Technical Field
[0001] The present invention relates to a shoe, which has comfort to wear and which is capable
of efficiently converting grounding impact into a thrust force occurring upon push
off and is suitable for running or walking.
Background Art
[0002] In a conventional running shoe or a conventional walking shoe (hereinafter referred
to as "shoe"), as shown in Fig. 6, a cushion material 24 is provided to an entire
sole member 22 of a shoe 20 so as to reduce grounding impact applied to a sole of
foot and obtain flexibility and a thrust force occurring upon push off. The shoe having
such structure is disclosed in, for example, Patent Literature 1 (Japanese Laid-open
Patent Publication No.
2002-85104).
[0003] The inventor of the present invention has invented a shoe, which is capable of storing
grounding impact as energy and radiating the stored energy as a repulsion force when
pushing off by a front foot part and is capable of reducing fatigue and burden of
the foot and running or walking efficiently, and the shoe is disclosed in Patent Literature
2 (Japanese Laid-open Patent Publication No.
2010-162318). Concretely, as shown in Fig. 7, a hard stepping plate 31 and a hard grounding plate
34 are connected, by a connecting section 34 of a heel part (a rear foot part), with
a suitable clearance 33, so that a plate spring 35, which returns the clearance 33
to an original state when an external force for narrowing the clearance 33 is applied,
is formed, and the plate spring 35 is attached to a bottom part of the shoe at a front
foot part of the hard stepping plate 31.
Citation List
Patent Literature
[0004]
Patent Literature 1: Japanese Laid-open Patent Publication No. 2002-85104
Patent Literature 2: Japanese Laid-open Patent Publication No. 2010-162318
Summary of Invention
Technical Problem
[0005] In the conventional shoe disclosed in Patent Literature 1, if the cushion materials
are partially provided on a ground contact surface so as to improve cushioning properties
and obtain an effective thrust force for push off while running or walking, pressure
is partially applied to the sole of foot and comfortableness will be worse. Therefore,
providing the cushion materials on the grounding surface is restricted. Further, in
the conventional shoe disclosed in Patent Literature 2, a structure of the plate spring,
which is capable of receiving grounding impact and which has suitable mechanical strength
for obtaining the repulsion force for push off, is complex, and it is difficult to
mass-produce the plate spring. Even if the plate spring is composed of a light material,
an entire weight of the shoe must be heavier.
Solution to Problem
[0006] Thus, an object of the present invention is to provide a shoe, which is light and
capable of improving cushioning properties and a thrust force occurring upon push
off without sacrificing comfort to wear and which has a simple structure and can be
mass-produced.
[0007] Namely, the shoe of the present invention comprises: a shoe body into which a foot
is inserted; a hard plate covering a necessary area on a bottom side of the shoe body
in a length direction and being fixed to the bottom side of the shoe body only at
a necessary location including a position of a front foot part; and cushion materials
being attached to at least both end parts of a ground contact side of the hard plate
in the length direction.
[0008] Preferably, the necessary area is the entire shoe body in the length direction. With
this structure, options of attachment positions of the cushion materials can be increased.
[0009] Preferably, the necessary area is an area from the front foot part to a heel part
except a toe part. With this structure, flexibility of the shoe body for pushing off
and following capability of the hard plate to the shoe body can be improved.
[0010] Preferably, the cushion material is attached to a position on the bottom side of
the shoe body which corresponds to the toe part. With this structure, comfort to wear
when pushing off can be improved, and a repulsion force can be increased.
[0011] Preferably, the hard plate is curved and projected, at a position corresponding to
the front foot part, toward a ground. With this structure, the hard plate can easily
follow the shoe body when pushing off, and a separation (a distance) between the hard
plate and the heel part of the shoe body is shortened, so that inertia moment of the
shoe can be made smaller, and fatigue and burden of the foot can be reduced.
[0012] Preferably, a sectional shape of the hard plate in a width direction is formed into
a corrugated shape. With this structure, a weight of the hard plate can be reduced,
and a strength of the hard plate in the length direction can be increased, so that
performance of the hard plate can be kept for a long period.
[0013] Preferably, a bending resistance of a part of the hard plate corresponding to the
area of the front foot part is smaller than that of another part corresponding to
an area from an intermediate foot part to the heel part. With this structure, flexibility
of the shoe while running can be secured, and a repulsion force occurring upon push
off can be increased.
[0014] Preferably, the hard plate and the cushion material are backwardly projected from
the shoe body. With this structure, dispersion and reduction of grounding impact can
be accelerated. Further, an area of a ground contact side of the hard plate, in which
the cushion materials can be provided, can be broadened, so that options of attachment
positions of the cushion materials can be increased, and the cushion materials can
be optionally provided.
Advantageous Effects of Invention
[0015] As described above, the hard plate is provided on the bottom side of the shoe body,
so that the cushion materials can be partially provided on the ground contact side
of the hard plate without sacrificing comfort to wear. The hard plate is fixed to
the bottom side of the shoe body only at the necessary location of the front foot
part, so that the heel part of the shoe body (a rear foot part) separates from the
hard plate when pushing off and flexibility of the shoe body can be maintained. The
cushion materials are attached to the both end parts (the heel part and the toe part
or the front foot part) of the ground contact side of the hard plate in the length
direction, so that the cushion material need not be provided to the intermediate foot
part and the weight of the shoe can be reduced.
[0016] By partially providing the cushion materials on the ground contact side of the shoe,
an amount of deformation of the cushion materials can be increased, and cushioning
properties and the repulsion force can be improved. Namely, grounding impact while
running can be absorbed by the cushion materials of the heel part and the front foot
part, and the cushion material of the heel part restores by weight shift, so that
the cushion material upwardly lifts a user wearing the shoes and the cushion material
of the front foot part is further compressed. Therefore, the hard plate and the shoe
body are inclined forward, and restoring the shoe can be accelerated. Further, the
cushion material of the front foot part, which has been compressed when pushing off,
restores, so that the user wearing the shoes is upwardly lifted and the thrust force
is generated. Therefore, the cushion materials are deformed when grounding, so that
the stored energy can be efficiently converted into the thrust force occurring upon
push off. Further, the structure of the shoe can be simplified, so that the light
shoe can be mass-produced.
Brief Description of Drawings
[0017]
Fig. 1 is a side view of a shoe of Embodiment 1.
Fig. 2 is a perspective view of a hard plate.
Fig. 3 is a side view of the shoe shown in Fig. 1, in which the shoe is pushed off.
Fig. 4 is a side view of a shoe of Embodiment 2.
Fig. 5 is a side view of a shoe of Embodiment 3.
Fig. 6 is a side view of the conventional shoe (Prior Art).
Fig. 7 is a side view of another conventional shoe (Prior Art).
Description of Embodiments
[0018] Embodiments of the shoe of the present invention will be described.
(Embodiment 1)
[0019] As shown in Fig. 1, a shoe 10 of the present embodiment comprises: a shoe body 1
into which a foot F is inserted; a hard plate 2 covering a necessary area on a bottom
side of the shoe body in a length direction; and cushion materials 3 being attached
on a ground contact side of the hard plate 2.
[0020] The hard plates 2 entirely covers a bottom side of the shoe body 1 in a length direction.
A suitable material of the hard plate 2 is a light and has high mechanical strength.
In the present embodiment, the hard plate 2 is composed of carbon fiber resin, but
the material of the hard plate 2 is not limited to the carbon fiber resin. As shown
in Fig. 1, the hard plate 2 is curved and projected, at a position of a front foot
part, toward a ground when seen from a side. The hard plate 2 is fixed to a bottom
side of the shoe body 1 only in a necessary length area including a border part between
a phalange and a metatarsal (a necessary location of the front foot part). Namely,
the hard plate 2 is not fixed to the bottom side of the shoe body 1 in an area from
an intermediate foot part to a heel part (a rear foot part), and the hard plate 2
is capable of moving to and away from a bottom surface of the shoe body 1.
[0021] Fig. 2 is a perspective view of the hard plate 2 seen from a lower side. In the hard
plate 2, a plurality of projecting stripes 2a are arranged, in a width direction of
the hard plate 2, with prescribed separations. Recessed stripes 2b are respectively
formed between the projecting stripes 2a. Namely, in an upper surface of the hard
plate 2, the projecting stripes 2a shown in Fig. 2 form the recessed stripes 2b, and
the recessed stripes 2b in a bottom surface of the hard plate 2 form the projecting
stripes 2a, so that a sectional shape of the hard plate 2 in the width direction is
formed into a corrugated shape. By forming the sectional shape in the width direction
into the corrugated shape, a weight of the hard plate 2 can be reduced, and a strength
(a bending strength) of the hard plate 2 in the length direction can be improved.
[0022] As to a height of each projecting stripe 2a (a depth of each recessed stripe 2b),
a depth of the intermediate foot part and the heel part is deeper than that of the
front foot part. With this structure, a bending resistance (a bending strength) of
the hard plate 2 in an area of the front foot part can be smaller than a bending resistance
(a bending strength) thereof in an area from the intermediate foot part to the heel
part. The upper and the bottom surfaces of the hard plate 2 may be formed flat. By
changing the shape of the hard plate 2, the shoe 10 having a suitable repulsion force
and comfortableness according to user's object and preference can be provided.
[0023] Cushion materials 3 are respectively attached to both end parts, i.e., the front
foot part and the heel part, of a ground contact side (the bottom side) of the hard
plate 2 in the length direction. Namely, as clearly shown in Fig. 1, no cushion material
3 is attached to a part of the hard plate 2 corresponding to the intermediate foot
part, so that the parts of the cushion materials 3 contact the ground but the part
of the hard plate 2 corresponding to the intermediate foot part is separated from
the ground in a state where the shoe 10 is merely put on the ground.
[0024] When the user wearing the shoes 10 begins to run as shown in Fig. 3, only the front
foot part of the shoe 10 contacts the ground, so that an area of the hard plate 2,
which corresponds to the area from the intermediate foot part to the heel part, is
separated from the ground and the heel part of the shoe body 1. Therefore, bending
properties of the shoe 10 is not sacrificed, so that the user can smoothly push off
the ground. When contacting the ground, a pressure applied to the front foot part
and the heel part can be dispersed to an entire sole of user's foot by the hard plate
2, so that comfortableness of the shoe 10 can be improved.
[0025] The cushion materials 3 are respectively attached to the locations of the ground
contact side of the hard plate 2 corresponding to the front foot part and the heel
part (at least the both end parts of the ground contact side of the hard plate 2 in
the length direction). The cushion materials 3 are composed of a material having superior
softness and elasticity, e.g., EVA (Ethylene-Vinyl Acetate). By partially providing
the cushion materials 3 on the ground contact side of the hard plate 2, the shoe 10
can be suitably lightened.
[0026] In the shoe 10 having the above described structure, grounding impact can be efficiently
stored in the cushion materials 3 as elastic energy (repulsion energy). Therefore,
when the user pushes off the ground by a ground contact surface of the shoe 10, the
repulsion energy generated by restoring the cushion materials 3 can be applied in
a direction of push off as a thrust force, so that high power push off can be obtained.
(Embodiment 2)
[0027] In the shoe 10 of the present embodiment, an area of attaching the hard plate 2 to
the shoe body 1 and locations of attaching the cushion materials 3 are different from
those of the shoe 10 of Embodiment 1. Concretely, as shown in Fig. 4, the hard plate
2 is provided to the bottom side of the shoe body 1 and in an area in the length direction
from the front foot part to the heel part except a toe part. Namely, the hard plate
2 does not cover the toe part of the shoe 10. The hard plate 2 is attached to the
bottom side of the shoe body 1 only in the necessary length area including the border
part between the phalange and the metatarsal (the necessary location of the front
foot part).
[0028] As described above, the part not covered with the hard plate 2 is formed on the bottom
side of the shoe body 1, a bending angle of a bending part of the shoe 10, which is
a border part between the part covered with the hard plate 2 and the part not covered
therewith, can be made wider. With this structure, following capability of the hard
plate 2 to the shoe body 1 can be improved when pushing off, so that comfort to wear
can be further improved.
[0029] In the shoe 10 of the present embodiment, the cushion material 3 is additionally
provided to the bottom side of the shoe body 1 in the toe part which is not covered
with the hard plate 2. The cushion material 3 provided to the toe part is separated
from the cushion materials 3 which are attached to the both end parts of the ground
contact side of the hard plate 2 in the length direction, and it is formed into a
triangular shape when seen from a side.
[0030] A maximum thickness of the cushion material 3 covering the toe part is approximately
equal to that of the cushion materials 3 attached to the bottom side of the hard plate
2. By employing such cushion materials 3, stumbling which is caused when the cushion
material 3 of the toe part unexpectedly contacts the ground while running or walking
can be prevented. By wearing the shoes 10, the thrust force occurring upon push off
and comfort to wear can be further improved. Elastic coefficients of the cushion materials
3 of the toe part, the front foot part and the heel part may be different from each
other.
(Embodiment 3)
[0031] In Fig. 5, the part of the shoe 10 not covered with the hard plate 2 is covered with
the cushion material 3 of the front foot part. Namely, the cushion material 3 of the
front foot part and the cushion material 3 of the toe part described in Embodiment
2 are integrated in the present embodiment. With this structure, in comparison with
Embodiment 2, producing and attaching the cushion material 3 can be simplified, and
durability can be improved.
[0032] In the present embodiment, as shown in Fig. 5, the hard plate 2 and the cushion material
3 attached to the heel part of the hard plate 2 are backwardly projected from a rear
end of the shoe body 1 and form a projecting part 4. By forming the projecting part
4, impact absorbability when grounding can be improved, so that burden of the foot
can be suitably reduced.
[0033] The present invention has been explained in detail with reference to the embodiments,
but the present invention is not limited to the embodiments. For example, the shoe
10 of the above described embodiments is but the shoe may be suitably applied to a
walking shoe.
[0034] In the above described embodiments, the cushion materials 3 act as ground contact
members of the shoe 10, but outer sole members may be attached to the bottom surfaces
of the cushion materials 3 as ground contact members. In Embodiment 1, the bending
resistance of the hard plate 2 in the length direction may be partially differed.
Concretely, by employing the hard plate 2 in which the bending resistance in the area
of the front foot part is smaller than that in the area from the intermediate foot
part to the heel part, flexibility of the shoe 10 can be suitably secured even if
the hard plate 2 is attached to the entire shoe body 1 in the length direction. Further,
by attaching the hard plate 2 to the entire shoe body 1 in the length direction, the
shoe 10 having stable comfort to wear can be produced.
[0035] In Embodiment 2, the cushion material 3 is attached to the toe part of the shoe body
1 (the part not covered with the hard plate 2), but the cushion material 3 attached
to the toe part of the shoe body 1 may be omitted. With this structure, the weight
of the shoe 10 can be further reduced. On the other hand, the cushion material 3 may
be attached to cover the entire ground contact side of the hard plate 2. With this
structure, stability of the shoe 10 can be improved and the hard plate 2 can be protected
when running or walking on an uneven ground.
[0036] Further, the structures of Embodiments 1-3 may be selectively combined or applied
to other examples.
1. A shoe comprising:
a shoe body into which a foot is inserted;
a hard plate covering a necessary area on a bottom side of the shoe body in a length
direction and being fixed to the bottom side of the shoe body only at a necessary
location including a position of a front foot part; and
cushion materials being attached to at least both end parts of a ground contact side
of the hard plate in the length direction.
2. The shoe according to claim 1, wherein the necessary area is the entire shoe body
in the length direction.
3. The shoe according to claim 1, wherein the necessary area is an area from the front
foot part to a heel part except a toe part.
4. The shoe according to claim 3, wherein the cushion material is attached to a position
on the bottom side of the shoe body which corresponds to the toe part.
5. The shoe according to any one of claims 1-4, wherein the hard plate is curved and
projected, at a position corresponding to the front foot part, toward a ground.
6. The shoe according to any one of claims 1-5, wherein a sectional shape of the hard
plate in a width direction is formed into a corrugated shape.
7. The shoe according to any one of claims 1-6, wherein a bending resistance of a part
of the hard plate corresponding to the area of the front foot part is smaller than
that of another part corresponding to an area from an intermediate foot part to the
heel part.
8. The shoe according to any one of claims 1-7, wherein the hard plate and the cushion
material are backwardly projected from the shoe body.