Insert lock type packaging box

Abstract

To provide an insertion-lock type packaging box that is allowed to easily and positively engage an outer flap and an inner flap with each other and excellent in handling workability in a stack state during transportation.SOLUTION: An insertion-lock type packaging box, in which an outer flap 5 and an inner flap 6 are extended respectively from one and the other of side plates 1, 2 adjacent to each other in a peripheral direction so that an insertion piece 8 of the outer flap 5 is inserted into an insertion hole 9 of the inner flap 6 while bending the outer flap 5 along an inward-fold line 7, comprises an extended portion 8a, engagement edge 8b and inclination edge 8c that are provided in the insertion piece 8, a first swing piece 10 and triangular second swing piece 11 that are provided in a portion to become the insertion hole 9, and an engagement edge 12 that is formed by cutting in a slit form from an end of the second swing piece 11. When inserting the insertion piece 8 into the insertion hole 9, the outer flap 5 is inhibited from returning by the first swing piece 10 and the second swing piece 11 sequentially swinging by being pushed by the insertion piece 8 and the engagement edge 8b of the extended portion 8a of the insertion piece 8 and the engagement edge 12 of the insertion hole 9 being engaged with each other.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] This invention relates to a plug - lock type packaging box that can be sealed without using staples or adhesive tapes.

Background Art

[0002] When shipping agricultural products such as vegetables and fruits, a plug - lock type packaging box that can quickly pack and seal agricultural products at the workplace is widely used. The applicant of this application has proposed a plug - lock type packaging box as shown in FIG. 9 in Patent Document 1 below.

[0003] In this packaging box, among the side plates 51 and 52 adjacent to each other in the circumferential direction, an outer flap 53 extends from the side plate 51 on the width side, and an inner flap 54 extends from the side plate 52 on the long side. While bending the outer flap 53 along the middle fold line 57 spanning between both side edges at the middle part in the extending direction, the insertion pieces 55 protruding from both side parts at the tip of the outer flap 53 are inserted into the insertion holes 56 of the inner flap 54 for sealing. A handle hole 51a is formed in the side plate 51 on the width side.

[0004] In this packaging box, the insertion piece 55 is pressed by a swing piece 58 that swings around a hinge line 58a inside the insertion hole 56, and the protrusion 55a of the insertion piece 55 and the inclined edge 56a of the insertion hole 56 interfere with each other, preventing the insertion piece 55 from coming out of the insertion hole 56.

[0005] Moreover, in Patent Document 2 below, as shown in FIG. 10, an engagement edge 55b is formed on the base side of the insertion piece 55, and the engagement edge 55b is engaged with an engagement edge 56b facing the notch of the insertion hole 56 to make the insertion piece 55 difficult to come out of the insertion hole 56. The engagement edge 56b of the insertion hole 56 is inserted from the end of the hinge line 58a of the swing piece 58, and the hinge line 58a is orthogonal to the insertion direction of the insertion piece 55 into the insertion hole 56.

Prior Art Documents

Patent Documents

[0006] [Patent Document 1] Patent No. 3897737 [Patent Document 2] Japanese Patent Publication No. 2009-149332 [Overview of the project] [Problems that the invention aims to solve]

[0007] However, conventional snap-lock type packaging boxes have drawbacks, such as the high resistance of corrugated cardboard to bending, which make it difficult to insert the insert piece 55 into the insertion hole 56. Furthermore, when a large quantity of bulky agricultural products are packed into the packaging box, a gap may form between the incompletely inserted insert piece 55 and the insertion hole 56. This can cause the engagement between the outer flap 53 and the inner flap 54 to unexpectedly disengage due to internal pressure and vibration from the contents during transport.

[0008] Furthermore, the common configuration has an outer flap 53 extending from the side panel 51 on the width side. In such a configuration, when multiple packaging boxes are stacked, and the upper packaging boxes are pulled forward or pushed backward using the handle holes 51a of the side panel 51 on the width side, the bottom surface of the upper packaging boxes gets caught on the outer flap 53 of the lower packaging boxes. This necessitates lifting them slightly before moving them, resulting in poor work efficiency.

[0009] Therefore, this invention aims to provide a snap-lock type packaging box that allows the outer flap and inner flap to be easily and reliably engaged when sealing, and offers excellent handling efficiency when stacked during transport. [Means for solving the problem]

[0010] To solve the above-mentioned problems, this invention provides a snap-lock type packaging box in which an outer flap extends from one side plate adjacent to the other in the circumferential direction, and an inner flap extends from the other, and the outer flap is bent along a central fold line that runs between both side edges in the middle of the extension direction, and insertion pieces protruding from both sides of the tip of the outer flap are inserted into insertion holes in the inner flap, The outer flap is provided with an outward projection on the insertion piece, and an engaging edge is formed on the projection, located on the front side in the direction of insertion of the insertion piece into the insertion hole, and an inclined edge is formed on the outer edge of the insertion piece, sloping inward from the projection towards the tip. The portion of the inner flap that forms the insertion hole is provided with a first and second pivoting piece that pivots around the hinge wire as an axis, and an engaging edge is formed from the end of the second pivoting piece by a slit-shaped notch, and the hinge wire of the second pivoting piece is inclined so that the second pivoting piece is triangular in shape. When inserting the insertion piece into the insertion hole, the first and second swinging pieces are sequentially swung by being pushed by the tip and inclined edge of the insertion piece, and the insertion piece is inserted into the insertion hole, which has an enlarged opening. After the protruding portion of the insertion piece pushes open the slit-shaped portion facing the engagement edge of the insertion hole and passes through, the first and second oscillating pieces return to their original positions, the portions facing the engagement edge of the insertion hole close, and the engagement between the engagement edge of the insertion piece and the engagement edge of the insertion hole suppresses the return of the outer flap.

[0011] Furthermore, the end of the engagement edge in the notch of the insertion hole has a curved portion formed thereon, which is rounded in the direction in which the insertion piece is inserted into the insertion hole.

[0012] Furthermore, the portion of the inner flap facing the insertion hole has a pressing portion formed thereon, which protrudes toward the front from the tip of the insertion piece in the direction of insertion into the insertion hole.

[0013] Furthermore, among the side plates adjacent to each other in the circumferential direction, the outer flap extends from the long-faced side plate, and the inner flap extends from the wide-faced side plate.

[0014] In addition, the outer flap is slightly bent along the central fold line, so that the engaging edge of the insertion piece and the engaging edge of the insertion hole engage with each other. [Effects of the Invention]

[0015] In the plug-in lock type packaging box according to the present invention, when inserting the plug-in piece into the plug-in hole, at the portion facing the tip of the first swing piece that is swung by being pushed by the tip of the plug-in piece, the opening of the plug-in hole expands. Subsequently, the second swing piece that forms a triangular shape by being pushed by the inclined edge of the plug-in piece swings about the hinged line that is inclined, and the opening of the plug-in hole expands on the side of the first swing piece at the portion facing the tip of the second swing piece. Therefore, the plug-in piece can be easily inserted into the plug-in hole.

[0016] Then, the portion facing the engaging edge of the plug-in hole is pushed and expanded by the protruding portion of the plug-in piece and slightly opens. After the protruding portion of the plug-in piece passes through, it immediately closes. Therefore, the protruding portion of the plug-in piece cannot escape from the portion facing the engaging edge of the plug-in hole, and the engagement between the outer flap and the inner flap does not accidentally come off during transportation or the like, and the sealed state is reliably maintained.

[0017] For this reason, when the long side is the outer flap and the width side is the inner flap, even if the outer flap tries to open and float due to strong repulsion, the engaging edge of the plug-in piece and the engaging edge of the plug-in hole engage, suppressing the return of the outer flap and maintaining the sealed state. Therefore, the step difference on the overlapping surface of the outer flap and the inner flap can be eliminated as much as possible, preventing the stacked packaging boxes from getting hooked on each other, and improving the workability during transportation.

Brief Explanation of Drawings

[0018] [Figure 1] Perspective view showing the sealed state of the plug-in lock type packaging box according to the first embodiment of the present invention [Figure 2] Partially enlarged perspective view showing the insertion process of the above plug-in piece into the plug-in hole [Figure 3] Partially enlarged plan view showing the insertion state of the above plug-in piece into the plug-in hole [Figure 4] Partially enlarged perspective view showing the insertion state of the above plug-in piece into the plug-in hole from inside the box [Figure 5] View showing the blank of the above plug-in lock type packaging box [Figure 6]Perspective view showing the sealed state of the plug-in lock type packaging box according to the second embodiment of the present invention [Figure 7] Partial enlarged perspective view showing the insertion process of the insertion piece into the insertion hole as described above [Figure 8] View showing the blank of the plug-in lock type packaging box as described above [Figure 9] Perspective view showing the sealing process of the plug-in lock type packaging box described in Patent Document 1 [Figure 10] Perspective view showing the sealing process of the plug-in lock type packaging box described in Patent Document 2

Mode for Carrying Out the Invention

[0019] <First Embodiment> The first embodiment of the present invention will be described based on FIGS. 1 to 5.

[0020] (Overview) As shown in FIG. 1, the plug-in lock type packaging box to be sealed is a rectangular parallelepiped for storing agricultural products such as vegetables and fruits shipped from farmers. Through the process shown in FIG. 2, the top surface is closed with a lock structure as shown in FIGS. 3 and 4.

[0021] (Blank) As shown in FIG. 5, in the blank of this packaging box made of cardboard, the step direction is oriented in the vertical direction, and the side plates 1 of each pair of long sides and the side plates 2 of the width sides are alternately connected via ruled lines. Handle holes 2a are formed in the upper parts of the pair of side plates 2. A substitute piece 3 is connected via a ruled line to the outer end of the side plate 1 located at the end of the blank.

[0022] At the lower ends of each pair of side plates 1 and 2, bottom flaps 4a and 4b that overlap each other during assembly to form the bottom wall 4 are respectively connected via ruled lines.

[0023] An outer flap 5 is connected to the upper end of a pair of side plates 1, and an inner flap 6 is connected to the upper end of a pair of side plates 2, both via a scoring line. In the middle of the outer flap 5 in the direction extending from the side plate 1, a central fold line 7 is provided, extending between both edges, and the central fold line 7 is a lead line in which pressing lines and cuts are intermittently arranged.

[0024] The outer flap 5 has insertion pieces 8 protruding from both sides of its tip, and the inner flap 6 has a pair of insertion holes 9 formed therein. The insertion pieces 8 are inserted into the insertion holes 9 when sealing the package.

[0025] The insertion piece 8 is provided with an outwardly protruding portion 8a, and an engaging edge 8b is formed on the protruding portion 8a, located on the front side in the direction of insertion into the insertion hole 9 of the insertion piece 8. The outer edge of the insertion piece 8 has an inclined edge 8c that slopes inward from the protruding portion 8a towards the tip.

[0026] An inclined edge 5a is formed on the side edge of the outer flap 5 that is closer to the tip than the central fold line 7. At the base of the insertion piece 8 of the outer flap 5, a notch is made on the opposite side of the protruding portion 8a, and a curved portion 5b is formed at its end that is rounded inward.

[0027] The insertion hole 9 of the inner flap 6 is made by a notch, and the portion that becomes the insertion hole 9 is provided with a first pivot piece 10 and a second pivot piece 11 so as to fill the entire interior, and an engagement edge 12 is formed from the end of the second pivot piece 11 by a slit-shaped notch. The first pivot piece 10 and the second pivot piece 11 pivot about the hinge wires 10a and 11a respectively, and the hinge wires 10a and 11a are lead lines in which press marks and cuts are intermittently made.

[0028] The hinge line 10a of the first pivot piece 10 extends in a direction perpendicular to the scribe line at the base of the inner flap 6, and the hinge line 11a of the second pivot piece 11 is inclined from the hinge line 10a of the first pivot piece 10 to the engagement edge 12 in the direction of insertion into the insertion hole 9 of the insertion piece 8, so that the second pivot piece 11 has a triangular shape.

[0029] At the end of the notch in the insertion hole 9 on the engagement edge 12 side, a curved portion 12a is formed, which is rounded in the direction of insertion of the insertion piece 8 into the insertion hole 9.

[0030] The portion of the inner flap 6 facing the insertion hole 9 has a pressing portion 6a that protrudes from the tip of the insertion piece 8 in the direction of insertion into the insertion hole 9 toward the front. The pressing portion 6a is sized to cover most of the insertion hole 9.

[0031] (Assembly and sealing of packaging boxes) The blanks described above are folded along the grid lines at the boundary between side panels 1 and 2, and the connecting piece 3 is attached to the inner surface of the opposite side end for storage in a flattened state. When storing agricultural products or other contents, each pair of side panels 1 and 2 is assembled into a rectangular tube shape to form the bottom wall 4, and the contents are stored through the opening on the top.

[0032] (Sealed) When sealing the packaging box, as shown in Figure 2, the outer flap 5 is bent along the center fold line 7, and the insertion piece 8 is inserted into the insertion hole 9. As this insertion occurs, the first swing piece 10 swings when pushed by the tip of the insertion piece 8, and then the second swing piece 11 swings when pushed by the inclined edge 8c of the insertion piece 8, and as a result the insertion piece 8 is inserted into the opening of the insertion hole 9.

[0033] Then, after the protruding portion 8a of the insertion piece 8 pushes open the portion facing the engagement edge 12 of the insertion hole 9 and passes through, the first swing piece 10 and the second swing piece 11 return to their original positions, as shown in Figures 3 and 4, and the portion facing the engagement edge 12 of the insertion hole 9 closes. When sealed in this way, the engagement between the engagement edge 8b of the insertion piece 8 and the engagement edge 12 of the insertion hole 9 suppresses the return of the outer flap 5.

[0034] At this time, with the outer flap 5 slightly bent along the central fold line 7, the engaging edge 8b of the insertion piece 8 and the engaging edge 12 of the insertion hole 9 engage. Therefore, even when the box is filled to capacity with agricultural products or other items, inserting the insertion piece 8 into the insertion hole 9 ensures that the engaging edge 8b of the insertion piece 8 and the engaging edge 12 of the insertion hole 9 engage, resulting in a secure seal.

[0035] (effect) In the above-described insert-lock type packaging box, when inserting the insert piece 8 into the insertion hole 9, the opening of the insertion hole 9 expands at the point where the tip of the first pivot piece 10, which is pushed and oscillated by the tip of the insert piece 8, is located. Subsequently, the second pivot piece 11, which is triangular in shape and pushed by the inclined edge 8c of the insert piece 8, oscillates around the inclined hinge wire 11a as an axis, and the opening of the insertion hole 9 expands on the first pivot piece 10 side of the point where the tip of the second pivot piece 11 is located. As a result, the insert piece 8 can be easily inserted into the insertion hole 9.

[0036] Furthermore, when the protruding portion 8a of the insertion piece 8 passes the portion facing the engaging edge 12 of the insertion hole 9, the presence of the curved portion 12a causes the portion facing the engaging edge 12 of the insertion hole 9 to open slightly, making it easier to insert the insertion piece 8 into the insertion hole 9 and preventing the cardboard from tearing after insertion.

[0037] Furthermore, since the outer flap 5 has an inclined edge 5a that slopes inward on the side edge of the outer flap 5 that is closer to the tip than the center fold line 7, when inserting the insert piece 8 into the insertion hole 9, even if the inclined edge 5a of the outer flap 5 comes into contact with the end of the notch in the insertion hole 9 on the engagement edge 12 side, the cardboard is less likely to tear, and the notch in the insertion hole 9 will expand.

[0038] Furthermore, the portion of the insertion hole 9 facing the engagement edge 12 is pushed open slightly by the protruding portion 8a of the insertion piece 8, and immediately closes after the protruding portion 8a of the insertion piece 8 has passed through. Therefore, unless the cardboard is torn near the engagement edge 12 of the insertion hole 9, the protruding portion 8a of the insertion piece 8 cannot come out from the portion facing the engagement edge 12 of the insertion hole 9. As a result, the engagement between the outer flap 5 and the inner flap 6 will not unexpectedly come undone during transport, and the sealed state will be reliably maintained.

[0039] Furthermore, a pressing portion 6a is formed on the part of the inner flap 6 facing the insertion hole 9, extending forward from the tip of the insertion piece 8 in the direction of insertion into the insertion hole 9. As a result, the pressing portion 6a presses against the insertion piece 8, and the insertion piece 8 is sandwiched between the pressing portion 6a, the first swing piece 10, and the second swing piece 11, thereby more reliably preventing the insertion piece 8 from coming out of the insertion hole 9 due to internal pressure from the stored items.

[0040] Furthermore, at the base of the insertion piece 8 of the outer flap 5, a curved portion 5b is formed at the end of the inner notch opposite the protruding portion 8a, which is rounded inward. Therefore, even if a tensile force is applied in the direction of opening the outer flap 5 while the engaging edge 8b of the insertion piece 8 and the engaging edge 12 of the insertion hole 9 are engaged, the corrugated cardboard will not tear from the base of the insertion piece 8.

[0041] Furthermore, since the outer flap 5 is on the longer side of this snap-lock type packaging box, the outer flap 5 tends to open by lifting due to a strong repulsive force. However, the engaging edge 8b of the insertion piece 8 and the engaging edge 12 of the insertion hole 9 engage, suppressing the return of the outer flap 5. As a result, the step on the top surface is minimized by the outer flap 5 on the longer side, preventing stacked packaging boxes from getting caught on each other and improving handling efficiency during transportation.

[0042] <Second Embodiment> Next, a second embodiment of the present invention will be described with reference to Figures 6 to 8. Since this embodiment shares common configurations with the first embodiment described above, only its characteristic features will be mentioned here.

[0043] This packaging box takes the form shown in Figure 6 when sealed, and as shown in Figure 7, the insertion piece 8 of the outer flap 5 is inserted into the insertion hole 9 of the inner flap 6 to seal it. In this embodiment, in the blank state shown in Figure 8, the first swing piece 10 is short, and there is a through hole between its tip and the edge of the insertion hole 9. Therefore, the insertion piece 8 can be easily inserted into the insertion hole 9 without first pushing the first swing piece 10 with the tip of the insertion piece 8.

[0044] In the sealed state, the pressing force of the first oscillating piece 10 on the insertion piece 8 is slightly weaker than in the first embodiment, but the function of preventing the insertion piece 8 from coming out of the insertion hole 9 is the same as in the first embodiment.

[0045] <Other> In the embodiments described above, the inclined edge 8c of the insert piece 8 is shown to be straight, but the inclined edge 8c may also be curved in an arc.

[0046] Furthermore, while the above embodiments illustrate packaging boxes where the long side becomes the outer flap 5 and the wide side becomes the inner flap 6, the above-described locking structure can also be applied to packaging boxes where, conversely, the wide side becomes the outer flap 5 and the long side becomes the inner flap 6.

[0047] Furthermore, the locking structure described above can be applied not only to the top side of the packaging box, as in the exemplified embodiments, but also to the bottom side. [Explanation of Symbols]

[0048] 1,2 Side panels 2a Handle hole 3. Sectional pieces 4 Bottom wall 4a, 4b Bottom flap 5. Outer flap 5a Sloping edge 5b Curved section 6. Inner flap 6a Pressing part 7. Center line 8 Insertion piece 8a Overhang 8b Engagement edge 8c Sloping edge 9 insertion holes 10 First oscillating piece 10a Hinge wire 11 Second oscillating piece 11a Hinge wire 12 Engagement edge 12a Curved section

Claims

1. In a snap-lock type packaging box in which an outer flap (5) extends from one of two adjacent side plates (1,2) in the circumferential direction, and an inner flap (6) extends from the other, and the outer flap (5) is bent along a central fold line (7) that runs between both edges in the middle of the extension direction, and insertion pieces (8) protruding from both ends of the tip of the outer flap (5) are inserted into insertion holes (9) of the inner flap (6), The outer flap (5) is provided with an outwardly protruding portion (8a) on the insertion piece (8), and an engaging edge (8b) is formed on the protruding portion (8a) on the front side in the direction of insertion of the insertion piece (8) into the insertion hole (9), and an inclined edge (8c) is formed on the outer edge of the insertion piece (8) that slopes inward from the protruding portion (8a) toward the tip. The portion of the inner flap (6) that forms the insertion hole (9) is provided with a first pivot piece (10) and a second pivot piece (11) that pivot around the hinge wires (10a, 11a), and an engagement edge (12) is formed from the end of the second pivot piece (11) by a slit-shaped notch. The hinge line (10a) of the first pivot piece (10), located on the tip side of the inner flap (6), is parallel to the side end of the inner flap (6), and the hinge line (11a) of the second pivot piece (11), located on the root side of the inner flap (6), is inclined away from the side end of the inner flap (6) from the hinge line (10a) side of the first pivot piece (10) toward the root side of the inner flap (6), and the inclination of the hinge line (11a) of the second pivot piece (11) causes the second pivot piece (11) to have a triangular shape. When inserting the insertion piece (8) into the insertion hole (9), the first swinging piece (10) and the second swinging piece (11) swing sequentially, pushed by the tip and inclined edge (8c) of the insertion piece (8), and the insertion piece (8) is inserted into the insertion hole (9) whose opening has been enlarged. A snap-lock type packaging box characterized in that, after the protruding portion (8a) of the insertion piece (8) pushes open and passes through the slit-shaped portion facing the engaging edge (12) of the insertion hole (9), the first swinging piece (10) and the second swinging piece (11) return to their original positions, the portion facing the engaging edge (12) of the insertion hole (9) closes, and the engagement between the engaging edge (8b) of the insertion piece (8) and the engaging edge (12) of the insertion hole (9) suppresses the return of the outer flap (5).

2. The insert-lock type packaging box according to claim 1, characterized in that a curved portion (12a) is formed at the end of the notch of the insertion hole (9) on the engagement edge (12) side, which is rounded in the direction of insertion of the insertion piece (8) into the insertion hole (9).

3. The insert-lock type packaging box according to claim 1, characterized in that the portion of the inner flap (6) facing the insertion hole (9) has a pressing portion (6a) formed thereon that protrudes toward the front from the tip of the insertion piece (8) in the direction of insertion into the insertion hole (9).

4. The insert-lock type packaging box according to any one of claims 1 to 3, characterized in that, of the side plates (1,2) adjacent in the circumferential direction, the outer flap (5) extends from the long-faced side plate (1) and the inner flap (6) extends from the wide-faced side plate (2).

5. The insert-lock type packaging box according to any one of claims 1 to 3, characterized in that the outer flap (5) is slightly bent along the middle fold line (7), and the engaging edge (8b) of the insert piece (8) engages with the engaging edge (12) of the insert hole (9).

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