US1998743A

US1998743A - Electric circuit breaker

Info

Publication number: US1998743A
Application number: US621039A
Authority: US
Inventors: Thommen Hans
Original assignee: BBC Brown Boveri France SA
Current assignee: BBC Brown Boveri AG Germany; BBC Brown Boveri France SA
Priority date: 1931-07-06
Filing date: 1932-07-06
Publication date: 1935-04-23
Anticipated expiration: 1952-04-23
Also published as: FR739471A; GB408564A

Description

April 23, 1935. H. THOMMEN ELECTRIC CIRCUIT BREAKER Filed July 6, 1932 4 3 3 m a 7 2 r 2 M. d 33 m2 Patented Apr. 23, 1935 ,PATENTQOFFICE 1,998,743 ELECTRIC CIRCUIT BREAKER Hans Thommen, Ennetbaden, Switzerland, .as-

signer to Aktiengcsellschaft Brown Boveri & Cie., Baden, Switzerland, a joint-stock company of Switzerland Application July 6, 1932, Serial No. 621,039

In Germany July 6, 1931 13 Claims. (Cl. 200150) This invention relates to improvementsin electric circuit breakers and more particularly tothe type of circuit breaker in which an are, formed uponseparation of the contacts to interrupt the circuit, is quenched by the interposition of an insulating fluid between the contacts.

When an electric power circuit is interrupte by a circuit breaker with the contacts thereof immersed in an insulating fiuidsuch as oil, the fluid is partially vaporized by the arc'formed, thus producing pressure by which. the fluid is forced away from the vicinity of the arc. When the contacts are separated in a fluid retained within a closed chamber, the pressure forces the fluid from the chamber through the openings provided therefor or for movement of the movable contact therethrough. The flow of fluid through such openings cools the arc and deionizes 'the gas formed thereby and conducting the same and causes quenching of the are thus interrupting the circuit. In the usual construction of such circuit breakers the oil blast takes place in only one direction and diminishes with decrease in the gas I production. The interrupting action of the oil blast can be materially improved if the chamber is so constructed as to produce an oil flow in both directions from the center of the are about the ceased.

It is, therefore, among the objects of the present invention to provide an electric circuit breaker of the interposed insulating fluid arc quenching type in which the arc produces gases which cause the formation of fluid blasts about the arc.

Another object of the invention is to provide an electric circuit breaker of the interposed insulating fluid arc quenching type in which the circuit is interrupted in a chamber so constructed that fluid blasts are produced directed toward the points of attachment of the arc on the contacts of the circuit breaker.

Another object of the invention is to provide an electric circuit breaker of the interposed insulating fluid arc quenching type in which the circuit is interrupted in a chamber so constructed that fluid blasts are produced in both directions from the center of the are about the contacts of the circuit breaker.

Another object of the invention is to provide an electric circuit breaker of the interposed insulating fluid arc quenching type in which the-circuit is interrupted in a chamber so constructed that the fluid blasts, produced upon separation of the present invention.

the contacts of the circuit breaker to interrupt the circuit, are continued after the gas producing action of, the arc has ceased.

Objects and advantages other than those above set forth will be apparent from the following de-' '5 scription when read in connection with the'ac- .companying drawing in which: I

Fig. 1 is a partial vertical sectional view of a portion of an electric circuit breaker of the inter posed insulating fluid arc quenching type em- 10 bodying the present invention;

Fig. 2 is a vertical sectional viewof a pressure pot-similar to that shown in Fig. l, but having an additional partition member;

Fig. 3 is a vertical sectional view of a preferred form of a pressure pot embodying the'invention;

and T Fig. 4 is a vertical sectional view of a pressure pot which is a modification of Fig. 3, and embodies Referring more particularly to the drawing by characters of reference, the reference numeral 6 designates a portion of a chamber or tankprovided with a top or cover I and designed to enclose the operating portions of a circuit breaker structure within a body of oil such asindicated at 8. Hollow insulating bushings l I extend through the top plate I and support substantially closed chambers I2 within each of which is arranged a fixed contact I3 which contacts are each connected with the electric circuit (not shown) exterior of the tank by a conductor I4 connected with a conductor l5 extending through the bushing. II.

An aperture I6 is provided in the top of the chamber I2 to permit a contact I! to be moved into and out of engagement with the fixed contact I3. A second aperture I8' is provided in the exterior wall of the chamber l2 below the oil level within the tank 6 for a purpose which will appear hereinafter.

A second chamber 2| is arranged coaxially within chamber l2 and is secured toor integral with the top of the chamber I2 as shown, thereby forming with chamber'IZ asubstantially enclosed space above the oil level within the tank 6. The chamber 2! is provided with a partition 22 which has an aperture 23 therethrough in alinement with the aperture I6 through the top of the chamber I2 and with an aperture 24 through the bottom of the chamber 2I above the fixed contact I3. The movable contact I! may thus be moved into and out of engagement with fixed contact I3 through the alined apertures through the chambers I2 and 2! by means of a cross bar Z5 connected with the contact and connected with an operating rod 21 which is arranged to be moved by any of the usual operating means which are, therefore, not shown. It will be understood, of course, that the portion of the structure shown in elevation on the right hand side of Fig. 1 corresponds to the portion of the structure described imm diately above and shown on the left hand side of Fig. 1.

When the electric circuit (not shown), in which the contacts 53 and ii are connected, is interrupted; the contact i"! is moved out of engagement with contact l3. As soon as the contacts are separated from each other the are formed acts on the oil. and produces partial vaporization thereof which forces the unvaporized oil in chamber l2 upv-Jardly, thus securing a compres sion of the gases in the chamber l2 above the oil level. Further movement of contact i"! through apertures and in succession draws the arc out and causes the oil in chamber El to be partially vaporized. Such vaporization produces a high pressure which causes an oil to how through

apertures

24 and 23 in sequence in opposite directions due to expansion of the gases in the chamber 2! The oil blast through aperture 2' 5 surrounds and moves our the fixed contact i3 and the oil blast flowing tln'ough aperture moves over contact ll. As soon as the gas produced in chamber 2! diminishes, thus decreasi' g the pressure on the oil in chamber 22, the pre viously compressed gases in the upper portion of chamber i2 force oil to surround the fixed contact !3 and to flow through aperture 24 into chamber 2! in a direction opposite to that taken by the oil blast from such chamber when the movable contact I? was drawn thereinto. The excess and incondensible gases collect in the upper portion of chamber i2 and escape therefrom through aperture i8 and sufficient oil then enters the chambers 52 and 2! through such aperture to maintain the level therein substantially the same as that in tank 6.

The contact enclosing chambers shown in the embodiment in Fig. 2 are substantially similar to the embodiment illustrated in Fig. l excepting for the provision of a partition 23 arranged across chamber 2! and provided with an aperture 29 in alinement with

apertures

23 and 24 thus dividing chamber 2| into two portions. The arc quenching and circuit interrupting action which takes place in the present embodiment is also similar to that described as taking place in the embodiment shown in l with the exception that an oil blast is forced through apertures 24 and 29 in opposite directions as long as the end of the movable contact ll is between the bottom of the chamber 2! and the partition 28 and that the direction of the oil blast through aperture 29 reversed as soon as contact l'i moves between par tions 28 and thus producing oil blasts in opposite directions through apertures 23 and The reversal of the direction of oil flow through the apertures through the walls of the chamber 2! causes an intensive cooling and deionization of those portions of the gases providing a conductive path for the are immediately adjacent such apertures and materially facilitates the interruption of the circuit by expediting the quenching of the arc.

Fig. 3 illustrates a modified embodiment of the invention which is similar to that shown in Fig. 2 excepting that the chain er 2! is divided into several substantially closed portions by partitions 3i and 32 arranged between the upper wall .2 of the chamber 2% and the bottom of the chamber 2!. Each of the partitions 3i and 32 is provided with an aperture therethrough designated by reference numerals 33 and 3:?- respectively. Apertures 25 and Bl are provided through the side wall of chamber 2i between the partitions 3| and 32. When contact I3 is moved out of engagement with fixed contact 13 the gases formed by the are within chamber l2 force the oil therein upwardly to compress the gases in the upper portion of such chamber. Further movement of movable contact ii and extension of the arc into chamber 25 between partition 32 and the bottom thereof produces an oil blast through

apertures

36 and 24 in opposite'directions. Movement of movable contact ll between partitions 3! and 22 likewise causes an oil blast through apertures 33 and in opposite directions. The oil blasts through

apertures

34 and 33 meet in the space between partitions 3i and 32 and flow radially through apertures 38 and 3'! into chamber l2. Decrease of the gases produced by the action of the arc on the oil in the seveal portions of the chamber 25 by flow of the oil through the apertures therein permits the gases compressed at the beginning of the circuit interrupting action the upper rtion of the chamber E3 to expand to force oil through

ap rtures

24, 34, 33 and in the reverse direction. from that described immediately above, thus materially increasing the eiiective .e. s of the arc quenching action of the 0 Under some circumstances, it may to omit reversal of the direction of the oil flow through the apertures as described above with reference to Figs. 1, 2 and 3. In such case chamber l2 shown in Figs. 1, 2 and merely omitted as illustrated in Fig. i and the apertures from chamber 2| are arranged to discharge directly into tank If interrupting action has taken place which causes e' ulsion of the oil from the several closed portions of chamber 25 oil will fiow back into such closed porti through the apertures therethrough from the tank, thus causa complete filling of all of the portions of ch ber 2! after each circuit interrupt ng action. The oil blasts then flow through the several apertures from the spaces in which the gases produced at relatively high pressure directly into oil retained within the tank 5 under the low pressure therein. When the chamber 52 is omitted the fixed contact i3 is supported in alinement with the apertures through the the partitions the bottom of chamber 21 by sui able means such the supports 4-! secured to the chamber 2! by such as the bolts Although but a embodiments of the I rcsem. invention have been illustrated a d described. it will be apparent to those skilled in the art that various changes and modifications may be made therein without departing from the spirit of the invention or from the scope of the appende claims.

It is claimed and desired to secure by Letters Patent:

3. In an electric circuit breaker. a tanl; containarc extinguishing liquid. an insulai extending into said tank, a pressu cured to aid insulating bushing and be desirable u AL,

secured thereto adjacent said ope 1a11s i11- eluding a movable contact rod extending through ber extending into said tank, a pressure put secured to said insulating member and partially immersed in said fluid,'a smaller pressure potwithin said pressure pot forming a pressurechamber between said pots, a fixed contact mounted Within said pressure pot but externally of said smaller pressure pot, said pressure pot having an opening therethrough in alinement with said fixed contact, a contact rod movable through said opening into engagement with said fixed con-' tact, and means secured within said smaller pressure pot defining a series of chambers interconnected by alined openings for the passage'of said contact rod, and for the discharge-of arc extinguishing liquid.

3. In an electric circuit breaker, a tank containing arc extinguishing liquid, an insulating member extending into said tank, a pressure pct secured to said insulating member and partially immersed in said fluid, a fixed contact mounted withinsaid pressure pot, said pressure pot having an opening therethrough in alinement with said fixed contact, a contact rod movable through said opening into engagement with said fixed contact, an insulating structure secured to the interior of said pressure pot adjacent said opening, said structure defining a series of closed chambers of considerably smaller lateral dimensions than said pressure pot, said chambers having alined openings therethrough in communication 'with said opening in said pressure pot for the discharge of arc extingu shing liquid the lowermost of said alined openings being directly above said fixed contact, and means for equalizing the level of the oil in the said tank and said pressure pot so as to provide an air space above the oil level between said pressure pot and said structure. 4. In an electric circuit breaker, a tank containing arc extinguishing liquid, an insulating member extending into saidtank, a pressure pot secured to said insulating member and immersed in said fluid, a fixed contact mounted within said pressure pot, said pressure pot having an opening therethrough in alinement with said fixed contact, a contact rod movable through said opening into engagement with said fixed contact, and a second pressure pot in communication with said first mentioned pressure pot through said opening, said second pressure pot having a plurality of partitions therein having holes therethrough in alinement with said opening and means whereby upon disconnection of said contact said are extinguishing liquid is forced through said opening first in one direction and then in the other direction.

'5.In an electric circuit breaker, atank containing arc extinguishing liquid, an insulating member extending into said tank, a pressure pot secured to said insulating member and immersed in said fluid, a fixed contact mounted within said pressure pot, said pressure pot having an opening therethrough in alinement with said fixed contact, a contact rod movable through said opening into engagement with said fixed contact,

and an auxiliary pressure pot secured to said.

first mentioned pressure pot so as to be in communication with said opening, said second pressure pot having a plurality of partitions therein forming a series of chambers interconnected by openings in said partitions in alinement with the 1 opening in said first mentioned pressure pot, said auxiliary pressure pot having a plurality of additional openings therein for the lateral discharge of arc extinguishing liquid.

6. In an electric circuit breaker, a tank containingarc extinguishing liquid, an insulating member extending into said tank, a pressure pot secured to said insulating member and immersed in said fluid, a fixed contact mounted within said pressure pot, said pressure pot having an opening therethrough in alinement with said fixed contact, a contact rod movable through said opening into engagement with said fixed contact, and an aux tioned pressure pot so as to surround said opening, said secondpressure pot having a plurality of partitions therein forming a series ,of chambers interconnected by openings in said partitions in alinement with said opening in said pressure pot, said second pressure pot also having a plurality of additional openings therein constituting discharge passageways between said pressure pots.

7. In an electric circuit breaker, a tank containing an arc extinguishing liquid, an insulating member extending into said tank, a pressure pot secured to said insulating member and immersed in said liquid, said pressure pot having a plurality of partitions therein with vertically alined holes therethrough defining a series of inter-communieating chambers, one of said chambers having an additional opening for the lateral discharge of arc extinguishing liquid into said tank, and means for drawing an are through said vertically alined holes.

8. In an electric circuit breaker, a tank containing an arc extinguishing liquid, an insulating member extending into said tank, a pressure potsecured to said insulating member and immersed in said liquid, said pressure pot having a plurality of partitions therein with vertically alined holes therethrough defining a series of in ter-communicating chambers, said pressurepot having a transverse discharge passageway opening into said tank from one of said chambers which is immediately adjacent and between two of said chambers, and relatively movable contacts for drawing an are through said vertically alined holes.

9. In an electric circuit breaker, a tank containing an arc extinguishing liquid, an insulating member extending into said tank, a pressure pot secured to said insulating member and immersed .in said liquid, said pressure pot having a plurality of partitions therein with vertically alined holes therethrough defining a series of inter-communication chambers, said pressure pot having a transverse discharge passageway opening into said tank from one of said chambers which is immediately adjacent and between two of said chambers, a fixed contact carried by said pressure pot in alinement with said alined holes, said partitions being so spaced that when said .movable contact is withdrawn from said fixed contact it first passes through a plurality of relatively small chambers and then through a larger chamber.

10. In an electric circuit breaker, a closed chamber to retain a quantity of insulating fluid, an insulating bushing extending into said chamber, a substantially closed chamber supported by said iliary pressure pot secured within said first menbushing and extending into the fluid, the second said chamber being divided into an inner and an outer portion forming a gas compressing chamber above the level of the fluid in the first said chamber, a fixed contact arranged within the second said chamber, and a contact extending into the second said chamber and movable into and out of engagement with said fixed contact.

11. In an electric circuit breaker, a closed chamber to retain a quantity of insulating fluid, an insulating bushing extending into said chamher, a substantially closed chamber supported by said bushing and extending into the fluid, the second of said chambers being divided into an outer and an inner portion, the outer portion of chamber having an aperture below the level of the fluid in the first said chamber, a fixed contact arranged Within the second said chamber, and a contact extending into the second said chamber and movable into and out of engagement with said fixed contact.

12. In an electric circuit breaker, a closed chamber to retain a. quantity of insulating fluid, an insulating bushing extending into said chamber, a substantially closed chamber supported by said bushing and extending into the fluid, the second of said chambers being divided into an outer and an inner portion, the inner portion of said chamber being divided into a plurality of portions having apertures for discharging into the outer portion thereof, a fixed contact arranged Within the second said chamber, and a contact extending into the second said chamber and movable into and out of engagement with said fixed contact.

13. In an electric circuit breaker, a closed chamber to retain a quantity of insulating fluid, an insulating bushing extending into said chamber, a substantially closed chamber supported by said bushing and extending into the fluid, the second said chamber being divided into an inner and an outer portion having alined apertures in the Walls thereof, the outer portion of said chamber having an aperture below the level of the fluid in the first said chamber and the inner portion of said chamber being divided into a plurality of closed portions having apertures for discharging only into the outer portion thereof, a fixed contact arranged within the second said chamher, and a contact extending into the second said chamber and movable into and out of engagement with said fixed contact, said movable contact substantially closing the apertures in the inner portions of the second said chamber when engaging said fixed contact.

HANS THOMMEN.