US1477792A - Casing for electrical apparatus - Google Patents

Description

Dec. 18, 1923. 1,477,792

' R. E. WAGNER CASING FOR ELECTRICAL APPARATUS Filed Sept. 28. 1920 2 Sheets-Sheet 1 Inventor Robert. EWagnen by M) a a.

H i s AttoPney Dec. 18 1923. 1,477,792 R E. WAGNER AAAAAAAAAAAAAAAAAAAAAAAAAA US Filed Sept. 28 1920 2 Sheets-Sheet 2 Inventor: RoberftE-iwagner;

H is Attorney.

Patented Dec. 18, 1923.

UNITED STATES PATIENT oFFicE.

BOIBERTE. WAGNER, F PIT'liSFIIELD, MASSACHUSETTS, ASSIGNOR TO GENERAL ELEC- TRIO COMPANY, A CORPORATION OF NEW YORK.

CASING FOR ELECTRICAL APPARATUS.

Application filed September 28, 1920. Serial No. 413,429.

To all whom it may concern Be it known that I, RoBnnrE. WAGNER, a

citizen of the United States, residing at Pittsfield, in the county of Berkshire, State of Massachusetts, have invented certain new and useful Improvements in Casings for Electrical Apparatus, ofwhich the followin is a specification.

y invention relates to casings for electrical apparatus submerged in oil, such as transformers and the like. r

More'specifically my invention relates to casings provided with deep corrugations in their side walls in order to increase the cooling capacity of so-called self-cooled apparatus.

The object of my invention is to provide an improved arrangement of parts which may be readily and economically manufactured.

The load which may be safely carried by any piece of electrical apparatus is determined by its ability to dissipate properly the heat generated while performing under load. This is, particularly true of oil submerged electrical a paratus such as transformers. In the so-ca led self-cooled variety, which depend mainly on radiation to the surrounding medium or atmosphere to effect the necessary cooling, various forms of external radiators have been used to increase the radiating surface and thus increase the'rating of the apparatus.

Another and cheaper way for increasing the radiating surface of the casingfor electrical apparatus is to provide the slde walls of the casing with corrugations; an advantageous form of such corrugations being disclosed in U. S. Letters Patent to Moody N 0. 713,901. Much difficulty however has been experienced in providing deep corrugations for apparatus of large capaclty in a cheap and efilcient manner; such corrugations are generally required to be six, eight or more inches deep.

In accom lishinguthe object of my 1nvention, I emp 0y corrugated units preferably having two or more convolutions wh ch can be made by simple shearing and bending operations without the aid of drawing processes involving the use of expensive dies. I

close the ends of such units by inserted pieces of novel desi all the parts being I adapted to be assemb together by welding operations.

For a more complete understanding of the nature and objects of my invention reference should be had to the following detailed descriptlon taken in connection with the accompany ng drawings in which:

1g. 1 1s a view, partly in vertical section and partly in side elevation, of a tank constructed in accordance with my invention B 1g. 2 is aperspective view of an end portion of acorrugated unit such as I employ w thout having its end pieces inserted; while F 1g. 3 is a fragmentaryview of the same unit to a different scale with about to be inserted.

eferring now to the drawings, represents a base surmounted by a corrugated tank 11, housing a transformer 12. The tank 11 has a bottom'member 13 formed with a downturned rim 14 and a top member or ring 15 rovided with an exterior welding lip 16. etween the top and bottom members is secured the corrugated wall 17 which completes the tank.

In accordance with my invention the wall 17 is made of corrugated units which preferably have two convolutions or corrugations such as disclosed in the patent application filed by M. L. Elder on July 16, 1920, Serial No. 396,824. An upper end of this preferred form of unit is shown in Fig. 2, and comprises an intermediate back portion 20, corrugated portions 21 and 21 at each side of the back portion, and side portions 22 and 22 in the plane of the back portion which in turn are provided with upturned edge portions 23 and 23' and are adapted to abut against a corresponding edge portion of an adjacent unit, thereby providing an in g. 1. The blanks thus sheared out are formed into corrugated units by simple bending operations along parallel longituendFpo'rtionsof the corrugations shown at 25 p dinal lines which intersect with the cusps of the serrations, thus avoiding the use of delicate and expensive tools. The ends of the bent up units thus formed are closed by Wedge-shaped end pieces 26 which are provided with upstanding edges 27 and 28 about its back and sides, the tip of the end being rounded oil and the edges cut back therefrom as shown at 29 for a reason which will appear hereinafter.

These wedge-shaped end or triangular pieces 26, when thus formed, have a iconfiguration corresponding to the open spaces defined by the walls or sides of a corrugated portion 21, so as to snugly lit therein and close the ends of such open spaces when inserted; the triangular pieces being united with the walls of portions 21 by welding along the edges Q8. The crests of the corrugations are also notched out as 30 to correspond to the cut back tips 29 ot' the pieces 26, the edges ct these port-ions be also united by a weld thereabo-ut in the assembled unit.

Units thus formed are adapted to be assembled by welding along longitudinal meeting edges, such as are shown at 24C; and when assembled form the walls of a tank ll, as has been indicated. When subsequently shaped to have the desired peripheral endconiiguration, they are ready to have the top-ring or member 15 and bottom member 13 secured in place. lt should be observed that the provision of pieces 26 with upstanding edges 27 provides each unit with a continous flat welding end which may readily be united to the top and bottom members to form the tanlr.

The top ring 15 is provided with lugs or eyelets 31 through which vertical rods or bolts 32 pass to engage with the base 10 in order to secure the tank 11 in place. The rods 32, in addition to securing the tank to the base, are provided with eyelets 33 as shown in order to permit the tank to be readily lifted through their instrument-silty by cranes and the like. The tank is closed by the cover member shown at 35.

Tanks thus formed with deep corrugations facilitate the rapid dissipation of heat from the transformers, much heat being lost by convection as well as by radiation by reason of the air currents passing up between the corrugations. Self-cooled units as a consequence may be considerably increased in size and extended well into the region of transformer units which now employ an auxiliary cooling medium such as water in addition to the main cooling medium such as oil in the tank.

Substantially the only practical limitation at present on the depth of the corrugations is the size in which the stock, used to make the corrugated units, is now manufactured.

Tanks of this construction are rugged describing the process for uniting the several members composing the tank ot' my invention, obviously any convenient process known to the art, such as brazing and the like, can

be employed to unite the members.

Having now described what is at present the best means known to me for carrying out an embodiment of my invention, would have it understood that such means are merely illustrative and that I do not mean to be limited thereby to the exact details shown nor restricted in the choice of recog nized equivalents except as defined in my claims hereunto appended,

ill/hat I claim as new and desire to secure by Letters Patent of the United States, is

l. A sheet metal casing comprising top and bottom members, corrugated walls secured therebetween, said walls being composed oi members bent on parallel longitudinal lines to form corrugations with spaced sides, and triangular end pieces with upturned edges inserted between the spar/ed sides of the corrugations, said upturned edges'being out back from the tips of said triangular end pieces and the edges of said members beinw cut back at the tips of said triangular end pieces to avoid pockets at the crests of the corrugations.

2. A sheet metal casing comprisin top and bottom members, corrugated wal s secured therebetween, said walls being com posed of members bent on parallel longitu dinal lines to form corrugations with spaced sides and being cut to have drooping ends, and triangular pieces inserted in the spaces between the sides of said corrugations, said triangular pieces being provided with upturned edges except at their tips, whereby the ends of said members are closed and provided with watersheds without pockets.

3. A sheet metal casing comprising top and bottom members, corrugated walls secured therebetween, said walls being com posed of members bent on parallel longitudinal lines to form corrugations with spaced sides and being cut to have drooping ends notched at their extremities, and pieces inserted in the spaces between the sides of said corrugations and inclined to shed water. c

l. A corrugated unit for side walls of casings, said unit including a pair of convolutions joined by an integral fiat back portion, said convolutions having spaced sides cut back to provide drooping ends and till lilll triangular pieces closing the ends of the spaces between said sides, said triangular pieces having upturned edges forming with the ends of said back portion continuous fiat ends on the unit.

5. A corrugated unit for side walls of casings, said unit including a pair of convolutions joined by an integral fiat back walls secured therebetween and comprising units having a plurality of convolutions with spaced sides joined by plane integral back portions, and end pieces closing the ends of the spaces between said spaced sides of the convolutions, said end pieces and said back portions forming continuous fiat ends of the walls, and said units being joined together between the convolutions.

7. A casing for electrical apparatus, said casing comprising top and bottom members, corrugated walls secured therebetween and 7 comprising units having a plurality of convolutions with spaced sides joined by plane integral back portions, said spaced sides having upstanding edges, and end pieces closing the ends of the spaces between said spaced sides of the convolutions,.said end pieces having upstanding edges forming with the ends of said back portions continuous fiat wall ends, said units being united by welding along said upstanding edges 8. The method of making a casing for electrical apparatus which consists in forming corrugated members by shearing the ends of stock to have a plane serrated development and bending the stock on longitudinal straight lines to form convolutions having spaced walls and drooping ends, inserting triangular pieces in said convolutions, and welding said corrugated members together and to top and bottom members.

9. The method of making corrugated members for the walls of casings for electrical apparatus which consists in shearin the ends of stock to have a plane serrated development, bending the stock on parallel longitudinal straight lines intersecting with the cusps of said serrations to form corrugations, forming end pieces having upturned edges and shaped to have the configuration defined by the corrugations produced by the bending, and securing said end pieces with their edges outermost in the ends of said members.

10. The method of making corrugated members for the walls of casings for electrical apparatus which consists in shearing the ends of stock to have a plane serrated development, bending the stock on parallel longitudinal straight lines intersecting with the cusps of said serrations to form corrugations, forming end pieces having upturned edges and shaped to have the configuration defined by the corrugations produced by the bending, cutting back the upturned edges from the tips of said end pieces and forming notches at the crests of the corrugations to correspond, and securing said end pieces in the ends of said members by welding along said upturned edges.

In witness whereof, I have hereunto set my hand this 24th day of Se t., 1920.

, ROBERT .WAGNER.

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