JP2000333705A - Structure of shoe sole - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a shoe sole structure that can absorb sufficiently tread impact and suppress pronation. SOLUTION: The heel portion 2B of a midsole 2 is provided with an exposed portion 21 that is not covered with an outersole 1B nearly in the center of the exterior and interior of a foot. A recess 22 sunk outwardly is formed in the exposed portion 21. The recess 22 has a valley portion 22m deepest in the cross section of the midsole 2. The valley portion 22m of the recess 22 is provided in a position shifted outside 10 from the foot. The recess 22 gradually deepens toward the valley portion 22m from the inside 11 of the foot. The recess 22 sharply shallows toward the outside 10 of the foot from the valley bottom portion 22m. Thus, by locating the valley portion 22m nearer to the outside 10 of the foot, the heel portion 2B of the midsole 2 is shaped so as to be compressively deformed more easily to the outside 10 than the inside 11.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to shoes worn when going out, jogging, exercising, etc., and more particularly to the structure of soles.

[0002] Jogging shoes, which are common today, are equipped with a midsole. The midsole is arranged on an outer sole (outsole, ground bottom) and absorbs a shock at the time of landing. Therefore, the midsole is made of a material having excellent shock absorbing properties and resilience, such as a resin sponge (foam).

[0003] USP No. 4,372,058, USP No. 4,741,11
4, USP No. 5,079,856 and JP-A-5-115306 each disclose a structure of a midsole for enhancing impact cushioning. In these prior arts, a recess recessed upward from the bottom side of the midsole is provided in the rear foot portion of the midsole. In these prior arts,
The provision of the recess reduces the cross-sectional area of the midsole. Therefore, in these prior arts, the rear foot portion of the midsole is easily compressed and deformed, and the deformation absorbs the impact at the time of landing.

However, when the midsole is easily deformed, the stability of the shoe sole decreases. For this reason, the action of the foot falling inward after landing, that is, the pronation action is likely to increase, which causes overpronation.

[0005]

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a shoe sole structure capable of sufficiently absorbing a shock at the time of landing and suppressing pronation.

[0006] The sole structure of the present invention comprises an outer sole and a midsole. The outer sole has treads on the forefoot and hindfoot. The midsole is formed on the outer sole from the front foot to the rear foot. The rear foot portion of the midsole is provided from the inside to the outside of the foot. An exposed portion which is not covered by the outer sole is provided at a rear foot portion of the midsole substantially at the center of the inside and outside of the foot. The exposed portion is formed with a recess that is depressed upward from the tread surface (bottom surface). The recess has a valley bottom with the deepest depression in the cross section of the midsole. The valley bottom of the recess is provided at a position offset to the outside of the foot. The recess gradually deepens from the inside of the foot toward the valley bottom. By setting the shape of the recess in this way, the rear foot portion of the midsole has a shape that is easier to compress and deform on the outside than on the inside.

[0007]

Next, the principle and effects of the present invention will be described. Most people land on the outside of the hindfoot of the foot during walking and running. At the time of this landing, the greatest impact load is applied to the outside of the rear foot of the foot. Therefore, it is necessary to reduce the impact load applied to the outside of the rear foot of the foot.

According to the present invention, a recess is formed in the rear foot portion of the midsole upward from the bottom side, and the position of the valley bottom of the recess is offset to the outside of the foot. ing. For this reason, the outside of the rear foot portion of the midsole has a smaller pressure-receiving cross-sectional area than the inside of the rear foot portion of the midsole, and is therefore easily deformed by compression.
As a result, the outside of the rear foot portion of the midsole is greatly compressed and deformed at the time of landing, so that the shock absorbing property at the time of landing is enhanced.

[0009] On the other hand, most people perform a pronation operation in which their feet fall slightly inward after landing. Here, in the present invention, the position of the valley bottom of the recess is offset to the outside of the foot. For this reason, the inside of the rear foot portion of the midsole has a larger pressure-receiving cross-sectional area than the outside of the rear foot portion of the midsole, and therefore, is less likely to be compressed and deformed. As a result, the inside of the rear foot portion of the midsole does not compressively deform after landing, so that the pronation operation can be suppressed, and there is no possibility of causing overpronation.

In the present invention, the shape of the midsole is complicated because the impact buffering property is improved and the pronation operation is suppressed by devising the shape of the recess provided in the midsole. Not even.

In a preferred embodiment of the present invention, the rear foot portion of the outer sole is formed in a horseshoe shape. Such a horseshoe-shaped outer sole increases stability upon landing.

[0012] In another preferred embodiment of the present invention, the midsole is formed of foam, and the inside of the rear foot and the inside of the footstep of the midsole are the rear foot and the front foot of the mid sole. The hardness is set to a larger value. As described above, by setting the hardness of the midsole, the outside of the rear foot portion of the midsole is further easily compressed and deformed. On the other hand, the inside of the rear foot portion or the inside of the step portion of the midsole is less likely to be compressed and deformed. Therefore, the effect of buffering the impact and the effect of suppressing pronation are enhanced.

[0013]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be more clearly understood from the following description of the preferred embodiments with reference to the accompanying drawings. However, the examples and figures are for illustration and description only. The scope of the present invention must be determined based on the claims. In the accompanying drawings, the same part numbers in a plurality of drawings indicate the same or corresponding parts.

First Embodiment FIGS. 1 to 5 show a first embodiment. In FIG. 3, 1F and 1B are outer soles,
Reference numeral 2 denotes a midsole, 3 denotes an upper for wrapping the upper, and 4 denotes a reinforcing device made of a resin plate. In FIG. 3, the upper 3 is shown by a two-dot chain line in order to clarify the portion of the upper 3.

The outer soles 1F and 1B are divided into a front foot 1F and a rear foot 1B. The front foot 1F and the rear foot 1B of the outer sole each have a tread surface 12. The outer soles 1F and 1B are often formed of, for example, rubber and have irregularities not shown in the drawings.

The midsole 2 is fixed on the outer soles 1F and 1B across the front foot 2F, the stepping portion 2M, and the rear foot 2B. The midsole 2
Is generally formed of a resin or rubber foam, and has a shock-absorbing property and a rebound resilience.

As shown in FIG. 2, the reinforcing device 4 is fixed to the bottom surface side of the step portion 2M of the midsole 2. As shown in FIG. 1, the forefoot portion 1F and the rear foot portion of the outer sole are provided. 1B. The strengthening device 4
Is divided into an inner reinforcement device 41 and an outer reinforcement device 40, each of which has an inner arch 11 and an outer arch 10,
As shown in FIG. 3 and FIG. 4 (a), it is formed in an arch shape.

As shown in FIG.
The diagonally reinforced portion 42 provided at the approximate center of the inside and outside of the foot, the innermost inner portion 43, the front end portion 44, and the rear end portions 45 and 47 are integrally molded and penetrated near the center. Hole 48
have. The diagonally reinforced portion 42 is disposed obliquely outwardly 10 toward the front end 1b of the rear sole 1B from the rear end 1f of the front sole 1F of the outer sole. Front end portions 49, 44 of the respective reinforcing devices 40, 41
Is sandwiched between the midsole 2 and the forefoot portion 1F of the outer sole. On the other hand, the rear ends 45, 46, 47 of the reinforcing devices 40, 41 are sandwiched between the mid sole 2 and the rear sole 1B of the outer sole.

The hardness of the inner portion 43 of the reinforcing device is set to a value larger than the hardness of the outer reinforcing device 40. Thereby, the bending rigidity of the inner portion 43 of the inner reinforcing device 41 is set to a value larger than the bending rigidity of the outer reinforcing device 40. It is preferable that the hardness of the obliquely reinforced portion 42 is set to an intermediate hardness between the hardness of the inner portion 43 and the hardness of the outer reinforced device 40. 3 and 4
As shown in (a), the inner portion 43 of the inner reinforcing device 41
Is shorter than the outer reinforcing device 40 and the curvature of the arch is large, so that the bending rigidity is further increased.

As shown in FIG. 1, the rear foot portion 1B of the outer sole is generally formed in a horseshoe shape, and is divided into two parts inside and outside the foot. On the other hand, the mid soles 2F, 2M, 2B are arranged from the inside 11 of the foot to the outside 1
0 is provided over substantially the entire area. An exposed portion 21 that is not covered with the outer sole 1B is provided in the rear foot portion 2B of the midsole substantially at the center of the inside and outside of the foot.

The exposed portion 21 has a recess 22 formed therein. As shown in FIGS. 4B and 5A, the recess 22 is formed so as to be recessed upward from the tread surface 12 substantially at the center of the rear foot portion 2B of the midsole. The recess 22 has a valley-bottomed portion 22m with the deepest depression in the cross section of the midsole 2. As shown in FIG. 1, the valley bottom portion 22m is formed to be generally long along the longitudinal direction 50 of the shoe sole.

In the cross section of FIG. 5A,
In the cross section of the sole of the shoe where the width of the recess 22 is the widest in FIG. 1, the width 22d of the recess 22 in FIG. It is preferable to set so that the degree is as follows. The depth 2 of the valley bottom 22m
In the case of adult shoes, 2h is generally preferably set to 5 mm or more.

As shown in FIGS. 5A and 5B, the recess 22 gradually deepens from the inside of the foot toward the valley bottom 22m. Meanwhile, the recess 2
2 gradually becomes shallower as it approaches the outer side 10 of the foot from the valley bottom 22m. That is, the valley bottom portion 22m of the recess 22 is provided at a position closer to the outside 10 than the inside 11 of the foot. As a result, the rear foot portion 2B of the mid sole has a smaller pressure receiving area at the outer portion 24 than at the inner portion 23, and thus has a shape that is easily compressed and deformed at the time of landing.

The midsole of this embodiment comprises a high hardness portion 25 and a low hardness portion 26. As shown in FIG.
The high hardness portion 25 is provided on the inside 11 of the rear foot portion 2B and the inside 11 of the stepping portion 2M of the midsole. On the other hand, the low hardness portion 26 is provided at a portion other than the high hardness portion 25, for example, at the center and the outer side 10 of the rear foot portion 2B of the midsole, at the center and the outer side 10 of the tread portion 2M, and at the portion of the forefoot portion 2F. ing.

Second Embodiment FIGS. 6 (a), 6 (b) and 6 (c) show a second embodiment. In the second embodiment,
The thickness T1 of the inner reinforcing device 41 is set to be larger than the thickness T0 of the outer reinforcing device 40. Thereby, the bending rigidity of the inner portion 43 in the reinforcing device is set to a value larger than the bending rigidity of the outer reinforcing device 40. FIG.
As shown in (c), in the present embodiment, the cross section of the recess 22 is formed with a smooth curved surface. The midsole 2 is formed with uniform hardness. Other configurations of the second embodiment are the same as those of the first embodiment, and the same or corresponding portions are denoted by the same reference characters and description and illustration thereof are omitted.

FIGS. 7A to 7C show modified examples. In the first modified example of FIG. 7A, the valley bottom 22 m is provided at a position offset toward the outermost 10 in the recess 22. In the second modified example of FIG. 7B, the concave portion 22 is formed by a downwardly convex curve. Third in FIG. 7C
In the modified example, the valley bottom 22 m is hollowed toward the outside 10.

As described above, the preferred embodiments have been described with reference to the drawings. However, those skilled in the art can easily envisage various changes and modifications within the obvious scope by referring to the present specification. There will be. For example, a recess may be provided on the upper surface of the midsole, and a cushion member such as a rubber or resin foam or gel having low hardness may be embedded in the recess. Further, in the present invention, the midsole may be formed with a uniform hardness.
In the above embodiment, the reinforcing device 4 is connected to the outer reinforcing device 40.
Although it is divided into the inner reinforcement device 41 and the inner reinforcement device 41, in the present invention, the reinforcement device 4 may be integrated without being divided inside and outside. In this case, it is preferable to connect the rear end portion 47 of the oblique reinforcement portion 42 of FIG. 1 and the rear end portion 46 of the inner reinforcement device 41. In the present invention, it is not always necessary to provide the shank 4. In addition, the outer soles 1F and 1B may have a resin non-foamed convex portion in addition to a rubber foamed or non-foamed body. Accordingly, such changes and modifications are to be construed as being within the scope of the invention as defined by the appended claims.

[Brief description of the drawings]

FIG. 1 is a bottom view of a shoe sole according to a first embodiment of the present invention.

FIG. 2 is a bottom view of the midsole and the reinforcing device according to the first embodiment of the present invention.

FIG. 3 is a side view of a shoe sole as viewed from the inside of a foot.

FIG. 4 (a) is a side view of a shoe sole viewed from the outside of a foot. FIG. 4B is a longitudinal sectional view of the midsole.

FIG. 5A is a sectional view taken along line Va-Va of FIG. 1; FIG. 5B is a sectional view taken along line Vb-Vb in FIG.

6 (a), 6 (b) and 6 (c) show a second embodiment, and FIG. 6 (a) is a side view of the shoe sole viewed from the inside of the foot, and FIG. b) is a side view of the sole viewed from the outside of the foot,
FIG. 6C is a cross-sectional view of the rear foot of the shoe sole.

7 (a) is a cross-sectional view of a shoe sole showing a first modification of the recess according to the present invention, FIG. 7 (b) is a cross-sectional view of the shoe sole showing a second modification thereof, FIG. 7C is a cross-sectional view of the shoe sole showing the third modification.

[Explanation of symbols]

 1B: rear sole part of outer sole 1F: front foot part of outer sole 2: mid sole 2B: rear foot part 2F: front foot part 2M: stepping part 22: recess 22d: width 22m: valley bottom part 23: inner part 24: Outer part 25: High hardness part 26: Low hardness part 4: Strengthening device 40: Outside strengthening device 41: Inside strengthening device 42: Diagonal strengthening portion 43: Inside portion 10: Outside 11: Inside

Claims (6)

[Claims] 1. A shoe sole structure comprising: an outer sole having a tread surface on a front foot portion and a rear foot portion; and a mid sole formed on the outer sole from a front foot portion to a rear foot portion, The hindfoot portion of the midsole is provided from the inside to the outside of the foot, and the hindfoot portion of the midsole is provided with an exposed portion that is not covered by the outer sole at substantially the center of the inside and outside of the foot, The exposed portion is formed with a recess that is recessed upward from the tread surface, and the recess has a valley-bottomed portion where the recess is deepest in the cross section of the midsole, The valley bottom of the recess is formed long along the longitudinal direction of the shoe sole,
The valley bottom of the recess is provided at a position offset to the outside of the foot, and the recess gradually becomes deeper as approaching the valley bottom from the inside of the foot, as described above. , The rear sole portion of the mid sole has a shape that is more easily deformed by compression on the outer side than on the inner side. 2. The shoe sole structure according to claim 1, wherein a rear foot portion of the outer sole is formed in a horseshoe shape. 3. The cross section of the sole at the point where the width of the recess is the widest, wherein the width of the recess is 1 / the width of the midsole.
2. The shoe sole structure according to claim 1, wherein the shoe sole structure is set to at least about 4 and at most about 1/2. 4. The shoe sole structure according to claim 1, wherein a depth of a valley bottom portion of the recess is set to 5 mm or more. 5. The shoe sole structure according to claim 1, wherein the recess is provided over substantially the entire area of the exposed portion. 6. The midsole is formed of a foam material over a forefoot portion, a tread portion, and a hindfoot portion, and the inside of the hindfoot portion and the inside of the tread portion of the midsole are the hindfoot portion of the midsole. 2. The shoe sole structure according to claim 1, wherein the hardness is set to a value larger than that of the outside and the forefoot.