US2111416A

US2111416A - Electric circuit breaker

Info

Publication number: US2111416A
Application number: US113914A
Authority: US
Inventors: Balachowsky Georges
Original assignee: General Electric Co
Current assignee: General Electric Co
Priority date: 1935-12-12
Filing date: 1936-12-02
Publication date: 1938-03-15
Anticipated expiration: 1955-03-15
Also published as: FR810720A

Description

March l5, 1938. G. BALAcHowsKY 2,111,416

ELECTRIC CIRCUIT BREAKER Filed Dec. 2, 195e 5 sheets-sheet 1 .www l Il.,

Inventor: Georges Baluchowsk b9 5.6/

is Attovvneg.

5 Sheets-Sheet 2 March 15, 1938. G. BALAcHowsKY ELECTRIC CIRCUIT BREAKER Filed Dec. 2, 1936 March l5, 1938. G. BALACHQWSKY 2,111,416

ELECTRIC CIRCUIT BREAKER Filed Deo. 2, 1936 5 Sheets-Sheet 3 u... k U.. m O rh w mam 5 j i: W55 m Tm H g w# e G n: D

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March 15, 1938. G. BALAcHowsKY ELECTRIC CIRCUIT BREAKER Filed Dec. 2, 1936 5 Sheers-Sheel 4 I nventor". Goges Balachowskg,

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ls Attorney.'

March 15, 1938. G, BALACHOWSKY 2,111,416

ELECTRIC C IRCUIT BREAKER Filed Dec. 2, 1936 5 Sheets-Sheet 5 Inventor; G eovges Balocho 5kg,

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is Attovneg.

Patented Mar. 15, 1938' Edilllgdlb ELECTRIC CmCUIT BREAKER Georges Balacliowsky, Paris, France, assignor to General Electric icmpany, a corporation oi New York Application December 2 19%, Serial No. llllld In France December l2,.ll935 9 @laima This invention relates to electric circuit breakers of the liquid blast type wherein a blast or jet of arc-extinguishing liquid, such as oil for example, is projected through the arc by means actuated in accordance with opening of the circuit, and has for its principal object the provision of an improved circuit breaker of the aforesaid type which is simple and compact in construction, efficient and positive in operation and which requires a comparatively small amount of arc-extinguishing liquid.

My invention will be more fully set forth in the following description referring to the accompanying drawings, and the features of novelty which characterize my invention will be pointed out with particularity in the claims annexed to and forming a part of this specication.

Referring to the drawings, Fig. l'is an elevational View partly in section of a high voltage electric circuit breaker embodying the present invention; Fig. 2 is a similar enlarged view showing a modified form of the contact construction; Fig. 3 is a similar view illustrating a construction generally similar to Fig. 1; Fig. 4 is an elevational sectional-view of a modified form of circuit breaker embodying my invention; Figs. 5 and 6 are elevational views, partly in section, showing a modified form of circuit breaker in the closed and open circuit positions. respectively; Fig. 7 is a partly diagrammatic View of a "form of circuit breaker embodying the present invention; Fig. 8 is an elevational view partly in section of another form my invention may assume, and Figs. 9, 10, 11 and 12 illustrate a modied form of circuit breaker for interrupting high voltage circuits, Fig. 9 being an elevational sectional-view, Fig. 10 being a plan View ofthe device shown by Fig. 9, and Figs. 11 and 112 being sectional views indicated respectively by the lines B-B and C-C of Fig. l0.

Referring to Fig. l, there is shown one embodiment of my invention wherein the piston for producing the arc-extinguishing liquid blast is directly connected to the movable contact rod, and is operablewithin a cylinder concentric with respect to said rod. The contact rod which is of tubular construction in part is in communication with said cylinder so that the opening movement of the rod contact causes a blast of liquid through the tubular contact and through the arc at the point of contact separation.

As illustrated, the circuit-interrupter, which is particularly adapted for interrupting high voltage power circuits, is in the closed circuit position. The circuit breaker comprises essentially u a base or supporting structure I to which is secured a mechanism housing t for the operating linkage generally indicated at 2'. The linkage is suitably actuated for moving the insulating rod 3, to which the movable rod contact 4 is secured, between open and closed. circuit positions.

The insulating rod 3 is movable within and airlally or" a lower supporting insulator 5 which may be composed of a suitable ceramic material. The insulator E in turn supports an intermediate housing G which includes one of the terminals l of the circuit breaker, the terminal being electrically connected through a sliding contact at t to the movable rod contact il. The intermediate housing G may, if desired, contain a current transformer 6 surrounding the rod contact d.

Supported on the intermediate housing is an upper ceramic insulator Q which contains the main contact structure and arc interrupting apparatus. A piston l@ which is secured to and carried by the rod contact t is reciprocally movable within a cylinder lll, the contact rod being tubular in construction and in communication with said cylinder below the piston I0 by means of apertures indicated at i'. The tubular contact is open at its upper end so that when the rod is moved downward in accordance with the circuit opening operation, arc extinguishing liquid in the switch chamber, the level of which is indicated at l2, is projected from the cylinder upward through the tubular contact to the point of contact separation. The coacting xed contact at I3 'is resiliently mounted at I3' and is suitably electrically connected to the other circuit breaker terminal at I4. The circuit breaker can also be provided with suitable baille and cooling structure indicated at I2' for preventing throw of oil.

Referring more particularly to the movable contact structure, a contact element I5 is carried at the end of the tubular contact for directly engaging the fixed contact I3. The contact I5 is normally surrounded by and operable within an insulating member I6 forming a nozzle-like structure for guiding the jet of oil from the tubular contact.

As best illustrated by Fig. 2 which is an enlarged view of a generally similar contact structure, the insulating member I6 may, if desired, be formed in part at least as an intermediate contact between the coacting contacts I3 and I5. Referring more particularly to the construction shown, a movable contact I5 which is suitably mounted at thev upper terminal of the hollow rod contact 4 is provided with an arcing tip Il. 'I'he insulating nozzle I6 is mounted in sleeve-like fashion on the rod contact 4 and is normally biased by a spring Il towards the end of the contact into engagement with contact I3. The insulating nozzle I8 which is operatively connected through a pin and slot connection I9 and 20.L to the rod 4 is accordingly limited to a predetermined range of movement indicated at a.

'I'he intermediate contact at 2i comprises the upper part of the nozzle structure and is formed as an annular member so that the arcing contact I'I extends through the same the contact I5 however closing the nozzle exhaust passage. In the closed circuit position shown, the fixed contact I3 and the intermediate contact 2| are in direct engagement and the contact Il engages in a valve-like manner the intermediate contact. As in the previous instance the xed contact is resiliently mounted at I3 'in order to insure properfcontact pressure.

In this arrangement wherein the nozzle member forms an intermediate contact the actual contact area is completely surrounded by external oil and is therefore thoroughly cooled, thereby resulting in eiilcient contact operation. For the purpose of preventing excessive pressures in the cylinder II and for limiting application of the oil. jet during the opening stroke of the breaker, ports II' are formed in the cylinder walls a predetermined distance below the piston III. 'I'hese ports also facilitate refilling of the cylinder with oil when the breaker is closed and also reduce the power required for operating the contact rod 4. It will be apparent that the ports prevent any appreciable projection of oil through the arc before the arc has lengthened a predetermined extent. That is, it is desirable that the jet of oil-be applied when the arc has reached a length most favorable for circuit interruption. The piston Ill is suitably provided with ports 23 which coact with a flap valve 23 in a well-known inanner.

'I'he operation of the device is as follows: When the contact rod is moved downward in accord- -ance with the circuit opening operation, the piston III forces oil from the cylinder I I into the tubular contactthrough the openings 24. The oil passes outward through the openings 25 around the contact I5 and exhausts through an annular opening formed between the contacts 2| and I3 immediately upon separation of contacts I3 and 2i as presently described. I'he `vents II in the cylinder II provide for initial release of the oil under pressure.

\It will be noted that the nozzle I8 which is biased by the spring I3 into engagement with the contact I3 remains in such engagement by reason of the lost motion connection at I9 and 2li until the contact I5 has moved through the distance a. During this contact movement an arc of predetermined length is drawn between 'the contacts I5 and 2|. When the lost motion between the rod contact 4 and the nozzle Il is taken up contact separation at I3 and 2i is immediately effected with the result that a strong oil blast is directed through the aforesaid annular'passage into the arc and towards the nxed contact I3. That is. after they movable contact has completed that part of the stroke indicated at"a, the nozzle I6 moves as a unit with the rod contact 4 so as to separate contacts 2i and I3. The arc then tendstostrike between the contact I3sand the arcing tip I1 by reason of the vradial converging force of the jet exhausting through contact 2i so that it is again centrally positioned and in the zone swept by the oil jet from the nozzle. v f

Upon closing of the circuit breaker, the oil enters the cylinder II by the ports 22 in the piston which are now unobstructed by the flap valve 23. The contacts engage in the reverse order, that is, the contacts I3 and 2i nrst engage and subse`5 quentlythe tubular contact rod 4 in compressing the spring I3 so as to force the nozzle against the contact I3 forcesr the contact I3 into engagement with intermediate contact 2I.

In Fig. 3, there is shown a generally similar 10 arrangement wherein the nozzle I6 is composed entirely of insulating material. In the closed circuit position the movable contact I5 extends through the exhaust passage of the nozzle directly to engage the fixed contact I3. As in the previous l5 instances the movable contact Il carries the piston I0 and is surrounded by a vtubular structure 23 which provides an annular space through which the oil is forced by the piston during the circuit opening operation. 20

'I'he operation is believed to be apparent with-- out further description, the piston I0 after predetermined movement thereof within the cylinder I I projecting oil upwardly through the ports 21. The insulating nozzle which remains in en- 25 gagement with the ilxed contact I3 during the initial opening movement of the contact Il is ilnally picked up by the movable contact structure and moved away from the contact Il so that the nozzle exhaust passage is clear. 'Ihe arc 30 which is formed between the central part of the contact I3 andthe arc tip of the arcing contact I5 extends generally axially oi' the insulating nozzle and is therefore subjected to a radial oil blast through the annular exhaust passage formed 35 betweenv the contact Il and the nozzle I8. This radial oil blast serves to envelop the arc and sweep away the are products so as eifectively to extinguish the arc.

Fig. 4 illustrates a simplified form of the nozzle 40 arrangement wherein the nozzle serves a dual purpose, namelythat of creating the uid pressure and, guiding the oil blast through the arc. The interrupting or arc chamber which is formed by the insulating cylinder 26 serves as the cyl- 46 inder for the piston structure carried by the movable rod contact 4. 'I'he piston in the present instance is composed of a funnel-likev member 23 which is suitably secured at the desired position to the movable contact rod by means of a clamp- 60 ing collar 29. The upper or exhaust opening of the inverted funnel structure is defined by an insulating nozzle 30 which is positioned adjacent the fixed contact I3. l

When the circuit breaker is opened the funnel 55 28 is moved downward by the rod 4 within the cylinder 26, the open circuit position being indicated by dotted lines. 'I'he oil beneath the funnel within the cylinder 26 is accordingly forced through the annular opening 3| formed between 60 the contact member I5 and the insulating nozzle 3i)k to sweep the arc formed between the contacts I3 and I5. Accordinglyya ,strong jet of oil is projected radially on the arc at the contact I5 throughout the entire stroke of the movable con- 65 tact structure.

Figs. 5 and 6 illustrate anotherjorm of circuit breaker in the closed and partly open positions respectively. In this arrangement the iixed contact structure is modified, the movable contact I5 70 as in the previous instances being operable within an insulating nozzle I6. When the movable contact structure is lowered the contact I5 and nozzle I6 coact in the manner previously described and an oil blast is produced generally indi- 75 cated by the flow direction arrows 32 through the annular opening' at the nozzle exhaust.

The xed contact structure comprises an annular contact 33 which is resiliently mounted on a spring 34, and a centrally positioned contact rod 35 which is also biased towards a lower limiting position by a spring 36. f

When the circuit breaker is closed as illustrated by Fig. 5, the contact I5 directly engages the ccntact 35 and holds it retracted against the bias oi spring 36, the contact I5 also engaging an annular contact seat formed by a cylindrical member 3'I constituting a part of contact 33.

When the circuit breaker is opened the contact I5 first separates at the contact seat at 35i, the contact rod 35, however, remaining in following engagement. After a limited movement dened by the stop member 38, the contacts I5 and A 35 separate and` the arc formed between the same is subjected to the oil blast above described. The oil blast is .directed at the tip oi contact which in its limiting position extends through an opening in an insulating plate 39. The plate 39 serves as a partition to prevent restriking of the arc between the contacts I5 and 33.

Fig. '7 shows an arrangement wherein the oil blast is directed transversely of the arc, the cil jet in this case being projected through the tubular rod 4 of the movable contact in a direction indicated by the flow arrows 40. The insulating nozzle I6 is provided with a lateral port iii' and carries an intermediate contactdll. The xed contact is indicated at I3 and the movable contact member at I5. In` the closed circuit pcsition of the breaker, the intermediate contact 4I engages the fixed contact I3 and the contact ,I5 in turn engages Contact 4I. It is not essential that the nozzle I6 be spring biased toward the xed contact I3 since the oil which is forced through the tubular contact 4 upon opening of the breaker lifts the intermediate contact 4I and so brings the exhaust passage of the nozzle into alignment with the fluid passage formed by the movable contact structure. Accordingly the arc between the contacts I5 and 4I is transversely swept by the oil jet. In this arrangement high pressures are automatically avoided within the nozzle I6.

In the modification shown by Fig. 8, the arc is subjected to separate oil blasts at its roots, namely, at the contacts I3 and I5. In this arrangement, the lower part of the cylinder II in which the piston Ill operates, communicates with a conduit 42 which terminates in a nozzle 43 positioned adjacent the fixed contact I3. The exhaust passage of the nozzle is so positioned that the fluid jet is substantially transverse of the arc at the contact I3.

When the circuit breaker is opened by the contact rod 4 as indicated by Fig. 8, the down- .ward movement of the piston I0 produces a primary jet of oil in the manner previously described through the nozzle I6 and around the -movable contact I5 and a secondary jet of oil directly from the nozzle y43 towards the fixed contact I3. Accordingly substantially throughout the opening operation the arc formed between the contacts I3 and I5 is subjected to the action of an oil jet or jets.

The conduit 42 may be replaced if desired by -an annular passage formed between the cylinder 26 and an internal concentrically arranged cylinder, the aforesaid annular passage communicating with the lower part of the cylinder II and terminating at its upper part in one or more nozzle passages such as indicated at 43.

In the interruption of high voltage power circuits, it may be advantageous to utilize a plurality of transverse oil jets, each jet tending to form a lm of insulating uid for interrupting the arc. It is also advantageous to direct one of these oil jets directly on the crater or root of the arc. Figs. 9 to 12 inclusive, illustrate a particular form of high voltage breaker wherein a plurality of transverse oil jets are utilized in the manner above referred to.

Fig. 9 which is an axial view of the contact arrangement and illustrates the breaker in the closed circuit position, the contact I5 carried by the rod 4 and the fixed contact I3 being in direct engagement. The rod 4 is connected to the piston [I6 and forms with the insulating cylinder 26 an annular space communicating with the piston cylinder ii. The oil in accordance with the circuit opening movement is forced by the piston llt upwardly through the cylinder 26 generally in the manner oi Fig. 3. The oil exhausts through the arc by way of a plurality of double oil jets that are directed in divergent directions as presently described.

Referring more speciically'to the disclosure the arc interrupting device which is carried at the upper part oi the tube 26 comprises an nsulating structure forming, as shown by Fig. 9,

a main po-rt d5 leading from the cylinder 26 directly to a pair of transverse passages 46 and di adjacent the point of contact engagement. These passages may be nozzle-shaped in form. A double jet is therefore directed transversely ci the arc upon initial opening of the circuit.

A second double jet which subsequently comes intc action as the circuit opening operation proceeds is indicated by Fig. 11 which illustrates a sectional view of the apparatus shown by Fig. 9, 120 degrees from the position shown in Fig. 9. This is best illustrated by Fig. 10 which is a plan view of the breaker arrangement, line B-B indicating the section shown by Fig. 11. In Fig. l1 a second double jet is in communication with l the cylinder 46 through a main passage 48 which 9 and 1l and is directed through a main passage 5I which communicates with the cylinder 26 and terminates in the

transverse passages

52 and 53. This arrangement provides a third transverse double blast across the arc when the contact I3 clears the

passages

52 and 53.

vAccordingly it will be noted that the three double transverse oil jets. are not only axially spaced with respect to the opening stroke so as to cause application of the oil jets in successive stages, but each initial application of an oil jet is at the crater or root of the arc at the contact I3. The interrupting action is therefore quite eiective throughout the entire opening stroke. It will be apparent, of course, that the shape of the

main oil passages

45, 48 and 5I, and the corresponding transverse blast passages may assume different forms so as to reduce as much as possible the fluid friction.

One of the important advantages in the radial or diverging arrangement of the jet passages resides in the fact that the reaction of the various jets offset each other as regards the transversal thrust exerted on the movable contact rod. In this manner, binding of the contact rod is avoided.

It shall be understood that the relative axial spacing o1' the transverse Jets may be selected in accordance with the operating characteristics required. That is, when it is desired to interrupt a veryhigh voltage circuit at low current, it is advantageous to increase the axial distance between the double oil jets. Such an arrangement, however, is not advantageous in the case of a very high voltage circuit at high,current since there would be a comparatively high back pressure interfering with the downward stroke of the piston. It is therefore preferable to reduce the spacing between the jets and to increase the width or cross sectional area of the ,iets so that the arc gases generated may readily escape prior to the actual oil blast.

The application oi the oil Jet is also most effective when the contacts are sumciently separated so that the arc interruption may be accomplished at the rst passage oi.' the voltage throughl zero. Too early application of the oil jet may result in high voltage surges without necessarily extinguishing the arc. The desired delay in applying the oil Jet may be obtained, as previously indicated, by providing ports as at II in the main piston cylinder II through which' the oil may escape during the rst few' centimeters of the piston opening stroke.

It should be understood that my invention is not limited to specic details of construction and arrangement thereof herein illustrated, and that changes and modications may occur to one skilled in the art without departing from the spirit of my invention.

What I claim as new and desire to secure by Letters Patent of the United States is:

1. An electric circuit breaker of the liquid blast type comprising relatively movable contact structure, including a nozzle-like member, a contact eleme'nt coacting as a unit with said member and positioned centrally thereof, said element mounted for limited movement with respect to the nozzle exhaust, and a relatively iixed coacting contact element, an arc-extinguishing liquid and piston structure operatively related to said contact structure for projecting a blast of said liquid through said noz'zle and across said iirstnamed contact element in the direction of said i'lrst coacting contact element upon opening bf the circuit.

2. An electric circuit breaker of the liquid blast type comprisingkrelatively movable contact structure including a nozzle-like member, a contact element operable between limits within said member and positioned centrally with respect to the longitudinal axis of said member so as substantially to close the nozzle exhaust in the closed circuit position, and a coacting contact element generally in alignment with said axis, an arc-extinguishing liquid and piston structure operatively related to said contact structure for projecting a blast of said liquid through said nozzle along said axis and in the direction of said coacting contact element upon predetermined separation of said contact structure.

3. An electric circuit breaker oi' the liquid blast type comprising relatively movable contact structure including a nozzle-like member secured to and movable with a part of said structure, said member having a lost-motion connection with respect to said part of said structure, means for biasing said nozzle-like member towards its type comprising a ilxed contact, a coacting movable contact, a nozzle member'having Aa. lostmotion connection with said movable contact, the passage through said nozzle member being closed in the closed circuit position of said contacts, an arc-extinguishing liquid, operating means forefl'ecting circuit opening of said contacts, said lost-motion connection effecting subsequent movement oi said nozzle member and opening of its passage, and piston structure operable in accordance with the circuit opening movement for projectinga blast oi' said liquid through said nozzle for interrupting the arc formed between said contacts.

5. An electric circuit breaker oi' the liquid blasttype comprising relatively movable contact structure including coacting contacts and a contact operable intermediate said contacts, a nozzle member connected to said intermediate oontact, means providing a lost-motion connection between said nozzle member and one of said coacting contacts, the passage through said nozzle member being closed in the closed circuit position of said contact structure. and arc-extinguishing liquid, operating means for eiIecting initial separation of one of said coactingcontacts and said intermediate contact and for eiiecting subsequent movement oi said nozzle member to open said passage and to separate said intermediate contact and the other oi said other coacting contacts, and uid pressure means for projecting a blast of said liquid through said nozzle for interrupting the arc formed between said., contacts upon opening oi' the circuit.

6. An electric circuit breaker of the iluid'blast type comprising a xed contact, a movable tubular contact, an intermediate contact adapted to form two arcs in series between said xed and movable contacts, an insulating member having a sleeve-like ilt with respect to said tubular contact and forming with said intermediate contact a uid passage in alignment with the bore of said tubular contact, said insulating member having a lost-motion connection with said tubular contact, means resiliently biasing said insulating member towards said fixed contact, opening movement of said tubular contact causing initial separation of said tubular and intermediate contacts within said insulating member, said lost- 4 motion connection causing subsequent separation of said intermediate and xed contacts, an arcextinguishing liquid and uid pressure means operated in accordance with the circuit opening movement for projecting a blast oi said liquid through said tubular contact and the passage formed by said insulating member and intermediate contact for interrupting the arc.

"1. An electric circuit breaker of the iluid blast type comprising a pair of relatively movable contacts including a rod contact, a tubular member surrounding said rod contact and terminating in an insulating sleeve forming with said tubular member a iiuid passage to the point of engagement of said contacts, said insulating member beminne ing mounted for limited movement with respect to said tubular member and normally biased so as to close said passage in the closed circuit position, an arc-extinguishing liquid and a piston movable with said contact and tubular member for projecting a blast of said liquid tlnrougln said tubular member to exhaust at the point ci separation of said contacts, separation of said con-a tacts being effected prior to movement of said in-n sulating member for opening said uid passage.

8. An electric circuit, breaker of the fluid blast type comprising relatively movable contact structure including a resiliently mounted Contact, a coacting movable contact and an annular current-carrying contact normally engaged by said movable contact, an insulating member coacting with said movable contact and forming therewith ailuid passage adjacent the region of contact separation, an insulating partition having an aperture generally in alignment with said passage positioned between said current-carrying contact and insulating member, said movable contact being withdrawn into said insulatingl member in the circuit opening operation, said movable con tact being initially separated from said currentcarrying contact and subsequently separated from said resiliently biased contact adjacent the aperture in said insulating partition, an are extinguishing liquid, and fluid pressure means actuated in accordance with the circuit opening operation tor projecting a blast of said liquid through the passage formed by said insulating member and towards said resiliently biased contact.

9. An electric circuit breaker of the liquid blast type comprising relatively movable contacts, means forming a sleeve-like arc-interrupting structure in which said contacts coact, separation of said contacts being in a direction gen= eralltr coincident with the longitudinal axis of said structure, an arc-extinguishing liquid in which said contacts are immersed, piston structure operatively connected to one of said contacts :for creating liquid pressure in said structure upon opening of tlie circuit, and insulating means constituting a part or said structure forming a plurality of exhaust passages for said liquid, said passages being in direct communication with said piston structure and spaced axially along the path of the arc formed between said contacts so that said liquid in exhausting traverses the arc path, said passages likewise being radially positioned so as to exhaust in diverging directions,

the liquid blast being deferred until the passages respectively are cleared by the contact-opening operation.

GEORGES BALACHOWSKY.

CERTIFICA TE OF CORRECTION@ Patent No. 2,111,1416;

March l5, 1958.

GEORGES BAIA CHOWSKYo It is hereby certified that error appears inrthe' printed specification of the above numbered patent requiring correction as follows: Page' il, first column', line 52,' claim l, for the word "first" read fixed; and that the said Letters Patent shouldbe read with this correction therein that the same may conform to the' record of the case in the Patent Office.

Signed and.` sealed this 5d day of May, A. D. 1958.

(Seal) Henry Van Arsdale, Acting Commissioner of Patents.