Paper boxes

Abstract

To provide a paper box that can hold a lid flap at a closed position when transferring, prevent a loss of workability when opened, and prevent a loss of an appearance when opened, with a simple configuration.SOLUTION: A paper box 10 includes a bottom plate 11, side plates 13A, 13B, a top plate 12, a rear plate 14 closing an opening 17 in a rear side in a front / rear direction Y, a front plate 15 closing an upper portion of an opening 18 on an a front side of the front / rear direction Y, and a lid flap 16 closing a lower side portion of the opening 18. The lid flap 16 is connected to the bottom plate 11, and is rotatable to a closed position where the lower side of the front plate 15 of the opening 18 is closed and an opened position where the lower side of the opening 18 is opened. At a lower end of the front plate 15, a holding piece 50 for holding the lid flap 16 at the closed position is provided by overlapping the outer surface of the lid flap 16 at the closed position, connected via an opening fold curve 51.SELECTED DRAWING: Figure 2

Description

Technical Field

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

Background Art

[0002] Patent Document 1 discloses a paper box including a bottom plate, a pair of side plates, a top plate, a rear plate, and a front plate. In this paper box, an opening is formed on the bottom plate side of the front plate, and a rotatable lid flap for closing the opening is continuously provided on the bottom plate. By opening the opening by rotating the lid flap from the closed position to the open position, the stored article can be taken out.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In the paper box of Patent Document 1, during transportation, when a pressing force is applied to the lid flap from the inside to the outside due to the collision of the stored article, the lid flap may rotate from the closed position to the open position, and the opening may be opened. To prevent the lid flap from rotating open, it is conceivable to attach the front plate and the lid flap with melt or tape, or to continuously provide the front plate and the lid flap via a breaking line. In the former case, when opening, it is necessary to peel off the melt or tape, so the opening workability of the paper box is impaired, and since a part of the printing on the surface of the front plate or the lid flap is peeled off, the appearance of the paper box is impaired. In the latter case, when opening, it is necessary to break between the front plate and the lid flap along the breaking line, so the opening workability is also impaired, and the appearance of the paper box is impaired by the breaking part. Regarding these inconveniences, Patent Document 1 does not consider them at all.

[0005] The present invention aims to provide a paperboard box with a simple structure that can hold the lid flap in a closed position during transport, prevent impairment of workability when opened, and prevent damage to the appearance when open. [Means for solving the problem]

[0006] This invention paper carton box The structure comprises a bottom plate extending in a first direction and a second direction intersecting the first direction; a pair of side plates connected to both sides of the bottom plate in the first direction and extending in a second direction and a third direction intersecting both the first and second directions; a top plate connected to the pair of side plates and facing the bottom plate in the third direction; a rear plate that closes a first opening at one end of the second direction defined by the bottom plate, the pair of side plates, and the top plate; a front plate that closes the upper part of a second opening at the other end of the second direction defined by the bottom plate, the pair of side plates, and the top plate; a lid flap connected to the bottom plate and rotatable between a closed position that closes the lower part of the second opening below the front plate and an open position that opens the lower part of the second opening; and a retaining piece connected to the lower end of the front plate via a bend curve and overlapping the outer surface of the lid flap in the closed position to hold the lid flap in the closed position. 。 Furthermore, in the first aspect of the present invention, the opening fold line is located above a point 5 mm above the lower end of the retaining piece, and below the lower end of the connecting portion between the front plate and the pair of side plates. We provide paper boxes. Furthermore, a second aspect of the present invention provides a paper box comprising a pair of frame plates, each connected to both sides of the lid flap in the first direction and positioned adjacent to the inside of the pair of side plates, and a pair of inner flaps, each connected to the front plate side of the pair of side plates and positioned inside the front plate, wherein the inner flaps are provided with a projection that protrudes downward, adjacent to the frame plate on the side opposite to the side plate. Furthermore, a third aspect of the present invention provides a paper box comprising an inclined plate connected to the rear plate side of the bottom plate, folded back onto the bottom plate and inclined downward from the rear plate side toward the front plate side, wherein the dimension of the inclined plate in the first direction is smaller than the dimension between the pair of side plates, and protrusions are provided on both sides of the inclined plate in the first direction that abut against the inner surface of the side plates.

[0007] The cardboard box has a retaining piece attached to the lower end of the front panel via a fold line to hold the lid flap in the closed position. This simple configuration, with a retaining piece protruding from the lower end of the front panel, securely holds the lid flap in the closed position, while the lid flap can be easily opened from the closed position by folding the retaining piece along the fold line. This prevents the lid flap from rotating from the closed position to the open position and opening the second opening during transport, due to pressure from the movement of the contained goods. Therefore, there is no need to attach the front panel and lid flap with melt adhesive or tape, nor is there a need to connect them via a break line. Consequently, there is no need to peel off melt adhesive or tape when opening, nor is there a need to break the front panel and lid flap along the break line, thus preventing any impairment to the ease of opening the cardboard box. Moreover, the printing on part of the surface of the front panel or lid flap does not peel off, and the broken part is not exposed, thus preventing any damage to the appearance of the cardboard box when it is open. [Effects of the Invention]

[0008] In this invention, with a simple configuration, the lid flap can be held in the closed position during transport, workability can be prevented when it is opened, and the appearance can be prevented from being damaged when it is open. [Brief explanation of the drawing]

[0009] [Figure 1] A perspective view of a paper box according to an embodiment of the present invention. [Figure 2] Cross-sectional view along line II-II in Figure 1. [Figure 3] A perspective view of a paperboard box in an open state. [Figure 4] Figure 3 shows a cross-sectional view along line IV-IV. [Figure 5] Plan view of the blank paperboard box shown in Figure 1. [Figure 6] A perspective view showing one of the processes involved in box manufacturing. [Figure 7] A perspective view showing another process in the box-making process. [Figure 8] A perspective view showing another process in the box-making process. [Figure 9]Perspective view of the back side of the manufactured cardboard box. [Figure 10] Perspective view showing the posture of the cardboard box during transportation. [Figure 11] Perspective view of the cardboard box of the first modification example. [Figure 12] Plan view of a part of the blank of the cardboard box in the second modification example.

Mode for Carrying Out the Invention

[0010] Hereinafter, embodiments of the present invention will be described with reference to the drawings.

[0011] Referring to FIGS. 1 to 4, a cardboard box 10 according to an embodiment of the present invention is a stocker in which a plurality of rollable articles (capsules) are accommodated, and the articles can be taken out from an opening 18. The opening 18 is closed by a rotatable lid flap 16 during transportation (see FIGS. 1 and 2), and is opened by an opening operation of the lid flap 16 during use (see FIGS. 3 and 4).

[0012] In the attached drawings, the X direction is the width direction (first direction) of the cardboard box 10. The Y direction is the front-rear direction (second direction) of the cardboard box 10, the direction indicated by the arrow is the rear side, and the direction opposite to the arrow is the front side. The Z direction is the height (thickness) direction (third direction) of the cardboard box 10. Referring to FIGS. 1 and 2, the dimension in the width direction X of the cardboard box 10 is larger than the dimension in the front-rear direction Y, and the dimension in the height direction Z is larger than the dimension in the width direction X. However, the dimensions in the width direction X, the front-rear direction Y, and the height direction Z can be changed as necessary.

[0013] The paper box 10 is manufactured by pasting and folding a single blank shown in FIG. 5 at predetermined portions. The blank is formed by punching a cardboard sheet with a well-known paper box punching device. The cardboard sheet has a well-known configuration in which a corrugated medium is disposed between a front liner (on the outer surface side of the paper box 10) and a back liner (on the inner surface side of the paper box 10). The portion described by a dashed line in FIG. 5 is a general-purpose ruled line formed by ruling from the back liner so as to compress the thickness. The portion described by a solid line in FIG. 5 is a cutting line formed by cutting from the back liner to the front liner and a shape line (side) formed by punching.

[0014] Referring to FIGS. 1 and 2, the paper box 10 includes a bottom plate 11, a top plate 12, side plates 13A and 13B, a rear plate 14, a front plate 15, and a lid flap 16. Of the rectangular outer peripheral wall formed by the bottom plate 11, the top plate 12, and the side plates 13A and 13B, an opening (first opening) 17 at the rear end located on the left side (one end side) in FIG. 2 is closed by the rear plate 14. The upper part of an opening (second opening) 18 at the front end located on the right side (the other end side) in FIG. 2 is closed by the front plate 15, and the lower part of the opening 18 is closably closed by the lid flap 16.

[0015] Hereinafter, the configurations of the bottom plate 11, the top plate 12, the side plates 13A and 13B, the rear plate 14, the front plate 15, and the lid flap 16 will be specifically described.

[0016] The bottom plate 11 has a rectangular shape extending along the XY plane. The top plate 12 has the same rectangular shape as the bottom plate 11, faces the bottom plate 11 in the height direction Z, and extends along the XY plane. The top plate 12 of the present embodiment is composed of a top plate body 19 and an attached piece 20, and is adhered by, for example, a vinyl acetate emulsion-based adhesive.

[0017] The side plates 13A and 13B both have the same rectangular shape extending along the YZ plane and face each other in the width direction X. The lower ends of the side plates 13A and 13B are connected to both sides of the bottom plate 11 in the width direction X via bending portions 22, respectively, and the upper ends of the side plates 13A and 13B are connected to both sides of the top plate 12 in the width direction X via bending portions 23, respectively.

[0018] Referring to Figure 5, the attachment piece 20, side plate 13A, bottom plate 11, side plate 13B, and top plate body 19 are arranged in this order from left to right. Between the bottom plate 11 and side plate 13A, and between the bottom plate 11 and side plate 13B, there are folding curves 22a that constitute the folded portion 22 shown in Figure 1. Between the side plate 13A and attachment piece 20, and between the side plate 13B and top plate body 19, there are folding curves 23a that constitute the folded portion 23 shown in Figure 1. Both folding curves 22a and 23a are made of general-purpose creases.

[0019] Referring to Figures 2, 8, and 9, the rear plate 14 is rectangular in shape extending along the YZ plane and is connected to the side plate 13A via a bent portion 24. At the end of the rear plate 14 opposite to the bent portion 24, an insertable piece 25 is connected via a bent portion 26 to be inserted into the inside of the side plate 13B. A locking groove 27 is provided on the bent portion 26, penetrating the corrugated cardboard sheet in the thickness direction. The side plate 13B is provided with a locking piece 28 that is inserted into the locking groove 27 to prevent the insertable piece 25 from coming out. The top plate 12 is connected via a bent portion 30 to a rear inner flap 29 that is placed overlapping the inside of the rear plate 14.

[0020] Referring to Figure 5, the rear plate 14 is connected to the underside of the side plate 13A, and a folding curve 24a, which constitutes the folded portion 24 shown in Figure 9, is provided between them. The insert piece 25 is connected to the underside of the rear plate 14, and between them is a folding curve 26a, which constitutes the folded portion 26 shown in Figure 9, and a lock groove 27, which is formed by a cutting line. Note that the folding curve 26a is not formed in the part where the lock groove 27 is formed. The lock piece 28 is provided on the underside of the side plate 13B and is demarcated by a cutting line. The rear inner flap 29 is connected to the underside of the top plate body 19, and a folding curve 30a, which constitutes the folded portion 30 shown in Figure 9, is provided between them. Folding curves 24a, 26a, and 30a are all made of general-purpose creases.

[0021] Referring to Figures 1 and 2, the front panel 15 is rectangular in shape, extending along the YZ plane, and is connected to the top panel 12 via a bent portion 32, facing the rear panel 15 in the front-to-back direction Y. The total height of the front panel 15 is such that it covers approximately the upper half (top) of the opening 18. Referring to Figures 1 and 6, the front inner flap 33 is connected to the front end (front panel 15 side) of the side panel 13A via a bent portion 34, and the front inner flap 35 is connected to the front end of the side panel 13B via a bent portion 36. The front inner flaps 33 and 35 are arranged overlapping inside the front panel 15, and the lower ends of the front inner flaps 33 and 35 protrude below the lower end of the front panel 15.

[0022] Referring to Figure 5, the front panel 15 is connected to the upper side of the top panel body 19, and a fold line 32a, which constitutes the folded portion 32 shown in Figure 1, is provided between them. The front inner flap 33 is connected to the upper left side of the side panel 13A, and a fold line 34a, which constitutes the folded portion 34 shown in Figure 1, and a through groove 38, which will be described in detail later, are provided between them. The front inner flap 35 is connected to the upper right side of the side panel 13B, and a fold line 36a, which constitutes the folded portion 36 shown in Figure 1, and a through groove 38 are provided between them. The fold lines 32a, 34a, and 36a are all made of general-purpose creases.

[0023] Referring to Figures 2 and 6, the side plates 13A, 13B and the bent portions 34, 36 of the front inner flaps 33, 35, as well as the front plate 15, are provided with connecting portions 37 for connecting the side plates 13A, 13B and the front plate 15. The connecting portion 37 is located in the central region of the total height of the front plate 15 and consists of through grooves 38 provided in the bent portions 34, 36 and connecting pieces 39 provided on both sides of the front plate 15 in the width direction X. The through grooves 38 are provided adjacent to the bent portions 34, 36 so as to be located on the front inner flaps 33, 35 side, penetrate the corrugated cardboard sheet in the thickness direction, and extend in the height direction Z. The connecting pieces 39 are connected to the front plate 15 via the bent portion 40 and have protrusions 39a that project outwards on both sides in the height direction Z. The distance between the tops of the pair of protrusions 39a, that is, the maximum width of the connecting piece 39, is set to be larger than the total length of the through groove 38, within the range in which it can be inserted into the through groove 38.

[0024] Referring to Figure 5, the through grooves 38 are each composed of cutting lines and are provided adjacent to the upper side of the folding curves 34a and 36a. Folding curves 34a and 36a are not formed in the portion where the through grooves 38 are formed. The connecting pieces 39 are connected to both sides of the front plate 15, and between them is a folding curve 40a that constitutes the folded portion 40 shown in Figure 6. The folding curve 40a is composed of a general-purpose crease line.

[0025] Referring to Figure 5, the left connecting piece 39 (one of a pair of connecting pieces 39) is provided adjacent to the flap 35. The front inner flap 35 extends to the position where the connecting piece 39 is formed. In order to suppress the swinging of the front plate 15 in the blank state, the adjacent front inner flap 35 and connecting piece 39 are separated by a cutting line 41 and connected by a continuous section 41a with a breakable total length. Here, the breakable total length means the length to which adjacent cutting lines 41 can be connected relatively easily by applying an external force.

[0026] Referring to Figures 1 to 4, the lid flap 16 is connected to the front end of the bottom plate 11 via a bent portion 43. The lid flap 16 is rotatable around the bent portion 43 to a closed position as shown in Figures 1 and 2 and an open position as shown in Figures 3 and 4. In the closed position, it closes the portion of the opening 18 below the front plate 15, and in the open position, it opens the portion of the opening 18 below.

[0027] As is most clearly shown in Figure 2, the upper end of the lid flap 16 in the closed position is located below the lower end of the front plate 15 and above and on the outer side of the lower ends of the front inner flaps 33 and 35. As is most clearly shown in Figure 4, when the lid flap 16 is rotated to the open position, the lid flap 16 is inclined upward as it moves away from the bottom plate 11. The angle θ between the bottom plate 11 and the lid flap 16 is set to a predetermined opening angle. The angle θ is located at the opening 18 and is set to an opening angle (e.g., 160 degrees) that prevents rolling articles under the load of other articles from falling out of the lid flap 16 and allows for good removal of articles located on the lid flap 16.

[0028] Referring to Figures 2, 3, and 4, frame plates 44 are connected to both sides of the lid flap 16 in the width direction X via bent portions 45. Each pair of frame plates 44 is fan-shaped with a bent portion 43 as its center, bent relative to the lid flap 16, and positioned adjacent to the inside of the side plates 13A and 13B, respectively. At the end of the frame plate 44 on the bottom plate 11 side, there is a contact portion 44a that protrudes upward when the lid flap 16 is in the open position shown in Figure 4 and can abut against the inner surfaces of the front inner flaps 33 and 35. By changing the position of this contact portion 44a, the angle θ between the bottom plate 11 and the lid flap 16 can be changed.

[0029] Referring to Figure 5, the lid flap 16 is connected to the upper side of the bottom plate 11, and a fold line 43a forming the bent portion 43 shown in Figure 1 is provided between them. The pair of frame plates 44 are connected to both sides of the lid flap 16, and a fold line 45a forming the bent portion 45 shown in Figure 4 is provided between them. The pair of frame plates 44 are also located above the side plates 13A and 13B and adjacent to the front inner flaps 33 and 35. The pair of frame plates 44 and the side plates 13A and 13B are both demarcated by a cutting line 46 and connected by a continuous portion 46a that is breakable along its entire length. The pair of frame plates 44 and the front inner flaps 33 and 35 are also both demarcated by a cutting line 47.

[0030] Referring to Figures 1 to 4, in this embodiment, the paper box 10 configured in this way is provided with a retaining piece 50 for holding the lid flap 16 in the closed position and a protruding piece 53 for preventing the frame plate 44 from collapsing. In addition, an inclined plate 56 is provided on the bottom plate 11 to guide the article to the opening 18.

[0031] The configurations of the retaining piece 50, the projection piece 53, and the inclined plate 56 will be described in detail below.

[0032] Referring to Figures 1 and 2, the retaining piece 50 is rectangular in shape with the same width as the width X of the front plate 15, and protrudes downward from the lower end of the front plate 15 via the opening fold curve 51. Referring to Figure 5, the retaining piece 50 is connected to the upper side of the front plate 15. The opening fold curve 51 is made up of lead lines, which are made by providing multiple cutting lines on a general-purpose crease at intervals that make it difficult to break. An interval that makes it difficult to break means a length that makes it difficult for adjacent cutting lines to connect when an external force is applied. However, the opening fold curve 51 may also be a half-cut line that cuts only the back liner or a general-purpose crease, and can be changed as needed as long as the retaining piece 50 can be folded relative to the front plate 15 and cannot be separated.

[0033] The total height of the retaining piece 50 is formed to overlap the outer surface of the lid flap 16 when the lid flap 16 is in the closed position shown in Figure 2. If the overlap Os of the retaining piece 50 with respect to the lid flap 16 is made excessively small, for example, if a pressing force is applied to the lid flap 16 from the inside to the outside due to a collision with the contained articles, the lid flap 16 may not be able to be held in the closed position. On the other hand, if the overlap Os is made excessively large, the blank shown in Figure 5 will become excessively large in only a part of it, which will reduce the number of paper boxes 10 that can be punched out from the corrugated cardboard sheet (yield). To prevent these problems, it is preferable to set the overlap Os of the retaining piece 50 with respect to the lid flap 16 to a range of 1 mm or more and 1 / 3 or less of the total height H of the lid flap 16.

[0034] The opening fold curve 51 is formed above the upper end of the lid flap 16 in the closed position, and above a position 5 mm above the lower end of the retaining piece 50 (more than 5 mm). Also, the opening fold curve 51 is formed below the lower end of the connecting portion 37 between the front plate 15 and the side plates 13A and 13B (less than the position of the lower end of the connecting portion 37). If the position of the opening fold curve 51 is formed too low, in other words, if the height Z dimension of the front plate 15 is made too long, the gap between the lower end of the front plate 15 and the upper end of the lid flap 16 will narrow, which may impair the operability when rotating the lid flap 16 from the closed position to the open position. On the other hand, if the position of the opening fold curve 51 is formed too high, the retaining piece 50 will be more likely to bend along the opening fold curve 51 due to interference with other members, and if a pressing force is applied to the lid flap 16 from the inside to the outside in this state, the lid flap 16 may rotate to open. To prevent these inconveniences, it is preferable that the opening bend curve 51 be formed within the range defined above.

[0035] For example, in this embodiment, when the paper box 10 contains 40 items weighing 30g each (total weight 1.2kg), the overlap Os of the lid flap 16 and the retaining piece 50, and the position where the opening fold curve 51 is formed are set as follows to prevent the lid flap 16 from rotating from the closed position to the open position. First, the thickness of the corrugated cardboard sheet that makes up the paper box 10 is 1mm. The overlap Os of the retaining piece 50 is set to 7mm relative to the lid flap 16, which has a total height of 79mm. The gap between the lower end of the front plate 15 and the upper end of the lid flap 16 is set to 13mm, and the position where the opening fold curve 51 is formed, i.e., the total height of the retaining piece 50, is set to 20mm. In this way, when the box contains items with a total weight of 1.2kg, even if a pressing force is applied to the lid flap 16 from the inside to the outside due to collisions of items during transport, the opening rotation of the lid flap 16 held by the retaining piece 50 can be suppressed.

[0036] Referring to Figures 2, 4, and 7, the projection 53 is provided projecting downward from the lower end of the inner flap 29 so as to be adjacent to the side plates 13A and 13B located near the frame plate 44 on the opposite side. The projection 53 is semicircular in shape, and the top of its lower end is located below the upper end of the lid flap 16 and the outer edge of the frame plate 44. However, the shape of the projection 53 can be changed as needed, as long as its lower end is located below the outer edge of the frame plate 44. This projection 53 forms a guide groove 54 between the frame plate 44 and the nearby side plates 13A and 13B, preventing the frame plate 44 from collapsing inward in the width direction X, i.e., towards the center of the lid flap 16, while guiding the frame plate 44. Referring to Figure 5, the projection 53 is formed by making a part of the cutting line 47 that demarcates the space between the projection 53 and the frame plate 44 project toward the frame plate 44.

[0037] Referring to Figures 2 to 4, the inclined plate 56 is connected to the rear plate 14 side of the bottom plate 11, folded back onto the bottom plate 11, and inclined downward from the rear plate 14 side toward the front plate 15 side. More specifically, the inclined plate 56 is connected to the back plate 58 via a bent portion 57, and this back plate 58 is connected to the bottom plate 11 via a bent portion 59. The back plate 58 is a rectangular shape extending along the XZ plane and is positioned adjacent to the inner surface of the rear plate 14. The total height of the back plate 58 is set according to the required inclination angle of the inclined plate 56 and the length of the bottom plate 11 in the front-rear direction Y. The total height of the rear inner flap 29 is such that it covers the area above the back plate 58 of the opening 17.

[0038] Referring to Figures 5 and 8, the width dimension X of the inclined plate 56 is smaller than the dimension between the side plates 13A and 13B. On both sides of the inclined plate 56 near the rear plate 14 in the width dimension X, there are protrusions 56a that abut against the inner surfaces of the side plates 13A and 13B. The dimension between the tips of the pair of protrusions 56a is equivalent to the dimension between the inner surfaces of the side plates 13A and 13B. When the number of stored items decreases and the weight on the inclined plate 56 decreases, the frictional resistance between the protrusions 56a and the side plates 13A and 13B prevents the inclined plate 56 from lifting up. In addition, the protrusions 56a ensure a space between the inclined plate 56 and the side plates 13A and 13B through which the frame plate 44 can be inserted.

[0039] Referring to Figure 5, the back plate 58 is connected to the underside of the bottom plate 11, and a folding curve 59a, which constitutes the folded portion 59 shown in Figure 8, is provided between them. The inclined plate 56 is connected to the underside of the back plate 58, and a folding curve 57a, which constitutes the folded portion 57 shown in Figure 8, is provided between them. Both folding curves 57a and 59a are made of general-purpose creases. No folding curves or cutting lines are provided between the inclined plate 56 and the protrusion 56a. The adjacent left protrusion 56a and the back plate 14 are separated by a cutting line.

[0040] Next, an example of a method for manufacturing the paperboard box 10 will be described. However, the method for manufacturing the paperboard box 10 is not limited to the following order and can be changed as needed.

[0041] First, as shown in Figure 5, the side panel 13A is folded along the fold line 22a relative to the bottom panel 11, and then the top panel body 19 is folded along the fold line 23a relative to the side panel 13B. Next, the overlapping attachment piece 20 and the top panel body 19 are bonded together with adhesive. In this state, the paper box 10 is shipped.

[0042] Next, as shown in Figure 6, the bottom plate 11, side plates 13A, 13B, and top plate 11 are spread out to form a rectangular tube shape. At this time, the continuous section 41a between the front inner flap 35 and the connecting piece 39 shown in Figure 5 is broken, and the continuous section 46a between the side plates 13A, 13B and the frame plate 44 is also broken.

[0043] Next, as shown in Figure 7, the front inner flaps 33 and 35 are folded relative to the side plates 13A and 13B, respectively. After folding the pair of frame plates 44 relative to the lid flap 16, the lid flap 16 is folded relative to the bottom plate 11 so that each frame plate 44 is positioned between the side plates 13A and 13B and the protruding pieces 53.

[0044] Next, the connecting piece 39 is bent relative to the front plate 15, then the front plate 15 is bent relative to the top plate 12, and the connecting piece 39 is inserted into the through groove 38. As a result, as shown in Figures 1 and 2, the front plate 15 is connected to the side plates 13A and 13B via the front inner flaps 33 and 35. The front inner flaps 33 and 35, the lid flap 16, and the retaining piece 50 overlap in this order from the rear (inside) to the front (outside) in the front-to-back direction X.

[0045] Next, as shown in Figure 8, the inclined plate 56 is folded relative to the back plate 58, and the back plate 58 is folded relative to the bottom plate 11, and the inclined plate 56 is inserted between the side plates 13A and 13B. As a result, the inclined plate 56 is folded back relative to the bottom plate 11 and placed on the bottom plate 11. In this state, the goods are placed inside the paper box 10 through the opening 17.

[0046] Next, the rear inner flap 29 is folded relative to the top panel 12, and then the rear panel 14 is folded relative to the side panel 13A while the insertion piece 25 is folded relative to the rear panel 14. Finally, as shown in Figures 2 and 9, the insertion piece 25 is inserted into the inside of the side panel 13B, and then the locking piece 28 is inserted into the locking groove 27 to complete the paper box 10.

[0047] Referring to Figure 10, the sealed paper box 10 is transported to a designated retailer with the front panel 15 and lid flap 16 positioned on the upper side and the rear panel 14 on the lower side, and is used as is in the store. First, the retaining piece 50 is folded along the opening fold curve 51 relative to the front panel 15 as shown in Figures 1 and 2. Next, a finger is hooked onto the upper end of the exposed lid flap 16 and the lid flap 16 is pulled towards the user. As a result, the lid flap 16 and the frame panel 44 rotate together, as shown in Figures 3 and 4, and the lower part of the opening 18 can be opened. The rotation of the lid flap 16 and the frame panel 44 is stopped by the contact of the contact portion 44a with the inner surface of the front inner flaps 33 and 35.

[0048] The paper box 10 configured in this way has the following features.

[0049] The cardboard box 10 is connected to the lower end of the front panel 15 via an opening fold curve 51 and is equipped with a retaining piece 50 for holding the lid flap 16 in the closed position. With this simple configuration of having a retaining piece 50 protruding from the lower end of the front panel 15, the lid flap 16 can be reliably held in the closed position, while the lid flap 16 can be easily opened from the closed position to the open position by folding the retaining piece 50 along the opening fold curve 51. Therefore, even if a pressing force is applied to the lid flap 16 from the inside to the outside due to collision with the contained goods during transport, it is possible to prevent the lid flap 16 from rotating from the closed position to the open position and opening the opening 18.

[0050] As described above, the opening and rotational movement of the lid flap 16 can be suppressed with a simple configuration, so there is no need to attach the front plate 15 and the lid flap 16 with melt adhesive or tape, nor is there a need to connect them via a break line. Therefore, when opening, there is no need to peel off melt adhesive or tape, nor is there a need to break the front plate 15 and the lid flap 16 along the break line, thus preventing any impairment to the ease of opening the paperboard box 10. Moreover, since no part of the printing on the surface of the front plate 15 or the lid flap 16 will peel off, and the broken part will not be exposed, the appearance of the paperboard box 10 when open is prevented from being damaged.

[0051] The overlap Os of the retaining piece 50 with respect to the lid flap 16 is 1 mm or more, and 1 / 3 or less of the total height H of the lid flap 16. This ensures that the retaining piece 50 securely holds the lid flap 16 in the closed position, while preventing the blank of the paperboard box 10 from becoming excessively large.

[0052] The opening fold curve 51 between the front plate 15 and the retaining piece 50 is located above a point 5 mm above the lower end of the retaining piece 50, and below the position of the connecting portion 37 between the front plate 15 and the pair of side plates 13A and 13B. As a result, when the lid flap 16 is opened, the retaining piece 50 is bent along the opening fold curve 51, reliably exposing the upper end of the lid flap 16, and the lid flap 16 can be easily rotated from the closed position to the open position, thereby improving the operability of the lid flap 16.

[0053] The connecting section 37 consists of a through groove 38 provided on the edge of the side plates 13A and 13B and the inner flap 29, and a connecting piece 39 provided on the front plate 15. This ensures that the upper part of the opening 18 of the paper box 10 is securely closed, and that the lid flap 16 is securely held in the closed position via the retaining piece 50 during transport.

[0054] The inner flap 29, which is connected to the side plates 13A and 13B, is provided with a projection 53 that is adjacent to the frame plate 44 on the opposite side from the side plates 13A and 13B and protrudes downward. This prevents the frame plate 44 from collapsing towards the center of the lid flap 16. Therefore, the lid flap 16 can be rotated stably from the closed position to the open position. In addition, since the projection 53 abuts against the inner surface of the lid flap 16 in the closed position, it also prevents the lid flap 16 from rotating inward beyond the inner flap 29. Furthermore, since the lid flap 16 is sandwiched between the retaining piece 50 and the projection 53, it is securely held in the closed position.

[0055] The pair of frame plates 44 have a contact portion 44a that protrudes upward when the lid flap 16 is in the open position and abuts against the inner surface of the inner flap 29. This prevents the frame plates 44 from coming out from the inside to the outside of the front plate 15, and ensures that the lid flap 16 can be reliably rotated to the predetermined open position.

[0056] The bottom plate 11 is folded back and an inclined plate 56 is provided that slopes downward from the rear plate 14 side toward the front plate 15 side. This allows articles contained within the paper box 10 to roll to the underside of the open opening 18 if they are of a shape that allows them to roll. Thus, the ease of removing articles in the open state can be improved.

[0057] The width dimension X of the inclined plate 56 is smaller than the distance between the pair of side plates 13A and 13B, and protrusions 56a are provided on both sides of the inclined plate 56 in the width dimension X, which abut against the inner surfaces of the side plates 13A and 13B. This ensures that the inclined state of the inclined plate 56 is reliably maintained by the contact between the protrusions 56a and the side plates 13A and 13B. Furthermore, the protrusions 56a provide space between the inclined plate 56 and the side plates 13A and 13B for the frame plate 44 to be placed, thus preventing the frame plate 44 from obstructing the rotation of the lid flap 16.

[0058] Other embodiments and various modifications of the present invention will be described below, but unless otherwise specified, they will be the same as in the first embodiment. In the drawings referred to below, the same elements as in the first embodiment are denoted by the same reference numerals.

[0059] As shown in the first modified example in Figure 11, the retaining piece 50 may be provided only on a part of the lower end of the front plate 15. In this case, the retaining piece 50 can be arc-shaped as shown in the figure. However, the retaining piece 50 may have a shape other than an arc, and the number of retaining pieces 50 may be two or more.

[0060] As shown in the second modified example in Figure 12, the projection 39a of the connecting piece 39 may be only one. Furthermore, the connecting portion 37 is not limited to a configuration consisting of a through groove 38 and a connecting piece 39, and can be changed as needed as long as it can maintain the front plate 15 in a closed state.

[0061] The paperboard box 10 may not have the inclined plate 56 shown in Figures 2 and 4. In this case, the rear panel 14 may consist of a plurality of fixed flaps, and the opening 17 may be automatically closed with a one-touch mechanism by spreading the bottom panel 11, side panels 13A, 13B, and top panel 11 to form a rectangular tube shape. The configuration of the rear panel 14 can be changed as needed.

[0062] The material of the paper box 10 is not limited to corrugated cardboard sheets made of paper, but may also be corrugated cardboard sheets made of resin. Furthermore, the material of the paper box 10 is not limited to corrugated cardboard sheets, but may also be single-layer cardboard or resin sheets. [Explanation of symbols]

[0063] 10 Paper carton box 11 Bottom plate 12 Top plate 13A,13B side plate 14 Rear plate 15 Front panel 16 Lid flap 17. Opening (First opening) 18. Opening (Second Opening) 19. Tabletop body 20 Additional allowance piece 22~24 Bend part 22a~24a folding line 25 Insertion piece 26 Bend section 26a folding line 27 Lock groove 28 rock pieces 29 Rear inner flap 30 Bend section 30a folding line 32 Bend section 32a folding line 33 Front inner flap (inner flap) 34 Bend section 34a folding line 35 Front inner flap (inner flap) 36 Bend section 36a folding line 37 Connecting part 38 Through groove 39 Connecting piece 39a Protrusion 40 Bend section 40a folding line 41 Cutting line 41a Continuous section 43 Bend section 43a folding line 44 Frame board 44a Contact part 45 Bend section 45a folding line 46 Cutting line 46a Continuous section 47 Cutting line 50 Holding piece 51 Folding line for opening 53 Projection piece 54 Guide grooves 56 Inclined plate 56a Convex part 57 Bend section 57a folding line 58 Back plate 59 Bend part 59a folding line Os overlap H Total height of the lid flap X width direction (first direction) Y: Forward / backward direction (second direction) Z: Height direction (third direction)

Claims

1. A base plate extending in a first direction and in a second direction intersecting the first direction, A pair of side plates are connected to both sides of the base plate in the first direction, and extend in the second direction and in a third direction that intersects both the first and second directions. A top plate connected to each of the pair of side plates and facing the bottom plate in the third direction, A rear plate that closes the first opening at one end of the second direction defined by the bottom plate, the pair of side plates, and the top plate, A front plate that covers the upper part of the second opening on the other end side in the second direction defined by the bottom plate, the pair of side plates, and the top plate, A lid flap connected to the bottom plate, which is rotatable between a closed position that closes the lower part of the second opening below the front plate and an open position that opens the lower part of the second opening, A retaining piece is connected to the lower end of the front plate via an opening bend, overlapping the outer surface of the lid flap in the closed position, and holding the lid flap in the closed position. Equipped with, The aforementioned folding curve for opening is located above a point 5 mm above the lower end of the retaining piece, and below the lower end of the connection between the front plate and the pair of side plates, in a paperboard box.

2. The paper box according to claim 1, wherein the overlap of the retaining piece with respect to the lid flap is 1 mm or more, and is 1 / 3 or less of the total height of the lid flap.

3. The pair of side panels are each connected to the front panel side and are provided with a pair of inner flaps positioned inside the front panel, The connecting portion is composed of a through groove provided on the edge of the side plate and the inner flap, and a connecting piece provided on the front plate that can be connected by being inserted into the through groove. The paper box according to claim 1 or 2.

4. A pair of frame plates are provided on both sides of the lid flap in the first direction, and are arranged adjacent to the inside of the pair of side plates, A pair of inner flaps are connected to the front panel side of the pair of side panels and are positioned on the inside of the front panel. Equipped with, The inner flap is provided with a projection that is adjacent to the side of the frame plate opposite to the side plate and protrudes downward. The paper box according to claim 1 or 2.

5. A base plate extending in a first direction and in a second direction intersecting the first direction, A pair of side plates are connected to both sides of the base plate in the first direction, and extend in the second direction and in a third direction that intersects both the first and second directions. A top plate connected to each of the pair of side plates and facing the bottom plate in the third direction, A rear plate that closes the first opening at one end of the second direction defined by the bottom plate, the pair of side plates, and the top plate, A front plate that covers the upper part of the second opening on the other end side in the second direction defined by the bottom plate, the pair of side plates, and the top plate, A lid flap connected to the bottom plate, which is rotatable between a closed position that closes the lower part of the second opening below the front plate and an open position that opens the lower part of the second opening, A retaining piece is provided which is connected to the lower end of the front plate via an opening bend, overlaps the outer surface of the lid flap in the closed position, and holds the lid flap in the closed position. A pair of frame plates are provided on both sides of the lid flap in the first direction, and are arranged adjacent to the inside of the pair of side plates, A pair of inner flaps are connected to the front panel side of the pair of side panels and are positioned on the inside of the front panel. Equipped with, A paperboard box, wherein the inner flap is provided with a projection that is adjacent to the side of the frame plate opposite to the side plate and protrudes downward.

6. The paper box according to claim 5, wherein the pair of frame plates have contact portions that protrude upward when the lid flap is in the open position and contact the inner surface of the inner flap.

7. The bottom plate is connected to the rear plate side, and is provided with an inclined plate that is folded back onto the bottom plate and slopes downward from the rear plate side toward the front plate side, The dimension of the inclined plate in the first direction is smaller than the dimension between the pair of side plates. On both sides of the inclined plate in the first direction, protrusions are provided that abut against the inner surface of the side plate. A paper box according to any one of claims 1, 2, 5, or 6.

8. A base plate extending in a first direction and in a second direction intersecting the first direction, A pair of side plates are connected to both sides of the base plate in the first direction, and extend in the second direction and in a third direction that intersects both the first and second directions. A top plate connected to each of the pair of side plates and facing the bottom plate in the third direction, A rear plate that closes the first opening at one end of the second direction defined by the bottom plate, the pair of side plates, and the top plate, A front plate that covers the upper part of the second opening on the other end side in the second direction defined by the bottom plate, the pair of side plates, and the top plate, A lid flap connected to the bottom plate, which is rotatable between a closed position that closes the lower part of the second opening below the front plate and an open position that opens the lower part of the second opening, A retaining piece is provided which is connected to the lower end of the front plate via an opening bend, overlaps the outer surface of the lid flap in the closed position, and holds the lid flap in the closed position. An inclined plate is connected to the rear plate side of the bottom plate, folded back onto the bottom plate, and inclined downward from the rear plate side toward the front plate side. Equipped with, The dimension of the inclined plate in the first direction is smaller than the dimension between the pair of side plates. A paperboard box, wherein protrusions are provided on both sides of the inclined plate in the first direction, which abut against the inner surface of the side plate.

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