US2449208A - Circuit breaker - Google Patents

Description

E. EICHENBERGER CIRCUIT BREAKER Filed Jan. 16! 1946 m .Sm

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Patented Sept. 14, 1948 Anarran 4.sunurses .fornisca f CIRCUIT BREAKR lErnstiEicheiilcergerf- Wettingen 'Sttze'rlad,`-'asffvsignorf to l-Ak'tien'gesellsch'alf Application' January; 16, 1946fSerial "NoI..6`41"I571 `I Switzerland J anu'ary'i26,"1945 vThis l'invention relates in @general :.to'-circuit breakersand in particularto circuiti; breakers constructed for use in interruptingdireot'. current power loads.

Generally speakingfarcs '.iormed by` separation of Ithe 'contact' 'elements or circuit'. breakers .ofconventional design wheninterruptinga direct current load are extinguished by extending the length rvof `the'arc untilthe voltage requiredto maintain it is; greater' than vthe line voltage., of .the directcurrent 'systeminwhich thecircuit breaker isf connected. Various.:.expedientshave been devised .for accomplishing-this. In one arrangement, `,the circuitbreakers.` have been vprovided withwalls of` metal or insulating material which arev positionedftransversely. of .the arc path, so that the arc can applynitself. in wave form .tothe edgesof .thesefwalls .The extension of the'loop pcrtionof the arc betweensuch walls'kk has also been aided by theusey ofr pressure gasin order to improve yits l extinguishing characteristic. Furthermore, iti has also been proposed"to"arrange metalparts in an arc extinguishingr chamber of insulating material so -that Vthese "parts are touched bythe "loops of the`V arc -wnerebyheat is e'xtracted'from the 4arc' andiits extinguishing facilitated.

For use on alternating current circuits; 'circuit breakers have been' disclosedwhichfcomprise at least'- one hollow, nozzlercontactthrough which .the

are, formed uponseparation of the circuit breaker contacts, -is-'blownfwith pressuregas. *Such constructionv is quite-satisfactory Vfor breaking." alternating current loads. Since thearcrln `the'hollow contact --isl surrounded `Aon alli sides vwith' the? gas streamlan'd cooled' downf greatly, L andialso` since the space -between the contacts 'is rapidly deionized by the flowing gas, theiarc is: extinguished as the current wave-passes through. zero .and will not reestablish itself.

' Circuit-breakers of the lattertype',.howeveiare not suitable for! use f in interruptingdirect current loads because, in a direct current system, theamplitude of the current? and. voltage Visrmaintained atsload values and' hencer doesznot possess a, .zero characteristic as in alternating.; current systems.

Arr object of thislfinventionis to providea novel and improved circuitbreaker construction for use on circuitswhich carry direct 'current' loads. `.In a preferred formffmy improved circuit..y breaker includes'a pair of contact e1ements,'ronezof which is hollow,` and the; other-being 4,in the shape, of; a pin` havinglaniend portiorrwhichfenters5 and nor- :r1-'allyv rests? against :the lower-wendfofr the hollow contact-tdrclose a "circuit therethrough. v-:lnei ytwoi contactelements are mounted sothat oneofthem separatesffrom the other whensubjected to a blast of' gas under-pressure- An arc blowingrchamber `adj oins thehollowcontact and the sidewall thereofr supports a"-plurality-of-metal pins whichare arranged vertically'oneabove the other. One of the circuit"breaker'contacts has 'connected to it amaro-receiving eleotrodewhich extendsinto the lower end of the blowing" chamber. Upon separation vofthe' circuitbreak'ercontacts, one root of the'arc4 formed thereby f ascends thisarc-'receiving electrode and thefother'rootof the arc is hel'd`by`the 'ther circuit breaker contact. The medial portion of the arc loop is blown up through theiarc blowingchaniber;climbingupwardly from pin *to pinf and thusfleng'thening until' extinction takes place.

'In the''drawingsf--wliichillustrate preferred embodimentsof 'theinvention Fig, l is a vertical section"showing1 a construction wherein twol circuit breaker sections each embodying the invention are connectedlin series. flig.M la is av transversefsection taken'fonline Ict-#Ia ofliig. l. Fig. 2y alsok al verticalfsection -showsvvv` another arrangeirientfwherein` Va single gas conduit is used to feed gas to; the contact/i vsets off both "circuitbreaker sections.

*Referring-'nowi-to Fig. l ofthe drawing, atank I having a flattop'surface isf'provided, and. is adapted-'tc receive gas underpr'essure from pipe 2 and to supply the'- pressure fg'as' to the circuit through a control valve 3. Twoicircuit'breaker sectionsld and-idf embodying thelinvention are supported by tank .I.

Circ:uitibreaker-Lsection` #includes annular casing sections 6' andA II separated by anannulariinsulating columna-to constitute a' contact chamber 9. v.Thelower section I is bowl-'shaped and the bottom'thereofterminates in a ilange Il] which restsnupon': anlannulareinsulator I I, lthe latter being supported upon and'in communication with theiinterior tif-:tank Ilkthrough the valve 3. One side of fthedirectfr currentc'ircuit to be broken is connectedatfterminal .I 2 to thev lower :section l.

.;'Ihecontact structure of .circuit breakerl section 4,1'which'ish'ousedwithin chamber 9 includes a hollowl Contact'.` element I3 which may be cylindri'cal,` 'as snown,ortapered. outwardly from the bottom,"anda pintype.contactelement I4 cooperating therewith. The middle-portion vl5 of pin I4 .hasa ,diametery slightly.'largerI than the inside diameter of the opening .through hollow contact elementzl the bottom 'portion iii-of the pin contact 'I 4=is taperedland .i-hefnpper portion I 'I `thereofoissharr'edf-to rod'iform ofafcornparatively small diameter to constitute an arc-receiving electrode of the circuit breaker.

Pin I4 is iixed in position by means of supporting ribs I8 which extend upwardly from the lower section 1 of contact chamber 9.

Contact element I3 is provided with a ilange 20 at the bottom thereof. The upper section 6 of contact chamber 9 also carries an internal flange 2I. A coil spring 22 inserted between the two flanges 20 and 2I urges the lower end of hollow contact element i3 into engagement with the enlarged medial portion I of contact pin I4.

Adjacent the upper or outlet side of the hollow contact I3 is a. tubular housing 23 which may be cylindrical, as shown, or tapered outwardly from the bottom up, if desired. Housing 23 is made from insulating material and forms an arc blowing chamber for the arc. A plurality of pins 24 of conductive material are arranged in vertically spaced relation inside of the housing and are supported in the wall thereof, it being noted that these pins project through the wall on both sides.

Surrounding tubular housing 23 is another tubular housing 25 also of insulation material which is supported within an annular groove 26 formed at the top of the upper contact chamber portion 6. Supported by, and projecting through, the wall of housing 25 are a plurality of auxiliary pins 21 spaced vertically, there being a pin paired with and at the same level as each of the pins 24.

A metallic cap member or mufer 28 extends across the top of housings 23 and 25.

The component parts of the circuit breaker section 4' are constructed and arranged in the same manner as corresponding parts of circuit breaker section 4. Accordingly, corresponding parts of the two circuit breaker sections have been designated by corresponding reference numerals, but with primes added thereto, and no further description of circuit breaker section 4' is deemed necessary.

The two circuit breaker sections 4 and 4' are electrically connected in series. Hence metallic caps 28 and 23 are interconnected by conductor 39; corresponding sets of auxiliary pins 21 and 21' are interconnected by conductors 3 I; and the upper contact chamber sections 6, 6 are interconnected by conductor 32. The other side of the line adapted to be broken by the circuit breakers 4 and 4' is connected to terminal I2' on the lower control chamber section 1 of circuit breaker section 4.

Operation of the two circuit breaker sections 4 and 4 shown in Fig. 1 is started by opening valves 3, and 3 which permit gas under pressure to flow up through the insulator sections I I, I I' into the contact chambers 9 and 9. Here the gas pressure is applied to the undersides of the ilanges 20, 2G' on hollow contact elements I3 and I3', causing the latter to be lifted upwardly against the action of springs 22, 22 to break the electrical contact between the pins I4, I4' and their mated hollow contacts I3, I3'. The arcs formed at the two circuit breaking points are blown up through the hollow contacts I3, I3 under the action of the pressure gas and then extended to form arc loops. One end of each of the arc loops travels upwardly to the top of the electrodes I1, I1' which terminate inside of the housings 23, 23', and these end portions of the arcs are bathed on all sides by the pressure gas stream which forces the arcs into the blowing chambers.

The other end portions of the respective arcs are blown into the housings 25, 25', and are there extended upwardly to bring the medial portions o! the arc loops across the gap between the opposed ends of the lowermost sets of pins 24, 2l and 24', 21', respectively. Portions of the arc loops are thereby short-circuited and extinguished; and the arc loops are similarly transferred upwardly to succeeding sets of pins 24, 21 and 24', 21 by the pressure gas blast.

When current is eventually interrupted by the stretching of the arcs which spring from electrodes I1, I1', reignition is effectively prevented as the ilow of pressure gas has completely deionized the spaces between the respective sets of circuit breaker contacts I3, I4 and I3', I4.

A modified construction of a circuit breaker incorporating the invention is shown in Fig. 2. Here both circuit breaker sections 4a and 4b have a common contact housing, the lower bowl-like portion 1a of which is supported upon a single tubular insulator IIa that is in turn supported upon the tank Ia. The lower portion of the contact housing divides into two chambers 9a and 9b which include hollow contacts I3a, I3b and mating contact pins I4a, I4b.

The electrodes Ila and I1b of contact pins, Ilia, I4b differ from the construction used in Fig. l in that the electrodes I1a, Ilb terminate within and just below the top of the hollow contacts I3a, 13b.

In the Fig. 2 arrangement, additional arc-receiving electrodes 34a, 34h are supported upon the hollow contacts I3a, |312 and these electrodes are extended to a point within the arc blowing chambers formed by housings 23a, 23h. The line terminals I2a, I2b are carried by the housings 6a, 6b in this form of the invention. Operation of the circuit breakers shown in Fig. 2 is substantially the same as that of Fig. 1.

If desired, only one of the circuit breaker sections such as the section on the left in Fig. 1 need be utilized to interrupt a direct current load in which case the projections 21 must be interconnected among themselves and to the contact I3; however, connection of two circuit breaker sections in series is advantageous in that it breaks the arc gap into a greater number of sections which are more easily extinguished.

I claim:

1. In a pressure gas circuit breaker for interrupting a direct current load, a pair of contact elements, one of said elements being hollow, means supporting said contact elements for movement of at least one contact relative to the other to open a circuit therebetween under the action of pressure gas, an inner tubular casing of insulating material constituting an arc blowing chamber, the bottom of said casing being open 'and disposed adjacent said hollow contact, an arc-receiving electrode connected to at least one of said contact elements, said electrode being extended into the lower portion of said casing, a plurality of conductive pins spaced one above the other and extending through the wall of said casing, an outer tubular casing of insulating material surrounding said inner casing and through which pressure gas iiows, and at least one arc attracting electrode located in the space between said inner and outer casings and carrying the potential of the other of said contact elements.

2. A circuit breaker as dened in claim 1 wherein a plurality of arc attracting electrodes are located in the space between 'the inner and outer casings, said electrodes being constituted by conductive pins secured in the wal1of the outer casing, said pins being electrically connected with,

each other and with the other of said contact elements.

3. A circuit breaker as defined in claim 1 characterized by the feature that said casing is cylindrical.

4. A `circuit breaker as deiined in claim 1 characterized by the feature that said supporting means for said contact elements include a spring normally urging said elements into engagement with each other but which is yieldable under the action of pressure gas to permit separation of said elements.

5. In a pressure gas operated circuit breaker system for use in interrupting direct current loads; a pair of circuit breakers; each said circuit breaker including a pair of contact elements, one of said elements being hollow, means Supporting said contact elements for movement of one relative to the other under the action of gas pressure to open a circuit therebetween, an inner tubular casing of insulating material constituting an arc blowing chamber, the bottom of said casing being open and disposed adjacent said hollow contact element, an arc-receiving electrode connected to at least one of said contact elements, said electrode being extended into the lower portion of said casing, a plurality of metal pins, said pins being spaced one above the other in the wall of said casing, an outer tubular casing of insulating material surrounding said inner casing and through which pressure gas flows, and a plurality of vertically spaced pins extending through the Wall of said outer casing; means connecting corresponding pins in the walls of the outer casings of the two circuit breakers; means connecting said breakers electrically in series; and means for actuating the contact elements of both said breakers simultaneously.

6. A circuit breaker system as defined in claim 5 and further including separate tubular insulator means for supporting each said circuit breaker, the interior of each said insulator means being in communication with the contact elements of its respectively associated circuit breaker and adapted to pass pressure gas therethrough to said contact elements.

'7. A circuit breaker as defined in claim 5 and further including 'a single tubular insulator supporting both said circuit breakers, the interior of said insulator beingr in communication with the contact elements of both said circuit breakers to pass pressure gas therethrough to said contact elements.

8. In a gas pressure operated circuit breaker system; a pair of circuit breakers; each said circuit breaker including a pair of contact elements, one of said elements being hollow, means supporting said contact elements for movement of one relative to the other under the action of gas pressure to open a circuit therebetween, a pair of concentric casings of insulating material constituting arc blo-wing chambers, the bottoms of said casings being open and disposed adjacent said hollow 'contact element, an arc-receiving electrode connected to at least one of said contact elements, said electrode being extended into one of said casings, and a plurality of metal pins in the wall of each said casing, said pins being disposed one above the other and projecting through the walls of said casings at the same levels to form sets of auxiliary arc-electrodes; connections between corresponding pins in the outer casings of said breakers; means connecting the contact elements of said breakers in series; and means for actuating the contact elements of both said breakers simultaneously,

ERNST EICHENBERGER.

REFERENCE S CITED The following references are of record in the le of this patent:

UNITED STATES PATENTS Number Name Date Re. 20,044 Clerc July 28, 1936 1,959,183 Uebermuth May 15, 1934 2,240,233 Thommen Apr. 29, 1941 2,306,186 Rankin Dec. 22, 1942

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