Fastener for corrugated cardboard, corrugated cardboard case including the same, and corrugated cardboard coffin

Abstract

To provide a fastener for corrugated cardboard capable of reducing the amount of protrusion of the fastener from the front surface or the back surface of the corrugated cardboard by fixing the fastener to the corrugated cardboard, and a corrugated cardboard case including the fastener for corrugated cardboard.SOLUTION: A fastener for connecting or separating corrugated cardboards, the fastener comprising a first fastener fixed to one of the corrugated cardboards and a second fastener fixed to the other of the corrugated cardboards, the first fastener and the second fastener maintaining a connected state by being hooked to each other, the first fastener and the second fastener being separated from each other by releasing a hooked state, the first fastener or the second fastener comprising a pair of hooking pieces, the pair of hooking pieces having a shape extending in an extending direction of the plate-shaped corrugated cardboard within a range of a thickness of the plate-shaped corrugated cardboard, the problem is solved by the fastener for the corrugated board fixed to one corrugated board or the other corrugated board by inserting the pair of hooking pieces into a core layer of the corrugated board, and the corrugated board case including the same.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a fastener for cardboard, and a cardboard case and a cardboard coffin equipped with the fastener. [Background technology]

[0002] A fastener for connecting one piece of corrugated cardboard to another piece of corrugated cardboard is known, as disclosed in Patent Document 1 below. The fastener in Patent Document 1 has a plate-shaped opening / closing base plate that contacts the front surface of the corrugated cardboard, a fixing pin that is inserted through the thickness of the corrugated cardboard, and a plate-shaped backing plate that contacts the back surface of the corrugated cardboard. The fixing pin is formed integrally with the base plate. The base plate and backing plate are connected by inserting the tip of the fixing pin into the backing plate. One piece of corrugated cardboard can be connected to the other piece of corrugated cardboard by fixing one fixing pin and backing plate to the end of one piece of corrugated cardboard and fixing the other fixing pin and backing plate to the end of the other piece of corrugated cardboard. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Utility Model Application Publication No. 54-102416 Summary of the Invention [Problem to be solved by the invention]

[0004] The fasteners described above require both a front member and a back member to support the fixing pin. The front and back members of the fasteners interfere with other items, which is undesirable. For example, when transporting multiple cardboard boxes side by side, a fastener attached to one cardboard box may come into contact with another cardboard box, damaging that box. Furthermore, items stored inside the cardboard boxes may come into contact with the back member, damaging the items stored inside the cardboard boxes.

[0005] The present invention aims to provide a fastener for cardboard that can reduce the amount of the fastener protruding from the front or back of the cardboard by fixing the fastener to the cardboard with a hook piece that has a shape that extends in the extension direction of the cardboard plate within the thickness of the cardboard plate, and to provide a cardboard case and a cardboard coffin that are equipped with the cardboard fastener. [Means for solving the problem]

[0006] The above problem is solved by a fastener for connecting or separating one piece of cardboard to another piece of cardboard, the fastener having a first fastener fixed to one piece of cardboard and a second fastener fixed to the other piece of cardboard, the first fastener and the second fastener being hooked together to maintain the connected state, and the first fastener and the second fastener being separated by releasing the hooked state, the first fastener or the second fastener having a pair of hooking pieces that are shaped to extend in the extension direction of the plate-shaped cardboard within the thickness of the plate-shaped cardboard, the pair of hooking pieces being inserted into the core layer of the cardboard to be fixed to one piece of cardboard or the other cardboard.

[0007] The fastener for cardboard is fixed to the cardboard by inserting a hook piece, which has a shape extending in the extension direction of the cardboard within the thickness range of the cardboard, into the core layer of the cardboard. In order to fix the fastener to the cardboard, the front member, the back member, or a fixing pin is not required, and the amount by which the fastener protrudes from the front or back surface of the cardboard can be reduced.

[0008] The above-mentioned problems are also solved by a cardboard case equipped with the cardboard fastener.The above-mentioned problems are also solved by a cardboard coffin equipped with the cardboard fastener.

[0009] In the cardboard fastener and the cardboard case, the first fastener or the second fastener may further include a flange that abuts against the surface of the cardboard. The flange can hide cuts in the cardboard at the boundary between the cardboard and the fastener.

[0010] In the cardboard fastener and the cardboard case, the first fastener or the second fastener may further include a first hooking piece disposed on the front side of the cardboard and a second hooking piece disposed on the back side of the cardboard, thereby making it possible to more stably secure the first fastener or the second fastener attached to the cardboard.

[0011] In the cardboard fastener and the cardboard case, it is preferable that one of the first fastener and the second fastener has a convex portion, and the other of the first fastener and the second fastener has a concave portion, and that the position of one cardboard and the other cardboard be adjusted by storing the convex portion in the concave portion. This makes it possible to connect the first fastener and the second fastener in an appropriate position when they are hooked together, and makes it difficult for the first fastener and the second fastener to shift position after they are connected.

[0012] In the cardboard fastener and the cardboard case, the first fastener or the second fastener has a frame and a plate-shaped operating part housed within the frame, and the latching state of the first fastener and the second fastener can be switched by operating the operating part. With this configuration, the amount by which the first fastener or the second fastener protrudes from the front or back surface of the cardboard can be reduced.

[0013] In the cardboard fastener and the cardboard case, the frame body has a shape formed when the first fastener and the second fastener are connected, and when the operating part is supported by the fulcrum, the opening of the frame body can be shaped so that it is closed by the operating part. With this configuration, the amount by which the first fastener or the second fastener protrudes from the front or back surface of the cardboard can be made smaller.

[0014] In the cardboard fastener and the cardboard case, the first fastener or the second fastener has an operating part, which is supported on a fulcrum while the first fastener and the second fastener are connected, and by pressing the force point, the engaging part of the operating part moves away from the engaging part of the second fastener, and by pressing the engaging part of the operating part, the engaging part of the second fastener and the engaging part of the operating part can be engaged.

[0015] In the cardboard fastener and the cardboard case, the hooking piece can be shaped to contact the liner layer that makes up the cardboard, thereby making it possible to more stably secure the first fastener or the second fastener attached to the cardboard. [Effects of the Invention]

[0016] According to the present invention, a fastener for cardboard can be provided that can reduce the amount of the fastener protruding from the front or back of the cardboard by fixing the fastener to the cardboard using a hanging piece that has a shape that extends in the extension direction of the cardboard plate within the thickness of the cardboard plate, and a cardboard case and a cardboard coffin that are equipped with the cardboard fastener can be provided. [Brief explanation of the drawings]

[0017] [Figure 1] FIG. 1 is a perspective view showing an example of a cardboard case. [Figure 2] 2 is a perspective view showing a first fastener and a second fastener used in the cardboard case of FIG. 1. FIG. [Figure 3] FIG. 3 is a bottom view of the second fastener shown in FIG. 2. [Figure 4] FIG. 3 is a right side view of the second fastener shown in FIG. 2. [Figure 5] FIG. 3 is a vertical cross-sectional view of the fastener shown in FIG. 2. [Figure 6] FIG. 10 is a perspective view showing another embodiment of the second fastener as viewed from the bottom side. [Figure 7] FIG. 7 is a bottom view of the second fastener of FIG. 6. [Figure 8]FIG. 8 is a right side view of the second fastener shown in FIG. 7. [Figure 9] FIG. 10 is a perspective view showing another embodiment of the second fastener as viewed from the bottom side. [Figure 10] FIG. 10 is a right side view of the second fastener shown in FIG. 9. [Figure 11] FIG. 10 is a perspective view showing another embodiment of the first fastener and the second fastener. [Figure 12] FIG. 12 is a bottom view of the second fastener of FIG. 11. [Figure 13] FIG. 10 is a perspective view showing another embodiment of the second fastener as viewed from the bottom side. [Figure 14] FIG. 10 is a perspective view showing another embodiment of the second fastener as viewed from the bottom side. [Figure 15] FIG. 10 is a front view showing another embodiment of the first fastener and the second fastener. [Figure 16] 16 is a vertical cross-sectional view of the first fastener and the second fastener shown in FIG. 15. FIG. DETAILED DESCRIPTION OF THE INVENTION

[0018] An embodiment of the fastener for cardboard and a cardboard case equipped with the same according to the present invention will be described below. The embodiment shown below is merely a limited example of the present invention, and the technical scope of the present invention is not limited to the illustrated embodiment.

[0019] FIG. 1 shows an embodiment of a cardboard case (hereinafter simply referred to as a case), and FIGS. 2 to 15 show embodiments of a fastener for cardboard.

[0020] The case 1 in FIG. 1 has a main body 11, a lid 12, and a fastener 13. The main body 11 has a bottom plate 111 and a side wall 112 that surrounds the bottom plate 111. The case 1 can store any item in the storage space defined by the side wall 112 and the bottom plate 111. The lid 12 has a top plate 121 and a side wall 122 that surrounds the top plate 121. An edge of the side wall 122 of the lid 12 abuts against an edge of the side wall 112 of the main body 11 to close the opening of the main body 11.

[0021] The case 1 in FIG. 1 is rectangular in plan view and has a flat shape with a width greater than its height in side view. The case in FIG. 1 is used as a toolbox for storing tools and other items. The inside of the main body 11 and the lid 12 may be provided with cushioning or fixing materials made of foamed resin or the like to secure or protect the stored items. The shape of the case is not limited to the example in FIG. 1 and can be modified as appropriate to fit the shape of the items to be stored, such as a cube. The size of the case is also not particularly limited; for example, if small items such as a mobile phone are to be stored, the case can be made smaller to accommodate them.

[0022] A decorative sheet can be attached to the surface of the cardboard that constitutes the main body 11 and the surface of the cardboard that constitutes the lid 12. Examples of decorative sheets include sheets that have a color, pattern, or texture that differs from the base color of the cardboard, such as a wood-grain sheet. The decorative sheet can be made of any appropriate material, such as paper, synthetic resin, or cloth.

[0023] The main body 11 and the lid 12 may be connected by a known hinge so that the lid 12 swings around one end of the main body 11 as a fulcrum to open and close. Alternatively, the decorative sheet may be attached continuously to the end surfaces of the main body 11 and the lid 12 so that the lid 12 swings around one end of the main body 11 as a fulcrum to open and close.

[0024] The main body 11 and the lid 12 can be made of multi-layer corrugated cardboard having multiple core layers, or they can be made of single-layer corrugated cardboard having a single core layer. In the example of Figure 1, the number of core layers 47 is two. The corrugated cardboard 4 has a shape including a first liner layer 41 on the front side, a third liner layer 43 on the back side, and a second liner layer 42 separating the first core layer 44 and the second core layer 45. The number of core layers may be three or more. The number of liner layers separating the core layers increases or decreases depending on the number of core layers. The core layer is a layer formed by a corrugated core. The width of the meandering core, i.e., the type of flute, is not particularly limited, and any type can be used.

[0025] As shown in FIG. 1 , a first fastener 131 is fixed to the side wall 112 of the main body 11. A second fastener 132 is fixed to the side wall of the lid 12. The positions of the first fastener 131 and the second fastener 132 may be interchanged, with the first fastener 131 fixed to the lid 12 and the second fastener 132 fixed to the main body 11. The main body 11 and the lid 12 are provided with recessed cutouts 46 that penetrate through the thickness of the cardboard. The first fastener 131 or the second fastener 132 is fitted into the respective cutouts 46.

[0026] The first fastener 131 and the second fastener 132 are hooked together to maintain a connected state, and can be separated by releasing the hooked state, thereby maintaining the case 1 in a closed state and allowing the case to be opened as needed.

[0027] 1 and 2, the first fastener 131 or the second fastener 132 has a pair of hooking pieces 5 that protrude laterally from base materials 61, 62, which will be described later. The pair of hooking pieces 5 have a shape that extends in the extension direction of the plate-shaped corrugated cardboard 4 within the thickness of the plate-shaped corrugated cardboard 4, and the pair of hooking pieces 5 are inserted into the core layer 47 of the corrugated cardboard 4 to fix the first fastener 131 or the second fastener 132 to the corrugated cardboard 4 that constitutes the main body 11 or the corrugated cardboard that constitutes the lid body 12. "Within the thickness of the corrugated cardboard" refers to a shape in which the pair of hooking pieces are not exposed from the front or back side of the corrugated cardboard when inserted into the core layer.

[0028] The hooking piece 5 is preferably inserted by pressing it into the core layer 47, thereby crushing the core layer. In this way, the core layer 47 is pressed against the hooking piece 5, and the first fastener 131 or the second fastener 132 is stably fixed. The tip of the hooking piece 5, i.e., the portion where the hooking piece 5 first contacts the core layer 47 when inserting the hooking piece 5 into the core layer 47, is preferably shaped with a slope that tapers toward the tip. This makes it easier to insert the hooking piece 5 into the core layer 47 while crushing the core layer 47 with the tip of the hooking piece 5. Note that before inserting the hooking piece 5 into the core layer 47, a cut may be made in the core layer 47 with a blade or the like to make it easier to insert the hooking piece 5 into the core layer 47. The hooking piece 5 is preferably shaped like a plate extending in the vertical direction. By making it plate-shaped, when an external force acts on first fastener 131 or second fastener 132 in a pushing or pulling direction relative to the thickness direction of the cardboard, the stress is dispersed and received by the plate-shaped surface, making it possible to more stably fix first fastener 131 or second fastener 132. The plate-shaped hooking piece is preferably provided on the side surface of the base and has a shape that extends vertically so as to fit within the range of the core layer.

[0029] In the example of FIG. 2, one hanging piece 5 is arranged on the front side and one on the back side of the cardboard. That is, the hanging piece arranged on the front side of the cardboard is the first hanging piece 51, and the hanging piece arranged on the back side of the cardboard is the second hanging piece 52. The first hanging piece 51 and the second hanging piece 52 are arranged spaced apart in the thickness direction of the cardboard. The hanging pieces 5 are arranged in pairs on bases 61 and 62, which will be described later, so that the first fastener 31 or the other fastener 132 shown in FIG. 2 has a total of four hanging pieces 5. The number of hanging pieces to be provided is not particularly limited. For example, if the number of core layers is three, three hanging pieces may be provided on one side of the bases 61 and 62.

[0030] As shown in Figure 2, when the first fastener 131 and the second fastener 132 are connected, the upper end of the hanging piece 5 of the first fastener 131 abuts the lower end of the hanging piece 5 of the second fastener 132.

[0031] In the example shown in FIG. 2, each of the hooking pieces 5 is plate-shaped and fits within the thickness of each core layer. In the first fastener 131 and the second fastener 132 shown in FIG. 2, as shown in FIGS. 1 and 3, the first fastener 51 is arranged such that, in a plan view or bottom view, the end of the first fastener 51 opposite the base of the first fastener 51 is inclined toward the front surface of the cardboard, relative to a line A parallel to the horizontal direction. The second fastener 52 is arranged such that, in a plan view or bottom view, the end of the second fastener 52 opposite the base of the second fastener 52 is inclined toward the back surface of the cardboard, relative to a line A' parallel to the horizontal direction. As a result, as shown in FIG. 1, the end of the first fastener 51 contacts the back side of the first liner 41, and the end of the second fastener 52 contacts the back surface of the third liner 43. This allows the first fastener 131 and the second fastener 132 to be more stably fixed to the cardboard. In FIG. 3, the second fastener 132 is shown as an example, but the same applies to the first fastener 131.

[0032] As shown in Figures 1 and 5, the first fastener 131 or the second fastener 132 comprises a frame body 6 having a thickness equivalent to that of the cardboard 4, and a roughly plate-shaped operating part 7 that is housed within the frame body 6, and by operating the operating part 7, the latching state of the first fastener 131 and the second fastener 132 can be switched.

[0033] As shown in FIGS. 2 and 5, the frame body 6 has a shape formed when the first fastener 131 and the second fastener 132 are connected, and when the operation unit 7 is supported by the fulcrum 613, the opening 63 of the frame body 6 is closed by the operation unit 7. In the example of FIG. 5, the frame body 6 and the operation unit 7 are both rectangular. The opening 63 of the rectangular frame body 6 is closed by the approximately plate-shaped operation unit. The shapes of the frame body and the operation unit are not limited to rectangular, and can be circular, elliptical, polygonal, or the like.

[0034] The first fastener 131 has a base 61 that constitutes one of the upper and lower parts of the frame body 6. The second fastener 132 has a base 62 that constitutes the other of the upper and lower parts of the frame body 6. The bases 61, 62 are shaped to constitute the frame body 6 when the first fastener 131 and the second fastener 132 are connected. In the examples of Figures 2 and 5, the bases 61, 62 have wall surfaces 611, 612 on the back side of the cardboard 4, but the wall surfaces 611, 612 may be omitted.

[0035] The base 61 of the first fastener 131 has an opening on the front side of the cardboard, and also has an opening at the end where it is connected to the base 62 of the second fastener 132. The opening on the front side and the opening at the end are connected to each other. The base 62 of the second fastener 132 has an opening on the front side of the cardboard, and also has an opening at the end where it is connected to the base 61 of the first fastener. The opening on the front side and the opening at the end are connected to each other.

[0036] As shown in FIG. 2, a protrusion 82 is provided at the lower end of the base 63 of the second fastener 131. A recess 82 is provided at the upper end of the base 61 of the first fastener 131. When the first fastener 131 and the second fastener 132 are brought close to each other, the protrusion 82 fits into the recess 81, fixing the positions of the first fastener 131 and the second fastener 132 so that they do not shift laterally, preventing malfunction of the operating unit 7, which will be described later. The protrusion 82 may be provided on the first fastener 131. The recess 81 may be provided on the second fastener 132. The shapes of the protrusion and recess are not limited to the rectangular parallelepiped and hole that can accommodate the rectangular parallelepiped shown in FIG. 2, and may be any appropriate shape.

[0037] The base 61 of the first fastener 131 has a fulcrum 613 formed by a rod extending in the horizontal direction. The base 62 of the second fastener 132 has an engagement portion 614 formed by a rod extending in the horizontal direction. Both rods are disposed inside the bases 61, 62 so as to cross the hollow portions of the bases 61, 62. In this specification, the horizontal direction refers to the direction perpendicular to the vertical direction when the connected first fastener and second fastener are viewed from the front, where the vertical direction is the direction in which the first fastener and second fastener move toward or away from each other. Depending on the angle at which the fasteners are attached, the vertical direction and the vertical direction do not necessarily coincide.

[0038] 5, the operation unit 7 is supported by a fulcrum 613 of the first fastener 131 with the first fastener 131 and the second fastener 132 connected together. By pressing the force point 73, the engagement portion 72 of the operation unit 7 moves away from the engagement portion 614 of the second fastener 132, and the engagement portion 614 of the second fastener 132 and the engagement portion 72 of the operation unit 7 become disengaged. By pressing the engagement portion 72 of the operation unit 7, the engagement portion 614 of the second fastener 132 and the engagement portion 72 of the operation unit 7 move closer to each other, and the engagement portion 614 of the second fastener 132 and the engagement portion 72 of the operation unit 7 become engaged with each other. The back side of the force point 73 of the operation unit 7 is hollow, and when the force point 73 is pressed, a space is formed to accommodate the end of the swinging operation unit. In the example of FIG. 5, the force point 73 is located at one end of the operating unit 7, the engagement portion 72 is located at the other end of the operating unit, and the fulcrum 613 is located between the force point 73 and the engagement portion 72. The engagement portion 72 is located at the point of application. Due to the principle of leverage, the engagement portion 72 can be operated with a small force. This improves the operability of the operating unit.

[0039] The operating unit 7 has an engaging portion 71 on its back surface that engages with the fulcrum 613, and an engaging portion 72 that engages with the engaging portion 614, which is composed of a rod. Both engaging portions 71 and 72 of the operating unit 7 are composed of recessed holes that can accommodate the rod. A portion of the recessed hole is formed with an elastically deformable engaging piece 74. When the rod and the recessed hole are pressed together, the engaging piece elastically deforms, and the rod is accommodated in the recessed hole. When the rod and the recessed hole are separated, the engaging piece 74 elastically deforms, and the rod is released from the recessed hole. The operating unit 7 is generally plate-shaped and has a shape that can cover and conceal the opening of the frame body 6, which is composed of the first fastener 131 and the second fastener 132. The internal structure of the frame body 6 is concealed by the operating unit 7, resulting in a smart appearance. Note that the shape may be modified so that a rod is provided in the operating unit and a recess that engages with the rod is provided in the base.

[0040] As described above, the first fastener 131 and the second fastener 132 are locked in a connected state by fitting the engagement portions 71 and 72 of the operating unit 7 into the fulcrum 613 at the base of the first fastener 131 and the engagement portion 614 of the second fastener 132. By pressing the force point 73 arranged at one end of the operating unit 7, the other end of the operating unit 7 swings around the fulcrum 613, the engagement portions 72 and 74 move apart, and the first fastener 131 and the second fastener 132 are unlocked.

[0041] The angle of the pair of hooking pieces is not limited to the above example. For example, as shown in FIG. 7, the end of the first hooking piece 51 opposite the base may be angled toward the back surface, in plan view or bottom view, relative to the line A parallel to the horizontal direction. The end of the second hooking piece 52 opposite the base may be angled toward the front surface, relative to the line A' parallel to the horizontal direction. In this case, it is preferable that the end of the first hooking piece 51 and the end of the second hooking piece 52 contact the liner (second liner layer 42) separating the core layers. This allows the first fastener 131 or the second fastener 132 to be stably fixed to the cardboard 4. While FIGS. 6 to 8 show the second fastener 132 as an example, the same applies to the first fastener 131.

[0042] The angle of the pair of hooking pieces is not limited to the above example. For example, as shown in FIGS. 9 and 10 , in a side view, the tip of the first hooking piece 51 may be inclined toward the front surface with respect to a line B parallel to the vertical direction, and the tip of the second hooking piece 52 may be inclined toward the back surface with respect to a line B' parallel to the vertical direction. In this case, it is preferable that the end of the first hooking piece 51 and the end of the second hooking piece 52 contact the first liner layer 41 or the third liner layer 43 of the cardboard box 4. This allows the first fastener 131 or the second fastener 132 to be stably fixed to the cardboard box 4. While FIGS. 9 and 10 show the second fastener 132 as an example, the same applies to the first fastener 131.

[0043] Although not shown, in a side view, the tip of the first hooking piece 51 may be inclined toward the back surface with respect to a line B parallel to the vertical direction, and the tip of the second hooking piece 52 may be inclined toward the front surface with respect to a line B' parallel to the vertical direction. In this case, it is preferable that the ends of the first hooking piece and the second hooking piece are in contact with the liner layer that separates the core layer. This allows the first fastener 131 or the second fastener 132 to be stably fixed to the cardboard 4.

[0044] Although not shown, in a plan view or a bottom view, the first hook piece 51 or the second hook piece 52 may be parallel to the line A or the line A' parallel to the horizontal direction. Also, although not shown, in a side view, the first hook piece 51 or the second hook piece 52 may be parallel to the line B or the line B' parallel to the vertical direction.

[0045] As shown in FIG. 11 , the second fastener 132 may be configured to include a flange 53 that abuts against the surface of the cardboard. The flange 53 is a generally plate-shaped portion that protrudes horizontally and vertically from the front-side ends of the bases 61, 62. The flange 53 abuts against the surface of the cardboard, and can conceal the joint between the cardboard 4 and the second fastener 132. By concealing the joint between the cardboard and the second fastener 132, the case can be finished with an aesthetically pleasing appearance. While the second fastener 132 has been shown above as an example, the same applies to the first fastener 131.

[0046] In the first fastener 131 or the second fastener 132 having the flange 53, the flange 53 contacts the edge of the notch 46 provided in the cardboard 4, so even if only one hooking piece 5 is provided on each side, the flange 53 can stably fix the first fastener 131 or the second fastener 132 to the cardboard 4. As shown in Figure 12, in a plan view or bottom view, the end of the hooking piece 5 opposite the base is positioned at an angle toward the back surface of the cardboard 4 with respect to the straight lines C and C' parallel to the lateral direction, and is positioned so as to contact the back surface of the third liner layer 43.

[0047] As shown in Figure 13, the hooking piece 5 may be provided with multiple protrusions 54. By providing multiple protrusions 54, the first fastener 131 or the second fastener 132 is less likely to fall off the cardboard 4. In the example of Figure 13, the multiple protrusions 54 are triangular prism-shaped. When the hooking piece 5 is inserted into the core layer 47, the corners of the protrusions 54 are shaped to easily bite into the core layer. While the second fastener 132 has been shown as an example above, the same applies to the first fastener 131.

[0048] As shown in FIG. 14, the hooking piece 5 may be provided with an inclined surface 55 that tapers toward the direction of insertion into the cardboard 4. In the example of FIG. 14, a step 54 extending horizontally is provided on the hooking piece 5, and the step 54 and inclined surface 55 make the width of the hooking piece 5 narrower at the step portion. The inclined surface 55 makes it easier to insert the hooking piece into the core layer of the cardboard. The step 54 makes it more difficult for the first fastener 131 or the second fastener 132 to fall off the cardboard. While the second fastener 132 was shown above as an example, the same applies to the first fastener 131.

[0049] As shown in FIGS. 15 and 16 , the rod forming the fulcrum 613 of the first fastener 131 and the rod forming the engagement portion 614 of the second fastener 132 may be provided with a reinforcing piece 83. The reinforcing piece 83 is plate-shaped and extends in the horizontal direction. One end of the reinforcing piece 83 is shaped to be connected to the rod. The left and right ends of the reinforcing piece 83 can be connected to the left and right side walls of the bases 61 and 62. The other end of the reinforcing piece 83 can be connected to the back wall surfaces 611 and 612 of the bases 61 and 62. Reinforcing the rod can improve the durability of the rod.

[0050] The fasteners 14 shown in Figures 2 to 16 are all flat plates that are secured to the cardboard 4 by the latching pieces 5. Therefore, they can be made to be the same thickness as the cardboard to which they are applied, or the end of the fastener can be made to protrude from the surface of the cardboard by 0.1 to 5 mm. Unlike conventional snap locks, the locking parts do not protrude from the surface of the case. For example, when multiple cases 1 are transported side by side, even if the fastener 6 comes into contact with an adjacent case 1, it is unlikely to damage the adjacent case 1.

[0051] The fasteners described above can be used not only for cases but also for cardboard coffins. [Explanation of symbols]

[0052] 131 First fastener 132 Second fastener 5 Latch piece 51 1st latch piece 52 Second latching piece 44 Core layer 53 Tsuba 82 Convex part 81 Recess 6 Frame 7 Control section 613 Fulcrum 73 Emphasis 1 cardboard case

Claims

1. A fastener for connecting or separating one cardboard box with another cardboard box, The fasteners include a first fastener fixed to one of the cardboard boxes and a second fastener fixed to the other fastener, The first fastener and the second fastener are engaged to maintain a connected state, and the first fastener and the second fastener are separated by releasing the engaged state, The first fastener or the second fastener includes a pair of hook pieces, The pair of hooking pieces have a shape that extends in the extension direction of the cardboard sheet within the range of the thickness of the cardboard sheet, The fastener for corrugated cardboard is fixed to one or the other of the corrugated cardboard by inserting the pair of hooking pieces into the core layer of the corrugated cardboard.

2. The fastener for corrugated cardboard according to claim 1 , wherein the first fastener or the second fastener further comprises a flange portion that abuts against the surface of the corrugated cardboard.

3. The fastener for cardboard according to claim 1 or 2, wherein the first fastener or the second fastener further has a first hooking piece arranged on the front side of the cardboard and a second hooking piece arranged on the back side of the cardboard.

4. One of the first fastener and the second fastener has a protrusion, the other of the first fastener and the second fastener includes a recess; 3. The fastener for corrugated cardboards according to claim 1 or 2, wherein the positions of one piece of corrugated cardboard and the other piece of corrugated cardboard are adjusted by storing the convex portion in the concave portion.

5. A fastener for cardboard according to claim 1 or 2, wherein the first fastener or the second fastener comprises a frame body and a plate-shaped operating part housed within the frame body, and the latching state of the first fastener and the second fastener is switched by operating the operating part.

6. The frame body has a shape formed in a state where the first fastener and the second fastener are connected to each other, The fastener for cardboard boxes according to claim 5, wherein the opening of the frame body is closed by the operating part when the operating part is supported by the fulcrum.

7. The first fastener or the second fastener includes an operating portion, The operating portion is supported by a fulcrum in a state in which the first fastener and the second fastener are connected, By pressing the force point, the engaging portion of the operating portion is separated from the engaging portion of the second fastener, The fastener for cardboard boxes according to claim 1 or 2, wherein the engaging portion of the operating portion is engaged with the engaging portion of the second fastener by pushing in the engaging portion of the operating portion.

8. 3. The fastener for corrugated cardboard according to claim 1, wherein the hooking piece is shaped to contact a liner layer of the corrugated cardboard.

9. A cardboard case comprising the fastener for cardboard according to claim 1 or 2.

10. A cardboard coffin comprising the fastener for cardboard according to claim 1 or 2.

Images