casing means, an arc-extinguishing unit supported by a movable contact assembly movable linearly and including two movable contacts spaced along the the base section, means defining apressure-generating chamber, means defining two interrupting chambers, a relatively stationary contact, another relatively stationary contact electrically isolated from the first said relatively stationary contact, a movable contact assembly movable linearly and including two movable contacts spaced along the direction of motion and operatively connected by an insulating portion, one movable contact separating from the first said relatively stationary contact to establish an interrupting arc within one of the interrupting chambers, the-other movable contact separating from the said other relatively stationary contact to establish a pressure-generating are within the pressure-generating chamber, means electrically connecting the said other relatively stationary contact to the first said movable contact during and after the time of arc extinction, a third' movable contact, means causing the separation of the third movable contact from the first said relatively stationary contact to establish another interrupting are within the other interrupting chamber, and passage means interconnecting the pressure-generating chamber with both interrupting chambers.

7. In a circuit interrupter, grounded support means, terminal bushing means extending through the support means, insulating casing means depending from the grounded support means, a base section supported by the casing means, an arc-extinguishing unit supported by the base section, means defining a pressure-generating chamber, means defining two interrupting chambers, a relatively stationary contact, another relatively stationary contact electrically isolated from the aforesaid contact, a movable contact assembly movable linearly and including two movable contacts spaced along the directionof motion and operatively connected by an insulating portion, one movable contact separating from the first said relatively stationary contact to establish an interrupting are within one of the ber; means electrically connecting the said other re1ati vely stationary contact to the first said jmovable contact during and after the time of arc extinction, a third movable contact, means caus- 1, 5 the separation of the third movable contact from the first said relatively stationary contact 'to establish another interrupting are within the other interrupting chamber, passage means interconnecting the pressure-generating chamber with both interrupting chambers, and operating means supported by the grounded support means -for simultaneously actuating the movable contact assembly and the third movable contact.

linked to the lever means, a movable contact having a shoulder portion thereon, and the shoulder portion striking the yoke member during the closing operation to cause actuation of the contact means.

ROBERT E. FRIEDRICH. OSWALD vow MEHREN.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,706,158 Hendricks, Jr -1 Mar. 19, 1929 2,164,175 Frank June 27, 1939 2,223,731 Lingal Dec. 3, 1940 Baker Dec. 17, 1946

Images