U.S. patent application number 12/047735 was filed with the patent office on 2008-06-26 for footwear sole.
This patent application is currently assigned to WOLVERINE WORLD WIDE, INC.. Invention is credited to Mary L. Schoenborn.
Application Number | 20080148598 12/047735 |
Document ID | / |
Family ID | 38480473 |
Filed Date | 2008-06-26 |
United States Patent
Application |
20080148598 |
Kind Code |
A1 |
Schoenborn; Mary L. |
June 26, 2008 |
FOOTWEAR SOLE
Abstract
A sole for an article of footwear having an insert with a
plurality of forefoot support tubes are configured to control the
support characteristics of the sole in a forefoot region of the
sole. In one embodiment, the forefoot support tubes each include a
base, and a wall extending from the base. The wall is formed from a
material that has a lower durometer value than the base. In another
embodiment, the forefoot support tubes are arranged in a radiating
pattern, such that at least two of the forefoot support tubes
diverge as they extend toward the lateral side of the insert.
Inventors: |
Schoenborn; Mary L.;
(Rockford, MI) |
Correspondence
Address: |
WARNER NORCROSS & JUDD LLP
900 FIFTH THIRD CENTER, 111 LYON STREET, N.W.
GRAND RAPIDS
MI
49503-2487
US
|
Assignee: |
WOLVERINE WORLD WIDE, INC.
Rockford
MI
|
Family ID: |
38480473 |
Appl. No.: |
12/047735 |
Filed: |
March 13, 2008 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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11419043 |
May 18, 2006 |
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12047735 |
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Current U.S.
Class: |
36/28 |
Current CPC
Class: |
A43B 13/181 20130101;
A43B 13/186 20130101; A43B 7/144 20130101; A43B 13/026 20130101;
A43B 7/08 20130101; A43B 13/12 20130101; A43B 13/143 20130101; A43B
13/206 20130101; A43B 13/188 20130101 |
Class at
Publication: |
36/28 |
International
Class: |
A43B 13/18 20060101
A43B013/18 |
Claims
1. An article of footwear comprising: a two-component insert
including a plurality of resilient compressible front support
tubes, each of said front support tubes defining a base, and a wall
extending from said base, wherein said base is formed from a first
material, and said wall is formed from a second material softer
than said first material, and; an outsole positioned below said
insert and forming a ground engaging wear surface for the article
of footwear.
2. The article of footwear of claim 1 wherein said insert includes
a lateral side and a medial side, and wherein at least two of said
front support tubes are arranged in a radiating pattern such that
they diverge as they extend from said medial side towards said
lateral side.
3. The article of footwear of claim 2 wherein said insert includes
a forefoot portion, said front support tubes positioned in said
forefoot portion.
4. The article of footwear of claim 1 wherein said bases of each of
said support tubes are connected to form a forefoot web, said
forefoot web formed from said first material.
5. The article of footwear of claim 1 wherein said insert includes
an arch portion and a heel portion, said heel portion including a
plurality of resilient compressible rear support tubes, each of
said rear support tubes defining an internal void; and a plurality
of webs, each of said webs being disposed within a corresponding
one of said rear support tubes and extending at an orientation,
said orientation of each of said webs being pre-selected to provide
said insert with a support profile.
6. The article of footwear of claim 1 wherein said front support
tubes include a first end and a second end, at least one of said
first and second ends of each of said front support tubes being
open.
7. The article of footwear of claim 6 wherein at least one of said
first and second ends of at least one of said front support tubes
is closed.
8. The article of footwear of claim 6 wherein at least one of said
first and second ends of each of said front support tubes includes
a generally flat base and a generally semi-circular wall extending
from said base.
9. The article of footwear claim 1 wherein said plurality of front
support tubes includes at least one central support tube and at
least two peripheral support tubes on opposite sides of said at
least one central support tube, said at least one central support
tube extending substantially across the lateral extent of said
insert, said peripheral support tubes extending from the lateral
side of said insert only partially across said insert.
10. An article of footwear having a forefoot region, the article of
footwear comprising: a two-component insert permanently affixed in
the article of footwear, said insert including a lateral side, a
medial side and a plurality of resilient compressive front support
tubes, said front support tubes positioned in the forefoot region
of the article of footwear and extending laterally across at least
a portion of said insert, at least two of said front support tubes
positioned in a radiating arrangement such that said at least two
of said front support tubes diverge as they extend toward said
lateral side of said insert, each said support tube including a
base comprised of a first material and a wall extending from the
base and formed from a second material, said second material being
softer than said first material; a cushioned midsole disposed above
said insert; and an outsole disposed below said insert and forming
a wear resistant, ground engaging surface of the article of
footwear.
11. The article of footwear of claim 10 wherein said plurality of
front support tubes include at least one central front support
tube, and at least one peripheral front support tube, said central
front support tube extending substantially across said insert, said
peripheral front support tube extending partially across said
insert.
12. The article of footwear of claim 11 wherein at least one of
said front support tubes has a semi-circular cross section.
13. The article of footwear of claim 11 wherein said at least one
peripheral front support tube extends from an open end adjacent to
said lateral side of said insert to a closed end partially across
said insert.
14. The article of footwear of claim 11 wherein said at least one
peripheral front support tube tapers to a point at said closed
end.
15. An article of footwear having a forefoot region, the article of
footwear comprising: an upper; an outsole having a ground engaging
surface and an upper surface; and an insert between said upper and
said outsole, said insert positioned in the forefoot region of the
article of footwear, said insert including a base formed from a
first material, and a plurality of support tube walls attached to
said base and extending upwardly from said base, said plurality of
support tube walls formed integrally with each other from a second
material that is softer than said first material.
Description
BACKGROUND OF THE INVENTION
[0001] The present invention relates to footwear, and more
particularly to a sole construction for an article of footwear.
[0002] There is a continuing effort to provide ever more
comfortable footwear. Running shoes, as well as other footwear,
have undergone tremendous evolutionary advances in technology over
the past 20 years. Many of the technological advances have occurred
in the midsole. In most footwear, the midsole functions as the
"suspension system" of the sole and it often provides both
protective cushioning and a stable platform for the wearer's foot.
Variations in the characteristics of the midsole can have a
dramatic affect on the performance of the shoe. In an effort to
provide improved performance, it is often desirable to vary the
support characteristics of the sole from one region to another. For
example, it may be desirable to provide a higher density material
in the heel and a lower density material in the forefoot. A higher
density material in the heel provides greater support upon heel
strike while a lower density material provides appropriate
cushioning and support for the typically smaller loads encountered
in the forefoot. A wide variety of soles have been developed to
provide variable support over the foot. In some applications,
variable support is provided by forming different regions of the
midsole from different materials, such as softer EVA foam in the
forefoot and firmer EVA foam in the heel. In other applications,
the sole is provided with a support plate that can be configured to
provide the sole with the desired overall support profile. Although
a marked improvement over conventional uniform sole constructions,
there remains a need for a sole construction that is inexpensive to
manufacture and that is highly tunable with a wide range of
adjustability.
[0003] At the same time, there is also an ongoing effort to extend
the life of footwear soles. In conventional footwear, the midsole
(as well as other sole components) may begin to lose its
performance over a relatively short period of time. Degradation of
the sole material can cause the sole to lose its resiliency over
time, particularly in regions of high and repeated impact, such as
the heel. The rate of degradation will vary from sole to sole, but
is largely dependent on the specific characteristics of the sole
material and the types of loads applied to the sole. For example,
conventional closed and open cell foams, such as EVA, have a
relatively short life as the material naturally breaks down over
relatively short periods of use. Conventional foam materials are
also susceptible to temperature changes, which can cause the
resiliency of the foam to vary noticeably. For example, the sole
may become noticeably stiffer in colder temperatures and noticeably
softer in higher temperatures. As a result, temperature can have a
significant adverse affect on the support characteristics of a sole
manufactured from conventional foam materials.
[0004] Accordingly, there remains a need for a highly reliable,
highly tunable sole that has an extended life and is relatively
inexpensive to manufacture.
SUMMARY OF THE INVENTION
[0005] The aforementioned problems are overcome by the present
invention which provides a sole having an insert with a plurality
of support tubes that are tuned to provide the desired support
profile. Each support tube may include an internal web having an
orientation that is selected to provide the desired support
characteristics. By varying the orientation of the webs from
support tube to support tube, the overall support profile of the
sole can be controlled.
[0006] In one embodiment, the support layer is disposed between the
outsole and the midsole. If desired, the sole may further include a
heel wedge disposed between the outsole and the insert in the heel
region. The heel wedge may be manufactured from a material that is
firmer than the midsole material. As a result, the heel wedge may
provide additional support in the heel region of the sole.
[0007] In another embodiment, the insert may include a plurality of
support tubes on the medial (or inner) side of the sole and a
plurality of support tubes on the lateral (or outer) side of the
sole. The internal webs may be disposed in a more vertical
orientation along the medial side of the sole to provide greater
vertical support on the medial side of the sole. If desired, the
orientation of the webs can vary from tube to tube. For example,
the webs may be oriented in an increasingly more vertical direction
moving from front to rear to provide increasingly more vertical
support toward the rear of the heel. The support tubes on the
medial side may be connected to the support tubes on the lateral
side by struts. The struts may be concave to provide the heel with
an inherent centering capability.
[0008] In yet another embodiment, the support tubes are disposed in
at least a portion of the heel region of the insert and the insert
includes an arch portion extending through the arch region of the
sole. The arch portion of the insert may include two layers spaced
apart from one another to provide a structure to receive a gaiter
strap. The lower layer helps to protect the gaiter strap from
damage associated with ground contact. If desired, the insert may
further include a forefoot extension that extends through at least
a portion of the forefoot region of the sole. The forefoot
extension may extend only along the medial side of the forefoot
region to provide a sole that is more rigid along the medial side.
The forefoot extension may extend through different regions of the
forefoot or may cover the entire forefoot region, as desired.
[0009] In another embodiment of the present invention, the insert
includes a plurality of front support tubes. In one embodiment, the
front support tubes are positioned in the forefoot region and
extend across the forefoot region from the medial side to the
lateral side of the sole. The front support tubes may be arranged
in a radiating pattern such that they diverge as they approach the
lateral edge of the sole. In another embodiment, the front support
tubes are formed from a first material that forms a base, and a
second material that extends upwardly from the base and has a lower
durometer value than the first material.
[0010] The present invention provides a unique footwear sole that
can be easily tuned to provide the desired support profile. The
insert may be manufactured from TPU or other relatively durable
materials that do not degrade as quickly as conventional foam
materials and therefore extend the cushioning life of the midsole.
The support profile may be varied between the medial and lateral
sides of the sole. For example, the support tubes on the medial
side of the sole can be tuned to provide increasing vertical
stiffness toward the back of the shoe, thereby address the problem
of overpronation. The insert is relatively inexpensive to
manufacture and its support characteristics can be readily adjusted
by controlling, among other things, the nature and orientation of
the support tubes and the webs. The insert can be combined with a
heel wedge to provide even greater control over its support
profile. The arch portion of the insert can be tuned to provide
control over the support profile of the sole in the arch region.
The gaiter slot can be incorporated into the arch portion to
protect a gaiter strap from premature wear. The support profile of
the sole in the forefoot region can be controlled through the use
of the forefoot extension. When included, the struts assist in
centering the foot on heel strike. The front support tubes enable
controlled cushioning in the forefoot regions and can be arranged
in proper alignment for an efficient toe-off.
[0011] These and other objects, advantages, and features of the
invention will be readily understood and appreciated by reference
to the detailed description of the preferred embodiment and the
drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0012] FIG. 1 is an exploded perspective view of a sole in
accordance with an embodiment of the present invention.
[0013] FIG. 2 is a medial side elevational view of the shoe.
[0014] FIG. 3 is a side elevational view of the midsole.
[0015] FIG. 4 is a top plan view of the midsole.
[0016] FIG. 5 is a bottom plan view of the midsole.
[0017] FIG. 6 is a top plan view of the insert.
[0018] FIG. 7 is a bottom plan view of the insert.
[0019] FIG. 8A is a right (medial) side elevational view of the
insert.
[0020] FIG. 8B is a left (lateral) side elevational view of the
insert.
[0021] FIG. 9 is a side elevational view of the heel wedge.
[0022] FIG. 10 is a bottom plan view of the insert and midsole.
[0023] FIG. 11 is a bottom plan view of the insert, midsole and
heel wedge.
[0024] FIG. 12 is a bottom plan view of the shoe.
[0025] FIG. 13 is an exploded perspective view of a sole in
accordance with another aspect of the present invention.
[0026] FIG. 14 is a top view of the insert according to the second
embodiment.
[0027] FIG. 15 is a medial side view of the insert according to the
second embodiment.
[0028] FIG. 16 is an exploded perspective view of the insert
according to the second embodiment.
[0029] FIG. 17 is a lateral side view of the insert according to
the second embodiment.
DETAILED DESCRIPTION OF THE CURRENT EMBODIMENTS
[0030] A footwear sole manufactured in accordance with an
embodiment of the present invention is shown in FIG. 1, and
generally designated 10. The footwear sole 10 generally includes an
outsole 12, a heel wedge, 14, an insert 16 and a midsole 18. The
sole 10 may be incorporated into an article of footwear, such as
shoe 200 shown in FIG. 2. The shoe 200 may include an upper 202
that is affixed to the sole 10. The shoe 200 may also include a
footbed (not shown) that is removably fitted into the upper 202
atop of the sole 10. The insert 16 may include support tubes 46a-j
with internal webs 48a-j that are configured to control the support
profile of the sole 10. Although the present invention is described
in connection with a conventional standard height running or trail
running shoe 200, the present invention is not limited to use in
shoes of that type. The present invention is well-suited for use in
essentially any type of sole and can be incorporated into
essentially any type of footwear. The footwear sole 10 is intended
to be secured to an upper (not shown) using essentially any
attachment construction, including without limitation cement,
stitch, welt and direct attach constructions. The footwear sole 10
may also include a shank or other conventional sole components, as
desired.
[0031] To facilitate disclosure of the present invention, reference
will be made to various general areas of the foot, such as the
heel, arch and forefoot areas. When used to refer to locations on
the various sole components, these terms should be interpreted to
include those areas of the sole that are disposed generally (and
not necessarily directly) beneath the corresponding elements of the
foot. For purposes of general reference only, the heel area is
generally defined as that area behind (toward the rear of the heel
of the sole 10) phantom line A1 (See FIG. 2), the arch area is
generally defined as that area between phantom lines A1 and A2 and
the forefoot region is generally defined as that area ahead of
(toward the tiptoe of the sole 10) phantom line A2. It should be
understood, however, that the boundaries between the heel, arch and
forefoot areas are not precise and that these terms should be
interpreted loosely and with a great deal of flexibility.
[0032] In the described embodiment, the outsole 12 is generally
conventional and defines the primary wear surface for the sole 10.
The outsole 12 is generally conventional and is secured to the
bottom of the sole 10 to provide a durable and non-slip wear
surface (See FIG. 2). The design and configuration of the outsole
12 may vary from application-to-application. However, in the
illustrated embodiment, the outsole 12 is a two-piece outsole
having a main part 20 and heel part 22 (See FIGS. 1 and 12). The
main part 20 of this embodiment extends across portions of the heel
wedge 14, insert 16 and midsole 18. The main part 20 is cemented or
otherwise secured to the bottom of the various sole components 14,
16 and 18 using generally conventional techniques and apparatus.
The heel part 22 is disposed at the back of the heel and is
cemented to the undersurface of the heel wedge 14 using generally
conventional techniques and apparatus. Separation of the main part
20 and the heel part 22 provides the outsole 12 with a degree of
articulation in the heel. The lower surface of each part 20 and 22
includes a plurality of lugs or other traction elements, which are
generally identified in the drawings by reference numeral 24. The
design and configuration of the traction elements 24 may vary from
application to application as desired. The outsole 12 may be
manufactured from a wide variety of conventional sole materials,
such as natural and synthetic rubbers, leather, PVC, EVA and
polyurethane.
[0033] As noted above, the sole 10 includes a heel wedge 14
disposed above the outsole 12 in the heel region (See FIGS. 1 and
2). The heel wedge 14 provides a resilient, compressible platform
for the insert 16 as described in more detail below. Referring now
to FIG. 9, the heel wedge 14 is generally wedge-shaped having an
upper surface 26 that is contoured to compliment the shape of the
bottom surface 30 of the insert 16 and a lower surface 32 that is
contoured to compliment the shape of the upper surface 34 of the
outsole 12. More specifically, the upper surface 26 of the
illustrated embodiment includes a plurality of tube recesses 36a-j
that corresponds in shape with the support tubes 46a-j. The tube
recesses 36a-j closely receive the support tubes 46a-j in the
assembled sole 10. The heel wedge 14 may be manufactured from a
variety of sole material, such as EVA and polyurethane. In the
illustrated embodiment, the heel wedge 14 defines a central opening
80 that is aligned with a corresponding absence of material in the
heel region of the outsole 12. Among other things, the opening 30
permits viewing of portions of the midsole 16 and insert 18. As
perhaps best shown in FIG. 11, the heel wedge 14 may include an
arrangement of small ridges 86 on its undersurface 88 that, among
other things, provide a guide for placing the outsole 12 parts. In
the illustrated embodiment, the heel wedge 14 extends only through
the heel region of the sole 10 and is generally wedge-shaped. The
heel wedge 14 may extend through different regions of the sole and
may, for example, extend through the arch region or be coextensive
with the entire sole. The heel wedge 14 is not necessarily
wedge-shaped and may take on different thickness configurations as
desired. In the illustrated embodiment, the heel wedge 14 is
manufactured from EVA foam having a durometer value of
approximately 55-60 Asker C Scale. The type of material and density
of the heel wedge 14 material may, however, vary from application
to application. If desired, the density of the heel wedge 14 may
vary from region to region within the heel wedge 14.
[0034] The insert 16 is disposed above the outsole 12 and the heel
wedge 14, and provides the sole 10 with a highly tuned support
profile (See FIGS. 1 and 2). Referring now to FIGS. 6, 8, 8A and
8B, the insert 16 generally includes a heel portion 40, an arch
portion 42 and a forefoot extension 44. The heel portion 40, as its
name implies, extends through at least a portion of the heel region
of the sole 10 and includes a plurality of support tubes 46a-j. In
the illustrated embodiment, the support tubes 46aj extend in a
generally lateral orientation. The insert 16 may include a first
plurality of support tubes 46a-e extending through a peripheral
marginal portion of the lateral side of the heel region ("lateral
support tubes") and a second plurality of support tubes 46fj
extending through a peripheral marginal portion of the medial side
of the heel region ("medial support tubes"). The medial support
tubes 46fj and lateral support tubes 46a-e may be spaced apart so
that the support tubes 46aj do not extend through the central
region of the sole 10. The absence of support tubes 46aj in the
central region may provide a relatively soft center that helps to
center the wearer's foot on the sole 10. The use of separate medial
and lateral support tubes is not strictly necessary, and in some
applications, the support tubes may be located only on one side or
may extend entirely across the sole 10. In the illustrated
embodiment, the support tubes 46aj are generally annular in
cross-section. The support tubes 46aj may alternatively have other
cross-sectional shapes (both regular and irregular), such as oval,
square, rectangular and triangular. The characteristics of each
support tube 46aj may be varied to control its particular response
to different loads. For example, the number, shape, diameter,
length and wall thickness of the support tubes 46aj may be varied
to tune the support characteristics of the sole 10. Each support
tube 46a-j may also include an internal web 48a-j that affects the
support characteristics of the tube 46a-j. In the illustrated
embodiment (where the support tubes 46a-j are generally annular in
cross-section), the webs 48a-j are chords, and more particularly
extend along diameters of the support tubes 48a-j. But, the
characteristics of each web 48a-j may be varied to control its
affect on the support characteristics. For example, the number,
orientation, position, length and thickness of the webs 48a-j can
be varied. In the illustrated embodiment, the lateral support tubes
46a-e each include a web 48a-e that extends in a generally
horizontal direction following the general extent of the insert 16.
Accordingly, the webs 48a-e have little affect on the rigidity of
the lateral support tubes 46a-e in the vertical direction. In the
illustrated embodiment, the orientation of the webs 48fj of the
medial support tubes 46fj varies from front to rear. More
specifically, the medial webs 48f-i are arranged at a more vertical
orientation toward the rear of the heel region as can be seen in
FIGS. 2 and 8A. As a result, the medial support tubes 46fj provide
increasingly more resistance to vertical compression toward the
rear of the heel region. In the illustrated embodiment, the webs
48a-j are integrally formed with the support tubes 46aj. This is
not, however, strictly necessary and the webs 48aj may
alternatively be separately manufactured, for example, as inserts
that are fitted into the support tubes 46a-j.
[0035] The insert 16 may also include a plurality of struts 38a-d
that join the support tubes 48a-d on one side of the sole 10 with
the support tubes 48f-I on the opposite side. The characteristics
of the struts 38a-d may be varied to control the support
characteristics of the sole 10. For example, changes in the number,
width, thickness and shape of the struts 38a-d will impact the
support characteristics of the insert 16. As shown, the struts
38a-c are of this embodiment are generally concave to follow a
convex structure on the undersurface of the midsole 18. In this
embodiment, the struts 38a-c are concave primarily to accommodate
recess 64 and plug 62.
[0036] The arch portion 42 of the illustrated embodiment is
integral with and extends from the heel portion 40. It may
alternatively be a separate component. The arch portion 42 includes
a pair of wings 50a-b that extend upwardly from its lateral and
medial edges. The wings 50a-b may be cemented or otherwise secured
to the midsole 18. In use, the wings 50a-b provide the midsole 18
with enhanced support in the arch region. The arch portion 42 may
also define a slot 52 for receiving the strap of a gaiter. The arch
portion 42 of the illustrated embodiment includes a pair of spaced
apart layers 54a-b that cooperatively define the slot 52. The size,
shape and configuration of the layers 54a-b may vary from
application to application as desired. The arch portion 42 is
optional and may be eliminated, if desired.
[0037] The forefoot extension 44 of the illustrated embodiment is
integral with and extends from the arch portion 42. It may
alternatively be a separate component. The forefoot extension 44
may extend only along a peripheral portion of the medial side of
the sole 10 (as shown in the illustrated embodiment). It may,
however, be designed to extend through essentially any portion of
the forefoot region or over the entire forefoot region, if desired.
The forefoot extension 44 may define a plurality of flex slots
56a-c configured to provide flex points. The forefoot extension 44
is optional and may be eliminated in some applications, as
desired.
[0038] The insert 16 may be manufactured from a variety of
conventional materials, but typically it will be manufactured from
a material that is stiffer than the heel wedge 14 and/or midsole
18. For example, the insert 16 may be injection molded from TPU,
TPR or PVC. The insert 16 may be manufactured from other materials,
such as nylon, rubber, synthetic rubber or silicone, but it is
likely that the insert 16 would not be manufactured by injection
molding if any of these alternative materials was used. If desired,
the insert 16 may be manufactured from a collection of different
materials. For example, the arch portion 42 may be manufactured
from a stiffer material than the heel portion 40.
[0039] In the illustrated embodiment, the support tubes 46a-j
extend only through the heel region of the sole 10. In alternative
embodiments, the support tubes 46a-j may in addition (or
alternatively) extend through the arch and/or forefoot regions of
the sole. The size, configuration, layout and other characteristics
of the support tubes 46a-j may vary from region to region and from
application to application.
[0040] The midsole 18 is disposed between the insert 16 and the
upper 202, and is designed to provide a compressible, resilient
foot platform (See FIGS. 1 and 2). As it is designed to support the
foot and to be incorporated into conventional footwear, the midsole
18 is generally foot-shaped. The midsole 18 may, however, take on
other shapes, as desired, to accommodate various alternative sole
designs. In the illustrated embodiment, the midsole 18 is
manufactured from EVA foam having a durometer value of
approximately 55-60 Asker C Scale. The type of material and density
of the midsole 18 material may, however, vary from application to
application. In the illustrated embodiment, the midsole 18 is a
one-piece, unitary structure, but it may alternatively include a
collection of separate elements that cooperatively support the
foot. For example, in an alternative embodiment, the midsole 18 may
include a forefoot segment that is manufactured from a relatively
soft material and heel region manufactured from a more rigid
material. The midsole 18 includes a generally smooth upper surface
60 designed to support the wearer's foot (See FIG. 4). The upper
surface 60 may include contours, if desired. For example, the upper
surface 60 of the midsole 18 may be contoured to match the natural
contours of the wearer's foot, for example, by providing the upper
surface 60 with a concave heel area, a raised arch area or
essentially any other desired shape. The midsole 18 of the
illustrated embodiment includes a peripheral lip 68 that extends
upwardly around the peripheral edge of the midsole 18. The midsole
18 may directly engage the undersurface of the wearer's foot. In
most applications, however, an additional component (not shown)
will be incorporated into the sole 10 above the midsole 18. For
example, an insole (not shown), sock liner (not shown), footbed
(not shown) or other sole element may be incorporated into the sole
10 above the midsole 18. This additional component may be removably
fitted into the shoe 200 atop the sole 10.
[0041] In the illustrated embodiment, the midsole 18 includes a
disc-shaped plug 62 that is fitted into a corresponding recess 64
in the heel area (See FIG. 1). The plug 62 is manufactured from a
relatively soft cushioning material, such as closed cell foam. In
the illustrated embodiment, the plug 62 is manufactured from a
material having a lower density than the material of the midsole
18. As a result, the plug 62 and recess 64 combination help to
center the foot in the heel of the sole 10. The size, shape and
configuration of the plug 62 and recess 64 may vary from
application to application. For example, the plug 62 and recess 64
combination may be replaced by one or more perforations or cutouts
that reduce the resistance of the corresponding region to
compression. In this embodiment, the recess 64 is vertically
aligned with the convex region of the struts, but that is not
strictly necessary.
[0042] The midsole 18 may be configured to provide ventilation as
shown in the illustrated embodiment. In this embodiment, the
midsole 18 defines a plurality of ventilation holes 70 through the
sidewall of the midsole 18 and a series of ventilation channels 72
in the upper surface 60 of the midsole 18 (See FIG. 4). The
ventilation channels 72 communicate with the ventilation holes 70
to permit air and water to ventilate through the midsole 18 (See
FIG. 3). Again, this is optional and the present invention may be
incorporated into a non-ventilated midsole as desired.
[0043] Referring again to FIG. 4, the midsole 18 may also include a
plurality of flex grooves 74a-c to facilitate flexing of the
midsole 18. In the illustrated embodiment, the midsole 18 includes
flex grooves 74a-c extending substantially laterally across the
sole 10 in the forefoot region. If desired, the flex grooves 74a-c
may be eliminated or replaced by other structure intended to
improve flexibility. For example, the flex grooves 74a-c may be
replaced by a relatively shallow recess (not shown) in the top
surface of the midsole 18 that is filled with a pad (not shown).
The pad may have a lower density than the material of the midsole
18. The pad may be cemented within the recess.
[0044] The undersurface 66 of the midsole 18 may be contoured to
compliment the shape of the outsole 12, heel wedge 14 and insert 16
(See FIG. 5). In the illustrated embodiment, the undersurface 66 of
the midsole 18 is contoured to define a plurality of support tube
recesses 78 that are adapted to closely receive the support tubes
46a-j of the insert 16. If desired, an insert recess 76 may be
defined in the undersurface 66 so that the insert 16 can be
recessed or inset into the midsole 18. For example, the midsole 18
may define a plurality of strut recesses 82 adapted to receive the
struts 38a-d of the insert 16. The recess 76 may also extend
through the extents of the arch portion 42 (including the wings
50a-b) and forefoot extension 44. Alternatively (or in addition),
recesses (not shown) may be formed in the top surface of the
outsole 12 to receive all or a portion of the insert 16.
[0045] The midsole 18 and heel wedge 14 are separate components in
the illustrated embodiment. The present invention extends, however,
to applications in which the midsole and heel wedge are integral.
For example, in an alternative embodiment, the appropriate material
(e.g. EVA foam) may be injected or poured into a mold about the
insert to entrap the insert in a single piece midsole/heel wedge
combination.
Alternative Embodiment
[0046] An alternative embodiment of the footwear sole of the
present invention is shown in FIGS. 13-17, and generally designated
100. In this embodiment, the insert 160 includes a plurality of
forefoot support tubes 510a-e. Similar to the first described
embodiment, the insert 160 is disposed above the outsole 120 and
the heel wedge 140, and provides the sole with a highly tuned
support profile in the forefoot region. Referring now to FIGS.
14-17, the insert 160 may include a heel portion 400, an arch
portion 420 and a forefoot portion 440. The heel portion 400 is
generally the same as the heel portion 40 described in connection
with the first embodiment, and therefore will not be described
again in detail. Suffice it to say that the heel portion 400 may
include support tubes 460a-j including internal webs, and struts
380a-d. Similarly, the arch portion 420 is generally the same as
the arch portion 42 described in connection with the first
embodiment. The arch portion 420 includes a pair of wings 500a-b
that extend upwardly from its lateral and medial edges. The wings
500a-b include a plurality of holes 502 extending therethrough. The
arch portion 420 may also define a slot 520 for receiving the strap
of a gaiter--as shown, the slot 520 is formed by first and second
layers 540a-b. The slot 520 may be oval in shape as illustrated,
however, the slot 520 may have a variety of shapes. Both the arch
portion 420 and the heel portion 400 are optional and may be
eliminated, if desired.
[0047] In the illustrated embodiment, the forefoot portion 440 of
the alternative embodiment is integral with and extends from the
arch portion 420. It may alternatively be a separate component, or
the only component if the heel portion 400 and/or the arch portion
420 are eliminated. A plurality of forefoot support tubes 510a-e
are provided in the forefoot portion, or at least at a position in
front of the arch region. In the illustrated embodiment, three of
the central forefoot support tubes 510b-d extend laterally all the
way across the insert 160, and a peripheral two of the forefoot
support tubes 510a and 510e extend from the lateral side of the
insert 160 partially across the insert 160 where they converge to a
point at a closed end 530. Functionally, these two support tubes
510a and 510e are stiffer at the closed end than they are at the
open end. The forefoot support tubes may be positioned in a
radiating arrangement, to enable an efficient toe-off towards the
medial side of the shoe 100. As illustrated, forefoot support tubes
510c and 510d are positioned in a radiating arrangement, such that
they diverge as they extend from the medial side to the lateral
side of the insert 160. Alternatively, more than two of the
forefoot support tubes 510a-e may be arranged radially, or in
another arrangement.
[0048] As shown in FIGS. 16 and 17, in one embodiment, the forefoot
support tubes 510a-e each include a generally flat base 550a-e, and
a generally semi-circular wall 570a-e extending upwardly from the
base 550a-e and forming a tube. The upwardly extending walls 570a-e
may alternatively have a variety of shapes. They may be hollow, as
shown, or may be filled with a support material, such as EVA. In
another embodiment, the bases may have different shapes, for
example, they may be semi-circular to form round tubes. In yet
another embodiment, the walls may extend downwardly from the base,
or both upwardly and downwardly from the base.
[0049] The bases 550a-e of each forefoot support tube 510 may be
integrally connected to each other and to the arch portion 420, for
example, as a forefoot extension of the insert 160. As shown, the
bases 550a-e are integrally connected to each other to form a web
590 extending from the arch portion 420. The web 590 is cut off
just in front of the forward most forefoot support tube 510a. It
may, however, be designed to extend through essentially any portion
of the forefoot region or over the entire forefoot region, if
desired. Alternatively, one or more of the bases and forefoot
support tubes may be separate sections. As shown, the web 590
additionally integrally includes a peripheral portion of each of
the upwardly extending walls 570a-e. Referring to FIGS. 14 and 16,
a first set of loops 610a-e extend upwardly from the web 590 to
form a first peripheral portion of the forefoot support tubes
510a-e on the lateral side of the insert 160. A second set of loops
630a-c extend upwardly from the web 590 to form a second peripheral
portion of the forefoot support tubes 510a-e on the medial side of
the insert 160. The web 590 may additionally define a plurality of
flex slots 560 configured to provide flex points. As in the first
embodiment, the insert 160 can be attached to the outsole 120 by a
variety of conventional methods.
[0050] The insert 160, including the forefoot support tubes 510a-e,
may be manufactured from a variety of conventional materials, but
typically it will be manufactured from a material that is stiffer
than the heel wedge 140 and/or midsole (not shown). For example,
the insert 160 may be injection molded from TPU, TPR, PVC or other
injected polymers. The insert 160 may be manufactured from other
materials, such as nylon, rubber, synthetic rubber or silicone, but
it is likely that the insert 160 would not be manufactured by
injection molding if any of these alternative materials was used.
If desired, the insert 160 may be manufactured from a collection of
different materials. For example, the arch portion 420 may be
manufactured from a stiffer material than the heel portion 400.
[0051] Referring now to FIG. 16, in one embodiment, the forefoot
support tubes 510a-e are formed from two different materials. The
web 590, including base portions 550a-e and the first and second
sets of loops 610a-e and 630a-c, are formed from a first material.
The upwardly extending walls 570a-e are formed from a second
material. In the illustrated embodiment, the upwardly extending
walls 570a-e are connected together by an upper web 650, such that
they may be formed from a single piece of the second material. As
illustrated, all of the insert 160 except for the upwardly
extending walls 570a-e is formed from the first material. The
second material is typically softer than the first material, such
that the forefoot support tubes 510a-e provide the desired level of
cushioning and support. In one embodiment, the first material has a
durometer value of 85 Shore A, and the second material has a
durometer value of 65 Shore A. In another embodiment, the first
material is approximately 10-30 Shore A points higher than the
second material, however, the range may vary, and alternatively the
first material may be softer than the second material. If desired,
the forefoot support tubes may be formed from more than two
materials, for example, the walls 570a-e may each be formed from a
different material with a different durometer value in order to
even more closely control the support and cushioning
characteristics of the insert 160. The second material may be
attached to the first material by a variety of conventional
methods, such as cement, adhesive, or bonding by heating one or
both of the materials.
[0052] Although not shown, in this embodiment, the midsole is
similar to the midsole 18 of the first embodiment. The undersurface
of the midsole may be contoured to compliment the shape of the
outsole 120, heel wedge 140 and insert 160--including the forefoot
support tubes 510a-e, as in the first embodiment, such the midsole
is contoured to define a plurality of support tube recesses that
are adapted to closely receive the support tubes 460a-j and the
forefoot support tubes 510a-e of the insert 160. The midsole may
include a plug, similar to the plug 62 of the first embodiment. The
heel wedge 140 is also similar to the heel wedge of the first
embodiment, and will not be described in detail. As in the first
embodiment, the heel wedge may include tube recesses 360, and a
central opening 800.
[0053] The above description identifies certain approximate
durometer values for the various components of the sole 10 of the
illustrated embodiment. The recited values are merely exemplary and
the present invention is not limited to sole constructions with the
specific recited durometer values. To the contrary, the present
invention should be broadly interpreted to extend to sole
components having different compressibility values.
[0054] The above description is that of the current embodiments of
the invention. Various alterations and changes can be made without
departing from the spirit and broader aspects of the invention as
defined in the appended claims, which are to be interpreted in
accordance with the principles of patent law including the doctrine
of equivalents. Any reference to claim elements in the singular,
for example, using the articles "a," "an," "the" or "said," is not
to be construed as limiting the element to the singular.
* * * * *