Self-locking packaging

Abstract

The invention relates to packaging (1) made from a paper or cardboard blank, comprising a base (10) bordered by four side walls (20, 30, 40, 50), including two opposing first side walls and two opposing second side walls. According to the invention, each pair of adjacent first and second side walls is joined to each other by a gusset (60) having two panels folded against each other and against the first side wall. The second side wall and a first panel of the gusset adjoining the second side wall are bordered on the opposite side from the base by a return (70) that is folded over the first side wall. Figure for the abstract: Fig. 4

Description

Title of the invention: Self-locking packaging Technical field of the invention

[0001] The present invention relates generally to the field of packaging.

[0002] It relates more particularly to packaging made from a paper or cardboard blank and comprising a base bordered by four side walls, including two first opposing side walls and two second opposing side walls.

[0003] It also relates to a method of creating a volume of such packaging.

[0004] It applies more specifically to tray-type packaging. State of the art

[0005] In the field of cardboard packaging, it is known to offer trays, that is to say boxes open at the top.

[0006] These trays are generally made from a piece of cardboard cut into a cross shape and folded so that each arm of the cross forms one of the side walls of the tray. These side walls are generally edged with glue-coated tabs, which allow the side walls to be glued together.

[0007] Such trays have two major drawbacks.

[0008] The first drawback is the presence of numerous cut lines. Indeed, cut lines are provided on both sides of each side panel. However, when the tray contains a potentially moist item (such as fruit, for example), the moisture risks penetrating the thickness of the cardboard through these cut lines, thus degrading the mechanical properties of the tray.

[0009] Another drawback is the use of glue, which is expensive, environmentally unfriendly, and inconvenient to use when the packaging is manually assembled into a volume. Presentation of the invention

[0010] In order to remedy the aforementioned drawbacks of the prior art, the present invention proposes a packaging whose folds allow the packaging to be rolled into volume without difficulty and without requiring many cutting lines, and to lock the packaging in this configuration without glue.

[0011] More specifically, the invention proposes packaging as defined in the introduction in which: - each first and second adjacent side walls are attached to each other by means of a bellows comprising two panels folded against each other and against the first side wall, and - the second side wall and a first section of the bellows which adjoins the second side wall are bordered on the opposite side of the bottom by a return which is folded over part of the first side wall.

[0012] Thus, thanks to the invention, the bellows eliminate the need for cut lines between the side walls while allowing them to fold relative to each other. The returns are then designed to take advantage of this coupling between each pair of adjacent side walls in order to lock these side walls in position (after they have been folded relative to the bottom).

[0013] Other advantageous and non-limiting features of the packaging according to the invention, taken individually or in all technically possible combinations, are as follows: - each bellows is folded back on the inside of the first side wall; - each first side wall has a first fold line by which it attaches to the bottom and two second fold lines which together with the first fold line form an isosceles triangle; - each isosceles triangle has, opposite the base, a vertex that is truncated; - each isosceles triangle has, opposite the base, a vertex which is located on the edge of the first lateral wall; - each isosceles triangle has, opposite the base, a vertex which is located at a distance from the edge of the first lateral wall, in which case the first lateral wall has three other fold lines which meet at said vertex, two of which extend substantially parallel to the first fold line and a last one which extends in the continuation of a median of the isosceles triangle, to the edge of the first lateral wall, over a determined height; - each second side wall has a main fold line by which it is attached to the bottom and a secondary fold line which extends substantially parallel to said main fold line; - each return being attached to the second corresponding side wall by at least one third fold line, the distance between the secondary fold line and said at least one third fold line is substantially equal to said determined height; - the secondary folding line and the third folding line extend onto the first panels of each bellows; - the packaging being made of cardboard, the returns are attached to the second side walls each by two parallel folding lines spaced apart by a distance less than three times the thickness of the cardboard.

[0014] The invention also proposes a method for creating a volumetric form of packaging as described above, in which: - the two panels of each bellows are folded against each other and against the first side wall to which the bellows is attached, - the first side walls are folded so that the returns each extend in a plane, - the returns are folded back relative to the second side walls in opposite directions, - the second side walls are separated from each other (preferably to a configuration where the first side walls are flat).

[0015] Of course, the various features, variants, and embodiments of the invention can be combined with one another in various ways, provided they are not incompatible or mutually exclusive. Detailed description of the invention

[0016] The following description with regard to the attached drawings, given by way of non-limiting examples, will make it clear what the invention consists of and how it can be carried out.

[0017] On the attached drawings:

[0018] [Fig-1] is a schematic plan view of a pre-cut blank which, once placed in volume, will form a package conforming to the invention;

[0019] [Fig.2] is a schematic perspective view of the side of [Fig.1], during a first folding step;

[0020] [Fig.3] is a schematic perspective view of the side of [Fig.1], during a second folding stage;

[0021] [Fig.4] is a schematic perspective view of the resulting packaging;

[0022] [Fig.5] is a schematic perspective view of an alternative embodiment of the packaging conforming to the invention.

[0023] Figures 4 and 5 show two embodiments of a package 1, 2 in the form of a tray.

[0024] The term "tray" refers to a container used for packaging and transporting items, particularly food, typically fruits and vegetables. A tray is open at the top but may be fitted with a lid to maintain the freshness of the items and / or protect them.

[0025] In [Fig.1], a cardboard blank 1' is shown which, once folded (we speak of "building into volume"), allows us to obtain the packaging 1 illustrated in [Fig.4].

[0026] As a preliminary point, it should be noted that on this plan, solid lines represent cutting lines while dotted and mixed lines represent pre-folding lines, hereinafter referred to as "folding lines".

[0027] A cutting line is a line along which the material is cut through.

[0028] A fold line is an area of ​​least resistance that ensures the fold between two panels occurs at the desired position. It can be created in various ways. When the panels are made from a multi-layered cardboard sheet, it can be created by creasing, using a press, or by half-cutting. The creasing operation consists of pressing the multi-layered cardboard sheet along the desired line. The half-cutting operation consists of cutting only a portion of the cardboard sheets along this line.

[0029] The folding line can alternatively be made in other ways, typically by alternating creasing or half-cut lines with cutting lines.

[0030] Here, most of the folding lines will preferably be made by creasing. If these lines are made by half-cutting, the cut will then be located on the outer side of the packaging.

[0031] It will be noted that on [Fig.1], the folding lines shown in dotted lines are intended to be folded on one side of the blank 1' while the folding lines shown in dashed lines are intended to be folded on the opposite side.

[0032] In the following description, the terms "external" and "internal" will be used in relation to figures 4 and 5, the internal side of an element designating the side turned towards the center of the package while the external side will designate the opposite side.

[0033] As shown in [Fig. 4], the packaging 1 has a base 10 from the edge of which rise side walls 20, 30, 40, 50. There are four of these side walls. They are identical in opposite pairs. In the embodiment illustrated in Figures 1 to 4, two opposing side walls 20, 40 and two opposing side walls 30, 50 larger than the first two are distinguished.

[0034] To understand how this packaging 1 is formed, we can start by describing more precisely the blank 1' illustrated in [Fig.1].

[0035] This blank 1' preferably has two orthogonal axes of symmetry Al, A2, one cutting the first lateral walls 20, 40 in two and the other cutting the second lateral walls 30, 50 in two.

[0036] Due to these symmetries, to ensure the clarity of [Fig. 1], only some of the blank panels 1' and the fold lines will be referenced in this figure. Therefore, not all blank panels 1' and all fold lines will be described systematically, but sometimes only some of them, the others being considered identical by symmetry.

[0037] On [Fig.1], it can be seen that the blank 1' has a cross shape, with a rectangular central panel which is internally devoid of a fold line and which, once the packaging is in volume, will form the base 10.

[0038] The first side walls 20, 40 are attached to this base 10 by parallel folding lines L1. The second side walls 30, 50 are attached to this base 10 by folding lines L7 parallel and orthogonal to the folding lines LL

[0039] Here, the first and second side walls have fold lines internally (within their contour), but alternatively, the second side walls could be provided without them. This is notably the case in the variant illustrated in [Fig. 5], which will be described below.

[0040] According to the invention, there is no cut line between the different side walls 20, 30, 40, 50.

[0041] On the contrary, bellows 60 are provided at the junction between each pair of adjacent first lateral walls 20, 40 and second lateral walls 30, 50. Therefore, four bellows 60 are provided here.

[0042] Here, each bellows 60 comprises exactly two panels 61, 62 articulated to each other by a fold line L12 and articulated respectively to the first lateral wall 20, 40 and second lateral wall 30, 50 adjacent by two fold lines L13, L14. These three fold lines L12, L13, L14 are straight and inclined to each other.

[0043] The fold line L12 forms the bisector of the two other fold lines L13, L14. It is observed that the fold along this fold line L12 is carried out in a direction opposite to the fold carried out along the two other fold lines L13, L14.

[0044] These two other folding lines L13, L14 are inclined at an angle less than or equal to 90°. This angle depends on the desired inclination between the side walls 20, 30, 40, 50 and the bottom 10 of the packaging 1.

[0045] Here, this angle is strictly less than 90°. Thus, once the packaging 1 is in volume, its side walls flare out (they move away from each other from the bottom upwards).

[0046] Thanks to this acute angle, the packages 1 can therefore be stacked inside each other, which allows them to be stacked in volume and then stored in this configuration.

[0047] Of course, alternatively, this angle could be equal to 90° (in which case the packages would not be stackable).

[0048] The bellows 60 allow, once their two sides 61, 62 are folded against each other and against the first corresponding side wall 20, 40 (i.e. the one to which it is attached), the packaging 1 to be put into volume.

[0049] However, this simple folding does not allow the packaging 1 to be locked in this position. For this purpose, it is provided that the second side walls 30, 50 and the first panels 61 of the gussets 60 are edged, opposite the base 10, by a return 70.

[0050] In other words, each return 70 runs along the edge of one of the second side walls 30, 50 and the edges of the first two panels 61 which are attached to this second side wall. It is attached to these edges by the fold lines LU.

[0051] Each return 70 could be interrupted, for example at the center of the edge of the corresponding second side wall. However, it is uninterrupted over parts straddling the edge of the second side wall 30, 50 and the edges of the first panels 61.

[0052] Here, each return 70 is attached to the corresponding second side wall 30, 50 and to the corresponding first panels 61 by two parallel fold lines L11 spaced apart by a distance less than three times the thickness of the cardboard. These two fold lines L11 allow the cardboard to be easily folded 180° on either side of another panel of the packaging 1.

[0053] These L11 folding lines, unlike the others, are formed by alternating creasing lines and through-cutting lines. The advantage is that the edges of the cutting lines, once the 90° fold is made, lock together (the edge of one edge resting against the side of another edge), and allow the folds 70 to be held in this folded position.

[0054] It should be noted that the fold lines L11 are not straight here, but each has three straight sections L11A, L11B, L11C inclined relative to each other. Thus, a central section L1 IB is provided at the junction between the second side wall 30, 50 and the return 70, and two end sections L1 IA, L1 IC are provided between the first faces 61 of the bellows 60 and the return 70. These two end sections L1 IA, LUC are inclined inwards relative to the central section L1 IB, so as to form an obtuse angle open towards the center of the blank 1'. This obtuse angle is a function of the angle provided between the fold lines L13, L14.

[0055] When the packaging 1 is folded into its volume, the folding of each return 70 is such that: - a central part 70B of each return 70 is folded at 180° against the corresponding second lateral wall, and that - end parts 70A, 70C of each return 70 are found folded against the first side walls 20, 40, over the second sides 62 of the bellows 60 (that is to say in such a way that each second side 62 is sandwiched between a first side 61 and a first side wall 20, 40).

[0056] The returns 70 being folded at the junction of each end part 70A, 70C with the central part 70A, they allow the package 1 to be locked in this configuration.

[0057] To allow the folding of these returns 70 in relation to the second side walls 30, 50 and the first sides 61 of the bellows 60, it is necessary that the latter not be folded at these junctions at the time of this folding (but that they extend on the contrary each in a plane).

[0058] This is why each first side wall has fold lines internally.

[0059] In practice, each first side wall 20, 40 has internally at least two fold lines L2, L3 which together with the fold line L1 form an isosceles triangle (the fold line L1 forming the base of this triangle and the two fold lines L2, L3 being of the same length).

[0060] As shown in [Fig.5], if the first lateral walls 20, 40 were wider than the second lateral walls 30, 50, the isosceles triangles would be truncated on the side of their vertices.

[0061] However, here, as shown in [Fig.1], these isosceles triangles are complete.

[0062] The two fold lines L2, L3 allow each first side wall 20, 40 to be folded into three parts so that the returns 70 can extend each in a plane, supporting each other (see [Fig.3]).

[0063] One might expect that the vertices of these triangles would be located on the free edges of the first lateral walls 20, 40 (those located opposite the bottom 10). However, for a reason that will become clear later, they are preferably located at a distance from these free edges.

[0064] To allow the first side walls 20, 40 to be folded into three parts, it is then provided that the vertex of each isosceles triangle extends to the free edge of the corresponding first side wall 20, 40 by a folding line L6 which extends along the axis of the median of the triangle.

[0065] In this way, as shown in [Fig.3], it is possible to fold each first side wall 20, 40 into three parts.

[0066] However, in order for the two returns 70 to flatten well against each other and for it to then be possible to fold them 180° in opposite directions around the folding lines L11, it is preferable to provide inside each of the second side walls 30, 50 a folding line L8 parallel to the folding lines L7.

[0067] Each of these folding lines L8 extends onto the first panels 61 of the corresponding bellows 60. In the same way that the folding line L11 has three sections L1A, L11B, L11C inclined relative to each other, the two folding lines L8 have three sections L8A, L8B, L8C inclined in the same way relative to each other.

[0068] For the same purpose, the first side walls 20, 40 are provided to have fold lines L4, L5. In practice, it is then provided in each first side wall 20, 40 two folding lines L4, L5 which extend from the apex of the isosceles triangle, substantially parallel to the folding line L1 (an angle is provided here, which angle is a function of the angle between the folding lines L13, L14).

[0069] These folding lines L4, L5 extend into the second panels 62 of the bellows 60 (along the same axis).

[0070] The fold lines L4, L5 and L8 have coincident ends, located on the edge of the blank 1'. To achieve this, the blank 1', which is generally rectangular in shape, has a notch at its four corners with two straight edges that meet at the point of junction between the fold lines L4, L5 and L8. Thus, the blank 1' more precisely has the shape of a cross.

[0071] At this stage, it can be noted that the only cutting lines planned are those located on the edge of the blank 1'. No cutting lines are planned inside the blank 1' (except possibly those in the LU fold lines).

[0072] It can also be seen in [Fig. 1] that the corners of the flan 1' are rounded. Of course, alternatively, they could not be.

[0073] Here, the outer edge of the blank 1' also has notches 90 facilitating the cutting of several identical blanks 1' from the same cardboard panel, in adjacent positions. Here, a notch 90 is thus provided on this outer edge at each of the fold lines L13, L14. These notches 90 are therefore located on either side of the straight cutting lines that join two identical blanks 1' in the cardboard panel.

[0074] At this stage, we can describe how to proceed to fold the blank 1' illustrated in [Fig.1] so as to obtain the packaging 1 illustrated in [Fig.4].

[0075] This folding operation can be carried out manually, thanks to the folding lines provided in the blank 1'.

[0076] In a first step, the operator folds the two second side walls 30, 50 relative to the bottom 10, around the two folding lines L7.

[0077] In a second step illustrated in [Fig. 2], the operator folds the first two side walls 20, 40 relative to the bottom 10, around the two fold lines L1. To do this, he also folds the two panels 61, 62 of each bellows 60 against each other, at 180° around the fold lines L12, and he also folds these two panels relative to the side walls 20, 30, 40, 50, at 180° around the fold lines L14 and at approximately 90° around the fold lines L13. Here, the bellows 60 are then provided to rest against the inner faces of the first side walls 20, 40.

[0078] This folding is facilitated by the fact that the folding line L13 which attaches the bellows 60 to the second side wall 30, 50 extends into the return 70 (along the same axis).

[0079] Once this step has been carried out, the packaging 1 has a parallelepiped shape open at the top, and the returns 70 extend over the four side walls 20, 30, 40, 50.

[0080] To fold these returns 70 back to 180°, the operator then flattens the upper part of the packaging 1 so that these two returns 70 rest against each other, as shown in [Fig.3].

[0081] For this purpose, the first side walls 20, 40 are folded in three around the folding lines L2, L3. In addition, the side walls and bellows are folded slightly around the folding lines L4, L5, L8 so that the two returns 70 can lean against each other by their inner faces, in the same plane.

[0082] At this stage, the lower parts of the second lateral walls 20, 30, 40, 50 (under the folding lines L8) form with the bottom 10 an isosceles triangular prism, while their upper parts extend along this plane.

[0083] Then, the operator folds the returns 70 outwards at 180°, against the second side walls 30, 50 and against the folded upper parts of the first side walls 20, 40.

[0084] Then, by separating the second side walls 30, 50, the operator obtains the package 1 illustrated in [Fig.4].

[0085] At this stage, the packaging 1 can then be used, for example by being filled with fruit or vegetables.

[0086] It should be noted that the packaging, once folded, can be flattened (in the configuration illustrated in [Fig. 1]). Indeed, the absence of glue allows it to be unfolded and then refolded several times without difficulty and without damaging the cardboard used. Thus, the packaging is easily reusable.

[0087] In the variant illustrated in [Fig. 5], where the first side walls 20, 40 are wider than the second side walls 30, 50, so that the isosceles triangles are truncated at their vertices, it is not necessary to provide fold lines L4, L5, L8 in the side walls. It is understood that when the first side walls are folded around the fold lines L2, L3, the returns 70 will each be able to extend in a plane (the two planes being inclined relative to each other), which will allow these returns 70 to be folded outwards at 180° without difficulty.

[0088] According to another variant, the isosceles triangles formed by the fold lines in the first side walls could be complete and their vertices located at the level of the upper edge of the first side walls. In this variant, the fold lines L4, L5, L8 would not be necessary either.

[0089] The present invention is in no way limited to the embodiments described and represented, but a person skilled in the art will be able to make any variation in accordance with the invention.

[0090] Typically, one could plan to fold the bellows on the outside of the first side walls, in which case the returns should be folded inwards.

[0091] However, this variant is not preferred for the following reason. When the flaps 70 are folded outwards and the final shape of the package is given (with the first side walls returning to a flat shape), the flaps are folded at the corners of the package, which causes tensile forces in these flaps on either side of each corner. These forces contribute to locking the package in this final shape (which is not the case in the variant considered above).

[0092] Furthermore, if the described and illustrated packaging is in the shape of a tray, it could have a different shape. Thus, the packaging could consist of a body closed by a lid, in which case the body and / or the lid could have a shape similar to that illustrated in the figures.

[0093] Typically, in the embodiment illustrated in the figures and described above, the two fold lines L13, L14 are inclined at an angle of less than 90° (thanks to this acute angle, the packages 1 can therefore be stacked one inside the other). Alternatively, however, this angle could be equal to 90°, in which case the folded blank could serve as a lid.

[0094] According to another embodiment of the invention, the flan could be made in a sheet of paper, provided that the latter is sufficiently rigid considering its function and size. This would typically be feasible if the tray were intended to hold a small number of berries (about twenty raspberries, a few blueberries, etc.).

Claims

Demands

1. Packaging (1) made from a blank (1') of paper or cardboard, comprising a base (10) bordered by four side walls (20, 30, 40, 50) of which two first side walls (20, 40) are opposite and two second side walls (30, 50) are opposite, characterized in that each pair of first and second adjacent side walls joined to each other by a gusset (60) comprising two panels (61, 62) folded against each other and against the first side wall (20, 40), the second side wall (30, 50) and a first panel (61) of the gusset (60) which adjoins the second side wall (30, 50) are bordered on the opposite side of the base (10) by a return (70) which is folded over a part of the first side wall (20, 40).

2. Packaging (1) according to claim 1, in which each gusset (60) is folded back from the inside of the first side wall (20, 40).

3. Packaging (1) according to claim 1 or 2, wherein each first side wall (20, 40) has a first fold line (L1) by which it is attached to the bottom (10) and two second fold lines (L2, L3) which together with the first fold line (L1) form an isosceles triangle.

4. Packaging (1) according to claim 3, wherein each isosceles triangle has, opposite the base (10), a vertex which is truncated or which is located on the edge of the first side wall (20, 40).

5. Packaging (1) according to claim 3, wherein each isosceles triangle has, opposite the base (10), a vertex which is located at a distance from the edge of the first side wall (20, 40) and wherein the first side wall (20, 40) has three other fold lines (L4, L5, L6) which meet at said vertex, two of which extend substantially parallel to the first fold line (L1) and a last one which extends in the continuation of a median of the isosceles triangle, to the edge of the first side wall (20, 40), over a determined height.

6. Packaging (1) according to any one of claims 1 to 5, wherein each second side wall (30, 50) has a main fold line (L7) by which it is attached to the bottom (10) and a secondary fold line (L8) which extends substantially parallel to said main fold line (L7).

7. Packaging (1) according to claims 5 and 6, wherein each return (70) is attached to the corresponding second side wall (30, 50) by at least one third fold line (L11), the distance between the secondary fold line (L8) and said at least one third fold line (LU) is substantially equal to said determined height.

8. Packaging (1) according to claim 7, wherein the secondary fold line (L8) and the third fold line (LU) extend over the first panels (61) of each gusset (60).

9. Packaging (1) according to any one of claims 1 to 8, made from a cardboard blank (1'), in which the returns (70) are attached to the second side walls (30, 50) each by two parallel fold lines (LU) separated from each other by a distance less than three times the thickness of the cardboard.

10. A method for creating a volume of a package (1) according to any one of claims 1 to 9, wherein: - the two sides (61, 62) of each gusset (60) are folded against each other and against the first side wall (20, 40) to which the gusset (60) is attached, - the first side walls (20, 40) are folded so that the returns (70) each extend in a plane, - the returns (70) are folded with respect to the second side walls (30, 50) in opposite directions, - the second side walls (30, 50) are separated from each other.