US2445424A

US2445424A - Bus bar support

Info

Publication number: US2445424A
Application number: US562785A
Authority: US
Inventors: Lawrence L Fountain
Original assignee: Westinghouse Electric Corp
Current assignee: CBS Corp
Priority date: 1944-11-10
Filing date: 1944-11-10
Publication date: 1948-07-20
Anticipated expiration: 1965-07-20

Description

July 20 1948.

'Filed Nov. 10, 1944 L. L. FOUNTAIN BUS BAR SUPPORT V:a sheets-sheet 1 ATTORN July 20, 1948.

Filed Nov.y 10, 1944 L. L. FOUNTAIN BUS BAR SUPPORT 2 Sheets-Sheet 2 WITNESSES:

520W ATTOR Y Patented July 20, 1948 BUS BAR SUPPQRT .Lawrence L. Fountain, Wilkinsblu'gglia.,.assigner to Westinghouse vEleetric f Corporation, V`liest v'1-ittsbl1.rg,f,h, Pa., 1.al corporation of Renngylvania Application November-"10, 1944,; Serial No: 562,7 85

.sv claims. (c1. 114-199) Myinvention relates, generally, to electrical distribution systems and, more particularly. to multia-phasebus-duct structures of the llots/lmpedanceltype, commonly known as feeder-busduct.

The vclose spacing between the conducting barsl ofr a bus-duct structure is conducive to very highrstresses on the supportingmembers when currentsv of VVhigh magnitude flow, as is the case during short-circuit conditions. vWhen rectangular supports and blocks are utilized to en case bus hars of the type disclosed in the cependingapplication of C. F. Wagner `and L.L. Fountain, F'Seriallo 543,936, filed July 7, 1944, the forcesibetween bars impart stresses Vto the material, comprising a rectangular yoke, which are :a combination of shear and tension. Whenfthe bus-duct is installed in systems whereexcessive amounts of .current-mayfiow undershort.cir cuitfconditions, theseior-.ces twist and bend the sides :of :thex rectangular yoke in a manner that leavestheintermediate blocks of insulating material y.out .of .compression and they no longer form anfadequate supporting structure for the bus-bar angles.

.One object ofmy invention is to provide a busduct structure. which is: an improvement Vover the structure disclosed in the .aforesaid .copendingapfplication.

Another .object of my invention isto provide a hns-ductstructure which Yshallbe simple and emeient Ain .operationand which may-be economieallyrnanufactured and installed.

`vAimore specific .objectrofiny invention is--to proridea'busfduct structure capa-ble .of With.- standingvthe stresses imposed thereon when `conducting-currents of a high magnitude.

V'Anotherobject vof my invention is to Aprov-ide forimountin-g-an enclosed bus-duct in-a building orother structure.

Other objects of my invention will be explained fully-hereinafter/or will be apparent to those skilled .in the art.

'Infaccordance -Withxone embodiment of -m-y inventlon, the outer surfaces of the insulating blocks which-support the bus-bars -in an. enclosed busen-notare` lcurved Aand the vlolocks are bound together with a-.steel yoke which is madefrom portions 'of two circles of different diameters, therehy'making it impossible for the bus structure and the .supporting insulating lnlocllzs to turn out of position.

' Eer-'a fuller understanding ofthenature and obiectsaofzmy invention, referencemaybe had to the following @detailed description, takeninl con- 2 junction with the accompanying edrawings, in which:

Figure l is a viewf-inend elevation, of abus structure embodying i the principal features .of my invention;

Fig.' 2 is a. view, inperspectivegof the busstructure shown in 1;

-Fig.f3 is a viewyin elevation,` ofsa'portioniofa bus support illustrating a slightly modiiied form of the structurershown infEigsgls-andiZ.

FigA yis a view, insection, of .a modification .of the invention, and

Fig. 5 isa view; insection, ofanother modification of the invention.

Referring to the. drawings andparticulerlyto Figs. 1l and 2,1the structure-shown: therein. com.- prises a rectangular housing. I 0 rhavingright .angle bus-bars Hand I2 and'eilatfbus-bar: I3 disposed within the housing to lform a lT. As shown, one leg of the right angle bar II. is paired withone fleg of the: rig-ht angl-e -bar' I2. The. .other legof1 :the har Ill is paired-with -one `half .of thefatfbar. I3 and the other legof .the .bar- I2fis'paired with the otherhalf of the bar i3.

Therefore, as explained in the aforesaid rco.- pending application, when the 'bar' I I :is;connect ed to phase A. of'a three-phase system; the'bar- I3 is connected to .phase Bzand the baz-.I 2 -is 'connected to phase C-.a'mutualcoupling `is.obtainedwhich provides the desired-equivalentof.a single phase effect without resortingtoua'lla-rger-number of busbars. The `bars nare -preferably insulated from eachy other throughout ltheir entire length by sheets ofinsulation I4. Additional strips of insulation I6 and -I 'I Y arealso lprovided between the bars where `theyaresupported the housing I0.

v*As shown, the bars .are supported at desired intervals throughout the length ofthe housing'by a pair of -insulating blocks -I 8; one ofswhichengages the right angle bar I I and the other of which engages the right angle Ihar' I2, `VandaI third -block I9 which-engages the -latf-bar t3. Ass-hownmore clearly lin"1=*ig.l, theblockis provided 'with a-recess12l for -thel bar I3.

The lhlocks Iandl I 9 are provided wi-th* curved outer surfaces and areflbound togetherewith a metal yoke 22 which, in this particular embodiment, corn-prises an lupper portion 23A andfa lower portion 24. 'The upper-portion 23- may bea semicircular section from a Ishort length of Ametal- -pipe ofMpredeterm-i-ned diameter, Lfor example 9 inches, andr the lower portionlll may be la segmental sectionv from a I length of pipe of a slightlylarger diameter, `for example 1-0- inches. `='.,[-he sections 23and1'24 may besecured-togethenbybolts 25 ex tending through lugs 26 and 2l which may be welded to the

sections

23 and 24, respectively.

The blocks I8 and I9 may be retained in position by metal clips 28 of a U-shape which may be spot welded to the yoke 22. Felt strips 29, or other suitable material, may be disposed between the blocks and the yoke 22 to provide a certain amount of resiliency in the support for the bus bars.

As shown, each yoke 22 may be supported in the housing I by means of angular brackets 3| which may be welded to the side walls of the housing I0. If desired, the heads of the bolts 25 may be welded to the brackets 3I to retain the bolts in the brackets, thereby facilitating the assembly of the yokes and the bus-bars in the housing. In accordance with the usual practice, the bus-bar structure is manufactured in sections of a suitable length and as many sections as are required are joined together in end-to-end relation when the structure is installed.

The making of the yoke 22 in two sections, an upper and a lower part, each section being a portion of a circle of a different diameter from the other makes it impossible for the bus structure and the supporting insulating blocks to turn -out of position because of the relationship of the upper and lower parts with respect to one another. Furthermore, by providing curved outerl surfaces on the insulating blocks and securing them together `with the curved yoke members, the stresses imposed upon the yoke members become almost entirely of a tensile nature. Consequently, any twisting `of the bus-bars will not tend to bend the yoke out of shape and thereby leave the insulating blocks out of compression.

By this method of supporting and bracing the bus-bars with a curved yoke, the unequal forces transmitted by the angular bus-bars during short-circuit conditions are redirected so as to ultimately become tensile stresses instead of deforming shear stresses. In this manner, the structure is enabled to withstand 'the high stresses produced by the ilow of currents of a high magnitude.

The -ability of the structure to withstand the forces produced by large amounts of current under short-circuit conditions may be still further increased by providing helical springs 32 between the lugs 26 and the nuts of the bolts 25 as shown in Fig. 3. The springs 32 will be compressed by the forces encountered under short-circuit `conditions, thereby increasing the resiliency of the structure and enabling it to withstand the stresses imposed thereon without deforming the yokes 22. In this manner, the two parts of the yokes are returned to their normal positions after the shortcircuit conditions are removed and the `insulating blocks are retained under compression at all times.

In the modification of the invention shown in Fig. 4, the yoke 22 is formed from

channel members

33 and 34 which are bent to conform to the curved surfaces of the blocks I8 and I9. As shown, the blocks I8 and I9 are retained in position by the sides of the

channels

33 and 34, respectively. y

The two channel sections may be secured together by bolts 35 which extend through lugs 33 and 3l formed on

theehannels

33 and 34, respectively, by bending the ends of the channels outwardly. Gu-

sset plates

38 and 39 may be welded onto the sides of the

channels

33 and 34, respectively, to prevent the lugs 36 and 3l from bending underthe ystresses imposed upon the channels.

4 A rib 4I may be formed integrally with the flat bus-bar I3 to prevent its buckling between adjacent supports under short `circuit conditions.

As shown in Fig. 4, the bus-duct may be supported in a building or other structure by extending the bolts 35 through the upper side of the housing I0, and `connecting hanger bolts 42 to the ends of the 'bolts 35 by couplings 43. The long bolts 35 may be provided at desired intervals along the duct and the short bolts 25 utilized for the other supports, as shown in Figs. 1 and 2.

When it is desired to mount the bus-duct in the position shown in Fig. 5, hanger brackets 44 may be attached to bolts 45 which extend through opposite sides of the housing l0. As shown, thc bolts 45 are also utilized to clamp the two sections of the yoke 22 together at the ltop of the duct. The short bolts 25 may be utilized as clamping bolts at the bottom of the duct.

-From the foregoing description, it is apparent Ithat I have provided for supporting a multi-phase bus-bar structure in a manner which enables it to withstand the forces encountered during the flowing of currents of a high magnitude. The structure may be easily manufactured and readily assembled in an enclosed housing thereby providing an enclosed bus-duct which may be easily installed Vin manufacturing plants and other locations requiring a power-distribution system.

Since numerous changes may be made in the above-described construction and diierent embodiments of the invention may be made without departing from the spirit and scope thereof, it is intended that all matter contained in the foregoing description or shown in the accompanying drawings shall be interpreted as illustrative and not in a limiting sense.

I claim as my invention:

l. A multi-phase bus structure comprising, a pair of right angle bars and a flat bar disposed in a T formation, insulating means disposed between said bars, a curved yoke surrounding the bars, insulating blocks disposed between the bars and the yoke, said blocks having curved outer surfaces engaging substantially the entire inner surface of the curved yoke, the radius of said outer surface of one of said blocks being different from the others, and means for drawing the yoke together to compress the blocks against the bars.

2. A. multi-phase bus structure comprising, a pair ci right angle bars and a flat bar disposed in a T formation, insulating means disposed between said bars, a curved yoke surrounding the bars, insulating blocks disposed between the bars and the yoke, said blocks having curved outer surfaces engaging substantially the entire inner surface of the curved yoke, the radius of said outer surface of one of said blocks being different from the others, and means for resiliently drawing the yoke together to compress `the blocks against the bars.

3. A multi-phase bus structure comprising, a pair of right angle bars and a flat bar disposed in a T formation, insulating means disposed between said bars, a curved yoke having a semicircular section and a segmental section surrounding the bars, said segmental section having a greater radius than the semi-circular section, insulating blocks disposed between the bars and the yoke, and means on said yoke for retaining said blocks in position without attaching the blocks to the yoke.

4. iA multi-phase bus structure comprising, a pair of right angle bars and a flat bar disposed in a T formation, insulating means disposed between said bars, a curved yoke having a semicircular section and a segmental section surrounding the bars, said segment-a1 section having a greater radius than the semi-circular section, and insulating blocks disposed between the bars and the yoke, said blocks having curved outer surfaces engaging substantially the entire inner surface of the curved yoke, the radius of said outer surface of `one -of said blocks being different from the others.

5. A multi-phase bus structure comprising, a pair of right angle bars and -a iiat bar disposed in a T formation, insulating means disposed between said bars, a sectional curved yoke surrounding the bars, insulating blocks disposed between the bars and the yoke, said blocks having curved outer surfaces engaging substantially the entire inner surface yof the curved yoke, the radius of said outer surface of one of said blocks being different from the others, means for drawing the sections of the yoke together to compress the blocks against the bars, a rectangular housing enclosing the bars, and means on the sides of the housing cooperating with said drawing means to support the yoke in the housing.

LAWRENCE L. FOUNTAIN.

REFERENCES CITED The following references are of record in the iile of this patent:

UNITED STATES PATENTS 10 Number Name Date 225,268 Boone Mar. 9, 1880 264,722 Mackintosh Sept. 19, 1882 1,851,940 Williams Mar. 29, 1932 2,039,025 Papst Apr. 28, 1936` 15 2,044,580 Leach June 16, 1936 2,223,300 De Bellis Nov. 26, 1940 2,287,502 Togesen et al. June 23, 1942 2,288,078 Fisher et a1 June 30, 1942 2,310,919 Adam Feb. 16, 1943 20 2,318,859 Huguelet May 1.1, 1943 2,320,093 Moore May 25, 1943 2,356,006 Samer Aug. 15, 1944 2,400,223 Cole May 14, 1946