US2764652A - Interrupter for high current intensity - Google Patents

Description

P 25, 1956 I L. DEBUIT 2,764,652

INTERRUPTER FOR HIGH CURRENT INTENSITY Filed April 1, 1954 3 Sheets-Sheet 1 INVENTOR. Lou i s DE BU I T Attorney Sept. 25, 1956 L. DEBUIT 2,764,652

INTERRUPTER FOR HIGH CURRENT INTENSITY Filed April 1, 1954 3 Sheets-Sheet 2 INVENTOR.

Louis DEBUIT BY XXMMMZIQ Attorney Sept. 25, 1956 DEBUIT I 2,764,652

I INTERRUPTER FOR HIGH CURRENT INTENSITY Filed April 1, 1954 3 Sheets-Sheet 3 Fig .11

INVENTOR.

Louis DEBU IT BY NW-A XWMM Attorney United States Patent INTERRUPTER FOR HIGH CURRENT INTENSITY Louis Debuit, Grenoble, France, assignor to Etablissements Merlin &.Gerin, Grenoble, France Application April 1, 1954, Serial No. 420,374 Claims priority, application France April 14, 1953 11 Claims. Cl. 200-146 'The invention relates'to an interrupter for high current intensity and more particularly to an interrupter in which for each pole of the interrupter there is provided a pair of stationary contacts to be electrically connected by a bridging contact member.

Particularly, it is an object of the invention to develop an interrupter of the aforesaid type of small space requirement which; however, simply by modification of a single dimension, viz. the width, may be adapted to a great range'of current intensities, While the other dimen A still further object of'the invention is a development of a bridging contact member, hereinafter shortly designated as contact bridge, such that at each pole to be interrupted, the circuit, through the lifting of the contact bridge from the stationary contacts, is doubly broken, and

the are thus rapidly extinguished.

It is a further object of the invention to provide for the contact bridge an actuating mechanism which is to start the opening motion with a shock so as to counteract any'efiects of an accidental prior welding of the sta-,

tionary and mobile contacts.

These and other objects of the invention will be achieved when, in accordance with the invention, in current interrupters with a pair of stationary contacts for each pole to be interrupted, the contact bridge comprises at least one rotary contact member or one or more units, each unit of one or more rotary contact members. This rotary'contact member or the units of rotary contact members thus constitute a movable bridge which by means ,of an actuating mechanism may be moved into or out of the bridging, contact making position between the stationary contacts. 7

These contact bridges comprising one or more contact members or rollers shaped as bodies of revolution, such as cylinders, rollers or rings, and which as a rule are rotary, will be arranged to bridge the stationary main contacts themselves and further contact bridges with one or more such contact members will be arranged to bridge the arc horns or runners with which the main contacts may be provided. t

In this case, a primarycontact bridge of one or more units, each unit of one or more rotary contact members, will serve for bridging the main contacts directly and thus as main movable contact of the interrupter whereas a secondary contact bridge comprising one or more rotary contact members each, will serve as movable arcing contact and bridge the arc horns, with its axis of rotationspaced from and parallel to the bridging of the ice - bridges for moving by means of the connecting members both contact bridges concurrently into the circuit making or the circuit breaking position, into or out of the bridging, contact making position between the contact pieces and between the arc horns, respectively. Re-

' tarding mechanisms are interposed between the connecting members and the rotary contact members of both contact bridges for delaying the circuit breaking through the secondary or arcing contact bridge relatively to the circuit breaking through the primary contact bridge, retarding mechanisms which may also delay the circuit making of the primary contact bridge relatively to the circuit making of the secondary, arcing contact bridge. Thus, while the movements of both axes which carry the principal and the arcing contact bridges are coupled, the arcing rotary contact members, when the interrupter is to be opened, are separated from thearc horns only after the primary rotary contact arated from the stationary main contacts and, are closed first,

For thus delaying the action of the one contact bridge relatively to the other, in accordance with this development of the invention, the motion transmitting members which couple the drivingmembers of the actuating mechanism with the rotary contact members ofthe contact bridges provide for an idle path between the driving members and the rotary contact member or members of the secondary contact bridge. Such an idle path,.but of shorter length, is also provided between the driving members and the rotary contact member or members of the primary contact bridge.

This idle path makes it possible, during the movement accelerate the driving members to a velocity such that they strike on the contact bridge or bridges in a shock movement and thus lift abruptly the rotary contact member or members from contact with the stationary contacts.

Through this opening of the contacts under a shock, the effects of an accidental Welding of the stationary and mobile contacts are eliminated.

The invention further provides for a mounting of the rotary contact members on their supporting shaft or axle which makesunnecessary any particular regulating of the setting of the contacts.

The interrupter, furthermore, through the employ of rotary contact members, such as rollers or revolvable rings, is rendered remarkably insensitive to deposits which might settle between the stationary and the mobile contacts when the atmosphere surrounding the interrupter is contaminated.

Since from their contact making position, where they bridge a pair .of stationary contacts, the rotary contact members are lifted in the direction towards which the arc develops, the arched sectors of the rotary contact members in contact with the stationary main contacts or with the arc horns are particularly suited for the development of the arcs since for the current to be interrupted an arc is drawn at two places, i. e. at both sides of each rotary contact member. I

Furthermore, since there are no movable parts to be conductively connected with the incoming and outgoing leads, no conductor strands are needed. A possible source of defects and disturbances thus, is eliminated and the structure simplified.

The above and other features and objects of the inmembers had been sep' conversely,

3. vention and'its nature will become apparent as the now ensuing specific description of the invention proceeds in which the invention will be described with reference to the accompanying drawings which form part of this sp eei fi'cation and which byway ofexample .illustrateanern bodiment of the invention and a modification thereof. It will be readily understood, however, that these drawings are intended to be explicative off the invention but not limitative of its scope and' that the invention rnay be embodied in other. forms without" departing from the principle underlying" my invention and the ambit of my appended claims.

In the drawings:

Fig. 1 is a schematic elevational side view, partly in section along line 1-1' of Fig, 2, of a pole oflan interrup'ter of the invention, the r ota rycontact members of the stationary main contacts and of; the arc horns being in bridgingQciIcuit making:position;

Fig; 2*is a schematic elevation-a1 section along line 2"-2-'of Fig. 1 and partly a front view of'theinterrupter;

' Figs; 3'and 4 respectively are, on. an enlarged scale, sectionsalong line 3 3of Fig. 4 and line 4 4 o f Eig. 3}: o f-arotary contact member of the, main contacts in,v closed, or bridging, position; i

Fig. 5 is a view similar to that of' Fig l' whichhowever shows therotary contact members both of 'the main contacts and of-the arcing contacts in open, circuit-breaking position? Figs. 6 and 7 respectively are, on an enlarged; scale, sections along line 66' of Fig. 7" and; line, 7"- -7 of Fig, 6' showing,- similar to Figs. 3 and 4, a rotary contact member in open, circuit breaking position;

Figs. 8', 9-and 1'O respe ctively are a front, a side view, and a top- View, On an enlarged scale, of a connecting member provided between both contact bridges and Fig.- 11', similar to Fig, 2, is a schematic elevational front view, partly in section correspondingto the section line 11 11 of Fig. 1, of an embodiment; in which the interrupter'pole is composed of two stationary and mobile contact units aligned in the width direction.

In the embodiments of Figs. 1 to 10, thestati'onary main contacts are designated by 11 and 12. These two contacts arearranged symmetrically at a certain distance from the median symmetry'plane of. the apparatus when seen as illustrated in Figs. 1 and 5. In the modification of "Fig; 11, thevisible main contacts are designated by 41, 43, the complementary co11tact pieces are 42, 4;4 written in brackets-since not visible, onthe figure.

Thesestationary main contacts: are supported upon the bars 13, 14, 15, 16, which form part ofthe frarnework of the apparatua which framework, however, since it forms no partofflthe invention is not shown here, as are not, for: the same reason, the means for securingi the parts at the framework. These bars, for apparatusof lowercurrent intensity, are of insulating megawa t as, for apparatus of higher current' intensity metal bars may be employed which are coated with insulating ma For securing the terial as indicated at in 1. e I contact pieces 11, 12; against lateral displacement they may be held in positionat both their sides by rings, of

square-form secured by sc're ws to the bars. These square rings or perforated, square members; embracing the bars arenot shown here in order motto crowd therepresem tation.

The incoming and outgoing leads are respectively-deg ignated by-19 and 20. Each stationary main contact carriesat its top'an arcing horn or arc runner 21', 22 l, 2 and 5, and 23, 24," 25-, 26' in Fig. ll. 7

the opposite pair: of arcing horns not visible in this-figure.. 'l'she arcing; horns. are disposed between-walls 31-, 32, 335,394,015 refractory material. of an arcing chamber. and are secured byconventional means, here not v shown, to the frame bars 13 and 15. The rotary-contaetmem; bers or,rolle1 ,s, 3;6,, Figs. 1 to,-7,;and;37,- 38, Fig, 11, are

In this fig ure, the numerals 25, 26 are in brackets, they'designate here in the form of rings which, together with their shafts 39, 40, respectively, about which they are revolvable, form the main or primary contact bridge. This primary contact bridge in its circuit making or closed position bridges the main contacts 11, 12, directly and thus closes the current on the main circuit 1911-36-12-20. When raised out of their closing or bridging position, e ont ct: o l e he. c r u t hrough he. main contacts 11, 12, and the primary contact bridge con- Stitutedzby the contact rollers outings--35; Similarly,- in. the embodiment of-Eig; 1.1, wherethe-main- contacts 41, 43 are connectedtotheone leadpfthe networleand the main contacts 42', 44 to the other lead; the circuit through the ma ni CDHIBSIiWillt-bfia. broken; through! the lifting of the contact rings37, 3 8, from the main contacts 41, 42 and 43, 44, respectively.

The rings 36 may be of any number, for instance five as shown in the embodiment of Figs. 1 to 7, or they may be,- ,a rranged-,- in sevcraLsets of any=;nurnber;o fi;rings such ssye: et fif t 3. ac 50f; fiy in s as. sh0wn;. u, g-; 11: Ev ording. o-tlte ntens ty ange; a he Q e e trwl a rsken any t er umb r. frollers or-x ll q units may be employed, each-unitv of any'desiredg num ewio lers nrings, o esppnding o t rr ntbreakns; a a i r a t. h. e ui b ake 1 s esi ned;

rhex n a se r n the haft ,,3 .40, l os ly s that. they mayv revolvethereabout. I The shaft 3 9,or, 40, of

the. contact; bridge is op er ate dv by connecting, members or, bars two, Of them SS, 5 6,,in-,the embodiment of Fig s.

1 to 10, and three in the embodiment of Fig. 11, once interrupterfurther comprises the, actuating; shaft 61 which maybe rocked by any. conwntional, or. convenient:- means, by hand or, remote. control, here not shown. Shaft ;61,;fu1 ther carries. for eachconnecting bar, a pinion,

62}Which.,engages,a toothed, rack 63, of metal, secured,

by. screws,, rivets or; otherwise as indicated at.64,; Fig l, to the; connectingbars 5 5, 56, or 5,7, 58, 59. Shaft 61' when rocked in the opening,sense,counterclockwise in the, sense of Fig, 1, will; thus lift, by means, ofthe pinions .r6 2;.and,racks 63,, the connectingbars 55, 56, on 57,, 58,, 59,, intothe; positiomshown in. Fig. 5 and on re; QrSp motion. lower. them, into.the positionof, Figs. 1, and. 2, or 11. i

In order, to proyide anidle-palh betweenthe motion ransmit ng; lements; nd-the con act bridges-1 w sk, they actuate, shaft 39,;insidethe rings 36,- and,also, inside the rings,. 3,' 7 38,, isshapedwith. a throat 46. and is thusfifitw t n Onpneratioua f. heac uat ngmeans, ulina he.

otion ith transmitting elements. or. on e ingbarsa 55,, .6,, or, 57.7,. ,52. he motion of hqactllatinggneaust and part ularlyof shaft39, or 40. may thus be acseler; .v lsc ty o etheringe 316 o 217,. 8,, re. l fted.outf he-bridging posi ionbetweenthe; ta n ry. main contacts 11, 12, or 41, 42; 43, 4 4.,. The shaftfi? or, 4!) willthus strike inashock movementpn the bridging c on tact rollers-1 or, rings, 36,; 01;. 37, 38, and, lift them abr p ly. pm he. stationa y. main, ntact tnd.v h s na et ge ests of a y, pniqru rid ntal lding of he al s,

Throat is; shape,d with afi linclrical bore, 47.,ne aem. q fi -Qrin the .diametriical directionflqf, ach; ring, 36; 37, 38. This bore 47 houses a, sp 1 ing 48 whichbears upon a ball 49 whose, diameter corresponds to that. of the bore. Ball 49 thus urged'by spring 48against ring 36; or37=,38; engages and-guides the-ringbymeans of acir c-ular groove 50-intheinsidecircumference of-the ring and urges the ring-towards the contact-making position;

- The contouriof the throatiis composedtof twosectors; a:

lowenone, 51-,;ho,u singz thespringtandzballvand 10f er-radius: ula-Me t n slightlyrsmaller-th-an thatrtoftthednner-cireumr ferenee of pthei ring-and: aniupper sector-.5-2.t 05-; the; same! radius as the inner circumference of the ringbut with the center axis displaced between the center axis of the lower sector and the diametrically opposed side or underside of the throat. Thus, in the closed, bridging position, shaft 39 or 40 itself with the lower sector 51 of its throat 46 does not contactthe rings but presses them by means of the springs 48 and balls 49 and causes the rings to bear against the stationary contact pieces 11, 12, or 41, 42; 43, '44. Through this provision of the throat, the free space I), Fig. 3, or an idle path is provided at the upper side ofshaft 39, or 40, between the upper sectors 52 and thei nside circumferences of the rings 36, or 37, 38, when the-rings are in the closed or contact bridging position, Figs.- 3 and 4. Conversely, in the open position of the contact bridge, the upper sector 52 of throat 46 will bear withits whole surface against the inner circumference of the rings, Figs. 6 and 7.

The mobile arcing contact bridge, in the embodiments illustrated, comprises for each pair of arc horns 21, 22; and 23, 25; 24, 26,a single roller 66 and 67, 68 rotatable about or with its shaft 69 and 70, respectively. These shafts are mounted, vertically slidable with their journals 71, 72; and 73, 74, 75, in slots 76 of the connecting bars 55, 56 and 57, 58, 59, respectively. correspondingly slotted caps or sockets 77 are inserted into the upper ends of bars 55, 56; 57, 58, 59 and are secured therein by means of screws, as indicated at 78. These caps'77 house springs 79 which urge shafts 69, 70 and thus rollers 66; 67, 68, downwards, towards the bridging, circuit closing position. I i

The connecting bars 55,'56,.Figs. lto 10, and 57, 58, 59; Fig. 11, are of electrically insulating material while the racks 63 and the caps or sockets 77 housing the springs I are of metal.

The slots 76 are so disposed in the connecting bars 55, 56and 57, 58, 59 relatively to the shafts 69 and 70, respectively, and are of such a length that the actuating mechanisms together with the connecting bars may idly move alongan' idle path of a length a, Fig. 2, relatively to the shafts 69 or 70 and the arcing rollers 66 or 67, 68

before the connecting bars at the'ends of the slots strike against the shafts and raise the roller 66 or the rollers 67, 68 out of contact with the arcing horns 21, 22, or 23, 25; 24, 26, respectively, for the purposes set forth hereinabove. W

The operation of the device is as follows:

7 When the interrupter, for instance the interrupter illustrated by Figs. 1 to 10, is in the closed position, the springs 48 of the rings 36 on shaft 39 and the springs 79 of the connecting bars 55, 56 are compressed. The springs 48 by means of the balls 49 press the rings 36 against the contact pieces 11, 12 and the springs 79 bias the arcing roller 66 againstthe arc horns 21, 22. When the interrupter is to be opened, actuation shaft 61 is rocked, counter-clockwiseas seen in Fig. 1. The pinions 62 by driving the racks 63 move both'bars 55, 56 upwards, raising with them shaft 39. -During the first part of the course of shaft 39, along the idle path b, or the clearance provided through the throat 46 of shaft 39 between shaft 39 and the rings 36, springs 48 will be released and will expand while by means of the balls 49 they still hold the rings 36 against the main contacts 11, 12. Only when shaft 39 has been raised through the idle path b, will shaft 39 strike the contact rings 36and abruptly separate them from themain contacts 11, 12 and thus accomplish the first phase of the opening cycle of the interrupter. At this instant the circuit of the current is as follows:

, Incoming lead 19-main contact ll-arc horn 21 arcing contact roller 66arc horn 22-main contact 12-' outgoing lead v During the upward motion of the connecting bars 55, 56 along the idle path or distance b, the springs 79 of the secondary contact bridge will be released and will expand while they still hold roller .66 biased against the arcing contacts 21, 22. The'slots 76 are of a length to make possible upward movement of the connecting bars 55, 56, without striking the ' journals 71, 72 of shaft 69 for a distance or an idle path a, Fig. 2, a distance which is somewhat greater than the distance b. Only after, during this upward motion, the connecting bars 55, 56 have traversed the idle path a, that is after the rings 36 have already been separated from the contact pieces 11,"

12, will the connecting bars strike against the journals 71, 72, lift shaft 69 and will thus separate the arcing contact roller 66 from the arcing horns 21, 22 and thus completely and finally open the interrupter, Figs. 5 to 7. The springs 79 will then have expanded through the full length a.

At the separation of arcing roller 66 from the arc horns 21, 22, two current breaking arcs are developed, one between arc horn 21 and the one side of roller 66 and the other between arc horn 22 and the other side of roller 66. Both arcs will be extinguished in the arcing chamber formed by the walls 31, 32, 33, 34, be it exclusively through their natural expansion, be it by means of a magnetic blow field, not shown here.

Since the current is opened simultaneously at two points, the extinction of the arc is greatly facilitated. On the other hand, since shaft 39 strikes against the rings 36 only after the shaft has reached a certain velocity, the shaft strikes on the rings with a certain shock effect which will allow the rings to overcome the resistance which might be opposed to the separation of rings 36 from the contact pieces 11, 12 owing to a preceding accidental welding of rings and contact pieces. Similarly, the lifting of the arcing contact roller 66 from the arcing contacts 21", 22, is abrupt.

During the closing cycle, roller 66 will close the circuit first and only thereafter will the rollers 36 bridge the main contacts 11, 12.

By subdividing the pole of the interrupter into two contact pieces 11, 12, between which a mobile contact bridge constituted by the rollers 36 is inserted, the employ of wire strands becomes unnecessary and the construction is" considerably simplified.

In the embodiment as illustrated in Figs. 1 to 10, the primary contact bridge comprises five rollers. It will be readily understood, however, that the number of the rollers may be any, varying in dependence upon the nominal intensity or current breaking capacity of the circuit breaker. Moreover, a standard unit for interrupting a certain nominal amperage may be established and the pole of the interrupter accordingly composed of an appropriate number of such standard units.

Fig. 11 as described hereinabove illustrates an embodiment where a pole of the interrupter is set up from two of such units. There are two sets of stationary contacts,

one set comprising the contacts 41, 42, the other the. contacts 43, 4-4. The contacts 41, 43 of one side of the sets 37, 38, of primary contact rollers, each set of five rollers, and three connecting ba-rs, two, 57, 59, at the outside .and one, 58, in the midst.

In the multipolar circuit breakers the primary and secondary contact bridges may be mounted upon and actuated by the same actuating shaft (61) with the obvious condition, of course, that the poles are electrically insulated from one another. The manufacture and holding in stock of the detached pieces of the circuit breaker will thus be greatly simplified, with the additional advantage that dependent upon the circuit breaking capacity of the circuit breaker only one dimension, viz. the width, is to be changed while the other dimensions may be the same.

I claim:

1. Current interrupter including a pair of stationary mainr oontaetszaforeeaoh pole=,:to.:,be ainterruptedg. each .zof r said main contacts 1, beiugnprovided, with; an:- arcborn, a; Primary roontact bridge. comprisingira-t: least one.- contacb member'shapedaszanbody Qf'il'CEVOllltlQfir being. associated? with .saidrmainrcontacts;for bridging; the-same directly; a; secondary,. arcing; .contaotbridge:comprising; atnleast onc Contact: .memberr -shaped:: ass 21;; body; of revolution being: associated-1withnsaidr arcr'hornsa fort: bridging :the: same parallelzto.thebriclging :of :themain contactstthroughtsaid primarxcoontact bridge, both; said; contact bridges: being. disposed with theiii-axeszparallekto andzat aidistance from each Qiherg ands? actuating:mechanism: fon: moving said contact bridges in predetermined sequence into andioute, ofathe bridgingncontact: making; POSitiOHil 5tW6IU said mainicontactszandasaidara-hornsn I 2: Currentn interrupterrincludin as; pair: of: stationary mainvcontacts; for'eiachiipole to; berrinternupted; .each; of saidttmain .:.cont-ao sasbeing. proyidedi with: am arc horn, .aprhnarytcontactz bridge..-comprising ate leastzrone rotary= contact: member; beingrassociated; with; said; main-scone tacts for bridging the same:.dir.eotly; 13-). secondary; arc.- ing,;contact: bridge-comprising. at; leastzaone:. rotary.i contactimemben being;; associated: with: said are; horns. for; bridgingrthecsame. parallel. to: the: bridging; of the: main contacts through said primary contactzbridge, both; said contact bridges; .being;disposed with their;,axesvpara1lel to and at: a i distance from:. each:..othe.r.; and; actuating:;mecha+ lSlfls-fQI' movingzsa-id contact bridgesin;predetermined. SCqllGIlCQx'iHtO; and; out. oftthezzubridging. contact making: position between, saidimainmontaetsi andrsa-iduarcr hornsc urrent.interrupter;includingaa-na'in of; stationary: main contacts for each pole to be interrupted, anpain of? are;::hornsz provided; at;"said;mama-contacts; one how. at eachrmains. contact a-primary contact: bridgetcomprising: at least one rotary contact member being associatedtwith: saidrmain contacts; forrb'ridging the; same: directly, a secondary,. arcing gcontactt bridgewornprising at least: one: rotary: contact; member; being associated; with; said. arc horns; for: bridging; the: same. parallel. tovthe bridging; of: the main contacts through said primary con-tact-;bridge;-; both bridges being disposed; Withbtl1i axes parallel. to each-jother, connecting ;members; being providedbetween botliisaidt contact. bridges, and actuating: mechanism: for moving; by "means; ofasaid; connecting members, both said; contact bridges-5. concurrently into; circuit... making. and; breaking positionn. into: and: outv of; the bridging contact making-mentions; etweemsaid; main: contacts": andtsaidi rc-horns; respectivelw. retarding mechanism: being r-intcrposed between said connecting members-rand, the;;-rotar.y. contacttmemherszotrf both; s-aidtcontact;bridgesion delayingr heacireuiti breaking; hroughrsaid secondary Contact: bridgemrelativelya to the; circuit; breaking through: said; nrim rymontact bridge;

- 4. Current. interrup er: including a'tpair;ofjstationary: main rcontacts: for each polez o 1 be:interrupted--,; a .pair; of; re: horns: provided;- at:.said;; main: contacts, one h0rn at- 3.611: mainrcontact; at primary; Contact; bridge comprisingaleasttone rotary contactrnemberi-beingassociated with; said; mainpontactssfor bridging the samecdirectly; .a L'secr, ondary, arcingcontacttbridge-comprisinga-t least one To..- ar!contact membernbeingaassociated withtsaidarchornsfor bridging the same parallel-to.,thebriclging.ofthewmain contacts: -through' zsaidaptimarywcontact bridge; both said contact: bridges; being; disposed. with; their: axes; parallel; toreachothen; connect-ing; members; beingprovided; be.- tweenboth. said contact: bridges. and: actuating mechanismfor moving-,- by means: 0ft fsaid. connecting members, both. said.contact-.bridges= c,oncurrently;into,circuitv making, and.v reakinglp ositions, .into i and; out: of the bridging, contact makingpositionsbetween said, contact pieces. and. saidarozhorns; respectively, retarding rnechanismrbeing inter? posed, between said. connecting members: and; the. rotary, contact members of both said contact bridges for delay.- ing the circuit breaking of said secondary contactrbridge relatiyely. to the: circuit, breaking of, said. nrimaI-y, contact the contour; of; said: thro bridges;.saidaretarding: mechanism: being? adapted 011. de- 1ayingrthezcincuit-makiug on said; primarys. Contact; bridge; relatiyelyz-t-o; :thezt circuitam-aking;-of:;thevsecondary zcontactir bridge.

5. Gurrentainterrupten-includingga pair ofcstation-ary mainrcontacts ionteachzpole; to bewintexrupted,,a pairrofi 3.116351111011183" provided.:-at=; said: maini contacts, one:.hor-n atl each main: contact,i. avpriinary; contact :bridge; comprising; at 'leastronezrotary, contact: member. associated with-said! main-.contiacts foribridg-ing thezsame directly; arsecondary arcing. contact bridge-comprising; at. least; one rotary..- C011? tactn member-s assooiatedri with said-r arc: hornsr for; bridge ingrthe-same:paraileltorthe -bridging;of=.the;main contacts.

through saidiprimary contaotibridge; actuating mechanismfi including:drivingrmemhersrforr op.enatingathe.interrupter;L

connectingr members: being; provided; between-both: saidv contact bridges, said actuating mechanism foramovingtbw means": Of) said; connectingmembers; both saidsi contact bridgesa.concurrently:v into: circuit making: and breakinzc positions, intoand; out; of: the bridging. contaotamalcinz-x positions between-:said. main', contacts-.-andtsaid arcrhornsta respectively; said; actuatingz meehanismrfurthen including; motion: transmitting members. coupling said. connecting; members i with. said contact bridges-,-. said. motionztr-ansmitzvtingrmemberstprovidingztfor'an idle. path between; said;

connecting; members .tandi; eachrofti saidi; contact; bridges; the idle! pathrofthe motion: transmitting; members-i pror' videdratather secondary a contact-bridge. beingrlonger;than;v the idle pathrofi, the; motion transmitting; members: pro,-

1 vided at the primary contact bridge; thereby, on actuation,

off said; 'actuatingrmechanism fontbrealiing :the: circuit; .to

allow,- duringzthe-zmoyement; of said-.motion; transmitting: members:-along;s.aid idlepaths; acceleration of saidantuatm ing mechanism to a velocity to strike in a shock-mover mentr' theirespective :contactz bridge, and. further; cause,

first, abrupt raisin-gqof .the :;rotary. contact memhen; from. the; main: contacts a-nd,;.timely. delayed; thereafter-,1 the, raisingtofi the. rotaryicontactz member-from the. arc.-horns;-.

6'.i.Cur rent interrupter including a 'painofstationary- Contaotsnforr each pole; to: be interrupted and: a. contactt shaft :bearingrwi-th. said:ba1l :uponzthc; innensurfacerofthe;

ring so: asztoz biasa-it: elastically towards; the contac'nmak. ing-position;saidtthroatzfurthcr shaped to;pro,vide anidle; path: between. itselfiandithe; inner: circumference. of thering whenitherring is helid. ingcontact position by said spring;

. urged-ball, saidjdleapath, Whentthe. ac-tuatingmechanism:

is: operated. forvbreaki'ng the :-circuit,. allowing said shaft with..its.= throat to; be-r-raisedila,certaindistancewithoutliftin'gtthe ring-from its: contact .with thefStatiOHa-I'y con: acts; andtjto; b e: accelerated tot a. velocity; so as; to; strike.

; withzatshock.movementzsaid contact ring; whereupon, on-

further; upward; movement of the? shaft, the; ring is: lifted and .thetcircuit throughgsaidl. stationary, contacts 1 and said ringis-brok'en:

7; flurrentzinterrupten'asa SfitifOIithzlIl'; claim. 6 wherein ;is composed. of two, sectors; a:lower sector; housing'ithez-spring and. ball,..of a radius smaller than that; of: the inner, circumference of, the ring withithecenter axis; when shaft. and ring are inrthe bridging-position,-..generally. concentric with. theuaxis of the ring; and an upper sector of the same radius as the inner, circumference of the ring but with the center axis displacednbetween the.-center axis of the lower. sector. and. the, d-iametnal-ly opposedside ofthe throat.so,that when ,the. shaft holds, by .meansof. ball and. spring, the. ring; in, its closed, position. the. shaft, isi. closeto. but does not contact the ring, and free space is provided between the upper sector and the inner circumference of the ring.

8. Current interrupter as set forth in .claim '5 wherein the rotary contact member bridging said main contacts is a ring, a shaft being provided and supported non-re volvably by said connecting members, said shaft carrying said ring freely revolvable thereabout; said shaft pene-.

trati-ng said ring with e. throat, said throat housing a spring urged ball [and bearing therewith upon the inner surface of the ring so as to bias it elastically towards the contact making position; said throat further shaped to provide said idle path between its upper surface and the upper inner circumference of the ring when the ring is held in contact position on said main contacts by said spring urged ball, said idle path allowing said throat and shaft to be raised a certain distance Without lifting the ring when the actuating means are operated to break the circuit, whereupon, on further upward movement of the shaft, the ring is lifted :and the circuit through said main contacts and said ring is broken.

9. Current interrupter as set forth in claim 8 wherein the rotary contact member bridging the arc horns is a roller, a shaft carrying said roller being slidably mounted in slots of said connecting members, springs being housed in said slots for urging said shaft and thereby said roller towards the contact making position of the roller between the arc horns; said slots in said connecting members being disposed relatively to said shaft and being of a length so as to allow idle motion of said actuating means together with said connecting membersrrelatively to said shaft for a certain distance before the roller is raised out of contact with said are horns.

10. Current interrupter as set forth in claim 9 wherein 10 the idle path constituted by said throat is shorter than the idle path constituted by said slots.

11. Current interrupter as set forth in claim 5 wherein the rotary contact member associated with said arc horns :is a roller, a shaft carrying said roller being secured thereto and being mounted in said connecting members, said motion transmitting members for providing an idle path and interposed between said actuating means and said secondary contact bridge being constituted by slots in said connecting members, said shaft being displaceably guided within said slots, springs being housed in said slots, said springs bearing on said shaft for urging through said shaft said roller elastically towards the contacting position bridging said are horns; said slots in said connecting members being disposed relatively to said shaft and being of a length so as to cause, on actuation of the actuating means for breaking the circuit, idle motion of said actuating means together with said connecting members relatively to said shaft for a certain distance before the roller is raised out of contact with said are horns; thereby to delay the circuit breaking of said roller and further rallow, during said idle motion, acceleration of said actuating means together with said connecting members, and, thereon, an abrupt raising of the roller from its contact with said are horns.

References Cited in the file of this patent UNITED STATES PATENTS 693,416 Merrick et al Feb. 18, 1902 1,740,640 Austin Dec. 24, 1929 2,491,010 Lewis Dec. 13, 1949

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