U.S. patent application number 13/110876 was filed with the patent office on 2011-11-24 for multiple response property footwear.
This patent application is currently assigned to MONTRAIL CORPORATION. Invention is credited to Craig Binzer, Xu Bo, Wei Yi Jiang, Todd Lewis, Mark Nenow, William Scott Portzline.
Application Number | 20110283560 13/110876 |
Document ID | / |
Family ID | 44971223 |
Filed Date | 2011-11-24 |
United States Patent
Application |
20110283560 |
Kind Code |
A1 |
Portzline; William Scott ;
et al. |
November 24, 2011 |
MULTIPLE RESPONSE PROPERTY FOOTWEAR
Abstract
Embodiments herein relate generally to the field of footwear,
and more particularly to components of performance footwear, such
as midsoles, as well as methods of making midsoles. In various
embodiments, multiple response property midsoles and/or portions of
footwear are provided that may include strategically arranged
multiple response property areas having blended transition zones
disposed there between. Such blended transition zones may help
facilitate a more fluid foot movement, improve manufacturing and
production techniques, and prevent injury to the foot, ankle,
and/or legs during exercise, such as running, hiking, walking, and
other impact-generating activities.
Inventors: |
Portzline; William Scott;
(Portland, OR) ; Nenow; Mark; (Portland, OR)
; Lewis; Todd; (Portland, OR) ; Binzer; Craig;
(Portland, OR) ; Jiang; Wei Yi; (Zhuhai City,
CN) ; Bo; Xu; (Zhuhai City, CN) |
Assignee: |
MONTRAIL CORPORATION
Portland
OR
|
Family ID: |
44971223 |
Appl. No.: |
13/110876 |
Filed: |
May 18, 2011 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
61345978 |
May 18, 2010 |
|
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Current U.S.
Class: |
36/31 ;
12/146B |
Current CPC
Class: |
A43B 13/186 20130101;
A43B 13/04 20130101; B29D 35/0063 20130101; B29D 35/122 20130101;
A43B 13/188 20130101 |
Class at
Publication: |
36/31 ;
12/146.B |
International
Class: |
A43B 13/14 20060101
A43B013/14; A43D 8/00 20060101 A43D008/00 |
Claims
1. A multiple response property midsole comprising: a first foam
material having a first material response property; a second foam
material having a second material response property, wherein the
second foam material is coupled to the first foam material at a
first junction zone; wherein the first junction zone comprises a
blended transition between the first foam material and the second
foam material.
2. The multiple response property midsole of claim 1, further
comprising a third foam material having a third material response
property, wherein the third foam material is coupled to the second
foam material at a second junction zone, wherein the second
junction zone comprises a blended transition between the third foam
material and the second foam material.
3. The multiple response property midsole of claim 2, further
comprising a fourth foam material having a fourth material response
property, wherein the fourth foam material is coupled to the third
foam material at a third junction zone, wherein the third junction
zone comprises a blended transition between the fourth foam
material and the third foam material
4. The multiple response property midsole of claim 1, wherein the
first and second material response properties are density or
durometer.
5. The multiple response property midsole of claim 1, wherein the
midsole lacks a linear or planar seam between the first foam
material and the second foam material.
6. The multiple response property midsole of claim 1, where the
first foam material is positioned in an arch region of the midsole,
and wherein the first foam material comprises a higher density or
durometer foam than the second foam material.
7. The multiple response property midsole of claim 6, further
comprising a third foam material, wherein the second foam material
comprises a higher density or durometer foam than the third foam
material, and wherein the second foam material is positioned
between the first and the third foam materials.
8. The multiple response property midsole of claim 7, wherein the
third foam material is coupled to the second foam material at a
second junction zone; and wherein the second junction zone
comprises a blended transition between the second foam material and
the third foam material.
9. The multiple response property midsole of claim 1, where the
first foam material is positioned in both a medial midfoot region
and a lateral midfoot region of the midsole, and wherein the first
foam material comprises a higher density or durometer foam than the
second foam material.
10. The multiple response property midsole of claim 8, further
comprising a third foam material, wherein the second foam material
comprises a higher density or durometer foam than the third foam
material, and wherein the second foam material is positioned
between the first and the third foam materials in both the medial
and lateral midfoot regions.
11. The multiple response property midsole of claim 10, wherein the
third foam material is coupled to the second foam material at a
second junction zone; and wherein the second junction zone
comprises a blended transition between the second foam material and
the third foam material.
12. The multiple response property midsole of claim 1, where the
first foam material is positioned in a heel region, a medial
midfoot region, and a lateral midfoot region of the midsole, and
wherein the first foam material comprises a higher density or
durometer foam than the second foam material.
13. The multiple response property midsole of claim 12, further
comprising a third foam material, wherein the second foam material
comprises a higher density or durometer foam than the third foam
material, and wherein the second foam material is positioned
between the first and the third foam materials in the heel region,
in the medial midfoot region, and in the lateral midfoot
region.
14. The multiple response property midsole of claim 13, wherein the
third foam material is coupled to the second foam material at a
second junction zone; and wherein the second junction zone
comprises a blended transition between the second foam material and
the third foam material.
15. The multiple response property midsole of claim 1, wherein at
least one of the first and second foam material comprise ethylene
vinyl acetate foam.
16. The multiple response property midsole of claim 1, wherein the
midsole does not comprise any glue.
17. The multiple response property midsole of claim 1, where the
midsole is free of volatile organic compounds.
18. A method of making a multiple response property midsole,
comprising: positioning a first foam material having a first
density or durometer in a midsole mold; positioning a second foam
material having a second density or durometer adjacent the first
foam material in the midsole mold, wherein the first foam material
forms a first interface with the second foam material; and heating
the first and second foam materials sufficiently to cause blending
of the first and second foam materials at the first interface.
19. The method of claim 18, wherein the method further comprises
positioning a third foam material having a third density or
durometer adjacent the first or second foam material, wherein the
third foam material forms a second interface with the first and/or
second foam material, and wherein heating the first, second, and
third foam materials causes blending of the first, second, and/or
third foam materials at the first and second interfaces.
20. The method of claim 19, wherein the method further comprises
positioning a fourth foam material having a fourth density or
durometer adjacent the first, second, and/or third foam material,
wherein the fourth foam material forms a third interface with the
first, second, and/or third foam material, and wherein heating the
first, second, third, and fourth foam materials causes blending of
the first, second, third, and/or fourth foam materials at the
first, second, and third interfaces.
21. The method of claim 18, wherein the method further comprises:
forming a first pre-molded portion of a midsole from first foam
pellets to form the first foam material.
22. The method of claim 21, wherein the method further comprises:
forming a second pre-molded portion of a midsole from second foam
pellets to form the second foam material.
23. The method of claim 21, wherein forming a first pre-molded
portion of the midsole comprises: positioning the first foam
pellets in a pre-mold; heating the first foam pellets to a
temperature of about 130.degree. C.; and cooling the first
pre-molded portion before positioning the first pre-molded portion
in the midsole mold.
24. The method of claim 18, wherein the first density or durometer
is greater than the second density or durometer.
25. The method of claim 18, wherein the method further comprises:
pre-cutting the first foam material in a first desired shape.
26. The method of claim 25, wherein the method further comprises:
pre-cutting the second foam material in a second desired shape.
27. The method of claim 18, further comprising positioning the
first and/or second foam material in the midsole mold using a jig
or cage.
28. The method of claim 27, wherein the cage is configured to melt
or dissolve when heated to a temperature of about 130.degree.
C.
29. The method of claim 18, wherein at least one of the first and
second foam materials comprise ethylene vinyl acetate.
Description
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] The present application claims priority to U.S. Provisional
Patent Application No. 61/345,978, filed May 18, 2010, entitled
"MULTIPLE RESPONSE PROPERTY FOOTWEAR," 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, as well as methods of making
midsoles.
BACKGROUND
[0003] The sole assembly of athletic footwear generally has a
layered configuration that includes a comfort-enhancing insole, a
resilient midsole formed from a polymer foam material, and a
ground-contacting outsole that provides both abrasion-resistance
and traction. The midsole imparts cushioning and helps control foot
motion.
[0004] The midsole may be formed from a single-layer polymer foam
that extends throughout the length and width of the footwear. With
the exception of a difference in thickness between the heel and
forefoot areas of the footwear, such a unitary midsole has
substantially uniform properties. In order to vary the properties
of midsole, some conventional midsoles incorporate dual- or
multi-density or multi-durometer polymer foams. For instance, the
lateral side of the midsole may be formed from one foam material,
and the medial side of the midsole may be formed from a second,
less-compressible, denser foam material.
[0005] Generally, the layers of foam are cut, placed, and glued
together using a vertical or angled seam. This results in an
undesirable lever effect during a footstrike as the weight of the
foot travels over the abrupt transition point between foam
densities or durometers. The sudden transition from firmer foam to
softer foam (or visa versa) can result in instabilities in the
footstrike, such as over-rapid pronation of the foot. Additionally,
this method of construction can require the use of glues that may
contain volatile organic compounds (VOCs), which may have
undesirable environmental and health impacts, both for the
manufacturer of the footwear and the wearer. Furthermore, the use
of a glued seam creates a potential site of physical failure, and
the midsole layers may separate with use.
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, 1B, 1C, 1D, 1E, and 1F illustrate examples of
multiple response property midsoles in accordance with various
embodiments;
[0008] FIGS. 2A and 2B illustrate a method of making a multiple
response property midsole, in accordance with various
embodiments;
[0009] FIGS. 3A and 3B illustrate another method of making a
multiple response property midsole, in accordance with various
embodiments;
[0010] FIG. 4 illustrates another method of making a multiple
response property midsole, in accordance with various embodiments;
and
[0011] FIG. 5 illustrates another method of making a multiple
response property midsole, in accordance with various
embodiments.
DETAILED DESCRIPTION OF EMBODIMENTS
[0012] 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.
[0013] 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.
[0014] 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.
[0015] 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 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.
[0016] For the purposes of the description, a phrase in the form
"A/B" 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.
[0017] 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.
[0018] Embodiments of the present disclosure are directed to
performance footwear having portions that may help facilitate a
more fluid foot movement, improve manufacturing and production
techniques, and prevent injury to the foot, ankle, and/or legs
during exercise, such as running, hiking, walking, and other
impact-generating activities. In various embodiments, multiple
response property midsoles and/or portions of footwear are provided
that may include strategically arranged multiple response property
areas having blended transition zones disposed there between.
[0019] In various embodiments, the multiple response property areas
(and the differences between them) may be characterized as having
various properties, such as density, durometer, specific gravity,
and other footwear design characteristics. In various embodiments,
the blended transition zones between adjacent response property
areas may allow for a variety of biomechanical improvements,
including, but not limited to, improved impact cushioning, support,
and stability, as well as a more fluid footstrike motion. As used
herein, the term blended transition zone and any variation thereof
may generally refer to the interlocking, intermingling, and/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, but rather a gradual
transition from one defined material/property to another.
[0020] In some embodiments, blending the transition zones in the
midsole may help avoid the lever effect that is common when
materials having different response properties are glued together,
for instance with a vertical or angled seam. For example, when a
denser or a higher durometer material is positioned directly
against a less dense or lower durometer foam without a blended
transition region, the foot may undergo an undesirably rapid and
sudden pronation when it travels over the abrupt transition between
densities. By contrast, the blended transitions in the multiple
response property midsoles disclosed herein may provide a gradual
transition between the portions with different material response
properties, which in-turn may help to ensure a more fluid
footstrike motion. In addition, the lack of traditional glued seams
enhances the strength and integrity of the midsole, while also
permitting the different response property material areas to be
arranged in any desired configuration. Further, embodiments of the
midsole may use a glueless construction method that effectively
eliminates the VOCs present in the glues typically used to couple
the different materials in a traditional midsole.
[0021] FIG. 1A illustrates an example of a midsole with blended
transitions between areas of differing (e.g., multiple) material
response properties (e.g., density or durometer) in accordance with
various embodiments. In the illustrated embodiment, materials of
different response properties have been strategically positioned in
a posted configuration that may be useful in, for example, athletic
shoes, to help control the rate of pronation. Midsole 100a may
include different response property areas arranged from medial to
lateral, with, for example, a higher density or durometer material
disposed in the medial arch region, and transitioning to a less
dense or softer material toward the lateral side of the midsole. In
one embodiment, a first response property material 10 may be
located in the immediate arch area, with a second response property
material 12 disposed immediately adjacent to (e.g., on the lateral
side of) the first response property material 10. A blended
transition 16 may be disposed between the first and second response
property materials. In some embodiments, a third response property
material 14 may be positioned adjacent to the second response
property material 12, and may generally comprise the rest of the
midsole 100a. A blended transition area 18 may be disposed between
the second and third response property materials.
[0022] In various embodiments, in transition zones 16 and 18, the
different materials having different response properties may
intermingle and blend over a certain distance, instead of having a
traditional glued seam. In various embodiments, these blended
transition zones 16 and 18 may help avoid the lever effect, which
is common with an abrupt transition between materials such as is
found with glued seams, and may help enhance fluid connection and
movement between the different response property materials. In one
embodiment, first response property material 10 may have a higher
density or durometer, with second response property material 12
having a density or durometer that is less than that of first
response property material 10, but greater than that of third
response property material 14. Such a configuration may provide
support and stability for a user who over-pronates during a stride,
for example. As illustrated, the strategic alignment of the
different material response properties and resulting blended
transition zones may provide a midsole that may be useful in
providing a combination of impact absorption, flexibility, and
stability, for instance, for walking, jogging, comfort,
cross-training, such as in running shoes, hiking boots, or trail
shoes.
[0023] FIG. 1B illustrates another example of a multiple response
property midsole with blended transitions in accordance with
various embodiments. In the illustrated example, a first response
property material 10 may be located at the sides of the midfoot
region of the midsole 100b, for instance generally in the medial
arch region and opposite the arch region near the lateral edge of
the foot. In various embodiments, second response property material
12 may generally surround first response property material 10, with
the remainder of the midsole comprising third response property
material 14. In the illustrated embodiment, blended transition
zones 16 and 18 may be disposed between the different response
property materials, 10, 12, and 14, and may contribute to the fluid
motion, strength, and mechanics of midsole 100b. For example, as
described above, first response property material 10 may have a
higher density or durometer than second response property material
12, which in turn may have a higher density or durometer than third
response property material 14. In some embodiments, this
configuration may provide lateral stability, which may be useful,
for instance, on rocky or uneven terrain, or for a user who is
prone to either over-pronation or over-supination. In various
embodiments, this configuration also may provide enhanced
flexibility, cushioning, and comfort in the heel and forefoot
portions of the midsole. As illustrated, the strategic alignment of
the different material response properties and resulting blended
transition zones may provide a midsole that may be useful in
providing a combination of impact absorption, flexibility, and
stability, for instance, for jogging or running shoes, hiking
boots, or trail shoes.
[0024] FIG. 1C illustrates another example of a multiple response
property midsole with blended transitions in accordance with
various embodiments. In this example, first response property
material 10 may be located at the lateral and medial sides of the
midfoot and the heel of midsole 100c, for instance generally in a
horseshoe-like pattern. In various embodiments, second response
property material 12 may generally surround first response property
material 10, and third response property material 14 may comprise
the rest of the midsole. In various embodiments, blended transition
zones 16 and 18 may be disposed between the different response
property materials, and may contribute to the fluid motion,
strength, and mechanics of the midsole. For example, first response
property material 10 may be of a higher density or durometer than
second response property material 12 and third response property
material 14, which may provide stability in the side and rear areas
of the foot. This may be useful, for instance, on rocky or uneven
terrain, while providing enhanced pronation/supination prevention,
enhanced flexibility, and cushioning and comfort in the central and
forefoot regions of the midsole. As illustrated, the strategic
alignment of the different response property materials and
resulting blended transition zones may provide a midsole that may
be useful in providing stability, for instance, for hiking boots or
trail shoes.
[0025] FIG. 1D illustrates yet another multiple response property
midsole 100d with blended transitions in accordance with various
embodiments. As illustrated, the strategic placement of the
different response property material areas may include arranging a
first response property material 10 in the heel region, a second
response property material 12 in the mid-foot region, and a third
response property material 14 in the toe region, with blended
transition zones 16 and 18 formed between the different response
property material areas. Such an embodiment may be useful, for
instance, in sandals where a higher density or durometer material
may be used as the first response property material 10, for
instance to improve impact absorbance of the heel region, support,
and durability. The second response property material 12 may have a
density or durometer less than that of the first response property,
and may be positioned to provide additional support and cushioning
for the midfoot area. Finally, the third response property material
14 may be the least dense of the three response property materials,
and may be placed to provide enhanced comfort and flexibility in
the forefoot region.
[0026] FIG. 1E illustrates still another multiple response property
midsole with blended transitions in accordance with various
embodiments. As illustrated, different response property material
areas may be arranged or layered vertically within the midsole
100e, from bottom to top. In some embodiments, a layer of second
response property material 12 may be sandwiched between first
response property material 10 and third response property material
14. In some embodiments, first blended transition 16 may be
disposed between first response property layer 10 and second
response property layer 12, and second blended transition zone 18
may be disposed between second response property layer 12 and third
response property layer 14. In one embodiment, the response
properties may be selected such that a less dense or lower
durometer (e.g., softer) third response property material 14 may be
used as the upper layer to provide comfort, whereas second 12 and
first 10 response property materials may have higher densities or
durometers, for instance to provide durability, support and
resilience. Such an embodiment may be particularly useful in
comfort shoes, work shoes, etc.
[0027] FIG. 1F illustrates another example of a multiple response
property midsole with blended transitions in accordance with
various embodiments. As shown in the illustrated embodiment,
midsole 100f may have multiple response property materials arranged
to enhance lateral stability. In the illustrated example, lateral
stability bars of first response property material 10 may be
disposed at the medial and lateral edges of the midsole. In various
embodiments, the center portion of the midsole may include a third
response property material 14, and second response property
material 12 may be disposed there between. In various embodiments,
blended transition 16 may be disposed between first response
property material 10 and second response property material 12, and
second blended transition 18 may be disposed between second
response property material 12 and third response property material
14. In various embodiments, such an arrangement may provide a
balance of cushioning (e.g., where third response property material
14 is a lower density or durometer foam) and stability (e.g., where
first response property material 10 is a higher density or
durometer foam).
[0028] In the foregoing embodiments, one of skill in the art will
appreciate that, although three different response property
materials/areas are illustrated in each example, any number of
response property areas may be used, for instance 2, 3, 4, 5, 6, or
even more response property areas. Such different response property
areas may be arranged in a number of strategic configurations. For
example, a low density or durometer material may be used wherever
extra softness or cushioning is needed, such as in the forefoot
area, heel layer, or upper layer of the midsole, or for use when
the user has an injury or otherwise requires more cushioning. In
another example, a higher density or durometer material may be
included in any area requiring firm support, extra stability, or
extra durability, such as in the arch region, the midfoot region,
the heel region, or the lower portions of the midsole. In some
embodiments, the specific configuration of the midsole may be
customized to suit the needs, footstrike pattern, or running style
of an individual user. In other embodiments, the blended
transitions of the midsole may allow the shoe to respond to the
individual needs of a particular user or the particular terrain
conditions.
[0029] Although the response property areas are referred to herein
as low, medium, and high (e.g., as it relates to a material
response property that is density or durometer), one of skill in
the art will appreciate that these terms are relative. In one
embodiment where the material response property is durometer, for
instance, the low, medium, and high identifiers may correspond to
55, 60, and 65 Asker C; or 55, 65, and 75 Asker C. In other
embodiments, greater or lower response property materials also may
be used to suit the desired application.
[0030] In embodiments, changing the material hardness of the
midsole may change the activity in various lower extremity muscles,
such as rectus femoris, biceps femoris, medial gastrocnemius, and
tibialis anterior. For instance, when running on a dense midsole,
the tibialis anterior muscle may exert significantly more force
before the heel strike and less force following the heel strike
than when running on a medium midsole. Additionally, using shoes
with a denser midsole may reduce the energy dissipated at the
metatarsophalangeal joints and aid in improving jumping
performances and economy of foot movement. Thus, in various
embodiments, the response may be varied in particular regions of
the midsole and/or other portions of the footwear for a variety of
reasons.
[0031] FIGS. 1G and 1H illustrate a multiple response property
article of footwear in accordance with various embodiments, where
the multiple response property materials comprise not only the
midsole, but also portions of, for example, the heel cup 70 and/or
upper 80. For example, midsole 100g may also extend upward around
the heel cup region 70, which may provide greater heel stability
and/or protection. As illustrated, the strategic placement of the
different response property material areas may include arranging a
first response property material 10 in the heel region of the
midsole, a second response property material 12 in the foot bed
region of the midsole, and a third response property material 14 in
heel cup region, with blended transition zones 16 and 18 formed
between the different response property material areas. In some
embodiments, the multiple response property materials may extend to
encompass all or a portion of the vamp or upper 80, such as the toe
box, the instep, the tongue, or the ankle collar, or all or part of
the insole or, outsole (not shown).
[0032] In other embodiments, the midsole material may extend around
and/or over the instep, for instance to provide greater protection
and stability through the midfoot region. In still other
embodiments, the midsole material may extend around and/or over the
forefoot region, for instance to provide protection to the toes. In
some 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] In other embodiments, methods of making a multiple response
property midsoles and other footwear portions are provided.
Conventional multiple response property midsoles are typically
constructed by stock-fitting or gluing together individual material
components prior to final molding or after final molding. This
leaves a distinct line and a generally solid border between the
different response property materials, which border is often
delineated by a glue seam. By contrast, the disclosed methods may
allow the different response property material areas to have
blended transition zones, which again may produce a more fluid,
gradual change in the midsole response property as detected by the
foot.
[0034] In various embodiments, the different response properties
may be achieved by a variety of materials suitable for midsole
construction. In some embodiments, polymer foam pellets may be
arranged such that compression molding of the pellets may result in
blending of the different response properties in the transition
zones, as illustrated in the examples shown in FIGS. 1A-1H. In some
embodiments, the polymer foam pellets may be ethylene vinyl acetate
(EVA) pellets. EVA is a polymer that may approach elastomeric
materials in softness and flexibility, yet may be processed like
other thermoplastics. The material has good clarity and gloss,
barrier properties, low-temperature toughness, stress-crack
resistance, hot-melt adhesive waterproof properties, and resistance
to UV radiation. In other embodiments, the midsole may include one
or more other types of material, such as rubberized EVA,
polyurethane, and/or any other midsole/footwear construction
material known to those of skill in the art.
[0035] Although the foregoing examples illustrate embodiments
having three distinct response property materials, one of skill in
the art will appreciate that some embodiments, of the midsole may
include only two different response property materials, whereas
other embodiments may include four, five, six, or even more
response property materials. In addition, these materials may be
distributed about the midsole wherever a particular response
property is desired. For instance, more or less of the midsole may
comprise higher density or durometer foams than in the illustrated
examples. Additionally, in some embodiments, lower or higher
density or durometer materials may be incorporated under the
metatarsals, for instance, to form crash pads.
[0036] In various embodiments, multiple response property midsoles
with blended transition areas may be formed in a number of ways,
for example using known midsole forming techniques, such as
pre-form and compression molding, injection molding, pellet pour,
and the like. In one embodiment, as illustrated in FIGS. 2A and 2B,
the midsole may be formed by arranging foam pellets of different
response properties in a specifically designed jig. As illustrated,
a jig 200 having one or more compartments may be positioned within
a midsole mold 50. EVA or other midsole forming pellets may be
poured into the compartments 20, 21 of jig 200, as well as into a
space 22 created between jig 200 and mold 50. As illustrated, a jig
with two different compartments may allow for the midsole to be
formed using pellets 24, 26, 28 of three different response
properties, although other jig configurations are contemplated that
have more or fewer compartments.
[0037] In various embodiments, the different response properties of
pellets 24, 26, 28 may be color-coded for visual determination and
placement in the proper compartments 20, 21, 22 of the jig 200. In
some embodiments, once the pellets 24, 26, 28 are positioned
correctly, the jig 200 may then be removed by lifting in a vertical
direction, thereby allowing the pellets 24, 26, 28 to intermingle,
or at least providing the potential to intermingle during the
midsole formation process. The strategically positioned pellets 24,
26, 28 in the mold may then be subjected to a pre-form process,
which includes addition of heat and temperature to activate the
blowing agent in, for example, the EVA to induce the intended
properties. During the pre-form process, blended transition zones
are formed by virtue of contiguity between the different pellets,
which allows for some flow or migration of the differing response
property materials between strategic response property zones. The
blocker or pre-form may then be compression molded, giving the
midsole its final dimensions.
[0038] In various embodiments, blended transition zones formed
during the pre-form and molding process may result in a mechanical
coupling of the different response property areas without using an
adhesive. Further, in some embodiments, the absence of harsh,
inflexible lines/seams between traditional multi-density midsoles
may provide a more fluid and gradual tactile feel as the foot
naturally pronates during the running or walking motion. In some
embodiments, different colors may be chosen for the different
response property pellets 24, 26, 28, which may allow for the
blended transition zones to be visually distinguishable, and which
may also give the final midsole a unique look.
[0039] FIGS. 3A and 3B illustrate side and top views of an example
of another method for forming midsoles in accordance with various
embodiments. In various embodiments, a cage 300 may be inserted
into mold 50, and may be configured to separate different response
property pellets. In various embodiments, cage 300 may surround
second response property pellets 36, and may separate them from
first response property pellets 34 and third response property
pellets 38. In some embodiments, cage 300 may be generally shaped
like jig 200 in the previous embodiment, forming one or more
compartments for the different response property pellets. In some
embodiments, the cage may be configured to melt during the pre-form
formation stage, thereby allowing the cage material to integrate
with and become part of the midsole. In various embodiments, the
melting of cage 300 may allow different response property pellets
34, 36, 38 to intermingle at the cage borders and form blended
transition zones between differing response property material
areas. As in the previous embodiment, the blocker or pre-form may
then be compression molded, giving the midsole its final
dimensions.
[0040] FIG. 4 illustrates an example of another method for forming
midsoles in accordance with various embodiments. A quantity of
pellets of each desired response property may be lightly molded
prior to the pre-form stage, thereby forming one or more pre-molds
44, 46, 48, of a material that will achieve a desired response
property. One or more different pre-molds 44, 46, 48 may then be
placed within the mold 50 in the desired configuration. In some
embodiments, given that the pre-mold does not significantly change
the pellet characteristics, but only temporarily holds like
response property pellets in a desired configuration for placement
in the mold, during the pre-form process the pellets/materials may
still flow into adjacent response property materials, and thereby
form the blended transition zones.
[0041] In various embodiments, the pre-molds 44, 46, 48 may be
formed in a variety of ways. In one example, the pre-mold may
include gently and briefly heating certain response property foam
pellets in an individual mold such that that the pellets adhere to
one another to form the desired pre-form shape. In particular
embodiments, the pellets may be heated to approximately 130.degree.
C. for about 4 minutes, and then cooled prior to placement in the
pre-form mold. In some embodiments, slight pressure may be added to
ensure that a one-piece formation of the pre-form is achieved. In
some embodiments, a binder may be used to hold the response
property material pellets together for strategic placement in the
mold. The binder may be selected such that it may mix with the
multiple response property materials during the pre-form process,
similar to the aforementioned cage embodiments where the cage
material is selected to melt and integrate with the pre-form.
[0042] In one embodiment, the pre-molds 44, 46, 48 may be placed in
the pre-form mold, for instance, with a higher response property
pre-mold 44 in the medial arch position, and with a medium response
property pre-mold 46 sandwiched between the higher response
property pre-mold 44 and the low response property pre-mold 48,
which may be placed in the lateral position. The pre-molds 44, 46,
48 may then undergo the pre-form treatment and allow the different
response property materials to intermingle and form the blended
transition zones. As in the previous embodiments, the blocker or
pre-form may then be compression molded, giving the midsole its
final dimensions.
[0043] FIG. 5 illustrates yet another example method for forming
midsoles in accordance with various embodiments. Similar to the
embodiment described with respect to FIG. 4, a single pre-mold 46
may be positioned within the pre-form mold in order to control
placement of other lose pellets 54 and 58 having different response
properties. For example, the pre-mold 46 may be made from a second
or a medium-response property pellet, and may be positioned within
the pre-form mold such that it creates one or more partitions
within the pre-form mold. Pellets 54 and 58 of different response
properties may be disposed in the areas adjacent to the pre-mold.
In the pre-form process, the different response property materials
may intermingle to thereby form a blended transition zone. As in
the previous embodiments, the blocker or pre-form may then be
compression molded, giving the midsole its final dimensions.
[0044] In various embodiments, different response property
separation techniques may be used in order to strategically place
the different response properties in/on the midsole to accomplish
the desired effect of manufacturing a multiple response property
midsole having blended transitions between the materials of
different response properties. Further, the various examples
illustrated and described herein may be used together as needed
(e.g., use of a jig with different pre-molds, etc.). Finally,
though certain formed midsoles with strategically positioned
response property areas have been illustrated, a variety of
different response property placements are possible depending on
the particular need.
[0045] Although the foregoing examples illustrate methods of making
midsoles having three distinct response property materials, one of
skill in the art will appreciate that some embodiments, the methods
may be adapted for making midsoles that may include only two
different response property materials, or midsoles that may include
four, five, six, or even more response property materials.
[0046] 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.
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