ES2379699T3 - Banana transport tray comprising upper tray supports and easy assembly, assembly procedure attached - Google Patents

Abstract

Tray for transporting products such as bananas, comprising a bottom wall (2), a reinforced side wall (4, 4 ') that extends from the long side (35, 35') of the bottom wall and is formed by the fold of a panel (40, 40 ') on itself articulated on the long side (35, 35'), and a simple side wall (5a, 5b) extending from a short side (11a, 11b) of the bottom wall (2), adjacent to the long side (35, 35 '), said simple wall being formed by a flap (8a, 8b) articulated on the short side (11a, 11b), said tray comprising supports (27a, 27b , 28a, 28b) that support an upper tray, and extend between the reinforced wall (4, 4 ') and the single wall (5a, 5b), each support (27a, 27b, 28a, 28b) being articulated around the upper part (9a, 9b) of the single wall (5a, 5b) between an initial position and a position in which the support (31a, 31b, 32a, 32b) rests on the upper part (39, 39 ') of the reinforced wall (4, 4 ') characterized in that each single wall (5a, 5b) comprises two supports (27a, 27b, 28a, 28b) independent of each other in terms of movement and because the tray comprises positioning parts (41a, 41b, 42a, 42b) for each support (27a, 27b, 28a, 28b) in the support position, each part (41a, 41b, 42a, 42b) being movable around an axis between an interposed position in the panel folding path (40, 40 ') and a retractable position it occupies when the panel (40, 40 ') is folded, the positioning part (41a, 41b, 42a, 42b) being joined in motion with the corresponding support (27a, 27b, 28a, 28b), of so that when said part occupies the retractable position, the support (27a, 27b, 28a, 28b) occupies the support position.

Description

Banana transport tray comprising supports of an upper tray and easy assembly, assembly procedure attached.

The present invention relates to a tray for transporting and presenting products such as bananas, as well as the attached assembly procedure.

As can be seen in Figure 3, such a tray comprises a bottom wall 2 as well as articulated side walls around the sides of the bottom wall and defining the reinforced walls 4 and the simple walls 5a, 5b.

Each reinforced wall 4 of said tray is formed by bending the length of the articulation side 35 of said wall, and also comprises two reinforcing legs 15a, 15b visible in Figure 2, articulated respectively around the two lateral edges 20a, 20b more near adjacent simple walls 5a, 5b and a retractable panel 40 articulated around the articulation side 35 on the bottom wall 2 of the reinforced wall 4, said panel 40 comprising a folding line 25 separating it into an external part 401 and an internal part 402, respectively intended to go against the external faces and the internal faces of the two legs 15a, 15b after the assembly of the reinforced wall 4.

In addition, in a stack of trays, in order to avoid an engagement of the upper tray with an underlying tray, the tray comprises, according to Figure 3, four supports 28a. 28b located at the height of the upper edges 9a, 9b, 39 of its side walls 5a, 5b, 4 and at the same level as the corners of the tray.

According to Figure 1, each support is formed by a base 32a, 32b articulated around the upper edge 9a, 9b of a simple wall 5a, 5b to occupy the horizontal position of Figure 2, in which said base 32a, 32b extends up to the upper edge of the reinforcement legs 15a, 15b and is maintained in said position thanks to a user by means of a fixing flap 30a, 30b attached to the outer face of said legs.

The folding of the folding panel 40 around the reinforcement legs 15a is carried out by the same user who, at the same time, must at all times maintain the corresponding fixing fins against the external face of the reinforcement legs.

Thus, the assembly of said tray becomes difficult due to the need for the user to hold the fixing fins 30a, 30b of the supports 28a, 28b against the two side legs 15a, 15b while gluing the external part 402 of the retractable panel 40 against said side legs 15a, 15b and folds the inner part 401 of said panel 40 against the inner face of the reinforcement legs 15a, 15b.

According to Figure 3, after the folding of the folding panel 40 around the reinforcement legs 15a, 15b each fixing flap 30b of the bases must be placed between the corresponding reinforcement leg 15b and the outer part 402 of the folding panel 40.

As a consequence, there is an excess thickness of the cardboard which extends over a part of the height of the reinforced wall 4 and interposes between the various layers 15b, 402 of said wall 4, which initiates a bulging effect on said reinforced wall 4.

In this way, a tray of this type presents an important fire risk, even more so when it is arranged in a stack of trays, as it contains heavy, moist products and / or the fact that the surrounding atmosphere is warm and also humid.

The general structure of the tray is thus weakened.

The present invention aims to alleviate said drawbacks.

For this purpose, the present invention concerns a tray for transporting products such as bananas, which comprises a bottom wall, a reinforced side wall that extends from a long side of the bottom wall, and is formed by the folding over itself of an articulated panel on the long side and a simple side wall extending from a short side of the bottom wall adjacent to the long side, said simple wall being formed by an articulated flap on the short side; The tray comprises a support for an upper tray, which extends between the reinforced wall and the single wall, said support being formed by an articulated base around the upper edge of the single wall between an initial position and a support position in which the base rests on the upper edge of the reinforced wall.

According to the present invention, the tray comprises a positioning part of the base in the support position, said part being able to move between an interposed position on the panel folding path and a retractable position it occupies when the panel is folded, the positioning part joined in motion with the base, so that when said part occupies the retractable position, the base occupies the support position.

In other words, the positioning part occupies an elevated or interposed initial position on the panel withdrawal path when said panel is not retracted, and after the panel withdrawal, that is, when the panel is retracted, it occupies the retractable position. . In fact, it is the folding of the panel on itself that spontaneously displaces the positioning part from the raised position to the retractable position, since said positioning part is in the panel withdrawal path in its elevated initial position. In addition, the passage of said positioning part to the retractable position places the base in its support position, also automatically.

Due to the moving connection of the support base with the band of the positioning part, during the folding of the panel around the side legs, said base automatically occupies a support position, without specific user precautions to maintain the parts that they constitute the support during panel folding.

In addition, no cardboard thickness is interposed between the constituent elements of the reinforced wall, which ensures its verticality and avoids any risk of fire.

According to another characteristic, the simple wall comprises a reinforcing leg articulated around a lateral edge of the simple wall, having a height slightly lower than that of the adjacent reinforced wall and being interposed between the parts retracted on themselves of the collapsible panel that forms the adjacent reinforced wall, the positioning part of the base in the support position comprising a positioning band articulated around the upper edge of the reinforcement leg, which forms the axis of rotation of said band between the position interposed in the path of panel folding, in which the band is located in the extension of the reinforcement leg and the retractable position, in which the band is applied against the internal face of the reinforcement leg.

Advantageously, the positioning band is joined in motion to the support by means of a flap comprising an articulation fold in said support, and an articulation fold in the positioning band destined to skirt the inner face of the reinforcement leg when the support occupies The support position.

Preferably, the articulation fold of the flap in the positioning band borders the upper edge of the reinforcement leg when the base occupies the support position, so that the support occupies a remarkably horizontal position.

According to one possible embodiment, the articulation fold of the flap in the positioning band comprises a part slightly above the upper edge of the reinforcement leg when the base occupies the support position, so that the support is slightly tilted toward the top of the tray.

According to a variant embodiment, the collapsible panel comprises a longitudinal end portion of a length remarkably similar to the reinforced wall that the panel is intended to form, said part coming against the inner face of the reinforcing leg when the panel is retracted, and a fixing leg articulated around the side edges of the end portion, the fixing leg being attached against the inner face of the adjacent single wall and comprising a retention tab that comes into contact in a retention cut made in the adjacent support.

Advantageously, a stiff post extends vertically in a corner of the tray under the support, said post being formed by a part of the end part of the retractable panel.

The present invention also relates to the tray assembly process mentioned above, which comprises at least the steps of:

-

 arrangement of the positioning part of the support on the panel folding path,

-

 folding the panel over the positioning part until said part reaches its retractable position, and the support joined in motion with the positioning part reaches its support position on the upper edge of the adjacent reinforced wall.

The present invention will be better understood after reading the following description made with reference to the attached figures by way of illustration and not limitation, among which:

-

 Figure 1 mentioned above represents a perspective view of a first stage of mounting a transport tray of known type;

-

 Figure 2 mentioned above represents a perspective view of the tray of Figure 1 during a second assembly stage;

-

 Figure 3 mentioned above illustrates a third stage of mounting the tray of Figure 1;

-

 Figures 4 to 13 represent the successive stages of mounting a tray according to the present invention;

-

 Figure 14 represents a perspective view of the tray according to the present invention,

-

 Figure 15 illustrates a top view of the cardboard mold constituting the tray according to the present invention.

Figure 4 depicts a tray according to the present invention 1, comprising a substantially rectangular bottom wall 2 and side walls extending from the sides of said bottom wall 2 defining lower edges for said side walls.

Said tray 1 is intended for transporting objects such as food products, such as bananas.

In order to withstand the moisture and weight of said products, as well as the surrounding hot and humid atmosphere, the cardboard mold constituting the tray 1 is advantageously constituted of double grooved cardboard of parallel orientation to one of the sides of the back wall 2.

In the example shown in the figures, the grooves are parallel to the longer side of the bottom wall 2.

According to Figure 14, the side walls of the tray define the reinforced walls 4, 4 ', that is, with more than two thicknesses of the cardboard mold, and the simple walls with two thicknesses of cardboard mold 5a, 5b, alternated with each other.

Each single wall 5a, 5b of the tray 1 is formed from a simple flap 8a, 8b of the remarkably rectangular general cardboard mold 7 of Figure 15.

As Figure 4 illustrates, each single flap 8a, 8b is articulated around a fold 11a, 11b that coincides with a long side of the rectangular central face 13 of the cardboard mold 7 intended to form the bottom wall 2 of the tray one.

It comprises a central part 12a, 12b which extends in the extension of the central face 13 of the cardboard mold 7 which is articulated in relation to said face 13 around the corresponding fold 11a, 11b.

As can be seen in Figure 14, the upper free edge 9a, 9b of said central part 12a, 12b defines a transverse upper edge for the tray 1.

Furthermore, as illustrated in Figure 4, each flap 8a, 8b comprises two reinforcing side legs 14a, 15a, 14b, 15b each articulated with respect to the corresponding central part 12a, 12b around a fold 19a, 20a, 19b, 20b intended to form the side edge 23a, 24a, 23b, 24b of the tray of Figure 14.

According to Figure 5, said leg is delimited laterally by its articulation edge 19a, 19b in the central part 12a, 12b of the flap 8a, 8b and a free lateral edge not marked in the figure, and in height by an upper edge 45a, 45b intended to coincide with the longitudinal upper edge 39, 39 'of the tray marked in Figure 14 and a lower edge not indicated.

According to Figure 5, the formation of the reinforced walls 4, 4 'is carried out by folding along the side of the central face 13, of the two reinforcing legs 15a, 15b and then the folding against the internal face of said reinforcing legs 15a, 15b, of a retractable panel 40 articulated around the long side 35 of the central face 13 whose length is remarkably equal to twice the desired height for the reinforced wall that is intended to be formed.

For this purpose, each reinforcement leg 14a, 15a, 14b, 15b has a height slightly less than the height of the reinforced wall 4, 4 'which is intended to be formed, in order to be covered by the associated collapsible panel 40, 40 '.

More specifically, each collapsible panel 40, 40 'comprises a longitudinal end portion 402 and a longitudinal portion 401 interposed between the central face 13 and the end portion 402.

The two parts of the panel 40, 40 'are separated by a double fold line 25 intended to coincide with the longitudinal upper edge 39, 39' of the reinforced wall 4, 4 'that the panel 40, 40' is intended to form.

In addition, said parts have the same length, so that the part 402, called the external part, is folded over the entire height of the internal part 401, that is, to the central face 13 of the tray.

In order to form supports on which an upper tray can be supported, tray 1 comprises, as can be seen in Figure 14, four supports 27a, 28a, 27b, 28b located at the level of its corners, at the height of the transverse upper edges 9a, 9b and longitudinal 39, 39 ', and each extending over a small part of the short and long walls of the tray. These four supports are also independent of each other, in terms of movement.

Each support 27a, 28a, 27b, 28b is formed by a part of the cardboard mold constituting the base 31a, 32a, 31b, 32b, particularly illustrated in Figure 4, articulated around the upper edge 46a, 46b of the central part 12a , 12b of the simple flap 8a, 8b between the raised position of Figure 4 and the horizontally collapsed position of Figure 14.

In the collapsed position of Figure 14, the base 31a, 32a, 31b, 32b of the support 27a, 28a, 27b, 28b comprises an edge 36a, 37a, 36b, 37b located along the upper edge 39, 39 'of the 4, 4 'adjacent reinforced wall. Therefore, said base occupies a remarkably horizontal position.

In order to return the base 27a, 28a, 27b, 28b to its retractable position indicated in Figure 14, spontaneously during the assembly of the tray 1, said tray comprises positioning bands 41a, 42a, 41b, 42b of the bases 31a, 32a, 31b, 32b in their support position, which are interposed in the folding path of the end part 402 of the panel 40 against the reinforcement legs 15a, 15b and which are joined in motion with the corresponding base 31a , 32a, 31b, 32b in order to bring it to its horizontal position during the folding of the end portion 402 of the panel.

More specifically, as can be seen in the left part of Figure 5, a positioning band 41a, 42a, 41b, 42b is articulated around the upper edge 45a, 45b of a reinforcing leg 14a, 14b which constitutes a first fold of joint 45a, 45b between a position located in the extension of the reinforcement leg 14a, 14b illustrated on the right side of the same figure, and a position attached to the inner face of said reinforcement leg 14a, 14b represented on the right side of Figure 9.

Each positioning band 41a, 42a, 41b, 42b is similarly articulated in the corresponding base 31a, 32a, 31b, 32b by means of a connecting triangle 53a, 53b, 54a, 54b, according to Figure 5.

On the one hand, each triangle 53a, 53b, 54a, 54b is articulated at the adjacent base 31a, 32a, 31b, 32b by a second joint fold 48a, 48b (marked only on the left side of Figure 5) intended to constitute the edge 36a, 37a located along the upper edge 39, 39 'of the adjacent reinforced wall 4, 4' as illustrated in Figure 14.

According to the left part of Figure 5, said second fold 48a, 48b extends the lateral edge 19a, 19b of the central part 12a, 12b of the flap 8a, 8b.

On the other hand, each triangle 53a, 53b, 54a, 54b is articulated in the adjacent positioning band 41a, 42a, 41b, 42b by a third fold 49a, 49b (marked only on the left side of Figure 5), emerging at the union of the first fold 45a, 45b and the second fold 48a, 48b, and leading to the upper free edge 51a, 51b of the band 41a, 41b.

More specifically, according to the left part of Figure 5, the third fold 49a, 49b separates the angular sector defined by the first fold 45a, 45b and the third fold 48a, 48b into two remarkably equal parts.

According to the right part of Figure 5, one of the first stages of mounting the tray consists in starting the formation of a first reinforced wall 4.

From this point of view, both simple flaps 8a, 8b of the tray are positioned vertically with respect to the central face 13 of the cardboard mold.

Next, the legs 15a, 15b against the flaps 8a, 8b are arranged along the longitudinal side 35 of the central face 13 of the cardboard mold. In this configuration, the base 32b, the positioning band 42b and the joining triangle 54b of the first corner of the tray, as well as the base 32a, the band 42a and the triangle 54a of the second corner, are arranged vertically.

In addition, each base 32a, 32b is perpendicular to the assembly formed by the positioning band 42a, 42b and the connecting triangle 54a, 54b, and is connected to it by the second fold 48b (marked only on the left side of the Figure) .

At that time, the panel 40 occupies an unfolded position, in which it is flat, and extends by extending the initial part 13 of the cardboard mold.

In their initial vertical position, the positioning bands 42a and 42b are upright and therefore are in the folding path of the collapsible panel 40 from its flat position, that is, not folded, to its folded position.

Because, according to Figures 6 to 8, the retractable panel 40 is folded around the reinforcement legs 15a, 15b towards the inner face of said legs, the positioning bands 42a, 42b that are in the withdrawal path of the end portion 402 of said panel 40 they are also dragged from their initial vertical position to one of abatement against the inner face of the leg 15a, 15b in which they are articulated.

During said change of position, both equal angular parts of the band 42a, 42b come against each other.

As a result, the second fold (vertical on the right side of Figure 5) that constitutes one of the edges 37b of the base 32b forming the support, coincides with the first fold that is at the same level as the edge Reinforced wall top.

Because the other edge 56b of the base 32b coincides with the upper edge of the transverse wall, said base 32b then occupies a substantially horizontal position.

Each band 42a, 42b joined in motion to the adjacent base 32a, 32b by the corresponding triangle 54a, 54b thus draws said base 32a, 32b from the initial position to the support position.

Finally, when the positioning bands 42a, 42b occupy their positions when they are glued against the inner face of the corresponding reinforcement leg 15a, 15b, the bases 32a, 32b occupy their support position.

As can be seen in Figure 9, the first reinforced wall 4 is then constituted.

To complete the assembly of the tray, the opposite reinforced wall 4 ’is mounted according to Figures 10 to 13 in the same way as described for the previous stages.

The independence of movement of the two supports 27b, 28b of the same single wall 5b is what allows the assembly of a reinforced wall 4 independent of the opposite reinforced wall.

According to an advantageous embodiment of the present invention, not shown, which makes it possible to return the prominent supports so that they constitute the first elements on which the upper tray rests, the angles a of the four mounting bands are not 45 °, but slightly higher.

Similarly, the bases of the supports are slightly inclined towards the top of the tray from its articulation edge in the central part 12a, 12b of the single flaps.

The positioning legs of the bases in their support position by folding the folding panel on themselves allow to facilitate the assembly of the tray according to the present invention.

In addition, due to the absence of any fixing fin to the base, no excess thickness is interposed between the different layers of the reinforced wall, so that there is no risk of fire at the level of said wall.

Likewise, the multiple cardboard thickness formed at the level of the wall edge reinforced on one side by the folding on the internal faces of the reinforcement legs of the positioning bands, and on the other side by the folding of the folding panel on the positioning bands and reinforcement legs, helps to provide the tray with better fire resistance.

Indeed, the positioning bands act as stiffening stringers arranged along the reinforced wall.

On the other hand, the support maintained in its horizontal position by means of the underlying triangle and underlying reinforcement leg ensures better support of the upper tray.

Another function of said support, useful during the transport of said stacked trays, is the blocking of any lateral movement of the fixing legs of the folding panels, towards the outside of the tray.

Indeed, according to Figure 14, each support comprises a retention cutout 61 of a tongue embedded in the underlying fixing leg 404a.

Thus, the structure of the tray according to the present invention allows to facilitate and accelerate the process of assembling said tray, and also to provide rigidity to its structure.

On the other hand, the fact that the supports of the same simple flap are independent of each other in terms of movement facilitates the assembly of the tray.

Indeed, this independence of movement allows the placement of the first support of said flap independently of the placement of the second support, by a user.

Said user can then fold a first collapsible panel for the formation of the first support and then fold the opposite panel to place the second support in place, without being obliged to fold said panels simultaneously, which would be a heavy operation of the tray assembly.

Claims (8)

one.

 Tray for transporting products such as bananas, comprising a bottom wall (2), a reinforced side wall (4, 4 ') that extends from the long side (35, 35') of the bottom wall and is formed by the fold of a panel (40, 40 ') on itself articulated on the long side (35, 35'), and a simple side wall (5a, 5b) extending from a short side (11a, 11b) of the bottom wall (2), adjacent to the long side (35, 35 '), said simple wall being formed by a flap (8a, 8b) articulated on the short side (11a, 11b), said tray comprising supports (27a, 27b , 28a, 28b) that support an upper tray, and extend between the reinforced wall (4, 4 ') and the single wall (5a, 5b), each support (27a, 27b, 28a, 28b) being articulated around the upper part (9a, 9b) of the single wall (5a, 5b) between an initial position and a position in which the support (31a, 31b, 32a, 32b) rests on the upper part (39, 39 ') of the reinforced wall (4, 4 ') characterized in that each single wall (5a, 5b) comprises two supports (27a, 27b, 28a, 28b) independent of each other in terms of movement and because the tray comprises positioning parts (41a, 41b, 42a, 42b) for each support (27a, 27b, 28a, 28b) in the support position, each part (41a, 41b, 42a, 42b) being movable around an axis between an interposed position in the panel folding path (40, 40 ') and a retractable position it occupies when the panel (40, 40 ') is folded, the positioning part (41a, 41b, 42a, 42b) being joined in motion with the corresponding support (27a, 27b, 28a, 28b), of so that when said part occupies the retractable position, the support (27a, 27b, 28a, 28b) occupies the support position.

2.

 Tray according to claim 1, characterized in that the single wall (5a, 5b) comprises a reinforcing leg (14a, 14b, 15a, 15b) articulated around a side edge (23a, 23b, 24a, 24b) of the single wall ( 5a, 5b), having a height slightly lower than that of the adjacent reinforced wall (4, 4 ') and being interposed between the parts retracted on themselves (401, 402, 401', 402 ') of the retractable panel (40, 40 ') forming the adjacent reinforced wall (4, 4'), and because the positioning part (41a, 41b, 42a, 42b) of the base (31a, 31b, 32a, 32b) in the support position comprises a positioning band (41a, 41b, 42a, 42b) articulated around the upper edge (45a, 45b) of the reinforcement leg (14a, 14b, 15a, 15b) that forms the axis of rotation of said band (41a, 41b, 42a, 42b) between the position interposed in the panel withdrawal path (40, 40 ') in which the band (41a, 41b, 42a, 42b) is placed in the extension of the reinforcement leg (14a, 14b, 15a, 15b) and the retractable position, in which the band (41a, 41b, 42a, 42b) is placed against the inner face of the reinforcing leg (14a, 14b, 15a, 15b).

3.

 Tray according to claim 2, characterized in that the positioning band (41a, 41b, 42a, 42b) is connected in motion with the support (27a, 27b, 28a, 28b) by a fin (53a, 53b, 54a, 54b) which it comprises an articulation fold (48a, 48b) in the support (27a, 27b, 28a, 28b) and an articulation fold (49a, 49b) in the positioning band (41a, 41b, 42a, 42b) intended to lengthen the internal face of the reinforcement leg (14a, 14b, 15a, 15b) when the support (27a, 27b, 28a, 28b) occupies the support position.

Four.

 Tray according to claim 3, characterized in that the articulation fold (49a, 49b) of the fin (53a, 53b, 54a, 54b) in the positioning band (41a, 41b, 42a, 42b) borders the upper edge (45a, 45b) of the reinforcement leg (14a, 14b, 15a, 15b) when the base occupies the support position, so that the support (27a, 27b, 28a, 28b) occupies a substantially horizontal position).

5.

 Tray according to claim 3, characterized in that the articulation fold (49a, 49b) of the fin (53a, 53b, 54a, 54b) in the positioning band (41a, 41b, 42a, 42b) comprises a part slightly above of the upper edge (45a, 45b) of the reinforcement leg (14a, 14b, 15a, 15b) when the base occupies the support position, so that the support (27a, 27b, 28a, 28b) is slightly inclined towards the top of the tray.

6.

 Tray according to any of the preceding claims, characterized in that the collapsible panel (40, 40 ') comprises a longitudinal end portion (402, 402') of a length substantially equal to that of the reinforced wall (4, 4 ') than the panel (40, 40 ') is intended to form, said part (402, 402') going against the inner face of the reinforcing leg (14a, 14b, 15a, 15b) when the panel (40, 40 ') is folded , and a fixing leg (404a, 404b, 404'a, 404'b) articulated around the side edges of the end portion (402, 402 '), said fixing leg (404a, 404b, 404'a being) , 404'b) attached to the inner face of the adjacent single wall (5a, 5b) and comprising a retention tab (60) that comes into contact in a retention cutout (60) made in the adjacent support (27a, 27b , 28a, 28b).

7.

 Tray according to claim 6, characterized in that it comprises a stiffening post (403a, 403b, 403'a, 403'b) that extends vertically in a corner of the tray under the support (27a, 27b, 28a, 28b), being said post (403a, 403b, 403'a, 403'b) formed by a part of the end part (402, 402 ') of the collapsible panel (40, 40').

8.

 Assembly procedure of the tray according to any one of claims 1 to 7 comprising at least the steps of:

-

 assembly of a first side of the tray by: a) the arrangement of the positioning parts (41a, 41b, 42a, 42b) of two opposite supports (27a, 27b, 28a, 28b) of two single walls (5a, 5b) in the withdrawal path of the adjacent panel (40, 40 ') and by

b) the folding of the panel (40, 40 ') on the positioning parts (41a, 41b, 42a, 42b) until said 5 parts reach their retractable positions, the supports (27a, 27b, 28a, 28b) moving together with the positioning parts to their support position on the upper edge of the adjacent reinforced wall, independently of the two supports ( 28a, 28b, 27a, 27b) on the second side of the tray,

-

 assembly of the second side of the tray by.

c) the arrangement of the positioning parts (42a, 42b, 41a, 41b) of both opposing supports (28a, 10 28b, 27a, 27b) of both simple walls (5a, 5b) on the folding path of the adjacent panel (40 ', 40) and by d) the folding of the panel (40 ', 40) on the positioning parts (42a, 42b, 41a, 41b) until said parts reach their retractable positions, the supports (28a, 28b, 27a, 27b) being joined together in movement with the positioning parts towards their support position on the upper edge of the reinforced wall 15 adjacent.