box

Abstract

By engaging a pair of latching pieces on the left and right sides of the box body with slits in the lid, the box eliminates the need for separate parts such as hook-and-loop fasteners, while distributing and absorbing the repulsive force of the sheet material and external pressure, reliably preventing the lid from opening unexpectedly, and providing a box that offers good operability and can withstand repeated use over a long period of time, all while avoiding interference with the contents. [Solution] A pair of latching pieces 30, 31 are provided on both the left and right sides of the upper end of the box body 11, and a pair of slits 25a, 27a corresponding to the left and right sides of the lid 12 are provided. As a result, when the lid is closed, the left and right latching pieces 30, 31 are inserted into the corresponding slits 25a, 27a, and the lid 12 is latched in place. As a result, while eliminating the need for separate parts such as hook-and-loop fasteners, the repulsive force of the thick resin sheet material and external pressure are dispersed and absorbed, reliably preventing the lid 12 from opening unexpectedly, and while avoiding interference with the stored items, good lid opening and closing operation and durability for long-term repeated use are achieved.

Description

Technical Field

[0001] The present invention relates to a box for storing items such as trading cards.

Background Art

[0002] Conventionally, as a case for storing and carrying trading cards and small items, for example, a box formed by punching out and folding a thin synthetic resin sheet is widely known. As one type of such a box, for example, as in Non-Patent Document 1, there is a vertically long cigarette case type provided with a lid portion that covers the opening of the box body to prevent the stored items from accidentally popping out, and the front lid plate is locked to the front surface of the box body by a surface fastener.

Prior Art Documents

Patent Documents

[0003]

Non-Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] However, in the conventional cigarette case type box using a surface fastener, during repeated opening and closing of the lid portion, the adhesive material fixing the surface fastener to the synthetic resin sheet deteriorates, and there is a risk that the surface fastener itself may peel off from the box body or the lid portion, resulting in poor durability in long-term repeated use. Also, there is a problem that the manufacturing cost increases because parts cost and the labor cost of the pasting process are required for attaching the surface fastener.

[0005] Furthermore, if a thicker sheet material is used to improve the overall shape retention of the box, the strong rigidity (rebound force) of the material increases the force that tries to open the lid. To resist this and maintain the closed state, stronger or larger hook-and-loop fasteners are required, which not only requires more force to open and close, but also raises concerns about a deterioration in usability, such as a loud ripping sound when opening.

[0006] Therefore, after diligent research, the inventor discovered that by providing a pair of latching pieces protruding from both the left and right sides of the upper end of the box body, and forming a corresponding pair of slits on both the left and right sides of the lid, when the lid rotates to cover the opening, the pair of latching pieces on the box body are inserted into the corresponding pair of slits on the lid, respectively, thereby firmly locking the lid in place. This solved all of the aforementioned problems, and thus the inventor completed the present invention.

[0007] Furthermore, this structure distributes the load during opening and closing operations to two points on the left and right, suppressing wear and damage around the latching mechanism and increasing durability for repeated use. In addition, even if a thicker sheet material is used to improve durability, the strong resilience of the material and external pressure are efficiently distributed and absorbed by the latching mechanisms on both sides, making it less likely for the lid to open unexpectedly due to external forces during transport. This led to the completion of this invention.

[0008] This invention was made in view of the problems of the conventional invention, and aims to provide a box that, by engaging a pair of latching pieces on the left and right sides of the box body with the slits in the lid, eliminates the need for separate parts such as hook-and-loop fasteners, while dispersing and absorbing the repulsive force of the sheet material and external pressure, reliably preventing the lid from opening unexpectedly, and avoiding interference with the contents, while also providing good operability and durability for long-term repeated use. [Means for solving the problem]

[0009] The present invention as described in claim 1 is a box made of a synthetic resin sheet comprising a box body and a lid portion connected to the upper edge of the box body via a hinge portion and covering the opening of the box body in an openable and closable manner, wherein the box has a pair of latching pieces provided on both the left and right sides of the upper end of the box body and a pair of slits provided on both the left and right sides of the lid portion and corresponding to the pair of latching pieces, and in a closed state in which the lid portion rotates around the hinge portion as a pivot point to cover the opening, the pair of latching pieces are inserted into each of the pair of slits, thereby locking the lid portion.

[0010] The type of synthetic resin sheet is not limited. For example, single-layer or multi-layer sheet materials made of thermoplastic resins such as polypropylene (PP), polyethylene terephthalate (PET), polyvinyl chloride (PVC), and polyethylene (PE) may be used. The thickness of the synthetic resin sheet is not limited. However, from the viewpoint of maintaining the shape of the box and obtaining appropriate resilience in the latching mechanism, a thickness of about 0.4 mm to 1.5 mm is preferred.

[0011] The type (purpose) of the box is arbitrary and depends on the contents. For example, if the contents are trading cards for display or game use, a card storage box would be used. The shape of the box is arbitrary. For example, it could be a cigarette case-like box with a right-angled trapezoidal lid when viewed from the side, or a horizontally elongated rectangular box.

[0012] The construction of the box body and lid is arbitrary. For example, it may be made by punching out a single sheet of synthetic resin as the base, folding it along predetermined lines to create hinges or other bending points, and assembling it into a three-dimensional shape. Furthermore, to join adjacent sheet pieces in order to maintain the three-dimensional shape, welding techniques such as ultrasonic welding, high-frequency welding, and heat welding, or any joining means such as adhesives, can be employed.

[0013] The shape of the pair of latching pieces is not limited. For example, a trapezoidal or semicircular shape that narrows towards the tip can be used to make it easy to insert into the slit and difficult to accidentally come loose. Other shapes, such as those with a step or constriction on the base side, are also acceptable. Furthermore, the pair of slits are not limited to straight cuts, but may also be curved, wave-shaped, U-shaped, or elongated openings. In addition, circular holes (stop holes) may be provided at both ends to prevent cracking due to repeated use.

[0014] Furthermore, the statement that "the lid is secured by inserting the locking piece into the slit" means that the locking piece penetrates the slit or engages with the edge of the slit, creating frictional or physical engagement forces that restrict the lid from rotating in the opening direction, thus maintaining the closed state.

[0015] The present invention as described in claim 2 is the box according to claim 1, characterized in that the box body is assembled into a three-dimensional shape by joining adjacent sheet pieces together by ultrasonic welding.

[0016] In this context, "welded area by ultrasonic welding" refers to a joint formed by applying ultrasonic vibration energy to cause the contact surface of the synthetic resin sheet to self-heat, melting and bonding the resin. By employing ultrasonic welding, extremely high bonding strength is achieved that prevents peeling even with thick, highly resilient sheet materials, compared to using adhesives or double-sided tape. Furthermore, a robust three-dimensional shape can be maintained without compromising the aesthetics of the area around the joint.

[0017] Furthermore, the specific shape and arrangement pattern of the welded areas are not limited to any particular type and may be point-like (spot-like), linear, continuous, or intermittent. Depending on the area of ​​the overlapping sheet pieces and the required strength of the box, for example, multiple spot-like welded areas may be arranged in one or more rows at predetermined intervals, or the welded areas may be formed in a shape that also serves as a specific design element.

[0018] Furthermore, the adjacent sheet pieces referred to here widely include the portions that physically overlap when assembling the box body from a single unfolded diagram (blank). Specifically, this includes multiple bottom flaps that overlap each other to form the bottom surface of the box body, and the flange portions that overlap at the side ends to form the box body in a cylindrical shape.

[0019] The box according to the present invention as claimed in claim 3 is the box according to claim 1 or claim 2, characterized in that the synthetic resin sheet is a polypropylene sheet with a thickness of 0.4 mm to 1.5 mm.

[0020] By adopting a polypropylene (PP) sheet as the synthetic resin sheet, excellent flexural fatigue resistance (so-called hinge characteristics) can be obtained, and the hinge portion and the base portion of the latching piece are less likely to turn white and break against repeated opening and closing of the lid portion. In addition, polypropylene has extremely high affinity for ultrasonic welding and is optimal for the structure of the present invention in that it can achieve stable high joint strength with short-time energy application.

[0021] Furthermore, when the thickness of the synthetic resin sheet is less than 0.4 mm, the strength of the entire box is insufficient and it is likely to be deformed by external pressure. At the same time, an appropriate repulsive force (snapping property) of the latching piece cannot be obtained, and it becomes difficult to firmly maintain the locking mechanism of the lid portion. Also, if it exceeds 1.5 mm, bending at the ruled lines (crease lines) becomes difficult due to excessive rigidity, and the workability of assembly is significantly reduced. In addition, since the repulsive force of the sheet becomes too strong, the operation of inserting the latching piece into the slit becomes too difficult, and there is a possibility that the energy required for ultrasonic welding becomes excessive.

[0022] Incidentally, the preferred thickness of the synthetic resin sheet is around 0.75 mm. Within this range, it is possible to achieve an optimal balance between the rigidity (shape retention) necessary to protect the contents inside the box from external impact and pressure, the ease of bending at the ruled lines during manufacturing, and the flexibility necessary to achieve smooth opening and closing operation of the lid portion during use, which are conflicting requirements.

[0023] The polypropylene sheet may have either a single-layer structure or a multi-layer structure, and may be colorless and transparent, translucent, or opaque and colored in any color (e.g., white). Further, in order to enhance the design and practicality, various surface treatments such as various printing (decoration), embossing (texturing), scratch-resistant processing (hard coating), or antistatic processing may be applied to the front or back surface of the synthetic resin sheet.

[0024] The present invention according to claim 4 is a box according to claim 1 or claim 2, characterized in that the lid portion has a lid front plate that covers the front side of the upper part of the box body when the lid is closed, and the pair of latching pieces are configured to be concealed from the outside by the lid front plate when the lid is closed.

[0025] The phrase "concealed from the outside by the lid front plate" as used herein means that in the state where the lid portion is closed, at least a part of the lid front plate (e.g., including side piece portions extending left and right from the lid front plate) is arranged to overlap and cover the outside of the latching piece, so that at least the main part of the latching piece cannot be directly visually recognized from the outside of the box.

[0026] The lid front plate may integrally have a portion that flatly covers the front side of the box body and side piece portions that bend and extend from both left and right ends thereof to the side surface side of the box. In this case, a pair of slits may be provided at both ends of the lid front plate.

Advantages of the Invention

[0027] According to the present invention described in claim 1, since the entire box is composed of a synthetic resin sheet and the lid portion is connected to the box body via a hinge portion, it is possible to prevent the loss of the lid portion during use and enable stable opening and closing operations in a certain orbit with the hinge portion as a fulcrum. Further, by utilizing the appropriate elasticity and rigidity inherent in the synthetic resin sheet, the shape retention of the box and the latching mechanism can function effectively.

[0028] Furthermore, because a pair of latching pieces and a pair of slits are distributed on both the left and right sides, the repulsive force generated in the lid due to the bending of the hinge can be efficiently received and distributed at two points on the left and right. This allows the closed state to be maintained more firmly and in a balanced manner.

[0029] When closing the lid, the left and right latching pieces are inserted into their corresponding slits in a natural trajectory as they rotate around the hinge, eliminating the need for separate parts such as hook-and-loop fasteners, and enabling smooth and reliable latching.

[0030] Furthermore, because of the engagement structure at two points on the side, even if the box is slightly bent due to unexpected external pressure on the front or back of the box when it is being carried, the locking piece is less likely to come out of the slit, preventing the lock from being released and the lid from opening unintentionally.

[0031] Furthermore, according to the present invention as described in claim 2, since adjacent sheet pieces constituting the box body are joined by welding using ultrasonic welding rather than by interlocking engagements or adhesives, the sheet materials are firmly integrated at the material level, resulting in extremely high joint strength. As a result, even when a thick synthetic resin sheet with strong resilience is folded and assembled into a three-dimensional shape, the bond can be reliably maintained against the elastic recovery force (folding resilience) of the sheet material, and a stable, distortion-free three-dimensional shape can be maintained over a long period of time.

[0032] Furthermore, since ultrasonic welding is a joining method that melts and bonds the resin material itself through internal heat generation, the joint is less prone to peeling due to aging or changes in temperature and humidity. Therefore, even if heavy items are stored in the box and carried around, or if it is subjected to unexpected impacts such as dropping, the joint is less likely to break. The high shape retention of the box body ensures that the positional relationship between the pair of latching pieces and the slit is always accurately maintained, allowing for more reliable and smoother locking and unlocking of the latching mechanism.

[0033] Furthermore, according to the invention described in claim 3, since a polypropylene sheet is used as the synthetic resin sheet, the excellent bending fatigue resistance (hinge characteristics) of this material can be obtained. This makes it less likely for the hinge, which acts as the pivot point when opening and closing the lid, and the base of the latching piece, which is repeatedly inserted into and removed from the slit, to whiten or break (hinge breakage) due to repeated bending stress, thus maintaining the lid's opening and closing function over a long period of time.

[0034] Furthermore, by setting the sheet thickness to 0.4mm to 1.5mm, it is possible to achieve an optimal balance between conflicting requirements: the rigidity (shape retention) necessary to protect the contents inside the box from external impacts and pressure, the ease of folding along the crease lines during manufacturing, and the flexibility required to enable smooth opening and closing of the lid during use.

[0035] In particular, by using a polypropylene sheet within this specific thickness range, the pair of latching pieces defined in claim 1 are given appropriate elasticity (snapability). As a result, when inserting the latching pieces into the slit, the appropriate flex of the sheet makes insertion easy, while after insertion is complete, the elastic restoring force of the latching pieces presses them against the opening edge of the slit, maintaining a firm engagement. Therefore, it is possible to achieve a stable locking state that is light and reliable to operate, without requiring excessive force from the user, and that is less likely to come undone unintentionally.

[0036] Furthermore, according to the invention described in claim 4, the latching piece is concealed by the front plate of the lid when the lid is closed, so the latching piece is not exposed to the outside, making it less likely for surrounding items or clothing fibers to get caught on the latching piece when carrying the box, etc. As a result, the risk of the latching state being unintentionally released or the latching piece itself being damaged due to this snagging can be greatly reduced, and reliability during use can be increased.

[0037] Furthermore, concealing the latching pieces allows for a smooth, unified appearance on the sides and front of the entire box, providing excellent aesthetics while maintaining functionality. In addition, when subjected to impacts such as drops, the outer lid front panel (or its extension) acts as a protective layer, reducing the direct impact transmitted to the inner latching pieces and further enhancing the overall durability of the box. [Brief explanation of the drawing]

[0038] [Figure 1] This is an overall perspective view showing the open state of the box according to Embodiment 1 of the present invention. [Figure 2] This is an overall perspective view showing the closed state of the box according to Embodiment 1 of the present invention. [Figure 3] This is an unfolded view of a box according to Embodiment 1 of the present invention. [Figure 4] This is an enlarged cross-sectional view of the main part showing the box fastening mechanism according to Embodiment 1 of the present invention. [Modes for carrying out the invention]

[0039] The following describes specific embodiments of this invention. Here, we will take a cigarette case-shaped card storage box for storing trading cards as an example. Unless otherwise specified, directions such as front, back, left, and right refer to the orientation of the box in its assembled state. [Examples]

[0040] In Figures 1 to 3, 10 is a card storage box (box) according to Embodiment 1 of the present invention. This card storage box 10 is assembled in the shape of a cigarette case from a single blank A, which is made by punching out a large sheet of polypropylene (PP) with a thickness of 0.75 mm. This blank A is constructed by unfolding a vertically elongated rectangular box-shaped box body 11 and connecting the lower region with the unfolded right-angled trapezoidal lid portion 12, which has a slanted side pointing downwards when viewed from the side, via a horizontal fold (hinge portion) i.

[0041] The box body 11 of Blank A has a horizontally elongated rectangular bottom plate 13, a large, roughly square front plate 14 connected to the front end of the bottom plate 13 via a horizontal fold a, and a large, vertically elongated rectangular rear plate 15 connected to the rear end of the bottom plate 13 via a horizontal fold d. A pair of vertically elongated rectangular outer plates 16 and 17 are connected to the left and right ends of the front plate 14 via vertical folds b and c, respectively. Small outer retaining pieces 16a and 17a, which are flaps for joining the lid, are provided protruding from the front upper corners (inner lower ends in the unfolded view of Figure 3).

[0042] At both ends of the base plate 13, a pair of oval, right-angled trapezoidal bottom flaps 18 and 19 are connected via vertical folds e and f, respectively, with the hypotenuse facing backward (the hypotenuse facing upward in the unfolded diagram of Figure 3). A pair of large inner panels 20 and 21 are connected to the left and right ends of the rear panel 15 via vertical folds g and h, respectively.

[0043] Each inner panel 20, 21 has a pair of inner latching pieces 20a, 21a that project forward, integrally formed at the front upper corner (outer upper end in the unfolded view of Figure 3). When assembling the box, the corresponding inner and outer latching pieces 16a-20a and inner and outer latching pieces 17a-21a are overlapped and welded together to form a pair of left and right latching pieces 30, 31 for latching the lid to the box body (see also Figure 4). Furthermore, each inner plate 20, 21 is provided with a pair of right-angled trapezoidal notches 20b, 21b at its lower part for fitting the corresponding bottom flaps 18, 19.

[0044] On the other hand, the area of ​​the lid portion 12 of blank A has a horizontally elongated rectangular lid top plate 22 connected to the upper end of the rear plate 15 via a horizontal fold (hinge portion) i, ​​and a horizontally elongated rectangular lid front plate 23 connected to the front end of the lid top plate 22 via a horizontal fold j.

[0045] At both ends of the lid top plate 22, a pair of right-angled trapezoidal lid side plates 24 and 26 are connected via vertical folds k and l, respectively, with their hypotenuses facing outwards. Furthermore, at the front ends of these pairs of lid side plates 24 and 26, a pair of oval rectangular lid corner flaps 25 and 27 are connected via short horizontal folds m and n, respectively. The inner portion of each lid corner flap 25, 27 has a pair of slits 25a, 27a cut out along the lines of each fold m, n, into which corresponding fastening pieces 30, 31 are inserted, respectively.

[0046] Next, with reference to Figures 1 to 4, the assembly procedure for the card storage box 10 according to Embodiment 1 of the present invention will be described. First, the lid portion 12 is assembled into a three-dimensional shape as shown in Figures 1 to 3. Specifically, the left and right side panels 24 and 26 of the lid are bent downwards by 90° through vertical folds k and l relative to the top panel 22. Next, fold the lid corner flaps 25 and 27 inward by 90° via the horizontal folds m and n, respectively.

[0047] Then, the front lid panel 23 is folded downwards by 90° along the horizontal fold j and overlapped with the outer surfaces of the inner lid corner flaps 25 and 27. These overlapping portions are joined by ultrasonic welding to create a three-dimensional lid portion 12. As a result, slits 25a and 27a open at the left and right front corners of the lid portion 12.

[0048] Next, as shown in Figures 1 to 3, the box body 11 is assembled into a three-dimensional shape. Specifically, the left and right bottom flaps 18 and 19 are folded upward by 90° with respect to the base plate 13 via vertical folds e and f.

[0049] Next, the left and right inner panels 20 and 21 are folded forward 90° from the rear panel 15 via folds g and h. At this time, the corresponding bottom flaps 18 and 19 are fitted into the notches 20b and 21b of the inner panels 20 and 21, so that the inner panels 20 and 21 and the corresponding bottom flaps 18 and 19 are flush. After that, the rear panel 15 is raised 90° upward from the bottom panel 13 via a horizontal fold d.

[0050] Next, the front panel 14 is raised 90° upward relative to the bottom panel 13 via the horizontal fold a, and the left and right outer panels 16 and 17 are folded 90° backward via the vertical folds b and c, respectively, and overlapped with the outer surfaces of the inner panels 20 and 21 that were raised earlier. At this time, the outer portion locking pieces 16a and 17a located at the front ends of each outer plate 16 and 17 are superimposed on the base (or surrounding area) of the inner portion locking pieces 20a and 21a of the inner plates 20 and 21.

[0051] The overlapping portions of these inner and outer fastening pieces 16a-20a and the overlapping portions of the inner and outer fastening pieces 17a-21a are firmly integrated by ultrasonic welding, so that a pair of 1.5 mm thick fastening pieces 30 and 31 are provided protruding from the left and upper right corners of the front plate 14 of the box body 11 (see also Figure 4). This welding process securely fixes the outer panels 16 and 17 and the corresponding inner panels 20 and 21 to both sides of the card storage box 10, maintaining the three-dimensional shape of the box body 11 against the strong elastic restorative force of the thick polypropylene resin sheet.

[0052] Furthermore, as shown in Figures 1, 2, and 4, when closing the lid 12 around the horizontal fold (hinge) i, the pair of left and right latching pieces 30 and 31 that protrude forward are inserted into the corresponding slits 25a and 27a of the lid 12, respectively. After insertion is complete, the elastic restoring force of the latching pieces 30 and 31 firmly engages with the edges of the slits, maintaining the locked state of the lid 12.

[0053] Thus, according to the card storage box 10 of Example 1, in a synthetic resin box in which the lid 12 is hinged to the box body 11, a two-point lid latching structure is adopted on the left and right sides, with latching pieces 30, 31 on the box body 11 side and slits 25a, 27a on the lid 12 side. This eliminates the need for separate parts such as hook-and-loop fasteners that were previously required, while preventing the loss of the lid 12 and enabling stable opening and closing operation. In particular, by distributing the latching parts on the left and right sides, the repulsive force of the lid 12 and external pressure can be efficiently distributed and absorbed, preventing accidental opening while avoiding interference with trading cards (stored items).

[0054] Furthermore, the strong material-level bonding achieved through ultrasonic welding allows the three-dimensional shape to be maintained without distortion for a long period of time, resisting the elastic recovery force (rebound force) of the thick polypropylene resin sheet. This prevents peeling of the joint due to aging or impact, and ensures that the lid 12 can always be locked in place smoothly and accurately.

[0055] Furthermore, the use of a thick (0.75mm) polypropylene resin sheet prevents hinge breakage due to its excellent resistance to bending fatigue. In addition, the sheet's balanced rigidity and flexibility, along with its elastic recovery force, provides the user with a light and secure locking feel.

[0056] Furthermore, the configuration in which the latching pieces 30 and 31 are concealed by the front lid plate 23 when the lid is closed significantly reduces the risk of the latching pieces 30 and 31 catching on external objects in the vicinity, and the risk of damage to the lid 12 or accidental opening due to such catching. This not only improves the reliability of the box when it is carried, but also enables the creation of a box with a superior design, featuring smooth and integrated sides and front. [Industrial applicability]

[0057] This invention is a useful technology for a box used to store items such as trading cards. [Explanation of Symbols]

[0058] 10 card storage boxes (boxes) 11 Box 12 Lid 13 Bottom plate 14 Front panel 15 Rear plate 16,17 Outer plate 16a,17a Outer part hook piece 18,19 Bottom flap 20,21 Inner panel 20a,21a Inner part hook piece 22 Lid top plate 23 Lid front plate 24,26 Lid side plate 25,27 Cover corner flaps 25a, 27a Slit 30,31 Latch piece a-n Vertical and horizontal folds (i is the hinge part)

Claims

1. A box made of a synthetic resin sheet, comprising a box body and a lid portion connected to the upper edge of the box body via a hinge portion, which covers the opening of the box body so as to be openable and closable, A pair of fastening pieces are provided on both the left and right sides of the upper end of the box body, The lid portion is provided on both the left and right sides and has a pair of slits corresponding to the pair of latching pieces, A box characterized in that, when the lid rotates around the hinge to cover the opening in a closed state, the pair of latching pieces are inserted into each of the pair of slits to latch the lid.

2. The box according to claim 1, characterized in that the box body is assembled into a three-dimensional shape by joining adjacent sheet pieces together by ultrasonic welding.

3. The box according to claim 1 or 2, characterized in that the synthetic resin sheet is a polypropylene sheet with a thickness of 0.4 mm to 1.5 mm.

4. The lid portion has a front lid plate that covers the front side of the upper part of the box body when the lid is closed. The box according to claim 1 or 2, characterized in that the pair of latching pieces are configured to be concealed from the outside by the front lid plate when the lid is closed.

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