Method for joining corrugated cardboard sheets and furniture formed by members using the same

Abstract

To provide a method for joining two overlapping surfaces of a corrugated board sheet without being accompanied by adhesion and maintaining the state.SOLUTION: A trapezoidal insertion part side 1a having inclinations on both sides by widening a tip and narrowing a root part is arranged on a joining surface side 1c on the outside of two surfaces to be joined, and is projected by a folded side 1d of an upper bottom of a trapezoid. A projecting piece side 1b of the fixing part is provided on an inside joining surface side 1e, and a tip part side 1g is folded. The insertion part side 1e is pushed and inserted into a hole opened by folding the projecting piece side 1c to the inside, and is fixed by being erected at a right angle inside. Then, the protruding piece 1e of the fixing portion is pushed up so as to close the hole formed by the insertion of the insertion portion 1c from the inside, and the tip portion 1g of the protruding piece is brought into close contact with the insertion portion 1c to maintain the fixed state.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to a joining method that does not involve bonding two surfaces of cardboard sheets, a box-shaped member that uses the method, and cardboard furniture formed from the member. [Background technology]

[0002] When making rectangular tubular items using cardboard sheets, it is common to join both ends with adhesive, which requires a bonding process during manufacturing, and the bonded items become bulky when folded. Also, when combining multiple cardboard boxes, tape, string, etc. are generally required separately, making it difficult to join the boxes together. Therefore, as a joining method that does not involve adhesive, Patent Document 1 proposes a method in which trapezoidal protrusions on both overlapping sheets are folded inward and fixed by inclinations on both sides. Patent Document 3 proposes a method in which ears are provided on the outer trapezoidal protrusions that are folded inward, thereby fixing the protrusions so that they do not easily come off. Patent Document 4 proposes a method in which a square tube formed on the edge of a sheet is fixed with a trapezoidal protrusion. Patent Document 5 proposes a method in which a square tube formed on the edge of a sheet is fixed in a rolled-up state.

[0003] Cardboard is also used for furniture such as beds, and is often stockpiled as an emergency measure in case of disasters, so there are a variety of types, including those specifically designed for beds, and those that can also be used as chairs and tables. All of them can be assembled in several parts, or they can be folded up and unfolded into pre-assembled pieces. As in (Patent Document 6), most of them have a structure formed by two members with slits fitted together by the slits, and are assembled using several types of members and parts. In (Patent Document 7), multiple boxes with this structure are used as a bed, chair, or table. In (Patent Document 8), an expandable product with this structure is proposed. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2007-1594 [Patent Document 2] Patent No. 7046749 [Patent Document 3] Japanese Patent Application Laid-Open No. 2010-36958 [Patent Document 4] Patent No. 50431655 [Patent Document 5] Utility Model Registration No. 3236422 [Patent Document 6] Japanese Patent Publication No. 2022-169875 [Patent Document 7] Patent No. 6955737 [Patent Document 8] Patent No. 6953008 Summary of the Invention [Problem to be solved by the invention]

[0005] In the joining method that does not involve adhesive bonding (Patent Document 1), the trapezoidal protrusion that is pressed inward is not fixed in a folded upright position, and if force is applied and the upright part tilts, it will no longer be in a tightly adhered state. In (Patent Document 2), a protrusion is provided at the base of the protruding piece to provide a catch, and joints are provided on both sides to fix the two surfaces so that they do not shift.However, if there is only one joint, the two surfaces will shift and if they move to the wider part of the hole, they will easily come out. In (Patent Document 3), ears are provided to prevent them from easily coming out, and the ears can be folded to allow them to be easily inserted into the hole, but the ears can also be folded and removed, and even if the ears are held down with a protruding piece with a hole, the lower part of the protruding piece with the ears is not fixed at all, so the two surfaces can separate, and it is not completely fixed, so if a strong force is applied it will come out. In (Patent Document 4), a trapezoidal protrusion is pushed into a square hole and fixed by the wider part of the trapezoid, but this is fine because this item is a cushioning material and the square tube formed by the wrapping is not subjected to any force that would separate it from the base surface, but if it were subjected to such force it would easily come out. In (Patent Document 5), a square tube is wrapped around and fixed, but the bottom of the square tube is not joined to the sheet, and there are protruding pieces on the top surface and locking pieces on the sides, creating wasted space.

[0006] Regarding cardboard furniture, (Patent Document 6) shows that it is made by fitting slits together, but it has many parts and is not intended for use as a bed. (Patent Document 7) shows that it is possible to use it for multiple purposes by using a box reinforced with partition boards using slits inside, but part of the partition board and the outer frame of the box are glued at the edges, so it can be assembled by spreading it out, but it is bulky when folded. (Patent Document 8) shows that the bed is extendable, but the length that it can be extended is fixed and it cannot be adjusted to any length. When there are many different types and numbers of parts, working in a cluttered place can lead to parts being lost and making it impossible to assemble, and when packed, there can be wasted empty space. Packaging for assembled items tends to be large. Most beds come in a fixed size, making them difficult for tall people to use, and none can be customized to fit two short women or children. Also, although the materials are inexpensive, there are many different parts and it requires processes such as gluing and folding, so it is not that cheap.

[0007] In view of the problems of the prior art described above, the present invention provides a joining method that can join two surfaces of cardboard sheets without adhesive and can reliably maintain that state. It is also an object of the present invention to use this joining method to form a three-dimensional member from a single rectangular sheet, and to provide furniture such as a cardboard bed that can be connected in multiple ways to suit different uses at low cost. [Means for solving the problem]

[0008] A joining method for cardboard sheets that does not involve gluing two overlapping surfaces, One side On the surface of Insert Entrance is provided, The other one On the side of A shape that matches the insertion of the insertion part, The protruding piece has been broken off and has a hole that protrudes. The insertion portion is inserted into the hole. It is inserted and protrudes at a nearly right angle. The protruding piece or the inserting part has two surfaces that are in close contact with each other, and both sides of the protruding inserting part are folded to form a fixing part that is fixed in place at a position where they are in close contact with the hole. In the case where the inserting part has a shape in which the tip widens and the folded part narrows, so that both sides are inclined, the folded and inserted inserting part is fixed by folding the protruding piece of the fixing part. .

[0009] The insertion portion has a tip that widens and a folded portion that narrows, so that both sides are inclined. By shape, The aforementioned The protruding piece of the fixing part is bent to match the fixing position of the insertion part. The A tip portion is provided that comes into close contact with the insertion portion, and the protruding piece is applicable The hole opened by the protrusion of the insertion part is closed, and the insertion part is fixed by the folded tip part.

[0010] The insertion portion has a shape in which the tip widens and the folded portion narrows, so that both sides are inclined, The protruding piece of the fixing part , insert The insertion part has a fold on both sides of the inclined side, and two protruding pieces are separated between the sides. Applicable A hole is provided in advance at the position where the insertion part is inserted and protrudes, or another protruding piece is provided for making a hole, and the insertion part is inserted between the roots of the two protruding pieces on both sides. Folding It is fixed in part.

[0011] The insertion portion is folded on both sides. Divided into upper and lower , a protrusion with flat top and bottom between the left and right folds One side is folded inward, and the other side protrudes outward. The tip is narrowed for insertion. On the other side, the insertion part can be fixed vertically and horizontally. The hole is provided. The protruding insertion portion is inserted into the surface and has a notch formed at the position of the protruding side of the surface. It becomes a fixed part with a fold that holds it in place. .

[0012] A rectangular sheet with cuts and creases, without holes or slits, is folded and assembled to form a rectangular top and an open bottom. The upper part of both sides of the short side of the top surface has a three-layer structure like a kimono collar, and the width is narrowed by folding the left and right sides of the innermost surface. A box-shaped member is formed.

[0013] A plurality of the above members are connected or combined to form cardboard furniture.

[0014] The member is a box-shaped member with two rectangular cylindrical legs, with the open portions of the U-shape facing downwards on both long sides of the upper surface. [Effects of the Invention]

[0015] According to the present invention, two overlapping surfaces of cardboard sheets can be easily joined without adhesive and the joining state can be firmly maintained. Also, using this joining method, a single rectangular sheet without holes or slits can be cut and folded to assemble into a box-shaped member, and multiple such members can be connected to form cardboard furniture of various shapes depending on the usage situation. [Brief explanation of the drawings]

[0016] [Figure 1] This is an example of the shape of the joining method, where the insertion part is trapezoidal. A is an exploded view, and B is a front view of the insertion part and fixing part overlapping. [Figure 2] This is an example of the shape of the joining method, and is an assembly diagram when the insertion part is trapezoidal, where A is a perspective view and B is a cross-sectional view. [Figure 3] This is an example of the shape of the joining method, where the insertion part is shaped like an extension of the lower base of a trapezoid, where A is an expanded view and B is a front view of the insertion part and fixed part overlapping. [Figure 4] This is an assembly diagram of an example of the joining method, where the insertion part is shaped like an extension of the lower base of a trapezoid, where A is a perspective view and B is a cross-sectional view. [Figure 5] This is an example of the joining method, where the fixed part consists of two protruding pieces. A is an exploded view, and B is a front view of the inserted part and the fixed part overlapping. [Figure 6] This is an example of the joining method, and is an assembly diagram when the fixed part has two protruding pieces. A is an oblique view, B is a partial front view of the fixed part seen from the inside, and C is an exploded view and oblique view of a small square tube. [Figure 7]This is an example of the shape of the joining method, where the insertion part protrudes inward and outward at the top and bottom, where A is a front view and B is a front view of the insertion part and insertion hole. [Figure 8] FIG. 10 is a perspective view of an example of a joining method in which the insertion portion protrudes inward and outward at the top and bottom. [Figure 9] Exploded view of a box-shaped component. [Figure 10] FIG. [Figure 11] FIG. [Figure 12] This is a diagram of a box-shaped component, showing the side structure. A shows the invention in terms of the unfolded view on the left, the full view on the bottom right, and the top view on the top right. B is a diagram of a simple structure. [Figure 13] A diagram of a box-shaped component, where A is a perspective view of one side and B is a perspective view of the other side. [Figure 14] A diagram of a box-shaped member, showing a perspective view of the member joint. [Figure 15] This is a perspective view of a box-shaped member, showing multiple members connected together. [Figure 16] This is a perspective view of an example of a cardboard bed, where A is an example of a normal size with a shortened length, and B is an example of a wider width. [Figure 17] This is a perspective view of an application example of cardboard furniture, where A is a table and chair, and B is another example of a table. [Figure 18] An exploded view of a box-shaped member with an open section. [Figure 19] FIG. 10 is a perspective view of an assembly of a box-shaped member having an opening. [Figure 20] FIG. 10 is a perspective view of an example of a box-shaped member having an opening used as a ladder. DETAILED DESCRIPTION OF THE INVENTION

[0017] Hereinafter, an embodiment of the present invention will be described. The joining method of the present invention is a method for easily joining two overlapping surfaces of corrugated cardboard sheets without adhesive. As shown in Figure 1A, the outer joint surface 1a of the two ends that are joined to form the square tube has an insertion portion 1c, which is trapezoidal in shape with slopes on both sides as the tip widens and the base narrows, and the upper base of the trapezoid is shaped as a fold 1d of the insertion portion, which protrudes due to this fold. The inner joint surface 1b has a protruding piece 1e of the fixing portion, which is also trapezoidal in shape like the insertion portion 1c, and the lower base of the trapezoid is shaped as a fold 1f of the protruding piece, forming a trapezoid that is taller than the insertion portion 1c as shown in Figure 1B, and the tip portion 1g is designed to be folded.

[0018] Figures 2A and 2B show the assembly diagram of this joint. of Fold it inward, fold it at the fold 1f, and push the entire fixed part's protrusion 1e into the inside of the tube to open a hole so that the insertion part 1c can be inserted. Then, overlap the outer joint surface 1a, fold and insert the insertion part 1c, and push it in so that it forms a right angle inside. Then, push the fixed part's protrusion 1e up from the inside of the tube to close the hole opened by the insertion of the insertion part 1c, and fasten the tip part 1g of the protrusion tightly to the insertion part 1c. The tip part 1g of the protrusion is folded in a position where it will tightly fit the insertion part 1c and will not easily come off. This allows the fixed state to be firmly maintained.

[0019] In Figure 2, the protrusion 1e of the fixing part is pushed up from the inside of the tube to fix it, but if it is not possible to reach inside with one's hand, the following configuration can be used to fix it without reaching inside with one's hand. As shown in Figure 3, the trapezoidal lower base of the insertion part 1c is extended by the same width, and the tip part 1h of the extended insertion part is folded inward. The protruding piece 1e of the fixing part is formed by extending the trapezoidal shape accordingly. Make it into shape. As shown in Figure 4, first fold the tip 1h of the insertion part so that it is perpendicular to the inside, then fold the tip 1g of the protruding piece 1e of the fixing part inward and fold the entire protruding piece 1e outward. When the outer joint surface 1a is placed over the inner joint surface 1b, fold the tip 1h of the insertion part so that the protruding piece 1e protrudes from the hole. Now, push the insertion part 1c into the hole so that it is at about a right angle inside. Then, insert the protruding piece 1e so that it closes the hole, and fasten the tip 1g by adhering it tightly to the insertion part 1c. This allows assembly to be performed from the outside without having to reach inside.

[0020] Figures 2 and 4 show a form in which the open hole is closed while being fixed, but this requires the tip of the protruding piece 1g, which requires space. However, by leaving the hole open as shown below, it is possible to join in a small space. As shown in Figure 5, the insertion part 1c has a shape that is an extension of the bottom base of a trapezoid. This could simply be a trapezoid, but when pushed inward, the width of the folded part of a trapezoid is small, and to fit the width of the finger, the width of the entire trapezoid must be increased. However, by inserting the bottom base of the trapezoid by folding it and extending it by the thickness that protrudes from the inner surface, the insertion part 1c can be made smaller. As shown in Figure 5B, the fixing part is a trapezoid of a size that allows the insertion part 1c to be inserted, and has bends on both sides with inclination, and two protruding pieces 1e divided between both sides are provided. Side A triangular hole 1i is provided with its apex at the point where the two protruding pieces 1e are separated.

[0021] 6A and 6B, first fold the two protrusions 1e inward, overlap the outer joining surface 1a with the inner joining surface 1b, push the insertion part 1c inward, spread the two protrusions 1e on both sides, and pass the protruding parts of the protrusions 1e and at the base of the protrusions 1e, the protrusions 1e on both sides are pressed down by the force trying to close, and are fixed in a protruding and standing state. Also, by providing two protrusions 1e at the ends of the sheet as shown in Figure 6C, even small square tubes can be joined. The fixed triangular hole 1i may be opened by bending the protrusion to make it protrude, and the insertion part 1c may be fixed by being sandwiched between this triangular protrusion and two protrusions 1e.

[0022] The configurations shown in Figures 7 and 8 are for joining the surfaces of two members, one having a surface 2 on which an insertion portion is provided and the other having a surface 3 on which an insertion hole is provided. The surface 2 on which the insertion section is provided has protrusions that are connected at the top and bottom as shown in Figure 8, and the lower protrusion is connected between folds 2a provided on the left and right sides of the base of the upper protrusion 2b, and when the upper protrusion 2b is folded at fold 2a and protrudes inward, the connected lower protrusion protrudes outward. The protruding inner and outer sides form a single flat surface, and the outer side is the insertion section 2c, with slopes on both sides and a narrowed tip. On the surface 3 where the insertion hole is provided, the protrusion 3b protrudes toward the inside of the member due to the fold 3a of the protrusion, creating the insertion hole 3c. As shown in Figure 7B, the insertion hole 3c is shaped so that when the insertion part 2c is inserted, the upper part is fixed at the left and right ends and the lower part is fixed at the center, rather than the entire part. Normally, in this case, a long, narrow hole is made to match the thickness of the insertion part 2c, but with this shape, it is possible to fix it with a larger hole, which can be made by the protrusion of the protrusion.

[0023] In addition, the insertion hole 3c has a space at the top that is sloped to narrow in the direction of the fold 3a of the protrusion. As a result, when the insertion portion 2c is inserted into this space and surfaces 2 and 3 come into close contact, the slope of this space and the slope of the tip of the insertion portion 2c cause the insertion portion 2c to reliably move to the fixed position as shown in Figure 7B, and be fixed up, down, left, and right. The insertion portion 2c has a slit 2d aligned with the inside of the surface 3 where the insertion hole 3c is provided. Normally, it is not possible to fold it like this and provide a slit at a position equal to the thickness of the sheet from the fold, but this is possible by making the inside and outside into one flat surface. As a result, by folding the insertion portion at fold 2e, the slit 2d presses the inside of the surface 3 where the insertion hole is provided, and the insertion portion 2c can be fixed not only vertically and horizontally but also front and back. As with this joining method, the embodiments of Figs. 1, 3 and 5 are not limited to joining when forming a rectangular tube, but can also be used to join the surfaces of separate members.

[0024] By using these joining methods, a box-shaped component can be made from a single square sheet without adhesive. A typical cardboard box has four sides joined together by gluing, and flaps extending from the sides to form the top and bottom lids have slits between them. However, the present invention uses only a single rectangular sheet with cuts and creases, no holes or slits, and no other components, as shown in Figure 9. The single sheet is assembled and joined on both sides as shown in Figures 10 and 11, forming a single box-shaped member with a rectangular top 4c and an open bottom.

[0025] Normally, when creating such a shape, the side surfaces would be as shown in Figure 12B, but in this shape, the innermost side surface 4d has the same width as the top surface 4c, so it juts out to the left and right and is not flat. Simply narrowing the side surface 4d would result in the inner side surface 4e and the outer side surface 4f being higher than the top surface 4c. In the present invention, the upper part of the side has a three-layer structure shaped like the collar of a kimono, as shown in Figure 12A. With this shape, protrusions can be provided on the left and right sides of the innermost side 4d, and by folding these protrusions, the width of the left and right sides can be narrowed to eliminate any protrusions. Also, since it is not joined by adhesive, the edge of the outer side surface 4f will lift up a little, but as shown in Figure 12B, it will lift up at the corner with the top surface 4c, and the edge will also warp, making it easier to get caught. Figure 12A is slanted at the bottom, so opening is also prevented.

[0026] The assembled box-shaped components have joints on both long sides of the top surface 4c to join the components together, as shown in Figure 13. Insertion section 2c is provided on surface 4a, and protrusions 3b, which form insertion holes 3c, are provided on surface 4b. Then, as shown in Figure 14, they are inserted and fixed. As shown in Figure 15, multiple components can be connected together, and as shown in Figure 16, they can be used as a cardboard bed. Since there is no limit to the number of components that can be connected, it can be made to fit the user's height. It can be made for people over 2 meters tall, as well as for small children. It can also be widened by adding more components horizontally, as shown in Figure 16B. While the figure shows a vertical head section, this can be removed to accommodate two small children. In this case, since the sides cannot be joined together, tape can be used to secure the bed securely. In this way, various configurations can be used to make effective use of space.

[0027] Depending on how many you connect, you can use it as a chair or a table, as shown in Figure 17A. The sheet can also be used as is without assembling it in this way. In this case, if you tape the cut edges of the sheet, it can be used as a normal sheet for partitions, tabletops, etc. This allows you to surround a small bed with the sheet and use it as a baby bed. As shown in Figure 17B, a table with this as a top can be made with less assembly by fixing the parts with tape without connecting them, and it can be made taller than one that is simply connected. Two of the parts on the top of this table can also be joined together to add several steps to make a desk. In this case, the open part of the part can be placed on the outside so that things can be placed inside. In this way, two pieces of material can be joined together to create a thick wall-like partition. In this case, crumpled newspaper can be placed inside to provide heat and sound insulation.

[0028] Furthermore, as shown in Figure 18, the box-shaped member can be assembled by providing inward-folding sections on both long sides of the top surface 4c, creating a U-shaped open section at the bottom, as shown in Figure 19. The structure is such that the top surface 4g of the open section is supported by the side surfaces 4h of the open section, and the top surface 4g of the open section is folded upward, with the edges touching the top surface internally, making this section double, resulting in a structure that is strong against loads. This material can be used to make beds, and also chairs and tables, with openings that allow users to stretch or tuck their legs in. The part that folds inwards can be taped to eliminate the opening, so it can also be used as a thick, wall-like partition. Also, by having an open section, it can be fixed with tape to form the shape shown in Figure 20, and can be attached to a wall to be used as a ladder, or by adding slopes to both sides, it can be used as a stepladder.

[0029] In this way, a single rectangular sheet with cuts and creases, but no holes or slits, can be assembled into a single component by folding and joining without glue, and by connecting and combining these components, it can be used in a wider variety of forms than furniture made from regular cardboard.In addition, it can be used as is, and packaging requires only the rectangular sheet, so there is no need for other components or parts, which means there is no wasted space. Since it is simply a die cut from a cardboard sheet, it can be provided at low cost. [Explanation of symbols]

[0030] 1 Square tube formed by joining 1a Outer joint surface 1b Inner joint surface 1c Insertion section 1d Insertion part folding 1e Protrusion of fixing part 1f Folding of the fixed part 1g Tip of the fixed part 1h Tip of the insertion part 1i Fixing hole 2. Surface where the insertion part is provided 2a Folding on the left and right 2b Upper protrusion 2c Insertion section 2d Insertion notch 2e Folding the insertion part 3 Surface with insertion holes 3a Folding of the protrusion 3b Projection piece 3c Insertion hole 4 Sheets forming the components 4a Long side 4b Long side 4c Top surface 4d. The innermost side 4e Inner side 4f outer side 4g Top of the opening 4h Side of the opening

Claims

1. A method for joining two overlapping surfaces of cardboard sheets without gluing them together, in which the outer surface is provided with an insertion section that is folded and protrudes, with the tip widening and the folded section narrowing to form an insertion section with slopes on both sides, and the inner surface is provided with a fixing section that has a hole formed by a protruding piece that is folded and protrudes, and the insertion section is folded and inserted into the hole and protrudes at approximately a right angle, and has a means for fixing the insertion section by the protruding piece at the position of the hole, which is of a width that will not allow it to come out.

2. 2. The method for joining two surfaces of claim 1, wherein the fixing portion is shaped to fit the insertion of the inserting portion, the protruding piece of the fixing portion is bent to fit the fixing position of the inserting portion, and a tip portion is provided that fits tightly to the inserting portion, and the protruding piece fixes the inserting portion with the folded tip portion while closing the hole opened by the protrusion of the inserting portion on the outer surface.

3. In the method for joining two surfaces of claim 1, the protrusions of the fixing part have folds on both sides of the inclined edges of the insertion part that is inserted into the fixing part, and the two protrusions separated between the two sides have holes pre-drilled at the position where the insertion part is inserted and protrudes, or another protrusion is provided for drilling a hole, and the insertion part is fixed at the base portions of the two protrusions on both sides.

4. A method for joining two overlapping surfaces of cardboard sheets without gluing them together, in which one surface has a protruding piece that is divided into upper and lower parts and is connected between folds on the left and right between the top and bottom, and one side is folded inward so that the other side that protrudes outward becomes an insertion part with a narrowed tip, and on the other surface an insertion hole that can fix the insertion part vertically and horizontally is made by folding the protruding piece, and the inserted insertion part is folded so that it is fixed by pressing the surface with a cut made at the position of the protruding surface.

5. A box-shaped member formed using the joining method of claim 1 or 2, wherein the box-shaped member is assembled by folding a single rectangular sheet having cuts and creases and no holes or slits, and has a rectangular top surface and an open bottom surface.

6. 6. The box-shaped member of claim 5, wherein the upper portions of both short sides of the top surface of the member have a three-layer structure like a kimono collar, and the width of the innermost surface is narrowed by folding the left and right sides.

7. 6. Corrugated cardboard furniture using the box-shaped member of claim 5, which is formed by connecting or combining a plurality of said members.

8. 8. The cardboard furniture of claim 7, wherein both long sides of the upper surface of the member are box-shaped members with the open portions of a U-shape facing downward and two rectangular cylindrical legs.

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