EP2626313A1 - Box-shaped collapsible container, open towards the top - Google Patents

Abstract

The tray (1) has a lower frame (2), an upper frame (9), and a bottom wall (4) that is supported by the lower frame. A set of movable side walls (5-8) is articulated with the upper frame between a position drawn up with regard to the bottom wall, and a position that is folded up flat with regard to the bottom wall. A set of locking units (12, 14) is utilized for marking a set of positions in the drawn up position and in the folded up position, where the tray is able to be stored in the drawn up position and in the folded up position.

Description

The present invention relates to foldable bins for the transport of products, of parallelepipedal shape and open upwards.

For the transport of products such as parts between different workshops of a factory, it is generally used such trays that are circulated by shuttle. Once the pieces have arrived at their destination, the empty bins are often returned to the shipping shop for refilling. To be suitable for such a use, this type of tray is made of a plastic material sufficiently strong and rigid to withstand heavy loads, as well as handling shocks without deformation or tear, withstand soil and can be cleaned. It is also light so that one does not have to carry useless masses. Moreover, as its use involves empty transport phases, it must be foldable so as to reduce its volume.

These foldable plastic bins are also widely used because they are inexpensive and can be used in industry as well as in other fields as long as it is desired to transport products safely. in such bins in unfolded, upright use position and a return thereof with a minimum space in the folded storage position, flat, after unloading the products.

For example, such a foldable parallelepiped bin has two frames respectively lower and upper, a bottom wall supported by said lower frame, and movable side walls hinged to the upper frame between a position erected relative to the bottom wall, for which the tray is in the position of use, and a folded position flat with respect to the bottom wall, for which the tray is in the storage position.

Although giving good results, this type of tank may present a risk in maintaining the use and storage positions due to the side walls hinged to the upper frame. If the walls are not properly erected, they can fall back and if they are not correctly laid down, the storage position with minimal space is not strictly obtained, so that the subsequent stacking of the bins in this position can be dangerous because of the instability generated.

We know from the document DE 29809950 a foldable container having locking means for marking the positions respectively for use with the erected walls, and storage with the folded walls.

The present invention aims to provide such a foldable container with locking means.

For this purpose, the foldable parallelepipedic tray with locking means is as defined in the appended claim 1.

Thus, thanks to the invention, it is certain that the position occupied by the tray is retained as the locking means concerned is operational.

When the tank is in use, for the transport of products, the side walls are upright, perpendicular to the bottom wall, the frames being spaced parallel to one another and thus held by the locking means immobilizing the erect walls.

When the tray is empty, for storage with a minimum volume and stacking with other trays, the side walls then folded parallel to the bottom are held flat in this position by the locking means concerned with this function, the frames being in contact with each other. Of course, the transition from one position to the other tray is effected after erasing the previously active locking means.

In addition, the two side walls are hinged by their upper edges to the upper frame, while the lower free edges of the walls are locked between said tabs and the lower frame, in the position of use of the tray. And the passage of the cleats by the notched edges at the time of installation in upright or flat position of the side walls, is facilitated by the fact that the edges can deform safely and spontaneously resume their original position in the wall plane side.

In a preferred embodiment, the locking means for marking the storage position comprises elastically deformable tongues provided on one of the frames and thickenings provided on the other frames, said tongues and overthickness being intended to cooperate together when the two frames are brought one on the other in storage position.

In particular, the tabs are located on the upper frame, and the extra thicknesses are provided on the lower frame.

According to a preferred embodiment of the tray, the upper frame consists of opposite sections parallel in pairs and assembled by corner reinforcing pieces on which are located the locking tabs, and the lower frame is made by injection and has the extra thicknesses for locking the tabs.

Two of the opposite side walls of the tray are independent and have fold lines with the upper frame, while the other two opposite side walls, articulated to the upper frame, and the bottom wall are from the same panel around lines of folding, so as to occupy a U-shaped section when these side walls are erected, and zigzag flat when folded, said walls having in addition to the fold lines with the bottom wall and the upper frame, lines of median folding to ensure zigzag folding.

Advantageously, the side walls and the lower and upper frames are made of a plastic material of the polypropylene type, so that the tray is recyclable in addition to having the qualities described above. For example, the independent side walls can be made of a cellular polypropylene ensuring the rigidity of the tray, while the bottom wall panel and associated side walls is made of a polypropylene bubble structure, reducing the weight of the tray and facilitating its flattening by its greater flexibility.

• Les figures du dessin annexé feront bien comprendre comment l'invention peut être réalisée.
• La figure 1 représente, en perspective éclatée, un exemple de réalisation du bac pliable conformément à l'invention.
• La figure 2 montre en perspective le bac en position d'utilisation, dressée.
• Les figures 3 et 4 représentent, en perspective et en coupe, le moyen de verrouillage du bac dans une telle position d'utilisation.
• La figure 5 montre en perspective le bac en position de stockage, à plat.
• Les figures 6 et 7 représentent, en vue extérieure et en coupe, le moyen de verrouillage du bac en position de stockage.

A reinforcing plate may also be provided between the lower frame and the bottom wall in case of heavy products and to strengthen the tray during a roller conveyance.

• The figures of the appended drawing will make it clear how the invention can be realized.
• The figure 1 represents, in exploded perspective, an embodiment of the foldable tray according to the invention.
• The figure 2 shows in perspective the tray in use position, erect.
• The Figures 3 and 4 represent, in perspective and in section, the tray locking means in such a position of use.
• The figure 5 shows in perspective the tray in storage position, flat.
• The Figures 6 and 7 represent, in external view and in section, the tray locking means in the storage position.

As we see on the figure 1 , the foldable tray 1 has, in this embodiment, a parallelepiped shape and mainly comprises a lower frame 2, a panel 3 with a U-shaped cross section forming a bottom wall 4 and two opposite side walls 5, 6, two others independent side walls, opposite, 7, 8 perpendicular to the previous, an upper frame 9 formed of sections 10, and corner reinforcing pieces 11 at the four corners of the upper frame to join the profiles.

Advantageously, the positions of use of the tray 1 with the side walls erected, and storage with the flat walls, shown on the figures 1 , 2 and 5 and obtained by folding the walls relative to the upper frame, are marked by respective locking means 12 and 14. The latter avoids any unexpected passage of the tray to a flat position when in service and, conversely, to a standing position when stored flat during empty handling. These means will be detailed later.

First, the lower frame 2 is made of injected polypropylene and assembled by ultrasonic welding (bouterollage), and it has a cross section in L, at right angles, so that the wings (or sides) horizontal 15 of the frame serve as support for the bottom wall 4 of the panel 3 registering, within play, within this frame. The vertical wings 16 thereof ensure the implementation in abutment of the side walls 7, 8 upright, vertical position.

The foldable panel 3 is, for example, made of polypropylene with a bubble structure, such as in particular known under the trademark Akyboard, and whose methods of manufacture are described in the patents EP 1477299 and 1638770 . Such polypropylene imparts lightness to the panel with, ultimately, a less heavy tray, and improves its recovery flat through the side walls 5, 6 (large sides of the tray) zigzag folding as will be seen later.

The two independent side walls 7, 8 (small sides of the tray) are, for their part, made of cellular polypropylene brand Akylux for example, ensuring in particular, by a thickness of the appropriate walls, the rigidity of the tray 1 and the recovery of load when the latter contains the products, in the position of use. The structure of the walls is made by extrusion of material into dies to obtain two flat sheets separated from each other by parallel intermediate spacers, such a structure providing a very good resistance to crushing in the direction of spacers.

We see, on the figure 1 , that the lower edge 17 of each independent side wall 7, 8 has vertical notches 18 which are capable of cooperating, in upright position of the tray, with corresponding ribs 19 or the like provided in the vertical wings concerned 16 of the lower frame 2. Central openings 20 are further provided in the walls 7, 8, near their upper edge 21, into which are inserted flexible handles 22 for handling.

The upper edges 21 of the independent side walls 7, 8 and the end edges 23 of the side walls 5, 6 terminating the panel, receive the profiles 10 corresponding to the upper frame 9. These profiles 10 are made by extrusion and are in form U reversed. They are, by for example, glued to the edges of said walls, inserted therein. And the connection between the four sections 10 is provided by the four corner reinforcing pieces 11 perpendicularly joining the profiles to form the upper frame 9. These reinforcing pieces 11 thus overlap the relevant ends of the profiles 10 by being attached to them. ci and the upper edges of the walls 5-8 by fastening elements 24 of the type screws, rivets, welds or the analogs passing through them.

Due to the U-shaped panel 3 advantageously forming the bottom wall 4 and two of the side walls 5, 6 of the tray, it is made collapsible by lines of articulation or folding 25 of the walls 5, 6, located just under the relevant sections 10 of the upper frame 9. And, to allow the parallel approximation or removal of the two frames, with such a U-shaped panel, the walls 5, 6 comprise, in addition to the fold lines 26 with the wall bottom 4 of the panel, folding lines 27 parallel to the preceding and located substantially in the middle of the height of said walls 5, 6. The latter can thus take a straight up, erect, when the tray is erected, and a position accordion , zigzag, when the tray is flat, for a small footprint.

Regarding the independent walls 7, 8 of the tray 1, they can pivot relative to the corresponding profiles 10 of the upper frame 9 around fold lines 28 provided in the walls and substantially at the same level as the lines 25 of folding walls 5 , 6.

A reinforcing plate 29 of the bottom of the tank 1 is also provided at the bottom wall 4 of the U-shaped panel, taking into account the mass parts that can contain the tray. This plate 29 is attached by gluing or welding under the bottom wall 4 and fits into the frame 2 between the horizontal wings 15 thereof ( figure 4 ). In addition, we see that the plate 29 is at the same level as the horizontal flanges 15, allowing a conveying on rolls without attachment or deformation of the frame. It is for example made of rigid alveolar polypropylene, identical to that constituting the independent side walls.

The parallelepiped bin 1 assembled and shown on the figure 2 is in open use position upwards, ready to contain parts not shown, with the side walls 5, 6, 7, 8 straight, erect. The two lower frames 2 and upper 9 are thus spaced parallel (and horizontally) from each other. Note that the independent walls 7, 8, in the manner of erecting the tray, are located between the side walls 5, 6 of the panel and maintain the latter spaced erect position, by the side edges 33 of the walls 7, 8.

To guarantee such a position of use of the tray ( figure 2 ) and avoid its passage to the storage position, it is necessary to immobilize the independent walls in the erected position by the locking means concerned 12. Indeed, when the articulated walls 7, 8 are straight, the lower free edges 17 of these, close or in contact with the bottom wall 4, are, on one side, in abutment against the corresponding vertical wings 16 of the lower frame 2, with the ribs 19 thereof engaged in the notches 18 of the walls but, although the latter are straight, they can be pushed unexpectedly on the other side, towards the inside of the tray corresponding to the flattening of the tray, and pivot around the fold lines 28 at the upper edges.

To prevent this when the tray 1 is in use, the locking means 12 comprises, as shown by the Figures 2, 3 and 4 , cleats 31 protruding from the bottom wall 4 of the panel, so as to block the lower edges 17 of the walls 7, 8 between the cleats 31 and the vertical flanges 16 of the lower frame 2.

In this example, the cleats 31 are provided on the horizontal flanges 15 of the frame 2 on which the bottom wall 4 of the foldable panel 3 rests, and they pass through this bottom wall by means of cutouts 32 formed in correspondence therewith. We see that the tabs 31 are located near the vertical flanges 16 leaving between them a space sufficient to receive the thickness of the walls 7, 8 to be immobilized. If the number of stops is, in this example, two per lower edge 17 to immobilize, it could be different. One could also consider only one cleat per side wall to immobilize.

The tabs 31 shown open from the bottom wall 4, towards the inside of the tray, and have a tooth-shaped cross section with a vertical face 34 against which the free edge 17 of the independent side walls 7, 8, which are thus locked in position. Tray 1 is then immobilized in an erect use state. The cleats are then terminated by an inclined face 35 to encourage their crossing by the free edges 17 of the walls behind the cleats, during the transition from the flat position to the upright position of the tray.

Note, moreover, that the cleats 31 allow the operator to have a visual control of the lock. When the cleats are visible, apparent, this means that the independent side walls 7, 8 are locked thus marking their upright position, the lower edges 17 having crossed the tabs 31 being wedged between the vertical wings 16 of the lower frame 2 and the vertical faces 34 stops acting stop.

To facilitate the passage of the free edges 17 without damaging the passage of the cleats as and when changes in positions of the tray, we also note that each cleat 31 of the bottom wall 4 is close to one of the notches 18 walls 7, 8 receiving the ribs 19 of the frame 2. Thus, a wedge zone 36 is created in the lower edge 17 being delimited by this notch, which allows this wedge zone 36 of the edge 17 to easily cross the cleat by deformation without folds and then spontaneously resume its initial state in the plane of the walls 7, 8.

After unloading the products, the foldable container 1 is designed to move from the high use position to the unfolded, upstanding side walls ( figure 2 ), at the low storage position of the tray with the walls flat, folded ( figure 5 ). For this purpose, the operator pushes from the outside on the locked sidewalls 7, 8 (arrows F), approximately near the lower edges 17, so that the zones 36 of the latter, by deformation due to their embodiment in FIG. deformable plastic material, the tabs 31 pass, to pivot the walls 7, 8 upwardly around the respective hinge lines 28, at least up to the level of the profiles 10 of the upper frame 9. The locking means 12 is then rendered inoperative.

The side walls 5, 6 of the panel 3 are then released and, acting from the outside on these walls, they fold zigzag around the corresponding hinge lines 25, 26, 27, towards the inside of the tray .

With this, the upper frame 9 descends parallel to the lower frame 2, while the folded parts 5.1, 5.2 and 6.1, 6.2 of the side walls of the panel continue to bend around the hinge lines until they are flat on one another and on the horizontal bottom wall 4 of the panel, as shown by the Figures 5 and 6 .

At this moment, the independent lateral walls 7, 8 are folded flat, around the hinge lines 28 to the profiles 10, against the outer part 5.2, 6.2 of the folded walls 5, 6, and the upper frames 9 and lower 2 are in contact with each other.

Tray 1 occupies, as shown in figure 5 , a storage position flat, low, having a small footprint, minimal.

The locking means 14, shown more particularly on the Figures 6 and 7 , is provided to also guarantee the marking of such a storage position of the tray.

This locking means 14 is located on the reinforcing pieces 11 of the upper frame 9 and on the vertical wings 16 of the lower frame 2. An elastically deformable tab or clip 40 is provided, in this embodiment, in each side of the piece wedge reinforcement 11, in the outer leg 41 of the inverted U of each piece.

This tab 40 has a protruding internal rim 42, for example semi-cylindrical, to cooperate with an extra thickness 43 provided horizontally at each free edge 44 of the vertical flanges of the frame 2, for receiving a tab.

Thus the elastic tabs 40 at the moment of the descent of the frame higher 9 pass, by their protruding flanges 42, on the extra thicknesses 43 located at the corners of the lower frame 2, to overcome these extra thicknesses by deforming, then spontaneously return under the extra thicknesses 43 by the projecting flanges. At this moment, the two frames 2, 9 are one on the other and immobilized in this low position, flat by the locking means 14.

The "clipping" force is determined to be sufficient to maintain the frames of the tray against each other and to manipulate the latter, without risk of opening or yawning between the two frames.

In this way, the bins 1 thus folded and locked can be stacked with optimum stability, the reinforcing pieces 11 of a tray that has just been folded and locked fitting in the usual way in the reinforcing pieces of a tray already folded.

Thus, a pile of stacked bins in a flat and stacked position can be stacked without problems with good stability, which maximizes the number of bins in a stack and reduces the frequency of empty returns to the supply point of the bins. bins and therefore the costs.

The unfolding of a tray to pass it in the position of use does not raise difficulties. After deliberately spacing the elastic tabs 40 and release with the extra thicknesses 43, the upper frame 9 is pulled upwards, causing the spontaneous passage of the side walls 5, 6 of the panel 3 in the upright position around the respective fold lines, and the two other independent lateral walls 7, 8 are then folded by pivoting until the lower edges 17 thereof pass, by a voluntary action, the catches 31 abutting against the vertical wings of the lower frame 2. The parallelepiped bin is in the use position ready to be filled with products.

Moreover, the fact that the bins are made of polypropylene makes it possible to recycle them to 100%. The design of the tanks with honeycomb polypropylene walls (with a thickness of about 10 mm) and polypropylene walls with a bubble structure (with a thickness of about 3.2 mm) makes it possible to recover the load. (walls 7, 8), reduce the weight (panel 3) and improve its flattening for the folding of the side walls forming the long sides. Compared to an injected plastic tray, this design results in a weight gain of several kilograms per tray, which increases the payload without increasing the total load limited to a certain value for reasons of ergonomics.

Claims (7)

Foldable parallelepipedic box having two lower and upper frames (2) respectively, a bottom wall (4) supported by said lower frame, movable side walls (5, 6, 7, 8) articulated to the upper frame (9) between a position erected relative to the bottom wall, for which the container is in the position of use, and a folded position flat with respect to the bottom wall, for which the container is in the storage position with the two frames one on the other, and locking means (12, 14) for marking the positions respectively for use with the erected walls, and storage with the walls folded flat,
characterized in that the locking means (12) for marking the position of use comprises tabs (31) projecting from said bottom wall (4) so as to immobilize, in the upright position, the free edges (17). two (7, 8) of said opposite side walls between said tabs and vertical wings of the lower frame, the tabs (31) being provided on the corresponding horizontal wings (15) of the lower frame (2), receiving the bottom wall ( 4), and, in the free edges (17) of the two side walls (7, 8), are provided notches (18) adapted to cooperate with ribs (19) of the lower frame (2), the locking tabs ( 31) in the vicinity of the notches concerned. Tray according to claim 1, wherein the locking means (14) for marking the storage position comprises elastically deformable tabs (40) provided on one of the frames and extra thicknesses (43) provided on the other of the frames, said tongues and overthickness being intended to cooperate together when the two frames (2, 9) are brought one on the other in the storage position. Tray according to claim 2, wherein the tongues (40) are located on the upper frame (9), and the extra thicknesses (43) are provided on the lower frame (2). Tray according to claim 3, wherein the upper frame (9) is consists of sections (10) opposed parallel in pairs and assembled by corner reinforcing pieces (11) on which are located the locking tabs (40), and the lower frame (2) is made by injection and has the extra thicknesses (43) for locking the tabs. Container according to one of claims 1 to 4, wherein two of the opposite side walls (7, 8) are independent and have fold lines (28) with the upper frame (9), while the other two opposite side walls (5, 6), articulated to the upper frame, and the bottom wall (4) are derived from the same panel (3) around fold lines, so as to occupy a U-shaped section when these side walls are erected, and zigzag flat when folded, said walls having, in addition to the fold lines (25, 26) with the bottom and the top frame, median fold lines (27) for zigzag folding. Tray according to claim 5, wherein the side walls and the lower and upper frames are made of a plastic polypropylene type, the independent side walls (7, 8) being made of a cellular polypropylene, while the wall panel of base (4) and associated side walls (5, 6) is made of a bubble structure polypropylene. Tray according to one of claims 1 to 6, wherein a reinforcing plate (29) is provided between the lower frame (2) and the bottom wall (4).

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