container

Abstract

To provide a container that can be assembled with a simple configuration. [Solution] The container 1 comprises a bottom wall 10, a pair of first side walls 20, a second side wall 30, an adhesive piece 40, and a locking piece 60. The container 1 can establish a folded state in which the first side wall 20 is folded along the first bottom edge 11 so that the first side wall 20 overlaps the bottom wall 10, the second side wall 20 is folded along the fold line 36 so that the second region 38 overlaps the first region 37, and the locking piece 60 is positioned between the bottom wall 10 and the first side wall 20, and an assembled state in which the first region 37 of the second side wall 30 is folded along the lower edge 31 from the folded state so that the second side wall 30 rises from the second bottom edge 12 and the pair of first side walls 20 are folded back relative to the bottom wall 10 so that they rise from the first bottom edge 11, and the locking piece 60 locks to the first side wall 20.

Description

Technical Field

[0001] The present invention relates to a container.

Background Art

[0002] For example, Patent Document 1 discloses a container having a bottom portion and a plurality of side wall portions rising from the bottom portion. This container can be assembled from a folded state to an assembled state. In the assembled state of the container, a mechanism for maintaining the posture of the side wall portion with respect to the bottom portion is incorporated.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] The mechanism has a relatively large elastic body member with respect to the side wall portion. In maintaining the posture of the side wall portion, this relatively large elastic body member must move from the inner surface of one side wall portion to the inner surface of the other side wall portion. This necessity for such movement complicates the structure of this container and thus increases the manufacturing cost of the container.

[0005] The present invention has been made in view of the above problems, and an object thereof is to provide a container that can establish an assembled state with a simple structure.

Means for Solving the Problems

[0006] To achieve the above objective, the container according to the present invention comprises a bottom wall defining a pair of opposing first bottom edges and a second bottom edge intersecting the first bottom edges; a pair of first side walls connected to the first bottom edges of the bottom wall at their lower edges and defining a first side edge intersecting the lower edges; a second side wall connected to the second bottom edge of the bottom wall at their lower edges and defining a second side edge overlapping the first side edge of the first side wall; a pair of adhesive pieces protruding from each of the second side edges and attached to the inner surface of the first side wall, respectively; and a locking piece protruding from each of the second side edges, wherein the second side wall has folds that extend from two endpoints of the lower edge toward the upper edge of the second side wall, so as they move toward each other, the first side on the lower edge side A container divided into a first region and two second regions on the upper edge side, wherein the container can establish a folded state in which the first side walls are each folded along the first bottom edge so that the first side walls overlap the bottom wall, the second side walls are folded along the fold so that the second region overlaps the first region, and the locking piece is positioned between the bottom wall and the first side wall, and an assembled state in which the first region of the second side wall is folded along the lower edge from the folded state so that the second side wall rises from the second bottom edge and a pair of the first side walls are folded back relative to the bottom wall so that they rise from the first bottom edge, and the locking piece locks to the first side wall.

[0007] In establishing the aforementioned assembled state, the locking piece protrudes from the outer surface of the adhesive piece when the first region of the second side wall is bent along the lower edge such that the inner surface of the first region approaches the inner surface of the bottom wall.

[0008] In establishing the assembly state, after the locking piece protrudes from the outer surface of the adhesive piece, the inner surface of the first region is returned in a direction away from the inner surface of the bottom wall based on the restoring force generated by the fold, and the locking piece locks to the first side edge or near the first side edge.

[0009] The first side wall has a second locking piece that protrudes from the first side edge, and in the folded state, the locking piece is positioned between the bottom wall and the second locking piece, and in the assembled state, the tip of the locking piece locks to the inner surface of the second locking piece.

[0010] The second locking piece extends along the same plane as the first side wall.

[0011] In establishing the aforementioned assembled state, the locking piece protrudes from the outer surface of the adhesive piece when the first region of the second side wall is bent along the lower edge such that the inner surface of the first region approaches the inner surface of the bottom wall.

[0012] In establishing the assembled state, after the locking piece protrudes from the outer surface of the adhesive piece, the inner surface of the first region is returned in a direction away from the inner surface of the bottom wall based on the restoring force generated by the fold, and the tip of the locking piece locks into the inner surface of the second locking piece. [Effects of the Invention]

[0013] According to the present invention, it is possible to provide a container that can be assembled with a simple configuration. [Brief explanation of the drawing]

[0014] [Figure 1] This is a schematic perspective view showing the structure of the assembled container 1 according to the first embodiment of the present invention. [Figure 2] This is a schematic perspective view showing a part of the structure of the assembled container 1 according to the first embodiment of the present invention. [Figure 3] This is a schematic side view showing a part of the structure of the assembled container 1 according to the first embodiment of the present invention. [Figure 4] This is a schematic side view showing a part of the structure of the assembled container 1 according to the first embodiment of the present invention. [Figure 5] This is a schematic plan view showing a part of the structure of the assembled container 1 according to the first embodiment of the present invention. [Figure 6]It is a plan view showing the developed body 2 used for assembling the container 1 according to the first embodiment of the present invention. [Figure 7] It is a plan view showing the folded body 3 used for assembling the container 1 according to the first embodiment of the present invention. [Figure 8] It is a partially enlarged plan view with a part of the folded body 3 enlarged. [Figure 9] It is a perspective view during the deformation from the folded state to the assembled state for explaining the method of assembling the container 1 according to the first embodiment of the present invention. [Figure 10] It is a perspective view during the deformation from the folded state to the assembled state for explaining the method of assembling the container 1 according to the first embodiment of the present invention. [Figure 11] It is a partially enlarged plan view during the deformation from the folded state to the assembled state for explaining the method of assembling the container 1 according to the first embodiment of the present invention. [Figure 12] It is a plan view schematically showing the configuration of the developed body 2A used for assembling the container 1A according to the second embodiment of the present invention. [Figure 13] It is a perspective view schematically showing the structure of the assembled container 1B according to the third embodiment of the present invention. [Figure 14] It is a plan view schematically showing the configuration of the developed body 2B used for assembling the container 1B according to the third embodiment of the present invention.

Embodiments for Carrying Out the Invention

[0015] Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a perspective view schematically showing the structure of the assembled container 1 according to the first embodiment of the present invention. The container 1 is formed from a single flat plate including, for example, cardboard, corrugated board, or other paper or resin sheets. Specifically, the container 1 is formed in an assembled state by bending a single flat plate along predetermined fold lines. The thickness of the flat plate constituting the container 1 is set to about 0.15 mm to 2.5 mm, for example. The container 1 is, as an example, a tray used for storing foods such as confectionery.

[0016] In container 1, there are two mutually orthogonal directions, D1 and D2, and a third direction D3 that is orthogonal to both D1 and D2. For example, the first direction D1 defines the length direction of container 1, the second direction D2 defines the width direction of container 1, and the third direction D3 defines the depth direction of container 1. In this example, the depth of container 1 is defined to be relatively small compared to the length and width of container 1. That is, container 1 has a relatively shallow depth.

[0017] Container 1 has a bottom wall 10 that extends along a plane. The bottom wall 10 defines first bottom edges 11, 11 on the longer sides facing each other in a first direction D1, and second bottom edges 12, 12 on the shorter sides facing each other in a second direction D2. The first bottom edges 11, 11 are defined parallel to each other. The second bottom edges 12, 12 are defined parallel to each other. The first bottom edges 11, 11 and the second bottom edges 12, 12 intersect each other and, in this example, are perpendicular to each other. The bottom wall 10 defines an inner surface 13 enclosed by the first bottom edges 11, 11 and the second bottom edges 12, 12. The inner surface 13 is formed in a rectangular shape in plan view.

[0018] The container 1 comprises a pair of first side walls 20, 20 rising in a third direction D3 from the first bottom edges 11, 11 of the bottom wall 10, and a pair of second side walls 30, 30 rising in a third direction D3 from the second bottom edges 12, 12 of the bottom wall 10. In this example, both the first side walls 20, 20 and the second side walls 30, 30 rise at approximately 90 degrees, or nearly right angles, to the bottom wall 10. As a result, the first side walls 20, 20 and the second side walls 30, 30 are defined at right angles to each other.

[0019] Each first side wall 20 has a lower edge 21, an upper edge 22 opposite to the lower edge 21, and a pair of first side edges 23, 23 connecting the lower edge 21 and the upper edge 22 to each other. In this example, the lower edge 21 and the upper edge 22 are defined parallel to each other. Similarly, the pair of first side edges 23, 23 are defined parallel to each other. Each first side wall 20 is connected to the first bottom edge 11 of the bottom wall 10 at its lower edge 21. In other words, the lower edge 21 of each first side wall 20 coincides with the first bottom edge 11 of the bottom wall 10.

[0020] Each second side wall 30 has a lower edge 31, an upper edge 32 opposite to the lower edge 31, and a pair of second side edges 33, 33 that connect the lower edge 31 and the upper edge 32 to each other. In this example, the lower edge 31 and the upper edge 32 are defined parallel to each other. Similarly, the pair of second side edges 33, 33 are defined parallel to each other. Each second side wall 30 is connected to the second bottom edge 12 of the bottom wall 10 at its lower edge 31. In other words, the lower edge 31 of the second side wall 30 coincides with the second bottom edge 12 of the bottom wall 10. Each second side edge 33, 33 of the second side wall 30 overlaps with the first side edges 23, 23 of one or the other side of the pair of first side walls 20, 20.

[0021] Each first side wall 20 has an inner surface 24 and an outer surface 25 facing away from the inner surface 24. In this example, both the inner surface 24 and the outer surface 25 are formed in a rectangular shape. The inner surface 24 and the outer surface 25 are defined to be parallel to each other. Each second side wall 30 has an inner surface 34 and an outer surface 35 facing away from the inner surface 34. The inner surface 34 and the outer surface 35 are defined to be parallel to each other. Both the inner surface 34 and the outer surface 35 are formed in a rectangular shape.

[0022] Each second side wall 30 has a pair of folds 36, 36 that extend from two endpoints 31a, 31a of the lower edge 31 toward the upper edge 32, approaching each other. The folds 36, 36 divide each second side wall 30 into a single first region 37 on the lower edge 31 side and a pair of second regions 38, 38 on the upper edge 32 side. In the assembled container 1, each second side wall 30 is not folded at the folds 36, 36. That is, the inner surface 34 and outer surface 35 of each second side wall 30 are defined by a single plane. However, each second side wall 30 may have slight folds at the folds 36, 36.

[0023] In this example, the first region 37 is formed in a trapezoidal shape when viewed from the front. The second region 38 is formed in a triangular shape when viewed from the front. The lower edge 31 of the second side wall 30 is defined by the lower edge of the first region 37. That is, the lower edge 31 corresponds to the longer side of the trapezoid that forms the first region 37. The upper edge 32 of the second side wall 30 is defined by the upper edges of the first region 37 and the pair of second regions 38. That is, the upper edge 32 corresponds to the shorter side of the trapezoid that forms the first region 37 and one side of the triangle that forms each of the second regions 38. The second side edge 33 is defined by the side edge of each of the second regions 38.

[0024] The container 1 includes a pair of adhesive pieces 40, 40 that protrude from the second side edges 33, 33 of each second side wall 30. The adhesive pieces 40 are adhesive tabs. In this example, the adhesive pieces 40 are formed in a trapezoidal shape when viewed from the front. The adhesive piece 40 has an inner surface 41 and an outer surface 42 that face away from each other. The inner surface 41 and the outer surface 42 are defined to be parallel to each other. The adhesive piece 40 is attached to the inner surface 24 of the first side wall 20 by its outer surface 42. When attaching, an adhesive layer (not shown) is formed between the outer surface 42 of the adhesive piece 40 and the inner surface 24 of the first side wall 20 by applying an adhesive or the like. By attaching the adhesive piece 40 to the inner surface 24 of the first side wall 20 in this way, a pair of first side walls 20, 20 and a pair of second side walls 30, 30 are connected to each other. The adhesive layer may be formed by, for example, adhesive tape.

[0025] Figure 2 is a schematic perspective view showing a part of the structure of the assembled container 1 according to the first embodiment of the present invention. Figures 3 and 4 are schematic side views showing a part of the structure of the assembled container 1. Figure 5 is a schematic plan view showing a part of the structure of the assembled container 1. Figures 2 to 5 are partially enlarged views showing the corner portion 50 of the container 1 where one first side wall 20 and one second side wall 30 intersect. Figure 3 is a view of the first side wall 20 from one side in the second direction D2, Figure 4 is a view of the second side wall 30 from one side in the first direction D1, and Figure 5 is a view of the corner portion 50 from above in the third direction D3.

[0026] Referring to Figures 1 to 5, the container 1 is provided with first locking pieces 60 that protrude from a pair of second side edges 33, 33 of each second side wall 30. In this example, the first locking pieces 60 are formed over a portion of the entire length of the second side edge 33 in the third direction D3. In the assembled container 1, the first locking pieces 60 protrude generally along the second direction D2. In this example, the first locking pieces 60 are formed offset in the third direction D3 towards the upper edge 32 rather than at an intermediate position between the lower edge 31 and the upper edge 32. The thickness of the first locking pieces 60 is set to be the same as the thickness of the second side wall 30.

[0027] In particular as shown in Figure 5, the first locking piece 60 has an inner surface 61 and an outer surface 62 facing away from each other. The inner surface 61 is continuous with the inner surface 34 of the second side wall 30. The outer surface 62 is continuous with the outer surface 35 of the second side wall 30. In this example, in particular as shown in Figures 2 and 4, the first locking piece 60 is formed from a first portion 63 that increases the amount of protrusion from the second side edge 33 from its lower end to its upper end, and a second portion 64 that defines a constant amount of protrusion in the third direction D3. The amount of protrusion of the second portion 64 is set, for example, to the maximum value of the amount of protrusion of the first portion 63. The first portion 63 and the second portion 64 are continuous in the third direction D3.

[0028] The container 1 includes second locking pieces 70 that project from a pair of first side edges 23, 23 of each first side wall 20. In this example, the second locking pieces 70 are formed over a portion of the entire length of the first side edge 23 in the third direction D3. In the assembled container 1, the second locking pieces 70 project along the first direction D1. In this example, the second locking pieces 70 are formed offset towards the upper edge 22 rather than an intermediate position between the lower edge 21 and the upper edge 22 in the third direction D3. Also, in the third direction D3, the second locking pieces 70 are positioned in a position corresponding to the first locking pieces 60. The thickness of the second locking pieces 70 is set to be the same as the thickness of the first side wall 20.

[0029] In particular, as shown in Figure 5, the second locking piece 70 has an inner surface 71 and an outer surface 72 facing away from each other. The inner surface 71 is continuous with the inner surface 24 of the first side wall 20. The outer surface 72 is continuous with the outer surface 25 of the first side wall 20. That is, the second locking piece 70 extends along the same plane as the first side wall 20. In this example, the second locking piece 70 is formed from a first portion 73 that increases the amount of protrusion from the first side edge 23 from its lower end to its upper end, and a second portion 74 that defines a constant amount of protrusion in the first direction D1. The amount of protrusion of the second portion 74 is set, for example, to the maximum value of the amount of protrusion of the first portion 73. The first portion 73 and the second portion 74 are continuous in the third direction D3.

[0030] In particular, as shown in Figures 2, 4, and 5, in the assembled container 1, the second locking piece 70 protrudes from the first side edge 23 of the first side wall 20 in the first direction D1. On the other hand, the first locking piece 60 protrudes from the second side edge 33 of the second side wall 30 in the second direction D2. Thus, the tip of the first locking piece 60 in the second direction D2 abuts against the inner surface 71 of the second locking piece 70. As a result, a portion of the second side wall 30 including the first locking piece 60 deforms outward from the container 1 in the first direction D1, while a portion of the first side wall 20 including the second locking piece 70 deforms outward from the container 1 in the second direction D2.

[0031] With this configuration, at each corner 50, the tip of the first locking piece 60 locks onto the inner surface 71 of the second locking piece 70. Specifically, at the corner 50 where both second side edges 33, 33 of each second side wall 30 are located, a pair of first locking pieces 60, 60 of the second side wall 30 lock onto the inner surface 71 of a pair of second locking pieces 70, 70 of the first side wall 20. Each first side wall 20 is supported by a pair of second side walls 30, 30. As a result, in the container 1, the posture in which a pair of first side walls 20, 20 and a pair of second side walls 30, 30 rise from the bottom wall 10, i.e., the assembled state, is maintained.

[0032] Figure 6 is a plan view showing an unfolded body 2 used in the assembly of a container 1 according to the first embodiment of the present invention. In Figure 6, components similar to those in the container 1 are given the same reference numerals. The unfolded body 2 is a blank sheet punched out from a single flat sheet of cardboard, corrugated cardboard, or other paper or resin sheet. In the example in Figure 6, the unfolded body 2 is shown in a plan view from the inner surface 13 side of the bottom wall 10. In the unfolded body 2, the bottom wall 10, the first side walls 20, 20, the second side walls 30, 30, the adhesive piece 40, the first locking piece 60, and the second locking piece 70 all extend along the same plane.

[0033] A first fold F1 is formed between the bottom wall 10 and each first side wall 20, and a second fold F2 is formed between the bottom wall 10 and each second side wall 30. The first fold F1 corresponds to the first bottom edge 11 and the lower edge 21. The second fold F2 corresponds to the second bottom edge 12 and the lower edge 31. Similarly, a third fold F3 is formed between the second side wall 30 and the adhesive piece 40. The third fold F3 corresponds to the second side edge 33. Fourth folds F4, F4 are formed on each second side wall 30, extending from the endpoints 31a, 31a of the lower edge 31 toward the upper edge 32, moving toward each other. The fourth fold F4 corresponds to fold 36.

[0034] The first locking piece 60 is formed by a cut C formed within the adhesive piece 40 along the second fold F2. That is, the first locking piece 60 occupies a portion of the adhesive piece 40. Alternatively, half-cutting, where a cutting blade is made to a depth of about half the thickness of the unfolded body 2 along the first fold F1, second fold F2, third fold F3, and fourth fold F4, or lead creasing, where creases and blades are alternately made, may be performed. Half-cutting or lead creasing makes it easier to fold along the first fold F1, second fold F2, third fold F3, and fourth fold F4.

[0035] Figure 7 is a plan view showing a folding body 3 used in the assembly of a container 1 according to the first embodiment of the present invention. In Figure 7, components similar to those in the container 1 are given the same reference numerals. The folding body 3 is formed from an unfolded body 2. In formation, first, in the unfolded body 2 which is in a flat state, each second side wall 30 is folded along a pair of fourth folds F4, F4. Specifically, each second region 38 and adhesive piece 40 is folded along the fourth fold F4 relative to the first region 37, and the second region 38 is superimposed on the inner surface 34 of the first region 37 with its inner surface 34. The adhesive piece 40 is superimposed on the inner surface 13 of the bottom wall 10 with its inner surface 41. An adhesive layer (not shown) is formed on the outer surface 42 of the adhesive piece 40 by applying adhesive. Note that since the first locking piece 60 needs not to be attached to the first side wall, no adhesive layer is formed on the outer surface 62 of the first locking piece 60.

[0036] Subsequently, each first side wall 20 is folded along the first fold F1. Specifically, the first side wall 20 is folded along the first fold F1 so that its inner surface 24 overlaps the inner surface 13 of the bottom wall 10. At this time, each adhesive piece 40 is sandwiched between the inner surface 13 of the bottom wall 10 and the inner surface 24 of the first side wall 20. As a result, both ends of each first side wall 20 in the first direction D1 overlap the outer surface 42 of the adhesive piece 40. The outer surface 42 of the adhesive piece 40 is then attached to the inner surface 24 of the first side wall 20 by the adhesive layer. In this way, a folded body 3, or a folded container 1, is formed from the flat unfolded body 2.

[0037] Figure 8 is a partially enlarged plan view of a portion of the folding body 3. Referring together to Figures 7 and 8, the folding body 3 is formed into a flat plate state when the second regions 38 of the first side wall 20 and the second side wall 30 are folded at the first fold F1 and the fourth fold F4, respectively. Each second locking piece 70 extends along the outer surface 35 of the second region 38 in one direction of the first direction D1. On the other hand, the first locking piece 60 protruding from the second side edge 33 of the second side wall 30 extends in the other direction of the first direction D1. The first locking piece 60 is positioned between the inner surface 13 of the bottom wall 10 and the inner surface 24 of the first side wall 20. In this example, as is clear from Figure 8, the first locking piece 60 and the second locking piece 70 partially overlap in plan view.

[0038] Next, the method for assembling the container 1 from the folded body 3 will be described below. Figures 9 and 10 are perspective views of the container 1 in the process of transforming from a folded state to an assembled state, illustrating the method for assembling the container 1 according to the first embodiment of the present invention. Figure 11 is a partially enlarged plan view of a part of the form in the process of transforming from a folded state to an assembled state, illustrating the method for assembling the container 1 according to the first embodiment of the present invention. First, in the folded body 3 shown in Figure 7, the first regions 37 of each of the pair of second side walls 30, 30 are folded along the second fold F2 from the folded state. Specifically, as shown in Figure 9, by folding the pair of second side walls 30, 30 along the second fold F2, the pair of second side walls 30, 30 are lifted in the direction of arrow A1 from the bottom wall 10, i.e., the plane on which the folded body 3 extends.

[0039] The adhesive piece 40, which is continuous with the second region 38 of the second side wall 30, is attached to the inner surface 24 of the first side wall 20 with its outer surface 42. Therefore, as the second side wall 30 is folded along the second fold F2, a pair of second regions 38, 38 open up relative to the first region 37 along the fourth folds F4, F4. At the same time, the first side wall 20, which is attached to the outer surface 42 of the adhesive piece 40 continuous with each second region 38, opens up relative to the bottom wall 10 in the direction of arrow A2 along the first fold F1. At this time, the first locking piece 60 protrudes from the outer surface 42 of the adhesive piece 40. Meanwhile, at the same time, the second region 38 closes relative to the first side wall 20 along the third fold F3. As the second side wall 30 rises from the bottom wall 10 at the second fold F2, the first side wall 20 is folded back at the first fold F1 and rises from the bottom wall 10.

[0040] Subsequently, when the first region 37 becomes upright from the bottom wall 10, the fold at the fourth fold F4 in the second side wall 30 is almost completely eliminated, and the second side wall 30 becomes upright from the bottom wall 10. That is, the first region 37 and the pair of second regions 38, 38 spread out along almost the same plane. At the same time, the first side wall 20 also becomes upright from the bottom wall 10. The angle at which the inner surface 61 of the first locking piece 60 and the inner surface 71 of the second locking piece 70 intersect is approximately 90 degrees. From this state, as shown in Figures 10 and 11, when the pair of first regions 37, 37 are further folded in the direction of arrow A3 so that they move closer to each other, the second side walls 30, 30 are positioned inside the second folds F2, F2 in the first direction D1. The inner surface 34 of each second side wall 30 moves closer to face the inner surface 13 of the bottom wall 10. On the second side wall 30, a pair of second regions 38, 38 are folded along the fourth fold F4 in the opposite direction to the folding direction in the folded body 3 (i.e., from the inner surface 34 side, from a valley fold to a mountain fold) relative to the first region 37.

[0041] As the folding direction of the second region 38 along the fourth fold F4 reverses from a valley fold to a mountain fold, the tip of the first locking piece 60 of each second side wall 30 slides from the inner surface 24 of the first side wall 20 to the inner surface 71 of the second locking piece 70. At this time, the angle at which the inner surface 61 of the first locking piece 60 and the inner surface 71 of the second locking piece 70 intersect decreases from the aforementioned 90 degrees. Finally, the inner surface 34 of the second side wall 30 faces the inner surface 13 of the bottom wall 10 at an angle of, for example, 30 to 60 degrees. Subsequently, as the first regions 37, 37 are folded back along the second fold F2 in directions away from each other, the first side wall 20 and the second side wall 30 become almost upright from the bottom wall 10. At this time, as shown in Figure 5, the second side wall 30 and the first side wall 20 deform so that the inner surface 61 of the first locking piece 60 and the inner surface 71 of the second locking piece 70 partially face each other. In this way, the tip of the first locking piece 60 locks onto the inner surface 71 of the second locking piece 70. The assembled state of the container 1 is established.

[0042] In the container 1 described above, a pair of second regions 38, 38 are folded opposite the first region 37 at each second side wall 30 of the folded body 3. That is, with respect to the inner surface 34 of the second side wall 30, the pair of second regions 38, 38 are valley-folded relative to the first region 37 along the fourth fold F4. This valley fold creates a crease at the fourth fold F4. On the other hand, in establishing the assembled state of the container 1, the pair of second regions 38, 38 are reversed from a valley fold to a mountain fold relative to the first region 37 along the fourth fold F4. In the assembled state, the second side wall 30 stands upright from the bottom wall 10, that is, the first region 37 and the second regions 38, 38 extend along approximately the same plane. As shown in Figure 5, the second side wall 30 and the first side wall 20 are maintained in a deformed state such that the inner surface 61 of the first locking piece 60 and the inner surface 71 of the second locking piece 70 partially face each other.

[0043] At this time, based on the crease formed during the valley fold at the fourth fold F4, a restoring force is generated at the fourth fold F4 that causes the second regions 38, 38 to return to their valley fold state relative to the first region 37. This restoring force attempts to move the pair of first regions 37, 37 away from each other. That is, the inner surface 34 of the first region 37 is returned to a position away from the inner surface 13 of the bottom wall 10. Simultaneously, the restoring force attempts to move the two pairs of second regions 38, 38 at each second side wall 30 away from each other. As a result, the first locking piece 60 protruding from the second region 38 is encouraged to abut against the inner surface 71 of the second locking piece 70 at its tip. Thus, the restoring force generated at the fourth fold F4 acts to promote the locking of the first locking piece 60 against the inner surface 71 of the second locking piece 70.

[0044] In this container 1, the assembled state of the container 1 is maintained by the locking of the first locking piece 60 and the second locking piece 70. The first locking piece 60 protrudes from the second side edge 33 of the second side wall 70, while the second locking piece 70 protrudes from the first side wall 20. As shown in Figures 1 to 11, the size of the first locking piece 60 and the second locking piece 70 is set to be extremely small relative to the size of the first side wall 20 and the second side wall 30. Furthermore, the first locking piece 60 and the second locking piece 70 are configured to protrude only from the second side wall 30 and the first side wall 20, respectively. With this container 1, the assembled state can be established with a simple configuration. In container 1, the first locking piece 60 is locked to the inner surface 71 of the second locking piece 70, that is, near the first side edge 23 of the first side wall 20. However, it may also be locked to the tip of the second locking piece 70 or to the inner surface 24 of the first side wall 20.

[0045] Figure 12 is a schematic plan view showing the configuration of the unfolded body 2A used in assembling the container 1A according to the second embodiment of the present invention. As shown in Figure 12, in this unfolded body 2A, the formation of the second locking piece 70 is omitted at the first side edge 23 of each first side wall 20. Other components similar to those of the unfolded body 2, i.e., container 1, are given the same reference numerals, and redundant explanations are omitted here. Prior to assembling the container 1A, a folded body (not shown) is formed from this unfolded body 2A. The configuration of this folded body is the same as that of the folded body 3, except that the formation of the second locking piece 70 is omitted. In this folded body, when the second side walls 30, 30 are folded along the second fold F2, the first locking piece 60 can be locked to the first side edge 23 of the first side wall 20. With this configuration, the assembled state of the container 1A can be established with an even simpler configuration.

[0046] Figure 13 is a schematic perspective view showing the structure of an assembled container 1B according to a third embodiment of the present invention. In this container 1B, a pair of first side walls 20, 20 are formed at an angle such that they move away from each other as they move from the lower edge 21 to the upper edge 22. Similarly, a pair of second side walls 30, 30 are formed at an angle such that they move away from each other as they move from the lower edge 31 to the upper edge 32. In other words, both the first side walls 20, 20 and the second side walls 30, 30 rise from the bottom wall 10 at an angle less than 90 degrees. In the aforementioned containers 1 and 1A, a flat rectangular parallelepiped space is formed by the bottom wall 10, the first side walls 20, 20 and the second side walls 30, 30, but in this container 1B, a truncated square pyramidal space is formed in the third direction D3 as it tapers towards the bottom wall 10 of the container 1B. Even with such a container 1B, an assembled state can be established with a simple configuration.

[0047] Figure 14 is a schematic plan view showing the configuration of the unfolded body 2B used in assembling the container 1B according to the third embodiment of the present invention. As shown in Figure 14, in this unfolded body 2B, a pair of first side edges 23, 23 of each first side wall 20 extend away from each other as they move from the lower edge 21 to the upper edge 22 of the first side wall 20. Similarly, a pair of second side edges 33, 33 of each second side wall 30 extend away from each other as they move from the lower edge 31 to the upper edge 32 of the second side wall 30. That is, the first side wall 20 and the second side wall 30 are formed in a trapezoidal shape in the plan view of Figure 14. Other components similar to those of the unfolded bodies 2 and 2A described above are given the same reference numerals, and redundant explanations are omitted here. In the third embodiment, the first side walls 20, 20 and the second side walls 30, 30 are all raised at an angle less than 90 degrees, but the angles of each side wall may be different. For example, one pair of first side walls 20, 20 may be raised at an angle less than 90 degrees, and one pair of second side walls 30, 30 may be raised at approximately 90 degrees.

[0048] Furthermore, in the container 1 according to the first embodiment of the present invention, the bottom wall 10 is formed in a rectangular shape in plan view, but as another modification, the bottom wall 10 may be formed in other polygonal shapes, such as a trapezoid, as long as a locking is established between the first side wall 20 and the second side wall 30 based on bending. Also, in the container 1, the first side wall 20 and the second side wall 30 are formed on the first bottom edge 11 and the second bottom edge 12 of the bottom wall 10, respectively, but for example, the formation of the second side wall 30 may be omitted on either of the second bottom edges 12. The trays 1, 1A, and 1B according to the first to third embodiments of the present invention are trays without lids, but for example, they may be containers that combine a tray with a lid that is separate from the tray, or they may be containers in which a lid is connected to the upper edge 20 of the first side wall 20 or the upper edge 32 of the second side wall 30. Furthermore, the shapes of the first locking piece 60 and the second locking piece 70 described above are merely examples, and the first locking piece 60 and the second locking piece 70 may have other shapes as long as locking is established. Also, although one first locking piece 60 and one second locking piece 70 are formed on each side edge 23, 33, multiple pieces may be formed on each side edge 23, 33. [Explanation of symbols]

[0049] 1, 1A, 1B Tray, 2, 2A, 2B Unfolded, 3, 3A, 3B Folded, 10 Bottom wall, 11 First bottom edge, 12 Second bottom edge, 13 Inner surface, 20 First side wall, 21 Lower edge, 22 Upper edge, 23 First side edge, 24 Inner surface, 25 Outer surface, 30 Second side wall, 31 Lower edge, 31a Endpoint, 32 Upper edge, 33 Second side edge, 34 Inner surface, 35 Outer surface, 36 Fold, 37 First region, 38 Second region, 40 Attachment piece, 41 Inner surface, 42 Outer surface, 50 Corner section, 60 First locking piece (locking piece), 61 Inner surface, 62 Outer surface, 63 First part, 64 Second part, 70 Second locking piece, 71 Inner surface, 72 Outer surface, 73 First part, 74 Part 2, C cut, D1 first direction, D2 second direction, D3 third direction, F1 first fold, F2 second fold, F3 third fold, F4 fourth fold

Claims

1. A bottom wall defining a pair of first bottom edges facing each other, and a second bottom edge intersecting the first bottom edges, A pair of first side walls are connected at the lower edge to the first bottom edge of the bottom wall and define a first side edge that intersects the lower edge, A second side wall is connected at its lower edge to the second bottom edge of the bottom wall and defines a second side edge that overlaps with the first side edge of the first side wall, A pair of adhesive pieces protruding from each of the second side edges and attached to the inner surface of the first side wall, Each of the second side edges comprises a locking piece protruding from it, The container is divided into a first region on the lower edge side and two second regions on the upper edge side by folds that extend from two endpoints of the lower edge toward the upper edge of the second side, The aforementioned container is In a folded state, the first side walls are each bent along the first bottom edge so that the first side walls overlap the bottom wall, the second side walls are bent along the fold so that the second region overlaps the first region, and the locking piece is positioned between the bottom wall and the first side wall. A container capable of establishing an assembled state in which, by folding the first region of the second side wall along the lower edge from the folded state, the second side wall rises from the second bottom edge, and a pair of the first side walls fold back relative to the bottom wall and rise from the first bottom edge, and the locking piece locks to the first side wall.

2. The container according to claim 1, wherein, in establishing the assembled state, when the first region of the second side wall is bent along the lower edge such that the inner surface of the first region approaches the inner surface of the bottom wall, the locking piece protrudes from the outer surface of the adhesive piece.

3. The container according to claim 2, wherein, in establishing the assembled state, after the locking piece protrudes from the outer surface of the adhesive piece, the inner surface of the first region is returned in a direction away from the inner surface of the bottom wall based on the restoring force generated by the fold, and the locking piece locks to the first side edge or near the first side edge.

4. The first side wall has a second locking piece that protrudes from the first side edge, In the folded state, the locking piece is positioned between the bottom wall and the second locking piece. The container according to claim 1, wherein in the assembled state, the tip of the locking piece locks onto the inner surface of the second locking piece.

5. The container according to claim 4, wherein the second locking piece extends along the same plane as the first side wall.

6. The container according to claim 4 or 5, wherein, in establishing the assembled state, when the first region of the second side wall is bent along the lower edge such that the inner surface of the first region approaches the inner surface of the bottom wall, the locking piece protrudes from the outer surface of the adhesive piece.

7. The container according to claim 6, wherein, in establishing the assembled state, after the locking piece protrudes from the outer surface of the adhesive piece, the inner surface of the first region is returned in a direction away from the inner surface of the bottom wall based on the restoring force generated by the fold, and the tip of the locking piece locks onto the inner surface of the second locking piece.

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