Packing box

Abstract

To provide a packaging box that allows for easy assembly of the base and increases the load-bearing capacity of the base. [Solution] The packaging box 1 has a bottom 30 which includes a front flap 31 connected to the front end wall 11, left and right side flaps 33, 33 connected to the side walls 12, 12 respectively and overlapping the underside of the front flap 31, and a rear flap 32 connected to the rear end wall 11. The rear flap 32 has a flap body 31a which overlaps the underside of the side flaps 33, 33, and an insertion portion 32b which protrudes forward from the front end of the flap body 31a and is inserted into the upper side of the front flap 31. The rear edge of the front flap 31 is formed in a straight line.

Description

Technical Field

[0001] The present invention relates to a packaging box.

Background Art

[0002] As the bottom of a cardboard packaging box, there is one that closes by combining a front flap continuously provided on the front wall, left and right side flaps continuously provided on the left and right side walls, and a rear flap continuously provided on the rear wall in the American lock method (for example, see Patent Document 1). When assembling such a bottom, with the side flaps overlapped on the lower surface of the front flap, the rear flap is overlapped on the lower surfaces of the side flaps, and the insertion portion of the rear flap is inserted into the upper surface side of the front flap.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In the bottom of the American lock method as described above, it is desirable to increase the load-bearing capacity of the bottom by increasing the area where the insertion portion of the rear flap overlaps the upper surface of the front flap and making the insertion portion easily come off the front flap. However, in the conventional bottom of the American lock method, a recessed portion is formed at the trailing edge of the front flap, the base portion of the insertion portion is disposed within the recessed portion, and only the tip portion of the insertion portion is overlapped on the upper surface of the front flap, so the area where the insertion portion overlaps the upper surface of the front flap is small.

[0005] In particular, if the contents are leafy vegetables such as cabbage or lettuce, water released from the vegetables may seep into the cardboard at the bottom, causing the cardboard to soften. When the cardboard softens, the insertion point of the rear flap becomes more likely to detach from the top surface of the front flap, reducing the load-bearing capacity of the bottom. Therefore, it is advisable to increase the load-bearing capacity of the bottom beforehand.

[0006] The present invention aims to solve the aforementioned problems and provide a packaging box that allows for easy assembly of the bottom and increases the load-bearing capacity of the bottom. [Means for solving the problem]

[0007] To solve the aforementioned problems, the present invention provides a packaging box comprising a cylindrical body having front and rear end walls and left and right side walls, and a bottom provided at an opening on the lower side of the body. The bottom comprises a front flap connected to the lower edge of the front end wall, left and right side flaps connected to the lower edges of the side walls and overlapping the lower surface of the front flap, and a rear flap connected to the lower edge of the rear end wall. The rear flap has a flap body that overlaps the lower surfaces of the side flaps, and an insertion portion that protrudes forward from the front end of the flap body and is inserted into the upper surface of the front flap. The rear edge of the front flap is formed in a straight line.

[0008] The packaging box of the present invention allows for easy assembly of the bottom without the use of adhesive tape or glue. Furthermore, in the packaging box of the present invention, since the rear edge of the front flap is formed in a straight line, the area over which the insertion part of the rear flap overlaps with the front flap is larger compared to the bottom of the conventional American lock type, which has a recess formed in the rear edge of the front flap. As a result, in the packaging box of the present invention, the insertion part of the rear flap is less likely to come off the front flap, thus increasing the load-bearing capacity of the bottom.

[0009] In the aforementioned packaging box, it is preferable to make the width of the front end of the insertion portion wider in the left-right direction than the width of the front end of the flap body in the left-right direction, thereby increasing the area over which the insertion portion overlaps with the front flap.

[0010] In the side flaps of the aforementioned packaging box, it is preferable to form a projection that protrudes forward at the central end in the left-right direction, and to overlap the projection with the upper surface of the insertion portion of the rear flap. In this configuration, the protrusions on the side flaps press the insertion points of the rear flaps against the upper surface of the front flaps, making it more difficult for the insertion points of the rear flaps to detach from the front flaps, thus increasing the load-bearing capacity of the bottom.

[0011] In the aforementioned packaging box, the body portion may be provided with inclined walls formed between adjacent end walls and side walls, thereby forming the body portion into a polygonal cylindrical shape such as a hexagon or an octagon. This configuration reduces the dead space that forms at the corners of the body when spherical contents such as watermelons or melons are packed inside. Furthermore, by providing inclined walls at the corners of the body, the material area can be reduced compared to packaging boxes with a rectangular, cylindrical body. Furthermore, product information can be printed not only on the outer surfaces of the end walls and side walls, but also on each inclined wall, allowing customers to view product information from multiple angles.

[0012] In the aforementioned packaging box, it is preferable that at least one edge portion of the front flap and the rear flap is formed along the inner surface of the inclined wall and is in contact with the inner surface of the inclined wall. In this configuration, the inner surface of the inclined wall is supported by the front or rear flap, so that the body can be accurately formed into a polygonal cylindrical shape even when empty, and the inclination angle of the inclined wall relative to the end wall and side wall can be maintained.

[0013] In the above-described packaging box, when the lower end portion of the inclined wall protrudes below the lower edge portion of the end wall and the lower edge portion of the side wall, the inner surface of the inclined wall can be reliably supported by the front flap or the rear flap.

Advantages of the Invention

[0014] In the packaging box of the present invention, the bottom can be easily assembled, and each flap constituting the bottom is difficult to come off, so the load-bearing capacity of the bottom can be increased.

Brief Description of the Drawings

[0015] [Figure 1] The perspective view seen from the upper right front of the packaging box according to an embodiment of the present invention. [Figure 2] The figure which showed the blank sheet of the packaging box which concerns on embodiment of this invention. [Figure 3] The III-III sectional view of FIG. 1 showing the packaging box according to an embodiment of the present invention. [Figure 4] The perspective view seen from the lower right front of the packaging box according to an embodiment of the present invention. [Figure 5] In the packaging box according to an embodiment of the present invention, it is the perspective view seen from the lower right front of the state before closing the rear flap. [Figure 6] The perspective view seen from the upper right front of the top of the packaging box according to another embodiment of the present invention. [Figure 7] The figure which showed the blank sheet of the packaging box which concerns on other embodiment of this invention.

Modes for Carrying Out the Invention

[0016] Embodiments of the present invention will be described in detail with reference to the drawings as appropriate. In the following description, the front-back, left-right directions are set for convenience in explaining the packaging box of the present embodiment, and do not limit the configuration and usage state of the packaging box.

[0017] As shown in FIG. 1, the packaging box 1 of this embodiment includes a body portion 10 formed in an octagonal cylindrical shape, a top portion 20 provided at the upper opening of the body portion 10, and a bottom portion 30 provided at the lower opening of the body portion 10.

[0018] As shown in FIG. 2, the packaging box 1 is formed by mountain - folding or valley - folding a blank sheet S cut out from a cardboard sheet at each fold line. The blank sheet S shown in FIG. 2 is arranged so that the inner surface side is visible. The fold lines of the blank sheet S are ruled lines (pressed ruled lines) formed by linearly pressing the surface of the blank sheet S. Note that intermittent cuts may be formed in the ruled lines. By doing so, it becomes easier to bend the blank sheet S at the ruled lines. Alternatively, the fold lines may be constituted by intermittently forming linear half - cut cuts that only cut the surface of the sheet or cuts that penetrate the sheet.

[0019] As shown in FIG. 1, the body portion 10 includes front and rear end walls 11, 11, left and right side walls 12, 12, and four inclined walls 15 formed between adjacent end walls 11 and side walls 12. The body portion 10 is formed in an octagonal cylindrical shape in plan view. The end walls 11 and the side walls 12 are formed in a quadrangular shape. In this embodiment, the width of the end wall 11 in the left - right direction is formed larger than the width of the side wall 12 in the front - rear direction. The end wall 11 and the side wall 12 are arranged perpendicularly.

[0020] The inclined wall 15 is formed in a rectangular shape extending in the vertical direction. As shown in FIG. 3, the inclined wall 15 is inclined with respect to the end wall 11 and the side wall 12. The angle formed by the inner surface of the inclined wall 15 and the inner surface of the end wall 11, or the angle formed by the inner surface of the end wall 11 and the inner surface of the side wall 12, is formed larger than 90 degrees. As shown in FIG. 1, the upper end portion of the inclined wall 15 protrudes above the upper edge portions of the end wall 11 and the side wall 12 (see FIG. 2). Also, the lower end portion of the inclined wall 15 protrudes below the lower edge portions of the end wall 11 and the side wall 12 (see FIG. 2).

[0021] A strip-shaped connecting piece 13 (see Figure 2) is attached to the left edge of the right rear inclined wall 15. As shown in Figure 3, the connecting piece 13 is joined to the inner surface of the left side wall 12. As the blank sheet S (see Figure 2) is folded along each fold line, and the joining piece 13 is joined to the inner surface of the left side wall 12, an octagonal cylindrical body 10 is formed in plan view by the front and rear end walls 11, 11, the left and right side walls 12, 12, and the four inclined walls 15.

[0022] As shown in Figure 1, the top portion 20 comprises front and rear top plates 21, 21 connected to the upper edges of the front and rear end walls 11, 11, respectively, and left and right upper flaps 22, 22 connected to the upper edges of the left and right side walls 12, 12, respectively (see Figure 2). The top portion 20 is closed by overlapping the top plates 21, 21 on the upper surfaces of the two upper flaps 22, 22 and bringing the leading edges of the two top plates 21, 21 together.

[0023] The front left and right corners of the front top plate 21 are inclined along the inner surfaces of the front left and right inclined walls 15, 15. Similarly, the rear left and right corners of the rear top plate 21 are inclined along the inner surfaces of the rear left and right inclined walls 15, 15. The corners of the top plate 21 are in contact with the inner surfaces of the inclined walls 15.

[0024] As shown in Figure 4, the bottom portion 30 includes a front flap 31 connected to the lower edge of the front end wall 11, a rear flap 32 connected to the lower edge of the rear end wall 11, and left and right side flaps 33, 33 connected to the lower edges of the left and right side walls 12, 12, respectively.

[0025] As shown in Figure 5, the front flap 31 is bent backward relative to the front end wall 11, closing off the front half of the opening on the underside of the fuselage 10. As shown in Figure 3, the left and right edges of the front flap 31 are formed along the lower edges of the left and right side walls 12, 12. The trailing edge L1 of the front flap 31 is formed in a straight line along the lower edge of the end wall 11 (see Figure 2). The trailing edge L1 of the front flap 31 extends straight in the left-right direction without bending and parallel to the lower edge of the end wall 11. The front left and right corners of the front flap 31 are inclined along the inner surfaces of the front left and right inclined walls 15, 15. In addition, the corners of the front flap 31 are in contact with the inner surfaces of the inclined walls 15.

[0026] As shown in Figure 5, the side flaps 33 are bent inward relative to the side wall 12. The left and right side flaps 33, 33 are spaced apart in the left-right direction. The front portion of the side flap 33 is formed such that its width in the left-right direction increases from the front end towards the rear. Furthermore, at the rear portion of the side flap 33, a projection 33a is formed at the end that is on the left-right central side of the bottom portion 30 (the inner end of the side flap 33), projecting forward.

[0027] When the side flap 33 is folded inward relative to the side wall 12, the front part of the side flap 33 overlaps the lower surfaces of the left and right portions of the front flap 31. At this time, the rear part of the side flap 33 is positioned behind the trailing edge L1 of the front flap 31, and the projection 33a overlaps the lower surface of the front flap 31.

[0028] As shown in Figure 4, the rear flap 32 has a flap body 32a that overlaps the lower surfaces of the side flaps 33, 33, and an insertion portion 32b that protrudes forward from the front end of the flap body 32a and is inserted into the upper surface of the front flap 31.

[0029] As shown in Figure 5, the flap body 32a is formed such that its width in the left-right direction narrows from the base end (rear end) to the tip end (front end) (see Figure 2). As shown in Figure 3, the left and right corners of the rear of the flap body 32a are inclined along the inner surfaces of the left and right inclined walls 15, 15 on the rear side. Also, the corners of the flap body 32a are in contact with the inner surfaces of the inclined walls 15.

[0030] The insertion portion 32b protrudes forward from the leading edge of the flap body 32a. The width of the insertion portion 32b in the lateral direction is formed to increase from the base end (rear end) to the tip end (front end) (see Figure 5). Thus, the width of the insertion portion 32b in the lateral direction is formed to be wider than the width of the front end of the flap body 32a in the lateral direction, and the width of the rear flap 32 in the lateral direction is minimized at the boundary between the flap body 32a and the insertion portion 32b.

[0031] When assembling the bottom section 30, as shown in Figure 5, the front flap 31 is folded inward relative to the end wall 11, and the left and right side flaps 33, 33 are placed on top of the underside of the front flap 31. Next, as shown in Figure 4, the rear flap 32 is folded inward relative to the end wall 11, and the rear flap 32 is placed on top of the lower surfaces of the side flaps 33, 33. Then, when the rear flap 32 is pushed upward, both side flaps 33, 33 and the front flap 31 are pushed upward, and the insertion portion 32b of the rear flap 32 fits into the upper surface of the front flap 31.

[0032] When the rear flap 32 is pushed down from inside the fuselage 10, the rear flap 32, the side flaps 33, 33 and the front flap 31 are assembled flat. The insertion portion 32b of the rear flap 32 is superimposed on the upper surface of the front flap 31, as shown in Figure 3. Also, the protrusions 33a, 33a of the side flaps 33, 33 are superimposed on the upper surface of the insertion portion 32b. In this way, the bottom 30 of the packaging box 1 can be easily assembled without using adhesive tape or glue.

[0033] In the packaging box 1 described above, the rear edge of the front flap 31 is formed in a straight line, and the tip of the insertion portion 32b of the rear flap 32 is wider than the base end. Therefore, in the packaging box 1 of this embodiment, the area over which the insertion portion 32b of the rear flap 32 overlaps the upper surface of the front flap 31 is larger than that of the bottom of the conventional American lock type. Furthermore, in the packaging box 1 of this embodiment, the projection 33a of the side flap 33 is superimposed on the upper surface of the insertion portion 32b, and the projection 33a of the side flap 33 presses the insertion portion 32b against the upper surface of the front flap 31. As a result, in the packaging box 1 of this embodiment, the insertion portion 32b of the rear flap 32 is less likely to come off from the front flap 31, thereby increasing the load-bearing capacity of the bottom 30 against the weight of the contents.

[0034] In the packaging box 1 of this embodiment, as shown in Figure 1, an inclined wall 15 is provided between adjacent end walls 11 and side walls 12, and the body 10 is formed in an octagonal cylindrical shape. When spherical contents such as watermelons or melons are packed into such a body 10, the dead space formed at the corners of the body 10 can be reduced. In other words, the packaging box 1 can be made compact. As a result, the packaging box 1 of this embodiment can reduce the material area compared to a packaging box with a rectangular cylindrical body.

[0035] In this embodiment, product information can be printed not only on the outer surfaces of the end walls 11 and side walls 12, but also on the outer surface of the inclined wall 15. As a result, when the packaging boxes 1 are placed on the sales floor, customers can clearly see the product information from the front, back, left, right, and diagonally, thus effectively promoting the products contained inside the packaging box 1.

[0036] In the packaging box 1 of this embodiment, a portion of the edges of both top plates 21, 21 of the top portion 20 are in contact with the inner surface of each inclined wall 15, and as shown in Figure 3, a portion of the edges of the front flap 31 and rear flap 32 of the bottom portion 30 are in contact with the inner surface of each inclined wall 15. Thus, in the packaging box 1 shown in Figure 1, the inner surfaces of each inclined wall 15 are supported by the top 20 and bottom 30, so that even when the body 10 is empty, the body 10 can be accurately formed into a polygonal cylindrical shape, and the inclination angle of the inclined walls 15 relative to the end walls 11 and side walls 12 can be maintained.

[0037] Furthermore, in the packaging box 1 of this embodiment, the upper end of the inclined wall 15 protrudes below the lower edge of the end wall 11 and the lower edge of the side wall 12, and the lower end of the inclined wall 15 protrudes below the lower edge of the end wall 11 and the lower edge of the side wall 12. This ensures that the inner surface of each inclined wall 15 is reliably supported by the top 20 and bottom 30.

[0038] Although embodiments of the present invention have been described above, the present invention is not limited to the embodiments described above, and can be modified as appropriate without departing from its spirit. In the packaging box 1 of this embodiment, as shown in Figure 3, the width of the insertion portion 32b of the rear flap 32 is formed to be wider than the width of the front end of the flap body 32a, but the width of the insertion portion 32b may be formed to be the same as or narrower than the width of the front end of the flap body 32a. Furthermore, in this embodiment, a projection 33a is formed at the end of the side flap 33, but it is not necessary to form a projection 33a on the side flap 33.

[0039] In the present invention, the configuration of the top portion is not limited, and the upper opening of the body portion 10 may be closed with a single top plate. Furthermore, as shown in Figure 6, as in the packaging box 1A, an opening may be formed in the center of the top portion 20 by arranging the front and rear top plates 21, 21 with a gap between them in the front-to-back direction. The packaging box 1A shown in Figure 6 is formed from the blank sheet S1 shown in Figure 7. In the packaging box 1A shown in Figure 6, the top portion 20 is formed by a cross-assembly in which the front and rear top plates 21, 21 and the left and right upper flaps 22, 22 are alternately stacked vertically. Note that the way in which the top plates 21 and the upper flaps 22 are stacked is not limited. Alternatively, the packaging box 1 may be formed in a tray shape without providing a top portion 20 at the upper opening of the body portion 10 shown in Figure 1.

[0040] In this invention, the number and angle of inclination of the inclined walls are not limited. For example, a hexagonal cylindrical body can be formed by providing two inclined walls diagonally opposite each other, or a pentagonal cylindrical body can be formed by providing one inclined wall on the body. Furthermore, the width and height of the end walls, side walls, and inclined walls are not limited. For example, the end walls, side walls, and inclined walls of the packaging box may be formed to the same width, and the body may be formed into a regular hexagonal or regular octagonal cylindrical shape.

[0041] Although the packaging box 1 in this embodiment is made of corrugated cardboard, the packaging box can also be formed from various known types of paperboard. [Explanation of Symbols]

[0042] 1 packaging box 1A Packaging box (other embodiments) 10 Torso 11 End wall 12 Side wall 13 Joint piece 15 Slanted wall 20 Top 21 Top plate 22 Top flap 30 bottom 31 Front flap 32 Rear flap 32a Flap body 32b Insertion part 33 Side flaps 33a Protrusion L1 trailing edge S Blank Sheet S1 Blank sheet (other embodiments)

Claims

1. A cylindrical body having front and rear end walls and left and right side walls, The body comprises a bottom provided at the lower opening of the body, The bottom is, A front flap is provided connected to the lower edge of the front end wall, The left and right side flaps are connected to the lower edges of the aforementioned side walls and are superimposed on the lower surface of the front flap, It comprises a rear flap connected to the lower edge of the rear end wall, The aforementioned rear flap has, A flap body that is superimposed on the lower surface of the aforementioned side flaps, An insertion portion is formed that protrudes forward from the front end of the flap body and is inserted into the upper surface of the front flap. A packaging box characterized in that the rear edge of the front flap is formed in a straight line.

2. A packaging box according to claim 1, A packaging box characterized in that the width of the front end of the insertion portion in the left-right direction is wider than the width of the front end of the flap body in the left-right direction.

3. A packaging box according to claim 1, In the aforementioned side flap, a projection is formed at the central end in the left-right direction, which protrudes forward. A packaging box characterized in that the aforementioned projection is superimposed on the upper surface of the insertion portion of the rear flap.

4. A packaging box according to claim 1, A packaging box characterized in that the body portion is provided with an inclined wall formed between adjacent end walls and side walls.

5. The packaging box according to claim 4, A packaging box characterized in that at least one edge portion of the front flap and the rear flap is formed along the inner surface of the inclined wall and is in contact with the inner surface of the inclined wall.

6. A packaging box according to claim 4 or claim 5, A packaging box characterized in that the lower end of the inclined wall protrudes below the lower edge of the end wall.

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