Footwear and insole

Abstract

This footwear includes a sole, an upper, and a cushioning material 30. The upper is provided above the sole and surrounds a foot insertion part. The cushioning material 30 is accommodated in the foot insertion part. The cushioning material 30 is constituted by overlapping at least two members including a first member 40 positioned on the upper side and a second member 50 positioned on the lower side. The first member 40 has a protrusion 42 protruding in the direction of the sole at a position corresponding to the heel, and the first member 40 covers the whole of the second member 50 in a plan view. The second member 50 has an opening part 52 capable of accommodating the heel.

Description

Footwear and insoles

[0001] The present disclosure relates to footwear and insoles.

[0002] Footwear having a cushioning material such as a midsole disposed between an upper and a sole is known. For example, Patent Document 1 (JP-A-2003-102666) describes footwear having a removable outsole, midsole, and upper. The underside of the midsole of this footwear is provided with a plurality of protrusions that fit into pockets in the outsole. The protrusions are separated by slots that fit into raised walls provided in the pockets. This footwear is also configured to be customizable for each user by replacing the midsole, etc.

[0003] U.S. Patent No. 9,737,109

[0004] However, although the footwear described in Patent Document 1 is configured with a replaceable midsole to ensure comfort according to the user's preferences, different characteristics cannot be obtained with a single midsole.

[0005] The present disclosure has been made in light of the above circumstances, and its purpose is to provide footwear and an insole that can improve cushioning and stability.

[0006] One embodiment of footwear disclosed herein comprises a sole, an upper provided above the sole and surrounding a foot insertion section, and a cushioning material housed within the foot insertion section, the cushioning material being constructed by stacking at least two members, a first member located on the upper side and a second member located on the lower side, the first member having a convex portion that protrudes toward the sole at a position corresponding to the heel portion, and covering the entire second member in a planar view, the second member having an opening capable of accommodating the heel portion.

[0007] Another aspect of the present disclosure is an insole to be accommodated in a foot insertion section of footwear including a sole and an upper disposed above the sole and surrounding the foot insertion section, the insole being configured by stacking at least two members, a first member located on the upper side and a second member located on the lower side, the first member having a convex portion that protrudes toward the sole at a position corresponding to a heel portion and that covers the entire second member in a plan view, and the second member having an opening that can accommodate the heel portion.

[0008] Any combination of the above components, or mutual substitution of the components or expressions of the present invention between methods, devices, etc., are also valid aspects of the present invention.

[0009] According to certain aspects of the present disclosure, footwear and insoles that can improve cushioning and stability can be provided.

[0010] 1 is a plan view schematically showing footwear according to an embodiment. FIG. 1 is a plan view of the cushioning material shown in FIG. 1. FIG. 2 is a side view of the cushioning material shown in FIG. 1. FIG. 3 is a bottom view of the cushioning material shown in FIG. 1. FIG. 4 is a rear view of the cushioning material shown in FIG. 1. FIG. 5 is a plan view of the second member shown in FIG. 2. FIG. 6 is a plan view of the second member according to a first modified example. FIG. 7 is a plan view of the second member according to a second modified example. FIG. 8 is a plan view of the second member according to a third modified example. FIG. 9 is a plan view of the second member according to a fourth modified example. FIG. 10 is a plan view of the second member according to a fifth modified example. FIG. 11 is a plan view of the second member according to a sixth modified example. FIG. 12 is a cross-sectional view taken along line A-A in FIG. 2. FIG. 13 is a cross-sectional view taken along line B-B in FIG. 2. FIG. 14 is a plan view of a portion of the toe side of the second member shown in FIG. 2. FIG. 15 is a plan view of a portion of the toe side of the second member according to a seventh modified example. FIG. 16 is a diagram schematically showing the shapes of the first member shown in FIG. 2 and the second member shown in FIG. 2 in an unloaded state. FIG. 17 is a diagram schematically showing the shapes of the first member shown in FIG. 2 and the second member shown in FIG. 2 in an applied state of a first load. 3 is a diagram schematically showing the shapes of the first member shown in FIG. 2 and the second member shown in FIG. 2 in a state in which a second load is applied; FIG.

[0011] The present disclosure will be described below based on preferred embodiments with reference to the drawings. In the embodiments and modifications, identical or equivalent components are designated by the same reference numerals, and duplicate explanations will be omitted as appropriate. The dimensions of the components in each drawing are enlarged or reduced as appropriate to facilitate understanding. Some components that are not important for explaining the embodiments are omitted from the drawings.

[0012] Furthermore, terms including ordinal numbers such as first and second are used to describe various components, but these terms are used only to distinguish one component from another and do not limit the components.

[0013] Fig. 1 is a plan view schematically illustrating footwear 100 according to an embodiment. Unless otherwise specified, Fig. 1 and the following figures illustrate footwear for the right foot, but the description in this specification is equally applicable to footwear for the left foot. Also, shoelaces are omitted from the following figures.

[0014] The footwear 100 of this embodiment can be used as, for example, shoes for walking or running, safety shoes, or shoes for sports such as tennis or basketball, and its uses are not limited. The footwear 100 includes a sole 10, an upper 20, and a cushioning material 30. The sole 10 is the part that comes into contact with the ground. The upper 20 encloses an internal space serving as a foot insertion section 20a for accommodating the foot. The upper 20 is provided above the sole 10 and is joined to the sole 10 by adhesive or the like. The cushioning material 30 is housed within the foot insertion section 20a when in use. These components will be described in detail below.

[0015] As shown in FIG. 1 , the direction along the widthwise center line La of the footwear 100 is referred to as the "front-rear direction" and "foot length direction." Therefore, the widthwise direction is a direction perpendicular to the center line La. The direction along the center line La toward the toes is referred to as the "front side" or "forward," and the opposite side toward the heel is referred to as the "rear side." Furthermore, when the footwear 100 is placed on a horizontal surface (hereinafter referred to as the "horizontal state"), the upper side is referred to as the "upper side" or "upward," and the opposite side is referred to as the "lower side" or "downward." Furthermore, in the horizontal state, the direction extending vertically is referred to as the "vertical direction." In each drawing, the front in the front-rear direction is indicated as the positive direction of the X-axis, the medial side of the foot in the widthwise direction is indicated as the positive direction of the Y-axis, and the upper side in the vertical direction is indicated as the positive direction of the Z-axis.

[0016] Furthermore, the portion of the footwear 100 that corresponds to the metatarsals in the front-to-back direction is referred to as the midfoot. Furthermore, the portion of the footwear 100 that is forward of the midfoot in the front-to-back direction is referred to as the forefoot, and the portion that is rearward of the midfoot is referred to as the rearfoot. The forefoot generally corresponds to the phalanges, and the rearfoot generally corresponds to the tarsal bones. When the front-to-back length of the footwear 100 is taken as 100%, the midfoot is a region that is approximately 30% to 80% from the tip, within a range parallel to a straight line perpendicular to the center line La. The forefoot is a region that is approximately 0% to 30% from the tip, and the rearfoot is a region that is approximately 80% to 100% from the tip.

[0017] An opening 20b for inserting the foot is formed in the rear foot portion of the upper 20. A central opening 20c is formed in the upper 20 forward from the opening 20b. Eyelets 20h are formed on the edge of the central opening 20c of the upper 20 for passing shoelaces through. A shoe tongue 70 is provided inside the central opening 20c. Note that the central opening 20c does not necessarily have to be formed in the upper 20, and the upper 20 may have a so-called monosock structure. Similarly, the upper 20 does not necessarily have to have eyelets 20h, and the shoe tongue 70 does not necessarily have to be provided.

[0018] The cushioning material 30 will now be described. The cushioning material 30 is made of a flexible material. The cushioning material 30 is interposed between the foot and the sole 10 while the wearer is wearing the footwear 100, and cushions the impact of landing on the foot. The cushioning material 30 functions as an insole. The cushioning material 30 may be removable through the opening 20b of the upper 20.

[0019] FIG. 2 is a plan view of the cushioning material 30 as viewed from above. FIG. 3 is a side view of the cushioning material 30 as viewed from the lateral side of the foot. FIG. 4 is a bottom view of the cushioning material 30 as viewed from below. FIG. 5 is a rear view of the cushioning material as viewed from the heel side. As shown in FIGS. 2 to 5, the cushioning material 30 includes a first member 40 located on the upper side and a second member 50 located on the lower side. The first member 40 and the second member 50 are overlapped with each other. The cushioning material 30 may include members other than the first member 40 and the second member 50, but is generally configured by overlapping at least two members, the first member 40 and the second member 50. In this embodiment, the first member 40 is located on the uppermost surface of the cushioning material 30.

[0020] As shown in Fig. 2, the first member 40 covers the entire second member 50 in a plan view. In other words, the wearer's foot comes into contact with only the first member 40 of the cushioning material 30, and does not come into contact with the second member 50. Fig. 2 shows the second member 50 covered by the first member 40 with a dashed line. As shown in Fig. 4, the first member 40 has a protrusion 42 that protrudes from the underside of the first member 40 toward the sole 10 at a position corresponding to the heel of the wearer's foot.

[0021] The upper surface of the first member 40 may be provided with projections and depressions to conform to the shape of the foot. For example, a certain region of the upper surface of the first member 40 that includes a position corresponding to the heel may be cup-shaped to conform to the shape of the heel. Also, for example, a certain region of the upper surface of the first member 40 that includes a position corresponding to the arch may be convex in the center in the front-to-back direction to conform to the shape of the arch, as shown in FIG. 3. This reduces the gap between the foot and the cushioning material 30, improving the fit.

[0022] The second member 50 is positioned below the first member 40 and supports the first member 40 in a certain region including at least the heel portion. In this embodiment, the second member 50 has a shape that follows the contour of the first member 40 in a plan view in a region including the entire rear foot portion and part of the midfoot portion. As shown in FIG. 4 , the second member 50 has an opening 52 that penetrates in the vertical direction at a position corresponding to the heel portion. The opening 52 is an opening that can accommodate the convex portion 42 of the first member 40 and is configured to be able to accept at least a portion of the convex portion 42. The second member 50 can release the pressing force caused by the load applied to the first member 40 downward through the opening 52.

[0023] 3, the lower surface of the cushioning material 30 formed by the lower surface of the first member 40 and the lower surface of the second member 50 is substantially flat. This makes it difficult to feel the step formed by the boundary line between the first member 40 and the second member 50, and the lower surface is smoothly continuous along the lower surface, making it comfortable to wear.

[0024] The vertical thickness of the cushioning material 30 in the forefoot portion is 3 mm or more and 20 mm or less, preferably 4 mm or more and 5.5 mm or less. This reduces impact from the ground and ensures cushioning. By making the vertical thickness of the cushioning material 30 in the forefoot portion 30 3 mm or more, effects such as making it difficult to feel unevenness in the ground or foreign objects such as stones, and ensuring cushioning to reduce foot fatigue are achieved. Furthermore, by making the vertical thickness of the cushioning material 30 in the forefoot portion 20 mm or less, effects such as less difficulty in putting on the foot and less deformation of the overall shape of the footwear 100 are achieved. Of these, it is preferable that the vertical thickness of the first member 40 in the rearfoot portion be equal to or greater than the thickness of the forefoot portion. For example, the thickness of the first member 40 may increase from the forefoot side toward the rearfoot side. Similarly, the thickness of the second member 50 may increase from the forefoot side toward the rearfoot side.

[0025] The periphery of the cushioning material 30 may be arranged along the periphery of the foot insertion section 20a as a whole. That is, the cushioning material 30 may have a size corresponding to the foot insertion section 20a and may be configured so that movement within the foot insertion section 20a is restricted. In particular, it is preferable that the cushioning material 30 be arranged along the periphery of the foot insertion section 20a in the rear foot area. This allows the cushioning material 30 to be positioned within the foot insertion section 20a, making it easier for the cushioning material 30 to exhibit the various effects described below.

[0026] In the following description, the periphery of the cushioning material 30 is assumed to be disposed along the outer periphery of the foot insertion section 20a.

[0027] FIG. 6 is a plan view of the second member 50. FIG. 13 is a cross-sectional view taken along line A-A in FIG. 2. FIG. 14 is a cross-sectional view taken along line B-B in FIG. 2. The upper surface of the second member 50 has a contact region 54 that contacts the first member 40 around the opening 52 in a plan view. In this embodiment, the second member 50 makes contact with the first member 40 at the contact region 54 along the circumferential direction around the opening 52 without any gaps. The upper surface of the second member 50 further has an inclined region 56 that is inclined toward the sole 10, i.e., downward in FIGS. 13 and 14, as it approaches the opening 52, closer to the opening 52 than the contact region 54. When the wearer's foot is not inserted into the foot insertion portion 20a (hereinafter referred to as the "unloaded state"), the inclined region 56 of the second member 50 is spaced apart from the first member 40. In an unloaded state, the area on the upper surface of the second member 50 that is located around the opening 52 and that comes into contact with the first member 40 is referred to as the contact area 54, and the area that does not come into contact with the first member 40 is referred to as the inclined area 56.

[0028] The inclined region 56 of the second member 50 may have a tapered shape that narrows downward. The contact region 54 and the inclined region 56 may be smoothly connected to each other. That is, in the cross-sectional views shown in Figures 13 and 14, the tangent to the boundary of the contact region 54 with the inclined region 56 and the tangent to the boundary of the inclined region 56 with the contact region 54 coincide with each other. The inclined region 56 may be smoothly inclined downward toward the opening 52.

[0029] 6 , the contact area 54 is located within a range of 0.5 mm to 30 mm from the heel-side end point 58 of the second member 50 toward the opening 52. Specifically, the contact area 54 may start from the heel-side end point 58 of the second member 50 and end at a distance 60 of 0.5 mm to 30 mm from the starting point along the shoe center axis SC, preferably 3 mm to 20 mm, and more preferably 5 mm to 10 mm from the starting point. The shoe center axis SC may be the widthwise center line of the cushioning material 30, or may be a line corresponding to a straight line connecting the center of the calcaneus and the space between the first and second toes of a typical wearer of the footwear 100 provided with the cushioning material 30.

[0030] For example, the contact region 54 may be located in the rearfoot in a range that starts at the periphery of the second member 50 and ends at the above-mentioned distance along a direction perpendicular to the boundary line with the inclined region 56. The contact region 54 does not need to completely surround the inclined region 56 in a plan view, and for example, the toe-side end of the contact region 54 in the foot length direction may be located at approximately the same position as the toe-side end of the opening 52.

[0031] As shown in FIGS. 13 and 14 , in an unloaded state, the outer peripheral surface 44 of the convex portion 42 of the first member 40 forms a gap with the opposing inclined region 56 of the second member 50. The inclination of the outer peripheral surface 44 of the convex portion 42 of the first member 40 may be gentler than the inclination of the opposing inclined region 56 of the second member 50. Here, "gentle inclination" means that the angle with respect to the horizontal plane is smaller than that of the comparative object. The outer peripheral surface 44 of the convex portion 42 of the first member 40 and the inclined region 56 of the second member 50 may have the above-described relationship at their opposing positions, and their respective inclinations may vary depending on their positions. For example, as shown in FIG. 7 , the inclination of the inclined region 56 of the second member 50 on the toe side relative to the opening 52 may be gentler than the inclination on the heel side relative to the opening 52. By making the inclination of the inclined region 56 on the toe side gentler, the feeling of being pushed up can be reduced.

[0032] The inclination of the outer peripheral surface 44 of the convex portion 42 of the first member 40 and the inclination of the inclined region 56 of the second member 50 may change toward the opening 52. The vertical distance between the outer peripheral surface 44 of the convex portion 42 of the first member 40 and the inclined region 56 of the second member 50 may increase toward the opening 52. The inclination of the outer peripheral surface 44 of the convex portion 42 and the inclination of the inclined region 56 have different inclinations. The inclination of the inclined region 56 is greater than the inclination of the outer peripheral surface 44 of the convex portion 42. Therefore, a gap space can be provided between the convex portion 42 of the first member 40 and the opening 52 of the second member 50. Note that while FIGS. 13 and 14 show an example in which the outer peripheral surface 44 of the convex portion 42 is a smooth surface, the outer peripheral surface 44 may have an uneven shape, for example.

[0033] In the no-load state, the convex portion 42 of the first member 40 does not come into contact with the opposing surface that faces the sole 10 through the opening 52 of the second member 50. Here, the opposing surface is, for example, the upper surface of the sole 10. If the cushioning material 30 includes a member such as a sheet-like member closer to the sole 10 than the second member 50, or if another member is disposed between the cushioning material 30 and the sole 10, the opposing surface may be the upper surface of that member. Examples of the above-mentioned sheet-like member and another member include a midsole and an insole.

[0034] The second member 50 may include an unbonded region that is not bonded to the first member 40 within the contact region facing the first member 40. Here, the contact region refers to the region where the first member 40 and the second member 50 contact each other in an unloaded state. In other words, the first member 40 and the second member 50 may or may not be partially bonded in the contact region.

[0035] As a result, the first member 40 and the second member 50 slide against each other and change their relative positions in response to the load from the wearer, thereby supporting the load and further improving stability. Furthermore, if the entire contact area between the first member 40 and the second member 50 were bonded, strain would be placed on specific locations in response to deformation due to the load, which could cause deterioration of the cushioning material 30. Including an unbonded area in the second member 50 can also lead to a longer lifespan of the cushioning material 30.

[0036] Furthermore, even when the second member 50 includes an unbonded region, the first member 40 and the second member 50 may have specific shapes that correspond to each other in the unbonded region, thereby suppressing misalignment between them. For example, to suppress sliding of the first member 40 against the second member 50 due to load, a shape such as a groove or unevenness that runs circumferentially around the opening 52 in a plan view may be provided in the contact region between the first member 40 and the second member 50. Furthermore, sliding can be suppressed by matching the shapes of the portions of the first member 40 and the second member 50 that correspond to the arch of the midfoot.

[0037] The joining region where the first member 40 and the second member 50 are joined together preferably ranges from 30% to 65% of the heel-side end point 32 of the cushioning material 30 along the shoe center axis SC shown in FIG. 2 , and more preferably ranges from 45% to 62%. Here, the above range indicates the length between the heel-side end point 32 of the cushioning material 30 and the toe-side end point 34 of the cushioning material 30 along the shoe center axis SC, and this length is defined as 100%. The joining in the joining region may be mechanical or chemical, such as by bonding with an adhesive. One example of a mechanical joining is a structure in which the most protruding point of the end of the joining region of the second member 50 fits into a step provided on the first member. Another example of a mechanical joining is a fitting structure in which grooves, protrusions, or other shapes are provided on the contact surfaces of the first member 40 and the second member 50. Another example of mechanical joining is a structure in which the first member 40 and the second member 50 are three-dimensionally aligned at the arch portion of the midfoot to prevent slippage. By joining the first member 40 and the second member 50 at a portion in this manner, the stability of the midfoot can be improved and misalignment between the first member 40 and the second member 50 can be suppressed.

[0038] The hardness of the first member 40 is equal to or lower than the hardness of the second member 50. The hardness of the first member 40 may be the same as or lower than the hardness of the second member 50. If the hardness of the first member 40 is lower than the hardness of the second member 50, the first member 40 is supported by the harder second member 50 in response to the load from the wearer, while deforming more than the second member 50 to support the wearer's foot, thereby improving cushioning and stability. Furthermore, by making the hardness of the first member 40, which comes into direct contact with the wearer's foot, relatively low, the sole can provide a comfortable fit. The hardness can be adjusted according to the hardness and thickness of the sole 10. For example, the hardness of the first member 40 may be 30 degrees or more and 60 degrees or less, and the hardness of the second member 50 may be 40 degrees or more and 80 degrees or less, as measured using an Asker Type C rubber hardness tester.

[0039] The first member 40 and the second member 50 can be formed from various materials with desired characteristics. As an example, the first member 40 can be formed from a resin foam made from a thermoplastic elastomer (TPE), such as EVA resin (ethylene vinyl acetate copolymer) or TPU resin (thermoplastic polyurethane). The first member 40 may be a structure made from a photocurable resin whose main ingredient is urethane acrylate. The second member 50 may be formed from the same material as the first member 40, or from a different material. The first member 40 and the second member 50 may each be formed from a single member or multiple members. These members may be separate, or may have foam materials of different hardness, such as GEL® material, inside or on the surface. In this case, the foot feel and cushioning can be varied.

[0040] The opening 52 of the second member 50 may have a planar shape whose foot length dimension is greater than its foot width dimension. The opening 52 may be located within a range of 5% to 40% of the heel-side end point of the foot insertion portion 20a in the foot length direction. In this embodiment, the periphery of the cushioning material 30 is located along the periphery of the foot insertion portion 20a, so that the heel-side end point of the foot insertion portion 20a is the same as the heel-side end point 32 of the cushioning material 30. That is, the opening 52 is located within a range of 5% to 40% of the heel-side end point 32 along the shoe center axis SC shown in FIG. 2 , between the heel-side end point 32 and the toe-side end point 34 of the cushioning material 30. Thus, the opening 52 is located at a position corresponding to the wearer's heel, thereby effectively supporting the load.

[0041] To further enhance the above-described effects, the foot width direction dimension of the planar shape of the opening 52 of the second member 50 may be greatest at the center position corresponding to the heel. The planar shape of the opening 52 may also be substantially symmetrical about the heel center axis HC shown in FIG. 2. The heel center axis HC refers to the straight line connecting the center of the calcaneus and the space between the third and fourth toes of a typical wearer of the footwear 100. It is preferable that the planar shape of the opening 52 does not have any corners. This reduces discomfort to the wearer.

[0042] The planar shape of the opening 52 may be elliptical or oval in which the heel side is larger in the foot width direction than the toe side as shown in Fig. 6. When the planar shape of the opening 52 is, for example, elliptical or oval, a straight line passing through the major axis of the planar shape may pass between the shoe center axis SC and the heel center axis HC.

[0043] FIGS. 7 to 12 are plan views showing second members 50A to 50F according to the first to sixth modifications. The second members 50A to 50F each have an opening 52A to 52F with a planar shape different from the opening 52 of the second member 50. As shown in FIG. 7, the planar shape of the opening 52A of the second member 50A is a substantially elliptical shape with its longitudinal direction aligned along the heel center axis HC. As shown in FIG. 8, the planar shape of the opening 52B of the second member 50B is a substantially rounded rectangular shape with its longitudinal direction aligned along the heel center axis HC. As shown in FIG. 9, the planar shape of the opening 52C of the second member 50C is a substantially circular shape with its center positioned along the heel center axis HC. As shown in FIG. 10, the planar shape of the opening 52D of the second member 50D is a substantially elliptical shape with its longitudinal direction aligned along the heel center axis HC, with the medial side of the toe-side end projecting further toward the toe than the lateral side. As shown in Figure 11, the planar shape of opening 52E of second member 50E is approximately line-symmetrical with respect to the heel center axis HC, and has a total of four portions that protrude in directions inclined outward in the width direction from the heel center axis HC on the toe side and the heel side. As shown in Figure 12, the planar shape of opening 52F of second member 50F is approximately line-symmetrical with respect to the heel center axis HC, and has a total of ten portions that protrude radially from approximately the center. Note that second members 50A to 50F are similar to second member 50 except for the configuration described above, and therefore description thereof will be omitted.

[0044] When using any of the second members 50A to 50F instead of the second member 50 included in the cushioning material 30, the first member 40 may be used as is, or a first member (not shown) having a convex portion (not shown) of a different shape corresponding to the openings 52A to 52F of the second members 50A to 50F may be used instead of the first member 40. Even when using any of such second members 50A to 50F, the same effects as when using the second member 50 can be obtained.

[0045] In the example shown in FIG. 2 , the second member 50 is positioned within a range extending from the heel-side end point of the foot insertion portion 20a to 70% or less in the foot length direction. That is, in the example shown in FIG. 2 , the second member 50 is positioned along the shoe center axis SC within a range beginning at the heel-side end point 32 of the cushioning material 30 and ending at 70% or less from end point 32 toward the toe-side end point 34. Furthermore, the outer foot-side end 68a and inner foot-side end 68b on the toe side of the second member 50 are positioned at positions other than those corresponding to the ball of the big toe and the ball of the little toe. This allows the second member 50 to support the wearer's midfoot and other regions while ensuring freedom of movement in the forefoot. The range in which the second member 50 is positioned is not limited to the above-described range; for example, the second member 50 may be positioned across the entire surface of the cushioning material 30 in a plan view.

[0046] 15 is a plan view showing a portion of the toe side of the second member 50. In plan view, the second member 50 has a shape that is convex toward the toe side at a position along the heel center axis HC. This allows the second member 50 to more effectively perform its function of supporting the arch of the midfoot.

[0047] 16 is a plan view showing a portion of the toe side of the second member 50G according to the seventh modified example. In plan view, the second member 50G has a shape that is concave toward the toe side at a position between the shoe center axis SC and the heel center axis HC. Note that the second member 50G is similar to the second member 50 except for the configuration described above, and therefore a description thereof will be omitted.

[0048] Hereinafter, with reference to FIGS. 17 to 19, the manner in which the first member 40 and the second member 50 deform in response to the load F will be described. The load F is a load applied downward from the upper surface of the cushioning material 30 at a position corresponding to the heel. FIG. 17 is a diagram schematically showing the shapes of the first member 40 and the second member 50 in an unloaded state. FIG. 18 is a diagram schematically showing the shapes of the first member 40 and the second member 50 in a state in which a first load F1 is applied. FIG. 19 is a diagram schematically showing the shapes of the first member 40 and the second member 50 in a state in which a second load F2 is applied.

[0049] 17 , in a no-load state (load F=0), a gap is formed between the outer peripheral surface 44 of the convex portion 42 of the first member 40 and the opposing inclined region 56 of the second member 50, and the outer peripheral surface 44 is configured not to come into contact with the opposing inclined region 56. In addition, the convex portion 42 of the first member 40 does not come into contact with the opposing surface 12 that faces the direction of the sole 10 through the opening 52 of the second member 50. A gap space is formed between the convex portion 42 of the first member 40 and the opening 52 of the second member 50.

[0050] When a load F is applied to the upper surface of the first member 40, the first member 40 is pushed downward as the load F increases. The vertical distance between the outer peripheral surface 44 of the convex portion 42 of the first member 40 and the inclined region 56 of the second member 50 increases toward the opening 52. Therefore, when the first member 40 is pushed downward, the first member 40 deforms such that the contact area between the outer peripheral surface 44 and the inclined region 56 gradually expands from the periphery of the opening 52 toward the center. That is, the contact area between the outer peripheral surface 44 of the convex portion 42 and the inclined region 56 gradually expands from a position away from the opening 52. This phenomenon becomes more pronounced when the inclination of the inclined region 56 is configured to be greater than the inclination of the outer peripheral surface 44. Thus, as the load F increases, the gap between the outer peripheral surface 44 and the inclined region 56 is filled, thereby reducing the clearance space.

[0051] Although not shown in FIG. 17 , the contact region 54 (see FIG. 14 , etc.) of the second member 50, which is less inclined than the inclined region 56, is in contact with the underside of the first member 40. Therefore, as the load F increases, the first member 40 deforms to fill the gap while restricting movement of the first member 40 relative to the second member 50 to some extent. The second member 50 is disposed along the periphery of the foot insertion section 20a in the rearfoot region, so deformation is restricted. Then, as shown in FIG. 18 , when the load F reaches a predetermined first load F1, the gap between the outer peripheral surface 44 of the convex portion 42 and the inclined region 56 is filled. This displacement is referred to as the first displacement. Thus, until the displacement reaches the first displacement, the first member 40 deforms to fill the gap, and the increase in load F relative to the increase in displacement is relatively small, making it easier to obtain cushioning. Furthermore, because the contact area expands from the periphery toward the center of the opening 52, even if the direction in which the load F is applied is slightly tilted from the vertical direction, the first member 40 can be displaced toward the center of the opening 52 while being supported by the second member 50. This reduces shaking in the horizontal direction, and stability is likely to be improved.

[0052] When the load F applied to the upper surface of the first member 40 further increases and reaches a predetermined second load F2, the convex portion 42 comes into contact with the opposing surface 12 through the opening 52, as shown in Figure 19. The displacement at this time is referred to as the second displacement. When the load F applied to the upper surface of the first member 40 further increases, the first member 40 and the second member 50 are compressed.

[0053] The period during which the load F increases from the no-load state to the first load F1 is the period until the gap between the outer peripheral surface 44 of the convex portion 42 and the inclined region 56 is filled, and since the first member 40 can move relatively freely, the displacement in response to the load F is relatively large. Therefore, during this period, the buffer material 30 ensures cushioning properties.

[0054] The period during which the load F increases from the first load F1 to the second load F2 is the period until the convex portion 42 comes into contact with the opposing surface 12 with the gap between the outer peripheral surface 44 of the convex portion 42 and the inclined region 56 filled, and the first member 40 moves while being partially restricted, thereby reducing displacement with respect to the load F. Therefore, during this period, the cushioning material 30 reduces its cushioning properties while increasing its stability.

[0055] During the period in which the load F increases beyond the second load F2, the movement of the convex portion 42 is substantially restricted, and the first member 40 and the second member 50 undergo compressive deformation, further reducing the displacement in response to the load F. Therefore, during this period, the stability of the buffer material 30 is further enhanced. Note that when the load F decreases from a state in which it is greater than the second load F2 to a no-load state, the above-described deformation states are reversed in order.

[0056] When a wearer wearing the footwear 100 repeatedly performs an action such as walking, the first member 40 and the second member 50 repeatedly transition through the above-mentioned deformation states each time the wearer lands, so that the foot can be protected at the beginning of the landing due to the high cushioning, and when the wearer lands and takes a step, the high stability allows the wearer to perform the action stably.

[0057] The cushioning material 30 may be configured such that the first member 40 and the second member 50 are detachable. In this case, a plurality of first members 40 each differing in at least one of shape and material and a plurality of second members 50 each differing in at least one of shape and material may be prepared, and a cushioning material 30 made of any combination may be produced. This allows cushioning materials 30 with different characteristics for each wearer to be produced. Furthermore, when a cushioning material 30 wears down with use, one of the first member 40 and the second member 50 may be replaceable. For example, if the first member 40 is more likely to wear down because it comes into contact with the wearer's feet, replacing only the first member 40 can prevent waste of material.

[0058] The present disclosure has been described above based on the embodiments. These embodiments are merely examples, and it will be understood by those skilled in the art that various modifications are possible in the combination of the respective components and processing steps, and that such modifications are also within the scope of the present disclosure. Furthermore, the above-described embodiments can be generalized to provide the following aspects.

[0059] [Mode 1] Footwear comprising: a sole; an upper provided above the sole and surrounding a foot insertion section; and a cushioning material housed within the foot insertion section, wherein the cushioning material is constructed by stacking at least two members, a first member located on the upper side and a second member located on the lower side, the first member having a convex portion that protrudes toward the sole at a position corresponding to the heel portion and covering the entire second member in a plan view, and the second member having an opening capable of housing the heel portion.

[0060] As a result, in the footwear of Aspect 1, the convex portion of the upper first member can be received in the opening of the lower second member at a position corresponding to the heel of the wearer. Therefore, depending on the load, the convex portion can be in or out of contact with other parts of the foot, achieving both cushioning and stability. Furthermore, because the first member entirely covers the second member in a plan view, the wearer's foot does not straddle and come into contact with the first and second members, which reduces discomfort to the wearer.

[0061] [Aspect 2] The footwear according to Aspect 1, wherein the upper surface of the second member has a contact area that contacts the first member around the opening in a plan view, the contact area being located in a range of 0.5 mm to 30 mm from the heel-side end point of the second member toward the opening, and the upper surface of the second member further has an inclined area, on the opening side of the contact area, that inclines toward the sole as it approaches the opening.

[0062] As a result, in the footwear of Aspect 2, the second member contacts the first member around the opening, which prevents misalignment between the first member and the second member and prevents the first member from dropping into the opening of the second member due to a load. Thus, the footwear of Aspect 2 has improved vertical stability while maintaining cushioning properties.

[0063] [Aspect 3] The footwear according to Aspect 2, wherein a gap is formed between the outer peripheral surface of the convex portion and the opposing inclined region, and the convex portion does not come into contact with the opposing surface facing the sole through the opening.

[0064] As a result, in the footwear of aspect 3, when the load from the heel of the wearer is within a predetermined range or less, the convex portion moves through the gap, thereby further improving cushioning properties.

[0065] [Aspect 4] The footwear according to any one of Aspects 1 to 3, wherein the second member includes an unbonded region that is not bonded to the first member in a contact region that faces the first member.

[0066] As a result, the footwear of Aspect 4 supports the load from the wearer while changing the relative positional relationship between the first member and the second member, thereby further improving stability.

[0067] [Aspect 5] The footwear according to any one of aspects 1 to 4, wherein the hardness of the first member is equal to or less than the hardness of the second member.

[0068] As a result, in the footwear of aspect 5, the first member is supported by the second member, but deforms more than the second member in response to the load from the wearer, thereby supporting the wearer's foot, thereby further improving cushioning and stability.

[0069] [Aspect 6] The footwear according to any one of Aspects 1 to 5, wherein the opening has a planar shape whose dimension in the foot length direction is greater than its dimension in the foot width direction, and is located within a range of 5% to 40% in the foot length direction from an end point on the heel side of the foot insertion part.

[0070] As a result, the footwear of aspect 6 provides more effective support at a position that corresponds more closely to the heel of the wearer, thereby further improving stability.

[0071] [Aspect 7] The footwear according to any one of Aspects 1 to 6, wherein the second member is located within a range of 70% or less in the foot length direction from the heel-side end point of the foot insertion portion, and the outer foot side end and inner foot side end on the toe side of the second member are located at positions other than those corresponding to the ball of the big toe and the ball of the little toe.

[0072] As a result, in the footwear of aspect 7, the second member supports the wearer's midfoot and other areas, but is not positioned in a position corresponding to the ball of the big toe and the ball of the little toe, thereby ensuring freedom of movement on the toe side.

[0073] [Aspect 8] An insole to be placed in a foot insertion section of footwear having a sole and an upper disposed above the sole and surrounding the foot insertion section, the insole being constructed by stacking at least two members, a first member located on the upper side and a second member located on the lower side, the first member having a convex portion that protrudes toward the sole at a position corresponding to the heel portion and covering the entire second member in a plan view, and the second member having an opening capable of accommodating the heel portion.

[0074] As a result, footwear containing the insole of aspect 8 can achieve the same effects as footwear of aspect 1.

[0075] The present disclosure relates to footwear and insoles.

[0076] 10...sole, 12...opposing surface, 20...upper, 20a...foot insertion portion, 30...cushioning material, 32...heel side end point, 40...first member, 42...convex portion, 44...outer surface, 50...second member, 52...opening, 54...contact area, 56...inclined area, 58...heel side end point, 60...width, 68a...outer foot side end, 68b...inner foot side end, 100...footwear.

Claims

1. Footwear comprising: a sole; an upper provided above the sole and surrounding a foot insertion section; and a cushioning material contained within the foot insertion section, wherein the cushioning material is constructed by stacking at least two members, a first member located on the upper side and a second member located on the lower side, the first member has a convex portion that protrudes toward the sole at a position corresponding to the heel portion and covers the entire second member in a plan view, and the second member has an opening capable of accommodating the heel portion.

2. Footwear as described in claim 1, wherein an upper surface of the second member has a contact area that contacts the first member around the opening in a plan view, the contact area being located in a range of 0.5 mm to 30 mm from the heel side end point of the second member toward the opening, and the upper surface of the second member further has an inclined area, on the opening side of the contact area, that inclines toward the sole as it approaches the opening.

3. The footwear according to claim 2, wherein a gap is formed between the outer peripheral surface of the convex portion and the opposing inclined region, and the convex portion does not come into contact with the opposing surface facing the direction of the sole through the opening.

4. Footwear according to any one of claims 1 to 3, wherein the second member includes an unbonded region that is not bonded to the first member in a contact region facing the first member.

5. The footwear according to claim 1, wherein the hardness of said first member is equal to or less than the hardness of said second member.

6. The footwear according to claim 1, wherein the opening has a planar shape whose dimension in the foot length direction is greater than its dimension in the foot width direction, and is located within a range of 5% to 40% in the foot length direction from the heel side end point of the foot insertion part.

7. Footwear as described in claim 1, wherein the second member is located within a range of 70% or less in the foot length direction from the heel side end point of the foot insertion part, and the outer foot side end and inner foot side end of the toe side of the second member are located other than the positions corresponding to the ball of the big toe and the positions corresponding to the ball of the little toe.

8. An insole to be placed in a foot insertion section of footwear comprising a sole and an upper disposed above the sole and surrounding the foot insertion section, the insole being constructed by stacking at least two members, a first member located on the upper side and a second member located on the lower side, the first member having a convex portion that protrudes toward the sole at a position corresponding to the heel portion and covering the entire second member in a plan view, and the second member having an opening capable of accommodating the heel portion.

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