Sole structure and shoe including the same

Abstract

To acquire physical characteristics required for a sole structure and stably keep the sole structure.SOLUTION: A sole structure 1 includes a first midsole part 21 made of a first material, a second midsole part 22 made of a second material, and an exterior part 30 made of a third material having rigidity higher than that of the first and second materials. A boundary part 25 of an overlapping part 24 where the first midsole part 21 and the second midsole part 22 overlap in the vertical direction, includes linear first boundary parts 26 and 26 respectively located on a medial side and a lateral side in side view and extending in a foot length direction. The exterior part 30 is configured to cover the first boundary parts 26 and 26 from the outside of the first midsole part 21 and the second midsole part 22.SELECTED DRAWING: Figure 6

Description

[Technical Field]

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

[0002] BACKGROUND ART Conventionally, a sole structure applicable to sports shoes such as running shoes is known, as disclosed in Patent Document 1.

[0003] Patent Document 1 discloses a sole structure (sole 10) including a first cushion body (first cushion body 30) and a second cushion body (first cushion body 32). The first cushion body has a first hardness. The first cushion body is made of a first foam material. The second cushion body has a second hardness greater than the first hardness (i.e., a hardness different from the first hardness). The second cushion body is made of a second foam material different from the first foam material. A portion of the first midsole portion and a portion of the second cushion body are stacked on top of each other in the vertical direction of the sole. The boundary portion where the first midsole portion and the second cushion body overlap each other in the vertical direction is exposed to the outside on the sides located on the front and medial sides of the sole (see Figures 3 and 6 of Patent Document 1). [Prior art documents] [Patent documents]

[0004] [Patent Document 1] US Patent Application Publication No. 2023 / 0035794 Summary of the Invention [Problem to be solved by the invention]

[0005] As described above, the sole structure of Patent Document 1 includes a first cushion body and a second cushion body that have different hardnesses and are made of different foam materials. As a result, the sole structure of Patent Document 1 can impart physical properties (mainly cushioning and rigidity) based on the respective foam materials to each part of the foot of a person wearing shoes equipped with the sole structure (hereinafter referred to as "wearer").

[0006] However, with the sole structure of Patent Document 1, when the wearer's foot touches the road surface while running (hereinafter referred to as "ground contact"), an impact (external force) caused by thrust from the road surface is applied to the sole structure. This impact can have a significant effect on the sole structure, particularly on the portion where the first cushion body and the second cushion body overlap each other in the vertical direction (hereinafter referred to as "overlapping portion"). Specifically, stress concentration is likely to occur at the boundary of the overlapping portion, so that when, for example, the above-mentioned impact acts on the boundary of the overlapping portion, there is a problem in that the overlapping portion is likely to break or the like, starting from the boundary.

[0007] The present disclosure has been made in view of the above points, and its purpose is to obtain the physical properties required for a sole structure while maintaining the stability of the sole structure. [Means for solving the problem]

[0008] To achieve the above object, the first disclosure relates to a sole structure, which includes a first midsole portion made of a first material, a second midsole portion made of a second material that is the same as or different from the first material and at least a portion of which is laminated above or below the first midsole portion, and an exterior portion made of a third material that is more rigid than the first and second materials. The boundaries of the overlapping portions where the first and second midsole portions are vertically overlapped have linear first boundaries located on the medial and lateral instep sides in a side view and extending in the foot length direction. The exterior portion is configured to cover the first boundaries from the outside of the first and second midsole portions.

[0009] The sole structure according to the first disclosure includes a first midsole portion made of a first material and a second midsole portion made of a second material, which allows physical properties (e.g., cushioning, rebound, shock absorption) based on the first material and the second material to be imparted to each part of the foot of a person wearing shoes equipped with the sole structure (hereinafter referred to as "wearer").

[0010] On the other hand, for example, when a wearer is running and the wearer's foot touches the road surface (at the time of contact), an impact caused by the thrust from the road surface is applied to the sole structure. This impact can have a significant effect on the sole structure, particularly on the overlapping portion. Specifically, since stress is likely to concentrate at the boundary of the overlapping portion, for example, if the impact acts on the boundary of the overlapping portion, the overlapping portion may break or the like, starting from the boundary.

[0011] To solve the problems caused by such overlapping portions, the sole structure according to the first disclosure includes an exterior portion made of a third material having higher rigidity than the first and second materials. The exterior portion is configured to cover the first boundary portion from the outside of the first midsole portion and the second midsole portion. With this configuration, the relatively rigid exterior portion functions to reinforce and protect the first boundary portion. This makes it less likely that the overlapping portion will break or otherwise break starting from the first boundary portion, even if the sole structure is subjected to the impact when the shoe touches the ground. In other words, it is possible to maintain the stability of the sole structure. Furthermore, the exterior portion made of the third material can impart a rigidity (physical property based on the third material) higher than the rigidity of each of the first and second materials to the portion of the sole structure where the exterior portion is located.

[0012] Therefore, in the first disclosure, the physical properties required for the sole structure can be obtained, and the sole structure can be kept stable.

[0013] In the second disclosure, in the first disclosure, the exterior portion has a pair of side wall portions located on each of the medial and lateral sides, and each of the pair of side wall portions is configured to cover the first boundary portion from the sides of the first midsole portion and the second midsole portion.

[0014] In this second disclosure, the pair of side walls functions to reinforce and protect the first boundary portion. As a result, even if the impact is applied to the sole structure when the shoe touches the ground, the overlapping portion is less likely to break or break starting from the first boundary portion. Therefore, the sole structure can be maintained in a stable state.

[0015] The third disclosure is the shoe of the second disclosure, wherein the boundary of the overlapping portion further includes a linear second boundary located below the first midsole portion and the second midsole portion in a bottom view. The exterior portion has a bottom located below the first midsole portion and the second midsole portion. The bottom is configured to cover the second boundary from below the first midsole portion and the second midsole portion.

[0016] In the third disclosure, the bottom of the exterior part functions to reinforce and protect the second boundary part. As a result, even if the above-mentioned impact is applied to the sole structure when the shoe touches the ground, the overlapping part is less likely to break or break from the second boundary part, which is located in a position facing the road surface when the shoe touches the ground. Therefore, the sole structure can be maintained stable.

[0017] In the fourth disclosure, in the third disclosure, the bottom portion extends from a position on the sole structure corresponding to the midfoot of the wearer's foot toward a position corresponding to the forefoot.

[0018] In the fourth disclosure, the bottom portion functions to increase the rigidity of the underside of the sole structure from a position corresponding to the midfoot to a position corresponding to the forefoot of the wearer. This function of the bottom portion facilitates stable weight transfer when the wearer's foot contacts the ground while running, for example.

[0019] In a fifth disclosure, a first reinforcing portion made of a fourth material having higher rigidity than the third material is provided on the upper surface of the bottom portion.

[0020] In the fifth disclosure, the first reinforcing portion further increases the rigidity of the underside of the sole structure from a position corresponding to the midfoot to a position corresponding to the forefoot of the wearer, thereby increasing the push-off force (so-called rocker function) when pushing off the road surface, particularly in the forefoot of the wearer.

[0021] In the sixth disclosure, the first material is made of a material having higher resilience than the second material in the first disclosure. The second material is made of a material having better shock absorption than the first material but lower resilience than the first material. The first midsole portion is arranged in a position of the sole structure corresponding to at least the forefoot portion of the wearer's foot. The second midsole portion is arranged in a position of the sole structure corresponding to at least the rearfoot portion of the wearer's foot.

[0022] In this sixth disclosure, a second midsole portion made of a second material is located in the sole structure at a position corresponding to the rear foot portion of the wearer's foot. As a result, when the rear foot portion (particularly the heel portion) of the wearer's foot touches the road surface, the physical properties (shock absorption and low resilience) of the second material improve shock absorption at the time of contact. Meanwhile, a first midsole portion made of a first material is located in the sole structure at a position corresponding to the forefoot portion of the wearer's foot. As a result, when the forefoot portion of the wearer touches the road surface, the physical properties (high resilience) of the first material can enhance resilience at the position corresponding to the forefoot portion. Furthermore, acceleration of the forefoot portion of the wearer's foot when kicking off forward can be increased.

[0023] In the seventh disclosure, in the sixth disclosure, the overlapping portion is positioned in a range of the sole structure from a position corresponding to the midfoot portion of the wearer's foot to a position corresponding to the front portion of the rearfoot portion.

[0024] In the seventh disclosure, the first midsole portion and the second midsole portion are vertically stacked in the thickness direction of the sole structure in a range from a position corresponding to the midfoot of the wearer's foot to a position corresponding to the front part of the rear foot. This allows the physical properties of the first material and the second material to coexist in the range from a position corresponding to the midfoot of the wearer's foot to a position corresponding to the front part of the rear foot. As a result, a smooth transition in the ground contact state can be achieved from when the rear foot begins to contact the road surface to when the forefoot kicks off.

[0025] In the eighth disclosure, in the seventh disclosure, the first boundary portion extends from the underside to the upper side of the sole structure, from a position on the sole structure corresponding to the midfoot portion of the wearer's foot to a position corresponding to the front portion of the rearfoot portion.

[0026] In the eighth disclosure, the physical properties of the first material and the second material can be gradually changed from the time when the rear foot of the wearer's foot starts to contact the road surface until the forefoot starts to push off. In other words, the contact state can be smoothly transitioned from the time when the wearer's foot starts to contact the road surface until the push off.

[0027] Furthermore, in the eighth disclosure, as in the first disclosure, the exterior part is configured to cover the first boundary part from the outside of the first midsole part and the second midsole part. That is, the range of the sole structure from a position corresponding to the midfoot part of the wearer's foot to a position corresponding to the front part of the rearfoot part is reinforced and protected by the exterior part. As a result, when the wearer is running, weight transfer can be stabilized when the ground contact state of the wearer's foot shifts from the rearfoot part to the forefoot part.

[0028] In the ninth disclosure, the first and second materials are each made of a material that is softer and has higher resilience than the third material. The first midsole portion is disposed in the sole structure in a range from a position corresponding to the forefoot of the wearer's foot to a position corresponding to the front part of the rearfoot. The second midsole portion is disposed in the sole structure in a range from a position corresponding to the midfoot of the wearer's foot to a position corresponding to the rearfoot.

[0029] In the ninth disclosure, the positional relationship between the first midsole portion and the second midsole portion makes it possible to obtain the common physical properties (softness and high resilience) of the first material and the second material in the range of the sole structure from the position corresponding to the forefoot to the position corresponding to the rearfoot of the wearer's foot.

[0030] Also in the ninth disclosure, as in the first disclosure, the exterior part is configured to cover the first boundary part from the outside of the first midsole part and the second midsole part. That is, in the ninth disclosure, the exterior part can reinforce and protect the range of the sole structure from a position corresponding to the midfoot part of the wearer's foot to a position corresponding to the front part of the rearfoot part. As a result, when the wearer is running, weight transfer can be stabilized when the ground contact state of the wearer's foot shifts from the rearfoot part to the forefoot part.

[0031] In the tenth disclosure, in the first disclosure, the first material is made of a material that is more rigid than the second material. The second material is made of a material that is softer than the first material and has higher resilience than the first material. The first midsole portion is arranged in a range of the sole structure from a position corresponding to the forefoot to a position corresponding to the midfoot of the wearer's foot. The second midsole portion is arranged in a range of the sole structure from a position corresponding to the forefoot to a position corresponding to the rearfoot of the wearer's foot.

[0032] In the tenth disclosure, a second midsole portion made of a second material is located in the sole structure in a range extending from a position corresponding to the forefoot to a position corresponding to the rearfoot of the wearer. This allows for enhanced cushioning and resilience in the range extending from a position corresponding to the forefoot to a position corresponding to the rearfoot of the wearer, based on the physical properties (softness and high resilience) of the second material. Meanwhile, a first midsole portion made of a first material is located in the sole structure in a range extending from a position corresponding to the forefoot to a position corresponding to the midfoot of the wearer. This allows for enhanced forward kicking force (rocker function), particularly in the forefoot of the wearer, based on the physical properties (rigidity) of the first material, when the forefoot of the wearer touches the road surface.

[0033] In the eleventh disclosure, the overlapping portion is disposed in a range from a position corresponding to a forefoot to a position corresponding to a midfoot of a wearer's foot in the sole structure, and the first midsole portion is positioned below the second midsole portion in the overlapping portion.

[0034] In the eleventh disclosure, the first midsole portion and the second midsole portion are vertically overlapped in the thickness direction of the sole structure in a range from a position corresponding to the forefoot to a position corresponding to the midfoot of the wearer. This allows the physical properties of the first material and the second material to coexist in the range from a position corresponding to the forefoot to a position corresponding to the midfoot of the wearer. Furthermore, because the first midsole portion is located below the second midsole portion in the overlapping portion, cushioning and resilience are obtained in the range from a position corresponding to the forefoot to a position corresponding to the midfoot of the wearer, and forward kicking force (rocker function) can be improved.

[0035] In the twelfth disclosure, in the eleventh disclosure, the first boundary portion extends from the lower side to the upper side of the sole structure as it moves from a position corresponding to the midfoot of the wearer's foot to a position corresponding to the forefoot of the wearer's foot in the sole structure. The sole structure further includes a second reinforcing portion made of a fourth material having a higher rigidity than the third material. The second reinforcing portion is disposed at the first boundary portion and is layered between the first midsole portion and the second midsole portion.

[0036] In the twelfth disclosure, the second reinforcing portion further increases the rigidity of the position corresponding to the first boundary portion (the range of the sole structure from the position corresponding to the midfoot to the position corresponding to the forefoot of the wearer), thereby increasing the push-off force (rocker function) when pushing off the road surface, particularly in the forefoot of the wearer.

[0037] A thirteenth disclosure is a shoe having a first sole structure.

[0038] In the thirteenth disclosure, a shoe can be obtained that exhibits the same effects as those of the sole structure according to the first disclosure. [Effects of the Invention]

[0039] As described above, according to the present disclosure, it is possible to obtain the physical properties required for the sole structure and to maintain the stability of the sole structure. [Brief explanation of the drawings]

[0040] [Figure 1] FIG. 1 is a side view showing a shoe equipped with a sole structure according to an embodiment of the present disclosure, as viewed from the instep side. [Figure 2] FIG. 2 is a perspective view showing the sole structure as viewed from above. [Figure 3] FIG. 3 is an exploded perspective view showing the midsole and the exterior part as viewed from above. [Figure 4] FIG. 4 is a plan view showing the sole structure shown in FIG. 1 as viewed from above. [Figure 5] FIG. 5 is a bottom view of the sole structure shown in FIG. [Figure 6] FIG. 6 is a side view showing the sole structure shown in FIG. 1 as viewed from the medial side. [Figure 7] FIG. 7 is a cross-sectional view taken along line VII-VII in FIG. [Figure 8] FIG. 8 is a cross-sectional view taken along line VIII-VIII in FIG. [Figure 9] FIG. 9 is a view equivalent to FIG. 1 of a shoe having a sole structure according to the second modification. [Figure 10] FIG. 10 is a view equivalent to FIG. 1 of a shoe having a sole structure according to the third modification. [Figure 11] FIG. 11 is a view equivalent to FIG. 1 of a shoe having a sole structure according to the fourth modification. DETAILED DESCRIPTION OF THE INVENTION

[0041] Hereinafter, embodiments of the present disclosure will be described in detail with reference to the accompanying drawings. The following description of the embodiments is merely exemplary in nature and is not intended to limit the present disclosure, its applications, or its uses.

[0042] (Shoes) 1 shows an entire shoe S including a sole structure 1 according to an embodiment of the present disclosure and an upper 2 for covering a wearer's foot. The shoe S is suitable for running, for example. However, the shoe S is not limited to running shoes and can be used as shoes for various sports competitions.

[0043] (Sole structure) As shown in FIGS. 1 to 6, the sole structure 1 includes an outsole 10 and a midsole 20.

[0044] The sole structure 1 according to the embodiment of the present disclosure is illustrated only for the left foot. Although not shown, the sole structure for the right foot is bilaterally symmetrical to the sole structure 1 for the left foot. In the following description, only the sole structure 1 for the left foot will be described, and a description of the sole structure for the right foot will be omitted. Note that the shoe S shown in FIG. 1 is also illustrated only for the left foot.

[0045] In the following description, "upper" and "lower" shown in each figure represent the positional relationship in the thickness direction (vertical direction) of the sole structure 1. "Medial side" and "lateral side" shown in each figure represent the positional relationship in the foot width direction of the sole structure 1. Furthermore, "front" and "rear" shown in each figure represent the positional relationship in the foot length direction of the sole structure 1.

[0046] 1 and 4 to 7, in the sole structure 1, the area corresponding to the forefoot of the wearer is indicated by the symbol F, the area corresponding to the midfoot of the wearer is indicated by the symbol M, and the area corresponding to the rearfoot of the wearer is indicated by the symbol H. Note that in Figs. 1 to 3, the symbols F, M, and H are omitted for the sake of simplicity.

[0047] (Outsole) 1 to 3 and 6, the outsole 10 is disposed under the midsole 20. The outsole 10 is made of a hard elastic material that is harder than the midsole 20.

[0048] Specifically, suitable materials for the outsole 10 include thermoplastic synthetic resins such as ethylene-vinyl acetate copolymer (EVA), thermosetting resins such as polyurethane (PU), rubber materials such as butadiene rubber and chloroprene rubber, and foam materials obtained by expanding these materials. The hardness of the outsole 10 is preferably set to, for example, 50A to 80A (more preferably 60A to 70A) in durometer C or A.

[0049] As shown in FIGS. 5 and 7, the outsole 10 has a first outsole portion 11, a second outsole portion 12, and a third outsole portion 13.

[0050] The first outsole portion 11 is disposed in a position of the sole structure 1 corresponding to the forefoot portion F of the wearer's foot. The first outsole portion 11 is attached to the lower surface of a first midsole portion 21, which will be described later.

[0051] The second outsole portion 12 is disposed in a position of the sole structure 1 corresponding to the forefoot portion F of the wearer's foot. The second outsole portion 12 is attached to an exterior portion 30, which will be described later. Specifically, the second outsole portion 12 is attached to the underside of a bottom portion 32, which will be described later.

[0052] The third outsole portion 13 is disposed in a position of the sole structure 1 corresponding to the rear foot portion H of the wearer's foot. The third outsole portion 13 is attached to the lower surface of the second midsole portion 22, which will be described later.

[0053] (Midsole) As shown in Figures 1 to 3 and 6, the midsole 20 is disposed by layering it on the upper side of the outsole 10. The midsole 20 has the upper 2 (see Figure 1) attached thereto.

[0054] 1 to 8, the midsole 20 is composed of a first midsole portion 21 and a second midsole portion 22. The first midsole portion 21 and the second midsole portion 22 are arranged such that a portion of each of them overlaps with the other in the vertical direction.

[0055] The upper surfaces of the first midsole portion 21 and the second midsole portion 22 are configured as a sole support surface 23 for supporting the sole of the wearer's foot. The sole support surface 23 may be configured to directly support the sole of the wearer's foot, or may be configured to support the sole of the wearer's foot via an insole (not shown) or the like.

[0056] (First midsole part) The first midsole portion 21 is made of a first material. In this embodiment, the first material is made of a material having higher resilience than a second material, which will be described later. A specific example of the first material is thermoplastic polyurethane (TPU) foam having a hardness of 40C on the Asker C scale.

[0057] As shown in FIGS. 4 to 6, the first midsole portion 21 is disposed in the sole structure 1 in a range from a position corresponding to the forefoot portion F of the wearer's foot to a position corresponding to the front part of the rearfoot portion H.

[0058] (Second midsole part) The second midsole portion 22 is made of a second material. In this embodiment, the second material is made of a material different from the first material. For example, the second material is made of a material that has better shock absorption properties than the first material and lower resilience than the first material. A specific example of the second material is polyurethane (PU) foam having a hardness of 30C on the Asker C scale.

[0059] 4 to 6, the second midsole portion 22 is disposed in the sole structure 1 in a range extending from a position corresponding to the midfoot portion M of the wearer's foot to a position corresponding to the rearfoot portion H. As shown in Fig. 4, in a plan view, the upper surface of the second midsole portion 22 is disposed in a position corresponding to the rearfoot portion H of the sole supporting surface 23.

[0060] 6 and 7, in this embodiment, a portion of the second midsole portion 22 is layered above a portion of the first midsole portion 21. Specifically, a front portion of the second midsole portion 22 is layered below a rear portion of the first midsole portion 21.

[0061] (overlapping part) As shown in Figures 1 to 8, the sole structure 1 has an overlapping portion 24. The overlapping portion 24 corresponds to the portion where the first midsole portion 21 and the second midsole portion 22 overlap each other in the up-down direction. Note that Figure 8 shows the components on a larger scale than Figures 4 to 7 in order to make them easier to understand.

[0062] In this embodiment, the overlapping portion 24 is disposed in the sole structure 1 in a range from a position corresponding to the midfoot portion M of the wearer's foot to a position corresponding to the front portion of the rearfoot portion H. In the overlapping portion 24 of this embodiment, the front portion of the second midsole portion 22 is located below the rear portion of the first midsole portion 21. As shown in Fig. 4, the overlapping portion 24 is disposed in a position on the sole support surface 23 corresponding to the front portion of the rearfoot portion H of the wearer's foot in a plan view.

[0063] (first boundary) 1, 3, and 6, the overlapping portion 24 is configured as a linear boundary portion 25. The boundary portion 25 has a linear first boundary portion 26 in a side view. The first boundary portion 26 is located on each of the medial and lateral sides in a side view.

[0064] The first boundary portion 26 is arranged to include at least a position of the sole structure 1 that corresponds to the midfoot portion M of the wearer's foot. In this embodiment, the first boundary portion 26 is arranged in a range that extends from the position that corresponds to the midfoot portion M of the wearer's foot to a position that corresponds to the front part of the rearfoot portion H of the sole structure 1.

[0065] The first boundary portion 26 extends in the foot length direction. Specifically, in this embodiment, the first boundary portion 26 extends from the lower side to the upper side of the sole structure 1, from a position in the sole structure 1 corresponding to the midfoot portion M of the wearer's foot toward a position corresponding to the front part of the rearfoot portion H.

[0066] (Second boundary) 5, the boundary 25 of the overlapping portion 24 has a linear second boundary 27 in a bottom view. The second boundary 27 is located below the first midsole part 21 and the second midsole part 22 in a bottom view.

[0067] In a bottom view, the second boundary portion 27 is disposed at a position in the sole structure 1 that corresponds to the midfoot portion M of the wearer's foot. The second boundary portion 27 is continuous with the first boundary portion 26 below the first midsole portion 21 and the second midsole portion 22.

[0068] (exterior part) 1 to 8, the sole structure 1 includes an exterior portion 30. The exterior portion 30 is made of a third material having higher rigidity than the first material and the second material. A specific example of the third material is ethylene-vinyl acetate copolymer (EVA) foam having a hardness of 60C on the Asker C scale.

[0069] The exterior part 30 is arranged in the sole structure 1 in a range extending from a position corresponding to the midfoot part M of the wearer's foot to a position corresponding to the rearfoot part H. The exterior part 30 is attached to the first midsole part 21 and the second midsole part 22 by, for example, an adhesive.

[0070] As a characteristic configuration according to the embodiment of the present disclosure, the exterior part 30 is configured to cover the first boundary parts 26, 26 from the outside of the first midsole part 21 and the second midsole part 22. The exterior part 30 of this embodiment is configured so that none of the first boundary parts 26, 26 are exposed to the outside (see FIGS. 1 and 6).

[0071] (Side wall) As shown in Figures 3 to 5, the exterior part 30 has a pair of side walls 31, 31. Each side wall 31 is located on the medial side and the lateral side. Each side wall 31 is formed integrally with the bottom part 32 at the rear part of the bottom part 32 (see Figures 3 and 5), which will be described later. Each side wall 31 extends obliquely upward from the bottom part 32 as it moves rearward from the rear part of the bottom part 32.

[0072] 6 and 8, the side wall 31 located on the medial side is configured to cover the first boundary 26 located on the medial side from the sides of the first midsole part 21 and the second midsole part 22. Also, as shown in Figures 1 and 8, the side wall 31 located on the lateral side is configured to cover the first boundary 26 located on the lateral side from the sides of the first midsole part 21 and the second midsole part 22.

[0073] (bottom) 3 and 5, the exterior part 30 has a bottom part 32. The bottom part 32 is configured to be located below the first midsole part 21 and the second midsole part 22. The bottom part 32 is continuous with each of the pair of side wall parts 31, 31.

[0074] 3 and 7, a storage section 33 for storing a first reinforcing section 41 (described later) is provided on the upper surface of the bottom section 32. The storage section 33 is formed in a bottomed shape that is recessed downward from the upper surface of the bottom section 32.

[0075] 5, the bottom 32 is configured to extend from a position corresponding to the midfoot M of the wearer's foot in the sole structure 1 toward a position corresponding to the forefoot F. In bottom view, the tip portion of the bottom 32 is formed so that it tapers from the portion located on the medial instep side and the portion located on the lateral instep side toward approximately the center in the width direction of the foot as it moves from the position corresponding to the midfoot M to the position corresponding to the forefoot F.

[0076] 5 and 7, the bottom portion 32 is configured to cover the second boundary portion 27 from below the first midsole portion 21 and the second midsole portion 22. Specifically, the rear portion of the bottom portion 32 overlaps with the second boundary portion 27 in the up-down direction (see FIG. 7).

[0077] (First reinforcement part) As shown in Figures 3 and 7, a first reinforcing part 41 is provided on the upper surface of the bottom part 32. The first reinforcing part 41 is housed in the housing part 33 of the exterior part 30. Specifically, when housed in the housing part 33, the first reinforcing part 41 is layered between the first midsole part 21 and the bottom part 32 of the exterior part 30 (see Figure 7). The first reinforcing part 41 is formed in a substantially plate shape (see Figure 3).

[0078] The first reinforcing portion 41 is made of a fourth material having higher rigidity than the third material. Specific examples of the fourth material include carbon fiber reinforced plastic (CFRP) and polyamide (PA).

[0079] [Effects of the embodiment] As described above, the sole structure 1 includes the first midsole portion 21 made of the first material and the second midsole portion 22 made of the second material. With this configuration, it is possible to impart physical properties (e.g., cushioning, resilience, shock absorption) based on the first material and the second material to each part of the wearer's foot.

[0080] On the other hand, for example, when the wearer's foot touches the road surface while running (hereinafter referred to as "contact point"), an impact caused by thrust from the road surface is applied to sole structure 1. This impact can have a significant effect on overlapping portion 24 in sole structure 1. Specifically, stress is likely to concentrate at boundary portion 25 of overlapping portion 24, so if the impact acts on boundary portion 25 of overlapping portion 24, for example, fracture of overlapping portion 24 may occur, starting from boundary portion 25.

[0081] To solve the problems caused by the overlapping portion 24, the sole structure 1 includes an exterior portion 30 made of a third material having higher rigidity than the first and second materials. The exterior portion 30 is configured to cover the first boundary portion 26 from the outside of the first midsole portion 21 and the second midsole portion 22. With this configuration, the relatively high rigidity of the exterior portion 30 functions to reinforce and protect the first boundary portion 26. As a result, even if the above-mentioned impact is applied to the sole structure 1 when the shoe touches the ground, breakage or the like of the overlapping portion 24 originating from the first boundary portion 26 is unlikely to occur. In other words, the sole structure 1 can be maintained stable. Furthermore, the exterior portion 30 made of the third material can impart a rigidity (physical property based on the third material) higher than the rigidity of each of the first and second materials to the portion of the sole structure 1 where the exterior portion 30 is located.

[0082] Therefore, in the embodiment of the present disclosure, the physical properties required for the sole structure 1 can be obtained, and the sole structure 1 can be kept stable.

[0083] Incidentally, when the first midsole portion 21 and the second midsole portion 22 are molded using the first material and the second material, for example, by two-color molding, the boundary portion 25 of the overlapping portion 24 may become distorted and wavy when visually observed. If the boundary portion 25 in such a distorted state were to be exposed to the outside, it could impair the aesthetics of the sole structure 1 and the shoes S. In contrast, in the sole structure 1 according to the embodiment of the present disclosure, the exterior portion 30 covers the first boundary portion 26 from the outside of the first midsole portion 21 and the second midsole portion 22 (i.e., the exterior portion 30 prevents the first boundary portion 26 from being exposed to the outside), so even if the boundary portion 25 of the overlapping portion 24 is distorted, the aesthetics of the sole structure 1 and the shoes S can be prevented from being impairing.

[0084] Additionally, the exterior portion 30 has a pair of side walls 31, 31 located on the medial and lateral sides, and each side wall 31 is configured to cover the first boundary portion 26 from the sides of the first midsole portion 21 and the second midsole portion 22. With this configuration, each side wall 31 functions to reinforce and protect the first boundary portion 26. As a result, even if the above-mentioned impact is applied to the sole structure 1 when the shoe touches the ground, breakage or the like of the overlapping portion 24 originating from the first boundary portion 26 is unlikely to occur. Therefore, the sole structure 1 can be maintained in a stable state.

[0085] Furthermore, the bottom 32 of the exterior part 30 is configured to cover the second boundary part 27 from below the first midsole part 21 and the second midsole part 22. With this configuration, the bottom part 32 functions to reinforce and protect the second boundary part 27. As a result, even if the above-mentioned impact is applied to the sole structure 1 when the shoe touches the ground, breakage or the like of the overlapping part 24 is unlikely to occur starting from the second boundary part 27 that faces the road surface when the shoe touches the ground. Therefore, the sole structure 1 can be maintained stable.

[0086] Furthermore, the bottom 32 extends from a position in the sole structure 1 that corresponds to the midfoot M of the wearer's foot toward a position that corresponds to the forefoot F. With this configuration, the bottom 32 functions to increase the rigidity of the underside of the sole structure 1 from a position that corresponds to the midfoot M of the wearer's foot to a position that corresponds to the forefoot F. This function facilitates stable weight transfer when the wearer's foot shifts from the midfoot M to the forefoot F during ground contact, for example, while running.

[0087] Additionally, a first reinforcing portion 41 made of a fourth material having higher rigidity than the third material is provided on the upper surface of the bottom portion 32. This first reinforcing portion 41 further increases the rigidity of the underside of the sole structure 1 from a position corresponding to the midfoot portion M of the wearer's foot to a position corresponding to the forefoot portion F. This makes it possible to increase the push-off force (rocker function) particularly when the forefoot portion F of the wearer pushes off the road surface.

[0088] In this embodiment, the first material is made of a material with higher resilience than the second material. The second material is made of a material with better shock absorption than the first material but lower resilience than the first material. In this embodiment, a second midsole portion 22 made of the second material is located in the sole structure 1 at a position corresponding to the rear foot portion H of the wearer's foot. As a result, when the rear foot portion H (particularly the heel portion) of the wearer's foot touches the road surface, the physical properties (shock absorption and low resilience) of the second material improve shock absorption at the time of contact. Meanwhile, a first midsole portion 21 made of the first material is located in the sole structure 1 at a position corresponding to the forefoot portion F of the wearer's foot. As a result, when the forefoot portion F of the wearer touches the road surface, the physical properties (high resilience) of the first material can improve resilience at the position corresponding to the forefoot F. Furthermore, the acceleration of the forefoot portion F of the wearer's foot when kicking off forward can be increased.

[0089] In this embodiment, the overlapping portion 24 is disposed in a range of the sole structure 1 from a position corresponding to the midfoot portion M of the wearer's foot to a position corresponding to the front portion of the rearfoot portion H. That is, in a range of the sole structure 1 from a position corresponding to the midfoot portion M of the wearer's foot to a position corresponding to the front portion of the rearfoot portion H, the first midsole portion 21 and the second midsole portion 22 are vertically overlapped in the thickness direction of the sole structure 1. This allows the physical properties of the first material and the second material to coexist in a range from a position corresponding to the midfoot portion M of the wearer's foot to a position corresponding to the front portion of the rearfoot portion H. As a result, a smooth transition of the ground contact state can be achieved from the time the rearfoot portion H of the wearer's foot begins to contact the road surface to the time the forefoot portion F kicks off.

[0090] Furthermore, the first boundary portion 26 extends from the bottom to the top of the sole structure 1, moving from a position in the sole structure 1 corresponding to the midfoot portion M of the wearer's foot to a position corresponding to the front portion of the rearfoot portion H. This allows the physical properties of the first material and the second material to change gradually from the time the rearfoot portion H of the wearer's foot begins to contact the road surface until the forefoot portion F pushes off. That is, the ground contact state from the time the wearer's foot begins to contact the road surface until the push-off can be smoothly transitioned. Furthermore, in this embodiment, the range of the sole structure 1 from the position corresponding to the midfoot portion M of the wearer's foot to the position corresponding to the front portion of the rearfoot portion H is reinforced and protected by the exterior portion 30. As a result, when the wearer is running, weight transfer can be stabilized as the ground contact state of the wearer's foot shifts from the rearfoot portion H to the forefoot F.

[0091] (Modification 1 of the embodiment) In the above embodiment, the second material is made of a material different from the first material, but this is not limiting. For example, the second material may be made of the same material as the first material.

[0092] Specifically, as a first modification of the above embodiment, each of the first material and the second material may be made of a material that is softer and has higher resilience than the third material. A specific example of the first material and the second material in this modification is a polyester-based thermoplastic elastomer (TPEE) foam having a hardness of 40C on the Asker C scale.

[0093] In this variant 1, as in the above embodiment, the first midsole portion 21 is positioned in a range of the sole structure 1 from a position corresponding to the forefoot F of the wearer's foot to a position corresponding to the front part of the rear foot H, while the second midsole portion 22 is positioned in a range of the sole structure 1 from a position corresponding to the midfoot M of the wearer's foot to a position corresponding to the rear foot H.

[0094] In this modified example, due to the positional relationship between the first midsole portion 21 and the second midsole portion 22, the common physical properties (softness and high resilience) of the first material and the second material can be obtained in the range of the sole structure 1 from the position corresponding to the forefoot F of the wearer's foot to the position corresponding to the rearfoot H.

[0095] Furthermore, in this modified example as well, the range of the sole structure 1 from the position corresponding to the midfoot portion M of the wearer's foot to the position corresponding to the front part of the rearfoot portion H is reinforced and protected by the exterior portion 30. As a result, when the wearer is running, weight transfer can be stabilized when the ground contact state of the wearer's foot shifts from the rearfoot portion H to the forefoot portion F.

[0096] (Modification 2 of the embodiment) In the above embodiment, the overlapping portion 24 is located in a range of the sole structure 1 from a position corresponding to the midfoot portion M of the wearer's foot to a position corresponding to the front part of the rearfoot portion H, but this is not limiting. For example, it may be configured as in Modification 2 shown in Fig. 9. Note that the boundary portion 25 of the overlapping portion 24 in this modification does not have the second boundary portion 27 described in the above embodiment.

[0097] 9, the overlapping portion 24 may be disposed over the entire range of the sole structure 1 from a position corresponding to the midfoot portion M of the wearer's foot to a position corresponding to the rearfoot portion H. That is, the first midsole portion 21 and the second midsole portion 22 are overlapped in the vertical direction over the entire range of the sole structure 1 from a position corresponding to the midfoot portion M of the wearer's foot to a position corresponding to the rearfoot portion H. This makes it possible to impart physical properties based on both the first material and the second material to the entire range from a position corresponding to the midfoot portion M of the wearer's foot to a position corresponding to the rearfoot portion H.

[0098] Also, like in this modified example, the first boundary portion 26 may extend from a position on the sole structure 1 that corresponds to the midfoot portion M of the wearer's foot, beyond a position that corresponds to the front portion of the rear foot portion H, to a position that corresponds to the rear portion of the rear foot portion H. Furthermore, the exterior portion 30 of this modified example may be disposed in a range of the sole structure 1 that extends from the position that corresponds to the midfoot portion M of the wearer's foot to a position that corresponds to the rear portion of the rear foot portion H, in a side view. This makes it possible to obtain rigidity due to the third material of the exterior portion 30 in the range of the sole structure 1 that extends from the position that corresponds to the midfoot portion M of the wearer's foot to a position that corresponds to the rear portion of the rear foot H.

[0099] Furthermore, in the exterior part 30 of this modified example, the outer contour lines of the peripheral edges located on both the upper and lower sides of the side wall part 31 are formed in a curved, wavy shape relative to the extension direction of the first boundary part 26. Such a shape of the side wall part 31 increases the rigidity of the side wall part 31.

[0100] Furthermore, even if the rear portion of the first boundary portion 26 (the rear portion of the first boundary portion 26 located near the rear end portion of the sole structure 1 as shown in Figure 9) is exposed to the outside as in this modified example, as long as the exterior portion 30 (side wall portion 31) covers the area that occupies most of the first boundary portion 26, the functional effects of the exterior portion 30 (side wall portion 31) described in the above embodiment can be fully achieved.

[0101] (Modification 3 of the embodiment) As a further modification of the above embodiment, the positional relationship between the first midsole portion 21 and the second midsole portion 22 exemplified in the above modification 2 (see FIG. 9) may be inverted in the up-down direction as in modification 3 shown in FIG. 10. Specifically, as shown in FIG. 10, the entire second midsole portion 22 may be configured to be located above the first midsole portion 21.

[0102] (Fourth Modification of the Embodiment) As a fourth variation of the above embodiment, the physical properties of the first material and the second material described in the above embodiment, the positional relationship between the first midsole portion 21 and the second midsole portion 22, the position and range of the overlapping portion 24, and the position of the exterior portion 30 may be replaced with the following configuration based on Figure 11.

[0103] Specifically, in this modification, the first material is made of a material having higher rigidity than the second material. A specific example of the first material in this modification is ethylene-vinyl acetate copolymer (EVA) foam having a hardness of 50C on the Asker C scale. Note that the first material in this modification has lower rigidity than the third material.

[0104] The second material is softer and more resilient than the first material, and an example of the second material in this variation is polyether block amide (PEBA) foam having a hardness of 40C on the Asker C scale.

[0105] 11, the first midsole portion 21 is disposed in the sole structure 1 in a range from a position corresponding to the forefoot portion F of the wearer's foot to a position corresponding to the midfoot portion M. On the other hand, the second midsole portion 22 is disposed in the sole structure 1 in a range from a position corresponding to the forefoot portion F of the wearer's foot to a position corresponding to the rearfoot portion H.

[0106] In the sole structure 1 according to the fourth modification, the second midsole portion 22 can enhance cushioning and resilience based on the physical properties (softness and high resilience) of the second material in a range from a position corresponding to the forefoot F of the wearer to a position corresponding to the rearfoot H. On the other hand, the first midsole portion 21 can enhance, based on the physical properties (rigidity) of the first material, particularly the forward kicking force (rocker function) of the forefoot F of the wearer when the forefoot F of the wearer touches the road surface.

[0107] 11 , the overlapping portion 24 is disposed in the sole structure 1 in a range from a position corresponding to the forefoot F of the wearer's foot to a position corresponding to the midfoot M. In the overlapping portion 24, the first midsole portion 21 is located below the second midsole portion 22. That is, in the range of the sole structure 1 from a position corresponding to the forefoot F to a position corresponding to the midfoot M of the wearer's foot, the first midsole portion 21 and the second midsole portion 22 are overlapped vertically in the thickness direction of the sole structure 1.

[0108] This allows the physical properties of the first material and the second material to coexist in the range from the position corresponding to the forefoot F to the position corresponding to the midfoot M of the wearer. Furthermore, in the overlapping portion 24, the first midsole portion 21 is located below the second midsole portion 22, so that in the range from the position corresponding to the forefoot F to the position corresponding to the midfoot M of the wearer, cushioning and resilience are obtained while increasing the forward kicking force (rocker function).

[0109] Furthermore, as shown in Figure 11, the first boundary portion 26 extends from the bottom to the top of the sole structure 1, moving from a position corresponding to the midfoot portion M of the wearer's foot to a position corresponding to the forefoot portion F of the sole structure 1.

[0110] The sole structure 1 according to the fourth modification includes a second reinforcing portion 42 made of a fourth material having higher rigidity than the third material. The second reinforcing portion 42 is disposed at the first boundary portion 26 and is laminated between the first midsole portion 21 and the second midsole portion 22. Specific examples of the fourth material in this modification include carbon fiber reinforced plastic (CFRP) and polyamide (PA), as in the above embodiment.

[0111] This second reinforcing portion 42 further increases the rigidity of the position corresponding to the first boundary portion 26 (the range of the sole structure 1 from the position corresponding to the midfoot portion M of the wearer's foot to the position corresponding to the forefoot portion F). As a result, it is possible to increase the push-off force (rocker function) particularly when the forefoot portion F of the wearer pushes off the road surface.

[0112] [Other embodiments] In the above embodiment, the first reinforcing portion 41 is provided, but the present invention is not limited to this. That is, in the above embodiment, the first reinforcing portion 41 may be omitted.

[0113] Although the embodiments of the present disclosure have been described above, the present disclosure is not limited to the above-described embodiments, and various modifications are possible within the scope of the present disclosure. [Industrial Applicability]

[0114] The present disclosure is industrially applicable, for example, to a sole structure of a shoe suitable for running and a shoe including the same. [Explanation of symbols]

[0115] S: Shoes 1: Sole structure 2: Upper 10: Outsole 20: Midsole 21: First midsole part 22: Second midsole part 23: Sole support surface 24: Overlapping part 25: Boundary 26:First boundary 27:Second boundary 30:Exterior part 31: Side wall 32: Bottom 41:First reinforcement part 42:Second reinforcement part F:Forefoot M: Midfoot H: Rear foot

Claims

1. a first midsole portion made of a first material; a second midsole portion made of a second material that is the same as or different from the first material, at least a portion of which is laminated above or below the first midsole portion; an exterior portion made of a third material having a higher rigidity than the first material and the second material, a boundary portion of an overlapping portion where the first midsole portion and the second midsole portion are overlapped with each other in the up-down direction has a linear first boundary portion located on each of the medial instep side and the lateral instep side in a side view and extending in the foot length direction, The exterior portion is configured to cover the first boundary portion from the outside of the first midsole portion and the second midsole portion.

2. The sole structure according to claim 1, The exterior portion has a pair of side wall portions located on the medial side and the lateral side, A sole structure, wherein each of the pair of side wall portions is configured to cover the first boundary portion from the sides of the first midsole portion and the second midsole portion.

3. The sole structure according to claim 2, the boundary portion of the overlapping portion further includes a linear second boundary portion located below the first midsole portion and the second midsole portion in a bottom view, the exterior portion has a bottom portion located below the first midsole portion and the second midsole portion, The bottom portion is configured to cover the second boundary portion from below the first midsole portion and the second midsole portion.

4. The sole structure according to claim 3, The sole structure, wherein the bottom portion extends from a position on the sole structure corresponding to a midfoot portion of a wearer's foot toward a position corresponding to a forefoot portion.

5. The sole structure according to claim 4, A sole structure, wherein a first reinforcing portion made of a fourth material having higher rigidity than the third material is provided on an upper surface of the bottom portion.

6. The sole structure according to claim 1, the first material is made of a material having a higher resilience than the second material, the second material is made of a material having a higher impact absorption property than the first material and a lower resilience than the first material, the first midsole portion is disposed in the sole structure at a position corresponding to at least a forefoot portion of a wearer's foot; The second midsole portion is disposed in the sole structure at a position corresponding to at least a rear foot portion of a wearer's foot.

7. The sole structure according to claim 6, The overlapping portion is positioned in a range of the sole structure from a position corresponding to a midfoot portion of a wearer's foot to a position corresponding to a front portion of a rearfoot portion.

8. The sole structure according to claim 7, The first boundary portion extends from the underside of the sole structure toward the upper side thereof, from a position on the sole structure corresponding to a midfoot portion of a wearer's foot toward a position on the sole structure corresponding to a front portion of a rearfoot portion.

9. The sole structure according to claim 1, each of the first material and the second material is made of a material that is softer than the third material and has higher resilience than the third material; the first midsole portion is disposed in a range of the sole structure from a position corresponding to a forefoot portion of the wearer's foot to a position corresponding to a front portion of a rearfoot portion, The second midsole portion is disposed in the sole structure in a range from a position corresponding to a midfoot portion of a wearer's foot to a position corresponding to a rearfoot portion of the sole structure.

10. The sole structure according to claim 1, the first material is made of a material having a higher rigidity than the second material; the second material is made of a material that is softer than the first material and has higher resilience than the first material, the first midsole portion is disposed in a range of the sole structure from a position corresponding to a forefoot portion of the wearer's foot to a position corresponding to a midfoot portion, The second midsole portion is disposed in a range of the sole structure from a position corresponding to a forefoot portion of a wearer's foot to a position corresponding to a rearfoot portion of the wearer's foot.

11. The sole structure according to claim 10, the overlapping portion is disposed in a range of the sole structure from a position corresponding to a forefoot portion of a wearer's foot to a position corresponding to a midfoot portion of the wearer's foot, A sole structure in which the first midsole portion is positioned below the second midsole portion in the overlapping portion.

12. The sole structure according to claim 11, the first boundary portion extends from a lower side to an upper side of the sole structure while moving from a position corresponding to a midfoot portion of the wearer's foot to a position corresponding to a forefoot portion of the sole structure, a second reinforcing portion made of a fourth material having a higher rigidity than the third material; A sole structure, wherein the second reinforcing portion is disposed at the first boundary portion and is layered between the first midsole portion and the second midsole portion.

13. A shoe comprising the sole structure according to claim 1.

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