FR2955838A1 - BODY AND FOLDABLE BAG RESISTANT TO COMPRESSION - Google Patents

Abstract

The invention relates to a collapsible container (2) comprising a bottom wall (10) and side walls (11-, 14) made from a blank made of semi-rigid material, the bottom wall (10) forming a polygon (100) having a central area (101), the side walls (11-14) surrounding the bottom wall (10) and being movable between a first substantially flat position with respect to the bottom wall (10) and a second position folded relative to the bottom wall (10), corresponding to a setting volume of the tray (2). This tray (2) is intended to cooperate with a lid (3) made from a blank of semi-rigid material, in order to cover it. According to the invention, this tray (2) also comprises at least one reinforcing column (30, 40) arranged so that, when this tray (2) is put in volume, the column (30, 40) is adjacent to the least one of the side walls (11-14), and the column (30,40) at least partially supports the load that can be applied to the cover (3) facing the central area (101). The invention also relates to a box (1) comprising such a foldable tray (2), and a method of mounting such a box (1).

Description

The present invention relates to the field of packaging products and, more particularly, a tray or a foldable tray, made of a semi-rigid material such as corrugated cardboard or a plastic plate, for the transport of perishable food products. especially. For the transport of such products, for example fish, between different workshops of a plant, parallelepiped-shaped tanks, possibly covered with lids, are generally used.

To be suitable for such use, this type of tray must be made of a sufficiently strong and rigid material to withstand heavy loads, as well as handling shocks without deformation or tear, while being light enough for one do not have to carry unnecessary masses. In addition, since its use involves empty transport phases, it is desirable that it be foldable so as to reduce its volume.

A suitable material commonly used to meet such needs is expanded polystyrene. It is a rigid material, lightweight, good thermal insulator, with sufficient mechanical strength for this use and is water resistant. It is easy to implement by injection into a mold and also cheap. However, this material has the disadvantage of being brittle, bulky and crates made with this material can not be laid flat. In addition, at the end of its life, it constitutes a cumbersome waste that is difficult to valorize. The applicant has therefore set itself the objective of developing a foldable container that can advantageously replace those currently used for transporting fish or any other product. Foldable bins comprising a bottom wall are known for this purpose. and side walls, all made from a blank of semi-rigid material. The bottom wall forms a polygon having a central area. The side walls surround the bottom wall and are movable between a first substantially flat position relative to the bottom wall and a second folded position relative to the bottom wall, corresponding to a volume of the tray. It is intended to cooperate with a cover made from a blank of semi-rigid material, for the purpose of covering it.

Such a tray has the advantage of being able to be flattened for delivery, which ensures a transport gain, to then be made volume and covered with a lid to form a transport case, which can operate by simple and basic editing operations. The elementary nature of these assembly operations is intended to allow automation and the use of the box by industrial, fishing for example, which must deal with large quantities of fast rate boxes.

However, such a foldable tray suffers from a major disadvantage, resulting from the semi-rigid nature of the material used, as well as the shape of the bottom wall. Indeed, the lack of total rigidity of the material used makes the lid ù and thus the entire body including the tray not very resistant to compression, and more particularly in the case of a stacking brick. However, the transport of stacked boxes is mandatory in many cases, especially when it comes to convey a large number of crates with the same shuttle to ensure both space saving and time savings.

The applicant therefore proposes to make a collapsible tray of this type, arranged to take advantage of the advantages conferred by the use of a semi-rigid material, while having sufficient compressive strength for transport applications of boxes stacked on top of each other.

The Applicant also proposes to ensure that this collapsible tray can be delivered flat and then mounted as easily as possible by a user, for a volume made possible directly on the production site from which the products in question.

It is possible to achieve this objective in accordance with the invention with a folding tray of the type described above, characterized in that it also comprises at least one reinforcing column arranged so that, when the tray is set volume, this column is adjacent to at least one of the side walls, and this column supports at least partly the load that can be applied to the lid facing the central zone.

Thanks to the invention, it improves the support of the potential subsidence zone, substantially coincides with the central zone of the polygon formed by the bottom wall of the tray. This zone is found at the level of the polygon forming the bottom wall of the lid, since the latter is intended to cover the tray to form a box and therefore comprises a bottom wall in the form of a polygon substantially identical to the one forming the bottom wall of the tank.

Since this central zone is the area likely to be subjected to the largest load because of its distance from the side walls - and in particular the side walls which are the farthest from each other and which therefore leave a zone weakened all the greater, so the foldable box thus constituted is reinforced. It is therefore understood that, to be done, the reinforcing columns are arranged to be as close as possible to the center of the potential settlement zone, while remaining adjacent to some of the side walls.

In other words, these reinforcing columns can overcome the structural weakness of the central area of the tray and the lid. A collapse of a box according to the invention is therefore avoided when it has to bear other similar boxes, or more generally when any type of object mechanically urges it from above.

Moreover, these columns can be added in a simple way to the blank forming the bottom wall and the side walls, so that the process of setting volume of the foldable container according to the invention can be performed by elementary mounting operations.

In addition, insofar as each column is arranged to be adjacent to one of the side walls when the tray is volume, it does not interfere with the filling of the tray with the products to be transported, before the tray be put in volume for transport. Thus, the box filling routine is not affected.

The structure is advantageous when the semi-rigid material is a plastic plate and more particularly when the semi-rigid material is a honeycomb-type plate formed of two sheets at least connected to each other by spacers parallel to one another and arranging with the sheets said cells. A suitable material is a polypropylene honeycomb plate.

In order to ensure a volume development that is both simple and robust, it can be advantageously provided that at least two opposite side walls are provided with flaps that can be folded in order to be secured to the other side walls when they are put into place. volume of the tray.

Preferably, the tray is arranged so that, after its setting volume, it is held in volume only by the cover which covers it. Thus, it is not necessary to stick the side walls to each other, which can be complex editing operations when it comes to volume of dozens of cases successively. It is sufficient here to fold the side walls of the tray and then cover the tray of the cover, so that all is set volume and maintained as well.

According to one embodiment, at least one reinforcing column being of triangular section, this column is advantageously obtained by folding four longitudinal flaps made from a blank of semi-rigid material, the two extreme flaps being superimposed one on the other for their joining. In this way, the corresponding reinforcing column is easily brought into volume, by elementary mounting operations, to be associated with the semi-rigid blank forming the walls of the tray. In addition, its semi-rigid structure avoids the disadvantages of rigid materials such as expanded polystyrene.

It will be understood, however, that the reinforcing column may have any cross section, polygonal or semicircular, for example, the particular case of the triangular section being the one that ensures a compromise between the number of flaps required and therefore the complexity to volume of the reinforcement column - and the support function of the weakened zone of the lid.

The invention also proposes a box comprising a foldable container as presented above, as well as a lid from a blank made of semi-rigid material, able to cooperate with the container so as to cover it when this container is put in volume. .

The assembly formed by the foldable container and the lid thus constitutes a product transport case enjoying the advantages conferred by the foldable container according to the invention, which it is provided with. In particular, this box can be delivered flat and then volume volume of a basic way by a user. Being made of a semi-rigid material, it is therefore particularly recyclable. The reinforcing columns provide support for at least a portion of the load that can be applied to the lid opposite the central zone of the tray to the area subjected to the largest load - to make this box resistant to the compression exerted on it when several crates are stacked.

It would be particularly advantageous if the reinforcing columns could be arranged without gluing and by simple operations. Also, in order to secure the reinforcing columns to the blanks forming the walls of the tray and the lid, it can be provided that: cavities are formed in the tray, at the edges between the bottom wall and the side walls of the adjacent tray reinforcement columns are also provided in the cover, at the edges between the bottom wall and the side walls of the cover intended to be brought closer to the reinforcing columns during the cover of the tray, and these reinforcing columns are provided tenons arranged so as to cooperate with these cavities during the setting volume and tray cover.

So that the box benefits from the same advantages as the foldable container according to the invention, it advantageously comprises a bottom wall and side walls made from a blank of semi-rigid material, the bottom wall forming a polygon of substantially identical to that formed by the bottom wall of the tray, the side walls of the lid surrounding the bottom wall of the cover and being movable between a first substantially flat position relative to the bottom wall and a second position folded relative to this bottom wall, corresponding to a setting volume of the lid.

Insofar as a box according to the invention is intended, for practical reasons of logistics and transport, to be superimposed on other identical boxes so as to form a stack, it is desirable that each box can be secured to the others. adjacent boxes, which facilitates stacking and prevents collapse of the stack during transport. To achieve this, the tray and the lid are advantageously provided respectively with tenons and auxiliary cavities, arranged so that, during the superposition of at least one lower box and at least one upper box, the auxiliary cavities of the lower box cooperate with the auxiliary posts of the upper box. These tenons and cavities thus provide a function of maintaining the boxes on each other during stacking.

In a particularly advantageous embodiment, the shape and the dimensions of the bottom wall of the tray and the position of the reinforcing columns are determined so that, during the superposition of at least one lower box and at least one upper box, at least one reinforcing column of the lower box supports a lower corner of the upper box.

In this way, the reinforcing columns have a double advantage. First, as mentioned above, these columns can prevent the collapse of the body when it must support other objects of weight. In addition, thanks to the particular arrangement of the bottom wall and the reinforcing columns, when performing stack stacking brick (for example two boxes in the direction of the length superimposed two boxes in the width direction ), the reinforcing columns of the boxes of the bottom come to support not only their lids, but also the lower corners of the boxes of the top. Stacking is therefore more resistant to compression.

In a preferred embodiment, the bottom wall of the tray forming a rectangle whose length is twice the width, it is expected that two reinforcing columns are disposed adjacent respectively to the two longer side walls, the middle level of the length of these walls.

In all cases, it is particularly advantageous to stack crates according to the invention, according to a brick stacking principle, so as to limit as much as possible the compression effect of the lower crates.

The invention finally proposes a method of mounting a box as presented above, the side walls of the foldable tray are initially in a substantially flat position relative to the bottom wall of the tray, at least two opposite side walls of the tray being provided with flaps adapted to be folded for securing to the other side walls during the setting volume of said tray, process consisting of: forming at least one reinforcing column, folding the side walls, folding the flaps, arranging each reinforcement column adjacent to a different side wall, so that these columns support at least partly the load that can be applied to the lid opposite the central zone of the polygon formed by the bottom wall of the tray, and have the container cooperate with the lid, possibly after the filling of the container, in order to cover it.

The invention will be better understood with the aid of the appended drawing in which: FIG. 1 is a perspective view of a plate capable of forming a rectangular foldable container according to a variant of the invention, FIGS. 2B are two perspective views of a reinforcing column intended to equip a container according to the invention, - Figure 3 is a perspective view of the plate on which are arranged two reinforcing columns, - Figures 4 to 6 are perspective views of the container according to the invention in successive steps of setting volume, - Figures 7 and 8 are two perspective views of a lid in positions respectively flat and folded, - Figures 9 and 10 are two perspective views of a tray and a lid respectively before and after nesting, - Figure 11 is a perspective view of a brick stack of a plurality of crates according to the invention, and - the figures 12A and 12B are two top views of the bottom wall of u tray, respectively with and without a reinforcing column.

For a better readability of the figures, identical reference numerals will designate similar technical elements.

The box of the invention is advantageously made of a plastic material such as an olefin, a polyethylene, PE, or a polypropylene, PP, for example. The polyolefins have the advantage of being extruded into a plate and are recyclable. A so-called cellular plate is obtained by extrusion of a plastic material through a flat die which is shaped so as to continuously form two sheets connected by partitions forming longitudinal struts, regularly spaced from each other. The still malleable plate is guided between two parallel calibration panels and against which the sheets are sucked and held until the shape is frozen. The cells are longitudinal and defined between the spacers and the cover sheets. The configuration of the partitions and internal sheets between the two sheets of covers may be more or less complex depending on the applications to which the cellular sheets are intended. The simplest, suitable for packaging, is formed of spacers perpendicular to two sheets of cover.

Foldable tray 2 of Figure 1 may be tray type or tray. It is intended to form a container for products, particularly perishable products. It comprises a wall (or panel) bottom 10, bordered by four side walls (or panels) 11 to 14. These walls 10 to 14 are made from a blank made of a semi-rigid material, preferably plastic, such as described above. The bottom wall 10 forms a rectangle 100 whose length (2L) is twice the width (L), as shown in Figure 11A.

The lines joining these elements 10 to 14 are fold lines of the plate. These lines, known in the art, can be achieved by crushing the plate to form a hinge line, or by removal of material. In this way, the side walls 11 to 14 are made movable between two positions: a first substantially flat position relative to the bottom wall 10, as shown in Figure 1, and a second position folded relative to the bottom wall 10, as shown in Figures 4 to 6, which corresponds to a setting volume of the foldable container 2.

In order to be able to secure these walls and thus subsequently maintain the volume of the tray 2, the side wall 13 is provided with flaps 20 and 22, while the side wall 14, opposite the wall 13, is provided with flaps 21 and 23. joints between the flaps and these two walls consist of fold lines, so that these flaps can be movable between two positions: a first position substantially flat relative to the side walls to which they are respectively attached, and a second position folded by relative to said side walls 13 and 14, so that these flaps can be made adjacent to the other side walls 11 and 12 during the setting volume of the tray 2.

Once these flaps in the second position, they can be secured to the other side walls 11 and 12, for example by gluing or, preferably, by simply covering the tray 2 by the cover 3. In the latter case, it does not it is not necessary to secure the walls of the tray by ancillary means, the walls of the lid sufficient to maintain the side walls and the flaps of the tray in their folded position, corresponding to the volume of the tray. It saves so tedious editing steps.

In the bottom wall of the tank, there are two cavities 70 and 71, at the edges between the bottom wall 10 and the side walls 11 and 12, which are the side walls adjacent to the reinforcing columns to be disposed later . More specifically, these cavities are arranged in the middle of the length of the fold lines. These cavities are intended to cooperate with pins provided on the reinforcing columns for their joining, as explained below with reference to Figure 4.

Referring now to Figures 2A and 2B, a reinforcing column is made from a blank of a semi-rigid material, preferably plastic, as previously described. This blank has four flaps 31 to 34, separated by fold lines so that these flaps can move between two positions: a first substantially flat position of the flaps relative to each other (Figure 2A), and a second folded position of flaps, so that the two end flaps 31 and 34 are superimposed on one another for their subsequent joining (Figure 2B).

A reinforcing column 30 is thus formed for equipping the foldable container 2 as described above with reference to FIG. 1. This column also comprises two pins 74 and 75, which will allow the column to be secured to the container and the lid during the assembly of the body, as explained further with reference to Figures 4, 10 and 11.30 Those skilled in the art will note that it can be used a number N of flaps, N being any integer greater than or equal to four, in order to obtain a reinforcing column whose section forms a polygon of N-1 sides.

Referring now to Figure 3, two columns 30 and 40 are disposed adjacent opposite sidewalls 11 and 12 respectively - the longer walls - at the middle of the length of these walls. The two extreme flaps, folded over one another, are thus placed against these panels 11 and 12.

The height of the columns is equal to the height of the side walls of the tray, as well as to the height of the side walls of the lid described below, so that the columns are enclosed between the bottom walls of the tray and the lid, and therefore to ensure the support of the cover in the case where it must withstand heavy loads.

It can be seen in FIG. 3 that the bottom wall 10 forms a polygon 100, here a rectangle of length two greater than the width, the sides of which merge with the join lines between the bottom wall 10 and the four lateral walls 11 14. This polygon 100 has a central zone 101, which conventionally corresponds to the zone farthest from the sides of the polygon. Due to the rectangular shape, this central area is centered on the intersection of the mediators on each side.

The volume of the foldable container according to the invention is now described with reference to FIGS. 4 to 6.

Starting from the tray of FIG. 3, provided with two reinforcing columns, the lateral walls 11 and 12 are folded so that they are perpendicular with respect to the bottom wall 10 (FIG. 4). Therefore, the lower lugs 74 of the columns 30 and 40 cooperate with the cavities 70 and 71 provided on the bottom wall 10, so that these columns can be secured to the bottom wall, as well as to the adjacent side walls 11 and 12.

The two other side walls 13 and 14 are then folded so that they are perpendicular with respect to both the bottom wall 10 and the side walls 11 and 12. The walls 13 and 14 abut and on the walls 11 and 12, so that their positioning is well controlled.

Finally, the flaps 20 to 23 are folded against the side walls 11 and 12 (FIG. 6). These flaps may optionally be glued to the walls 11 and 12, or preferably held against them by the cover 3 when the latter has covered the tray.

It is understood here that it is easy to volume the tray, before or after having filled with goods, by assembling operations at once simple, elementary and fast.

We now describe the production of a foldable lid according to the invention, with reference to FIGS. 7 and 8.

This cover 3 comprises a bottom wall 50, bordered by four side walls 51 to 54, substantially identical to those 10 to 14 of the foldable container (Figure 7).

In particular, these walls 50 to 54 are made from a blank made of a semi-rigid material, preferably plastic, as described above. The bottom wall 50 forms a rectangle 500 whose length (2L) is twice the width (L), that is to say a rectangle of substantially identical shape to that formed by the bottom wall 10 of the tray 2. The central zone 501 of the polygon 500 is centered on the intersection of the mediators of the fold lines between the bottom wall 50 and the side walls 51-54.

The side walls 51 to 54 are made movable between two identical positions to those of the walls 11 to 14. They are provided with flaps 60 to 63, of the same shape as the flaps 20 to 23, and made movable between two positions identical to those of the flaps 20 to 23.

Note however that the bottom wall 50 has a dimension slightly greater than that of the bottom wall 10, so that the tray 2 and the lid 3 can fit easily when forming the body 1, while ensuring a as small a distance as possible between the side walls respectively of the tray and the lid, so that the lid can maintain the tray volume.

After folding the walls 51-52, then the walls 53-54 and finally the flaps 60-63, it leads to the volume of the cover of Figure 8. In this way, the cover can be delivered flat, as well as the tank, with a view to a volume increase directly on the production site of the goods.

In the bottom wall 50 of the lid, there are two cavities 72 and 73, at the edges between the bottom wall 50 and the side walls 51 and 52, which are the side walls intended to be brought closer to the reinforcing columns 30 and 40. More precisely, these cavities are arranged in the middle of the length of the fold lines. These cavities are intended to cooperate with pins provided on the reinforcing columns for their joining, as explained below with reference to Figures 10 and 11.

Note that this lid can be obtained by other means, particularly in the form of a single piece already volume, but it is preferable to have at first in a flat form, before putting it in volume, so as to allow a flat transport before filling.

We now describe the realization of a box according to the invention, by fitting 5 of the tray and lid described above, with reference to Figures 9 and 10.

Once the tray 2 and the lid 3 set volume, and the products to be transported possibly arranged inside the tray, the next handling operation is to close the box 1, covering the tray by means of the lid. For this purpose, these two elements are fitted (FIG. 9).

Therefore, the upper tenons 75 of the columns 30 and 40 cooperate with the cavities 72 and 73 provided on the bottom wall 50, so that these columns can be secured to the bottom wall, as well as to the adjacent side walls 15 51 and 52 (Figure 10). The columns 30 and 40 are then locked between the bottom walls 10 and 50 (the side walls of the container and the lid having the same height as that of the reinforcing columns), as well as between the side walls 11, 12, 51 and 52, which ensures their attachment for the duration of the stacking. FIGS. 9 and 10 show respectively that the tray 2 is provided with auxiliary posts 80 and 81, arranged on the edge between the bottom wall 10 and the side wall 13, and that the lid 3 is provided with cavities 82 and 83, disposed on the edge between the bottom wall 50 and the side wall 51.

Referring to Figure 11, a set of boxes 1, and the 1g according to the invention is stacked brick. In this case, the auxiliary tenons of the tray of an upper box cooperate with the auxiliary cavities of the lid of a lower box 30, which makes it possible to secure the boxes adjacent to each other and thus to prevent the set collapses during transport, during which time the battery is likely to wobble.

Note also that, by the positioning of the reinforcing columns and the judicious choice of the shape and dimensions of the bottom wall of the tray, the columns are able to play a dual function during a stack of brick. Their first function is to support a part of the load on the lid of the box of which it is part. Their second function comes from the fact that the reinforcement columns of a lower box, for example the column 30 of the box 1, are superimposed on the lower corners of an upper box, for example the corner 90c of the box 1c. This column 30 thus supports not only the lid of the lower box 1, but also the lower corner 90c of the upper box 1c. The compressive strength during brick stacking is thus reinforced.

Note that the positioning of the columns and the choice of the bottom wall mentioned above are conditioned by the stacking mode provided for the boxes. The example described above applies to the case of a brick stack, but the skilled person will adapt the principle of the invention to other modes of stacking.

Figures 12A and 12B illustrate the advantages provided by the invention.

In the case where no reinforcing column is disposed (Figure 12A), the central zone 501 of the polygon formed by the bottom wall 50 of the lid 3 has a large dimension. The resultant weakening zone 502 of the cover then merges with this zone 501, so that the load to which the cover is liable to be subjected is important.

In the case now, where two reinforcing columns 30 and 40 are disposed adjacent to the longest sides of the wall polygon 50, in the middle thereof (i.e., so as to be as close as possible to the center of the potential subsidence zone 502), it is observed that the weakening zone 502 of the cover is reduced close to the columns 30 and 40, so that the dimension of this zone 502 is reduced overall and therefore that the load to which the cover is likely to be subjected is low.

In addition to the advantage that a box according to the invention provides in terms of compressive strength, it appears that it can be mounted simply and quickly by elementary mounting operations. In particular, the mounting of the box can be operated in the following manner, from a foldable tray initially placed flat: two reinforcing columns 30 and 40 are formed by folding the panels as shown in FIGS. 2A and 2B, the side walls 11 and 12 are folded, then the side walls 13 and 14, the flaps 20 to 23 are joined to the walls 13 and 14 so that they are brought closer to the walls 11 and 12, each reinforcing column is arranged. 30 or 40 adjacent to each of the longer side walls 11-12, so that these columns support at least in part the load that can be applied to the cover 3 facing the central area 101 of the polygon 100 formed by the bottom wall 10, that is to say as close as possible to the central zone 101 or 501, the lid 3 is optionally formed, if it is delivered flat, the tray 2 is made to cooperate with the lid 3, possibly after filling tray 2, for recovery and maintenance volume of the box.

The embodiments described above are given by way of non-limiting examples of the invention. Those skilled in the art will in particular be able to adapt the invention for cases whose bottom wall is not rectangular, but any polygon, without departing from the scope of the invention.

Claims (14)

Revendications1. Folding container (2) comprising a bottom wall (10) and side walls (11-14) made from a blank of semi-rigid material, the bottom wall (10) forming a polygon (100) having a zone central (101), said side walls (11-14) surrounding said bottom wall (10) and being movable between a first substantially flat position with respect to said bottom wall (10) and a second position folded relative to said wall bottom (10), corresponding to a setting volume of the tray (2), tray (2) for cooperating with a lid (3) made from a blank of semi-rigid material, for its recovery, tray (2) characterized in that it also comprises at least one reinforcing column (30,40) arranged so that, when said tray (2) is set in volume, said column (30,40) is adjacent to at least one of said sidewalls (11-14), and said column (30,40) at least partially supports the load likely to be liquefied on said lid (3) opposite said central zone (101). 2. Tray according to claim 1, wherein the semi-rigid material is a plastic plate. 3. Tray according to claim 2, wherein the semi-rigid material is a honeycomb type plate formed of two sheets at least connected to each other by spacers parallel to each other and forming with said leaves said cells. 4. Container according to one of the preceding claims, wherein at least two opposite side walls (13; 14) are provided with flaps (20,22; 21,23) adapted to be folded for securing to the other side walls ( 11,12) during the setting volume of said tray (2). 5. Tray according to one of the preceding claims, arranged so that, after its volume, it is kept in volume only by the cover (3) which covers it. 6. Tray according to one of the preceding claims, wherein the reinforcing column has a polygonal section or a half circle. 7. Tank according to claim 6, wherein, at least one reinforcing column (30) being triangular section, said column (30) is obtained by folding four longitudinal flaps (31-34) made from a blank in semi-rigid material, the two end flaps (31,34) being superimposed on one another for their joining. 8. Box (1) comprising a foldable container (2) according to one of claims 1 to 7, and a lid (3) made from a blank of semi-rigid material, adapted to cooperate with said container ( 2) so as to cover it when said tray (2) is set volume. 9. Box according to claim 8, wherein recesses (70,71) are formed in the tray (2) at the edges between the bottom wall (10) and the side walls (11,12) adjacent to the columns. reinforcement (30,40), recesses (72,73) are also provided in the cover (3) at the edges between the bottom wall (50) and the side walls (51,52) intended to be brought closer together said reinforcing columns (30, 40) during the covering of the container (2), and said reinforcing columns (30, 40) are provided with pins (74, 75) arranged so as to cooperate with said cavities (70-73) when the setting volume and recovery tray (2). 10. Case according to claim 8 or 9, wherein the cover (3) comprises a bottom wall (50) and side walls (51-54) made from a blank of semi-rigid material, the bottom wall. (50) forming a polygon (500) of substantially identical shape to that formed by the bottom wall (10) of the tray (2), said side walls (51-54) of said lid (3) surrounding said bottom wall (50). ) and being movable between a first substantially flat position relative to said bottom wall (50) and a second position folded relative to said bottom wall (50), corresponding to a setting volume of said lid (3). 11. Case according to one of claims 8 to 10, wherein the tray (2) and the lid (3) are provided respectively with tenons (80,81) and cavities (82,83) auxiliaries, arranged so that when superposing at least one lower crate (1, 1a, 1b) and at least one upper crate (1c, 1d), said cavities (82, 83) of the lower crate (1, la, 1b) ) cooperate with said tenons (80,81) of the upper body (lc, ld). Box according to one of claims 8 to 11, in which the shape and the dimensions of the bottom wall (10) of the tray (2) and the position of the reinforcing columns (30, 40) are determined so that when superposing at least one lower box (1, 1a, 1b) and at least one upper box (1c, 1d), at least one reinforcing column (30, 40) of the lower box (1, 1a, 1b) , la, lb) supports a lower corner (90) of the upper box (1c, 1d). 13. Box according to one of claims 8 to 12, wherein, the bottom wall (10) forming a rectangle whose length is twice the width, two reinforcing columns (30,40) are arranged so adjacent respectively to the two longer side walls (11,12), at the mid-point of the length of said walls (11,12). 14. A method of mounting a box (1) according to one of claims 8 to 13, the side walls (11-14) of the collapsible tray (2) are initially in a substantially flat position relative to the wall of bottom (10) of said tray (2), at least two opposite side walls (13; 14) of said tray (2) being provided with flaps (20,22; 21,23) adapted to be folded for securing to other side walls (11,12) during the setting volume of said tray (2), comprising: forming at least one reinforcing column (30,40), folding said side walls (11-14), folding said flaps (20-23), arranging each reinforcing column (30, 40) adjacent to a different side wall (11, 12), so that said columns (30, 40) support at least part of the load capable of to be applied on the cover (3) facing the central zone (101) of the polygon (100) formed by said bottom wall (10), and to make said tray (2) cooperate with said neck vercle (3), possibly after the filling of said tray (2), for its recovery.