Sole and shoe provided with same

Abstract

A sole (10) includes a sole body including: a first elastic member (20) formed of a foam material and a second elastic member (30A2, 30B2) formed of a solid viscoelastic material and higher in elastic modulus than the first elastic member (20). The sole body includes a facing region where the first elastic member (20) and the second elastic member (30A2, 30B2) face each other, and at least a part of the facing region includes a cavity (S), so that a first wall surface that is a surface of a part of the first elastic member (20) that defines the cavity (S) is unrestrained, and a second wall surface that is a surface of a part of the second elastic member (30A2, 30B2) that defines the cavity (S) is unrestrained. A third wall surface that is a part of a surface of the second elastic member (30A2, 30B2) and is located opposite to the second wall surface is exposed outward, so that the third wall surface is unrestrained.

Description

TECHNICAL FIELD

[0001] The present disclosure relates to a sole and a shoe including the sole.BACKGROUND

[0002] For example, WO2018 / 070045 (PTL 1) discloses a shoe having a sole including a shock absorber for the purpose of alleviating an impact applied when landing on the ground. The sole disclosed in the above-referenced publication includes a midsole, an outsole, and a shock absorber that is located to be sandwiched by the midsole and the outsole in a rearfoot portion that supports a heel portion of the wearer's foot.CITATION LISTPATENT LITERATURE

[0003] PTL 1: WO 2018 / 070045SUMMARYTECHNICAL PROBLEM

[0004] The sole disclosed in the above-referenced publication is designed mainly to serve as a sole of an athletic competition shoe, and the sole is excellent in shock absorbing performance in a high load region, and performs well in terms of stability when it lands on the ground, as well as durability and weight reduction.

[0005] As for designing of a sole of a common walking shoe, it is necessary to design the sole so as to exhibit good shock absorbing performance in a lower load region, instead of designing it so as to exhibit good shock absorbing performance only in a high load region, like designing a sole of an athletic competition shoe. However, a sole that exhibits good shock absorbing performance in a low load region is likely to have low durability, which requires improvements in this respect.

[0006] Accordingly, the present disclosure is made in view of the above-described problems, and an object of the present disclosure is to provide a shoe and a sole included in the shoe exhibiting improved shock absorbing performance in a low load region and also being excellent in durability.SOLUTION TO PROBLEM

[0007] A sole according to one aspect of the present disclosure includes: a sole body defining a supporting surface configured to support a sole of a foot of a wearer; and an outsole defining a ground contact surface. The sole body includes a first elastic member and a second elastic member higher in elastic modulus than the first elastic member, the first elastic member is formed of a foam material, and the second elastic member is formed of a solid viscoelastic material. The sole body includes a facing region where the first elastic member and the second elastic member face each other in a first direction orthogonal to a normal direction to the ground contact surface. In the sole according to the one aspect of the present disclosure, in at least a part of the facing region, the first elastic member and the second elastic member are spaced from each other to form a cavity between the first elastic member and the second elastic member, so that a first wall surface that is a surface of a part of the first elastic member that defines the cavity is unrestrained, and a second wall surface that is a surface of a part of the second elastic member that defines the cavity is unrestrained. Moreover, in the sole according to the one aspect of the present disclosure, a third wall surface that is a part of a surface of the second elastic member and is located opposite to the second wall surface in the first direction is exposed outward, so that the third wall surface is unrestrained.

[0008] A shoe according to one aspect of the present disclosure includes the sole according to the one aspect of the present disclosure as described above, and an upper provided above the sole.ADVANTAGEOUS EFFECTS OF INVENTION

[0009] According to the present disclosure, it is possible to provide a shoe and a sole included in the shoe exhibiting improved shock absorbing performance in a low load region and also being excellent in durability.BRIEF DESCRIPTION OF THE DRAWINGS

[0010] Fig. 1 is a schematic perspective view of a shoe according to Embodiment 1. Fig. 2 is a schematic plan view of a sole shown in Fig. 1. Fig. 3 is a schematic side view of the sole shown in Fig. 1 as seen from the medial foot side. Fig. 4 is a schematic side view of the sole shown in Fig. 1 as seen from the lateral foot side. Fig. 5 is a schematic cross-sectional view taken along a line V-V shown in Figs. 3 and 4. Fig. 6 is a schematic cross-sectional view taken along a line VI-VI shown in Fig. 2. Fig. 7 is a schematic cross-sectional view taken along a line VII-VII shown in Fig. 2. Fig. 8 is an exploded perspective view of the sole shown in Fig. 1. Fig. 9 is a partially cutaway perspective view of a midsole included in the sole shown in Fig. 1. Fig. 10 is a schematic cross-sectional view of a sole according to Embodiment 2. Fig. 11 is a schematic cross-sectional view of a sole according to Embodiment 3. Fig. 12 is a schematic cross-sectional view of a sole according to Embodiment 4. Fig. 13 is a schematic side view of a midsole included in a sole according to Embodiment 5, as seen from the lateral foot side. Fig. 14 is a schematic side view of a midsole included in a sole according to Embodiment 6, as seen from the lateral foot side. Fig. 15 is a schematic cross-sectional view of a sole according to Embodiment 7. Fig. 16 is a schematic cross-sectional view of a sole according to Embodiment 8. Fig. 17 is a schematic cross-sectional view of a sole according to Embodiment 9. Fig. 18 is a schematic cross-sectional view of a sole according to Embodiment 10. Fig. 19 is a schematic cross-sectional view of a sole according to Embodiment 11. Fig. 20 is a schematic cross-sectional view of a sole according to Embodiment 12. Fig. 21 is a schematic cross-sectional view of a sole according to Embodiment 13. Fig. 22 is a schematic cross-sectional view of a sole according to Embodiment 14. Fig. 23 is a schematic cross-sectional view of a sole according to Embodiment 15. Fig. 24 is a schematic cross-sectional view of a sole according to Embodiment 16. Fig. 25 is a schematic cross-sectional view of a sole according to Embodiment 17. Fig. 26 is a schematic cross-sectional view of a sole according to Embodiment 18. Fig. 27 is a schematic cross-sectional view of a sole according to Embodiment 19. Fig. 28 is a schematic side view of a sole according to Embodiment 20 as seen from the medial foot side. Fig. 29 is a schematic side view of the sole shown in Fig. 28 as seen from the lateral foot side. Fig. 30 is a schematic cross-sectional view taken along a line XXX-XXX shown in Figs. 28 and 29. Fig. 31 is a schematic cross-sectional view taken along a line XXXI-XXXI shown in Figs. 28 and 29. Fig. 32 is an enlarged view of a region XXXII shown in Fig. 31. Fig. 33 is a partially cutaway perspective view of a midsole included in the sole shown in Fig. 28. Fig. 34 is a perspective view of a shock absorber included in the sole shown in Fig. 28. DETAILED DESCRIPTION

[0011] Embodiments of the present disclosure are described hereinafter in detail with reference to the drawings. In the following embodiments, the same or common parts in the drawings are denoted by the same reference characters, and the description thereof is not herein repeated.<Embodiment 1>

[0012] Fig. 1 is a schematic perspective view of a shoe according to Embodiment 1, and Fig. 2 is a schematic plan view of a sole shown in Fig. 1. Figs. 3 and 4 are schematic side views of the sole shown in Fig. 1, as seen from the medial foot side and the lateral foot side, respectively. Fig. 5 is a schematic cross-sectional view taken along a line V-V shown in Figs. 3 and 4, and Figs. 6 and 7 are schematic cross-sectional views taken along lines VI-VI and VII-VII shown in Fig. 2, respectively. Fig. 8 is an exploded perspective view of the sole shown in Fig. 1, and Fig. 9 is a partially cutaway perspective view of a midsole included in the sole shown in Fig. 1. In the following, a shoe 100 and a sole 10 included in the shoe according to the present embodiment are described with reference to Figs. 1 to 9.

[0013] As shown in Fig. 1, the shoe 100 includes a sole 10 and an upper 60. The sole 10 has a substantially flat shape, and includes: a top surface defining a supporting surface 11 (see Figs. 2 to 4 and the like) that supports the sole of the wearer's foot; a bottom surface defining a ground contact surface 12 that lands on the ground during use such as during walking and running; and a medial-foot-side side surface and a lateral-foot-side side surface that connect the top surface and the bottom surface. The sole 10 is a member that supports the sole of the wearer's foot. The upper 60 is located above the sole 10 and shaped to cover the substantially entire portion extending from an ankle of the inserted wearer's foot to a distal end.

[0014] As shown in Figs. 2 to 4, the sole 10 is divided into a forefoot portion R1, a midfoot portion R2, and a rearfoot portion R3 in the front-rear direction (the top-bottom direction in Fig. 2 and the left-right direction in Figs. 3 and 4) that corresponds to the foot length direction of the wearer's foot in a plan view, the forefoot portion R1 supports a toe portion and a ball portion of the wearer's foot, the midfoot portion R2 supports an arch portion of the wearer's foot, and the rearfoot portion R3 supports a heel portion of the wearer's foot.

[0015] In this case, with reference to the front end of the sole 10, a first boundary position is defined at a position located at 40% of the dimension of the sole 10 from the front end in the front-rear direction, and a second boundary position is defined at a position located at 70% of the dimension of the sole 10 from the front end in the front-rear direction. In this case, the forefoot portion R1 corresponds to a portion included between the front end and the first boundary position in the front-rear direction, the midfoot portion R2 corresponds to a portion included between the first boundary position and the second boundary position in the front-rear direction, and the rearfoot portion R3 corresponds to a portion included between the second boundary position and the rear end of the shoe sole in the front-rear direction.

[0016] Further, as shown in Fig. 2, the sole 10 is divided into a medial-foot-side portion (a portion on the S1 side shown in the figure) and a lateral-foot-side portion (a portion on the S2 side shown in the figure) in the left-right direction corresponding to the foot width direction of the wearer's foot (in the left-right direction in the figure) when seen in a plan view. In this case, the medial-foot-side portion corresponds to the medial side of the foot in anatomical position (i.e., the side close to the midline) and the lateral-foot-side portion is opposite to the medial side of the foot in anatomical position (i.e., the side away from the midline).

[0017] In this case, a boundary line that divides the sole 10 into the medial-foot-side portion and the lateral-foot-side portion is what is called a shoe center SC. The shoe center SC is an imaginary straight line obtained by projecting a straight line onto the sole 10 in the top-bottom direction in the state in which a standard wearer having a foot size suitable for the shoe 100 wears the shoe 100, the straight line connecting a central portion of a calcaneus bone (what is called a heel center (the heel center is denoted by reference characters "HC" in Fig. 2 and the like)) to a portion between the first toe and the second toe of this standard wearer. The front end and the rear end of the sole 10 described above correspond to the ends of the sole 10 located on the shoe center SC.

[0018] As shown in Fig. 1, the upper 60 includes an upper body 61, a shoe tongue 62, and a shoelace 63. Among them, the shoe tongue 62 and the shoelace 63 each are fixed or attached to the upper body 61.

[0019] The upper body 61 has a top portion including a top side opening through which the upper portion of an ankle of the wearer's foot and a part of the instep of the wearer's foot are exposed. Further, the upper body 61 has a bottom portion including, as one example, a bottom side opening covered by the sole 10 and, as another example, a bottom portion formed by stitching the bottom end of the upper body 61 with French seam or the like.

[0020] The shoe tongue 62 is fixed to the upper body 61 by sewing, welding, bonding, or a combination thereof so as to cover a portion of the top side opening disposed in the upper body 61 through which a part of the instep of the wearer's foot is exposed. For the upper body 61 and the shoe tongue 62, for example, woven fabric, knitted fabric, nonwoven fabric, synthetic leather, resin, or the like can be used. For shoes particularly required to be air permeable and lightweight, a double raschel warp knitted fabric with a polyester yarn knitted therein can be used.

[0021] The shoelace 63 is formed of a member in the form of a string for pulling together, in the foot width direction of the wearer's foot, portions of a peripheral edge of the top side opening which is disposed in the upper body 61 and through which a part of the instep of the wearer's foot is exposed. The shoelace 63 is passed through a plurality of holes disposed along the peripheral edge of the top side opening. When the shoelace 63 is tightened in the state in which the wearer's foot is inserted into the upper body 61, the upper body 61 can be brought into close contact with the foot.

[0022] As shown in Figs. 1 to 8, the sole 10 includes a midsole 20, a shock absorber 30, a reinforcing member 40, and an outsole 50. Among them, the midsole 20 and the shock absorber 30 form the sole body, the midsole 20 corresponds to the first elastic member, and the shock absorber 30 corresponds to the second elastic member. In Figs. 1 to 8, in order to facilitate understanding, the midsole 20 corresponding to the first elastic member is shown in light color, and the shock absorber 30 corresponding to the second elastic member is shown in dark color (similarly, in Fig. 9and Figs. 10 to 34 described later herein, the first elastic member is shown in light color, and the second elastic member is shown in dark color).

[0023] The midsole 20 is disposed in a top side area of the sole 10, and the outsole 50 is disposed in a bottom side area of the sole 10. The shock absorber 30 is disposed at a predetermined position of each of the medial-foot-side end and the lateral-foot-side end of the sole 10, and the reinforcing member 40 is disposed so as to extend from the medial-foot-side end to the lateral-foot-side end in the left-right direction in a substantially central portion in the front-rear direction of the sole 10.

[0024] As shown in Figs. 1 to 4 and 8, the midsole 20 is a portion serving as a base of the sole 10 and is located to continuously extend from the forefoot portion R1 through the midfoot portion R2 to the rearfoot portion R3. The midsole 20 has a substantially flat plate shape and is relatively thicker than the outsole 50 described later herein. The midsole 20 can be formed of a single member or can be made up of a plurality of members.

[0025] Referring particularly to Fig. 8, the midsole 20 includes a top surface 21, a bottom surface 22, a medial-foot-side side surface 23, and a lateral-foot-side side surface 24, among which the top surface 21 defines the supporting surface 11 of the sole 10. The top surface 21 of the midsole 20 is bonded to the upper body 61, for example, by adhesion or the like, and thereby, the sole 10 is fixed to the upper 60 (see Fig. 1).

[0026] The top surface 21 of the midsole 20 has a peripheral edge shaped to protrude from its surrounding region. Thereby, the top surface 21 of the midsole 20 includes a recessed portion in which the upper 60 is received. The top surface 21 of the midsole 20 in the portion of the bottom surface of this recessed portion that excludes the above-mentioned peripheral edge has a smooth curved surface so as to be fitted to the bottom of the wearer's foot.

[0027] As shown particularly in Figs. 6 and 7, a depressed portion having an inverted step shape as seen in a cross-sectional view is disposed at a predetermined position of the bottom end of the medial-foot-side side surface 23 and the lateral-foot-side side surface 24 of the midsole 20. The depressed portion having an inverted step shape as seen in a cross-sectional view defines a space into which the shock absorber 30 is fitted to be disposed.

[0028] The midsole 20 is preferably excellent in shock absorbing performance while having proper strength. From this viewpoint, the midsole 20 is made, for example, using a resin-made foam material containing: a resin material as a main component; and a foaming agent and a cross-linking agent as sub-components. Alternatively, the midsole 20 can be made using a rubber-made foam material containing: a rubber material as a main component; and a plasticizer, a foaming agent, a reinforcing agent, and a cross-linking agent as sub-components.

[0029] Examples of the above-mentioned resin material applicable in this case can be ethylene-vinyl acetate copolymer (EVA), polyolefin resin, thermoplastic polyurethane, thermoplastic polyamide-based elastomer (TPA, TPAE), thermoplastic polyester-based elastomer, or the like. Examples of the above-mentioned rubber material suitably applicable in this case can be butadiene rubber.

[0030] Thus, the midsole 20 is formed of a member that is generally low in elastic modulus and soft. Therefore, the midsole 20 is elastically deformed relatively easily when being subjected to a compressive load, and thus excellent in shock absorbing performance.

[0031] As shown in Figs. 1, 3, 4, and 6 to 8, the outsole 50 is joined mainly to the midsole 20 and has a substantially flat plate shape. The outsole 50 is relatively thinner than the midsole 20.

[0032] Referring particularly to Fig. 8, the outsole 50 includes a top surface 51 and a bottom surface 52, of which the bottom surface 52 defines the ground contact surface 12 of the sole 10. In order to improve grip performance, the bottom surface 52 of the outsole 50 can include protrusions and recesses to form a tread pattern. The top surface 51 of the outsole 50 is bonded mainly to the bottom surface 22 of the midsole 20 by adhesion or the like, and in addition, bonded for example by adhesion or the like to the shock absorber 30 and the reinforcing member 40.

[0033] The outsole 50 can be formed of a single member or can be made up of a plurality of members. Further, the outsole 50 can be located to extend continuously, for example, from the forefoot portion R1 through the midfoot portion R2 to the rearfoot portion R3 or can be provided only in the forefoot portion R1 and the rearfoot portion R3 except for the midfoot portion R2.

[0034] In the present embodiment, the outsole 50 is made up of a medial-foot-side outsole 50A, a lateral-foot-side outsole 50B, and a central front outsole 50C. More specifically, the medial-foot-side outsole 50A extends along the medial-foot-side end of the sole 10 from the front end of the forefoot portion R1 to the rear end of the rearfoot portion R3, the lateral-foot-side outsole 50B extends along the lateral-foot-side end of the sole 10 from a location near the rear end of the forefoot portion R1 to the rear end of the rearfoot portion R3, and the central front outsole 50C is located in a central portion excluding the peripheral edge of the forefoot portion R1.

[0035] The outsole 50 is preferably excellent in wear resistance and grip performance. From this viewpoint, the outsole 50 is formed using a member, for example, made of a material containing: a rubber material as a main component; and a plasticizer, a reinforcing agent, and a cross-linking agent as subcomponents. As the rubber material, for example, butadiene rubber can be suitably used.

[0036] Thereby, the outsole 50 is formed of a member that is generally high in elastic modulus and hard. Thus, the outsole 50 is excellent in durability such as wear resistance.

[0037] As shown in Figs. 1 to 8, the shock absorber 30 is joined mainly to the midsole 20 and formed of a plurality of thin-plate-shaped or block-shaped members. The shock absorber 30 is mainly relatively easily elastically deformed when it receives a compressive load and is provided for locally enhancing the shock absorbing performance of the sole 10 and the stability when it lands on the ground.

[0038] Referring particularly to Figs. 6 to 8, the shock absorber 30 includes a top surface 31, a bottom surface 32, and a medial-foot-side side surface 33 and a lateral-foot-side side surface 34 that connect the top surface 31 and the bottom surface 32 to each other. The shock absorber 30 is designed such that its shape is variously adjusted so as to enhance the deformability when it receives a load in the top-bottom direction. The detailed shape of the shock absorber 30 is described later herein.

[0039] In the present embodiment, the shock absorber 30 is made up of a medial-foot-side front shock absorber 30A1, a medial-foot-side rear shock absorber 30A2, a lateral-foot-side front shock absorber 30B1, and a lateral-foot-side rear shock absorber 30B2. The medial-foot-side front shock absorber 30A1 is located at the medial-foot-side end of the sole 10 so as to extend across a part of the forefoot portion R1 that is located closer to its rear end and a part of the midfoot portion R2 that is located closer to its front end, and the medial-foot-side rear shock absorber 30A2 is located at the medial-foot-side end of the sole 10 so as to extend across a part of the midfoot portion R2 located closer to its the rear end and the rearfoot portion R3. The lateral-foot-side front shock absorber 30B 1 is located at the lateral-foot-side end of the sole 10 so as to extend across a part of the forefoot portion R1 that is located closer to its rear end and a part of the midfoot portion R2 that is located closer to its front end, and the lateral-foot-side rear shock absorber 30B2 is located at the lateral-foot-side end of the sole 10 so as to extend across a part of the midfoot portion R2 that is located closer to its rear end and the rearfoot portion R3.

[0040] As shown in Figs. 2 and 5, particularly the medial-foot-side rear shock absorber 30A2 and the lateral-foot-side rear shock absorber 30B2 are located so as to be substantially continuous from a portion near the rear end of the midfoot portion R2 to the peripheral edge of the rearfoot portion R3, forming a generally U-shape as a whole so as to surround the heel center HC of the sole 10.

[0041] In the state of being fitted in the above-described depressed portion provided in the medial-foot-side side surface 23 of the midsole 20, the medial-foot-side front shock absorber 30A1 has its top surface 31 and its lateral-foot-side side surface 34 bonded, for example by adhesion or the like, to a part of the medial-foot-side side surface 23 of the midsole 20 that defines the depressed portion, and has its bottom surface 32 bonded, for example by adhesion or the like, to the top surface 51 of the outsole 50. That is, the medial-foot-side front shock absorber 30A1 in the state of being sandwiched in the top-bottom direction between the midsole 20 and the outsole 50 is joined to the sole 10 and has its lateral-foot-side side surface 34 joined to the midsole 20.

[0042] In the state of being fitted in the above-described depressed portion provided in the medial-foot-side side surface 23 of the midsole 20, the medial-foot-side rear shock absorber 30A2 has its top surface 31 and its lateral-foot-side side surface 34 bonded, for example by adhesion or the like, to a part of the medial-foot-side side surface 23 of the midsole 20 that defines the depressed portion, and its bottom surface 32 bonded, for example by adhesion or the like, to the top surface 51 of the outsole 50. That is, similarly to the medial-foot-side front shock absorber 30A1, the medial-foot-side rear shock absorber 30A2 in the state of being sandwiched in the top-bottom direction between the midsole 20 and the outsole 50 is also joined to the sole 10 and has its lateral-foot-side side surface 34 joined to the midsole 20.

[0043] In the state of being fitted in the above-described depressed portion provided in the lateral-foot-side side surface 24 of the midsole 20, the lateral-foot-side front shock absorber 30B1 has its top surface 31 and its medial-foot-side side surface 33 bonded, for example by adhesion or the like, to a part of the lateral-foot-side side surface 24 of the midsole 20 that defines the depressed portion, and has its bottom surface 32 bonded, for example by adhesion or the like, to the top surface 51 of the outsole 50. That is, the lateral-foot-side front shock absorber 30B1 in the state of being sandwiched in the top-bottom direction between the midsole 20 and the outsole 50 is joined to the sole 10 and has its medial-foot-side side surface 33 joined to the midsole 20.

[0044] In the state of being fitted in the above-described depressed portion provided in the lateral-foot-side side surface 24 of the midsole 20, the lateral-foot-side rear shock absorber 30B2 has its top surface 31 and its medial-foot-side side surface 33 bonded, for example adhesion or the like, to a part of the lateral-foot-side side surface 24 of the midsole 20 that defines the depressed portion, and its bottom surface 32 bonded, for example by adhesion or the like, to the top surface 51 of the outsole 50. That is, similarly to the lateral-foot-side front shock absorber 30B1, the lateral-foot-side rear shock absorber 30B2 in the state of being sandwiched in the top-bottom direction between the midsole 20 and the outsole 50 is also joined to the sole 10 and has its medial-foot-side side surface 33 joined to the midsole 20.

[0045] The shock absorber 30 is preferably excellent in shock absorbing performance while having proper strength. From this viewpoint, the shock absorber 30 is formed of a solid viscoelastic material, for example. As the solid viscoelastic material, for example, a soft elastomer can be used. When the shock absorber 30 is made of resin, the material for the shock absorber can be polyolefin resin, ethylene-vinyl acetate copolymer (EVA), polyamide-based thermoplastic elastomer (TPA, TPAE), thermoplastic polyurethane (TPU), and polyester-based thermoplastic elastomer (TPEE). On the other hand, when the shock absorber 30 is made of rubber, for example, butadiene rubber can be used.

[0046] The shock absorber 30 can also be formed of a polymer composition. In that case, examples of polymer to be contained in the polymer composition include olefinic polymers such as olefinic elastomers and olefinic resins. Examples of the olefinic polymers include polyolefins such as polyethylene (e.g., linear low density polyethylene (LLDPE), high density polyethylene (HDPE), and the like), polypropylene, ethylene-propylene copolymer, propylene-1-hexene copolymer, propylene-4-methyl-1-pentene copolymer, propylene-1-butene copolymer, ethylene-1-hexene copolymer, ethylene-4-methyl-pentene copolymer, ethylene-1-butene copolymer, 1-butene-1-hexene copolymer, 1-butene-4-methyl-pentene, ethylene-methacrylic acid copolymer, ethylene-methyl methacrylate copolymer, ethylene-ethyl methacrylate 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), propylene-vinyl acetate copolymer, and the like.

[0047] The polymer can be an amide-based polymer such as amide-based elastomer and amide-based resin. Examples of the amide-based polymer include polyamide 6, polyamide 11, polyamide 12, polyamide 66, polyamide 610, and the like.

[0048] The polymer can be an ester-based polymer such as ester-based elastomer and ester-based resin. Examples of the ester-based polymer include polyethylene terephthalate and polybutylene terephthalate.

[0049] The polymer can be a urethane-based polymer such as urethane-based elastomer and urethane-based resin. Examples of the urethane-based polymer include polyester-based polyurethane and polyether-based polyurethane.

[0050] The polymer can be a styrene-based polymer such as styrene-based elastomer and styrene-based resin. Examples of the styrene-based elastomer include styrene-ethylene-butylene copolymer (SEB), styrene-butadiene-styrene copolymer (SBS), a hydrogenated product of SBS (styrene-ethylene-butylene-styrene copolymer (SEBS)), styrene-isoprene-styrene copolymer (SIS), a hydrogenated product of SIS (styrene-ethylene-propylene-styrene copolymer (SEPS)), styrene-isobutylene-styrene copolymer (SIBS), styrene-butadiene-styrene-butadiene (SBSB), styrene-butadiene-styrene-butadiene-styrene (SBSBS), and the like. Examples of the styrene-based resin include polystyrene, acrylonitrile styrene resin (AS), acrylonitrile butadiene styrene resin (ABS), and the like.

[0051] Examples of the polymer include acrylic polymers such as polymethylmethacrylate, urethane-based acrylic polymers, polyester-based acrylic polymers, polyether-based acrylic polymers, polycarbonate-based acrylic polymers, epoxy-based acrylic polymers, conjugated diene polymer-based acrylic polymers and hydrogenated products thereof, urethane-based methacrylic polymers, polyester-based methacrylic polymers, polyether-based methacrylic polymers, polycarbonate-based methacrylic polymers, epoxy-based methacrylic polymers, conjugated diene polymer-based methacrylic polymers and hydrogenated products thereof, polyvinyl chloride-based resins, silicone-based elastomers, butadiene rubber (BR), isoprene rubber (IR), chloroprene rubber (CR), natural rubber (NR), styrene-butadiene rubber (SBR), acrylonitrile-butadiene rubber (NBR), butyl rubber (IIR), and the like.

[0052] Thus, the shock absorber 30 is formed of a member that is generally low in elastic modulus and soft. Therefore, the shock absorber 30 is elastically deformed relatively easily when being subjected to a compressive load, and thus excellent in shock absorbing performance.

[0053] As shown in Figs. 1, 3, 4, and 8, the reinforcing member 40 is joined mainly to the midsole 20, and is formed of a plate-shaped member that is substantially U-shaped as seen in a cross-sectional view. The reinforcing member 40 is provided mainly for the purpose of locally increasing the rigidity of the sole 10.

[0054] The reinforcing member 40 is disposed in the state of being sandwiched between the midsole 20 and the outsole 50 in a substantially central portion of the midfoot portion R2 in the front-rear direction. The reinforcing member 40 has its top surface bonded to the bottom surface 22 of the midsole 20 by adhesion or the like, for example, and its bottom surface bonded to the top surface 51 of the outsole 50 by adhesion or the like, for example. Moreover, the reinforcing member 40 has its medial-foot-side end sandwiched between the medial-foot-side front shock absorber 30A1 and the medial-foot-side rear shock absorber 30A2 in the front-rear direction of the sole 10, and the reinforcing member 40 has its lateral-foot-side end sandwiched between the lateral-foot-side front shock absorber 30B1 and the lateral-foot-side rear shock absorber 30B2 in the front-rear direction of the sole 10. The reinforcing member 40 is also bonded to the medial-foot-side front shock absorber 30A1, the medial-foot-side rear shock absorber 30A2, the lateral-foot-side front shock absorber 30B1, and the lateral-foot-side rear shock absorber 30B2 by adhesion or the like, for example.

[0055] The reinforcing member 40 is formed of a member that is higher in rigidity than the midsole 20 and the shock absorber 30, and more preferably formed of a member that is higher in rigidity than the outsole 50. That is, the reinforcing member 40 is larger in elastic modulus and hardness than the midsole 20 and the shock absorber 30.

[0056] The material forming the reinforcing member 40 is not particularly limited, but examples of the material suitably applicable in this case can be: non-fiber-reinforced resin made of a polymer resin such as urethane-based thermoplastic elastomer (TPU), amide-based thermoplastic elastomer (TPA), or ethylene-vinyl acetate copolymer (EVA); or fiber-reinforced resin formed using, as reinforcing fibers, carbon fibers, glass fibers, aramid fibers, Dyneema fibers, Zylon fibers, boron fibers, or the like.

[0057] As shown particularly in Figs. 5 to 7, in the shoe 100 and the sole 10 included in the shoe according to the present embodiment, the sole body made up of the midsole 20 and the shock absorber 30 includes a facing region where the midsole 20 serving as the first elastic member and the shock absorber 30 serving as the second elastic member face each other in the first direction orthogonal to the normal direction to the ground contact surface 12. The first direction refers to any direction overlapping a plane parallel to the ground contact surface 12, and corresponds to any direction among in-plane directions of the plane of Fig. 2, for example.

[0058] Specifically, the facing region includes a boundary portion defined by the lateral-foot-side side surface 34 of the medial-foot-side rear shock absorber 30A2 and a part of the medial-foot-side side surface 23 of the midsole 20 that faces the lateral-foot-side side surface. A part of the medial-foot-side side surface 23 of the midsole 20 that defines the boundary portion corresponds to a part of the wall surface that defines the above-described depressed portion provided in the medial-foot-side side surface 23 of the midsole 20.

[0059] The facing region also includes a boundary portion defined by the medial-foot-side side surface 33 of the lateral-foot-side rear shock absorber 30B2 and a part of the lateral-foot-side side surface 24 of the midsole 20 that faces the medial-foot-side side surface. A part of the lateral-foot-side side surface 24 of the midsole 20 that defines the boundary portion corresponds to a part of the wall surface that defines the above-described depressed portion provided in the lateral-foot-side side surface 24 of the midsole 20.

[0060] As shown in Figs. 5 and 7 to 9, a recess 25 recessed inward of the sole 10 is disposed at a predetermined position of each of the medial-foot-side side surface 23 and the lateral-foot-side side surface 24 of the midsole 20, in the portion defining the facing region. Thus, the midsole 20 and the shock absorber 30 are spaced from each other in the portion where the recess 25 is located, and accordingly, a cavity S is formed between the midsole 20 and the shock absorber 30. In other words, the cavity S is formed by a space surrounded by the midsole 20 and the shock absorber 30 in the boundary portion between the midsole 20 and the shock absorber 30, and embedded in the sole 10.

[0061] As shown in Figs. 2 to 9, in the present embodiment, a part of the facing region is located in a first region that is a medial-foot-side portion of the sole 10 and included in the rearfoot portion R3, and this first region includes with two recesses 25 in a part of the medial-foot-side side surface 23 of the midsole 20 that faces the medial-foot-side rear shock absorber 30A2. Accordingly, two cavities S are located in the medial-foot-side portion of the sole 10 that is included in the rearfoot portion R3.

[0062] The part of the facing region that is located in the first region extends in a second direction intersecting the first direction and substantially parallel to the ground contact surface 12 (the second direction corresponds to a direction intersecting the left-right direction of the sole 10 coinciding with the width direction of the wearer's foot, and specifically the second direction is substantially the front-rear direction of the sole 10), and the two cavities S are disposed at a distance from each other in the second direction. That is, these two cavities S are arranged in the front-rear direction along the medial-foot-side end of the rearfoot portion R3.

[0063] Moreover, in the present embodiment, a part of the facing region is located in a second region that is a lateral-foot-side portion of the sole 10 and included in the rearfoot portion R3, and this second region includes three recesses 25 in a part of the lateral-foot-side side surface 24 of the midsole 20 that faces the lateral-foot-side rear shock absorber 30B2. Accordingly, three cavities S are located in the lateral-foot-side portion of the sole 10 that is included in the rearfoot portion R3.

[0064] The part of the facing region that is located in the second region extends in the second direction intersecting the first direction and substantially parallel to the ground contact surface 12 (the second direction corresponds to a direction intersecting the left-right direction of the sole 10 that coincides with the width direction of the wearer's foot, and specifically the second direction is substantially the front-rear direction of the sole 10), and the three cavities S are disposed at a distance from each other in the second direction. That is, these three cavities S are arranged in the front-rear direction along the lateral-foot-side end of the rearfoot portion R3.

[0065] Therefore, in cross sections of the portion including the first region and the second region of the sole 10, each taken along a plane orthogonal to the front-rear direction, a cross-sectional shape as shown in Fig. 6 and a cross-sectional shape as shown in Fig. 7 appear alternately in the front-rear direction.

[0066] In contrast, such a cavity S is not formed in the part of the facing region that is defined by the medial-foot-side side surface 23 of the midsole 20 and the medial-foot-side front shock absorber 30A1 and the part of the facing region that is defined by the lateral-foot-side side surface 24 of the midsole 20 and the lateral-foot-side front shock absorber 30B1.

[0067] In the sole 10 according to the present embodiment configured in such a manner, the surface of the part of the midsole 20 that defines the cavity S (the surface corresponds to the first wall surface) faces the cavity S without being in contact with other members, so that the surface is unrestrained, and the surface of the part of the shock absorber 30 that defines the cavity S (the surface corresponds to the second wall surface) faces the cavity without being in contact with other members, so that the surface is unrestrained.

[0068] In addition, a third wall surface that is a part of the surface of the shock absorber 30 and is located opposite to the second wall surface (i.e., the surface of the part of the shock absorber 30 that defines the cavity S) in the first direction is exposed outward of the sole 10, so that the third wall surface is also unrestrained without being in contact with other members.

[0069] Accordingly, the shoe 100 and the sole 10 included in the shoe according to the present embodiment exhibit improved shock absorbing performance in a low load region, and are also excellent in the durability. In the following, reasons therefor are described in detail.

[0070] In general, while the foam material is excellent in deformability, the foam material repeatedly subjected to a load is eventually deteriorated, which is so-called collapse and, in this respect, the foam material is not necessarily excellent in durability. In contrast, the solid viscoelastic material is generally superior to the foam material in durability, and has deformability close to that of the foam material.

[0071] However, while the foam material generally has a small Poisson's ratio and accordingly can ensure its high deformability even when being externally restrained in the direction intersecting the direction in which the load is applied, the solid viscoelastic material generally has a large Poisson's ratio and is thus significantly inferior in deformability when being externally restrained in this direction.

[0072] In this regard, in the sole 10 and the shoe 100 including the sole according to the present embodiment, the shock absorber 30 is unrestrained without being restrained by other members (particularly the midsole 20) in the portion where the cavity S is disposed as described above, so that the cavity S serves as a room for deformation of the shock absorber 30 and the deformability of the shock absorber is not significantly reduced. In addition, the midsole 20 is also unrestrained without being restrained by other members (particularly the shock absorber 30) in the portion where the cavity S is disposed, the cavity S also serves as a room for deformation of the midsole 20.

[0073] Therefore, in the shoe 100 and the sole 10 included in the shoe according to the present embodiment, the amount of the foam material used for forming the midsole 20 can be reduced to thereby suppress reduction of the durability due to occurrence of collapse, and the cavity S can be disposed in a part of the facing region to ensure a room for deformation of the shock absorber 30 and the midsole 20 (particularly the shock absorber 30) by means of the cavity, which allows improved shock absorbing performance to be exhibited. Accordingly, the sole and the shoe including the sole configured in such a manner can exhibit improved shock absorbing performance in a low load region and also exhibit excellent durability.

[0074] The shock absorber 30 serving as the second elastic member is required to be higher in elastic modulus than the midsole 20 serving as the first elastic member, and required to have an elastic modulus of 2.5 MPa or less. This is for the reason: if the shock absorber 30 serving as the second elastic member is lower in elastic modulus than the midsole 20 serving as the first elastic member, there is a possibility that the shock absorber 30 serving as the second elastic member is collapsed like the midsole 20 serving as the first elastic member and, if the shock absorber 30 serving as the second elastic member has an elastic modulus of more than 2.5 MPa, the rigidity of the shock absorber 30 is too high, resulting in deterioration in its deformability.

[0075] As long as this condition is satisfied, the shock absorber 30 serving as the second elastic member is not necessarily formed of a solid viscoelastic material like the present embodiment, and other materials may be used for the shock absorber. The elastic modulus of the midsole 20 serving as the first elastic member is preferably 0.5 MPa or more and 2.0 MPa or less, and the elastic modulus of the shock absorber 30 serving as the second elastic member is preferably 0.9 MPa or more and 2.8 MPa or less.

[0076] Moreover, since the shock absorber 30 serving as the second elastic member disposed along the peripheral edge of the rearfoot portion R3 has a higher elastic modulus than the midsole 20 serving as the first elastic member disposed in the central portion which is a portion excluding the peripheral edge of the rearfoot portion R3, the rigidity of the peripheral edge of the rearfoot portion R3 is increased as compared with the central portion of the rearfoot portion R3. Therefore, such a configuration enables local increase of the rigidity of the peripheral edge of the rearfoot portion R3, and accordingly enables suppression of wobbling of the heel portion when landing on the ground or standing, for example, which also contributes to improvement in stability.

[0077] Moreover, the shock absorber 30 serving as the second elastic member is preferably lower in hardness than the midsole 20 serving as the first elastic member. The midsole 20 serving as the first elastic member may have an Asker C hardness of 30 or more and 90 or less, for example, and the shock absorber 30 serving as the second elastic member may have an Asker C hardness of 10 or more and 60 or less, for example, on the condition that the shock absorber 30 is lower in hardness than the midsole 20 serving as the first elastic member.

[0078] Moreover, the shock absorber 30 serving as the second elastic member is preferably smaller in compression set than the midsole 20 serving as the first elastic member. The midsole 20 serving as the first elastic member may have a compression set of 70% or less, for example, and the shock absorber 30 serving as the second elastic member may have a compression set of 20% or less, for example, on the condition that the shock absorber is smaller in compression set than the midsole 20 serving as the first elastic member.

[0079] Moreover, as described above, the shock absorber 30 serving as the second elastic member is supposed to be larger in Poisson's ratio than the midsole 20 serving as the first elastic member. The midsole 20 serving as the first elastic member is supposed to have a Poisson's ratio of 0.2 or more and 0.3 or less, for example, and the shock absorber 30 serving as the second elastic member is supposed to have a Poisson's ratio of 0.35 or more and 0.5 or less, for example.

[0080] The shock absorber 30 serving as the second elastic member is not necessarily formed of a solid viscoelastic material as in the present embodiment, but may be formed of any of other materials as long as it satisfies these conditions of the hardness, the compression set, and the Poisson's ratio.

[0081] As shown in Fig. 7, in the shoe 100 and the sole 10 included in the shoe according to the present embodiment, a part of the shock absorber 30 that corresponds to the cavity S (i.e., a part of the shock absorber 30 that is defined by the second wall surface and the third wall surface as described above) includes a substantially plate-shaped portion whose thickness is the dimension, in the first direction, of the contour of the substantially plate-shaped portion. More specifically, an upper portion of the part of the shock absorber 30 that corresponds to the cavity S forms the substantially plate-shaped portion having the thickness in the left-right direction.

[0082] The plate-shaped portion configured in such a manner is likely to be buckled by a load applied in the top-bottom direction to the shock absorber 30 when landing on the ground, even when the applied load is a relatively low load, which enables deformation of the shock absorber 30 to be further promoted. Accordingly, further improved shock absorbing performance can be obtained.

[0083] Moreover, as described above, in the shoe 100 and the sole 10 included in the shoe according to the present embodiment, the top surface 31 and the lateral-foot-side side surface 34 of the medial-foot-side rear shock absorber 30A2 are bonded to a part of the medial-foot-side side surface 23 of the midsole 20 that faces these surfaces, by adhesion or the like, for example, and the top surface 31 and the medial-foot-side side surface 33 of the lateral-foot-side rear shock absorber 30B2 are bonded to a part of the lateral-foot-side side surface 24 of the midsole 20 that faces these surfaces, by adhesion or the like, for example. That is, in the shoe 100 and the sole 10 included in the shoe according to the present embodiment, the shock absorber 30 is bonded to the midsole 20 along the entire surface of the part of the facing region that does not include the cavity S.

[0084] This configuration makes it possible to maximize the area where the midsole 20 and the shock absorber 30 are bonded to each other, which accordingly enables the shock absorber 30 to be fixed firmly to the midsole 20 and eventually enables the sole and the shoe including the sole to be excellent in durability. However, the midsole 20 and the shock absorber 30 are not necessarily required to be bonded to each other along the entire surface of the part of the facing region that excludes the cavity S, but may be partially un-bonded to each other.

[0085] Moreover, in connection with the above, in the shoe 100 and the sole 10 included in the shoe according to the present embodiment, a plurality of cavities S are disposed in the facing region as described above, so that increase of the size of each cavity S beyond the necessary extent is avoided. This is for the reason: if the size of the cavity S is excessively larger, the bonding area where the midsole 20 and the shock absorber 30 are bonded to each other is accordingly smaller, resulting the possibility that the joint strength is insufficient, and the above-described configuration is adopted to avoid deterioration of the durability. Since the size of the cavity S and the bonding area have a trade-off relationship therebetween, it is preferable to appropriately adjust the size of the cavity S and the bonding area in order to achieve both the durability and the shock absorbing performance.

[0086] Moreover, as shown in Fig. 9, in the shoe 100 and the sole 10 included in the shoe according to the present embodiment, each cavity S is configured to extend in the normal direction to the ground contact surface 12. It is preferable that each cavity S has an elongated shape extending in the above-described direction, and it is further preferable that each cavity S has an inclined shape inclined toward the front end of the sole 10 while extending toward the top end of the sole 10.

[0087] Such a configuration makes it likely that the part of the midsole 20 that is adjacent to the cavity S undergoes shear deformation in the front-rear direction caused by a load applied in the top-bottom direction to the shock absorber 30 when landing on the ground, and accordingly makes it possible to cause the direction in which the load is propagated to coincide with the direction in which force is applied when the shoe lands on the ground, in the order of the rearfoot portion R3, the midfoot portion R2, and the forefoot portion R1. Thus, energy loss during walking or running can be reduced.

[0088] Moreover, as shown in Figs. 2 and 5, in the shoe 100 and the sole 10 included in the shoe according to the present embodiment, the total volume of the two cavities S located in the above-described first region (i.e., a medial-foot-side portion of the sole 10 that corresponds to the rearfoot portion R3) is configured to be smaller than the total volume of the three cavities S located in the above-described second region (i.e., the lateral-foot-side portion of the sole 10 that corresponds to the rearfoot portion R3). The total volume of the cavities S located in the first region and that in the second region can be changed, for example, by adjusting the size of each cavity S and the number of the cavities S as seen in a side view of the sole 10, for example.

[0089] Thus, the volume of the cavities S located in the first region is made smaller than the volume of the cavities S located in the second region, which makes it possible to make the rigidity of the medial-foot-side end of the sole 10 generally higher than the rigidity of the lateral-foot-side end of the sole 10. It is therefore possible to suppress occurrence of overpronation, i.e., the heel portion of the wearer excessively rolls toward the medial-foot-side when it lands on the ground.

[0090] Moreover, as shown in Figs. 1 to 9, in the shoe 100 and the sole 10 included in the shoe according to the present embodiment, a plurality of grooves 27 extending in a direction intersecting the normal direction to the ground contact surface 12 are disposed in respective surfaces of the medial-foot-side side surface 23 and the lateral-foot-side side surface 24 of the midsole 20 that are exposed outward, and a plurality of grooves 37 extending in a direction intersecting the normal direction to the ground contact surface 12 are disposed in respective surfaces of the medial-foot-side side surface 23 and the lateral-foot-side side surface 24 of the shock absorber 30 that are exposed outward.

[0091] Such a configuration promotes deformation of the midsole 20 and the shock absorber 30 caused by a load applied in the top-bottom direction to the midsole 20 and the shock absorber 30 when landing on the ground, which makes it possible to further improve the shock absorbing performance. In particular, the part of the shock absorber 30 that corresponds to the cavity S (i.e., the part of the shock absorber 30 that is defined by the second wall surface and the third wall surface as described above) includes a portion exposed outward (i.e., the third wall surface) and this portion includes the grooves 37, which makes it possible to obtain further improved deformability, also by the fact that the cavity S ensures a room for deformation of the shock absorber 30, and accordingly, the shock absorbing performance is improved significantly.

[0092] Further, in the shoe 100 and the sole 10 included in the shoe according to the present embodiment, the surface of the shock absorber 30 that is exposed outward includes a plurality of recessed portions 36 at a predetermined position of the surface, larger in groove depth and the groove width than the grooves 37. Each of the recessed portions 36 preferably has an elongated shape extending in the normal direction to the ground contact surface 12, and further, each of the recessed portions 36 preferably has an inclined shape inclined toward the front end of the sole 10 while extending toward the top end of the sole 10.

[0093] Such a configuration makes it likely that the part of the shock absorber 30 that is adjacent to the recessed portion 36 undergoes shear deformation in the front-rear direction caused by a load applied in the top-bottom direction to the shock absorber 30 when landing on the ground, and accordingly makes it possible to cause the direction in which the load is propagated to coincide with the direction in which force is applied when the shoe lands on the ground, in the order of the rearfoot portion R3, the midfoot portion R2, and the forefoot portion R1. Thus, energy loss during walking or running can be reduced.

[0094] In addition, as shown in Figs. 2, 5, and 7 to 9, in the shoe 100 and the sole 10 included in the shoe according to the present embodiment, the midsole 20 at a position corresponding to each cavity S includes a communication path 26 for a respective one of the cavities S, and the communication path has one end opened in a part of the wall that defines the cavity S and the other end opened in the top surface 21. The communication path 26 allows the cavity S to communicate with the outside.

[0095] The communication path 26 is provided to avoid closure, against the outside, of each cavity S formed inside the sole 10. Specifically, the communication path is provided for avoiding unintended deformation or the like of the sole 10, caused by expansion of the air enclosed in the cavity S during heat treatment or the like in the process of manufacturing the sole 10, if each cavity S is closed against the outside.

[0096] Therefore, such a configuration makes it possible to prevent occurrence of defect during manufacturing, and thus makes it possible to manufacture the sole 10 and the shoe 100 including the sole with a high yield. While the present embodiment is illustrated in connection with the case where the communication path 26 is provided so as to reach the top surface 21 of the midsole 20, the communication path may be provided so as to reach the bottom surface 22, the medial-foot-side side surface 23, or the lateral-foot-side side surface 24. Moreover, instead of providing the communication path 26 in the midsole 20, the communication path may be provided in the shock absorber 30, or the communication path may be provided so as to extend along the boundary portion between the midsole 20 and the shock absorber 30.<Embodiment 2>

[0097] Fig. 10 is a schematic cross-sectional view of a sole according to Embodiment 2. In the following, a sole 10A according to the present embodiment is described with reference to Fig. 10. The sole 10A according to the present embodiment is included in the shoe 100, instead of the sole 10 according to Embodiment 1.

[0098] As shown in Fig. 10, the sole 10A according to the present embodiment has a structure similar to that of the sole 10 according to Embodiment 1, and differs from the sole 10 according to Embodiment 1 only in terms of the material for the medial-foot-side rear shock absorber 30A2 and the lateral-foot-side rear shock absorber 30B2.

[0099] Specifically, each of the medial-foot-side rear shock absorber 30A2 and the lateral-foot-side rear shock absorber 30B2 is formed of a resin-made foam material containing: a resin material as a main component; and a foaming agent and a cross-linking agent as sub-components. Alternatively, it may be formed of a rubber-made foam material containing: a rubber material as a main component; and a plasticizer, a foaming agent, a reinforcing agent, and a cross-linking agent as sub-components.

[0100] Examples of the above-mentioned resin material applicable in this case can be an ethylene-vinyl acetate copolymer (EVA), a polyolefin resin, thermoplastic polyurethane, a thermoplastic polyamide-based elastomer (TPA, TPAE), a thermoplastic polyester-based elastomer, or the like. Examples of the above-mentioned rubber material suitably applicable in this case can be butadiene rubber.

[0101] In the sole 10A according to the present embodiment, the midsole 20 is formed of a foam material similarly to the sole 10 according to Embodiment 1, and therefore, both the midsole 20 and the shock absorber 30 are formed of a foam material. However, the foam material forming the shock absorber 30 serving as the second elastic member is higher in elastic modulus than the foam material forming the midsole 20 serving as the first elastic member, and has an elastic modulus of 2.5 MPa or less.

[0102] Such a configuration also provides, like Embodiment 1, the cavities S in a part of the facing region to thereby enable a room for deformation of the shock absorber 30 and the midsole 20 (particularly the shock absorber 30) to be ensured by the cavities S, and thus makes it possible to provide the sole exhibiting improved shock absorbing performance. Accordingly, it is possible to obtain the advantageous effects similar to those described above in connection with Embodiment 1.<Embodiments 3 and 4>

[0103] Figs. 11 and 12 are schematic cross-sectional views of soles according to Embodiments 3 and 4, respectively. In the following, soles 10B and 10C according to these embodiments are described with reference to Figs. 11 and 12. The soles 10B and 10C are each included in the shoe 100 instead of the sole 10 according to Embodiment 1.

[0104] As shown in Fig. 11, the sole 10B according to Embodiment 3 differs from the sole 10 according to Embodiment 1 only in terms of the position where the cavities S are disposed. Specifically, in the sole 10B, the cavities S are disposed only in the first region (i.e., the first region is a medial-foot-side portion of the sole 10B and corresponds to the rearfoot portion R3) of the facing region where the midsole 20 and the shock absorber 30 face each other.

[0105] As shown in Fig. 12, the sole 10C according to Embodiment 4 differs from the sole 10 according to Embodiment 1 only in terms of the position where the cavities S are disposed. Specifically, in the sole 10C, the cavities S are disposed only in the second region (i.e., the second region is a lateral-foot-side portion of the sole 10C and corresponds to the rearfoot portion R3) of the facing regions where the midsole 20 and the shock absorber 30 face each other.

[0106] In the case of adopting any of these configurations, the cavities S are also disposed in a part of the facing region, similarly to Embodiment 1, so that the cavities S can ensure a room for deformation of the shock absorber 30 and the midsole 20 (particularly the shock absorber 30), which enables the sole to exhibit improved shock absorbing performance. Accordingly, it is possible to obtain the advantageous effects similar to those described above in connection with Embodiment 1.<Embodiments 5 and 6>

[0107] Figs. 13 and 14 are schematic side views of midsoles included in respective soles according to Embodiments 5 and 6, respectively, as seen from the lateral foot side. In the following, soles 10D and 10E according to these embodiments are described with reference to Figs. 13 and 14. The soles 10D and 10E are each included in the shoe 100 instead of the sole 10 according to Embodiment 1.

[0108] As shown in Fig. 13, the sole 10D according to Embodiment 5 differs from the sole 10 according to Embodiment 1 only in that the recesses 25 disposed in the midsole 20 for forming cavities S are disposed not only in the rearfoot portion R3 but also in the midfoot portion R2. In such a configuration, the cavity S is formed not only in the rearfoot portion R3 but also in the midfoot portion R2 of the sole 10D. In Fig. 13, the recess 25 is hatched for the sake of easier understanding.

[0109] As shown in Fig. 14, the sole 10E according to Embodiment 6 differs from the sole 10 according to Embodiment 1 only in that the recess 25 disposed in the midsole 20 for forming the cavity S has an elongated shape extending in the front-rear direction of the sole 10E. In Fig. 13, the recess 25 is hatched for the sake of easier understanding.

[0110] In the case of adopting any of these configurations, the cavity S is also disposed in a part of the facing region, similarly to Embodiment 1, so that the cavity S can ensure a room for deformation of the shock absorber 30 and the midsole 20 (particularly the shock absorber 30), which enables the sole to exhibit improved shock absorbing performance. Accordingly, it is possible to obtain the advantageous effects similar to those described above in connection with Embodiment 1.<Embodiments 7 to 19>

[0111] Figs. 15 to 27 are schematic cross-sectional views of soles according to Embodiments 7 to 19, respectively. In the following, soles 10F to 10R according to Embodiments 7 to 19 are described with reference to Figs. 15 to 27. The soles 10F to 10R according to Embodiments 7 to 19 differ from the sole 10 according to Embodiment 1 only in terms of the shapes of the midsole 20 and the shock absorber 30, and are each included in the shoe 100 instead of the sole 10 according to Embodiment 1.

[0112] As shown in Fig. 15, in the sole 10F according to Embodiment 7, depressed portions having an inverted step shape as seen in a cross-sectional view are disposed respectively in the medial-foot-side side surface 23 and the lateral-foot-side side surface 24 of the midsole 20, recesses 25 having a rectangular shape as seen in a cross-sectional view are further disposed in respective wall surfaces defining the depressed portions, and the recesses 25 are covered respectively with the lateral-foot-side side surface 34 of the shock absorber 30 disposed on the medial-foot-side and having a substantially I-shape as seen in a cross-sectional view, and the medial-foot-side side surface 33 of the shock absorber 30 disposed on the lateral-foot-side and having a substantially I-shape as seen in a cross-sectional view, and these shock absorbers 30 are fitted in the depressed portions, respectively. In this case, each cavity S is defined by the recess 25 disposed in the midsole 20 and the wall surface of the shock absorber 30 that covers the recess.

[0113] As shown in Fig. 16, in the sole 10G according to Embodiment 8, depressed portions having an inverted step shape as seen in a cross-sectional view are disposed respectively in the medial-foot-side side surface 23 and the lateral-foot-side side surface 24 of the midsole 20, recesses 25 having an inverted step shape as seen in a cross-sectional view are further disposed in respective wall surfaces defining the depressed portions, and the recesses 25 are covered respectively with the lateral-foot-side side surface 34 of the shock absorber 30 disposed on the medial-foot-side and having a substantially I-shape as seen in a cross-sectional view, and the medial-foot-side side surface 33 of the shock absorber 30 disposed on the lateral-foot-side and having a substantially I-shape as seen in a cross-sectional view, and these the shock absorbers 30 are fitted in the depressed portions, respectively. In this case, each cavity S is defined by the recess 25 disposed in the midsole 20, the wall surface of the shock absorber 30 that covers the recess 25, and the top surface 51 of the outsole 50.

[0114] As shown in Fig. 17, in the sole 10H according to Embodiment 9, recesses 25 having an inverted step shape as seen in a cross-sectional view are disposed respectively in the medial-foot-side side surface 23 and the lateral-foot-side side surface 24 of the midsole 20, and the shock absorbers 30 are fitted in respective recesses 25 in such a manner that the recesses 25 are covered respectively with the lateral-foot-side side surface 34 of the shock absorber 30 disposed on the medial-foot-side and having a substantially I-shape as seen in a cross-sectional view and the medial-foot-side side surface 33 of the shock absorber 30 disposed on the lateral-foot-side and having a substantially I-shape as seen in a cross-sectional view. In this case, each cavity S is defined by the recess 25 disposed in the midsole 20, the wall surface of the shock absorber 30 that covers the recess 25, and the top surface 51 of the outsole 50.

[0115] As shown in Fig. 18, in the sole 10I according to Embodiment 10, recesses 25 having a rectangular shape as seen in a cross-sectional view are disposed respectively in the medial-foot-side side surface 23 and the lateral-foot-side side surface 24 of the midsole 20, and the recesses 25 are covered respectively with the lateral-foot-side side surface 34 of the shock absorber 30 disposed on the medial-foot-side and having a substantially I-shape as seen in a cross-sectional view and the medial-foot-side side surface 33 of the shock absorber 30 disposed on the lateral-foot-side and having a substantially I-shape as seen in a cross-sectional view. In this case, each cavity S is defined by the recess 25 disposed in the midsole 20 and the wall surface of the shock absorber 30 that covers the recess.

[0116] As shown in Fig. 19, in the sole 10J according to Embodiment 11, recesses 35 having a rectangular shape as seen in a cross-sectional view are disposed respectively in the lateral-foot-side side surface 34 of the shock absorber 30 disposed on the medial-foot-side and the medial-foot-side side surface of the shock absorber 30 disposed on the lateral-foot-side, and these recesses 35 are covered respectively with the medial-foot-side side surface 23 and the lateral-foot-side side surface 24 of the midsole 20. In this case, each cavity S is defined by the recess 35 disposed in the shock absorber 30 and the wall surface of the midsole 20 that covers the recess.

[0117] As shown in Fig. 20, in the sole 10K according to Embodiment 12, recesses 25 having a step shape as seen in a cross-sectional view are disposed respectively in the medial-foot-side side surface 23 and the lateral-foot-side side surface 24 of the midsole 20, recesses 35 having an inverted step shape as seen in a cross-sectional view are disposed respectively in the lateral-foot-side side surface 34 of the shock absorber 30 disposed on the medial-foot-side and the medial-foot-side side surface of the shock absorber 30 disposed on the lateral-foot-side, and the midsole 20 and the shock absorber 30 are combined in such a manner that the recess 25 and the recess 35 cover each other. In this case, each cavity S is defined by the recess 25 disposed in the midsole 20 and the recess 35 disposed in the shock absorber 30.

[0118] As shown in Fig. 21, in the sole 10L according to Embodiment 13, recesses 35 having an inverted step shape as seen in a cross-sectional view are disposed respectively in the lateral-foot-side side surface 34 of the shock absorber 30 disposed on the medial-foot-side and the medial-foot-side side surface of the shock absorber 30 disposed on the lateral-foot-side, and these recesses 35 are covered respectively with the medial-foot-side side surface 23 and the lateral-foot-side side surface 24 of the midsole 20. In this case, each cavity S is defined by the recess 35 disposed in the shock absorber 30, the wall surface of the midsole 20 that covers the recess, and the top surface 51 of the outsole 50.

[0119] As shown in Fig. 22, in the sole 10M according to Embodiment 14, recesses 25 having an inverted step shape as seen in a cross-sectional view are disposed respectively in the medial-foot-side side surface 23 and the lateral-foot-side side surface 24 of the midsole 20, recesses 35 having a step shape as seen in a cross-sectional view are disposed respectively in the lateral-foot-side side surface 34 of the shock absorber 30 disposed on the medial-foot-side and the medial-foot-side side surface of the shock absorber 30 disposed on the lateral-foot-side, and the midsole 20 and the shock absorber 30 are combined in such a manner that the recess 25 and the recess 35 cover each other. In this case, each cavity S is defined by the recess 25 disposed in the midsole 20 and the recess 35 disposed in the shock absorber 30.

[0120] As shown in Fig. 23, in the sole 10N according to Embodiment 15, recesses 25 having an inverted step shape as seen in a cross-sectional view are disposed respectively in the medial-foot-side side surface 23 and the lateral-foot-side side surface 24 of the midsole 20, and these recesses 25 are covered respectively with the lateral-foot-side side surface 34 of the shock absorber 30 disposed on the medial-foot-side and having a substantially I-shape as seen in a cross-sectional view and the medial-foot-side side surface 33 of the shock absorber 30 disposed on the lateral-foot-side and having a substantially I-shape as seen in a cross-sectional view. In this case, each cavity S is defined by the recess 25 disposed in the midsole 20, the wall surface of the shock absorber 30 that covers the recess 25, and the top surface 51 of the outsole 50.

[0121] As shown in Fig. 24, in the sole 10O according to Embodiment 16, a single shock absorber 30 is disposed so as to extend from the medial-foot-side end to the lateral-foot-side end of the sole 10O, a recess 35 having a rectangular shape as seen in a cross-sectional view is disposed in the bottom surface 32 of the shock absorber 30, and the midsole 20 is fitted in the recess 35 so as to be spaced from the side wall of the recess 35. In this case, each cavity S is defined by the recess 35 disposed in the shock absorber 30, the side surface of the midsole 20, and the top surface 51 of the outsole 50.

[0122] As shown in Fig. 25, in the sole 10P according to Embodiment 17, the midsole 20 is disposed so as to extend from the medial-foot-side end to the lateral-foot-side end of the sole 10P, a recess 25 having a rectangular shape as seen in a cross-sectional view is disposed in the bottom surface 22 of the midsole 20, and a pair of shock absorbers 30 each include a recess 35 having an inverted step shape as seen in a cross-sectional view are fitted respectively in the opposite end portions of the recess 25 of the midsole 20 so as to be spaced from the side wall of the recess 25. In this case, each cavity S is defined by the recess 25 disposed in the midsole 20, the recess 35 disposed in the shock absorber 30, and the top surface 51 of the outsole 50.

[0123] As shown in Fig. 26, in the sole 10Q according to Embodiment 18, the midsole 20 is disposed so as to extend from the medial-foot-side end to the lateral-foot-side end of the sole 10Q, a recess 25 having a rectangular shape as seen in a cross-sectional view is disposed in the bottom surface 22 of the midsole 20, and a pair of shock absorbers 30 each include a recess 35 having a step shape as seen in a cross-sectional view are fitted respectively in the opposite end portions of the recess 25 of the midsole 20 so as to be spaced from the side wall of the recess 25. In this case, each cavity S is defined by the recess 25 disposed in the midsole 20 and the recess 35 disposed in the shock absorber 30.

[0124] As shown in Fig. 27, in the sole 10R according to Embodiment 19, the midsole 20 is disposed so as to extend from the medial-foot-side end to the lateral-foot-side end of the sole 10R, a recess 25 having a rectangular shape as seen in a cross-sectional view is disposed in the bottom surface 22 of the midsole 20, and a pair of shock absorbers 30 having an I-shape as seen in a cross-sectional view are fitted respectively in the opposite end portions of the recess 25 of the midsole 20 so as to be spaced from the side wall of the recess 25. In this case, each cavity S is defined by the recess 25 disposed in the midsole 20, the side surface of the shock absorber 30, and the top surface 51 of the outsole 50.

[0125] In the case of adopting any of these configurations, the cavities S are also disposed in a part of the facing region, similarly to Embodiment 1, so that the cavities S can ensure a room for deformation of the shock absorber 30 and the midsole 20 (particularly the shock absorber 30), which enables the sole to exhibit improved shock absorbing performance. Accordingly, it is possible to obtain the advantageous effects similar to those described above in connection with Embodiment 1.<Embodiment 20>

[0126] Figs. 28 and 29 are schematic side views of the sole according to Embodiment 20 as seen from the medial-foot-side and the lateral-foot-side, respectively. Figs. 30 and 31 are schematic cross-sectional views taken along lines XXX-XXX and XXXI-XXXI shown in Figs. 28 and 29, respectively, and Fig. 32 is an enlarged view of a region XXXII shown in Fig. 31. Fig. 33 is a partially cutaway perspective view of a midsole included in the sole shown in Fig. 28, and Fig. 34 is a perspective view of a shock absorber included in the sole shown in Fig. 28. In the following, a sole 10S according to the present embodiment is described with reference to Figs. 28 to 34. The sole 10S according to the present embodiment differs from the sole 10 according to Embodiment 1 in that the former does not include the reinforcing member 40 (see Figs. 1, 3, 4, and 8, for example), and in terms of respective shapes of the midsole 20 and the shock absorber 30, and the sole 10S is included in the shoe 100 instead of the sole 10 according to Embodiment 1.

[0127] As shown in Figs. 28 to 32, the sole 10S includes a midsole 20, a shock absorber 30, and an outsole 50. Among them, the midsole 20 and the shock absorber 30 form the sole body, the midsole 20 corresponds to the first elastic member, and the shock absorber 30 corresponds to the second elastic member. The midsole 20 is disposed in a top side area of the sole 10S, and the outsole 50 is disposed in a bottom side area of the sole 10S. The shock absorber 30 is disposed at a predetermined position of each of the medial-foot-side end and the lateral-foot-side end of the sole 10S.

[0128] In the present embodiment, the shock absorber 30 is made up of a medial-foot-side shock absorber 30A and a lateral-foot-side shock absorber 30B. The medial-foot-side shock absorber 30A is located to extend across a part of the medial-foot-side end of the sole 10S that corresponds to the rearfoot-portion R3, and a part of the lateral-foot-side end of the sole 10S that corresponds to a part of the rearfoot portion R3 located closer to its rear end. The lateral-foot-side shock absorber 30B is located to extend across a part of the lateral-foot-side end of the sole 10S that corresponds to a part of the midfoot portion R2 located closer to its rear end and the rearfoot portion R3. Thus, the medial-foot-side shock absorber 30A and the lateral-foot-side shock absorber 30B are located to be substantially continuous along the peripheral edge of the rearfoot portion R3 to form a generally U-shape as a whole, around the heel center HC of the sole 10S.

[0129] As shown particularly in Figs. 30 and 31, in the sole 10S according to the present embodiment, the sole body made up of the midsole 20 and the shock absorber 30 includes a facing region where the midsole 20 serving as the first elastic member and the shock absorber 30 serving as the second elastic member face each other in the first direction orthogonal to the normal direction to the ground contact surface 12. The first direction refers to any direction overlapping a plane parallel to the ground contact surface 12, and corresponds for example to any direction among in-plane directions of the plane of Fig. 30.

[0130] As shown in Figs. 30 to 34, a recess 25 recessed inward of the sole 10S is disposed at a predetermined position of each of the medial-foot-side side surface 23 and the lateral-foot-side side surface 24 of the midsole 20, in the portion defining the facing region, and a recess 35 recessed outward of the sole 10S is disposed at a predetermined position of each of the lateral-foot-side side surface 34 of the medial-foot-side shock absorber 30A and the medial-foot-side side surface 33 of the lateral-foot-side shock absorber 30B in the portion defining the facing region.

[0131] As described above, the medial-foot-side shock absorber 30A is located not only in a part of the medial-foot-side end of the sole 10S that corresponds to the rearfoot portion R3, but also in a part of the lateral-foot-side end of the sole 10S that corresponds to a portion, located closer to the rear end, of the rearfoot portion R3, and therefore, the surface of the medial-foot-side shock absorber 30A that faces the sole 10S is located not only in the medial-foot-side end of the sole 10S but also in the lateral-foot-side end of the sole 10S. Therefore, while the part of the surface of the medial-foot-side shock absorber 30A that faces the sole 10S and located in the lateral-foot-side end can strictly be regarded as a medial-foot-side end face facing the medial foot side, this part is also referred to herein as lateral-foot-side side surface 34 of the medial-foot-side shock absorber 30A for the sake of convenience.

[0132] The recess 25 disposed in the midsole 20 and the recess 35 disposed in the shock absorber 30 are located to face each other. Thus, in the portion where the recesses 25 and 35 are located, the midsole 20 and the shock absorber 30 are spaced from each other, and accordingly, a cavity S is formed between the midsole 20 and the shock absorber 30. In other words, the cavity S is defined by the recess 25 disposed in the midsole 20 and the recess 35 disposed in the shock absorber 30, so that the cavity S is surrounded by the midsole 20 and the shock absorber 30 in the boundary portion between the midsole 20 and the shock absorber 30 and, as such, the cavity S is formed by the space embedded in the sole 10S.

[0133] As shown in Figs. 28 to 34, in the present embodiment, a part of the facing region is located in a first region that is a medial-foot-side portion of the sole 10S and included in the rearfoot portion R3, and this first region includes one recess 25 and one recess 35. Accordingly, one cavity S is located in the medial-foot-side portion of the sole 10S that is included in the rearfoot portion R3.

[0134] Moreover, in the present embodiment, a part of the facing region is located in a second region that is a lateral-foot-side portion of the sole 10S and included in the rearfoot portion R3, and this second region includes two recesses 25 and two recesses 35. Accordingly, two cavities S are located in the lateral-foot-side portion of the sole 10S that is included in the rearfoot portion R3.

[0135] Accordingly, one cavity S disposed in the first region and the two cavities S disposed in the second region are located to surround the heel center HC of the sole 10S.

[0136] In the sole 10S according to the present embodiment configured as described above, the part of the surface (wall surface corresponding to the first wall surface) of the midsole 20 that defines the cavity S faces the cavity S without being in contact with other members, so that the part of the surface is unrestrained, and the part of the surface (wall surface corresponding to the second wall surface) of the shock absorber 30 that defines the cavity S faces the cavity S without being in contact with other members, so that the part of the surface is unrestrained.

[0137] In addition, the third wall surface that is a part of the surface of the shock absorber 30 and located opposite to the second wall surface (i.e., a part of the surface of the shock absorber 30 that defines the cavity S) in the above-described first direction is exposed outward of the sole 10S, so that the third wall surface is also unrestrained without being in contact with other members.

[0138] Thus, in the sole 10S according to the present embodiment configured in the above-described manner, like the sole 10 according to Embodiment 1, the cavity S functions as a room for deformation of the shock absorber 30 and the midsole 20 (particularly the shock absorber 30), and therefore, the sole exhibits improved shock absorbing performance in a low load region and, in addition, the amount of the foam material forming the midsole 20 is reduced to thereby enable occurrence of collapse to be suppressed, which improves the durability.

[0139] As shown in Fig. 32, in the sole 10S according to the present embodiment, a constricted portion 38 is provided in a part of the lateral-foot-side shock absorber 30B that is adjacent to the cavity S. The constricted portion 38 is formed by providing a bulged portion 39 protruding outward in the lateral-foot-side side surface 34 of the lateral-foot-side shock absorber 30B, in a portion adjacent to the constricted portion.

[0140] More specifically, in the sole 10S according to the present embodiment, the lateral-foot-side shock absorber 30B includes a first portion P1 adjacent to the cavity S in the first direction (i.e., the direction in which the midsole 20 and the lateral-foot-side shock absorber 30B face each other), and the lateral-foot-side shock absorber 30B includes a second portion P2 that is not adjacent to the cavity S in the first direction and is adjacent to the first portion P1 in the normal direction to the ground contact surface 12, and a dimension T1, in the first direction, of the contour of the first portion P1 is smaller than a dimension T2, in the first direction, of the contour of the second portion P2, so that the constricted portion 38 is disposed at a position of the lateral-foot-side shock absorber 30B that corresponds to the cavity S.

[0141] Moreover, in the sole 10S according to the present embodiment, a constricted portion similar to the constricted portion 38 provided in the lateral-foot-side shock absorber 30B is also provided in a part of the medial-foot-side shock absorber 30A that is adjacent to the cavity S, which, however, is not described in detail herein.

[0142] Thus, the constricted portion 38 is provided in the part of the shock absorber 30 that is adjacent to the cavity S, to thereby induce buckling in a part of the shock absorber 30 that includes the constricted portion 38. Such a configuration makes it likely that buckling occurs to the shock absorber 30, which enables the shock absorber 30 to have improved deformability in a lower load region, and accordingly enables the sole and a shoe including the sole to exhibit improved shock absorbing performance.

[0143] In the sole 10S according to the present embodiment, the volume of each cavity S is configured to be smaller than that of the sole 10 according to Embodiment 1. Such a configuration makes it possible to suppress unintended deformation or the like of the sole 10S, caused by expansion of the air enclosed in the cavity S during heat treatment or the like in the process of manufacturing the sole 10S, without providing the communication path 26 (see Fig. 7, for example) connecting the cavity S and the external space to each other, and accordingly makes it possible to manufacture the sole and the shoe including the sole with a high yield.<Summary of the Disclosure in Embodiments and Modifications>

[0144] The following is a summary of the features disclosed in connection with Embodiments 1 to 20 as described above.[Supplementary Note 1]

[0145] A sole including: a sole body defining a supporting surface configured to support a sole of a foot of a wearer; and an outsole defining a ground contact surface, wherein the sole body includes a first elastic member and a second elastic member higher in elastic modulus than the first elastic member, the second elastic member has an elastic modulus of 2.5 MPa or less, the sole body includes a facing region where the first elastic member and the second elastic member face each other in a first direction orthogonal to a normal direction to the ground contact surface, in at least a part of the facing region, the first elastic member and the second elastic member are spaced from each other to form a cavity between the first elastic member and the second elastic member, so that a first wall surface that is a surface of a part of the first elastic member that defines the cavity is unrestrained, and a second wall surface that is a surface of a part of the second elastic member that defines the cavity is unrestrained, and a third wall surface that is a part of a surface of the second elastic member and is located opposite to the second wall surface in the first direction is exposed outward, so that the third wall surface is unrestrained. [Supplementary Note 2]

[0146] The sole according to Supplementary Note 1, wherein the first elastic member is formed of a foam material, and the second elastic member is formed of a solid viscoelastic material. [Supplementary Note 3]

[0147] The sole according to Supplementary Note 1, wherein the first elastic member and the second elastic member are both formed of a foam material.[Supplementary Note 4]

[0148] A sole including: a sole body defining a supporting surface configured to support a sole of a foot of a wearer; and an outsole defining a ground contact surface, wherein the sole body includes a first elastic member and a second elastic member higher in elastic modulus than the first elastic member, the first elastic member is formed of a foam material, the second elastic member is formed of a solid viscoelastic material, the sole body includes a facing region where the first elastic member and the second elastic member face each other in a first direction orthogonal to a normal direction to the ground contact surface, in at least a part of the facing region, the first elastic member and the second elastic member are spaced from each other to form a cavity between the first elastic member and the second elastic member, so that a first wall surface that is a surface of a part of the first elastic member that defines the cavity is unrestrained, and a second wall surface that is a surface of a part of the second elastic member that defines the cavity is unrestrained, and a third wall surface that is a part of a surface of the second elastic member and is located opposite to the second wall surface in the first direction is exposed outward, so that the third wall surface is unrestrained. [Supplementary Note 5]

[0149] The sole according to any one of Supplementary Notes 1 to 4, wherein a part of the second elastic member that is defined by the second wall surface and the third wall surface includes a substantially plate-shaped portion whose thickness is a dimension, in the first direction, of a contour of the substantially plate-shaped portion.[Supplementary Note 6]

[0150] The sole according to any one of Supplementary Notes 1 to 5, wherein the second elastic member includes a first portion adjacent to the cavity in the first direction, the second elastic member includes a second portion that is not adjacent to the cavity in the first direction and is adjacent to the first portion in the normal direction to the ground contact surface, and a dimension, in the first direction, of a contour of the first portion is smaller than a dimension, in the first direction, of a contour of the second portion, so that a constricted portion is disposed at a position of the second elastic member that corresponds to the cavity.[Supplementary Note 7]

[0151] The sole according to any one of Supplementary Notes 1 to 6, wherein a first recess is disposed in a part of the first elastic member that defines the facing region, a second recess is disposed in a part of the second elastic member that defines the facing region, and the first recess and the second recess face each other to form the cavity defined by the first recess and the second recess. [Supplementary Note 8]

[0152] The sole according to any one of Supplementary Notes 1 to 7, wherein the facing region includes a portion where the cavity is not disposed, and the first elastic member and the second elastic member are bonded to each other in the portion.[Supplementary Note 9]

[0153] The sole according to Supplementary Note 8, wherein the sole body includes a communication path allowing the cavity to communicate with an outside.[Supplementary Note 10]

[0154] The sole according to Supplementary Note 8 or 9, wherein the facing region extends in a second direction intersecting the first direction and substantially parallel to the ground contact surface, and a plurality of the cavities are disposed at a distance from each other in the second direction. [Supplementary Note 11]

[0155] The sole according to any one of Supplementary Notes 1 to 9, wherein the facing region extends in a second direction intersecting the first direction and substantially parallel to the ground contact surface, and the second direction is a direction intersecting a left-right direction of the sole that coincides with a width direction of a foot of a wearer. [Supplementary Note 12]

[0156] The sole according to Supplementary Note 11, wherein the cavity extends in the normal direction to the ground contact surface, and has an inclined shape inclined toward a front end of the sole while extending toward a top end of the sole.[Supplementary Note 13]

[0157] The sole according to Supplementary Note 11 or 12, including: a forefoot portion configured to support a toe portion and a ball portion of a foot of a wearer; a midfoot portion configured to support an arch portion of the foot of the wearer; and a rearfoot portion configured to support a heel portion of the foot of the wearer, wherein the facing region is located at least in a first region that is a medial-foot-side portion of the sole and included in the rearfoot portion, and a second region that is a lateral-foot-side portion of the sole and included in the rearfoot portion, and the cavity is located in each of the first region and the second region. [Supplementary Note 14]

[0158] The sole according to Supplementary Note 13, wherein a volume of the cavity located in the first region is smaller than a volume of the cavity located in the second region.[Supplementary Note 15]

[0159] The sole according to any one of Supplementary Notes 1 to 14, wherein a groove extending in a direction intersecting the normal direction to the ground contact surface is disposed in the third wall surface.[Supplementary Note 16]

[0160] The sole according to Supplementary Note 15, wherein a recessed portion extending to reach a top end and a bottom end of the third wall surface and deeper than the groove is disposed in the third wall surface, and the recessed portion has an inclined shape inclined toward a front end of the sole while extending toward the top end of the sole. [Supplementary Note 17]

[0161] A shoe including: the sole according to any one of Supplementary Notes 1 to 16; and an upper provided above the sole. <Other Configurations>

[0162] While Embodiments 1 to 20 are described above, by way of example, in connection with the case where the facing region defined by the midsole serving as the first elastic member and the shock absorber serving as the second elastic member is disposed to extend along the peripheral edge of the sole, the position where the facing region is disposed is not necessarily limited to this, and the facing region may be disposed to extend longitudinally or laterally across the sole. In this case, a cavity / cavities provided in the part of the facing region that extends longitudinally or laterally across the sole also enable the various advantageous effects as described above to be obtained.

[0163] Moreover, the shape and the size of each part, the number of parts, and the position where each part is disposed, for example, disclosed above in connection with Embodiments 1 to 20 can be changed to any of various ones, unless going beyond the scope of the present disclosure.

[0164] Furthermore, the characteristic configurations illustrated above in connection with the embodiments can be combined with each other unless going beyond the scope of the present disclosure.

[0165] Thus, the embodiments disclosed herein are given by way of illustration in all respects, not by way of limitation. The technical scope of the present invention is defined by claims, and encompasses all modifications and variations equivalent in meaning and scope to the claims.REFERENCE SIGNS LIST

[0166] 10, 10A-10S sole; 11 supporting surface; 12 ground contact surface; 20 midsole; 21 top surface; 22 bottom surface; 23 medial-foot-side side surface; 24 lateral-foot-side side surface; 25 recess; 26 communication path; 27 groove; 30 shock absorber; 30A medial-foot-side shock absorber; 30A1 medial-foot-side front shock absorber; 30A2 medial-foot-side rear shock absorber; 30B lateral-foot-side shock absorber; 30B1 lateral-foot-side front shock absorber; 30B2 lateral-foot-side rear shock absorber; 31 top surface; 32 bottom surface; 33 medial-foot-side side surface; 34 lateral-foot-side side surface; 35 recess; 36 recessed portion; 37 groove; 38 constricted portion; 39 bulged portion; 40 reinforcing member; 50 outsole; 50A medial-foot-side outsole; 50B lateral-foot-side outsole; 50C central front outsole; 51 top surface; 52 bottom surface; 60 upper; 61 upper body; 62 shoe tongue; 63 shoelace; 100 shoe; HC heel center; P1 first portion; P2 second portion; R1 forefoot portion; R2 midfoot portion; R3 rearfoot portion; S cavity; SC shoe center.

Claims

1. A sole comprising: a sole body defining a supporting surface configured to support a sole of a foot of a wearer; and an outsole defining a ground contact surface, wherein the sole body includes a first elastic member and a second elastic member higher in elastic modulus than the first elastic member, the first elastic member is formed of a foam material, the second elastic member is formed of a solid viscoelastic material, the sole body includes a facing region where the first elastic member and the second elastic member face each other in a first direction orthogonal to a normal direction to the ground contact surface, in at least a part of the facing region, the first elastic member and the second elastic member are spaced from each other to form a cavity between the first elastic member and the second elastic member, so that a first wall surface that is a surface of a part of the first elastic member that defines the cavity is unrestrained, and a second wall surface that is a surface of a part of the second elastic member that defines the cavity is unrestrained, and a third wall surface that is a part of a surface of the second elastic member and is located opposite to the second wall surface in the first direction is exposed outward, so that the third wall surface is unrestrained.

2. The sole according to claim 1, wherein a part of the second elastic member that is defined by the second wall surface and the third wall surface includes a substantially plate-shaped portion whose thickness is a dimension, in the first direction, of a contour of the substantially plate-shaped portion.

3. The sole according to claim 1, wherein the second elastic member includes a first portion adjacent to the cavity in the first direction, the second elastic member includes a second portion that is not adjacent to the cavity in the first direction and is adjacent to the first portion in the normal direction to the ground contact surface, and a dimension, in the first direction, of a contour of the first portion is smaller than a dimension, in the first direction, of a contour of the second portion, so that a constricted portion is disposed at a position of the second elastic member that corresponds to the cavity.

4. The sole according to claim 1, wherein a first recess is disposed in a part of the first elastic member that defines the facing region, a second recess is disposed in a part of the second elastic member that defines the facing region, and the first recess and the second recess face each other to form the cavity defined by the first recess and the second recess.

5. The sole according to claim 1, wherein the facing region includes a portion where the cavity is not disposed, and the first elastic member and the second elastic member are bonded to each other in the portion.

6. The sole according to claim 5, wherein the sole body includes a communication path allowing the cavity to communicate with an outside.

7. The sole according to claim 5, wherein the facing region extends in a second direction intersecting the first direction and substantially parallel to the ground contact surface, and a plurality of the cavities are disposed at a distance from each other in the second direction.

8. The sole according to claim 1, wherein the facing region extends in a second direction intersecting the first direction and substantially parallel to the ground contact surface, and the second direction is a direction intersecting a left-right direction of the sole that coincides with a width direction of a foot of a wearer.

9. The sole according to claim 8, wherein the cavity extends in the normal direction to the ground contact surface, and has an inclined shape inclined toward a front end of the sole while extending toward a top end of the sole.

10. The sole according to claim 8, comprising: a forefoot portion configured to support a toe portion and a ball portion of a foot of a wearer; a midfoot portion configured to support an arch portion of the foot of the wearer; and a rearfoot portion configured to support a heel portion of the foot of the wearer, wherein the facing region is located at least in a first region that is a medial-foot-side portion of the sole and included in the rearfoot portion, and a second region that is a lateral-foot-side portion of the sole and included in the rearfoot portion, and the cavity is located in each of the first region and the second region.

11. The sole according to claim 10, wherein a volume of the cavity located in the first region is smaller than a volume of the cavity located in the second region.

12. The sole according to claim 1, wherein a groove extending in a direction intersecting the normal direction to the ground contact surface is disposed in the third wall surface.

13. The sole according to claim 12, wherein a recessed portion extending to reach a top end and a bottom end of the third wall surface and deeper than the groove is disposed in the third wall surface, and the recessed portion has an inclined shape inclined toward a front end of the sole while extending toward the top end of the sole.

14. A shoe comprising: the sole according to any one of claims 1 to 13; and an upper provided above the sole.

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