Buffer structure and floor material

Abstract

A buffer structure 100 comprises: a top plate 11 having an upper surface for receiving a load; a plurality of leg parts 12 arranged along the periphery of the top plate 11, each of which extends in the -Z direction from the lower surface of the top plate 11 and has a cross-sectional shape that is convexly bent in a radial direction with respect to the center of the top plate 11 in an XY plane; and a bottom surface 17 connected to the tip of each of the plurality of leg parts 12 and having an opening 17a at the center. Accordingly, the displacement stroke in the -Z direction of the top plate 11 can be maximized, and the buffer structure 100 can be made thinner with less material while maintaining a buffering effect.

Description

Cushioning structures and flooring

[0001] The present invention relates to a shock-absorbing structure and a flooring material equipped with a shock-absorbing structure.

[0002] To prevent injuries such as fractures of the femur (especially the intertrochanter) caused by falls while walking on the floor, cushioning materials are known that are installed beneath the floor surface to absorb the impact of falls. For example, Patent Document 1 discloses a flooring material comprising a foamed layer molded using a foam material such as polyurethane. The elastic modulus of such a foamed layer increases linearly with respect to the applied load. Therefore, if the elastic modulus is set high (small displacement, i.e., hard) for small loads applied during walking, stability during walking is maintained, but it will not be able to absorb large impacts during falls, leading to fractures. Conversely, if the elastic modulus is set low (large displacement, i.e., soft) to absorb large impacts during falls, it will displace softly even with small loads during walking, making walking difficult. Therefore, there is a need for a cushioning structure and flooring material that has a high elastic modulus (i.e., hard) for small loads during walking and a low elastic modulus (i.e., soft) for large impacts during falls (see Patent Document 2). Furthermore, it is also important to construct the cushioning structure thinly with less material while maintaining the cushioning effect (see Patent Document 3). Patent Document 1: Japanese Unexamined Patent Publication No. 2019-178519 Patent Document 2: Japanese Unexamined Patent Publication No. 2022-114615 Patent Document 3: International Publication No. 2024 / 128197 General disclosure

[0003] (Item 1) A shock-absorbing structure may be provided. The shock-absorbing structure may include a top plate having a load-bearing top surface. The shock-absorbing structure may include a plurality of legs arranged around the perimeter of the top plate, each having a cross-sectional shape that extends in a first direction from the underside of the top plate and is bent convexly in a second direction with respect to the center of the top plate in a plane intersecting the first direction. The shock-absorbing structure may include a bottom surface connected to the ends of each of the plurality of legs and having an opening in the center. (Item 2) The opening may have a shape that extends from the center of the bottom surface toward each of the plurality of legs. (Item 3) At least one of the plurality of legs may be inclined in the opposite direction to the second direction with respect to the underside of the top plate. (Item 4) At least one of the plurality of legs may have a tip with a shape similar to the cross-sectional shape. (Item 5) At least one of the plurality of legs may have a cross-sectional shape that is bent convexly in the second direction. (Item 6) At least one of the plurality of legs may have a recess formed in at least a part of the corner in the second direction. (Item 7) At least one of the plurality of legs may have a recess formed in at least a part of at least one of the two sides. (Item 8) The at least one side may face a direction rotated in the second direction with respect to the direction facing the side of an adjacent leg among the plurality of legs. (Item 9) Two adjacent legs among the plurality of legs may form a gap between them. The bottom surface may have a notch that connects to the gap. (Item 10) The top plate may have a frame shape including an opening in the center. (Item 11) The top plate may have a polygonal shape. The plurality of legs may each be arranged at the corner of the top plate. (Item 12) The tabletop may include overhangs that extend outward from the points where the plurality of legs are connected. (Item 13) The tabletop may have a first wall surface that extends in the first direction from the overhangs located on at least one side of the tabletop.(Item 14) The buffer structure according to Item 13, wherein the top plate has a second wall surface that extends in the first direction from the overhang located on another side adjacent to the at least one side and is spaced apart from the side surface of the first wall surface to form a slit between itself and the first wall surface.

[0004] (Item 15) A flooring material may be provided comprising a surface material and a buffer structure according to any one of Items 1 to 14 that supports the surface material and is placed on the ground beneath the floor.

[0005] It should be noted that the above summary of the invention does not enumerate all of its features. Furthermore, subcombinations of these features may also constitute an invention.

[0006] The overall structure of the buffer structure according to this embodiment is shown in an oblique view. The overall structure of the unit structure constituting the buffer structure is shown in an oblique view. The internal structure of the unit structure is shown in an oblique view, with some parts omitted. The structure of the unit structure is shown in a top view. The structure of the unit structure is shown in a bottom view. The structure of the unit structure is shown in a side view. The buffering principle of the buffer structure (unit structure) (unloaded state) is shown. The buffering principle of the buffer structure (unit structure) (contracted state) is shown. The buffering principle of the buffer structure (unit structure) (closed leg state) is shown. The buffering principle of the buffer structure (unit structure) (buckling state) is shown. The buffering principle of the buffer structure (unit structure) (torsional state) is shown. The cross-sectional structure of the floor material equipped with the buffer structure according to this embodiment is shown. The side structure of the buffer structure according to this embodiment is shown in an oblique view. The side structure of the buffer structure according to this embodiment is shown in a bottom view. The overall structure of the unit structure constituting the buffer structure according to a modified example is shown in an oblique view. The structure of the unit structure according to a modified example is shown in a top view.

[0007] The present invention will be described below through embodiments, but these embodiments are not intended to limit the scope of the claimed invention. Furthermore, not all combinations of features described in the embodiments are necessarily essential to the solution of the invention.

[0008] In embodiments of the present invention, the size of a component may be described using the term "approximately." It should be noted that this means that the size is correct at least within the significant figures (significant digits), but includes uncertainty outside the significant figures. For example, approximately 1 mm includes uncertainty of about 0.1 mm.

[0009] Figure 1 shows a perspective view of the overall structure of the buffer structure 100 according to this embodiment. Here, the thickness direction of the buffer structure 100 is the Z-axis direction, and the mutually orthogonal directions in a plane perpendicular to it are the X-axis direction and the Y-axis direction. The buffer structure 100 constitutes a floor material that supports the floor surface on a subfloor S (see Figure 3A, etc.) as an example, and mitigates the impact applied to the floor surface. Here, the subfloor S may be one surface of a floor slab (concrete slab) in a reinforced concrete building, one surface on which flooring or the like is laid, a floorboard in a wooden building, the ground, etc., which have a walking surface on which people walk. In particular, the buffer structure 100 is a structure that is hard against small loads during walking, enabling stable walking, and soft against large impacts during falls, absorbing the impact and preventing fractures.

[0010] The buffer structure 100 is constructed by integrally connecting unit structures 10 having a thickness in the Z-axis direction via the protruding portions 11b of each other's top plates 11, arranging multiple units in a single row in the X-axis direction or the Y-axis direction, or arranging multiple units in a matrix in the XY direction. In this embodiment, the buffer structure 100 is composed of a total of nine unit structures 10, three of which are arranged in the X-axis direction and three in the Y-axis direction. However, the number of unit structures 10 arranged in the X-axis direction and the Y-axis direction can be arbitrarily determined, and the lengths of the buffer structure 100 in the X-axis direction and the Y-axis direction can also be arbitrarily determined.

[0011] Figures 2A to 2E show the structure of the unit structure 10 that constitutes the buffer structure 100. The unit structure 10 is the smallest constituent unit of the buffer structure 100. Here, Figure 2A shows the overall structure of the unit structure 10 in a perspective view, Figure 2B shows the internal structure of the unit structure 10 in a perspective view with some parts omitted, Figure 2C shows the structure of the unit structure 10 in a top view, Figure 2D shows the structure of the unit structure 10 in a bottom view, and Figure 2E shows the structure of the unit structure 10 in a side view. The unit structure 10 has a top plate 11, a plurality of legs 12, and a bottom surface 17.

[0012] The top plate 11 is a member having an upper surface that receives a load. In this embodiment, the top plate 11 is rectangular (particularly square). However, the shape of the top plate 11 may be a hexagon or other polygon, for example, as long as it is a shape suitable for arranging a plurality of unit structures 10 in one axis direction or two axis directions. As a result, the unit structures 10 can be densely arranged in a polygonal grid, such as a square grid if the top plate 11 is rectangular, or a hexagonal grid if the top plate 11 is hexagonal.

[0013] The size of the tabletop 11 is set to be sufficiently smaller than the area over which a person (including children as well as adults) bears weight when walking on the floor, that is, the area of ​​the soles of the feet that come into contact with the floor when walking, and the area of ​​the knees that hit the floor when falling. In this embodiment, as an example, the length of one side of the tabletop 11 W １１ The thickness is approximately 15 mm. This allows the load applied to the floor surface to be absorbed by multiple unit structures 10, preventing injuries such as fractures, not only for adults but also for children who fall on the floor.

[0014] As will be described later, in order to support the surface material 120 etc. that forms the floor surface on the cushioning structure 100, the tabletop 11 is not limited to a flat plate shape that extends across one surface, but may also have a frame shape that includes an opening 11a in the center, as long as it can receive the load applied to the unit structure 10 via the surface material 120 etc. The shape of the opening 11a may be circular (it may also be elliptical), rectangular (including square), hexagonal, or other polygonal shape. A tabletop 11 with a plate shape has somewhat strong rigidity, making it difficult for the legs 12 to tilt relative to the tabletop 11, whereas a tabletop 11 with a frame shape has moderately low rigidity, making it easy for the legs 12 to tilt and buckle relative to the tabletop 11, thereby becoming softer against large impacts in the event of tipping over and being able to absorb the impact.

[0015] Furthermore, by inserting the multiple legs 12 of multiple unit structures 10 included in another cushioning structure 100 between the multiple legs 12 through the opening 11a of the top plate 11, multiple cushioning structures 100 can be stacked with a small thickness in the Z-axis direction.

[0016] In this embodiment, the tabletop 11 is a rectangular (particularly square) frame containing a rectangular opening 11a in the center. The tabletop 11 has an overhang 11b that extends outward (in the ±X and ±Y directions) from the inner edge that demarcates the opening 11a, where the legs 12 described later are connected. The width w of the overhang 11b １１ｂ The width of the inner edge to which the leg portion 12 connects may be approximately the same as or greater than the width of the inner edge portion to which the leg portion 12 connects. In this embodiment, the width of the inner edge portion is, for example, the thickness d of the leg portion 12. １２ It is set to approximately 0.8 mm, which is roughly equal to the width of the protruding part 11b. In other words, the frame width w of the top plate 11 １１ This is set to approximately 1.6 mm. This increases the support surface, allowing for stable support of the upper layer 120, etc.

[0017] Also, the thickness d of the protruding portion 11b １１ The thickness d of the leg portion 12 is １２ It may be equal to or less than. In this embodiment, the thickness d of the leg portion 12 １２is set to 0.8 mm, which is substantially equal to the aforementioned value. Accordingly, since the thickness of the overhanging portion 11b is relatively small, the rigidity of the top plate 11 is moderately reduced, so that the leg portions 12 are inclined relative to the top plate 11 and easily buckle, thereby increasing the deformation stroke of the top plate 11 displaced in the Z-axis direction.

[0018] The plurality of leg portions 12 are members that extend in the -Z direction from the lower surface of the top plate 11 and support the top plate 11 on the floor substrate S. A plurality of leg portions 12 are provided for each of the top plates 11 of the plurality of unit structures 10 constituting the buffer structure 100, and in particular, a plurality of leg portions 12 are arranged along the periphery of each top plate 11. When the top plate 11 is polygonal, the leg portions 12 are respectively arranged near a plurality of corners, and when the top plate 11 is circular, the leg portions 12 are respectively arranged at at least three positions at arbitrary intervals. Accordingly, when a load is applied to the top plate 11, the load is distributed to the plurality of leg portions 12, so that the top plate 11 can be stably supported.

[0019] The height H of the leg portion 12 １２ can be determined according to the deformation stroke required for absorbing load for one unit structure 10. In this embodiment, as an example, the height H of the leg portion 12 １２ is about 7 mm.

[0020] Each leg portion 12 may extend perpendicularly to the lower surface of the top plate 11, but in this embodiment, it is inclined toward the center of the top plate 11 (or the unit structure 10) (in the opposite radial direction). In a side view in the X-axis direction (see FIG. 2E), the inclination angle θ of the leg portion 12 with respect to the Z axis １２ is 8 to 16 degrees, preferably 10 to 14 degrees, more preferably about 12 degrees. The same applies to the inclination angle of the leg portion 12 in a side view in the Y-axis direction. This makes it easy for the leg portion 12 to buckle in the opposite radial direction, that is, toward the center of the top plate 11.

[0021] Each leg portion 12 has a cross-sectional shape that is bent convexly in the radial direction with respect to the center of the tabletop 11 in the XY plane. The leg portion 12 may be curved convexly in the radial direction, preferably bent convexly in the radial direction. This makes the transition of the deformation mode of the leg portion 12 when a load is applied, i.e., the transition from the expansion / contraction mode to the buckling mode or from the buckling mode to the expansion / contraction mode, clearer. In other words, the characteristic transition of the leg portion 12, which is stiff until the load exceeds the threshold strength and softens thereafter, becomes clearer. Here, the thickness d of the leg portion 12 １２ By selecting this option, the threshold load at which the deformation mode transitions is adjusted. In this example, thickness d is used as an example. １２ Let it be approximately 0.8 mm.

[0022] In this embodiment, since the tabletop 11 is rectangular, the four legs 12 are positioned near the four corners of the tabletop 11, with their convexly curved outer surfaces facing outward in the radial direction relative to the center of the unit structure 10 (or tabletop 11) when viewed from above. That is, the legs 12 positioned near the -X and -Y corners of the tabletop 11 are bent outward from the center of the tabletop 11, that is, convexly at an angle of approximately 90 degrees in the -X and -Y directions (L-shaped from the -X direction to the +Y direction), with their inner surfaces flush with the inner surfaces of the -X and -Y corners of the tabletop 11, and their upper ends connected to the lower surfaces of the -X and -Y corners of the tabletop 11. Furthermore, the legs 12 positioned near the -X and +Y corners of the tabletop 11 are bent outward from the center of the tabletop 11, that is, at a convex angle of approximately 90 degrees in the -X and +Y directions (L-shaped from the +Y direction to the +X direction), with their inner surfaces flush with the inner surfaces of the -X and +Y corners of the tabletop 11, and their upper ends connected to the lower surfaces of the -X and +Y corners of the tabletop 11. Furthermore, the legs 12 positioned near the +X and +Y corners of the tabletop 11 are bent outward from the center of the tabletop 11, that is, at a convex angle of approximately 90 degrees in the +X and +Y directions (L-shaped from the +X direction to the -Y direction), with their inner surfaces flush with the inner surfaces of the +X and +Y corners of the tabletop 11, and their upper ends connected to the lower surfaces of the +X and +Y corners of the tabletop 11. Furthermore, the legs 12 positioned near the +X and -Y corners of the tabletop 11 are bent outward from the center of the tabletop 11, that is, convex at approximately 90 degrees in the +X and -Y directions (L-shaped from the -Y direction to the -X direction), with their inner surfaces flush with the inner surfaces of the +X and -Y corners of the tabletop 11, and their upper ends connected to the lower surfaces of the +X and -Y corners of the tabletop 11. As a result, the tabletop 11 is supported by multiple (four in this example) legs 12 positioned around it, and when a load exceeding the threshold load is applied to the tabletop 11, the legs 12 buckle inward in the radial direction, preventing them from spreading outward and interfering with the legs 12 of adjacent unit structures 10.

[0023] The legs 12 have tip and base ends with shapes similar to the convexly bent cross-sectional shape described above. In other words, the entire leg 12 has a convexly bent cross-sectional shape. As a result, the four legs 12 deform so that their respective bodies (centers in the Z-axis direction) spread out by more than 90 degrees in the XY plane, and the entire structure buckles towards the center of the tabletop 11, allowing the tabletop 11 to be displaced significantly in the -Z direction. Due to the shape of the legs 12, the rigidity of the legs 12 can be maintained until they buckle, even though the amount of material they occupy in space is small.

[0024] Each leg portion 12 has a recess 12a formed in at least a portion of the outer corner in the radial direction relative to the center of the unit structure 10 (or tabletop 11) when viewed from above. This allows each leg portion 12 to bend radially inward, i.e., toward the center of the tabletop 11, starting from the recess 12a, when a load exceeding a threshold load is applied to the tabletop 11 of the unit structure 10.

[0025] Here, the recess 12a is located in the center of the leg portion 12 in the Z-axis direction. In particular, the recess 12a is formed in a wedge shape, becoming deepest in the center of the leg portion 12, from the base end (i.e., the upper end connected to the lower surface of the tabletop 11) to the tip (i.e., the lower end). Maximum width w of the recess 12a １２ａ For example, the depth is approximately 1 mm. The recess 12a may be formed in a concave shape. Alternatively, multiple recesses 12a may be arranged in parallel in the Z-axis direction.

[0026] Furthermore, each leg portion 12 has a recess 12b formed on at least a portion of at least one of its two sides (i.e., the sides located at the two ends that are bent in an L-shape when viewed from above). Here, the recess 12b is located in the center of the leg portion 12 in the Z-axis direction and is formed in a wedge shape in the center of the leg portion 12, close to the corner of the leg portion 12, from the base end (i.e., the upper end that connects to the lower surface of the tabletop 11) to the tip (i.e., the lower end). As a result, the center of the leg portion 12 is formed to be the narrowest point relative to the base and tip, and buckling of the leg portion 12 can be induced at the central position.

[0027] In this embodiment, recesses 12b are provided on both sides of the leg portion 12, but recesses 12b may be provided on only one side, or the depths of the recesses 12b on the two sides of the leg portion 12 may be made different. This makes it possible to guide the rotation of the bottom surface 17, described later, toward the side with the recess 12b or the side with the deeper recess 12b, thereby allowing the leg portion 12 to bend in the XY plane. Furthermore, among the multiple leg portions 12, recesses 12b may be provided on only one side of two adjacent leg portions 12 that form a gap 12c, described later, and the depths of the respective recesses 12b may be made different, and the inclination of each with respect to the top plate 11 may be made different. This allows the legs 12 to bend in the XY plane by inducing the rotation of the bottom surface 17, described later, toward one of the two adjacent sides of the legs 12, toward the side with the recess 12b, toward the side with the deeper recess 12b, or toward the side with the greater inclination.

[0028] Here, the two sides of the leg portion 12 are formed to face a direction that is rotated slightly outward (i.e., radially) with respect to the direction facing the side of the adjacent leg portion 12. This allows the leg portion 12 to be guided to buckle toward the center of the top plate 11. In addition, when the cushioning structure 100 is injection molded, the mold inserted between the two leg portions 12 is easier to withdraw, making the molding of the cushioning structure 100 easier.

[0029] Two adjacent legs 12 of the multiple legs 12 form a gap 12c between them. The gap 12c is narrower between the upper and lower ends of the two legs 12, and wider in the center. As a result, when the multiple legs 12 buckle, the air inside the unit structure 10 can easily flow outward through the gap 12c, moderately reducing the air damper effect and making the legs 12 more prone to buckling.

[0030] The base surface 17 is a plate-like member that connects to the ends of each of the multiple leg portions 12 and forms the base surface of the unit structure 10 between them. Here, the thickness d of the base surface 17 is １７ The thickness d of the top plate 11 (protruding part 11b) １１ and the thickness d of the leg portion 12 １２It is smaller, for example, about 0.5 mm. By providing the bottom surface 17, the deformation modes of the unit structure 10 can be limited to expansion / contraction mode, buckling mode, and torsion mode (see Figures 3A to 3E) without or with reduced influence from friction with the floor base S. In addition, because the bottom surface 17 is thinner than the other parts, it can induce torsional deformation of the leg portion 12 in particular in the torsion mode. The bottom surface 17 has an opening 17a located in the center and notches 17c located on each of its multiple sides.

[0031] The opening 17a has one of the following shapes: circular, rectangular, or cross-shaped. A rectangular shape may be a square with four vertices positioned at the center of the base surface 17, each pointing towards one of the four legs 12 (especially the L-shaped corners). A cross-shaped shape may be a shape that extends from the center of the base surface 17 toward each of the multiple (four in this example) legs (especially the corners). This allows the tips of the multiple legs 12 to move closer together when the opening 17a of the base surface 17 is closed.

[0032] The notch 17c connects to the gap 12c between two adjacent legs 12 among the multiple legs 12. By closing the notch 17c in the base surface 17, the tips of the two legs 12 that form the gap 12c connected to the notch 17c come closer together, allowing the base surface 17 to rotate and the legs 12 to bend and extend as a whole (deforming into a swastika shape, avoiding each other).

[0033] The shape of the notch 17c is, for example, triangular, so that the base 17 has a cross shape in which the width between its outer edge and the inner edge that demarcates the cross-shaped opening 17a is approximately constant. Here, the triangular shape may be an isosceles triangle in which the inclinations of the two slopes toward the center of the base 17 are equal, or it may be a triangle in which the inclinations are different. By having the inclinations of the two slopes of each of the multiple notches 17c be different, and in particular by greatly unifying the inclination of one of the slopes, it is possible to induce rotation of the base 17 in the direction of that one side, as described later, and enable the leg portion 12 to bend.

[0034] 3A to 3E illustrate the buffering principle of the buffer structure 100 (unit structure 10). Here, one unit structure 10 among the plurality of unit structures 10 constituting the buffer structure 100 is exemplified. The upper and lower parts of FIG. 3A show the unit structure 10 in an unloaded state in a top view and a side view, respectively. The unit structure 10 is installed on the floor substrate S. The top plate 11 of the unit structure 10 has its height H supported by four leg portions 12 １２ (see FIG. 2E).

[0035] The upper and lower parts of FIG. 3B show the unit structure 10 in a contracted state in a top view and a side view, respectively. A downward load (in the direction of the outlined arrow) is applied from the upper surface side of the top plate 11. However, the load is smaller than a predetermined threshold load. In such a case, the four leg portions 12 supporting the top plate 11 contract somewhat in the Z-axis direction, and lower the top plate 11 somewhat downward (in the direction of the solid black arrow) to absorb the load.

[0036] The upper and lower parts of FIG. 3C show the unit structure 10 in a leg-closed state in a top view and a side view, respectively. Assume that the load applied to the top plate 11 (outlined arrow) exceeds the threshold load and becomes large. In such a case, the four leg portions 12 supporting the top plate 11 tilt at the connecting portions with the top plate 11 (in the direction of the small solid black arrow), and slide their tips on the floor substrate S in the horizontal direction (in the direction of the small solid black arrow) to approach each other inward and deform so as to close. Thereby, the bottom surface 17 deforms within the plane to close the cross-shaped opening 17a, and the top plate 11 is lowered somewhat downward (in the direction of the large solid black arrow) to absorb the load.

[0037] In the upper and lower rows of FIG. 3D, the unit structure 10 in a buckled state is shown in a top view and a side view, respectively. Assume that the load applied to the top plate 11 (indicated by the white-filled arrow) exceeds the threshold load and further increases. In such a case, the four legs 12 supporting the top plate 11 deform such that their tips slide on the floor base S in the horizontal direction (the direction of the small black-filled arrow) to approach each other inwardly and close. Thereby, the bottom surface 17 deforms within the plane, and the triangular notch 17c closes. Furthermore, the four legs 12 bend toward the inner side of the unit structure 10 (the direction of the small black-filled arrow) (i.e., buckle) while expanding their convexly curved cross-sections in the XY plane particularly at respective central portions, thereby being largely displaced in the Z-axis direction and becoming soft. Accordingly, the top plate 11 is greatly lowered downward (in the direction of the large black-filled arrow).

[0038] In the upper and lower rows of FIG. 3E, the unit structure 10 in a twisted state is shown in a top view and a side view, respectively. Assume that the load applied to the top plate 11 (indicated by the white-filled arrow) further increases. The bottom surface 17 rotates counterclockwise, and the four legs 12 supporting the top plate 11 extend while bending the whole body with their respective tips directed toward the rotation direction of the bottom surface (the direction of the small black-filled arrow), that is, the four legs 12 avoid each other so as not to overlap in the Z-axis direction, and undergo swastika-shaped torsional deformation in the XY plane. When a further load is applied to the top plate 11, the four legs 12 contract in the Z-axis direction, thereby displacing the top plate 11 further downward (in the direction of the large black-filled arrow) to cushion a large load.

[0039] The threshold load is set to be larger than the load applied to the top plate 11 during walking and smaller than the load applied to the top plate 11 during a fall. Thereby, the cushioning structure 100 (the unit structure 10) is hard against a small load less than the threshold load applied during walking, provides stability during walking, and is soft against a large impact equal to or greater than the threshold load during a fall. Particularly, after the four legs buckle, they avoid each other so as not to overlap with one another and undergo torsional deformation to maximize the displacement stroke of the top plate 11 in the Z-axis direction, thereby absorbing large impacts.

[0040] Figure 4 shows the cross-sectional structure of the flooring material 200 equipped with the cushioning structure 100 according to this embodiment. The flooring material 200 comprises a surface material 120, an intermediate material 110, and the cushioning structure 100.

[0041] The surface material 120 is a layered material whose upper surface forms the floor surface (i.e., the walking surface). The surface material 120 may be made of hard materials such as wood, plywood, stone, vinyl chloride, cushion flooring, tiles, carpet, cork, or long sheets to provide walking surface. The surface material 120 may also be integrally formed with the intermediate material 110.

[0042] The intermediate material 110 is a layered material placed between the surface material 120 and the cushioning structure 100 to smooth out the unevenness of the upper surface of the cushioning structure 100 arranged on the floor base S. As an example, the intermediate material 110 may be a foamed layer molded using a foam material such as polyurethane. The intermediate material 110 is placed across at least two cushioning structures 100. This distributes the localized load applied to the surface material 120 across the multiple cushioning structures 100.

[0043] Multiple buffer structures 100 are arranged on the floor base S and support the surface material 120 and the intermediate material 110. The buffer structures 100 are configured as described above and absorb the load applied through the surface material 120.

[0044] Here, in the buffer structure 100, when a large load exceeding the threshold load is applied to the top plate 11 and the unit structures 10 constituting the buffer structure 100 deform and transition to a torsional mode (see Figure 3E), recesses 12b may be formed on the side surface of the leg portion 12 so that the bottom surfaces 17 of adjacent unit structures 10 rotate in the same direction, the depth of the recesses 12b may be selected, the inclination of the side surface may be selected, or a notch 17c may be formed on the bottom surface 17. By having the bottom surfaces 17 of adjacent unit structures 10 rotate in the same direction, interference between them can be prevented when the leg portions 12 of adjacent unit structures 10 undergo twist deformation in a swastika shape. Alternatively, when transitioning to a torsional mode (see Figure 3E), recesses 12b may be formed on the side surface of the leg portion 12 so that the bottom surfaces 17 of adjacent unit structures 10 rotate in different directions, the depth of the recesses 12b may be selected, the inclination of the side surface may be selected, or a notch 17c may be formed on the bottom surface 17. By allowing the bottom surfaces 17 of adjacent unit structures 10 to rotate in different directions, it is possible to prevent the top plate 11 from tilting in the same direction relative to each of the bottom surfaces 17.

[0045] Figures 5A and 5B show the side structure of the buffer structure 100 according to this embodiment in an oblique view and a bottom view, respectively. The buffer structure 100 is composed of a plurality of unit structures 10 arranged in a matrix in the XY direction, and in this example in particular, these arrangements terminate at the -X end and the -Y end. Here, the top plate 11 of the unit structure 10 located at the -X end has a wall surface 21 extending in the -Z direction from an overhang 11b located on the -X side of the top plate 11. The top plate 11 of the unit structure 10 located at the -Y end has a wall surface 22 extending in the -Z direction from an overhang 11b located on the -Y side of the top plate 11. The wall surfaces 21 and 22 prevent water flowing over the floor substrate S from entering the interior of the buffer structure 100.

[0046] Among the multiple unit structures 10 included in the buffer structure 100, for example, the top plate 11 of the unit structure 10 located at the -X and -Y corners has both a wall surface 21 extending in the -Z direction from an overhang 11b located on the -X side of the top plate 11 and a wall surface 22 extending in the -Z direction from an overhang 11b located on the -Y side adjacent to the -X side. Here, the wall surface 22 is spaced apart from the wall surface 21, forming a slit 20a between them. The width of the slit 20a is set to a size such that the wall surfaces 21 and 22 do not interfere with each other when a load is applied to the unit structure 10, causing it to buckle and the leg portion 12 to twist and deform, causing the top plate 11 to be displaced significantly in the -Z direction. This prevents water and the like from entering the inside of the buffer structure 100 with the wall surfaces 21 and 22, and allows the buffer structure 100 to deform in the -Z direction without them interfering with each other with the slit 20a between the wall surfaces 21 and 22.

[0047] The cushioning structure 100 according to this embodiment can be manufactured by injection molding. Here, the top plate 11, the legs 12, and the bottom surface 17 are integrally molded. The cushioning structure 100 is formed using an elastic material such as NR rubber or thermoplastic elastomer so that when released from a load, the buckled legs 12 restore to their upright position. As a result, the legs 12 have a rubber hardness of 10 to 100, preferably 50 to 80.

[0048] With the floor material 200 configured as described above, when a load is applied from the upper surface side of the top plate 11 to the cushioning structure 100 placed on the floor surface S, the legs 12 contract in the -Z direction to absorb the load until the load exceeds a threshold (contraction mode in Figure 3B). When the load exceeds the threshold, the tips of the legs 12 move closer together and close the opening 17a of the bottom surface 17 (closed leg mode in Figure 3C), and the convexly bent cross section in the XY plane widens as it bends toward the center (i.e., buckles) and displaces significantly, becoming softer (buckling mode in Figure 3D). Further load application causes the bottom surface 17 to rotate, and the tips of the legs 12 point in that direction and extend while bending the entire structure (avoiding each other and twisting in a swastika shape) (twisting mode in Figure 3E), thereby further displacing the top plate 11 in the -Z direction and cushioning a large load.

[0049] The cushioning structure 100 according to this embodiment comprises a top plate 11 having a load-bearing upper surface, and a plurality of legs 12 arranged around the top plate 11, each of which extends in the -Z direction from the lower surface of the top plate 11 and has a cross-sectional shape that is bent convexly in the radial direction with respect to the center of the top plate 11 in the XY plane, and a bottom surface 17 connected to the tip of each of the plurality of legs 12, with an opening 17a in the center. This maximizes the displacement stroke of the top plate 11 in the -Z direction, and allows the cushioning structure 100 to be made thin with less material while maintaining the cushioning effect.

[0050] The flooring material 200 according to this embodiment comprises a surface material 120 and a cushioning structure 100 that supports the surface material 120 and is placed on the subfloor S. By supporting the surface material 120 on the subfloor S with the cushioning structure 100, the flooring material 200 is rigid against small loads applied during walking, providing stability during walking, and soft against large impacts during falls, allowing it to displace significantly and absorb the impact.

[0051] Figures 6A and 6B show the overall structure of the unit structure 10d constituting the modified buffer structure 100 in an oblique view and a top view, respectively. The unit structure 10d has a top plate 11, a plurality of legs 12, and a bottom surface 17. The top plate 11 and the plurality of legs 12 are constructed in the same way as those in the unit structure 10 described above. The bottom surface 17 is also constructed in the same way as those in the unit structure 10 described above, except that a plurality of protrusions 17b are arranged on the upper surface of the bottom surface 17. The plurality of protrusions 17b are, for example, hemispherical and are arranged between a cross-shaped opening 17a and an L-shaped bent corner of the leg 12. This prevents the upper surface of the bottom surface 17 from coming into close contact with the lower surface of the intermediate material 110 (especially when no opening 17a is formed in the bottom surface 17) when a large load is applied to the unit structure 10d, causing it to buckle and the legs 12 to twist and deform, causing the top plate 11 to be displaced significantly in the -Z direction. This allows the unit structure 10d to extend its legs 12 in the Z-axis direction and return to its original shape when the load is released.

[0052] Although the present invention has been described above using embodiments, the technical scope of the present invention is not limited to the scope described in the above embodiments. It will be apparent to those skilled in the art that various modifications or improvements can be made to the above embodiments. It will be clear from the claims that such modified or improved forms may also be included in the technical scope of the present invention.

[0053] It should be noted that the execution order of operations, procedures, steps, and stages in the devices, systems, programs, and methods shown in the claims, specifications, and drawings is not explicitly stated as "before," "prior to," etc., and that these can be performed in any order unless the output of a previous process is used in a later process. Even if the operation flow in the claims, specifications, and drawings is described using phrases such as "first," "next," etc. for convenience, this does not mean that it is mandatory to perform the operations in that order.

[0054] 10, 10d...unit structure, 11...top plate, 11a...opening, 11b...protruding part, 12...leg part, 12a, 12b...recess, 12c...gap, 17...bottom surface, 17a...opening, 17b...protrusion, 17c...notch, 20a...slit, 21, 22...wall surface, 100...cushion structure, 110...intermediate material, 120...surface material, 120...top layer, 200...flooring material, S...floor base (floor surface).

Claims

1. A shock-absorbing structure comprising: a top plate having a load-bearing upper surface; a plurality of legs arranged around the perimeter of the top plate, each of which extends in a first direction from the lower surface of the top plate and has a cross-sectional shape that is bent convexly in a second direction with respect to the center of the top plate in a plane intersecting the first direction; and a bottom surface connected to the tip of each of the plurality of legs and having an opening in the center.

2. The cushioning structure according to claim 1, wherein the opening has a shape that extends from the center of the bottom surface toward each of the plurality of legs.

3. The buffer structure according to claim 1, wherein at least one of the plurality of legs is inclined in the opposite direction to the second direction with respect to the underside of the top plate.

4. The buffer structure according to claim 1, wherein at least one of the plurality of legs has a tip shape similar to the cross-sectional shape.

5. The buffer structure according to claim 1, wherein at least one of the plurality of legs has a cross-sectional shape that is bent convexly in the second direction.

6. The buffer structure according to claim 1, wherein at least one of the plurality of legs has a recess formed in at least a portion of the corner in the second direction.

7. The cushioning structure according to claim 1, wherein at least one of the plurality of legs has a recess formed on at least a portion of at least one of the two sides.

8. The buffer structure according to claim 7, wherein at least one side faces a direction rotated in the second direction with respect to the direction facing the side of an adjacent leg among the plurality of legs.

9. The buffer structure according to claim 7, wherein two adjacent legs among the plurality of legs form a gap between them, and the bottom surface has a notch connected to the gap.

10. The cushioning structure according to claim 1, wherein the top plate has a frame shape including an opening in the center.

11. The cushioning structure according to claim 1, wherein the top plate has a polygonal shape, and the plurality of legs are each arranged at the corners of the top plate.

12. The cushioning structure according to claim 11, wherein the top plate includes an overhang that extends outward from the point where the plurality of legs are connected.

13. The buffer structure according to claim 12, wherein the top plate has a first wall surface extending in the first direction from the overhang located on at least one side of the top plate.

14. The buffer structure according to claim 13, wherein the top plate has a second wall surface that extends in the first direction from the overhang located on another side adjacent to the at least one side and is spaced apart from the side surface of the first wall surface to form a slit between itself and the first wall surface.

15. A flooring material comprising a surface material and a buffer structure according to any one of claims 1 to 14 that supports the surface material and is disposed on the ground beneath the floor.

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