US2154349A - Can closure - Google Patents

Description

, Patented lApr. '11,

PATENT? OFFICE om cnosm l i v rmx J. o'arnn, rams. remmer u oon- -tinental Can Company, Ine.,'New York, N; Y.,

a corporation York .Appulon December-za, 1937, senin No. 181,438

. l Claim. The invention relates generally to metallic receptacles andhas for an object to provide a novel form of cover or end closure 'memberadapted to be applied in completion of such receptacles land 5 which embodies means'v for eii'ectively lubricating the endA seam by which the closure--is'secured in Y place in a manner for avoiding chipping and breaking away of can body coatingenanel and the resultant presentation of bare metal portions.

l and for aiding intheveifective sealingof saidseam.' 1

' It is customary to lnterlorly'coat metallic containers'ivadapted to receive certain products, so

,y that direct contact betweensaid products and l ,the metal of the containers isavoided. This isfvJ particularly true in the canning of 'beer since it has been found that the slightest exposure of the tin forming the inner surface oi-the metal cans'- vcauses'a chemical reaction upon the'beersuf# cient to change' its appearance.- making it Acloudy-and marketable. Can' body coatings have been applied in various ways, asV by dipplns. I'

flushing, or llooding the can bodies in the coating solutions, usually lacquer or enamel. Surplus- 2'5 coating material, however applied, is drained of! by suitably suspending thecan bodies with 'one open end downwardly disposed. An example of this draining of sin-plus solution, following an l application by the dippingmethod, is to be found in the application for Letters Patent led by Alfred L. Kronqueshcn April 12, 1937, Serial Number 136,473. l .f

it has been found that when cans are thus permitted to drain olf their'surplus coating, the

lowermost en of the cans will retain an adequate coating nlm, but due to lcapillary action.'

or the surface tension of the draining coating material, the v,iilm at the upper ty of the cans will.` become thin and often. inadequate. 40- After the protective coatings are applied and the surplus drained therefrom, they' are suitably hardened, as by baking.

v Hardened coatings of the character stated are somewhat brittle, and when the can end closures' are secured in place. usually by double roll seams, 'portions ofthe hard coatings are cracked or rupe- .turecl by the rolling of the se l bare metal surfaces are exposed to @intact with products to be contained in thecans. particularly at the ends of the cans where the'coating's Ihave thinned out during the'draining away of. surplus coating'material.A v In its 'more detailed naturethe invention .resides in the provision of a novel form of can` carer at the upper end of the can, leavinga thin, come or end closure member comprising a body 'portion. a peripherally yextended seam flange portion, a heel portion for snugly viitting within the open end of .a can body, and a lubricant coating applied to the heel .portion and extending into a 5 part of the liange portion serving to lubricate the rubbing contact of can body end and cover member surfaces during formation of theseam, so as to prevent rupturing of protective coatings and baring of the metal, and to improve the eiliciency of the seam seal.

With the above; and otherobjects in view which will more fully appear; thenature of the invention will be more clearly understood by following the description, the' appended claim, and the sevl5 eral views illustrated inf the accompanying drawing.V I Y In the drawing: a Figure 1 is a top plan view illustrating one half of a can cover or end closure embodying the invention. r

Figure 2 is a central vertical cross section of the cover. 'r Figure 3 is an enlarged fragmentary vertical cross section illustrating the cover applied to a 'can body prior .to commencement ofthe seeming operations.

Figure 4 is a. view. similar to Figure 3 illustrat ing the seam partially formed, as by the rst operation seeming roll.4

Figure 5 is a view similar to Figure 3 illustrating the seam completed, as by application oi' the second operation seeming roll. ,Y

Figure 6 is an enlargedvertical -cross section of a fragment of` can body upon which the improved body is te be applied. y

In the drawing l'. have illustrated a fragment of a canbodyj including thenusual outwardly turned end flange t which is rolled into the seam by which the cancover or end closureis secured in place as shownin Figures 4 and 5. 'The provtective coating ci lacquer or enamel by which products contained in the can are protected from- ?ontact with the metal of the lcan is indicated at After the ,can bodies have been coa by dipping, spraying, oociing or ushing, the sur? plus of coating material is drained of by sus pending the can bodies with one end downward, and during' this draining the coating'thins out w times inadequate coating at the extreme upper end. When the coating is hardened by baking it becomes brittle and -subiect tov rupture at the portions engaged during the end closing 'or cover l iunction, and it citen happens that porfing operation.

tions of the can body metal are bared by this rupturing of coating material. This is particularly true at the thinnest end sector indicated at 8 in Figure 2 of the drawing. As has been previously stated, the invention resides in the provision of a novel form of cover or end closure applicable to interiorly coated can bodies and having means for engaging and lubricating coated can body surfaces heretofore subject to rupture during the shifting of the surfaces relative to each other, incident to the reforming of the metal parts in the seaming operation.

The improved cover comprises a body portion '9 and a peripherally extended seam ange portion I0 joined with the body portion by a substantially vertically disposed heel portion II proporticned to snugly :tit within the end of a can body with the seam flange portion overlying and extending beyond the can body flange 6 as shown in Figure 3 of the drawing. This heel portion is formed by the recessing of the cover so-as to receive the seaming chuck. On its under surface the cover body, heel and flange portions-carry a protective coating'of enamel or lacquer designated I2. A ring of sealing compound I3 is apy plied to the under surface of the seam flange beginning just outwardly of the juncture with the heel portion II, and a lubricating film I4 of a suitable substance such as wax is applied to the heel portion II and extends outwardly to the inner terminus of the sealing compound and inwardly over the rounded juncture between the heel portion II and the countersunk main body portion of the cover, as shown in Figures '2 and 3 of the drawing.

The usual procedure of double seaming the end closure is shown in the'enlarged fragmentary sectional views3, 4 and 5. Inliigure 3 the cover is shown loosely applied to the can body end with the waxed surface I2 of the heel portion II thereof contacting the coated sector 8 of thecan body which has heretofore been subject to rupturing and baring of metal during the seam- In Figure 4 that condition of the seam is shown which results from the functioning' of the `first operation roller. It will be noted that the sealing ring I3 has been rolled` into the seam, and that the wax film I4 is drawn over the opposed can body surface and rolled partly into the seam, all

shifting contact of the cover and can body surfaces in the critical sector 8 hereinbefore referred to being lubricated by the wax lm with the result that' rupturing of coating and baring `of metal is avoided. It will be obvious also that the wax lm I4 aids in the eilicient sealing of the seam. Figure' illustrates the seam as completed by the `function of the second operation seaming roller. The wax film I4 not only lubricates the engaging, brittle coating bearing surfaces during the rolling of the seam but also lls the space between the'can body end portion and the countersink or heel portion II, providing a protective coating around the` entire can. In cans embodying the usual lock and lap side seam structure this lubricating and sealing eiect of the wax film is found to be particularly effective at the area of the lapped portion of the side seam.

I claim: A

A closure member for interiorly coated can bodies comprising a peripheral flange portion adapted to be rolled into sealing engagement with the ange of a can body, and a central depressed portion shaped so as to t within the open end of the can body, said closure member on its inner face having an overall protective 'coating and a coating of wax applied to said protective coating and extending from the bottom of the wall of the depressed portion to the flange and terminating adjacent the inner portion of said ange, and a coating of sealing 'material extending from the outer edge of the wax coating to the outer edge of the flange whereby said sealingmatewall of the depressed portion in.- the closure member.

FRANK OBRIEN.

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