U.S. patent application number 10/263466 was filed with the patent office on 2003-05-08 for footwear with a hybrid outsole structure.
Invention is credited to Ho, James.
Application Number | 20030084592 10/263466 |
Document ID | / |
Family ID | 26949874 |
Filed Date | 2003-05-08 |
United States Patent
Application |
20030084592 |
Kind Code |
A1 |
Ho, James |
May 8, 2003 |
Footwear with a hybrid outsole structure
Abstract
A hybrid outsole construction comprises high-density carbon
rubber molded to low-density blown rubber, providing increased
flexibility, cushion, and comfort while maintaining durability,
traction, and shock absorbency of the footwear. In accordance with
another aspect of the present invention, the hybrid outsole
construction is stitched to the upper layers of the footwear, for
example using a welt.
Inventors: |
Ho, James; (Northridge,
CA) |
Correspondence
Address: |
LIU & LIU LLP
811 WEST SEVENTH STREET, SUITE 1100
LOS ANGELES
CA
90017
US
|
Family ID: |
26949874 |
Appl. No.: |
10/263466 |
Filed: |
October 2, 2002 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
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60327139 |
Oct 3, 2001 |
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Current U.S.
Class: |
36/25R ; 36/30R;
36/59R |
Current CPC
Class: |
A43B 13/42 20130101 |
Class at
Publication: |
36/25.00R ;
36/30.00R; 36/59.00R |
International
Class: |
A43B 013/00 |
Claims
What is claimed is:
1. A shoe including an upper portion and an outsole portion coupled
to the upper portion, the outsole portion comprising: an outer sole
layer formed from a substantially wear resistant material for
traction on a walking surface, wherein the outer sole layer
includes a shaped hole defined through the outer sole layer; and an
inner sole layer formed from a substantially resilient cushioning
material, wherein the inner sole layer is disposed between the
outer sole layer and the upper portion, wherein a portion of the
inner sole layer extends through the shaped hole in the outer sole
layer.
2. The shoe of claim 1, wherein the outer sole layer includes a
plurality of treads, and wherein the portion of the inner sole
layer extending through the shaped hole defines a tread.
3. The shoe of claim 2, wherein the inner sole layer comprises a
heel section and a toe section, wherein the heel section is
substantially thicker than the toe section.
4. The shoe of claim 1, wherein the upper portion and the outsole
portion are coupled by stitching a welt to the upper portion and
the outsole portion.
5. The shoe of claim 3, wherein the sides of the inner sole layer
are exposed, so to allow the inner sole layer to deform out through
the sides of the outer sole layer under the weight of a wearer.
6. The shoe of claim 5, further comprising an upper sole layer
disposed between the upper portion and the inner sole layer.
7. The shoe of claim 6, wherein the wear resistant material
comprises carbon rubber, and the resilient material comprises blown
rubber.
8. A footwear comprising: an upper portion; and a lower portion
coupled to the upper portion, said lower portion having a toe
section and a heel section, and comprising an outsole portion
having a hybrid structure that includes an outer layer for traction
on a walking surface and made of a wear resistant material, and an
inner layer for cushioning made of a resilient material softer than
the wear resistant material, wherein the outer layer covers
entirely the front of the toe section and rear of the heel section
of the inner layer, but exposing lateral sides of the inner
layer.
9. The footwear as in claim 8, wherein the lower portion defines an
arch area, at which the outer layer exposes the inner layer.
10. The footwear as in claim 8, wherein the exposed lateral sides
of the inner layer has a convex profile in the absence of the
weight of a user, and a concave profile under the weight of the
user.
11. The footwear as in claim 8, wherein the upper portion and the
lower potion are coupled by stitching.
12. The footwear as in claim 11, wherein the upper portion and the
lower portion are coupled by stitching a welt to the upper portion
and lower portion.
13. The footwear as in claim 8, wherein the exposed lateral side of
the inner layer is recessed from an edge of the outer layer.
14. The footwear as in claim 8, wherein the resilient material
comprises blown rubber, and the wear resistant material comprises
carbon rubber.
15. A footwear comprising: an upper portion; and a lower portion
coupled to the upper portion, and comprising an outsole portion
having a hybrid structure that includes an outer layer for traction
on a walking surface and made of a wear resistant material, and an
inner layer for cushioning made of a resilient material softer than
the wear resistant material; wherein the upper portion is coupled
to the lower portion by stitching a welt to the upper portion and
the lower portion.
16. The footwear as in claim 15, wherein the inner layer includes
an exposed lateral side recessed from an edge of the outer
layer.
17. The footwear as in claim 15, wherein the exposed lateral side
of the inner layer has a convex profile in the absence of the
weight of a user, and a concave profile under the weight of the
user.
18. The footwear as in claim 15, wherein the resilient material
comprises blown rubber, and the wear resistant material comprises
carbon rubber.
19. The footwear as in claim 15, wherein the lower portion defines
an arch area, at which the outer layer exposes the inner layer.
Description
[0001] This application claims the priority of U.S. Provisional
Patent Application No. 60/327,139, filed Oct. 3, 2001.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] This invention relates to footwear, particularly to footwear
to be used in a rugged environment, of lighter weight, additional
comfort, and durability.
[0004] 2. Description of Related Art
[0005] A principal goal in shoe design is to design footwear that
is sturdy enough to protect the wearer's feet, yet flexible enough
to provide for comfortable walking. This is particularly true for
rugged footwear such as work boots or hiking boots, where comfort
is often compromised in a design for well-built footwear that can
withstand harsh conditions.
[0006] The outsole of rugged footwear is designed to resist wear,
provide durability, traction and absorb shock. Commonly, the
outsole material is made of high-density carbon rubber, which is a
relatively heavy and durable but stiff material. High-density
carbon rubber provides very little in the area of flexibility and
cushion. Thus, the construction of an outsole of a rugged footwear
must take into account the weight, flexibility and durability of
materials used in providing the necessary comfort and strength to
the footwear.
SUMMARY OF THE INVENTION
[0007] The present invention is directed to a hybrid outsole
construction comprised of high-density carbon rubber and
low-density blown rubber, providing increased flexibility, cushion,
and comfort while maintaining durability, traction, and shock
absorbency of the footwear. Unlike prior art outsole construction,
the present invention makes use of a hybrid structure to
manufacture the outsole. High-density carbon rubber molded to
low-density blown rubber comprises the hybrid outsole
construction.
[0008] One aspect of the invention contains low-density blown
rubber for added cushioning throughout the outsole as well as
high-density carbon rubber for durability, especially in high-wear
areas like the heel. A material for the low-density blown rubber
should be flexible, such as EMAX. EMAX provides the desired
flexibility, increased cushion, and lighter weight. Ethylene-vinyl
acetate (EVA) can also be used instead of the blown rubber. Other
low density, resilient synthetic plastic foam materials may be
used, such as polyurethane, polyethylene and polyethylene vinyl
acetate.
[0009] The use of low-density blown rubber, made by injecting air
into a rubber compound, is well known in prior art associated with
fitness-related footwear. No prior art, however, suggests the use
of low-density blown rubber for providing increased agility and
padding in rugged footwear like work boots.
[0010] Low-density blown rubber, however, is less durable against
wear than high-density carbon rubber. High-density carbon rubber
molded around the EMAX, exhibits good wear resistance
characteristics and preserves the strength and efficacy of the
footwear. In accordance with another aspect of the present
invention, the hybrid outsole construction is stitched to the upper
layers of the footwear, for example using a welt.
[0011] In another aspect of the present invention, the hybrid
outsole construction includes providing the high-density carbon
rubber layer with holes to expose the underlying low-density blown
rubber. Portions of the exposed low-density blown rubber can extend
through the holes to be formed into structures such as treads.
BRIEF DESCRIPTIONS OF THE DRAWINGS
[0012] The present invention will be more clearly understood when
considered in conjunction with the accompanying drawings. In the
following drawings, like reference numerals designate like or
similar parts throughout the drawings.
[0013] FIG. 1 is a right side view of a footwear incorporating a
hybrid outsole construction in accordance with one embodiment of
the present invention.
[0014] FIG. 2 is a cross sectional view of the footwear shown in
FIG. 1, taken along line 2-2.
[0015] FIG. 3 is a bottom view of the footwear shown in FIG. 1.
[0016] FIG. 4 is a side view of one embodiment of a
three-quarter-welt cup heel footwear showing the various components
of the footwear including the hybrid outsole construction with
exposed low-density blown rubber arch.
[0017] FIG. 5 is a rear heel-sectional view taken along line 5-5 in
FIG. 4.
[0018] FIG. 6 is a front toe-sectional view taken along line 6-6 in
FIG. 4.
[0019] FIG. 7 is a side view of another embodiment of a lightweight
welted footwear showing the various components of the footwear
including the hybrid outsole construction, with high-density carbon
rubber undersurface.
[0020] FIG. 8 is a rear heel-sectional view taken along line 8-8 in
FIG. 7.
DESCRIPTION OF PREFERRED EMBODIMENTS
[0021] The present description is the best contemplated mode of
carrying out the invention. This description is made for the
purpose of illustrating general principles of the invention and
should not be taken in a limiting sense.
[0022] FIG. 1 illustrates a right side view of a footwear or shoe
70 incorporating a hybrid outsole construction 75 in accordance
with one embodiment of the present invention. The footwear 70
comprises an upper portion 80 and the hybrid outsole construction
or the lower outsole portion 75. The upper portion 80 is shaped to
receive the right foot of a wearer and to secure the right foot of
the wearer within the upper portion 80. The lower outsole portion
75 is coupled to the upper portion 80, and is adapted to support
the weight of the wearer on top, and is capable of traction against
rough outside contact surfaces on bottom. The lower outsole portion
75 comprises an outer sole layer 85 and an inner sole layer 90. The
outer sole layer 85 is formed from a substantially wear resistant
material, such as high-density carbon rubber. The inner sole layer
90 is disposed between the upper portion 80 and the outer sole
layer 85. The inner sole layer 90 is formed from a substantially
resilient cushioning material that is substantially softer than the
wear resistant material forming the outer sole layer 85. The
resilient material can be low-density blown rubber, such as EMAX,
EVA, polyurethane, polyethylene or polyethylene vinyl acetate. The
lower outsole portion 75 can also comprise an upper sole layer 95
disposed between the upper portion 80 and the inner sole layer 90.
The upper sole layer 95 can be formed from the same wear resistant
material, such as high-density rubber. The inner sole layer 90 is
therefore sandwiched between the upper sole layer 95 and the outer
sole layer 85.
[0023] The outer sole layer 85, the inner sole layer 90, and the
upper sole layer 95 are coextensive along their lengths and widths.
As shown in FIG. 1, the inner sole layer 90 is exposed along its
perimeter sides. In some embodiments of the present invention, the
exposed sides of the inner sole layer 90 allow the inner sole layer
90 to deform or expand laterally as the wearer applies vertical
pressure to the lower outsole portion 75. The amount of deformation
will depend on the resilience of the inner sole layer material 90.
In some embodiments of the present invention, the inner sole layer
90 will not substantially deform under application of vertical
pressure.
[0024] In the embodiment shown in FIG. 1, the inner sole layer 90
has a variable thickness along its length. The inner sole layer 90
is thicker at a heel section 100 of the lower outsole portion 75
than at a toe section 105 of the lower outsole portion 75. Since
vertical pressure can be greatest at the heel section 100, the
additional thickness at the heel section 100 allows for additional
cushion at the heel section 100 to provide additional wearer
comfort. In some embodiments of the present invention (not shown),
the thickness of the inner sole layer 90 is uniform along its
length.
[0025] The lower outsole portion 75 may be assembled to the upper
portion 80 using a welt construction, such as the American Goodyear
welt 110. The American Goodyear welt 110 is used for heavy-duty
shoe construction, such as a work boot or hiking boot. The welt
construction utilizes treated cotton twine to stitch the welt 110
to the upper portion 80 and to the lower outsole portion 75. As
shown in FIG. 1, the welt 110 can run around the entire perimeter
of the upper portion 80 and the lower outsole portion 75.
Alternatively, the welt can run around the front perimeter of the
toe area and approximately three-quarters the inner and outer
length of the footwear ending at the cup heel (not shown).
[0026] FIG. 2 is a cross sectional view of the footwear 70 shown in
FIG. 1, taken through line 2-2. The outer sole layer 85 comprises
one or more holes 115 defined through the layer 85. The holes 115
expose the underlying inner sole layer 90, allowing portions of the
inner sole layer 90 to extend and be formed through the holes 115.
For example, portion 92 of the inner sole layer 85 can be formed
into a tread.
[0027] FIG. 3 illustrates a bottom view of the footwear 70 shown in
FIG. 1. The outer sole layer 85 includes a plurality of treads 87
for contact with the ground. The treads 87 can have any shape and
pattern that allows for optimum traction with the ground. FIG. 3
also illustrates a plurality of treads 92 formed from portions of
the inner sole layer 90 exposed through the holes 115 in the outer
sole layer 85. Treads 92 and 87 form a contact surface with the
ground. As treads 92 contact with the ground, the more resilient
treads 92 can provide additional impact absorption, while the more
wear resistant treads 87 can provide sufficient traction with the
ground.
[0028] FIG. 4 illustrates a side view of one embodiment of the
present invention by way of illustration only and not by
limitation, a three-quarter-welt cup heel footwear 10 incorporating
a hybrid outsole construction 14. It is noted that the illustration
shows the right side of the footwear. The three-quarter-welt cup
heel footwear 10 is made of an upper 12 that is created to conform
to the shape of the right foot of the wearer, and the hybrid
outsole 14 for support of the weight of the wearer on top and for
traction against rough outside contact surfaces on bottom. The
hybrid outsole 14 is comprised of layers of different materials: a
wear resistant layer of high-density carbon rubber (outer sole
layer) 16 trimmed at the edges, and a relatively soft, cushion
layer of low-density blown rubber (inner sole layer) 18, such as
EMAX, untrimmed and set back from the outsole sidewall, which is
made of the high-density carbon rubber 16. Other low density,
resilient synthetic plastic foam materials may be used in place of
EMAX, such as EVA, polyurethane, polyethylene and polyethylene
vinyl acetate.
[0029] The hybrid outsole construction 14 is achieved by molding
the high-density carbon rubber 16 around certain areas of
previously created low-density blown rubber 18. High-density carbon
rubber 16 bounds the low-density blown rubber 18 on all sides
(e.g., underneath the upper 12, at the toe and heel areas, and the
bottom), but not on the lateral sides and the underside of an arch
area 28. Without high-density carbon rubber underneath the arch 28,
the footwear 10 can be more flexible to the wearer's movement.
[0030] In some embodiments of the present invention, because the
low-density blown rubber 18 is not bound on all sides and because
it is set back or recessed from the outsole sidewall, space is
provided to allow the low-density blown rubber 18 to substantially
deform or expand laterally as vertical pressure (i.e., under the
weight of the wearer) is applied to the hybrid outsole 14. Further,
the low-density blown rubber 18 in the arch area 28 substantially
deforms into the space beneath the arch area 28 when vertical
pressure is applied to the hybrid outsole 14. When the pressure is
removed, the low-density blown rubber 18 recovers its shape and
once again is recessed from the outsole sidewall. In some
embodiments of the present invention (not shown), the low-density
blown rubber 18 does not substantially deform under the vertical
pressure.
[0031] The hybrid outsole 14 may be assembled to the upper 12 using
a welt construction, such as the American Goodyear welt 20, which
utilizes stitching 22, with treated cotton twine, the welt to the
upper 12 and the outsole 14 (e.g., for a heavy duty shoe
construction, such as a work boot or hiking boot). The welt 20 runs
around the front perimeter of the toe area and approximately
three-quarters the inner and outer length of the footwear 10 ending
at the cup heel 24.
[0032] FIG. 5 illustrates a rear heel-sectional view of FIG. 4
displaying the hybrid outsole 14 and its components: the
high-density carbon rubber 16, which is trimmed at the edges of the
footwear; and the low-density blown rubber 18, which is untrimmed
and recessed from the high-density carbon rubber 16 sidewall. FIG.
5 shows the state in which the low-density blown rubber 18 expands
laterally to a convex profile, acting as a cushion when vertical
weight is applied. When the weight is removed, the low-density
blown rubber 18 contracts back to its original position, with the
lateral edge of the rubber 18 in a concave profile (see dotted line
17). The cup heel 24 and the high-density carbon rubber 16 of the
hybrid outsole 14 are one continuous piece of rubber. The cup heel
24 may be cement lasted and stitched.
[0033] FIG. 6 illustrates a front toe-sectional view of FIG. 4
showing the hybrid outsole 14 consisting of high-density carbon
rubber 16 and low-density blown rubber 18. As shown in FIG. 6, when
vertical pressure is applied to the hybrid outsole 14, the
low-density blown rubber 18 expands laterally here as well, forming
a convex profile. When vertical pressure is released, the sidewall
of the rubber 18 contracts to a concave profile 17.
[0034] FIG. 7 illustrates a side view of another embodiment of a
hybrid outsole 54, a lightweight welted footwear 50. The hybrid
outsole 54 is comprised of trimmed high-density carbon rubber
(outer sole layer) 56 and untrimmed, recessed, low-density blown
rubber (inner sole layer) 58, such as EMAX. The high-density carbon
rubber 56 covers the low-density blown rubber 58 in certain areas:
at the top, bottom, front and back, but not on the sides. The
low-density blown rubber 58 is able to substantially deform and
expand laterally as pressure is applied vertically to the hybrid
outsole 54. When the pressure is removed, the low-density blown
rubber 58 will contract to its original state. Alternatively, the
low-density rubber 58 does not substantially deform under the
applied pressure.
[0035] The hybrid outsole 54 is assembled to the upper 52 with a
welt 60 and treated cotton twine stitching 62. The stitching 62
extends through the hybrid outsole 54, the welt 60, and the upper
52. The welt 60 runs completely around the lightweight welted
footwear 50.
[0036] FIG. 8 illustrates a rear heel-sectional view of FIG. 7
displaying the trimmed high-density carbon rubber 56 and the
untrimmed, recessed, low-density blown rubber 58 comprising the
hybrid outsole 54. When vertical pressure is applied to the hybrid
outsole, the low-density blown rubber 58 expands laterally until
the pressure is removed, retracting back to a convex profile
17.
[0037] While the invention has been described in detail with
respect to the illustrated embodiments in accordance therewith, it
will be apparent to those skilled in the art that various changes,
modifications, substitutions, alterations and improvement may be
made without departing from the scope and spirit of the invention
as defined by the appended claims.
* * * * *