U.S. patent application number 14/742319 was filed with the patent office on 2015-10-08 for structure of front foot portion of shoe sole.
The applicant listed for this patent is ASICS CORPORATION. Invention is credited to Kiyomitsu Kurosaki, Tsuyoshi Nishiwaki.
Application Number | 20150282559 14/742319 |
Document ID | / |
Family ID | 39313787 |
Filed Date | 2015-10-08 |
United States Patent
Application |
20150282559 |
Kind Code |
A1 |
Nishiwaki; Tsuyoshi ; et
al. |
October 8, 2015 |
STRUCTURE OF FRONT FOOT PORTION OF SHOE SOLE
Abstract
There is provided a structure of a sole which may suppress
excessive bending, thereby improving the running efficiency, by
reinforcing the front foot portion of a sole having a reduced
weight. The disclosure is directed to a shoe sole, including a mid
sole 2 for absorbing an impact of landing, an outer sole 1 placed
under the mid sole 2 so as to be in contact with ground, and a
reinforcement element 3 for suppressing bending of a front foot
portion Ff during push-off. The reinforcement element 3 is an
integral resin part formed in a loop shape, the reinforcement
element 3 including a medial reinforcement portion 34 extending in
a front-rear direction L along a medial side IN of the front foot
portion Ff; a lateral reinforcement portion 35 extending in the
front-rear direction along a lateral side of the front foot
portion; a connection and reinforcement portion 37 for connecting
together the medial and lateral reinforcement portions 34 and 35
and also for providing reinforcement; and a connection portion 38
for connecting together the medial reinforcement portion 34 and the
lateral reinforcement portion 35 in an area posterior to the
connection and reinforcement portion 37.
Inventors: |
Nishiwaki; Tsuyoshi;
(Chuo-ku, JP) ; Kurosaki; Kiyomitsu; (Kobe,
JP) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
ASICS CORPORATION |
Kobe-shi |
|
JP |
|
|
Family ID: |
39313787 |
Appl. No.: |
14/742319 |
Filed: |
June 17, 2015 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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12311796 |
Apr 13, 2009 |
9089185 |
|
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PCT/JP2007/068609 |
Sep 26, 2007 |
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14742319 |
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Current U.S.
Class: |
36/31 |
Current CPC
Class: |
A43B 13/183 20130101;
A43B 7/1495 20130101; A43B 13/20 20130101; A43B 13/141 20130101;
A43B 13/181 20130101; A43B 13/122 20130101; A43B 13/12 20130101;
A43B 13/127 20130101; A43B 13/187 20130101; A43B 13/16 20130101;
A43B 5/06 20130101; A43B 13/026 20130101; A43B 7/1425 20130101;
A43B 13/189 20130101 |
International
Class: |
A43B 13/16 20060101
A43B013/16 |
Foreign Application Data
Date |
Code |
Application Number |
Oct 20, 2006 |
JP |
2006-285751 |
Claims
1. A shoe sole, comprising: a mid sole for absorbing an impact of
landing, an outer sole placed under the mid sole so as to be in
contact with ground, and a reinforcement element for suppressing
bending of a front foot portion during push-off, wherein the
reinforcement element is an integral resin part formed in a loop
shape, the reinforcement element including a medial reinforcement
portion extending in a front-rear direction along a medial side of
the front foot portion; a lateral reinforcement portion extending
in the front-rear direction along a lateral side of the front foot
portion; a connection and reinforcement portion for connecting
together the medial reinforcement portion and the lateral
reinforcement portion and also for reinforcing the shoe sole; and a
connection portion for connecting together the medial reinforcement
portion and the lateral reinforcement portion in an area posterior
to the connection and reinforcement portion.
2. A shoe sole according to claim 1, wherein the medial
reinforcement portion includes an area of a ball of a big toe; the
lateral reinforcement portion includes an area of an
interphalangeal joint of a little toe; and the connection and
reinforcement portion extends diagonally forward from the ball of
the big toe, connecting together the medial reinforcement portion
and the lateral reinforcement portion.
3. A shoe sole according to claim 1, wherein the medial
reinforcement portion includes an area of a ball of a big toe; the
lateral reinforcement portion includes an area of an
interphalangeal joint of a little toe; and the connection and
reinforcement portion includes a first connection and reinforcement
portion and a second connection and reinforcement portion, wherein
the first connection and reinforcement portion extends diagonally
forward from the ball of the big toe, connecting together the
medial reinforcement portion and the lateral reinforcement portion
and also reinforcing the shoe sole, and the second connection and
reinforcement portion extends, between the connection portion and
the first connection and reinforcement portion, diagonally forward
from the medial reinforcement portion so as to be connected to the
lateral reinforcement portion, connecting together the medial
reinforcement portion and the lateral reinforcement portion and
also reinforcing the shoe sole.
4. A shoe sole according to claim 1, wherein the front foot portion
of the outer sole includes a plurality of first island-like
portions spaced apart from one another in a peninsula-like or
island-like pattern at least in a front-rear direction of a foot;
the front foot portion of the mid sole includes a plurality of
second island-like portions spaced apart from one another in a
peninsula-like or island-like pattern so as to break continuity of
deformation at least in the front-rear direction of the foot; and
the reinforcement element is placed between the plurality of second
island-like portions in the front-rear direction of the foot,
thereby serving to suppress the bending.
5. A shoe sole according to claim 4, wherein the reinforcement
element is placed on an upper surface of the outer sole while being
sandwiched between the first island-like portions and the second
island-like portions.
6. A shoe sole according to claim 5, wherein the reinforcement
element is spaced apart from a lower surface of the mid sole
between the first island-like portions.
7. A shoe sole according to claim 5, wherein the reinforcement
element is attached to a lower surface of the mid sole and curved
in an upwardly protruding shape between the first island-like
portions.
8. A shoe sole according to claim 4, wherein the mid sole includes
a main mid sole of a foamed resin, and a rubber-like or pod-like
compressively deformable member exposed on a side surface of the
mid sole; the reinforcement element serves also as a holding member
for holding, in cooperation with the main mid sole, the
compressively deformable member in a predetermined area; and the
holding member includes an attachment portion secured to an upper
surface of the outer sole, and an engagement portion extending
upwardly from the attachment portion on the side surface of the mid
sole.
9. A shoe sole according to claim 8, wherein the main mid sole
includes a first main mid sole covering a sole of the foot, and a
second main mid sole placed below the first main mid sole; and the
compressively deformable member is sandwiched between the first
main mid sole and the second main mid sole.
10-20. (canceled)
Description
TECHNICAL FIELD
[0001] The present invention relates to a structure of a front foot
portion of a shoe sole.
BACKGROUND ART
[0002] In recent years, there is proposed a sole having island-like
portions obtained by dividing a front foot portion of the shoe sole
in the front-rear or medial-lateral direction (for example, the
first and second patent documents identified below). Such a sole is
easily bent along grooves between the island-like portions.
[0003] [First Patent Document] WO 2006/038338 A1
[0004] [Second Patent Document] WO 2004/066771 A1
[0005] The third patent document identified below discloses a
resilient member extending across a sole groove in a front foot
portion for reinforcement. The resilient member is placed between
the mid sole and the outer sole, and is attached to the lower
surface of the mid sole.
[0006] [Third Patent Document] Japanese Laid-Open Patent
Publication No. 2001-70004
[0007] The fourth to sixth patent documents identified below
disclose a sole element that connects between the front foot
portion and the rear foot portion along the medial side and/or the
lateral side. The sole element may regain the energy used for the
deformation of the sole.
[0008] [Fourth Patent Document] Japanese Laid-Open Patent
Publication No. 2000-225002
[0009] [Fifth Patent Document] U.S. Pat. No. 6,199,303 B1
[0010] [Sixth Patent Document] U.S. Pat. No. 6,477,791 B2
[0011] The seventh patent document identified below discloses a
sole including a plurality of columnar leg portions in the rear
foot portion. In this sole, the leg portions are connected together
by a plate provided on the upper surface of the outer sole separate
from the mid sole.
[0012] [Seventh Patent Document] US 2004/0181969 A1
[0013] In the eighth patent document identified below, an outer
sole being a wear resistant reinforcement member is provided across
a groove in the front foot portion. Such an outer sole will
suppress the bending of the sole along the groove.
[0014] [Eighth Patent Document] Japanese Laid-Open Patent
Publication No. 2004-65978
DISCLOSURE OF THE INVENTION
[0015] One object of the present invention is to reduce the weight
of the front foot portion of a sole.
[0016] Another object of the present invention is to provide a
structure of a sole which may suppress excessive bending, thereby
improving the running efficiency, by reinforcing the front foot
portion of a sole having a reduced weight.
[0017] Still another object of the present invention is to prevent
the divergence between the direction of push-off of the foot and
the direction of travel.
[0018] Yet another object of the present invention is to provide a
novel structure for the attachment of a compressively deformable
member having a large resiliency.
[0019] A first aspect of the present invention is directed to a
shoe sole, including: a mid sole for absorbing an impact of
landing, an outer sole placed under the mid sole so as to be in
contact with ground, and a reinforcement element for suppressing
bending of a front foot portion during push-off, wherein the
reinforcement element is an integral resin part formed in a loop
shape, the reinforcement element including a medial reinforcement
portion extending in a front-rear direction along a medial side of
the front foot portion; a lateral reinforcement portion extending
in the front-rear direction along a lateral side of the front foot
portion; a connection and reinforcement portion for connecting
together the medial reinforcement portion and the lateral
reinforcement portion and also for reinforcing the shoe sole; and a
connection portion for connecting together the medial reinforcement
portion and the lateral reinforcement portion in an area posterior
to the connection and reinforcement portion.
[0020] With the running speed being constant, excessive bending of
the front foot portion increases the ground reaction force. In
other words, it leads to an increase in the kick force. Thus, this
is not suitable for running efficiently at a constant speed since
it increases the loss of energy.
[0021] The medial and lateral reinforcement portions suppress
excessive bending of the front foot portion. Therefore, the loss of
energy is small, resulting in a desirable efficiency in maintaining
the speed where one runs at a constant speed.
[0022] The sole with reinforcement portions has an increased
flexural rigidity, thus allowing for a reduction in weight by
reducing the thickness of the mid sole or by forming the mid sole
in an island-like pattern.
[0023] A reduction in weight cannot be realized if a resin part is
provided across the entire surface of the front foot portion or if
the resin part is thick. If the resin part is formed in such a
shape as a thin bar or a V shape, the resin part is likely to
undergo a deflection in the molding process.
[0024] With a loop-shaped resin part, the reinforcement portions
and the connection portion are bound by one another in the molding
process. Therefore, a deflection in the molding process is unlikely
to occur even if the part is formed to be thin and in a strip-like
shape. Thus, it is possible to reduce the weight.
[0025] In a preferred embodiment of the first aspect, the medial
reinforcement portion includes an area of a ball of a big toe; the
lateral reinforcement portion includes an area of an
interphalangeal joint of a little toe; and the connection and
reinforcement portion extends diagonally forward from the ball of
the big toe, connecting together the medial and lateral
reinforcement portions.
[0026] The phrase "to include an area" as used herein means that
the medial and lateral reinforcement portions extend from the area
in the frontward direction, the rearward direction or the
front-rear direction so as to suppress the bending of the foot
around the area, being the ball of the big toe or the
interphalangeal joint. Therefore, a through hole may be formed in
the medial and lateral reinforcement portions directly under or in
the vicinity of the ball of the big toe or the interphalangeal
joint.
[0027] When the front foot portion takes off the ground after
landing during a forward running, the front foot portion undergoes
a bending that bends the diagonal axis extending from directly
under the ball of the big toe of the foot toward the tip of the
little toe. This bending directs the push-off of the foot in the
diagonally forward direction. Therefore, there is a divergence
between the direction of push-off and the direction of travel,
thereby resulting in a loss of energy.
[0028] In the present embodiment, the provision of the connection
and reinforcement portion extending along the diagonal axis
suppresses the bending of the diagonal axis. Therefore, the
divergence is reduced, which also reduces the loss of energy,
thereby improving the running efficiency.
[0029] Moreover, if there is no reinforcement element present in
the area of the tips of the second to fourth toes, the bending of
the second to fourth toes is unlikely to be inhibited, thereby
allowing for smooth bending of the toes.
[0030] A more preferred embodiment of the first aspect includes a
first and a second connection and reinforcement portion. The
provision of a plurality of connection and reinforcement portions
is effective in suppressing a deflection of the resin part and is
also effective in suppressing a bending that bends the diagonal
axis.
[0031] A second aspect of the present invention is directed to a
shoe sole, including: a mid sole for absorbing an impact of
landing, an outer sole placed under the mid sole so as to be in
contact with ground, and a reinforcement element for suppressing
bending of a front foot portion during push-off, wherein the front
foot portion of the outer sole includes a plurality of first
island-like portions spaced apart from one another in a
peninsula-like or island-like pattern at least in a front-rear
direction of a foot; the front foot portion of the mid sole
includes a plurality of second island-like portions spaced apart
from one another in a peninsula-like or island-like pattern so as
to break continuity of deformation at least in the front-rear
direction of the foot; and the reinforcement element is placed
between the plurality of second island-like portions in the
front-rear direction of the foot, thereby serving to suppress the
bending.
[0032] The front foot portion including island-like portions formed
in a peninsula-like or island-like pattern is effective in reducing
the weight of the sole. Moreover, the introduction of variations in
terms of material properties and deformation properties among the
second island-like portions of the mid sole is effective in
designing the shoe depending on the area of the foot and the
application of the shoe.
[0033] The provision of the reinforcement element extending in the
front-rear direction between a plurality of second island-like
portions suppresses the bending of the sole along grooves between
the second island-like portions. This improves the running
efficiency.
[0034] In a preferred embodiment of the second aspect, the
reinforcement element is placed on an upper surface of the outer
sole while being sandwiched between the first island-like portions
and the second island-like portions.
[0035] In this case, it is preferred that the reinforcement element
is spaced apart from a lower surface of the mid sole between the
first island-like portions.
[0036] The reinforcement element spaced apart from the lower
surface of the mid sole as described above is placed at a position
that is at a distance from the neutral axis (an axis at the center
of a curved beam) of the sole being bent, whereby the reinforcement
element is effective in significantly increasing the flexural
rigidity of the sole.
[0037] Thus, the reinforcement element spaced apart from the lower
surface of the mid sole may be parallel to the lower surface of the
outer sole, i.e., in a flat-plate shape, or may be slightly curved
in an upwardly protruding shape.
[0038] The area of the reinforcement element that is curved in an
upwardly protruding shape as described above has a small stretch
when the sole is bent, whereby there will be no excessive
stress.
[0039] A third aspect of the present invention is directed to a
shoe sole, including: a mid sole for absorbing an impact of
landing, and an outer sole attached to a lower surface of the mid
sole so as to be in contact with ground, wherein the mid sole
includes a main mid sole of a foamed resin, and a rubber-like or
pod-like compressively deformable member exposed on a side surface
or a back surface of the mid sole; a holding member is provided for
holding, in cooperation with the main mid sole, the compressively
deformable member in a predetermined area; the main mid sole
includes a first main mid sole covering a sole of the foot, and a
second main mid sole placed below the first main mid sole; the
compressively deformable member is sandwiched between the first
main mid sole and the second main mid sole; and the holding member
includes an attachment portion secured to a lower surface of the
second main mid sole, and an engagement portion extending upwardly
from the attachment portion on the side surface of the mid
sole.
[0040] In this case, the second main mid sole is unlikely to
deform, whereby even if the wearer attempts to pull out the
compressively deformable member out of curiosity, it will not
easily be done.
[0041] In a preferred embodiment of the third aspect, the
engagement portion is engaged with the compressively deformable
member.
[0042] According to the embodiment, in cases where the
compressively deformable member is placed so as to be exposed on
the side surface or the back surface of the sole in order to reduce
the impact or enhance the resilient ability, or from an aesthetic
point of view, the member is held more stably. In other words, it
is possible to prevent the compressively deformable member from
popping out. Moreover, even if the wearer, etc., attempt to pull
out the compressively deformable member out of curiosity, it will
not easily be done.
[0043] In a preferred embodiment of the third aspect, the
engagement portion is engaged with the second main mid sole.
[0044] In this embodiment, the engagement portion is engaged with
the second main mid sole, whereby it is possible to prevent the
second main mid sole from popping out from the side surface.
[0045] In a preferred embodiment of the third aspect, the second
main mid sole is provided in the front foot portion, and the
compressively deformable member is located both in a medial area
and a lateral area of the front foot portion.
[0046] In another preferred embodiment, the compressively
deformable member is provided at a position of a ball of a big toe
of a front foot portion.
[0047] This embodiment provides a desirable cushioning for the ball
of the big toe pushing off strongly, and also provides the
stability by the holding member.
[0048] The engagement portion is preferably formed integrally with
the reinforcement element.
[0049] In such a case, it is not necessary to separately provide
the holding member.
[0050] While the compressively deformable member may be a
rubber-like or pod-like compressively deformable member, it is
preferred to use a rubber-like compressively deformable member.
[0051] A "rubber-like or pod-like compressively deformable member"
is a member capable of accumulating a repulsive force while being
deformed when it is compressed, and may include a member with
rubber elasticity such as a thermoplastic elastomer or a vulcanized
rubber, as well as a pod-like or bag-like member filled with the
air, a gel substance, a soft rubber-like elastic member, or the
like. Note that a thermoplastic elastomer is a polymer material
that exhibits the property of a vulcanized rubber at room
temperature but can be plasticized at high temperature so as to be
molded by a plastic processing machine.
[0052] As used in the present specification, a rubber-like member,
i.e., a member that exhibits a rubber-like elasticity, refers to a
member that can deform substantially (e.g., a fracture elongation
of 100% or more) and that can restore its original shape upon
removal of the stress. Typically, in a stress-deflection diagram of
such a member, the change in the stress .sigma. with respect to the
change in the deflection .delta. increases as the deflection
.delta. increases.
BRIEF DESCRIPTION OF THE DRAWINGS
[0053] FIG. 1 is a perspective view showing, by a phantom line, an
upper of a shoe according to Embodiment 1 of the present
invention.
[0054] FIG. 2 is an exploded perspective view of a shoe sole of the
shoe.
[0055] FIG. 3 is a perspective view showing a reinforcement element
detached from a mid sole of the shoe sole.
[0056] FIG. 4 is a perspective view of the shoe sole as viewed from
below.
[0057] FIG. 5 is a bottom view of the shoe sole.
[0058] FIG. 6A is a plan view of a reinforcement element, and FIG.
6B is a side view thereof.
[0059] FIG. 7 is a side view of a front foot portion of a shoe sole
as viewed from the medial side of the foot.
[0060] FIG. 8 is a bottom view of a shoe sole according to
Embodiment 2.
[0061] FIG. 9 is a plan view showing the relationship between the
reinforcement member and a bone structure of a foot.
[0062] FIG. 10 is a perspective view of a shoe sole.
[0063] FIG. 11A is a plan view of a reinforcement element, and FIG.
11B is a side view thereof.
[0064] FIG. 12A is a partial cross-sectional view taken along line
XIIA-XIIA of FIG. 8, and
[0065] FIG. 12B is a perspective view of a front foot portion of
the embodiment.
DESCRIPTION OF THE REFERENCE NUMERALS
[0066] 1: Outer sole
[0067] 2: Mid sole
[0068] 3: Reinforcement element
[0069] 4: Second main mid sole
[0070] 5: First main mid sole
[0071] 11: First island-like portions
[0072] 31: Engagement portion
[0073] 32: Attachment portion
[0074] 34: Medial reinforcement portion
[0075] 35: Lateral reinforcement portion
[0076] 37: First connection and reinforcement portion
[0077] 38: Second connection and reinforcement portion
[0078] 39: Connection portion
[0079] 42: Second island-like portions
[0080] B1.sub.5: Little toe
[0081] Ff: Front foot portion
[0082] IN: Medial side
[0083] J.sub.5: Interphalangeal joint of little toe
[0084] O1: Ball of big toe
[0085] OUT: Lateral side
BEST MODE FOR CARRYING OUT THE INVENTION
Embodiment 1
[0086] Embodiments of the present invention will now be described
with reference to the drawings.
[0087] FIGS. 1 to 7 show Embodiment 1.
[0088] The following description is directed to the structure of
the front foot portion, which is a characteristic portion of the
present shoe sole.
[0089] As shown in FIG. 1, the shoe of Embodiment 1 includes an
outer sole 1, a mid sole 2, a reinforcement element 3, and an upper
7 denoted by a broken line.
[0090] Outer Sole 1:
[0091] As shown in FIG. 4, the outer sole 1 includes five first
island-like portions 11 formed in an island-like pattern in the
front-rear direction L and the width direction W of the foot. The
outer sole 1 is formed by a rubber having a desirable wear
resistance against ground contact, and has a tread surface 15 to be
in contact with the ground upon landing. The first island-like
portions 11 are separated from one another in the front-rear and
medial-lateral directions of the foot in the front foot portion
Ff.
[0092] Mid Sole 2:
[0093] As shown in FIG. 2, the mid sole 2 includes a first main mid
sole 5 covering the sole of the foot, a second main mid sole 4
located under the first main mid sole 5, and compressively
deformable members 6.
[0094] Main Mid Sole:
[0095] As shown in FIG. 3, the first main mid sole 5 extends to the
rear foot portion Fb denoted by a two-dot chain line. On the other
hand, as shown in FIG. 2, the second main mid sole 4 includes, in
the front foot portion Ff, five second island-like portions 42 each
protruding in a peninsula-like pattern so as to break the
continuity of deformation in the front-rear direction L and the
width direction W of the foot. Specifically, grooves 43 are formed
between the second island-like portions 42 and 42, thereby breaking
the continuity of deformation between the second island-like
portions 42 in the front-rear direction L. The five second
island-like portions 42 are thicker than a central area of the
second main mid sole 4, and are protruding more toward the road
surface than the central area as shown in FIG. 3. These upper and
lower main mid soles 5 and 4 are formed by, for example, a foamed
resin such as EVA.
[0096] Compressively Deformable Member 6:
[0097] In the figures, areas of the compressively deformable
members are densely dotted.
[0098] In each of the second island-like portions 42, a
compressively deformable member 6 is sandwiched between a lower
surface 5d of the first main mid sole 5 and an upper surface 4u of
the second main mid sole 4. The compressively deformable member 6
is formed by a rubber-like member. As shown in FIG. 1, the
compressively deformable member 6 is exposed toward the outside on
the side surface of the mid sole 2.
[0099] The formation of the second island-like portions 42 is
effective in reducing the weight of the mid sole 2. Moreover, with
variations in terms of properties of material that comprises the
second island-like portion 42 and deformation properties among the
second island-like portions 42, it is possible to increase the
freedom of design depending on the area of the foot and the
application of the shoe.
[0100] As represented by the dense dotting in FIG. 5, the
compressively deformable members 6 are provided separately on the
medial side IN and on the lateral side OUT of the second main mid
sole 4. The compressively deformable member 6 provided on the
medial side IN is provided in a position directly under the ball O1
of the big toe (see FIG. 9) of the front foot portion Ff. The
provision of the compressively deformable member 6 at the ball O1
of the big toe (FIG. 9) improves the cushioning property and the
resiliency for the ball O1 of the big toe producing a strong
push-off.
[0101] Reinforcement Element 3:
[0102] The reinforcement element 3 is formed by a non-foamed resin.
As represented by the sparse dotting in FIG. 5, the reinforcement
element 3 is placed to extend in the front-rear direction L of the
foot between the plurality of second island-like portions 42 on the
medial side IN of the second main mid sole 4 so as to suppress the
bending of the sole along the grooves 43.
[0103] As shown in FIG. 3, the reinforcement element 3 has a lower
surface 3d facing the outer sole 1 (FIG. 4), and an upper surface
3u, shown in FIG. 2, opposite to the lower surface 3d.
[0104] As shown in FIG. 2, an attachment portion 32 to be attached
to a lower surface 4d of the second island-like portions 42 of the
second main mid sole 4 is formed on the upper surface 3u of the
reinforcement element 3.
[0105] A through hole 32a is formed in the attachment portion 32 of
FIG. 3 provided directly under the ball O1 of the big toe (FIG. 9).
A protruding portion 42a protruding downward from the second
island-like portion 42 fits in the through hole 32a.
[0106] As shown in FIG. 6A, the reinforcement element 3 includes
bending suppressing portions 33 formed between the attachment
portions 32 to be bonded to the second island-like portions 42 on
the medial side IN (FIG. 3). As shown in FIGS. 4 and 7, the bending
suppressing portions 33 are spaced apart from the lower surface of
the second main mid sole 4 along the grooves 43 of the mid sole
2.
[0107] Thus, the reinforcement element 3 placed to extend in the
front-rear direction L between the plurality of second island-like
portions 42 suppresses the bending of the mid sole 2 along the
grooves 43 between the second island-like portions 42. This
improves the running efficiency.
[0108] With the bending suppressing portions 33 being spaced apart
from the lower surface of the mid sole 2 along the grooves 43, it
is possible to suppress excessive bending of the front foot portion
Ff without hindering the reduction in weight of the second
island-like portions 42 of the mid sole 2.
[0109] As shown in FIG. 7, the bending suppressing portions 33 are
spaced apart from the lower surface 5d of the first main mid sole 5
along the grooves 43 of the second main mid sole 4, and are formed
in a flat-plate shape parallel to the lower surface of the outer
sole 1.
[0110] The reinforcement element 3 spaced apart from the lower
surface 5d of the mid sole 2 is placed at a position that is at the
distance Z from a neutral axis (an axis at the center of a curved
beam) 44 of the mid sole 2. Therefore, the reinforcement element 3
is effective in significantly increasing the flexural rigidity of
the mid sole 2.
[0111] Engagement Portion 31:
[0112] As shown in FIGS. 5 and 6A, the reinforcement element 3
includes a medial reinforcement portion 34 extending in the
front-rear direction L along the medial side IN of the front foot
portion Ff. As shown in FIGS. 6B and 7, the reinforcement element 3
includes an engagement portion 31 formed so as to rise upward on
the medial side of the ball O1 of the big toe (FIG. 9). The
engagement portion 31 engages with a lower portion of a side
surface 6s of the compressively deformable member 6 so as to cover
the compressively deformable member 6 from the side, whereby the
compressively deformable member 6 is prevented from popping
out.
[0113] Thus, in a case where the compressively deformable member 6
and the side surface of the mid sole 2 are exposed toward the
outside, the provision of the engagement portion 31 stabilizes the
fixing of the member 6 to the mid sole 2.
[0114] By forming the engagement portion 31 as an integral part of
the reinforcement element 3, it is not necessary to separately
provide a holding member for holding the compressively deformable
member 6.
Embodiment 2
[0115] FIGS. 8 to 11 show Embodiment 2.
[0116] As represented by the sparse dotting in FIG. 8, the
reinforcement element 3 is an integral resin part including the
medial reinforcement portion 34, a lateral reinforcement portion
35, a first connection and reinforcement portion 37, a second
connection and reinforcement portion 38, and a connection portion
39.
[0117] The medial reinforcement portion 34 extends in the
front-rear direction L so as to connect together the three second
island-like portions 42 from the tip of the big toe along the
medial side IN of the front foot portion Ff.
[0118] The lateral reinforcement portion 35 extends in the
front-rear direction L so as to connect together the three second
island-like portions 42 from the tip of the little toe along the
lateral side OUT of the front foot portion Ff.
[0119] The "front foot portion" as used herein refers to an area
that is anterior to the area Fm (FIG. 8) of the mid foot portion
that does not contact the ground.
[0120] As shown in FIG. 10, the medial and lateral reinforcement
portions 34 and 35 are bonded to the mid sole 2 in the front foot
portion Ff. This suppresses bending of the front foot portion,
thereby suppressing an increase in the kick force during
constant-speed running. As a result, where one runs at a constant
speed, the efficiency in maintaining the speed is improved.
[0121] Since a greater load acts on the medial side of the foot
than on the lateral side, it is necessary to provide a higher
rigidity on the medial side to prevent bending. The medial
reinforcement portion 34 of FIG. 8 is wider than the lateral
reinforcement portion 35. Thus, the medial side has a higher
rigidity. As an alternative method, the higher rigidity on the
medial side can be realized by making the medial reinforcement
portion thicker than the lateral reinforcement portion.
[0122] As shown in FIG. 11A, the through hole 32a is formed in each
of the attachment portions 32 bonded to the second island-like
portions 42 of the mid sole 2. This is for reducing the weight of
the reinforcement element 3.
[0123] As shown in FIG. 10, small through holes 11a are formed in
the first island-like portions 11 of the outer sole 1. This is for
reducing the weight of the outer sole 1.
[0124] Areas such as the ball O1 of the big toe and the ball O5 of
the little toe shown in FIG. 9 on the sole of the foot catch the
road surface. If the sole corresponding to these areas is hard, it
may inhibit the catching of the road surface. In contrast, in the
present embodiment, the through holes 32a are formed in the
attachment portions 32, and the through holes 11a are formed in the
first island-like portions 11. Therefore, the rigidity of the
attachment portions 32 and that of the first island-like portions
11 are reduced. Therefore, the force of the sole of the foot is
transmitted to the road surface and the road surface can be caught
more easily, thus enabling one to run easily.
[0125] The first connection and reinforcement portion 37 connects
together the medial and lateral reinforcement portions 34 and 35,
and also reinforces the shoe sole. The second connection and
reinforcement portion 38 connects together the medial reinforcement
portion 34 and the lateral reinforcement portion 35 in the area
posterior to the first connection and reinforcement portion 37.
[0126] As shown in FIG. 11, the medial reinforcement portion 34 and
the lateral reinforcement portion 35 are connected to each other by
the V-shaped connection portion 39 at a rear end portion 36 of the
reinforcement element 3. Thus, the reinforcement element 3 is
formed in a loop shape including the connection portion 39, the
first connection and reinforcement portion 37 and the medial and
lateral reinforcement portions 34 and 35. Moreover, the
reinforcement element 3 is formed in two loops passing through the
second connection and reinforcement portion 38.
[0127] Thus, by forming the resin reinforcement element 3 in a loop
shape, the reinforcement portions 34, 35, 37 and 38 are bound by
one another in the molding process. Therefore, a deflection in the
molding process is unlikely to occur even if the resin part is
formed to be thin and in a strip-like shape. Moreover, the
loop-shaped reinforcement element 3 has a desirable shape-retaining
property, and is unlikely to be misaligned when being
bonded/attached to the sole. Thus, it is possible to reduce the
weight of the reinforcement element 3.
[0128] The medial and lateral reinforcement portions 34 and 35 and
the first and second connection and reinforcement portions 37 and
38 shown in FIG. 10 are bonded to the lower surface of the mid sole
2. On the other hand, the connection portion 39 is not bonded to
the lower surface of the mid sole 2 in the area posterior to the
most posterior ones of the second island-like portions 42. A
through hole 36a of the rear end portion 36 fits around a
protruding portion 29 protruding from the mid sole 2. The
protruding portion 29 is provided on the mid foot portion.
[0129] As shown in FIG. 9, the medial reinforcement portion 34 is
continuous in the front-rear direction so as to include the area of
the ball O1 of the big toe. The lateral reinforcement portion 35 is
continuous in the front-rear direction so as to include the area of
the interphalangeal joint J.sub.5 of the little toe B1.sub.5. The
first connection and reinforcement portion 37 extends diagonally
forward from the ball O1 of the big toe, connecting together the
medial and lateral reinforcement portions 34 and 35.
[0130] Thus, the connection and reinforcement portion 37 is
provided extending along the first diagonal axis, which extends
from directly under the ball O1 of the big toe of the foot toward
the interphalangeal joint J.sub.5 or the tip of the little toe
B1.sub.5, thereby suppressing the bending of the first diagonal
axis. Therefore, the divergence between the direction of push-off
and the direction of travel is reduced. This also reduces the loss
of energy, thereby improving the running efficiency.
[0131] As shown in FIG. 9, the reinforcement element 3 is absent in
the area anterior to the base of the proximal phalanx B3.sub.2 of
the second toe, the shaft of the proximal phalanx B3.sub.3 of the
third toe, and the base of the distal phalanx B1.sub.4 of the
fourth toe. Therefore, the bending of the second to fourth toes is
unlikely to be hindered, allowing for smooth bending of the
toes.
[0132] The medial reinforcement portion 34 includes the area of the
base of the metatarsal bone B4.sub.1 of the big toe. The lateral
reinforcement portion 35 includes the area of the ball O5 of the
little toe including the base of the proximal phalanx B3.sub.5 of
the little toe and the head of the metatarsal bone B4.sub.5 of the
little toe. The second connection and reinforcement portion 38
extends diagonally forward from the base of the metatarsal bone
B4.sub.1 of the big toe, connecting together the medial and lateral
reinforcement portions 34 and 35.
[0133] Thus, the second connection and reinforcement portion 38 is
provided extending along the second diagonal axis, which extends
from the base of the metatarsal bone B4.sub.1 of the big toe of the
foot toward the ball O5 of the little toe, thereby suppressing the
bending of the second diagonal axis. This further reduces the loss
of energy, thereby further improving the running efficiency.
[0134] The first island-like portions 11 and the second island-like
portions 42 are provided at positions corresponding to the ball O1
of the big toe and the ball O5 of the little toe of FIG. 9 (FIG.
8). The second main mid sole 4 includes the grooves 43 formed
anterior to and posterior to the ball O1 of the big toe and the
ball O5 of the little toe of FIG. 9 thereby being separated. The
second island-like portions 42 are also provided anterior to and
posterior to the grooves 43 (FIG. 10). The attachment portions 32
of FIG. 8 are provided corresponding to the second island-like
portions 42.
[0135] As shown in FIGS. 10 and 11B, the bending suppressing
portions 33 provided between the second island-like portions 42 are
slightly curved in an upwardly protruding shape. The bending
suppressing portions 33 are narrower with smaller widths than the
attachment portions 32, and are attached to the lower surface 5d of
the first main mid sole 5 along the grooves 43 of the second main
mid sole 4. The bending suppressing portions 33 curved in a
protruding shape have a small stretch when the mid sole 2 is bent.
Therefore, there will be no excessive stress.
[0136] As shown in FIG. 12A, the second main mid sole 4 is
sandwiched between a lower surface 6d of the compressively
deformable member 6 and an upper surface 31u of the engagement
portion 31.
[0137] The engagement portion 31 is formed so as to rise upward on
the medial side of the ball O1 of the big toe (FIG. 9). As a
result, the second main mid sole 4 sandwiched between the lower
surface 6d of the compressively deformable member 6 and the upper
surface 31u of the engagement portion 31 is engaged with the
engagement portion 31 on the medial side IN of the foot. Therefore,
when the mid sole is compressed upon landing, the engagement
portion 31 prevents the second main mid sole 4 from popping out to
the side surface.
[0138] The compressively deformable member 6 laminated on the
second main mid sole 4 is formed so as to roll up toward the medial
side IN of the foot. Since the side surface of the second main mid
sole 4 is covered by the engagement portion 31 from the medial side
IN, the second main mid sole 4 is unlikely to deform. Thus, even if
the wearer attempts to pull out the compressively deformable member
6 out of curiosity, it will not easily be done.
[0139] Otherwise, the configuration is similar to that of
Embodiment 1, and like elements are denoted by like reference
numerals and will not be further described below.
[0140] The first island-like portions 11 of the outer sole 1 and
the second island-like portions of the second main mid sole 4 may
be formed in a peninsula-like pattern.
[0141] The compressively deformable member 6 may be formed as a
pod-like member.
[0142] It is not necessary that the reinforcement element 3 is
provided with the engagement portion 31.
[0143] The bending suppressing portions 33 curved in a protruding
shape may be spaced apart from the lower surface of the mid
sole.
INDUSTRIAL APPLICABILITY
[0144] The present invention is applicable to the front foot
portion structure of the shoe sole of shoes suitable for various
kinds of athletic sports.
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