U.S. patent application number 11/226050 was filed with the patent office on 2006-03-09 for breathable workshoes and methods for manufacturing such.
This patent application is currently assigned to Crocs, Inc.. Invention is credited to Scott Seamans.
Application Number | 20060048407 11/226050 |
Document ID | / |
Family ID | 33458796 |
Filed Date | 2006-03-09 |
United States Patent
Application |
20060048407 |
Kind Code |
A1 |
Seamans; Scott |
March 9, 2006 |
Breathable workshoes and methods for manufacturing such
Abstract
Among other things, the present invention provides various
footwear pieces, and methods for manufacturing such pieces. In
various cases, the footwear pieces are molded from a lofting
material. Further, in various cases, the footwear pieces include
one or more ventilators formed in the footwear piece that are
surrounded by liquid conductors capable of channeling liquid
spilled on the surface of the footwear pieces away from a foot
within the footwear pieces.
Inventors: |
Seamans; Scott; (Longmont,
CO) |
Correspondence
Address: |
TOWNSEND AND TOWNSEND AND CREW, LLP
TWO EMBARCADERO CENTER
EIGHTH FLOOR
SAN FRANCISCO
CA
94111-3834
US
|
Assignee: |
Crocs, Inc.
Niwot
CO
|
Family ID: |
33458796 |
Appl. No.: |
11/226050 |
Filed: |
September 13, 2005 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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10603126 |
Jun 23, 2003 |
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11226050 |
Sep 13, 2005 |
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60473360 |
May 23, 2003 |
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60473371 |
May 23, 2003 |
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Current U.S.
Class: |
36/3R |
Current CPC
Class: |
A43B 7/06 20130101; A43B
1/0081 20130101; A43B 7/08 20130101; A43B 3/12 20130101; B29D 35/02
20130101; A43B 1/14 20130101; A43B 3/0042 20130101 |
Class at
Publication: |
036/003.00R |
International
Class: |
A43B 7/06 20060101
A43B007/06 |
Claims
1-20. (canceled)
21. A breathable footwear piece comprising: a base section
including an upper and a sole formed as a single part manufactured
from a moldable foam material; and a strap section formed of a
moldable foam material that is attached at opposite ends thereof to
the upper of the base section at a pair of attachment points such
that the strap section is in direct contact with the base section
at the attachment points and pivots relative to the base section at
the attachment points, and wherein frictional forces developed by
the contact between the moldable foam material of the strap section
and the moldable foam material of the base section at the
attachment points are sufficient to maintain the strap section in
place after pivoting; and wherein the upper includes a
substantially horizontal portion and a substantially vertical
portion.
22. The breathable footwear piece of claim 21, wherein liquid
conductors are formed around a plurality of ventilators formed in
the upper, each liquid conductor comprising a raised structure that
can divert liquid falling from above the footwear piece from
entering through the ventilator.
23. The breathable footwear piece of claim 22, wherein the liquid
conductors are attached to the upper.
24. The breathable footwear piece of claim 22, wherein the liquid
conductors are formed as part of the upper.
25. The breathable footwear piece of claim 22, wherein the
plurality of ventilators in the form of holes are formed in the
upper as part of molding the base section.
26. The breathable footwear piece of claim 21, wherein the sole
comprises a bottom surface and a support base, and wherein the
support base includes a raised pattern extending throughout the
surface where a foot contacts the support base.
27. The breathable footwear piece of claim 21 wherein the upper
includes an open rear region defined by an upper opening perimeter,
and wherein a decorative pattern is molded or otherwise created in
the upper near to and extending the length of the upper opening
perimeter.
28. The breathable footwear piece of claim 27 wherein the upper
opening perimeter extends between the points of attachment of the
strap section to the base section and contacts an area of the foot
in front of and below the ankle.
29. The breathable footwear piece of claim 21 wherein the sole
includes a bottom surface having front and rear tread patterns
longitudinally connected by a flat section without tread patterns
bounded by raised side portions, and wherein each of the front and
rear tread patterns comprises an inner longitudinal tread portion
and outer rectangular tread portion.
30. The breathable footwear piece of claim 21 wherein the bottom
surface of the sole includes a toe section and heel section, both
of which are raised slightly from the generally flat plane of the
sole.
31. The breathable footwear piece of claim 21 wherein the sole
further includes a top surface having a support base including a
raised pattern where a foot contacts the support base.
32. The breathable footwear piece of claim 21 wherein the
substantially horizontal portion and a substantially vertical
portion of the upper form a toe region that generally follows the
contour of a human foot, wherein the toe region tapers from the
inner area of the base section where the larger toes exist to the
outer area of the base section where the smaller toes exist.
33. A footwear piece comprising: a base section including an upper
and a sole formed as a single part manufactured from a moldable
foam material; and a strap section formed of a molded foam material
attached at opposite ends thereof to the base section such that the
strap section is in direct contact with the base section and pivots
relative to the base section; and wherein the upper includes an
open rear region defined by an upper opening perimeter; and wherein
the sole includes a rear perimeter; and wherein the strap section
pivots between a first contact point on the upper opening perimeter
and a second contact point on the rear perimeter, and wherein
frictional forces developed by the contact between the strap
section and the base section at the points of attachment are
sufficient to maintain the strap section in place in an
intermediary position after pivoting whereby the strap section
lends support to the Achilles portion of a human foot inserted in
the open rear region; wherein the upper includes a substantially
horizontal portion and a substantially vertical portion forming a
toe region that generally follows the contour of a human foot,
wherein the toe region tapers from the inner area of the base
section where the larger toes exist to the outer area of the base
section where the smaller toes exist; wherein a plurality of
ventilators are formed in both the substantially vertical portion
or the substantially horizontal portion; wherein the sole includes
a bottom surface having front and rear tread patterns
longitudinally connected by a flat section; and wherein the sole
further includes a top surface having a support base including a
raised pattern where a foot contacts the support base.
34. A footwear piece as in claim 33, wherein a decorative pattern
of raised bumps is molded or otherwise created in the upper near to
and extending the length of the upper opening perimeter.
35. A footwear piece as in claim 33, wherein the vertical portion
of the upper includes an upper strip, wherein the ventilators are
formed in the upper strip, wherein the upper strip extends from the
toe region to the points of attachment for the strap section, and
wherein the sole includes a lower strip that parallels the upper
strip and is separated by a line that extends from the toe region
to a heel of the footwear piece, and wherein the lower strip
vertically rises in a direction toward the heel.
36. A footwear piece comprising: a base section including an upper
and a sole formed as a single part manufactured from a moldable
foam material; and a strap section formed of a moldable material
that is attached at opposite ends thereof to the upper of the base
section with plastic connectors such that the moldable foam
material of the strap section is in direct contact with the
moldable material of the base section and pivots relative to the
base section at the connectors; wherein the upper includes an open
rear region defined by an upper opening perimeter, and wherein
frictional forces developed by the contact between the strap
section and the base section at the plastic connectors are
sufficient to maintain the strap section in place in an
intermediary position after pivoting, whereby the strap section
lends support to the Achilles portion of the human foot inserted in
the open rear region; and wherein the upper includes a
substantially horizontal portion and a substantially vertical
portion forming a toe region that generally follows the contour of
a human foot, wherein the toe region tapers from an inner area of
the base section where the larger toes exist to an outer area of
the base section where the smaller toes exist; and wherein the sole
includes a bottom surface having tread patterns.
Description
CROSS-REFERENCES TO RELATED APPLICATIONS
[0001] The present application claims priority to U.S. Provisional
Pat. Appl. No. ______ (Attorney Docket No. 040130-050000), entitled
"FOOTWEAR PIECES AND METHODS FOR MANUFACTURING SUCH," filed May 23,
2003 and assigned to an entity common herewith; and U.S.
Provisional Pat. Appl. No. ______ (Attorney Docket No.
040130-051000), entitled "METHODS AND COMPOSITES FOR MANUFACTURING
FOOTWEAR PECES," also filed May 23, 2003 and assigned to an entity
common herewith. Further, the present application is related to
U.S. Pat. Appl. No. ______ (Attorney Docket No. 040130-050010),
entitled "FOOTWEAR PIECES AND METHODS FOR MANUFACTURING SUCH",
filed on a date even herewith and assigned to an entity common
herewith. The entirety of each of the aforementioned patent
applications are incorporated herein by reference for all
purposes.
BACKGROUND OF THE INVENTION
[0002] The present invention is related to footwear, and in
particular to footwear including ventilation.
[0003] Current trends are toward wearing comfortable footwear in
the work environment. However, many types of comfortable footwear
are not compatible with various work environments. For example,
many work environments would allow the use of the commonly known
flip-flop, however, such flip-flops are typically not compatible
with the work environment because they are not secure and are not
waterproof. Similarly, sandals are not waterproof, and are thus not
compatible with various work environments. As just one example, in
a hospital setting it may be possible to wear comfortable shoes,
however, it is common for liquids to be spilled. Thus, neither a
flip-flop or sandal may not offer sufficient protection from such
spilled liquids.
[0004] Thus, there exists a need in the art to address these and
other limitations.
BRIEF SUMMARY OF THE INVENTION
[0005] Among other things, the present invention provides various
footwear pieces, and methods for manufacturing such pieces. In
various cases, the footwear pieces are molded from a lofted
material. Further, in various cases, the footwear pieces include
liquid conductors formed around ventilators, or openings in the
upper of the footwear piece. Such liquid conductors operate to
disperse liquids away from a foot inserted in the footwear
piece.
[0006] Some embodiments of the present invention provide breathable
footwear pieces that include a base section comprising an upper and
a sole. The upper includes a substantially horizontal portion and a
substantially vertical portion. The substantially horizontal
portion is a solid portion, while the substantially vertical
portion includes one or more ventilators formed in the
substantially vertical portion. In particular instances, liquid
conductors are formed around each of the ventilators. In some
cases, the liquid conductors are molded as part of the upper, while
in other cases, the liquid conductors are attached to the upper
after the upper is otherwise formed. In one particular case, the
material used to form the base section exhibits a final growth
value of approximately 1.51. Such a growth value provides a
lightweight, comfortable footwear piece that floats in water, and
is slip resistant when used on, for example, wet floors.
[0007] Other embodiments of the present invention provide sectional
shoe pieces that include a base section and a strap section. The
base section includes an upper and a sole formed as a part. The
strap section is formed as a second part that is attached to the
base section such that the strap pivots relative to the base
section. In some instances, the base section is molded of a
continuous piece of foam material. Such foam material can be lofted
material manufactured using a resin. Where a resin material is
used, it can be mixed to exhibit an expansion coefficient, and a
contraction coefficient. In particular cases, multiplying the
expansion coefficient and the contraction coefficient results in a
product of between 1.46 and 1.58, inclusively.
[0008] In various instances, the base section and the strap section
are formed of the same material. Such material can be the
aforementioned foam material formed into different shapes. In other
cases, the strap section and the base section are formed of
different materials. For example, the base section may be formed of
leather and/or rubber, while the strap section is formed of foam.
As another example, the base section may be formed of one type of
foam, while the strap section is formed of another type of
foam.
[0009] In some cases, the strap section is attached to the base
section by rivets. In particular, one end of the strap section is
riveted to one side of the base section, while the other end of the
strap is riveted to the other side of the base section. In some
cases, both the base section and the strap are punched to form
holes through which the rivet is placed. In other cases, holes are
formed in the strap section and/or base section as part of the
manufacturing process. Such holes can be subsequently used to
receive the rivets attaching the strap section to the base section.
The rivets can be plastic rivets, or rivets formed of other
materials such as, for example, metal and rubber. In many cases,
the rivets are formed of a material that is denser than that of
either the base section or the strap section.
[0010] The rivets can be placed at attachment points located on
either side of the base section. Such attachment points can be
located near a rear sole perimeter and/or near a upper opening
perimeter. In some cases, the distance from the one attachment
point to the other attachment point along the rear sole perimeter
is approximately the same as the distance between the attachment
points measured along the strap section. Thus, the strap section
can pivot relative to the base section such that an inner portion
of the strap section contacts an outer portion of the rear sole
perimeter. A frictional force between the strap section and the
base section at the contact between the inner portion of the strap
section and the outer portion of the rear sole perimeter maintains
the strap section fixed relative to the base section. In such a
position, the strap section forms what appears to be a decorative
portion of the base section, and does not interfere with inserting
and removing a foot from the base section.
[0011] Similarly, the distance from one attachment point to the
other attachment point along the upper opening perimeter is
approximately the same as the distance between the attachment
points measured along the strap section. Thus, the strap section
can pivot relative to the base section such that an inner portion
of the strap section contacts an outer portion of the upper opening
perimeter. A frictional force between the strap section and the
base section at the contact between the inner portion of the strap
section and the outer portion of the upper opening perimeter
maintains the strap section fixed relative to the base section.
Again, in such a position, the strap section forms what appears to
be a decorative portion of the base section, and does not interfere
with inserting and removing a foot from the base section. Further,
in some cases, the strap can be fixed in contact with either the
upper opening perimeter or the rear sole perimeter.
[0012] In various cases, a number of ventilators are formed in the
upper. Such ventilators can be holes of varying sizes that allow
liquid and or air to pass through at prescribed locations in the
upper. In some cases, such ventilators are formed in both a
substantially horizontal portion of the upper and a substantially
vertical portion of the upper. This provides for a significant
amount of ventilation for applications where it is not necessary to
protect the foot from exposure to liquids entering through the
ventilators. Such applications can include, but are not limited to,
boating, beach use, fishing, and the like.
[0013] Alternatively, some instances include a solid covering over
the substantially horizontal portion of the upper, while including
ventilators formed in the vertical portions of the uppers. This
provides for sufficient ventilation, while at the same time
protecting a foot from spilled liquids. Such an approach may be
desirable for applications including use by medical personnel,
chefs, and the like. Further, in some cases, a liquid conductor is
formed around at least a portion of a perimeter of each of the
plurality of ventilators. Such a liquid conductor transfers a
liquid spilled on the upper around and away from the various
ventilators formed in the substantially vertical portion. Such
conductors can thus further protect the foot from exposure to
spilled liquids.
[0014] In particular cases, the toe region of the upper is extended
at a location corresponding to the larger toes of the human foot.
Thus, the toe region of the upper generally follows the contour of
a human foot from larger toes on the inside of the shoe to smaller
toes on the outside of the shoe. Such an approach can provide
increased comfort and/or functionality. Further, the rear perimeter
of the sole can be raised above a support base further increasing
the functionality of the shoe. This support base can include a
raised pattern where the foot contacts the shoe.
[0015] Other embodiments of the present invention provide sectional
shoe pieces that include a base section and a strap section. The
strap section is attached to the base section using a rivet such
that the strap is pivotable relative to the base section. The rivet
can be made of metal, plastic, or some other material. In some
cases, the base section is formed of a continuous piece of foam,
while in other cases, the base section includes an assemblage of
multiple constituent parts. The parts can be formed of various
materials including, but not limited to, foam, plastic, rubber,
leather, and/or the like.
[0016] Yet other embodiments of the present invention provide
methods for manufacturing a sectional shoe. The methods include
molding a base section and a strap section. The methods further
include attaching the strap section to the base section such that
the strap pivots relative to the base section. In some cases, the
strap section is attached to the base section by riveting opposite
ends of the strap to opposing sides of the base section. In various
cases, holes are punched through the base section and the strap
section prior to riveting the strap section in place. In other
cases, the holes through which the rivet are placed are formed
during the molding of the base section and/or strap section.
[0017] The base section can include a sole and an upper. The sole
includes a rear sole perimeter, and the upper includes an upper
opening perimeter. In particular cases, rivet holes are placed
approximately equidistant from a midway point of the rear sole
perimeter and from a midway point of the upper opening perimeter.
Thus, the strap can be folded over the upper and the sole and worn
as a decorative feature, or in contrast worn away from either the
sole or the upper as a functional strap.
[0018] This summary provides only a general outline of some
embodiments according to the present invention. Many other objects,
features, advantages and other embodiments of the present invention
will become more fully apparent from the following detailed
description, the appended claims and the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0019] A further understanding of the various embodiments of the
present invention may be realized by reference to the figures which
are described in remaining portions of the specification. In the
figures, like reference numerals are used throughout several to
refer to similar components. In some instances, a sub-label
consisting of a lower case letter is associated with a reference
numeral to denote one of multiple similar components. When
reference is made to a reference numeral without specification to
an existing sub-label, it is intended to refer to all such multiple
similar components.
[0020] FIGS. 1-6 are views of a footwear piece in accordance with
embodiments of the present invention;
[0021] FIGS. 7-8 are views of another footwear piece in accordance
with other embodiments of the present invention;
[0022] FIG. 9 is a flow diagram illustrating methods for
manufacturing in accordance with embodiments of the present
invention;
[0023] FIG. 10 illustrates another footwear piece in accordance
with other embodiments of the present invention; and
[0024] FIG. 11 illustrates yet another footwear piece in accordance
with various embodiments of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
[0025] Among other things, the present invention provides various
footwear pieces, and methods for manufacturing such pieces. In
various cases, the footwear pieces are molded from a lofted, or
foam material material. Further, in various cases, the footwear
pieces include liquid conductors formed around ventilators, or
holes, in the footwear piece. Such liquid conductors operate to
disperse liquids away from a foot inserted in the footwear
piece.
[0026] Turning to FIG. 1, a footwear piece 100 in accordance with
some embodiments of the present invention is illustrated. Footwear
piece 100 includes a base section 110 and a strap section 120. Base
section 110 includes an upper 150 and a sole 162. In some
embodiments, base section 110 is molded as a single piece of foam
material. In other embodiments, sole 162 is molded from a foam or
other foam like material, while upper 150 is manufactured of a
different material that is later assembled with sole 162 to form
base section 110.
[0027] Upper 150 includes a substantially horizontal portion 152
that can include one or more ventilators 182. Ventilators 182 can
be, but are not limited to, openings that are formed in upper 150
as base section 110 is being molded. Alternatively, ventilators 182
can be openings formed in upper 150 after formation and/or assembly
of upper 150. As yet another alternative, ventilators 182 can be
formed as part of an assembly process associated with upper 150.
Thus, for example, ventilators 182 can be openings between
assembled parts of upper 150. Based on the disclosure provided
herein, one of ordinary skill in the art will appreciate a number
of different ventilator types and methods for forming such.
[0028] Upper 150 further includes a substantially vertical region
151 that includes one or more ventilators 181. As with ventilators
182, ventilators 181 can be, but are not limited to, openings that
are formed in upper 150 as base section 110 is being molded.
Alternatively, ventilators 181 can be openings formed in upper 150
after formation and/or assembly of upper 150. As yet another
alternative, ventilators 181 can be formed as part of an assembly
process associated with upper 150. Thus, for example, ventilators
181 can be openings between assembled parts of upper 150. Based on
the disclosure provided herein, one of ordinary skill in the art
will appreciate a number of different ventilator types and methods
for forming such.
[0029] Upper 150 further includes a toe region 155 that surrounds
the toes of a human foot inserted into base section 110. In some
embodiments, toe region 155 tapers from the inner area of base
section 110 to the outer area of base section 110 such that it
generally follows the contour of a human foot where larger toes
exist at the inside of the foot, and the foot tapers to smaller
toes on the outside. This can be functionally advantageous as the
footwear piece 100 conforms to the shape of the human foot. In
other embodiments, toe region 155 is a square cross section that
does not exhibit tapering, while yet other embodiments provide a
rounded square where the toe section has its greatest extension
near the a central point of base section 110, and tapers in both
directions from the central point. Based on the disclosure provided
herein, one of ordinary skill in the art will appreciate a number
of shapes for toe region 155.
[0030] As depicted, upper 150 includes a substantially horizontal
region 152 that rises toward an upper opening perimeter 170. When
worn, the upper opening perimeter can contact an area of the human
foot in front of, and below the ankle. Upper 150 can be designed
such that upper opening perimeter 170 is disposed only a short
distance from toe region 155, in which case it will be formed in
substantially horizontal region 152. Alternatively, upper 150 can
be designed to extend farther up the foot toward the ankle, in
which cases it will be in a more vertical region of upper 150. A
decorative pattern 190 may or may not be formed or created near
upper opening perimeter 170. As depicted, upper opening perimeter
170 can extend from the location of rivet 131a to that of rivet
131b (shown in other figures).
[0031] Sole 162 includes a rear sole perimeter 160 that defines the
rear portion of sole 160. In some cases, this region is raised
above a support base 165 that is the area that is in contact with
the bottom part of the human foot. Such a raised rear sole
perimeter provides some support to the heel of the human foot and
helps maintain footwear piece 100 in position. In other
embodiments, rear sole perimeter 160 is not raised.
[0032] Strap section 120 includes an outer region 122, an inner
region 121, and rounded ends 130. In some cases, strap section 120
is attached to base section 110 by rivets 131 that are placed
through holes in both strap ends 130, and in upper 150 at an
attachment point. Strap section 120 can be pivoted in relation to
base section 110 such that strap section 120 can contact upper
opening perimeter 170 when pivoted in one direction, and rear sole
perimeter 160 when pivoted in the other direction. In some
embodiments, strap section 120 includes dimensions such that when
strap section 120 is pivoted forward, inner region 121 contacts an
outer surface of upper opening perimeter 170. A frictional force at
the contact of inner region 121 and upper opening perimeter 170
maintains strap section 120 in a fixed position relative to base
section 110.
[0033] Alternatively, strap section 120 can include dimensions such
that when strap section 120 is pivoted backward, inner region 121
contacts an outer surface of rear sole perimeter 160. A frictional
force at the contact of inner region 121 and rear sole perimeter
160 maintains strap section 120 in a fixed position relative to
base section 110. In such positions, strap 120 can be a decorative
portion of footwear piece 100.
[0034] As yet another alternative, strap section 120 can be placed
in an intermediary position between rear sole perimeter 160 upper
opening perimeter 170. In this position, the strap serves the
utilitarian purpose of lending support to the Achilles portion of
the human foot, thus helping to maintain footwear piece 100 in
position on the human foot. In some embodiments, a frictional force
developed between strap 120 and upper 150 at the location of the
rivets is sufficient to maintain strap 120 in place. This helps to
assure that strap 120 remains in place even when the Achilles part
of the foot is not pressing against strap 120. Without such
friction, strap 120 would succumb to gravity and fall to a position
where the foot would not be supported. At the same time, it can be
desirable to reduce the friction at the contact point sufficient to
allow strap 120 to be readily moved.
[0035] In particular embodiments, strap 120 is formed of a foam
material capable of significant deformation making footwear piece
100 comfortable for a large number of foot types. In other
embodiments, strap 120 is form of a less deformable material that
provides a stronger security for the foot. Yet other embodiments
include an adjustable strap that includes significant
deformability, yet is capable of being securely strapped to the
foot. Such embodiments are discussed further in relation to FIG. 10
below.
[0036] FIG. 2 depicts a side view of footwear piece 100, while FIG.
3 provides a top view of footwear piece 100. FIGS. 4 and 5 provide
front and rear views, respectively, of footwear piece 100. Further,
FIG. 6 illustrates the bottom of sole 162. As illustrated, sole 162
includes raised side portions 198, front tread pattern 196, and
rear tread pattern 194. Front tread pattern 196 includes inner
longitudinal tread portions 199, and outer rectangular tread
portions 197. Similarly, rear tread pattern 194 includes inner
longitudinal tread portions 193, and outer rectangular tread
portions 192. Based on this, one of ordinary skill in the art will
appreciate a number of other trade patterns and/or formations that
can be used in relation to footwear piece 100.
[0037] Turning to FIG. 7, another footwear piece 200 in accordance
with other embodiments of the present invention is illustrated.
Footwear piece 200 includes a number of features similar to that of
the previously described footwear piece 100. In contrast, however,
substantially horizontal portion 250 of the upper is of solid
construction. As such, liquid materials that are spilled or
otherwise contact substantially horizontal portion 250 do not
permeate footwear piece 200. This can be advantageous in medical or
other commercial applications where the foot needs at least some
protection from spilled materials. Further, a number of ventilators
281 are formed in the substantially vertical portion of the upper.
Liquid conductive portions 210, 211, 212 are formed around each of
ventilators 281. Liquid conductive portions 210, 211, 212 can be
any formation or structure that can divert a liquid falling from
above footwear piece 200 from entering through ventilators 281. In
one embodiment, liquid conductive portions 210, 211, 212 are molded
as part of the upper. FIG. 8 is a top view of footwear piece
depicting the various liquid conductive portions.
[0038] FIG. 9 is a flow diagram 900 illustrating a method in
accordance with the present invention for manufacturing footwear
pieces. Following flow diagram 900, a base section and strap
section are molded (blocks 910, 920). The base section and strap
section are perforated at the location where the two pieces are to
be connected (blocks 930, 940). The perforations in the strap and
base section are aligned (block 950), a male portion of a rivet is
inserted through the aligned perforations (block 960), and a female
portion of the rivet is mated to the male portion, thus securing
the strap to the base section.
[0039] Turning to FIG. 10, another footwear piece 1000 in
accordance with other embodiments of the present invention is
illustrated. Footwear piece 1000 is similar to previously described
footwear piece 100, except that strap 1120 has been modified to
allow for adjustment. As illustrated, strap 1120 includes a main
portion 1121 and a connection portion 1160. Connection portion 1160
is attached to a base section 1110 of footwear piece 1000 by a
rivet 1170, or some other pivotable connection as is known in the
art. Main portion 1121 is attached to the opposite side via a rivet
(not shown), and includes a male Velcro portion 1140 attached
thereon, and a female Velcro portion 1130 extending like a tongue
therefrom.
[0040] Female Velcro portion 1130 is fed through a buckle 1150 that
is attached to connection portion 1160 and pulled until the desired
tightness is achieved. Female Velcro portion 1130 is then laid over
male Velcro portion 1140 as depicted in FIG. 10b. One of ordinary
skill in the art will appreciate that other connection materials
can be used in place of Velcro and that the male 1140 and female
1130 Velcro portions can be interchanged. Further, based on the
disclosure provided herein, one of ordinary skill in the art will
appreciate that an adjustment can be used on either or both sides
of strap 1120, or can be placed in the center of strap 1120.
[0041] FIG. 11 illustrates yet another footwear piece 1100 in
accordance with some embodiments of the present invention. Footwear
piece 1100 is an open toe model with a pivotable strap. Based on
the disclosure provided herein, one of ordinary skill in the art
will appreciate that adjustable strap 1120 depicted in FIG. 10 can
also be used in relation to footwear piece 1100.
[0042] As previously suggested, the footwear pieces disclosed
herein can be made of a lofted foam material. Manufacturing
footwear pieces using such a lofted foam material can include
providing a resin that includes a pre-mixture of resin, pigment,
and a growth additive. The resin, originally in pellet form, is
heated to a liquid state. This liquid resin is screwed into a mold
that has been heated prior to receiving the resin. The volume of
resin injected into the mold is controlled by the pitch of the
screw that drives the liquid resin into the mold. The liquid resin
is allowed to set, at which time the mold is opened and the formed
footwear piece is removed from the mold. The formed footwear piece
is then placed on a cooling last, where it is allowed to air
dry.
[0043] During this process, a relatively small footwear piece
confirming to the size of the mold is created, but when the mold
opens, the footwear piece springs out as it expands in size. Then,
as the footwear piece is air cooled, it contracts to a final size.
Thus, the process involves both an expansion characteristic and a
contraction characteristic. Multiplying the size of the shoe in the
mold by the expansion characteristic yields the size of the
footwear piece after the mold is opened. Multiplying the expansion
characteristic by the contraction characteristic provides a final
growth value representative of the final size of the shoe relative
to the mold.
[0044] In such a manufacturing process, a number of elements can be
controlled to achieve the desired end result. These elements
include, the volume of material introduced into the mold, the size
of the mold, the composition of the material being used, and the
size of the cooling last. Previous manufacturers of molded footwear
products have used, for example, four sizes of molds to create six
different sizes of footwear pieces. Thus, for example, to create
two different sized shoes from the same mold, one volume of a
material is screwed into a mold to create one shoe size, and
another volume of the same material is screwed into the same mold
to create a different shoe size. Once removed from the mold, the
shoes are cooled on cooling lasts of different sizes. Thus, the
process uses a modified volume and cooling last size to control the
end product, while keeping the mold size and the composition fixed.
While this creates shoes of different sizes, it has been found that
control of the final sizes is somewhat limited and/or
unpredictable.
[0045] In part to address this, embodiments of the present
invention use a fixed volume and composition of material, and
cooling last size, while varying mold sizes to control the size of
the end product. It has been found that such an approach results in
a heightened degree of control, when compared to the previously
described approach. This approach is particularly valuable for
shoes manufactured of the same color resin. Where different colors
are involved, the composition of the resin may be varied across the
colors to achieve size control between colors. This composition
adjustment is more fully described below.
[0046] In one particular embodiment, the resin is Ethylene Vinyl
Acetate copolymer (EVA) based material. In this particular case,
additives are included with the EVA base to create an expansible
and cross-linking material. More particularly, an expanding powder
is added which decomposes at a specific temperature to produce
gases which cause the material to rise as it sets within a mold.
Accordingly, when the mold is opened, an instantaneous expansion of
the molded part results. During this expansion, the dimensions of
the part increase rapidly, while the proportions and shape remain
reasonably constant providing a consistent shape of the end part
relative to the original mold. Additional disclosure of such
cross-linking and expansion is provided in European Patent 0 802
039 A2, filed on Mar. 25, 1997, and assigned to FINPROJECT.TM. of
Italy.
[0047] Some embodiments of the present invention utilize an EVA as
previously described that is known commercially as LEVIREX.TM., and
is marketed by FINPROJECT.TM. of Italy. It has been found desirable
to create a mixture of LEVIREX.TM. that exhibits a final growth
value of between 1.47 and 1.58. In one particularly desirable
embodiment, a final growth value of approximately 1.51 is used.
This includes an expansion characteristic of approximately 2.5, and
a contraction characteristic of approximately 0.6. This provides a
relatively soft footwear piece that has very good anti-slip
capabilities, and at the same time, size reproducibility and
durability.
[0048] In some cases, the resin mixture (LEVIREX.TM., growth
additive such as ENGAGE.TM. by DUPONT.TM., and pigment) is modified
depending upon the desired color of the footwear piece. This is at
least in part due to the density of the pigment associated with
certain colors. Were the resin mixture not adjusted, a green shoe
would be produced appreciably smaller than a khaki shoe where all
other factors remain constant. This can be unacceptable where, for
example, the footwear pieces are to be sold over the Internet and
the consumer is not capable of trying the footwear piece on before
purchasing. To alleviate this, the final growth value for a green
resin is adjusted to approximately 1.515, where the final growth
value for the khaki resin is adjusted to approximately 1.505. Thus,
by modifying the mixture, shoes of accurate sizes across multiple
colors can be produced.
[0049] While footwear pieces can be molded as previously described,
based on the disclosure provided herein, one of ordinary skill in
the art will appreciate that various embodiments of the present
invention can be utilized in relation to other molding processes,
and or assembly methods. For example, a hard plastic footwear piece
could be injection molded using techniques known in the art, or a
footwear piece could be at least partially made of leather or other
natural materials. As another example, the footwear piece could be
Freon cooled, rather than air cooled. This could be used to speed
the manufacturing process.
[0050] The invention has now been described in detail for purposes
of clarity and understanding. However, it will be appreciated that
certain changes and modifications may be practiced within the scope
of the appended claims. Accordingly, it should be recognized that
many other systems, functions, methods, and combinations thereof
are possible in accordance with the present invention. Thus,
although the invention is described with reference to specific
embodiments and figures thereof, the embodiments and figures are
merely illustrative, and not limiting of the invention. Rather, the
scope of the invention is to be determined solely by the appended
claims.
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