U.S. patent application number 13/480447 was filed with the patent office on 2012-12-20 for pressure relief system for footwear.
This patent application is currently assigned to BROWN SHOE COMPANY, INC.. Invention is credited to David L. Vattes.
Application Number | 20120317845 13/480447 |
Document ID | / |
Family ID | 47259767 |
Filed Date | 2012-12-20 |
United States Patent
Application |
20120317845 |
Kind Code |
A1 |
Vattes; David L. |
December 20, 2012 |
PRESSURE RELIEF SYSTEM FOR FOOTWEAR
Abstract
A shoe having a last which includes a shape and volume that
reflects the thickness of an internal sock liner, and a shoe
interior made specifically for inclusion of the sock liner. The
sock liner itself includes an anatomically shaped foot bed surface
with a cupped heel, contoured arch, radiused forepart and beveled
toe area. The sock liner material specifications and thicknesses
are engineered or tuned to have a high amount of deflection when
compressed without getting stiff.
Inventors: |
Vattes; David L.;
(University City, MO) |
Assignee: |
BROWN SHOE COMPANY, INC.
St. Louis
MO
|
Family ID: |
47259767 |
Appl. No.: |
13/480447 |
Filed: |
May 24, 2012 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
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61491190 |
May 28, 2011 |
|
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Current U.S.
Class: |
36/30R |
Current CPC
Class: |
A43B 7/141 20130101;
A43B 13/38 20130101; A43B 7/142 20130101; A43B 7/144 20130101 |
Class at
Publication: |
36/30.R |
International
Class: |
A43B 13/12 20060101
A43B013/12 |
Claims
1. A shoe sole construction comprising: an outsole; a sockliner
having an anatomical shape which creates at least about a 75%
contact rate between a wearer's foot and a top surface of the
sockliner during weight bearing of the wearer's foot by the
sockliner, the sockliner comprised of a material having a hardness
between about 10 C and 70 C on the Asker C scale, having a material
density of between about 0.05 g/cc and 0.60 g/cc, and having a
thickness of between about 5 mm and 50 mm at the heel center and
between about 3 mm to 35 mm at the forefoot center, where the
anatomical shape and material composition of the sockliner cause it
to deflect by about 25% at about 25 psi and by about 50% at about
70 psi; wherein a top surface of the outsole is sized and shaped to
receive and conform to a bottom surface of the sockliner.
2. The shoe sole of claim 1 wherein the sockliner is comprised of
one of: polyurethane, SEBS foam, EVA, rubber sponge, latex and/or a
co-polymer blended foam.
3. The shoe sole of claim 1 wherein the deflection of the sockliner
is about 25% during weight bearing when a wearer is standing
thereon.
4. The shoe sole of claim 1 wherein the deflection of the sockliner
is about 50% during weight bearing when a wearer is running.
5. The shoe sole of claim 1 wherein the outsole includes a
midsole.
6. The shoe sole of claim 1 wherein sockliner includes a
midsole.
7. The shoe sole of claim 1 wherein the sockliner is raised at the
midfoot region to underlie the medial arch of the wearer's
foot.
8. The shoe sole of claim 1 wherein the sockliner is cupped at the
hind foot region to underlie a wearer's heel.
9. The shoe sole of claim 8 wherein peripheral edges of the
sockliner are raised at the hind foot region from a medial side to
a lateral side of the sockliner to wrap around a wearer's heel.
10. The shoe sole of claim 1 wherein the sockliner includes a
radiused forepart region and a beveled toe area at the forefoot
region.
11. The shoe of claim 1 wherein the outsole is comprised by at
least one of: leather, elastomer, and polymer.
12. The shoe sole of claim 1 wherein the sockliner yields a target
threshold pressure of 40 psi or below.
Description
CROSS-REFERENCE TO RELATED APPLICATION
[0001] The present application claims priority to and incorporates
herein by reference U.S. Provisional Patent Application Ser. No.
61/491,190 filed on May 28, 2011.
BACKGROUND OF INVENTION
[0002] The present invention relates to a pressure relief system
for footwear that relieves plantar pressures via an anatomical sock
liner which is engineered with a shape designed to achieve a high
amount of deflection when compressed without becoming stiff.
[0003] Many footwear brands market shoes as "comfortable," and
there are many footwear products in the marketplace which claim to
deliver on comfort. However, there is a misconception in the
footwear industry as to what the definition of comfort actually is.
Indeed, there is no universal standard for "comfort." Consumers
have a hard time understanding precisely what comfort means, and
how it is designed into the footwear they are buying.
[0004] Most articles of footwear are designed for the masses to
wear. However, the resulting fit and comfort experience will be
different for everyone wearing a single shoe design, and satisfying
such a broad range in population is very difficult.
[0005] Most non-athletic shoes today contain hard materials,
flatter interior foot contact surfaces and/or are made with low
density foams that easily bottom out (i.e., which fully compress
too quickly, and therefore fail to provide sufficient cushioning).
These constructions lead to higher than desired interior pressures
created against the plantar surface of the foot, which eventually
lead to discomfort. Essentially, most non-athletic shoes are build
to be too hard and stiff.
[0006] Athletic shoes, on the other hand, are generally made with
softer cushioning materials designed to provide shock absorption
during high impact activities. However, these designs are not as
comfortable when used for everyday wear, because the cushioning
materials are tuned for the high-impact performance conditions,
rather than the lower impact casual situations.
[0007] In order to correct for these design deficiencies in
athletic and non-athletic shoes, many consumers buy after-market
insoles in an attempt to compensate for a shoe's short comings.
However, many of today's after-market insoles marketed for
improving comfort or relieving foot problems cause fit and comfort
compromises because these insoles were not designed holistically
together with the shoes they are to be put inside. The comfort
potential of these insoles is often offset by the functional
deficits of the footwear into which they are installed (hard,
stiff, inflexible, heavy, etc.).
[0008] Numerous combinations of after-market insoles and shoe
constructions have been used in shoes in attempts to provide
comfort. In most cases, layers of foam or other similar materials
are added to the sole construction to create the initial perception
of comfort, but such constructions typically lose their effect
after a short time. Many actually end up creating discomfort.
Beneath the soft foams are often hard, stiff structural components.
Insoles, sock liners and bottom shapes generally don't match the
plantar surface of a person's foot. When the shapes of the insole
and/or the sock liner don't match the plantar surface of a wearer's
foot, such shoe interiors have minimal/low arch and heel contact
with the foot. When combined with increased pressures encountered
when toeing off, inflexible soles create pressures on the plantar
area of the foot up to four times higher as compared to standing
still.
[0009] This invention improves upon the comfort benefits delivered
in footwear by focusing on a specific comfort dimension: plantar
pressure relief.
[0010] Specific advantages and features of the present invention
will be apparent from the attached drawings and the description of
an illustrative embodiment of the present invention.
SUMMARY OF INVENTION
[0011] A shoe is designed utilizing a last having a shape and
volume that reflect the thickness of an internal sock liner, and a
shoe interior made specifically for inclusion of this sock liner.
The sock liner itself contains an anatomically shaped foot bed
surface with a cupped heel, contoured arch, radiused forepart and
beveled toe area. The sock liner material specifications and
thicknesses are engineered or "tuned" to have a high amount of
deflection when compressed without getting "stiff."
[0012] The sock liner of the present invention includes a raised
area in the midfoot region and a recessed area located in the hind
foot or heel region. The raised area is positioned to underlie the
medial arch of the wearer's foot and the recessed area is
positioned to underlie the heel of the wearer's foot. The recessed
area is defined by the peripheral edges formed around the hind foot
region from the medial side to the lateral side of the heel. The
peripheral edge in the hind foot region forms a raised portion
where it wraps around the heel of the wearer's foot. The
anatomically shaped and formed sock liner reflects the natural
shapes of the human foot. The shaped plantar surface topography
maximizes surface contact with the wearer's foot and increases
comfort.
[0013] In order to "tune" the sock liner material dimensions,
design and specifications are engineered through an analysis of: 1)
the desired deflection ranges, which are generally between 40-70%
of the overall thickness of the sock liner; 2) the target loading
ranges being designed for active wearing occasions, which are
generally between 30-70 pounds, depending on gender and/or foot
size; 3) the physical properties of the materials to be used (as
specified below); 4) the desired pressure range targets for various
plantar areas of the foot, which are generally below 40 pounds per
square inch; and 5) anatomical shapes that create additional
surface contact with the foot. The deflection of the sock liner is
preferably approximately 25% while standing and approximately 50%
while running or walking.
[0014] Unlike most shoes designed for "extra comfort," the exterior
of the shoe can be designed for any wearing occasion and/or end
use. The shoe may be designed with less midsole thickness than
conventional shoes, in order to compensate for added thickness of
the sock liner. In this way, the system can be applied to any type
of footwear category or end use as long as there is adequate
sockliner thickness available. Athletic shoes (running, training,
walking), sandals, work shoes (duty/service industries), and casual
shoes may all incorporate such sock liners. Consideration is given
for the exterior shoe sole design to complement the functionality
designed for this system, such as: anatomically correct flex
location; and material thicknesses and specifications that do not
contribute to inflexibility, thus increasing pressure against the
foot's plantar surface by the poor shoe design/materials.
[0015] Preferably, materials may include polyurethane, SEBS foam,
EVA, rubber sponge, latex, and/or co-polymer blended foams. The
materials preferably have a hardness of between 10 C and 70 C on
the Asker C scale, with a material density of between 0.05 g/cc and
0.60 g/cc. The thickness of the sock liner (measured at the center
of the heel and center of the forefoot--not wall heights) varies by
shoe design. However, the thickness generally ranges from 5 mm to
50 mm at the heel center, and from 3 mm to 35 mm in the forefoot
center.
[0016] The overall design of a sock liner according to the present
invention should increase contact between the foot and sock liner
surface--especially during weight bearing--preferably at or above
75% rate of surface contact between the foot and sock liner. The
sock liner also improves pressure re-distribution from peak
pressure areas, and spreads the pressure across the entire plantar
surface area such that preferably no single location experiences a
pressure above 40 psi. In so doing, cushioning and shock absorption
protection should prevent stresses above 10 Gs.
[0017] In order to reduce such pressures exerted by the shoe
against the plantar surface of the foot, the sock liner surface
yields and deflects under the foot without a significant increase
of hardness and stiffness of the sock liner, which could create
discomfort. Such deflection can also increase foot stimulation
through more utilization of bones, tendons, muscles during
foot-strike. The deflection can also promote a wearer's natural
gait/foot-strike during walking, by straightening the wearer's
center of force trajectory during foot-strike. Further, a
flexibility improvement may be realized where less foot force is
required to bend a shoe across the foot's flex area. Preferably
below about 5 pounds of force is required to bend flex the shoe at
such flex areas.
[0018] The sock liners may be removable, and as noted above, either
polyurethane or EVA materials may be utilized (both as 100%
standalone sock liners, i.e., not combined). Alternatively,
non-removable sock liner foot beds may be utilized in an open
sandal or other type of shoe. Alternative embodiments may utilize:
"gel" as either a shock absorber or comfort element on the sock
liner; the addition of flex grooves on the bottom of the sock
liner; a visible sock liner, either through a window of the upper
or midsole; multiple foam types in one sock liner unit; a sockliner
made via injection molding, compression molding, open-pouring or
die-cut/cementing; a closed shoe with a non-removable sock liner;
additives to provide anti-microbial, anti-hydrolysis, and/or
anti-UV enhancements and/or to strengthen the cell structure; a
sock liner which can be combined with an insole layer (above or
below) to reduce thickness/weight and/or can be designed as a
"midsole" unit that is dropped into a unit sole or laminated with
an outsole layer in a stitch-out construction.
[0019] These and other objects and advantages of the present
invention will become more apparent to those skilled in the art
after considering the following detailed specification taken in
conjunction with the accompanying drawings.
BRIEF DESCRIPTION OF DRAWINGS
[0020] FIG. 1 is a three dimensional perspective view of a last,
the sock liner of the present invention, and an outsole designed
with a recess to receive the sock liner's added thickness.
[0021] FIG. 2 is a typical material "Force/Compression" chart which
illustrates a typical relationship between force (in pounds) and
percent deflection of the material.
[0022] FIGS. 3A and 3B are a bottom plan view and side elevational
view, respectively, of an exemplary sock liner.
[0023] FIGS. 4A, 4B and 4C are schematics of a right elevational
view, a top plan view and a left elevational view, respectively, of
a sock liner according to the present invention.
[0024] FIGS. 5A, 5B and 5B are cross sectional schematic views,
taken along the horizontal lines of FIGS. 4A-4C at the ball, arch
and heel of the sock liner, respectively.
[0025] FIG. 6A is an exemplary pressure test-image of a sock liner
according to the present invention.
[0026] FIG. 6B is an exemplary pressure test image of a prior art
sock liner.
[0027] It should be understood that the present drawings are not
necessarily to scale and that the present embodiments are sometimes
illustrated by graphic symbols, phantom lines, diagrammatic
representations and fragmentary views. In certain instances,
details which are not necessary for an understanding of the present
invention or which render other details difficult to perceive may
have been omitted. It should also be understood that the present
invention is not necessarily limited to the particular embodiments
illustrated herein. Like numbers utilized throughout the various
Figures designate like or similar parts or structure.
DETAILED DESCRIPTION
[0028] In the present invention, a sock liner is provided which
improves comfort and can be built into any type of shoe. As shown
in FIG. 1, a shoe will include an upper or last 5, the sock liner
10 and the midsole/outsole 20 ("outsole"). Outsole 20 is positioned
on the underside of the shoe for engagement with a walking surface
such as the ground, sidewalk, floor or other supporting surface.
Preferably, the top surface of the outsole is shaped to conform to
the bottom surface of the sock liner 10. The thickness of outsole
20 may be less than conventional shoes in order to compensate for
the added thickness of the sock liner 10. The outsole 20 may be
constructed of any suitable material for example, leather,
elastomer, polymer, a composite thereof or the like depending upon
the type of shoe desired. The sock liner 10 and outsole 20 may be
secured to one another using any suitable attachment means
including cement, adhesives, glue, welt and direct attachment
constructions
[0029] For ease of reference herein, the foot of a human may be
considered to have three regions: the forefoot region (area
adjacent the toes), the midfoot region (area adjacent the arch),
and the hind foot region (area adjacent the heel). As shown in
FIGS. 3A, 3B, 4A-4C and 5A-5C, the sock liner 10 similarly includes
three regions substantially underlying the above-referenced
corresponding three regions of the wearer's foot: the forefoot
region 16 of the sock liner 10, the midfoot region 14 of the sock
liner 10, and the hind foot region 12 of the sock liner 10. It
should be understood, however, that the boundaries between the
forefoot, midfoot and hind foot areas are not precise and that
these terms should be interpreted loosely and with a great deal of
flexibility. The ball of the foot is generally the area of the foot
at the juncture between the metatarsal bones and the phalange
bones.
[0030] The midfoot region 14 of sock liner 10 is raised to underlie
the medial arch of the wearer's foot, while the hind foot region 12
is cupped to underlie the heel of the wearer's foot. The hind foot
region 12 is defined by the peripheral edges 13 formed around the
hind foot region 12 from the medial side to the lateral side of the
heel. The peripheral edge 13 in the hind foot region 12 forms a
raised portion where it wraps around the heel of the wearer's foot.
The forefoot region 16 includes a radiused forepart and a beveled
toe area. The anatomically shaped and formed sock liner is thereby
designed to reflect the natural shapes of the human foot. The
shaped plantar surface topography maximizes surface contact with
the wearer's foot and increases comfort.
[0031] The sock liner material specifications and thicknesses are
engineered or "tuned" to have a high amount of deflection when
compressed without getting "stiff." In order to "tune" the sock
liner 10 material dimensions, design and specifications are
engineered through an analysis of: a) the desired deflection
ranges, which are generally between 40-70% of the overall thickness
of the sock liner and preferably about 25% while standing and about
50% while running or walking; b) the target loading ranges being
designed for active wearing occasions, which are generally between
30-70 pounds, depending on gender and/or foot size; c) the physical
properties of the materials to be used (as specified below); d) the
desired pressure range targets for various plantar areas of the
foot, which are generally below 40 pounds per square inch; and e)
anatomical shapes that create additional surface contact with the
foot.
[0032] An exemplary chart of the relationship between pressures
exerted on the sock liner 10 as compared to the deflection of the
sock liner 10 is shown in FIG. 2. As can be seen, as the force (in
pounds per square inch) increases, so too does the deflection of
the sock liner 10. At about 70 psi, which as noted above is at the
high end of the target loading range for an active wearing occasion
(e.g., running), the deflection is shown to be approximately
55%--close to the desired 50% deflection discussed above. Further,
at about 25 psi, which is below the low end target loading range
for an active wearing occasion (e.g., walking or standing), the
deflection is close to 25%--approximately the desired deflection
discussed above. Thus, the exemplary specimen tested in FIG. 2 is
appropriately "tuned" to provide optimal pressure relief according
to the present invention. It is noted that FIG. 2 illustrates the
measured characteristics of an exemplary material of an exemplary
thickness. Other materials would need to be "tuned" to determine
the proper thicknesses for achieving improved pressure relief.
[0033] Preferably, materials for the sock liner 10 may include
polyurethane, SEBS foam, EVA, rubber sponge, latex, and/or
co-polymer blended foams. The materials preferably have a hardness
of between 10 C and 70 C on the Asker C scale, with a material
density of between 0.05 g/cc and 0.60 g/cc. The thickness of the
sock liner 10 (measured at the center of the heel 12 and center of
the forefoot 16--not wall heights) varies by shoe design. However,
the thickness generally ranges from 5 mm to 50 mm at the heel
center 12, and from 3 mm to 35 mm in the forefoot center 16.
[0034] The overall design of a sock liner 10 according to the
present invention should increase contact between the foot and sock
liner 10--especially during weight bearing--preferably at or above
75% rate of surface contact between the foot and sock liner 10. The
sock liner 10 also improves pressure re-distribution from peak
pressure areas, and spreads the pressure across the entire plantar
surface area such that preferably no single location experiences a
pressure above 40 psi. In so doing, cushioning and shock absorption
protection should prevent stresses above 10 Gs. This can be seen in
FIG. 6A as compared to 6B. FIG. 6A illustrates an exemplary foot
pressure diagram of a foot utilizing the sock liner 10 of the
present invention, in which the hind foot portion 12 and forefoot
portion 16 of the foot experience a pressure level below the target
threshold of 40 psi (shown by the blue image color). In FIG. 6B,
which illustrates a prior art foot pressure diagram without an
improved sock liner 10, the forefoot region 16, and the hind foot
region 12 experience a pressure level well above (2-3 times) the
target threshold of 40 psi (shown by the red image color). Thus, by
tuning the thickness and shape of the material used in the sock
liner 10 construction, the deflection has been tuned such that the
forces experienced by the foot have been greatly reduced to below
40 psi from over 100 psi.
[0035] The sock liners 10 may be removable, and as noted above, or
they may be formed from polyurethane or EVA materials (both as 100%
standalone sock liners, i.e., not combined). Alternatively,
non-removable sock liner 10 foot beds may be utilized in an open
sandal or other type of shoe. Alternative embodiments may utilize:
"gel" as either a shock absorber or comfort element on the sock
liner 10; the addition of flex grooves on the bottom of the sock
liner 10; a visible sock liner 10, either through a window of the
upper or outsole 20; multiple foam types in one sock liner unit 10;
a sock liner 10 made via injection molding, compression molding,
open-pouring or die-cut/cementing; a closed shoe with a
non-removable sock liner 10; additives to provide anti-microbial,
anti-hydrolysis, and/or anti-UV enhancements and/or to strengthen
the cell structure; or a sock liner 10 which can be combined with
an insole layer (above or below) to reduce thickness/weight and/or
can be designed as a "midsole" unit that is dropped into a unit
sole or laminated with an outsole layer in a stitch-out
construction.
[0036] Further, the overall dimensions of the present sockliner 10
and outsole 20 as well as the specific shape and configuration of
the various sections thereof are also subject to wide variations
and may be sized and shaped into a wide variety of different sizes
and configurations so as to be compatible with the size and shape
of the particular footwear onto which the present structures may be
mounted, or to conform with any space limitations associated
therewith out impairing the teachings and practice of the present
invention.
[0037] It is also understood that various modifications may be made
to all of the various embodiments without departing from the spirit
and scope of the present invention.
[0038] Thus, there has been shown and described several embodiments
of an anatomical sock liner system. As is evident from the
foregoing description, certain aspects of the present invention are
not limited by the particular details of the examples illustrated
herein, and it is therefore contemplated that other modifications
and applications, or equivalents thereof, will occur to those
skilled in the art. The terms "having" and "including" and similar
terms as used in the foregoing specification are used in the sense
of "optional" or "may include" and not as "required". Many changes,
modifications, variations and other uses and applications of the
present invention will, however, become apparent to those skilled
in the art after considering the specification and the accompanying
drawings. All such changes, modifications, variations and other
uses and applications which do not depart from the spirit and scope
of the invention are deemed to be covered by the invention which is
limited only by the claims which follow.
* * * * *