U.S. patent application number 13/424243 was filed with the patent office on 2012-09-20 for high-stability multi-density midsole.
This patent application is currently assigned to COLUMBIA SPORTSWEAR NORTH AMERICA, INC.. Invention is credited to John Swigart.
Application Number | 20120233877 13/424243 |
Document ID | / |
Family ID | 46827296 |
Filed Date | 2012-09-20 |
United States Patent
Application |
20120233877 |
Kind Code |
A1 |
Swigart; John |
September 20, 2012 |
HIGH-STABILITY MULTI-DENSITY MIDSOLE
Abstract
Embodiments herein relate generally to the field of footwear,
and more particularly to components of performance footwear, such
as midsoles, and in particular related to high-stability,
multi-density midsoles. In some embodiments, the midsoles disclosed
herein may protect a user from over-pronation and/or
over-supination of the foot. Embodiments of the high stability
midsoles disclosed herein may include a cushioning element and a
mid-foot element. In various embodiments, the mid-foot element may
be configured to mate with the cushioning element in the mid-foot
portion, and may include at least one posterior tail configured to
align with a medial or lateral edge of the heel portion of the
cushioning element. Alternatively, the midsole may have integrated
cushioning regions with different response property regions.
Inventors: |
Swigart; John; (Portland,
OR) |
Assignee: |
COLUMBIA SPORTSWEAR NORTH AMERICA,
INC.
Portland
OR
|
Family ID: |
46827296 |
Appl. No.: |
13/424243 |
Filed: |
March 19, 2012 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
61454441 |
Mar 18, 2011 |
|
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|
Current U.S.
Class: |
36/28 |
Current CPC
Class: |
A43B 7/142 20130101;
A43B 7/143 20130101; A43B 7/226 20130101; A43B 7/223 20130101; A43B
7/148 20130101; A43B 7/24 20130101; A43B 13/127 20130101; A43B
3/0063 20130101; A43B 13/186 20130101; A43B 13/188 20130101 |
Class at
Publication: |
36/28 |
International
Class: |
A43B 13/18 20060101
A43B013/18 |
Claims
1. A high stability midsole comprising: a cushioning element
comprising mid-foot and heel portions; and a mid-foot element
configured to mate with the cushioning element in the mid-foot
portion, wherein the mid-foot element comprises at least one
posterior tail configured to align with a medial or lateral edge of
the heel portion of the cushioning element.
2. The high stability midsole of claim 1, wherein the heel portion
comprises low density foam, and wherein the low density foam
comprises 40-60 Asker C foam.
3. The high stability midsole of claim 1, wherein the heel portion
comprises low density foam, and wherein the low density foam
comprises 50-60 Asker C foam.
4. The high stability midsole of claim 1, wherein the mid-foot
element comprises high density foam, and wherein the high density
foam comprises 60-75 Asker C foam.
5. The high stability midsole of claim 1, wherein the mid-foot
element comprises high density foam, and wherein the high density
foam comprises 65-75 Asker C foam.
6. The high stability midsole of claim 1, wherein the heel portion
comprises 50-60 Asker C foam, and wherein the mid-foot element
comprises 60-75 Asker C foam.
7. The high stability midsole of claim 1, wherein the mid-foot
element comprises a medial posterior tail configured to align with
a medial edge of the heel portion of the cushioning element, and a
lateral posterior tail configured to align with a lateral edge of
the heel portion of the cushioning element.
8. The high stability midsole of claim 7, wherein the medial
posterior tail is long and the lateral posterior tail is of medium
length.
9. The high stability midsole of claim 7, wherein the medial
posterior tail is long and the lateral posterior tail is short.
10. The high stability midsole of claim 7, wherein the medial
posterior tail is of medium length and the lateral posterior tail
is of medium length.
11. The high stability midsole of claim 7, wherein the medial
posterior tail is of medium length and the lateral posterior tail
is short.
12. The high stability midsole of claim 7, wherein the medial
posterior tail is of medium length and the lateral posterior tail
is long.
13. The high stability midsole of claim 7, wherein the medial
posterior tail is longer than the lateral posterior tail.
14. The high stability midsole of claim 7, wherein the medial
posterior tail is shorter than the lateral posterior tail.
15. The high stability midsole of claim 7, wherein the medial
posterior tail and the lateral posterior tail are substantially the
same length.
16. The high stability midsole of claim 1 wherein the cushioning
element further comprises a fore-foot portion, and wherein the
mid-foot element comprises a medial anterior tail configured to
align with a medial edge of the fore-foot portion of the cushioning
element and a lateral anterior tail configured to align with a
lateral edge of the fore-foot portion of the cushioning
element.
17. The high stability midsole of claim 16, wherein the medial
anterior tail is longer than the lateral anterior tail.
18. The high stability midsole of claim 1, wherein the midsole is
configured to be customizable to suit a particular user, gait
problem, or terrain.
19. The high stability midsole of claim 1, wherein the cushioning
element and the mid-foot element are two separate components of the
midsole.
20. The high stability midsole of claim 1, wherein the cushioning
element and the mid-foot element are integral components of the
midsole.
21. A high stability midsole comprising: a cushioning element
comprising fore-foot, mid-foot, and heel portions, wherein the heel
portion comprises 40-60 Asker C foam; and a mid-foot element
comprising 60-75 Asker C foam and configured to mate with the
cushioning element in the mid-foot portion, wherein the mid-foot
element comprises: a medial posterior tail configured to align with
a medial edge of the heel portion of the cushioning element; a
lateral posterior tail configured to align with a lateral edge of
the heel portion of the cushioning element; a medial anterior tail
configured to align with a medial edge of the fore-foot portion of
the cushioning element; and a lateral anterior tail configured to
align with a lateral edge of the fore-foot portion of the
cushioning element.
22. The high stability midsole of claim 21, wherein the medial
posterior tail is longer than the lateral posterior tail.
23. The high stability midsole of claim 21, wherein the medial
posterior tail is shorter than the lateral posterior tail.
24. The high stability midsole of claim 21, wherein the medial
posterior tail is substantially the same length as the lateral
posterior tail.
25. The high stability midsole of claim 21, wherein the medial
anterior tail is longer than the lateral anterior tail.
26. The high stability midsole of claim 21, wherein the cushioning
element and the mid-foot element are two separate components of the
midsole.
27. The high stability midsole of claim 21, wherein the cushioning
element and the mid-foot element are integral components of the
midsole.
Description
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] The present application claims priority to U.S. Provisional
Patent Application No. 61/454,441, filed Mar. 18, 2011, entitled
"HIGH-STABILITY MULTI-DENSITY MIDSOLE," the disclosure of which is
hereby incorporated by reference in its entirety.
TECHNICAL FIELD
[0002] Embodiments herein relate generally to the field of
footwear, and more particularly to components of performance
footwear, such as midsoles.
BACKGROUND
[0003] Since the introduction of cushioned midsoles in running
shoes, injuries associated with the impact of foot strikes have
been reduced. Concomitantly, runners have adapted to cushioned
running shoes by increasing stride length and landing more toward
the lateral posterior edge of the heel. This adaptation may be
associated with excessive foot/ankle motion. Moreover, pronation
injuries such as inversion and eversion sprains are thought to
occur if the initial pronation velocity is too high or the maximum
pronation angle is too great.
[0004] To mitigate the negative effects of a cushioned heel, the
modern running shoe evolved to feature different midsole stiffness
regions. The heel "crash pad" is a soft, beveled midsole feature
that facilitates compression of the lateral posterior portion of
the midsole as the heel impacts the ground, thereby reducing the
initial rate of pronation. "Medial posting" is a common midsole
feature designed to reduce maximum pronation. As the stride
transitions from heel to mid-stance, the foot pronates in greater
measure until it is opposed by a stiffer, less compressive midsole
in the arch and just posterior to the arch.
[0005] Both of these concepts effectively use local midsole
stiffness to control motion when running on a smooth surface such
as a road, in which heel strike kinematics are predictable and
repeatable. However, for the trail runner, the surface is much more
variable and much less predictable. The smooth, firm road is
replaced by a wide range of grades potentially covered with loose
gravel, scree, talus, and many other impediments. Consequently, the
initial point of heel contact can greatly vary from step-to-step.
For example, if the foot lands on a rock under the medial posterior
portion of a medially posted running shoe heel, the stiff and less
yielding medial midsole will work to force the ankle to quickly
rotate to an inverted position and the soft, beveled crash pad may
not provide enough resistance to contain excessive and potentially
catastrophic inversion of the foot.
BRIEF DESCRIPTION OF THE DRAWINGS
[0006] Embodiments will be readily understood by the following
detailed description in conjunction with the accompanying drawings.
Embodiments are illustrated by way of example and not by way of
limitation in the figures of the accompanying drawings.
[0007] FIGS. 1A-1D illustrate bottom (FIGS. 1A and 1B) and top
(FIGS. 1C and 1D) views of a high-stability, impact-absorbing,
multi-density midsole that includes a generally soft cushioning
element and a firmer mid-foot element, in accordance with various
embodiments;
[0008] FIGS. 2A-2D illustrate a medial side view (FIG. 2A), a
bottom view (FIG. 2B), a lateral side view (FIG. 2C), and a
posterior view (FIG. 2D) of the mid-foot element shown in FIG. 1,
in accordance with various embodiments; and
[0009] FIGS. 3A-3D illustrate four examples of a high stability,
impact-absorbing, multi-density midsole and its corresponding
mid-foot element, including an example with a medium length lateral
posterior tail and a long medial posterior tail (FIG. 3A), an
example with a short lateral posterior tail and a long medial
posterior tail (FIG. 3B), an example with a medium lateral
posterior tail and a medium medial posterior tail (FIG. 3C), and an
example with a short lateral posterior tail and a medium medial
posterior tail (FIG. 3D), in accordance with various
embodiments.
DETAILED DESCRIPTION OF DISCLOSED EMBODIMENTS
[0010] In the following detailed description, reference is made to
the accompanying drawings which form a part hereof, and in which
are shown by way of illustration embodiments that may be practiced.
It is to be understood that other embodiments may be utilized and
structural or logical changes may be made without departing from
the scope. Therefore, the following detailed description is not to
be taken in a limiting sense, and the scope of embodiments is
defined by the appended claims and their equivalents.
[0011] Various operations may be described as multiple discrete
operations in turn, in a manner that may be helpful in
understanding embodiments; however, the order of description should
not be construed to imply that these operations are order
dependent.
[0012] The description may use perspective-based descriptions such
as up/down, back/front, and top/bottom. Such descriptions are
merely used to facilitate the discussion and are not intended to
restrict the application of disclosed embodiments.
[0013] The terms "coupled" and "connected," along with their
derivatives, may be used. It should be understood that these terms
are not intended as synonyms for each other. Rather, in particular
embodiments, "connected" may be used to indicate that two or more
elements are in direct physical or electrical contact with each
other. "Coupled" may mean that two or more elements are in direct
physical or electrical contact. However, "coupled" may also mean
that two or more elements are not in direct contact with each
other, but yet still cooperate or interact with each other.
[0014] For the purposes of the description, a phrase in the form
"NB" or in the form "A and/or B" means (A), (B), or (A and B). For
the purposes of the description, a phrase in the form "at least one
of A, B, and C" means (A), (B), (C), (A and B), (A and C), (B and
C), or (A, B and C). For the purposes of the description, a phrase
in the form "(A)B" means (B) or (AB) that is, A is an optional
element.
[0015] The description may use the terms "embodiment" or
"embodiments," which may each refer to one or more of the same or
different embodiments. Furthermore, the terms "comprising,"
"including," "having," and the like, as used with respect to
embodiments, are synonymous.
[0016] Embodiments herein are directed to performance footwear
components, such as midsoles, that may reduce the initial pronation
and supination rates that may occur when the heel strikes on a
surface, including uneven, rough surfaces such as gravel roads,
scree, talus, or rutted trails. In some embodiments, this may be
accomplished by providing a midsole having a full heel area that
may provide a long, soft spring rate to absorb shock and/or impact
from rocks and debris at heel strike. In various embodiments, the
disclosed midsoles may also reduce the maximum pronation and
supination angles that result from heel-to-mid-stance transition on
uneven, irregular surfaces. For instance, various examples of the
disclosed high-stability midsoles may provide a mid-foot
structure/element that may guide either a pronated or supinated
foot to a neutral position by the mid-stance-to-toe-off phase of a
running gait.
[0017] While certain embodiments are discussed with reference to
trail running, embodiments herein may be applicable to a wide
variety of activities, such as running and hiking; various sports,
such as volleyball, basketball, and tennis; various professions,
such as medical, industrial, safety, rescue, and military, and
other suitable applications.
[0018] Various embodiments of the midsole may include both a
generally soft cushioning element and a firmer mid-foot element. In
various embodiments, the generally soft cushioning element may
include a heel portion that may provide a cushioning and
impact-absorbing layer and that is configured to absorb the impact
and/or shock of the heel hitting a rock or other uneven surface,
without causing the instability (e.g., pronation or supination)
that may be caused by a traditional (e.g. firm) posted midsole. In
various embodiments, the mid-foot element may be any suitable shape
including angled curved, parabolic, hyperbolic, etc.
[0019] In various embodiments, the midsole also may include a
mid-foot element that may be firmer than the soft cushioning
element, and that may have one or more medial and/or lateral
posterior "tails" that may extend along at least a portion of a
corresponding medial or lateral edge of the heel portion of the
cushioning element. In various embodiments, after the initial
heelstrike, as the foot begins to roll forward, the firmer
consistency of the medial and or posterior tails of the mid-foot
element may then begin to correct any pronation or supination and
may return the foot to a neutral position, for instance by the time
the foot has transitioned to the midstrike or toe-off phases. In
various embodiments, the firmness of the cushioning element and/or
mid-foot element and the length and/or height of the mid-foot
element and/or posterior tails may be varied to suit a particular
condition or set of conditions, such as the surface conditions, a
user's running/walking style, a particular sport, activity, or
profession, weight of the user, weight and distribution of carried
objects such as backpacks, leg length or height of the user, or to
accommodate or correct a particular gait problem, such as
over-pronation or oversupination.
[0020] FIGS. 1A-1D illustrate bottom (FIGS. 1A (partially exploded)
and 1B (coupled)) and top (FIGS. 1C (partially exploded) and 1D
(coupled)) views of a high-stability, impact-absorbing midsole 100
that includes a generally soft cushioning element 110 and a firmer
mid-foot element 112, in accordance with various embodiments. In
various embodiments, cushioning element 110 may include at least a
heel portion 114 configured to absorb shock or impact force from a
heelstrike, for instance on uneven terrain. In various embodiments,
mid-foot element 112 may be configured to mate or align with
cushioning element 110, and may include one or more posterior
tails, such as a medial posterior tail 116 and/or a lateral
posterior tail 118. In some embodiments, medial posterior tail 116
may extend at least partially along the medial edge 120 of heel
portion 114, and/or lateral posterior tail 118 may extend at least
partially along the lateral edge 122 of heel portion 114.
[0021] In various embodiments, cushioning element 110 and mid-foot
element 112 may have different response properties, which may be
characterized in terms of density, durometer, flex, specific
gravity, and other footwear design characteristics. These different
properties may allow for a variety of biomechanical improvements,
including, but not limited to improved impact cushioning, support,
and stability, for instance when used on uneven terrain. In the
illustrated embodiment, materials having different response
properties (e.g., different durometers, which may generate
different sensations of softness or firmness) are strategically
positioned in a configuration that may be useful in, for example,
athletic shoes or boots, to help reduce the initial pronation
and/or supination rate and the maximum pronation and supination
angle. For instance, midsole 100 may include different response
property areas arranged about one or more edges 120, 122 of heel
portion 114, with, for example, a higher density or durometer
material disposed therein in mid-foot element 112. In use, as heel
portion 114 absorbs the impact force of the initial heelstrike, one
or more posterior tails 116, 118 may serve to arrest and reverse
any excessive pronation or supination and return the foot to a more
neutral position.
[0022] Although FIGS. 1A-1D depict midsole 100 as having two
separate (discrete, couplable) components (e.g., cushioning element
110 and mid-foot element 112), one of skill in the art will
appreciate that midsole 100 may be constructed as a single
component having different response property regions, i.e., the
cushioning element and the frame may be integral components of the
midsole. For instance, instead of discrete components, midsole 100
may be constructed as a unitary structure, which, in some
embodiments, may have blended transitions between materials having
different densities or durometers, such as described in U.S. Patent
Application No. 61/345,978, which is incorporated by reference
herein. As used herein, the term "blended transition zones" and any
variation thereof may generally refer to the interlocking or
intermixing of materials (e.g. foams) having different response
properties (e.g. densities or durometers), such that there is not a
definite, clearly defined linear or planar path between the
materials with different response properties.
[0023] Cushioning element 110 may also include a midfoot portion
124 and a forefoot portion 126. Thus, in some embodiments,
cushioning element 110 may form an entire upper surface of midsole
100, providing the entire footbed with cushioning, for instance for
comfort and impact absorption. In various embodiments, mid-foot
element 112 also may include an anterior medial tail 128 and/or an
anterior lateral tail 130, and may maintain a neutral foot position
during toe-off. Furthermore, anterior medial tail 128 and anterior
lateral tail 130 may provide lateral stabilization, and they may
help the shoe to flex across the forefoot in an anatomically
correct location.
[0024] Additionally, one of skill in the art will appreciate that
although mid-foot element 112 is depicted as mating with a bottom
surface of cushioning element 110, midsole 100 may be constructed
only as a mid-foot element 112, or as a mid-foot element 112
configured to mate with a top surface of cushioning element 110.
Furthermore, although midsole 100 is illustrated as having forefoot
126, mid-foot 124, and heel 114 portions, one of skill in the art
will appreciate that some embodiments of midsole 100 may only
include a heel portion 114 and a mid-foot portion 124.
[0025] FIGS. 2A-2D illustrate a medial side view (FIG. 2A), a
bottom view (FIG. 2B), a lateral side view (FIG. 2C), and a
posterior view (FIG. 2D) of the mid-foot element 112 shown in FIGS.
1A-1D, in accordance with various embodiments. As illustrated in
FIGS. 2A and 2C, mid-foot element 212 may have a thickness
dimension 232 that may vary in different regions. For instance, the
thickness 232 of mid-foot element 212 may be greater in regions
where greater firmness or support is desired (for example, in a
mid-foot portion), and it may be smaller or non-existent in regions
where less firmness or support is needed (e.g., in a heel portion
or fore-foot portion). The thickness 232 of mid-foot element 212
also may be greater at the medial and/or lateral edges, for
instance, when greater stabilization or protection from supination
or pronation is desired.
[0026] FIGS. 3A-3D illustrate four examples of a high stability,
impact-absorbing, multi-density midsole 300(a-d), including
cushioning element 310(a-d) and its corresponding mid-foot element
312(a-d). These include an example of a cushioning element 310a and
corresponding mid-foot element 312a, wherein mid-foot element 312a
may have a medium length lateral posterior tail 318a and a long
medial posterior tail 316a (FIG. 3A), an example of a cushioning
element 310b and corresponding mid-foot element 312b, wherein
mid-foot element 312b may have a short lateral posterior tail 318b
and a long medial posterior tail 316b (FIG. 3B), an example of a
cushioning element 310c and corresponding mid-foot element 312c,
wherein mid-foot element 312c may have a medium lateral posterior
tail 318c and a medium medial posterior tail 316c (FIG. 3C), and an
example of a cushioning element 310d and corresponding mid-foot
element 312d, wherein mid-foot element 312d may have a short
lateral posterior tail 318d and a medium medial posterior tail 316d
(FIG. 3D), in accordance with various embodiments.
[0027] As illustrated, the length of the posterior tails 316(a-d),
318(a-d) may be varied to suit a particular condition or set of
conditions. For instance, the medium length lateral posterior tail
318a and long medial posterior tail 316a illustrated in FIG. 3A may
serve to stabilize the foot in both medial and lateral directions
and may provide strong protection from over-pronation and moderate
protection from over-supination. In another example, the short
lateral posterior tail 318b and a long medial posterior tail 316b
illustrated in FIG. 3B may provide strong protection from
over-pronation, for instance for a user or set of conditions prone
to over-pronation but not at serious risk of over-supination. The
example illustrated in FIG. 3C has a medium lateral posterior tail
318c and a medium medial posterior tail 316c, and may provide
moderate protection from both overpronation and over-supination.
Finally, the example illustrated in FIG. 3D includes a short
lateral posterior tail 318d and a medium medial posterior tail
316d, which may provide moderate protection from over-pronation,
for instance for a user or set of conditions in which
over-pronation is more of a risk than over-supination.
[0028] FIGS. 3A-3D illustrate the lengths of the lateral posterior
tail(s) and the medial posterior tail(s) measured as a percentage
of entire sole length measured from the heel. For example, the long
tails reach back to about 10% of full length from the heel, for
example, about 3-14%, about 5-13%, or about 7-12%. Likewise, a
medium tail reaches back to about 20% of full length from the heel,
for example, about 15-24%, about 17-23%, or about 18-21%, and a
short tail reaches back to about 30% of full length from the heel,
for example about 25-37%, about 27-35%, or about 28-33%. These
lengths are merely examples, and may be modified in line with the
teachings herein as desired for different functionality. For
instance, a tail may be as long as about 3%, 5% or 7% of full
length from the heel, as short as about 37%, 35%, or 33% of full
length from the heel, or any length therebetween. In addition to
varying the length of the tails, the thickness and/or height of
each tail may be individually configured for a desired amount of
lateral or medial support. For example, a slightly thicker tail may
provide more support, and a slightly thinner tail may provide less
support, as compared to the illustrated examples.
[0029] One of skill in the art will appreciate that, although not
illustrated, anterior tails 128, 228, 328(a-d), and 130, 230,
330(a-d) may be similarly varied in length to create a desired
degree of stability and mid-foot alignment during toe-off.
Additionally, in various embodiments, the thickness and/or height
of each anterior or posterior tail may be optimized to provide the
degree of support desired for a particular user or set of
conditions. Furthermore, in various embodiments, the thickness of
mid-foot element 112, 212, 312(a-d) may be increased in any region
where more stabilization or firmer support is desired, or for a
heavier or taller user. Many conventional midsoles include a
support shank for this purpose or to stabilize the midsole from
torsional motion. Although a support shank such as a steel shank
may be included in some embodiments, in other embodiments, mid-foot
element 112, 212, 312(a-d) may make a support shank unnecessary. In
some embodiments, mid-foot element 112 may occupy the full
thickness of the midsole in some regions, such as in the mid-foot
portion 126 for instance to provide firm arch support. Additionally
or alternatively, in some embodiments, cushioning element 110,
310(a-d) may be made thicker in a particular region or throughout
midsole 100, 200, 300(a-d) if greater comfort or cushioning is
required, for instance for a heavier user, for certain terrain
conditions, or for a user with foot pain or an injury.
[0030] In the foregoing embodiments, one of skill in the art will
appreciate that, although only two different material response
property areas are illustrated (e.g., cushioning element 110 and
mid-foot element 112), any number of response property areas may be
used, for instance 3, 4, 5, 6, or even more. Such different
response property areas may be arranged in a number of strategic
configurations. For example, an additional low density or low
durometer material may be used wherever extra softness or
cushioning is needed, such as in the heel or fore-foot portions, or
for use when the user has an injury or otherwise requires more
cushioning. In another example, an additional higher density or
higher durometer material may be included in any area requiring
firm support, extra stability, or extra durability. As described
above, in some embodiments, the specific configuration of the
midsole may be customized to suit the needs, footstrike pattern,
terrain, or running style of an individual user.
[0031] Although the response property areas are referred to herein
as low and high (e.g., as it relates to firmness, density, or
durometer), one of skill in the art will appreciate that these
terms are relative. For example, where the material response
property is durometer, the term "low" may correspond to about 40-60
Asker C, or about 50-60 Asker C in some embodiments.
Correspondingly, where the material response property is durometer,
the term "high" may correspond to about 60-75 Asker C, or about
65-75 Asker C in some embodiments. In other embodiments, greater or
lower response property materials also may be used to suit the
desired application.
[0032] In some embodiments, the midsole material may extend around
and/or over the instep, for instance to provide greater protection
and stability through the midfoot portion. In still other
embodiments, the midsole material may extend around and/or over the
fore-foot portion, for instance to provide protection to the toes.
In particular embodiments, the midsole material may extend around
the entire foot and may form a part of or all of the footwear
upper, for instance in boots or shoes that provide extra ankle
support or foot protection. In some embodiments, the portion of the
midsole material that extends past the midsole may include a less
dense material, such as an extra soft response property
material.
[0033] The different response properties may be achieved by a
variety of materials suitable for midsole construction. For
example, in some embodiments, EVA foam materials may be formed or
cut to a desired size and shape to form the cushioning element 110,
210, 310(a-d) and/or mid-foot element 112, 212, 312(a-d), and the
two components may be glued or otherwise affixed together. A
variety of midsole-forming techniques are known, such as pre-form
and compression molding, injection molding, pellet pour and the
like. In other embodiments, polymer foam pellets (such as EVA
pellets) may be arranged such that compression molding of the
pellets results in blending of the different response properties in
the transition zones. In other embodiments, the midsole may include
one or more other types of material in foamed or solid form, such
as rubberized EVA, polyurethane, thermo-plastic elastomers,
polyolefins, rubber, or any other suitable midsole/footwear
construction material.
[0034] Although certain embodiments have been illustrated and
described herein, it will be appreciated by those of ordinary skill
in the art that a wide variety of alternate and/or equivalent
embodiments or implementations calculated to achieve the same
purposes may be substituted for the embodiments shown and described
without departing from the scope. Those with skill in the art will
readily appreciate that embodiments may be implemented in a very
wide variety of ways. This application is intended to cover any
adaptations or variations of the embodiments discussed herein.
Therefore, it is manifestly intended that embodiments be limited
only by the claims and the equivalents thereof.
* * * * *