US2188291A - Method of forming rolled seams on preserve tins and the like - Google Patents

Description

Jun. 23,. 1940. H. ZEIGMEISTER 2,188,291

METHOD OF FORMING ROLLED SEAMS 0N PRESERVE TINS AND THE LIKE Filed Nov. 50, 1937 it without.-

Patented Jan. 23, 1940 UNITED STATES PATENT OFFICE METHOD OF FQB'MING ROLLED 'SEAMS ON PRESERVE TENS AND THE LIKE- Herbert Zelgmeister, Hamburg-Wandsbek,

Germany 2 Claims.

This invention relates to preserve tins and the like the body of which is provided with a longitudinal, rolled seam and is also connected to the.

end pieces by means of rolled seams. I

In, tins of this kind an hermetic, cooking-proof closure between the body and the end pieces has been obtained by the introduction into each seam of an elastic packing ring. In order to obtain an hermetic closure of the longitudinal seam, however, it has hitherto been considered necessary to employ soldering, particularly when the tin has to be subjected to high internal or external pressure.

The object of the present invention is' to obtain an hermetic and cooking-proof closure of such tins without the employment of solder and without materially increasing the cost of manufuture, and the invention consists essentially in forming a longitudinal body seam by providing the blank of the body with radial, outwardly directed flanges, arranging between said flanges a strip of elastic packing material, rolling the flanges together to form the seam, and finally compressing and depressing the seam so that it will be flush with the outer surface or the tin. I In connecting this body with the end pieces by means of similar seams, the problem presents itself of how to avoid accumulation of material and consequent leakage-at the point where the longitudinal body seam meets the seams oi the end pieces. This problem is solved according to the invention by reducing the four corners of the body blank to a depth substantially equal to the'width of the material used up in the,

seaming. This reduction is effected by an oblique cut with straight or curved outline, so that the tearing stress will be propagated along said outline without weakening and tearing the metal.

The removal of the corners has the-further advantage that the ends of the longitudinal packing strips will be exposed for joint inclusion with the packing rings in the seams whereby the body is connected to the end pieces. In this manner a perfectly reliable, hermetic and cooking-proof closure of the tin will be obtained which will resist high pressure from within as well as from different steps of the improved method panying drawing.

. Figa land 2 of said drawing illustrate the,"

fir'ediittibn' ofthe corners of the body blank,

. Fig. 3 shows the application of the packing strip to one longitudinal edge of the blank,

are illustrated by way of example in the accom- Fig. 4 is a sectional view showing the flanges formed at the opposing edges of the blank,

Fig. 5 is a similar view showing the flanges brought together for seaming,

Fig. '6 is a sectional view showing the flanges 5 rolled together to form the seam.

Fig. '7 shows the seam compressed and depressed,

Fig. 8 is a side view of one end of the body after it has been flanged for connection to the end Piece.

Fig. 9 is a. sectional side view oi' the flanged body taken across the longitudinal seam,

Fig. 10 is a sectional view showing the end piece placed in seaming position, and

Fig. 11 is a sectional view showing the completed seam.

In making the tin, the body blank is formed with reduced corners I and 2 which are cut with straight or curved outlines 3 and I. To one of the opposing edges of the blank a packing strip 5 of rubber or the like is attached, the strip being long enough to project at both ends over the reduced corners, as shown in Fig. 3. The opposing edg as of the blank are then bent to a sharp angle so as to form flanges 6 and I (Fig. 4), the flange I, which carries the packing strip being somewhat longer than the other. The two flanges are brought together as shown in Fig. 5 and then rolled over together with the packing strip, as shown in Fig. 6, so as to form the seam. In-the process the packing strip will be flattened and spread out so as to form an hermetically closed joint. Finally the seam is compressed and depressed as shown in Fig. 7 so that it will be flush with the outer surface of the tin.

The ends of the cylindrical body thus formed are then bent 011' in outward direction, as shown in Figs. 8 and 9, so as to form, in known manner, the flanges or lipsfwhereby the body is connected to the end pieces. The dished end pieces 9 are provided with wide. marginal flanges III to which packing rings 8 are applied, whereupon the end pieces are placed in position on the flanged body as shown in Fig. 10. The projected end of the packing strip 5 is placed between the ring 8 and the flange of the body. The seam is subsequently formed in a machine by rolling the flanges together with the packing elements between them. In this process the ends of the strip .5 will be intimately combined with the rings 8, so that the joint'wlll be perfectly tight all round the tin.

The invention is not restricted to the manuiacture oi preserve tins. It may also be applied to cans for the reception of oils and fat, the top 65.

resilient material; forming radial outwardly di-.

rected flanges at the opposing edges of the blank, the flange at the edge to which the packing strip is attached being longer than the other flange; bringing the flanges together and rolling said flanges and the strip spirally together'with the longer flange on the outside to form a longitudinal seam; and compressing and depressing said seam so that it is flush with the surface of the container. 2. The method of making a sheet metal container having a side flanging seam provided with a packing strip consisting in cutting a blank for the body of the container reducing the four corners of said blank to a depth equal to the width of material used in seaming; attaching to one of the opposing edges 0! the blank a packing strip of resilient material, said strip extending at the ends beyond the corner cuts; forming radial outwardly directed flanges at the opposing edges of the blank, the flange at the edge to which the packing strip is attached being longer than the otherflange; bringing the flanges together and rolling said flanges and the strip spirally together with' the longer flange on the outside to form a longitudinal seam; and compressing and depressing said seam so that it is flush with the surface of the container; forming flanges on the ends of the seamed body; placing closing pieces against the flanges of the body; inserting elastic packing rings between the closing pieces and the body flanges; bringing said rings and the ends of the strip into a mutually overlapping position; and spirally'rolling the flanges, the ends of the strips, the margins of the closing pieces, and said packing rings together to form closing seams.

HERBERT ZEIGMEISTER.

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