US2473892A - Circuit interrupter - Google Patents

Description

June 1949- R. LUDWIG ET AL 7 CIRCUIT I INTERRUPTER Filed Dec. 5, 1944 INVENTORS [eon RLUdW/g &

jer/jam/h R Baker ATTORN Patented June 21,1949

2,473 892. CIRCUIT INTEBRUP'IERE Leon R. Ludwig, Wilkinsburg and Benjaminl. Baker, Turtle Creek, Pa., assignors toWestinghouse Electric Corporation, East Pittsburgh,

Pa, a 'corporation oi Pennsylvania Application December 5, 19 14; Serial :No, 566,710-

whims 1.

This invention relates, to circuit; interrupters in, general, and, morerparticularly, to circuit interrupters which utilize a, gas under pressure to effect the .extinction of one ormore, arcs drawn within the vcircuit ;interrupter.

In .United- Statespatent application, Seria1;N o. 565,456, filed Novernhen2i3 Q44; by-LeonR. Ludwig andBenjainin P. Bakerandassigned to the assignee of the instantapplication, there is illustrated and claimed a novel compressed gas cirquitinterrupter of the type utilizing a pair. of high voltage condenser, bushings extending through the co ver of t: a: pressurized tank, Pref erably, the construction is sirnilar tothat which is utilized in conventional 7 dead tank -oil circuit interrupters, and such aconstruction lends itself very efliciently toan improved rugged construction in which the dimensions may begconsiclerably reduced because of. the :highdielectric strength of the pressurizedgas-contained within the tank.

It is. an object of our; invention to-improve the constructional mounting arrangement set forth in the aforesaidapplication.

A morespecific object ;is.to provide an improved circuit interrupter of theses-blast typ .inwhich improved mounting constructions are employed to render i-mproved performance witha more safe and ruggedconstruction,

Another object 7 is; to p vide an improved mounting: arrangementfor -the three interrupters which interrupt the three :phases of a. transmis sion line, providingsuch an air type housing with adiacently disposed cubicles therein a s to enable the attendant to easily inspfiiit the circuit interrupters and to make necessary adjustments and replacements therein,

Another object is to vpr 't'avirie an improved arcex-tinguishing .ofrthe gas-blast type in which the blastvalve is positioned closely adjacent to the unit at line potential;

Another object is to provide an. improved compressed gas circuit interrupter for the three phases of a transmission systemin which the compressor equipment-is disposedclosely adjacent to the interrupting elements so that the heat formed during the compressing of I the gas --,may be; utilized to, diminish dainpness 1 adjacent the interrupting units. Preferably, wall means space. the interrupting units and the operating room. in such a'manner that convection currents of air are permitted;to .passxbetween adjacently disposed cubicles andalsotbetweenthetoperating room and the cubicles Further objects.-and- -adv ntages will J readily become apparent upon ,a treadingrofl the following specification -taken in conjunction with the, drawing, in which Figure: 1 is a vertical sectional view taken along the line 1-1 of 'Fig, 2, showing a circuit interrupter of the compressedgas type embody ing our invention, the contacts beingshownin the partly open circuit position;

Fig. 2 is a vertical sectional view taken along the-line, II-II.of Fig, 1;

Fig. 3 is an elevational view of ,amodiiied type of mounting construction; and

Fig, 4. shows a modified type ofarc-extinguisjm ing unit which may be employed in ,place of the arc-extinguisher units. utilized in Figs. 1-3,

Referring to the. drawing, and-more .particu-: larly to Fig. 1 thereof, it will be. observed that we have provided an air type housing generally designated by the reference. numeral I, which encloses three cubicles 2 and an operating room 3', all of which are -at; substantially atmospheric pressure. Within the. operating room}, the com pressor 4 may be located together withtheope eratingswitch 5, control panel 6 and pistonoperating arrang ment 1. The-thre operating rods 8, associated with the three poles of the interrupter, may be simultaneously operated by three bell-cranks 9, pivotally mounted at I0, being interconnected {by a horizontally vextending operating rod II.

The operating rod ll isv preferably actuated by the rotation. of a bell-crank. l2 pivotally mounted at l3, being operated by lthe vertical reciprocating.

motion of .a piston rod l4. At the lower end of the piston rod I4 is secured a piston, not shown, operated within the piston chamber I5.

Blast-valves I6 are associated with thetank-- l I, storing the compressed :gas and are operated-by bell-cranks l8, simultaneouslyoperated byan operating rod l9 extending lengthwise inside of thehousing. l on bothsides thereof. The two operating rods l9 are interconnected by a trans-,- verse rod 20, having ;a, roller 2i disposed .at its center, the roller 2l being actuated by a cam surface 22 fixed to an extension 23 of the piston rod l4 and extending out of the piston cham-v ber l5.

Consequently, opening operation, or upward travel of the piston rod sM, not.on ly effects a downward movement of the several operating rods 8 but also eifects by cam action, the opening of the several blast-valves lite-permit com-e. pressedygassuch as air, to pass, from the tanks I-l upwardly through the.conduits :24. into the arcextinguishing units, generally designated-by the reference numeral 25,11tocifeot theiextinction of the arcs drawn therein. When the severa1 crossbars 26 have moved a predetermined distance toward their fully open circuit position, as shown by the dotted lines 21 of Fig. 1, the cam surface 22 rides off of the roller 2| to permit reclosing of the blast-valves Hi.

The compressor 4 serves to maintain a suitable supply of compressed gas under pressure within the two tanks 11, extending lengthwise of the housing l. Each cubicle 2 may be entered by means of a door 28 so that the station attendant may easily inspect the arc-extinguishing units 25.

The arc-extinguishing units 25 are preferably of a type set forth in the aforesaid patent application by Leon H. Ludwig and Benjamin P. Baker. Preferably, their construction is as follows. Each unit 25 comprises a contact foot 29 which is preferably clamped to the lower end of the terminal stud, not shown, extending through the high voltage condenser bushings 35. The contact foot 29 has a plurality of apertures 31 formed therein, the purpose for which will appear more fully hereinafter. The contact foot 29 also has integrally formed therewith, an orifice plate 32 formed of conducting material and having an orifice 33 formed therein which cooperates with a rod-shaped movable contact 34 to draw an are 35.

Secured to the lower ends of the movable rodshaped contacts 34 are pairs of resilient fingers 36, only one of each of which is shown, which frictionally engage the opposed outer ends of the conducting cross-bar 26. A flange 31 is rigidly secured to the movable contact 34 and serves as an upper seat for a compression spring 38 which biases the movable contact 34 upwardly toward its closed circuit position. Guide fingers 39 may be provided to guide the movable contact 34 during its reciprocating vertical travel. Preferably, the guide fingers 39 are pivotally mounted at 43 and are spring-biased inwardly by suitable means not shown.

It will be observed that downward motion of the cross-bar 28 by means of the frictional engagement with the fingers 36 causes downward opening movement of the movable contact 34 against the upward biasing action of the compression spring 33. This draws an are 35 between the upper end of the contact 34 and the stationary orifice-shaped contact 33, which are is extinguished by a blast of compressed gas passing upwardly through the conduit 24, upwardly through the orifice 33 and out of the unit 25 through the apertures 3! formed in the contact foot 23.

After the arc 35 is extinguished, further downward movement of the cross-bar 26 causes a disengagement thereof from the fingers 36 to introduce two isolating gaps into the circuit controlled by the interrupter, the cross-bar 25 finally reaching its fully open circuit position as indicated by the dot and dash lines El of Fig. 1.

In the meantime, the compression spring 33 has retracted the moveable contact 34 to its closed circuit position in which it engages the orificeshaped stationary contact 33. To effect a closing of the interrupter, the piston rod M is moved downwardly to thereby effect upward movement of the operating rods 3 and, hence, upward movement of the cross bars 26. This effects an engagement between the opposed outer ends of the cross-bar 26 and the fingers 35 to thereby complete the electrical circuit through the interrupter.

, The three cubicles 2 may be separated by wire mesh screening 41 or other foraminous or perforated barriers which permit a transmission of heat therethrough and provide a grounded barrier between adjacent phases. Also by such a. construction, the heat generated by the operation of the compressor 4 may be utilized to eliminate any dampness within the housing I. Also the mounting arrangement is compact, easily inspectable and provides structural rigidity for supporting the several parts.

Fig. 3 shows, in elevation, a modified form of mounting construction which is of the open type as contrasted with the enclosed type heretofore described. In the mounting construction shown in Fig. 3 it will be observed that the six highvoltage condenser bushings 30 in this instance extend vertically, being supported by a horizontal roof member 58. The roof 58 is preferably supported by a framework generally designated by the reference numeral 64 and comprising a plurality of girder members 65 forming a substantially horizontal framework. Again at the lower ends of the bushings 30 are supported the arcextinguishing units 25. The compressed air tanks ll are preferably supported on a framework 53, the latter being supported at its ends by vertically extending members 60. Thus, the framework 59 may serve as a catwalk for a station attendant to stand upon while inspecting the units 25.

The framework 58 may be supported at its ends by upstanding structures 6|, only one of which is shown. The high-tension leads are designated by the reference numerals 62, 63. The operation of the units 25 is identical to that previously described; consequently, a further description is unnecessary. It suflices to remark that the construction of Fig. 3 is open and may be supported from any substantially horizontal mounting.

Fig. 4 shows in enlargement a modified type of arc-extinguishing unit, generally designated by the reference numeral 42, which may be used in place of the arc-extinguishing units 25 shown in Figs. 1-3. The unit 42 utilizes a blast valve l6 associated with the conduit 24 and actuated by a cam 43 rigidly secured to the movable contact 44. The movable contact 44 cooperates with a movable conducting orifice plate 45, spring-biased downwardly by a compression spring 46. When the plate 45 has struck the top of the casing 41, the movable contact 44 separates from the orifice 48 to draw an arc therebetween, not shown.

However, by this time, the cam 43 has opened the blast valve [6 so that pressure gas exists in the region 49 adjacent the orifice 48. The blast of gas passing through the orifice 48 effects the extinction of the arc, and the downward movement of the movable contact 44 being halted by the cylinder 50 striking the plate 5| secured to the movable contact 44, permits a separation to take place between the cross-bar 26 and the fingers 35 secured to the lower end of the movable contact 44. This permits two isolating gaps to be placed in the circuit and the retraction effected by the compression spring 52 causes the cam 43 to move upwardly thereby permitting the compression spring 53 to effect closing of the blast valve l6.

Consequently, in this embodiment of our invention, we have shown an arrangement whereby the blast valve is actuated directly by the downward movement of the movable contact 44, but where the introduction of the isolating gaps into the circuit is, as previously described, effected by separation of the cross-bar 26 from the resilient fingers 36. If desired, a roller 54, supported by a bracket 55, may be provided to counteract the lateral stress exerted on the movable contact 44 by the roller 56 which serves to actuate the valve l6.

From the foregoing description of three embodiments of our invention, it will be apparent that We have provided an improved form of a compressed gas circuit interrupter in which the mounting construction not only affords greatly increased rigidity, but also by positioning the operating room 3 adjacent to the cubicles with wall means therebetween to permit convection currents to pass therethrough, have afforded an arrangement in which the heat generated in the operating room can be utilized to eliminate dampness within the entire housing. It will also be apparent that by employing the construction shown, high voltage condenser bushings may be supported from the slanted roof 51 or peaked portion of the housing i.

It will be apparent to one skilled in the art that the broader aspects of our invention are not necessarily confined to a housing of the enclosed type, but may be embodied in a compressed gas circuit interrupter supported by a framework having a configuration generally similar to the configuration of the housing I as shown in Fig. 3. If desired, such a framework could be of open construction, or the breaker elements could be appended from the underside of a substation roof, with the bushings protruding through as wall bushings.

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

We claim as our invention:

1. A multi-pole circuit interrupter of the compressed gas type including an enclosed housing containing air at atmospheric pressure, a plurality of pairs of high-voltage terminal bushings, means including the roof portion of the housing for mounting substantially vertically the pairs of high-voltage terminal bushings in spaced sideby-side relationship, an arc-extinguishing unit disposed at the lower end of each terminal bushing, a conducting cross-bar for each pair of terminal bushings to electrically connect the two units of each pair of terminal bushings in electrical series, means including an elongated operating rod extending lengthwise of the housing for simultaneously moving the cross-bars in unison to efiect the simultaneous opening and closing of the interrupter, the cross-bars moving downwardly during the opening operation to a position spaced from the arc-extinguishing units to effect thereby two isolating disconnect gaps in each pole of the interrupter, a pair of elongated grounded compressed gas reservoir tanks disposed below the arc-extinguishing units and spaced laterally apart to accommodate vertical travel of the cross-bars, a short length of insulating conduit pneumatically connecting each arc-extinguishing unit with its respective tank to minimize the pressure drop along the conduit, a compressor disposed Within the housing to store gas under pressure within the tanks, and the heat generated by the operation of the compressor diminishing dampness Within the housing to obtain more efiicien-t operation of the interrupter.

2. A multi-pole circuit interrupter of the compressed gas type including an enclosed housing containing air at atmospheric pressure, a plurality of pairs of high-voltage terminal bushings, means including the roof portion of the housing for mounting substantially vertically the pairs of high-voltage terminal bushings in spaced sideby-side relationship, an arc-extinguishing unit disposed at the lower end of each terminal bushing, a conducting cross-bar for each pair of terminal bushings to electrically connect the two uni-ts of each pair of terminal bushingsin electrical series, means including an elongated operating rod extending lengthwise of the housing for simultaneously moving the cross-bars in unison to effect the simultaneous opening and closing of the interrupter, the cross-bars moving downwardly during the opening operation to a position spaced from the arc-extinguishing units to effect thereby two isolating disconnect gaps in each pole of the interrupter, a pair of elongated grounded compressed gas reservoir tanks disposed below the arc-extinguishing units and spaced laterally apart to accommodate vertical travel of the cross-bars, a short length of insulating conduit pneumatically connecting each arc-extinguishing unit with its respective tank to minimize the pressure drop along the conduit, a compressor disposed within the housing adjacent one end thereof, the heat generated by the operation of the compressor diminishing dampness within the housing to obtain more efficient operation of the interrupter, a blast valve associated with each conduit, an operating rod extending lengthwise of each tank to cause simultaneous opening and closing of the blast valves associated therewith, and means in proximate relation to the compressor for simultaneously causing operation of the three operating rods of the interrupter.

LEON R. LUDWIG. BENJAMIN P. BAKER.

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

UNITED STATES PATENTS Number Name Date 597,150 Knudsen Jan. 11, 1898 1,043,014 Jackson Oct. 29, 1912 1,098,531 Rolph June 2, 1914 1,510,265 Filkins Sept. 30, 1924 1,619,385 Wallace Mar. 1, 1927 1,694,618 Burnham Dec. 11, 1928 1,873,388 Greenwood Aug. 23, 1932 1,898,901 Ruppel Feb, 21, 1933 1,995,213 Martin Mar. 19, 1935 2,237,812 Paxton Apr. 8, 1941 2,290,560 Ileman July 21, 1942 2,294,824 Baker et al Sept. 1, 1942 FOREIGN PATENTS Number Country Date 565,048 Germany Nov. 25, 1932 588,443 Germany Nov. 28, 1933

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