Shoe sole, and shoe comprising the same

Abstract

To improve stability at the time of landing in a shoe sole in which two plates are oppositely arranged via a cushion layer.SOLUTION: A shoe sole 10 comprises a cushion layer 20, an upper plate, and a lower plate. The cushion layer 20 has: a first region A1 that is a portion supporting MP joints of a foot of a wearer; and a second region A2 included in a portion on a rear side of the first region A1 and on a front side of a rear foot part R3. The second region A2 includes in a left-right direction: a third region A3 located in a central part; a fourth region A4 located in an inner foot side end part; and a fifth region A5 located in an outer foot side end part. Both compression rigidity in the fourth region A4 and compression rigidity in the fifth region A5 are made lower than compression rigidity in the first region A1. Compression rigidity in the third region A3 is made lower than both the compression rigidity in the fourth region A4 and the compression rigidity in the fifth region A5.SELECTED DRAWING: Figure 14

Description

[Technical Field]

[0001] The present disclosure relates to a shoe sole and a shoe including the same. [Background technology]

[0002] BACKGROUND ART In recent years, shoes have become popular that are equipped with a high-rigidity plate in the sole, and that utilize the restoring force of the plate to improve forward propulsion during running, etc.

[0003] In particular, in shoes for short distance racing, a spike plate with spikes is provided on the ground surface side, and the above-mentioned high-rigidity plate is generally provided inside the sole so as to face the spike plate via a cushion layer. For example, U.S. Patent Publication No. 2021 / 0378358 (Patent Document 1) discloses this type of shoe. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] U.S. Patent Publication No. 2021 / 0378358 Summary of the Invention [Problem to be solved by the invention]

[0005] In shoes with two plates as disclosed in the above-mentioned Patent Document 1, the cushioning layer is sandwiched between the two plates, which prevents the cushioning layer from deforming differently depending on the foot pressure when landing, resulting in the cushioning layer deforming more uniformly as a whole. Therefore, unless some ingenuity is taken, stability when landing may be impaired.

[0006] Therefore, an object of the present disclosure is to improve stability when landing in a shoe sole having two plates arranged opposite each other with a cushion layer interposed therebetween, and in a shoe equipped with the same. [Means for solving the problem]

[0007] A sole according to one aspect of the present disclosure has an upper surface configured as a support surface for supporting the sole of a wearer's foot and a lower surface configured as a ground contact surface, with a forefoot portion configured to support the toes and footbed of the wearer's foot, a midfoot portion configured to support the arch of the wearer's foot, and a rear foot portion configured to support the heel of the wearer's foot all connected together in a front-to-back direction, which is a direction that coincides with the longitudinal direction of the wearer's foot.

[0008] The sole according to one aspect of the present disclosure includes a cushioning layer, an upper plate, and a lower plate. The cushioning layer is positioned across the forefoot, midfoot, and rearfoot. The upper plate is positioned closer to the support surface than the cushioning layer to cover an upper surface of the cushioning layer, and is positioned across at least the forefoot and midfoot. The lower plate is positioned closer to the ground contact surface than the cushioning layer to cover a lower surface of the cushioning layer, and is positioned across at least the forefoot and midfoot.

[0009] In a shoe sole according to one embodiment of the present disclosure, the cushion layer includes a first region supporting the MP joints of the wearer's foot and a second region located rearward of the first region in the front-to-rear direction and forward of the rearfoot portion in the front-to-rear direction, and the second region includes a third region located in the center in the left-to-right direction corresponding to the foot width direction of the wearer's foot, a fourth region located at the medial end, and a fifth region located at the lateral end. The compression stiffness of the fourth region and the fifth region are both configured to be lower than the compression stiffness of the first region, and the compression stiffness of the third region is configured to be lower than the compression stiffness of both the fourth region and the fifth region.

[0010] A shoe according to one aspect of the present disclosure includes the above-described sole according to one aspect of the present disclosure and an upper provided above the sole. [Effects of the Invention]

[0011] According to the present disclosure, it is possible to improve stability when landing in a shoe sole in which two plates are arranged opposite each other with a cushion layer interposed therebetween, and in a shoe equipped with the same. [Brief explanation of the drawings]

[0012] [Figure 1] 1 is a perspective view of a shoe according to an embodiment. [Figure 2] FIG. 2 is a plan view of the shoe sole shown in FIG. [Figure 3] FIG. 2 is a bottom view of the shoe sole shown in FIG. [Figure 4] FIG. 2 is a side view of the shoe sole shown in FIG. 1, viewed from the medial side of the foot. [Figure 5] FIG. 2 is a side view of the shoe sole shown in FIG. 1, viewed from the outer side of the foot. [Figure 6] FIG. 2 is a perspective view of the shoe sole shown in FIG. [Figure 7] FIG. 2 is an exploded perspective view of the shoe sole shown in FIG. [Figure 8]2A and 2B are perspective views of a cushioning material having a structure basically similar to that of a first cushioning material provided in the sole shown in FIG. 1, and perspective views of a unit structure of the cushioning material. [Figure 9] 2A and 2B are perspective views of a cushioning material having a structure similar to that of a first cushioning material provided in the sole shown in FIG. 1, and perspective views of a unit structure of the cushioning material. [Figure 10] 2 is a perspective view showing the sole of the shoe shown in FIG. 1 with the additional cushioning material and the upper plate removed. FIG. [Figure 11] 2 is a plan view showing the state in which the additional cushioning material and the upper plate are removed from the sole shown in FIG. 1. FIG. [Figure 12] 1. FIG. 4 is a schematic cross-sectional view of the shoe sole shown in FIG. 1 taken along line XII-XII shown in FIG. [Figure 13] 1. FIG. 4 is a schematic cross-sectional view of the shoe sole shown in FIG. 1 taken along lines XIIIA-XIIIA, XIIIB-XIIIB, and XIIIC-XIIIC shown in FIG. [Figure 14] 2 is a schematic plan view showing the compression stiffness of each portion of a cushion layer provided in the sole of the shoe shown in FIG. 1. FIG. DETAILED DESCRIPTION OF THE INVENTION

[0013] Hereinafter, embodiments will be described in detail with reference to the drawings. In the embodiments shown below, the same or common parts are denoted by the same reference numerals in the drawings, and their description will not be repeated. The shoes and soles provided therefor according to the embodiments described below are spike shoes and soles provided therefor intended to be used exclusively in short-distance events.

[0014] <Embodiment> Fig. 1 is a perspective view of a shoe according to an embodiment. Figs. 2 and 3 are a plan view and a bottom view, respectively, of a shoe sole according to an embodiment, and Figs. 4 and 5 are side views of the shoe sole as seen from the medial side and the lateral side, respectively. Fig. 6 is a perspective view of the shoe sole according to an embodiment, and Fig. 7 is an exploded perspective view of the shoe sole. First, the general configuration of a shoe 1 and a shoe sole 10 according to this embodiment will be described with reference to Figs. 1 to 7.

[0015] As shown in Fig. 1, shoe 1 comprises a sole 10 and an upper 60. Sole 10 has a generally flat shape and includes a support surface 10a (see Figs. 2, 4, 5, etc.) that supports the sole of the wearer's foot, and a ground contact surface 10b that comes into contact with the ground when walking, running, or otherwise using the shoe. Upper 60 is located above sole 10 and has a shape that covers almost the entire portion of the wearer's foot distal to the ankle when inserted. Upper 60 is joined to sole 10, for example, by adhesive bonding.

[0016] Here, the front-to-rear direction of the sole 10 is defined as the direction that coincides with the foot length direction of a wearer wearing the shoe 1 equipped with the sole 10. The left-to-right direction of the sole 10 is defined as the direction that coincides with the foot width direction of a wearer wearing the shoe 1. Furthermore, the up-to-down direction of the sole 10 is defined as the direction that is perpendicular to both the front-to-rear direction and the left-to-right direction.

[0017] As shown in Figures 2 to 5, the sole 10 includes, along the front-to-rear direction, a forefoot portion R1 configured to support the toes and tread of the wearer's foot, a midfoot portion R2 configured to support the arch of the wearer's foot, and a rearfoot portion R3 configured to support the heel of the wearer's foot.

[0018] The forefoot portion R1, midfoot portion R2, and rearfoot portion R3 are defined as follows based on the shoe center SC of the shoe 1 (see FIGS. 2 and 3). Here, the shoe center SC is a line obtained by projecting a line connecting the area between the wearer's first and second toes and the center of the calcaneus (the so-called heel center (the heel center is indicated by the symbol HC in FIGS. 3 and 4)) onto the sole 10 in the up-down direction when the shoe 1 is worn by a standard wearer with a foot size that fits the shoe 1. The direction in which the shoe center SC extends corresponds to the aforementioned front-to-rear direction. As a premise, the foremost and rearmost ends of the support surface 10a in the front-to-rear direction that are on the shoe center SC are referred to as the front end position PF and the rear end position PR, respectively, and the distance between the front end position PF and the rear end position PR in the front-to-rear direction is referred to as the total length of the sole 10.

[0019] In other words, if the first boundary plane P1 is an imaginary plane that passes through a position 40% of the total length of the sole 10 from the front end position PF and is perpendicular to the shoe center SC, and the second boundary plane P2 is an imaginary plane that passes through a position 80% of the total length of the sole 10 from the front end position PF and is perpendicular to the shoe center SC, the forefoot R1 corresponds to the part between the front end position PF and the first boundary plane P1 along the front-to-back direction, the midfoot R2 corresponds to the part between the first boundary plane P1 and the second boundary plane P2 along the front-to-back direction, and the rearfoot R3 corresponds to the part between the second boundary plane P2 and the rear end position PR along the front-to-back direction.

[0020] As shown in Figures 2 and 3, shoe 1 is divided along the left-right direction when viewed in a plane into an inner foot part (the S1 side part shown in Figures 2 and 3) that is on the midline side (i.e., the side closer to the midline) of the anatomical orthogonal position of the foot, and an outer foot part (the S2 side part shown in Figures 2 and 3) that is on the opposite side of the midline side of the anatomical orthogonal position of the foot (i.e., the side farther from the midline).

[0021] 1, the upper 60 has an upper body 61, a shoe tongue 62, and shoelaces 63. Of these, the shoe tongue 62 and the shoelaces 63 are both fixed or attached to the upper body 61.

[0022] An upper opening is provided at the top of the upper body 61 to expose the upper part of the ankle and part of the instep of the wearer. On the other hand, a lower opening is provided at the bottom of the upper body 61, which is covered by the sole 10, as one example, and as another example, the bottom is formed by sealing the lower end of the upper body 61.

[0023] The shoe tongue 62 is fixed to the upper body 61 by sewing, welding, bonding, or a combination of these, etc., so as to cover the portion of the upper opening provided in the upper body 61 that exposes part of the wearer's instep. The upper body 61 and the shoe tongue 62 are made from, for example, woven fabric, knitted fabric, nonwoven fabric, synthetic leather, resin, etc., and for shoes that require particular breathability and lightness, double raschel warp knit fabric woven with polyester yarn is used.

[0024] The shoelaces 63 are made of string-like members that draw together the periphery of an upper opening in the upper body 61, which exposes part of the instep of the wearer, in the width direction of the wearer's foot, and are inserted into a plurality of holes provided around the periphery of the upper opening. By tightening the shoelaces 63 with the wearer's foot inserted into the upper body 61, the upper body 61 can be fitted tightly to the foot.

[0025] 1 to 7, the sole 10 includes a cushioning layer 20, an upper plate 30, a lower plate 40, and additional cushioning material 24. The cushioning layer 20, the upper plate 30, the lower plate 40, and the additional cushioning material 24 are all positioned across the forefoot region R1, the midfoot region R2, and the rearfoot region R3. The cushioning layer 20 includes a first cushioning material 21, a second cushioning material 22, and a third cushioning material 23.

[0026] The cushion layer 20 has a layered shape as a whole, with the above-mentioned first cushion material 21, second cushion material 22, and third cushion material 23 arranged in a line along the front-to-rear direction. The cushion layer 20 absorbs the impact when landing by compressing and deforming each of the first cushion material 21, second cushion material 22, and third cushion material 23 when landing. Therefore, the first cushion material 21, second cushion material 22, and third cushion material 23 constituting the cushion layer 20 are all made of soft materials with low elastic modulus. Furthermore, the cushion layer 20 is configured to be relatively thick to ensure its deformation allowance.

[0027] The upper plate 30 elastically deforms when subjected to a load, such as when kicking off, and the restoring force generated in the upper plate 30 as a result of this elastic deformation provides forward propulsion. For this reason, the upper plate 30 is made of a hard material with a high elastic modulus. Furthermore, the upper plate 30 is made relatively thin to ensure the amount of deformation.

[0028] The lower plate 40 is a so-called spike plate and constitutes the ground contact surface 10b described above. Cleats 50 are attached to the lower plate 40. Similarly to the upper plate 30, the lower plate 40 undergoes elastic deformation when subjected to a load, such as during kicking off. The restoring force generated in the lower plate 40 due to this elastic deformation provides forward propulsion. For this reason, the lower plate 40 is made of a hard material with a high elastic modulus. The lower plate 40 is also made relatively thin to ensure sufficient deformation.

[0029] The additional cushioning material 24 constitutes the support surface 10a described above, and is primarily intended to improve the feel of the sole of the wearer's foot, and, like the cushioning layer 20 described above, is compressively deformed when the wearer lands, thereby absorbing the impact of the landing. For this reason, the additional cushioning material 24 is made of a soft material with a low elastic modulus. Note that, since the additional cushioning material 24 is primarily intended to improve the feel of the sole of the wearer's foot as described above, it is thinner than the cushioning layer 20.

[0030] The cushion layer 20, upper plate 30, lower plate 40, and additional cushioning material 24 are stacked in the vertical direction. Specifically, the cushion layer 20 is disposed on the lower plate 40, the upper plate 30 is disposed on the cushion layer 20, and the additional cushioning material 24 is disposed on the upper plate 30.

[0031] That is, as shown in FIG. 7 , the upper surface 41 of the lower plate 40 is overlapped with the lower wall portion 212 of the first cushion material 21 (the lower wall portion 212 will be described in detail later), the lower surface 22 b of the second cushion material 22, and the lower surface 23 b of the third cushion material 23, and these are joined together, for example, by an adhesive, etc., thereby fixing the cushion layer 20 on the lower plate 40; the upper wall portion 211 of the first cushion material 21 (the upper wall portion 211 will be described in detail later), the upper surface 22 a of the second cushion material 22, and the lower surface 32 of the upper plate 30 are overlapped with the lower surface 32 of the upper plate 30, and these are joined together, for example, by an adhesive, etc., thereby fixing the upper plate 30 on the cushion layer 20; and the upper surface 31 of the upper plate 30 is overlapped with the lower surface 24 b of the additional cushion material 24, and these are joined together, for example, by an adhesive, etc., thereby fixing the additional cushion material 24 on the upper plate 30. As a result, the above-mentioned cushion layer 20, upper plate 30, lower plate 40 and additional cushion material 24 are stacked in the order of lower plate 40, cushion layer 20, upper plate 30 and additional cushion material 24 from the bottom in the vertical direction.

[0032] Also, with this configuration, the majority of the support surface 10a of the sole 10 (excluding the front end in the front-to-rear direction) is made up of the upper surface 24a of the additional cushioning material 24, and the remaining portion (the front end in the front-to-rear direction) is made up of part of the upper surface 23a of the third cushioning material 23. Furthermore, with this configuration, the ground contact surface 10b of the sole 10 is made up of the lower surface 42 of the lower plate 40.

[0033] 2 to 6, the first cushion material 21 is positioned across the forefoot portion R1 and the midfoot portion R2. More specifically, the first cushion material 21 is positioned so as to extend from approximately the center of the forefoot portion R1 in the front-to-rear direction to approximately the center of the midfoot portion R2 in the front-to-rear direction, and its left-to-right ends reach the medial and lateral sides of the sole 10. As a result, as shown in Fig. 2, the first cushion material 21 is positioned so as to include as part of the portion of the sole 10 that supports the MP joints of the wearer's foot (in Fig. 2, an imaginary line 100 is drawn around the portion where the MP joints of the wearer's foot will be located when the shoe is worn).

[0034] Here, referring particularly to Figure 7, the first cushion material 21 is composed of a three-dimensional structure having multiple recesses and protrusions, unlike the second cushion material 22, the third cushion material 23 and the additional cushion material 24, which will be described in detail later.

[0035] Fig. 8(A) is a perspective view of a cushioning material having a structure basically similar to that of the first cushioning material provided in the sole of the present embodiment, and Fig. 8(B) is a perspective view of a unit structure of the cushioning material. Before describing the detailed structure and materials of the first cushioning material 21 described above, cushioning material 21A having a structure basically similar to that of the first cushioning material 21 will be described below with reference to Figs. 8(A) and 8(B).

[0036] As shown in Fig. 8(A), the cushioning material 21A includes a three-dimensional structure S having a plurality of unit structures U. Each of the plurality of unit structures U has a three-dimensional shape formed by walls W whose outer shape is defined by a pair of parallel planes (see Fig. 8(B)), and therefore the three-dimensional structure S also has a three-dimensional shape formed by walls W whose outer shape is defined by a pair of parallel planes.

[0037] The unit structure U has a structure in which thickness is added to a structural unit having a geometric planar structure. More specifically, the unit structure U is constructed by dividing a structural unit consisting of a plurality of planes arranged to intersect with each other so as to have an internal cavity into two in any of the three orthogonal axial directions, and then adding thickness to the resulting divided structure.

[0038] Here, in the unit structure U shown in Figure 8(B), the aforementioned surface structure is a Kelvin structure, and the unit structure U is composed of a structural unit of the Kelvin structure that is divided into two in the height direction (the Z-axis direction shown in the figure) of the three orthogonal axial directions, and then further thickened.

[0039] More specifically, the unit structure U includes one upper wall portion 211, a lower wall portion 212a divided into four, and four standing wall portions 213 that individually connect the upper wall portion 211 and the lower wall portion 212a. Each of the standing wall portions 213 extends so as to intersect with the upper wall portion 211 and the lower wall portion 212a, and is connected to adjacent standing wall portions 213 at its side ends. As a result, the four standing wall portions 213 form a ring shape as a whole. Note that each of the upper wall portion 211, the lower wall portion 212a, and the standing wall portions 213 has a flat plate shape.

[0040] The four divided lower wall portions 212a are integrated by being continuous with the lower wall portions 212a included in other unit structures U that are arranged adjacent to the unit structure U that includes them. As a result, in the three-dimensional structure S, the lower wall portions 212a included in each of these four adjacent unit structures U are continuous with each other, thereby forming one lower wall portion 212 having substantially the same shape as the one upper wall portion 211 described above.

[0041] The cushioning material 21A is designed to provide a shock-absorbing function in the height direction. Therefore, as shown in Fig. 8(A), a plurality of unit structures U are regularly and continuously arranged in a repeated pattern along each of the width direction (X direction shown in the figure) and depth direction (Y direction shown in the figure) of the three orthogonal axial directions. As a result, the three-dimensional structure S has a structure in which upwardly convex portions and downwardly convex portions are alternately arranged when viewed from above. Note that Fig. 8(A) shows three unit structures U adjacent to each other in the width direction and depth direction.

[0042] The cushioning material 21A may be made of any material having a suitable elasticity, but is preferably made of a resin or rubber material. More specifically, if the cushioning material 21A is made of resin, the cushioning material 21A may be made of, for example, polyolefin resin, ethylene-vinyl acetate copolymer (EVA), polyamide-based thermoplastic elastomer (TPA, TPAE), thermoplastic polyurethane (TPU), or polyester-based thermoplastic elastomer (TPEE). On the other hand, if the cushioning material 21A is made of rubber, the cushioning material 21A may be made of, for example, butadiene rubber.

[0043] The cushioning material 21A may also be made of a polymer composition. In this case, examples of the polymer contained in the polymer composition include olefin-based polymers such as olefin-based elastomers and olefin-based resins. Examples of olefin-based polymers include polyethylene (e.g., linear low-density polyethylene (LLDPE), high-density polyethylene (HDPE)), polypropylene, ethylene-propylene copolymers, propylene-1-hexene copolymers, propylene-4-methyl-1-pentene copolymers, propylene-1-butene copolymers, ethylene-1-hexene copolymers, ethylene-4-methyl-pentene copolymers, ethylene-1-butene copolymers, 1-butene-1-hexene copolymers, 1-butene-4-methyl-pentene, ethylene-methacrylic acid copolymers, ethylene-methyl methacrylate copolymers ... Examples of the polyolefin include ethyl acrylate copolymer, ethylene-butyl methacrylate copolymer, ethylene-methyl acrylate copolymer, ethylene-ethyl acrylate copolymer, ethylene-butyl acrylate copolymer, propylene-methacrylic acid copolymer, propylene-methyl methacrylate copolymer, propylene-ethyl methacrylate copolymer, propylene-butyl methacrylate copolymer, propylene-methyl acrylate copolymer, propylene-ethyl acrylate copolymer, propylene-butyl acrylate copolymer, ethylene-vinyl acetate copolymer (EVA), and propylene-vinyl acetate copolymer.

[0044] The polymer may be an amide polymer such as an amide elastomer or an amide resin, etc. Examples of the amide polymer include polyamide 6, polyamide 11, polyamide 12, polyamide 66, and polyamide 610.

[0045] The polymer may also be an ester-based polymer such as an ester-based elastomer or an ester-based resin, etc. Examples of the ester-based polymer include polyethylene terephthalate and polybutylene terephthalate.

[0046] The polymer may be a urethane polymer such as a urethane elastomer or a urethane resin, etc. Examples of the urethane polymer include polyester polyurethane and polyether polyurethane.

[0047] The polymer may also be a styrene-based polymer such as a styrene-based elastomer or a styrene-based resin. Examples of styrene-based elastomers include styrene-ethylene-butylene copolymer (SEB), styrene-butadiene-styrene copolymer (SBS), hydrogenated SBS (styrene-ethylene-butylene-styrene copolymer (SEBS)), styrene-isoprene-styrene copolymer (SIS), hydrogenated SIS (styrene-ethylene-propylene-styrene copolymer (SEPS)), styrene-isobutylene-styrene copolymer (SIBS), styrene-butadiene-styrene-butadiene (SBSB), and styrene-butadiene-styrene-butadiene-styrene (SBSBS). Examples of styrene-based resins include polystyrene, acrylonitrile-styrene resin (AS), and acrylonitrile-butadiene-styrene resin (ABS).

[0048] Furthermore, the polymer may be, for example, an acrylic polymer such as polymethyl methacrylate, a urethane-based acrylic polymer, a polyester-based acrylic polymer, a polyether-based acrylic polymer, a polycarbonate-based acrylic polymer, an epoxy-based acrylic polymer, a conjugated diene polymer-based acrylic polymer and hydrogenated products thereof, a urethane-based methacrylic polymer, a polyester-based methacrylic polymer, a polyether-based methacrylic polymer, a polycarbonate-based methacrylic polymer, an epoxy-based methacrylic polymer, a conjugated diene polymer-based methacrylic polymer and hydrogenated products thereof, a polyvinyl chloride resin, a silicone-based elastomer, butadiene rubber (BR), isoprene rubber (IR), chloroprene rubber (CR), natural rubber (NR), styrene-butadiene rubber (SBR), acrylonitrile-butadiene rubber (NBR), butyl rubber (IIR), or the like.

[0049] The method for manufacturing the cushion material 21A described above is not particularly limited. The cushion material 21A can be manufactured by, for example, injection molding using a mold, cast molding, or sheet molding, or by modeling using a three-dimensional additive manufacturing device. In particular, the cushion material 21A described above has a relatively simple shape, and therefore can be easily manufactured by molding using a mold. This eliminates the need for modeling using a three-dimensional additive manufacturing device or molding using a complex mold, and enables a significant reduction in manufacturing costs.

[0050] In the cushion material 21A configured as described above, when a load is applied along its height direction (the Z-axis direction shown in the drawing), compressive deformation occurs. At that time, due to the structure of the cushion material 21A, buckling occurs at the upright wall portion 213. Furthermore, when the application of the load is released, the buckling at the upright wall portion 213 is also eliminated, and the cushion material 21A returns to its original shape.

[0051] As shown in Figures 1 to 6, the first cushion material 21 provided in the sole 10 of this embodiment is obtained by slightly modifying the shape, thickness, etc. of the unit structure U for each part while maintaining the basic structure of the cushion material 21A described above in order to provide the first cushion material 21 to the sole 10, and in other respects is configured in the same way as the cushion material 21A described above.

[0052] As a result, the unit structure of the first cushion material 21 provided in the sole 10 of this embodiment is also composed of a structural unit of the Kelvin structure divided into two in the height direction (Z-axis direction shown in the figure) of the three orthogonal axial directions, and then further thickened, so that the first cushion material 21 is composed of a three-dimensional structure in which these unit structures are repeatedly arranged adjacent to each other.

[0053] With this configuration, in the sole 10 according to the present embodiment, buckling occurs in the first cushion material 21 when the foot lands, and as a result, the cushion layer 20 in the portion supporting the MP joint of the wearer's foot not only has high shock-absorbing performance but also high resilience. In other words, by virtue of having the above structural characteristics, the first cushion material 21 exhibits high shock-absorbing performance, while its compression rigidity is higher than that of the second cushion material 22, which will be described later.

[0054] Here, the above-described first cushion material 21 has a unit structure U formed by dividing a structural unit of a Kelvin structure in two in the height direction and adding thickness to the divided structural unit, but structural units of other planar structures may be used instead of the structural unit of the Kelvin structure. For example, in the case of a cushion material having a three-dimensional shape formed by walls whose outline is defined by a pair of parallel planes, similar to the above-described first cushion material 21, structural units such as an octet structure, a cubic structure, and a cubic octet structure may be used in addition to the Kelvin structure.

[0055] The structural units of these planar structures are structural units consisting of multiple planes arranged to intersect with each other so as to have a cavity inside, and by dividing this into two in any of the three orthogonal axial directions and adding further thickness to create a cushioning material, it is possible to create a cushioning material that not only has high shock-absorbing performance but also high resilience performance.

[0056] 9(A) is a perspective view of a cushioning material having a structure similar to that of the first cushioning material provided in the sole of this embodiment, and FIG. 9(B) is a perspective view of a unit structure of the cushioning material. Here, the sole 10 of this embodiment may be provided with a cushioning material 21B as shown in FIG. 9(A) as the first cushioning material, instead of the above-described first cushioning material 21. Hereinafter, with reference to FIGS. 9(A) and 9(B), the cushioning material 21B having a structure similar to that of the first cushioning material 21 provided in the sole of this embodiment will be described.

[0057] The cushioning material 21B shown in Fig. 9(A) has a unit structure U in which a thickness is added based on a structural unit of a geometrical plane structure. More specifically, the unit structure U is formed by dividing a structural unit of a mathematically defined triply periodic minimal surface in half in any of the three orthogonal axial directions, and then adding thickness to the resulting structure. A minimal surface is defined as a surface with the smallest area among those having a given closed curve as its boundary.

[0058] Here, in the unit structure U shown in Figure 9(B), the aforementioned surface structure is a Schwartz P structure, and the unit structure U is composed of a structural unit of the Schwartz P structure that is divided into two in the height direction (the Z-axis direction shown in the figure) of the three orthogonal axial directions, and then further thickened.

[0059] Similarly to the cushion material 21A described above, the cushion material 21B configured as described above also undergoes compressive deformation when a load is applied along its height direction (the Z-axis direction shown in the drawing). At this time, due to the structure of the cushion material 21B, buckling occurs at the upright wall portion 213. Furthermore, when the application of the load described above is released, the buckling at the upright wall portion 213 is also eliminated, and the cushion material 21B returns to its original shape.

[0060] Therefore, even if the first cushion material 21 provided in the sole 10 of this embodiment is replaced with a material having basically the same structure as the cushion material 21B instead of the above-mentioned cushion material 21A, buckling will occur in the first cushion material 21 when the foot lands, and as a result, the cushion layer 20 in the portion supporting the MP joint of the wearer's foot will have not only high cushioning performance but also high resilience performance.

[0061] It should be noted that instead of the structural unit of the Schwartz P structure described above, other structural units of triple periodic minimal curved surfaces may be used. Examples of other structural units that can be used as the structural unit of triple periodic minimal curved surfaces include a gyroid structure and a Schwartz D structure. By dividing these structural units into two in any of the three orthogonal axial directions and then adding thickness to the resulting structure, a cushioning material can be obtained that not only has high shock absorption performance but also high resilience.

[0062] 2 to 7, the second cushion material 22 is made of a flat block-shaped member and is positioned across the midfoot portion R2 and rearfoot portion R3. More specifically, the second cushion material 22 is positioned so as to extend from approximately the center of the midfoot portion R2 in the longitudinal direction to the rear end portion of the rearfoot portion R3 in the longitudinal direction, and its left and right ends reach the medial and lateral sides of the sole 10.

[0063] The second cushion material 22 preferably has a moderate strength and excellent cushioning properties, and its compression rigidity is lower than that of the first cushion material 21. From this viewpoint, the second cushion material 22 may be made of, for example, a resin or rubber member, and is preferably made of a resin or rubber foam material. As an example, the second cushion material 22 may be made of a foam or non-foam material such as polyolefin resin, ethylene-vinyl acetate copolymer (EVA), polyamide-based thermoplastic elastomer (TPA, TPAE), thermoplastic polyurethane (TPU), or polyester-based thermoplastic elastomer (TPEE).

[0064] 2 to 7, the third cushion material 23 is made of a flat block-shaped member and is located at the front end of the forefoot portion R1 in the front-to-rear direction. Both left and right ends of the third cushion material 23 reach the medial and lateral sides of the sole 10.

[0065] The third cushion material 23 preferably has adequate strength and excellent cushioning properties, and its compression rigidity is preferably lower than that of the first cushion material 21. From this perspective, the third cushion material 23, like the second cushion material 22, can be made of, for example, a resin or rubber member, and is preferably made of a resin or rubber foam material. As an example, the third cushion material 23 can be made of a foam or non-foam material such as polyolefin resin, ethylene-vinyl acetate copolymer (EVA), polyamide-based thermoplastic elastomer (TPA, TPAE), thermoplastic polyurethane (TPU), or polyester-based thermoplastic elastomer (TPEE). The third cushion material 23 may be made of the same material as the second cushion material 22, or may be made of a different material from the second cushion material 22.

[0066] 2 to 7, the upper plate 30 is made of a member configured to be sufficiently thin and is positioned across the forefoot portion R1, midfoot portion R2, and rearfoot portion R3. More specifically, the upper plate 30 is positioned so that it extends from a portion near the front end of the forefoot portion R1 in the longitudinal direction to approximately the center of the rearfoot portion R3 in the longitudinal direction, and its left and right ends reach the medial and lateral sides of the sole 10.

[0067] The upper plate 30 is not particularly limited in material as long as it is made of a material harder than the material making up the cushion layer 20. Examples of materials for the upper plate 30 include fiber-reinforced resins using carbon fiber, glass fiber, aramid fiber, Dyneema fiber (registered trademark), Zylon fiber (registered trademark), boron fiber, or the like as reinforcing fibers and epoxy resin, polyester resin, phenolic resin, polyamide resin, polypropylene resin, polyethylene resin, polyurethane resin, or the like as a base material, and non-fiber-reinforced resins made of polymer resins such as urethane-based thermoplastic elastomer (TPU), amide-based thermoplastic elastomer (TPA), and ethylene-vinyl acetate copolymer (EVA).

[0068] 2 to 7, the additional cushioning material 24 is made of a member configured to be sufficiently thin and is positioned across the forefoot portion R1, midfoot portion R2, and rearfoot portion R3. More specifically, like the upper plate 30, the additional cushioning material 24 is positioned so as to extend from a portion near the front end of the forefoot portion R1 in the longitudinal direction to approximately the center of the rearfoot portion R3 in the longitudinal direction, and its both lateral ends reach the medial and lateral sides of the sole 10.

[0069] The additional cushioning material 24 preferably has adequate strength and excellent cushioning properties, and its compression rigidity is preferably lower than that of the first cushioning material 21. From this perspective, the additional cushioning material 24, like the second cushioning material 22 and the third cushioning material 23, can be made of, for example, a resin or rubber member, and is preferably made of a resin or rubber foam material. As an example, the additional cushioning material 24 can be made of a foam or non-foam material such as polyolefin resin, ethylene-vinyl acetate copolymer (EVA), polyamide-based thermoplastic elastomer (TPA, TPAE), thermoplastic polyurethane (TPU), or polyester-based thermoplastic elastomer (TPEE). The additional cushioning material 24 may be made of the same material as the second cushioning material 22 and / or the third cushioning material 23, or may be made of a different material from the second cushioning material and / or the third cushioning material 23.

[0070] 2 to 7, the lower plate 40 is made of a member configured to be sufficiently thin and is positioned across the forefoot portion R1, midfoot portion R2, and rearfoot portion R3. More specifically, the lower plate 40 is positioned so as to extend from the front end of the forefoot portion R1 in the longitudinal direction to the rear end of the rearfoot portion R3 in the longitudinal direction, and its both lateral ends reach the medial and lateral sides of the sole 10.

[0071] As described above, lower plate 40 is a spike plate, and the portions of lower plate 40 included in forefoot portion R1 and midfoot portion R2 are provided with a plurality of seats 43 for holding cleats 50 (see FIG. 1). Each of these seats 43 is formed, for example, by embedding a metal nut-shaped part in lower plate 40, leaving a plurality of exposed retaining holes 43a for attaching cleats 50 positioned on the underside 42 (i.e., ground contact surface 10b) of lower plate 40. Cleats 50 protrude like pins from ground contact surface 10b of sole 10, thereby increasing propulsion force during push-off.

[0072] Additionally, a plurality of protrusions 44 are provided at predetermined positions on the underside 42 of the lower plate 40, in portions that are included in the forefoot portion R1 and midfoot portion R2 and that do not include the above-described plurality of seats 43. Similar to the above-described plurality of cleats 50, these plurality of protrusions 44 protrude from the ground contact surface 10b of the sole 10, thereby increasing the propulsion force during kick-off.

[0073] Furthermore, uneven portions 45 are provided on the rear end of the midfoot portion R2 and the rearfoot portion R3 of the lower surface 42 of the lower plate 40. These uneven portions 45 improve grip when landing.

[0074] In addition, a first rib 46 and a second rib 47 are provided at the medial end and lateral end of the midfoot portion R2 of the underside 42 of the lower plate 40, respectively. These first rib 46 and second rib 47 are formed by locally increasing the thickness of the lower plate 40 compared to other portions. Here, the first rib 46 extends along the medial edge of the sole 10, and the second rib 47 extends along the lateral edge of the sole 10. These first rib 46 and second rib 47 are intended to locally increase the rigidity of the sole 10, and their function will be described later.

[0075] The material of the lower plate 40 is not particularly limited as long as it is made of a material harder than the material making up the cushion layer 20. Examples of materials for the lower plate 40 include fiber-reinforced resins using carbon fiber, glass fiber, aramid fiber, Dyneema fiber (registered trademark), Zylon fiber (registered trademark), boron fiber, or the like as reinforcing fibers and epoxy resin, polyester resin, phenolic resin, polyamide resin, polypropylene resin, polyethylene resin, polyurethane resin, or the like as a base material, and non-fiber-reinforced resins made of polymer resins such as urethane-based thermoplastic elastomer (TPU), amide-based thermoplastic elastomer (TPA), and ethylene-vinyl acetate copolymer (EVA).

[0076] Figures 10 and 11 are a perspective view and a plan view, respectively, showing a sole according to this embodiment with the additional cushioning material and upper plate removed, and Figure 12 is a schematic cross-sectional view of the sole according to this embodiment taken along line XII-XII in Figure 3. Figures 13(A) and 13(B) are schematic cross-sectional views of the sole according to this embodiment taken along lines XIIIA-XIIIA, XIIIB-XIIIB, and XIIIC-XIIIC in Figure 3, respectively, and Figure 14 is a schematic plan view showing the compression stiffness of each portion of the cushion layer provided in the sole. Next, with reference to Figures 10 to 14, the structure of sole 10 according to this embodiment and the compression stiffness of each portion of cushion layer 20 provided in sole 10 will be described in more detail.

[0077] As described above, in the sole 10 according to this embodiment, the cushioning layer 20, upper plate 30, lower plate 40, and additional cushioning material 24 are stacked in the following order from bottom to top: lower plate 40, cushioning layer 20, upper plate 30, and additional cushioning material 24. That is, the upper plate 30 is located on the support surface 10a side so as to cover the upper surface of the cushioning layer 20, and the lower plate 40 is located on the ground surface 10b side so as to cover the lower surface of the cushioning layer 20.

[0078] As a result, the upper plate 30 and the lower plate 40 are arranged opposite each other in the vertical direction, and the first cushion material 21, the second cushion material 22 and the third cushion material 23 that constitute the cushion layer 20 are sandwiched between the upper plate 30 and the lower plate 40 except for the front end portion of the third cushion material 23.

[0079] 10 to 12 and 13(A) to 13(C), the first cushion material 21 is positioned so as to extend from approximately the center of the forefoot portion R1 in the front-to-rear direction to approximately the center of the midfoot portion R2 in the front-to-rear direction, the second cushion material 22 is positioned so as to extend from approximately the center of the midfoot portion R2 in the front-to-rear direction to the rear end portion of the rearfoot portion R3 in the front-to-rear direction, and the third cushion material 23 is positioned at the front end portion of the forefoot portion R1 in the front-to-rear direction. That is, the first cushion material 21, the second cushion material 22, and the third cushion material 23 are arranged side by side from the front side in the front-to-rear direction in the order of the third cushion material 23, the first cushion material 21, and the second cushion material 22.

[0080] 10 and 11, the second cushion member 22 has a generally Y-shaped planar shape including a base end portion 22A, an inner foot-side branch portion 22B, and an outer foot-side branch portion 22C. The base end portion 22A is located so as to extend from approximately the center of the midfoot portion R2 in the longitudinal direction to the rear end of the rearfoot portion R3. The inner foot-side branch portion 22B protrudes forward from the inner foot-side portion of the fore end of the base end portion 22A. The outer foot-side branch portion 22C protrudes forward from the outer foot-side portion of the fore end of the base end portion 22A. As a result, the inner foot-side branch portion 22B is located at the inner foot-side end of the approximate center of the midfoot portion R2 in the longitudinal direction, and the outer foot-side branch portion 22C is located at the outer foot-side end of the approximate center of the midfoot portion R2 in the longitudinal direction.

[0081] That is, the second cushion material 22 has a bifurcated shape forward in the longitudinal direction, with an inner branch portion 22B reaching an inner end of the foot that is forward of the rear foot portion R3 in the longitudinal direction and an outer branch portion 22C reaching an outer end of the foot that is forward of the rear foot portion R3 in the longitudinal direction, and the base end 22A extends from approximately the center of the midfoot portion R2 to the rear end of the rear foot portion R3. Therefore, the second cushion material 22 has a gap G between the inner branch portion 22B and the outer branch portion 22C, and this gap G is located approximately in the center of the midfoot portion R2 in the longitudinal direction.

[0082] The rear edge of the first cushion material 21, which is adjacent to the front edge of the second cushion material 22, where the medial branch portion 22B, the lateral branch portion 22C, and the gap G are provided, extends generally in the left-right direction. Therefore, the gap G, where no cushion material is provided, is located in a portion of the cushion layer 20 that corresponds to the approximate center of the midfoot portion R2 in the front-to-back direction.

[0083] In the sole 10 of this embodiment configured as described above, as shown in FIG. 14, the cushion layer 20 has a first region A1, which is a portion that supports the MP joints of the wearer's foot, and a second region A2 that is included in a portion that is rearward in the anterior-posterior direction from the first region A1 and forward in the anterior-posterior direction from the rear foot portion R3. Of these, the second region A2 includes, in the lateral direction that coincides with the width direction of the wearer's foot, a third region A3 located in the center, a fourth region A4 located at the medial end of the foot, and a fifth region A5 located at the lateral end of the foot.

[0084] Additionally, in the sole 10 according to this embodiment, the first region A1 is formed of a part of the first cushion material 21 having a higher compressive rigidity than the second cushion material 22, the fourth region A4 of the second region is formed of the medial foot side branch portion 22B provided in the second cushion material 22 having a lower compressive rigidity than the first cushion material 21, and the fifth region A5 of the second region is formed of the lateral foot side branch portion 22C provided in the second cushion material 22 having a lower compressive rigidity than the first cushion material 21. The third region A3 of the second region is formed of a gap G provided between the medial foot side branch portion 22B and the lateral foot side branch portion 22C of the second cushion material 22.

[0085] Therefore, in the sole 10 of this embodiment, the compression stiffness in the fourth region A4 and the compression stiffness in the fifth region A5 are both configured to be lower than the compression stiffness in the first region A1, and the compression stiffness in the third region A3 is configured to be lower than both the compression stiffness in the fourth region A4 and the compression stiffness in the fifth region A5.

[0086] By configuring in this manner, the shoe sole 10 according to this embodiment can achieve the following effects.

[0087] First, the first region A1 of the cushion layer 20, which is the portion that supports the MP joints of the wearer's foot, is formed of the first cushion material 21, which exhibits high shock-absorbing performance as described above but has a compressive rigidity higher than that of the second cushion material 22. This allows the deformation of the upper plate 30 and the lower plate 40 when landing to be prevented, and the repulsive force generated when the upper plate 30 and the lower plate 40 return to their original shapes during push-off can be obtained by superimposing the repulsive force generated when the buckling of the first cushion material 21 is released, thereby resulting in a sole with enhanced forward propulsion. Here, the portion that supports the MP joints of the wearer's foot, i.e., the first region A1, is the portion that receives the greatest foot pressure on the sole 10 during push-off. By configuring the sole in this manner, it is possible to maximize the repulsive force generated in the upper plate 30, the lower plate 40, and the first cushion material 21.

[0088] Secondly, by arranging a second cushion material having lower compression rigidity than the first cushion material 21 in a portion of the cushion layer 20 adjacent to the rear end edge of the first cushion material 21 in the front-to-rear direction, not only is it less likely that deformation of the upper plate 30 and the lower plate 40 in the portion where the first cushion material 21 is arranged to be hindered when landing, but deformation of the first cushion material 21 itself is also less likely to be hindered, so that the above-mentioned rebound force can be obtained more reliably, resulting in a sole with increased forward propulsion force.

[0089] Third, the occurrence of torsion can be suppressed and the sole can have improved stability when landing. That is, in a configuration in which the upper plate 30 and the lower plate 40 are arranged opposite each other, the cushion layer 20 located between them is prevented from deforming differently in different regions in response to foot pressure when landing. This causes the cushion layer 20 to deform more uniformly as a whole, which could significantly impair stability when landing. However, with the above-described configuration, the second region A2 is provided between the first region A1, which supports the MP joints of the wearer's foot, and the rear foot portion R3, in which the compression stiffness in the central portion (corresponding to the third region A3) is low and the compression stiffness in the medial end portion (corresponding to the fourth region A4) and the lateral end portion (corresponding to the fifth region A5) is high in the left-right direction. This suppresses the occurrence of torsion in the sole 10 and increases stability when landing. This makes it possible to prevent the wearer's foot from collapsing toward the inside or outside of the foot.

[0090] Therefore, by using the sole 10 of the present embodiment and the shoe 1 equipped with the same, it is possible to improve stability when landing without compromising the forward propulsion force when kicking off, while adopting a configuration in which the upper plate 30 and the lower plate 40 are arranged opposite each other via the cushion layer 20.

[0091] Additionally, in the sole 10 according to the present embodiment and the shoe 1 equipped therewith, as described above, the first rib 46 and the second rib 47 are provided at the medial and lateral ends of the midfoot portion R2 of the lower surface 42 (i.e., the ground-contact surface 10b) of the lower plate 40, respectively. This configuration increases the rigidity of the medial and lateral portions of the lower plate 40 relative to the center of the lower plate 40 in the left-right direction, thereby suppressing twisting of the sole 10 and improving stability upon landing. As shown in FIG. 11 , the first rib 46 and the second rib 47 are preferably provided so as to overlap the fourth region A4 and the fifth region A5 described above. This configuration further enhances the effect of suppressing twisting.

[0092] Furthermore, in the sole 10 according to this embodiment and the shoe 1 equipped with the same, as shown in Fig. 13(A), the portion of the upper plate 30 included in the forefoot portion R1 has a curved shape in which the central portion bulges downward in the vertical direction relative to the medial and lateral ends. This configuration increases the amount of deformation of the upper plate 30 when this portion lands, thereby providing a greater repulsive force when the upper plate 30 returns to its original shape during a push-off. This increases the forward propulsion force during a push-off.

[0093] Additionally, in the sole 10 according to the present embodiment and the shoe 1 equipped with the same, as shown in FIG. 13(A), the portion of the lower plate 40 included in the forefoot portion R1 has a curved shape in which the central portion bulges downward in the vertical direction relative to the medial and lateral ends, similar to the upper plate 30. This configuration increases the amount of deformation of the lower plate 40 when the foot lands in this portion, thereby providing a greater repulsive force when the lower plate 40 returns to its original shape during a push-off. This further increases the forward propulsion force during a push-off.

[0094] The degree to which the portions of the upper plate 30 and the lower plate 40 included in the forefoot portion R1 are curved in the left-right direction is preferably such that the radius of curvature is 150 mm or more and 400 mm or less. This is because if the radius of curvature is smaller than 150 mm, sufficient repulsion force may not be obtained, and if the radius of curvature is larger than 400 mm, stability when landing may be impaired.

[0095] As described above, in the sole 10 according to the present embodiment and the shoe 1 including the same, the first rib 46 and the second rib 47 are provided at the medial and lateral ends of the portion of the lower plate 40 included in the midfoot region R2, respectively. With this configuration, when the portions of the upper plate 30 and the lower plate 40 included in the forefoot region R1 are curved in the left-right direction, the deformation of these portions upon landing is not hindered by the first rib 46 and the second rib 47. In other words, if the rigidity of the portion of the lower plate 40 included in the midfoot region R2 is increased by increasing the overall thickness of this portion in order to suppress twisting, this may hinder the deformation of the portions of the upper plate 30 and the lower plate 40 included in the forefoot region R1. However, by locally increasing the rigidity of only the medial and lateral ends of the portion of the lower plate 40 included in the midfoot region R2 as described above, such a problem can be avoided.

[0096] Furthermore, in the sole 10 according to this embodiment and the shoe 1 equipped with the same, as shown in Fig. 12, the distance between the upper plate 30 and the lower plate 40 in the forefoot portion R1 is configured to gradually decrease toward the front in the front-to-back direction. That is, in the forefoot portion R1, the thickness of the cushion layer 20 is configured to gradually decrease toward the front in the front-to-back direction. With this configuration, weight can be transferred more smoothly toward the front when landing, and forward propulsion force can be further increased.

[0097] <Summary of the Disclosure in the Embodiments> The characteristic configurations of the shoe sole and the shoe provided with the sole according to the above-described embodiment can be summarized as follows.

[0098] [Appendix 1] A sole comprising a forefoot portion configured to support the toes and tread of the wearer's foot, a midfoot portion configured to support the arch of the wearer's foot, and a rearfoot portion configured to support the heel of the wearer's foot, which are connected in a front-to-rear direction that coincides with the longitudinal direction of the wearer's foot, the upper surface of which is configured as a support surface for supporting the sole of the wearer's foot, and the lower surface of which is configured as a ground contact surface, a cushioning layer positioned across the forefoot portion, the midfoot portion, and the rearfoot portion; an upper plate positioned closer to the support surface than the cushion layer so as to cover an upper surface of the cushion layer and positioned across at least the forefoot portion and the midfoot portion; a lower plate positioned closer to the ground surface than the cushion layer so as to cover a lower surface of the cushion layer, and positioned across at least the forefoot portion and the midfoot portion; The cushion layer has a first region that is a portion that supports the MP joint of the wearer's foot, and a second region that is included in a portion that is rearward in the front-to-back direction from the first region and forward in the front-to-back direction from the rear foot portion, The second region includes, in a left-right direction that coincides with the width direction of the wearer's foot, a third region located in a central portion, a fourth region located at an inner foot side end portion, and a fifth region located at an outer foot side end portion, The compression stiffness of the fourth region and the compression stiffness of the fifth region are both lower than the compression stiffness of the first region, and the compression stiffness of the third region is lower than both the compression stiffness of the fourth region and the compression stiffness of the fifth region.

[0099] By adopting the configuration described in Supplementary Note 1 above, it is possible to create a sole that can significantly improve stability when landing without compromising forward propulsion force when kicking off, even while adopting a configuration in which an upper plate and a lower plate are arranged opposite each other with a cushioning layer interposed between them.

[0100] [Appendix 2] The cushion layer includes a first cushion material that is disposed at least in a portion of the cushion layer that supports the MP joint of the wearer's foot, thereby constituting the first region, and a second cushion material that is disposed so as to straddle at least a portion of the cushion layer that is included in the midfoot portion and a portion of the cushion layer that is included in the rearfoot portion, thereby constituting the second region, the second cushion material has an inner foot-side branch portion that reaches an inner foot-side end portion that is forward of the rear foot portion in the front-to-rear direction, and an outer foot-side branch portion that reaches an outer foot-side end portion that is forward of the rear foot portion in the front-to-rear direction, and has a bifurcated shape toward the front side in the front-to-rear direction, the fourth region is formed by the medial foot side branch portion of the second cushion material, the fifth region is formed by the outer foot side branch portion of the second cushioning material, The sole of claim 1, wherein the third region is formed by a gap provided between the medial branch portion and the lateral branch portion of the second cushioning material.

[0101] By adopting the configuration described in Supplementary Note 2 above, it becomes possible to more easily construct a sole that can significantly improve stability upon landing without compromising forward propulsion force upon kicking off.

[0102] [Appendix 3] the first cushioning material is a unit structure having a three-dimensional shape formed by walls whose outer shape is defined by a pair of parallel planes or curved surfaces, and is configured as a three-dimensional structure made of resin or rubber in which a plurality of unit structures are repeatedly arranged adjacent to each other; The sole of claim 2, wherein the second cushioning material is a plate-shaped or block-shaped member made of a resin or rubber foam material.

[0103] By adopting the configuration described in Supplementary Note 3 above, the first cushioning material undergoes buckling deformation, and therefore it is possible to obtain not only the repulsive force obtained when the upper and lower plates return to their original shapes, but also the repulsive force generated when the buckling of the first cushioning material is released, resulting in a sole with increased forward propulsion.

[0104] [Appendix 4] The sole of claim 3, wherein the unit structure is formed by dividing a structural unit consisting of a plurality of planes arranged to intersect with each other so as to have a hollow space inside into two in any of the three orthogonal axial directions and then adding thickness to the resulting divided structural unit.

[0105] By adopting the configuration described in Supplementary Note 4 above, it is possible to further increase the rebound force generated when the buckling of the first cushioning material is released, resulting in a sole with increased forward propulsion force.

[0106] [Appendix 5] The sole of claim 4, wherein the structural unit is any one of a Kelvin structure, an octet structure, a cubic structure, and a cubic octet structure.

[0107] By adopting the configuration described in Supplementary Note 5 above, it is possible to reliably increase the repulsive force that occurs when the buckling of the first cushion material is released.

[0108] [Appendix 6] The shoe sole according to Appendix 3, wherein the unit structure is formed by dividing a structural unit of a triple periodic minimal surface in two in any of the three orthogonal axial directions and then adding thickness to the divided unit.

[0109] By adopting the configuration described in Supplementary Note 6 above, it is possible to further increase the rebound force generated when the buckling of the first cushioning material is released, resulting in a sole with increased forward propulsion force.

[0110] [Appendix 7] The shoe sole according to Appendix 6, wherein the structural unit is any one of a Schwarz P structure, a gyroid structure, and a Schwarz D structure.

[0111] By adopting the configuration described in Supplementary Note 7, it is possible to reliably increase the repulsive force that occurs when the buckling of the first cushion material is released.

[0112] [Appendix 8] A sole as described in any one of Appendices 1 to 7, wherein a first rib extending along the medial edge of the sole is provided on a portion of the lower surface of the lower plate that is included in the medial end of the midfoot portion, and a second rib extending along the lateral edge of the sole is provided on a portion of the lower surface of the lower plate that is included in the lateral end of the midfoot portion.

[0113] By adopting the configuration described in Appendix 8 above, the rigidity of the medial and lateral parts of the lower plate in the left-right direction is increased compared to the central part of the lower plate, which makes it possible to prevent twisting of the sole and increases stability when landing.

[0114] [Appendix 9] The sole of claim 8, wherein each of the first rib and the second rib is formed by locally increasing the thickness of the lower plate more than other portions.

[0115] By adopting the configuration described in Supplementary Note 9 above, it is possible to more reliably prevent twisting of the shoe sole.

[0116] [Appendix 10] 10. The sole of claim 1, wherein at least one of the portion of the upper plate included in the forefoot portion and the portion of the lower plate included in the forefoot portion has a curved shape in which the central portion bulges downward in the left-right direction further than the medial end and the lateral end.

[0117] By adopting the configuration described in Supplementary Note 10 above, it is possible to increase the amount of deformation of the upper plate and / or the lower plate when landing, which makes it possible to obtain a greater rebound force and further increase the forward propulsion force when kicking off.

[0118] [Appendix 11] the lower plate is a spike plate provided with spikes, 11. The sole of any one of appendixes 1 to 10, wherein the ground contact surface is formed by the lower surface of the lower plate.

[0119] By adopting the configuration described in Supplementary Note 11 above, it is possible to significantly improve stability upon landing without compromising the forward propulsion force upon kicking off, particularly in the soles of spiked shoes.

[0120] [Appendix 12] A shoe sole according to any one of appendices 1 to 11; and an upper provided above the sole.

[0121] By adopting the configuration described in Supplementary Note 12 above, it is possible to obtain a shoe that can significantly improve stability when landing without compromising forward propulsion force when pushing off.

[0122] <Other forms, etc.> In the above-described embodiment, the sole and shoe are described with the second region provided in the approximate center of the midfoot in the front-to-rear direction, but the position of the second region is not limited to this position. That is, the second region only needs to be formed so as to be included in at least a portion of the midfoot that is rearward in the front-to-rear direction from the first region, which supports the MP joints of the wearer's foot, and forward in the front-to-rear direction from the rearfoot, and only a portion of this portion may be configured as the second region, or the entire portion may be configured as the second region.

[0123] In the above-described embodiment, the sole and shoe are described as examples in which the first cushion material is arranged from approximately the center of the forefoot in the longitudinal direction to approximately the center of the midfoot in the longitudinal direction, thereby providing the first region, which supports the MP joints of the wearer's foot, with the same compression rigidity as the first region, as well as the regions before and after that. However, the region in which the first cushion material is arranged can be changed as appropriate. That is, the region having the same compression rigidity as the first region can be enlarged or reduced in the longitudinal direction as appropriate, and the position of the second region can also be enlarged, reduced, or moved in the longitudinal direction accordingly.

[0124] Furthermore, in the above-described embodiment, the first cushion material is described as being made of a three-dimensional structure having a plurality of recesses and protrusions, but it may also be made of a foamed or non-foamed resin or rubber material similar to the second and third cushion materials.

[0125] Furthermore, in the above-described embodiment, an example has been given in which the features of the present disclosure are applied to spike shoes intended to be used primarily in short-distance competitions and the soles provided therewith, but it goes without saying that the features of the present disclosure can also be applied to shoes for other purposes and the soles provided therewith.

[0126] As such, the above-described embodiments disclosed herein are illustrative in all respects and are not restrictive. The technical scope of the present invention is defined by the claims, and includes all modifications within the meaning and scope of the claims. [Explanation of symbols]

[0127] 1 shoe, 10 sole, 10a support surface, 10b ground contact surface, 20 cushion layer, 21 first cushion material, 21A, 21B cushion material, 211 upper wall portion, 212, 212a lower wall portion, 213 standing wall portion, 22 second cushion material, 22A base end portion, 22B medial foot side branch portion, 22C lateral foot side branch portion, 22a upper surface, 22b lower surface, 23 third cushion material, 23a upper surface, 23b lower surface, 24 additional cushion material, 24a upper surface, 24b lower surface, 30 upper plate, 31 upper surface, 32 lower surface, 40 lower plate, 41 upper surface, 42 lower surface, 43 seat portion, 43a retaining hole, 44 protrusion portion, 45 uneven portion, 46 first rib, 47 second rib, 50 Cleats, 60 Upper, 61 Upper body, 62 Shoe tongue, 63 Shoelace, A1 First region, A2 Second region, A3 Third region, A4 Fourth region, A5 Fifth region, G Void, P1 First boundary surface, P2 Second boundary surface, PF Front end position, PR Rear end position, R1 Forefoot, R2 Midfoot, R3 Rearfoot, S Three-dimensional structure, SC Shoe center, U Unit structure, W Wall.

Claims

1. A sole comprising a forefoot portion configured to support the toes and tread of the wearer's foot, a midfoot portion configured to support the arch of the wearer's foot, and a rearfoot portion configured to support the heel of the wearer's foot, which are connected in a front-to-rear direction that coincides with the longitudinal direction of the wearer's foot, the upper surface of which is configured as a support surface for supporting the sole of the wearer's foot, and the lower surface of which is configured as a ground contact surface, a cushioning layer positioned across the forefoot portion, the midfoot portion, and the rearfoot portion; an upper plate positioned closer to the support surface than the cushioning layer so as to cover an upper surface of the cushioning layer and positioned across at least the forefoot portion and the midfoot portion; a lower plate positioned closer to the ground surface than the cushioning layer so as to cover a lower surface of the cushioning layer, and positioned across at least the forefoot portion and the midfoot portion; The cushion layer has a first region that is a portion that supports the MP joint of the wearer's foot, and a second region that is included in a portion that is rearward in the front-to-back direction from the first region and forward in the front-to-back direction from the rear foot portion, The second region includes, in a left-right direction that coincides with the width direction of the wearer's foot, a third region located in a central portion, a fourth region located at an inner foot side end portion, and a fifth region located at an outer foot side end portion, a compression stiffness in the fourth region and a compression stiffness in the fifth region both lower than the compression stiffness in the first region, and a compression stiffness in the third region lower than both the compression stiffness in the fourth region and the compression stiffness in the fifth region.

2. The cushion layer includes a first cushion material that is disposed at least in a portion of the cushion layer that supports the MP joint of the wearer's foot, thereby constituting the first region, and a second cushion material that is disposed so as to straddle at least a portion of the cushion layer that is included in the midfoot portion and a portion that is included in the rearfoot portion, thereby constituting the second region, the second cushioning material has an inner foot-side branch portion that reaches an inner foot-side end portion that is forward of the rear foot portion in the front-to-rear direction, and an outer foot-side branch portion that reaches an outer foot-side end portion that is forward of the rear foot portion in the front-to-rear direction, and has a bifurcated shape toward the front side in the front-to-rear direction, the fourth region is formed by the medial branch portion of the second cushioning material, the fifth region is formed by the outer foot side branch portion of the second cushioning material, The shoe sole according to claim 1 , wherein the third region is formed by a gap provided between the medial branch portion and the lateral branch portion of the second cushioning material.

3. the first cushion material is a unit structure having a three-dimensional shape formed by walls whose outer shape is defined by a pair of parallel planes or curved surfaces, and is configured as a three-dimensional structure made of resin or rubber in which a plurality of unit structures are repeatedly arranged adjacent to each other, 3. The shoe sole according to claim 2, wherein the second cushioning material is a plate-shaped or block-shaped member made of a foam material made of resin or rubber.

4. 4. The sole of claim 3, wherein the unit structure is formed by dividing a structural unit consisting of a plurality of planes arranged to intersect with each other so as to have a hollow space inside into two in any of three orthogonal axial directions, and then adding thickness to the resulting divided structural unit.

5. The sole according to claim 4, wherein the structural unit is any one of a Kelvin structure, an octet structure, a cubic structure, and a cubic octet structure.

6. 4. The shoe sole according to claim 3, wherein the unit structure is formed by dividing a structural unit of a triply periodic minimal surface in two in any of three orthogonal axial directions and then adding thickness to the divided unit.

7. The shoe sole according to claim 6, wherein the structural unit is any one of a Schwartz P structure, a gyroid structure, and a Schwartz D structure.

8. 2. The sole of claim 1, wherein a first rib extending along the medial edge of the sole is provided on a portion of the underside of the lower plate that is included in the medial end of the midfoot portion, and a second rib extending along the lateral edge of the sole is provided on a portion of the underside of the lower plate that is included in the lateral end of the midfoot portion.

9. The shoe sole according to claim 8 , wherein each of the first rib and the second rib is formed by locally increasing the thickness of the lower plate more than other portions.

10. 2. The sole according to claim 1, wherein at least one of a portion of the upper plate included in the forefoot portion and a portion of the lower plate included in the forefoot portion has a curved shape in which a central portion bulges downward in the left-right direction further than an inner end portion and an outer end portion.

11. the lower plate is a spike plate provided with spikes, The sole of claim 1 , wherein the ground contact surface is formed by a lower surface of the lower plate.

12. A shoe sole according to any one of claims 1 to 11; and an upper provided above the sole.

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