The present invention relates generally to a sole structure for a sport shoe, and more particularly, to an improved sole structure that can increase accelerating force during activities and enables quick movements.
The applicant of the present invention proposed a sole structure for a sport shoe such as shown in Japanese Patent No. 3215664. In the sole structure shown in the patent publication, the wavy corrugated sheet is interposed inside the midsole of a soft elastic member and it extends from the heel part of the midsole through the midfoot part to the position near the thenar eminence of the forefoot part. Thereby, a lateral swing can be prevented at the region from the heel part to the midfoot part of the midsole after impacting the ground, thus securing stability during running (see para. [0091] and FIGS. 5-7).
In the structure described in the above publication, the wavy corrugated sheet, which is disposed at the region extending from the midfoot part of the midsole to the position near the thenar eminence of the forefoot part, enabled an increase of resiliency to some degree when impacting the ground on the forefoot part during activities, but it was not sufficient. For example, in indoor sports such as volleyball, handball or the like, the prior-art structure did not adequately correspond to demand that accelerating force is further increased during activities and quicker movements are achieved.
The present invention has been made in view of these circumstances and its object is to provide a sole structure for a sport shoe that can increase accelerating force during activities and achieve quick movements.
A sole structure for a sport shoe according to the present invention includes a sole body formed of a soft elastic member and a plate-like member that is disposed at a position corresponding to toes of a foot on a foot sole contact surface side of the sole body and that has a higher hardness than that of the sole body.
According to the present invention, since the plate-like member of a higher hardness than that of the sole body is provided at the position corresponding to the toes of the foot on the foot sole contact surface side of the sole body, when a load is applied to the sole body from the toes during activities, the load acts on the soft sole body through the hard plate-like member. At this moment, compared to the case in which the load from the toes is imparted directly to the sole body and the soft sole body is thus locally deformed such that the load is absorbed by the sole body, the load from the toes is imparted to the sole body through the hard plate-like member thus restraining a local deformation of the sole body to prevent the load from the toes from being absorbed by the sole body. Since a greater resiliency can thus be achieved accelerating force can be increased during activities. As a result, quick movements can be achieved. For example, one can quickly move onto a dash, sidestep and jumping that require a push-off motion of the toes.
The plate-like member may be located at a position directly under a first distal phalanx to a fourth distal phalanx of the foot. In this case, the load at the time of the push-off motion can be effectively transmitted to the plate-like member.
The plate-like member may extend substantially in a foot width direction along the toes and have a short length in a foot length direction at a region between a first toe and a second toe. In this case, on opposite sides of a region between the first toe and the second toe, a region on the first toe side and a region on the second toe side are easy to bend respectively in the foot width direction, thereby smoothly transferring the load (strictly speaking, the center of foot pressure) in either case in which the foot pushes off on the first toe or on the fourth toe. As a result, quick movements due to an increase of accelerating force during activities can be achieved and at the same time transfer of the center of foot pressure can be smoothly conducted in either case in which the foot pushes off on the first toe or on the fourth toe.
The plate-like member may be composed of a first plate-like member disposed at a position corresponding to the first toe and a second plate-like member that is spaced away from the first plate-like member and that is disposed at a position corresponding to the second toe to the fourth toe. In this case, on opposite sides of a space of gap between the first and second plate-like members, the region on the first toe side and a region on the second to fourth toe sides are much easier to bend respectively in the foot width direction, thereby smoothly transferring the load (strictly speaking, the center of foot pressure) in either case in which the foot pushes off on the first toe or on the fourth toe. As a result, quick movements due to an increase of accelerating force during activities can be achieved and at the same time transfer of the center of foot pressure can be smoothly conducted in either case in which the foot pushes off on the first toe or on the fourth toe.
With regard to a rigidity of a midfoot region of the sole body, the rigidity of the midfoot region between a forefoot medial side and a heel lateral side may be made lower than that of the midfoot region between a forefoot lateral side and a heel medial side. In this case, since the midfoot region of the sole body has a structure that allows for ease of pronation, pronation is promoted at the time of activities and thus during activities the load easily concentrates on the thenar eminence side of the forefoot region of the sole body. Thereby, transfer of the load (strictly speaking, the center of foot pressure) to the thenar eminence side can be smoothly conducted. As a result of this, the center of foot pressure can be smoothly transferred to the plate-like member on the toe side. In such a way, accelerating force during activities can be further enhanced and much quicker movements can be achieved.
The plate-like member may extend to an outer circumferential edge portion of the sole body and have an upraised portion extending upwardly at the outer circumferential edge portion. In this case, a lateral swing of the foot at the time of push-off motion can be prevented by the upraised portion.
The upraised portion may act as a toe guard. The sport shoe may be an indoor shoe.
Embodiments of the present invention will be hereinafter described in accordance with the appended drawings.
As shown in
On the foot sole contact surface 2A of the sole body 2, there is formed an upraised portion 2B that rises upwardly (i.e. out of the pages of
The sole body 2 is formed of a soft elastic material, more specifically, thermoplastic resin such as ethylene-vinyl acetate copolymer (EVA) and the like, foamed thermoplastic resin, thermosetting resin such as polyurethane (PU) and the like, foamed thermosetting resin, rubber materials such as butadiene rubber, chloroprene rubber and the like, or foamed rubber materials. A hardness of the sole body 2 is set at, for example 45-75 C (in the Asker C scale). In this embodiment, formed EVA is used for the sole body 2 and its hardness is set at 55 C (±4 C for a tolerance).
There is provided a plate-like member 3 at a position corresponding to toes of the foot on the foot sole contact surface 2A of the sole body 2. The plate-like member 3 is preferably embedded into the foot sole contact surface 2A and a top surface of the plate-like member 3 is preferably flush with the foot sole contact surface 2A. As shown in
More specifically, as shown in
The plate-like member 3 is formed of a hard elastic material which has a higher hardness than that of the sole body 2, more specifically, thermoplastic resin such as ethylene-vinyl acetate copolymer (EVA) and the like, thermosetting resin such as polyurethane (PU) and the like, rubber materials such as butadiene rubber, chloroprene rubber and the like. A hardness of the plate-like member 3 is set at 45-75 D (in the Asker D scale) in the case of the resin material for the plate-like member 3, or 60-80 A (in the Asker A scale) in the case of the rubber material for the plate-like member 3. In this embodiment, a hard EVA sheet is used for the plate-like member 3 and its hardness is set at 80 A (±3 A for a tolerance), which is higher than the hardness 55 C of the sole body 2.
As shown in
As shown in
The wavy corrugated sheet 6 is preferably formed of a hard elastic material, more specifically, thermoplastic resin such as thermo plastic polyurethane (TPU), polyamide elastomer (PAE), acrylonitrile-butadiene-styrene (ABS) resin and the like, or thermosetting resin such as epoxy resin, unsaturated polyester resin and the like. In addition, the wavy corrugated sheet 6 may be formed of fiber reinforced prastics (FRP) formed of reinforcing fibers such as carbon fibers, aramid fibers, glass fibers or the like and matrix resin such as thermosetting resin or thermoplastic resin.
As shown in
By forming the rib 60 in the wavy corrugated sheet 6, with regard to a rigidity of the midfoot region M of the sole body 2, the midfoot rigidity between the forefoot medial side and the heel lateral side of the sole body 2 is made lower than the midfoot rigidity between the forefoot lateral side and the heel medial side of the sole body 2, thus allowing for ease of pronation of the midfoot region M of the sole body 2. Moreover, with regard to the rigidity of the midfoot region M of the sole body 2, the midfoot rigidity between the forefoot medial side and the heel medial side of the sole body 2 is made lower than the midfoot rigidity between the forefoot lateral side and the heel lateral side of the sole body 2, thus further allowing for ease of pronation of the midfoot region M of the sole body 2.
There is provided a toe guard 7 on the foot sole contact surface 2A at a toe portion of the sole body 2. The toe guard 7 extends upwardly and arcuately along the toe. The toe guard 7 includes protruded portions 7A and 7B each having a bonding part to the top surface of the sole contact surface 2A. The protruded portions 7A, 7B are disposed on the medial and lateral sides of the sole body 2, respectively.
The toe guard 7 is formed of a hard material including thermoplastic resin such as thermoplastic polyurethane, nylon and the like. As shown in
Next, in order to verify effects of the present embodiment, volleyball shoes employing the sole structure according to the present embodiment were prepared. Professional volleyball players wore the shoes and actually spiked a ball with their shoes on. Then, a foot pressure distribution and load (thus, center of foot pressure) transfer path were measured. Prior to measurement, a sock liner (or insole) with sensors for foot pressure measurement attached was inserted into each of the shoes. For comparison, the players wore the conventional volleyball shoes as well, spiked a ball similarly with their shoes on, and then the foot pressure distribution and load (i.e. center of foot pressure) transfer path were also measured.
In either case of
As mentioned above, in the sole structure 1 of the present embodiment, foot pressures at the time of activities are smoothly concentrated on the forefoot region and transfer of the foot pressures to the forefoot region is promptly conducted. It is considered that this is because formation of the rib 60 in the wavy corrugated sheet 6 allows for ease of pronation of the midfoot region M of the sole body 2. Also, the ground reaction force against the toes (especially, the first and second toes) is increased. It is considered that this is due to provision of the plate-like member 3 of high hardness on the foot contact surface 2A of the sole body 2. In this manner, as the ground reaction force increases, accelerating force during activities can be increased. Thereby, one can quickly move onto for example, a dash, sidestep, jumping and the like that require a push-off motion of the toes, and quick movements can thus be achieved.
Then, we conducted an experiment by computer simulation in order to verify the effects of the sole structure 1 of the present embodiment, especially the plate-like member only.
As shown
As can be seen from
Since the plate-like member 3 is located at the position corresponding to the toes of the foot on the foot sole contact surface 2A of the sole body 2, when the load is applied to the sole body 2 from the toes at the time of activities, a greater repulsion or rebound force can be obtained compared with the case in which the load from the toes is applied directly to the sole body 2 without the plate-like member 3. Thereby, accelerating force can be increased during activities, and as a result, one can quickly move onto for example, a dash, sidestep, jumping and the like that require a push-off motion of the toes. Quick movements can thus be attained. On the other hand, because the plate-like member 3 does not overlap with the metatarsophalangeal joints MP (see
Moreover, according to the present embodiment, since the plate-like member 3 is located right under the first distal phalanx DP1 to the fourth distal phalanx DP4, the load at the time of push-off motion of the foot can be effectively transmitted to the plate-like member 3.
According to the present embodiment, as the plate-like member 3 has the narrow part 3C between the first plate-like portion 3A and the second plate-like portion 3B (that is, at the region between the first toe and the second to fourth toes), the region on the first toe side and the region on the second toe side, which are respectively disposed on opposite sides of the region between the first toe and the second toe, are easy to bend respectively in the foot width direction. Thereby, in either case of push-off motion on the first toe side or push-off motion on the fourth toe side, a smooth load (thus, COP: center of foot pressure) transfer can be attained. As a result, quick movements due to an increase of accelerating force at the time of activities can be achieved and at the same time a smooth COP transfer can be attained in either case of push-off motion on the first toe side or on the fourth toe side.
According to the present embodiment, as the toe guard 7 is provided, shifting of the foot at the time of push-off motion can be prevented by the toe guard 7.
The second embodiment differs from the above-mentioned first embodiment in that respective protruding portions 7A′, 7B′ of the toe guard 7 protrude further inwardly than the respective protruding portions 7A, 7B of the toe guard 7 in the first embodiment and the plate-like member 3 in the first embodiment is not provided. In this case, the protruding portion 7A′ corresponds to the first plate-like portion 3A in the first embodiment and the protruding portion 7B′ corresponds to the second plate-like portion 3B in the first embodiment. Also, in this case, a member corresponding to the narrow part 3C in the first embodiment is not provided and there is formed a gap between the protruding portions 7A′ and 7B′.
In other words, in this second embodiment, first and second plate-like portions 7A′, 7B′ extend up to the outer circumferential edge portion of the sole body 2 and have the upraised portion 7 extending upwardly around the outer circumferential edge portion. The upraised portion 7 functions as a toe guard.
According to the second embodiment, the region on the first toe side and the region on the second to fourth toe sides are easy to bend respectively in the foot width direction on opposite sides of the gap between the protruding portions 7A′ and 7B′. Thereby, in either case of push-off motion on the first toe side or push-off motion on the fourth toe side, a smooth load (thus, COP: center of foot pressure) transfer can be attained. As a result, quick movements due to an increase of accelerating force at the time of activities can be achieved and at the same time a smooth COP transfer can be attained in either case of push-off motion on the first toe side or on the fourth toe side.
Also, according to the second embodiment, since the protruding portions 7A′, 7B′, which respectively correspond to the first and second plate-like members 3A, 3B in the first embodiment, are located at the position corresponding to the toes of the foot on the foot sole contact surface 2A of the sole body 2, as with the first embodiment, when the load is applied to the sole body 2 from the toes at the time of activities, a greater repulsion or rebound force can be obtained compared with the case in which the load from the toes is applied directly to the sole body 2. Thereby, accelerating force can be increased during activities, and as a result, one can quickly move onto, for example, a dash, sidestep, jumping and the like that require a push-off motion of the toes. Quick movements can thus be attained.
According to the second embodiment, since the protruding portions 7A′, 7B′ that function as the plate-like member 3 in the first embodiment are located right under the first distal phalanx DP1 to the fourth distal phalanx DP4, the load at the time of push-off motion of the foot can be effectively transmitted to the protruding portions 7A′, 7B′.
According to the second embodiment, in the same manner as the first embodiment, as the toe guard 7 is provided, shifting of the foot at the time of push-off motion can be prevented by the toe guard 7.
As above-mentioned, preferred embodiments of the present invention have been discussed, but application of the present invention is not limited to these embodiments. The present invention includes various variants or alternative embodiments. Some of the alternative embodiments will be mentioned below.
In the first embodiment, as the plate-like member 3, a deformed M-shaped member in a planar shape was taken for an example (see
In the first embodiment, an example in which the plate-like member 3 has the narrow part 3C was shown, but the present invention also has application to the plate-like member 3 without the narrow part 3C. In this case, the plate-like member 3 may be formed of an arcuate or band-shaped member that overlaps at least partially with the first to fourth toes (preferably, the first to fourth distal phalanges) and that extends substantially in the foot width direction. Alternatively, the plate-like member 3 may be composed of the first plate-like member 3A and the second plate-like member 3B that is spaced away and separated from the first plate-like member 3A and that overlaps at least partially with the second to fourth toes (preferably, the second to fourth distal phalanges).
In the first embodiment, an example in which the sole body 2 has the toe guard 7 at the front end portion thereof was shown, but the toe guard 7 may be omitted.
In the first embodiment, an example was shown in which there is provided the wavy corrugated sheet 6 and formed the rib 60 at the midfoot region of the wavy corrugated sheet 6 and with regard to rigidity of the midfoot region M of the sole body 2 the midfoot rigidity between the forefoot medial side and the heel lateral side of the sole body 2 is made lower than the midfoot rigidity between the forefoot lateral side and the heel medial side of the sole body 2 and also the midfoot rigidity between the forefoot medial side and the heel medial side of the sole body 2 is made lower than the midfoot rigidity between the forefoot lateral side and the heel lateral side of the sole body 2. However, a flat sheet may be substituted for the wavy corrugated sheet 6 and a rib may be formed in the flat sheet. In the alternative, a shank member may be provided at a position corresponding to the rib 60 in the midfoot region M of the sole body 2 in the first embodiment.
In the second embodiment, an example was shown in which there is formed the gap between the protruding portion 7A′ and 7B′, but these protruding portions 7A′, 7B′ may be integral with each other without forming the gap. In this case, a narrow part may be formed between the protruding portion 7A′ and 7B′. Alternatively, the protruding portions 7A′, 7B′ may be coupled with each other in an arcuate shape or a band-shape without the narrow part.
As mentioned above, the present invention is of use to a sole structure for a sport shoe, and it is especially suitable for a sport shoe preferred for indoor sports (in particular, ball-game sports) that requires accelerating force during activities and quick movements.
Number | Date | Country | Kind |
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2014-092161 | Apr 2014 | JP | national |
Filing Document | Filing Date | Country | Kind |
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PCT/JP2015/062631 | 4/21/2015 | WO | 00 |