Sole Structure and Shoe Including the Sole Structure

This application claims priority to Japanese Patent Application No. 2024-057196 filed on Mar. 29, 2024, the entire disclosure of which is incorporated by reference herein.

The present disclosure relates to a sole structure and a shoe including the sole structure.

Japanese Patent No. 6708595 discloses a sole structure including an upper midsole and a lower midsole, where the lower midsole is set firmer than the upper midsole (see, for example, paragraph [0070] of the specification).

In general, a midsole of each shoe that a person wears for walking or running is required to have great cushioning properties to reduce impacts on a foot and also required to have stability not to make a foot unsteady. In order to reduce impacts on a foot, not only on an upper part near a foot sole but also a lower part near the ground of the midsole preferably have great cushioning properties. However, if both the upper part and the lower part of the midsole have great cushioning properties, it is difficult to maintain the stability for supporting a foot.

In view of the foregoing, an object of the present disclosure is to ensure the stability for supporting a foot even if both the upper part and the lower part of the midsole have great cushioning properties.

A first aspect of the present disclosure relates to a sole structure including: 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.

The sole structure of the first aspect of the present disclosure includes: a midsole; a first support which is formed in a plate shape; which is firmer than the midsole; and which is disposed along a lower surface of the midsole. Thus, even if the upper part and the lower part of the midsole have great cushioning properties, the first support can stably support a foot sole. Further, the midsole includes 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. Thus, the second supports 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 have greater cushioning properties, the stability for supporting a foot can be ensured.

A second aspect of the present disclosure is an embodiment of the first aspect. In the second aspect, 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.

In the second aspect, the second supports include the inner section 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.

A third aspect of the present disclosure is an embodiment of the second aspect. In the third aspect, 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.

In the third aspect, in addition to the inner section, the second supports include the outer section extending backward along the outer side of the midsole, and thus a foot is supported on both the inner side and the outer side, thereby ensuring greater stability.

A fourth aspect of the present disclosure is an embodiment of any one of the first to third aspects. In the fourth aspect, the first support is provided in the midfoot region and a forefoot region of the midsole.

In the fourth aspect, the first support is also provided in the forefoot region, thereby ensuring greater stability.

A fifth aspect of the present disclosure is an embodiment of the second or third aspect. In the fifth aspect, the second support extends so that a back side of the second support () is positioned higher.

In the fifth aspect, the second support extends so that a back side of the second support is positioned higher. Thus, when a person wearing shoes is running, in the heel-strike phase Tin which the cushioning properties of the midsole is particularly required, the firm second support is less likely to come into contact with the ground, and there is less impact on a foot sole.

A sixth aspect of the present disclosure is an embodiment of the second or third aspect. In the sixth aspect, 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.

In the sixth aspect, the second supports are provided on the recesses provided on the side portions of the midsole, and thus the second supports can be easily positioned to overlap a heel portion in the vertical direction. As a result, the firm second supports can more easily support a load vertically applied on the midsole, and thus greater stability for supporting a foot can be achieved.

A seventh aspect of the present disclosure is an embodiment of any one of the first to third aspects. In the seventh aspect, the sole structure further includes: a support plate which is disposed along the first support and which is more solid than the first support.

In this seventh aspect, a support plate which is more solid than the first support is disposed along the first support, and thus greater stability can be achieved.

An eighth aspect of the present disclosure is an embodiment of the sixth aspect. In the eighth aspect, 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.

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

A ninth aspect of the present disclosure is an embodiment of the eighth aspect. In the ninth aspect, a maximum thickness of each single structure of the repetitive structure of the second support () becomes smaller in a back side.

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

A tenth aspect of the present disclosure relates to a shoe including the sole of any one of the first to third aspects and an upper.

This tenth aspect provides a shoe that exhibits the advantages of the first to third aspects.

As described above, according to the present disclosure, both the upper part and the lower part of the midsole have greater cushioning properties, whereas the stability for supporting a foot can be ensured.

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.

In the following description, each region of a sole structurein 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 (R) is a region of 0% to about 40%; a midfoot region (R) is a region of about 40% to about 70%; and a heel region (R) is a region of about 70% to 100%; a front heel region (R) is a region of about 70% to about 85%; and a back heel region (R) 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.

show the sole structureof the first embodiment, andshow a shoeincluding the sole structureand an upper. The shoeis not limited to any particular use, and may be used as a running shoe, for example. The shoeor the sole structureshown inis a shoe or its sole structure for a left foot.

The sole structureincludes a midsole; a first supportformed in a plate shape and disposed along a lower surface of the midsole; a pair of second supports(,) located behind the first supportand provided on the inner lateral side and the outer lateral side of the midsolein the foot width direction, respectively; and an outsoleprovided below the midsoleand the first support.

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

As shown in, the upper surface of the midsoleis formed along the shape of a foot sole. The upper surface of the midsoleconsists of a regionon which a foot sole is placed and a rimwhich is provided at the inner side and the outer side in the foot width direction and at the back side, where the rimis positioned higher than the regionso 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.

As can be seen from the comparison between, the part of the lower surface of the midsolein the part of the forefoot region Rand the midfoot region Ron which the first supportis positioned is located slightly higher than the other part of the lower surface of the midsolein the other part of the forefoot region RI and the midfoot region R, in order to secure a space for the first support. As shown in, the lower surface of the midsolein the forefoot region Rhas a rocker structure R that looks a curved shape in side view, where the front side of the lower surface is gradually curled upward.

As shown in, the side portions of the midsoleon the inner side and the outer side in the foot width direction are provided with recessesandrespectively, on each of which the second supportis provided. The recessesandprovided on the side portions of the midsoleon 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 midsolenear the front end of the midfoot region Rto the upper end of the midsolein the back heel region R

The first supportis provided below the midsoleand extends from the forefoot region Rto the midfoot region R. The first supportonly has to be provided in at least a part of the midfoot region Rand is not necessarily provided in the whole of the midfoot region R. The first supportis not necessarily provided in the forefoot region R.

The first supportis 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. According to the durometer C or A, the hardness of the supportis, for example, 45 C to 90 A, and preferably 50 C to 80 A.

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

In the present disclosure, the thickness of the first supportin 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 midsoleimmediately above the first support.

The pair of second supportsinclude an inner sectionextending from the inner side of the first supportbackward along the inner side of the midsole; and an outer sectionextending from the outer side of the first supportbackward along the outer side of the midsole. The second supportsextend along the direction in which the recessesandof the midsole extend, and the second supportsare provided in the recessesandThe second supportextends so that its back side is positioned higher. In other words, the second supportis formed so that its front side is positioned lower. The lower end of the second supportat its front end is located on a higher position than the lower surface of the midsole. In other words, every part of the second supportis located on a higher position than the lower surface of the midsole.

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

The sole structurefurther includes the outsole. As shown in, the outsoleincludes a first partprovided on the front side of the first supportand provided on the lower surface of the midsole; a second partprovided on the lower surface of the first support; and third partsandprovided behind the second partand provided on the lower surface of the midsole. The sole structureof the present disclosure does not necessarily include the outsole.

The sole structureof this embodiment includes the midsoleand the first supportwhich is formed in a plate shape; which is firmer than the midsole; and which is disposed along the lower surface of the midsole. Thus, even if the upper part and the lower part of the midsolehave greater cushioning properties, a foot sole can be stably supported by the first support. The midsoleincludes the second supportwhich is firmer than the midsole; which is located behind the first support; and which is provided on the side portions of the midsole. Thus, the second supportssupport 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 midsolehave greater cushioning properties, the stability for supporting a foot can be ensured.

In this embodiment, the second supportsinclude the inner sectionextending 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.

In this embodiment, in addition to the inner sectionthe second supportsinclude the outer sectionextending backward along the outer side of the midsole, and thus a foot is supported on both the inner side and the outer side in the foot width direction, thereby ensuring greater stability.

In this embodiment, the first supportis also provided in the forefoot region R, thereby ensuring greater stability.

In this embodiment, the second supportsare provided on the recessesandprovided on the side portions of the midsole, and thus the second supportscan be easily positioned to overlap a heel portion in the vertical direction. As a result, the firm second supportscan more easily support a load vertically applied on the midsole, and thus greater stability for supporting a foot can be achieved.

If the shoeof 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 structureprovides to a foot should be more required.shows the relationship during running between the shoeand the ground G in three phases: a heel-strike phase (T), a foot-flat phase (T), and a kick-out phase (T). 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 T; the stability not to make a foot unsteady should be more required in the foot-flat phase T; and the repulsiveness (the cushioning properties) should be more required in the kick-out phase Tto achieve a smooth kick-out. Then, they created the sole structureof this embodiment providing the advantages described below.

Specifically, in this embodiment, the first supportis disposed in the midfoot region Rof the midsole. Thus, during running, in the foot-flat phase Tin which the stability is particularly required, the midfoot region Rwhich often receives a load can be easily stabilized.

In this embodiment, every part of the second supportis located on a higher position than the lower surface of the midsole. Thus, during running, in the heel-strike phase Tin which the cushioning properties of the midsoleis particularly required, the firm second supportis less likely to come into contact with the ground, and there is less impact on a foot sole. Further, in this embodiment, the second supportextends 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 Tis further enhanced.

In this embodiment, the first supportis formed in a thin plate shape having a thickness less than or equal to half the thickness of the midsoleimmediately thereabove, and thus, even the first supportprovided in the forefoot region Rdoes not affect the cushioning properties and the repulsiveness of the midsolein the forefoot region R. As a result, during running, in the kick-out phase T, it is easier to obtain comfortable feeling and propulsion of running. Further, the firm first supportextends to the forefoot region R, and thus it is easy to keep the shape of the lower surface of the midsolethat is curled upward in the forefoot region Rby 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 T.