This application claims priority to Japanese Patent Application No. 2023-055245 filed on Mar. 30, 2023, the entire disclosure of which is incorporated by reference herein.
The present disclosure relates to a sole structure and a shoe having the sole structure.
As a sole structure that is usable for, for example, trail running, one shown in Japanese Unexamined Patent Publication No. 2022-521032 is known.
Japanese Unexamined Patent Publication No. 2022-521032 discloses a sole structure including an outsole (an outsole 7), a midsole (a comfort sole 9) arranged on an upper side of the outsole, and a plate (a shell 13) arranged on an upper side of the midsole. The plate may be made of plastic or a composite material. The plate is arranged in the sole structure to extend from a position corresponding to a tiptoe of a foot of a wearer to a position corresponding to a heel of the foot of the wearer.
The sole structure of Japanese Unexamined Patent Publication No. 2022-521032 has rigidity improved by the plate made of plastic or a composite material. This can stably support the feet of a person wearing shoes including the sole structure (hereinafter referred to as a “wearer”). Further, when the foot of the wearer touches the ground or a rough road surface (hereinafter referred to as the “ground or any other surface”), the rigidity of the plate in the sole structure can reduce an impact pushing up the foot when, for example, the wearer steps on a stone on the ground or any other surface.
Although the rigidity improves, the sole structure having the plate tends to decrease in bendability. Consequently, the sole structure restricts the movements of joints of the wearer's foot more than necessary and possibly makes the movements of the foot less flexible. In particular, for a competitive sport involving walking or running on the ground or any other surface (e.g., trail running), the less flexible movements of the wearer's foot increase a load on the joints of the foot. During the trail running that takes relatively long race time, the load is kept applied to the joints for a long time and may possibly hurt the foot of the wearer.
For the higher bendability of the sole structure, for example, the plate can be removed from the sole structure of Japanese Unexamined Patent Publication No. 2022-521032. However, the sole structure without the plate cannot provide the rigidity required for the sole structure. This makes stable support of the wearer's foot difficult. Even if the sole structure without the plate has a sufficiently thick midsole, it is difficult to reduce the impact pushing up the foot when the foot touches the ground.
In view of the foregoing background, an object of the present disclosure is to ensure the rigidity of the sole structure without loss of the bendability of the sole structure.
In order to achieve the object, a first aspect of the disclosure relates to a sole structure of a shoe. The sole structure includes an outsole, a midsole stacked on an upper side of the outsole, and a plate that is arranged between the outsole and the midsole and is made of a material having a higher rigidity than the outsole and the midsole. The plate includes a plurality of cuts formed to extend from a peripheral edge of the plate in a first direction or a second direction intersecting with the first direction and a plurality of movable portions defined by phantom lines running along extending directions of the cuts. The movable portions are configured to be movable independently of each other in a thickness direction of the sole structure.
In the first aspect, the plate arranged between the outsole and the midsole improves the rigidity of the sole structure. This can stably support the wearer's foot. The rigidity of the plate can reduce an impact pushing up the foot when the foot touches the ground.
The cuts formed in the plate lower the rigidity of the plate locally at the phantom lines running along the extending directions of the cuts. Thus, the plate easily bends along the phantom lines. For example, when the impact pushing up the foot (an external pressure in the vertical direction) is applied to any of the movable portions, the plate bends along the phantom lines defining the movable portion.
The movable portions are configured to be movable independently of each other in the thickness direction of the sole structure. This configuration avoids loss of the bendability of the sole structure. Thus, the movements of joints of the foot of the wearer are less likely to be restricted, allowing each of the movable portions to follow the flexible movements of the foot of the wearer. This reduces a load applied to the joints of the wearer's foot during, for example, trail running that takes relatively long race time, keeping the wearer's foot from hurting. Further, this configuration ensures that the movable portions have the same rigidity as the plate, allowing the movable portions to reduce the impact pushing up the foot when the foot touches the ground.
Thus, in the first aspect, the rigidity of the sole structure can be ensured without loss of the bendability of the sole structure.
A second aspect of the present disclosure is an embodiment of the first aspect. In the second aspect, the cuts include at least one first cut extending in a first direction and at least one second cut extending in a second direction.
In the second aspect, the movable portions can be subdivided. This can further enhance the ability of the sole structure to follow the flexible movements of the foot of the wearer.
A third aspect of the present disclosure is an embodiment of the first aspect. In the third aspect, the midsole has a plurality of grooves formed in an upper surface of the midsole. Each of the grooves extends along the first direction or the second direction.
In the third aspect, the midsole can bend in accordance with the movements of the movable portions. This can avoid loss of the bendability of the sole structure.
A fourth aspect of the present disclosure is an embodiment of the third aspect. In the fourth aspect, the grooves include at least one first groove extending in the first direction and at least one second groove extending in the second direction.
In the fourth aspect, the midsole easily bends in accordance with the movements of the movable portions. This can avoid loss of the bendability of the sole structure.
A fifth aspect of the present disclosure is an embodiment of the first aspect. In the fifth aspect, the first direction corresponds to a foot width direction of the sole structure, and the second direction corresponds to a foot length direction of the sole structure.
In the fifth aspect, the sole structure can bend in the foot width direction and the foot length direction.
A sixth aspect of the present disclosure is an embodiment of the first aspect. In the sixth aspect, the outsole includes an outsole body and a plurality of projections projecting downward from the outsole body. Each of the movable portions is arranged to overlap with any of the projections in a thickness direction of the sole structure.
In the sixth aspect, the projections do not interfere with the movements of the movable portions and can give improved traction to the outsole.
A seventh aspect of the present disclosure is an embodiment of the sixth aspect. In the seventh aspect, the cuts include at least one first cut extending in a first direction and at least one second cut extending in a second direction. The first direction corresponds to a foot width direction of the sole structure, the second direction corresponds to a foot length direction of the sole structure. Each of the projections is arranged not to overlap with the first cut in a bottom view.
In the seventh aspect, loss of bendability of the sole structure can be avoided.
An eighth aspect of the present disclosure is an embodiment of the first aspect. In the eighth aspect, the plate is arranged in an area of the sole structure extending from a position configured to correspond to a tiptoe of a wearer's foot to a position configured to correspond to a center of an arch of the wearer's foot.
In the eighth aspect, the rigidity of the sole structure can be ensured without loss of bendability in the area of the sole structure extending from the position configured to correspond to the tiptoe of the wearer's foot to the position configured to correspond to the center of the arch of the wearer's foot.
A ninth aspect of the present disclosure is an embodiment of the first aspect. In the ninth aspect, the grooves are arranged in an area of the midsole extending from a position corresponding to a tiptoe of a wearer's foot to a position corresponding to a center of an arch of the wearer's foot.
In the ninth aspect, loss of the bendability of the sole structure can be avoided in the area of the sole structure extending from the position corresponding to the tiptoe of the wearer's foot to the position corresponding to the center of the arch of the wearer's foot.
A tenth aspect of the present disclosure is directed to a shoe including the sole structure of any one of the first to ninth aspects.
In the tenth aspect, shoes having advantages similar to those of the first to ninth aspects can be obtained.
As can be seen from the foregoing description, the present disclosure can provide a sole structure with rigidity without loss of bendability.
Embodiments of the present disclosure will be described in detail below with reference to the drawings. The following description of the embodiments is merely exemplary in nature, and is not intended to limit the scope, applications, or use of the present disclosure.
In the embodiments of the present disclosure, the sole structure 1 is for a right foot alone. A sole structure for a left foot is configured to be symmetrical to the sole structure for the right foot. In the following description, only the sole structure for the right foot will be described, and no description is made on the sole structure for the left foot.
In the following description, the terms “upper side” and “lower side” shown in the drawings represent a positional relationship in a thickness direction (vertical direction) of the sole structure 1. The terms “medial side” and “lateral side” shown in the drawings represent a positional relationship in a foot width direction of the sole structure 1. In the following description, a “first direction D1” corresponds to the foot width direction of the sole structure 1, and a “second direction D2” corresponds to a foot length direction of the sole structure 1.
Further, as shown in
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The outsole 2 is made of a hard elastic material harder than the midsole 5. Specific examples of the material of the outsole 2 include thermoplastic synthetic resins such as an ethylene-vinyl acetate copolymer (EVA), thermosetting resins such as polyurethane (PU), rubber such as butadiene rubber and chloroprene rubber, and foam materials obtained by foaming these materials. The outsole 2 preferably has a hardness of, for example, 50 A to 80 A (more preferably 60 A to 70 A) measured by a durometer C or A.
As shown in
Each of the projections 4 projects downward from the lower surface of the outsole body 3 as shown in
The midsole 5 is stacked on an upper side of the outsole 2 (see
The midsole 5 is made of a soft elastic material which is less rigid than the outsole 2. Specific examples of the material of the midsole 5 include thermoplastic synthetic resins such as an ethylene-vinyl acetate copolymer (EVA) and foams thereof, thermosetting resins such as polyurethane (PU) and foams thereof, and rubbers such as butadiene rubber and chloroprene rubber and foams thereof. The midsole 5 preferably has a hardness of, for example, 15 C to 65 C on the Asker C scale.
As shown in
The first midsole 6 is arranged in the sole structure 1 to correspond to the wearer's foot ranging from the forefoot F to hindfoot H. The first midsole 6 is stacked on the upper side of the outsole 2 (see
As shown in
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As shown in
The upper surface of the first midsole 6 and the upper surface of the second midsole 9 serve as a planta support surface for supporting the planta of the wearer's foot. The planta support surface may be configured to directly support the planta of the wearer's foot or indirectly support the planta of the wearer's foot via an insole (not shown).
As shown in
As shown in
The grooves 12 include a plurality of first grooves 13 and a plurality of second grooves 14. Each of the first grooves 13 extends in the first direction D1. Specifically, each of the first grooves 13 extends substantially in the same direction as first cuts 21a to 21e described later. Each of the second grooves 14 extends in the second direction D2. Specifically, each of the second grooves 14 extends substantially in the same direction as second cuts 22a and 22b described later.
In the bending region 11, a protrusion 15 is surrounded by each adjacent pair of the first grooves 13, 13 and each adjacent pair of the second grooves 14, 14. The protrusion 15 has a substantially quadrangular shape in a plan view. The protrusion 15 protrudes upward from the bottom of the groove 12 (see
The protrusions 15 are formed integrally with the first midsole 6 and are made of the same soft elastic material as the first midsole 6. That is, the protrusions 15 are elastically deformable.
For example, when the wearer's foot steps on a stone on the ground or any other surface upon touching the ground or any other surface (hereinafter referred to as “when touching the ground”), the sole structure 1 is pushed up (hereinafter referred to as “push-up”). At this time, the part of the bending region 11 (first midsole 6) at the bottom of each groove 12 bends, and the adjacent protrusions 15, 15 approach or separate from each other. Thus, the bending region 11 improves the bendability of the sole structure 1 when the foot touches the ground.
Further, when the foot touches the ground and is pushed up, each of the protrusions 15, sandwiched between the ground and the planta surface of the wearer, is likely to receive a pressure in the vertical direction. At this time, each of the protrusions 15 elastically deforms toward the groove 12 so that the wall surfaces of the adjacent protrusions 15, 15 approach each other. Such elastic deformation of the protrusions 15 can reduce the impact pushing up the foot when the foot touches the ground in the forefoot F and midfoot M of the foot of the wearer. That is, the bending region 11 of the midsole 5 improves cushioning properties of the sole structure 1.
As shown in
The plate 19 is arranged between the outsole 2 and the midsole 5 (see
The plate 19 is arranged in the sole structure 1 to correspond to the forefoot F and midfoot M of the foot of the wearer. Specifically, the plate 19 is arranged in an area of the sole structure 1 extending from a position corresponding to the tiptoe of the wearer's foot to a position corresponding to the center of the arch of the wearer's foot. As shown in
The plate 19 is formed as a thin layer having a higher rigidity than the midsole 5 and the outsole 2. The plate 19 is preferably made of a hard elastic material. Examples of the hard elastic material include thermoplastic resins such as thermoplastic polyurethane (TPU), polyamide elastomer (PAE), and an ABS resin, thermosetting resins such as an epoxy resin and an unsaturated polyester resin, and an ethylene-vinyl acetate copolymer resin (EVA). Also usable is fiber-reinforced plastic (FRP) containing reinforcement fibers such as carbon fibers, aramid fibers, or glass fibers in a matrix resin such as a thermosetting resin or a thermoplastic resin.
As shown in
The first cuts 21a to 21e are formed to extend from the peripheral edge of the plate 19 in the first direction D1 in the surface direction of the plate 19. Specifically, the first cuts 21a to 21e extend in a substantially band shape along the foot width direction of the sole structure 1. Each of the first cuts 21a to 21e is formed to have a substantially arc-shaped tip end. This shape avoids easy concentration of stress on the tip ends of the first cuts 21a to 21e.
The first cuts 21a and 21b are formed on the medial side of the plate 19. The first cuts 21a and 21b are spaced from each other in the second direction D2 (the foot length direction). The first cut 21a is arranged in the sole structure 1 to correspond to a joint of the wearer's foot between a proximal head of the first proximal phalanx PP1 and a distal head of the first metatarsal MT1 (i.e., the metacarpophalangeal (MP) joint of the foot indicated by a reference sign “MP” in
The first cuts 21c, 21d, and 21e are formed on the lateral side of the plate 19. The first cuts 21c, 21d, and 21e are arranged at intervals in the second direction D2 (the foot length direction). The first cut 21c is arranged in the sole structure 1 to mainly correspond to a joint of the wearer's foot between a proximal head of the fourth distal phalanx DP4 and a distal head of the fourth middle phalanx IP4. The first cut 21d is arranged in the sole structure 1 to mainly correspond to a distal head of the fifth proximal phalanx PP5 of the wearer's foot. The first cut 21e is arranged in the sole structure 1 close to a position mainly corresponding to a distal head of the fifth metatarsal bone MT5 of the wearer's foot.
The second cuts 22a and 22b are formed to extend from the peripheral edge of the plate 19 in the second direction D2 in the surface direction of the plate 19. Specifically, the second cuts 22a and 22b extend in a substantially band shape along the foot length direction of the sole structure 1. Each of the second cuts 22a and 22b is formed to have a substantially arc-shaped tip end. This shape avoids easy concentration of stress on the tip ends of the second cuts 22a and 22b.
The second cut 22a is formed on the front side (the tiptoe side) of the plate 19. The second cut 22a is arranged in the sole structure 1 mainly to be close to the second middle phalanx IP2 and to correspond to a distal head of the second proximal phalanx PP2 of the wearer's foot.
The second cut 22b is formed on the rear side (the arch side) of the plate 19. The second cut 22b is arranged in the sole structure 1 to mainly correspond to a proximal head of the second metatarsal bone MT2 and a proximal head of the third metatarsal bone MT3 of the wearer's foot.
As shown in
Each of the movable portions 31 to 37 is defined by phantom lines (VL1 to VL7 shown in
The movable portion 31 is defined by the phantom line VL1 running along the extending direction of the first cut 21a and the phantom line VL6 running along the extending direction of the second cut 22a. The movable portion 31 is arranged in the sole structure 1 to mainly correspond to the first distal phalanx DP1 and first proximal phalanx PP1 of the wearer's foot.
The movable portion 32 is defined by the phantom line VL1 running along the extending direction of the first cut 21a, the phantom line VL2 running along the extending direction of the first cut 21b, and the phantom line VL6 running along the extending direction of the second cut 22a. The movable portion 32 is arranged in the sole structure 1 to mainly correspond to the first metatarsal bone MT1 and second metatarsal bone MT2 of the wearer's foot.
The movable portion 33 is defined by the phantom line VL2 running along the extending direction of the first cut 21b and the phantom line VL7 running along the extending direction of the second cut 22b. The movable portion 33 is arranged in the sole structure 1 to mainly correspond to the first metatarsal bone MT1 and second metatarsal bone MT2 of the wearer's foot.
The movable portion 34 is defined by the phantom line VL3 running along the extending direction of the first cut 21c and the phantom line VL6 running along the extending direction of the second cut 22a. The movable portion 34 is arranged in the sole structure 1 to mainly correspond to the third distal phalanx DP3, fourth distal phalanx DP4, second middle phalanx IP2, third middle phalanx IP3, and second proximal phalanx PP2 of the wearer's foot.
The movable portion 35 is defined by the phantom line VL3 running along the extending direction of the first cut 21c, the phantom line VL4 running along the extending direction of the first cut 21d, and the phantom line VL6 running along the extending direction of the second cut 22a. The movable portion 35 is arranged in the sole structure 1 to mainly correspond to the fifth distal phalanx DP5, fourth middle phalanx IP4, second to fifth proximal phalanges PP2 to PP5, and second metatarsal MT2 of the wearer's foot.
The movable portion 36 is defined by the phantom line VL4 running along the extending direction of the first cut 21d, the phantom line VL5 running along the extending direction of the first cut 21e, and the phantom line VL6 running along the extending direction of the second cut 22a. The movable portion 36 is arranged in the sole structure 1 to mainly correspond to the fifth proximal phalanx PP5 and third to fifth metatarsal bones MT3 to MT5 of the wearer's foot.
The movable portion 37 is defined by the phantom line VL5 running along the extending direction of the first cut 21e and the phantom line VL7 running along the extending direction of the second cut 22b. The movable portion 37 is arranged in the sole structure 1 to mainly correspond to the third to fifth metatarsal bones MT3 to MT5 of the wearer's foot.
(Positional Relationship between Movable Portions and Projections)
As shown in
As shown in
As described above, the plate 19 arranged between the outsole 2 and the midsole 5 of the sole structure 1 increases the rigidity of the sole structure 1. This can stably support the wearer's foot. In the sole structure 1, the rigidity of the plate 19 can reduce the impact pushing up the foot when the foot touches the ground.
The plate 19 includes the cuts 20 and the movable portions 31 to 37 defined by the phantom lines running along the extending directions of the cuts 20. The cuts 20 formed in the plate 19 lower the rigidity of the plate 19 locally at the phantom lines running along the extending directions of the cuts 20. Thus, the plate 19 easily bends along the phantom lines. For example, when the impact pushing up the foot (an external pressure in the vertical direction) is applied to any of the movable portions 31 to 37, the plate 19 bends along the phantom lines defining the movable portion.
The movable portions 31 to 37 are configured to be movable independently of each other in the vertical direction (the thickness direction of the sole structure 1). This configuration avoids loss of the bendability of the sole structure 1. Thus, the movements of the joints of the wearer's foot are less likely to be restricted, allowing each of the movable portions 31 to 37 to follow the flexible movements of the wearer's foot. This reduces a load applied to the joints of the wearer's foot during, for example, trail running that takes relatively long race time, keeping the wearer's foot from hurting. Further, this configuration ensures that the movable portions 31 to 37 have the same rigidity as the plate 19, allowing the movable portions 31 to 37 to reduce the impact pushing up the foot when the foot touches the ground.
Thus, the sole structure 1 of the embodiment of the present disclosure can ensure the rigidity without loss of the bendability.
The cuts 20 include the first cuts 21a to 21e extending along the first direction D1 and the second cuts 22a and 22b extending along the second direction D2. This configuration can subdivide the movable portions into, for example, the movable portions 31 to 37 shown in
The midsole 5 may have the grooves 12 formed in the upper surface of the midsole 5. The grooves 12 include the first grooves 13 extending along the first direction D1 and the second grooves 14 extending along the second direction D2. Specifically, each of the first grooves 13 extends along the same direction as the extending direction of the first cuts 21a to 21e, and each of the second grooves 14 extends along the same direction as the extending direction of the second cuts 22a and 22b. This configuration allows the midsole 5 to bend in accordance with the movements of the movable portions 31 to 37. This can avoid loss of the bendability of the sole structure 1.
As described in this embodiment, the first direction D1 may extend along the foot width direction of the sole structure 1, and the second direction D2 may extend along the foot length direction of the sole structure 1. That is, in this embodiment, the first cuts 21a to 21e and the first grooves 13 extend along the foot width direction, and the second cuts 22a and 22b and the second grooves 14 extend along the foot length direction. This configuration allows the plate 19 and the midsole 5 to bend in the foot width direction and the foot length direction.
Each of the movable portions 31 to 37 is arranged to overlap with some of the projections 4 in the thickness direction of the sole structure 1. This configuration allows each of the projections 4 to easily move in the vertical direction following the bending movements of the plate 19 along the phantom lines. Thus, the projections 4 do not interfere with the movements of the movable portions 31 to 37 and can give improved traction to the outsole 2.
Further, the projections 4 are arranged not to overlap with the first cuts 21a to 21e in the bottom view. This configuration keeps the projections 4 from interfering with the bending movements of the plate 19 starting from the phantom lines VL1 to VL5. This does not block the vertical movements of the movable portions 31 to 37, allowing the movable portions 31to 37 to easily follow the flexible movements of the wearer's foot. Thus, the embodiment of the present disclosure can avoid loss of the bendability of the sole structure 1.
The projections 4 near the center of the arch may be arranged not to overlap with the second cut 22b. Thus, the projections 4 near the center of the arch do not interfere with the bending movements of the plate 19 starting from the phantom line VL7. This does not block the vertical movements of the movable portions 33 and 37 in particular, allowing the movable portions 33 and 37 to easily follow the flexible movements of the wearer's foot.
Preferably, the plate 19 is arranged in an area of the sole structure 1 extending from a position corresponding to the tiptoe of the wearer's foot to a position corresponding to the center of the arch of the wearer's foot. Likewise, the grooves 12 are preferably arranged in an area of the midsole 5 extending from a position corresponding to the tiptoe of the wearer's foot to a position corresponding to the center of the arch of the wearer's foot. This configuration can avoid loss of the bendability of the area of the sole structure 1 extending from the position corresponding to the tiptoe of the wearer's foot to the position corresponding to the center of the arch of the wearer's foot. In general, MP joints are present in an area of a human foot structure extending from the tiptoe to the center of the arch. Thus, the plate 19 and the grooves 12 arranged as described above can reduce the load on the MP joints of the foot of the wearer. This configuration is less likely to hurt the wearer's foot during, for example, trail running that takes relatively long race time.
It has been described in the embodiment that the plate 19 is arranged in the lower receiving part 7 of the first midsole 6, but the plate 19 is not limited to this embodiment. For example, the plate 19 may be arranged in a receiving part (not shown) formed in the upper surface of the outsole 2. Alternatively, the plate 19 may be arranged between the upper surface of the outsole 2 and the lower surface of the first midsole 6 without providing the lower receiving part 7 in the first midsole 6.
It has been described in the embodiment that the grooves 12 include the first grooves 13 and the second grooves 14, but the grooves 12 are not limited to this embodiment. For example, the grooves 12 may include the first grooves 13 alone (or at least one first groove 13 alone). Alternatively, the grooves 12 may include the second grooves 14 alone (or at least one second groove 14 alone).
It has been described in the embodiment that the cuts 20 include the first cuts 21a to 21e and the second cuts 22a and 22b, but the cuts 20 are not limited to this embodiment. For example, the cuts 20 may include the first cuts 21a to 21e alone (or only one of the first cuts 21a to 21e). Alternatively, the cuts 20 may include the second cuts 22a and 22b alone (or only one of the second cuts 22a and 22b). That is, if the plate 19 has the first cuts 21a to 21e or the second cuts 22a and 22b, the multiple movable portions can be provided.
It has been described in the embodiment that the projections 4 are arranged not to overlap with the cuts 20 in the vertical direction, but the projections 4 are not limited to this embodiment. Specifically, each of the projections 4 may partially overlap with any of the cuts 20.
It has been described in the embodiment that the “first direction D1” corresponds to the foot width direction of the sole structure 1, and the “second direction D2” corresponds to the foot length direction of the sole structure 1. However, the first and second directions are not limited to this embodiment. Specifically, each of the “first direction D1” and the “second direction D2” may be a direction intersecting with each of the foot width direction and the foot length direction.
It has been described in the embodiment that the projection 4 on the tiptoe side and the second cut 22a overlap with each other in the vertical direction in
Although the embodiments of the present disclosure have been described above, the present disclosure is not limited to the above embodiments, and various modifications can be made within the scope of the present disclosure.
The present disclosure can be industrially applicable as a sole structure of a shoe suitable for trail running, for example, and a shoe including the same.
Number | Date | Country | Kind |
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2023-055245 | Mar 2023 | JP | national |