JP2003276731A - Paper-made container - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To make an interlock type paper-made container strong when the same is closed by a flap and to increase the overall rigidity of the same. <P>SOLUTION: The wall faces 2A-2D of a paper-made container 1 are provided with roughly square first, third flaps 6A, 6C and second, fourth flaps 6B, 6D, and the tip ends of the flaps 6A-6D are formed to be positioned flush. A pair of slits 9 or notches 12 extending toward a continuous wall face 2 is provided at least on the first flap 6A, and a catching piece 10 is formed between the slits or the notches to be buried and catch the inner face side of the facing third flap 6C or the adjoining second and fourth flaps 6B, 6D. After folding the flap 6D from the flap 6B, the flap 6A is folded and the catching piece 10 is pushed inward for closing. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a paper container capable of closing at least the bottom surface without using a fixing means such as an adhesive tape or hot melt.

[0002]

2. Description of the Related Art Conventionally, an interlock type paper container of this type is provided with a flap that closes the bottom surface from the wall surface that surrounds four sides, as shown in Japanese Utility Model Laid-Open No. 59-80216. , The flap has an engaging tongue,
Cuts or overlapping strips are provided.

In this paper container, the flap provided with the engaging tongue is folded in a state where the flap provided with the cut line or the overlapping piece is folded, and then the engaging tongue is pushed inward. Thus, the engaging tongue piece is retracted inward from the slit. Thereby, the engaging tongue piece is configured to be locked to the inner surface side of the adjacent flap and to maintain the closed state.

[0004]

However, in order to improve the workability when the engaging tongue is retracted, the paper container has a large extension extending toward both sides of the engaging tongue toward a continuous wall surface. A cut-off part is provided. Therefore, there is a problem that the strength of the bottom surface in the closed state becomes low and the weight of the articles accommodated inside is also limited. Further, the rigidity against the force from the side is lowered, and there is a problem that the paper container is easily deformed when an external force is applied from the side.

Therefore, an object of the present invention is to provide a paper container capable of improving the strength of the bottom surface closed by the flap and the overall rigidity.

[0006]

In order to solve the above-mentioned problems, a paper container of the present invention is provided with substantially rectangular first and third flaps, which face each other at the upper and lower edges of wall surfaces surrounding four sides. In a paper container in which the second and fourth flaps are provided and the tips of the flaps are flush with each other, at least the first flap has a pair of slits extending from the tips toward a continuous wall surface or A cutout is provided, and a locking piece for retracting and locking is provided on the inner surface side of the opposing third flap or the adjacent second and fourth flaps, and the first flap is bent from the second flap and then the first flap. By bending the flap and pushing the locking piece inward, the second flap adjacent to the first flap
At least a portion of the outer surface of the fourth flap is covered, and the locking piece is configured to be locked by being locked to the inner surface of the third flap or the second and fourth flaps.

According to this paper container, when it is closed by the flaps formed in a substantially rectangular shape, the side edges of the flaps are located at the ridges which are the boundaries between the wall surface and the flaps. Therefore, most of the bottom surface can have a two-layer structure, and the strength of the bottom surface can be improved. Moreover, the rigidity against the force applied from the outside can be increased.

In the paper container, it is preferable that the second and fourth flaps are provided with a second slit or notch extending outward from the lower portion of the locking piece in the bent first flap. With this configuration, workability when pushing the locking piece inward can be improved.

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings. 1 to 6 show a paper container 1 according to a first embodiment of the present invention. This paper container 1 is provided with wall surfaces 2A to 2D surrounding four sides, upper flaps 5A to 5D and lower flaps 6A to 6D projecting from the upper and lower end edges of the wall surfaces 2A to 2D, of which the bottom lid is included. The lower flaps 6A to 6D constituting the above are of an interlock system that can be closed without using a fixing means such as an adhesive tape or hot melt.

Specifically, the paper container 1 is made of corrugated cardboard paper in which a corrugated medium is provided between a front cover and a back cover as shown in FIG.
It is formed by cutting into a developed state as shown in (1) and gluing at a predetermined position.

Specifically, as shown in FIG. 2, the paper container 1 in the unfolded state is provided so that four wall surfaces 2A to 2D are continuous at the same height in a straight line. These wall surfaces 2A
2D, the margin portion 3 is provided at the edge of the wall surface 2A at one end. Further, among these wall surfaces 2A to 2D, oblong grip holes 4 are provided above the narrow wall surfaces 2B and 2D.

At the upper and lower edges of each of the wall surfaces 2A to 2D,
The upper flaps 5A to 5D and the lower flaps 6A to
6D are provided to have a rectangular shape with the same protruding length. That is, these flaps 5A to 5D, 6
Each of A to 6D is formed such that the respective tips are flush with each other and are located on a straight line.

Each of the wall surfaces 2A to 2D and the upper flap 5A
.. 5D and the lower flaps 6A to 6D, a folding line 7 formed by compressing the wall thickness is linearly provided. Further, a folding curve 8 similar to the folding curve 7 is provided at the boundary portion between the wall surface 2A and the glue margin portion 3 and the boundary portion between the wall surfaces 2A to 2D.

In this embodiment, the upper flaps 5A-5D
Is formed in such a size that the tip ends of the upper flaps 5A and 5C that are continuous with the wide wall surfaces 2A and 2C are in a state of being bent along the folding curve 7. That is, the protrusion length L1 of the upper flaps 5A to 5D is the same as the wall surfaces 2B and 2D having the narrow width.
Is approximately half of the width H1.

Further, the lower flaps 6A to 6D have wide wall surfaces 2A and 2C in a state of being bent along the folding curve 7.
The front ends of the lower flaps 6A and 6C that are continuous with each other are formed so as to overlap each other. That is, the lower flap 6A-
The protruding length L2 of 6D is the width H of the narrow wall surfaces 2B and 2D.
It is formed longer than half of 1.

Of the four lower flaps 6A to 6D, the first lower flap 6A located at the left end is provided with a pair of first slits 9 extending from the tip toward the continuous wall surface 2A. Specifically, the first slit 9 is
First cutting portion 9a extending vertically from the tip toward the wall surface 2A
A second cutting portion 9b extending outwardly from the end of the first cutting portion 9a and an arcuate cutting portion 9c provided at the end of the second cutting portion 9b.

As shown in FIG. 1, the first slits 9 have second and fourth lower flaps 6B and 6 adjacent to each other.
It is formed so as to be located on D. Also, the first
The third lower flap 6 facing each other is provided between the cutting portions 9a and 9a.
A locking piece 10 that locks into the inner surface of C is formed. The second cutting portion 9b prevents the corrugated cardboard from breaking due to the concentration of the locking force on the edge of the locking piece 10, and the first lower flap 6A is linear along the first cutting portion 9a. It plays a role to prevent bending up. The arcuate cutting portion 9c serves to prevent the end portion of the first lower flap 6A from being broken by the force of the deformation of the first lower flap 6A. In addition, a continuous portion (not shown) which is not cut is provided at the central position of the second cutting portion 9b, and the first slit 9 is provided at the time of punching, gluing processing described later, and before assembly.
The gap and the both sides of the first slit 9 are prevented from bending and interfering with other members.

Of the four lower flaps 6A to 6D, the second and fourth lower flaps 6B and 6D, which are adjacent to the first lower flap 6A, are bent along a folding line 7 (see FIG. 5), the second slits 11 extending from the lower portion of the locking piece 10 toward the outer side in the width direction are provided. Specifically, the second slit 11 includes a first cutting portion 11a that extends vertically from the tip toward the continuous wall surfaces 2B and 2D, and the locking piece 10 from the end of the first cutting portion 11a.
A second cutting portion 11b extending obliquely in a direction away from
It comprises an arcuate cutting portion 11c provided at the end of the second cutting portion 11b.

The first cutting portion 11a has a first slit 9
Is formed so as to intersect with the first cutting portion 9a and the end portion thereof is located outside the locking piece 10. 2nd cutting part 11b
The arcuate cutting portion 11c plays a role of preventing breakage due to the force due to the deformation of the second and fourth lower flaps 6B and 6D. A continuous portion (not shown), which is not cut, is provided at the central position of the second cutting portion 11b, like the first slit 9.

The paper container 1 having the above-mentioned structure is a general-purpose processing machine which can automatically form the structure excluding the gripping holes 4 and the slits 9 and 11 only by inputting the sizes of the paper containers 1 of various sizes. Also, it is manufactured by the rotary type flexo die cutter Gloa.

Here, in the manufacturing by the flexo gluer, the grip hole 4 and the slits 9 and 11 are small punching dies having cutting blades so as to have a predetermined punching shape,
The receiving die that receives the punching die is formed by a punching device that is detachably attached to a pair of rotating shafts. In other words, unlike the die cutter method, a large die for punching the entire shape (configuration) at once is unnecessary, so that the production cost can be reduced.

Further, in both the flexo-gluer and flexo-die-cutter-grower manufacturing methods, when the formation in the developed state shown in FIG. 2 is completed, the glue margin 3 and the edge of the wall surface 2D at the other end are attached by the same processing glue. Perform gluing process to wear.

The line for executing this gluing process is shown in FIG.
A stacker for stacking a plurality of punched products shown in (1) and sending out one by one, and a sticking device are provided.

As shown in FIG. 3, the stacker includes a mounting table 20, a stopper 21, a kicker 22, and a feed roller 23, and stacks punched products at high speed (200 to 300).
It can be supplied at a rate of one sheet / minute. A gap corresponding to the thickness of the corrugated paper is provided between the upper surface of the mounting table 20 and the lower end of the stopper. The kicker 22 has a plurality of shafts 22a that are positionally adjustable in the width direction and that can move forward and backward.
A pressing member 22b that is detachably attached to the shaft 22a and presses the edge of the punched product, and pushes out so that the tip of the punched product located at the lower end is located at the position of the feed roller 23. .

In the pasting device, after the adhesive margin portion 3 is coated with a vinyl acetate emulsion adhesive or the like, the wall surfaces 2A, 2
By positioning the boundary portion of B and bending the wall surface 2A along the folding curve 8 between them, positioning the boundary portion of the wall surfaces 2C and 2D and bending the wall surface 2D along the folding curve 8 between them This is a well-known technique in which the margin portion 3 and the edge of the wall surface 2D are overlapped and attached.

Here, in the stacker, a punched part is formed in a wide range at the tip (upper flaps 5A to 5D) of the punched product to be sent out, and when the tip shape has many irregularities, it interferes with the stopper 21. It cannot be used for any reason such as being caught in the machine or causing a malfunction.
In addition, when a wide range of punched parts are formed at the rear end (lower flaps 6A to 6D) of the punched product, and the rear end shape has many irregularities, the position adjustment of the kicker 22 becomes troublesome and It cannot be used because the punching product is likely to be deformed due to the concentration of the pushing force on the protruding portion.

That is, as in the paper container 1 described in Japanese Utility Model Laid-Open No. 59-80216, a punched product having a complicated shape in which irregularities are formed in a wide range at the front end or the rear end is used as a stacker. It cannot be used. Therefore, such a punched product is a punched product laminated by a belt.
You have to use a special device called one-touch gluer that picks up and sends out one by one. However, since the feeding operation of this device is low speed (50-100 sheets / minute),
The production efficiency is lower than the stacker, which is a general-purpose device.

In the paper container 1 of the first embodiment, the punched product has an upper flap 5A which is the front end in the delivery direction.
.About.5D and the lower flaps 6A to 6D, which are the rear ends, have no unevenness. Therefore, it is possible to use the high-speed stacker having the above configuration. As a result, production efficiency can be improved.

Further, in the paper container 1 of the first embodiment, there is no punching portion except the grip hole 4. That is, since the production of punch scraps is suppressed to the minimum during the punching process, the production efficiency can be further improved. Here, there is a problem that if the punching dust adheres to the punched product, it will hinder the gluing process and affect the punching of the subsequent product. However, the paper-made container 1 can improve the production efficiency because the punching dust hardly occurs.

When the paper container 1 thus formed is used, first, the bottom flaps 6A to 6D are arranged facing upward, and the bottom surface is closed by these bottom flaps 6A to 6D.

Specifically, as shown in FIG. 4, first, the third lower flap 6C, which faces the first lower flap 6A having the locking piece 10, is bent along the folding curve 7, and then the third lower flap 6C is bent.
The second and fourth lower flaps 6B and 6D are respectively provided with folding lines 7.
Fold along.

Then, as shown in FIG. 5, the first lower flap 6A on which the locking piece 10 is finally formed is bent along the folding curve 7. In this state, the tip of the first lower flap 6A overlaps with the tip of the third lower flap 6C that faces the second and fourth lower flaps 6B and 6D. Further, from both ends of the locking piece 10, second slits 11 formed in the second and fourth lower flaps 6B and 6D extend outward.

Then, as shown in FIG. 6, the tip portion of the locking piece 10 is pushed inward. Then, as shown, in the second and fourth lower flaps 6B and 6D, the first
A region located below the lower flap 6A, and a second
A substantially trapezoidal portion a between the slit 11 and the leading edge bends inward in association with the first lower flap 6A. Further, the third lower flap 6C also flexes inward. In addition, in the first lower flap 6A, both sides of the locking piece 10 are located at the uppermost portion with almost no inward bending.

Then, the tip of the locking piece 10 has the first slit of the second slit 11 in the second and fourth lower flaps 6B and 6D.
When located inside the third lower flap 6C beyond the edge of the cutting portion 11a and the tip edge of the third lower flap 6C, the second to fourth lower flaps 6B to 6D are included in the corrugated cardboard paper. The elastic force restores the original condition. When the pushing of the first lower flap 6A is released, the first lower flap 6A is pushed by the elastic force of the corrugated paper and the elastic forces of the second and fourth lower flaps 6B and 6D. Returns to its original state.

As a result, as shown in FIGS. 1 and 7, the bottom surface of the paper container 1 covers the outer surfaces on both sides of the third lower flap 6C with the second and fourth lower flaps 6B and 6D. The outer surfaces of the half regions of the second and fourth lower flaps 6B and 6D are covered with the first lower flap 6A, and the locking piece 10 formed on the first lower flap 6A is attached to the third lower flap 6C. It locks on the inner surface and maintains its closed state.

In the closed state of the bottom surface, the central locking portion is, as shown in FIG. 7, located outside the locking piece 10 at the third lower flap 6C and the second and fourth lower flaps 6B, 6B.
D is coated, and the second and fourth lower flaps 6B and 6D are covered.
A first lower flap 6A is further coated on the outer side of the.
Therefore, even if an outward force is applied to the first lower flap 6A by accommodating and lifting a predetermined article inside the paper container 1, it is possible to prevent the first lower flap 6A from flexing outward, and the third lower flap 6A. It is possible to prevent the locking piece 10 from coming off from 6C. That is, the strength of the bottom surface in the closed state can be improved, and the restriction on the weight of the articles accommodated inside can be eased.

In the closed state, as shown in FIG. 1, one side edge of the second and fourth lower flaps 6B and 6D is located at the ridge between the wall surface 2A and the first lower flap 6A, Both side edges of the third lower flap 6C are located at the ridges of the wall surfaces 2B and 2D and the lower flaps 6B and 6D. Therefore, most of the bottom surface has a two-layer structure, so that the strength of the bottom surface can be further improved. Moreover, the rigidity against the force applied from the outside is increased, and it is possible to prevent the deformation easily.

On the other hand, when opening the closed bottom surface,
The exposed portion of the third lower flap 6C is pressed inward. As a result, the locking piece 10 of the first lower flap 6A together with the third lower flap 6C is bent downward, and the tip end edge of the locking piece 10 is crossed so that the locking piece 10 can be opened.

FIG. 8 shows a developed state of the paper container 1 according to the second embodiment. In the second embodiment, the first lower flap 6
With the first cut portion 9a of the first slit 9 formed in A, with the second and fourth lower flaps 6B and 6D bent,
The lower flap 6 is provided so as to be located between these tips.
This is different from the first embodiment in that the second slit 11 is not provided in B and 6D.

In the paper container 1 according to the second embodiment, the first
Similar to the embodiment, since the upper and lower flaps 5A to 5D and the lower flaps 6A to 6D are not formed with the unevenness, and the punching waste hardly occurs, the production efficiency can be improved. Also, the lower flap 6A-
When the bottom surface is closed by 6D, the third lower flap 6C and the second and fourth lower flaps 6B and 6D are covered on the outside of the locking piece 10, and the outer surface thereof is further covered with the first lower flap 6A. Since it is covered, the strength can be improved. Further, the side edges of each of the lower flaps 6A to 6D are the wall surface 2
Since it is located at the ridge with A to 2D, the rigidity can be increased.

Moreover, in the second embodiment, the locking piece 1 of the first lower flap 6A is used in the work of closing the bottom surface.
When pushing 0 inward, the second and fourth lower flaps 6
B and 6D do not interfere with the locking piece 10. Therefore, the pushing workability can be improved.

FIG. 9 shows a developed state of the paper container 1 according to the third embodiment. In this 3rd Embodiment, instead of the 1st slit 9 shown in 1st Embodiment, the pair of 1st notch part 12 notched in the substantially V shape was provided, and the locking piece 10 was provided between these. It is different from the first embodiment in points. In addition, the first cutout portion 12 of the third embodiment is the actual cut-out 59-8021.
As in the paper container 1 described in Japanese Patent Publication No. 6, the lower flap 6
It is not a large cutout so as to extend from the tip of A to the boundary portion with the continuous wall surface 2A, but is cut into only a region necessary for forming the locking piece 10.
Further, in the present embodiment, the cutting portion 1 corresponding to the second cutting portion 9b of the first embodiment is provided at the lower end of the first notch portion 12.
2a and a cutting portion 12 corresponding to the arc-shaped cutting portion 9c
b is provided.

In the paper container 1 of the third embodiment, since the lower flap 6A is provided with the first cutout portion 12, a slight unevenness is formed, but the range is very small, and therefore the stacker described above is used. Can be used. for that reason,
The production efficiency can be improved. Further, similarly to the first embodiment, the strength of the bottom surface and the rigidity of the whole can be improved.

FIG. 10 shows a developed state of the paper container 1 according to the fourth embodiment. In the fourth embodiment, the second slit 11
Instead of the above, the second notch 1 cut out in the second and fourth lower flaps 6B, 6D adjacent to the first lower flap 6A so as to extend outward in the width direction from the lower portion of the locking piece 10.
3 is different from the first embodiment. It should be noted that, like the first notch 12 of the third embodiment, the second notch 13 is formed in the lower flaps 6B and 6D like the paper container 1 described in Japanese Utility Model Laid-Open No. 59-80216. It is not a large cutout so as to extend from the tip to the boundary portion between the continuous wall surfaces 2B and 2D, but is cut out only by a region necessary to prevent the locking piece 10 from being pushed in.

In the paper container 1 according to the fourth embodiment, since the lower flaps 6B and 6D are provided with the second cutout portions 13, slight irregularities are formed in the shaking motion as compared with the third embodiment.
Since the range is very small, it is possible to use the stacker. Therefore, the production efficiency can be improved. Further, similarly to the first embodiment, the strength of the bottom surface and the rigidity of the whole can be improved.

Moreover, in the fourth embodiment, since the second notch portion 13 is provided in the second and fourth lower flaps 6B and 6D, when the locking piece 10 is pushed inward, it interferes and pushes in. It is possible to prevent obstacles, and as a result, it is possible to improve workability.

11 and 12 show a paper container 1 according to the fifth embodiment. In the fifth embodiment, the right end having a narrow width is defined as a first lower flap 6A, a pair of first slits 9 is provided in the lower flap 6A, and a locking piece 10 is provided therebetween.
Is formed. Also, the locking piece 10 is similarly provided on the third lower flap 6C facing the first lower flap 6A.
Is formed. The second and fourth lower flaps 6B and 6D having a wider width have the second slits 11 on both sides.
The configuration is different from that of the first embodiment. In addition, the lower flaps 6A to 6 of the fifth embodiment.
The protrusion length L2 of D is the width H2 of the narrow wall surfaces 2A and 2C.
Is formed in about half.

When using the paper container 1 of the fifth embodiment, first, after bending the second and fourth lower flaps 6B and 6D having the second slit 11 along the folding curve 7, , The first and third lower flaps 6 with the locking pieces 10 formed
Bend A and 6C along the bending line 7.

Then, as in the first embodiment, the locking pieces 10 of the first and third lower flaps 6A and 6C are pushed inward. As a result, the adjacent second and fourth lower flaps 6
While bending B and 6D, when they are located inside these second and fourth lower flaps 6B and 6D beyond the edge of the first cutting portion 11a in the second slit 11, the second and fourth lower flaps 6B are formed. , 6D return to the original state due to the elastic force of the corrugated paper. Also, the first and third lower flaps 6A,
6C is released, these lower flaps 6
A and 6C are the elastic force of the corrugated paper and the second and fourth
The elastic force of the lower flaps 6B and 6D restores the original state before pushing.

In the state where the bottom surface is closed, the first and third lower flaps 6A and 6C having the narrow widths and the second and fourth flaps having the wide widths.
By covering the outer surfaces on both sides of the lower flaps 6B and 6D and locking the locking pieces 10 to the inner surfaces of these lower flaps 6B and 6D, the closed state is maintained.

As described above, the first lower flap 6A forming the locking piece 10 is not limited to the wide flap, but may be the narrow flap. Further, the locking piece 10 is the first
It may be provided not only on the lower flap 6A but also on the opposed third lower flap 6C. Even in this case, similarly to the first embodiment, the production efficiency, the strength of the bottom surface, and the overall rigidity can be improved. Moreover, since there are few members that interfere when the locking piece 10 is pushed inward, the workability involved in pushing can be improved.

13 to 15 show a paper container 1 according to the sixth embodiment. In the sixth embodiment, the first lower flap 6A having a wide width is provided with a pair of third notches 14 cut out to both side edges, and the locking piece 10 is provided between them. In addition, the third that faces the first lower flap 6A
The lower flap 6C is provided with a fourth notch 15 slightly wider than the width of the engaging piece 10 at the center of its tip, and an engaging portion 16 for engaging with the inner surface of the first lower flap 6A is provided on both sides thereof. It is different from the first embodiment in the respect. In the sixth embodiment, the second and fourth lower flaps 6B, 6 having a narrow width are provided.
Neither the second slit 11 nor the second cutout 13 is provided in D.

When the paper container 1 according to the sixth embodiment is used, first, as shown in FIG.
After bending the fourth lower flaps 6B, 6D, the locking portion 1
Bend the 3rd lower flap 6C which formed 6.

After that, the first lower flap 6A having the locking piece 10 is bent and the locking piece 10 is pushed inward.
As a result, the second and fourth lower flaps 6B and 6D on both sides together with the third lower flap 6C are deflected inward, and the tip edge of the third lower flap 6C is crossed, and the inside of the third lower flap 6C is reached. When the first lower flap 6A is released from being pushed in, the lower flaps 6A to 6D return to the original state before pushing by the elastic force of the corrugated paper.

With this bottom closed, the second, fourth
The lower flaps 6B and 6D are replaced by the first and third lower flaps 6
It is covered with A and 6C. Also, the first lower flap 6A
The locking piece 10 is locked to the inner surface of the third lower flap 6C, and the third lower flap 6C has the locking portion 16 that is the first.
It is locked to the inner surface of the lower flap 6A. That is, the flaps 6A and 6C maintain the closed state by the engaging pieces 10 and the engaging portions 16 alternately interlocking with each other and engaging.

In the paper container 1 of the sixth embodiment, as described above, the locking piece 10 of the first lower flap 6A and the locking portion 16 of the third lower flap 6C are alternately arranged on the inner surface side. Since it is locked, as in the first embodiment, the strength of the bottom surface in the closed state can be improved, and the restriction on the weight of the articles accommodated inside can be eased. Further, since the side edges of the lower flaps 6A to 6D are located at the ridges of the wall surfaces 2A to 2D, the rigidity can be increased.

The paper container 1 of the present invention is not limited to the configuration of the above embodiment. For example, in the third embodiment, the second slit 11 may be replaced by the second notch 13 shown in the fourth embodiment. Also,
In the fifth embodiment, the first slit 9 may be replaced by the first notch 12 shown in the third embodiment,
Further, instead of the second slit 11, the second cutout portion 13 shown in the fourth embodiment may be provided. In this way, the paper container 1 in which the configurations of the respective embodiments are variously combined can be formed.

Further, although the paper container 1 of each of the above-described embodiments is formed of corrugated cardboard, it may be formed of single paper.
If it is formed of a known paper, the same action and effect as described above can be obtained.

[0059]

As is clear from the above description, in the paper container of the present invention, since each flap is formed in a substantially rectangular shape, the locking piece formed on the first flap is replaced by the third flap or the third flap. When the inner surfaces of the second and fourth flaps are immersively locked and closed, the side edges of each flap are located at the ridge portion that is the boundary between the wall surface and the flap. Therefore, most of the closed surface can have a two-layer structure, and the strength of the bottom surface can be improved. Moreover, the rigidity against the force applied from the outside can be increased.

[Brief description of drawings]

FIG. 1 is a perspective view showing a paper container according to a first embodiment of the present invention.

FIG. 2 is a plan view showing a developed state of the paper container according to the first embodiment.

FIG. 3 is a side view showing a part of a production line for a paper container.

FIG. 4 is a perspective view showing one step of closing the bottom of the paper container of the first embodiment.

FIG. 5 is a perspective view showing another process of closing the bottom of the paper container of the first embodiment.

FIG. 6 is a perspective view showing another step of closing the bottom of the paper container of the first embodiment.

7 is a partially enlarged perspective view of FIG.

FIG. 8 is a plan view showing a developed state of the paper container according to the second embodiment.

FIG. 9 is a plan view showing a developed state of the paper container of the third embodiment.

FIG. 10 is a plan view showing a developed state of the paper container according to the fourth embodiment.

FIG. 11 is a perspective view showing a paper container according to a fifth embodiment.

FIG. 12 is a plan view showing a developed state of the paper container of the fifth embodiment.

FIG. 13 is a perspective view showing a paper container according to a sixth embodiment.

FIG. 14 is a plan view showing a developed state of the paper container according to the sixth embodiment.

FIG. 15 is a perspective view showing a step of closing the bottom of the paper container of the sixth embodiment.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Paper container, 2A-2D ... Wall surface, 5A-5D ... Upper flap, 6A-6D ... Lower flap, 9 ... 1st slit, 10 ... Locking piece, 11 ... 2nd slit, 12 ... 1st notch Part, 13 ... 2nd notch part.

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Claims (2)

[Claims] 1. The first and third flaps and the second and fourth flaps of substantially rectangular shape facing each other are provided at the upper and lower edges of the wall surface surrounding the four sides, and the tips of these flaps are flush with each other. In the paper container formed so as to be positioned, at least the first flap is provided with a pair of slits or notches extending from its tip toward a continuous wall surface, and the third flap or the adjacent second and second flaps therebetween is provided therebetween. Four
By providing a locking piece for retracting locking on the inner surface side of the flap, bending the fourth flap from the second flap, bending the first flap, and pushing the locking piece inward, the first flap At least a part of the outer surfaces of the adjacent second and fourth flaps are covered, and the locking pieces are locked to the inner surfaces of the third flap or the second and fourth flaps so as to be closed. Paper container. 2. The second and fourth flaps are provided with a second slit or notch extending outward from a lower portion of the locking piece in the bent first flap. 1. The paper container according to 1.