U.S. patent application number 15/760515 was filed with the patent office on 2018-09-13 for shoes.
The applicant listed for this patent is Mizuno Corporation. Invention is credited to Kazunori Iuchi, Shogo Matsui, Takeshi Naruo, Takao Oda, Hideya Okamoto.
Application Number | 20180255870 15/760515 |
Document ID | / |
Family ID | 58423098 |
Filed Date | 2018-09-13 |
United States Patent
Application |
20180255870 |
Kind Code |
A1 |
Oda; Takao ; et al. |
September 13, 2018 |
Shoes
Abstract
A shoe is configured such that front and back clearances, which
are respectively provided between a front wall surface of a second
receiving portion and a front end of a second buffering member
received in the second receiving portion and between a back wall
surface of the second receiving portion and a back end of the
second buffering member received in the second receiving portion,
permit the second buffering member made of an elastic material to
move in a longitudinal direction in the second receiving portion
when a ground surface of an outsole contacts the ground and the
weight of a human body is put on a heel support surface.
Inventors: |
Oda; Takao; (Osaka, JP)
; Naruo; Takeshi; (Osaka, JP) ; Iuchi;
Kazunori; (Osaka, JP) ; Okamoto; Hideya;
(Osaka, JP) ; Matsui; Shogo; (Osaka, JP) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Mizuno Corporation |
Osaka |
|
JP |
|
|
Family ID: |
58423098 |
Appl. No.: |
15/760515 |
Filed: |
October 3, 2016 |
PCT Filed: |
October 3, 2016 |
PCT NO: |
PCT/JP2016/004442 |
371 Date: |
March 15, 2018 |
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
A43B 13/188 20130101;
A43B 13/141 20130101; A43B 7/1405 20130101; A43B 7/1415 20130101;
A43B 13/125 20130101; A43B 13/40 20130101; A43B 13/04 20130101;
A43B 7/148 20130101 |
International
Class: |
A43B 13/14 20060101
A43B013/14; A43B 13/40 20060101 A43B013/40; A43B 13/12 20060101
A43B013/12 |
Foreign Application Data
Date |
Code |
Application Number |
Oct 1, 2015 |
JP |
2015-195815 |
Claims
1. A shoe comprising: a midsole arranged above an outsole having a
ground surface configured to contact a ground, and configured to
support a planta of a human body, the midsole including a
longitudinally-extending midsole body which is made of an elastic
material and has, on an upper surface, a planta support surface
configured to support a plantar surface of a foot of the human body
from the tiptoe to the back of the heel, a receiving portion which
is provided in a back region in the planta support surface of the
midsole body and which is a recess recessed toward the outsole, and
a buffering member which is received in the receiving portion in an
unfixed manner, includes, on an upper surface, a heel support
surface configured to support the heel support surface of the foot
of the human body, and is configured to absorb an impact applied in
a vertical direction to the heel support surface, wherein a front
clearance is provided between a front wall surface facing an inside
of the receiving portion and a front end of the buffering body
received in the receiving portion, and a back clearance is provided
between a back wall surface facing the inside of the receiving
portion and a back end of the buffering body received in the
receiving portion.
2. The shoe of claim 1, wherein each of the front and back
clearances ranges from 0.5 mm to 5.0 mm.
3. The shoe of claim 1, wherein the buffering member has a width,
in a width direction, which is substantially equal to a distance
between left and right wall surfaces facing the inside of the
receiving portion.
4. The shoe of claim 1, wherein a left clearance is provided
between a left wall surface facing the inside of the receiving
portion and a left end of the buffering body received in the
receiving portion, and a right clearance is provided between a
right wall surface facing the inside of the receiving portion and a
right end of the buffering body received in the receiving portion,
and the left and right clearances permit the buffering member to
move relatively in a width direction within the receiving portion
when the ground surface of the outsole contacts the ground and a
weight of the human body is put on the heel support surface.
5. The shoe of claim 4, wherein each of the left and right
clearances ranges from 0.5 mm to 5.0 mm.
6. The shoe of claim 1, wherein the buffering body has a stack
structure in which a plurality of thin plates each made of an
elastic material are stacked one above the other, and the thin
plates are movable independently and relatively within the
receiving portion.
7. The shoe of claim 1, wherein the buffering member is made of the
same material as that forming the midsole body.
8. The shoe of claim 1, wherein the buffering body is made of an
elastic material which has a lower specific gravity or lower
hardness than the midsole body.
Description
BACKGROUND
[0001] The present invention relates to a shoe. Shoes have been
known which are configured to absorb or cushion an impact applied
in vertical direction when the wearer of the shoes steps on the
ground during his/her running or walking. Specifically, such a shoe
includes a midsole structure for absorbing and cushioning an impact
applied in the vertical direction when the weight of a human body
is put on the planta support surface of the shoe, in particular, to
the heel support surface which supports the heel of a foot.
[0002] For example, Patent Document 1 discloses a shoe including a
sole comprised of an outer sole of a synthetic resin and a midsole
of a soft elastic member bonded to the upper surface of the outer
sole. The midsole has a recess formed in a portion, of its upper
surface, corresponding to the wearer's heel. A cushioning member
which is softer than the midsole is received in the recess without
leaving any gap between the cushioning member and the recess.
[0003] Patent Document 2 discloses a sport shoe including a shoe
body and a shoe sole. A receiving recess having a predetermined
depth is formed in the bottom surface of the shoe sole. A buffering
element is received in the receiving recess. In plan view, the
receiving recess has a shape similar to that of the buffering
element. The receiving recess has a deformation allowance space for
allowing the buffering element to become deformed freely in the
radial direction when the buffering element bulges in the radial
direction due to a vertical load applied thereonto.
CITATION LIST
Patent Documents
[0004] Patent Document 1: Japanese Unexamined Patent Publication
No. 2008-18167
[0005] Patent Document 2: Japanese Unexamined Patent Publication
No. H08-38211
SUMMARY
Technical Problem
[0006] Meanwhile, in general, main functions required for shoes
such as running shoes and walking shoes include, for example,
impact cushioning ability, heel stabilizing ability, fitting
ability, gripping ability, and torsional rigidity. Various
improvements have been made to enhance these functions. Among them,
enhancement of the impact cushioning ability has been needed to
provide shoes which can improve the wearer's performance. It has
been found that when a wearer of shoes steps on the ground during
his/her walking and running, a planta support surface (in
particular, a heel support surface) provided at a midsole is
subjected to not only an impact applied in a vertical direction,
but also impacts applied in non-vertical directions (e.g., in the
longitudinal and width directions of the shoes). This means that in
order to give sufficiently enhanced comfortable feeling to wearer's
feet when he/she steps on the ground, and to allow the wearer to
walk and run with sufficiently increased comfort, it is important
to appropriately absorb and cushion not only an impact applied in
the vertical direction to a heel support surface, but also impacts
applied in non-vertical directions to the heel support surface.
[0007] However, in the shoes of Patent Documents 1 and 2, although
the buffering member having cushioning ability absorbs only an
impact applied in the vertical direction to the heel support
surface, the buffering member is immovably received in the
receiving recess without any gap, and consequently, is not capable
of cushioning impacts applied in non-vertical directions. In other
words, the midsole structures of the shoes of Patent Documents 1
and 2 have insufficient impact cushioning ability, and thus, allow
the wearer to step on the ground, run and walk with
insufficiently-increased comfort.
[0008] In view of the foregoing background, it is therefore an
object of the present invention to achieve improvement of a midsole
structure so as to enable a wearer to step on the ground, walk and
run with increased comfort.
Solution to the Problem
[0009] To achieve the object, with attention to the fact that when
the weight of a human body is put on the heel support surface of a
shoe, strong impacts are applied not only in the vertical direction
but also in a non-vertical direction, the present invention is
configured to permit a buffering member to relatively move within a
receiving portion when a ground surface of an outsole contacts the
ground.
[0010] Specifically, a first aspect relates to a shoe including a
midsole which is arranged above an outsole having a ground surface
configured to contact the ground, and which is configured to
support a planta of a human body. The midsole include a
longitudinally-extending midsole body which is made of an elastic
material and has, on an upper surface, a planta support surface
configured to support a plantar surface of the foot of the human
body from the tiptoe to the back of the heel, a receiving portion
which is provided in a back region in the planta support surface of
the midsole body and which is a recess recessed toward the outsole,
and a buffering member which is received in the receiving portion
in an unfixed manner, includes, on an upper surface, a heel support
surface configured to support the heel of the foot of the human
body, and is configured to absorb an impact applied in a vertical
direction to the heel support surface. A front clearance is
provided between a front wall surface facing an inside of the
receiving portion and a front end of the buffering body received in
the receiving portion, and a back clearance is provided between a
back wall surface facing the inside of the receiving portion and a
back end of the buffering body received in the receiving
portion.
[0011] The first aspect has a configuration in which the front
clearance provided between the front wall surface of the receiving
portion and the front end of the buffering body received in the
receiving portion and the back clearance provided between the back
wall surface of the receiving portion and the back end of the
buffering body received in the receiving portion permit the
buffering body to relatively move in the longitudinal direction of
the shoe when the ground surface of the outsole contacts the ground
and the human body weight is put on the heel support surface. As a
result, an impact applied in the vertical direction to the heel
support surface is absorbed by the buffering member having
cushioning ability, and in addition, an impact applied in the
longitudinal direction to the heel support surface is relieved in
the midsole by the movement of the buffering member in the
longitudinal direction within the receiving portion. That is, the
buffering member having cushioning ability and movability cushions
the impacts which are applied in the vertical and longitudinal
directions to the heel support surface when the ground surface of
the outsole contacts the ground. As a result, the foot of a wearer
of the shoes of the first aspect can be given sufficiently enhanced
comfortable feeling when he/she steps on the ground during his/her
walking and running, and the wearer can run and walk with
sufficiently increased comfort.
[0012] A second aspect of the present invention is an embodiment of
the first aspect. According to the second aspect, each of the front
and back clearances ranges from 0.5 mm to 5.0 mm.
[0013] Further, according to the second aspect, the buffering
member is not allowed to relatively move in the longitudinal
direction more than necessary. Consequently, the wearer of the
shoes of the second aspect can be given sufficiently enhanced
comfortable feeling when he/she steps on the ground during his/her
walking and running, and can run and walk with sufficiently
increased comfort.
[0014] A third aspect is an embodiment of the first or second
aspect. In the third aspect, the buffering member has a width, in a
width direction, which is substantially equal to a distance between
left and right wall surfaces facing the inside of the receiving
portion.
[0015] According to the third aspect, the buffering member is
received in the receiving portion without leaving any gap between
the left wall surface of the receiving portion and the left end of
the second buffering member and between the right wall surface of
the receiving portion and the right end of the buffering member.
Consequently, the buffering member is permitted to move in the
longitudinal direction within the receiving portion. In other
words, the buffering member is restrained so as to resist relative
movement in the width direction within the receiving portion. This
makes it possible to relieve, with in the midsole, an impact
applied in the longitudinal direction to the heel support surface.
As a result, a wearer of the shoes of the third aspect can be given
further enhanced comfortable feeling when he/she steps on the
ground during his/her walking and running, and can run and walk
with further increased comfort.
[0016] A fourth aspect is an embodiment of the first or second
aspect. In the fourth aspect, a left clearance is provided between
a left wall surface facing the inside of the receiving portion and
a left end of the buffering body received in the receiving portion,
and a right clearance is provided between a right wall surface
facing the inside of the receiving portion and a right end of the
buffering body received in the receiving portion, and the left and
right clearances enable the buffering member to move relatively in
a width direction in the receiving portion when the ground surface
of the outsole contacts the ground and a weight of the human body
is put on the heel support surface.
[0017] The fourth aspect has a configuration in which the left
clearance provided between the left wall surface of the receiving
portion and the left end of the buffering body received in the
receiving portion and the right clearance provided between the
right wall surface of the receiving portion and the right end of
the buffering body received in the receiving portion permit the
buffering body made of the elastic material to relatively move also
in the width direction when the ground surface of the outsole
contacts the ground and the human body weight is put on the heel
support surface. As a result, an impact applied in the vertical
direction to the heel support surface is absorbed by the buffering
member having cushioning ability, and in addition, an impacts
applied in the longitudinal and width direction to the heel support
surface is relieved in the midsole by the movement of the buffering
member in the width direction within the receiving portion. That
is, impacts that are applied in the vertical, longitudinal, and
width directions to the heel support surface when the ground
surface of the outsole contacts the ground are cushioned by the
buffering member having cushioning ability and movability and
permitted to move within the receiving portion toward the four wall
surfaces of the receiving portion. As a result, a wearer of the
shoes of the fourth aspect can be given further enhanced
comfortable feeling when he/she steps on the ground during his/her
walking and running, and can run and walk with further increased
comfort.
[0018] A fifth aspect of the present invention is an embodiment of
the fourth aspect. According to the fourth aspect, each of the left
and right clearances ranges from 0.5 mm to 5.0 mm.
[0019] According to the fifth aspect, the buffering member is not
allowed to relatively move in the width direction more than
necessary. Consequently, the wearer of the shoes of the fifth
aspect can be given sufficiently enhanced comfortable feeling when
he/she steps on the ground during his/her walking and running, and
can run and walk with sufficiently increased comfort.
[0020] A sixth aspect is an embodiment of any one of the first to
fifth aspects. In the sixth aspect, the buffering body has a stack
structure in which a plurality of thin plates each made of an
elastic material are stacked one above the other, and the thin
plates are movable independently and relatively within the
receiving portion.
[0021] According to the sixth aspect, since the buffering member
has the stack structure comprised of the thin plates each made of
an elastic material, relative movement of the thin plates causes a
relative increase in the movement of the buffering member within
the receiving portion. This contributes to further improvement of
the cushioning ability for an impact applied to the heel support
surface.
[0022] A seventh aspect is an embodiment of any one of the first to
sixth aspects. In the sixth aspect, the buffering member is made of
the same material as that forming the midsole body.
[0023] According to the seventh aspect, the buffering member has a
cushioning capability equivalent to that of the midsole body. This
configuration allows the entire midsole to evenly absorb impacts
applied in the vertical direction to the planta support surface and
the heel support surface, and enables a wearer to walk and run with
increased comfort without making the wearer feel
unpleasantness.
[0024] An eighth aspect is an embodiment of any one of the first to
sixth aspect. In the eighth aspect, the buffering body is made of
an elastic material which has a lower specific gravity or lower
hardness than the midsole body.
[0025] According to the eighth aspect, the buffering member that
has a greater cushioning ability than the midsole body can more
concentratedly absorb an impact applied in the vertical direction
to the planta support surface, in particular to the heel support
surface.
Advantages of the Invention
[0026] As can be seen from the foregoing, according to the present
invention, the buffering member provided with cushioning ability
and movability increases the impact cushioning ability of the
shoes. The wearer of the shoes of the present invention can be
given further enhanced comfortable feeling when he/she steps on the
ground during his/her walking and running, and can run and walk
with further increased comfort.
BRIEF DESCRIPTION OF THE DRAWINGS
[0027] FIG. 1 is a plan view of a sole structure of a shoe
according to a first embodiment of the present invention.
[0028] FIG. 2 corresponds to FIG. 1, and shows a sole structure of
a shoe and a skeleton of a human foot in an overlapping
fashion.
[0029] FIG. 3 is a cross-sectional view taken along line in FIG.
1.
[0030] FIG. 4 is a cross-sectional view taken along line IV-IV in
FIG. 1.
[0031] FIG. 5 corresponds to FIG. 1, and shows a sole structure of
a shoe according to a second embodiment.
[0032] FIG. 6 corresponds to FIG. 4, and shows the sole structure
of the shoe according to the second embodiment.
[0033] FIG. 7 corresponds to FIG. 4, and shows a variation of the
second embodiment.
[0034] FIG. 8 corresponds to FIG. 4, and shows another variation of
the second embodiment.
[0035] FIG. 9 corresponds to FIG. 3, and shows a sole structure of
a shoe according to another embodiment.
[0036] FIG. 10 corresponds to FIG. 4, and shows a sole structure of
a shoe according to another embodiment.
[0037] FIG. 11 is a graph showing relation between time and
acceleration waveforms in the longitudinal direction in Example
1.
[0038] FIG. 12 is a graph showing accelerations in the longitudinal
direction in Example 2 and samples.
DESCRIPTION OF EMBODIMENTS
First Embodiment
[0039] A first embodiment of the present invention will now be
described in detail with reference to the drawings. Note that the
following description of the embodiments is a mere example in
nature, and is not intended to limit the scope, application, or
uses of the present invention.
[0040] FIGS. 1 to 4 show a shoe S according to a first embodiment
of the present invention. In the drawings, only the left shoe of a
pair of shoes S is shown as an example. Since the right shoe is
symmetrical to the left shoe S, only the left shoe S will be
described in the following description, and the description of the
right shoe will be omitted herein. In the following description,
the expressions "above," "upward," "on a/the top of," "below,"
"under," and "downward," represent the vertical positional
relationship between respective parts of the shoe S, and "front,"
"fore," "back," and "hind" represent the longitudinal positional
relationship between respective parts of the shoe S.
[0041] As shown in FIGS. 1 to 4, the shoe S includes an outsole 1
which includes ground surface 2 configured to contact the ground.
The outsole 1 is made from a hard elastic material which is harder
than a midsole body 4, which will be described later. Examples of
suitable materials for the outsole 1 include thermoplastic resins
such as ethylene-vinyl acetate copolymer (EVA), thermosetting
resins such as polyurethane (PU), and rubber materials such as
butadiene rubber and chloroprene rubber. The outsole 1 is designed
to have a thickness within the range, for example, from 2 mm to 7
mm. A more preferable proper range of the thickness is from 3 mm to
5 mm. Note that for the sake of convenience, hatching of the
outsole 1 is omitted from the cross sections shown in FIGS. 3 and
4.
[0042] A midsole 3 configured to support a planta of a human body
is provided above the outsole 1. A lower portion of the midsole 3
is bonded to an upper portion of the outsole 1 with an adhesive,
for example. An upper (not shown) configured to cover a foot of a
wearer is provided above the midsole 3.
[0043] The midsole 3 includes a midsole body 4 configured to
support a plantar surface of the wearer. As shown in FIGS. 1 and 2,
the midsole body 4 has, on its upper surface, a planta support
surface 5 which is configured to support the plantar surface of a
human body from the tiptoe to the back of the heel, and which
extends in the longitudinal direction of the shoe. The midsole body
4 is made of a soft elastic material. Examples of suitable
materials for the midsole body 4 include thermoplastic synthetic
resins such as ethylene-vinyl acetate copolymer (EVA) and foams of
the thermoplastic synthetic resins, thermosetting resins such as
polyurethane (PU) and foams of the thermosetting resins, and rubber
materials such as butadiene rubber and chloroprene rubber and foams
of the rubber materials. The midsole body 4 is designed to have a
hardness ranging from 30 C to 80 C (more preferably ranging from 45
C to 70 C, and specifically of 55 C) on the Asker C scale. The
midsole body 4 is also designed to have a thickness of, for
example, about 12 mm at a substantially middle portion in the
longitudinal direction.
[0044] As shown in FIGS. 1 and 2, a first receiving portion 6 and a
second receiving portion 7 are respectively formed in a front
region and a back region in the planta support surface 5 of the
midsole body 4. The first and second receiving portions 6, 7 are
configured to receive a first buffering member 8 and a second
buffering member 10, respectively, which will be described later.
As shown in FIG. 3, each of the first and second receiving portions
6 and 7 is a recess which is formed in the planta support surface 5
of the midsole body 4 and recessed downward toward the outsole
1.
[0045] The first receiving portion 6 is formed at a location
corresponding to a tread portion of a human foot (i.e., a front
portion of a foot). Specifically, as shown in FIG. 2, the first
receiving portion 6 is formed at a location corresponding to a
region around the boundary between the foot phalanx part F and the
metatarsal part M of the foot of the wearer wearing the shoe S.
[0046] As shown in FIGS. 1 and 2, a front wall surface 6a and a
back wall surface 6b facing the inside of the first receiving
portion 6 both extend linearly in the substantially width direction
of the shoe. A left wall surface 6c facing the inside of the first
receiving portion 6 (i.e., the wall surface close to the lateral
side of the left foot shown in FIG. 2) extends along a curved
portion of an outer edge 4a of the midsole body 4 which is adjacent
to the left wall surface 6c. A right wall surface 6d facing the
inside of the first receiving portion 6 (i.e., the wall surface
close to the medial side of the left foot shown in FIG. 2) extends
along a curved portion of an inner edge 4b of the midsole body 4
which is adjacent to the right wall surface 6d.
[0047] The second receiving portion 7 is formed at a location
corresponding to the heel of a foot of a human body, (i.e., a back
portion of a foot). Specifically, as shown in FIG. 2, the second
receiving portion 7 is formed in a region which is in contact
mainly with the heel bone H of the foot of the wearer wearing the
shoe S.
[0048] As shown in FIGS. 1 and 2, a front wall surface 7a facing
the inside of the second receiving portion 7 extends linearly in
the substantially width direction, while a back wall surface 7b
facing the inside of the second receiving portion 7 extends along a
curved portion of a back edge 4c of the midsole body 4 which is
adjacent to the back wall surface 7b. A left wall surface 7c facing
the inside of the second receiving portion 7 (i.e., the wall
surface close to the lateral side of the left foot shown in FIG. 2)
extends linearly along the outer edge 4a of the midsole body 4
which is adjacent to the left wall surface 7c. On the other hand, a
right wall surface 7d (i.e., the wall surface close to the medial
side of the left foot shown in FIG. 2) extends along a curved
portion of the inner edge 4b of the midsole body 4 which is
adjacent to the right wall surface 7d.
[0049] As shown in FIGS. 3 and 4, each of the front and back wall
surfaces 7a, 7b and the left and right wall surfaces 7c and 7d is
flat in the vertical direction, so that the second receiving
portion 7 has a cross-sectional structure in which its opening
portion (upper portion) and bottom portion (lower portion) have the
same shape. The second receiving portion 7 has a bottom 7e at a
depth corresponding to a third or a half of the thickness of a back
portion of the midsole body 4.
[0050] [As shown in FIGS. 1 and 2, the first receiving portion 6
receives therein the first buffering member 8 that is configured to
support the treading portion of a human foot. The first buffering
member 8 has, on its upper surface, a tread portion support surface
9 configured to support the tread portion of a human foot. The
first buffering member 8 is made of an elastic material capable of
absorbing an impact applied in the vertical direction to the tread
portion step support surface 9. The shape formed by the outer
peripheral surface of the first buffering member 8 corresponds to
the shape formed by the inner peripheral surface of the first
receiving portion 6. As a result, the first buffering member 8 is
received in the first receiving portion 6 without any gap
therebetween. In addition, the first buffering member 8 is
received, without being fixed to the wall surfaces 6a to 6d and the
bottom 6e of the first receiving portion 6, i.e., in an unfixed
manner. The first buffering member 8 is preferably made of the same
material as the material for thin plates 11, 11 forming the second
buffering member 10. The thin plates 11, 11 will be described
later.
[0051] As shown in FIGS. 1 and 2, the second receiving portion 7
receives therein the second buffering member 10 that is configured
to support the heel of a foot (i.e., a portion including the heel
bone H shown in FIG. 2). As shown in FIGS. 3 and 4, the second
buffering member 10 has a stack structure comprised of the two thin
plates 11, 11 made of an elastic material and stacked one above the
other. A heel support surface 12 configured to support the heel of
a human foot is formed on the upper surface of the upper thin plate
11. The thin plates 11, 11 forming the second buffering member 10
are made of the same material as that forming the midsole body
4.
[0052] As shown in FIG. 4, the heel support surface 12 is
downwardly recessed and curved to cover the heel of the human foot.
The heel support surface 12 has left and right ends which smoothly
continue to the planta support surface 5 of the midsole body 4,
except the second receiving portion 7. In other words, the second
buffering member 10 is configured to absorb an impact which is
applied in the vertical direction to the heel support surface 12
when the ground surface 2 of the outsole 1 contacts the ground and
the weight of a human body is put on the heel support surface 12.
In addition, just like the first buffering member 8, the second
buffering member 10 is received, without being fixed to the wall
surfaces 7a to 7d and the bottom 7e of the second receiving portion
7, i.e., in an unfixed manner.
[0053] As shown in FIG. 1, the present invention a feature in which
the front end 10a of the second buffering member 10 extends
linearly, in the width direction of the shoe, along the linear
front wall surface 7a of the second receiving portion 7 with a
predetermined clearance interposed between the front end 10a and
the front wall surface 7a of the second receiving portion 7. On the
other hand, the back end 10b of the second buffering member 10 is
curved along the curved back wall surface 7b of the second
receiving portion 7 with a predetermined clearance interposed
between the back end 10b and the back wall surface 7b of the second
receiving portion 7. In other words, in a state where the second
receiving portion 7 has the second buffering member 10 received
therein, the front clearance 21 is provided between the front wall
surface 7a facing the inside of the second receiving portion 7 and
the front end 10a of the second buffering member 10, and the back
clearance 22 is provided between the back wall surface 7b facing
the inside of the second receiving portion 7 and the back end 10b
of the second buffering member 10. Each of the front and back
clearances 21, 22 is preferably within the range from 0.5 mm to 5.0
mm, and more preferably is about 2.0 mm.
[0054] The front and back clearances 21, 22 enable the second
buffering member 10 to move relatively in the longitudinal
direction within the second receiving portion 7 when the ground
surface 2 of the outsole 1 contacts the ground and the weight of a
human body is put on the heel support surface 12. The thin plates
11, 11 forming the second buffering member 10 are unfixed to each
other and can move independently and relatively in the longitudinal
direction within the second receiving portion 7. To make the thin
plates 11, 11 further movable with respect to each other, portions
of the thin plates 11, 11 which are in contact with each other may
be provided with a surface treatment (e.g., a treatment to attach a
film), a treatment to apply lubricant, or a treatment to add powder
such as baby powder.
[0055] As shown in FIG. 1, the left end 10c of the second buffering
member 10 extends linearly along the left wall surface 7c facing
the inside of the second receiving portion 7, while the right end
10d of the second buffering member 10 is curved along the right
wall surface 7d facing the inside of the second receiving portion
7. The second buffering member 10 has a width, in the width
direction, which is equal to the distance between the left and
right wall surfaces 7c, 7d of the second receiving portion 7. In
other words, in a state where the second receiving portion 7 has
the second buffering member 10 received therein, no clearance is
provided between the left wall surface 7c of the second receiving
portion 7 and the left end 10c of the second buffering member 10,
and between the right wall surface 7d of the second receiving
portion 7 and the right end 10d of the second buffering member 10.
As a result, while being permitted to move relatively in the
longitudinal direction within the second receiving portion 7, the
second buffering member 10 is restrained so as to resist relative
movement in the width direction within the second receiving portion
7.
[0056] As can be seen from the foregoing, the shoe S of the first
embodiment has the front and back clearances 21, 22 respectively
provided between the front wall surface 7a of the second receiving
portion 7 and the front end 10a of the second buffering member 10
received in the second receiving portion 7 and between the back
wall surface 7b of the second receiving portion 7 and the back end
10b of the second buffering member 10 received in the second
receiving portion 7. The front and back clearances 21, 22 permit
the second buffering member 10 made of an elastic material to move
relatively in the longitudinal direction within the second
receiving portion 7 when the ground surface 2 of the outsole 1
contacts the ground and weight of a human body is put on the heel
support surface 12. As a result, an impact applied in the vertical
direction to the heel support surface 12 is absorbed by the second
buffering member 10 having cushioning ability, and in addition, an
impact applied in the longitudinal direction to the heel support
surface 12 is relieved in the midsole 3 by the movement of the
second buffering member 10 in the longitudinal direction within the
second receiving portion 7. That is, the second buffering member 10
having cushioning ability and movability cushions the impacts which
are applied in the vertical and longitudinal directions to the heel
support surface 12 when the ground surface 2 of the outsole 1
contacts the ground. As a result, a wearer of the shoes S can be
given enhanced comfortable feeling when he/she steps on the ground
during his/her walking and running, and can run and walk with
sufficiently increased comfort.
[0057] Further, since each of the front and back clearances 21, 22
is within the range from 0.5 mm to 5.0 mm, the second buffering
member 10 is not allowed to move more than necessary in the
longitudinal direction. Consequently, the wearer of shoes S can be
given enhanced comfortable feeling when he/she steps on the ground
during his/her walking and running, and can run and walk with
sufficiently increased comfort.
[0058] Furthermore, since the width in the width direction of the
second buffering member 10 is substantially equal to the distance
between the left and right wall surfaces 7c, 7d of the second
receiving portion 7, the second buffering member 10 is received in
the second receiving portion 7 without leaving any gap between the
left wall surface 7c of the second receiving portion 7 and the left
end 10c of the second buffering member 10, and between the right
wall surface 7d of the second receiving portion 7 and the right end
10d of the second buffering member 10. Consequently, the second
buffering member 10 is permitted to move in the longitudinal
direction within the second receiving portion 7. Thus, the second
buffering member 10 is restrained so as to resist relative movement
in the width direction within the second receiving portion 7. This
makes it possible to concentratedly reduce an impact applied in the
longitudinal direction to the heel support surface 12. As a result,
a wearer of the shoes S can be given further enhanced comfortable
feeling when he/she steps on the ground during his/her walking and
running, and can run and walk with further increased comfort.
[0059] The second buffering member 10 has a stack structure in
which two or more thin plates 11, 11 each made of an elastic
material are stacked one above the other and in which the thin
plates 11, 11 can move independently and relatively in the
longitudinal direction within the second receiving portion 7.
Therefore, the relative movement of the thin plates 11, 11 in the
longitudinal direction causes a relative increase in the movement
of the second buffering member 10 in the longitudinal direction
within the second receiving portion 7. This contributes to further
improvement of the cushioning ability for an impact applied in the
longitudinal direction to the heel support surface 12.
[0060] In addition, since the second buffering member 10 and the
midsole body 4 are made of the same material, the second buffering
member 10 has a cushioning ability equivalent to that of the
midsole body 4. This configuration allows the entire midsole to
evenly absorb an impact applied in the vertical direction to the
planta support surface 5 and the heel support surface 12, and
enables a wearer to walk and run with increased comfort without
making the wearer feel unpleasantness.
Second Embodiment
[0061] FIGS. 5 and 6 show a shoe S according to a second embodiment
of the present invention. This embodiment differs from the first
embodiment in that the second buffering member 10 of this
embodiment can move also in the width direction of the shoe with in
the second receiving portion 7. Note that except the second
receiving portion 10, the components and configurations of the shoe
S of this embodiment are the same as those of the shoe S of the
first embodiment. Therefore, components that are the same as those
shown in FIGS. 1 to 4 are denoted by the corresponding reference
characters, and a detailed description thereof is omitted
herein.
[0062] Specifically, as shown in FIGS. 5 and 6, the left end 10c of
the second buffering member 10 linearly extends along the linear
left wall surface 7c facing the inside of the second receiving
portion 7 with a predetermined clearance interposed between the
left end 10c and the left wall surface 7c of the second receiving
portion 7. On the other hand, the right end 10d of the second
buffering member 10 is curved along the curved right wall surface
7d facing the inside of the second receiving portion 7 with a
predetermined clearance interposed between the right end 10d and
the right wall surface 7d of the second receiving portion 7. In a
state where the second receiving portion 7 has the second buffering
member 10 received therein, the left clearance 23 is provided
between the left wall surface 7c facing the inside of the second
receiving portion 7 and the left end 10c of the second buffering
member 10, and the right clearance 24 is provided between the right
wall surface 7b facing the inside of the second receiving portion 7
and the right end 10d of the second buffering member 10. That is,
in the second receiving portion 7, the clearances 21 to 24 are
provided between the second buffering member 10 and the all wall
surfaces of the second receiving portion 7 including the front,
back, left, and side walls. Each of the left and right clearances
23, 24 is preferably within the range from 0.5 mm to 5.0 mm, and
more preferably is about 2.0 mm.
[0063] The left and right clearances 23, 24 enable the second
buffering member 10 to move relatively in the width direction
within the second receiving portion 7 when the ground surface 2 of
the outsole 1 contacts the ground and the weight of a human body is
put on the heel support surface 12. The thin plates 11, 11 forming
the second buffering member 10 are unfixed to each other and can
move independently and relatively in the width direction within the
second receiving portion 7.
[0064] As can be seen from the foregoing, the shoe S of the second
embodiment has the left and right clearances 23, 24 respectively
provided between the left wall surface 7c of the second receiving
portion 7 and the left end 10c of the second buffering member 10
received in the second receiving portion 7 and between the right
wall surface 7d of the second receiving portion 7 and the right end
10d of the second buffering member 10 received in the second
receiving portion 7. The left and right clearances 23, 24 permit
the second buffering member 10 made of an elastic material to move
relatively also in the width direction within the second receiving
portion 7 when the ground surface 2 of the outsole 1 contacts the
ground and the weight of a human body is put on the heel support
surface 12. As a result, an impact applied in the vertical
direction to the heel support surface 12 is absorbed by the second
buffering member 10 having cushioning ability, and in addition,
impacts applied to the heel support surface 12 in the longitudinal
and width directions of the shoe are relieved in the midsole 3 by
the movements of the second buffering member 10 in the longitudinal
and width directions within the second receiving portion 7. That
is, when the ground surface 2 of the outsole 1 contacts the ground,
impacts applied in the vertical direction and the longitudinal and
width directions to the heel support surface 12 are cushioned by
the second buffering member 10 that has cushioning ability and
movability toward the four wall surfaces 7a to 7d surrounding the
second receiving portion 10. As a result, a wearer of the shoes S
can be given further enhanced comfortable feeling when he/she steps
on the ground during his/her walking and running, and can run and
walk with further increased comfort.
[0065] Moreover, since each of the left and right clearances 23, 24
is within the range from 0.5 mm to 5.0 mm, the second buffering
member 10 is not allowed to move more than necessary in the width
direction. Consequently, a wearer of the shoes S can be given
sufficiently enhanced comfortable feeling when he/she steps on the
ground during his/her walking and running, and can run and walk
with sufficiently increased comfort.
[0066] Furthermore, the second buffering member 10 has a stack
structure in which two thin plates 11, 11 each made of an elastic
material are stacked one above the other. The thin plates 11, 11
can move independently in the width direction within the second
receiving portion 7. Therefore, the relative movement of the thin
plates 11, 11 in the width direction causes a relative increase in
the movement of the second buffering member 10 in the width
direction within the second receiving portion 7. This contributes
to further improvement of the cushioning ability for an impact
applied in the width direction to the heel support surface 12.
Variation of Second Embodiment
[0067] In this embodiment, the second receiving portion 7 provided
in the midsole 3 of the shoe S has the flat wall surfaces so as to
have a cross-sectional structure in which its opening portion
(upper portion) and bottom portion (lower portion) have the same
shape. However, this is a mere example.
[0068] For example, as shown in FIG. 7, each of the left and right
wall surfaces 7c and 7d facing inside of the second receiving
portion 7 may have a step such that its cross section is stepped in
the vertical direction. In this case, it is suitable that the lower
portions of the left and right wall surfaces 7c, 7d are less
distant in the width direction from each other than the upper
portions of the left and right wall surfaces 7c, 7d, and that the
lower thin plate 11 forming part of the second buffering member 10
is narrower in the width direction than the upper thin plate 11. In
this variation, the thin plates 11, 11 placed one above the other
can move independently in the width direction within the second
receiving portion 7.
[0069] Alternatively, as shown in FIG. 8, the second receiving
portion 7 may have a V-shaped cross section. Specifically, the
distance in the width direction between left and right portions of
the bottom 7e (the left and right side walls 7c, 7d) may decrease
downwardly. In this case, it is suitable that the second buffering
member 10 includes the lower thin place 11 which is bended to have
a V-shaped cross section and the upper thin plate 11 having a
cross-section in a substantially inverted triangle shape. Also in
this variation, the thin plates 11, 11 placed one above the other
can move relatively and independently in the width direction within
the second receiving portion 7.
[0070] Specifically, in each of the variations shown in FIGS. 7 and
8, the second receiving portion 7 is formed to have a width in the
width direction decreasing downward. This configuration easily
concentrates an impact applied in the vertical direction to the
heel support surface 12 to a central portion of the second
buffering member 10, and contributes to an increase in the impact
absorbability of the second buffering member 10. In each of the
variations, the thin plates 11, 11 placed one above the other can
move independently in the width direction within the second
receiving portion 7. As described previously, this configuration
causes a relative increase in the movement of the second buffering
member 10 in the width direction within the second receiving
portion 7, and consequently, contributes to improvement of the
cushioning ability for an impact applied in the width direction to
the heel support surface 12.
[0071] Moreover, in the variation shown in FIG. 8, the second
buffering member 10 having a cross section in a substantially
inverted triangle shape is fitted in the second receiving portion 7
having a V-shaped cross section. This configuration limits relative
movement in the width direction, as compared to the configuration
of the variation shown in FIG. 7, while facilitating relative
movement in the longitudinal direction. Even if an impact applied
in the width direction to the heel support surface 12 causes
relative movement of the thin plates 11, 11 in the width direction,
the central portion of the lower thin plate 11 (i.e., a vertex of
the inverted triangle) is easily returned to the central portion in
the width direction of the second receiving portion 7 (i.e., the
valley of the bottom 7e shown in FIG. 8), and the central portion
of the upper thin plate 11 (i.e., a vertex of the inverted
triangle) is easily returned to the valley on the upper surface of
the lower thin plate 11. As can be seen, in the variation shown in
FIG. 8, the second buffering member 10 is permitted to move
relatively also in the width direction within the second receiving
portion 7, while being easy to stably hold at its home position
(i.e., its initial position) within the second receiving portion
7.
Other Embodiments
[0072] As shown in FIGS. 9 and 10, the shoes S of the embodiments
described above may include an additional corrugated plate 30
between the outsole 1 and the midsole 3. The corrugated plate 30
extends from a portion corresponding to the plantar arch to the
back of the heel of a human foot, and is corrugated in the vertical
direction as viewed from a side. The provision of the corrugated
plate 30 substantially prevents the midsole 3 from being deformed
locally and significantly even if an impact is applied in the
vertical direction to the heel support surface 12 and the planta
support surface 5. Consequently, when the wearer is walking and
running, the wearer's ankle is substantially prevented from
excessively leaning inward or outward, thereby enabling increased
stability to be ensured.
[0073] In the midsole 3 of the shoe S of each embodiment described
above, the first buffering member 8 is received, without being
fixed to the wall surfaces 6a to 6d and the bottom 6e of the first
receiving portion 6, i.e., in an unfixed manner. However, this is a
mere example. Specifically, the first buffering member 8 may be
received in and fixed to the first receiving portion 6.
[0074] In the midsole 3 of the shoe S of each embodiment described
above, the thin plates 11, 11 forming the second buffering member
10 are made of the same material as that forming the midsole body
4. However, this is a mere example. The thin plates 11, 11 forming
the second buffering member 10 may be made of an elastic material
which has a lower specific gravity or a lower hardness than the
midsole body 4. With this configuration, the second buffering
member 10 that has a greater cushioning ability than the midsole
body 4 can concentratedly absorb an impact applied in the vertical
direction to the planta support surface 5, in particular, to the
heel support surface 12.
[0075] In the midsole 3 of the shoe S of each embodiment described
above, the second buffering member 10 is comprised of the thin
plates 11, 11 stacked one above the other. However, this is a mere
example.
[0076] Specifically, the second buffering member 10 may be
comprised of three or more thin plates 11, 11, . . . made of an
elastic material and stacked one above the other.
[0077] Note that the present invention is not limited to the
embodiments described above, and various changes and modifications
may be made without departing from the scope of the present
invention.
Examples
[0078] Next, examples which were actually implemented will be
described.
[Acceleration Characteristic Evaluation Test 1]
[0079] In this evaluation test, force acting on the foot of a
running test subject was studied from a kinematic view point.
Specifically, an accelerometer was attached to an area, of the test
subject, corresponding to a tibia and located above an ankle joint
(at a point about 4 cm directly above an inner malleolus).
Time-varying changes in the acceleration acting in the longitudinal
direction on the foot of the running test subject were
measured.
[0080] The results are shown in the graph of FIG. 11. Changes in
the state in which the test subject's foot contacted the ground are
represented by the peaks and valleys of each waveform. The
horizontal axis represents time (msec). The vertical axis
represents the acceleration waveform in the longitudinal direction
(Unit). Backward acceleration and the forward acceleration in the
running direction are shown above and below the origin,
respectively. Note that the values (each of which is an
acceleration value at a point of time) constituting each waveform
shown in FIG. 11 are actual values measured with the accelerometer
described above.
[0081] The waveforms shown in FIG. 11 correspond to two types of
shoes, i.e., the shoes of Example 1 and shoes of Comparative
Example 1. The waveform of Comparative Example 1 represents the
result of shoes of the known art not provided with the clearances,
which constitute a feature of the present invention. The waveform
of Example 1 represents the result of the shoes of the present
invention provided with the front, back, left, and right clearances
(each having a dimension of 2.0 mm).
[0082] FIG. 11 shows that, in a continuous cycle from the
contacting the ground to the separation from the ground, backward
acceleration and forward acceleration alternately act on the foot
of the running test subject. It has been found that in the time
range from 10 msec to 30 msec, the differences between the peaks
and the valleys of the waveform of Example 1 is smaller than those
of the waveform of Comparative Example 1. In particular, at the
point of time at about 17 msec (i.e., at which the first deep
valley of each waveform appears), the valley of the waveform of
Comparative Example 1 indicates an acceleration value of about
-4000, whereas the valley of the waveform of Example 1 indicates a
limited acceleration value of about -2000. Thus, with respect to
the forward acceleration, the waveform of Example 1 indicates a
value limited to about a half of the value indicated by the
waveform of Comparative Example 1. On the other hand, at the point
of time at about 19 msec (i.e., at which the first high peak of
each waveform appears), the peak of the waveform of Comparative
Example 1 indicates an acceleration value of about 7000, whereas
the peak of the waveform of Example 1 indicates a limited
acceleration value of about 5000. Thus, also with respect to the
backward acceleration, the waveform of Example 1 indicates a
limited value which is smaller than the value indicated by the
waveform of Comparative Example 1. It has been confirmed, from
these results, that the shoes of the present invention reduced the
impact applied in the longitudinal direction when the test subject
stepped on the ground, to a greater extent than the shoes of the
known art.
[Acceleration Characteristic Evaluation Test 2]
[0083] In this evaluation test, a test subject wore shoes of
Examples 2 to 7 and shoes of Comparative Examples 2 and 3 described
in Table 1, and the accelerations in the longitudinal direction
were measured for each pair of shoes.
TABLE-US-00001 TABLE 1 Second Buffering Member Clearances (Number
of layers of Front and Back Clearances Left and Right Clearances
Corrugated thin plates) (Clearance Dimension) (Clearance Dimension)
Plate Comparative Absent Absent Absent Absent Example 2 Example 2
Present Present Present Absent (Two Layers) (0.5 mm each) (0.5 mm
each) Example 3 Present Present Present Absent (One Layer) (0.5 mm
each) (0.5 mm each) Example 4 Present Present Present Absent (Two
Layers) (2.0 mm each) (2.0 mm each) Example 5 Present Present
Present Absent (Two Layers) (0.5 mm each) (0.5 mm each) Example 6
Present Present Absent Absent (Two Layers) (2.0 mm each)
Comparative Absent Absent Absent Present Example 3 Example 7
Present Present Present Present (Two Layers) (2.0 mm each) (2.0 mm
each)
[0084] Just like the evaluation test 1, the forward and backward
accelerations were measured with an accelerometer attached to an
area, of the test subject, corresponding to a tibia and located
above an ankle joint (at a point about 4 cm directly above an inner
malleolus). Time-varying changes in the acceleration acting in the
longitudinal direction on the foot of the running test subject were
measured. The results of this evaluation test are shown in FIG. 12.
The values represented in the bar graph of FIG. 12 were derived by
integrating the absolute values of actual values measured with the
accelerometer described above within the range from 0 ms to 100
ms.
[0085] FIG. 12 shows that the acceleration values in the
longitudinal direction of the shoes of Examples 2 to 6 and 7
provided with the clearances that constitute the feature of the
present invention, i.e. the front and back clearances within the
range from 0.5 mm to 5.0 mm are generally lower than those of the
shoes of Comparative Examples 2 and 3 not provided with the
clearances that constitute the feature of the present invention. It
has also been found that among the shoes of Examples 2 to 6, the
acceleration values in the longitudinal direction of the shoes of
Examples 2 and 4 to 6 including the second buffering member
comprised thin plates stacked in two layers are lower than those of
the shoes of Example 3 including the buffering member comprised of
only one layer of a buffering member.
[0086] The results also show that the acceleration values in the
longitudinal direction of the shoes of Example 6 provided with the
front and back clearances are yet lower than those of the shoes of
Examples 2 to 5 provided with the front, back, left, and right
clearances. The reason for this is as follows: In the shoes of
Example 6, while being permitted to move relatively in the
longitudinal direction within the second receiving portion, the
second buffering member is restrained so as to resist relative
movement in the width direction within the second receiving
portion. Therefore, the impact applied in the longitudinal
direction to the heel support surface is reduced concentratedly,
resulting in limitation of the acceleration values in the
longitudinal direction to lower values. As to the dimension of each
of the front and back clearances, it has been found that the
clearance of, in particular, 2.0 mm, which is included in the range
from 0.5 mm to 5.0 mm, limits the acceleration values in the
longitudinal direction to particularly low values.
[0087] In addition, it has been found that the acceleration values
in the longitudinal direction of the shoes of Example 7 provided
with the corrugated plate are lower than those of the shoes of
Examples 2 to 6.
[0088] It has been confirmed, from the foregoing results, that the
shoes of the present invention reduce the impact applied in the
longitudinal direction when the test subject stepped on the ground
to a greater extent than the shoes of the known art. Thus, it has
been found that the shoes of the present invention can give a
wearer enhanced comfortable feeling when he/she steps on the ground
during his/her walking and running, and allows the wearer to run
and walk with increased comfort.
INDUSTRIAL APPLICABILITY
[0089] The present invention is industrially applicable as shoes
such as walking shoes and running shoes.
DESCRIPTION OF REFERENCE CHARACTERS
[0090] S Shoe [0091] 1 Outsole [0092] 2 Ground Surface [0093] 3
Midsole [0094] 4 Midsole Body [0095] 5 Planta Support Surface
[0096] 7 Second Receiving Portion (Receiving Portion) [0097] 7a
Front Wall Surface [0098] 7b Back Wall Surface [0099] 7c Left Wall
Surface [0100] 7d Right Wall Surface [0101] 7e Bottom [0102] 10
Second Buffering Member (Buffering Member) [0103] 10a Front End
[0104] 10b Back End [0105] 10d Left End [0106] 10e Right End [0107]
11, 11 Thin Plate [0108] 12 Heel Support Surface [0109] 21 Front
Clearance [0110] 22 Back Clearance [0111] 23 Left Clearance [0112]
24 Right Clearance [0113] 30 Corrugated Plate
* * * * *