shoes

Abstract

The shoes are designed to absorb impact from the ground to the feet while maintaining ankle alignment and providing good control when the wearer is running on uneven terrain. [Solution] The shoe according to this embodiment includes a first groove extending forward from the inner foot side to the outer foot side on the bottom surface of the sole, and a second groove extending forward from the bottom surface side to the top surface side on the inner foot side of the sole, wherein the groove width at the inner foot side end of the first groove and the groove width at the bottom surface side end of the second groove overlap at least a portion along the boundary direction between the bottom surface and the inner foot side.

Description

[Technical Field]

[0001] This invention relates to shoes. [Background technology]

[0002] Shoes incorporate various innovations depending on their intended use. For example, in mountaineering shoes, trail running shoes, and climbing shoes, a technique is known to connect the upper and outsole without using binders to enhance stability and durability (see, for example, Patent Document 1). [Prior art documents] [Patent Documents]

[0003] [Patent Document 1] Japanese Patent Publication No. 2016-016329 [Overview of the Initiative] [Problems that the invention aims to solve]

[0004] Furthermore, when the intended use of the shoes is limited, for example, comparing hiking boots and trail running shoes reveals that the required functions differ. In trail running, the wearer runs on uneven terrain scattered with rocks and twigs. Therefore, unlike hiking boots, which have hard, thick soles to avoid being affected by uneven surfaces, trail running shoes preferably have soles that flexibly deform to follow changes in the terrain in response to continuous steps.

[0005] This disclosure is made to solve these problems and provides a shoe that allows the wearer to absorb the impact from the ground to their feet while maintaining ankle horizontality and providing good control when running on uneven terrain. [Means for solving the problem]

[0006] In a specific embodiment of the present disclosure, the shoe comprises a first groove extending forward from the medial side to the lateral side on the bottom surface of the sole, and a second groove extending forward from the bottom surface to the top surface on the medial side surface of the sole, wherein the groove width at the medial end of the first groove and the groove width at the bottom end of the second groove overlap at least in part along the boundary direction between the bottom surface and the medial side surface. [Effects of the Invention]

[0007] This disclosure makes it possible to provide a shoe that allows the wearer to absorb impact from the ground to their feet while maintaining ankle horizontality and providing good control when running on uneven terrain. [Brief explanation of the drawing]

[0008] [Figure 1] This is an exploded perspective view showing the appearance of the shoes according to this embodiment. [Figure 2] This is a perspective view of the shoe from the inside of the foot. [Figure 3] This is a perspective view of the shoe from the outside of the foot. [Figure 4] This is a schematic diagram illustrating the structure of the first groove. [Figure 5] This is a schematic diagram illustrating the structure of the second groove. [Figure 6] This is a schematic diagram illustrating the structure of the third groove. [Figure 7] This is an overall perspective view of the shoe to illustrate the effect of the three grooves. [Figure 8] This is a schematic diagram illustrating the configuration of the third groove in a modified example. [Figure 9] This is a cross-sectional view of the first groove to illustrate variations in the groove structure. [Figure 10] This is an exploded perspective view illustrating the structure of the sole in a modified example. [Modes for carrying out the invention]

[0009] The following disclosure will describe specific embodiments, but the invention claimed is not limited to these embodiments. Furthermore, not all of the configurations described in the embodiments are necessarily essential for solving the problem. In each figure, components with the same reference numerals have the same or similar configurations, and redundant explanations are omitted.

[0010] Figure 1 is an exploded perspective view showing the appearance of the shoe 300 according to this embodiment. The shoe 300 according to this embodiment is a shoe mainly intended for trail running. The shoe 300 has a sole 100 and an upper 200. The sole 100 has a two-layer structure consisting of an outsole 110 as a first layer located on the bottom side and a midsole 120 as a second layer laminated on the upper surface of the outsole 110. An insole that contacts the bottom side of the wearer's foot may be laminated on the sole 100. The upper 200 is bonded or sewn to the periphery of the midsole 120 and covers the top side of the wearer's foot.

[0011] The outsole 110 has a first groove 111, which will be described in detail later, on the side of the bottom surface 112 facing the ground. The outsole 110 also has a plurality of polygonal through-holes 113 for the purpose of weight reduction and design. The outsole 110 is made of synthetic rubber, such as SBR (styrene-butadiene rubber).

[0012] The midsole 120 is provided with a second groove 122 and a third groove 123 on its circumferential surface, which will be described in detail later. Depending on the required degree of flexure, the third groove may be omitted, and the midsole 120 may be provided only with the second groove. The midsole 120 is formed from an elastic material such as foam. For example, EVA resin (ethylene-vinyl acetate copolymer resin) is suitable as the material for the midsole 120.

[0013] Note that, although FIG. 1 shows only the right-foot side of the shoe 300, the shoe 300, of course, forms a pair with the left and right. In the following description, the shoe 300 will be described with the right-foot side as a representative, but the description of the left-foot side configuration will be omitted because it is symmetrical to the right-foot side configuration. Also, as shown in the figure, in the present embodiment, the side where the toe is located when the wearer wears the shoe 300 is called the toe side, and the side where the heel is located is called the heel side. The toe side may also be referred to as the front side or the front, and the heel side may be referred to as the rear side or the rear. Similarly, the side where the inner foot is located is called the inner foot side, and the side where the outer foot is located is called the outer foot side. Also, the direction connecting the inner foot side and the outer foot side may be referred to as the foot width direction. Similarly, the side in contact with the ground is called the bottom side, and the opposite side is called the top side.

[0014] FIG. 2 is a perspective view of the shoe 300 observed from the inner foot side. On the bottom surface 112 of the outsole 110, a first groove portion 111 is provided so as to obliquely cross near the center thereof. The first groove portion 111 is a concave portion formed so that the thickness of the outsole 110 is thinner than the periphery. More specifically, the first groove portion 111 extends forward from the inner foot side end portion 111a located at the inner foot side end to the outer foot side end portion 111b located at the outer foot side end, and when an external force is applied to the outsole 110 in the torsional direction, the outsole 110 bends relatively easily with this first groove portion 111 as a bending line.

[0015] In the present embodiment, considering the design property, the contour of the first groove portion 111 forms a polygonal shape in which two triangles share the top with each other as represented by a dotted line. Also, as described above, a plurality of through holes 113 are provided in the outsole 110, and when the outsole 110 is overlapped with the midsole 120, the surface of the midsole 120 appears as an exposed portion 126 through the through holes 113. In the present embodiment, from the viewpoint of design property, through holes 113 are also provided in the region surrounded by the contour of the first groove portion 111, and the exposed portion 126 constitutes the first groove portion 111 as a groove bottom surface. Note that, from the viewpoint of the functionality of the first groove portion 111, it may have a linear contour or a square contour, and through holes 113 may not be provided in the contour range.

[0016] On the medial side of the midsole 120, a second groove 122 is provided, which diagonally traverses the midsole 124 on the medial side near the center. The second groove 122 is a recess formed by excavating the midsole 120 from the surrounding area in the width direction of the foot. More specifically, the second groove 122 extends forward from the bottom end 122a located at the bottom end of the midsole 120 to the top end 122b located at the top end, and when an external force is applied in the twisting direction, the midsole 120 bends relatively easily with this second groove 122 as the bending line. Furthermore, if the second groove 122 reaches the top end 122b, it becomes even easier to bend.

[0017] In this embodiment, the contour of the second groove 122 is triangular in shape with the bottom surface as the base, as shown by the dotted line, taking aesthetics into consideration. However, from the viewpoint of functionality, the second groove 122 may have a straight or rectangular contour.

[0018] Groove width W at the inner foot end 111a of the first groove 111 bi The groove width W at the bottom end 122a of the second groove 122. si The grooves are set so that at least a portion of them overlap along the direction of the boundary line C1 (shown by a dashed line) between the bottom surface 112 of the outsole 110 and the medial foot side surface 124 of the midsole 120. In other words, the medial foot end 111a of the first groove 111 and the bottom surface end 122a of the second groove 122 share a portion of the boundary line C1 with each other. Here, sharing a portion of the boundary line C1 with each other does not mean that the ends of the two grooves are connected at least partially in a continuous manner, but even if they are not connected continuously, it is sufficient that they face each other at least partially across the boundary line C1. When this relationship is satisfied, if an external force is applied in the torsional direction to the sole 100 in which the outsole 110 and midsole 120 are laminated, stress concentrates in the first groove 111 and the second groove 122, and the sole 100 twists relatively easily along these grooves.

[0019] Figure 3 is a perspective view of the shoe 300 observed from the outer foot side. On the outer foot side 125 of the circumferential surface of the midsole 120, a third groove 123 is provided, which is positioned slightly forward and sectional diagonally. The third groove 123 is a recess formed by excavating the midsole 120 from the surrounding area in the width direction of the foot. More specifically, the third groove 123 extends forward from the bottom end 123a located at the bottom boundary to the top end 123b located near the top boundary. The third groove 123, which extends forward in this manner, plays a role in suppressing bending so that the midsole 120 does not bend too much due to the first groove 111 and the second groove 122 when an excessive external force is applied to the midsole 120 in the torsional direction.

[0020] In this embodiment, the contour of the third groove 123 is triangular in shape with the bottom surface as the base, as shown by the dotted line, taking aesthetics into consideration. However, from the viewpoint of functionality, the third groove 123 may simply have a straight contour.

[0021] Groove width W at the outer foot end 111b of the first groove 111 bo The groove width W at the bottom end 123a of the third groove 123. soThe grooves are set so that at least a portion of them overlap along the direction of the boundary line C2 (shown by the dashed line) between the bottom surface 112 and the outer foot side surface 125. In other words, the outer foot side end 111b of the first groove 111 and the bottom surface side end 123a of the third groove 123 share a portion of the boundary line C2 with each other. Here, sharing a portion of the boundary line C2 with each other does not mean that the ends of the two grooves are connected at least partially in a continuous manner, but even if they are not connected continuously, it is sufficient that they face each other at least partially across the boundary line C2. When this relationship is satisfied, if an external force is applied in the torsional direction to the sole 100 in which the outsole 110 and midsole 120 are laminated, stress concentrates in the first groove 111 and the third groove 123, and the sole 100 twists relatively easily along these grooves. Furthermore, considering the relationship with the second groove 122, stress concentrates along the second groove 122, the first groove 111, and the third groove 123, causing the sole 100 to twist relatively easily along these grooves.

[0022] Figure 4 is a schematic diagram illustrating the configuration of the first groove 111 in more detail. As described above, the first groove 111 is provided to extend forward from the inner foot end 111a located at the inner foot boundary to the outer foot end 111b located at the outer foot boundary. In the first groove 111 provided in this manner, the bending line that bends when a torsional external force is applied (specifically, the straight line where stress is concentrated in response to the external force, which will be described later) is the narrowest foot width line L on the bottom surface 112 in the foot width direction. w The angle θ with respect to is preferably between 20° and 45°.

[0023] Furthermore, the entirety of the first groove 111, with the medial foot end 111a and the lateral foot end 111b at both ends, corresponds to the MTP line L when the wearer is wearing the shoe 300. m The calcaneal line L is set to be further posterior and to cross the anterior end of the calcaneus. hIt is preferably contained within a more forward region. The middle phalangeal joint is the joint between the proximal phalanx and the middle metatarsal bone, and the calcaneus is the foot bone located at the rearmost end. Although these positions are strictly different for each wearer, since the shoes 300 are manufactured by being classified into sizes according to the size of the wearer's foot, for wearers wearing shoes 300 of the same size, they approximately match the positions shown in the figure.

[0024] FIG. 5 is a schematic diagram for explaining the configuration of the second groove portion 122. As described above, the second groove portion 122 is provided so as to extend forward from the bottom surface side end portion 122a of the midsole 120 toward the upper surface side end portion 122b. In the second groove portion 122 provided in this way, the angle α formed by the bending line (a straight line where stress concentrates with respect to an external force, similar to the bending line of the first groove portion 111) that bends when an external force in the torsional direction is applied with respect to the ground contact surface is preferably 20° or more and 45° or less.

[0025] FIG. 6 is a schematic diagram for explaining the configuration of the third groove portion 123. As described above, the third groove portion 123 is provided so as to extend forward from the bottom surface side end portion 123a of the midsole 120 toward the upper surface side end portion 132b. When the third groove portion 123 provided in this way has the function of suppressing the bending of the midsole 120, the angle β formed by the bending line (a straight line where stress concentrates with respect to an external force, similar to the bending line of the first groove portion 111) that bends when an external force in the torsional direction is applied with respect to the ground contact surface is preferably larger than the angle α formed by the bending line of the second groove portion 122 with respect to the ground contact surface.

[0026] Also, the length D in the extending direction of the bending line of the second groove portion 122 shown in FIG. 5 i is the length D in the extending direction of the bending line of the third groove portion 123 shown in FIG. 6 oIt is preferable that it be longer than this. In this relationship, the function of the second groove 122 in promoting the bending of the sole 100 can be appropriately suppressed by the third groove 123 to achieve balance. As shown in Figure 6, the upper end 132b of the second groove 122 does not necessarily have to reach the upper boundary, but as long as this length relationship is satisfied, the upper end 132b of the second groove 122 may be located at the upper end of the midsole 120.

[0027] When the first groove 111, second groove 122, and third groove 123 are formed in the shoe 300 to satisfy the conditions described using Figures 2 to 6, a better effect is achieved when the wearer runs on uneven terrain. Figure 7 is an overall perspective view of the shoe 300 to illustrate the effect of these three grooves.

[0028] The first groove 111, the second groove 122, and the third groove 123 function as three-dimensional, substantially continuous, and integrated grooves with respect to the sole 100, as shown by the dashed lines. When a wearer runs on uneven ground scattered with stones and twigs, the sole's bottom surface experiences a dispersion effect in response to the wearer's footsteps, with some areas receiving localized reaction forces due to the unevenness of the road surface, and others receiving no reaction forces at all. In this case, if the shoe has a rigid, non-flexible sole, the entire sole's bottom surface will conform to the unevenness of the road surface as a flat plane. As a result, the wearer's sole will tilt along this sole surface, and the wearer will feel discomfort because the direction of their footsteps and the sensation received by their ankle do not match. In other words, the wearer will feel that they cannot control the shoe freely. This feeling can evoke anxiety and fear in the wearer regarding running, and may cause them to slow down.

[0029] On the other hand, in the shoe 300 according to this embodiment, the three grooves function integrally, allowing the sole 100 to twist relatively easily in the direction indicated by the thick arrows in the figure. By twisting and deforming in this direction, the sole bottom surface follows the unevenness of the road surface more flexibly, without the toe or heel portion lifting up.

[0030] In particular, the first groove 111 is provided to extend forward from the inner side of the foot to the outer side of the foot, and the second groove 122 is provided to extend forward from the bottom surface to the top surface of the sole on the inner side of the foot. As a result, the sole 100 is divided into a part corresponding to the area centered on the wearer's big toe and a part corresponding to the area centered on the heel, and flexes accordingly. Consequently, the wearer can more easily keep their ankle horizontal, and the direction of stepping and the sensation received by the ankle can be more easily matched. In other words, the wearer feels that they can control the shoes freely. Furthermore, because the bottom surface of the sole conforms more flexibly to the unevenness of the road surface, the impact of the wearer's stepping can be appropriately dispersed, and the load on the ankle is also reduced.

[0031] Furthermore, depending on the performance required of the shoe 100, a greater twist in the direction indicated by the thick arrow may be preferable. In that case, the orientation in which the third groove 123 is provided should be changed. Figure 8 is a schematic diagram illustrating the configuration of the third groove 123 according to a modified example. As shown in the figure, when the third groove 123 is extended rearward from the bottom end 123a to the top end 123b, the third groove 123 plays a role in further enhancing the bending effect of the first groove 111 and the second groove 122. In this case, if the angle with respect to the ground surface is represented by β, as in Figure 6, then 180° > β > 90° is defined.

[0032] Next, the structure of the groove will be described. Figure 9 is a cross-sectional view of the first groove 111 to illustrate variations in the groove structure. A typical groove structure has a rectangular cross-section, as shown in Figure 9(A). When the cross-section is rectangular, stress concentration points 111c appear at the boundary between one side wall 111d and the groove bottom surface 111e, and at the boundary between the other side wall 111d and the groove bottom surface 111e, where stress concentrates during torsion. Since each stress concentration point 111c is formed along the extension direction of the first groove 111, the bending line of the first groove 111 can be defined as at least one of these.

[0033] As shown in Figure 9(B), a triangular cross-section can also be adopted. In this case, a stress concentration point 111c appears at the boundary between the side wall 111d and the groove bottom surface 111e, which is formed as an inclined surface, where stress concentrates during twisting. Since such a stress concentration point 111c is also formed along the extension direction of the first groove 111, the bending line of the first groove 111 can be defined as such an extending stress concentration point 111c. In the example shown in the figure, a triangular cross-section is formed by a vertical side wall 111d and an inclined groove bottom surface 111e, but a V-shaped cross-section formed by two inclined groove bottom surfaces 111e may also be used.

[0034] The examples in Figures 9(C) and 9(D) are variations of Figure 9(A). In the example of Figure 9(A), two bending lines could be defined, but in the examples of Figures 9(C) and 9(D), even if the cross-section is approximately rectangular, one boundary is defined as the bending line. Specifically, in the example of Figure 9(C), a stress concentration area 111c, where stress is more likely to concentrate, is formed by curving the groove bottom surface 111e near one boundary. In the example of Figure 9(D), a stress concentration area 111c, where stress is more likely to concentrate, is formed by providing a notch in the groove bottom surface 111e near one boundary. The cross-sectional shape is not limited to these examples and can be modified in various ways. The choice of which cross-sectional shape to adopt can be determined based on the degree of bending and design requirements for the shoe 300. In the above explanation, the first groove 111 was used as an example, but the cross-sectional shapes of the second groove 122 and the third groove 123 are similar.

[0035] Next, a modified version of the sole 100 will be described. Figure 10 is an exploded perspective view illustrating the structure of the modified sole 100'. In sole 100, the first groove 111 is formed in the outsole 110, and the second groove 122 and third groove 123 are formed in the midsole 120. However, in sole 100', all three grooves are formed in the midsole 120'. Therefore, no grooves are formed in the outsole 110'. However, like outsole 110, the outsole 110' may have through holes 113 or raised parts, taking into consideration aesthetics and functionality.

[0036] The first groove 121 provided in the midsole 120' can be formed in the same position and with the same structure as the first groove 111 provided in the outsole 110. However, the first groove 121 formed in the midsole 120' can be formed deeper than the first groove 111 provided in the outsole 110, which is relatively thin overall. Therefore, if the goal is to make the entire sole more torsionable, forming the first groove 121 in the midsole 120' in this way is effective. In addition, since the first groove 121 can be covered by the outsole 110', it is possible to prevent gravel and other debris from getting trapped.

[0037] The sole structure is not limited to the examples described above. For example, the first groove may be formed so deep that it penetrates the outsole 110 and reaches the midsole 120. Also, instead of a two-layer structure of outsole 110 and midsole 120, the grooves may be formed on a single-layer sole. Furthermore, depending on the required degree of flexion, a configuration may be adopted in which only the first and second grooves are provided, without a third groove. Conversely, in addition to the first, second, and third grooves, grooves may be added to further reinforce the flexion performance.

[0038] Furthermore, although the shoe 300 according to this embodiment described above was primarily intended for trail running, the sole structure described above can be applied to various shoes for walking on uneven terrain. [Explanation of Symbols]

[0039] 100, 100'...Sole, 110, 110'...Outsole, 111...First groove, 111a...Medial end, 111b...Outer end, 111c...Stress concentration area, 111d...Side wall, 111e...Groove bottom, 111f...Notch, 112...Bottom, 113...Through hole, 120, 120'...Midsole, 121...First groove, 122...Second groove, 122a...Bottom end, 122b...Top end, 123...Third groove, 123a...Bottom end, 123b...Top end, 124...Medial side, 125...Outer side, 126...Exposed part, 200...Upper, 300...Shoe

Claims

1. A first groove extends forward from the inner side to the outer side of the sole on the bottom surface, A second groove extends forward from the bottom side to the top side of the sole on the inner side of the sole. Equipped with, A shoe in which the groove width at the inner foot end of the first groove and the groove width at the bottom surface end of the second groove overlap at least in part along the boundary direction between the bottom surface and the inner foot side surface.

2. The shoe according to claim 1, wherein the first groove is at an angle of 20° to 45° with respect to the foot width line which is narrowest in the foot width direction on the bottom surface.

3. The shoe according to claim 1, wherein the first groove is located in a region posterior to the metatarsophalangeal joint and anterior to the calcaneus.

4. The shoe according to claim 1, wherein the first groove portion has a stress concentration portion formed along the stretching direction where stress concentrates during twisting.

5. The shoe according to claim 1, wherein the second groove is at an angle of 20° to 45° with respect to the contact surface.

6. The outer side surface of the sole is provided with a third groove that extends from the bottom surface to the top surface of the sole, The shoe according to claim 1, wherein the groove width at the outer foot side end of the first groove and the groove width at the bottom surface side end of the third groove overlap by at least a portion along the boundary direction between the bottom surface and the outer foot side surface.

7. The shoe according to claim 6, wherein the length of the second groove in the extension direction is longer than the length of the third groove in the extension direction.

8. The shoe according to claim 6, wherein the angle that the third groove makes with respect to the contact surface is greater than the angle that the second groove makes with respect to the contact surface.

9. The sole comprises a first layer positioned on the bottom surface and a second layer laminated on the upper surface of the first layer. The shoe according to claim 1, wherein the first groove is formed in the first layer and the second groove is formed in the second layer.

10. The second layer has an exposed portion that is exposed to the bottom side through a through hole provided in the first layer, The shoe according to claim 9, wherein the first groove is formed to include at least a portion of the exposed portion.

11. The sole comprises a first layer positioned on the bottom surface and a second layer laminated on the upper surface of the first layer. The shoe according to claim 1, wherein the first groove is formed in the second layer.

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