INSULATED SOLE FOR ARTICLE OF FOOTWEAR

SEMELLE ISOLEE POUR UN ARTICLE DE CHAUSSURE

English Abstract

An insulated sole having down feather insulation held captive therein and method of fabrication is described. The sole is formed with open top end cavities in which there is disposed down feathers r mixtures thereof to capture and retain heat. A membrane seals the open top end of the cavities. The insulated sole is used in the fabrication of articles of footwear for use in cold weather climate to resist to the cold emanating from the ground to shield against heat loss from the wearer's feet.

French Abstract

Il est décrit une semelle isolée dotée dun isolant en duvet et une méthode de fabrication. La semelle est formée avec des cavités de bout supérieur ouvertes dans lesquelles du duvet ou un mélange sont déposés dans le but de saisir et de conserver la chaleur. Une membrane isole le bout supérieur ouvert des cavités. La semelle isolée est utilisée dans la fabrication de chaussures utilisées par temps froid, dans le but de résister aux sols froids et pour protéger les pieds de la personne portant les chaussures contre la perte thermique.

Claims

CLAIMS
1. An outer insulated sole for an article of footwear, said outer insulated
sole having:
a ground engaging outer surface and an inner surface;
a plurality of cavities formed in said inner surface, said cavities being
delineated by spaced
apart supports;
down insulation or a mixture of down insulation with a material having
insulating properties
which is disposed within said cavities; and
a membrane disposed over said cavities to tap said down insulation or the
mixture of down
insulation with a material having insulating properties in said cavities to
provide a thermal insulating
barrier between said ground engaging outer surface and said inner surface.
2. The outer insulated sole as claimed in claim 1 wherein said supports
comprise vertical supports or
support posts which extend to said membrane to provide a support for said
membrane.
3. The outer insulated sole as claimed in claim 1, wherein said outer
insulated sole is molded from
waterproof material.
4. The outer insulated sole as claimed in claim 3, wherein said waterproof
material is one of rubber, or
moldable plastic material which is a polyurethane capable of flexing.
5. The outer insulated sole as claimed in claim 2, wherein said vertical
supports or support posts are
integrally formed with said outer insulated sole.
6. The outer insulated sole as claimed in claim 1, wherein said membrane is a
sealing insole formed of
rigid material, said membrane having holes therein for the passage of air and
being sized to prevent the
passage of said down insulation or said mixture of down insulation with a
material having insulating
properties.
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7. The outer insulated sole as claimed in claim 2, wherein said membrane is a
rubber or plastic material
sheet shaped to the contour of said outer insulated sole and fused or
adhesively secured over a top
surface of a plurality of the vertical supports.
8. The outer insulated sole as claimed in claim 5, wherein said vertical
supports comprise straight
transverse parallel support walls which are interconnected at their crossings
to form said cavities
therebetween, said vertical supports having flat outer surfaces disposed in a
membrane support plane.
9. The outer insulated sole as claimed in claim 5, wherein said cavities are
recessed from a contour
edge of said outer insulated sole, said cavities being disposed in a frontal
foot portion and a heel portion
of said outer insulated sole, at least some of said vertical support walls
having openings therein for the
passage of air between the cavities to distribute heat retained by the down
insulation or said mixture of
down insulation with a material having insulating properties disposed in said
cavities.
10. The outer insulated sole as claimed in claim 1, wherein said membrane is a
breathable membrane.
11. The outer insulated sole as claimed in claim 1, wherein said down
insulation is:
duck or goose down,
a mixture of duck and goose down, or
a mixture of duck or goose down and synthetic fibers which are distributed
throughout the
cavities of said insulated sole.
12. The outer insulated sole as claimed in claim 1, wherein said arficle of
footwear is a winter article of
footwear, said outer insulated sole substantially reduces heat loss when worn.
13. The outer insulated sole as claimed in claim 10, wherein said membrane
includes a mixture of down
material.
14. The outer insulated sole as claimed in claim 12, further comprising an
upper insole disposed over
said membrane .
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15. A method of fabricating an outer insulated sole for an article of
footwear, said method comprising
the steps of:
(i) molding a sole from a moldable material with said sole defining a ground
engaging outer surface and
an inner surface having a plurality of open top end cavities delineated,
(ii) filling said cavities with down insulation or a mixture of down
insulation with a material having
insulating properties, and
(iii) securing a membrane over said cavities to trap said down insulation or a
mixture of down
insulation with a material having insulating properties in said cavities to
form the outer insulated sole.
16. The method of claim 15, wherein said step of filling said cavities with
down insulation or a mixture
of down insulation with a material having insulating properties comprises
disposing a sheet of down
material or a mixture of down insulation with a material having insulating
properties of down insulation
with a material having insulating properties over said open top end of said
cavities, die-cutting said
sheet of down material or a mixture of down insulation with a material having
insulating properties to
form down inserts shaped to fit inside adjacent ones of said cavities, and
pushing said down inserts in
adjacent ones of said cavities.
17. The method of claim 16, wherein said step of disposing said sheet of down
material or a mixture of
down insulation with a material having insulating properties comprises
positioning said sheet of down
material or a mixture thereof in contact over said inner surface of said outer
insulated sole while
compressing said down on surrounding flat surface areas of vertical supports
which extend to said open
top end of said cavities to prevent movement of said sheet of down.
18. The method of claim 16, wherein said down sheet or mixture of down
insulation with a material
having insulating properties comprises loose down or a mixture thereof held
between a pair of
membranes, said down sheet having restoring properties after having been
compressed to trap air
therein.
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19. The method of claim 17, wherein there is further provided the step of
applying an adhesive over a
contour edge of said outer insulated sole inner surface and a flat outer
surface of said vertical supports,
and applying said membrane over said contour edge and said outer surface of
said vertical supports.
20. The method of claim 19, wherein there is further provided the step of
attaching an upper thermal
insole onto said membrane to provide further thermal insulation and comfort.

Description

CA 02888599 2015-04-21
INSULATED SOLE FOR ARTICLE OF FOOTWEAR
TECHNICAL FIELD
(0001) The present invention relates to an insulated sole for use in the
fabrication of
an article of footwear, and particularly, but not exclusively, to an article
of footwear for
use during cold weather conditions.
BACKGROUND OF THE INVENTION
(0002) Various articles of footwear structures are known for use during cold
weather
conditions and most of these consists in the insulation of the upper of the
article of
footwear. The sole structure usually consists of a solid structure and an
insulating
insole, such as "Thinsulate" a registered trademark of the 3M Corporation, is
disposed
thereover inside the article of footwear for use as a barrier between the cold
sole and
the wearer's feet. This provides minimal resistance against the transfer of
the cold
emanating from the ground through the sole and to the feet of the wearer
person. It is
known that a major part of cold feet is caused by the sole of the article of
footwear
which is not capable of resisting to the cold emanating from the ground and
thereby
resulting in major heat loss incurring from the wearer's feet. The risk of
frostbite on any
exposed skin can have a lasting effect on the sensory nerves of the foot,
especially the
toes. Keeping a thermal buffer between one's foot and the frozen ground is
very
important as a significant amount of body heat can be lost through one's feet.
It would
therefore be desirable to create soles that are more thermally efficient to
buffer the cold
emanating from the ground and provide the wearer person comfort to its feet
while
maintaining breathability and comfort during cold weather conditions.
(0003) It is known that the sole of a shoe deforms less during cold weather
conditions
due to an increase in stiffness resulting in that a smaller area of a wearer's
foot is in
contact with the shoe insole during impact of the sole of the shoe with the
ground
surface. This results in more localized pressure on the foot and putting more
pressure
or impact force on a smaller area of the foot, much like running on a hard
surface. It
would therefore be desirable to construct an article of footwear with a sole
providing
more flexibility, better impact absorbing, lightweight and better insulation
properties
during cold weather conditions.
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. '
(0004) Down insulation from duck and goose feathers is known as an excellent
insulator due to its superior heat retaining properties. However, down is
difficult to
handle during manufacturing of products containing down. My US Patent No.
6,025,041
addresses this problem and resolves it by the construction of down feather
sheets in
which the down is held captive in a substantially evenly distributed form. It
would
therefore also be desirable to use down in the construction of the sole of
article of
footwear to provide insulation therein.
SUMMARY OF THE INVENTION
(0005) It is therefore a feature of the present invention to provide an
insulated sole for
an article of footwear which provides the above mentioned desires and
overcomes
some of the problems associated with soles of articles of footwear adapted to
be worn
during cold weather conditions.
(0006) Another feature of the present invention is to provide an insulated
sole having
cavities in an inner surface thereof and wherein down insulation is disposed
in such
cavities and trapped therein to provide a thermal insulating barrier and
comfort to the
user's feet.
(0007) Another feature of the present invention is to provide a method of
manufacturing an insulated sole for an article of footwear using down
insulation or a
mixture thereof.
(0008) According to the above features, from a broad aspect, the present
invention
provides an insulated sole for an article of footwear. The insulated sole has
a ground
engaging outer surface and an inner surface. A plurality of cavities are
formed in the
inner surface. Down insulation or a mixture thereof with a material having
insulating
properties is disposed in each of the cavities and a membrane is disposed over
the
cavities to trap the down insulation or a mixture thereof therein to provide a
thermal
insulating barrier.
(0009) According to another broad aspect of the present invention there is
provided a
method of fabricating an insulated sole for an article of footwear. The method
comprises the steps of molding a sole from a moldable material with the sole
defining a
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ground engaging outer surface and an inner surface having a plurality of open
top end
cavities. The cavities are filled with down insulation or a mixture thereof. A
membrane,
shaped to the contour of the sole, is secured over the cavities to trap the
down
insulation or a mixture thereof in the cavities to form a thermally insulating
sole.
DESCRIPTION OF THE DRAWINGS
(0010) A preferred embodiment of the present invention will now be described
with
reference to the accompanying drawings in which:
(0011) Figure 1 is a partly fragmented perspective view illustrating the
construction of
the thermally insulated sole of the present invention;
(0012) Figure 2 is a fragmented cross-section view illustrating the sole
construction
with down feathers held captive in cavities formed in the sole and the
breathability of the
down trapped in the cavities;
(0013) Figure 3 is a further fragmented perspective view illustrating a
modification to
the construction of the thermally insulated sole of the present invention;
(0014) Figure 4 is a fragmented top view illustrating a modification of the
vertical
supports as being vertical support posts, instead of walls;
(0015) Figure 5 is a simplified side view illustrating a method of fabricating
the
thermally insulated sole of the present invention;
(0016) Figure 6 is a fragmented top view illustrating the various steps in the
method of
fabricating the thermally insulated sole of the present invention, and
(0017) Figure 7 is a fragmented side view showing a cold weather article of
footwear
incorporating in its construction the thermally insulated sole of the present
invention.
DESRIPTION OF THE PREFERRED EMBODIMENT
(0018) Referring now to the drawings, and more particularly to Figures 1 and
2, there
is shown generally at 10 the construction of the thermally insulated sole of
the present
invention for use in the fabrication of articles of footwear adapted for cold
weather
conditions to provide thermal comfort to a use's feet. As shown, a sole 11 is
molded
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from moldable waterproof material such as rubber or suitable moldable plastic,
such as
polyurethane of proper density with cavities 12 being formed in an inner
surface 13,
herein the top inner surface, of the sole. The bottom surface 14 of the sole
is formed as
a flat surface or with ground engaging ribs, not shown, depending on the use
of the
article of footwear to which the sole is to be used.
(0019) As shown in Figures 1 to 3, the cavities 12 are delineated by
surrounding
vertical support walls 15. The support walls 15 as herein shown have flat top
surfaces
extending in a foot support plane and are disposed transverse to one another
and are
interconnected at their crossings. The vertical support walls 15 may have
openings 15'
therein for the passage of air between the cavities 12. An outer contour edge
17 is
formed about the sole 11 and its top surface and the top surface of the
vertical support
walls 15 forms the inner surface 13 of the sole. Cavities 12 are distributed
throughout
the sole 11 in the heel portion 11', where the cavities 12 are deeper due to
the fact that
the heel portion 11' is thicker, and in the forward foot portion 11" where the
cavities are
more shallow. Down insulation 16, consisting of duck or goosed down or
mixtures
thereof or mixtures including feathers, or suitable polymer fibers is
contained in each of
the cavities 12. Figure 1 illustrates the down disposed in only a few of the
cavities to
better illustrate the construction of the thermally insulated sole, but it is
to be understood
that the down insulation is disposed in all of the cavities 12.
(0020) Figure 4 shows another modification of the vertical supports wherein
instead of
walls 15 the supports are constituted by spaced apart support posts 45 having
a flat top
surface 46 lying in a common foot support plane together with the outer
contour edge
17. The down insulation 16 is disposed in the cavity area surrounding the
posts 45.
(0021) The down insulation 16 is held captive in the cavities 12 by a membrane
20,
herein a sealing insole provided with holes 21 therein for breathability of
the down to
trap heat generated from the feet of a wearer person. The membrane 20 may also
be a
solid membrane and have thermally conductive fibers or consist of material
having
thermal conductivity to distribute heat from the user's feet. It may also
contain a layer of
down insulation or a mixture thereof as a layer therein. This sealing insole
21 is formed
of a suitable material having a certain rigidity to maintain its shape and
provide comfort
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to the wearer's feet. The membrane 20 is herein glued to the inner surface 13
of the
sole 11 by the application of glue 22 on the top surface of the vertical
support walls 15
or support posts 45and the contour top edge 17 of the sole by the use of a
roller
applicator or other suitable means.
(0022) Figure 3 illustrates another example of the construction of the
thermally
insulated sole 10 of the present invention. As herein illustrated, a
perforated
membrane 20', or a solid membrane shaped to the underfoot and formed of
fusible
material, is fused over the inner surface 13 of the soles 11 in a further
molding step with
the holes 21' being pre-formed in the membrane.
(0023) Referring now to Figures 5 and 6, there is described the method of
fabricating
the insulated sole 10 of the present invention using the support walls of
Figures 1 to 3. .
Firstly, the sole 11 is molded in a molding process of a type well known in
the art to form
the sole 11 with cavities 12 as illustrated in Figure 1. The cavities are
rectangular
shaped to facilitate mold construction. To disposed the down insulation into
the cavities
12, a down feather sheet 30, such as the type described in my previously
mentioned US
Patent No. 6,025,041, is positioned over the inner surface 13 of the sole 11
and held in
contact with the inner surface by a holding plate 31 shaped to clamp the down
feather
sheet 30 evenly over the inner surface 13 of the sole. A die cutting plate 32
having a
pattern of cutting knives 33 is then brought down on the feather sheet 30 to
cut down
insert pieces 39 shaped to fit in adjacent cavities 12. A pusher plate 34,
having a
pattern of pusher blocks 35, is then actuated to push the down insert pieces
into their
adjacent cavities 12. The sole 11, now having its cavities 12 filled with down
insulation,
is moved to another station where the membrane 20 or 20' is secured over the
inner
surface 13 of the sole 11 by gluing or fusing as above mentioned, to trap the
down in
the cavities. Because down has excellent shape restoring characteristics, any
compression of the down is automatically restored when the compression force
is
released.
(0024) Figure 7 illustrates an article of footwear 40 fabricated with the
thermally
insulated sole 10 of the present invention . As shown, an upper 411s secured
on the
sole 10 and is herein insulated with the down insulated sheet of my previous
invention.

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Accordingly, insulation is provided all about the upper of the article of
footwear. An
upper insole 42 is also shown disposed over the membrane 20 to provide added
comfort and insulation, such as the "Thinsulate" insole of the 3M Company. The
article
of footwear 40 as illustrated substantially completely surrounds a wearer's
feet with
thermally insulating down to provide comfort to the user's feet during cold
weather
conditions.
(0025) As can be appreciated, the insulated sole of the present invention
provides
several advantages to the sole. The sole provides a thermal barrier to act as
a buffer to
cold emanating from the ground. It can also act as a buffer the heat with its
ability to
cool. The cavities and supports also provides more flexibility, shock
absorbing, and
light weight.
(0026) It is within the ambit of the present invention to include any obvious
modifications of the preferred embodiment described herein, provided such
modifications fall within the scope of the appended claims.
6

Representative Drawing