Cup-shaped foil capsule

June 9, 1953

2,641,402

0. J. BRUUN

CUP-SHAPED FOIL CAPSULE Filed Jan, 14, 1948

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Inventor OTTo Jchannet Gru^n * Attorney

Patented June 9, 1953

2,641,402

UNITED STATES PATENT OFFICE

2,641,402

CUP-SHAPED FOIL CAPSULE

Otto Johannes Bruun, Slough, England

Application January 14,1948, Serial No. 2,220 In Denmark January 28,1947 (CL 229—4.5) which fits outside. Both members may be hard with their surfaces suitably formed to produce the indentations in the capsule, or one of the members may be of soft material such as rubber 5 and may form part of the walls of a chamber to which pressure fluid is introduced, thereby pressing the capsule sidewalls against the surface of the hard member.

In order that the invention may be the more 10 clearly understood a number of capsules in accordance therewith will now be described together with methods of producing them, reference being made to the accompanying drawings, wherein:

Figure 1 is a perspective view of a pleated capsule before indentations have been impressed into the side walls thereof in accordance with the invention;

Figure 2 is a similar view of the same after in20 dentations have been impressed into the side walls thereof in accordance with the invention;

Figure 3 is an end view to a much larger scale of a portion of the wall of the capsule of Figure 2.

Referring to· Figure 1, this shows an ordinary pleated capsule in which the side pleats are compressed to overlap each other all in the same direction. It will be appreciated that it is only for the better illustration of the structure of the 30 overlap that clearances are shown between the overlapping folds. Actually there would be little or no such clearance. Figure 2 shows the same capsule after a plurality of narrow relief grooves have been impressed into the pleated side walls ₃₅ thereof. The reference i designates the fold lines of the pleats and the reference 2 the relief grooves. It will be seen that the relief grooves 2 rim in line with the generatrix of the capsule. As the side pleats absorb a gradually increasing area 40 of foil towards the open end of the capsule they will increase in width and the fold lines I will run at an angle to the generatrix and consequently the said relief grooves 2 will intersect said fold lines. It will further be seen that the 45 spacing apart of the relief grooves 2 is several times narrower than that of the fold lines i.

Figure 3 illustrates the manner in which the relief grooves 2 produce an interlocking effect between the overlapping parts of the foil, and it 50 will readily be understood that there will be an enhanced interlock at the points at which the relief grooves and the fold lines intersect.

It will be seen that it is possible to use a punch and die as in Figure 3 only when the relief 65 grooves are to be in the line of the generatrix.

Claim.

The present invention relates to cup-shaped capsules of the kind which are made from thin pliable foil such as metal foil by forming a flat blank of foil into cup shape with pleated sidefolds which are compressed and flattened to overlap each other. Such capsules are commonly used as bottle capsules and as containers for confectionery, ice cream and the like.

The shape of the compressed sidefolds is retained by the inherent plasticity of the foil material, but with thin foil the stiffness is so small that the folds will easily open up and deform the capsule upon the exercise of the smallest tension. One object of the present invention is to produce a capsule of this kind in which the resistance against opening of the overlapping, flattened sidepleats is materially increased and the coherence of the walls is thereby improved.

A further object is to increase the stiffness of the sidewalls.

A still further object of the invention is to conceal the pleated structure of the sidewalls and thereby enhance the decorative effect of the capsule and to* hide the effect of irregularities in the pleating.

According to the invention this is achieved by impressing a number of indentations into the sidewalls of the capsule after forming the same, whereby the overlapping sidepleats are interlocked and the capsule sides stiffened.

Preferably these indentations take the form of narrow relief grooves which intersect and cut the folding lines of the pleats.

Such superimposed relief grooves improve the capsule in several ways. Firstly they stiffen the sidewalls in the same way as corrugated iron sheets are stiffened by the corrugation. Secondly they interlock the overlapping layers of the compressed sheets by compressing the layers jointly into the narrow grooves. Thirdly a work hardening of the foil material takes place by pressing the grooves, which is particularly remarkable with aluminum foil. Lastly the impressed grooves will conceal irregularities in the original folding of imperfectly pleated capsules and thereby improve the decorative effect of such capsules.

It is important that the pitch or spacing apart of the grooves is narrower than that of the side pleats, so that the grooves will form a close pattern which will overlap the folding lines in as many places as possible.

The impressing of the indentations may be effected by compressing the capsule between a male member which fits inside and a female member

3,641,402