US2677478A - Tank - Google Patents

Description

May 4, I954 T. T. WOODSON TANK Fig.2.

LINN f1:

Inventor- Thornas T. Woodson,

His Attorney- Patented May 4, 1954 Thomas Woodson Bridgeport, Conn assignor toGeneraLElectric Company, a. corporation or New 'York ApplicationJanuary 14, 1950, Serial No. 138,663-

.1 Glaim. 1.

This invention relates to tan improved-tank. and the methodsof constructing the samayand in particular relates toanimproved endaclosure. con.- struction in tanks: having-.an end. wall. orrwalls attached; to .a :body wall in telescoping. relation therewith.

Among the objects of myxinvention are to pro-.- vide :a method of. construction which willzsubstantially reducermaterial wastage in the 'fa'bri cation oftanksandthezlike; which willprovide a .fluidetight .jiointbetween the closure member and body wall withoutthe necessity of accurate: 1y dimensioning the rim. of .the closure member with respect. to the Lbody. wall; which lends itself to mass production "with relatively simple tools and .by unskilledlahor; which will function effectively in the "manufacture of irregularly shaped tanks; which zwillpro'ducea tank or tub structure in which the: relative thickness of the body wall and end walls may bees desired; and

of many types of low-pressure tanks or vessels.

Certain of the advantagesderivi-ngirom the .use of the invention-Tier example those relating to material costsaving, and mass production with simple tools-are particularly. "important. in the manufacture of washing. machine tubs inathe highly competitive and cost-conscious washing machine industry. The present-methods ofmanufacturing washing machine. tubs comprise variants of the basic technique of deep-drawing the tub and suspending it within an apron or mounting it on aiwrap-"around skirt. In the first of these, the apron provides external support for the tub and a decorative "housing therefor; in the second, the tub may "be exposed to view *and the skirt simulates an'extensionxof the tub while providing a supporting base. The waste in the drawing blank'amounts ordinarily to about'38- and for various reasons the rejects due tofimperfections in the drawn tub are high. Also, it is entirely impracticable to attempt to produce a .drawn tub having controlled 'oroptional differences in thickness of'the side wall'relative to the bottom.

Briefly stated, a preferred method of practicing my invention comprises forming the body; wall of the tub or tank by wrapping or rolling a rectangular blank into a cylindrical or prismatic form-in which latter term I mean to include polygonal shapes whose sides are not normal to the end surfaces-and joining the respective ends by-a; simple structure-such 9:578 :mash, seam, weld. I then provide a closure member having a rigid side rim configuration, which ;1; rovides a 'dDVBF tailed space or pocketof which the :body wall is an element. I prefer to spot weld the closure member to the body wall andwaccordingly the extreme outer dimension of the rim places; the closure rim sufficiently-closely a ainst-the Ibody wall for welding thereto at relatively close intervals. A, feature of particular importance in the manufacture of polygonalytubs is that-the closure rim may-be spaced from the body wall at the corner locations, thus.eli-minating, the necessity of maintaining close dimensional. tolerances at suchlocations. Whatever the tub-shape, the joint between the endzand-wall structures is made liquid tight byinserting within the dovetail space a distortable filler or-gasket-of rubber or -othersuitable material. Said gasketis :of ring form so as-to present nooverlapping or bufitipints along which leakage might occur. The insertion of said gasket may be accommished-after the fabricated and mutually secured body/and-closure members have been; given their protective or decorative finish. The body wall may provide th tubsupp rtin -structure. th re y. li ting th need for separatesupportingmeans. :I-f structural; considerationsso require, the body wall, may be=of heavier :gauge than the closure member, rrviccv r a- In the accompanying drawing, :Fig. .Lds a side elevation, in section, showing ioneiorm -01 .tanl constructed pursuant-1m the present invention; Fig. .2,= is 'aufragmentary side elevation similar to Fig. 1 with filler strip-removed; :Fig. .-3':isa view similar to Fig. 2 but showing the;-1'iller-.-strip in inserted position, saidzfigure being taken-.onrlines B -:3 iOf' Rig-' 3 'Eig. 45shows a planview-ofsalportiongof'the completed 'ta-nk, the "side wall being in section zimmediatelygabove the :filler strip; 5 i-issimilar to Fig. .3, but showing ;.a slightly (infer- .entffillerconfiguration; :andgliig, v6: is a side-sec: tional elevation :of the .filler strip of Fig. 5 :showing" its .relaxed shape.

In Eig. lithe tub -.l comprises :atubular bodylz, a. closure 3' esecure'd internally thereof,- and re. filler strip LOI': gasket :'4 .:sealing :the, joint ibetween thelbodyswall and :closure. In the open topped tub shown, the closure Tforms :theibottom thereof, but it will be understood that .a similarplosure may be applied at each end of the body wall, to form a closed-ended tank. As shown, the disposition of the closure 4 intermediate the ends of the body wall adapts the lower end of said wall as a supporting base to which legs or the like may be aflixed if desired. The body structure may be cylindrical or prismatic, as desired. When prismatic, as is frequently the practice in washing machine tubs, it is advantageous that corners between adjacent plane surfaces be somewhat rounded rather than sharply angular. The body structure may be seamless, or formed by wrapping or rolling a rectangular sheet on conventional metal working machinery. The wall material will be appropriate to the contemplated usage of the tub. My invention may, in fact, be used with wooden or other non-metallic structures. When of metal, the ends of the body sheet may be joined in any conventional manner; for example, by a mash seam weld (not shown). Where the tub is to be open topped, the upper edge may be rolled over or beaded as indicated.

The tub closure or bottom 3 also may be fabricated of any suitable material so long as said material will provide a rigid side wall or flange of necessary contour. The closure may be a casting or a molding; or, as will be most common, of drawn or stamped sheet metal, providing a relatively wide side wall or rim. By rolling or other conventional means, the rim is shaped to provide a bottom portion which fits sufficiently snugly against the wall 2 at a multiplicity of points therearound to permit structural securement thereto, and an upper portion 6 inwardly ofiset from the rim 5 in angular relation therewith. Said upper portion cooperates with the body wall 2 and the web 1 to form a pocket in which the transverse dimension increases from the mouth of the pocket toward the bottom thereof. Figs. 3 and 4 show how the lower rim portion 5 and a portion of the web 1 may be cut away to provide the narrow gap 8, which thereby eliminates the necessity of a closely matching fit between the rim portion and the body wall. Such an arrangement is possible in my invention because the liquid-tight joint between the body wall and the closure is provided by the filler strip 4 and is not dependent on the means for physically attaching the closure member to the body wall.

Thesecurement of the closure to the body wall may be by any means appropriate to the tub material or contemplated usage. In spot welding, it is desirable to apply a large area anvil against the outer wall and strike the welding electrode against the closure wall. The resulting weld joint is hardly discernible on the body wall. After the tub members have been assembled and secured, the desired exterior and/or interior finish may be applied.

The respective filler strips 44a are of a. resilient material impervious to the material to be contained in the tub. The strip may be of extruded or molded material and is closed-ended. When relaxed, the filler strip should contact the inner wall of the tub throughout the periphery thereof. Its maximum transverse dimension, in section, should be greater than the maximum transverse dimension of the pocket, and its vertical dimension such that when the filler strip is placed within the pocket it will rest upon the base of the pocket and the distortion of the strip by the walls thereof will effect a substantial area of tight contact with the respective side walls of the pocket. It is most desirable that the web I provide a continuous base at the corner areas of the tub wall. By soaping or otherwise lubricating the walls of the pocket, the filler strip may be manually inserted and driven home within the pocket. The circular cross sectional shape of the filler strip shown in Fig. 2 will assume substantially the shape of Fig. 3 after the strip has been forced into the pocket. Where it is desired to produce a fillet at the edge of the bottom member to avoid dirt-collecting pockets, a filler strip such as 4a, Fig. 6 will, when inserted produce the relatively smooth upper surface shown in Fig. 5. Filler strips may be removed and replaced without special tools, thus facilitating the maintenance or reconditioning of the tank or tub.

While I have shown a particular embodiment of my invention, it will be understood, of course, that I do not wish to be limited thereto since many modifications may be made; and I therefore contemplate by the appended claim to cover any such modifications as fall within the true spirit and scope of my invention.

What I claim as new and desire to secure by Letters Patent of the United States is:

A receptacle for containing liquid having a shell of polygonal cross section; an end closure for said shell comprising a central portion of substantially the same polygonal shape as said shell but of smaller dimensions, side walls depending from said central portion at an angle approaching but not equal to a right angle, a rim extending from said side walls and closely approaching the inside walls of said shell along the rectilinear portions thereof while being spaced from said walls at corners, and fianges depending from said rim rectilinear portions; means for securing said end closure within said shell, portions of the walls of said shell along with said end closure side walls and rim defining a pocket around the periphery of said end closure, said pocket having a maximum width at said rim and decreasing in width toward the mouth of the pocket because of the angular relation of said end closure side walls, and a continuous resilient and deformable band of a size and shape to fill completely said pocket and being insertable therein and removable therefrom without modification of the assembled position of said shell and end closure.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 699,174 Hoppes May 6, 1902 1,605,229 Hartmann Nov. 2, 1926 1,798,071 Deane Mar 24, 1931 2,037,151 Safiord Apr. 14, 1936 2,100,480 Hirshman Nov. 30, 1937 2,141,255 Schweller Dec. 27, 1938 2,148,858 Freeman et al Feb. 28, 1939 2,234,639 Wallace Mar. 11, 1941 2,344,986 Hothersall Mar. 28, 1944 2,346,566 Ford 1 Apr. 11, 1944 2,427,823 Turney, Jr Sept. 23, 1947 2,574,273 McLeod Nov. 6, 1951 FOREIGN PATENTS Number Country Date 769,271 France June 5, 1934

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