SOLE STRUCTURE AND SHOE INCLUDING THE SOLE STRUCTURE

Abstract

A sole structure includes: a midsole; a first support which is formed in a plate shape, which is firmer than the midsole, which is provided in a midfoot region of the midsole, and which is disposed along a lower surface of the midsole; and a second support which is firmer than the midsole, which is disposed behind the first support, and which is provided on a side portion of the midsole.

Claims

1. A sole structure comprising: a midsole; a first support which is formed in a plate shape; which is firmer than the midsole; which is provided in a midfoot region of the midsole; and which is disposed along a lower surface of the midsole; and a second support which is firmer than the midsole; which is disposed behind the first support; and which is provided on a side portion of the midsole.

2. The sole structure of claim 1, wherein the second support includes an inner section extending from an inner side of the first support backward along an inner side of the midsole in the foot width direction.

3. The sole structure of claim 2, wherein the second support further includes an outer section extending from an outer side of the first support backward along an outer side of the midsole in the foot width direction.

4. The sole structure of claim 1, wherein the first support is provided in the midfoot region and a forefoot region of the midsole.

5. The sole structure of claim 2, wherein the second support extends so that a back side of the second support is positioned higher.

6. The sole structure of claim 2, wherein the midsole includes a side portion provided with a recess which is formed in a groove shape and which extends backward from the first support, and the second support is disposed on the recess.

7. The sole structure of claim 1, further comprising: a support plate which is disposed along the first support and which is more solid than the first support.

8. The sole structure of claim 6, wherein a size of a cross-sectional area of the second support when being cut in a vertical direction and the foot width direction is defined as a thickness of the second support, and the second support has a repetitive structure where the thickness of the second support periodically varies in a direction in which the second support extends.

9. The sole structure of claim 8, wherein a maximum thickness of each single structure of the repetitive structure of the second support becomes smaller in a back side.

10. A shoe comprising: the sole structure of claim 1; and an upper.

11. A shoe comprising: the sole structure of claim 2; and an upper.

12. A shoe comprising: the sole structure of claim 3; and an upper.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0027] FIG. 1 is a perspective view of a sole structure of a first embodiment.

[0028] FIG. 2 is a cross-sectional view taken along the line II-II in FIG. 1.

[0029] FIG. 3 is a cross-sectional view taken along the line III-III in FIG. 1.

[0030] FIG. 4 is a cross-sectional view taken along the line IV-IV of FIG. 1.

[0031] FIG. 5 is a side view of the shoe of the first embodiment.

[0032] FIG. 6 is an exploded perspective view of the shoe of the first embodiment.

[0033] FIG. 7 is a schematic view showing the states of the shoe in a heel-strike phase, a foot-flat phase, and a kick-out phase.

[0034] FIG. 8 corresponds to FIG. 6 and shows a shoe of a variation of the first embodiment.

[0035] FIG. 9 corresponds to FIG. 6 and shows a shoe of a second embodiment.

[0036] FIG. 10 corresponds to FIG. 6 and shows a shoe of a variation of the second embodiment.

DETAILED DESCRIPTION

[0037] Embodiments of the present disclosure will now be described with reference to the drawings. The following description of preferred embodiments is merely illustrative in nature and is not intended to limit the present disclosure, its application, or its use.

[0038] In the following description, each region of a sole structure 1 in the foot length direction is defined using the percentage (%) as follows, where, in the foot length direction, the front end is regarded as 0% and the back end is regarded as 100%. A forefoot region (R1) is a region of 0% to about 40%; a midfoot region (R2) is a region of about 40% to about 70%; and a heel region (R3) is a region of about 70% to 100%; a front heel region (R3a) is a region of about 70% to about 85%; and a back heel region (R3b) is a region of about 85% to 100%. The inner side corresponds to the medial instep side in the shoe, and the outer side corresponds to the lateral instep side in the shoe.

First Embodiment

[0039] FIGS. 1 to 4 show the sole structure 1 of the first embodiment, and FIGS. 5 and 6 show a shoe 3 including the sole structure 1 and an upper 2. The shoe 3 is not limited to any particular use, and may be used as a running shoe, for example. The shoe 3 or the sole structure 1 shown in FIGS. 1 to 10 is a shoe or its sole structure for a left foot.

[0040] The sole structure 1 includes a midsole 4; a first support 5 formed in a plate shape and disposed along a lower surface of the midsole 4; a pair of second supports 6 (6a, 6b) located behind the first support 5 and provided on the inner lateral side and the outer lateral side of the midsole 4 in the foot width direction, respectively; and an outsole 7 provided below the midsole 4 and the first support 5.

Midsole

[0041] The midsole 4 is substantially formed in a plate shape that is vertically thick. The midsole 4 is made of a soft material, such as EVA foam and TPU foam, and can mainly provide cushioning properties to the sole structure 1. According to the durometer C, the hardness of the midsole 4 is, for example, 30 C to 60 C, and preferably 35 C to 50 C.

[0042] As shown in FIG. 1, the upper surface of the midsole 4 is formed along the shape of a foot sole. The upper surface of the midsole 4 consists of a region 4a on which a foot sole is placed and a rim 4b which is provided at the inner side and the outer side in the foot width direction and at the back side, where the rim 4b is positioned higher than the region 4a so as to fit the shape of a foot sole at the inner side and the outer side in the foot width direction and at the back side.

[0043] As can be seen from the comparison between FIGS. 2 and 3, the part of the lower surface of the midsole 4 in the part of the forefoot region R1 and the midfoot region R2 on which the first support 5 is positioned is located slightly higher than the other part of the lower surface of the midsole 4 in the other part of the forefoot region RI and the midfoot region R2, in order to secure a space for the first support 5. As shown in FIG. 5, the lower surface of the midsole 4 in the forefoot region R1 has a rocker structure R that looks a curved shape in side view, where the front side of the lower surface is gradually curled upward.

[0044] As shown in FIGS. 3 and 6, the side portions of the midsole 4 on the inner side and the outer side in the foot width direction are provided with recesses 4c and 4d, respectively, on each of which the second support 6 is provided. The recesses 4c and 4d provided on the side portions of the midsole 4 on the inner side and the outer side in the foot width direction are each shaped into a groove shape and extend from the lower end of the midsole 4 near the front end of the midfoot region R2 to the upper end of the midsole 4 in the back heel region R3b.

First Support

[0045] The first support 5 is provided below the midsole 4 and extends from the forefoot region R1 to the midfoot region R2. The first support 5 only has to be provided in at least a part of the midfoot region R2 and is not necessarily provided in the whole of the midfoot region R2. The first support 5 is not necessarily provided in the forefoot region R1.

[0046] The first support 5 is made of a foam material such as an EVA foam and a TPU foam or a firm resin material such as polyether block amide (PEBA) and synthetic rubber, each of which is firmer than the midsole 4. According to the durometer C or A, the hardness of the support 5 is, for example, 45 C to 90 A, and preferably 50 C to 80 A.

[0047] As shown in FIG. 6, the outer shape of the front side of the first support 5 in top view is a substantially V-shape tapered toward the front side. The back portion of the first support 5 is divided into two portions in top view which are connected to the pair of second supports 6. In this embodiment, the portion at 50% in the foot length direction serves as the boundary (B) between the first support 5 and the second supports 6.

[0048] In the present disclosure, the thickness of the first support 5 in the vertical direction is not limited to any particular thickness, and in this embodiment, the thickness is less than or equal to half the thickness of the midsole 4 immediately above the first support 5.

Second Support

[0049] The pair of second supports 6 include an inner section 6a extending from the inner side of the first support 5 backward along the inner side of the midsole 4; and an outer section 6b extending from the outer side of the first support 5 backward along the outer side of the midsole 4. The second supports 6 extend along the direction in which the recesses 4c and 4d of the midsole extend, and the second supports 6 are provided in the recesses 4c and 4d. The second support 6 extends so that its back side is positioned higher. In other words, the second support 6 is formed so that its front side is positioned lower. The lower end of the second support 6 at its front end is located on a higher position than the lower surface of the midsole. In other words, every part of the second support 6 is located on a higher position than the lower surface of the midsole.

[0050] The second support 6 is made of a material firmer than the midsole 4. In this embodiment, the second support 6 is made of the same material as that of the first support 5 and is integrated with the first support 5. Similarly to the first support 5, according to the durometer C or A, the hardness of the second support 6 is, for example, 45 C to 90 A, and preferably 50 C to 80 A.

Outsole

[0051] The sole structure 1 further includes the outsole 7. As shown in FIG. 6, the outsole 7 includes a first part 7a provided on the front side of the first support 5 and provided on the lower surface of the midsole 4; a second part 7b provided on the lower surface of the first support 5; and third parts 7c and 7d provided behind the second part 7b and provided on the lower surface of the midsole 4. The sole structure 1 of the present disclosure does not necessarily include the outsole 7.

Effects and Advantages

[0052] The sole structure 1 of this embodiment includes the midsole 4 and the first support 5 which is formed in a plate shape; which is firmer than the midsole 4; and which is disposed along the lower surface of the midsole 4. Thus, even if the upper part and the lower part of the midsole 4 have greater cushioning properties, a foot sole can be stably supported by the first support 5. The midsole 4 includes the second support 6 which is firmer than the midsole 4; which is located behind the first support 5; and which is provided on the side portions of the midsole 4. Thus, the second supports 6 support the vicinity of a heel portion of a foot sole, thereby ensuring greater stability. Accordingly, even if both the upper part and the lower part of the midsole 4 have greater cushioning properties, the stability for supporting a foot can be ensured.

[0053] In this embodiment, the second supports 6 include the inner section 6a extending backward along the inner side of the midsole, and thus pronation of a foot falling toward the inner side of an instep can be reduced. Accordingly, greater stability for supporting a foot can be achieved.

[0054] In this embodiment, in addition to the inner section 6a, the second supports 6 include the outer section 6b extending backward along the outer side of the midsole 4, and thus a foot is supported on both the inner side and the outer side in the foot width direction, thereby ensuring greater stability.

[0055] In this embodiment, the first support 5 is also provided in the forefoot region R1, thereby ensuring greater stability.

[0056] In this embodiment, the second supports 6 are provided on the recesses 4c and 4d provided on the side portions of the midsole 4, and thus the second supports 6 can be easily positioned to overlap a heel portion in the vertical direction. As a result, the firm second supports 6 can more easily support a load vertically applied on the midsole 4, and thus greater stability for supporting a foot can be achieved.

[0057] If the shoe 3 of this embodiment is a running shoe, it is also important to consider, in each phase of running, which one of the cushioning properties and the stability that the sole structure 1 provides to a foot should be more required. FIG. 7 shows the relationship during running between the shoe 3 and the ground G in three phases: a heel-strike phase (T1), a foot-flat phase (T2), and a kick-out phase (T3). The inventors of the present application assumed that the cushioning properties given to a heel portion should be more required in the heel-strike phase T1; the stability not to make a foot unsteady should be more required in the foot-flat phase T2; and the repulsiveness (the cushioning properties) should be more required in the kick-out phase T3 to achieve a smooth kick-out. Then, they created the sole structure 1 of this embodiment providing the advantages described below.

[0058] Specifically, in this embodiment, the first support 5 is disposed in the midfoot region R2 of the midsole 4. Thus, during running, in the foot-flat phase T2 in which the stability is particularly required, the midfoot region R2 which often receives a load can be easily stabilized.

[0059] In this embodiment, every part of the second support 6 is located on a higher position than the lower surface of the midsole 4. Thus, during running, in the heel-strike phase T1 in which the cushioning properties of the midsole 4 is particularly required, the firm second support 6 is less likely to come into contact with the ground, and there is less impact on a foot sole. Further, in this embodiment, the second support 6 extends so that its back side is positioned higher. Thus, the advantage of there being less impact on a foot sole in the heel-strike phase T1 is further enhanced.

[0060] In this embodiment, the first support 5 is formed in a thin plate shape having a thickness less than or equal to half the thickness of the midsole 4 immediately thereabove, and thus, even the first support 5 provided in the forefoot region R1 does not affect the cushioning properties and the repulsiveness of the midsole 4 in the forefoot region R1. As a result, during running, in the kick-out phase T3, it is easier to obtain comfortable feeling and propulsion of running. Further, the firm first support 5 extends to the forefoot region R1, and thus it is easy to keep the shape of the lower surface of the midsole 4 that is curled upward in the forefoot region R1 by the rocker structure R. As a result, it is possible to obtain a rolling, smooth feeling of running according to the rocker effect. It is also possible to achieve a smooth kick-out in the kick-out phase T3.

Variation of First Embodiment

[0061] As shown in FIG. 8, the sole structure 1 may further include a support plate 8 which is disposed along the upper surface of the first support 5 and which is more solid than the first support 5. The material of the support plate 8 is not limited to any particular material, and may be, for example, resin, synthetic rubber, fiber reinforced plastic (FRP), or the like. In this variation, the support plate 8 extends along the upper surface of the first support 5, but the support plate 8 may extend along the lower surface of the first support 5 or may be embedded in the first support 5.

[0062] In this variation, the support plate 8 which is more solid than the first support 5 is disposed along the first support 5, and thus it is easier to keep the shape of the lower surface of the midsole 4 that is curled upward by the rocker structure R. That is, it is possible to further enhance the rocker effect described above as the advantage of the sole structure 1 of the first embodiment.

Second Embodiment

[0063] A sole structure 1 of the second embodiment will be described below. In the following, the description of the configuration common to the first embodiment will be omitted, and the same reference characters are used to represent the configurations corresponding to those of the first embodiment.

[0064] In this embodiment, in particular, the shape of the second support 6 is different from that of the first embodiment. Specifically, as shown in FIG. 9, the second support 6 has a repetitive structure where the thickness of the second support 6 periodically varies in the longitudinal direction (or in the direction in which the second support 6 extends). In other words, the second support 6 with this repetitive structure includes smaller thickness portions and larger thickness portions arranged alternately in the length direction in vertical view and side view. In this specification, the thickness of the second support 6 is defined as the size of the cross-sectional area of the second support 6 when being cut in the vertical direction and the foot width direction.

[0065] The maximum thickness of each single structure of the repetitive structure of the second support 6 becomes smaller in a back side of the single structure. The single structure referred to herein means a structure of the second support 6 consisting of a thin part and a thick part immediately behind the thin part. That is, as shown in FIG. 9, each of the inner section 6a and the outer section 6b of the second support 6 includes three thick parts each having a large diameter, and the maximum thickness of each thick part becomes smaller in the back side.

[0066] In this embodiment, the second support 6 has the repetitive structure where the thickness of the second support 6 periodically varies in the direction in which the second support 6 extends, and thus there is greater resistance to shear deformation in the longitudinal direction between the midsole 4 and the first support 5 and between the midsole 4 and the second support 6. As a result, greater stability in walking and running can be achieved.

[0067] In this embodiment, the part of the firm second support 6 behind the midfoot region R2 becomes thinner when viewed as a whole, and thus the volume ratio of the midsole 4 in the sole structure 1 tends to be higher than the volume ratio of the second support 6 in the sole structure 1, in the back heel region R3b rather than in the midfoot region R2. As a result, greater cushioning properties can be easily achieved in the back heel region R3b rather than in the midfoot region R2, and also greater stability can be easily achieved in the midfoot region R2 rather than in the back heel region R3b. Thus, during running, greater stability for supporting the midfoot region R2 in which the stability is more required can be achieved, and the cushioning properties of the back heel region R3b in which the cushioning properties is more required can be achieved.

[0068] As shown in FIG. 9, the recesses 4c and 4d of the midsole 4 are formed in a shape corresponding to the repetitive structure of the second support 6.

[0069] In this embodiment, the configuration of the first support 5 is also different from that in the first embodiment, though this is not always necessary. Specifically, the first support 5 includes a front section 5a with a thickness that vertically increases from its front end toward the back side, and a back section 5b with a thickness that vertically decreases from its front end toward the back side. The second support 6 extends backward from the back section 5b.

Variation of Second Embodiment

[0070] As shown in FIG. 10, the sole structure 1 may include a pair of third supports 9 (9a and 9b) extending forward from the front section 5a of the first support 5. The third support 9 is firmer than the midsole 4; is made of the same material as that of the first support 5, for example; and is integrated with the first support 5. The pair of third supports 9 include an inner section 9a extending forward from the inner part of the front section 5a of the first support 5 in the foot width direction, and an outer section 9b extending forward from the outer part of the front section 5a of the first support 5 in the foot width direction. Similarly to the second support 6, each of the inner section 9a and the outer section 9b has a repetitive structure where the thickness of each of them periodically varies in the longitudinal direction (or in the direction in which the third support 9 extends). Recesses 4e corresponding to the third support 9 are provided on the side portions of the midsole 4.

[0071] The sole structure 1 of this variation includes the third supports 9 (9a and 9b) firmer than the midsole 4, thereby ensuring greater stability. Further, the third support 9 has the repetitive structure where the thickness of the third support 9 periodically varies in the direction in which the third support 9 extends, and thus there is greater resistance to shear deformation in the longitudinal direction between the midsole 4 and the first support 5, between the midsole 4 and the second support 6, and between the midsole 4 and the third support 9. As a result, greater stability in walking and running can be achieved.

Other Embodiments

[0072] In the above embodiments, the second support 6 is provided on the recesses 4c and 4d provided on the side portions of the midsole 4, but the recesses 4c and 4d are not always necessary. The second support 6 may be fixed to the side portions of the midsole 4 on which the recesses 4c and 4d are not provided.

[0073] In the above embodiments, the second support 6 includes the inner section 6a and the outer section 6b, but may include only any one of the inner section 6a and the outer section 6b. If the second support 6 includes only any one of the inner section 6a and the outer section 6b, the second support 6 preferably includes the inner section 6a in view of reducing pronation of a foot falling toward the inner side of an instep.

[0074] In the first embodiment, the thickness of the second supports 6 may gradually become smaller in its back side portion.

[0075] In the above embodiments, the second support 6 is integral and continuous with the first support 5, but is not limited to this configuration. The second support 6 may be discontinuous with the first support 5. The second supports 6 only has to be provided behind the first support 5 and on the side portions of the midsole 4.

[0076] In the variation of the second embodiment, the third support 9 is integral and continuous with the first support 5, but is not limited to this configuration. The third supports 9 may be discontinuous with the first support 5. The second supports 9 only has to be provided in front of the first support 5 and on the side portions of the midsole 4.

[0077] The present disclosure is useful for a sole structure and a shoe.