Fixture for board laminate

Abstract

To provide a fixture for a board laminate which can be produced only by machining a board-like material having a predetermined strength without adopting a resin molding technique.SOLUTION: The fixture for the board laminate includes: an annular plate that has a center hole and a flange portion surrounding the center hole; a pair of right and left movable projecting pieces that are located in the vicinity of a through-hole outlet of a board laminated body, clamp and fix the board laminated body between respective tip portions and the flange portion of the annular plate in an expanded state, and avoid interference between the respective tip portions and an inner wall of the through-hole of the board laminated body in a narrowed state to allow insertion and extraction into and from the through-hole; and a link mechanism that can selectively set a first operation state corresponding to the expanded state of the pair of movable projecting pieces and a second operation state corresponding to the narrowed state.SELECTED DRAWING: Figure 7

Description

[Technical Field]

[0001] The present invention relates to a fastener for a board stack, and more particularly to a fastener suitable for application to a stack of relatively lightweight boards such as corrugated cardboard. [Background technology]

[0002] As a fastener of this type, "Panajoint" (product name) manufactured by Takamura Industries Co., Ltd. has been known for some time (see Non-Patent Document 1).

[0003] This conventional product is attached to a through hole drilled in a board laminate (for example, three-ply reinforced cardboard or two-ply reinforced cardboard) and clamps and fixes the board laminate from both sides, and is made up of three parts that are all molded resin and joined together.

[0004] The first component has a sturdy cylindrical portion with a rectangular cross section, an inner diameter approximately equal to the through-hole, and a length approximately equal to the thickness of the board stack, and a rectangular annular flange portion protruding from the periphery of the inlet opening of the cylindrical portion. The second component is located within the cylindrical portion of the first component and has a rectangular movable piece (first movable piece) of a predetermined length L1 pivotally attached via a plastic hinge to one of a pair of opposing inner wall surfaces. The third component is located within the cylindrical portion of the first component and has a rectangular movable piece (second movable piece) of a predetermined length L2 (≠L1) pivotally attached via a plastic hinge to the other of the pair of opposing inner wall surfaces.

[0005] The first and second movable pieces are free to pivot symmetrically in opposite directions at a fixed stroke, each using a plastic hinge as a fulcrum, while tracing a predetermined pivot trajectory. When at the rear end of their pivot stroke, approximately the front half of each of the first and second movable pieces retracts into the tubular portion, leaving only its front end slightly open, to avoid interference when inserting or removing the pieces from the through-holes in the board stack. On the other hand, when at the front end of their pivot stroke, approximately the front half of each of the first and second movable pieces protrudes significantly from the outlet opening of the tubular portion and pivots approximately 90 degrees away from each other, to form an expanded, generally linear state. As a result, the board stack is clamped and fixed between the flange and the first and second movable pieces, with its upper surface abutting against the lower surface of the flange and its lower surface abutting against the upper surfaces of the first and second movable pieces.

[0006] When the first and second movable pieces are in an expanded state in which they are aligned in a substantially straight line, the approximately rear half portions of the movable pieces are engaged with each other by a predetermined operation via a predetermined engaging mechanism to form a coupled state, and in this coupled state the first and second movable pieces are maintained in the expanded state. [Prior art documents] [Non-patent literature]

[0007] [Non-Patent Document 1] https: / / takamura-tmsg.jp / shop / pana-b / Summary of the Invention [Problem to be solved by the invention]

[0008] The above-mentioned conventional products have the problem that it is difficult to manufacture them at low cost for the following reasons.

[0009] Reason 1: Of the three parts, at least the first part is a robust, three-dimensional structure that has a cylindrical section and a flange section integrated into one piece, so mass production requires the use of resin molding technology using molds.

[0010] Reason 2: The movable pieces (first and second movable pieces) that make up the second and third parts each have their own unique shapes and lengths, so they must be molded in separate molds, and ultimately, at least three molds are required for the entire product.

[0011] Reason 3: The first and second movable pieces are connected to a pair of opposing inner walls of the cylindrical portion that constitutes the first component via resin hinges, which requires complicated post-processing steps after the molding process.

[0012] In addition to the problems mentioned above, because conventional products are made of resin, when they are applied to the joint between the top and bottom boxes of a reinforced cardboard box, for example, there is the problem that when the cardboard box is opened at the delivery destination, the cardboard waste and the fasteners must be collected separately due to the difference in materials.

[0013] The present invention has been made in response to the above-mentioned problems with conventional fasteners, and its object is to provide a fastener for a board stack that can be manufactured at low cost.

[0014] Another object of the present invention is to provide a fixture for a board stack that can be manufactured by simply performing machining processes such as punching, cutting, mountain or valley folding, and joining on a board-shaped material of a predetermined strength, without employing resin molding technology.

[0015] Another object of the present invention is to provide a fastener for a board stack that can be manufactured without employing resin molding technology, by simply performing mechanical processing such as punching, cutting, mountain or valley folding, and joining on a board-like material of a predetermined strength, and that, even when applied to the joining portion between the top and bottom boxes of a reinforced cardboard box, allows the cardboard waste and the fastener to be collected together without being separated when the cardboard box is opened at the delivery destination.

[0016] Other objects and advantages of the present invention will be readily apparent to those skilled in the art by reading the following description of the specification. [Means for solving the problem]

[0017] It is believed that the above-mentioned technical problems can be solved by a fixture for a board stack having the following configuration and a method for manufacturing the fixture.

[0018] That is, the fixing device for a board stack according to the present invention is a fixing device that is attached to a through-hole formed in the board stack and clamps and fixes the board stack from both sides thereof, an annular plate having a central hole corresponding to the through-hole inlet of the board stack and a flange portion surrounding the central hole; a pair of left and right movable protrusions which, when in an expanded state in the vicinity of the exit of the through-hole of the board stack and forming an angle of approximately 180 degrees, clamp and fix the board stack between the tip ends of each protrusion and the flange of the annular plate, and, when in a contracted state in which the angle formed by each protrusion is narrowed, avoid interference between the tip ends and the inner wall of the through-hole of the board stack, allowing insertion and removal into the through-hole; a link mechanism that links the annular plate and each of the pair of movable protrusions and can be selectively set to a first operating state corresponding to the expanded state of the pair of movable protrusions and a second operating state corresponding to the contracted state of the pair of movable protrusions; It is equipped with the following.

[0019] With this configuration, it is possible to provide a fastener for a board stack that can be manufactured at low cost.

[0020] In a preferred embodiment, The link mechanism is a pair of left and right first link plates, one end of each of which is rotatably connected to a pair of center hole edge portions of the annular plate that are located opposite each other across the center hole; a pair of left and right second link plates each having one end pivotally connected to the other end of the pair of left and right first link plates, The pair of left and right movable protrusions may be a pair of left and right extensions formed by extending the other ends of the pair of left and right second link plates by a predetermined length.

[0021] With this configuration, the innovative idea of controlling the movement of a pair of left and right movable protrusions via a W-shaped link mechanism makes it possible to manufacture the product without using resin molding technology, facilitating low-cost manufacturing.

[0022] In a preferred embodiment, The link mechanism is A pair of left and right valley fold lines defining the pair of left and right second link plates and a pair of left and right mountain fold lines defining the pair of left and right first link plates are symmetrically arranged on both sides of a single mountain fold line that serves as a reference, and the board piece is then folded into a W shape along those fold lines, The pair of left and right movable protrusions are The cut-and-raised piece may be formed by cutting out a part of the pair of left and right valley fold processing lines that define the pair of left and right second link plates, and by providing a U-shaped cut line in the region of the pair of left and right first link plates that is continuous with the cut-out part, and cutting and raising this.

[0023] With this configuration, it is possible to provide a fixture for a board stack that can be manufactured without using resin molding technology, by simply performing machining processes such as punching, cutting, mountain or valley folding, and joining on a board-shaped material of a predetermined strength.

[0024] In a preferred embodiment, The length of the pair of left and right first link plates may be approximately equal to the thickness of the board stack, and the length of each of the pair of left and right second link plates may be approximately equal to 1 / 2 the distance between the pair of left and right first link plates.

[0025] With this configuration, the through holes formed in the board stack and the fasteners can be made to adhere well to each other, improving the clamping and fastening performance.

[0026] In a preferred embodiment, The through hole opened in the board stack and the central hole opened in the annular plate may both be elongated holes with an oval or rectangular cross section, and a pair of opposing long edge portions of this elongated hole may be provided with cover plates extending along the through hole.

[0027] With this configuration, when it is used as a handle, the load on the fingertips can be evenly distributed and the fingertips can be prevented from coming into direct contact with the rough surface that forms the inner surface of the through hole.

[0028] From another aspect, the present invention can be understood as a method for manufacturing a fastener for a board stack. That is, this manufacturing method includes: a first step of preparing a first board piece having at least an elongated central hole corresponding to the through hole having an elongated cross section of the board laminate and a flange portion surrounding the central hole in a band shape; a second step of preparing a second board piece having an elongated rectangular shape, in which a pair of valley fold lines defining a pair of second link plates and a pair of mountain fold lines defining a pair of first link plates are symmetrically arranged on both sides of a single mountain fold line serving as a reference, and a portion of the pair of valley fold lines defining the pair of second link plates is missing, and a U-shaped cut line is provided in the region of the pair of first link plates that is continuous with the missing portion; a third step of folding the elongated rectangular second board piece obtained in the second step into a W-shape as a whole along the mountain fold processing line or the valley fold processing line, and cutting and raising the first link plate region into a U-shape along the rectangular cut lines, thereby completing a link mechanism with a pair of left and right movable protrusions; The method may also include a fourth step of attaching a pair of left and right first link plates that constitute a link mechanism with a pair of left and right movable protrusions obtained in the third step to the flange portion of the rectangular board piece obtained in the first step.

[0029] With this configuration, it is possible to manufacture fasteners for board stacks at low cost without employing resin molding technology, by simply performing machining processes such as punching, cutting, mountain or valley folding, and joining on board-shaped materials of a predetermined strength.

[0030] In a preferred embodiment, The first board piece obtained in the first step has a rectangular blind board that closes the elongated central hole, linear slits along the longitudinal direction for dividing the rectangular blind board into two pieces, and mountain fold processing lines corresponding to the edges of the blind board along the two long sides of the elongated central hole, and The third step may include a process of forming a cover plate extending along the through hole of the laminated board by bending the approximately rectangular board piece with the blind plate obtained in the first step along a mountain fold processing line.

[0031] With this configuration, a fastener having a cover plate suitable for use as a handle can be manufactured at low cost.

[0032] In a preferred embodiment, The material for the first board piece obtained in the first step and / or the second board piece having an elongated rectangular shape obtained in the second step may be a board material that can be recycled and / or disposed of together with cardboard waste.

[0033] With this configuration, it is possible to manufacture fasteners for a board stack that can be collected together with the cardboard waste material and fasteners without separating them when the cardboard box is unpacked at the delivery destination.

[0034] In a preferred embodiment, The board material that can be recycled and / or disposed of together with the cardboard waste may be a hard fiber board having a thickness of 0.6 mm to 2.0 mm and a bending strength of 20 MPa to 100 MPa.

[0035] With this configuration, a high-performance fixture can be manufactured at low cost. [Effects of the Invention]

[0036] According to the present invention, it is possible to manufacture board-shaped materials of a predetermined strength using only mechanical processing such as punching, cutting, mountain or valley folding, and joining, without employing resin molding technology. Moreover, even when applied to the joining portion between the top and bottom boxes of a reinforced cardboard box, when the cardboard box is opened at the delivery destination, the cardboard waste and fasteners can be collected together without separating them. [Brief explanation of the drawings]

[0037] [Figure 1] FIG. 1 is a plan view and a cross-sectional view showing a developed state of a fixing side component that constitutes a fixing tool for a board stack. [Figure 2] FIG. 2 is a plan view and a cross-sectional view showing the developed state of a movable part that constitutes a fixture for a board stack. [Figure 3] FIG. 3 is a plan view and a cross-sectional view showing a developed state of a movable part (another embodiment) that constitutes a fixture for a board stack. [Figure 4] FIG. 4 is an exploded perspective view showing the relationship between a fixed part and a movable part that constitute a fixture for a board stack. [Figure 5]FIG. 5 is a plan view and a cross-sectional view showing the state of the board stack before the fasteners are attached. [Figure 6] FIG. 6 is a plan view and a cross-sectional view showing the state of the board stack after the fasteners have been attached. [Figure 7] FIG. 7 is an explanatory diagram showing the operation of the fixture for fixing the board stack. [Figure 8] FIG. 8 is a process diagram showing an example of a method for using a fixture for a board stack. DETAILED DESCRIPTION OF THE INVENTION

[0038] A preferred embodiment of a fastener for a board stack according to the present invention will be described in detail below, along with its manufacturing method, with reference to the accompanying drawings.

[0039] (Basic configuration of fixture) The fastener 1 (see FIG. 4) according to the present invention is attached to a through-hole 4 (see FIG. 7) formed in a board stack 41, 42, 43 (see FIG. 7) and clamps and fixes the board stack from both sides. The fastener 1 (see FIG. 4) is an annular plate (board piece) 21 (see FIG. 1) having a central hole 28 (see FIG. 4) corresponding to the through-hole entrance of the board stack and a flange 27 (see FIG. 4) surrounding the central hole 28, and when the fasteners are in an expanded state in which they form an angle of approximately 180 degrees with each other (see FIG. 7(c)), the fasteners 1 and 21 form the above-mentioned The device is equipped with a pair of left and right movable protrusions 35a, 35b (see Figure 7) that clamp and fix the board stack and, when the angle between them is narrowed and the protrusions are in a narrowed state (see Figure 7(a)), avoid interference between the respective tips of the protrusions and the inner wall of the through hole of the board stack, allowing the board stack to be inserted and removed into the through hole, and a link mechanism 3A (see Figures 5 and 6) that connects the annular plate and each of the pair of movable protrusions and can be selectively set to a first operating state corresponding to the expanded state of the pair of movable protrusions and a second operating state corresponding to the narrowed state of the pair of movable protrusions.

[0040] A fastener having such a configuration can be manufactured without using resin molding technology, by simply performing mechanical processing such as punching, cutting, mountain or valley folding, and joining on a board-like material of a predetermined strength. Moreover, even when applied to the joining portion between the top and bottom boxes of a reinforced cardboard box, when the cardboard box is opened at the delivery destination, the cardboard waste and the fastener can be collected together without being separated.

[0041] Such a fixture 1 (see FIGS. 4 to 8) can be manufactured from a fixed part 2 (see FIG. 1) and a movable part 3 (see FIGS. 2 and 3) that are prepared in a predetermined pre-process.

[0042] (Fixed side part) The fixed-side component 2 will be described with reference to FIG. 1. The fixed-side component 2 is mainly composed of a substantially rectangular board piece (annular plate) 21 having a long side length L21 and a short side length L22. The board piece 21 is preferably made of a board material that can be recycled and / or disposed of together with waste cardboard. Examples of such board materials include hard fiberboards with a thickness of 0.6 mm to 2.0 mm and a bending strength of 20 MPa to 100 MPa. As is well known to those skilled in the art, hard fiberboards are formed by laminating multiple single-layer sheets made primarily from wood fiber (e.g., fresh pulp) without any interlayer adhesive and pressurizing them together. Depending on the density, these boards are used for various purposes. For example, if the main raw material of the board material is wood fiber, the board can be reused as waste paper together with waste cardboard. For example, the waste cardboard and the board can be incinerated together.

[0043] A generally oval or elliptical opening area is defined in the center of board piece 21, and this opening area is closed by a rectangular blind plate, leaving arc-shaped openings 26a, 26b at both ends. This blind plate is separated into two cantilevered areas 23a, 23b by a cut line (slit) 22 extending along its centerline, and mountain fold lines 24a, 24b are formed at the base of each area 23a, 23b. Here, mountain fold lines 24a, 24b are formed by previously processing (e.g., cutting) narrow groove lines 25a, 25b along the ridge line that will be created when the board is mountain folded, making the mountain folding process easier (see Figure 1(c)).

[0044] When the two cantilever regions 23a, 23b are folded at approximately right angles along mountain fold lines 24a, 24b toward the inside of through-hole 4, these cantilever regions 23a, 23b each function as a cover plate that shields the inner wall surface of the through-hole (a rough surface caused by the hole drilling process). Therefore, for example, if fastener 1 of the present invention is attached to the side of a cardboard box with its longitudinal direction horizontal so that it functions not only to clamp and fix a laminate but also as a handle, when an attempt is made to lift the cardboard box by hooking a fingertip on the handle, cantilever regions 23a, 23b, which function as cover plates, are interposed between the fingertip and the rough inner wall surface of the through-hole, making it easier to lift and preventing injury to the fingertip.

[0045] In addition, by adjusting the bending angle, the cantilever regions 23a, 23b abut against the connection points (ridge portions) of the pair of left and right second link plates A11, A12, which also has the secondary effect of functioning as a stopper to maintain the link mechanism 3A in the first operating state corresponding to the expanded state.

[0046] (moving part) The movable part 3 will be described with reference to Figure 2. The movable part 3 is mainly composed of a board piece 30 in the shape of a long, narrow rectangle having a long side length L1 and a short side length L2. The material of the board piece 30 is preferably a board material that can be recycled and / or disposed of together with cardboard waste. An example of such a board material is a hard fiberboard having a thickness of 0.6 mm to 2.0 mm and a bending strength of 20 MPa to 100 MPa.

[0047] As is well known to those skilled in the art, hard fiberboards are made by laminating multiple single-layer sheets made primarily from wood fiber (e.g., fresh pulp) without any interlayer adhesive, and then pressurizing and integrating these sheets together. They are used for a variety of purposes depending on their density.

[0048] A single mountain fold processing line 31 is provided on the board piece 30 at a position that divides the longitudinal direction in half, and on both sides of this mountain fold processing line 31, a pair of valley fold processing lines 32a, 32b and a further pair of mountain fold processing lines 33a, 33b are arranged symmetrically.

[0049] Here, one mountain fold line 31 is a narrow groove line 31' having a width w and a depth d that is previously processed (for example, by cutting) along the ridge line formed when the paper is mountain folded (see FIGS. 2(b) and 2(c)). A pair of valley fold lines 32a, 32b is a pair of narrow groove lines 32a', 32b' having a width w and a depth d that is previously processed along the ridge line formed when the paper is valley folded (see FIGS. 2(b) and 2(c)). A pair of mountain fold lines 33a, 33b is a pair of narrow groove lines 33a', 33b' having a width w and a depth d that is previously processed (for example, by cutting) along the ridge line formed when the paper is mountain folded (see FIGS. 2(b) and 2(c)).

[0050] The area between the central mountain fold line 31 and the pair of valley fold lines 32a, 32b on either side thereof constitutes a pair of second link plates A11, A12, and the areas A21, A22 between the pair of valley fold lines 32a, 32b and the pair of mountain fold lines 33a, 33b constitute a pair of first link plates. The areas between the pair of mountain fold lines 33a, 33b and both longitudinal end edges of the board piece 30 are adhesive margin areas A31, A32 for adhesively fixing the movable part 3 assembled as a link mechanism to the fixed part 2.

[0051] Furthermore, the pair of valley fold lines 32a, 32b are missing midway over a width L7, and U-shaped cut lines 34a, 34b are formed in the pair of first link plates A21, A22 corresponding to this width L7. A pair of U-shaped regions surrounded by the pair of U-shaped cut lines 34a, 34b are cut and raised from the pair of first link plates A21, A22 toward the back surface, respectively, to form a pair of movable protrusions 35a, 35b that are reverse extensions of the pair of second link plates A11, A12 (see FIGS. 4, 5, and 6).

[0052] (Link mechanism with movable protrusion) The link mechanism with movable protrusions will be described with reference to Figures 2 and 4. When a long, narrow rectangular board piece 30 shown in Figure 2 is mountain-folded or valley-folded along one mountain fold processing line 31, a pair of valley fold processing lines 32a and 32b, and a pair of mountain fold processing lines 33a and 33b, respectively, a W-shaped link mechanism 3A appears in a side view, as shown in Figure 4.

[0053] This link mechanism 3A has four link plates, consisting of a pair of first link plates A21, A22, each having a length L4, and a pair of second link plates A11, A12, each having a length L3, and is configured by appropriately connecting each end of these link plates so that they can rotate.This link mechanism 3A is also equipped with a pair of movable protrusions 35a, 35b, which are formed by extending the pair of second link plates A11, A12 in opposite directions, thereby forming a link mechanism with movable protrusions.

[0054] The link mechanism with the movable protrusion thus completed is adhesively fixed to the underside of the flange 27 of the fixed component 2 via a pair of overlap areas A31, A32, as shown in Fig. 4. Any adhesive such as ethylene-vinyl acetate, vinyl acetate, acrylic, or cyanoacrylate adhesives can be used at this time, but an ethylene-vinyl acetate adhesive is preferred in consideration of adhesive strength and bonding time.

[0055] (Relationship between the first operating state of the link mechanism and the state of the pair of movable protrusions) The relationship between the first operating state of the link mechanism 3A and the state of the pair of movable projections 35a, 35b is shown in FIG. 5. As shown in FIG. 5, the pair of movable projections 35a, 35b are extensions of the pair of second link plates A11, A12 in the opposite direction. Therefore, the angle between the pair of movable projections 35a, 35b corresponds to the angle θ1 between the pair of second link plates A11, A12. Therefore, when the pair of second link plates A11, A12 are pinched between the thumb and index finger to narrow the angle θ1, the link mechanism 3A transitions to the first operating state. In this first operating state, the pair of movable projections 35a, 35b are squeezed together and slightly pulled upward by the action of the link mechanism 3A. This avoids interference between the tips of the pair of movable protrusions 35a, 35b and the inner walls of the through-holes 4 of the board stack 41, 42, 43, making it easy to insert and remove the fastener into the through-hole 4 (see FIG. 7(a)). In FIG. 7(a), reference numerals 41, 42, 43 respectively denote corrugated cardboard plates that make up the board stack.

[0056] (Relationship between the second operating state of the link mechanism and the state of the pair of movable protrusions) The relationship between the second operating state of the link mechanism 3A and the state of the pair of movable projections 35a, 35b is shown in FIG. 6. As shown in FIG. 6, the pair of movable projections 35a, 35b are extensions of the pair of second link plates A11, A12 in the opposite direction. Therefore, the angle between the pair of movable projections 35a, 35b corresponds to the angle θ1 between the pair of second link plates A11, A12. Therefore, when the angle θ1 is increased to approximately 180 degrees by pressing down the inverted V-shaped connection point of the pair of second link plates A11, A12 with a fingertip (see FIG. 7(b)), the link mechanism 3A transitions to the second operating state (see FIG. 7(c)). In this second operating state, the angle between the pair of movable projections 35a, 35b is increased to approximately 180 degrees and the pair of movable projections 35a, 35b are pulled slightly downward in the figure due to the action of the link mechanism 3A. As a result, the tips of the pair of movable protrusions 35a, 35b protrude horizontally in the figure, and the board stacks 41, 42, 43 are clamped and fixed between the flange portion 27 and the movable protrusions 35a, 35b (see Figure 7(c)).

[0057] Furthermore, the length of each of the pair of first link plates A21, A22 is set to approximately match the thickness of the board stack, and the length of each of the pair of second link plates A11, A12 is set to approximately match half the distance between the pair of first link plates, so that when the link mechanism 3A is in the second operating state, the pair of first link plates A21, A22 are maintained in an approximately vertical position in the figure, and the pair of second link plates A11, A12 are maintained in an approximately horizontal position in the figure, resulting in excellent adhesion between the board stack and the fastener.

[0058] Furthermore, once the link mechanism 3A is in the second operating state (clamped and fixed state), even if, for some reason, a force acts on the movable protrusions 35a and 35b to separate the layers of the board stack 41, 42, and 43, due to the principle of leverage, the movable protrusions 35a and 35b will not easily tilt, and therefore it is unlikely that the link mechanism 3A will return from the second operating state to the first operating state (release of the clamped and fixed state).

[0059] However, if the flange portion 27 is grasped and pulled out with great force, the movable protrusions 35a, 35b will easily tilt using the principle of leverage, and the link mechanism 3A will return from the second operating state to the first operating state, allowing the fixing device 1 to be removed from the through hole 4 in the board laminate.

[0060] (An example of how to use the fixture) A method of using the fastener according to the present invention will be described with reference to Figure 8. Let us now assume that a heavy product 200 is packed in a specially constructed cardboard box 100 for shipping, and then unpacked at the destination. Here, the cardboard box 100 is made up of a relatively tall top box 101 that is open on the bottom, and a relatively short bottom box 102 that is open on the top, and the top box 101 is fitted over the bottom box 102.

[0061] The top box 101 is made from a single piece of cardboard, while the bottom box 102 is made from two overlapping pieces of cardboard so that it can withstand the weight of the product 200. Two elongated through-holes 101a, 101a are provided in the lower part of each of the left and right sides of the top box 101, and two similar through-holes 102a, 102a are provided in the corresponding left and right sides of the bottom box 102.

[0062] After storing the product 200 inside the bottom box 102, when the top box 101 is placed over it, the through holes 101a and 102a are aligned, thereby revealing a board stack consisting of three stacked cardboard sheets and through holes that penetrate the board (see Figure 8(a)).

[0063] In this state, by fitting fastener 1 according to the present invention into the through holes (101a, 102a), top box 101 and bottom box 102 are joined together, completing the packaging process for cardboard box 100. To fit fastener 1, first narrow the pair of left and right movable protrusions 35a, 35b (see FIG. 5), then, in that state, insert fastener 1 into the through holes (101a, 102a) as shown by the arrows, and then, by pressing with your fingertips the ridge of the mountain fold formed by joining the pair of second link plates, the pair of left and right movable protrusions 35a, 35b expand (see FIG. 6), and the board stack formed by stacking three corrugated boards is firmly clamped and fixed from both sides (see FIG. 8(b)).

[0064] At the destination, the fixing device 1 can be easily removed from the through holes (101a, 102a) by simply pinching the flange portion 27 with the thumb and index finger and pulling it strongly (see FIG. 8(c)).

[0065] Thereafter, by holding both the left and right sides of the upper box 101 with both hands and lifting it, the upper box 101 can be pulled out from the bottom box 102, and the product 200 can be taken out, completing the unpacking process (see FIG. 8(d)).

[0066] The used fastener 1 obtained by unpacking in this way is not made of resin like conventional products, but is made of a material that can be recycled and / or disposed of together with cardboard waste, which has the advantage that there is no problem with separate collection.

[0067] (Support for stacks with different numbers of boards) The fastener of the present invention can be widely applied not only to board stacks made of corrugated cardboard sheets, but also to board stacks made of any other lightweight boards. It can also accommodate any number of stacked boards. An example of a fastener for a board stack made of two stacked corrugated cardboard sheets is shown in FIG. 3. In this example, the length L4' of the pair of left and right first link plates A21, A22 is set to approximately match the thickness of the board stack made of two stacked corrugated cardboard sheets, thereby enabling it to accommodate board stacks of different thicknesses.

[0068] (Meaning of link mechanism) The link mechanism is sufficient as long as it connects the annular plate and each of the pair of movable protrusions and has the function of selectively setting a first operating state (see, for example, Figure 7(c)) corresponding to the expanded state of the pair of movable protrusions and a second operating state (see, for example, Figure 7(a)) corresponding to the contracted state of the pair of movable protrusions, and the specific structure thereof varies, and the number and length of the link plates are not limited to the embodiments. Furthermore, the material is not necessarily limited to hard fiberboard, and if separate collection is not required, it may be a long, narrow rectangular resin plate that can be folded in a mountain or valley direction using resin hinges (thin hinges). [Example]

[0069] Next, a specific example of the fastener 1 according to the present invention will be described. The inventors have confirmed that the following design example provides good performance for a board stack made of three layers of corrugated cardboard. Materials of fixed and moving parts: 1.4mm thick special hard fiberboard (PASCO manufactured by Hokuetsu Corporation) Dimensions of each part (see Figure 1) L1=115mm L2=32mm L3=27.5mm L4=23mm L5=7mm L6=14.3mm L7=16mm w=1.4mm d=0.7mm [Industrial Applicability]

[0070] The board stack fastener according to the present invention can be used in the manufacturing and processing of special hard fiberboards. [Explanation of symbols]

[0071] 1 Fixture 2 Fixed side parts 3 Movable parts 3A Link Mechanism 4 through holes 21 Board Pieces 22 Cut line 23a, 23b Cantilever region 24a, 24b Mountain fold processing line 25a,25b Thin groove processed wire 26a,26b Arc-shaped opening 27 Tsuba 30 board pieces 31 Mountain fold processing line 31´ Narrow groove line 32a, 32b Valley fold processing line 32a´,32b´ Narrow groove line 33a, 33b Mountain fold processing line 33a´,33b´ Narrow groove line 34a, 34b U-shaped cut line 35a,35b Movable projecting piece A21, A22 Pair of left and right first link plates A11, A12 Pair of left and right second link plates A31, A32 Left and right pair of overlap areas L3 Length of second link plate L4 Length of first link plate L6 Length of movable protrusion L7 Width of movable protrusion w Width of narrow groove d Depth of narrow groove T-board piece thickness

Claims

1. A fixture that is attached to a through hole opened in a board stack and clamps and fixes the board stack from both sides, an annular plate having a central hole corresponding to the through-hole inlet of the board stack and a flange portion surrounding the central hole; a pair of left and right movable protrusions which, when in an expanded state in the vicinity of the exit of the through-hole of the board stack and forming an angle of approximately 180 degrees, clamp and fix the board stack between the tip ends of each protrusion and the flange of the annular plate, and, when in a contracted state in which the angle formed by each protrusion is narrowed, avoid interference between the tip ends and the inner wall of the through-hole of the board stack, allowing insertion and removal into the through-hole; a link mechanism that links the annular plate with each of the pair of movable protrusions and is selectively settable between a first operating state corresponding to the expanded state of the pair of movable protrusions and a second operating state corresponding to the contracted state of the pair of movable protrusions; A board stack fixture comprising:

2. The link mechanism is a pair of left and right first link plates, one end of each of which is rotatably connected to a pair of center hole edge portions of the annular plate that are located opposite each other across the center hole; a pair of left and right second link plates, one end of each of which is rotatably connected to the other end of the pair of left and right first link plates, and the other end of each of which is rotatably connected to the other end of the pair of left and right first link plates; 2. The fixing device for a board stack according to claim 1, wherein the pair of left and right movable protrusions are a pair of left and right extensions formed by extending the other ends of the pair of left and right second link plates by a predetermined length.

3. The link mechanism is A pair of left and right valley fold lines defining the pair of left and right second link plates and a pair of left and right mountain fold lines defining the pair of left and right second link plates are symmetrically arranged on both sides of a single mountain fold line serving as a reference, and the board piece is then folded into a W shape along those fold lines, The pair of left and right movable protrusions are 3. The fixing device for a board stack according to claim 2, wherein a portion of the pair of left and right valley fold processing lines defining the pair of left and right second link plates is missing, and a rectangular cut line is provided in the region of the pair of left and right first link plates that is continuous with the missing portion, and the cut-up piece is formed by cutting and raising the cut-up piece.

4. 3. A fixing device for a board stack according to claim 2, wherein the length of the pair of left and right first link plates is approximately equal to the thickness of the board stack, and the length of each of the pair of left and right second link plates is approximately equal to 1 / 2 of the distance between the pair of left and right first link plates.

5. 2. The fixing device for a board stack according to claim 1, wherein the through hole opened in the board stack and the central hole opened in the annular plate are both elongated holes having an oval or rectangular cross section, and a pair of opposing long side edges of the elongated holes are provided with cover plates extending along the through hole.

6. a first step of preparing a first board piece having at least an elongated central hole corresponding to the through-hole having an elongated cross section of the board stack and a flange portion surrounding the central hole in a band shape; a second step of preparing a second board piece having an elongated rectangular shape, in which a pair of left and right valley fold lines defining a pair of left and right second link plates and a pair of left and right mountain fold lines defining a pair of left and right second link plates are symmetrically arranged on both sides of a single mountain fold line serving as a reference, and a portion of the pair of left and right valley fold lines defining the pair of left and right second link plates is missing, and strip-shaped cut lines are provided in the region of the pair of left and right first link plates continuing from the missing portions; a third step of folding the elongated rectangular second board piece obtained in the second step into a W-shape as a whole along the mountain fold processing line or the valley fold processing line, and cutting and raising the first link plate region into a strip shape along the strip-shaped cut lines, thereby completing a link mechanism with a pair of left and right movable protrusions; and a fourth step of attaching a pair of left and right first link plates that constitute the link mechanism with the pair of left and right movable protrusions obtained in the third step to the flanges of the rectangular board pieces obtained in the first step.

7. The first board piece obtained in the first step is provided with a rectangular blind board that closes the elongated central hole, linear cut lines along the longitudinal direction for dividing the rectangular blind board into two pieces, and mountain fold processing lines that correspond to the edges of the blind board along the two long sides of the elongated central hole, and 7. The method for manufacturing a fastener for a board stack according to claim 6, wherein the third step includes a process of bending the approximately rectangular board pieces with blind panels obtained in the first step along mountain fold lines to form cover plates that extend along the through holes of the laminated boards.

8. 8. The method for manufacturing a fastener for a board stack according to claim 6 or 7, wherein the first board piece obtained in the first step and / or the second board piece having an elongated rectangular shape obtained in the second step are made of a board material that can be recycled and / or disposed of together with cardboard waste.

9. The method for manufacturing a fastener for a board laminate according to claim 8, wherein the board material that can be recycled and / or disposed of together with the cardboard waste material is a hard fiber board having a thickness of 0.6 mm to 2.0 mm and a bending strength of 20 MPa to 100 MPa.

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