US1444480A - Casing for electrical apparatus - Google Patents

Description

Feb. 6, 1923.

.11 W. PATCH CASING- FOR ELECTRICAL APPARATUS Filed Nov. 16, 1920 Patented Feb. 6, 1923.

UNITED. STATES 1,444,480 PATENT OFFICE.

JAMES PATCH, OF FORT WAYNE, INDIANA, ASSIGNOR TO GENERAL ELECTRIC COMPANY, A CORPORATION OF NEW YORK.

CASING FOR ELECTRICAL APPARATUS.

Application filed November 16, 1920. Serial No. 424,488.

To all w/zonzit may concern. Be it known that I, JAMEs W. PATCH, a

citizen of the United States, residing at.

Fort Wayne, county of Allen, State of Indiana, have invented certain new and useful Improvements in Casings for Electrical Apparatusfof which the following is a specification.

My invention relates to casings for elec trical apparatus submerged in oil, such as transformers and the like. 3

More specifically my invention relates to casings provided with deep corrugations in its side walls in order to increase the cooling capacity of so-called selfcooled'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 apparatus such as transformers. In the so-called self-cooled variety, which depends mainly on radiation to the surrounding medium or atmosphere to.

effect the necessary cooling, various forms of external radiators have been usedto 1ncrease the radiating surface and thereby increase the rating of the apparatus.

Another and cheaper way for increasing the radiating surface of the casing for electrical apparatus is to provide the sidewalls of the casing with corrugations, an advantageous form of such corrugations being disclosed in U; S. Letters Patent to Moody, No. {13,901. Much difficulty howeverhas been egperienced in providing deep corrugations for apparatus of large capacity in a cheap and efficient manner; such corru"- gations are generally required to be six, eight or more inches deep.

,In accomplishing the object of my inven- 'tion I employ corrugated units composed of aplurality of convolutionsfsuch units having a special development of a character to provide guides for bending. They may also I at the same time provide knobs of surplus stock for welding purposes. These units .ing welding edge.

same being braced and reinforced in a novel manner, as will hereinafter appear.

For a more complete understanding of the nature and objects of my invention reference should be had to the following detailed description taken in connection with the accompanying drawing in which:

Fig. 1 is a view in front elevation of the top portion of a corrugated unit from which to construct casings for electrical apparatus according to my invention; Fig. 2 is 'a top plan view of the corrugated unit shown in Fig. 1'; Fig. 3 is a fragmentary view of the plane development of an end of my unit; while Fig. 4 is -a fragmentary view mainly in vertical section of a casing constructed in accordance with my invention.

Referring now to the drawing, 10 denotes a unit ofmy invention shown in perspective as bent to,the desired. form and lying on a surface slightly curved.

' This unit is shown, as having four con volutions and is made by bending up a piece I of sheared stock 11 developed as shown in Flg. 3 which has ends provided with V shaped notches 12, likewise four in number -to provide the four convolutions in the formed unit.. Between the V shaped notches the stock is cut out to provide a back, the same bein preferabl'y'more deeply cut out at each si e in order to leave a knob or protruding portion as shown at 1,3. Each edge of the sheared blank formed as shown in hafif a back along the edge plus a portion adapted to be bent up to provide an upstand- The welding edges are 3 is cut to provide the development of Y adapted to be bent up sharply along the dotted lines If the convolution as a being similarly bent up from such edge along the dotted line indicated at 15. The crest of the corru ation is formed by bendlng along the dotte line 16 whichextends from, the bottom of a V, notch at the top of the blank to the bottom of one at the lower end, the

bending of course on the line 16 being in an opposite direction to that along lines 14 and 15 and not very sharp. The other backs are formed by bending along the lines indicated at.15'.

Units when thus bent along the longitudt . nallines 14, 15, 16, etc, are ready to have the ends of the convolutions closed. ends may be closed by any suitable drawing and pinching device which provides ofiset edges, asshown at 20, that may be-closed by welding, brazing and the like.

Units with ends closed and finished in this manner are adapted to be united to one another bywelding along their upstanding longitudinal edges shown at 21.

A sufficient number of units having been united in this manner to provide a tank of the desired perimeter. they are ready to be assembled on-top and. bottom rings 30 and 31 to form a tank as shown in Fig. 4:. The development shown in Fig. 3 is adapted to provide a corrugated unit. when bent as shown in Figs. 1 and 2. which will have its backs and ends lyingin a ruled or smooth surface. The now serrated ends of the formed unit 10 will consequent-l fit snugly against the curved surfaces (which are one species of ruled surface) of the top and bottom rings 30 and 31.

In welding the formed-units to the rings 30 and 31 the knobs 13 become fused and provide an excess of metal which may be flowed about the weld as needed. This is particularly advantageous when welding thin metal such that of which the formed units are made. while relatively thick metal is employed in the rings 30 and 31. This mode of welding produces welds along zig- Zag lines about the top and bottom rings,

as the welds are made upover the abutting portions of the C-OIlVOllltlOIlS where they join the rings and then down across the ends of theback portions about the knobs 13. These zig-zag welds brace the units welded to the rings 30 and 31 and prevent them from being easily pried loose from these rings.

The rings 30 and 31 are further braced and reinforced by the provision of inwardly projecting stiffening ribs 32, which may be provided by welding an angle iron about the interior peripheries as shown.

Tank bodies formed. of corrugated units 10 and top and bottom rings 30 and 31, as just described, are then ready to be welded or otherwise secured 'to suitable bases, such as that shown at 35; the tops being closed by suitable covers which are not shown.

While I have called the members 30 and 31 rings in the above, it will be understood that they need not be circular, but may be oval, elliptical or other suitable shape.

Having now described an embodiment of my invention which is at present the best means known to me for carrying the same into effect, 1 would have it understood that this is merely illustrative and that I do not mean to be limited thereby tothe precise details shown, nor restricted in the choice of recognized equivalents except as defined in my claims hereunto annexed.

What I claim as new and desire to secure by Letters Patent of the United States, is a 1. A sheet metal casing for electrical apparatus comprising top and bottom rings 7 hand this 12th day of November,

and corrugated walls secured therebetween:

along parallel longitudinal lines to providealternate convolut-ions-and flat backs to lie in a ruled surface, said convolutions being drawn {together at their ends to close the same and formed to provide zig-zag welding edges at the ends of the units.

3. A sheet metal casing for electrical apparatus comprising top and bottom, rings and corrugated walls secured therebetween; said walls being composed.- of units made from sheared blanks having ends formed with a plurality of spaced V shaped notches, ad acent V shaped notches being separated by an intervening projecting knob. the blank being bent along parallel longitudinal lines to provide flat backs and {a plurality of con volutions lying in a ruled surface, sa d con volutions being drawn together at their ends to close the same. 7

1. A'sheet metal casing for electrical app a-ratus comprising topand bottom rings and corrugated walls secured therebetween; said rings being provided with stiffening ribs and having said walls welded thereto along z1gzag paths.

5. A. sheet metal casing for electrical ap-, paratus comprising top and bottom rings and corrugated walls secured tlierebetween; said rings having angle irons welded lnteriorly about their peripheries to provide stiffening ribs therefor and having said walls welded thereto exteriorly along zig-zag paths.

6. A sheet metal casing for electrical ap paratus comprising top and bottom rings and corrugated walls secured therebetween; said rings being provided with stiffening ribs interiorlyand having said walls composed of units with serrated ends welded thereto exteriorly along paths following the serrated ends of said units. I

7. A sheet metal casing for electrical apparatus comprising top and bottom rings and along paths following said serrated end I edges.

In witness whereof, I have herepnQtg set my 9 JAMES W.

PATCH.

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