Note: Descriptions are shown in the official language in which they were submitted.
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DESCRIPTION
Sole Structure for a Shoe
TECHNICAL FIELD
The present invention relates generally to a sole
structure for a shoe, and more particularly, to an
improvement in the sole structure for enhancing cushioning
and bending properties of the heel portion of the sole.
BACKGROUND ART
Japanese patent application laying-open
publication No. 2003-339405 shows a sole structure for a shoe
to secure cushioning properties of the heel portion. In the
sole structure, an upper plate and a lower plate are disposed
on the upper side and the lower side, respectively, of a wavy
plate that is disposed at the heel region.
In this case, a plurality of voids formed between
the wavy plate and the upper and lower plates function as
cushion holes to secure cushioning properties of the heel
portion.
However, in the prior art structure shown in
JP publication No. 2003-339405, since the upper convex
portions and the lower convex portions of the wavy plate are
fixedly attached to the upper plate and the lower plate,
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respectively, a vertical deformation of the wavy plate is
restricted at the time of striking onto the ground.
Therefore, the prior art structure had the limitation on
improvement in cushioning properties of the sole heel
portion. Also, in the prior art structure, restriction on the
deformation of the wavy plate has impeded the bending
properties of the heel portion as well.
On the other hand, Japanese patent application
laying-open publication No. 2003-9906 shows a sole structure
for a shoe having an upper wavy sheet and a lower wavy sheet
that are oppositely disposed via a void between an upper
midsole and a lower midsole in the sole heel portion.
In this case, the void between the upper and lower
wavy sheet functions as a cushion hole to secure the
cushioning properties of the heel portion.
However, in the prior art structure shown in
JP publication No. 2003-9906, since there are provided the
upper midsole on the upper surface of the upper wavy sheet
and the lower midsole on the lower surface of the lower wavy
sheet, the upper and lower midsole restricts the vertical
deformation of the wavy sheet at the time of impacting the
ground. Therefore, the prior art structure had the limitation
on improvement in cushioning properties of the sole heel
portion. Also, in the prior art structure, restriction on the
deformation of the wavy sheet has impeded the bending
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properties of the heel portion as well.
An object of the present invention is to provide a
sole structure for a shoe that can improve bending properties
as well as cushioning properties of the sole heel portion.
DISCLOSURE OF INVENTION
A sole structure for a shoe according to a first
aspect of the present invention includes an upper plate
disposed on the upper side of the heel region of the sole
structure, a wavy lower plate disposed on the lower side of
the heel region and having at least two downwardly convex
portions and that form a void relative to the upper plate,
and a plurality of outsole portions separated in the
longitudinal direction and fitted to the lower surface of the
convex portions of the lower plate.
According to the first aspect of the present
invention, at the time of striking onto the ground, the lower
surface of the downwardly convex portions of the lower plate
contacts the ground through the outsole portions. At this
time, the void formed between the upper and lower plates acts
as a cushion hole to display cushioning properties of the
heel portion. Moreover, in this case, since the
longitudinally separated outsole portions are directly fitted
to the lower surfaces of the downwardly convex portions of
the wavy lower plate, deformation of the downwardly convex
portions of the wavy lower plate is not restricted
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at the time of striking onto the ground, thereby enhancing
the cushioning properties of the sole heel portion. Also, by
securing the deformation of the wavy lower plate, bending
properties of the sole heel portion is improved. As a result,
when a shoe wearer impacts the ground on the rear end of the
sole heel portion and the load transfers in the forward
direction, a "ride feeling" can be improved.
Here, FIG. 8 shows the result of an impact test of
the sole structure of the first aspect of the present
invention and the prior art sole structure shown in figure 3
of JP publication No. 2003-9906.
In this impact test, a weight of 10kg falls down
from the height of 60mm onto each of the sole structures, and
thereafter, the amount of deformation of each of the sole
structures is measured. The thickness of each of the sole
structures before falling of the weight is 30mm, and a hit
area on each of the sole structures is 15.9cm2.
The amount of deformation of each of the sole
structures after falling of the weight is 18.02mm for the
sole structure of the present invention and 14.38mm for the
prior art sole structure. In other words, the amount of
deformation of the first aspect of the present invention is
125.3 in the case where the amount of deformation of the prior
art structure is 100. That is, the deformation of the present
invention is about 1.25 times greater than that of the prior
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art structure.
In addition, a shoe wearer can sense the
difference in the cushioning properties if the deformation is
110 relative to 100 in the prior art structure. Therefore, if
the deformation is 125.3 as in the present invention, the
difference in the cushioning properties is remarkable.
A sole structure for a shoe according to a second
aspect of the present invention includes an upper plate
disposed on the upper side of the heel region of the sole
structure, a wavy lower plate disposed on the lower side of
the heel region and having at least two downwardly convex
portions and that form a void relative to the upper plate,
and a plurality of cleats provided on the lower surface of
the downwardly convex portions of the lower plate.
According to the second aspect of the present
invention, at the time of striking onto the ground, first,
the cleats stick into the ground and then, the lower surface
of the downwardly convex portions of the lower plate contacts
the ground. At this time, the void formed between the upper
and lower plates acts as a cushion hole to display cushioning
properties of the heel portion. Moreover, in this case, since
the cleats are provided on the lower surfaces of the
downwardly convex portions of the wavy lower plate,
deformation of the downwardly convex portions of the wavy
lower plate is not restricted at the time of striking onto
the ground, thereby enhancing the cushioning properties
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of the sole heel portion. Also, by securing the deformation
of the wavy lower plate, bending properties of the sole heel
portion is improved.
Here, FIG. 12 shows the result of an impact test
of the sole structure of the second aspect of the present
invention and the prior art sole structure shown in FIG. 11.
The prior art sole structure 100 shown in FIG. 11 differs
from the second aspect of the present invention (see FIG. 9A)
in that an upper plate is not provided above the lower plate
3 to form the void with the lower plate 3.
In this impact test, as with the first aspect of
the present invention, a weight of 10kg falls down from the
height of 60mm onto each of the sole structures, and
thereafter, the amount of deformation of each of the sole
structures is measured. The thickness of each of the sole
structures before falling of the weight is 20mm, and a hit
area on each of the sole structures is 15.9cm2.
The amount of deformation of each of the sole
structures after falling of the weight is 13.0mm for the sole
structure of the second aspect of the present invention and
11.3mm for the prior art sole structure. In other words, the
amount of deformation of the present invention is 115.0 in
the case where the amount of deformation of the prior art
structure is 100. That is, the deformation of the present
invention is about 1.15 times greater than that of the prior
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art structure.
In addition, a shoe wearer can sense the
difference in the cushioning properties if the deformation is
110 relative to 100 in the prior art structure. Therefore, if
the deformation is 115.0 as in the present invention, the
difference in the cushioning properties is remarkable.
A sole structure for a shoe according to a third
aspect of the present invention includes an upper plate
disposed on the upper side of the heel region of the sole
structure, a wavy lower plate disposed on the lower side of
the heel region and having at least two downwardly convex
portions that form a void relative to the upper plate, and a
cleat provided between the adjacent convex portions of the
lower plate.
According to the third aspect of the present
invention, at the time of striking onto the ground, first,
the cleats stick into the ground and then, the lower surface
of the downwardly convex portions of the lower plate
contacts the ground. At this time, the void formed between
the upper and lower midsole acts as a cushion hole to
display cushioning properties of the heel portion. Moreover,
in this case, since the cleat is provided between the
adjacent downwardly convex portions of the lower plate,
deformation of the downwardly convex portions of the wavy
lower plate is not restricted at the time of striking onto
the ground, thereby enhancing the cushioning properties
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of the sole heel portion. Also, by securing the deformation
of the wavy lower plate, bending properties of the sole heel
portion is improved.
In addition, the result of an impact test of the
sole structure of the third aspect of the present invention
is omitted here. However, as with the first and second aspect
of the present invention, when an impact load is applied the
void formed between the upper and lower plates acts as a
cushion hole to display cushioning properties of the heel
portion. Therefore, it is presumed that the numerical value
in which the shoe wearer can feel the difference of the
cushioning properties similar to the first and second aspect
of the present invention will be obtained.
The upper plate constituting the sole structure of
the present invention may have a wavy shape. In this case,
deformation of the wavy upper plate further improves the
cushioning properties of the sole heel portion.
Also, the upper plate may have an upwardly convex
portion. The convex curvature of which is opposite the convex
curvature of the downwardly convex portion of the lower plate
and that is located at a position corresponding to the
downwardly convex portion of the lower plate. In this case, a
large void can be secured between the upper and lower plates
to further enhance the cushioning properties of the sole heel
portion. In addition, the upper plate may have a downwardly
convex portion, the convex curvature of which is the same
direction as the convex curvature of the downwardly convex
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portion of the lower plate and is located at a position
corresponding to the convex portion of the lower plate.
Preferably, there is provided an elastic block
member as a cushioning member between the upper and lower
plates, and the upper plate and the lower plate are connected
to each other through the elastic block member. Suitable
adjustment of elasticity of the elastic block member can
further improve the cushioning properties of the sole heel
portion.
In the case of the wavy upper plate, a downwardly
convex portion of the wavy configuration of the upper plate
may be coupled through the elastic block to an upwardly
protruding convex portion between the adjacent downwardly
convex portions of the lower plate.
The upwardly convex portion of the lower plate and
the downwardly convex portion of the upper plate are disposed
oppositely to each other in the vertical direction, or
disposed offset in the longitudinal direction.
The number of downwardly convex portions of the
lower plate may be varied between the medial side and the
lateral side of the sole structure.
The upper plate may be flat in shape. In this
case, since a flat surface is secured on the upper surface
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of the upper plate, a foot contact surface for a shoe wearer
can be easily obtained without providing a midsole on the
upper side of the upper plate.
A midsole of a soft elastic material may be
provided on the upper side of the upper plate to attain an
improved favorable touch to the sole of a wearer's foot.
The longitudinally adjacent outsole portions may
be connected to each other though a connection in the
longitudinal direction. At this juncture, the lower surface
of the connection is preferably upwardly convex shaped.
In this case, by connecting the outsole portions
through the connection, the outsole portions can be
integrated with each other to improve the efficiency of
assembly. Also, in this case, since the lower surface of the
connection is formed upwardly convex, the connection does not
restrict the compressive deformation of the downwardly convex
portion of the lower plate.
The outsole portions may be separately disposed
on the medial side and the lateral side of the heel portion.
At this juncture, the outsole portions on the medial side may
be connected to each other in the longitudinal direction and
the outsole portions on the lateral side may be connected to
each other in the longitudinal direction. Also, the lower
surface of the connection on the lateral side may have a upwardly
convex shape and the lower surface of the connection on the medial
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side may have a flat shape to contact the ground.
In this case, the deformation of the downwardly
convex portion of the lower plate on the medial side of the
heel region is more restricted than the deformation of the
downwardly convex portion of the lower plate on the lateral
side. As a result, pronation can be prevented at the time of
striking onto the ground and the sole structure suitable for
a running shoe can thus be achieved.
On the other hand, in the case where the outsole
portions are separately disposed on the medial side and the
lateral side of the heel portion, the outsole portions on the
medial side may be connected to each other in the
longitudinal direction and the outsole portions on the
lateral side may be connected to each other in the
longitudinal direction, and the lower surface of the
connection on the medial side may have a upwardly convex
shape and the lower surface of the connection on the lateral
side may have a flat shape to contact the ground.
In this case, the deformation of the downwardly
convex portion of the lower plate on the lateral side of the
heel region is more restricted than the deformation of the
convex portion of the lower plate on the medial side. As a
result, supination can be prevented at the time of
sidestepping and the sole structure suitable for an indoor
shoe such as a tennis shoe or basketball shoe can thus be
achieved.
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A longitudinally extending rib may be integrated
with the upper plate or the lower plate. Since provision of a
rib increases the bending rigidity of the upper or lower
plate, deformation of the upper or lower plate is restrained,
and the bending and cushioning properties can be adjusted.
The rib may be formed either on the medial side or
the lateral side of the upper or lower midsole. In the case
where the rib is provided on the medial side of the plate,
pronation at the time of impacting the ground can be
prevented and the sole structure suited for a running shoe
can be proposed. In the case where the rib is provided on the
lateral side of the plate, supination at the time of
sidestepping can be prevented and the sole structure suited
for an indoor shoe such as a tennis shoe or a basketball shoe
can be proposed.
The number of ribs may be different between the
medial side and the lateral side of the upper or lower plate.
In this case, since the bending rigidity of the plate is made
greater on the side with more ribs than the other side, by
increasing the number of ribs on the medial side, a sole
structure suitable for a running shoe can be attained.
Alternatively, by increasing the number of ribs on the
lateral side, a sole structure suitable for indoor sports can
be attained.
A longitudinally extending rib may be
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integrally formed with the lower plate and at this juncture
the rib may be disposed only at the position corresponding to
the outsole portion and may not be disposed at the region
where no outsole portion is provided. Also, in the case where
the cleat is provided on the lower surface of the downwardly
convex portion of the lower plate, the rib may be disposed
only at the position corresponding to the cleat and may not
be disposed at the region where no cleat is provided.
Moreover, in the case where the cleat is provided between the
adjacent downwardly convex portions of the lower plate, the
rib may be disposed only at the position corresponding to the
downwardly convex portion and may not be disposed between the
adjacent downwardly convex portions. In these cases, at the
time of impacting the ground, the rib can be prevented from
excessively restricting the deformation of the wavy lower
plate.
As above-mentioned, according to the present
invention, since the upper plate and the wavy lower plate are
disposed in the sole heel portion with the void formed
therebetween and a plurality of longitudinally separated
outsole portions are attached on the lower surface of the
downwardly convex portions of the lower plate, or the cleats
are provided on the lower surface of the downwardly convex
portions of the lower plate, or the cleat is provided between
the adjacent downwardly convex portions of the lower plate,
the deformation of the downwardly convex portions of the wavy
lower plate is not restricted at the time of striking
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onto the ground, thereby improving the cushioning and bending
properties.
BRIEF DESCRIPTION OF DRAWINGS
FIG. 1A is a side view on the lateral side of a
sole structure according to a first embodiment of the present
invention;
FIG. 1B is a longitudinal sectional view of the
sole structure of FIG. 1A along the centerline, corresponding
to a section of line IB-IB of FIG. 2;
Fig. 2 is a bottom schematic view of the sole
structure of FIG. 1A;
FIG. 3 is a side view on the lateral side of a
sole structure according to a second embodiment of the
present invention;
FIG. 4 is a side view on the lateral side of a
sole structure according to a third embodiment of the present
invention;
FIG. 5 is a partial bottom view of a sole
structure according to a fourth embodiment of the present
invention;
FIG. 6 is a partial side view of the sole
structure of FIG. 5;
FIG. 7 is a partial top plan view of a lower plate
constituting the sole structure according to a seventh
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embodiment of the present invention;
FIG. 8 is a graph showing the result of the impact
test in which a weight falls from the predetermined height to
exert an impact load to the sole structure of the present
invention and the prior art sole structure shown in Japanese
patent application laying-open publication No. 2003-9906,
illustrating the difference of the amount of deformation in
both the sole structures;
FIG. 9A is a side view of a sole structure
according to an eighth embodiment of the present invention;
FIG. 9B is a variant of the sole structure of FIG.
9A;
FIG. 10A is a side view of a sole structure
according to a ninth embodiment of the present invention;
Fig. 10B is a bottom schematic view of the sole
structure of FIG. 10A;
FIG. 10C is a variant of the sole structure of
FIG. 10A;
FIG. 11 is a side view of a sole structure of
prior art; and
FIG. 12 is a graph showing the result of the
impact test in which a weight falls from the predetermined
height to exert an impact load to the sole structure of the
present invention (FIG. 9A) and the prior art sole structure
(FIG. 11), illustrating the difference of the amount of
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deformation in both the sole structures.
BEST MODE FOR CARRYING OUT THE INVENTION
Embodiments of the present invention will be
hereinafter described based upon the appended drawings.
<First Embodiment>
Referring now to the drawings, FIGS. 1A and 1B
show a sole structure or a sole assembly according to a first
embodiment of the present invention. As shown in FIGS. lA and
1B, a sole structure 1 includes an upper plate 2 extending
from a heel portion H through a midfoot portion M to the
forefoot portion F of the sole structure 1, and a lower plate
3 disposed below the upper plate 2 and extending from the
heel portion H through the midfoot portion M to the forefoot
portion F similar to the upper plate 2. Both of the upper
plate 2 and the lower plate 3 extend in the shoe width
direction (see FIG. 2), and the front end edges of the plates
2, 3 are coupled to each other and rear end edges of the
plates 2, 3 are also coupled to each other.
The upper plate 2 has wavy configurations that
progress longitudinally in the heel portion H and that have
two upwardly convex portions 20, 21 each protruding upwardly.
The lower plate 3 has wavy configurations that progress
longitudinally in the heel portion H similar to the upper
plate 2 and that have two downwardly convex portions 30, 31
each protruding downwardly.
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The corresponding convex portions 20, 30 and 21, 31 of the
upper and lower plates 2, 3 in the heel portion H are
oppositely disposed in the vertical direction. In other
words, the convex portions 20, 30 protrude in the opposite
directions. Similarly, the convex portions 21, 31 protrude in
the opposite directions. Between the corresponding convex
portions 20 and 30 is formed a void C and also between the
corresponding convex portions 21 and 31 is formed a void C,
Additionally, in the forefoot portion F as well, a void C' is
formed between the upper plate 2 and the lower plate 3.
As shown in FIG. 2, a plurality of longitudinally
separated outsole portions 51-55 are attached on the bottom
surface of the lower plate 3. The outsole portions 51, 55 are
disposed on the lower surface of the downwardly convex
portion 30 of the lower plate 3, and the outsole portions 52,
54 and a portion of 53 are disposed on the lower surface of
the downwardly convex portion 31 of the lower plate 3, as
shown in FIG. 1A. Also, in this example, the outsole portions
51, 55 are separated in the shoe width direction and
similarly, the outsole portions 52, 54 are separated in the
shoe width direction.
Turing back to FIG. lA, a pair of upwardly extending
upraised portions 2b are formed on opposite side edge
portions of the upper plate 2. On the upper surface of the
upper plate 2 is attached a midsole 4 that extends from the
heel portion H through the midfoot portion M to the forefoot
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portion F. The midsole 4 has a generally flat foot sole
contact surface 4a that contacts the foot sole of the shoe
wearer, and a pair of upraised portions 4b that extend
upwardly and that are disposed on opposite side edge portions
of the foot sole contact surface 4a. The upraised portions 2b
of the upper plate 2 are disposed on the outside of the
upraised portions 4b of the midsole 4. The upraised portions
4b of the midsole 4 are adapted to be fixedly attached to a
bottom portion of a shoe upper (not shown).
An elastic block member 6 is disposed between the
upper plate 2 and the lower plate 3 at the position where the
upper and lower plates 2, 3 are most close to each other in
the heel portion H. The upper plate 2 is coupled to the lower
plate 3 through the elastic block 6. In other words, the
downwardly convex portion 25 formed between the adjacent
upwardly convex portions 20 and 21 of the upper plate 2 and
the upwardly convex portion 35 formed between the adjacent
downwardly convex portions 30 and 31 of the upper plate 3 are
disposed opposite each other in the vertical direction, and
these oppositely disposed portions are connected to each
other through the elastic block 6.
The elastic block 6 is, in this embodiment, formed
of a pair of members disposed on opposite side ends of the
heel portion H (see FIG. 1B, a longitudinal sectional view,
in which the side surface of one of the elastic blocks
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6 is shown), but the elastic block 6 may be formed of only
one member extending along the entire width of the heel
portion H. The elastic block 6 is provided mainly for
preventing the upper and lower plates 2, 3 from directly
contacting each other, but it also helps improve the
cushioning properties of the sole heel portion by selectively
adjusting its elasticity.
The upper and lower plates 2, 3 is preferably
formed of a hard plastic resin in order to prevent loss of
elasticity due to repetitive deformation to maintain the
shape of the void C to some degree between the plates 2 and
3. For example, the upper and lower plates 2, 3 may be formed
of thermoplastic resin such as thermo plastic polyurethane
(TPU), polyamide elastomer (PAE), ABS resin or the like.
Alternatively, the upper and lower plates 2, 3 may be formed
of thermosetting resin such as epoxy resin, unsaturated
polyester resin or the like. Also, the upper and lower plates
2, 3 may be formed of fiber reinforced plastics including
carbon fibers or metal fibers.
The midsole 4 is preferably formed of the soft
elastic material to contact and support the sole of a shoe
wearer. For example, foamed thermoplastic resin such as
ethylene-vinyl acetate copolymer (EVA), foamed thermosetting
resin such as polyurethane (PU), and foamed rubber such as
butadiene rubber or chloroprene rubber may
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be used.
As shown in FIG. 1B, a plurality of vent holes 25
are formed in the heel portion H and the midfoot portion M
that extend vertically through the upper plate 2 and the
midsole 4 disposed above the upper plate 2. The lower ends of
the vent holes 25 are open into the void C formed between the
upper plate 2 and the lower plate 3. By forming such vent
holes 25, introduction of the open air into the inside of the
shoe is carried out through the void C between the upper
plate 2 and the lower plate 3, thereby facilitating and
hastening the introduction of the open air.
In the forefoot portion F and the midfoot portion
M, the upper plate 2 and the lower plate 3 are coupled to
each other through the elastic block 7, as shown in FIG. 1A.
Also, in the forefoot portion F, an outsole 58 is bonded onto
the bottom surface of the lower plate 3.
According to the above-mentioned sole structure,
at the time of striking onto the ground, the lower surfaces
of the downwardly convex portions 30, 31 of the lower plate 3
contacts the ground through the outsole portions. At this
time, the void C formed between the upper plate 2 and the
lower plate 3 acts as a cushion hole to display cushioning
properties of the heel portion H. Moreover, in this case,
since the longitudinally separated outsole portions 51-55 are
directly attached to the lower surfaces of the downwardly
convex portions 30, 31 of the wavy lower plate 3, compressive
deformation of the downwardly
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convex portions 30, 31 of the wavy lower plate 3 is not
restricted at the time of impacting the ground and the
cushioning properties of the sole heel portion can thus be
improved. Also, in this case, by securing the deformation of
the wavy lower plate 3, bending properties of the sole heel
portion can be enhanced. Thereby, a "ride feeling" can be
improved when the shoe wearer impacts the ground on the rear
end of the sole heel portion and the load travels in the
forward direction.
Furthermore, in this case, since the corresponding
convex portions 20, 30 between the upper and lower plates 2,
3 protrude in the opposite directions and the corresponding
convex portions 21, 31 between the upper and lower plates 2,
3 protrude in the opposite direction, a large void C can be
secured between the upper and lower plates 2, 3 and the
cushioning properties of the sole heel portion can be further
improved. Also, since the upper plate 2 is in the shape of a
wavy corrugation, deformation of the upper plate 2 also helps
improve the cushioning properties of the sole heel portion.
The corresponding convex portions 20, 30 between
the upper and lower plates 2, 3 may protrude in the same
direction and the corresponding convex portions 21, 31
between the upper and lower plates 2, 3 may protrude in the
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same direction. In this such embodiment, in order to secure a
void C between the upper plate 2 and the lower plate 3, the
radius of curvature of the upwardly convex portion 20 is
preferably different from the radius of curvature of the
downwardly convex portion 30 and/or the radius of curvature
of the upwardly convex portion 21 is preferably different
from the radius of curvature of the downwardly convex portion
31. In the alternative, the corresponding convex portions
between the upper plate 2 and the lower plate 3 may be offset
in the longitudinal direction.
In the above-mentioned first embodiment, an
example in which the lower plate 3 has two downwardly convex
portions 30, 31 was shown, but the application of the present
invention is not limited to such example. The lower plate 3
may have more than three downwardly convex portions. Also, in
the above-mentioned first embodiment, an example in which the
number of convex portions (i.e. two) on the medial side of
the upper and lower plates 2, 3 are the same as the number of
convex portions (i.e. two) on the lateral side of the upper
and lower plates 2, 3, but the application of the present
invention is not limited to such example. The number of
convex portions on the medial side may be different from that
on the lateral side: e.g. two convex portions on the medial
side and three convex portions on the lateral side.
Also, the first embodiment showed the upper plate
2 having a wavy corrugation in the heel portion H, but
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in the application of the present invention, the upper plate
2 may be flat in the heel portion H. In this case, since a
flat surface is secured on the upper surface of the upper
plate 2, a foot contact surface for the shoe wearer can be
easily obtained without providing a midsole on the upper side
of the upper plate 2.
In the above-mentioned first embodiment, the
elastic block may be omitted. In this case, the upper and
lower plates 2, 3 need not to be coupled to each other at the
position where the elastic block was provided. A clearance
may be formed between the upper plate 2 and the lower plate
3. In the case where the upper plate 2 and the lower plate 3
are coupled to each other, the upper and lower plates 2, 3
can be integrally formed, thereby simplifying the
manufacturing process and the assembly process.
<Second Embodiment>
FIG. 3 shows a sole structure according to a
second embodiment of the present invention. In FIG. 3, like
reference numbers indicate identical or functionally similar
elements.
In the above-mentioned first embodiment, the
upwardly convex portion 35 between the adjacent downwardly
convex portions 30, 31 of the lower plate 3 is positioned
against the downwardly convex portion 25 between the adjacent
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upwardly convex portions 20, 21 of the upper plate 2, whereas
in the second embodiment, these convex portions 25, 35 are
disposed offset in the longitudinal direction. Preferably, as
shown in FIG. 3, the downwardly convex portion 25 of the
upper plate 2 is disposed in front of the upwardly convex
portion 35 of the lower plate 3. An elastic block 6
connecting the downwardly convex portion 25 of the upper
plate 2 with the upwardly convex portion 35 of the lower
plate 3 extends obliquely upwardly from the lower plate 3 to
the upper plate 2.
In this case, at the time of striking onto the
ground, the elastic block 6 shear-deforms as well as bending-
deforms. At this juncture, the placement of the downwardly
convex portion 25 of the upper plate 2 in front of the
upwardly convex portion 35 of the lower plate 3 facilitates
the downward deformation of the upper plate 2, thereby
further improving the cushioning properties of the sole heel
portion.
Additionally, in the second embodiment, the upper
plate 2 does not extend to the forefoot portion F, but it is
disposed mainly at the heel portion H and its front end
portion is fixedly attached to the lower plate 3 at the
midfoot portion M.
<Third Embodiment>
FIG. 4 shows a sole structure according to a
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third embodiment of the present invention. In FIG. 4, like
reference numbers indicate identical or functionally similar
elements.
This third embodiment differs from the second
embodiment in that the upper and lower plates 2, 3 have third
upwardly and downwardly convex portions 22, 32, respectively.
The convex portions 22, 32 protruding in the opposite
directions are contraposed in the vertical direction, and a
third void C is formed between the convex portions 22, 32.
The upwardly convex portion between the adjacent downwardly
convex portions 31, 32 of the lower plate 3 is disposed
opposite the downwardly convex portion between the adjacent
upwardly convex portions 21, 22 of the upper plate 2. These
oppositely disposed portions are connected to each other
through the elastic block 61.
In this case, by forming the void C at the heel
rear end portion, when impacting the ground on the heel rear
end portion, downward deformation of the upper plate 2
becomes much easier, thereby further improving the cushioning
properties of the sole heel portion.
<Fourth Embodiment>
FIGS. 5 and 6 show a sole structure according to a
fourth embodiment of the present embodiment. In FIGS. and 6,
like reference numbers indicate identical or functionally
similar elements.
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As shown in FIGS. 5, the fourth embodiment differs
from the first to third embodiment in that the outsole
portions are longitudinally connected to each other through
the connections 50, 50'. The connections 50 are disposed on
the medial side of the heel portion and the connections 50'
are disposed on the lateral side of the heel portion. The
connections 50, 50' are band-shaped members and each of the
bottom surfaces 50a, 50'a of the connections 50, 50' is
upwardly convex in shape to form a clearance 4 between the
bottom surfaces 50a, 50'a and the ground surface S when the
sole heel portion is in contact with the ground surface S, as
shown in FIG. 6.
In this case, since the outsole portions 50-55 are
connected to each other via the connections 50, 50' in the
longitudinal direction, the outsole portions can be
integrated with each other. Thereby, during assembly, the
outsole portions 50-55 can be bonded to the bottom surface of
the lower plate 3 at one time. As a result, mis-bonding can
be prevented and the assembly accuracy can be improved. Also,
in this case, since the connections 50, 50' have upwardly
convex bottom surfaces 50a, 50'a, the connections 50, 50'
does not restrict the compressive deformation of the
downwardly convex portions 30, 31 of the lower plate 3.
Therefore, in this embodiment as well, cushioning and bending
properties of the sole heel portion can be improved similarly
to the first embodiment.
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<Fifth embodiment>
In the above-mentioned fourth embodiment, both of
the connections 50, 50' have upwardly convex bottom surfaces
50a, 50'a, but the present invention is not limited to such
an example.
In this fifth embodiment, only the bottom surface
50'a of the connection 50' disposed on the lateral side is
upwardly convex in shape as with the fourth embodiment,
whereas the bottom surface 50a of the connection 50 disposed
on the medial side is flat in shape so as to be in contact
with the ground surface S (see FIG. 6). Between the ground
contact surface S and the lower surface 50a of the connection
50, a clearance o is not formed.
In this case, the deformation of the downwardly
convex portions 30, 31 of the lower plate 3 on the medial
side in the sole heel portion is more restrained than the
deformation of the downwardly convex portions 30, 31 of the
lower plate 3 on the lateral side in the sole heel portion.
Thereby, pronation can be prevented and a sole structure
suitable for a running shoe can thus be achieved.
<Sixth Embodiment>
In contrast to the fifth embodiment, according to
a sixth embodiment, only the bottom surface 50a of the connection
50 disposed on the medial side is upwardly convex in shape
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as with the fourth embodiment, whereas the bottom surface
50'a of the connection 50' disposed on the lateral side is
flat in shape so as to be in contact with the ground surface
S (see FIG. 6). Between the ground contact surface S and the
lower surface 50'a of the connection 50', a clearance A is
not formed.
In this case, the deformation of the downwardly
convex portions 30, 31 of the lower plate 3 on the lateral
side in the sole heel portion is more restrained than the
deformation of the downwardly convex portions 30, 31 of the
lower plate 3 on the medial side in the sole heel portion.
Thereby, supination can be prevented and a sole structure
suitable for an indoor shoe such as a tennis shoe or a
basketball shoe can thus be achieved.
<Seventh Embodiment>
FIG. 7 shows a lower plate constituting a sole
structure according to a seventh embodiment of the present
invention. In this embodiment, a plurality of ribs 8, 9
extending in the substantially longitudinal direction are
integrated with the upper surface of the lower plate 3.
The ribs 8 are provided on the medial side of the
sole heel portion and the ribs 9 are provided on the lateral
side of the sole heel portion. Also, the ribs 9 are disposed
at the positions corresponding to the outsole portions 51,
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52, respectively. The ribs 8 are disposed at the positions
corresponding to the outsole portions 53, 54, respectively.
There are no ribs provided between the longitudinally
adjacent outsole portions 51, 52 and between the
longitudinally adjacent outsole portions 54, 55.
In this case, the bending rigidity of the lower
plate 3 is made higher at the portions where the ribs 8, 9
are provided than at the portions where the ribs 8, 9 are not
provided. Thereby, the deformation of the lower plate 3 is
more restricted at the portions where the ribs 8, 9 are
provided than at the portions where the ribs 8, 9 are not
provided. As a result, the bending and cushioning properties
of the lower plate 3 can be adjusted. Also, in this case, the
ribs 8, 9 are not provided between the outsole portions 51,
52 and between the outsole portions 54, 55, thereby
preventing the deformation of the wavy lower plate 3 from
being excessively restricted at the time of impacting the
ground and preventing the cushioning and bending properties
of the sole heel portion from being hindered.
Also, the number of ribs 8, 9 may be different
between the medial side and the lateral side of the lower
plate 3. Alternatively, a rib may be provided on either the
medial side or the lateral side of the lower plate 3.
In the case where a rib is provided only on
the medial side of the lower plate 3, or the number of the
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ribs 8 on the medial side is made greater than the number of
the ribs 9 on the lateral side, pronation can be prevented at
the time of impacting the ground and a sole structure suited
for a running shoe can be attained. On the other hand, in the
case where a rib is provided only on the lateral side of the
lower plate 3, or the number of the ribs 9 on the lateral
side is made greater than the number of the ribs 8 on the
medial side, supination can be prevented at the time of
sidestepping and a sole structure suited for an indoor shoe
such as a tennis shoe, basketball shoe or the like can be
attained. Additionally, the seventh embodiment showed the
example in which the ribs are provided on the lower plate 3,
but in the application of the present invention, the ribs may
be provided on the upper plate 2.
<Eighth Embodiment>
FIG. 9A shows a sole structure according to an
eighth embodiment of the present invention. As shown in FIG.
9A, a sole structure 1' includes an upper plate 2 extending
from a heel portion H to a midfoot portion M of the sole
structure 1', and a lower plate 3 disposed below the upper
plate 2 and extending from the heel portion H through the
midfoot portion M to a forefoot portion F. The upper plate 2
is coupled to the lower plate 3 at the rear end of the heel
portion H and at the front end of the midfoot portion M. Both
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of the upper plate 2 and the lower plate 3 extend in the shoe
width direction.
The upper plate 2 has wavy configurations that
progress longitudinally in the heel portion H and that have
two upwardly convex portions 20, 21 each protruding upwardly.
The lower plate 3 has wavy configurations that progress
longitudinally in the heel portion H similar to the upper
plate 2 and that have two downwardly convex portions 30, 31
each protruding downwardly. The corresponding convex portions
20, 30 and 21, 31 of the upper and lower plates 2, 3 in the
heel portion H are oppositely disposed in the vertical
direction. In other words, the convex portions 20, 30
protrude in the opposite directions. Similarly, the convex
portions 21, 31 protrude in the opposite directions. Between
the corresponding convex portions 20 and 30 is formed a void
C and also between the corresponding convex portions 21 and
31 is formed a void C.
A plurality of cleats or studs 15, 16 are provided
on the bottom surface of the lower plate 3. The cleat 15 is
disposed at the region of the heel portion H, and the cleat 16 is
disposed at the region of the forefoot portion F. The cleats
15, 16 are fixedly attached to the bottom surface of the
lower plate 3 via a thick base portion or a pedestal 17. In
the heel portion H, the base portions 17 and thus the cleats 15
are provided only on the bottom surface of the downwardly convex
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portions 30, 31 of the lower plate 3 and not between the
downwardly convex portions 30 and 31. Therefore, the base
portions 17 are separated in the heel portion H in the
longitudinal direction. For example, the respective base
portions 17 may be formed integrally with the lower plate 3.
Alternatively, when the respective cleats 15 are composed of
metal members, a portion thereof is embedded in and fixedly
attached to the base portion 17.
On the upper surface of the upper plate 2 is
attached a midsole 4 that extends from the heel portion H
through the midfoot portion M to the rear end of the forefoot
portion F.
An elastic block member 6 is disposed between the
upper plate 2 and the lower plate 3 at the position where the
upper and lower plates 2, 3 are most close to each other in
the heel portion H. The upper plate 2 is coupled to the lower
plate 3 through the elastic block 6. In other words, the
downwardly convex portion 25 formed between the adjacent
upwardly convex portions 20 and 21 of the upper plate 2 and
the upwardly convex portion 35 formed between the adjacent
downwardly convex portions 30 and 31 of the upper plate 3 are
disposed opposite each other in the vertical direction, and
these oppositely disposed portions are connected to each
other through the elastic block 6.
The elastic block 6 is, in this embodiment,
formed of a pair of members disposed on opposite side ends
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of the heel portion H, but the elastic block 6 may be formed
of only one member extending along the entire width of the
heel portion H. The elastic block 6 is provided mainly for
preventing the upper and lower plates 2, 3 from directly
contacting each other, but it also helps improve the
cushioning properties of the sole heel portion by selectively
adjusting its elasticity.
The upper and lower plates 2, 3 is preferably
formed of a hard plastic resin in order to prevent loss of
elasticity due to repetitive deformation to maintain the
shape of the void C to some degree between the plates 2 and
3. For example, the upper and lower plates 2, 3 may be formed
of thermoplastic resin such as thermo plastic polyurethane
(TPU), polyamide elastomer (PAE), ABS resin or the like.
Alternatively, the upper and lower plates 2, 3 may be formed
of thermosetting resin such as epoxy resin, unsaturated
polyester resin or the like. Also, the upper and lower plates
2, 3 may be formed of fiber reinforced plastics including
carbon fibers or metal fibers.
The midsole 4 is preferably formed of a soft
elastic material to contact and support the sole of a shoe
wearer. For example, foamed thermoplastic resin such as
ethylene-vinyl acetate copolymer (EVA), foamed
thermosetting resin such as polyurethane (PU), and foamed
rubber such as butadiene rubber or chloroprene rubber may
CA 02609635 2010-08-11
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be used.
According to the above-mentioned sole structure,
at the time of striking onto the ground, first, the cleat 15
sticks into the ground and then, the lower surfaces of the
downwardly convex portions 30, 31 of the lower plate 3
contact the ground. At this time, the void C formed between
the upper plate 2 and the lower plate 3 acts as a cushion
hole to display cushioning properties of the heel portion H.
Moreover, in this case, since the cleats 15 (and thus the
base portions 17) are provided only on the lower surface of
the downwardly convex portions 30, 31 of the wavy lower plate
3, compressive deformation of the downwardly convex portions
30, 31 of the wavy lower plate 3 is not restricted at the
time of impacting the ground and the cushioning properties of
the sole heel portion can thus be improved. Also, in this
case, by securing the deformation of the wavy lower plate 3,
bending properties of the sole heel portion can be enhanced.
Furthermore, in this case, since the
corresponding convex portions 20, 30 between the upper and
lower plates 2, 3 protrude in the opposite directions and
the corresponding convex portions 21, 31 between the upper
and lower plates 2, 3 protrude in the opposite directions,
a large void C can be secured between the upper and lower
plates 2, 3 and the cushioning properties of the sole heel
portion can be further improved. Also, since the upper plate
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2 is in the shape of a wavy corrugation, deformation of the
upper plate 2 also helps improve the cushioning properties of
the sole heel portion.
The corresponding convex portions 20, 30 between
the upper and lower plates 2, 3 may protrude in the same
direction and the corresponding convex portions 21, 31
between the upper and lower plates 2, 3 may protrude in the
same direction. In such an embodiment, in order to secure a
void C between the upper plate 2 and the lower plate 3, the
radius of curvature of the upwardly convex portion 20 is
preferably different from the radius of curvature of the
downwardly convex portion 30 and/or the radius of curvature
of the upwardly convex portion 21 is preferably different
from the radius of curvature of the downwardly convex portion
31. In the alternative, the corresponding convex portions
between the upper plate 2 and the lower plate 3 may be offset
in the longitudinal direction.
In the above-mentioned eighth embodiment, an
example in which the lower plate 3 has two downwardly
convex portions 30, 31 was shown, but the application of the
present invention is not limited to such example. The
lower plate 3 may have more than three downwardly
convex portions. Also, the present invention is not limited
to an example in which the number of convex portions
on the medial side of the upper and lower plates 2, 3 is
the same as the number of convex portions on the lateral
side of the upper and lower plates 2, 3, but the number of
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convex portions on the medial side may be different from that
on the lateral side: e.g. two convex portions on the medial
side and three convex portions on the lateral side.
Also, the eighth embodiment showed the upper plate
2 having a wavy corrugation in the heel portion H, but in the
application of the present invention, the upper plate 2 may
be flat in the heel portion H. In this case, since a flat
surface is secured on the upper surface of the upper plate 2,
a foot contact surface for the shoe wearer can be easily
obtained without providing a midsole on the upper side of the
upper plate 2.
In above-mentioned eighth embodiment, the elastic
block may be omitted. In this case, the upper and lower
plates 2, 3 need not to be coupled to each other at the
position where the elastic block was provided. A clearance
may be formed between the upper plate 2 and the lower plate
3. In the case where the upper plate 2 and the lower plate 3
are coupled to each other, the upper and lower plates 2, 3
can be integrally formed, thereby simplifying the
manufacturing process and the assembly process.
FIG. 9B shows a variant of the eighth embodiment
of the present invention. As shown in FIG. 9B, the variant
is different from the eighth embodiment in that a plurality
of U-shaped or V-shaped bent portions 38 are provided at
the lower plate 3 in the forefoot portion F and the midsole 4
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extends to the front end of the forefoot portion F. The
respective bent portions 38 extend in the width direction of
the forefoot portion F. In this case, not only cushioning
properties of the sole heel portion can be secured as with
the eighth embodiment but also bending properties of the sole
forefoot portion can be improved by the bent portions 38.
<Ninth Embodiment>
FIGS. 10A and 10B show a sole structure according
to a ninth embodiment of the present invention. In these
drawings, the same reference numbers as those in the eighth
embodiment indicate identical or similar elements. The ninth
embodiment differs from the eighth embodiment in that the
lower plate 3 has three downwardly convex portions 30, 31, 32
and the upper plate 2 has three upwardly convex portions 20,
21, 22 that correspond to the downwardly convex portions 30,
31, 32, respectively, and the thick base portions or
pedestals 17 (and thus the cleats 15) of the heel portion H
are provided only between the adjacent downwardly convex
portions 30 and 31 and between the adjacent downwardly convex
portions 31 and 32 of the lower plate 3. Therefore, the base
portions 17 are separated in the longitudinal direction in
the heel portion H as with the eighth embodiment.
In the above-mentioned sole structure, at the time
of striking onto the ground, first, the cleats 15 stick
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into the ground and then, the lower surface of the downwardly
convex portions 30, 31, 32 of the lower plate 3 contacts the
ground. At this time, the void C formed between the upper
plate 2 and the lower plate 3 acts as a cushion hole to
display cushioning properties of the heel portion H.
Moreover, in this case, since the cleat 15 (and thus the base
portions 17) is provided only between the adjacent downwardly
convex portions 30 and 31 and between the adjacent downwardly
convex portions 31 and 32 of the wavy lower plate 3,
compressive deformation of the downwardly convex portions 30,
31 of the wavy lower plate 3 is not restricted at the time of
impacting the ground and the cushioning properties of the
sole heel portion can thus be improved. Also, in this case,
by securing the deformation of the wavy lower plate 3,
bending properties of the sole heel portion can be enhanced.
Furthermore, in this case, since the corresponding
pairs of convex portions 20, 30; 21, 31; 22, 32 between the
upper and lower plates 2, 3 protrude in the opposite
direction, a large void C can be secured between the upper
and lower plates 2, 3 and the cushioning properties of the
sole heel portion can be further improved. Also, since the
upper plate 2 is in the shape of a wavy corrugation,
deformation of the upper plate 2 also helps improve the
cushioning properties of the sole heel portion.
The corresponding pairs of convex portions 20,
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30; 21, 31; 22, 32 between the upper and lower plates 2, 3
may protrude in the same direction. In such an embodiment, in
order to secure a void C between the upper plate 2 and the
lower plate 3, the radius of curvature of the convex portions
of the lower plate 3 is preferably different from the radius
of curvature of the corresponding convex portions of the
upper plate 2. In the alternative, the corresponding convex
portions between the upper plate 2 and the lower plate 3 may
be offset in the longitudinal direction.
The application of the present invention is not
limited to an example in which the number of convex portions
on the medial side of the upper and lower plates 2, 3 is the
same as the number of convex portions on the lateral side of
the upper and lower plates 2, 3, but the number of convex
portions on the medial side may be different from that on the
lateral side.
Also, the application of the present invention is
not limited to an example in which the upper plate 2 has a
wavy corrugation in the heel portion H, but the upper plate 2
may be flat in the heel portion H. In this case, since a flat
surface is secured on the upper surface of the upper plate 2,
a foot contact surface for the shoe wearer can be easily
obtained without providing a midsole on the upper side of the
upper plate 2.
Furthermore, the elastic block 6 may be omitted.
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In this case, the upper and lower plates 2, 3 need not to be
coupled to each other at the position where the elastic block
was provided. A clearance may be formed between the upper
plate 2 and the lower plate 3. In the case where the upper
plate 2 and the lower plate 3 are coupled to each other, the
upper and lower plates 2, 3 can be integrally formed, thereby
simplifying the manufacturing process and the assembly
process.
FIG. 1OC shows a variant of the ninth embodiment
of the present invention. As shown in FIG. 10B, the variant
is different from the ninth embodiment in that a plurality of
U-shaped or V-shaped bent portions 38 are provided at the
lower plate 3 in the forefoot portion F and the midsole 4
extends to the front end of the forefoot portion F. The
respective bent portions 38 extend in the width direction of
the forefoot portion F. In this case, not only cushioning
properties of the sole heel portion can be secured as with
the ninth embodiment but also bending properties of the sole
forefoot portion can be improved by the bent portions 38.
INDUSTRIAL APPLICABILITY
As above-mentioned, the sole structure
according to the present invention is useful for a sole
structure of a running shoe, or a sole structure of an indoor
shoe such as a tennis shoe, a basketball shoe and the like,
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alternatively, a sole of a cleated shoe such as a baseball
shoe, a golf shoe and the like. It is especially suitable for
a sole that requires high cushioning properties at the sole
heel portion.
