Leg structure and three-dimensional structure

Abstract

This invention provides a leg structure that is less likely to tip over unintentionally. [Solution] The first hypotenuse of the first outer leg and the second hypotenuse of the second outer leg 200b are rotatably connected to the first hypotenuse and the second hypotenuse of the central part, the first outer edge of the first inner leg and the second outer edge of the second inner leg are rotatably connected to the first side edge of the first outer leg and the second side edge of the second outer leg 200b, and the first inner edge of the first inner leg and the second inner edge of the second inner leg are rotatably connected. In the unfolded state, the first outer leg, the second outer leg 200b, the first inner leg and the second inner leg are unfolded, and in the upright state, the first outer leg and the second outer leg 200b are upright relative to the central part, and the first inner leg and the second inner leg are folded relative to the first outer leg and the second outer leg 200b, and the first inner leg and the second inner leg are valley-folded.

Description

Technical Field

[0001] The present invention relates to a leg structure and a three-dimensional structure.

Background Art

[0002] The following Patent Document 1 describes a conventional three-dimensional structure (campfire stand). This three-dimensional structure includes a central part, four surrounding plates, four first hinges, four legs, and four second hinges. The central part is a substantially square plate having four sides. The four surrounding plates have sides arranged along the four sides of the central part. The four first hinges rotatably connect the four sides of the central part and the sides of the four surrounding plates. The four second hinges rotatably connect the four legs to the lower surfaces of the four surrounding plates.

[0003] In the conventional three-dimensional structure, during use, the four surrounding plates are deployed at a predetermined angle with respect to the central part and the four legs stand up with respect to the four surrounding plates. On the other hand, during non-use, two of the four surrounding plates are overlapped on the upper surface of the central part, the remaining two surrounding plates are overlapped on the lower surface of the central part, and the four legs are arranged along the lower surfaces of the four surrounding plates.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] However, since the four legs are rotatably connected to the lower surfaces of the four surrounding plates by the four second hinges, even when the four legs are standing with respect to the four surrounding plates, if the conventional three-dimensional structure is subjected to an external impact or the like, at least one of the four legs may accidentally fall down from the standing state.

[0006] This invention provides a leg structure and a three-dimensional structure that are less likely to tip over unintentionally. [Means for solving the problem]

[0007] A leg structure according to one aspect of the present invention is a structure that is deformable between an unfolded state and an upright state and supports a central portion having a first hypotenuse and a second hypotenuse arranged in a substantially V-shape or substantially V-shape convex on one side in a first direction in the upright state. This leg structure has a plate-shaped first outer leg, a plate-shaped second outer leg, a plate-shaped first inner leg, and a plate-shaped second inner leg. The first outer leg has a first hypotenuse rotatably connected to the first hypotenuse of the central portion, and a first side on one side in a second direction substantially perpendicular to the first direction. The second outer leg has a second hypotenuse rotatably connected to the second hypotenuse of the central portion, and a second side on the other side in the second direction. The first inner leg has a first outer side on the other side in the second direction and a first inner side on one side in the second direction. The first outer side of the first inner leg is rotatably connected to the first side of the first outer leg. The second inner leg has a second outer edge on one side in the second direction and a second inner edge on the other side in the second direction. The second outer edge of the second inner leg is rotatably connected to the second side edge of the second outer leg. The first inner edge of the first inner leg and the second inner edge of the second inner leg are rotatably connected.

[0008] In the unfolded state, the first outer leg, second outer leg, first inner leg, and second inner leg are unfolded into a roughly plate-like shape and positioned on one side of the central part in the first direction. In the upright state, the first outer leg is folded upright on one side of the central part in a third direction substantially perpendicular to the first and second directions, the second outer leg is folded upright on one side of the central part in the third direction, the first inner leg is folded upright on the other side of the first direction relative to the first outer leg, the second inner leg is folded upright on the other side of the first direction relative to the second outer leg, and the first inner leg and second inner leg are valley-folded on the other side of the first direction, so that the first inner leg and second inner leg are positioned on one side of the central part in the third direction.

[0009] A leg structure according to one aspect of the present invention is less likely to tip over unintentionally compared to conventional examples. The reason for this is as follows: In the upright position, the first outer leg is bent to one side in a third direction relative to the center, and the second outer leg is also bent to one side in a third direction relative to the center, while the first inner leg is bent to the other side in a first direction relative to the first outer leg, and the second inner leg is also bent to the other side in a first direction relative to the second outer leg, and the first inner leg and the second inner leg are valley-folded to the other side in a first direction. Moreover, since the first inner edge of the first inner leg and the second inner edge of the second inner leg are rotatably connected, the valley-folded state of the first inner leg and the second inner leg is stable.

[0010] A leg structure according to another aspect of the present invention is a structure that is deformable between an upright state and a folded state and supports a central portion in the upright state. The central portion has a first central plate and a second central plate adjacent to each other in a second direction substantially perpendicular to a first direction. The first central plate has a first inner edge and a first hypotenuse on one side in the second direction. The second central plate has a second inner edge and a second hypotenuse on the other side in the second direction. The first inner edge of the first central plate and the second inner edge of the second central plate are rotatably connected. In the upright state, the first hypotenuse and the second hypotenuse are arranged in a substantially V-shape or a substantially V-shape with a convex side in the first direction.

[0011] Another embodiment of the leg structure includes a plate-shaped first support leg and a plate-shaped second support leg. The first support leg has a first slanted side rotatably connected to a first slanted side in the central part, and a first side on one side in the second direction. The second support leg has a second slanted side rotatably connected to a second slanted side in the central part, and a second side on the other side in the second direction. The first side of the first support leg and the second side of the second support leg are rotatably connected.

[0012] In the upright position, the first central plate and the second central plate are unfolded into a roughly plate-like shape, the first support leg is bent to one side in a third direction substantially perpendicular to the first and second directions relative to the first central plate and stands upright, the second support leg is bent to one side in a third direction relative to the second central plate and stands upright, and the first support leg and the second support leg are mountain-folded to one side in the first direction. In the folded position, the first central plate and the second central plate are mountain-folded to the other side in the third direction and overlap each other, the first support leg and the second support leg are mountain-folded to the other side in the third direction and overlap each other, the first support leg is located on one side in the first direction relative to the first central plate, and the second support leg is located on one side in the first direction relative to the second central plate.

[0013] A leg structure according to another aspect of the present invention is less likely to tip over unintentionally compared to the conventional example. The reason for this is as follows: The first hypotenuse of the first support leg is rotatably connected to the first hypotenuse of the first central plate. The second hypotenuse of the second support leg is rotatably connected to the second hypotenuse of the second central plate. The first side of the first support leg and the second side of the second support leg are rotatably connected. Therefore, in the upright position, the first support leg is bent to one side in the third direction relative to the first central plate in the central part, the second support leg is bent to one side in the third direction relative to the second central plate in the central part, and the state in which the first support leg and the second support leg are folded in a mountain fold to one side in the first direction is maintained.

[0014] A three-dimensional structure according to one aspect of the present invention is deformable between an unfolded state and an upright state. This three-dimensional structure comprises a central part, a first leg structure, and a second leg structure. The central part has a first and second hypotenuse arranged in a substantially V-shape or a substantially V-shape on one side in the first direction, and a third and fourth hypotenuse arranged in a substantially V-shape or a substantially V-shape on the other side in the first direction.

[0015] The first leg structure includes a plate-shaped first outer leg, a plate-shaped second outer leg, a plate-shaped first inner leg, and a plate-shaped second inner leg. The first outer leg has a first hypotenuse rotatably connected to a first hypotenuse in the central part, and a first side in one direction substantially perpendicular to the first direction. The second outer leg has a second hypotenuse rotatably connected to a second hypotenuse in the central part, and a second side in the other direction of the second direction. The first inner leg has a first outer side in the other direction of the second direction and a first inner side in one direction of the second direction. The first outer side of the first inner leg is rotatably connected to the first side of the first outer leg. The second inner leg has a second outer side in one direction of the second direction and a second inner side in the other direction of the second direction. The second outer side of the second inner leg is rotatably connected to the second side of the second outer leg. The first inner edge of the first inner leg and the second inner edge of the second inner leg are rotatably connected.

[0016] The second leg structure has a plate-shaped third outer leg, a plate-shaped fourth outer leg, a plate-shaped third inner leg, and a plate-shaped fourth inner leg. The third outer leg has a third hypotenuse rotatably connected to the third hypotenuse in the central part, and a third side in one direction of the second direction. The fourth outer leg has a fourth hypotenuse rotatably connected to the fourth hypotenuse in the central part, and a fourth side in the other direction of the second direction. The third inner leg has a third outer side in the other direction of the second direction and a third inner side in one direction of the second direction. The third outer side of the third inner leg is rotatably connected to the third side of the third outer leg. The fourth inner leg has a fourth outer side in one direction of the second direction and a fourth inner side in the other direction of the second direction. The fourth outer side of the fourth inner leg is rotatably connected to the fourth side of the fourth outer leg. The third inner side of the third inner leg and the fourth inner side of the fourth inner leg are rotatably connected.

[0017] In the unfolded state, the first outer leg, second outer leg, first inner leg, and second inner leg are unfolded into a roughly plate-like shape and positioned on one side of the first direction relative to the center, and the third outer leg, fourth outer leg, third inner leg, and fourth inner leg are unfolded into a roughly plate-like shape and positioned on the other side of the first direction relative to the center. In the upright state, the first outer leg is folded upright on one side of the first and second directions relative to the center in a third direction, the second outer leg is folded upright on one side of the third direction relative to the center, the first inner leg is folded upright on the other side of the first direction relative to the first outer leg, the second inner leg is folded upright on the other side of the first direction relative to the second outer leg, and the first inner leg and second inner leg are valley-folded on the other side of the first direction, and the first inner leg and second inner leg are positioned on one side of the third direction relative to the center. It is located on one side, with the third outer leg bent and standing upright on one side in the third direction relative to the central part, the fourth outer leg bent and standing upright on one side in the third direction relative to the central part, and the third inner leg bent on one side in the first direction relative to the third outer leg, and the fourth inner leg bent on one side in the first direction relative to the fourth outer leg, and the third inner leg and the fourth inner leg are valley-folded on one side in the first direction, so that the third inner leg and the fourth inner leg are located on one side in the third direction relative to the central part.

[0018] In the case of a three-dimensional structure according to one aspect of the present invention, the first and second leg structures are less likely to tip over unintentionally compared to conventional examples. The reason for this is as follows: In the upright position, the first outer leg is bent to one side in the third direction relative to the central part and the second outer leg is bent to one side in the third direction relative to the central part and the first inner leg is bent to the other side in the first direction relative to the first outer leg, the second inner leg is bent to the other side in the first direction relative to the second outer leg, and the first inner leg and the second inner leg are valley-folded to the other side in the first direction, so the first leg structure is less likely to tip over unintentionally. Similarly, in the upright position, the third outer leg is bent to one side in the third direction relative to the center, and the fourth outer leg is also bent to one side in the third direction relative to the center, while the third inner leg is bent to one side in the first direction relative to the third outer leg, the fourth inner leg is bent to one side in the first direction relative to the fourth outer leg, and the third and fourth inner legs are valley-folded to one side in the first direction, so the second leg structure is not easily toppled over unintentionally. Moreover, since the first inner edge of the first inner leg and the second inner edge of the second inner leg are rotatably connected, the valley-folded state of the first and second inner legs is stable, and since the third inner edge of the third inner leg and the fourth inner edge of the fourth inner leg are rotatably connected, the valley-folded state of the third and fourth inner legs is stable.

[0019] A three-dimensional structure according to another aspect of the present invention is deformable between an upright state and a folded state. This three-dimensional structure comprises a central part, a first leg structure, and a second leg structure.

[0020] The central section has a first central plate and a second central plate adjacent to each other in a second direction substantially perpendicular to the first direction. The first central plate has a first inner edge, a first hypotenuse, and a third hypotenuse on one side in the second direction. The second central plate has a second inner edge, a second hypotenuse, and a fourth hypotenuse on the other side in the second direction. The first inner edge of the first central plate and the second inner edge of the second central plate are rotatably connected. The first and second hypotenuses are arranged in a substantially V-shape or V-shape with a convexity on one side in the first direction when upright. The third and fourth hypotenuses are arranged in a substantially V-shape or V-shape with a convexity on the other side in the first direction when upright.

[0021] The first leg structure has a plate-shaped first support leg and a plate-shaped second support leg. The first support leg has a first slanted side rotatably connected to a first slanted side in the central part, and a first side on one side in the second direction. The second support leg has a second slanted side rotatably connected to a second slanted side in the central part, and a second side on the other side in the second direction. The first side of the first support leg and the second side of the second support leg are rotatably connected.

[0022] The second leg structure has a plate-shaped third support leg and a plate-shaped fourth support leg. The third support leg has a third hypotenuse rotatably connected to the third hypotenuse in the central part, and a third side in one direction of the second direction. The fourth support leg has a fourth hypotenuse rotatably connected to the fourth hypotenuse in the central part, and a fourth side in the other direction of the second direction. The third side of the third support leg and the fourth side of the fourth support leg are rotatably connected.

[0023] In an upright position, the first central plate and the second central plate are unfolded into a roughly plate-like shape, the first support leg is bent and standing upright in one direction in a third direction substantially perpendicular to the first and second directions relative to the first central plate, the second support leg is bent and standing upright in one direction in a third direction relative to the second central plate, the first and second support legs are folded in a mountain fold to one side in the first direction, the third support leg is bent and standing upright in one direction in a third direction relative to the first central plate, the fourth support leg is bent and standing upright in one direction in a third direction relative to the second central plate, and the third and fourth support legs are folded in a mountain fold to the other side in the first direction. In the folded state, the first central plate and the second central plate are folded in a mountain fold to the other side in the third direction and overlapped with each other, the first support leg and the second support leg are folded in a mountain fold to the other side in the third direction and overlapped with each other, the first support leg is located on one side in the first direction relative to the first central plate, the second support leg is located on one side in the first direction relative to the second central plate, the third support leg and the fourth support leg are folded in a mountain fold to the other side in the third direction and overlapped with each other, the third support leg is located on the other side in the first direction relative to the first central plate, and the fourth support leg is located on the other side in the first direction relative to the second central plate.

[0024] The three-dimensional structure according to another aspect of the present invention is less likely to accidentally fall compared to the conventional example. The reason is as follows. The first hypotenuse of the first support leg is rotatably connected to the first hypotenuse of the first central plate. The second hypotenuse of the second support leg is rotatably connected to the second hypotenuse of the second central plate. The first side of the first support leg and the second side of the second support leg are rotatably connected. Therefore, in the standing state, the first support leg is bent to one side in the third direction with respect to the first central plate at the center, the second support leg is bent to one side in the third direction with respect to the second central plate at the center, and the state where the first support leg and the second support leg are mountain-folded to one side in the first direction is maintained. Similarly, the third hypotenuse of the third support leg is rotatably connected to the third hypotenuse of the first central plate. The fourth hypotenuse of the fourth support leg is rotatably connected to the fourth hypotenuse of the second central plate. The third side of the third support leg and the fourth side of the fourth support leg are rotatably connected. Therefore, in the standing state, the third support leg is bent to one side in the third direction with respect to the first central plate at the center, the fourth support leg is bent to one side in the third direction with respect to the second central plate at the center, and the state where the third support leg and the fourth support leg are mountain-folded to the other side in the first direction is maintained.

Brief Description of the Drawings

[0025] [Figure 1] It is a plan view showing the unfolded state of the three-dimensional structure according to Example 1 of the present invention. [Figure 2A] It is a perspective view showing the standing state of the three-dimensional structure of Example 1 from the front, plan, and left side views. [Figure 2B] It is a perspective view showing the standing state of the three-dimensional structure of Example 1 from the back and bottom views. [Figure 2C] It is a perspective view showing the standing state of the three-dimensional structure of Example 1 from the bottom and right side views. [Figure 3A] It is a plan view showing the folded state of the three-dimensional structure of Example 1. [Figure 3B] It is a bottom view showing the folded state of the three-dimensional structure of Example 1. [Figure 4A]This is a schematic unfolded view of a three-dimensional structure according to Embodiment 2 of the present invention, as seen from the planar side. [Figure 4B] This is a schematic unfolded view of the three-dimensional structure of Example 2, as seen from the bottom side. [Figure 5A] This is a schematic perspective view showing the upright state of the three-dimensional structure of Example 2, from the front, top, and right side. [Figure 5B] This is a schematic perspective view showing the upright state of the three-dimensional structure of Example 2, from the bottom and right side. [Figure 6] This is a perspective view showing an upright state of a modified design of a three-dimensional structure according to Embodiment 2 of the present invention. [Figure 7A] This is a plan view showing the unfolded state of a modified design of a three-dimensional structure according to Embodiment 2 of the present invention. [Figure 7B] This is a bottom view showing the unfolded state of a three-dimensional structure, a modified design of Example 2. [Figure 8A] This is a front view showing the upright state of a three-dimensional structure, a modified design of Example 2. [Figure 8B] This is a plan view showing the upright state of a three-dimensional structure, a modified design of Example 2. [Figure 8C] This is a bottom view showing the upright state of a three-dimensional structure, a modified design of Example 2. [Figure 8D] This is a right side view showing the upright state of a three-dimensional structure, a modified design of Example 2. [Figure 8E] This is a perspective view showing the upright state of a three-dimensional structure representing a modified design of Example 2. [Figure 9A] This is a plan view showing the folded state of a three-dimensional structure in a modified design example of Example 2. [Figure 9B] This is a bottom view showing the folded state of the three-dimensional structure of a modified design example of Example 2. [Figure 10] This is a front view showing the first arm, third arm and the first connecting part connecting them, and the second arm, fourth arm and the second connecting part connecting them, of a three-dimensional structure of a design modification of Embodiment 2. [Figure 11] This is a plan view showing the support section of a three-dimensional structure in a modified design example of Example 2. [Figure 12A]This is a schematic perspective view showing the upright state of a three-dimensional structure according to Embodiment 3 of the present invention, from the folded front, top, and right side views. [Figure 12B] This is a schematic perspective view showing the upright state of the three-dimensional structure of Example 3, from the back and top views. [Figure 13A] This is a schematic perspective view showing the folding process of the three-dimensional structure in Example 3. [Figure 13B] This is a schematic perspective view showing the folded state of the three-dimensional structure of Example 3. [Modes for carrying out the invention]

[0026] The following describes several embodiments of the present invention, including Embodiments 1 to 3 and their design modifications. It should be noted that the components of the embodiments and design modifications described below can be combined with each other, as long as they do not contradict each other. Furthermore, the materials, shapes, dimensions, numbers, and arrangements of the components in each embodiment and design modification described below are merely illustrative examples, and can be arbitrarily modified as long as similar functions can be achieved. [Examples]

[0027] The following describes a three-dimensional structure S1 according to multiple embodiments of the present invention, including Embodiment 1 and its design modifications, with reference to Figures 1 to 3B. Figures 1 to 3B show the three-dimensional structure S1 of Embodiment 1. Figures 1 to 3B show the Y-Y' direction (first direction) and the X-X' direction (second direction). The Y-Y' direction includes the Y direction (one of the first directions) and the Y' direction (the other of the first direction). The X-X' direction is substantially orthogonal to the Y-Y' direction and includes the X direction (the other of the second direction) and the X' direction (one of the second directions). Figures 2A to 2C show the Z-Z' direction (third direction). The Z-Z' direction is substantially orthogonal to the Y-Y' direction and the X-X' direction and includes the Z direction (the other of the third direction) and the Z' direction (one of the third directions).

[0028] Hereinafter, a diagonal direction including components in the Y and X' directions will be referred to as the "first diagonal direction," a diagonal direction including components in the Y and X directions will be referred to as the "second diagonal direction," a diagonal direction including components in the Y' and X' directions will be referred to as the "third diagonal direction," and a diagonal direction including components in the Y' and X directions will be referred to as the "fourth diagonal direction."

[0029] The three-dimensional structure S1 can be used as a fire pit, a barbecue grill, a cooking appliance placed on top of a fire pit or barbecue grill to cook food, or furniture (e.g., a table, chair, bed, or shelf), but is not limited to these uses.

[0030] The three-dimensional structure S1 is deformable between an unfolded state (see Figure 1) and an upright state (see Figures 2A to 2C). The three-dimensional structure S1 may, but is not limited to, be further deformable between an unfolded state (see Figure 1) and a folded state (see Figures 3A and 3B).

[0031] The three-dimensional structure S1 includes a central section 100. When the three-dimensional structure S1 is used as a fire pit, barbecue grill, or cooking appliance, the central section 100 may be made of a heat-resistant plate (for example, a plate made of metal, carbon material, or heat-resistant resin). When the three-dimensional structure S1 is used as furniture, the central section 100 may be made of the aforementioned heat-resistant plate, or it may be made of a plate that does not have heat resistance (for example, a resin plate or a cardboard plate).

[0032] The central portion 100 may have a first central plate 110a and a second central plate 110b.

[0033] The first central plate 110a has a first inner edge 111a on the X' direction side. The second central plate 110b has a second inner edge 111b on the X direction side. The first inner edge 111a of the first central plate 110a and the second inner edge 111b of the second central plate 110b are rotatably connected. For example, the first inner edge 111a of the first central plate 110a and the second inner edge 111b of the second central plate 110b are rotatably connected according to one of the following connection structures (1) to (3).

[0034] (1) The central portion 100 has a plurality of sleeves 111a1, a plurality of sleeves 111b1, and a pivot shaft (not shown) (see Figures 1 to 3B). The plurality of sleeves 111a1 are provided at intervals along the first inner edge 111a. The plurality of sleeves 111b1 are provided at intervals along the second inner edge 111b. The plurality of sleeves 111a1 and the plurality of sleeves 111b1 are arranged alternately. The pivot shaft is inserted into the plurality of sleeves 111a1 and the plurality of sleeves 111b1. The first central plate 110a and the second central plate 110b are rotatable by the pivot shaft.

[0035] (2) The central portion 100 further has at least one hinge 101c that rotatably connects the first inner edge 111a of the first central plate 110a and the second inner edge 111b of the second central plate 110b (see Figures 6 to 9B). The at least one hinge 101c has one fixed plate, the other fixed plate, and a pivot shaft that rotatably connects the two. One fixed plate is fixed to the first inner edge 111a by known fixing means such as riveting, screwing, welding or bonding, and the other fixed plate is fixed to the second inner edge 111b by known fixing means such as riveting, screwing, welding or bonding. The pivot shaft allows the first central plate 110a and the second central plate 110b to rotate.

[0036] (3) The connected first inner edge 111a and second inner edge 111b are thinner than the other parts of the first central plate 110a and the second central plate 110b (not shown). The first central plate 110a and the second central plate 110b are rotatable in this thinned portion.

[0037] In the unfolded state, the first central plate 110a and the second central plate 110b are unfolded into a roughly plate-like shape (see Figure 1). In the upright state, the first central plate 110a and the second central plate 110b rotate and are folded in the Z' direction (see Figures 2A to 2C). In this upright state, the first central plate 110a and the second central plate 110b form a roughly V-shape in cross-sectional views along the X-X' and Z-Z' directions. In the folded state, the first central plate 110a and the second central plate 110b rotate and are folded in the Z direction (see Figures 3A and 3B) and overlap each other (see Figures 3A and 3B). In addition, in the unfolded state, a gap may be created between the first inner edge 111a of the first central plate 110a and the second inner edge 111b of the second central plate 110b, and in the upright state, the first inner edge 111a of the first central plate 110a and the second inner edge 111b of the second central plate 110b may be in contact with each other, maintaining a state in which the first central plate 110a and the second central plate 110b are folded in the Z' direction, but is not limited to this.

[0038] The first central plate 110a further has a first hypotenuse 112a on the Y-direction side. The second central plate 110b further has a second hypotenuse 112b on the Y-direction side. When unfolded, the first hypotenuse 112a and the second hypotenuse 112b are arranged in a roughly V-shape or a roughly H-shape that is convex in the Y-direction side. When the first hypotenuse 112a and the second hypotenuse 112b are arranged in a roughly V-shape that is convex in the Y-direction side, the first hypotenuse 112a extends in a first diagonal direction, and the second hypotenuse 112b extends in a second diagonal direction, and one end of the first hypotenuse 112a in the first diagonal direction (X' direction side and Y direction side) and one end of the second hypotenuse 112b in the second diagonal direction (X direction side and Y direction side) are abutted together. When the first hypotenuse 112a and the second hypotenuse 112b are arranged in a roughly V-shape that is convex in the Y direction, the first central plate 110a further has a first intermediate edge in the Y direction, and the second central plate 110b further has a second intermediate edge in the Y direction. The first intermediate edge of the first central plate 110a extends from one end of the first hypotenuse 112a in the first diagonal direction. The second intermediate edge of the second central plate 110b extends from one end of the second hypotenuse 112b in the second diagonal direction. The first and second intermediate edges may extend in a straight line in the X-X' direction, or they may extend in a curved shape that is convex in the Y direction.

[0039] The first central plate 110a may further have a third hypotenuse 113a on the Y' direction side. The second central plate 110b may further have a fourth hypotenuse 113b on the Y direction side. In the unfolded state, the third hypotenuse 113a and the fourth hypotenuse 113b are arranged in a substantially V-shape or a substantially V-shape that is convex in the Y' direction side. When the third hypotenuse 113a and the fourth hypotenuse 113b are arranged in a substantially V-shape that is convex in the Y' direction side, the third hypotenuse 113a extends in the third diagonal direction, and the fourth hypotenuse 113b extends in the fourth diagonal direction, and one end of the third hypotenuse 113a in the third diagonal direction (X' direction side and Y' direction side) and one end of the fourth hypotenuse 113b in the fourth diagonal direction (X direction side and Y' direction side) are abutted together. When the third hypotenuse 113a and the fourth hypotenuse 113b are arranged in a roughly V-shape that is convex in the Y direction, the first central plate 110a has a third intermediate side on the Y' direction and the second central plate 110b has a fourth intermediate side on the Y' direction. The third side of the first central plate 110a extends from one end of the third hypotenuse 113a in the third diagonal direction. The fourth side of the second central plate 110b extends from one end of the fourth hypotenuse 113b in the fourth diagonal direction. The third side of the first central plate 110a and the fourth side of the second central plate 110b may extend linearly in the X-X' direction or in a convex arc shape on the Y' direction.

[0040] The three-dimensional structure S1 further comprises a first leg structure. The first leg structure has a plate-shaped first outer leg 200a, a plate-shaped second outer leg 200b, a plate-shaped first inner leg 300a, and a plate-shaped second inner leg 300b. The first outer leg 200a, the second outer leg 200b, the first inner leg 300a, and the second inner leg 300b may each be made of a plate having the heat resistance described above, or a plate not having the heat resistance described above.

[0041] The first outer leg 200a has a first hypotenuse 210a, a first side 220a on the X' direction side, and a first ground contact side opposite the first hypotenuse 210a. The first hypotenuse 210a of the first outer leg 200a may, but is not limited to, extend along the first hypotenuse 112a of the first central plate 110a. The first hypotenuse 210a of the first outer leg 200a is rotatably connected to the first hypotenuse 112a of the first central plate 110a. For example, the first hypotenuse 210a of the first outer leg 200a is rotatably connected to the first hypotenuse 112a of the first central plate 110a in the same manner as any of the connection structures described in (1) to (3) above. Similar to the connection structure in (1) above, when the first hypotenuse 210a of the first outer leg 200a is rotatably connected to the first hypotenuse 112a of the first central plate 110a (see Figures 1 to 3A), the pivot shaft is inserted through a plurality of sleeves 211a provided on the first hypotenuse 210a of the first outer leg 200a and a plurality of sleeves 112a1 provided on the first hypotenuse 112a of the first central plate 110a. Similar to the connection structure in (2) above, when the first hypotenuse 210a of the first outer leg 200a is rotatably connected to the first hypotenuse 112a of the first central plate 110a (refer to Figures 6 to 9B), at least one hinge 102c rotatably connects the first hypotenuse 210a of the first outer leg 200a and the first hypotenuse 112a of the first central plate 110a.

[0042] The second outer leg 200b has a second hypotenuse 210b, a second side 220b on the X-direction side, and a second ground contact side opposite to the second hypotenuse 210b. The second hypotenuse 210b of the second outer leg 200b may, but is not limited to, extend along the second hypotenuse 112b of the second central plate 110b. The second hypotenuse 210b of the second outer leg 200b is rotatably connected to the second hypotenuse 112b of the second central plate 110b. For example, the second hypotenuse 210b of the second outer leg 200b is rotatably connected to the second hypotenuse 112b of the second central plate 110b in the same manner as any of the connection structures described in (1) to (3) above. Similar to the connection structure in (1) above, when the second hypotenuse 210b of the second outer leg 200b is rotatably connected to the second hypotenuse 112b of the second central plate 110b (see Figures 1 to 2C and 3B), the pivot shaft is inserted through a plurality of sleeves 211b provided on the second hypotenuse 210b of the second outer leg 200b and a plurality of sleeves 112b1 provided on the second hypotenuse 112b of the second central plate 110b. Similar to the connection structure in (2) above, when the second hypotenuse 210b of the second outer leg 200b is rotatably connected to the second hypotenuse 112b of the second central plate 110b (refer to Figures 6 to 9B), at least one hinge 103c rotatably connects the second hypotenuse 210b of the second outer leg 200b and the second hypotenuse 112b of the second central plate 110b.

[0043] The first inner leg 300a has a first outer edge 310a on the X' direction side and a first inner edge 320a on the X direction side. The first outer edge 310a of the first inner leg 300a is rotatably connected to the first side edge 220a of the first outer leg 200a. For example, the first outer edge 310a of the first inner leg 300a is rotatably connected to the first side edge 220a of the first outer leg 200a in the same manner as any of the connection structures described in (1) to (3) above. Similar to the connection structure in (1) above, when the first outer edge 310a of the first inner leg 300a is rotatably connected to the first side edge 220a of the first outer leg 200a (see Figures 1 to 3A), the pivot shaft is inserted into a plurality of sleeves 311a provided on the first outer edge 310a of the first inner leg 300a and a plurality of sleeves 221a provided on the first side edge 220a of the first outer leg 200a. Similar to the connection structure in (2) above, when the first outer edge 310a of the first inner leg 300a is rotatably connected to the first side edge 220a of the first outer leg 200a (refer to Figures 6 to 9B), at least one hinge 104c rotatably connects the first outer edge 310a of the first inner leg 300a and the first side edge 220a of the first outer leg 200a.

[0044] The second inner leg 300b has a second outer edge 310b on the X-direction side and a second inner edge 320b on the X'-direction side. The second outer edge 310b of the second inner leg 300b is rotatably connected to the second side edge 220b of the second outer leg 200b. For example, the second outer edge 310b of the second inner leg 300b is rotatably connected to the second side edge 220b of the second outer leg 200b in the same manner as any of the connection structures described in (1) to (3) above. Similar to the connection structure in (1) above, when the second outer edge 310b of the second inner leg 300b is rotatably connected to the second side edge 220b of the second outer leg 200b (see Figures 1 to 2C and 3B), the pivot shaft is inserted into a plurality of sleeves 311b provided on the second outer edge 310b of the second inner leg 300b and a plurality of sleeves 221b provided on the second side edge 220b of the second outer leg 200b. Similar to the connection structure in (2) above, when the second outer edge 310b of the second inner leg 300b is rotatably connected to the second side edge 220b of the second outer leg 200b (refer to Figures 6 to 9B), at least one hinge 105c rotatably connects the second outer edge 310b of the second inner leg 300b and the second side edge 220b of the second outer leg 200b.

[0045] The first inner edge 320a of the first inner leg 300a and the second inner edge 320b of the second inner leg 300b are rotatably connected. For example, the first inner edge 320a of the first inner leg 300a and the second inner edge 320b of the second inner leg 300b are rotatably connected in the same manner as any of the connection structures described in (1) to (3) above. In the same manner as the connection structure described in (1) above, when the first inner edge 320a of the first inner leg 300a and the second inner edge 320b of the second inner leg 300b are rotatably connected (see Figures 1 to 3B), the pivot shaft is inserted into a plurality of sleeves 321a provided on the first inner edge 320a of the first inner leg 300a and a plurality of sleeves 321b provided on the second inner edge 320b of the second inner leg 300b. Similar to the connection structure described in (2) above, when the first inner edge 320a of the first inner leg 300a and the second inner edge 320b of the second inner leg 300b are rotatably connected (see Figures 6 to 9B), at least one hinge 106c rotatably connects the first inner edge 320a of the first inner leg 300a and the second inner edge 320b of the second inner leg 300b.

[0046] The first inner leg 300a may further have a first support side 330a and a first ground contact side on the opposite side. The first support side 330a of the first inner leg 300a may extend along the first hypotenuse 112a of the first central plate 110a, but is not limited thereto. The second inner leg 300b may further have a second support side 330b and a second ground contact side on the opposite side. The second support side 330b of the second inner leg 300b, and the second hypotenuse 210b of the second outer leg 200b, may extend along the second hypotenuse 112b of the second central plate 110b, but is not limited thereto.

[0047] In the deployed state, the first outer leg 200a, the second outer leg 200b, the first inner leg 300a, and the second inner leg 300b are deployed in a roughly plate-like shape and positioned on the Y-direction side with respect to the central part 100 (see Figure 1). More specifically, the first outer leg 200a and the first inner leg 300a are positioned on the Y-direction side with respect to the first central plate 110a, the second outer leg 200b and the first inner leg 300a are positioned on the Y-direction side with respect to the second central plate 110b, and the first outer leg 200a, the first inner leg 300a, the second inner leg 300b, and the second outer leg 200b are arranged in this order in the X-X' direction.

[0048] In the unfolded state, the virtual lines L1 and L2 extending along the first outer edge 310a of the first inner leg 300a and the first side edge 220a of the first outer leg 200a have angles R1 and R2 of approximately 90 degrees with respect to the virtual line L3 extending along the first hypotenuse 112a of the first central plate 110a, and the virtual lines L4 and L5 extending along the second outer edge 310b of the second inner leg 300b and the second side edge 220b of the second outer leg 200b have angles R3 and R4 of approximately 90 degrees with respect to the virtual line L6 extending along the second hypotenuse 112b of the second central plate 110b (see Figure 1). However, angles R1 to R4 may be greater than or less than approximately 90 degrees (not shown).

[0049] In the upright position, the first outer leg 200a is bent toward the Z' direction by rotating relative to the first central plate 110a of the central part 100, the second outer leg 200b is bent toward the Z' direction by rotating relative to the second central plate 110b of the central part 100, the first inner leg 300a is bent toward the Y' direction by rotating relative to the first outer leg 200a, the second inner leg 300b is bent toward the Y' direction by rotating relative to the second outer leg 200b, and the first inner leg 300a and the second inner leg 300b are valley-folded toward the Y' direction by rotating (see Figures 2A to 2C). In other words, in an upright position, the first outer leg 200a and the first central plate 110a are folded in a mountain fold at their boundary, the second outer leg 200b and the second central plate 110b are folded in a mountain fold at their boundary, the first inner leg 300a and the first outer leg 200a are folded in a mountain fold at their boundary, the second inner leg 300b and the second outer leg 200b are folded in a mountain fold at their boundary, and the first inner leg 300a and the second inner leg 300b are folded in a valley fold at their boundary. In this upright position, the first outer leg 200a is upright relative to the first central plate 110a, the second outer leg 200b is upright relative to the second central plate 110b, the first inner leg 300a is located on the Z' side relative to the first central plate 110a, and the second inner leg 300b is located on the Z' side relative to the second central plate 110b.

[0050] When angles R1 and R3 are approximately 90 degrees, in the upright position, the first inner leg 300a and the second inner leg 300b support the folded first central plate 110a and the second central plate 110b (see Figures 2A to 2C). The first support edge 330a of the first inner leg 300a abuts against the first central plate 110a from the Z' direction side, and the second support edge 330b of the second inner leg 300b abuts against the second central plate 110b from the Z' direction side. In the upright position, the first ground contact edge of the first outer leg 200a, the first ground contact edge of the first inner leg 300a, the second ground contact edge of the second inner leg 300b, and the second ground contact edge of the second outer leg 200b are in contact with the mounting surface. Furthermore, the first contact surface of the first outer leg 200a, the first contact surface of the first inner leg 300a, the second contact surface of the second inner leg 300b, and the second contact surface of the second outer leg 200b in the upright position may each be approximately arc-shaped or approximately U-shaped, convex in the Z direction.

[0051] In the folded state, the first inner leg 300a and the second inner leg 300b rotate to fold in the Z direction and overlap each other, the first inner leg 300a and the first outer leg 200a are unfolded into a roughly plate shape and positioned on the Y direction side relative to the first central plate 110a, the second inner leg 300b and the second outer leg 200b are unfolded into a roughly plate shape and positioned on the Y direction side relative to the second central plate 110b, and the first outer leg 200a and the second outer leg 200b are overlapping each other.

[0052] The three-dimensional structure S1 may further comprise a second leg structure. The second leg structure has a plate-shaped third outer leg 200c, a plate-shaped fourth outer leg 200d, a plate-shaped third inner leg 300c, and a plate-shaped fourth inner leg 300d. The third outer leg 200c, the fourth outer leg 200d, the third inner leg 300c, and the fourth inner leg 300d may each be made of a plate having the heat resistance described above, or a plate not having the heat resistance described above.

[0053] The third outer leg 200c has a third hypotenuse 210c, a third side 220c on the X' direction side, and a third ground contact side opposite the third hypotenuse 210c. The third hypotenuse 210c of the third outer leg 200c may, but is not limited to, extend along the third hypotenuse 113a of the first central plate 110a. The third hypotenuse 210c of the third outer leg 200c is rotatably connected to the third hypotenuse 113a of the first central plate 110a. For example, the third hypotenuse 210c of the third outer leg 200c is rotatably connected to the third hypotenuse 113a of the first central plate 110a in the same manner as any of the connection structures described in (1) to (3) above. Similar to the connection structure in (1) above, when the third hypotenuse 210c of the third outer leg 200c is rotatably connected to the third hypotenuse 113a of the first central plate 110a (see Figures 1 to 3A), the pivot shaft is inserted through a plurality of sleeves 211c provided on the third hypotenuse 210c of the third outer leg 200c and a plurality of sleeves 113a1 provided on the third hypotenuse 113a of the first central plate 110a. Similar to the connection structure in (2) above, when the third hypotenuse 210c of the third outer leg 200c is rotatably connected to the third hypotenuse 113a of the first central plate 110a (refer to Figures 6 to 9B), at least one hinge 107c rotatably connects the third hypotenuse 210c of the third outer leg 200c and the third hypotenuse 113a of the first central plate 110a.

[0054] The fourth outer leg 200d has a fourth hypotenuse 210d, a fourth side 220d on the X-direction side, and a fourth ground contact side opposite to the fourth hypotenuse 210d. The fourth hypotenuse 210d of the fourth outer leg 200d may, but is not limited to, extend along the fourth hypotenuse 113b of the second central plate 110b. The fourth hypotenuse 210d of the fourth outer leg 200d is rotatably connected to the fourth hypotenuse 113b of the second central plate 110b. For example, the fourth hypotenuse 210d of the fourth outer leg 200d is rotatably connected to the fourth hypotenuse 113b of the second central plate 110b in the same manner as any of the connection structures described in (1) to (3) above. Similar to the connection structure in (1) above, when the fourth hypotenuse 210d of the fourth outer leg 200d is rotatably connected to the fourth hypotenuse 113b of the second central plate 110b (see Figures 1-2 and 3B), the pivot shaft is inserted through a plurality of sleeves 211d provided on the fourth hypotenuse 210d of the fourth outer leg 200d and a plurality of sleeves 113d1 provided on the fourth hypotenuse 113b of the second central plate 110b. Similar to the connection structure in (2) above, when the fourth hypotenuse 210d of the fourth outer leg 200d is rotatably connected to the fourth hypotenuse 113b of the second central plate 110b (refer to Figures 6-9B), at least one hinge 108c rotatably connects the fourth hypotenuse 210d of the fourth outer leg 200d and the fourth hypotenuse 113b of the second central plate 110b.

[0055] The third inner leg 300c has a third outer edge 310c on the X' direction side and a third inner edge 320c on the X direction side. The third outer edge 310c of the third inner leg 300c is rotatably connected to the third side edge 220c of the third outer leg 200c. For example, the third outer edge 310c of the third inner leg 300c is rotatably connected to the third side edge 220c of the third outer leg 200c in the same manner as any of the connection structures described in (1) to (3) above. Similar to the connection structure in (1) above, when the third outer edge 310c of the third inner leg 300c is rotatably connected to the third side edge 220c of the third outer leg 200c (see Figures 1 to 3A), the pivot shaft is inserted into a plurality of sleeves 311c provided on the third outer edge 310c of the third inner leg 300c and a plurality of sleeves 221c provided on the third side edge 220c of the third outer leg 200c. Similar to the connection structure in (2) above, when the third outer edge 310c of the third inner leg 300c is rotatably connected to the third side edge 220c of the third outer leg 200c (refer to Figures 6 to 9B), at least one hinge 109c rotatably connects the third outer edge 310c of the third inner leg 300c and the third side edge 220c of the third outer leg 200c.

[0056] The fourth inner leg 300d has a fourth outer edge 310d on the X-direction side and a fourth inner edge 320d on the X'-direction side. The fourth outer edge 310d of the fourth inner leg 300d is rotatably connected to the fourth side edge 220d of the fourth outer leg 200d. For example, the fourth outer edge 310d of the fourth inner leg 300d is rotatably connected to the fourth side edge 220d of the fourth outer leg 200d in the same manner as any of the connection structures described in (1) to (3) above. Similar to the connection structure in (1) above, when the fourth outer edge 310d of the fourth inner leg 300d is rotatably connected to the fourth side edge 220d of the fourth outer leg 200d (see Figures 1 to 2C and 3B), the pivot axis is inserted into a plurality of sleeves 311d provided on the fourth outer edge 310d of the fourth inner leg 300d and a plurality of sleeves 221d provided on the fourth side edge 220d of the fourth outer leg 200d. Similar to the connection structure in (2) above, when the fourth outer edge 310d of the fourth inner leg 300d is rotatably connected to the fourth side edge 220d of the fourth outer leg 200d (refer to Figures 6 to 9B), at least one hinge 110c rotatably connects the fourth outer edge 310d of the fourth inner leg 300d and the fourth side edge 220d of the fourth outer leg 200d.

[0057] The third inner edge 320c of the third inner leg 300c and the fourth inner edge 320d of the fourth inner leg 300d are rotatably connected. For example, the third inner edge 320c of the third inner leg 300c and the fourth inner edge 320d of the fourth inner leg 300d are rotatably connected in the same manner as any of the connection structures described in (1) to (3) above. In the same manner as the connection structure described in (1) above, when the third inner edge 320c of the third inner leg 300c and the fourth inner edge 320d of the fourth inner leg 300d are rotatably connected (see Figures 1 to 3B), the pivot shaft is inserted into a plurality of sleeves 321c provided on the third inner edge 320c of the third inner leg 300c and a plurality of sleeves 321d provided on the fourth inner edge 320d of the fourth inner leg 300d. Similar to the connection structure in (2) above, when the third inner edge 320c of the third inner leg 300c and the fourth inner edge 320d of the fourth inner leg 300d are rotatably connected (see Figures 6 to 9B), at least one hinge 111c rotatably connects the third inner edge 320c of the third inner leg 300c and the fourth inner edge 320d of the fourth inner leg 300d.

[0058] The third inner leg 300c may further have a third support side 330c and a third ground contact side on the opposite side. The third support side 330c of the third inner leg 300c may extend along the third hypotenuse 113a of the first central plate 110a, but is not limited thereto. The fourth inner leg 300d may further have a fourth support side 330d and a third ground contact side on the opposite side. The fourth support side 330d of the fourth inner leg 300d may extend along the fourth hypotenuse 113b of the second central plate 110b, but is not limited thereto.

[0059] In the deployed state, the third outer leg 200c, the fourth outer leg 200d, the third inner leg 300c, and the fourth inner leg 300d are deployed in a roughly plate-like shape and positioned on the Y' side relative to the central part 100 (see Figure 1). More specifically, the third outer leg 200c and the third inner leg 300c are positioned on the Y' side relative to the first central plate 110a, the fourth outer leg 200d and the third inner leg 300c are positioned on the Y' side relative to the second central plate 110b, and the third outer leg 200c, third inner leg 300c, fourth inner leg 300d, and fourth outer leg 200d are arranged in this order in the X-X' direction.

[0060] In the unfolded state, it is desirable that the angles R5 and R6 of imaginary lines L7 and L8 extending along the third outer edge 310c of the third inner leg 300c and the third side edge 220c of the third outer leg 200c are approximately 90 degrees with respect to imaginary line L9 extending along the third hypotenuse 113a of the first central plate 110a, and that the angles R7 and R8 of imaginary lines L10 and L11 extending along the fourth outer edge 310d of the fourth inner leg 300d and the fourth side edge 220d of the fourth outer leg 200d are approximately 90 degrees with respect to imaginary line L12 extending along the fourth hypotenuse 113b of the second central plate 110b are approximately 90 degrees (see Figure 1), however, angles R5 to R8 may be greater than or less than approximately 90 degrees (not shown).

[0061] In the upright position, the third outer leg 200c is bent toward the Z' direction by rotating relative to the first central plate 110a of the central section 100, the fourth outer leg 200d is bent toward the Z' direction by rotating relative to the second central plate 110b of the central section 100, the third inner leg 300c is bent toward the Y direction by rotating relative to the third outer leg 200c, the fourth inner leg 300d is bent toward the Y direction by rotating relative to the fourth outer leg 200d, and the third inner leg 300c and the fourth inner leg 300d are valley-folded toward the Y direction by rotating (see Figures 2A to 2C). In other words, in the upright position, the third outer leg 200c and the first central plate 110a are folded in a mountain fold at their boundary, the fourth outer leg 200d and the second central plate 110b are folded in a mountain fold at their boundary, the third inner leg 300c and the third outer leg 200c are folded in a mountain fold at their boundary, the fourth inner leg 300d and the fourth outer leg 200d are folded in a mountain fold at their boundary, and the third inner leg 300c and the fourth inner leg 300d are folded in a valley fold at their boundary. In this upright position, the third outer leg 200c is upright relative to the first central plate 110a, the fourth outer leg 200d is upright relative to the second central plate 110b, the third inner leg 300c is located on the Z' side relative to the first central plate 110a, and the fourth inner leg 300d is located on the Z' side relative to the second central plate 110b.

[0062] When angles R5 and R7 are approximately 90 degrees, in the upright position, the third inner leg 300c and the fourth inner leg 300d support the folded first central plate 110a and the second central plate 110b (see Figures 2A to 2C). The third support edge 330c of the third inner leg 300c abuts against the first central plate 110a from the Z' direction side, and the fourth support edge 330d of the fourth inner leg 300d abuts against the second central plate 110b from the Z' direction side. In the upright position, the third ground contact edge of the third outer leg 200c, the third ground contact edge of the third inner leg 300c, the fourth ground contact edge of the fourth inner leg 300d, and the fourth ground contact edge of the fourth outer leg 200d are in contact with the mounting surface. Furthermore, the third contact surface of the third outer leg 200c, the third contact surface of the third inner leg 300c, the fourth contact surface of the fourth inner leg 300d, and the fourth contact surface of the fourth outer leg 200d in the upright position may each be approximately arc-shaped or approximately U-shaped, convex in the Z direction.

[0063] In the folded state, the third inner leg 300c and the fourth inner leg 300d rotate to fold in the Z direction and overlap each other, the third inner leg 300c and the third outer leg 200c are unfolded into a roughly plate shape and positioned on the Y' direction side relative to the first central plate 110a, the fourth inner leg 300d and the fourth outer leg 200d are unfolded into a roughly plate shape and positioned on the Y' direction side relative to the second central plate 110b, and the third outer leg 200c and the fourth outer leg 200d are overlapping each other.

[0064] The following describes a non-limiting method for transforming the three-dimensional structure S1 described above from an unfolded state to an upright state.

[0065] The first central plate 110a and the second central plate 110b are folded in the Z' direction so that they form a roughly V-shape in cross-section.

[0066] As the central section 100 is folded in a valley fold, the first outer leg 200a is folded in the Z' direction relative to the first central plate 110a, and the second outer leg 200b is folded in the Z' direction relative to the second central plate 110b. Simultaneously or in a forward / backward motion, the first inner leg 300a is folded in the Y' direction relative to the first outer leg 200a, and the second inner leg 300b is folded in the Y' direction relative to the second outer leg 200b, while the first inner leg 300a and the second inner leg 300b are valley-folded in the Y' direction. As a result, the first outer leg 200a stands upright relative to the first central plate 110a, the second outer leg 200b stands upright relative to the second central plate 110b, and the first inner leg 300a and the second inner leg 300b are positioned in the Z' direction relative to the first central plate 110a and the second central plate 110b. When angles R1 and R3 are approximately 90 degrees, the first inner leg 300a and the second inner leg 300b support the first central plate 110a and the second central plate 110b from the Z' direction.

[0067] As the central section 100 is folded in a valley fold, the third outer leg 200c is folded in the Z' direction relative to the first central plate 110a, and the fourth outer leg 200d is folded in the Z' direction relative to the second central plate 110b. Simultaneously or in a forward / backward motion, the third inner leg 300c is folded in the Y direction relative to the third outer leg 200c, and the fourth inner leg 300d is folded in the Y direction relative to the fourth outer leg 200d, while the third inner leg 300c and the fourth inner leg 300d are valley-folded in the Y direction. As a result, the third outer leg 200c stands upright relative to the first central plate 110a, the fourth outer leg 200d stands upright relative to the second central plate 110b, and the third inner leg 300c and the fourth inner leg 300d are positioned in the Z' direction relative to the first central plate 110a and the second central plate 110b. When angles R5 and R7 are approximately 90 degrees, the third inner leg 300c and the fourth inner leg 300d support the first central plate 110a and the second central plate 110b from the Z' direction. In this way, the three-dimensional structure S1 deforms from the unfolded state to the upright state.

[0068] The following describes a non-limiting method for transforming the three-dimensional structure S1 described above from an upright state to an unfolded state.

[0069] The first central plate 110a and the second central plate 110b are rotated in the Z direction (releasing the valley fold) to unfold the first central plate 110a and the second central plate 110b (the central part 100) into a roughly plate-like shape.

[0070] As the valley fold of the central part 100 is released, the first outer leg 200a is rotated toward the Z direction relative to the first central plate 110a so that the first outer leg 200a is positioned toward the Y direction relative to the first central plate 110a, and the second outer leg 200b is rotated toward the Z direction relative to the second central plate 110b so that the second outer leg 200b is positioned toward the Y direction relative to the second central plate 110b. Simultaneously with or before / after this, the first inner leg 300a and the second inner leg 300b are rotated in the Y direction (releasing the valley fold), and the first inner leg 300a is rotated toward the Y direction relative to the first outer leg 200a so that the first inner leg 300a is positioned toward the Y direction relative to the first central plate 110a and toward the X' direction relative to the first outer leg 200a, while the second inner leg 300b is rotated toward the Y direction relative to the second outer leg 200b so that the second inner leg 300b is positioned toward the Y direction relative to the second central plate 110b and toward the X direction relative to the second outer leg 200b. In this way, the first outer leg 200a, the second outer leg 200b, the first inner leg 300a, and the second inner leg 300b are made into a roughly plate shape and positioned toward the Y direction relative to the first central plate 110a and the second central plate 110b (central part 100), which are plate-shaped as described above.

[0071] As the valley fold of the central section 100 is released, the third outer leg 200c is rotated toward the Z direction relative to the first central plate 110a, so that the third outer leg 200c is positioned toward the Y' direction relative to the first central plate 110a, and the fourth outer leg 200d is rotated toward the Z direction relative to the second central plate 110b, so that the fourth outer leg 200d is positioned toward the Y' direction relative to the second central plate 110b. Simultaneously with or before / after this, the third inner leg 300c and the fourth inner leg 300d are rotated in the Y' direction (releasing the valley fold), and the third inner leg 300c is rotated toward the Y' direction relative to the third outer leg 200c so that the third inner leg 300c is positioned toward the Y' direction relative to the first central plate 110a and toward the X' direction relative to the third outer leg 200c, while the fourth inner leg 300d is rotated toward the Y' direction relative to the fourth outer leg 200d so that the fourth inner leg 300d is positioned toward the Y' direction relative to the second central plate 110b and toward the X direction relative to the fourth outer leg 200d. In this way, the third outer leg 200c, the fourth outer leg 200d, the third inner leg 300c, and the fourth inner leg 300d are made into roughly plate shapes and are positioned on the Y' direction side with respect to the plate-shaped first central plate 110a and second central plate 110b (central part 100) as described above. In this way, the three-dimensional structure S1 is transformed from an upright state to an unfolded state.

[0072] The following describes a non-limiting method for transforming the three-dimensional structure S1 described above from an unfolded state to a folded state.

[0073] The first central plate 110a and the second central plate 110b of the central portion 100, which are unfolded into a roughly plate-like shape, are folded in the Z direction and overlapped with each other.

[0074] As the central section 100 is folded in a mountain fold, the first inner leg 300a and the second inner leg 300b are folded in the Z direction and overlapped with each other, and the third inner leg 300c and the fourth inner leg 300d are folded in the Z direction and overlapped with each other. Then, the first inner leg 300a and the first outer leg 200a unfold into a roughly plate-like shape and are positioned on the Y-direction side relative to the first central plate 110a, the second inner leg 300b and the second outer leg 200b unfold into a roughly plate-like shape and are positioned on the Y-direction side relative to the second central plate 110b, and the first outer leg 200a and the second outer leg 200b overlap each other, the third inner leg 300c and the third outer leg 200c unfold into a roughly plate-like shape and are positioned on the Y'-direction side relative to the first central plate 110a, the fourth inner leg 300d and the fourth outer leg 200d unfold into a roughly plate-like shape and are positioned on the Y'-direction side relative to the second central plate 110b, and the third outer leg 200c and the fourth outer leg 200d overlap each other. In this way, the three-dimensional structure S1 transforms from an unfolded state to a folded state.

[0075] The following describes a non-limiting method for transforming the three-dimensional structure S1 described above from a folded state to an unfolded state.

[0076] The first central plate 110a and the second central plate 110b (the central part 100), which are superimposed on each other, are separated from each other (the mountain folds are released) and unfolded into a roughly plate-like shape.

[0077] As the first central plate 110a and the second central plate 110b separate, the overlapping first inner leg 300a and the second inner leg 300b separate from each other (releasing the mountain fold), and the overlapping third inner leg 300c and the fourth inner leg 300d separate from each other (releasing the mountain fold). As a result, the first inner leg 300a, the second inner leg 300b, the first outer leg 200a, and the second outer leg 200b unfold into a roughly plate shape and are positioned on the Y-direction side with respect to the central part 100 which has been unfolded into a roughly plate shape as described above, while the third inner leg 300c, the fourth inner leg 300d, the third outer leg 200c, and the fourth outer leg 200d unfold into a roughly plate shape and are positioned on the Y'-direction side with respect to the central part 100 which has been unfolded into a roughly plate shape as described above. In this way, the three-dimensional structure S1 transforms from a folded state to an unfolded state.

[0078] The three-dimensional structure S1 described above is less prone to accidental collapse of the first and second leg structures compared to conventional examples. The reason for this is as follows: In the upright position, the first outer leg 200a is bent in the Z' direction relative to the first central plate 110a of the central section 100 and the second outer leg 200b is bent in the Z' direction relative to the second central plate 110b of the central section 100 and stands upright, while the first inner leg 300a is bent in the Y' direction relative to the first outer leg 200a, the second inner leg 300b is bent in the Y' direction relative to the second outer leg 200b, and both the first inner leg 300a and the second inner leg 300b are valley-folded in the Y' direction. Similarly, in the upright position, the third outer leg 200c is bent in the Z' direction relative to the first central plate 110a of the central section 100, the fourth outer leg 200d is bent in the Z' direction relative to the second central plate 110b of the central section 100 and stands upright, and the third inner leg 300c is bent in the Y direction relative to the third outer leg 200c and stands upright, while the fourth inner leg 300d is bent in the Y direction relative to the fourth outer leg 200d, and the third inner leg 300c and the fourth inner leg 300d are valley-folded in the Y direction. Furthermore, since the first inner edge 320a of the first inner leg 300a and the second inner edge 320b of the second inner leg 300b are rotatably connected, and the third inner edge 320c of the third inner leg 300c and the fourth inner edge 320d of the fourth inner leg 300d are rotatably connected, the state in which the first inner leg 300a and the second inner leg 300b are folded in a valley fold is stable, and the state in which the third inner leg 300c and the fourth inner leg 300d are folded in a valley fold toward the Y direction is also stable.

[0079] The three-dimensional structure S1 can be unfolded into a single plate shape, as in its unfolded state. In the unfolded state, the first central plate 110a and the second central plate 110b can be unfolded into a roughly plate shape, the first outer leg 200a, the second outer leg 200b, the first inner leg 300a, and the second inner leg 300b can be unfolded into a roughly plate shape and positioned on the Y-direction side relative to the central part 100, and the third outer leg 200c, the fourth outer leg 200d, the third inner leg 300c, and the fourth inner leg 300d can be unfolded into a roughly plate shape and positioned on the Y'-direction side relative to the central part 100. Therefore, the three-dimensional structure S1 is excellent in terms of storage and transportability.

[0080] Furthermore, the three-dimensional structure S1 can be folded in half, as in its folded state. In the folded state, the first central plate 110a and the second central plate 110b can be folded in the Z direction and overlapped with each other, the first inner leg 300a and the second inner leg 300b can be folded in the Z direction and overlapped with each other, the third inner leg 300c and the fourth inner leg 300d can be folded in the Z direction and overlapped with each other, the first outer leg 200a and the second outer leg 200b can be overlapped with each other, and the third outer leg 200c and the fourth outer leg 200d can be overlapped with each other. In this respect as well, the three-dimensional structure S1 is excellent in terms of storage and transportability.

[0081] When the first inner leg 300a and the second inner leg 300b support the first central plate 110a and the second central plate 110b, which are folded in a valley fold, the first central plate 110a and the second central plate 110b are stably supported. [Examples]

[0082] The following describes a three-dimensional structure S2 according to several embodiments of the present invention, including Embodiment 2 and its design modifications, with reference to Figures 4A to 5B. Figures 4A to 5B show the three-dimensional structure S2 of Embodiment 2. Figures 6 to 11 show design modifications of the three-dimensional structure S2 of Embodiment 2. Figures 4A to 5B, 7A, 7B, 8B, and 8C show the Y-Y' direction (first direction) and the X-X' direction (second direction). Figures 5A to 5B, 6, and 8E show the Y-Y' direction (first direction), the X-X' direction (second direction), and the Z-Z' direction (third direction). Figure 8A shows the Y-Y' direction (first direction) and the Z-Z' direction (third direction). Figure 8D shows the X-X' direction (second direction) and the Z-Z' direction (third direction).

[0083] In Figures 4A to 5B, the connection structure between the first inner edge 111a of the first central plate 110a and the second inner edge 111b of the second central plate 110b, the connection structure between the first hypotenuse 210a of the first outer leg 200a and the first hypotenuse 112a of the first central plate 110a, the connection structure between the second hypotenuse 210b of the second outer leg 200b and the second hypotenuse 112b of the second central plate 110b, the connection structure between the first outer edge 310a of the first inner leg 300a and the first side edge 220a of the first outer leg 200a, the connection structure between the second outer edge 310b of the second inner leg 300b and the second side edge 220b of the second outer leg 200b, and the connection between the first inner edge 320a of the first inner leg 300a and the second inner The connection structures between the second inner edge 320b of the side leg 300b, the third hypotenuse 210c of the third outer leg 200c and the third hypotenuse 113a of the first central plate 110a, the connection structure between the fourth hypotenuse 210d of the fourth outer leg 200d and the fourth hypotenuse 113b of the second central plate 110b, the connection structure between the third outer edge 310c of the third inner leg 300c and the third side edge 220c of the third outer leg 200c, the connection structure between the fourth outer edge 310d of the fourth inner leg 300d and the fourth side edge 220d of the fourth outer leg 200d, and the connection structure between the third inner edge 320c of the third inner leg 300c and the fourth inner edge 320d of the fourth inner leg 300d are not shown.

[0084] The three-dimensional structure S2 has the same configuration as the three-dimensional structure S1, except that it further comprises a first arm 400a, a second arm 400b, a third arm 400c, and a fourth arm 400d. Below, only the differences will be explained in detail, and any explanation of the three-dimensional structure S2 that overlaps with the explanation of the three-dimensional structure S1 will be omitted.

[0085] The first arm 400a may be configured to extend from the first outer leg 200a. For example, the first arm 400a can be configured to have a fixing part 410a and an arm body 420a (see Figures 4A to 5B). The fixing part 410a is fixed to the Z-direction side surface of the first outer leg 200a in the deployed state (see Figures 4A and 4B). The arm body 420a is a long plate or rod extending from the fixing part 410a. Alternatively, the first arm 400a may be a long plate or rod extending from the first hypotenuse 210a of the first outer leg 200a (not shown). In either configuration, in the unfolded state (see Figures 4A and 4B) and the folded state (not shown), the first arm 400a extends in the Y' direction and is positioned along the first central plate 110a, while in the upright state (see Figures 5A and 5B), the first arm 400a extends beyond the first central plate 110a in the Z direction.

[0086] Alternatively, the first arm 400a may be a long plate or rod, and in an upright position, it may be supported by at least the first central plate 110a and extend in the Z-Z' direction (not shown). The first central plate 110a may be provided with a first support hole 114a (see Figures 6 to 9B) or a first notch (not shown) that penetrates the first central plate 110a. In this case, in an upright position, the first arm 400a is inserted through and supported by the first support hole 114a or the first notch of the first central plate 110a. The first outer leg 200a may also be provided with a first support hole 230a (see Figures 6 to 9B) or a first notch (not shown) that penetrates the first outer leg 200a. In this case, in the upright position, the first arm 400a is inserted through the first support hole 114a or first notch of the first central plate 110a and the first support hole 230a or first notch of the first outer leg 200a and supported.

[0087] For example, the first support hole 114a or first notch of the first central plate 110a and the first support hole 230a or first notch of the first outer leg 200a may have any of the following configurations (a1) to (c1).

[0088] (a1) The first support hole 230a of the first outer leg 200a can be a roughly circular or roughly elliptical hole (see Figures 6 to 9B). The first notch of the first outer leg 200a can be configured to have a roughly circular or roughly elliptical first hole and a second hole that extends from this first hole in the X direction and opens in the X direction (not shown). In the unfolded state, the first support hole 114a of the first central plate 110a can be an elongated hole that is spaced apart in the Y' direction from the first support hole 230a of the first outer leg 200a or the first hole of the first notch and extends in the Y' direction (see Figures 6 to 9B), or an elongated hole that is spaced apart in a third oblique direction from the first support hole 230a of the first outer leg 200a or the first hole of the first notch and extends in a third oblique direction (not shown). In the unfolded state, the first notch of the first central plate 110a has a first hole and a second hole that extends from the first hole in the X direction and opens in the X direction. The first hole can be an elongated hole (not shown) that is spaced apart in the Y' direction from the first support hole 230a of the first outer leg 200a or the first hole of the first notch and extends in the Y' direction, or an elongated hole (not shown) that is spaced apart in a third oblique direction from the first support hole 230a of the first outer leg 200a or the first hole of the first notch and extends in a third oblique direction.

[0089] (b1) The first support hole 114a of the first central plate 110a can be a roughly circular or roughly elliptical hole (not shown). The first notch of the first central plate 110a can be configured to have a roughly circular or roughly elliptical first hole and a second hole that extends from this first hole in the X direction and opens in the X direction (not shown). In the deployed state, the first support hole 230a of the first outer leg 200a can be an elongated hole (not shown) that is spaced in the Y direction relative to the first support hole 114a of the first central plate 110a or the first hole of the first notch and extends in the Y direction, or an elongated hole (not shown) that is spaced in the second oblique direction relative to the first support hole 114a of the first central plate 110a or the first hole of the first notch and extends in the second oblique direction. In the deployed state, the first notch of the first outer leg 200a has a first hole and a second hole that extends from the first hole in the X direction and opens in the X direction. The first hole can be an elongated hole (not shown) that is spaced apart in the Y direction from the first support hole 114a of the first central plate 110a or the first hole of the first notch and extends in the Y direction, or an elongated hole (not shown) that is spaced apart in the second oblique direction from the first support hole 114a of the first central plate 110a or the first hole of the first notch and extends in the second oblique direction.

[0090] (c1) Both the first support hole 114a of the first central plate 110a or the first hole of the first notch and the first support hole 230a of the first outer leg 200a or the first hole of the first notch may be approximately circular or approximately elliptical holes (not shown).

[0091] If the first support hole 114a or first notch of the first central plate 110a and the first support hole 230a or first notch of the first outer leg 200a have the configuration of (a1) above, then (d1) the first arm 400a can be configured to be substantially L-shaped and have a hanging portion 430a that extends linearly in a direction including a component in the Z-Z' direction, and a tip portion 440a that is bent relative to the hanging portion 430a and extends from the hanging portion 430a in the Y direction or a second oblique direction (see Figures 6 and 10). The longitudinal dimension (Y direction or second oblique direction dimension) of the tip portion 440a of the first arm 400a is smaller than the longitudinal dimension of the first hole of the first support hole 114a or first notch of the first central plate 110a in the upright position. The dimension of the tip portion 440a of the first arm 400a in the short direction (dimension in the X direction or the first diagonal direction) is smaller than the dimension of the first support hole 114a of the first central plate 110a or the first hole of the first notch in the short direction in the upright position, and the dimension of the first support hole 230a of the first outer leg 200a or the first hole of the first notch in the short direction in the upright position. The dimension of the tip portion 440a of the first arm 400a in the Z-Z' direction is smaller than the dimension of the first support hole 230a of the first outer leg 200a or the first hole of the first notch in the Z-Z' direction in the upright position. The dimension of the hanging portion 430a of the first arm 400a in the longitudinal direction is smaller than the dimension of the first support hole 114a of the first central plate 110a or the first hole of the first notch in the longitudinal direction in the upright position. The dimension of the hanging portion 430a of the first arm 400a in the short-side direction is smaller than the dimension of the first support hole 114a of the first central plate 110a or the first hole of the first notch in the short-side direction when the arm is upright.

[0092] (d11) The tip portion 440a is inserted through the first support hole 114a of the first central plate 110a in the upright position or the first hole of the first notch, and then inserted through the first support hole 230a of the first outer leg 200a in the upright position or the first hole of the first notch, while the hanging portion 430a is inserted through the first support hole 114a of the first central plate 110a in the upright position or the first hole of the first notch. Or, (d12) The hanging portion 430a is inserted through the second hole to the first hole of the first notch of the first central plate 110a in the upright position, and then the tip portion 440a is inserted through the first support hole 230a of the first outer leg 200a in the upright position or the first hole of the first notch. Alternatively, (d13) the hanging portion 430a is inserted through the second hole to the first hole of the first notch in the first central plate 110a in the upright position, and the tip portion 440a is inserted through the second hole to the first hole of the first notch in the first outer leg 200a in the upright position. In this way, the first arm 400a is supported by the first central plate 110a and the first outer leg 200a.

[0093] If the first support hole 114a or first notch of the first central plate 110a and the first support hole 230a or first notch of the first outer leg 200a have any of the configurations described in (a1) to (c2) above, then (e1) the first arm 400a can be configured to extend linearly in a direction including a component in the Z-Z' direction (not shown). The dimensions of the first arm 400a in the Y direction or second oblique direction are smaller than the dimensions of the first support hole 114a or first notch of the first central plate 110a in the Y direction or second oblique direction and the dimensions of the first support hole 230a or first notch of the first outer leg 200a in the Y direction or second oblique direction in the upright state. The dimension of the first arm 400a in the X direction or first oblique direction is smaller than the dimension of the first support hole 114a of the first central plate 110a or the first hole of the first notch in the X direction or first oblique direction in the upright position, and the dimension of the first support hole 230a of the first outer leg 200a or the first hole of the first notch in the X direction or first oblique direction in the upright position.

[0094] (e11) The first arm 400a is inserted through the first support hole 114a or the first hole of the first notch in the first central plate 110a in the upright position and through the first support hole 230a or the first hole of the first notch in the first outer leg 200a in the upright position. Or, (e12) The first arm 400a is inserted from the second hole to the first hole of the first notch in the first central plate 110a in the upright position, and then inserted through the first support hole 230a or the first hole of the first notch in the first outer leg 200a in the upright position. Or, (e13) The first arm 400a is inserted from the second hole to the first hole of the first notch in the first central plate 110a in the upright position, and also inserted from the second hole to the first hole of the first notch in the first outer leg 200a in the upright position. In this way, the first arm 400a is supported by the first central plate 110a and the first outer leg 200a.

[0095] The second arm 400b may be configured to extend from the second outer leg 200b. For example, the second arm 400b can be configured to have a fixing part 410b and an arm body 420b (see Figures 4A to 5B). The fixing part 410b is fixed to the Z-direction side surface of the second outer leg 200b in the deployed state (see Figures 4A and 4B). The arm body 420b is a long plate or rod extending from the fixing part 410b. Alternatively, the second arm 400b may be a long plate or rod extending from the second hypotenuse 210b of the second outer leg 200b (not shown). In either configuration, in the unfolded state (see Figures 4A and 4B) and the folded state (not shown), the second arm 400b extends in the Y' direction and is positioned along the second central plate 110b, while in the upright state (see Figures 5A and 5B), the second arm 400b extends beyond the second central plate 110b in the Z direction.

[0096] Alternatively, the second arm 400b may be a long plate or rod, and in an upright position, it may be supported at least by the second central plate 110b and extend in the Z-Z' direction (not shown). The second central plate 110b may be provided with a second support hole (not shown) or a second notch 115b (see Figures 6 to 9B) that penetrates the second central plate 110b. In this case, in an upright position, the second arm 400b is inserted through and supported by the second support hole or second notch 115b of the second central plate 110b. The second outer leg 200b may also be provided with a second support hole 230b (see Figures 6 to 9B) or a second notch (not shown) that penetrates the second outer leg 200b. In this case, when upright, the second arm 400b is inserted through the second support hole or second notch 115b of the second central plate 110b and the second support hole 230b or second notch of the second outer leg 200b and supported.

[0097] For example, the second support hole or second notch 115b of the second central plate 110b and the second support hole 230b or second notch of the second outer leg 200b may have any of the following configurations (a2) to (c2).

[0098] (a2) The second support hole 230b of the second outer leg 200b can be a roughly circular or roughly elliptical hole (see Figures 6 to 9B). The second notch of the second outer leg 200b can be configured to have a roughly circular or roughly elliptical first hole and a second hole that extends from this first hole in the X' direction and opens in the X' direction (not shown). In the unfolded state, the second support hole of the second central plate 110b can be an elongated hole (not shown) that is spaced in the Y' direction relative to the second support hole 230b of the second outer leg 200b or the first hole of the second notch and extends in the Y' direction, or an elongated hole (not shown) that is spaced in the fourth oblique direction relative to the second support hole 230b of the second outer leg 200b or the first hole of the second notch and extends in the fourth oblique direction. In the unfolded state, the second notch 115b of the second central plate 110b has a first hole 115b1 and a second hole 115b2 that extends from the first hole 115b1 in the X' direction and opens in the X' direction. The first hole 115b1 can be an elongated hole (see Figures 6 to 9B) that is spaced apart in the Y' direction from the second support hole 230b of the second outer leg 200b or the first hole of the second notch and extends in the Y' direction, or an elongated hole (not shown) that is spaced apart in the fourth oblique direction from the second support hole 230b of the second outer leg 200b or the first hole of the second notch and extends in the fourth oblique direction.

[0099] (b2) The second support hole of the second central plate 110b can be a roughly circular or roughly elliptical hole (not shown). The second notch 115b of the second central plate 110b can be configured to have a roughly circular or roughly elliptical first hole 115b1 and a second hole 115b2 that extends from the first hole 115b1 in the X' direction and opens in the X' direction (not shown). In the deployed state, the second support hole 230b of the second outer leg 200b can be an elongated hole (not shown) that is spaced in the Y direction relative to the second support hole of the second central plate 110b or the first hole 115b1 of the second notch 115b and extends in the Y direction, or an elongated hole (not shown) that is spaced in the first oblique direction relative to the second support hole of the second central plate 110b or the first hole 115b1 of the second notch 115b and extends in the first oblique direction. In the deployed state, the second notch of the second outer leg 200b has a first hole and a second hole that extends from the first hole in the X' direction and opens in the X' direction, and the first hole can be an elongated hole (not shown) that is spaced in the Y direction relative to the second support hole of the second central plate 110b or the first hole 115b1 of the second notch 115b and extends in the Y direction, or an elongated hole (not shown) that is spaced in the first oblique direction relative to the second support hole of the second central plate 110b or the first hole 115b1 of the second notch 115b and extends in the first oblique direction.

[0100] (c2) The second support hole in the second central plate 110b or the first hole 115b1 in the second notch 115b and the second support hole 230b in the second outer leg 200b or the first hole in the second notch may both be approximately circular or approximately elliptical holes (not shown).

[0101] If the second support hole or second notch 115b of the second central plate 110b and the second support hole 230b or second notch of the second outer leg 200b have the configuration described in (a2) above, then (d2) the second arm 400b can be configured to be substantially L-shaped and to have a hanging portion 430b that extends linearly in a direction including a component in the Z-Z' direction, and a tip portion 440b that is bent relative to the hanging portion 430b and extends from the hanging portion 430b in the Y direction or a first diagonal direction (see Figures 6 and 10). The longitudinal dimension (Y direction or first diagonal direction dimension) of the tip portion 440b of the second arm 400b is smaller than the longitudinal dimension of the first hole 115b1 of the second support hole or second notch 115b of the second central plate 110b in the upright position. The dimension of the tip portion 440b of the second arm 400b in the short direction (dimension in the X' direction or second oblique direction) is smaller than the dimension of the second support hole or the first hole 115b1 of the second notch 115b of the second central plate 110b in the short direction and the dimension of the second support hole 230b or the first hole of the second notch of the second outer leg 200b in the short direction in the upright position. The dimension of the tip portion 440b of the second arm 400b in the Z-Z' direction is smaller than the dimension of the second support hole 230b or the first hole of the second notch of the second outer leg 200b in the Z-Z' direction in the upright position. The dimension of the hanging portion 430b of the second arm 400b in the long direction is smaller than the dimension of the second support hole or the first hole 115b1 of the second notch 115b of the second central plate 110b in the long direction in the upright position. The dimension of the hanging portion 430b of the second arm 400b in the short-side direction is smaller than the dimension of the first hole 115b1 of the second support hole or second notch 115b of the second central plate 110b in the short-side direction when the arm is upright.

[0102] (d21) The tip portion 440b is inserted through the second support hole 230b of the second central plate 110b or the first hole 115b1 of the second notch 115b in the upright position, and then inserted through the second support hole 230b of the second outer leg 200b or the first hole of the second notch in the upright position, while the hanging portion 430b is inserted through the second support hole 230b of the second central plate 110b or the first hole 115b1 of the second notch 115b in the upright position. Or, (d22) The hanging portion 430b is inserted through the second hole 115b2 to the first hole 115b1 of the second notch 115b of the second central plate 110b in the upright position, and then the tip portion 440b is inserted through the second support hole 230b of the second outer leg 200b or the first hole of the second notch in the upright position. Alternatively, (d23) the hanging portion 430b is inserted through the second hole 115b2 to the first hole 115b1 of the second notch 115b in the upright position, and the tip portion 440b is inserted through the second hole to the first hole of the second notch of the second outer leg 200b in the upright position. In this way, the second arm 400b is supported by the second central plate 110b and the second outer leg 200b.

[0103] If the second support hole or second notch 115b of the second central plate 110b and the second support hole 230b or second notch of the second outer leg 200b have any of the configurations described in (a2) to (c2) above, then (e2) the second arm 400b can be configured to extend linearly in a direction including a component in the Z-Z' direction (not shown). The dimension of the second arm 400b in the Y direction or first oblique direction is smaller than the dimension of the first hole 115b1 of the second support hole or second notch 115b of the second central plate 110b in the Y direction or first oblique direction and the dimension of the first hole of the second support hole 230b or second notch of the second outer leg 200b in the Y direction or first oblique direction in the upright state. The dimension of the second arm 400b in the X' direction or second oblique direction is smaller than the dimension of the second support hole or the first hole 115b1 of the second notch 115b of the second central plate 110b in the X' direction or second oblique direction in the upright position, and the dimension of the second support hole 230b or the first hole of the second notch of the second outer leg 200b in the X' direction or second oblique direction in the upright position.

[0104] (e21) The second arm 400b is inserted through the second support hole or the first hole 115b1 of the second notch 115b of the second central plate 110b in the upright position and through the second support hole 230b or the first hole of the second notch of the second outer leg 200b in the upright position. Or, (e22) The second arm 400b is inserted through the second hole 115b2 to the first hole 115b1 of the second notch 115b of the second central plate 110b in the upright position, and then through the second support hole 230b or the first hole of the second notch of the second outer leg 200b in the upright position. Alternatively, (e23) the second arm 400b is inserted through the second hole 115b2 of the second notch 115b of the second central plate 110b in the upright position, and through the second hole of the second notch of the second outer leg 200b in the upright position, and through the first hole. In this way, the second arm 400b is supported by the second central plate 110b and the second outer leg 200b.

[0105] The third arm 400c may be configured to extend from the third outer leg 200c. For example, the third arm 400c can be configured to have a fixing part 410c and an arm body 420c (see Figures 4A to 5B). The fixing part 410c is fixed to the Z-direction side surface of the third outer leg 200c in the deployed state (see Figures 4A and 4B). The arm body 420c is a long plate or rod extending from the fixing part 410c. Alternatively, the third arm 400c may be a long plate or rod extending from the third hypotenuse 210c of the third outer leg 200c (not shown). In either configuration, in the unfolded state (see Figures 4A and 4B) and the folded state (not shown), the third arm 400c extends in the Y direction and is positioned along the first central plate 110a, while in the upright state (see Figures 5A and 5B), the third arm 400c extends beyond the first central plate 110a in the Z direction.

[0106] Alternatively, the third arm 400c may be a long plate or rod that, in an upright position, is supported at least by the first central plate 110a and extends in the Z-Z' direction (not shown). The first central plate 110a may be provided with a third support hole (not shown) or a third notch 115a (see Figures 6 to 9B) that penetrates the first central plate 110a. In this case, in an upright position, the third arm 400c is inserted through and supported by the third support hole or third notch 115a of the first central plate 110a. The third outer leg 200c may also be provided with a third support hole 230c (see Figures 6 to 9B) or a third notch (not shown) that penetrates the third outer leg 200c. In this case, when upright, the third arm 400c is inserted through the third support hole or third notch 115a of the first central plate 110a and the third support hole 230c or third notch of the third outer leg 200c and supported.

[0107] For example, the third support hole or third notch 115a of the first central plate 110a and the third support hole 230c or third notch of the third outer leg 200c may have any of the following configurations (a3) ​​to (c3).

[0108] (a3) The third support hole 230c of the third outer leg 200c can be a roughly circular or roughly elliptical hole (see Figures 6 to 9B). The third notch of the third outer leg 200c can be configured to have a roughly circular or roughly elliptical first hole and a second hole that extends from this first hole in the X direction and opens in the X direction (not shown). In the unfolded state, the third support hole of the first central plate 110a can be an elongated hole (not shown) that is spaced in the Y direction relative to the third support hole 230c of the third outer leg 200c or the first hole of the third notch and extends in the Y direction, or an elongated hole (not shown) that is spaced in the first oblique direction relative to the third support hole 230c of the third outer leg 200c or the first hole of the third notch and extends in the first oblique direction. In the unfolded state, the third notch 115a of the first central plate 110a has a first hole 115a1 and a second hole 115a2 that extends from the first hole 115a1 in the X direction and opens in the X direction. The first hole 115a1 can be an elongated hole that is spaced apart in the Y direction from the third support hole 230c of the third outer leg 200c or the first hole of the third notch and extends in the Y direction (see Figures 6 to 9B), or an elongated hole that is spaced apart in the first oblique direction from the third support hole 230c of the third outer leg 200c or the first hole of the third notch and extends in the first oblique direction (not shown).

[0109] (b3) The third support hole of the first central plate 110a can be a roughly circular or roughly elliptical hole (not shown). The third notch 115a of the first central plate 110a can be configured to have a roughly circular or roughly elliptical first hole 115a1 and a second hole 115a2 that extends from the first hole 115a1 in the X direction and opens in the X direction (not shown). In the deployed state, the third support hole 230c of the third outer leg 200c can be an elongated hole (not shown) that is spaced in the Y' direction relative to the third support hole of the first central plate 110a or the first hole 115a1 of the third notch 115a and extends in the Y' direction, or an elongated hole (not shown) that is spaced in the fourth oblique direction relative to the third support hole of the first central plate 110a or the first hole 115a1 of the third notch 115a and extends in the fourth oblique direction. In the deployed state, the third notch of the third outer leg 200c has a first hole and a second hole that extends from the first hole in the X direction and opens in the X direction. The first hole can be an elongated hole (not shown) that is spaced apart in the Y' direction from the third support hole of the first central plate 110a or the first hole 115a1 of the third notch 115a and extends in the Y' direction, or an elongated hole (not shown) that is spaced apart in the fourth oblique direction from the third support hole of the first central plate 110a or the first hole 115a1 of the third notch 115a and extends in the fourth oblique direction.

[0110] (c3) Both the third support hole 115a1 of the first central plate 110a or the first hole 115a1 of the third notch 115a and the third support hole 230c of the third outer leg 200c or the first hole of the third notch may be approximately circular or approximately elliptical holes (not shown).

[0111] If the third support hole or third notch 115a of the first central plate 110a and the third support hole 230c or third notch of the third outer leg 200c have the configuration described in (a3) ​​above, then (d3) the third arm 400c can be configured to be substantially L-shaped and to have a hanging portion 430c that extends linearly in a direction including a component in the Z-Z' direction, and a tip portion 440c that is bent relative to the hanging portion 430c and extends from the hanging portion 430c in the Y' direction or a fourth oblique direction (see Figures 6 and 10). The longitudinal dimension (Y' direction or fourth oblique direction dimension) of the tip portion 440c of the third arm 400c is smaller than the longitudinal dimension of the first hole 115a1 of the third support hole or third notch 115a of the first central plate 110a in the upright position. The dimension of the tip portion 440c of the third arm 400c in the short direction (dimension in the X direction or third diagonal direction) is smaller than the dimension of the third support hole of the first central plate 110a or the first hole 115a1 of the third notch 115a in the short direction when the arm is upright, and the dimension of the third support hole 230c of the third outer leg 200c or the first hole of the third notch in the short direction when the arm is upright. The dimension of the tip portion 440c of the third arm 400c in the Z-Z' direction is smaller than the dimension of the third support hole 230c of the third outer leg 200c or the first hole of the third notch in the Z-Z' direction when the arm is upright. The dimension of the hanging portion 430c of the third arm 400c in the long direction is smaller than the dimension of the third support hole of the first central plate 110a or the first hole 115a1 of the third notch 115a in the long direction when the arm is upright. The dimension of the hanging portion 430c of the third arm 400c in the short-side direction is smaller than the dimension of the third support hole of the first central plate 110a or the first hole 115a1 of the third notch 115a in the short-side direction when the arm is upright.

[0112] (d31) The tip portion 440c is inserted through the third support hole 230c of the third outer leg 200c or the first hole 115a1 of the third notch 115a in the upright position, and then inserted through the third support hole 230c of the third outer leg 200c or the first hole of the third notch in the upright position, while the hanging portion 430c is inserted through the third support hole 230c of the first central leg 110a or the first hole 115a1 of the third notch 115a in the upright position. Or, (d32) The hanging portion 430c is inserted through the second hole 115a2 to the first hole 115a1 of the third notch 115a of the first central leg 110a in the upright position, and then the tip portion 440c is inserted through the third support hole 230c of the third outer leg 200c or the first hole of the third notch in the upright position. Alternatively, (d33) the hanging portion 430c is inserted through the second hole 115a2 to the first hole 115a1 of the third notch 115a of the first central plate 110a in the upright position, and the tip portion 440c is inserted through the second hole to the first hole of the third notch of the third outer leg 200c in the upright position. In this way, the third arm 400c is supported by the second central plate 110b and the second outer leg 200b.

[0113] If the third support hole or third notch 115a of the first central plate 110a and the third support hole 230c or third notch of the third outer leg 200c have any of the configurations described in (a3) ​​to (c3) above, then (e3) the third arm 400c can be configured to extend linearly in a direction including a component in the Z-Z' direction (not shown). The dimension of the third arm 400c in the Y' direction or fourth oblique direction is smaller than the dimension of the first hole 115a1 of the third support hole or third notch 115a of the first central plate 110a in the Y' direction or fourth oblique direction and the dimension of the first hole of the third support hole 230c or third notch of the third outer leg 200c in the Y' direction or fourth oblique direction in the upright state. The dimension of the third arm 400c in the X direction or third oblique direction is smaller than the dimension of the third support hole of the first central plate 110a or the first hole 115a1 of the third notch 115a in the X direction or third oblique direction in the upright position, and the dimension of the third support hole 230c of the third outer leg 200c or the first hole of the third notch in the X direction or third oblique direction in the upright position.

[0114] (e31) The third arm 400c is inserted through the third support hole or the first hole 115a1 of the third notch 115a of the first central plate 110a in the upright position and through the third support hole 230c or the first hole of the third notch of the third outer leg 200c in the upright position. Or, (e32) The third arm 400c is inserted through the second hole 115a2 to the first hole 115a1 of the third notch 115a of the first central plate 110a in the upright position, and then through the third support hole 230c or the first hole of the third notch of the third outer leg 200c in the upright position. Alternatively, (e33) the third arm 400c is inserted through the second hole 115a2 to the first hole 115a1 of the third notch 115a of the first central plate 110a in the upright position, and also through the second hole to the first hole of the third notch of the third outer leg 200c in the upright position. In this way, the third arm 400c is supported by the second central plate 110b and the second outer leg 200b.

[0115] The fourth arm 400d may be configured to extend from the fourth outer leg 200d. For example, the fourth arm 400d can have a configuration comprising a fixing part 410d and an arm body 420d (see Figures 4A to 5B). The fixing part 410d is fixed to the Z-direction side surface of the fourth outer leg 200d in the deployed state (see Figures 4A and 4B). The arm body 420d is a long plate or rod extending from the fixing part 410d. Alternatively, the fourth arm 400d may be a long plate or rod extending from the fourth hypotenuse 210d of the fourth outer leg 200d (not shown). In either configuration, in the unfolded state (see Figures 4A and 4B) and the folded state (not shown), the fourth arm 400d extends in the Y direction and is positioned along the second central plate 110b, while in the upright state (see Figures 5A and 5B), the fourth arm 400d extends beyond the second central plate 110b in the Z direction.

[0116] Alternatively, the fourth arm 400d may be a long plate or rod that, in an upright position, is supported at least by the second central plate 110b and extends in the Z-Z' direction (not shown). The second central plate 110b may be provided with a fourth support hole 114b (see Figures 6 to 9B) or a fourth notch (not shown) that penetrates the second central plate 110b. In this case, in an upright position, the fourth arm 400d is inserted through and supported by the fourth support hole 114b or fourth notch of the second central plate 110b. The fourth outer leg 200d may also be provided with a fourth support hole 230d (see Figures 6 to 9B) or a fourth notch (not shown) that penetrates the fourth outer leg 200d. In this case, when upright, the fourth arm 400d is inserted through the fourth support hole 114b or fourth notch of the second central plate 110b and the fourth support hole 230d or fourth notch of the fourth outer leg 200d and supported.

[0117] For example, the fourth support hole 114b or fourth notch of the second central plate 110b and the fourth support hole 230d or fourth notch of the fourth outer leg 200d may have any of the following configurations (a4) to (c4).

[0118] (a4) The fourth support hole 230d of the fourth outer leg 200d can be a roughly circular or roughly elliptical hole (see Figures 6 to 9B). The fourth notch of the fourth outer leg 200d can be configured to have a roughly circular or roughly elliptical first hole and a second hole that extends from this first hole in the X' direction and opens in the X' direction (not shown). In the unfolded state, the fourth support hole 114b of the second central plate 110b can be an elongated hole that is spaced in the Y direction relative to the fourth support hole 230d of the fourth outer leg 200d or the first hole of the fourth notch and extends in the Y direction (see Figures 6 to 9B), or an elongated hole that is spaced in the second oblique direction relative to the fourth support hole 230d of the fourth outer leg 200d or the first hole of the fourth notch and extends in the second oblique direction (not shown). In the unfolded state, the fourth notch of the second central plate 110b has a first hole and a second hole that extends from the first hole in the X' direction and opens in the X' direction. The first hole can be an elongated hole (not shown) that is spaced apart in the Y direction from the fourth support hole 230d of the fourth outer leg 200d or the first hole of the fourth notch and extends in the Y direction, or an elongated hole (not shown) that is spaced apart in the second oblique direction from the fourth support hole 230d of the fourth outer leg 200d or the first hole of the fourth notch and extends in the second oblique direction.

[0119] (b4) The fourth support hole 114b of the second central plate 110b can be a roughly circular or roughly elliptical hole (not shown). The fourth notch of the second central plate 110b can be configured to have a roughly circular or roughly elliptical first hole and a second hole that extends from the first hole in the X' direction and opens in the X' direction (not shown). In the deployed state, the fourth support hole 230d of the fourth outer leg 200d can be an elongated hole (not shown) that is spaced apart in the Y' direction from the fourth support hole 114b of the second central plate 110b or the first hole of the fourth notch and extends in the Y direction, or an elongated hole (not shown) that is spaced apart in the third oblique direction from the fourth support hole 114b of the second central plate 110b or the first hole of the fourth notch and extends in the third oblique direction. In the deployed state, the fourth notch of the fourth outer leg 200d has a first hole and a second hole that extends from the first hole in the X' direction and opens in the X' direction. The first hole can be an elongated hole (not shown) that is spaced apart in the Y' direction from the fourth support hole 114b of the second central plate 110b or the first hole of the fourth notch and extends in the Y' direction, or an elongated hole (not shown) that is spaced apart in the third oblique direction from the fourth support hole 114b of the second central plate 110b or the first hole of the fourth notch and extends in the third oblique direction.

[0120] (c4) Both the fourth support hole 114b of the second central plate 110b or the first hole of the fourth notch and the fourth support hole 230d of the fourth outer leg 200d or the first hole of the fourth notch may be approximately circular or approximately elliptical holes (not shown).

[0121] If the fourth support hole 114b or fourth notch of the second central plate 110b and the fourth support hole 230d or fourth notch of the fourth outer leg 200d have the configuration described in (a4) above, then (d4) the fourth arm 400d can be configured to be substantially L-shaped and to have a hanging portion 430d that extends linearly in a direction including a component in the Z-Z' direction, and a tip portion 440d that is bent relative to the hanging portion 430d and extends from the hanging portion 430d in the Y' direction or a third oblique direction (see Figures 6 and 10). The longitudinal dimension (Y' direction or third oblique direction dimension) of the tip portion 440d of the fourth arm 400d is smaller than the longitudinal dimension of the first hole of the fourth support hole 114b or fourth notch of the second central plate 110b in the upright position. The dimension of the tip portion 440d of the fourth arm 400d in the short direction (dimension in the X' direction or fourth oblique direction) is smaller than the dimension of the fourth support hole 114b or the first hole of the fourth notch of the second central plate 110b in the short direction when it is upright, and the dimension of the fourth support hole 230d or the first hole of the fourth notch of the fourth outer leg 200d in the short direction when it is upright. The dimension of the tip portion 440d of the fourth arm 400d in the Z-Z' direction is smaller than the dimension of the fourth support hole 230d or the first hole of the fourth notch of the fourth outer leg 200d in the Z-Z' direction when it is upright. The dimension of the hanging portion 430d of the fourth arm 400d in the long direction is smaller than the dimension of the fourth support hole 114b or the first hole of the fourth notch of the second central plate 110b in the long direction when it is upright. The dimension of the hanging portion 430d of the fourth arm 400d in the short-side direction is smaller than the dimension of the fourth support hole 114b of the second central plate 110b or the first hole of the fourth notch in the short-side direction when the arm is upright.

[0122] (d41) The tip portion 440a is inserted through the fourth support hole 114b of the second central plate 110b in the upright position or through the first hole of the fourth notch, and then through the fourth support hole 230d of the fourth outer leg 200d in the upright position or through the first hole of the fourth notch, and the hanging portion 430d is inserted through the fourth support hole 114b of the second central plate 110b in the upright position or through the first hole of the fourth notch. Or, (d42) The hanging portion 430d is inserted through the second hole to the first hole of the fourth notch of the second central plate 110b in the upright position, and then the tip portion 440a is inserted through the fourth support hole 230d of the fourth outer leg 200d in the upright position or through the first hole of the fourth notch. Alternatively, (d43) the hanging portion 430d is inserted through the second hole to the first hole of the fourth notch in the second central plate 110b in the upright position, and the tip portion 440a is inserted through the second hole to the first hole of the fourth notch in the fourth outer leg 200d in the upright position. In this way, the fourth arm 400d is supported by the second central plate 110b and the fourth outer leg 200d.

[0123] If the fourth support hole 114b or fourth notch of the second central plate 110b and the fourth support hole 230d or fourth notch of the fourth outer leg 200d have any of the configurations described in (a4) to (c4) above, then (e4) the fourth arm 400d can be configured to extend linearly in a direction including a component in the Z-Z' direction (not shown). The dimension of the fourth arm 400d in the Y' direction or third oblique direction is smaller than the dimension of the first hole of the fourth support hole 114b or fourth notch of the second central plate 110b in the Y' direction or third oblique direction in the upright position and the dimension of the first hole of the fourth support hole 230d or fourth notch of the fourth outer leg 200d in the Y' direction or third oblique direction in the upright position. The dimension of the fourth arm 400d in the X' direction or fourth oblique direction is smaller than the dimension of the fourth support hole 114b or the first hole of the fourth notch of the second central plate 110b in the X' direction or fourth oblique direction in the upright position, and the dimension of the fourth support hole 230d or the first hole of the fourth notch of the fourth outer leg 200d in the X' direction or fourth oblique direction in the upright position.

[0124] (e41) The fourth arm 400d is inserted through the fourth support hole 114b or the first hole of the fourth notch in the second central plate 110b in the upright position and through the fourth support hole 230d or the first hole of the fourth notch in the fourth outer leg 200d in the upright position. Or, (e42) The fourth arm 400d is inserted through the second hole to the first hole of the fourth notch in the second central plate 110b in the upright position, and then through the fourth support hole 230d or the first hole of the fourth notch in the fourth outer leg 200d in the upright position. Or, (e43) The fourth arm 400d is inserted through the second hole to the first hole of the fourth notch in the second central plate 110b in the upright position, and also through the second hole to the first hole of the fourth notch in the fourth outer leg 200d in the upright position. In this way, the fourth arm 400d is supported by the second central plate 110b and the fourth outer leg 200d.

[0125] The three-dimensional structure S2 may further include a first connecting portion 600a and a second connecting portion 600b (see Figures 6 and 10).

[0126] The first connecting portion 600a may connect the first arm 400a in any of the above-described embodiments with the third arm 400c in any of the above-described embodiments. For example, the first connecting portion 600a may be a rod or plate connecting the first arm 400a in any of the above-described embodiments with the third arm 400c in any of the above-described embodiments (see Figures 6 and 10).

[0127] The second connecting portion 600b may connect the second arm 400b in any of the above-described embodiments with the fourth arm 400d in any of the above-described embodiments. For example, the second connecting portion 600b may be a rod or plate connecting the second arm 400b in any of the above-described embodiments with the fourth arm 400d in any of the above-described embodiments (see Figures 6 and 10).

[0128] When the first arm 400a has the configuration described in (d1) and the third arm 400c has the configuration described in (d3), the first connecting portion 600a, the first arm 400a, and the third arm 400c are substantially U-shaped or substantially H-shaped, and are configured to be elastically deformable so that the hanging portion 430a of the first arm 400a and the hanging portion 430c of the third arm 400c move closer to each other.

[0129] With the hanging portion 430a of the first arm 400a and the hanging portion 430c of the third arm 400c displaced so that they are closer to each other (hereinafter referred to as the "first displaced state"), the tip portion 440a of the first arm 400a is inserted through the first support hole 114a of the first central plate 110a or the first hole of the first notch in the upright state, and the tip portion 440c of the third arm 400c is inserted through the third support hole of the first central plate 110a or the first hole 115a1 of the third notch 115a in the upright state. In addition, the hanging portion 430a of the first arm 400a is inserted through the first support hole 114a of the first central plate 110a or the first hole of the first notch in the upright position, and the hanging portion 430c of the third arm 400c is inserted through the third support hole of the first central plate 110a or the first hole 115a1 of the third notch 115a in the upright position. Subsequently, the hanging portion 430a of the first arm 400a and the hanging portion 430c of the third arm 400c are released from the first displacement state (hereinafter referred to as "release from the first displacement state"), the tip portion 440a of the first arm 400a is inserted into the first support hole 230a of the first outer leg 200a or the first hole of the first notch in the upright state, and the tip portion 440c of the third arm 400c is inserted into the third support hole 230c of the third outer leg 200c or the first hole of the third notch in the upright state.

[0130] If the first central plate 110a is provided with a first notch, in the first displacement state, the hanging portion 430a of the first arm 400a may be inserted through the second hole to the first hole of the first notch in the first central plate 110a in the upright state, and then, by releasing the first displacement state, the tip portion 440a of the first arm 400a may be inserted through the first support hole 230a of the first outer leg 200a or the first hole of the first notch in the upright state. In this case, the step of inserting the tip portion 440a of the first arm 400a through the first support hole 114a of the first central plate 110a or the first hole of the first notch in the upright state is omitted. If the first central plate 110a is provided with a third notch 115a, in the first displacement state, the hanging portion 430c of the third arm 400c may be inserted through the second hole 115a2 to the first hole 115a1 of the third notch 115a in the first central plate 110a in the upright state. Then, by releasing the first displacement state, the tip portion 440c of the third arm 400c may be inserted through the third support hole 230c of the third outer leg 200c in the upright state or the first hole of the third notch. In this case, the step of inserting the tip portion 440c of the third arm 400c into the third support hole of the first central plate 110a or the first hole 115a1 of the third notch 115a in the upright state is omitted.

[0131] If the second arm 400b has the configuration described in (d2) and the fourth arm 400d has the configuration described in (d4), the second connecting portion 600b, the second arm 400b, and the fourth arm 400d are substantially U-shaped or substantially H-shaped, and are configured to be elastically deformable so that the hanging portion 430b of the second arm 400b and the hanging portion 430d of the fourth arm 400d move closer to each other. With the hanging portion 430b of the second arm 400b and the hanging portion 430d of the fourth arm 400d displaced so that they are closer to each other (hereinafter referred to as the "second displacement state"), the tip portion 440b of the second arm 400b is inserted through the second support hole or the first hole 115b1 of the second central plate 110b or the second notch 115b in the upright state, and the tip portion 440d of the fourth arm 400d is inserted through the fourth support hole 114b or the first hole of the fourth notch of the second central plate 110b in the upright state. In addition, the hanging portion 430b of the second arm 400b is inserted through the second support hole or the first hole 115b1 of the second central plate 110b or the second notch 115b in the upright position, and the hanging portion 430d of the fourth arm 400d is inserted through the fourth support hole 114b or the first hole of the fourth notch in the second central plate 110b in the upright position. Subsequently, the hanging portion 430b of the second arm 400b and the hanging portion 430d of the fourth arm 400d are released from the second displacement state (hereinafter referred to as "release from the second displacement state"), the tip portion 440b of the second arm 400b is inserted into the second support hole 230b of the second outer leg 200b in the upright state or the first hole of the second notch, and the tip portion 440d of the fourth arm 400d is inserted into the fourth support hole 230d of the fourth outer leg 200d in the upright state or the first hole of the fourth notch.

[0132] If the second central plate 110b is provided with a second notch 115b, in the second displacement state, the hanging portion 430b of the second arm 400b may be inserted through the second hole 115a2 to the first hole 115b1 of the second notch 115b of the second central plate 110b in the upright state. Then, by releasing the second displacement state, the tip portion 440b of the second arm 400b may be inserted through the second support hole 230b of the second outer leg 200b in the upright state or the first hole of the second notch. In this case, the step of inserting the tip portion 440b of the second arm 400b into the second support hole of the second central plate 110b or the first hole 115b1 of the second notch 115b in the upright state is omitted. If the second central plate 110b is provided with a fourth notch, in the second displacement state, the hanging portion 430d of the fourth arm 400d may be inserted through the second hole to the first hole of the fourth notch in the second central plate 110b in the upright state. Then, by releasing the second displacement state, the tip portion 440d of the fourth arm 400d may be inserted through the fourth support hole 230d of the fourth outer leg 200d in the upright state or through the first hole of the fourth notch. In this case, the step of inserting the tip portion 440d of the fourth arm 400d through the fourth support hole 114b of the second central plate 110b in the upright state or through the first hole of the fourth notch is omitted.

[0133] The first connecting portion 600a may connect the first arm 400a in any of the above configurations to the second arm 400b in any of the above configurations, and the second connecting portion 600b may connect the third arm 400c in any of the above configurations to the fourth arm 400d in any of the above configurations (not shown). Alternatively, the first connecting portion 600a may connect the first arm 400a in any of the above configurations to the fourth arm 400d in any of the above configurations, the second connecting portion 600b may connect the second arm 400b in any of the above configurations to the third arm 400c in any of the above configurations, and the first connecting portion 600a and the second connecting portion 600b may intersect (not shown).

[0134] The three-dimensional structure S2 may further include at least one support portion 700 that, when viewed from the Z-direction side, is a polygonal annular shape in plan view (for example, a triangular annular shape (not shown), a quadrilateral annular shape (see Figures 6 and 10), a pentagonal annular shape (not shown), a hexagonal annular shape (not shown), an octagonal annular shape (not shown), or a circular annular shape (not shown), a plate-like shape (not shown), a slat-like shape (not shown), or a rod-like shape (not shown)). At least one support portion 700 may be configured to be supported on the first connecting portion 600a and the second connecting portion 600b in any of the above-described forms.

[0135] For example, at least one support portion 700 may be a polygonal annular or circular support portion 700 in plan view, and the first connecting portion 600a may be provided with a first engaging projection 610a that protrudes in the Z direction, and the second connecting portion 600b may be provided with a second engaging projection 610b that protrudes in the Z direction (see Figure 6). In this case, the support portion 700 has a pair of first engaging portions 710 and a pair of second engaging portions 720. The first engaging projection 610a is fitted between the pair of first engaging portions 710. The second engaging projection 610b is fitted between the pair of second engaging portions 720 (see Figure 6).

[0136] Alternatively, at least one support portion 700 may be the one support portion 700 described above, and the first connecting portion 600a may be provided with a pair of first engagement recesses that are concave in the Z' direction, and the second connecting portion 600b may be provided with a pair of second engagement recesses that are concave in the Z' direction (not shown). In this case, a pair of first engagement portions 710 are fitted into a pair of first engagement recesses. A pair of second engagement portions 720 are fitted into a pair of second engagement recesses (not shown). At least one support portion 700, which may be slat-shaped (not shown) or rod-shaped (not shown), may be configured to be fitted into a pair of first engagement recesses and to be fitted into a pair of first engagement recesses.

[0137] At least one support portion 700 may further have a first bent portion (not shown) and a second bent portion (not shown) (see Figure 11). The first bent portion is located outward from a pair of first engaging portions 710 or a pair of first engaging recesses and is bent toward the Z' direction. The first bent portion may be in contact with the first connecting portion 600a from the outside or may be spaced apart. The second bent portion is located outward from a pair of second engaging portions 720 or a pair of second engaging recesses and is bent toward the Z' direction. The second bent portion may be in contact with the second connecting portion 600b from the outside or may be spaced apart.

[0138] The first engaging projection 610a and the second engaging projection 610b, as well as the first engaging recess and the second engaging recess, are optional. The first bent portion and the second bent portion are also optional.

[0139] At least one support portion 700 (excluding rod-shaped ones) may be configured to be supported on the first arm 400a, second arm 400b, third arm 400c, and fourth arm 400d in any of the above-described forms, regardless of whether the first connecting portion 600a and the second connecting portion 600b are provided.

[0140] The first connecting portion 600a, the second connecting portion 600b, and at least one support portion 700 are optional. Alternatively, the first connecting portion 600a and the second connecting portion 600b may be provided while at least one support portion 700 is omitted. Furthermore, the first arm 400a, the third arm 400c, and the first connecting portion 600a may be provided while the second arm 400b, the fourth arm 400d, the second connecting portion 600b, and at least one support portion 700 are omitted, or vice versa.

[0141] The three-dimensional structure S2, like the three-dimensional structure S1, can be deformed from an unfolded state to an upright state and vice versa, and can also be deformed from an unfolded state to a folded state and vice versa. However, if the first arm 400a to the fourth arm 400d are inserted through the support holes or notches described above, the first arm 400a to the fourth arm 400d should be removed from the support holes or notches before deformation.

[0142] When the three-dimensional structure S2 is constructed as described above, it exhibits the same technical characteristics and effects as the three-dimensional structure S1 described above. Furthermore, when the first arm 400a is a long plate or rod, the upright position of the first outer leg 200a is more easily maintained by inserting the first arm 400a through the first support hole 114a or first notch of the first central plate 110a and the first support hole 230a or first notch of the first outer leg 200a. Similarly, when the second arm 400b to the fourth arm 400d are long plates or rods, the upright position of the second outer leg 200b to the fourth outer leg 200d is more easily maintained.

[0143] Furthermore, when the three-dimensional structure S2 is used as a fire pit or barbecue grill, cooking utensils can be supported on the first arm 400a to the fourth arm 400d, or food can be suspended from it, while it is upright. When the three-dimensional structure S2 is used as furniture, an object can be supported on at least one of the first arm 400a to the fourth arm 400d, while it is upright.

[0144] When the three-dimensional structure S2 is equipped with a first connecting section 600a and a second connecting section 600b and is used as a fire pit or barbecue grill, cooking utensils can be supported on the first connecting section 600a and the second connecting section 600b, or food can be suspended from them, while the structure is upright. Furthermore, when the three-dimensional structure S2 is equipped with a first connecting section 600a and a second connecting section 600b and is used as furniture or the like, an object can be supported on at least one of the first connecting section 600a and the second connecting section 600b.

[0145] If the three-dimensional structure S2 is equipped with at least one support part 700 and is used as a fire pit or barbecue grill, cooking utensils can be supported on at least one support part 700 (trivet) when it is upright. Also, if the three-dimensional structure S2 is equipped with at least one support part 700 and is used as furniture, objects can be supported on at least one support part 700. [Examples]

[0146] The following describes a three-dimensional structure S3 according to several embodiments of the present invention, including Embodiment 3 and its design modifications, with reference to Figures 12A to 13B. Figures 12A to 13B show the three-dimensional structure S3 of Embodiment 3. Figures 12A to 13B show the Y-Y' direction (first direction), the X-X' direction (second direction), and the Z-Z' direction (third direction). Note that the connection structure between the first inner edge 111a of the first central plate 110a and the second inner edge 111b of the second central plate 110b is omitted from the illustration in Figures 12A to 13B.

[0147] The three-dimensional structure S3 has the same configuration as the three-dimensional structure S1, except that it is deformable between an upright state (see Figures 12A and 12B) and a folded state (see Figures 13A and 13B), and that the configuration of the first and second leg structures of the three-dimensional structure S3 differs from that of the first and second leg structures of the three-dimensional structure S1. Below, only the differences will be explained in detail, and explanations that overlap with those for the three-dimensional structure S1 will be omitted.

[0148] The central part 100 of the three-dimensional structure S3 has a configuration that is substantially the same as the central part 100 of the three-dimensional structure S1, except for the configuration described later.

[0149] In the upright position, the first central plate 110a and the second central plate 110b of the central section 100 are spread out in a roughly plate-like shape (see Figures 12A and 12B). In this upright position, the first hypotenuse 112a and the second hypotenuse 112b are arranged in a roughly V-shape or a roughly H-shape convex toward the Y direction, and the third hypotenuse 113a and the fourth hypotenuse 113b are arranged in a roughly V-shape or a roughly H-shape convex toward the Y' direction. In the upright position, the first inner edge 111a of the first central plate 110a and the second inner edge 111b of the second central plate 110b may be in contact with each other, maintaining a roughly plate-like state between the first central plate 110a and the second central plate 110b, but is not limited to this.

[0150] In the folded state, the first central plate 110a and the second central plate 110b are folded in the Z direction and overlapped with each other (see Figure 13B).

[0151] The first leg structure includes a plate-shaped first support leg 500a and a plate-shaped second support leg 500b. The first support leg 500a and the second support leg 500b may each be made of a plate having the heat resistance described above, or they may each be made of a plate that does not have the heat resistance described above.

[0152] The first support leg 500a has a first hypotenuse 510a and a first side 520a on the X' direction side. The first hypotenuse 510a of the first support leg 500a is rotatably connected to the first hypotenuse 112a of the first central plate 110a. For example, the first hypotenuse 510a of the first support leg 500a is rotatably connected to the first hypotenuse 112a of the first central plate 110a in the same way as any of the connection structures (1) to (3) above. In the same way as the connection structure (1) above, when the first hypotenuse 510a of the first support leg 500a is rotatably connected to the first hypotenuse 112a of the first central plate 110a, a pivot shaft (not shown) is inserted into a plurality of sleeves (not shown) provided on the first hypotenuse 510a of the first support leg 500a and a plurality of sleeves (not shown) provided on the first hypotenuse 112a of the first central plate 110a.

[0153] The second support leg 500b has a second hypotenuse 510b and a second side 520b on the X-direction side. The second hypotenuse 510b of the second support leg 500b is rotatably connected to the second hypotenuse 112b of the second central plate 110b. For example, the second hypotenuse 510b of the second support leg 500b is rotatably connected to the second hypotenuse 112b of the second central plate 110b in the same way as any of the connection structures described in (1) to (3) above. In the case where the second hypotenuse 510b of the second support leg 500b is rotatably connected to the second hypotenuse 112b of the second central plate 110b in the same way as the connection structure described in (1) above, a pivot shaft (not shown) is inserted into a plurality of sleeves (not shown) provided on the second hypotenuse 510b of the second support leg 500b and a plurality of sleeves (not shown) provided on the second hypotenuse 112b of the second central plate 110b.

[0154] The first side 520a of the first support leg 500a and the second side 520b of the second support leg 500b are rotatably connected. For example, the first side 520a of the first support leg 500a and the second side 520b of the second support leg 500b are rotatably connected in the same manner as any of the connection structures described in (1) to (3) above. In the same manner as the connection structure described in (1) above, when the first side 520a of the first support leg 500a and the second side 520b of the second support leg 500b are rotatably connected, a pivot shaft (not shown) is inserted into a plurality of sleeves (not shown) provided on the first side 520a of the first support leg 500a and a plurality of sleeves (not shown) provided on the second side 520b of the second support leg 500b.

[0155] In the upright position, the first support leg 500a is folded in the Z' direction by rotating relative to the first central plate 110a of the central section 100, the second support leg 500b is folded in the Z' direction by rotating relative to the second central plate 110b of the central section 100, and the first support leg 500a and the second support leg 500b are folded in the Y direction by rotating (see Figures 12A to 12B). In other words, in the upright position, the first support leg 500a and the first central plate 110a are folded in the Z' direction at their boundary, the second support leg 500b and the second central plate 110b are folded in the Z' direction at their boundary, and the first support leg 500a and the second support leg 500b are folded in the Z' direction at their boundary. In this way, in the upright position, the first support leg 500a is upright relative to the first central plate 110a, the second support leg 500b is upright relative to the second central plate 110b, and the upright position of the first support leg 500a and the second support leg 500b is maintained by the connection between the first support leg 500a and the second support leg 500b. Furthermore, in the upright position, the first support leg 500a may be tilted inward (towards the Y' and X' directions) from a state where it is approximately perpendicular to the first central plate 110a, and the second support leg 500b may be tilted inward (towards the Y' and X' directions) from a state where it is approximately perpendicular to the second central plate 110b (see Figures 12A to 12B). Alternatively, the first support leg 500a may be tilted outward (towards the Y' and X' directions) from a state where it is approximately perpendicular to the first central plate 110a, and the second support leg 500b may be tilted outward (towards the Y' and X' directions) from a state where it is approximately perpendicular to the second central plate 110b (not shown).

[0156] The first support leg 500a and the second support leg 500b rotate, causing them to be folded in the Z direction and overlap each other (see Figure 13B). In other words, the first support leg 500a and the second support leg 500b are folded in the boundary between them and overlap each other.

[0157] The second leg structure includes a plate-shaped third support leg 500c and a plate-shaped fourth support leg 500d. The third support leg 500c and the fourth support leg 500d may each be made of a plate having the heat resistance described above, or they may each be made of a plate that does not have the heat resistance described above.

[0158] The third support leg 500c has a third hypotenuse 510c and a third side 520c on the X' direction side. The third hypotenuse 510c of the third support leg 500c is rotatably connected to the third hypotenuse 113a of the first central plate 110a. For example, the third hypotenuse 510c of the third support leg 500c is rotatably connected to the third hypotenuse 113a of the first central plate 110a in the same manner as any of the connection structures described in (1) to (3) above. In the case where the third hypotenuse 510c of the third support leg 500c is rotatably connected to the third hypotenuse 113a of the first central plate 110a in the same manner as the connection structure described in (1) above, a pivot shaft (not shown) is inserted into a plurality of sleeves (not shown) provided on the third hypotenuse 510c of the third support leg 500c and a plurality of sleeves (not shown) provided on the third hypotenuse 113a of the first central plate 110a.

[0159] The fourth support leg 500d has a fourth hypotenuse 510d and a fourth side 520d on the X-direction side. The fourth hypotenuse 510d of the fourth support leg 500d is rotatably connected to the fourth hypotenuse 113b of the second central plate 110b. For example, the fourth hypotenuse 510d of the fourth support leg 500d is rotatably connected to the fourth hypotenuse 113b of the second central plate 110b in the same way as any of the connection structures described in (1) to (3) above. In the case where the fourth hypotenuse 510d of the fourth support leg 500d is rotatably connected to the fourth hypotenuse 113b of the second central plate 110b in the same way as the connection structure described in (1) above, a pivot shaft (not shown) is inserted into a plurality of sleeves (not shown) provided on the fourth hypotenuse 510d of the fourth support leg 500d and a plurality of sleeves (not shown) provided on the fourth hypotenuse 113b of the second central plate 110b.

[0160] The third side 520c of the third support leg 500c and the fourth side 520d of the fourth support leg 500d are rotatably connected. For example, the third side 520c of the third support leg 500c and the fourth side 520d of the fourth support leg 500d are rotatably connected in the same manner as any of the connection structures described in (1) to (3) above. In the same manner as the connection structure described in (1) above, when the third side 520c of the third support leg 500c and the fourth side 520d of the fourth support leg 500d are rotatably connected, a pivot shaft (not shown) is inserted into a plurality of sleeves (not shown) provided on the third side 520c of the third support leg 500c and a plurality of sleeves provided on the fourth side 520d of the fourth support leg 500d.

[0161] In the upright position, the third support leg 500c is folded toward the Z' direction by rotating relative to the first central plate 110a of the central section 100, the fourth support leg 500d is folded toward the Z' direction by rotating relative to the second central plate 110b of the central section 100, and the third support leg 500c and the fourth support leg 500d are folded toward the Y' direction by rotating (see Figures 12A to 12B). In other words, in the upright position, the third support leg 500c and the first central plate 110a are folded toward the boundary between them, the fourth support leg 500d and the second central plate 110b are folded toward the boundary between them, and the third support leg 500c and the fourth support leg 500d are folded toward the boundary between them. In this way, in the upright position, the third support leg 500c is upright relative to the first central plate 110a, the fourth support leg 500d is upright relative to the second central plate 110b, and the upright position of the third support leg 500c and the fourth support leg 500d is maintained by the connection between the third support leg 500c and the fourth support leg 500d. Furthermore, in the upright position, the third support leg 500c may be tilted inward (towards the Y and X' directions) from a state where it is approximately perpendicular to the first central plate 110a, and the fourth support leg 500d may be tilted inward (towards the Y and X directions) from a state where it is approximately perpendicular to the second central plate 110b (see Figures 12A to 12B). Alternatively, the third support leg 500c may be tilted outward (towards the Y' and X directions) from a state where it is approximately perpendicular to the first central plate 110a, and the fourth support leg 500d may be tilted outward (towards the Y' and X' directions) from a state where it is approximately perpendicular to the second central plate 110b (not shown).

[0162] The third support leg 500c and the fourth support leg 500d rotate, causing them to be folded in the Z direction and overlap each other (see Figure 13B). In other words, the third support leg 500c and the fourth support leg 500d are folded in the boundary between them and overlap each other.

[0163] The following describes a non-limiting method for transforming the three-dimensional structure S3 described above from an upright state to a folded state.

[0164] The first central plate 110a and the second central plate 110b of the central section 100, which is unfolded into a roughly plate-like shape, are folded in the Z direction and overlapped with each other (see Figures 13A and 13B). As the central section 100 is folded in this way, the first support leg 500a and the second support leg 500b are folded in the Z direction and overlapped with each other, as are the third support leg 500c and the fourth support leg 500d. In this way, the three-dimensional structure S3 is transformed from an upright state to a folded state.

[0165] The following describes a non-limiting method for transforming the three-dimensional structure S3 described above from a folded state to an upright state.

[0166] The first central plate 110a and the second central plate 110b (central section 100), which are overlapping each other, are separated (the mountain folds are released) and unfolded into a roughly plate-like shape. As the first central plate 110a and the second central plate 110b are separated, the first support legs 500a and the second support legs 500b, which are overlapping each other, are separated (the mountain folds are released), and the third support legs 500c and the fourth support legs 500d, which are overlapping each other, are separated (the mountain folds are released). As a result, the first support leg 500a and the second support leg 500b stand upright relative to the first central plate 110a and the second central plate 110b, and the first support leg 500a and the second support leg 500b are folded in the Y direction, while the third support leg 500c and the fourth support leg 500d stand upright relative to the first central plate 110a and the second central plate 110b, and the third support leg 500c and the fourth support leg 500d are folded in the Y direction.

[0167] The three-dimensional structure S3 described above is less prone to accidental collapse of the first and second leg structures compared to conventional examples. The reason for this is as follows: The first hypotenuse 510a of the first support leg 500a is rotatably connected to the first hypotenuse 112a of the first central plate 110a. The second hypotenuse 510b of the second support leg 500b is rotatably connected to the second hypotenuse 112b of the second central plate 110b. The first side 520a of the first support leg 500a and the second side 520b of the second support leg 500b are rotatably connected. Therefore, in the upright position, the first support leg 500a is bent in the Z' direction relative to the first central plate 110a of the central section 100, the second support leg 500b is bent in the Z' direction relative to the second central plate 110b of the central section 100, and the state in which the first support leg 500a and the second support leg 500b are folded in the Y direction is maintained. Similarly, the third hypotenuse 510c of the third support leg 500c is rotatably connected to the third hypotenuse 113a of the first central plate 110a. The fourth hypotenuse 510d of the fourth support leg 500d is rotatably connected to the fourth hypotenuse 113b of the second central plate 110b. The third side 520c of the third support leg 500c and the fourth side 520d of the fourth support leg 500d are rotatably connected. Therefore, in the upright position, the third support leg 500c is bent in the Z' direction relative to the first central plate 110a of the central section 100, the fourth support leg 500d is bent in the Z' direction relative to the second central plate 110b of the central section 100, and the third support leg 500c and the fourth support leg 500d are maintained in a mountain-folded state in the Y' direction.

[0168] Furthermore, the three-dimensional structure S3 can be folded in half when folded. This is because, when folded, the first central plate 110a and the second central plate 110b can be folded in the Z direction and overlapped with each other, the first support leg 500a and the second support leg 500b can be folded in the Z direction and overlapped with each other, and the third support leg 500c and the fourth support leg 500d can also be overlapped with each other.

[0169] Furthermore, the three-dimensional structure and the first and second leg structures described above are not limited to the above embodiment, and can be arbitrarily designed and modified within the scope of the claims. Details are described below.

[0170] In any of the above-described embodiments, the first inner edge 111a of the first central plate 110a and the second inner edge 111b of the second central plate 110b may be connected in a way that prevents rotation, with the first central plate 110a and the second central plate 110b being folded in the Z' direction.

[0171] In any of the above-described embodiments, the first inner leg 300a and the second inner leg 300b can be configured to support the first and second central plates 110a and 110b in an upright position, even when angles R1 and R3 are not approximately 90. For example, the shape of the first support side 330a of the first inner leg 300a and the second support side 330b of the second inner leg 300b may be deformed or a protrusion may be provided so that they abut the first and second central plates 110a and 110b from the Z' direction side in an upright position. Similarly, the third inner leg 300c and the fourth inner leg 300d can also be configured to support the first and second central plates 110a and 110b in an upright position.

[0172] The three-dimensional structures S1 and S2 can be configured so that they cannot be transformed from an unfolded state to a folded state. In this case, for example, as will be described later, the central part 100 can be made of a single plate, or the rotation range of the connection structure between the first inner edge 111a of the first central plate 110a and the second inner edge 111b of the second central plate 110b can be restricted so that the first central plate 110a and the second central plate 110b cannot be folded in the Z direction when unfolded, or the rotation range of the connection structure between the first inner edge 320a of the first inner leg 300a and the second inner edge 320b of the second inner leg 300b can be restricted so that the first inner leg 300a and the second inner leg 300b cannot be folded in the Z direction when unfolded.

[0173] Any of the above-described embodiments of the three-dimensional structure S3 may further include a first arm 400a, a second arm 400b, a third arm 400c, and a fourth arm 400d. If the first arm 400a has a fixing portion 410a, the fixing portion 410a may be fixed to the Z-direction side surface of the first support leg 500a in the deployed state. The first arm 400a may be composed of a long plate or rod extending from the first support leg 500a instead of the first hypotenuse 210a of the first outer leg 200a. In the upright state, the first arm 400a may be supported by being inserted through a support hole or notch in the first central plate 110a, or it may be supported by being inserted through a support hole or notch in the first central plate 110a and a support hole or notch in the first support leg 500a. The second arm 400b, the third arm 400c, and the fourth arm 400d can also be configured in the same way as the first arm 400a described above.

[0174] The three-dimensional structure S3 may further include a first connecting portion 600a and a second connecting portion 600b, similar to the three-dimensional structure S2, or it may further include at least one support portion 700 in addition to the first connecting portion 600a and the second connecting portion 600b.

[0175] The second leg structure of the three-dimensional structure S1 and three-dimensional structure S2 in any of the above embodiments can be omitted. Accordingly, the third hypotenuse 113a and fourth hypotenuse 113b of the central part 100 of the three-dimensional structure S1 and three-dimensional structure S2 can also be omitted. In this case, the end of the central part 100 on the Y' direction side may be supported by another three-dimensional structure (for example, another fire pit, another barbecue grill, another cooking appliance, or another piece of furniture).

[0176] The second leg structure of the three-dimensional structure S3 in any of the above embodiments can be omitted. Accordingly, the third hypotenuse 113a and the fourth hypotenuse 113b of the central part 100 of the three-dimensional structure S3 can also be omitted. In this case, the end of the central part 100 on the Y' direction side may be supported by another three-dimensional structure (for example, another fire pit, another barbecue grill, another cooking appliance, or another piece of furniture).

[0177] The central portion 100 in any of the above embodiments may be composed of a single plate or the like having a first hypotenuse 112a and a second hypotenuse 112b arranged in a roughly V-shape or H-shape convex toward the Y direction, and a third hypotenuse 113a and a fourth hypotenuse 113b arranged in a roughly V-shape or H-shape convex toward the Y' direction. In the upright position, the first inner leg 300a, the second inner leg 300b, the third inner leg 300c, and the fourth inner leg 300d may be configured to support the central portion 100 made of a single plate or the like, or they may be configured to be positioned toward the Z' direction without supporting the central portion 100. If the second leg structure is omitted, the third hypotenuse 113a and the fourth hypotenuse 113b of the central portion 100 made of a single plate can be omitted. [Explanation of symbols]

[0178] S1~S3: Three-dimensional structure 100: Central part 110a: First center plate 111a: First inside side 112a: First hypotenuse 113a: Third hypotenuse 110b: Second center plate 111b: Second inside side 112b: Second hypotenuse 113b: Fourth hypotenuse 200a: 1st lateral leg 210a: First hypotenuse 220a: First side 200b: 2nd lateral leg 210b: Second hypotenuse 220b: Second side 300a: 1st medial leg 310a: First outer edge 320a: First inner edge 330a: First support edge 300b: 2nd inside edge 310b: Second outer edge 320b: Second inner edge 330b: Second supporting edge 200c: Third lateral leg 210c: Third hypotenuse 220c: Third side 200d: 4th lateral leg 210d: 4th hypotenuse 220d: 4th lateral side 300c: 3rd medial leg 310c: Third outer edge 320c: Third inner edge 330c: Third support edge 300d: 4th medial leg 310d: 4th outer edge 320d: 4th inner edge 330d: 4th supporting edge 400a: First arm 400b: Second arm 400c: Third arm 400d: Fourth arm 500a: 1st support leg 510a: First hypotenuse 520a: First side 500b:Second support leg 510b: 2nd hypotenuse 520b: 2nd side 500c: 3rd support leg 510c: 3rd hypotenuse 520c: 3rd side 500d: 4th support leg 510d: 4th hypotenuse 520d: 4th lateral side 600a: 1st connection part 600b: 2nd connection part 700: At least one support

Claims

1. A leg structure that is deformable between an unfolded state and an upright state, and supports a central portion having a first and second hypotenuse arranged in a substantially V-shape or substantially V-shape with a convex shape on one side in a first direction in the upright state, It has a plate-shaped first outer leg, a plate-shaped second outer leg, a plate-shaped first inner leg, and a plate-shaped second inner leg. The first outer leg has a first hypotenuse that is rotatably connected to the first hypotenuse of the central portion, and a first side in a second direction substantially perpendicular to the first direction. The second outer leg has a second slanted side that is rotatably connected to the second slanted side of the central portion, and a second side on the other side in the second direction. The first inner leg has a first outer edge on the other side in the second direction and a first inner edge on one side in the second direction, and the first outer edge of the first inner leg is rotatably connected to the first side edge of the first outer leg. The second inner leg has a second outer edge on one side in the second direction and a second inner edge on the other side in the second direction, the second outer edge of the second inner leg is rotatably connected to the second side edge of the second outer leg, and the first inner edge of the first inner leg and the second inner edge of the second inner leg are rotatably connected. In the deployed state, the first outer leg, the second outer leg, the first inner leg, and the second inner leg are deployed in a substantially plate-like shape and are located on one side in the first direction relative to the central portion. In the upright position, the first outer leg is bent to one side in a third direction substantially perpendicular to the first and second directions relative to the central portion and stands upright, the second outer leg is bent to one side in the third direction relative to the central portion and stands upright, the first inner leg is bent to the other side in the first direction relative to the first outer leg, the second inner leg is bent to the other side in the first direction relative to the second outer leg and the first inner leg and the second inner leg are valley-folded to the other side in the first direction, and the first inner leg and the second inner leg are located to one side in the third direction relative to the central portion.

2. In the leg structure according to claim 1, The central portion has a first central plate and a second central plate adjacent to each other in the second direction, The first central plate has a first hypotenuse and a first inner edge on one side in the second direction, The second central plate has the second hypotenuse and the second inner side on the other side in the second direction, The first inner edge of the first central plate and the second inner edge of the second central plate are rotatably connected, In the unfolded state, the first central plate and the second central plate are unfolded into a substantially plate shape, the first outer leg and the first inner leg are unfolded into a substantially plate shape and positioned on one side in the first direction relative to the first central plate, and the second outer leg and the second inner leg are unfolded into a substantially plate shape and positioned on one side in the first direction relative to the second central plate. In the upright position, the first central plate and the second central plate are folded in a valley fold to one side in the third direction, the first outer leg is bent in a valley fold to one side in the third direction relative to the first central plate and stands upright, the second outer leg is bent in a valley fold to one side in the third direction relative to the second central plate and stands upright, the first inner leg is bent in a valley fold to the other side in the first direction relative to the first outer leg, the second inner leg is bent in a valley fold to the other side in the first direction relative to the second outer leg, and the first inner leg and the second inner leg are valley fold to the other side in the first direction, the first inner leg is located on one side in the third direction relative to the first central plate, and the second inner leg is located on one side in the third direction relative to the second central plate.

3. In the leg structure according to claim 2, The aforementioned leg structure is further deformable between the unfolded state and the folded state. In the folded state, the first central plate and the second central plate are folded in a mountain shape to the other side in the third direction and overlapped with each other, the first inner leg and the second inner leg are folded in a mountain shape to the other side in the third direction and overlapped with each other, the first inner leg and the first outer leg are unfolded into a substantially plate shape and positioned on one side in the first direction relative to the first central plate, the second inner leg and the second outer leg are unfolded into a substantially plate shape and positioned on one side in the first direction relative to the second central plate, and the first outer leg and the second outer leg are overlapped with each other.

4. In the leg structure according to any one of claims 1 to 3, A leg structure in which the first inner leg and the second inner leg support the central portion.

5. A leg structure that is deformable between an upright state and a folded state and that supports the central part in the upright state, It has a plate-shaped first support leg and a plate-shaped second support leg. The aforementioned central portion has a first central plate and a second central plate adjacent to each other in a second direction substantially perpendicular to the first direction, The first central plate has a first inner edge on one side in the second direction and a first hypotenuse, The second central plate has a second inner edge on the other side in the second direction and a second hypotenuse, The first inner edge of the first central plate and the second inner edge of the second central plate are rotatably connected, and the first and second slanted edges are arranged in a substantially V-shape or a substantially V-shape with a convexity on one side in the first direction when in the upright position. The first support leg has a first slanted side that is rotatably connected to the first slanted side of the central part, and a first side on one side in the second direction. The second support leg has a second slanted side that is rotatably connected to the second slanted side of the central part, and a second side on the other side in the second direction, and the first side of the first support leg and the second side of the second support leg are rotatably connected. In the upright position, the first central plate and the second central plate are unfolded into a substantially plate shape, the first support leg is bent and standing upright on one side in a third direction substantially perpendicular to the first and second directions relative to the first central plate, the second support leg is bent and standing upright on one side in the third direction relative to the second central plate, and the first support leg and the second support leg are folded in a mountain fold on one side in the first direction. In the folded state, the first central plate and the second central plate are folded in a mountain fold to the other side in the third direction and overlapped with each other, the first support leg and the second support leg are folded in a mountain fold to the other side in the third direction and overlapped with each other, the first support leg is located on one side in the first direction relative to the first central plate, and the second support leg is located on one side in the first direction relative to the second central plate.

6. A three-dimensional structure that can be deformed between an unfolded state and an upright state, It comprises a central section, a first leg structure, and a second leg structure. The central portion has a first and second hypotenuse arranged in a roughly convex V-shape or roughly inverted V-shape on one side in the first direction, and a third and fourth hypotenuse arranged in a roughly convex V-shape or roughly inverted V-shape on the other side in the first direction. The first leg structure comprises a plate-shaped first outer leg, a plate-shaped second outer leg, a plate-shaped first inner leg, and a plate-shaped second inner leg. The first outer leg has a first hypotenuse that is rotatably connected to the first hypotenuse of the central portion, and a first side in a second direction substantially perpendicular to the first direction. The second outer leg has a second slanted side that is rotatably connected to the second slanted side of the central portion, and a second side on the other side in the second direction. The first inner leg has a first outer edge on the other side in the second direction and a first inner edge on one side in the second direction, and the first outer edge of the first inner leg is rotatably connected to the first side edge of the first outer leg. The second inner leg has a second outer edge on one side in the second direction and a second inner edge on the other side in the second direction, the second outer edge of the second inner leg is rotatably connected to the second side edge of the second outer leg, and the first inner edge of the first inner leg and the second inner edge of the second inner leg are rotatably connected. The second leg structure comprises a plate-shaped third outer leg, a plate-shaped fourth outer leg, a plate-shaped third inner leg, and a plate-shaped fourth inner leg. The third outer leg has a third slanted side that is rotatably connected to the third slanted side of the central portion, and a third side on one side in the second direction. The fourth outer leg has a fourth slanted side that is rotatably connected to the fourth slanted side of the central portion, and a fourth side on the other side in the second direction. The third inner leg has a third outer edge on the other side in the second direction and a third inner edge on one side in the second direction, and the third outer edge of the third inner leg is rotatably connected to the third side edge of the third outer leg. The fourth inner leg has a fourth outer edge on one side in the second direction and a fourth inner edge on the other side in the second direction, the fourth outer edge of the fourth inner leg is rotatably connected to the fourth side edge of the fourth outer leg, and the third inner edge of the third inner leg and the fourth inner edge of the fourth inner leg are rotatably connected. In the deployed state, the first outer leg, second outer leg, first inner leg, and second inner leg are deployed in a substantially plate shape and are located on one side in the first direction relative to the central portion, and the third outer leg, fourth outer leg, third inner leg, and fourth inner leg are deployed in a substantially plate shape and are located on the other side in the first direction relative to the central portion. In the upright position, the first outer leg is bent to one side in a third direction substantially perpendicular to the first and second directions relative to the central portion, the second outer leg is bent to one side in a third direction relative to the central portion, the first inner leg is bent to the other side in the first direction relative to the first outer leg, the second inner leg is bent to the other side in the first direction relative to the second outer leg, and the first inner leg and the second inner leg are valley-folded to the other side in the first direction, and the first inner leg and the second inner leg are one side in a third direction relative to the central portion A three-dimensional structure located on the side, wherein the third outer leg is bent and standing upright on one side in the third direction relative to the central part, the fourth outer leg is bent and standing upright on one side in the third direction relative to the central part, the third inner leg is bent on one side in the first direction relative to the third outer leg, the fourth inner leg is bent on one side in the first direction relative to the fourth outer leg, and the third inner leg and the fourth inner leg are valley-folded on one side in the first direction, with the third inner leg and the fourth inner leg located on one side in the third direction relative to the central part.

7. In the three-dimensional structure described in claim 6, The central portion has a first central plate and a second central plate adjacent to each other in the second direction, The first central plate has a first hypotenuse, a third hypotenuse, and a first inner edge on one side in the second direction. The second central plate has the second hypotenuse, the fourth hypotenuse, and the second inner side on the other side in the second direction. The first inner edge of the first central plate and the second inner edge of the second central plate are rotatably connected, In the unfolded state, the first central plate and the second central plate are unfolded into a substantially plate shape, the first outer leg and the first inner leg are unfolded into a substantially plate shape and positioned on one side in the first direction relative to the first central plate, the second outer leg and the second inner leg are unfolded into a substantially plate shape and positioned on one side in the first direction relative to the second central plate, the third outer leg and the third inner leg are unfolded into a substantially plate shape and positioned on the other side in the first direction relative to the first central plate, and the fourth outer leg and the fourth inner leg are unfolded into a substantially plate shape and positioned on the other side in the first direction relative to the second central plate. In the upright position, the first central plate and the second central plate are valley-folded to one side in the third direction, the first outer leg is bent to one side in the third direction relative to the first central plate and stands upright, the second outer leg is bent to one side in the third direction relative to the second central plate and stands upright, the first inner leg and the second inner leg are valley-folded to the other side in the first direction, the first inner leg is located on one side in the third direction relative to the first central plate and the second inner leg is located on one side in the third direction relative to the second central plate, the third outer leg is bent to one side in the third direction relative to the first central plate and stands upright, the fourth outer leg is bent to one side in the third direction relative to the second central plate and stands upright, the third inner leg and the fourth inner leg are valley-folded to the other side in the first direction, the second inner leg is located on one side in the third direction relative to the first central plate and the fourth inner leg is located on one side in the third direction relative to the second central plate.

8. In the three-dimensional structure described in claim 7, The aforementioned leg structure is further deformable between the unfolded state and the folded state. In the folded state, the first central plate and the second central plate are folded in a mountain fold to the other side in the third direction and superimposed on each other, the first inner leg and the second inner leg are folded in a mountain fold to the other side in the third direction and superimposed on each other, the first inner leg and the first outer leg are located on one side in the first direction relative to the first central plate, the second inner leg and the second outer leg are located on one side in the first direction relative to the second central plate, the first outer leg and the second outer leg are superimposed on each other, the third inner leg and the fourth inner leg are folded in a mountain fold and superimposed on each other, the third inner leg and the third outer leg are located on the other side in the first direction relative to the first central plate, the fourth inner leg and the fourth outer leg are located on the other side in the first direction relative to the second central plate, and the third outer leg and the fourth outer leg are superimposed on each other.

9. In the three-dimensional structure according to claim 6 or 7, A three-dimensional structure in which the first inner leg, second inner leg, third inner leg, and fourth inner leg support the central portion.

10. In the three-dimensional structure described in claim 7, A first arm extending from the first outer leg, A second arm extending from the second outer leg, A third arm extending from the third outer leg, It further comprises a fourth arm extending from the fourth outer leg, In the upright position, the first arm and the second arm extend beyond the central portion to the other side in the third direction, and the third arm and the fourth arm extend beyond the central portion to the other side in the third direction. A three-dimensional structure in which, in the deployed state, the first arm and the second arm are arranged along the central portion, and the third arm and the fourth arm are also arranged along the central portion.

11. In the three-dimensional structure described in claim 7, A first arm which is a long plate or rod, A second arm which is a long plate or rod, A third arm which is a long plate or rod, It further comprises a fourth arm which is a long plate or rod, The first central plate is provided with a first support hole or first notch that penetrates the first central plate, and a third support hole or third notch that penetrates the first central plate. The second central plate is provided with a second support hole and / or a second notch that penetrates the second central plate, and a fourth support hole or fourth notch that penetrates the second central plate. The first arm is inserted through the first support hole or first notch of the first central plate, The third arm is inserted through the third support hole or the third notch of the first central plate. The second arm is inserted through the second support hole or the second notch of the second central plate. A three-dimensional structure in which the fourth arm is inserted through the fourth support hole or the fourth notch of the second central plate.

12. In the three-dimensional structure according to claim 11, The first outer leg is provided with a first support hole or a first notch that penetrates the first outer leg, The second outer leg is provided with a second support hole or a second notch that penetrates the second outer leg, The third outer leg is provided with a third support hole or a third notch that penetrates the third outer leg, The fourth outer leg is provided with a fourth support hole or a fourth notch that penetrates the fourth outer leg, The first arm is inserted through the first support hole or first notch of the first central plate and the first support hole or first notch of the first outer leg, The third arm is inserted through the third support hole or third notch of the first central plate and the third support hole or third notch of the third outer leg. The second arm is inserted through the second support hole or second notch of the second central plate and the second support hole or second notch of the second outer leg, A three-dimensional structure in which the fourth arm is inserted through the fourth support hole or fourth notch of the second central plate and the fourth support hole or fourth notch of the fourth outer leg.

13. In the three-dimensional structure according to claim 10, 11, or 12, The first connecting section and It further includes a second connecting section, A three-dimensional structure in which the first connecting portion connects the first arm and the third arm and the second connecting portion connects the second arm and the fourth arm, the first connecting portion connects the first arm and the second arm and the second connecting portion connects the third arm and the fourth arm, or the first connecting portion connects the first arm and the fourth arm and the second connecting portion connects the second arm and the third arm.

14. In the three-dimensional structure according to claim 12, A first connecting portion that connects the first arm and the third arm, It further comprises a second connecting portion that connects the second arm and the fourth arm, The first support hole of the first outer leg is a hole that is approximately circular or approximately elliptical in shape. The first notch of the first outer leg has a first hole that is substantially circular or substantially elliptical, and a second hole that extends from the first hole of the first notch of the first outer leg in the other direction of the second direction and opens in the other direction of the second direction. In the unfolded state, the first support hole of the first central plate is positioned at a distance from the first support hole of the first outer leg or the first hole of the first notch to the other side in the first direction, and is an elongated hole extending to the other side in the first direction. In the unfolded state, the first notch of the first central plate has a first hole and a second hole that extends from the first hole of the first notch of the first central plate in the other direction of the second direction and opens in the other direction of the second direction, wherein the first hole of the first notch of the first central plate is an elongated hole that is spaced apart on the other side of the first direction from the first support hole of the first outer leg or the first hole of the first notch and extends in the other direction of the first direction, The third support hole of the third outer leg is a hole that is approximately circular or approximately elliptical in shape. The third notch of the third outer leg has a first hole that is substantially circular or substantially elliptical, and a second hole that extends from the first hole of the third notch of the third outer leg in the other direction of the second direction and opens in the other direction of the second direction. In the unfolded state, the third support hole of the first central plate is positioned at a distance from the third support hole of the third outer leg or the first hole of the third notch to one side in the first direction, and is an elongated hole extending to one side in the first direction. In the unfolded state, the third notch of the first central plate has a first hole and a second hole that extends from the first hole of the third notch of the first central plate in the other direction of the second direction and opens in the other direction of the second direction, and the first hole of the third notch of the first central plate is an elongated hole that is spaced apart on one side in the first direction from the third support hole of the third outer leg or the first hole of the third notch and extends in one direction of the first direction. The first arm has a hanging portion that extends linearly in a direction including the third direction component, and a tip portion that is bent relative to the hanging portion of the first arm and extends from the hanging portion of the first arm in one of the first directions, wherein the hanging portion of the first arm is inserted through the first support hole of the first central plate or the first hole of the first notch, and the tip portion of the first arm is inserted through the first support hole of the first central plate or the first hole of the first notch in the upright state. The third arm has a hanging portion that extends linearly in a direction including the component of the third direction, and a tip portion that is bent relative to the hanging portion of the third arm and extends from the hanging portion of the third arm in the other direction of the first direction, wherein the hanging portion of the third arm is inserted through the third support hole of the first central plate or the first hole of the third notch, and the tip portion of the third arm is inserted through the third support hole of the third outer leg or the first hole of the third notch in the upright state. The second support hole of the second outer leg is a hole that is approximately circular or approximately elliptical in shape. The second notch of the second outer leg has a first hole that is substantially circular or substantially elliptical, and a second hole that extends from the first hole of the second notch of the second outer leg in one of the second directions and opens in one of the second directions. In the unfolded state, the second support hole of the second central plate is positioned at a distance from the second support hole of the second outer leg or the first hole of the second notch to the other side in the first direction, and is an elongated hole extending to the other side in the first direction. In the unfolded state, the second notch of the second central plate has a first hole and a second hole that extends from the first hole of the second notch of the second central plate in one direction of the second direction and opens in one direction of the second direction, wherein the first hole of the second notch of the second central plate is an elongated hole that is spaced apart on the other side of the first direction from the second support hole of the second outer leg or the first hole of the second notch and extends in the other direction of the first direction. The fourth support hole of the fourth outer leg is a hole that is approximately circular or approximately elliptical in shape. The fourth notch of the fourth outer leg has a first hole that is substantially circular or substantially elliptical, and a second hole that extends from the first hole of the fourth notch of the fourth outer leg in one of the second directions and opens in one of the second directions. In the unfolded state, the fourth support hole of the second central plate is positioned at a distance from the fourth support hole of the fourth outer leg or the first hole of the fourth notch on one side in the first direction, and is an elongated hole extending in one side in the first direction. In the unfolded state, the fourth notch of the second central plate has a first hole and a second hole that extends from the first hole of the fourth notch of the second central plate in one direction of the second direction and opens in one direction of the second direction, wherein the first hole of the fourth notch of the second central plate is an elongated hole that is spaced apart in one direction of the first direction from the fourth support hole of the fourth outer leg or the first hole of the fourth notch and extends in one direction of the first direction. The second arm has a hanging portion that extends linearly in a direction including the third direction component, and a tip portion that is bent relative to the hanging portion of the second arm and extends from the hanging portion of the second arm in one of the first directions, wherein the hanging portion of the second arm is inserted through the second support hole of the second central plate or the first hole of the second notch, and the tip portion of the second arm is inserted through the second support hole of the second central plate or the first hole of the second notch in the upright state. The fourth arm is a three-dimensional structure having a hanging portion that extends linearly in a direction including the component of the third direction, and a tip portion that is bent relative to the hanging portion of the fourth arm and extends from the hanging portion of the fourth arm in the other direction of the first direction, wherein the hanging portion of the fourth arm is inserted through the fourth support hole of the second central plate or the first hole of the fourth notch, and the tip portion of the fourth arm is inserted through the fourth support hole of the fourth outer leg in the upright state or the first hole of the fourth notch.

15. In the three-dimensional structure described in claim 13, A three-dimensional structure further comprising a support portion supported by the first connecting portion and the second connecting portion.

16. A three-dimensional structure that can be deformed between an upright state and a folded state, It comprises a central section, a first leg structure, and a second leg structure. The aforementioned central portion has a first central plate and a second central plate adjacent to each other in a second direction substantially perpendicular to the first direction, The first central plate has a first inner edge on one side in the second direction, a first hypotenuse, and a third hypotenuse. The second central plate has a second inner edge on the other side in the second direction, a second hypotenuse, and a fourth hypotenuse. The first inner edge of the first central plate and the second inner edge of the second central plate are rotatably connected, the first and second hypotenuses are arranged in a roughly convex V-shape or roughly V-shape on one side of the first direction in the upright position, and the third and fourth hypotenuses are arranged in a roughly convex V-shape or roughly V-shape on the other side of the first direction in the upright position. The first leg structure comprises a plate-shaped first support leg and a plate-shaped second support leg. The first support leg has a first slanted side that is rotatably connected to the first slanted side of the central part, and a first side on one side in the second direction. The second support leg has a second slanted side that is rotatably connected to the second slanted side of the central part, and a second side on the other side in the second direction, and the first side of the first support leg and the second side of the second support leg are rotatably connected. The second leg structure has a plate-shaped third support leg and a plate-shaped fourth support leg. The third support leg has a third slanted side that is rotatably connected to the third slanted side of the central part, and a third side on one side in the second direction. The fourth support leg has a fourth slanted side that is rotatably connected to the fourth slanted side of the central part, and a fourth side on the other side in the second direction, and the third side of the third support leg and the fourth side of the fourth support leg are rotatably connected. In the upright position, the first central plate and the second central plate are unfolded into a substantially plate shape, the first support leg is bent and standing upright in one direction of a third direction substantially perpendicular to the first and second directions relative to the first central plate, the second support leg is bent and standing upright in one direction of a third direction relative to the second central plate, the first support leg and the second support leg are folded in a mountain fold to one side of the first direction, the third support leg is bent and standing upright in one direction of a third direction relative to the first central plate, the fourth support leg is bent and standing upright in one direction of a third direction relative to the second central plate, and the third support leg and the fourth support leg are folded in a mountain fold to the other side of the first direction. A three-dimensional structure in which, in the folded state, the first central plate and the second central plate are folded in a mountain fold to the other side in the third direction and overlapped with each other, the first support leg and the second support leg are folded in a mountain fold to the other side in the third direction and overlapped with each other, the first support leg is located on one side in the first direction with respect to the first central plate, the second support leg is located on one side in the first direction with respect to the second central plate, the third support leg and the fourth support leg are folded in a mountain fold to the other side in the third direction and overlapped with each other, the third support leg is located on the other side in the first direction with respect to the first central plate, and the fourth support leg is located on the other side in the first direction with respect to the second central plate.

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