EP0906225B1 - Reinforced folded package and assembling device - Google Patents

Abstract

The device is constituted by rectangular reinforcement pieces made from a strip of semi-rigid material, fixed on a thin flexible sheet on the median portion of the zones and mutually articulated by hinges located astride the folds separating the zones.

Description

The present invention relates to a pleated packaging having a reinforced resistance to vertical load, formed of a device for reinforcement of a packaging for convex bodies, associated with a packaging produced from a thin pleated sheet whose folds are attached at their ends to give it a hold to the vertical load.

We know by patents FR-A-2595666 and FR-A2628719 a packaging for convex bodies made from a thin and flexible sheet which allows in one of its applications of consuming a round sandwich leaving the packaging around the sandwich to collect the drips and fold it up as you go eating the sandwich. The flexibility of the sheet allows manually deploy the folds around the convex body; indeed, during the deployment of the folds with one hand, we hold the convex body with the other hand while squeezing between the fingers; the softer the film the less we need to tighten the convex body to hold it between the fingers; when this convex body is fragile like, for example, the sandwiches of shape appreciably cylindrical of revolution, fast food products, made from brioche bread, there is a risk of crushing the sandwich when the pleated packaging is deployed; the counterpart of the flexibility of the sheet used is that the packaging does not protect the sandwich from crushing during transport. Hence the idea of protecting the sandwich, when it is cylindrical in shape by a cardboard ring which surrounds it over its entire side wall, the whole then being surrounded by a sheet of thin paper. The disadvantage of such a device is that its implementation takes a long time and that when paired with the pleated packaging as described in patent FR-A-2676037, it is difficult to remove the cardboard ring without removing the pleated packaging which, as a result, no longer fulfills its protection against sagging. As part development of the pleated packaging, we tried to fix the reinforcement strip directly on the thin sheet in the direction perpendicular to the folds; but we are quickly limited in reinforcement thickness because it becomes quickly impossible to deploy the reinforcement without crushing the sandwich. We then tried to get around this difficulty, in patent FR-A-2734791, while keeping a reinforcing strip attached to the sheet, to leave it pre-deployed with equal folds while the pleated part packaging is pleated as previously described; the problem is that when paired with a flat sheet, as in patent FR-A-2676037, making it possible to protect the upper and lower openings left by the edges of the pleated part, it is no longer possible stack them properly to reduce volume busy when transporting the pleated packaging.

The object of the invention is to provide a pleated packaging with good resistance to vertical load, easy to deploy and easy to store when folded for transport.

For this purpose, and in accordance with claim 1, the following ranges are associated separated by a fold from the rectangular reinforcements from a strip of semi-rigid material, cut, laid and fixed by appropriate means. The preamble of claim 1 is based on the state of the art according to document FR-A 2676037.

The invention also relates to an assembly device, packaging as defined in claim 4.

In the accompanying drawings:

Figure 1 shows the reinforcement device of the thin sheet constituting the package before folding and fixing the end of the folds.

Figure 2 shows a section of the thin sheet in line with the reinforcement device according to the figure 1 with the successive phases allowing its folding.

Figure 3 shows an exploded perspective view of the reinforcement device when deployed around of the convex body which has not been shown.

Figure 4 shows an exploded elevation view essential elements of the cutting device positioning and fixing of the elements composing the reinforcement device according to the invention.

Figure 5 shows a view of the main elements, in exploded elevation, of the folding device of the reinforced thin sheet according to the phases of the fig.2 and produced according to the device in fig.4.

The device consists in associating with the flexible sheet 1 (fig. 1) no longer a continuous reinforcement strip, but a discontinuous band formed by rectangular reinforcements 2 placed in the vicinity of each other and articulated between them by a hinge 3 formed from the thin sheet 1 which connects them to each other. The pleating being formed of successive rectangular ranges 5 and 6 separated between them by folds 4 forming an integral part of the hinge 3, the rectangular reinforcements 2 are placed inside these rectangular ranges 5 and 6 and are fold over each other in the same way as the folds 4 of the thin sheet. When we fold the rectangular reinforcements 7 and 8 (fig. 2) successive one on the other so that these two rectangular reinforcements 7 and 8 successive are in direct contact, it is necessary that the distance 9 between them is greater than or equal to their thickness 10 and 11 cumulated otherwise the portion of the sheet thin serving as a hinge 12 is stressed tension which can either prevent the positioning of rectangular reinforcements 7 and 8 on top of each other, i.e. cause stretching of the thin sheet portion forming hinge 12, or its tear; in return, when fold 13 is made so that it is the sheet thin 14 which is in contact with itself and that the rectangular reinforcements 8 and 15 are placed on the side outside, they can be positioned one against the other.

Positioning of rectangular reinforcements 2 (fig.1) relative to each other is one of the main difficulties resolved by the device, object of the present invention, making it possible to position the rectangular reinforcements 2 correctly, one by compared to others. These rectangular reinforcements 2 (fig. 3) have a height 16 in coherence with the height of the body convex to protect and more particularly, as of nonlimiting example, of the sandwich of substantially shape cylindrical of revolution, previously described; when the packaging thus produced is deployed (fig. 3), the succession rectangular reinforcements 2 connected together by the hinges 17 of the flexible sheet 1 constitutes a series dihedrons substantially forming a ring 18; when apply vertical loads on this ring 18 placed on a horizontal plane, the buckling of the reinforcements rectangular 2 under load is limited by setting under tension stress oriented horizontally from the thin sheet forming a hinge 17; the resistance of this ring 18 is limited, among other causes, by the strength of thin sheet 1 which eventually tears under the action of voltage when the load becomes too important; the rectangular reinforcement 2 can then flex.

One way of considering the installation of the rectangles reinforcement 2 (fig. 4), consists of a coil of semi-rigid material whose width corresponds to the height 16 (fig.3) of the rectangular reinforcement; this strip 19 (fig. 4) is pulled by rollers 20 at a speed slightly slower than the sheet web running speed thin 21 on which it will be fixed. Band 19 semi-rigid material is then driven by a support cylinder 22 rotating with tangential speed equal to the speed of movement of the sheet strip thin 21; the strip 19 of semi-rigid material is maintained on the support cylinder 22 by a system 23 of holes or 24 suction slots that allow it to slide slightly considering the speed difference of scroll between the tangential speed of the support cylinder 22 and that of the strip 19. The support cylinder 22 serves anvil to knives 25, integral with a cylinder of section 26, the wire 27 of which tangents the support cylinder 22 according to its generators. The position of the knives 25 on the cutting cylinder 26 and its speed are determined for cutting rectangular reinforcements 2 whose width is such that it alternately adapts to the width of each of the thin sheet areas 5 and 6 (fig. 1) separating two successive folds 4 of the packaging when it is folded.

Generally the tangential speed of wire 27 (fig. 4) of knives 25 is equal to or near the speed tangential of the support cylinder 22 according to the degree of wear knives 25; in any event the contact points wire 27 from knives 25 on the surface of the support cylinder 22 is always done in the same places, the holes or slots 24 suction used to maintain the reinforcements rectangular 2 being located between these contact points. Given the speed difference between the belt 19 and the surface of the support cylinder 22, as soon as the rectangular reinforcement 28 is cut, it is driven to the speed of the support cylinder 22 and thus a space between two rectangular reinforcements 28 and 29 successive. We can then bring the strip formed of a thin sheet 21 to tangent the support cylinder 22 in the area comprising the rectangular reinforcements 30 which come to be applied precisely on the thin sheet 21 and attach to it according to a known means; then we cut the suction on the holes or slots 24 d. on the cylinder support 22 which held the rectangular reinforcements 31 in place and a thin sheet is released provided with rectangular reinforcements as shown in the figure 1. We can then proceed to pleating.

In a preferred version of the invention, the pleating is done using a process directly derived from the patent European 0 528 920; tracks 5 and 6 located on either side on the other side of a fold 4 are of width A 32 and B 33 with A> B; the beaches have alternately a width A 32 and a width B 33; the range 34 (fig. 2) of width A 32 is broken down into a range 35 of width A-B 36 and a range 37 wide B 38; these two ranges 34 and 35 are separate by a fold 39; the two ranges 37 and 41 of width B 38 and 33 being placed side by side; the rectangular reinforcement 40 includes a cut to the right of this fold 39; the cut of the rectangular reinforcement 40 (fig. 4) of width A is produced on the support cylinder 22 by a second cylinder cutting 42; the rectangular reinforcement 40 being already separated of strip 19 by cutting through the cutting cylinder 25, the two pieces 44 and 45 obtained by cutting 43 remain substantially side by side; it does not pose problem since part 44 of width A-B is at the head of the rectangular reinforcement 40 of the beach of width A taken in the direction of movement; the cut in line with fold 39 can also be made with knives placed on the cutting cylinder 26; there are in these conditions a space created between the two parts of the reinforcement. The sheet 46 provided with its rectangular reinforcements 2 passes on a preforming wheel 47 (fig. 5) having teeth 48, the rectangular reinforcements 49 being located on the side wheel 47; the range 50 of width A-B is placed at the bottom tooth 47, the two areas 51 and 52 of width B cover tooth 47 which is in the form of an inverted V. A fold tightening wheel 53 composed of bars 54 comes to take the preformed thin sheet with its rectangular reinforcements; tracks 55 of width A-B are placed at the top of the bars 54 while the two tracks 56 and 57 of width B are placed in the hollow formed by two successive bars 54 and 58; The reinforcements rectangular are then on the outside of the wheel tightening the folds 53; when the bars 54 are approach the ranges 59 and 60 of width B approach and the rectangular reinforcements can easily overlap due to the space 12 (fig. 2) left between two reinforcements rectangular 7 and 8 successive at the time of cutting and tracks 61 and 62 of width A-B are placed side by side; however, it is necessary that the width ranges B have sufficient play when the bars 63 and 64 are brought together so that they can be released easily due to their rigidity. Then the beaches 61 and 62 of width A-B are transferred to the cylinder grouping of folds 65 with the rectangular reinforcement facing the latter 65 and, the ranges 66 and 67 in width Successive B forming an outgrowth, the reinforcements corresponding rectangles being located inside outgrowth; then we proceed to the coating of the folds using a cylinder comprising, at the height of the reinforcements rectangular, a reduced diameter taking into account various thicknesses of rectangular reinforcement that come overlap and which make a significant allowance.

One way to fix rectangular reinforcements on the thin sheet, is to use a reinforcement rectangular coated with a thin layer of material heat sealable placed on the outside 70 relative to to the support cylinder 22; the thin sheet can also be coated with a thin layer of heat-sealable material side 69 facing the rectangular reinforcement; fixation reinforcement is then made when applying the flexible sheet on the rectangular reinforcement by heating with hot air 68 from the face of the opposite flexible sheet to the one that is coated.

Claims (6)

1. Folded packing having a reinforced resistance on vertical load and formed of an approximately annular-shaped reinforcement (16) device on vertical load and being of approximately constant height when deployed and associated with a packing for convex bodies and embodied from a thin sheet folded along successive areas (5,6) and having a width A (32) and B (33) respectively with A (32) larger than B (33) whose folds are fixed at their extremities, characterised in that the successive areas (5,6) separated by a fold (4) of the thin sheet (1) are reinforced in their median portion by rectangular reinforcing pieces (2) made of a semi-rigid material and fixed on the areas (5,6) and joined together by a hinge (3) made from the thin sheet (1) and integrating the fold (4) and with a sufficient width to enable the reinforced sheet to be folded by folding means.
2. Packing according to claim 1, characterised in that when the packing is folded and the reinforcing pieces (7,8) are in direct contact, the width (9) of the hinge (12) being greater than the respective total thicknesses (10, 11) of the reinforcing pieces (7,8).
3. Packing according to claim 2, characterised in that the reinforcing pieces concerning the width area A (32) comprises a cut located at the right hand side of the fold (39) parallel to the folds of the thin sheet and placed at a certain distance from the edge of the area with the width A (32) equal to the difference of the width between A (32) and B (33).
4. Device for assembling the reinforced packing according to claim 1, characterised in that it includes a support cylinder (22) fitted with a suction device (23, 24) driving a strip (19) made of a semi-rigid material, a cutting cylinder (26) whose knives (25) cut the strip (19) into successive rectangular reinforcing pieces on which a flexible sheet (21) is unwound and fixes a flexible sheet so as to form a composite sheet (46) kept in place on the support cylinder (22) by suction means, the unwinding speed of the semi-rigid strip (19) being slightly less than the tangential speed of the support cylinder (22) .
5. Packing device according to claim 4, characterised in that it includes a second cutting cylinder (42) for cutting the reinforcement piece with the width A (32) at the right of the fold (39) .
6. Device for fixing the rectangular reinforcement pieces according to claim 4, characterised in that at least one of the two elements constituted by the rectangular reinforcement (28, 29), and the sheet (21) is coated with a heat sealing material on the face in contact with the other element.

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