US1472863A

US1472863A - Method for forming transformer structures

Info

Publication number: US1472863A
Application number: US543130A
Authority: US
Inventors: Robert V Bingay
Original assignee: PITTSBURGH TRANSFORMER CO
Current assignee: PITTSBURGH TRANSFORMER CO
Priority date: 1920-06-02
Filing date: 1922-03-11
Publication date: 1923-11-06
Anticipated expiration: 1940-11-06
Also published as: US1473595A; US1583383A; FR540003A

Description

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- R v. ENGAY I METHOD FOR FORMIRG, TRANSFORMER STRUCTURES Filad Biarcn 11. 1922 2 Sheets-Sheet 1 usy:

Nmn 6, 1923.

v. Ema/Av METHOD FOR FORMING TRANSFORMER STRUCTURES Filed Marqh 11, 1922 2 Sheets-Sheet 2 I N VEN TOR TTORNEY)" V. BIEFZGAY, OF EIT'ZCSBUKEG-H, EENEZSYLVAEHA, ASSIG-NOB 1 30 TRANSFOEMEB COEZQEPANY, A. CORZGEA'Z'IOEI F FENNSYLVANI&

EEETEQD "33GB FQBlflING TEAlJSFGEIG/IER STRUCTURES.

original application filed June 2, 1920, Serial No. 886,115. Divided this application filed lierch 11, .1922. Serial No. scale-o.

To all from it may 00 ricer-n Be it known that 1', ROBERT V. BIXGAL a citizen of the United Stat s. residing at, Pittsburgh. in the county of Allegheny anal State 0? Pennsylvania, have invented certain net and useful improvements in -Qilcthods for Forming Transformer Structures, of which the following a specification.

This application is division of my application Serial Number 386.115. filed June 2, 1920. The. invention relates to method oi making tanks of sheet steel for containing electrical transi iers or other devices.

The invention will he described with re ference to the accompanying drawings in Which- Fig. 1 illustrates the tank in vertical sectionsl ii-9W.

Figs. 2 to 1'2 inclusive illustrate successive steps in the formation of the tank, and

Fig. 13 illustrates the tank.

The tank K is preferably of sheet metal and preferably circular oral or rounded in section and the sides 22 are corrugated to a depth dependent, upon the size oi the tank and the relative cooling surface required. Hitherto the depth of these side corrugations has been limited by strength and the diliiculty and expense of producing deep corrugations. 'lhe shallower corrugations give a correspondinglv restricted cooling surface and often it"ues been necessary to resort to extra cooling pipes or circulating means where the available air cooling of the tank itself would he. suflicient if properly provided for. in the tank oi this invention corrugations of the tank body may he of uny desired depth and strength required by practice and at the some time these corrugations are formed from sheet, metal plates in simple and inexpensive manner and the resultant structure is strong and self-sustaining and. when assembled with the hop and bottom port ions provides a rigid, durable container.

building up the tank sides or body 22 a. rectangular sheet 23 (Fig. 2) is chosen "or out from the stantlarl sheet steel sizes in --nd the top and hottom edges oil the =.re notched as at, Q leaving; straight .ls 25 between the notches, and in the specific example shown leaving halt intervals. 25 at each end. The notched sheet 23 is then bent, into a series of parallel corrugaconsiderations 9 thereon by outer hoops lions (Figs. 3 and 4) and preferably the bends are made by a pivoted bender 26 swinging around a former 27 and pressing or Wrapping the sheet around the former. This method of bending the corrugations in succession gives a predetermined identical diameter to each bend and avoids any overstressing of the metal and any irregular or war ed etl ects. The

bends

28, 29 at the ends of tie corrugations are separated by intermediate substantially flat portions 30 and the inner bends 28 are made between the notches 24 while. the outer bends :29 are cen- -tered at the peaks Ill of the notches the ends of corrugated sections having, the form shown 3 and} with the edges of bends 28 at right angles to the sheet and the edges of bends 29 inclined. The corners 3:2 or" the notches form a line near the inner bends .28.

The next step in the, formation of the tank body is illustrated in Figs. 5 and (5 and comprises bending the corrugated section as a Whole into a circular arc corresponding in diameter to the diameter oi the tank being built. This is accomplished by pressing the inner bends 28 toward each other to slightly narrow the spaces between them and correspondingly spreading apart the outer bends to increase their splicing. a template being used to gage the spacing of the bends. Then a number of sections have been formed and curved as shown in Figs. and 6 these sections are assembl d side by side in scniicir cular cradles 33 corresponding tovthe outer diameter of the tank and the assembled sections are welded together along their meeting edges which are on the inside of the tank, and in this way a circular section is onilt up in the form for instance of a semicircle snd corresnondino to half of the tank body. The. other hulf of the tank body is similarly built, up and the two halves are assembled together on circular needs or leinplates 35 {Fig 10) corresponding to the inner diameter of the tank and are hound The two sections are then welded together along their meeting edges at the inside of the 'llictank body so formed its corrugations open at the top and bottom and the nextv step in process is the closing of these corrugations in such manner as to iorm a rigid arched structure in which the corrugations mutually support each other .V is flattening turning no inner corrugations 28 incl" The. end edges of these "dg'ilolOfiS is alsttenetl out into sub s obiolly strai lines as indicated a t-38 s... e corrugations are spread ll? 3 i toward and finally into as indicated at; 40

"llZLlPlQ pot-- a o hamcontact; along together along of "he i- :19 o C2 axon s ing outward .lI L U'OIlS 28 forms t e corners 32 oi the notch es continuous annular ridge the tank from which the in opposite directions.

i ormgstion is arched A. i seam, and all corrugations converge to t s2 CQII nations are I bu reinforce sustain o other through 1 connection. All through this structure show a (-hsuc- 'itinuons corrugations with s bends, 1th a tank consortiu to the met'notl. of thi some one; sixteen HQFESSBYY U) ts in stoc;

l may be in to e tank and foe'for ea may be I it with ho shops which in tho finally bent The of corrngmion bends around a he metal and does not, draw J1EE it or leave it with interhe final closing of the corrusectiess houncl together and lvmoed against warping by the Inner heads 35 anol the outer ho ds no two encls of the tank body are l identical find sonosled c} h the corrugations inclined 1nd siolieel end and rigiclly l vertical sec n m r Y x 1 s is iClAeL on (and on nonzonml sot.

"welding is (lone with the tank 7 a continuous annular end portion at each and. This tank hotly is very strong irrespectivoof its connection with the bottom and cover pieces. At each encl it provides an annular howled surface formed by the ring: ot lfll'lliutl fluttvnotl surfaces 39 and this beveled surface serves for the attach: ment of tho bottom and top pieces in a simple and vol-y rigid manner.- "When the bot lom and top pieces are in place, as herein alter (loscriluul, this strong tubular portion ,YGlHi OTUS the end portions in such manner that each part is l'i'ussctl against the other to m ive the strains put upon the tank.

The bottom Ill of the tank is formed by a circular plute. preferably of rolled steel, with its edge flanged upwardly at on anglo (Fig. 11) and this edge flange s tlzs bottom is nearly at right angles to the beveled surfaces 39 and is just fitted to an intermediate portion of these surfaces. With the bottom piece M assembled and clamped in place a heavy Wllll 46 is Made in the cornei' between the surfaces 39 and the flange 515 so that the hottom surface of the tank is liclow the surface of this Weld which will tlie -et'ow he held spaced from the base B of the transformer in linsll assembled position. This ilzmging of the bottom plate ll l' gives this plate on arched construction and protects it against Warping due to tho host of the wchling opsration and sine to any strains on it, in service; and this arching at the bottom also holds the Welded seam away from conta t with the hose or other surfaces so that this seam (loos notv collect n'ioistni'e nnrl hccomo rusty or weaken or Wear in use. This c ms fruction permits the bottom plate and the top ring, or either, to be made eithor thicker or thinner than the metal in the tank body, or of the same thickness as may he most s lvantaqeous.

The top of the tank body has weltlecl to it the steel or iron angle ring .50 formed by rolling am angle into circular toz'm with its flange Sl'inclined :itv substantially the an gle of lhe tank cover (I and the ends of the circle welded together. This ring; 50 is sizerl to tit into the top of the tank and engage an intermediate portion of the beveled SUTTGCBS 39 at the top and is fastened in place liy lwavy Welding 52 all around in the annular corner between the surfaces 39 and ring 50. This Ilflg' formsa-(lrlitional reinforcement oi the tank hotly and provides a strong and simple connection for the tank cover (1.

In the combination of this invention the methorl of forming the tank and the tank hotly in its trussed or arc-lied structure per- Knit the usepf the sheet steel stock and this hotly is furthermore not required to sustain the weight of the transformer parts. The corrugations of the tank body may be mscls oisny depth to give the cooling surfsos required. ihese corrugations overhang at the sides and are formed with well rounded bends 29 to give a large passage for the circulation or, the oil along the most exposed surfaces and in their entire area provide an extended cross section acting like large pipes for the circulation of the oil. This system efi'ect noalnas pipes or conduits P of the corrugations which have a great proportion of their surface exposed to the air and "separate the inner heated currents of. oil from the outer cooled currents and an inner battle cylinder or guide vanes may he provided just Within the bends The columns of cooled oil in the corrugations are relatively heavy and pass down rapidly through the corrugations drawing in heated currents of oil at the top 61 and at the bottom 62 replacing the oil rising through the transformer coils.

By the method of this invention the relative area of the outer cooling dates and the inner passages through and around the coils and core may be made in most effective proportion and this circulatory system provides definite areas of heating and cooling, avoids interferene between the rising and descending currents, and in effect gives a forced circulation which by the outer rapid passing of the oil down through the-corrugations distributes the heated oil over a larger area of the transformer sides and instead of accumulating as hereto-lore within a relatively small area the top with slow and sluggish progress down the sides the oil is rapidly circulated downward through the pipes formed by the corrugations. The temperature gradient at the sides therefore is much less abrupt and the cooling taking place over a much larger area is much more eiiicient.

The tank of this invention also provides unobstructed paths for the cooling air rising around the sides and in between the cormnutions. These corrugations overhang even at their lower ends so that the cooling currents of air have access at the very bottom. They also meet with Warm surfaces at a relatively short distance from the bottom and their absorption of heat is distributed (HT-l a large proportion of their of path. All of these conditions make for a thorough and efiicicnt transfer of heat from the oil within the tan-k to the air outside so that the tank of this invention will efficiently cool a transformer under conditions whore it has heretofore. been necessary to use extra radiators or cooling coils or pump circulation.

The method and structure of this invention therei'orc combine an inexpensive procof i anufacture with etficiency and durability in service. This invention is adaptahis not only to standard lines and types of transformers to be made up in quantity be readiiy varied to newt the number of sections 23 in a given transformer body is a matter or the most economical use of the steel; in hand after the desired depth or" the corrugations and the total area of the body is determined. With transformers of excessively large size or where great strength is required an increase in the gage of metal in the body may make it economical to make only a single corrugation each section 23. in such case the bend of this corrugation is directed outward and the inner meeting edges of adjacent sections are also flanged over and turned outward and welded togetheralong the inside between these flanges as indicated at (36 (Figs. 5 and While this invention has been illustrated in connection with a specific embodiment of transformer and tank it is not confined thereto but is intended to cover such modifications thereof as fall within the scope of the appended claims it will also he understood that the parts may, desired, he brazed instead or welded.

I claim l. The method of forming a tank body from a plurality of sheets comprising notching' said sheets, corrugating and bending said sheets into desired shape to form the tank body with inner out-er channels between the corrugations and bending}; the. ends of the inner channels outward and closing the ends of the outer channels by hendingthem over in arched form and welding along the meeting edges, said corrugated sheets being loll fastened together by Welding to form the tank body.

2. The method offorrninga tank body from a plurality of steel sheets comprising corrugating and bending said sheets into desired shape to form the tank body, bending outward the inner portions of the ends of the corrugations to bring them together in the form of a ridge at the end of the tank, and closing the ends of the corrugations by welding, said corrugated sheets being fastened together by welding to form the tank body.

3. The method of forming a tank body comprising welding together corrugated steel sheets to form a tubular portion, bendin; over the ends of said corrugations so that they rneet in arched form edge to edge, closing the ends of said corrugations-by welding, and welding end portions to the ends of said tuhulur portion at the inner circumference thereof. o

4. The method of forming a tank body comprising Welding together corrugated steel sheets. bending the ends of the inner corrugations into a continuous circular edge. closing the ends of the corrugations by Welding, and Welding the edges of an end i and continuous circular edge. u, 'i he method of forming a tnllli which consists in cutting series oi rectangular h iiola has an and cut with a nil straight portions, forming 11 v of parallel hen ls coinciding: n the apcxes oi" said notches and :nnldlc of iid six-night portions, assciniiliiig said sheets h l'usicningg the edges of anliace I sheets; together to form a tubular struck me.

bending luu'li the inner oi the i-orz-iunnions to {win an in ()ill'nll iYCiIIi'il NCililzli surface, closing the open emle; of the corrugations. lilting 1 end portion against the inclined rci'niul SMITH/ itil l nelzlingg u filler n he-uncle between rlinwl p rtion.

liml of forming a tank of sheet the steps of cori'ngating b no sheet metal to form a tank of curved (:1058 section with inner'and outer hannels hendin; he ends of the inher {'lkr ill u. an inclination, and dosing; over ends of the outer anncls a ndingr and welding along sni'laces in s 1 that both the inner and Miss the fluid currents rod of forming a tank of sheet the steps oi commenting a slicemetal lo form it tank ;ion with inn'c and ilie ends of the inoutward at an inclination, over the en z-i of the outer channels face i. ciinn'ig inwardly by bring- Llm: and weicling so that and outer channels freely uppe r pass the fluid currents at their ends and welding circular members to the outwardly inclining ends of said inner channels at each end of the tank.

A method of forming a. tankl body of sheet metal'colnprising the steps of corrugating said sheet metal with successive rouinled bends in the sheet metal and relatively lint portions interveningbetween said bends-to provide outer and inner channels, bending said corrugated sheet metal into the curved form of the tank body by spreading the outer bends to space than farther apart and correspondingly widening the outer channels and'closing over the ends of the inner channels of said corrugations by bending and Welding along surfaces inclining inwardly so that both the inner and outer channels freely pass the fluid currents at their ends.

9. A method of forming a tank body 0;

sheet metal comprising the steps of corrugatinq said sheet metal with successive rounded bends in the sheet metal and relatively flat portions intervening between said bends to provide outer and inner channels, bending said corrugated sheet metal into til; curved form of the tank body by reading the outer bends to space them fart er apart and correspondingly widening the outer channels, and closing over the ends of the inner channels of said corrugations by bendingnnd welding along surfaces inclining inwardly so that both the inner and outer channels freely pass the fluid currents at their ends, the opposite fiat sides of each inner channel being nearly parallel to each other.

ROBERT V. BINGAY.