U.S. patent application number 12/932084 was filed with the patent office on 2011-08-18 for shoe sole with reinforcing structure.
This patent application is currently assigned to ASICS Corporation. Invention is credited to Seiji Kubo, Kiyomitsu Kurosaki, Tsuyoshi Nishiwaki.
Application Number | 20110197468 12/932084 |
Document ID | / |
Family ID | 34463266 |
Filed Date | 2011-08-18 |
United States Patent
Application |
20110197468 |
Kind Code |
A1 |
Kubo; Seiji ; et
al. |
August 18, 2011 |
Shoe sole with reinforcing structure
Abstract
This invention relates to a shoe sole that solves the problems
on weight saving in shoes, prevention of distortion, improvement in
the fitting property and prevention of upthrust simultaneously. The
reinforcing member 3 for reinforcing a part of the midsole 2 is
arranged so that the top surface 36 of the second arch 3c and the
bottom surface 29 of the first arch 2c are opposite to each other.
At least a part of the bottom surface 29 of the first arch is not
in contact with a part of the top surface 36 of the second arch in
vertically spaced relationship to each other, thereby that the
non-contact areas of the first arch 2c and the second arch 3c can
be deformed independently from each other when impact load of
landing is applied.
Inventors: |
Kubo; Seiji; (Chuo-ku,
JP) ; Kurosaki; Kiyomitsu; (Chuo-ku, JP) ;
Nishiwaki; Tsuyoshi; (Chuo-ku, JP) |
Assignee: |
ASICS Corporation
Chuo-shi
JP
|
Family ID: |
34463266 |
Appl. No.: |
12/932084 |
Filed: |
February 16, 2011 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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10562564 |
Dec 27, 2005 |
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12932084 |
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Current U.S.
Class: |
36/28 ; 36/30A;
36/30R |
Current CPC
Class: |
A43B 13/146 20130101;
A43B 13/181 20130101; A43B 13/12 20130101; A43B 13/16 20130101;
A43B 13/10 20130101; A43B 3/0036 20130101 |
Class at
Publication: |
36/28 ; 36/30.R;
36/30.A |
International
Class: |
A43B 13/18 20060101
A43B013/18; A43B 13/12 20060101 A43B013/12; A43B 13/42 20060101
A43B013/42 |
Foreign Application Data
Date |
Code |
Application Number |
Oct 17, 2003 |
JP |
2003-357974 |
Claims
1-19. (canceled)
20. A shoe sole comprising: a midsole having a foot bearing surface
and a bottom surface, the bottom surface including a middle foot
portion, a forefoot portion, and a rear foot portion, an outer sole
having a ground contacting surface and a top surface, the outer
sole being attached to the forefoot portion and the rear foot
portion of the bottom surface of the midsole, a first arch formed
in the bottom surface of the midsole at the middle foot portion, a
bottom surface of the first arch being concave downward, and a
reinforcing member for the middle foot portion, the reinforcing
member comprising: a second arch, the first and second arches
juxtaposed on each other, the top surface of the second arch being
convex upwards toward the bottom surface of the first arch, wherein
portions of the top surface of the second arch and the bottom
surface of the first arch are in spaced apart relationship to each
other and the portions deform independently from each other upon
application of an impact load to the sole, wherein the second arch
has a greater Young's modulus than the first arch, and a film-like
member fixed to the first arch, the film-like member having a
greater Young's modulus than the Young's modulus of the first arch,
the film-like member having a thickness that is less than the
second arch of the reinforcing member, the film-like member
permitting but minimizing sinking down of the first arch.
21. A shoe sole according to claim 20, wherein a thickness of the
film-like member is set within a range of 0.01 mm to 0.5 mm.
22. A shoe sole according to claim 20, wherein a ratio of product
T.sub.91E.sub.91 between the average thickness T.sub.91 and the
Young's modulus E.sub.91 of the film-like member to product
T.sub.3cE.sub.3c between the average thickness T.sub.3c and the
Young's modulus E.sub.3c of the second arch 3c is set by using a
formula (1) of
1/1000.ltoreq.T.sub.91E.sub.91/(T.sub.3cE.sub.3c).ltoreq.1/4
(1)
23. A shoe sole with a reinforcing structure, comprising: an outer
sole having a ground contact surface and a top surface opposite to
the ground contact surface; a midsole having a top surface and a
bottom surface, the bottom surface being attached to the top
surface of the outer sole and covering the top surface of the outer
sole; and a reinforcing member for reinforcing a part of the
midsole, wherein the midsole has a first arch positioned between
forefoot and rear foot portions of the midsole, the first arch is
formed of resin foam and has a bottom surface, the reinforcing
member has a second arch, a fore end part located in front of the
second arch and a rear end part located in the rear of the second
arch, the second arch has a top surface and a bottom surface, the
second arch located to be covered with the first arch, the fore end
part of the reinforcing member bonded to at least either the
midsole or the outer sole in front of the first arch, the rear end
part of the reinforcing member bonded to at least either the
midsole or the outer sole in the rear of the first arch, the first
arch and the second arch substantially unattached to the top
surface of the outer sole and not in ground contact when the outer
sole is grounded, the second arch having a Young's modulus greater
than a Young's modulus of the first arch, a film-like member fixed
to the first arch, the film-like member having a greater Young's
modulus than the Young's modulus of the first arch, the film-like
member having a thickness that is less than the second arch of the
reinforcing member, the film-like member permitting but minimizing
sinking down of the first arch, wherein the reinforcing member
arranged so that the top surface of the second arch and the bottom
surface of the first arch are opposite to each other, and at least
a part of the bottom surface of the first arch not in contact with
the top surface of the second arch in vertically spaced
relationship to each other, whereby non-contact areas of the first
arch and the second arch can be deformed independently from each
other when the impact load of landing is applied.
24. A shoe sole according to claim 23, wherein when the impact load
of landing is applied, downward displacement of the non-contact
area of the bottom surface of the first arch is set to be larger
than that of the non-contact area of the top surface of the second
arch.
25. A shoe sole according to claim 23, wherein the reinforcing
member has two side portions bonded to the midsole.
26. A shoe sole according to claim 23, wherein the bottom surface
of the first arch has a first curved surface which forms a concave
surface and the top surface of the second arch has a second curved
surface which is convex upwards.
27. A shoe sole according to claim 23, wherein the bottom surface
of the first arch and the top surface of the second arch define a
domain, and the domain is formed to be hollow.
28. A shoe sole according to claim 23, wherein the bottom surface
of the first arch and the top surface of the second arch define a
domain, and the domain is filled with a filler having a smaller
Young's modulus than the midsole and capable of varying its
volume.
29. A shoe sole according to claim 27, wherein an entire peripheral
edge of the reinforcing member is bonded to the midsole, thereby to
seal the domain.
30. A shoe sole according to claim 28, wherein an entire peripheral
edge of the reinforcing member is bonded to the midsole, thereby to
seal the domain.
31. A shoe sole according to claim 27, wherein an opening passing
through the second arch vertically is formed.
32. A shoe sole according to claim 23, wherein the first arch is
formed of foam of ethylene-vinyl acetate copolymer, and the
reinforcing member is formed of non-foam of polyurethane, foam or
non-foam of ethylene-vinyl acetate copolymer.
33. A shoe sole according to claim 23, wherein the reinforcing
member further comprises medial and lateral side portions on the
medial side and the lateral side of a foot of the second arch, and
the medial and lateral side portions of the reinforcing member are
bonded to the midsole.
34. A shoe sole according to claim 23, wherein the outer sole is
separated into a fore foot part and a rear foot part at a position
corresponding to an arch of the foot, the fore foot part and the
rear foot part of the outer sole each have a top surface and a
bottom surface, the fore end part of the reinforcing member is
sandwiched in between the top surface of the fore foot part of the
outer sole and the bottom surface of the midsole, and the rear end
part of the reinforcing member is sandwiched in between the top
surface of the rear foot part of the outer sole and the bottom
surface of the midsole.
35. A shoe sole according to claim 23, wherein the midsole includes
an upper midsole body and a lower midsole body, the upper and lower
midsole bodies are formed of an ethylene-vinyl acetate copolymer,
and the reinforcing member is bonded to the upper and lower midsole
bodies with both of the fore end part and the rear end part of the
reinforcing member sandwiched in between the upper midsole body and
the lower midsole body.
36. A shoe sole according to claim 23, further comprising a second
reinforcing member arranged below the first reinforcing member.
37. A shoe sole according to claim 23, wherein the center line of
the first arch in the longitudinal direction and the center line of
the second arch in the longitudinal direction are arranged at least
just under a navicular bone, a cuboid bone or the cuneiform bone of
the foot.
38. A shoe sole according to claim 23, wherein the first arch has a
top surface, the top surface of the first arch has a third curved
surface which is convex upwards so as to be approximately along
with the arch of the foot.
39. A shoe sole according to claim 23, wherein the bottom surface
of the second arch has a fourth curved surface which forms a
concave suffice recessed upwards.
40. A shoe sole according to claim 23, wherein a thickness of the
film-like member is set within a range of 0.01 mm to 0.5 mm.
41. A shoe sole according to claim 23, wherein a ratio of product
T.sub.91E.sub.91 between the average thickness T.sub.91 and the
Young's modulus E.sub.91 of the film-like member to product
T.sub.3cE.sub.3c between the average thickness T.sub.3c and the
Young's modulus E.sub.3c of the second arch 3c is set by using a
formula (1) of
1/1000.ltoreq.T.sub.91E.sub.91/(T.sub.3cE.sub.3c).ltoreq.1/4
(1)
42. A shoe sole according to claim 20, wherein portions of the top
surface of the second arch and portions of the bottom surface of
the first arch are spaced apart from each other with only the
film-like member as the intervening structure between the portions
of the top surface of the second arch and the portions of the
bottom suffice of the first arch.
43. A shoe sole according to claim 20, wherein only the film-like
member and portions of the second arch are positioned under
portions of the bottom surface of the first arch.
44. A shoe sole according to claim 23, wherein portions of the top
surface of the second arch and portions of the bottom surface of
the first arch are spaced apart from each other with only the
film-like member as the intervening structure between the portions
of the top surface of the second arch and the portions of the
bottom surface of the first arch.
45. A shoe sole according to claim 23, wherein only the film like
member and portions of the second arch are positioned under
portions of the bottom surface of the first arch.
Description
TECHNICAL FIELD
[0001] The present invention relates to a shoe sole with a
reinforcing structure having a so-called shank (reinforcing
member).
BACKGROUND ART
[0002] A shoe sole that has a reinforcing member conforming to the
shape of the arch of the midsole in the arch portion, for example,
a shoe sole in which a portion of the midsole not attached to the
outer sole does not have ground contact when the outer sole is
grounded, is known. Such a reinforcing structure increases the
rigidity of the arch portion of the midsole by suppressing
deformation of the midsole. Examples of such known structures are
shown in FIG. 9(a), FIG. 9(b), FIG. 10(a), FIG. 10(b) and FIG.
10(c).
[0003] FIG. 9(a) is a side view of a shoe sole disclosed in
Japanese Patent Laid Open No. 10-155511 (Abstract, therein)
(publication date: Jun. 16, 1998). This shoe sole is provided with
a supporting member 3 for supporting deformation of the arch of the
foot on the top surface of a midsole 2. A space R is provided
between the supporting member 3 and the midsole 2.
[0004] FIG. 9(b) is a bottom view of a shoe sole disclosed in
Japanese Utility Model Registration Publication No. 3070442 (FIG.
2, therein) (registration date: May 10, 2000). This shoe sole has,
a shock-absorbing member 3 composed of a sealed container attached
to the bottom surface of the midsole 2. The shock-absorbing member
3 functions as a so-called shank and maintains the shape of the
shoe sole.
[0005] FIG. 10(a) is a sectional view of a shoe sole disclosed in
Japanese Utility Model Laid Open No. 7-44268 (Abstract, therein)
(publication date: Nov. 14, 1995). In this shoe sole, a concave
part C is formed at the rear foot part of the midsole 2. The
concave part C is provided with a reinforcing piece 3 for
preventing deformation of the rear foot part.
[0006] FIG. 10(b) is a side view of a shoe sole disclosed in
Japanese Patent Laid Open No. 2003-19004 (FIG. 5, therein)
(publication date: Jan. 21, 2003). In this shoe sole, an arch C is
formed at the bottom of an arch portion of the midsole 2. A first
reinforcing member 3 is attached to the bottom surface of the arch
C and a second reinforcing member 4 is provided below the first
reinforcing member 3.
[0007] FIG. 10(c) is a side view of a shoe sole disclosed in
Japanese Patent Laid Open No. 2000-139508 (Abstract, therein)
(publication date: May 23, 2000). In this shoe sole, end portions
3f and 3b, located forward and backward of a reinforcing member 3
on the bottom surface of a midsole 2, are wedged between the
midsole 2 and an outer sole 1. This prevents the depression of the
arch of the midsole 2.
[0008] The first patent document: Japanese Patent Laid Open No.
10-155511 (abstract)
[0009] The second patent document: Japanese Utility Model
Registration Publication No. 3070442 (FIG. 2)
[0010] The third patent document: Japanese Utility Model Laid Open
No. 7-44268 (abstract)
[0011] The fourth patent document: Japanese Patent Laid Open No.
2003-19004 (FIG. 5)
[0012] The fifth patent document: Japanese Patent Laid Open No.
2000-139508 (abstract)
DISCLOSURE OF THE INVENTION
[0013] More generally, in known structures, a reinforcing structure
is provided to a shoe sole at a position located in the arch of the
foot. Such a structure decreases the weight in the shoe sole, in
particular, the middle foot part, and prevents distortion of the
shoe sole.
[0014] However, such a structure often creates a midsole arch that
is too stiff for the wearer and which is hard to fit to the arch of
the wearer's foot. In other words, the fitting properties of a shoe
sole having such a structure is lowered.
[0015] Further, as a part of the top surface of the arch of the
midsole forcefully contacts the arch of the foot sole, especially
at the time of landing, the wearer feels a so-called "upthrust".
That is, the wearer feels the foot sole being thrust upward or
being pushed up from below.
[0016] None of the aforedescribed art provides a shoe sole that is
light in weight, prevents distortion, has improved fitting
properties and prevents the described-upthrust. That is, the art
disclosed in each of the patent documents cannot solve
simultaneously the problems of weight saving, prevention of the
distortion, improvement in the fitting properties and prevention of
the upthrust.
[0017] It is thus an object of the present invention to provide a
shoe sole that is light in weight, prevents distortion, has
improved fitting properties and prevents the upthrust.
[0018] In order to achieve the foregoing object, a shoe sole is
provided that has a novel reinforcing structure.
[0019] The shoe sole, according to an aspect of the present
invention, comprises an outer sole, a midsole attached to a top
surface of the outer sole and a reinforcing member for reinforcing
a part of the midsole.
[0020] The midsole has a middle foot part. The midsole is formed of
resin foam and has a first arch at a bottom portion of the middle
foot part. The first arch has a bottom surface. The outer sole is
substantially not attached to the first arch of the midsole.
[0021] The reinforcing member has a second arch, a fore end part
located in front of the second arch and a rear end part located in
the rear of the second arch. The second arch has a top surface and
a bottom surface. The fore end part of the reinforcing member is
bonded to at least either the midsole or the outer sole, in front
of the first arch. The rear end part of the reinforcing member is
bonded to at least either the midsole or the outer sole, in the
rear of the first arch.
[0022] Young's modulus of the reinforcing member is set to be
greater than that of the first arch of the midsole. A member having
a greater Young's modulus than the first arch is substantially not
affixed to the bottom surface of the first arch.
[0023] The bottom surface of the first arch may have a first curved
surface which is a concave surface recessed upwards, if necessary,
and the top surface of the second arch may have a second curved
surface which is convex upwards.
[0024] The reinforcing member is arranged so that the top surface
of the second arch and the bottom surface of the first arch are
opposite each other. At least a part of the bottom surface of the
first arch of the midsole is in vertically spaced relationship with
at least a part of the top surface of the second arch of the
reinforcing member and not in contact therewith. That is, at least
a part of the bottom surface of the first arch of the midsole is in
vertically spaced relationship with the reinforcing member and not
in contact therewith, and further at least a part of the top
surface of the second arch of the reinforcing member is in
vertically spaced relationship with the midsole and not in contact
therewith. Such arrangement of the midsole and the reinforcing
member defines a non-contact area of the first arch and a
non-contact area of the second arch.
[0025] This allows the non-contact areas of the first arch and the
second arch to be deformed independently from each other when
impact load of landing is applied.
[0026] In the present invention, by the use of the description "the
outer sole is substantially not attached to the first arch", it is
meant to include the case wherein the outer sole is not attached to
any portion of the first arch of the midsole and the case wherein
the function of the first arch of the present invention is not
impaired even if the outer sole is attached to a portion or part of
the first arch (for example, the case where the outer sole is
attached only to a rim of the first arch).
[0027] According to another aspect of the invention, a shoe sole
comprises an outer sole having a ground contact surface and a top
surface opposite to the ground contact surface, a midsole having a
top surface and a bottom surface, the bottom surface being attached
to the top surface of the outer sole and covering the top surface
of the outer sole, and a reinforcing member for reinforcing a part
of the midsole.
[0028] In the present invention, by the use of the description "the
bottom surface of the midsole is attached to the top surface of the
outer sole", it is meant to include the case wherein the bottom
surface of the midsole is directly attached to the top surface of
the outer sole and the case wherein the bottom surface of the
midsole is indirectly attached to the top surface of the outer sole
with other member(s) interposed between the midsole and the outer
sole.
[0029] The midsole has a first arch covered with a middle foot part
of a foot. The first arch is formed of resin foam and has a bottom
surface. The reinforcing member has a second arch, a fore end part
located in front of the second arch and a rear end part located in
the rear of the second arch. The second arch has a top surface and
a bottom surface. The second arch is located so as to be covered
with the first arch. The fore end part of the reinforcing member is
bonded to at least either the midsole or the outer sole in front of
the first arch. The rear end part of the reinforcing member is
bonded to at least either the midsole or the outer sole in the rear
of the first arch.
[0030] The first arch and the second arch are substantially not
attached to the top surface of the outer sole and do not have
ground contact when the ground contact surface of the outer sole is
grounded. Young's modulus of the second arch is set to be greater
than that of the first arch. Such member having a greater Young's
modulus than the first arch of the midsole, is substantially not
affixed to the bottom surface of the first arch.
[0031] The bottom surface of the first arch may have a first curved
surface which is a concave surface recessed upward, if necessary,
and the top surface of the second arch may have a second curved
surface which is convex upwards, if necessary.
[0032] The reinforcing member is arranged so that the top surface
of the second arch and the bottom surface of the first arch are
opposite to each other. At least a part of the bottom surface of
the first arch is not in contact with a part of the top surface of
the second arch in vertically spaced relationship to each other,
thereby to make non-contact areas of the first arch and the second
arch defined.
[0033] Such a structure allows the non-contact areas to be deformed
independently from each other when an impact load of landing is
applied.
[0034] In the shoe sole of the present invention, when the foot
lands on the ground, the impact load at landing is transmitted from
the ground contact surface to the sole of the foot via the midsole.
At this landing, the first arch of the midsole and the second arch
of the reinforcing member, respectively, become deformed. The
non-contact areas of both arches deform independently from each
other.
[0035] The first arch of the midsole is formed of resin foam and
has a smaller Young's modulus than the reinforcing member. The
Young's modulus of the first arch is set at a value that wearers
feel that the first arch is soft.
[0036] Since the midsole has the first arch covered with the middle
foot part (the arch) of the foot, the bottom portion of the midsole
is hollowed out, thus minimizing the thickness of the arch portion
of the midsole.
[0037] In this manner, since the part of the midsole, which is
covered with the middle foot part of the foot is soft and
relatively thin, the midsole can easily conform to the shape of
arch of the foot.
[0038] In the present invention, by the use of the description
"have the first arch which is covered with the middle foot part",
it is meant to include the case where the first arch is formed so
that the center line of the first arch in the longitudinal
direction coincides with or comes in proximity of the center line
of the arch of the foot in the longitudinal direction. It is
preferable that the center lines of the first arch and the second
arch are arranged at least just under the navicular bone, the
cuboid bone or the cuneiform bone of the foot.
[0039] Furthermore, as the first arch is in vertically spaced
relationship to the second arch and not in contact with the second
arch (the first arch and the second arch face opposite each other
and are vertically spaced from each other so that the first arch is
not in contact with the second arch), the first arch of the midsole
can sink down sufficiently at the non-contact area when the foot
lands on the ground, thereby to suppress "upthrust".
[0040] A member having a greater Young's modulus than the first
arch is substantially not affixed to the bottom surface of the
first arch. As a result, the flexibility of the first arch is
maintained, and the fitting property of the shoe sole with respect
to the arch of the foot and the function of suppressing "upthrust"
are not unnecessarily impaired.
[0041] In the present invention, by the use of the description "a
member having a greater Young's modulus than the first arch is
substantially not affixed", it is meant that a member having a
greater Young's modulus than the first arch is not affixed
(laminated and fixed) onto the bottom surface of the first arch or
that the bottom surface of the first arch can have a greater
deformation than the top surface of the second arch at landing even
if such member is affixed. For example, in the case where the
above-mentioned member having a greater Young's modulus is affixed
only to a part of the bottom surface of the first arch, or in the
case where the above-mentioned member having a greater Young's
modulus, affixed to the bottom surface of the first arch, is very
thin (for example, 0.5 mm or less, preferably 0.2 mm or less, more
preferably 0.1 mm or less), the above-mentioned member having a
greater Young's modulus is substantially not affixed. Moreover, the
present invention also includes the case where the above-mentioned
member having a greater Young's modulus is not affixed to the
bottom surface of the first arch even if a member having a smaller
Young's modulus than the first arch is affixed to the bottom
surface of the first arch, and the case where a coating is merely
applied to the bottom surface of the first arch.
[0042] In the present invention, it is preferred that a member
having a greater Young's modulus than the second arch is
substantially not affixed to the bottom surface of the first arch.
By the use of the description "a member having a greater Young's
modulus than the second arch is substantially not affixed", it is
meant to include, for example, the case wherein no member is
affixed (laminate and fixed) onto the bottom surface of the first
arch and the case wherein a coating is merely applied to the bottom
surface of the first arch. Further, for example, in the case
wherein a member having a greater Young's modulus than the second
arch is not affixed to the bottom surface of the first arch even if
a member having a smaller Young's modulus is affixed to the bottom
surface of the first arch, and in the case wherein a member which
is thicker than the second arch is not affixed to the bottom
surface of the first arch even if a film-like member which is
thinner than the second arch is laminated and fixed onto the bottom
surface of the first arch, the above mentioned member having a
greater Young's modulus than the second arch is substantially not
affixed to the bottom surface of the first arch. The Young's
modulus of the film-like member may be set smaller than that of the
second arch, the same as that of the second arch, or greater than
that of the second arch. The thickness of the film-like member may
be set, for example, 0.5 mm or less, preferably 0.2 mm or less,
more preferably 0.1 mm or less.
[0043] Generally, the foam and the reinforcing member are not
manufactured on the basis of the Young's modulus but are
manufactured based on hardness. For example, the hardness of the
foam forming the, first arch is set within the range of SRIS-C
hardness (a value measured by a C-type hardness meter of Society of
Rubber Industry, Japan Standard) of about 30 degrees to 80 degrees.
On the other hand, the hardness of the reinforcing member forming
the second arch is set within the range of JIS-A hardness of about
70 degrees to 100 degrees. JIS-A hardness is a value obtained by
measuring with a JIS-A type hardness meter in conformity with JIS
K6301.
[0044] As the first arch is formed on the midsole, the midsole is
hollowed out at the area where the first arch is formed, thereby to
realize weight saving of the midsole.
[0045] Meanwhile, the hollowed area of the midsole is reinforced by
the reinforcing member, thereby to increase strength of the shoe
sole against distortion.
[0046] Further, the bottom surface of the first arch and the top
surface of the second arch are located so as to be opposed to each
other. That is, the bottom surface of the first arch and the top
surface of the second arch face opposite each other. This heightens
the effect of reinforcing the part which improves the fitting
property with respect to the foot.
[0047] In the present invention, "arch of a foot" means the
crescent-shaped recessed area in the middle foot part of a foot. On
the other hand, the "arch" shape of the midsole and the reinforcing
members broadly encompasses any gate shape, including but not
limited to a circular arc shape or a bow shape.
[0048] That is, the second "arch" of the reinforcing member means
the shape in which a hollow is formed continuously from the medial
side of the foot to the lateral side of the foot under the second
"arch" of the reinforcing member, and the first "arch" of the
midsole means the shape in which a hollow is formed continuously
from the medial side of the foot to the lateral side of the foot
under the first "arch" unless the reinforcing member is attached.
Accordingly, under the second "arch" of the reinforcing member,
something can go through from the medial side of the foot to the
lateral side of the foot. And, unless the reinforcing member is
attached, under the first "arch" of the midsole, something can go
through from the medial side of the foot to the lateral side of the
foot.
[0049] It is preferred that the top surface of the first arch of
the midsole is curved so as to be convex upwards approximately
along the arch of the sole of the foot and that the bottom surface
of the first arch is recessed upwards to form a passage under the
first arch. It is preferred that the top surface of the second arch
of the reinforcing member faces opposite to the bottom surface of
the first arch and that the bottom surface of the second arch has a
curved surface recessed upwards. The second arch of the reinforcing
member reinforces the first arch of the midsole.
[0050] In the present invention, the bottom surface of the first
arch may have the first curved surface which is concave in a
circular arc shape, if necessary, and the top surface of the second
arch may have the second curved surface which is convex upward in a
circular arc shape.
[0051] As the second arch has the second curved surface which is
convex upward, when an external force is applied to the reinforcing
member, uniform stress distribution (dispersion of the stress) is
realized. As a result, even a thin reinforcing member can provide a
great rigidity or strength.
[0052] The first curved surface and the second curved surface may
be provided in the area of the midsole or the reinforcing member
covered with the middle foot part of the foot, in only a portion of
the width of the foot. Such curved surfaces need not cover the full
width of the foot in the area of the midsole or the reinforcing
member covered with the arch of the foot.
[0053] The second arch may be formed only in at least a part of the
reinforcing member and need not be formed over the full width of
the reinforcing member.
[0054] The second arch optionally may only cover a portion of the
width of the arch of the foot and optionally may be located on only
a portion of the arch of the foot, e.g., medial or lateral
side.
[0055] Moreover, the reinforcing member may be provided only on at
least a part of the area of the midsole covered with the middle
foot part of the foot, and for example, may be provided on the
medial side and/or the lateral side, or part of middle of the
foot.
BRIEF DESCRIPTION OF THE DRAWINGS
[0056] FIG. 1(a) and FIG. 1(b) are longitudinal sectional views of
the shoe sole according to a first embodiment, and FIG. 1(c) and
FIG. 1(d) are longitudinal sectional views of modified examples of
the same shoe sole embodiment.
[0057] FIG. 2(a) is a side view of the shoe sole according to a
second embodiment and FIG. 2(b) is a bottom view thereof.
[0058] FIG. 3 is an exploded perspective view of parts of the shoe
sole of FIGS. 2(a) and 2(b) from the top side.
[0059] FIG. 4 is an exploded perspective view of parts of the shoe
sole of FIGS. 2(a) and 2(b) from the bottom side.
[0060] FIG. 5(a) is a sectional view taken along the line Va-Va of
FIG. 2(b) and FIG. 5(b) is a sectional view taken along the line
Vb-Vb of FIG. 2(b).
[0061] FIG. 6(a) is a longitudinal sectional view of the shoe sole
according to a third embodiment, and FIG. 6(b) and FIG. 6(c) are
longitudinal sectional views of modified examples of the same shoe
sole.
[0062] FIG. 7(a) is a transverse sectional view of the shoe sole
according to a fourth embodiment, FIG. 7(b) is a sectional view
taken along the line VIIb-VIIb of FIG. 7(a), and FIG. 7(c) is a
sectional view taken along the line VIIc-VIIc of FIG. 7(a).
[0063] FIG. 8(a), FIG. 8(b), FIG. 8(c) and FIG. 8(d) are bottom
views of different configurations for the reinforcing member.
[0064] FIG. 9(a) and FIG. 9(b) each illustrate a known shoe sole,
with FIG. 9(a) being a longitudinal sectional view of one known
shoe sole and FIG. 9(b) being a bottom view of another known shoe
sole.
[0065] FIG. 10(a), FIG. 10(b) and FIG. 10(c) each illustrate other
known shoe sole, with FIG. 10(a) being a longitudinal sectional
view of one known shoe sole, FIG. 10(b) being a side view of
another known shoe sole and FIG. 10(c) being a longitudinal
sectional view of yet another known shoe sole.
[0066] FIG. 11 is a longitudinal sectional view illustrating the
relationship between the shoe sole of the present invention and
foot bones.
[0067] FIG. 12(a) is a longitudinal sectional view of the shoe sole
according to a fifth embodiment, and FIG. 12(b) is a transverse
sectional view thereof.
EXPLANATIONS OF LETTERS OR NUMERALS
[0068] 1: Outer sole
[0069] 15: Ground contact surface
[0070] 16: Top surface of the outer sole
[0071] 1f: Fore foot part [0072] 1b: Rear foot part
[0073] 2: Midsole
[0074] 25: Bottom surface of the midsole
[0075] 26: Top surface of the midsole
[0076] 2c: First arch
[0077] 29: Bottom surface of the first arch
[0078] 3: Reinforcing member
[0079] 3c: Second arch
[0080] 3f: Fore end part
[0081] 3b: Rear end part
[0082] 35: Bottom surface of the second arch
[0083] 36: Top surface of the second arch
[0084] 37: Peripheral edge
[0085] 38: Opening
[0086] 39: First reinforcing member
[0087] 40: Second reinforcing member
[0088] 62: First curved surface
[0089] 63: Second curved surface
BEST MODE FOR CARRYING OUT THE INVENTION
[0090] The present invention will be understood more apparently
from the following description of preferred embodiments when taken
in conjunction with the accompanying drawings. However, it will be
appreciated that the embodiments and the drawings are given for the
purpose of mere illustration and explanation and that the scope of
the present invention is to be defined by the appended claims. In
the drawings annexed, the same reference numerals denote the same
or corresponding parts throughout several views.
First Embodiment
[0091] Hereinafter, a first embodiment of the invention will be
described with reference to the drawings. In this first embodiment,
the principle embodiment is shown and the basic structure and
principle of this invention will be described.
[0092] FIG. 1(a) and FIG. 1(b) are schematic sectional views of a
shoe sole S in the middle foot part, i.e., arch region of the foot.
The arrow F is the direction toward the front of the shoe and the
arrow B is the direction toward the rear or back of the shoe.
[0093] As shown in FIG. 1(a), the shoe sole S comprises an outer
sole 1, a midsole 2 and a reinforcing member 3 for reinforcing the
midsole 2.
[0094] The outer sole 1 is divided at just under the arch of the
foot into a fore foot part 1f and a rear foot part 1b. Each part
1f, 1b of the outer sole 1 has a ground contact surface 15 which
has ground contact at the time of landing, and a top surface 16
opposite to the ground contact surface 15.
[0095] As shown in FIG. 1(a), the midsole has a top surface 26 and
a bottom surface 25. A part of the bottom surface 25 of the midsole
2 is attached to the top surface 16 of the outer sole 1 so as to
cover the outer sole 1 from above. At a bottom portion 22 of this
midsole 2, a first arch 2c is formed just under the arch of the
foot. The first arch 2c is formed by hollowing out the bottom
surface 25 of the midsole 2 in an arch shape to thus form a concave
bottom surface 29 in the first arch 2c.
[0096] The top surface of the first arch 2c has a third curve
surface 120 which is curved convex upwards so as to be
approximately along the arch of the foot. The third curved surface
120 is gently curved in the central region in the widthwise
direction and is largely curved in the medial region.
[0097] There inforcing member 3 has a second arch 3c, a fore end
part 3f in front of the second arch 3c and a rear end part 3b in
the rear of the second arch 3c. As shown in FIG. 1(a), the second
arch 3c is formed to bulge upwards. A top surface 36 of the second
arch 3c is a curved face which is convex upwards, the bottom
surface 35 of the second arch 3c being a curved face which is
concave downwards. That is, the bottom surface 35 of the second
arch 3c has a fourth curved surface 130 which is recessed upwards.
The reinforcing member 3 is arranged so that the second arch 3c is
covered with the first arch 2c from above.
[0098] The reinforcing member 3 is supported with its fore and rear
end parts 3f, 3b sandwiched in between the outer sole 1 and the
midsole 2. That is, as shown in FIG. 1(a), the fore end part 3f is
sandwiched in between the top surface 16 of the fore foot part 1f
of the outer sole 1 and the bottom surface 25 of the midsole 2 and
the rear end part 3b is sandwiched in between the top surface 16 of
the rear foot part 1b of the outer sole 1 and the bottom surface 25
of the midsole 2 so that the reinforcing member is supported.
[0099] This reinforcing member 3 maintains the strength of the shoe
sole S at the position corresponding the first arch 3c and prevents
distortion of the shoe sole S. Accordingly, the Young's modulus of
the reinforcing member is set to be larger than that of the first
arch 2c of the midsole 2.
[0100] As shown in FIG. 1(a), the top surface 36 of the second arch
3c and the bottom surface 29 of the first arch 2c of the midsole 2
are arranged so as to be opposite to each other. Thus, the top
surface 36 of the second arch 3c and the bottom surface 29 of the
first arch 2c are vertically spaced from each other so that they
are not in contact with each other. These surfaces 36, 29 are not
in contact with each other and define a domain R, which is
hollow.
[0101] As shown in FIG. 1(b), when the foot lands on the ground,
impact load W1 is applied to the ground contact surface 15 of the
outer sole 1 of the shoe sole S. At this time, an impact load W1 is
transmitted to the sole of the foot via the outer sole 1 and the
midsole 2. Simultaneously, a load W2 from the sole of the foot
(from above) is applied to the midsole 2. Due to the load W2 from
above, the midsole 2 is compressed and sinks down.
[0102] At this time, since the first arch 2c is placed so as to be
spaced from the second arch 3c of the reinforcing member 3, the
bottom surface 29 of the first arch 2c and the top surface 36 of
the second arch 3c deform independently from each other. That is,
the sinkage (deflection) of the bottom surface 29 of the first arch
2c is not impeded by the reinforcing member 3. Because of this
sinkage (deflection) of the midsole 2, the fitting property of the
midsole 2 with respect to the sole of the foot is improved and the
"upthrust" at the time of landing of the foot is decreased or
suppressed.
[0103] In this case, it is preferred that, when the impact load of
landing is applied, downward displacement of the non-contact area
of the bottom surface 29 of the first arch 2c is set larger than
downward displacement of the non-contact area of the top surface
36. Such setting allows thrust-up feeling from below to be reduced
more.
[0104] On the other hand, the reinforcing member 3 is difficult to
deform due to its curved shape and the Young's modulus of the
reinforcing member 3 is set larger than that of the midsole 2.
Accordingly, the rigidity and strength of the shoe sole S is
maintained and distortion of the midsole 2 is prevented.
[0105] FIG. 1(c) and FIG. 1(d) show the modified examples.
[0106] In the example shown in FIG. 1(c), protrusions 121, 131 are
formed on a part of the first arch 2c and on a part of the second
arch 3c, respectively, and the protrusions 121, 131 of the first
and second arches 2c, 3c are in contact with each other. In this
case, the protrusions 121 of the first arch 2c have relatively
large compression deformation whereas the non-contact areas of both
arches 2c, 3c deform independently from each other. Accordingly, in
this example, the midsole 2 has the aforedescribed function of
sinking down, i.e., deflects and compresses downward.
[0107] As shown in FIG. 1(d), a hole 23 is provided in the bottom
surface 29 of the first arch 2c and a protrusion 33 engagable with
the hole 23 is provided on the top surface 36 of the second arch
3c.
[0108] The fore and rear end parts 3f, 3b need not be sandwiched
between the outer sole 1 and the midsole 2. As shown in FIG. 1(c)
and FIG. 1(d), both end parts 3f, 3b may merely be attached or
bonded to the outer sole 1.
Second Embodiment
[0109] Next, a second embodiment will be described with reference
to FIG. 2, FIG. 3, FIG. 4 and FIG. 5. In the following description
of embodiments, the parts which are identical or corresponding to
those of the first embodiment are designated by the same reference
numerals as the first embodiment and the detailed description and
illustration thereof will be omitted.
[0110] FIG. 2(a) is a side view showing the shoe sole S with an
outer sole 1f, 1b attached. FIG. 2(b) is a bottom view showing the
shoe sole S without the outer sole attached.
[0111] As shown in FIG. 2(a), the shoe sole S comprises an upper
midsole body 28, a lower midsole body 27 and a reinforcing member
3. In this embodiment, the upper and lower midsole bodies 28, 27
constitute the midsole 2. The lower midsole body 27 is divided at
the position corresponding to the arch of the foot into a front
part 27f and a rear part 27b. The fore foot part 1f of the outer
sole 1 is attached to the bottom surface 25f of the front part 27f
and the rear foot part 1b of the outer sole 1 is attached to the
bottom surface 25b of the rear part 27b. As shown in FIG. 4, in the
upper midsole body 28, the first arch 2c is provided at the
position corresponding to the arch of the foot. In the reinforcing
member 3, the second arch 3c is provided. The reinforcing member
has a fore end part 3f in front of the second arch 3c, a rear end
part 3b in the rear of the second arch 3c, a lateral side part 30
on the lateral side of the second arch 3c and a medial side part 31
on the medial side of the second arch 3c.
[0112] Referring to FIG. 3, the lower midsole body 27, the upper
midsole body 28 and the reinforcing member 3 are combined with each
other. In this combination, the fore and rear end part 3f, 3b of
the reinforcing member 3 are sandwiched in between the upper and
lower midsole bodies 28, 27, and the medial and lateral side parts
31, 30 are joined to the upper midsole body 28. In the front part
27f and the rear part 27b of the lower midsole body 27, joining
faces 51a, 51b are provided where the fore and rear end part 3f, 3b
of the reinforcing member 3 are joined. Referring to FIG. 4, in the
upper midsole body 28 joining faces 52a, 52b are provided where the
fore and rear end part 3f, 3b of the reinforcing member 3 are
joined and joining faces 53a, 53b are provided where the medial and
lateral side parts 31, 30 are joined.
[0113] As shown in FIG. 11, in the assembled shoe sole S, the first
arch 2c and the second arch 3c are covered with the middle foot
part of the foot. That is, the center line 82 of the first arch 2c
of the midsole 2 and the second arch 3c of the reinforcing member 3
in the longitudinal direction is in proximity of the center line 81
of the arch of the foot in the longitudinal direction. For example
the center line 82 may be located so as to pass through the
navicular bone 75 and the cuneiform bone 77. Optionally, the center
line 82 of the first arch 2c and the second arch 3c may be located
so as to pass through the cuboid bone 76. Thus, there are a range
of positions for the center line 82 with respect to the arch of the
foot.
[0114] Further, as shown in sectional view FIG. 5(a), the bottom
surface 29 of the first arch 2c and the top surface 36 of the
second arch 3c are arranged so that they are opposite to each other
and that they are vertically spaced from each other. Accordingly,
when the foot lands on the ground, the upper midsole body 28 sinks
down toward the second arch 3c, similarly to the first
embodiment.
[0115] As shown in FIG. 4, on the bottom surface 29 of the first
arch 2c, first curved surfaces 62, 62 which are concave in the
circular arc shape are provided at the medial and lateral portions
of the first arch 2c. As shown in FIG. 5(a), on the bottom surface
29 of the first arch 2c, such curved surfaces 62, 62 are also
provided at the front and rear end portions of the first arch 2c.
The central area of the bottom surface 29 of the first arch 2c is
very gently curved or is substantially flat or planar.
[0116] As shown in FIG. 3, on the top surface 36 of the second arch
3c, second curved surfaces 63, 63 which are convex upwards in a
circular arc shape are provided at the medial and lateral portions.
As shown in FIG. 5(a), on the top surface 36 of the second arch 3c,
such second curved surfaces 63, 63 are also provided at the front
and rear end portions of the second arch 3c. The remaining area of
the top surface 36 of the second arch 3c (for example, the central
area) is very gently curved or is substantially flat or planar.
[0117] The first and second curved surfaces 62, 63 are formed
approximately in the circular arc shape with a center line along
the transverse direction as a center. The first and second curved
surfaces 62, 63 are arranged so as to be opposite each other. That
is, the two surfaces 62, 63 face opposed to each other.
[0118] Further, as shown in a sectional view of FIG. 5(b), the fore
and rear end parts 3f, 3b of the reinforcing member 3 and lateral
side part 30 and medial side part 31 of the reinforcing member 3
are joined to the upper midsole body 28. That is, entire of the
peripheral edge of the reinforcing member is joined to the upper
midsole body 28. Such a joint improves the functions of preventing
the bend of the shoe and preventing the distortion of the shoe.
That is, the bend and distortion of the shoe is prevented or
minimized.
[0119] Such functions of preventing the bend of the shoe and
preventing the distortion of the shoe will be explained.
[0120] The function of preventing the bend of the shoe, in view of
the sectional shape, correlates with moment of inertia of area
I.sub.y (second moment of inertia, geometrical moment of inertia)
with respect to a neutral axis.
[0121] In this embodiment, since entire of the peripheral edge of
the reinforcing member 3 is joined to the upper midsole body 28,
the reinforcing member 3 integrally bends together with the upper
midsole body 28. Thus, the moment of inertia of area I.sub.y
increases by spacing the reinforcing member 3 away from the bottom
surface of the upper midsole body 28.
[0122] Accordingly, the function of preventing the bend of the shoe
is improved.
[0123] On the other hand, the function of preventing the distortion
of the shoe, in view of the sectional shape, correlates with polar
moment of inertia of area I.sub.p with respect to a centroid.
[0124] In this embodiment, since entire of the peripheral edge of
the reinforcing member 3 is joined to the upper midsole body 28,
the reinforcing member 3 is integrally distorted together with the
upper midsole body 28. Thus, the polar moment of inertia of area
I.sub.p increases by spacing the reinforcing member 3 away from the
bottom surface of the upper midsole body 28.
[0125] Accordingly, the function of preventing the distortion of
the shoe is improved.
[0126] Further, referring to FIGS. 3 and 4, by joining the entire
peripheral edge 37 of the reinforcing member 3 to the upper midsole
body 28, a sealed or closed space (domain) R is formed between the
upper midsole body 28 and the reinforcing member 3 (see FIG. 5(a)).
That is, the bottom surface 29 of the first arch 2c of the upper
midsole body 28 and the top surface 36 of the second arch 3c of the
reinforcing member 3 define the sealed or closed domain R. In such
joint structure that encompasses the entire peripheral edge 37 of
the reinforcing member 3, the air confined in the domain R supports
the first arch 2c softly, thereby to prevent the first arch 2c of
the upper midsole body 28 from, sinking down too much.
[0127] Each of the upper and lower midsole bodies 28, 27 is
preferably made of a foamed ethylene-vinyl acetate copolymer (EVA).
However, the upper and lower midsole bodies 28, 27 may be made of a
foam of another type resin. It is preferred that both upper and
lower midsole bodies 28, 27 be made of the same material in order
to improve the adhesiveness between the upper and lower midsole
bodies 28, 27 so that they can support the reinforcing member 3 in
a stable manner.
[0128] The reinforcing member 3 may be made of a non-foam of
polyurethane, or may be made of foam or non-foam of other resin.
Examples of resin materials that can be used to make the
reinforcing member 3, are nylon, fiber reinforced plastic (FRP),
carbon fiber reinforced plastic (CFRP), polyamide, polyester,
polypropylene, polyvinyl chloride (PVC),
acrylonitrile-butadiene-stylene (ABS), styrene. It is preferred
that a non-foam resin, which has certain strength and is easy to
mould, is used as the material for the reinforcing member 3. In
addition, when the reinforced member 3 is formed of transparent
resin, the quality of the design of the shoe is improved. A
preferred transparent resin that may be used is a non-foam
polyurethane or EVA, which can readily adhere to foamed EVA, the
main material of the midsole.
[0129] The midsole 2 in this embodiment is divided to the upper and
lower midsole bodies 28, 27, but the midsole 2 need not necessarily
be so divided. The midsole 2 may be formed integrally, i.e. an
integral one-piece unit. The shoe sole may be assembled with a
shock absorbing material, such as gel, enclosed within the midsole
2.
[0130] Referring to FIG. 4, the first curved surface 62 of the
first arch 2c is provided at both the medial portion and the
lateral portion of the first arch 2c, but the first curved surface
62 may be provided at either the medial portion or the lateral
portion of the first arch 2c or may be provided continuously from
the medial portion to the lateral portion of the first arch 2c. The
second curved surface 63 of the second arch 3c can be provided in a
similar way to the first arch 2c.
Third Embodiment
[0131] FIG. 6(a) is a longitudinal sectional view of a shoe sole
according to a third embodiment.
[0132] As shown in FIG. 6(a), a first reinforcing member 39 and a
second reinforcing member 40 are provided. The second reinforcing
member 40 is a different member from the first reinforcing member
39. The second reinforcing member 40 is located below the first
reinforcing member 39.
[0133] The first reinforcing member 39 corresponds to the
reinforcing member 3 according to the above-mentioned first and
second embodiments and has the second arch 3c. The second arch 3c
is arranged to be opposite to the first arch 2c of the midsole 2
and to be vertically spaced from the first arch 2c.
[0134] On the other hand, the second reinforcing member 40 is for
reinforcing the first reinforcing member 39. Such second
reinforcing member 40 further prevents the distortion of the shoe
sole at the arch of the foot.
[0135] In the example of FIG. 6(a), a fore end part 40f and a rear
end part 40b of the second reinforcing member 40 are sandwiched in
between the midsole 2 and the outer sole 1. Optionally, as shown in
FIG. 6(b), the fore and rear end parts 40f, 40b may be sandwiched
in between the lower midsole body 27 and the upper midsole body 28,
or, as shown in FIG. 6(c), may be sandwiched between the lower
midsole body 27 and the outer sole 1.
[0136] The second reinforcing member 40 is curved, similarly to the
first reinforcing member 39, below the second arch 3c of the first
reinforcing member 39, or may be substantially flat as shown in
FIG. 6(c).
[0137] The Young's modulus of the second reinforcing member 40 may
be set different from that of the first reinforcing member 39. It
is preferable that Young's modulus of the second reinforcing member
40 is set approximately equal to that of the first reinforcing
member 39 or that the Young's modulus of the first reinforcing
member 39 is set smaller than that of the second reinforcing member
40.
Fourth Embodiment
[0138] FIG. 7(a), FIG. 7(b) and FIG. 7(c) is sectional views of a
shoe sole according to a fourth embodiment.
[0139] As shown in the transverse sectional view of FIG. 7(a), the
first reinforcing member 39 is attached to a bottom surface 28b of
the upper midsole body 28 and belt-like grooves 61 which extend
approximately along the lengthwise direction of the shoe are formed
on the bottom surface 28b of the upper midsole body 28. At the
positions where the grooves 61 are formed, as shown in the
longitudinal sectional view of FIG. 7(b), the bottom surface 29 of
the first arch 2c and the top surface of the second arch 3c are
vertically spaced from each other so that hollow portions R are
formed. Accordingly, at the positions where the grooves 61 are
formed (for example, the position indicated by the line VIIb-VIIb
of FIG. 7(a)), the upper midsole body 28 can sink down similarly to
the above-mentioned embodiments. On the contrary, at the positions
where the grooves is not formed (for example, the position
indicated by the line VIIc-VIIc of FIG. 7(a)), as shown in the
longitudinal sectional view of FIG. 7(c), the top surface 36 of the
second arch 3c is in contact with the bottom surface 29 of the
first arch 2c.
Fifth Embodiment
[0140] FIG. 12(a) and FIG. 12(b) are sectional views of a shoe sole
according to a fifth embodiment.
[0141] As shown in a longitudinal sectional view of FIG. 12(a), a
film-like member 91 is laminated and fixed onto the bottom surface
29 of the first arch 2c of the midsole 2. Thus, the bottom surface
29 of the first arch is reinforced, and so the bottom surface 29 of
the first arch 2c is prevented from sinking down too much.
Accordingly it becomes possible to form the first arch 2c of the
midsole thinner. The film-like member is formed to be thinner than
the second arch 3c of the reinforcing member 3.
[0142] In this embodiment, in order to obtain a desirable function
of suppressing "upthrust" with the bottom surface 29 of the first
arch 2c sinking down, the rigidity ratio of the film-like member 91
and the reinforcing member 3 is preferably set within a certain
range. That is, a ratio of a product of multiplication between the
average thickness T.sub.91 and the Young's modulus E.sub.91 of the
film-like member 91 to a product of multiplication between the
average thickness Tac and the Young's modulus E.sub.3c of the
second arch 3c is set approximately 1/4 or less (i.e.
T.sub.91E.sub.91/(T.sub.3cE.sub.3c).ltoreq.about 1/4). It is
speculated that the ratio is preferably set approximately 1/6 or
less and that the ratio is more preferably set approximately 1/10
or less.
[0143] Further, it is preferred that the ratio is set at least
approximately 1/1000 or more, and it is more preferred that the
ratio is set approximately 1/100 or more. Such setting allows the
film-like member 91 to have a certain rigidity, thereby to prevent
the bottom surface of the first arch 2c from sinking down too
much
[0144] The thickness of the film-like member is set, for example,
within a range of approximately 0.01 mm to 0.2 mm. The thickness of
the second arch 3c is preferably set approximately 1.0 mm or more,
and more preferably set within a range of approximately 1.5 mm to
3.0 mm.
[0145] In this embodiment, as shown in a transverse sectional view
of FIG. 12(b), the first arch 2c and the reinforcing member 3 are
divided into two in the transverse direction of the foot,
respectively. A lateral side reinforcing member 300 and a medial
side reinforcing member 301 have two side parts 302, 302,
respectively. Each of the two side parts 302, 302 is joined to the
midsole 2, and two closed domains R, R are formed, one in a medial
direction and the other in a lateral direction of the foot.
[0146] FIG. 8(a), FIG. 8(b), FIG. 8(c) and FIG. 8(d) are bottom
views of the shoe soles at the first arch of the midsole and show
different configurations of the reinforcing member 3.
[0147] In the above mentioned second embodiment, the reinforcing
member 3 covers all of the first arch 2c. However, the reinforcing
member 3 need not always be in such shape. The reinforcing member 3
may be in any shape in which a part of the reinforcing member 3 can
be joined to the midsole or the outer sole. Accordingly, the planar
shape of the reinforcing member 3 may be formed into, for example,
an approximately "I"-shaped planar shape as shown in FIG. 8(a), an
approximately "X"-shaped planar shape as shown in FIG. 8(b) or an
approximately "N"-shaped planar shape as shown in FIG. 8(c).
Further, as shown in FIG. 8(d), the reinforcing member 3 may be
formed so as to have an opening 70 vertically passing through the
second arch 3c in the center of the reinforcing member 3.
[0148] Although the invention has been described hereinbefore in
connection with its preferred embodiments with reference to the
accompanying drawings, those skilled in the art could easily
imagine various modifications and corrections within the scope of
apparent range in view of the description thus far made.
[0149] For example, the reinforcing member which is provided with
the shoe sole may be divided into a medial piece and a lateral
piece, or the reinforcing member may be provided with only either
the medial side of the foot or the lateral side of the foot. A foam
or a filler which has a smaller Young's modulus than the midsole
and which is capable of varying its volume may be fitted in the
domain between the first arch and the second arch.
[0150] Therefore, such modifications and corrections should be
interpreted to fall within the scope of the invention, as defined
by the following claims.
INDUSTRIAL APPLICABILITY
[0151] The present invention is applicable to various athletic
shoes, in addition to running shoes.
* * * * *