Packaging box

Abstract

To provide a packaging box capable of preventing the periphery of a hand hole from being unintentionally fractured by its own weight when lifted using the hand hole.SOLUTION: A packaging box is provided with a square-cylindrical trunk part 2, and a pair of closure parts 5 for closing open ends thereof. The trunk part comprises a pair of side plates 12, a bottom plate 3, and a top plate 4. The closure parts are continuously provided to the side plates, and comprise: inner flaps 22 whose front end edges are opposed to each other in a predetermined clearance; an upper outside flap 21 continuously provided to the top plate; and a lower outside flap 23 continuously provided to the bottom plate. The upper outside flap is provided with a hand hole planned part 50A at a position of the clearance between front end edges of the inner flaps. The hand hole planned part comprises a hand hole crease line 51 extending along a boundary line between the top plate and the upper outside flap, and a hand hole breakable line 52 extending so as to be bent or curved by connecting both ends of the hand hole crease line. The hand hole breakable line comprises a pair of inclination parts 52a extending so as to be gradually separated from each other from both ends of the hand hole crease line.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a wraparound packaging box having a hand hole that is difficult to tear.

Background Art

[0002] Conventionally, on a blank sheet obtained by punching a corrugated cardboard sheet, packaged objects such as arranged plastic bottles and cans are placed, and the blank sheet is bent along the fold lines to wrap the packaged objects, and then a case is formed while packaging the packaged objects by joining the flaps. A wraparound packaging box of this type is known (see, for example, Patent Document 1).

[0003] More specifically, this packaging box includes a horizontally extending rectangular tube-shaped body portion and a pair of closing portions that respectively close the open ends of the body portion. The body portion has a pair of side plates facing each other, a bottom plate connecting the lower end edges of the pair of side plates, and a top plate connecting the upper end edges of the pair of side plates. The closing portion includes a pair of inner flaps that are continuously provided on the side plates and whose leading edges face each other with a predetermined gap therebetween, an upper outer flap that is continuously provided on the top plate and overlaps and adheres to the outer surface of the inner flap, and a lower outer flap that is continuously provided on the bottom plate and overlaps and adheres to the outer surface of the inner flap. The upper outer flap is provided with a rounded rectangular hand hole at a position corresponding to the gap sandwiched between the leading edges of the pair of inner flaps.

[0004] In the packaging box of Patent Document 1, at the stage of the blank sheet, the hand hole is pre-punched and formed, but punching waste is generated when punching and forming. Therefore, instead of the hand hole, a hand hole planned portion having a hand hole fold line extending parallel to the upper end edge and an inverted C-shaped hand hole breakable line connecting both ends of the hand hole fold line is formed in the middle portion of the upper outer flap, and in many cases, the hand hole can be formed as needed. In this case, for the packaging box in which the packaged object is packaged, the side plate can be broken along the hand hole breakable line, and the hand hole can be formed by mountain folding along the hand hole fold line.

Prior Art Documents

Patent Documents

[0005] Patent Document 1 Japanese Patent Application Laid-Open No. 2012-030834 Summary of the Invention Problems to be Solved by the Invention

[0006] However, in the hand holes of this type of packaging box, since the fingers are supported by making line contact with the periphery of the hand hole of a single cardboard sheet constituting the side plate, as a result of stress concentration at the periphery of the hand hole, there has been a problem that the upper flap is easily broken.

[0007] Therefore, an object of the present invention is to provide a packaging box capable of preventing the periphery of a hand hole from being broken unintentionally by its weight when lifted using the hand hole. Means for Solving the Problems

[0008] (1) The packaging box of the present invention includes a rectangular tube-shaped body portion extending in the horizontal direction and a pair of closing portions for closing the open ends of the body portion respectively. The body portion has a pair of side plates facing each other, a bottom plate connecting the lower end edges of the pair of side plates, and a top plate connecting the upper end edges of the pair of side plates. The closing portion includes a pair of inner flaps connected to the side plate and having their leading edges facing each other with a predetermined gap therebetween, an upper outer flap connected to the top plate and superposed and adhered to the outer surface of the inner flap, and a lower outer flap connected to the bottom plate and superposed and adhered to the outer surface of the inner flap. In the paper packaging box in which a hand hole planned portion is provided at a position corresponding to the gap sandwiched by the leading edges of the pair of inner flaps on the upper outer flap, the hand hole planned portion has a hand hole folding line extending along the boundary line between the top plate and the upper outer flap, and a hand hole breakable line connecting both ends of the hand hole folding line and extending in a bent or curved manner. The hand hole breakable line has a pair of inclined portions extending gradually away from each other from both ends of the hand hole folding line (hereinafter referred to as "the packaging box of the first aspect of the present invention").

[0009] In the packaging box of the first invention, a hand hole can be formed by breaking the hand hole planned portion along the hand hole breakable line and bending the broken piece of the hand hole planned portion inward of the packaging box along the hand hole fold line. At this time, since the hand hole fold line extends along the boundary line between the top plate and the upper outer flap, the broken piece of the hand hole planned portion is superposed on the inner surface of the top plate. Therefore, when inserting a finger into the hand hole, the entire palm side from the index finger to the little finger can be placed along the top plate to lift the box. That is, in the packaging box of the first invention, the load can be dispersed by bringing the entire palm side from the index finger to the little finger into surface contact with the top plate.

[0010] Further, since the hand hole breakable line in the hand hole planned portion has a pair of inclined portions that gradually separate from each other and extend from both ends of the hand hole fold line, when the broken piece of the hand hole planned portion is bent inward of the packaging box, the connection portion between the hand hole breakable line and the hand hole fold line, which is usually likely to be broken unintentionally, can be covered from the inner surface side of the top plate by the region sandwiched between the pair of inclined portions of the broken piece of the hand hole planned portion. That is, in the packaging box of the first invention, the load applied to the connection portion between the hand hole breakable line and the hand hole fold line can be dispersed by the broken piece of the hand hole planned portion.

[0011] Therefore, according to the packaging box of the first invention, when lifting using the hand hole, it is possible to prevent the periphery of the hand hole from being broken unintentionally due to its weight.

[0012] (2) Further, the packaging box of the present invention includes a rectangular tube-shaped body portion extending in the horizontal direction and a pair of closing portions that respectively close the open ends of the body portion. The body portion has a pair of side plates facing each other, a bottom plate connecting the lower end edges of the pair of side plates, and a top plate connecting the upper end edges of the pair of side plates. The closing portion includes a pair of inner flaps connected to the side plates and having their leading edges facing each other with a predetermined gap therebetween, an upper outer flap connected to the top plate and superposed and adhered to the outer surface of the inner flap, and a lower outer flap connected to the bottom plate and superposed and adhered to the outer surface of the inner flap. In the paper packaging box in which a handhole planned portion is provided at a position corresponding to the gap sandwiched by the leading edges of the pair of inner flaps on the top plate and the upper outer flap, the handhole planned portion is provided on the top plate and has a handhole folding line extending along the boundary line between the top plate and the upper outer flap, and a handhole breakable line provided across the top plate to the upper outer flap and extending by bending or curving while connecting both ends of the handhole folding line. The handhole breakable line has a pair of inclined portions extending gradually away from each other from both ends of the handhole folding line (hereinafter referred to as "the packaging box of the second aspect of the present invention").

[0013] In the above-described packaging box of the first aspect of the present invention, since a pair of inclined portions are formed on the upper outer flap, when the broken piece of the handhole planned portion is folded inward of the packaging box, a U-shaped periphery where the inclined portions come out of the upper outer flap is formed. Therefore, when lifting using the handhole, fingers come into line contact with the periphery where the inclined portions of the upper outer flap come out, and stress is concentrated, and there is a possibility that the periphery is crushed or broken.

[0014] On the other hand, in the packaging box of the second aspect of the present invention, since the handhole folding line is provided on the top plate, the U-shaped periphery is formed on the top plate (in the horizontal direction). Therefore, when lifting using the handhole, fingers do not come into line contact with the U-shaped periphery and stress is not concentrated.

[0015] Therefore, according to the packaging box of the second aspect of the present invention, when lifting using the handhole, it is possible to further prevent the periphery of the handhole from being broken unintentionally due to its weight.

[0016] (3) Further, in the packaging box of the present invention, in the first or second packaging box of the present invention, the handhole fold line is formed to have a length less than the average value of the hand width of Japanese adult women (hereinafter referred to as "the third packaging box of the present invention").

[0017] Originally, in a conventional packaging box, when inserting a finger into the handhole and gripping the box, since both ends in the width direction of the fingers (index finger to little finger) exactly correspond to the connection part between the handhole breakable line and the handhole fold line, there is a problem that stress concentrates on this connection part and it is easy to break from here.

[0018] On the other hand, in the third packaging box of the present invention, since the handhole fold line is formed to have a length less than the average value of the hand width of Japanese adult women, when bending the broken piece of the handhole planned part inward of the packaging box to cover the connection part between the handhole breakable line and the handhole fold line from the inner surface side of the top plate, the connection part between the handhole breakable line and the handhole fold line is arranged at the middle part in the width direction of the four inserted fingers (for example, near the middle finger and ring finger).

[0019] Therefore, since the periphery of the connection part can be supported by four fingers and through the broken piece of the handhole planned part, concentration of stress on the connection part can be avoided. It goes without saying that the handhole fold line being formed to have a length less than the average value of the hand width of Japanese adult women also means that it is less than the average value of the hand width of Japanese adult men.

[0020] Therefore, according to the third packaging box of the present invention, when lifting using the handhole, it is possible to further prevent the periphery of the handhole from being broken unintentionally due to its weight.

[0021] (4) Further, in the packaging box of the present invention, in the first or second packaging box of the present invention, the top plate is characterized in that inclined guiding fold lines extending from the four corners toward the central part are formed thereon (hereinafter referred to as "the fourth packaging box of the present invention").

[0022] The packaging box of the present invention is of the so-called wraparound type. In order to form the body by winding a blank sheet around the packaged items such as arranged PET bottles and cans, there is almost no gap between the top plate and the packaged items. Therefore, it may be tapered like a PET bottle, but in the case of a shape with a straight body like a canned beer, it may be difficult to bend the broken piece of the planned hand hole area inward of the packaging box and insert a finger between the packaged item and the top plate through the hand hole.

[0023] On the other hand, in the packaging box of the fourth aspect of the present invention, since the inclined guiding fold lines extending from the four corners toward the center are formed on the top plate, the top plate can be bent into a substantially square pyramid shape. As a result, by deforming the top plate upward, a finger can be easily inserted between the top plate and the packaged item through the hand hole, and the box can be lifted with the entire palm side from the index finger to the little finger along the top plate.

[0024] Therefore, according to the packaging box of the fourth aspect of the present invention, when lifted using the hand hole, it is possible to further prevent the area around the hand hole from being accidentally broken due to its weight.

[0025] (5) Further, in the packaging box of the present invention, in the packaging box of the fourth aspect of the present invention, a connection guiding fold line is formed at the center of the top plate by connecting the adjacent tips of the inclined guiding fold lines in a rectangular shape. When the planned hand hole area is broken along the hand hole breakable line and mountain-folded along the hand hole fold line, it is formed in a shape that overlaps inside the area surrounded by the pair of inclined guiding fold lines adjacent to the planned hand hole area on the inner surface of the top plate and the connection guiding fold line connecting these inclined guiding fold lines (hereinafter referred to as "the packaging box of the fifth aspect of the present invention").

[0026] In the fifth packing box of the present invention, in addition to the inclination guiding fold line, a connection guiding fold line is formed by connecting the adjacent tips of the inclination guiding fold line to form a rectangular shape, so that the top plate can be bent into a substantially frustum of a square pyramid shape. Thus, in the fifth packing box of the present invention, by deforming the top plate upward, fingers can be easily inserted between the top plate and the packaged object through the hand hole, and the box can be lifted with the entire palm side of the index finger to the little finger along the top plate.

[0027] In addition, the fact that the entire top plate is deformed into a substantially frustum of a square pyramid shape means that the outer flap side of the top plate constitutes the side surface of the frustum of a square pyramid. Specifically, the boundary line between the top plate and the outer flap is bent into a trapezoidal shape with the lower base, the connection guiding fold line as the upper base, and a pair of inclination guiding fold lines as the legs.

[0028] On the other hand, in the fifth packing box of the present invention, the broken piece of the hand hole planned portion is formed in a shape that fits inside the trapezoidal shape when polymerized on the inner surface of the top plate. Therefore, when the broken piece of the hand hole planned portion is bent inward of the packing box, it is polymerized without a gap on the inner surface of the trapezoidal shape, that is, the inclined side surface of the frustum of a square pyramid. Thereby, in the fifth packing box of the present invention, the load applied to the connection portion between the hand hole breakable line and the hand hole fold line can be dispersed by the broken piece of the hand hole planned portion.

[0029] Therefore, according to the fifth packing box of the present invention, when lifted using the hand hole, it is possible to further prevent the periphery of the hand hole from being broken unintentionally due to its weight.

[0030] (6) Further, in the packaging box of the second aspect of the present invention, on the top plate, inclined guide fold lines extending from the four corners thereof toward the central portion are formed. The handhole breakable line is provided on the upper outer flap, and has a lower edge portion extending along the boundary line between the top plate and the upper outer flap, and a connecting portion connecting the end of the lower edge portion and the tip of the inclined portion. At the boundary between the top plate and the upper outer flap, a pair of upper outer flap fold lines extending from each end thereof toward the central portion along the boundary line between the top plate and the upper outer flap, and a pair of branched fold lines branching and extending in an inverted V shape from the tips of the upper outer flap fold lines are provided. The branched fold lines are characterized in that one tip is connected to the base end of the inclined portion and the other tip is connected to the end of the lower edge portion (hereinafter referred to as "the packaging box of the sixth aspect of the present invention").

[0031] In the packaging box of the sixth aspect of the present invention, since the inclined guide fold lines extending from the four corners thereof toward the central portion are formed on the top plate, the top plate can be bent into a substantially quadrangular pyramid shape. When the entire top plate is thus deformed into a substantially quadrangular pyramid shape, it means that the upper outer flap side of the top plate becomes an obtuse angle with respect to the side plate and inclines as the side surface of the quadrangular pyramid.

[0032] In this case, similar to what has been described above for the packaging box of the second aspect of the present invention, when lifting using the handhole, fingers come into contact with the periphery (in this case, the top plate) from which the inclined portion has slipped out, and stress is concentrated, and there is a possibility that the periphery is crushed or broken.

[0033] However, in the packaging box of the sixth aspect of the present invention, a hexagonal fold line is formed by the handhole fold line, the upper outer flap fold line, and the pair of branched fold lines at the center in the width direction of the boundary between the top plate and the upper outer flap. Therefore, when the boundary between the top plate and the upper outer flap is bent at a right angle along the upper outer flap fold line, the center in the width direction of the boundary is bent along the hexagonal fold line, and an inclined portion that connects the top plate and the upper outer flap while inclining is formed.

[0034] The branched fold line that forms part of the outer periphery of the inclined portion has one tip connected to the base end of the inclined portion and the other tip connected to the end of the lower edge portion. As a result, it is arranged so as to surround the inclined portion from the outside. Therefore, when lifting using the hand hole, if the fingers come into contact with the periphery (in this case, the deformed and inclined top plate) from which the inclined portion has slipped out and stress concentrates and the periphery begins to collapse, along the branched fold line inside the inclined portion, the range of collapse gradually spreads.

[0035] This can prevent the range of collapse in an unintended direction from expanding from the periphery where the inclined portion has slipped out and prevent the top plate from breaking. Also, since the inside of the inclined portion collapses and serves as a cushion, it is possible to prevent unintended collapse and breakage from occurring on the outside of the inclined portion.

[0036] Therefore, according to the packaging box of the sixth aspect of the present invention, when lifting using the hand hole, it is further possible to prevent the periphery of the hand hole from being broken unintentionally due to its weight.

Brief Explanation of Drawings

[0037]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

Mode for Carrying Out the Invention

[0038] [Configuration of the packaging box 1 of the first embodiment] Hereinafter, with reference to FIGS. 1 to 3, a packaging box 1 (corresponding mainly to "the packaging box of the second invention") according to a first embodiment of the present invention (hereinafter simply referred to as "this embodiment") will be described. As shown in FIG. 1, the packaging box 1 of this embodiment is of a wrap-around case type having a rectangular parallelepiped appearance.

[0039] The packaging box 1 of this embodiment includes a cylindrical body portion 2 extending in the horizontal direction and a pair of closing portions 5 that close the open ends of the body portion 2, respectively. The body portion 2 is formed by a pair of side plates 12 facing each other, a bottom plate 3 connecting the lower end edges of the pair of side plates 12, and a top plate 4 connecting the upper end edges of the pair of side plates. The packaging box 1 of this embodiment is formed in a horizontally long shape in which the height (the length in the vertical direction) is shorter than the width (the length in the horizontal direction) when viewed from the side of the closing portion 5.

[0040] The closing portion 5 includes a pair of inner flaps 22 that are continuously provided on the side plate 12 and whose leading edges (the upper and lower end edges in FIG. 2, the same hereinafter) face each other with a predetermined gap therebetween, an upper outer flap 21 that is continuously provided on the top plate 4 and is superposed and adhered to the outer surface of the inner flap 22, and a lower outer flap 23 that is continuously provided on the bottom plate 3 and is superposed and adhered to the outer surface of the inner flap 22.

[0041] More specifically, the body portion 2 of the packaging box 1 is formed in a cylindrical shape by the top plate 4, a pair of side plates 12, and the bottom plate 3. Then, a pair of inner flaps 22 of the side plates 12 are bent so that their leading edges face each other, the upper outer flap 21 of the top plate 4 is superposed on the upper surfaces of the pair of inner flaps 22, the lower outer flap 23 of the bottom plate 3 is superposed on the upper surfaces of the pair of inner flaps 22, and the upper outer flap 21, the lower outer flap 23, and the inner flaps 22 are fixed by adhesion to form and seal the closing portion 5.

[0042] On the top plate 4 and the upper outer flap 21 constituting the closing portion 5, a hand hole planned portion 50A is formed at a position corresponding to a gap extending between the top plate 4 and the closing portion 5 on the upper end edge side and sandwiched by the leading edges of the pair of inner flaps 22.

[0043] The hand hole planned portion 50A is provided on the top plate 4 and has a hand hole fold line 51 extending along the boundary line between the top plate 4 and the upper outer flap 21, and a hand hole breakable line 52 provided across the top plate 4 and the upper outer flap 21, connecting both ends of the hand hole fold line 51 and extending by bending or curving.

[0044] Further, the hand hole breakable line 52 includes a pair of inclined portions 52a extending gradually away from each other from both ends of the hand hole fold line 51, and its lower region is also surrounded by a breakable line.

[0045] [Configuration of the corrugated cardboard 1X] Next, the configuration of the corrugated cardboard (blank) 1X forming the packaging box 1 will be described.

[0046] As shown in the developed view in Fig. 2, the packaging box 1 is formed from a single piece of corrugated cardboard 1X. Note that Fig. 2 shows the back side of the corrugated cardboard 1X that is the inner side when the packaging box 1 is assembled.

[0047] The cardboard sheet 1X includes, from the right side toward FIG. 2, a top plate 11 (corresponding to the top plate 4 of the present invention), a first side plate 12 connected to the left end edge of the top plate 11 via a body fold line a, a bottom plate 13 (corresponding to the bottom plate 3 of the present invention) connected to the left end edge of the first side plate 12 via the body fold line a, and a second side plate 12 connected to the left end edge of the bottom plate 13 via the body fold line a. Further, an adhesive piece 14 is connected to the left end edge of the second side plate 22 via the body fold line a.

[0048] The top plate 11 has an upper outer flap 21 connected to its upper end edge via an upper outer flap fold line b1. The top plate 11 has an upper outer flap 21 connected to its lower end edge via the upper outer flap fold line b1. Note that the upper outer flap fold line b1 branches into an upper (top plate 11 side) branch fold line b11 and a lower (upper outer flap 21 side) branch fold line b12 in front of reaching a hand hole planned portion 50A as described later, and is integrated with a hand hole fold line 51 or a hand hole breakable line 52 (lower edge portion 52c) that forms the hand hole planned portion 50A respectively (see FIG. 3).

[0049] The first side plate 12 has an inner flap 22 connected to its upper end edge via an inner flap fold line b2. Also, an inner flap 22 is connected to its lower end edge via the inner flap fold line b2.

[0050] The bottom plate 13 has a lower outer flap 23 connected to its upper end edge via a lower outer flap fold line b3. Also, a lower outer flap 23 is connected to its lower end edge via the lower outer flap fold line b3.

[0051] The second side plate 12 has an inner flap 22 connected to its upper end edge via an inner flap fold line b2. Also, an inner flap 22 is connected to its lower end edge via the inner flap fold line b2.

[0052] Next, the bulging portion (11a) of the top plate 11 will be described.

[0053] The top plate 11 has, at its outer edge, a body fold line a serving as the outer edge, an upper outer flap fold line b1, and a connection guiding fold line c1 that is linearly formed at an interval inward from the edge and is formed and arranged in a rectangular shape with a smaller area than the top plate 11 as a whole, and a bulging guiding line (c1, c2) composed of an inclined guiding fold line c2 extending from each corner of the connection guiding fold line c1 toward each adjacent corner of the top plate 11.

[0054] By mountain-folding the connection guiding fold line c1 and the inclined guiding fold line c2, the inclined guiding fold line c2 rises while inclining toward the central part to form a ridge line, and a bulging part 11a, which is the area surrounded by the connection guiding fold line c1, bulges out and protrudes outward from the plane of the top plate 11, and a space is formed between the lower surface of the top plate 11 and the packaged article such as a PET bottle.

[0055] The connection guiding fold line c1 and the inclined guiding fold line c2 are formed by ruled lines for forming normal fold lines.

[0056] Next, referring to FIG. 3, the planned handhole portion 50A will be described.

[0057] The planned handhole portion 50A is formed at a position extending across the upper outer flap 21 forming the closing portion 5 and the top plate 11. The planned handhole portion 50A includes a handhole fold line 51 formed on the top plate 11 side, and extends in a V-shaped manner gradually widening obliquely downward from both ends of the handhole fold line 51, that is, toward the upper outer flap 21, and then folds back while drawing an arc so as to face each other, and is formed by a handhole breakable line 52 that surrounds the lower region of the handhole fold line 51 in a U shape.

[0058] In the present embodiment, the handhole fold line 51 is formed parallel to the upper outer flap fold line b1 at a position that enters the top plate 11 side from the upper outer flap fold line b1.

[0059] The hand hole breakable line 52 is formed by a pair of inclined portions 52a that are shaped like an inverted V, gradually widening as they extend from both ends of the hand hole fold line 51 toward the upper outer flap 21 side where the interval is lower, that is, gradually separating from each other; a pair of connecting portions 52b that curve downward and inward from each end of the inclined portion 52a so as to approach each other; and a lower edge portion 52c that linearly connects the ends of each connecting portion 52b.

[0060] The planned hand hole portion 50A has a shape in which the corners at both lower ends of an isosceles trapezoid with the hand hole fold line 51 as the upper base and the lower edge portion 52c as the lower base are rounded with a curved line. Therefore, the hand hole fold line 51 and the lower edge portion 52c are straight and parallel to each other. The hand hole breakable line 52 consists of discontinuous cuts and can be easily broken.

[0061] The length L1 of the hand hole fold line 51 is formed to be less than the average value L0 of the hand width of Japanese adult women.

[0062] Here, the average value of the hand width of Japanese adult women is, for example, B03: hand width shown in the AIST Japanese Hand Dimension Data - Dimension Item List (https: / / www.airc.aist.go.jp / dhrt / hand / data / list.html), which is the straight-line distance passing through the metacarpale radiale (radial midpoint of the second metacarpal bone: the point protruding most toward the thumb side of the second metacarpal head) and the metacarpale ulnare (ulnar midpoint of the fifth metacarpal bone: the point protruding most toward the little finger side of the fifth metacarpal head) in the state where the hand is stretched (with the fingers and palm) and the second to fifth fingers are aligned and the thumb is abducted. Also, it is the length measured from the back of the hand with the palm placed on a table.

[0063] Specifically, according to the above data, B03 corresponding to the average value L0 of the hand width of Japanese adult women is 74.0 mm. The specific length L1 of the hand hole fold line 51 in this embodiment is not particularly regulated, but for example, it is 40 mm or less.

[0064] Incidentally, the average value of the hand width of Japanese adult men is B03: 83.3 mm, which is known to be longer than L0.

[0065] As described above, since the length L1 of the hand-hole fold line 51 is set to be less than the average value L0 of the hand width of Japanese adult women, at least a part of the second finger and the fifth finger comes into contact with the inclined portion 52a.

[0066] A pair of linear start break lines 53 are formed downward from the connection portion between the connection portion 52b and the lower edge portion 52c. Further, the lower end portions of the respective start break lines 53 are connected by a start fold line 54. The rectangular region surrounded by the lower edge portion 52c, the start break line 53, and the start fold line 54 becomes the start break portion 55.

[0067] In the present embodiment, the hand-hole planned portion 50A is formed across the upper outer flap fold line b1 over the top plate 11 and the upper outer flap 21.

[0068] Further, the upper outer flap fold line b1 branches vertically in front of the hand-hole planned portion 50, and a pair of branch fold lines b11 and b12 are formed which branch and extend in an inverted V shape from the tip of the upper outer flap fold line b1.

[0069] That is, an upper (one) branch fold line b11 that slopes upward toward the top plate 11 side and a lower (the other) branch fold line b12 that slopes downward toward the lower side of the closing portion 5 are formed. The upper branch fold line b11 is connected to the hand-hole fold line 51 which is the base end of the inclined portion 52a, and the lower branch fold line b12 is connected to the end of the lower edge portion 52c.

[0070] The inclined portion 60 surrounded by the upper branch fold line b11 on the left side, the hand-hole fold line 51, and the upper branch fold line b11 on the right side, and the lower branch fold line b12 on the left side, the lower edge portion 52c, and the lower branch fold line b12 on the right side has a shape of a hexagon approximated to a spindle shape as a whole.

[0071] Even if the upper outer flap 21 is bent from the upper outer flap fold line b1, this area will not bend. Therefore, when the upper outer flap 21 is bent, it bends along the lines reaching the upper left branch fold line b11, the handhole fold line 51, and the upper right branch fold line b11 on the left side, and the lines reaching the lower left branch fold line b12, the lower edge part 52c, and the lower right branch fold line b12 on the right side, respectively. Accordingly, the inclined part 60 forms an inclined surface of approximately 45° between the top plate 11 and the upper outer flap 21.

[0072] The upper branch fold line b11 and the lower branch fold line b12 are formed by ruled lines for forming a normal fold line.

[0073] [Assembly of Packaging Box 1] Next, the assembly of the packaging box 1 will be described.

[0074] To form the packaging box 1 using the corrugated cardboard 1X, first, place the packaged goods such as PET bottles on the bottom plate 13.

[0075] Next, raise the first side plate 12 and the second side plate 12 connected to both the left and right ends of the bottom plate 13 (left and right in FIG. 2, the same hereinafter) by valley-folding each body fold line a. Then, fold the top plate 11 connected to the first side plate 12 by valley-folding the body fold line a by 90° with respect to the side plate 12 to face the bottom plate 13.

[0076] At this time, also fold the adhesive piece 14 connected to the second side plate 12 by 90° with respect to the second side plate 12 by valley-folding the body fold line a. Then, adhere the surface of the adhesive piece 14 and the back surface near the open end of the top plate 11 to form a cylindrical body part 2.

[0077] Next, each inner flap 22 connected to the first side plate 12 and the second side plate 12 is bent approximately 90° inwardly of the packaging box 1 along the inner flap fold line b2, and their leading edges are opposed to each other. Next, the lower outer flap 23 connected to the bottom plate 13 is bent approximately 90° inwardly of the packaging box 1 along the lower outer flap fold line b3 and superposed on the surface of the inner flap 22.

[0078] Next, the upper outer flap 21 connected to the top plate 11 is bent approximately 90° inwardly of the packaging box 1 along the upper outer flap fold line b1 and superposed on the surface of the inner flap 22. Thereby, the leading end of the lower outer flap 23 and the leading end of the upper outer flap 21 are opposed to each other. Also, at this time, since there is no upper outer flap fold line b1 as described above in the inclined portion 60, this portion does not bend and the outer edge of the inclined portion 60 bends, so that the inclined portion 60 forms an inclined surface.

[0079] Finally, the surface of the inner flap 22, the back surface of the lower outer flap 23, and the back surface of the upper outer flap 21 are fixed with a folding material to form the closing portion 5. Thereby, the packaging box 1 is completed and the product is sealed.

[0080] [Formation of the handle hole 500A and gripping of the packaging box] Next, with reference to FIGS. 4 to 6, the operation of forming the handle hole 500A and gripping the packaging box 1 will be described.

[0081] First, as shown in FIG. 4, the upper part of the starting break portion 55 formed at the lower part of the handle hole planned portion 50A and formed by the lower edge portion 52c, the pair of starting break lines 53, and the starting fold line 54 is pressed toward the inside of the packaging box 1. Thereby, the lower edge portion 52c and the pair of starting break lines 53 are broken in sequence, the starting fold line 54 is mountain-folded, and the starting break portion 55 is pushed into the packaging box 1.

[0082] Next, as shown in FIG. 5, when the lower part of the handle hole planned portion 50A is pressed toward the inside of the packaging box 1, the handle hole fold line 51 is mountain-folded, and the pair of connection portions 52b and the pair of inclined portions 52a are broken in sequence. Then, it is bent so that fingers can be inserted as it is.

[0083] At this time, as shown in FIG. 6, when the four fingers P2 to P5 excluding the first finger (thumb) P1 are inserted into the formed hand hole 500A so as to lift the top plate 11, as shown in FIG. 7 (fingers are omitted for clarity of structure), the connection guiding fold line c1 and the inclination guiding fold line c2 are mountain-folded, and the bulging portion 11a bulges and deforms and protrudes outward from the plane of the top plate 11.

[0084] Thereby, a space is formed between the lower surface of the top plate 11 and the packaged article such as a plastic bottle, and the four fingers P2 to P5 that have entered the space from the hand hole 500A can be inserted to the deepest part. Further, along with the insertion operation of the fingers, the broken piece of the planned hand hole portion 50A bends inside the packaging box 1 with the hand hole fold line 51 as the rotation axis, and finally overlaps on the back surface of the top plate 11.

[0085] At this time, as shown in FIG. 6, since the length L1 of the hand hole fold line 51 is set to be smaller than the average value of the hand widths of Japanese women, the third finger (middle finger) P3 and the fourth finger (ring finger) P4 are arranged at the position of the hand hole fold line 51 and contact the hand hole fold line 51, and a part or all of the second finger (index finger) P2 or the fifth finger (little finger) P5 is arranged on each cut edge cut by the pair of inclined portions 52a and contacts each inclined portion 52a. Further, the tip sides of the inserted fingers P2 to P5 are in surface contact with the top plate 4 via the broken piece of the planned hand hole portion 50A.

[0086] Next, the thumb is applied to the inserted fingers from above, and the top plate 11 is gripped. At this time, since the broken piece of the planned hand hole portion 50A overlaps on the lower surface of the gripped top plate 11, two plates are gripped.

[0087] In this state, when the packaging box 1 is lifted, the four fingers mainly support the packaging box 1 via the top and bottom surfaces and the broken piece of the broken planned hand hole portion 50A, and the force applied in the direction parallel to the hand hole 500A formation surface becomes small.

[0088] Next, the effects of the first embodiment will be described.

[0089] In the packaging box 1 of this embodiment, since the handhole fold line 51 is provided on the top plate 11, the peripheral edge of the inverted V shape (inclined portion 52a) is formed on the top plate 11 (in the horizontal direction). Therefore, when lifting using the handhole 500A, the fingers do not come into line contact with the peripheral edge of the inverted V shape and stress does not concentrate.

[0090] Therefore, according to the packaging box 1 of this embodiment, when lifting using the handhole 500A, it is possible to further prevent the periphery of the handhole 500A from being broken unintentionally due to its weight.

[0091] Originally, in a conventional packaging box, when inserting a finger into the handhole and gripping the box, since both ends in the width direction of the fingers (index finger to little finger) exactly correspond to the connection portion between the handhole breakable line and the handhole fold line, stress concentrates on this connection portion and there is a problem that it is easy to break from here.

[0092] In contrast, in the packaging box 1 of this embodiment, since the handhole fold line 51 is formed to have a length L1 that is less than the average value of the hand width L0 of Japanese adult women, when bending the broken piece of the handhole planned portion 50A inward of the packaging box 1 to cover the connection portion between the handhole breakable line 52 and the handhole fold line 51 from the inner surface side of the top plate 11, the connection portion between the handhole breakable line 52 and the handhole fold line 51 is arranged at the intermediate portion in the width direction of the four inserted fingers P2 to P5 (for example, near the middle finger and ring finger).

[0093] Therefore, since the periphery of the connection portion can be supported by the four fingers P2 to P5 and through the broken piece of the handhole planned portion 50A, concentration of stress on the connection portion can be avoided. Note that the fact that the handhole fold line 51 is formed to have a length L1 that is less than the average value of the hand width of Japanese adult women naturally means that it is also less than the average value of the hand width of Japanese adult men.

[0094] The packaging box 1 of this embodiment is in the so-called wrap-around form. In order to form the body by winding the blank sheet 1X around the packaged items such as arranged PET bottles and cans, there is almost no gap between the top plate 11 and the packaged items. Therefore, it may be tapered like a PET bottle, but in the case of a straight-sided shape like a canned beer, it may be difficult to bend the broken piece of the hand-hole planned portion 50A inward of the packaging box and insert a finger between the packaged item and the top plate 11 through the hand-hole 500A.

[0095] In the packaging box 1 of this embodiment, inclined guide fold lines c2 extending from the four corners toward the center are formed on the top plate 11.

[0096] In addition to the inclined guide fold lines c2, connection guide fold lines c1 formed in a rectangular shape by connecting the adjacent tips of the inclined guide fold lines c2 are formed.

[0097] For this reason, the top plate 11 can be bent into a substantially frustum-of-a-square-pyramid shape. As a result, by deforming the top plate 11 upward, a finger can be easily inserted between the packaged item through the hand-hole 500A, and the box can be lifted with the entire palm side from the index finger P2 to the little finger P5 along the top plate 11.

[0098] Also, the fact that the entire top plate 11 is deformed into a substantially frustum-of-a-square-pyramid shape means that the outer flap 21 side of the top plate 11 constitutes the side surface of the frustum of a square pyramid. Specifically, the boundary line between the top plate 11 and the outer flap 21 is bent into a trapezoidal shape with the lower base, the connection guide fold line c1 as the upper base, and a pair of inclined guide fold lines c2 as the legs.

[0099] On the other hand, the broken piece of the hand-hole planned portion 50A is formed in a shape that fits inside the trapezoidal shape when polymerized on the inner surface of the top plate 11. Therefore, when the broken piece of the hand-hole planned portion 50A is bent inward of the packaging box 1, it is polymerized without a gap on the inner surface of the trapezoidal shape, that is, the inclined side surface of the frustum of a square pyramid. Thereby, the load applied to the connection portion between the hand-hole breakable line 52 and the hand-hole fold line 51 can be dispersed by the broken piece of the hand-hole planned portion 50A.

[0100] In the packaging box 1 of the present embodiment, since the inclination guiding fold line c2 extending from the four corners toward the center is formed on the top plate 11, the top plate 11 can be bent into a substantially quadrangular pyramid shape. The fact that the entire top plate 11 is deformed into a substantially quadrangular pyramid shape means that the outer flap 21 side on the top plate 11 becomes an obtuse angle with respect to the side plate as the side surface of the quadrangular pyramid and inclines.

[0101] In this case, as described above, when lifted using the handle hole 500A, fingers come into contact with the periphery (in this case, the top plate 11) from which the inclined portion 52a has slipped out, stress is concentrated, and there is a possibility that the periphery is crushed or broken.

[0102] However, a hexagonal fold line is formed at the center in the width direction at the boundary between the top plate 11 and the outer flap 21 by the handle hole fold line 51, the outer flap fold line b1, and a pair of branch fold lines b11, b12. Therefore, when the boundary between the top plate 11 and the outer flap 21 is bent at a right angle along the outer flap fold line b1, the center in the width direction of the boundary is bent along the hexagonal fold line, and an inclined portion 60 that connects the top plate 11 and the outer flap 21 while inclining is formed.

[0103] Since one end of each of the branch fold lines b11, b12 that form a part of the outer periphery of the inclined portion 60 is connected to the base end of the inclined portion 52a and the other end is connected to the end of the lower edge portion 52c, as a result, the inclined portion 60 is arranged so as to surround from the outside. Therefore, when lifted using the handle hole 500A, if fingers come into contact with the periphery (in this case, the top plate 11 that is deformed and inclined) from which the inclined portion 60 has slipped out and stress is concentrated and the periphery begins to be crushed, the crushed range gradually spreads along the branch fold line inside the inclined portion 60.

[0104] Thereby, the range crushed in an unintended direction from the periphery from which the inclined portion 60 has slipped out can be expanded, and it is possible to prevent the top plate 11 from being broken. In addition, since the inside of the inclined portion 60 is crushed and serves as a cushion, it is possible to prevent unintended crushing and breakage from occurring outside the inclined portion 60.

[0105] In this embodiment, since the start breaking part 55 connected thereto is formed below the hand hole planned part 50A, the hand hole planned part 50A can be easily broken by breaking from this part.

[0106] [Second Embodiment]

[0107] Hereinafter, with reference to FIG. 8, as an example of an embodiment of the present invention, a packaging box 1 according to a second embodiment (hereinafter, simply referred to as "this embodiment") (corresponding mainly to "the packaging box of the second aspect of the present invention") will be described. Note that for some configurations common to the first embodiment, the same reference numerals are given in the drawings and the description will be omitted as appropriate.

[0108] In FIG. 8, the hand hole planned part 50B of this embodiment is formed at a position extending across the outer flap 21 and the top plate 11, similarly to the first embodiment. Also, the detailed configurations of the hand hole fold line 51 and the hand hole breakable line 52 forming the hand hole planned part 50B are the same.

[0109] On the other hand, the upper branch fold line b11 and the lower branch fold line b12 are not formed, and thus the inclined part 60 is not formed either. Also, the upper outer flap fold line b1 extends linearly from one end to the other end of the upper outer flap 21 without interruption so as to penetrate the hand hole planned part 50B.

[0110] Of the hand hole breakable line 52, a pair of inclined parts 52a are formed on the top plate 11 side, and a pair of connecting parts 52b and a lower edge part 52c are formed on the upper outer flap 21.

[0111] Therefore, when a hand hole is formed, an opening by a pair of inclined parts 52a inclined in a V shape is formed on the top plate 11 side. On the other hand, an opening by each connecting part 52b and the lower edge part 52c is formed on the outer flap 21 side forming the closing part 5.

[0112] In addition, the broken piece of the hand hole planned portion 50B is folded back inward and overlaps with the back surface of the top plate 11. In this state, fingers can be inserted through the openings formed by the respective connecting portions 52b and the lower edge portion 52c, and the thumb can be applied from above to grip the top plate 11.

[0113] Therefore, also in this embodiment, since the broken piece of the hand hole planned portion 50B overlaps with the lower surface of the gripped top plate 11, two plates will be gripped.

[0114] Also, similar to the first embodiment shown in FIG. 6, the fingers inserted into the formed hand hole have the third finger (middle finger) P3 and the fourth finger (ring finger) P4 arranged at the position of the hand hole fold line 51, and the second finger (index finger) P2 or the fifth finger (little finger) P5 is arranged on each cut edge cut by each inclined portion 52a.

[0115] In addition, also in this embodiment, similar to the first embodiment, the top plate 11 has a bulging guiding line (c1, c2) composed of a connection guiding fold line c1 formed at an interval inward from the body fold line a and the upper outer flap fold line b1, and an inclined guiding fold line c2 extending from each corner of the connection guiding fold line c1 toward each corner of the top plate 11.

[0116] Next, the operation and effect of the second embodiment will be described.

[0117] In the packaging box 1 of this embodiment, since the hand hole fold line 51 is provided on the top plate 11, the peripheral edge of the U-shaped (inclined portion 52a) is formed on the top plate 11 (in the horizontal direction). Therefore, when lifting using the hand hole 500A, the fingers do not come into line contact with the U-shaped peripheral edge and stress does not concentrate.

[0118] Therefore, according to the packaging box 1 of this embodiment, when lifting using the hand hole 500A, it is possible to further prevent the periphery of the hand hole 500A from being accidentally broken by its weight.

[0119] In the conventional packaging box, when inserting a finger into the hand hole to grip the box, since both ends in the width direction of the fingers (from the index finger to the little finger) exactly correspond to the connection part between the hand hole breakable line and the hand hole fold line, stress concentrates on this connection part, and there is a problem that it is easy to break from here.

[0120] On the other hand, in the packaging box 1 of this embodiment, since the hand hole fold line 51 is formed to have a length L1 less than the average value of the hand width L0 of Japanese adult women, when the broken piece of the hand hole planned part 50A is bent inward of the packaging box 1 to cover the connection part between the hand hole breakable line 52 and the hand hole fold line 51 from the inner surface side of the top plate 11, the connection part between the hand hole breakable line 52 and the hand hole fold line 51 is arranged at the middle part in the width direction of the four inserted fingers P2 to P5 (for example, near the middle finger and the ring finger).

[0121] Therefore, since the periphery of the connection part can be supported by the four fingers P2 to P5 and through the broken piece of the hand hole planned part 50A, stress concentration on the connection part can be avoided. Note that the fact that the hand hole fold line 51 is formed to have a length L1 less than the average value of the hand width of Japanese adult women naturally means that it is also less than the average value of the hand width of Japanese adult men.

[0122] The packaging box 1 of this embodiment is in a so-called wrap-around form, and in order to form the body part by winding the blank sheet 1X around the packaged objects such as arranged PET bottles and cans, there is almost no gap between the top plate 11 and the packaged object. Therefore, it may be tapered like a PET bottle, but in the case of a cylindrical shape like a canned beer, it may be difficult to bend the broken piece of the hand hole planned part 50A inward of the packaging box and insert a finger between the packaged object and the top plate through the hand hole 500A.

[0123] In the packaging box 1 of this embodiment, inclined guiding fold lines c2 extending from the four corners to the central part are formed on the top plate 11.

[0124] In addition to the inclined guiding fold lines c2, connecting guiding fold lines c1 formed in a rectangular shape by connecting the adjacent tips of the inclined guiding fold lines c2 are formed.

[0125] Therefore, the top plate 11 can be bent into a substantially frustum of a square pyramid shape. As a result, by deforming the top plate 11 upward, a finger can be easily inserted between the top plate 11 and the packaged item through the hand hole 500A, and the box can be lifted with the entire palm side of the index finger P2 to the little finger P5 along the top plate 11.

[0126] In addition, the fact that the entire top plate 11 is deformed into a substantially frustum of a square pyramid shape means that the outer flap 21 side of the top plate 11 constitutes the side surface of the frustum of a square pyramid. Specifically, the boundary line between the top plate 11 and the outer flap 21 is bent into a trapezoidal shape with the lower base, the connection guiding fold line c1 as the upper base, and a pair of inclined guiding fold lines c2 as the legs.

[0127] On the other hand, the broken piece of the hand hole planned portion 50A is formed in a shape that fits inside the trapezoidal shape when superposed on the inner surface of the top plate 11. Therefore, when the broken piece of the hand hole planned portion 50A is bent inward of the packaging box 1, it is superposed on the inner surface of the trapezoidal shape, that is, the inclined side surface of the frustum of a square pyramid, without a gap. As a result, the load applied to the connection portion between the hand hole breakable line 52 and the hand hole fold line 51 can be dispersed by the broken piece of the hand hole planned portion 50A.

[0128] [Third Embodiment] Hereinafter, with reference to FIG. 9, as an example of an embodiment of the present invention, a packaging box 1 according to the third embodiment (hereinafter, simply referred to as "the present embodiment".) (corresponding mainly to "the packaging box of the first aspect of the present invention".) will be described. Note that, for some configurations common to the first embodiment, the same reference numerals are given in the drawings and the description will be omitted as appropriate.

[0129] In FIG. 9, the hand hole planned portion 50C of the present embodiment is formed in the upper part of the outer flap 21 that forms the closing portion 5. More specifically, the hand hole fold line 51 of the hand hole planned portion 50C of the present embodiment is formed at the same position as the outer flap fold line b1.

[0130] On the other hand, also in this embodiment, the upper branch fold line b11 and the lower branch fold line b12 are not formed, and thus the inclined portion 60 is not formed either.

[0131] A part of the upper outer flap fold line b1 overlaps with the hand hole fold line 51 and extends linearly from one end to the other end of the upper outer flap 21 without interruption.

[0132] The hand hole breakable line 52 is connected to the upper outer flap fold line b1 and is entirely formed on the outer flap 21 side that forms the closing portion 5.

[0133] Therefore, the hand hole breakable line 52 is formed on the outer flap 21 from both ends of the hand hole fold line 51 that overlaps with the upper outer flap fold line b1 where the hand hole breakable line 52 is formed. That is, the hand hole breakable line 52 is formed by a pair of inclined portions 52a formed in a V shape such that the interval therebetween widens toward the lower side, a pair of connecting portions 52b curved so as to approach each other downward and inward from each end of the inclined portion 52a, and a lower edge portion 52c linearly connecting the ends of each connecting portion 52b.

[0134] The detailed configurations of the other hand hole fold line 51 and the hand hole breakable line 52 are the same as those in the first embodiment.

[0135] The formed hand hole 500A opens to the outer flap 21 side that forms the closing portion 5. Also, the broken piece of the hand hole planned portion 50C is folded back inward and overlaps the back surface of the top plate 11.

[0136] In this state, a finger can be inserted into the formed hand hole 500A, and the thumb can be applied from above to grip the top plate 11.

[0137] Also, similar to the first embodiment shown in FIG. 6, the fingers inserted into the formed hand hole 500A have the third finger (middle finger) P3 and the fourth finger (ring finger) P4 arranged at the position of the hand hole fold line 51, and the second finger (index finger) P2 or the fifth finger (little finger) P5 is arranged on each cut edge cut by each inclined portion 52a.

[0138] In this embodiment, a pair of inclined portions 52a are also formed on the outer flap 21 side that forms the closing portion 5. For this reason, the second finger (index finger) P2 or the fifth finger (little finger) P5 is arranged at a right angle to the plane of the outer flap 21 on each cut edge cut by each inclined portion 52a. That is, the second finger (index finger) P2 or the fifth finger (little finger) P5 abuts on the cut surface of each inclined portion 52a from the vertical direction.

[0139] On the other hand, since the third finger (middle finger) P3 and the fourth finger (ring finger) P4 are arranged at the position of the hand hole fold line 51, these fingers are in surface contact with the portion where the top plate 11 and the broken piece of the hand hole planned portion 50C overlap.

[0140] In this embodiment as well, similar to the first embodiment, the top plate 11 has a bulge guiding line (c1, c2) composed of a connection guiding fold line c1 formed at an interval inward from the body fold line a and the upper outer flap fold line b1, and an inclined guiding fold line c2 extending from each corner of this connection guiding fold line c1 toward each corner of the top plate 11.

[0141] Next, the effects of the third embodiment will be described.

[0142] In the packaging box 1 of this embodiment, the planned hand hole portion 50A can be broken along the hand hole breakable line 52, and the broken piece of the planned hand hole portion 50A can be bent inward of the packaging box 1 along the hand hole fold line 51 to form the hand hole 500A. At this time, since the hand hole fold line 51 extends along the boundary line between the top plate 11 and the upper outer flap 21, the broken piece of the planned hand hole portion 50A is superposed on the inner surface of the top plate 11. Therefore, when inserting a finger into the hand hole 500A, the entire palm side from the index finger P2 to the little finger P5 can be placed along the top plate 11 to lift the box. That is, by bringing the entire palm side from the index finger P2 to the little finger P5 into surface contact with the top plate 11, the load can be dispersed.

[0143] Further, since the hand hole breakable line 52 of the planned hand hole portion 50A has a pair of inclined portions 52a that gradually separate from each other and extend from both ends of the hand hole fold line 51, when the broken piece of the planned hand hole portion 50A is bent inward of the packaging box 1, the connecting portion between the hand hole breakable line 52 and the hand hole fold line 51, which is usually easily broken unintentionally, can be covered from the inner surface side of the top plate 11 by the region sandwiched between the pair of inclined portions 52a of the broken piece of the planned hand hole portion 50A. That is, the load applied to the connecting portion between the hand hole breakable line 52 and the hand hole fold line 51 can be dispersed by the broken piece of the planned hand hole portion 50A.

[0144] Therefore, according to the packaging box 1 of this embodiment, when lifting using the hand hole 500A, it is possible to prevent the periphery of the hand hole 500A from being broken unintentionally due to its weight.

[0145] Originally, in a conventional packaging box, when inserting a finger into the hand hole 500A to grip the box, since both ends in the width direction of the finger (from the index finger to the little finger) exactly correspond to the connecting portion between the hand hole breakable line and the hand hole fold line, there is a problem that stress concentrates on this connecting portion and it is easy to break from here.

[0146] On the other hand, in the packaging box 1 of the present embodiment, since the hand hole folding line 51 is formed to have a length L1 less than the average value of the hand width L0 of Japanese adult women, when the broken piece of the hand hole planned portion 50A is bent inward of the packaging box 1 to cover the connection portion between the hand hole breakable line 52 and the hand hole folding line 51 from the inner surface side of the top plate 11, the connection portion between the hand hole breakable line 52 and the hand hole folding line 51 is arranged at the intermediate portion in the width direction of the four inserted fingers P2 to P5 (for example, near the middle finger and the ring finger).

[0147] Therefore, since the periphery of the connection portion can be supported by the four fingers P2 to P5 and through the broken piece of the hand hole planned portion 50A, the concentration of stress on the connection portion can be avoided. Note that the fact that the hand hole folding line 51 is formed to have a length L1 less than the average value of the hand width of Japanese adult women naturally means that it is also less than the average value of the hand width of Japanese adult men.

[0148] The packaging box 1 of the present embodiment is in a so-called wrap-around form. In order to form the body portion by winding the blank sheet 1X around the packaged objects such as arranged PET bottles and cans, there is almost no gap between the top plate 11 and the packaged objects. Therefore, it may be tapered like a PET bottle, but in the case of a shape with a straight body like a canned beer, it may be difficult to bend the broken piece of the hand hole planned portion 50A inward of the packaging box and insert a finger between the packaged object and the top plate 11 through the hand hole 500A.

[0149] In the packaging box 1 of the present embodiment, inclined guiding folding lines c2 extending from the four corners toward the center are formed on the top plate 11.

[0150] In addition to the inclined guiding folding lines c2, connecting guiding folding lines c1 formed in a rectangular shape by connecting the adjacent tips of the inclined guiding folding lines c2 are formed.

[0151] For this reason, the top plate 11 can be bent into a substantially frustum of a square pyramid shape. As a result, by deforming the top plate 11 upward, a finger can be easily inserted between the packaged object through the hand hole 500A, and the entire palm side from the index finger P2 to the little finger P5 can be placed along the top plate 11 to lift the box.

[0152] In addition, when the entire top plate 11 is deformed into a substantially frustum of a square pyramid shape, the outer flap 21 side on the top plate 11 will form the side surface of the frustum of a square pyramid. Specifically, the boundary line between the top plate 11 and the outer flap 21 will be bent into a trapezoidal shape with the lower base being the boundary line, the upper base being the connection guiding fold line c1, and the pair of inclined guiding fold lines c2 being the legs.

[0153] On the other hand, the broken piece of the planned handhole portion 50A is formed in a shape that fits inside the trapezoidal shape when polymerized on the inner surface of the top plate 11. Therefore, when the broken piece of the planned handhole portion 50A is bent inward of the packaging box 1, it is polymerized without a gap on the inner surface of the trapezoidal shape, that is, the inclined side surface of the frustum of a square pyramid. Thereby, the load applied to the connection portion between the handhole breakable line 52 and the handhole fold line 51 can be dispersed by the broken piece of the planned handhole portion 50A.

[0154] [Modification Example] Next, a modification example of the packaging box 1 of the present embodiment will be described.

[0155] In the present embodiment, an example has been shown and described where there is a gap between the tips of the inner flaps 22 through which the handhole 500A can be formed. However, the present invention is not limited to this. Even when the gap between the tips of the inner flaps 22 is narrow, a recess for forming the handhole 500A may be formed in the inner flaps 22.

[0156] In the present embodiment, a square tubular body 2 has been shown, but the present invention is not limited to this. The body 2 may be, for example, a multi-sided tubular body with more sides than four, such as a hexagonal or octagonal tubular body (not shown in the figures).

[0157] In the present embodiment, an example has been shown and described where the connection guiding fold line c1 and the inclined guiding fold line c2 for forming the bulging portion 11a are ruled lines for forming normal fold lines. However, the present invention is not limited to this. For reasons such as making it easier to bend, it may be formed with discontinuous cut lines, or a combination of ruled lines and discontinuous cut lines may be used.

[0158] In this embodiment, an example in which the connection guiding fold line c1 and the inclination guiding fold line c2 that form the bulging portion 11a are formed has been described. However, the present invention is not limited to this, and the connection guiding fold line c1 may be omitted and it may be configured only by the inclination guiding fold line c2. Alternatively, the bulging portion 11a may be configured by only one fold line.

[0159] In this embodiment, an example in which the bulging portion 11a is formed has been described. However, the present invention is not limited to this, and depending on the article to be packaged, the bulging portion 11a may be omitted.

[0160] In this embodiment, the tips of the lower outer flap 23 and the upper outer flap 21 are opposed to each other so as to abut against each other and are superposed on the outer surface of the inner flap 22. Thus, an example in which the tip of the lower outer flap 23 and the tip of the upper outer flap 21 face each other has been described. However, the present invention is not limited to this, and within a range where there is no problem in strength, the tip of the lower outer flap 23 and the tip of the upper outer flap 21 may be separated from each other to some extent.

[0161] In this embodiment, an example in which one hand hole planned portion 50A is formed at a position straddling the upper outer flap 21 and the top plate 11 has been described. However, the present invention is not limited to this, and it is sufficient if there is one or more on the upper outer flap, and it may be formed at a position straddling the lower outer flap 23 and the bottom plate 13, or a total of two may be provided at upper and lower positions.

[0162] In this embodiment, the connection portion 52b has been described as a broken line curved in an arc shape and the lower edge portion 52c as a straight line. However, the present invention is not limited to this, and the connection portion 52b may be formed in an inverted V shape or a part of a polygon, or the lower edge portion 52c may be a curved line, a waveform, etc., as a set of single or multiple curves.

[0163] In this embodiment, an example has been described in which a rectangular start break portion 55 surrounded by the lower edge portion 52c of the hand hole planned portion 50A, the start break line 53, and the start fold line 54 is formed, and the break operation at the initial stage of hand hole formation starts from the start break portion 55. However, the present invention is not limited to this, and the start break portion 55 may be omitted. In this case, the break operation at the initial stage of hand hole formation is started by breaking the lower edge portion 52c.

[0164] The length L1 of the hand hole fold line 51 was set to 40 mm or less, but it may be set to 35 mm or less.

[0165] In this embodiment, an example has been described in which the upper branch fold line b11 and the lower branch fold line b12 forming the inclined portion 60 are straight lines. However, the present invention is not limited to this, and the upper branch fold line b11 and the lower branch fold line b12 may be slightly curved or formed of a line having a plurality of folds as long as they can form the inclined portion 60.

[0166] In this embodiment, an example has been described in which the upper branch fold line b11 and the lower branch fold line b12 forming the inclined portion 60 are ruled lines for forming a normal fold line. However, the present invention is not limited to this, and they may be formed of discontinuous cut lines, or a combination of ruled lines and discontinuous cut lines may be used.

[0167] In this embodiment, an example has been described in which the commodity as the object to be packaged is placed on the bottom plate 13 and then the packaging box is assembled. However, the present invention is not limited to this, and after assembling the body portion 2 and one closing portion 5, the commodity may be stored inside, and then the other closing portion 5 may be assembled and sealed.

[0168] Also, in this embodiment, each breakable line is shown as being formed as a so-called perforation in which a plurality of straight cuts are intermittent. However, the present invention is not limited to this, and for example, although not shown in the figure, it may be formed as a zipper or the like having a plurality of cuts with one end bent.

Explanation of Reference Numerals

[0169] 1 Packaging box 2 Barrel part 3 Bottom plate 4 Top plate 5 Closing part 21 Upper outer flap 22 Inner flap 23 Lower outer flap 50A Scheduled hand hole part 51 Hand hole fold line 52 Hand hole breakable line 52a Inclined part 52b Connection part 52c Lower edge part a Barrel part fold line b1 Upper outer flap fold line b11, b12 Branch fold lines c1 Connection guiding fold line c2 Inclination guiding fold line

Claims

1. A cardboard packaging box comprising a rectangular tube-shaped body portion extending horizontally and a pair of closing portions for closing the open ends of the body portion respectively, wherein the body portion has a pair of side plates facing each other, a bottom plate connecting the lower end edges of the pair of side plates, and a top plate connecting the upper end edges of the pair of side plates, the closing portion includes a pair of inner flaps connected to the side plates and having their leading edges facing each other with a predetermined gap therebetween, an upper outer flap connected to the top plate and superposed and adhered to the outer surface of the inner flap, and a lower outer flap connected to the bottom plate and superposed and adhered to the outer surface of the inner flap, in the cardboard packaging box, a hand hole planned portion is provided at a position corresponding to the gap sandwiched between the leading edges of the pair of inner flaps on the upper outer flap, the hand hole planned portion has a hand hole folding line extending along the boundary line between the top plate and the upper outer flap, and a hand hole breakable line connecting both ends of the hand hole folding line and extending in a bent or curved manner, the hand hole breakable line is characterized by having a pair of inclined portions extending gradually away from each other from both ends of the hand hole folding line.

2. A cardboard packaging box comprising a rectangular tube-shaped body portion extending horizontally and a pair of closing portions for closing the open ends of the body portion respectively, wherein the body portion has a pair of side plates facing each other, a bottom plate connecting the lower end edges of the pair of side plates, and a top plate connecting the upper end edges of the pair of side plates, the closing portion includes a pair of inner flaps connected to the side plates and having their leading edges facing each other with a predetermined gap therebetween, an upper outer flap connected to the top plate and superposed and adhered to the outer surface of the inner flap, and a lower outer flap connected to the bottom plate and superposed and adhered to the outer surface of the inner flap, in the cardboard packaging box, a hand hole planned portion is provided at a position corresponding to the gap sandwiched between the leading edges of the pair of inner flaps on the top plate and the upper outer flap, the hand hole planned portion has a hand hole folding line provided on the top plate and extending along the boundary line between the top plate and the upper outer flap, and a hand hole breakable line provided across from the top plate to the upper outer flap, connecting both ends of the hand hole folding line and extending in a bent or curved manner, the hand hole breakable line is characterized by having a pair of inclined portions extending gradually away from each other from both ends of the hand hole folding line.

3. In the packaging box according to Claim 1 or 2, the hand hole folding line is formed to have a length less than the average value of the hand widths of adult women.

4. In the packaging box according to claim 1 or 2, the top plate is characterized in that inclined guiding crease lines extending from the four corners thereof toward the central portion are formed.

5. In the packaging box according to claim 4, a connection guiding crease line formed in a rectangular shape by connecting adjacent tips of the inclined guiding crease lines is formed at the central portion of the top plate, when the planned hand hole portion is broken along the hand hole breakable line and mountain-folded along the hand hole crease line, the planned hand hole portion is formed in a shape that overlaps inside a region surrounded by a pair of the inclined guiding crease lines adjacent to the planned hand hole portion and the connection guiding crease line connecting the pair of the inclined guiding crease lines on the inner surface of the top plate. The packaging box is characterized by this.

6. In the packaging box according to claim 2, the top plate is formed with inclined guiding crease lines extending from the four corners thereof toward the central portion, the hand hole breakable line is provided on the upper outer flap and has a lower edge portion extending along the boundary line between the top plate and the upper outer flap, and a connection portion connecting the end of the lower edge portion and the tip of the inclined portion, at the boundary between the top plate and the upper outer flap, a pair of upper outer flap crease lines respectively extending from each end thereof toward the central portion along the boundary line between the top plate and the upper outer flap, and a pair of branched crease lines branching and extending in an inverted V shape from the tips of the upper outer flap crease lines are provided, the branched crease lines are characterized in that one tip is connected to the base end of the inclined portion and the other tip is connected to the end of the lower edge portion. The packaging box is characterized by this.

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