US2244059A - Collapsible tube - Google Patents

Description

June 3, 1941- P. R. FECHHEIMER COLLAPS IBLE TUBE Original Filed Feb. 12, 1954 INVENTOR. B401. R i'EcHHE/MER.

, ATTORNEYS.

Patented June 3, 1941 ,STATE S DFFIC COLLAPSEBLE TUBE.

Paul It. Fechheimer, Cincinnati, Ohio,assignor'to TheKarl Kiefer Machine Company,

Cincinnati,

Ohio, a corporation of Ohio 3 Claims.

the tube so that its bottom edges are contiguous and lie in parallel planes, and then to fold these edges over upon themselves a plurality of times, afterward frequently holding the fold together by means of a clip of stiffer metal fastened thereto,

orby lockingthis'fold by means of a crimp or fold- 1 ing back of the corners. These methods of sealing, while effective for most purposes, are sometimes uneconomical because they involve added cost, but more importantly, they do not provide a hermetic seal for the bottom of the tube. This becomes of importance, for example, where tubes containing liquefiable paste are shipped into warm or torridclimates, or are stored under elevated temperatures, Where the contents of the tube become liquefied, or where for any reason a pressure is built up inside the tube, the contents are frequently forced outwardly through the bottom closure and serve to stain and destroy the appear- .ance and serviceability of the tube itself, and of the wrapplngs or package in which it is contained.

It therefore appears as another object of my invention, to providecollapsible tubes sealed so as to provide a liquid and gas tight joint in the nature of a hermetic seal.

These and other objectsof my invention, which will be set forth hereinafter, or will be apparent to one skilled in the art upon reading these specifications, I accomplish by that series of process steps and by and in the constructions which I hereinafter disclose in exemplary embodiments.

Reference is made to the drawing, wherein Figure l is a sectional View of a sealing means.

Figure 2 shows the bottom end of a tube sealed by welding, and the bead formed thereby.

Figure 3 is a view showing such a welded tube with its bottom folded in a simple fold.

It will be understood that after the filling of a collapsible tube, which is usually done through the open bottom thereof, while the tube is in an inverted position, the bottom edges of the tube are spread so as to form a fish tail, and so as to bring these bottom edges together flatwise, so that they lie in parallel planes. They are then held in this position by clamp members engaging the side Walls of the tube-from either side. The welding together of the juxtaposed bottom edges of the tube presents in practice, some serious problems. The metal of the tube edges is very thin and quite likely to burn through. Thus, if heat were applied to the clamping members engaging the juxtaposed bottom edges, while a weld might be effected therebetween the tube walls have a tendency to burn-through at the edges of the heated members. I-have found, however, that it is possible to do commercially successful and reliable Welding by the procedure hereinafter to be outlined in detail. This procedure involves in the main, the clamping of the edges of the bottom of the tube so as to hold these edges in juxtapositioned relationship, but in such a way as to leave these edges projecting a short distance beyond the clamping means. If this isdone and if the clamping means themselves are not relied upon to do the welding, successful welding can be carried on at the end of thetube in that portion thereof which projects freely above the clamping devices. I have found moreover, that it is preferable to carry on this welding in a continuous and progressive manner by starting with a tool at one end of the juxtaposed edges and progressively forming a Weld therealong, finally reaching the other end of the juxtaposed edges, In other words, it is preferable, although not a limitation upon the broader aspects of my invention, to carry on the welding with a tool which has, practically speaking, a point contact with the work, and by moving the work and the tool relatively to each other during the progress of the welding operation.

I have described in Patent 2,102,840, an exemplary filling and closing machine which happens to be of the continuous motion type. My invention is not, however, limited to this type, but is clearly applicable to machines having a step by step motion, or to filling and closing operations which are carried on as separate steps or disher 4a. The holder 41) is hollowed out as at T and 8, to accept the top of a collapsible tube when the tube is in inserted position, and the holder may likewise be provided with a kick-out device comprising a plunger 9, and a spring 10, serving to hold the plunger in depressed position. The base member 4a has ears thereon 40, which engage the track members H on the base i.

The holder member 41) has a projection (not shown) at its side, to which is attached a vertical rod, also not shown. This rod bears at its upper end a pair of clamping jaws l3 and I4, hinged thereto, and urged to an outward position by a spring.

. Empty collapsible tubes may be inserted into the holders, and the tubes are then conveyed to a filling device to be filled as will be readily understood without further description. When so filled they pass from beneath the filling spouts and are acted upon by some device which spreads or fishtails the bottom end of the tube so that the edges can later be brought into juxtaposition by the action of the clamp members l3 and [4.

During the further course of the progress of the tube, track members 23 and 24 engage the clamp members i3 and i4 and bring them together about the fishtailed tube end. In this way the tube edges are brought to lie against each other in parallel fiat planes. In Figure 1 it will be seen how the clamping members I3 and I4, held together by the track members 23 and 24, engage the end of the tube, and it will also be seen how a free portion of the tube ends projects above the clamping members [3 and M, as at C.

The tube so disposed and held is caused to pass beneath a welding device of cylindrical form, indicated at 25. This member is held above a suitable bracket 2'6. It is grooved as at 27 in that portion of its surface which is to contact the juxtaposed edges of the tube bottom. It is convenient to make the groove 27 an annular groove extending circumferentially about the surface of the welding member 25. If any portion of this groove becomes fouled or otherwise unsuitable, itwill thus be possible to rotate the welding member slightly in the bracket 26, so as to present to the tube edges afresh portion of the groove. The welding member 25 may comprise an outer casing 25a, and an interiorly disposed electric heating coil (not shown), having means for an electrical J connection indicated broadly at 29.

It is convenient and economical to use electrically heated members, but members otherwise heated may be used as well as, in some instances, means for generating electric heat in the tube walls, or means for applying a flame thereto. In the claims which follow, the term welding is to be understood as including any means for causing interfusion of the top walls of the tube.

It will be noted that the device of Figure 1 illustrates a preferred method of operation in which the welding is carried on in a progressive manner from one end of the tube bottom edges to the other end. I have found that more positive results can be secured more easily in this way. Figure 2 indicates that the welding operation preferably results in the production of a slight bead of consolidated metal indicated at 3|. In Figure 3 I have shown at 32 a simple fold produced in the metal of the tube end. This is by no means as complicated a fold as is ordinarily made, nor does it take as much length of tube. The bead in. part serves to stiffen the bottom of the tube, but the fold is advisable for further stiffening, and also to take up the lengths of the tube which extend between the clamping members l3 and I4, and the place where the welding is accomplished.

It will be understood that the embodiments of my invention which I have hereinabove described are exemplary only and that modifications may be made in my invention without departing from the spirit thereof.

Having thus described my invention, what I claim as new and desire to secure by Letters Patent is:

l. A collapsible tube having a flattened bottom portion presenting juxtaposed edges of the tube Wall, and a line of Welding joining said juxtaposed bottom edges, said line of welding comprising an accumulation of the metallic substance of the wall edges themselves providing a bead.

2. A collapsible tube having a flattened bottom portion presenting juxtaposed edges of the tube wall, and a line of Welding joining said juxtaposed bottom edges, said line of welding comprising an accumulation of the metallic substance of the wall edges themselves providing a bead of substantially greater thickness than said juxtaposed edges of the tube wall and having the characteristics of a bead formed by surface tension in molten metal, the bottom edge portions of said tube being folded over upon themselves to form an additional stifiening structure.

3. A collapsible tube or like container having thin walls in which for a seal juxtaposed edges of said thin walls are welded together by interfusion of the metal thereof, the weld comprising a head of substantially greater thickness than said juxtaposed walls and having the characteristics of a bead formed by surface tension in molten metal.

Images