U.S. patent application number 15/776899 was filed with the patent office on 2018-11-08 for covering member, fabric material-reinforcing structure, and sport shoe including same.
The applicant listed for this patent is Mizuno Corporation. Invention is credited to Kazunori Iuchi, Yuri Naka, Chie Yamamoto, Naoki Yoshikawa.
Application Number | 20180317607 15/776899 |
Document ID | / |
Family ID | 59056354 |
Filed Date | 2018-11-08 |
United States Patent
Application |
20180317607 |
Kind Code |
A1 |
Yamamoto; Chie ; et
al. |
November 8, 2018 |
COVERING MEMBER, FABRIC MATERIAL-REINFORCING STRUCTURE, AND SPORT
SHOE INCLUDING SAME
Abstract
A covering member is provided in a portion of an upper of a
shoe. The covering member includes: a fabric material comprised of
a stretchable mesh fabric; and an overlay material made of an
olefin-based thermoplastic elastomer and integrally provided on a
surface of the fabric material. A direction intersecting with a
stretch direction of the fabric material is defined as a width
direction. The covering member has such strain rate dependence that
a tensile load per unit width with respect to a strain amount of
the covering member is higher and the covering member is less
stretchable when a strain rate of the upper in the stretch
direction of the fabric material is in a high strain rate region
than when the strain rate of the upper is in a low strain rate
region.
Inventors: |
Yamamoto; Chie; (Osaka,
JP) ; Iuchi; Kazunori; (Osaka, JP) ;
Yoshikawa; Naoki; (Osaka, JP) ; Naka; Yuri;
(Osaka, JP) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Mizuno Corporation |
Osaka |
|
JP |
|
|
Family ID: |
59056354 |
Appl. No.: |
15/776899 |
Filed: |
December 2, 2016 |
PCT Filed: |
December 2, 2016 |
PCT NO: |
PCT/JP2016/085966 |
371 Date: |
May 17, 2018 |
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
A43B 23/0255 20130101;
A43B 1/14 20130101; A43B 5/00 20130101; A43B 23/0215 20130101; A43B
23/0235 20130101; A43B 23/0265 20130101; A43B 23/02 20130101; A43B
23/0275 20130101; A43B 23/027 20130101 |
International
Class: |
A43B 23/02 20060101
A43B023/02; A43B 5/00 20060101 A43B005/00; A43B 1/14 20060101
A43B001/14 |
Foreign Application Data
Date |
Code |
Application Number |
Dec 14, 2015 |
JP |
2015-243459 |
Claims
1. A covering member for covering a body, the covering member
comprising: a stretchable fabric material; and an overlay material
made of a thermoplastic elastomer and integrally provided on a
surface of the fabric material, wherein a direction intersecting
with a stretch direction of the fabric material is defined as a
width direction, a strain rate region with strain rates higher than
a reference strain rate is defined as a high strain rate region, a
strain rate region with strain rates equal to or lower than the
reference strain rate is defined as a low strain rate region, and
the covering member has such strain rate dependence that a tensile
load per unit width with respect to a strain amount of the covering
member is higher and the covering member is less stretchable when a
strain rate of the covering member in the stretch direction of the
fabric material is in the high strain rate region than when the
strain rate of the covering member is in the low strain rate
region.
2. The covering member of claim 1, wherein the overlay material is
bonded to the surface of the fabric material via an extensible
thermoplastic film material.
3. The covering member of claim 1, wherein a relationship between
the strain and the tensile load per unit width determined by a
tensile test is that the tensile load P per unit width (N/mm) with
respect to a strain amount of 1% is within the range of
0.05.ltoreq.P.ltoreq.1.09 in the low strain rate region, whereas
the tensile load P is within the range of 0.65.ltoreq.P.ltoreq.2.47
in the high strain rate region.
4. The covering member of claim 1, wherein a relationship between
the strain and the tensile load per unit width determined by a
tensile test is that the tensile load P per unit width (N/mm) with
respect to a strain amount of 5% is within the range of
0.25.ltoreq.P.ltoreq.2.05 in the low strain rate region, whereas
the tensile load P is within the range of 1.72.ltoreq.P.ltoreq.7.85
in the high strain rate region.
5. A covering member for covering a body, the covering member
comprising: a stretchable fabric material; and an overlay material
made of a thermoplastic elastomer and integrally provided on a
surface of the fabric material, wherein the covering member has
such strain rate dependence that as a strain rate of the covering
member in a stretch direction of the fabric material increases, a
tensile load per unit width with respect to a strain amount
increases and the covering member becomes less stretchable.
6. A sport shoe comprising an upper having the covering member of
claim 1.
7. A fabric material-reinforcing structure comprising: a
stretchable fabric material; and a reinforcing material made of a
thermoplastic elastomer, integrally provided on the fabric
material, and reinforcing a mechanical strength of the fabric
material, wherein a direction intersecting with a stretch direction
of the fabric material is defined as a width direction, a strain
rate region with strain rates higher than a reference strain rate
is defined as a high strain rate region, a strain rate region with
strain rates equal to or lower than the reference strain rate is
defined as a low strain rate region and the fabric
material-reinforcing structure has such strain rate dependence that
a tensile load per unit width with respect to a strain amount of
the fabric material-reinforcing structure is higher and the fabric
material-reinforcing structure is less stretchable when a strain
rate of the fabric material-reinforcing structure in the stretch
direction of the fabric material is in the high strain rate region
than when the strain rate of the fabric material-reinforcing
structure is in the low strain rate region.
8. The fabric material-reinforcing structure of claim 7, wherein
the reinforcing material is bonded to the surface of the fabric
material via an extensible thermoplastic film material.
9. The fabric material-reinforcing structure of claim 7, wherein a
relationship between the strain and the tensile load per unit width
determined by a tensile test is that the tensile load P per unit
width (N/mm) with respect to a strain amount of 1% is within the
range of 0.05.ltoreq.P.ltoreq.1.09 in the low strain rate region,
whereas the tensile load P is within the range of
0.65.ltoreq.P.ltoreq.2.47 in the high strain rate region.
10. The fabric material-reinforcing structure of claim 7, wherein a
relationship between the strain and the tensile load per unit width
determined by a tensile test is that the tensile load P per unit
width (N/mm) with respect to a strain amount of 5% is within the
range of 0.25.ltoreq.P.ltoreq.2.05 in the low strain rate region,
whereas the tensile load P is within the range of
1.72.ltoreq.P.ltoreq.7.85 in the high strain rate region.
11. A fabric material-reinforcing structure comprising: a
stretchable fabric material; and a reinforcing material made of a
thermoplastic elastomer, integrally provided on the fabric
material, and reinforcing a mechanical strength of the fabric
material, wherein the fabric material-reinforcing structure has
such strain rate dependence that as a strain rate of the fabric
material-reinforcing structure in the stretch direction of the
fabric material increases, the tensile load per unit width with
respect to the strain amount increases and the fabric
material-reinforcing structure becomes less stretchable.
12. A sport shoe comprising an upper including the fabric
material-reinforcing structure of claim 7.
Description
TECHNICAL FIELD
[0001] The present invention relates to a covering member, a fabric
material-reinforcing structure, and a sport shoe including the
same.
BACKGROUND ART
[0002] Shoes including an upper for covering the instep of a foot
have been known from Patent Document 1, for example. This upper
includes a mesh material having meshes and a reinforcement part
sewn on the mesh material at a position corresponding to a tiptoe
area of the foot. The reinforcement part is made of a material that
is difficult to stretch, such as artificial leather, and is
designed for maintaining the shape of a partial region of the upper
(for example, a portion corresponding to a front portion of a foot
including the toes).
CITATION LIST
Patent Documents
[0003] Patent Document 1: International Publication No.
2008/047659
SUMMARY OF THE INVENTION
Technical Problem
[0004] Meanwhile, it is generally desirable, for sport shoes or the
like, that for example, the upper has such fitting properties that
it fits with the shape of a foot of a user when the user puts on
the shoe, whereas the upper has such holding properties that it
firmly covers and holds the user's foot when the user does heavy
exercise.
[0005] However, the known shoes as disclosed in Patent Document 1
have a problem: the upper having the reinforcement part that is
difficult to stretch firmly covers and holds a user's foot, while
the upper is difficult to stretch and to fit with the shape of the
user's foot when the user puts on the shoes. Specifically, the
shoes of Patent Document 1 merely exhibit its holding properties
when the user wearing the shoes does heavy exercise and a sudden
external force is applied to the uppers. Unfortunately, when a
gentle external force is applied to the uppers in a situation where
the user puts on the shoes, for example, the fitting properties
that are generally needed are impaired. Thus, it is difficult for
the shoe structure of the known art to exhibit both the fitting
properties and the holding properties according to a state of
usage.
[0006] In view of the foregoing background, it is therefore an
object of the present invention to enable a covering member or a
fabric material-reinforcing structure to have both fitting
properties and holding properties and to exhibit the fitting or
holding properties according to a state of usage.
Solution to the Problem
[0007] In order to achieve the above object, a covering member or a
fabric material-reinforcing structure of the present invention is
configured such that it becomes flexible when a strain rate is low
and it becomes hard when the strain rate is high.
[0008] Specifically, a first aspect of the present invention is
directed to a covering member for covering a body. The covering
member includes a stretchable fabric material and an overlay
material made of a thermoplastic elastomer and integrally provided
on a surface of the fabric material. A direction intersecting with
a stretch direction of the fabric material is defined as a width
direction, a strain rate region with strain rates higher than a
reference strain rate is defined as a high strain rate region, and
a strain rate region with strain rates equal to or lower than the
reference strain rate is defined as a low strain rate region. The
covering member has such strain rate dependence that a tensile load
per unit width with respect to a strain amount of the covering
member is higher and the covering member is less stretchable when a
strain rate of the covering member in the stretch direction of the
fabric material is in the high strain rate region than when the
strain rate of the covering member is in the low strain rate
region.
[0009] According to the first aspect, the covering member, which is
formed by integrally providing the overlay material made of a
thermoplastic elastomer on a surface of the fabric material, has
such strain rate dependence that the tensile load per unit width
with respect to the strain amount is higher and the covering member
is less stretchable in the high strain rate region than in the low
strain rate region. That is, the covering member has such
characteristics that it is flexible and easy to stretch in the low
strain rate region while it is harder and less stretchable in the
high strain rate region than in the low strain rate region. Thanks
to the characteristics, when a gentle external force is applied to
the covering member (that is, the strain rate is in the low strain
rate region), such as when a user puts on the covering member, the
covering member is relatively flexible and easy to stretch. Thus,
the covering member has improved fitting properties and fits the
shape of a body. On the other hand, when the user wearing the
covering member does heavy exercise and a sudden external force is
applied to the covering member (that is, when the strain rate is in
the high strain rate region), the covering member is relatively
hard and less stretchable. Thus, the covering member has improved
holding properties and firmly holds the body covered with the
covering member. Thus, the covering member of the first aspect has
both the fitting properties and the holding properties described
above, and exhibits the fitting or holding properties according to
a state of usage. Note that the "tensile load per unit width"
refers to the value of a tensile load (N/mm) applied to a unit
width, where a direction intersecting with the stretch direction of
the fabric material is defined as the width direction and a
dimension of the covering member in the width direction is
converted to the unit width of 1 mm.
[0010] A second aspect of the present invention is an embodiment of
the first aspect. In the second aspect, the overlay material is
bonded to the surface of the fabric material via an extensible
thermoplastic film material.
[0011] According to the second aspect, the overlay material and the
surface of the fabric material can be bonded to each other, while
the thermoplastic film material separates them from each other and
substantially prevents part of the thermoplastic elastomer from
permeating the fabric material. This makes it possible to prevent
the stretchability of the covering member from being impaired,
while keeping the fabric material and the overlay material firmly
bonded to each other.
[0012] A third aspect of the present invention is an embodiment of
the first or second aspect. In the third aspect, a relationship
between the strain and the tensile load per unit width determined
by a tensile test is that the tensile load P per unit width (N/mm)
with respect to a strain amount of 1% is within the range of
0.05.ltoreq.P.ltoreq.1.09 in the low strain rate region, whereas
the tensile load P is within the range of 0.65.ltoreq.P.ltoreq.2.47
in the high strain rate region.
[0013] According to the third aspect, setting the tensile load per
unit width with respect to a strain amount of 1% within the
respective numerical range can specifically achieve the covering
member having such strain rate dependence that the covering member
is flexible and easy to stretch in the low strain rate region
whereas it is harder and less stretchable in the high strain rate
region than in the low strain rate region.
[0014] A fourth aspect of the present invention is an embodiment of
any one of the first to third aspects. In the fourth aspect, a
relationship between the strain and the tensile load per unit width
determined by a tensile test is that the tensile load P per unit
width (N/mm) with respect to a strain amount of 5% is within the
range of 0.25.ltoreq.P.ltoreq.2.05 in the low strain rate region,
whereas the tensile load P is within the range of
1.72.ltoreq.P.ltoreq.7.85 in the high strain rate region.
[0015] According to the fourth aspect, setting the tensile load per
unit width with respect to a strain amount of 5% within the
respective numerical range can specifically achieve the covering
member having such strain rate dependence that the covering member
is flexible and easy to stretch in the low strain rate region,
whereas it is harder and less stretchable in the high strain rate
region than in the low strain rate region.
[0016] A fifth aspect of the present invention is directed to a
covering member for covering a body, the covering member including:
a stretchable fabric material; and an overlay material made of a
thermoplastic elastomer and integrally provided on a surface of the
fabric material. The covering member has such strain rate
dependence that as a strain rate of the covering member in a
stretch direction of the fabric material increases, a tensile load
per unit width with respect to a strain amount increases and the
covering member becomes less stretchable.
[0017] Just like the first aspect, the fifth aspect can have both
the fitting properties and the holding properties and exhibit the
fitting or holding properties according to a state of usage.
[0018] A sixth aspect of the present invention is directed to a
sport shoe including an upper having the covering member of any one
of the first to fifth aspects.
[0019] According to the sixth aspect, thanks to the strain rate
dependence of the covering member, when a gentle external force is
applied to the upper (that is, when the strain rate is in the low
strain rate region), such as when a user puts on the sport shoes,
the upper is relatively flexible and easy to stretch. Thus, the
user is allowed to put on the sport shoes smoothly, and the sport
shoes suitably fit the shapes of the user's feet, exhibiting good
fitting properties. On the other hand, when the user wearing the
sport shoes does heavy exercise and a sudden external force is
applied to the upper (that is, when the strain rate is in the high
strain rate region), the upper is relatively hard and less
stretchable. Thus, the shoes firmly hold the user's feet covered
with the the upper, exhibiting good holding properties.
[0020] A seventh aspect of the present invention is directed a
fabric material-reinforcing structure including: a stretchable
fabric material; and a reinforcing material made of a thermoplastic
elastomer, integrally provided on the fabric material, and
reinforcing a mechanical strength of the fabric material. A
direction intersecting with a stretch direction of the fabric
material is defined as a width direction, a strain rate region with
strain rates higher than a reference strain rate is defined as a
high strain rate region, and a strain rate region with strain rates
equal to or lower than the reference strain rate is defined as a
low strain rate region. The fabric material-reinforcing structure
has such strain rate dependence that a tensile load per unit width
with respect to a strain amount of the fabric material-reinforcing
structure is higher and the fabric material-reinforcing structure
is less stretchable when a strain rate of the fabric
material-reinforcing structure in the stretch direction of the
fabric material is in the high strain rate region than when the
strain rate of the fabric material-reinforcing structure is in the
low strain rate region.
[0021] The seventh aspect provides the same advantages as in the
first aspect. Further, according to the seventh aspect, the
reinforcing material maintains the mechanical strength of the
fabric material constant, making it possible to reduce age
deterioration of the fabric material, for example.
[0022] An eighth aspect of the present invention is an embodiment
of the seventh aspect. In the eight aspect, the reinforcing
material is bonded to the surface of the fabric material via an
extensible thermoplastic film material.
[0023] The eighth aspect provides the same advantages as of the
second aspect.
[0024] A ninth aspect is an embodiment of the seventh or eighth
aspect. In the ninth aspect, a relationship between the strain and
the tensile load per unit width determined by a tensile test is
that the tensile load P per unit width (N/mm) with respect to a
strain amount of 1% is within the range of
0.05.ltoreq.P.ltoreq.1.09 in the low strain rate region, whereas
the tensile load P is within the range of 0.65.ltoreq.P.ltoreq.2.47
in the high strain rate region.
[0025] The ninth aspect provides the same advantages as of the
third aspect.
[0026] A tenth aspect of the present invention is an embodiment of
any one of the seventh to ninth aspects. In the tenth aspect, a
relationship between the strain and the tensile load per unit width
determined by a tensile test is that the tensile load P per unit
width (N/mm) with respect to a strain amount of 5% is within the
range of 0.25.ltoreq.P.ltoreq.2.05 in the low strain rate region,
whereas the tensile load P is within the range of
1.72.ltoreq.P.ltoreq.7.85 in the high strain rate region.
[0027] The tenth aspect provides the same advantages as of the
fourth aspect.
[0028] An eleventh aspect of the present invention is directed to a
fabric material-reinforcing structure comprising: a stretchable
fabric material; and a reinforcing material made of a thermoplastic
elastomer, integrally provided on the fabric material, and
reinforcing a mechanical strength of the fabric material. The
fabric material-reinforcing structure has such strain rate
dependence that as a strain rate of the fabric material-reinforcing
structure in the stretch direction of the fabric material
increases, a tensile load per unit width with respect to the strain
amount increases and the fabric material-reinforcing structure
becomes less stretchable.
[0029] The eleventh aspect provides the same advantages as of the
fifth aspect.
[0030] A twelfth aspect of the present invention is directed to a
sport shoe including an upper including the fabric
material-reinforcing structure of any one of the seventh to
eleventh aspects.
[0031] The twelfth aspect provides the same advantages as of the
sixth aspect.
Advantages of the Invention
[0032] As can be seen from the foregoing description, the covering
member or the fabric material-reinforcing structure of the present
invention, which has such characteristics (i.e., strain rate
dependence) that it is flexible and easy to stretch in the low
strain rate region and is harder and less stretchable in the high
strain rate region than in the low strain rate region, exhibits
high fitting properties in the low strain rate region, and high
holding properties in the high strain rate region.
BRIEF DESCRIPTION OF THE DRAWINGS
[0033] FIG. 1 is a perspective view of a shoe according to a first
embodiment of the present invention.
[0034] FIG. 2 is a plan view of the shoe according to the first
embodiment of the present invention.
[0035] FIG. 3 is a vertical cross-sectional view showing the
structure of a covering member used in an upper of a shoe.
[0036] FIG. 4 is a plan view schematically showing a positional
relationship between an overlay material and the skeleton structure
of a foot.
[0037] FIG. 5 is a side view schematically showing a positional
relationship between the overlay material and the skeleton
structure of a foot.
[0038] FIG. 6 is a graph showing the results (stress-strain
characteristics) of a tensile test on a sample p1.
[0039] FIG. 7 is a graph showing the results (stress-strain
characteristics) of a tensile test on a sample e3.
[0040] FIG. 8 schematically shows the shape of each sample.
[0041] FIG. 9 is a graph showing the results (a relationship
between strain and a tensile load per unit width) of a tensile test
on Sample 4.
[0042] FIG. 10 is a graph showing the results (a relationship
between strain and a tensile load per unit width) of a tensile test
on Sample 5.
[0043] FIG. 11 is a graph showing the results (a relationship
between strain and a tensile load per unit width) of a tensile test
on Sample 6.
DESCRIPTION OF EMBODIMENTS
[0044] Embodiments of the present invention will now be described
in detail with reference to the drawings. Note that the following
description of the embodiments is merely an example in nature, and
is not intended to limit the scope, application, or uses of the
present invention.
[0045] FIGS. 1 to 5 show a shoe S according to an embodiment of the
present invention, which is preferably used as a shoe for indoor
sports (e.g., volleyball, badminton, etc.) in which a player makes
sudden movements particularly frequently. In the drawings, only the
right shoe of a pair of shoes S is shown as an example. Since the
left shoe is symmetrical to the right shoe S, only the right shoe S
will be described in the following description, and the description
of the left shoe will be omitted herein. In the following
description, the expressions "above," "upward," "on a/the top of,"
"below," "under," and "downward," represent the vertical positional
relationship between respective components of the shoe S. The
expressions "front," "fore," "forward," "anterior," "rear," "hind,"
"behind," "backward," and "posterior" represent the positional
relationship in the longitudinal direction between respective
components of the shoe S. The expressions "left (side),"
"leftward," "right (side)," and "rightward" represent the
positional relationship in the width direction of the shoe S.
[0046] As shown in FIG. 1, the shoe S includes an outsole 1 which
includes a ground surface configured to contact the ground. The
outsole 1 is made of a hard elastic member having a high hardness.
A midsole 2 configured to support a planta of a human body is
provided above the outsole 1. The midsole 2 is made of, for
example, a soft elastic material, and has a lower portion bonded to
an upper portion of the outsole 1 with an adhesive or the like.
[0047] Above the midsole 2, an upper 3 is provided to cover a foot
of a body (specifically, from the tiptoe to the heel). The upper 3
has an ankle opening 3a in its top portion. The lower periphery of
the upper 3 is integrally bonded to the entire periphery of the
midsole 2 with an adhesive or the like. The shoe S has, in its top
portion, a throat opening 3b which is continuous with the ankle
opening 3a and extends in the longitudinal direction. Left and
right eyelet tapes 3c are fixed to the left and right edges of the
throat opening 3b by sewing or other means.
[0048] The upper 3 includes a stretchable fabric material 4. As the
fabric material 4, a mesh fabric having meshes and produced by
warp-knitting (i.e., double-raschel knitting) a polyester yarn may
be suitably used, for example. Such a mesh fabric is characterized
in that the fabric itself tends to become more flexible as the
diameter of the yarn decreases or as the stitches become coarser.
In addition, it is possible to produce a flexible mesh fabric by
reducing the thickness of the fabric. That is, a strain rate
dependence of the upper, which will be described later, can be
adjusted by appropriately changing the degree of stretch of the
mesh fabric. In this embodiment, the fabric material 4 is
configured to stretch in the width direction of the shoe S.
[0049] As shown in FIGS. 1 and 2, band-shaped overlay materials 5,
5, . . . which are made of a thermoplastic elastomer are integrally
provided on portions of the surface of the fabric material 4.
Specifically, as shown in FIG. 3, the overlay material 5 is bonded
to (i.e., combined with) the surface of the fabric material 4 via
an extensible thermoplastic film material 6 (i.e., a hot-melt
adhesive). In this embodiment, the overlay material 5 and the
portion of the fabric material 4 to which the overlay material 5 is
bonded together form a covering member 7 of the present invention.
The thickness of the overlay material 5 is preferably within the
range from 0.5 mm to 2.0 mm.
[0050] As shown in FIGS. 1 and 2, a pair of overlay materials 5, 5
are arranged along the shoe width in a front portion of the shoe S
and another pair of overlay materials 5, 5 are arranged along the
shoe width in a rear portion of the shoe S. In side view, each
overlay material 5 extends in an inverted V shape between the
eyelet tape 3c and the midsole 2. As shown in FIGS. 4 and 5, the
pair of overlay materials 5, 5 in the front portion of the shoe S
is arranged to correspond to, for example, a forefoot F
(specifically, a part including front end portions of the
metatarsals, the proximal phalanxes, and the distal phalanxes) of a
foot. The other pair of overlay materials 5, 5 in the rear portion
of the shoe S is arranged to correspond to, for example, a part
including a midfoot M and a front portion of a hindfoot H
(specifically, a part including rear end portions of the
metatarsals, the cuneiform bone, the cuboid bone, and the navicular
bone).
[0051] It is preferable to use, as the thermoplastic elastomer for
the present invention, an elastomer having such physical properties
that a value (so-called tan s) obtained by dividing a coefficient
of viscosity by a coefficient of elasticity exhibits a peak value
in the room temperature range. A thermoplastic elastomer having
such physical properties is likely to exhibit strain rate
dependence similar to that which will be described later. More
specifically, the thermoplastic elastomer used in this embodiment
is comprised of a composition containing a
4-methyl-1-pentene/.alpha.-olefin copolymer (manufactured by Mitsui
Chemicals, Inc.). A thermoplastic elastomer containing this
composition or any other similar composition can be configured such
that the tan s reaches the peak value in the room temperature range
and the hardness of the thermoplastic elastomer has a practical
value suitable for this embodiment, by adjusting the blend amount
of an olefin polymer component such as polypropylene (PP) and the
blend amount of an olefin rubber component such as ethylene
propylene rubber (EPR) and ethylene propylene diene rubber (EPDM).
Other specific examples of the thermoplastic elastomer include
olefin-based thermoplastic elastomers, urethane-based thermoplastic
elastomers, and styrene-based thermoplastic elastomers. In
particular, to reduce the weight of the overlay material 5, an
olefin-based thermoplastic elastomer is more preferable.
[0052] Next, the present invention has a feature: the covering
member 7 of the upper 3 has such strain rate dependence that as the
upper 3 increases in its strain rate in the stretch direction of
the fabric material 4 serving as a base, a tensile load per unit
width with respect to a strain amount increases and the covering
member 7 becomes less stretchable. Specifically, the covering
member 7 has such strain rate dependence that a tensile load per
unit width with respect to a strain amount of the covering member 7
is higher and the covering member 7 is less stretchable when a
strain rate of the upper 3 in the stretch direction of the fabric
material 4 is in a high strain rate region with strain rates above
a reference strain rate than when the strain rate of the upper 3 is
in a low strain rate region with strain rates at or below the
reference strain rate.
[0053] Here, the "tensile load per unit width" refers to the value
of a tensile load (N/mm) applied to a unit width, where a direction
intersecting with the stretch direction of the fabric material 4 is
defined as the width direction and a dimension of the covering
member 7 in the width direction is converted to the unit width of 1
mm. More specifically, it is general to determine the strain rate
dependence based on a change in tensile stress with respect to
stain amount. However, in this embodiment, in view of the fact that
the covering member 7 is unlikely to have a strictly uniform
thickness due to its combined structure including the fabric
material 4 and the overlay material 5, the concept of "tensile load
per unit width" is employed to determine the strain rate dependence
of the covering member 7, instead of the concept of stress
described as a force per unit cross-sectional area
(N/mm.sup.2).
[0054] For the sake of convenience in describing this embodiment,
as an example, a strain rate of, for example, 100%/s is defined as
the "reference strain rate", and a strain rate region with strain
rates equal to or lower than the reference strain rate (e.g., a
strain rate region from 4.2%/s to 100%/s) is defined as a "low
strain rate region," while a strain rate region with strain rates
higher than the reference strain rate (e.g., a strain rate region
less than or equal to 500%/s and higher than 100%/s) is defined as
a "high strain rate region."
[0055] As can be seen form foregoing, in the shoe S according to
this embodiment, the covering member 7 that is provided for the
upper 3 and comprised of the overlay material 5 made of the
thermoplastic elastomer and integrated with the surface of the
fabric material 4 has strain rate dependence described above. As a
result, specifically, the covering member 7 has such
characteristics that in the low strain rate region, it is
relatively flexible and easy to stretch, whereas it is harder and
less stretchable in the high strain rate region than in the low
strain rate region. Thanks to the characteristics, when a gentle
external force is applied to the upper 3 (i.e., when the strain
rate is in the low strain rate region), such as when a user puts on
the shoes S, the upper 3 is relatively flexible and easy to
stretch. Consequently, the user is allowed to smoothly insert
his/her foot into the ankle opening 3a to put on the shoe S, and
the shoe S suitably fits the shape of the user's foot, exhibiting a
good fitting property. On the other hand, when the user wearing the
shoes S does heavy exercise and a sudden external force is applied
to the upper 3 (i.e., when the strain rate is in the high strain
rate region), the upper 3 is relatively hard and less stretchable.
Thus, the shoe S firmly holds the user's foot covered with the
upper 3, exhibiting high holding properties. Thus, this embodiment
enables the upper 3 to have both the holding property and the
fitting property described above, and to exhibit the fitting or
holding properties according to a state of usage.
[0056] The overlay material 5 of the covering member 7 is bonded to
the surface of the fabric material 4 via the extensible
thermoplastic film material 6. Thanks to this configuration, the
overlay material 5 and the surface of the fabric material 4 can be
bonded to each other, while the thermoplastic film material 6
separates them from each other and substantially prevents part of
the thermoplastic elastomer from permeating the fabric material 4.
This makes it possible to prevent the stretchability of the upper 3
from being impaired, while keeping the fabric material 4 and the
overlay material 5 firmly bonded to each other.
[0057] For the covering member 7, strain and a tensile load per
unit width determined by a tensile test preferably have the
following relationship: in the low strain rate region, the tensile
load P per unit width (N/mm) with respect to a strain amount of 1%
is within the range of 0.05.ltoreq.P.ltoreq.1.09, whereas in the
high strain rate region, the tensile load P is within the range of
0.65.ltoreq.P.ltoreq.2.47. Alternatively, strain and the tensile
load per unit width determined by the same tensile test preferably
have the following relationship: in the low strain rate region, the
tensile load P per unit width (N/mm) with respect to a strain
amount of 5% is within the range of 0.25.ltoreq.P.ltoreq.2.05,
whereas in the high strain rate region, the tensile load P is
within the range of 1.72.ltoreq.P.ltoreq.7.85. Thus, setting the
tensile load P per unit width with respect to a strain amount of 1%
and/or 5% within the respective numerical range described above
enables the covering member 7 of the upper 3 to have such strain
rate dependence that the covering member 7 is flexible and easy to
stretch in the low strain rate region, while the covering member 7
is harder and less stretchable in the high strain rate region than
in the low strain rate region. In particular, the numerical value
of a strain amount of 5% is considered to be the average of strain
amounts generated when an external force is applied to the uppers
provided for sport shoes of the known art. Thus, configuring the
covering member 7 of the upper 3 such that the tensile load per
unit width with respect to a strain amount of 5% is within the
numerical range described above further ensures that both the
fitting properties and the holding properties are obtained.
Variation of Embodiment
[0058] The shoe S of the embodiment described above includes the
covering member 7 including the overlay materials 5, 5, . . . and
provided for the upper 3. However, the present invention is not
limited to this embodiment. Specifically, as a variation which is
an alternative to the embodiment in which the covering member 7 is
provided for the upper 3, a fabric material-reinforcing structure
for the fabric material 4 may be provided for the upper 3. The
fabric material-reinforcing structure is comprised of a reinforcing
material configured similarly to the overlay material 5 described
above and increasing the mechanical strength of the fabric material
4, and a portion of the fabric material 4 to which the reinforcing
material is bonded. This fabric material-reinforcing structure for
the fabric material 4 is as effective as the covering member 7, and
maintains the mechanical strength of the fabric material 4
constant. This makes it possible to reduce age deterioration of the
fabric material 4, for example.
OTHER EMBODIMENTS
[0059] In the above embodiment, the mesh fabric is used as the
fabric material 4. However, the present invention is not limited to
this embodiment. Specifically, the fabric material 4 may be any
stretchable material, such as a knitted fabric, a woven fabric, a
nonwoven fabric, an artificial leather, or a cloth. The strain rate
dependence of the covering member 7 of the upper 3 can be adjusted
by taking account of the stretchability and stress properties of
the fabric material 4 to be combined with the overlay material
5.
[0060] In the above embodiment, the overlay material 5 has a
thickness within the range from 0.5 mm to 2.0 mm. However, the
thickness is not limited to this range. For example, the thickness
of the overlay material 5 may be set to be larger than 2.0 mm. As
the thickness of the overlay material 5 increases, the stress with
respect to the strain amount increases. Changing the thickness of
the overlay material 5 as appropriate enables adjustment of the
strain rate dependence of the covering member 7. This applies also
to the thickness of the reinforcing material of the variation
described above.
[0061] In the embodiment described above, the fabric material 4 is
combined with the overlay material 5 by bonding the overlay 5 to
the surface of the fabric material 4 via the extensible
thermoplastic film material 6 (i.e., the hot-melt adhesive).
However, the present invention is not limited to this embodiment.
For example, the overlay material 5 may be combined with the fabric
material 4 by, for example, fusion bonding through injection
molding or hot pressing, adhesion with an adhesive, primer
treatment, or fixing by sewing. This applies also to the process
for combining the fabric material-reinforcing material of the
variation described above with the fabric material 4.
[0062] In the embodiment described above, the covering members 7
are provided in portions of the upper 3 of the shoe S. However, the
present invention is not limited to the embodiment. For example, a
covering member 7 having the same structure as that of the upper 3
can be used for socks, gloves, tights (compression wear),
brassieres, supporters, wear fitting the body, such as shirts and
pants, gloves for baseball, wristbands, stocking bands, and the
like. The fabric material-reinforcing structure for the fabric
material 4 according to variation described above can also be used
in these applications.
[0063] Note that the present invention is not limited to the
embodiments described above, and various changes and modifications
may be made without departing from the scope of the present
invention.
Examples
[Tensile Test 1]
[0064] First, the overlay material, which is one of the components
constituting the covering member, was subjected to static and
dynamic uniaxial tensile tests to confirm whether the overlay
material had strain rate dependence.
[0065] For these tensile tests, a tensile tester called
"ElectroPlus E 3000 electric tester" manufactured by Instron Japan
Co., Ltd. was used at a high strain rate of 100%/s or more. As the
main points of the specifications of this tensile tester, the
dynamic load capacity is .+-.3000 N and the stroke is 60 mm. The
tensile tester can perform static and dynamic tensile tests on
various materials and the like. At low strain rates of 4%/s and
42%/s, a tensile tester called "3365-Type Electromechanical
Universal Material Tester" manufactured by Instron Japan Co., Ltd.
was used. The dynamic load capacity of the load cell of this
tensile tester is .+-.1000 N. In addition, "ElectroPlus E 3000
electric tester" used for the test at the high strain rate was used
also to make measurements at strain rates of 4%/s and 42%/s. It was
confirmed that the same or similar measurement results were
obtained by using the "3365-Ttype Electromechanical Universal
Material Tester."
[0066] Sample e3 made of an olefin-based thermoplastic elastomer
and having a thickness of 2.0 mm was used as an example of this
test. Sample e3 was prepared so as to have, at a portion set on the
tensile tester, a length dimension (i.e. a dimension in the stretch
direction of a mesh fabric which will be described later) of 4 cm,
and a width dimension (i.e., a dimension in a direction
intersecting with the stretch direction of the mesh fabric) of 2
cm.
[0067] Further, as a comparative example for Sample e3, Sample p1
made of soft polyurethane and having a thickness of 2.0 mm was
used. Sample p1 was prepared so as to have the same size as that of
Sample e3 made of the elastomer.
[0068] FIG. 6 shows the results (stress-strain characteristics) of
the uniaxial tensile tests that were conducted on Sample p1 as the
comparative example, using the tensile testers described above and
at three different strain rates (i.e., 4.2%/s, 100%/s, and 500%/s).
Likewise, FIG. 7 shows the results of the tensile tests conducted
on Sample e3 as the example. Here, for the sake of convenience of
discussion of results, a strain rate of 100%/s was defined as the
"reference strain rate." Based on this, a low strain rate region
with strain rates equal to or lower than the reference strain rate
(i.e., a strain rate region from 4%/s to 100%/s) was defined as the
"low strain rate region," whereas a strain rate region with strain
rates higher than the reference strain rate was defined as the
"high strain rate region." The same applies to Tensile Test 2 which
will be described later.
[0069] As shown in FIG. 6, for Sample p1 (i.e., the comparative
example), the rate of change of the tensile stress values with
respect to the strain amount was substantially constant, and no
significant change was observed in the tensile stress values with
respect to the strain amount irrespective of differences in the
strain rate. That is, for Sample p1, the degree of stretch hardly
changed in both the low and high strain rate regions. Thus, Sample
p1 did not exhibit strain rate dependence.
[0070] In contrast, as shown in FIG. 7, for Sample e3 (i.e. the
example), the relationship between the tensile stress and the
strain amount varied so as to draw a nonlinear curve due to the
viscoelasticity of the olefin-based thermoplastic elastomer. In
particular, in the high strain rate region, the tensile stress
value with respect to the strain amount tended to vary so as to
draw a larger curve. For Sample e3, as the strain rate was
increased from a low rate to a high rate, the tensile stress value
with respect to the strain amount increased. For example, at the
reference strain rate (100%/s) that is the upper limit of the low
strain rate region, the tensile stress value was about 1.8
N/mm.sup.2 with respect to a strain amount of 5%. On the other
hand, at a strain rate of 500%/s included within the high strain
rate region, the tensile stress value was about 2.9 N/mm.sup.2 with
respect to a strain amount of 5%. That is to say, in the low strain
rate region, the tensile stress value with respect to a strain
amount of 5% was relatively low, whereas in the high strain rate
region, the tensile stress value with respect to a strain amount of
5% increased to be about 1.5 or more times as large as that in the
low strain rate region.
[0071] As can be seen, it has been confirmed that the olefin-based
thermoplastic elastomer has such characteristics that it is
flexible and easy to stretch in the low strain rate region and is
harder and less stretchable in the high strain rate region than in
the low strain rate region. Thus, the olefin-based thermoplastic
elastomer has strain rate dependence. It has become clear, from
these results, that a covering member formed by combining an
overlay material of the soft polyurethane with a fabric material
does not exhibit strain rate dependence, whereas a covering member
formed by combining an overlay material of the olefin-based
thermoplastic elastomer with the fabric material exhibits strain
rate dependence.
[Tensile Test 2]
[0072] Next, using the tensile testers described above, static and
dynamic uniaxial tensile tests were carried out on Samples 1 to 12
of the covering member shown below, and based on the obtained
results, the behavior of tensile load per unit width with respect
to the strain rate (strain rate dependence) of each sample was
observed. Here, in these tensile tests, the "tensile load per unit
width" refers to a tensile load value (N/mm) applied to a unit
width, where a direction intersecting with the stretch direction of
the mesh fabric is defined as the width direction and a dimension
of each sample in the width direction is converted to the unit
width of 1 mm.
[0073] Four different mesh fabrics m1 to m4 produced by
warp-knitting (i.e., double-raschel knitting) a polyester yarn were
used as fabric materials for the samples. Each of these mesh
fabrics was configured to stretch in the longitudinal direction of
each sample described later. Further, the mesh fabrics m1 to m4
were different in degree of stretch, depending on the
specifications (the yarn diameter, the coarseness of the stitches,
the thickness of the fabric itself, etc.). The mesh fabrics m1 to
m4 were designed so as to become less stretchable (harder) in the
order from m1 to m4.
[0074] Olefin-based thermoplastic elastomers e1 to e3 were used as
overlay materials to be bonded to the surfaces of the respective
mesh fabrics. The elastomers e1 to e3 had different thicknesses.
Specifically, the elastomer e1 had a thickness of 0.5 mm; the
elastomer e2 had a thickness of 1.0 mm (i.e., the same thickness as
that of the sample 2e used in Tensile Test 1 described above); and
the elastomer e3 had a thickness of 2.0 mm.
[0075] Samples 1 to 12 of the covering members were prepared by
appropriately combining the mesh fabrics m1 to m4 with the
elastomers e1 to e3 (see Tables 1 to 12 for combinations of the
mesh fabrics and the elastomers). The samples were prepared by
using a method in which each elastomer was bonded to the surface of
an associated one of the mesh fabrics via an extensible
thermoplastic film material (i.e., a hot-melt adhesive). As shown
in FIG. 8, each sample was prepared so as to have, at a portion set
on the tensile testers described above (the portion defined by the
dotted lines in FIG. 8), a length dimension of 4 cm in the stretch
direction of the associated mesh fabric, and a width dimension of 2
cm in the width direction.
[0076] Uniaxial tensile tests were conducted on each of Samples 1
to 12 prepared in the foregoing manner, by using the tensile
testers described above at four different strain rates (i.e.,
4.2%/s, 42%/s, 100%/s, and 500%/s). Based on the test results (that
is, the relationship between the strain and the tensile load per
unit width), it was verified whether each sample had the strain
rate dependence, and a study was conducted on appropriate ranges of
the tensile load P per unit width (N/mm) with respect to the strain
amount. Tables 1 to 4 show values of tensile load per unit width
(N/mm) of Samples 1 to 12 at respective strain rates when the
strain amount was 1%.
TABLE-US-00001 TABLE 1 Sample 1 Sample 2 Sample 3 (m1 + e1) (m1 +
e2) (m1 + e3) Thickness of Thickness of Thickness of Elastomer =
Elastomer = Elastomer = <Strain Amount = 1%> 0.5 mm 1.0 mm
2.0 mm Strain Rate 4.2%/s 0.05 N/mm 0.11 N/mm 0.34 N/mm 42%/s -- --
-- 100%/s -- -- -- 500%/s 0.65 N/mm 0.96 N/mm 1.35 N/mm
TABLE-US-00002 TABLE 2 Sample 4 Sample 5 Sample 6 (m2 + e1) (m2 +
e2) (m2 + e3) Thickness of Thickness of Thickness of Elastomer =
Elastomer = Elastomer = <Strain Amount = 1%> 0.5 mm 1.0 mm
2.0 mm Strain Rate 4.2%/s 0.11 N/mm 0.18 N/mm 0.32 N/mm 42%/s --
0.15 N/mm -- 100%/s -- 1.09 N/mm -- 500%/s 0.71 N/mm 1.51 N/mm 1.87
N/mm
TABLE-US-00003 TABLE 3 Sample 7 Sample 8 Sample 9 (m3 + e1) (m3 +
e2) (m3 + e3) Thickness of Thickness of Thickness of Elastomer =
Elastomer = Elastomer = <Strain Amount = 1%> 0.5 mm 1.0 mm
2.0 mm Strain Rate 4.2%/s 0.12 N/mm 0.21 N/mm 0.39 N/mm 42%/s -- --
-- 100%/s -- -- -- 500%/s 0.76 N/mm 0.71 N/mm 2.20 N/mm
TABLE-US-00004 TABLE 4 Sample 10 Sample 11 Sample 12 (m4 + e1) (m4
+ e2) (m4 + e3) Thickness of Thickness of Thickness of Elastomer =
Elastomer = Elastomer = <Strain Amount = 1%> 0.5 mm 1.0 mm
2.0 mm Strain Rate 4.2%/s 0.34 N/mm 0.34 N/mm 0.46 N/mm 42%/s -- --
-- 100%/s -- -- -- 500%/s 1.13 N/mm 1.95 N/mm 2.47 N/mm
[0077] Tables 5 to 8 show values of tensile load per unit width
(N/mm) of Samples 1 to 12 at respective strain rates when the
strain amount was 5%.
TABLE-US-00005 TABLE 5 Sample 1 Sample 2 Sample 3 (m1 + e1) (m1 +
e2) (m1 + e3) Thickness of Thickness of Thickness of Elastomer =
Elastomer = Elastomer = <Strain Amount = 5%> 0.5 mm 1.0 mm
2.0 mm Strain Rate 4.2%/s 0.25 N/mm 0.31 N/mm 0.73 N/mm 42%/s -- --
-- 100%/s -- -- -- 500%/s 1.72 N/mm 3.51 N/mm 5.17 N/mm
TABLE-US-00006 TABLE 6 Sample 4 Sample 5 Sample 6 (m2 + e1) (m2 +
e2) (m2 + e3) Thickness of Thickness of Thickness of Elastomer =
Elastomer = Elastomer = <Strain Amount = 5%> 0.5 mm 1.0 mm
2.0 mm Strain Rate 4.2%/s 0.36 N/mm 0.56 N/mm 0.96 N/mm 42%/s --
1.04 N/mm -- 100%/s -- 2.05 N/mm -- 500%/s 2.17 N/mm 4.41 N/mm 6.85
N/mm
TABLE-US-00007 TABLE 7 Sample 7 Sample 8 Sample 9 (m3 + e1) (m3 +
e2) (m3 + e3) Thickness of Thickness of Thickness of Elastomer =
Elastomer = Elastomer = <Strain Amount = 5%> 0.5 mm 1.0 mm
2.0 mm Strain Rate 4.2%/s 0.54 N/mm 0.72 N/mm 1.10 N/mm 42%/s -- --
-- 100%/s -- -- -- 500%/s 2.59 N/mm 4.06 N/mm 7.00 N/mm
TABLE-US-00008 TABLE 8 Sample 10 Sample 11 Sample 12 (m4 + e1) (m4
+ e2) (m4 + e3) Thickness of Thickness of Thickness of Elastomer =
Elastomer = Elastomer = <Strain Amount = 5%> 0.5 mm 1.0 mm
2.0 mm Strain Rate 4.2%/s 1.31 N/mm 1.59 N/mm 1.81 N/mm 42%/s -- --
-- 100%/s -- -- -- 500%/s 3.98 N/mm 5.79 N/mm 7.85 N/mm
[0078] FIGS. 9 to 11 and Tables 1 to 8 show that in Samples 1 to 12
for the covering member, each of which was formed by combining the
respective overlay material of olefin-based thermoplastic elastomer
with the surface of the respective fabric material, have such
characteristics that they are flexible and easy to stretch in the
low strain rate region whereas they are harder and less stretchable
in the high strain rate region than in the low strain rate
region.
[0079] Tables 1 to 4 show that the tensile load P per unit width
(N/mm) with respect to a strain amount of 1% is within the range of
0.05.ltoreq.P.ltoreq.1.09 in the low strain rate region, whereas
the tensile load P is within the range of 0.65.ltoreq.P.ltoreq.2.47
in the high strain rate region. Tables 5 to 8 show that the tensile
load P per unit width (N/mm) with respect to a strain amount of 5%
is within the range of 0.25.ltoreq.P.ltoreq.2.05 in the low strain
rate region, whereas the tensile load P is within the range of
1.72.ltoreq.P.ltoreq.7.85 in the high strain rate region.
[0080] As a result of further consideration, it has been found that
at a strain amount of 1%, the upper limit value (2.47 N/mm) of the
tensile load per unit width in the high strain rate region is about
twice as large as the upper limit value (1.09 N/mm) of the tensile
load per unit width within the low strain rate region. Further, it
has been found that at a strain amount of 5% (corresponding to an
average strain amount generated when an external force is applied
to the upper of known shoes), the upper limit value (7.85 N/mm) of
the tensile load per unit width in the high strain rate region is
about four times as large as the upper limit value (2.05 N/mm) of
the tensile load per unit width in the low strain rate region.
Based on these results, use of the samples of the covering member
for the uppers of the sport shoes, for example, makes it possible
to reliably obtain both the fitting property and the holding
property described in the embodiment.
[0081] As described above, it has been concluded that the covering
member of the present invention has such strain rate dependence
that a tensile load per unit width with respect to a strain amount
of the covering member is higher and the covering member is less
stretchable when a strain rate of the covering member in the
stretch direction of the fabric material is in a high strain rate
region with strain rates above a reference strain rate than when
the strain rate of the covering member is in a low strain rate
region with strain rates at or below the reference strain rate. As
to the fabric material-reinforcing structure according to the
variation described above, the same or similar test results and
conclusion as of the covering member can also be achieved.
INDUSTRIAL APPLICABILITY
[0082] The present invention is industrially applicable, for
example, as a covering member for an upper of shoes for indoor
sports in which a player makes sudden movements particularly
frequently.
DESCRIPTION OF REFERENCE CHARACTERS
[0083] S: Shoe [0084] 1: Outsole [0085] 2: Midsole [0086] 3: Upper
[0087] 4: Fabric Material [0088] 5: Overlay Material [0089] 6:
Thermoplastic Film Material [0090] 7: Covering Member
* * * * *