FIELD OF THE INVENTION
[0001] The present invention relates to the field of shoe and footwear constructions.
BACKGROUND OF THE INVENTION
[0002] Modern footwear is available in a myriad of materials and fabrications. Despite great
advances in support, there has been relatively little development in thermal management
of footwear. The foot generates heat while walking, running, or even at rest. As heat
is generated by the foot, the shoe temperature begins to rise, and the foot begins
to perspire. Excessive perspiration around the foot leads to foot and shoe odor among
other problems.
[0003] Specifically, the heat and perspiration released by the foot causes several problems.
A wet and warm shoe interior is uncomfortable for the user to wear. Further, the perspiration
released by the foot contains sodium chloride and urea, which can stain or discolor
the outer surface of the shoe, degrading the expressive value of the shoe to the wearer.
Moreover, the perspiration and heat around the foot creates an ideal environment for
fungi and bacteria to thrive. Fungi and bacteria consume dead skin cells, and produce
waste that is the source of foot odor. Fungi and bacteria convert the amino acid methionine
to methanethiol which has a sulfuric smell. As physical activity increases, foot perspiration,
bacterial growth, and bacterial waste production all increase, causing odor to intensify.
Finally, a warm and moist shoe provides an ideal environment for foot disease, such
as Athlete's foot, to thrive.
[0004] One approach minimizing the problems stated above is to provide shoe ventilation
to transfer heat and moisture away from the foot. The theory behind shoe ventilation
is to reduce the interior temperature and humidity of the shoe by transferring heat
and foot perspiration generated by the foot away from the interior of the shoe. Since
perspiration decreases with decreasing temperature, a decrease in the interior temperature
of the shoe decreases the rate of perspiration around the foot. Thus, the goal of
shoe ventilation is to maintain an interior shoe temperature as close to the ambient
air temperature as possible. By forcing ambient air around the foot and into the shoe
cavity, heat and moisture generated by the foot is transferred away from the foot
by the circulating air.
[0005] Systems have been proposed in the prior art for ventilating the area under the foot.
These systems have been directed at systems in the sole of the shoe actuated by foot
movement during walking or running to circulate air within the interior of the shoe.
While these systems help transfer excess heat away from the bottom of the foot surface
they are ineffective because they do not transfer heat away from the top, rear, and
sides of the foot. This allows excessive heat and moisture to build up inside the
shoe. It is possible to make a shoe upper out of mesh or another relatively breathable
material, however, these constructions are only suitable for certain types of running
shoes or water shoes, and are not appropriate for street shoe constructions or office
wear.
SUMMARY OF THE INVENTION
[0006] Accordingly, it is an object of the present invention to provide a shoe with an air
circulation system which cools the foot by incorporating an air circulation system
for transferring heat from the interior of the shoe to the ambient atmosphere.
[0007] These and other objects of the present are invention are achieved in one embodiment
by a shoe with an air circulation system has a porous ventilated upper and a compressible
pumping chamber in the heel which pumps cooling ambient air from an external air intake
into a three dimensional mesh air distribution pad and out through the porous ventilated
upper, providing cooling and reducing moisture in the cavity containing the wearer's
foot.
[0008] The invention and its particular features and advantages will become more apparent
from the following detailed description considered with reference to the accompanying
drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0009] FIG. 1 is a left side elevation view of an embodiment of a shoe with an air circulation
system in accordance with one embodiment of the invention.
[0010] FIG. 2 is a left side cross sectional view of the sole a shoe with an air circulation
system in accordance with one embodiment of the invention.
[0011] FIG. 3 is a detail cross sectional view of the heel area of the sole of the shoe
with an air circulation system of FIG. 2.
[0012] FIG. 4 is a left side elevation view of the sole of the shoe with an air circulation
system of FIG. 2.
[0013] FIG. 5 is a top plan view of the sole of the shoe with an air circulation system
of FIG. 2.
[0014] FIG. 6 is a cross-sectional view of a forefoot area of the sole of the shoe with
an air circulation system of FIG. 2.
[0015] FIG. 7 is a cross-sectional view of a forefoot area of the sole of the shoe with
an air circulation system of FIG. 2 having peripherally and upwardly extending channels
in the midsole thereof.
[0016] FIG. 8 is a top plan view of the sole of the shoe with an air circulation system
of FIG. 2 having peripherally and upwardly extending channels in the midsole thereof.
[0017] FIG. 9 is a cross-sectional view of a forefoot area of an embodiment of the shoe
with an air circulation system.
[0018] FIG. 10 is a rear elevation view of a snorkel of the shoe with an air circulation
system.
DETAILED DESCRIPTION OF THE DRAWINGS
[0020] Referring to FIGS. 1-10, a shoe 10 with an air circulation system in accordance with
the present invention is shown. The shoe with an air circulation system 10 includes
an upper 20 and a sole 40. The upper 20 and the sole 40 are positioned together to
form the shoe 10 with an air circulation system. The sole 40 and the upper 20 operate
together to provide a ventilation system that circulates ambient air through the sole
40 and upper 20, cooling the interior cavity 12 of the shoe 10.
[0021] Referring to FIGS. 1 and 9, the upper 20 includes an outer layer 22, a porous middle
layer 24, and an inner layer 26. The inner layer 26 is adjacent to the interior cavity
12 of the shoe 10. The outer layer 22 is adjacent to the ambient atmosphere 14. The
outer layer 22, porous middle layer 24, and inner layer 26 are positioned together
to form a shoe upper 20. The layers 22, 24, 26 may be positioned together by any means
known in the art, including stitching or gluing with an adhesive. It should be understood
that the upper 20 may include a greater or lesser number of layers, and may include
additional components, for example shoe laces.
[0022] Preferably the outer layer 22 is constructed from leather. However, the outer layer
22 may be constructed from canvas, synthetic leather, EVA, denim, wool, felt, or any
other material or combination of materials known in the art. The porous middle layer
24 is constructed from a porous material through which air can pass with little or
no resistance. Preferably the porous middle layer 24 is constructed from a synthetic
mesh fabric material. However, the porous middle layer 24 may be constructed from
any material or combination of materials through which air can pass with little or
no resistance. Preferably the inner layer 26 is constructed from a soft lining.
[0023] The inner layer 26 is preferably provided with a plurality of perforations 28 to
provide a fluid communication between the interior cavity 12 of shoe 10 and the porous
middle layer 24 for venting the inside of the upper 10 to the middle layer 24. A uniformly
applied plurality of small pinpoint perforations is preferable, however, any appropriate
number and size of perforations 28 can be used.
[0024] The outer layer 22 is provided with one or more vent openings 30 for venting air
out of the porous middle layer 24 to the atmosphere 14 outside of the upper 20. Desirably,
vent openings 30 are in the form of a plastic eyelet having desirable design or appearance
features. The upper may optionally include typical fastenings such as shoe lace holes
32 and shoe laces, or hook and loop fasteners, or buckles, or an elastic element.
[0025] In the embodiments shown in FIGS. 1 and 9, the upper 20 is positioned on the sole
40. Preferably the upper 20 is affixed to the sole 40. In the embodiment shown in
FIGS. 1 and 9, the upper 20 is stitched directly to the sole 40. It is preferable
that the upper 20 is attached directly to the sole 40 using a stitch. However, the
upper 20 may be affixed to the sole 40 by an adhesive, fastener, or any other means
known in the art.
[0026] Referring to FIGS. 1-10, the sole 40 includes an outsole 42, a midsole 44, and an
insole 46. Preferably a thermoplastic shank 48 is provided in the center area of the
shoe between the midsole 44 and insole 46.
[0027] The air circulation system includes a compressible pumping chamber 50 located in
a heel area 52 of the shoe between the insole 46 and the midsole 44. Pumping chamber
50 is a sealed chamber made from a resilient material. Desirably, the heel area 52
has a downwardly extending bump or bulge 53 which is comprised of a thin outsole 43
and thin, deformable portion 54 of the midsole 44, so that the pumping chamber 50
is periodically compressed by pressure applied thereto by a wearer walking in the
shoe 10. This periodic compression pumps air through the air circulation system of
shoe 10. The thin deformable midsole portion 54 is desirably formed as a series of
concentric ribs or rings as best illustrated in FIG. 5, or it may be formed as another
ribbed or perforated section to enhance the deformation of the portion 54 and the
pumping of chamber 50.
[0028] Air is drawn into the air circulation system through an external air intake port
60 (which may include multiple port openings). An inlet fluid passageway 62 connects
the external air intake port 60 to the pumping chamber 50. Preferably, the external
air intake port 60 is located at a level above a level of the pumping chamber 50 and
the inlet fluid passageway 62 includes an upwardly extending snorkel 64 as seen in
FIG. 10. Snorkel 64 is preferably positioned at a rear end 11 of the shoe 10, however,
in alternative embodiments, one or more snorkels and/or intake ports may be located
on the sides of the shoe or at the front of the shoe.
[0029] One or more outlet fluid passageways 66 connect the pumping chamber 50 with an air
distribution pad 70. Air distribution pad 70 is a three dimensional spacer mesh fabric
and is located in a cavity 71 in the insole 46 in a forefoot area of the shoe. The
upper surface of air distribution pad 70 is flush with the upper surface of insole
46. The three dimensional spacer mesh air distribution pad is preferably formed of
a polyester material and provides both comfort underfoot and a breathable material
that distributes circulated air under the wearer's foot. Examples of three dimensional
spacer mesh fabrics that may be used in the invention include fabrics such as those
disclosed in
U.S. Patents 5,385,036;
6,477,865;
6,630,414;
6,755,052; and
7,788,952, the disclosures of which are hereby incorporated by reference. The spacer mesh fabric
should have a compression set which is generally comparable to the compression set
of the foam material used in the insole 46, and should have a sufficient durability
to maintain usability over the expected life of the shoe without a significant deviation
in thickness compared to the surrounding insole 46.
[0030] In order to provide the desired pumping of air through the air circulation system,
an inlet check valve 80 is located in the midsole 44 between the external air intake
port 60 and the pumping chamber 50, and an outlet check valve 82 is located in each
of the more outlet fluid passageways 66 between the pumping chamber 50 and the air
distribution pad 70.
[0031] As best seen in FIGS. 7 and 8, one or more peripherally and upwardly extending channels
90 are provided in the insole 46 and/or midsole 44 and extend from cavity 71 to provide
fluid communication between the pumping chamber 50 and the porous middle layer 24
of the upper 20. In other embodiments, the peripherally and upwardly extending channels
90 may also or may alternately connect directly to the outlet fluid passageway 66
and extend through the insole and/or midsole and extend from cavity 71 to the perimeter
thereof to provide fluid communication between the pumping chamber 50 and the porous
middle layer 24 of the upper 20.
[0032] Pumping chamber 50 is being operable by periodic pressure applied thereto by a wearer
walking in the shoe 10, which causes air to be drawn into the pumping chamber 50 from
the external air intake port 60 through the inlet fluid passageway 62 and then expelled
from the pumping chamber 50 through the outlet fluid passageway 68 to the air distribution
pad 70, and from the upper 20 through the inner layer perforations 28 to the porous
middle layer 24 of the upper 20 to the outer layer vent openings 30.
[0033] The present invention provides a shoe with an air circulation system which circulates
cooling air underfoot and through a layer of the upper though the pumping action of
the pumping chamber.
[0034] Although the invention has been described with reference to a particular arrangement
of parts, features and the like, these are not intended to exhaust all possible arrangement
or features, and indeed many other modifications and variations will be ascertainable
to those of skill in the art.
1. A shoe with an air circulation system, comprising:
an upper having an outer layer (22), a porous middle layer (24) formed of a porous
material, and an inner layer (26), the inner layer having one or more inner layer
openings (28) for venting an inside of the upper to the middle layer, the outer layer
having one or more vent openings (30) for venting air out of the porous middle layer
to outside of the upper; and
a sole (40) including an outsole (42), midsole (44), and an insole (46);
characterized by: said sole having
an external air intake port (60),
a compressible pumping chamber (50) located in a heel area of the shoe,
an inlet fluid passageway (62) connecting the external air intake port and the pumping
chamber,
an inlet check valve (80) between the pumping chamber and the external air intake
port,
an air distribution pad (70) located within the shoe,
an outlet fluid passageway (66) connecting the chamber and the air distribution pad,
an outlet check valve (82) between the pumping chamber and the air distribution pad,
the pumping chamber being operable by periodic pressure applied thereto by walking
in the shoe by a wearer, which causes air to be drawn into the pumping chamber from
the external air intake port through the inlet fluid passageway and expelled from
the chamber through the outlet fluid passageway to the air distribution pad and from
the upper through the porous middle layer of the upper to the outer layer vent openings.
2. The shoe with an air circulation system of claim 1, wherein the air distribution pad
(70) is a three dimensional mesh material.
3. The shoe with an air circulation system of claims 1 or 2, wherein the air distribution
pad is a three dimensional polyester mesh fabric.
4. The shoe with an air circulation system of claims 1, or 2, wherein the external air
intake port is located at a level above a level of the pumping chamber in an upwardly
extending snorkel (64).
5. The shoe with an air circulation system of claim 4, wherein the snorkel is positioned
at a rear end of the shoe.
6. The shoe with an air circulation system of claims 1, or 2, wherein the pumping chamber
is in fluid communication with the porous middle layer of the upper by one or more
peripherally and upwardly extending channels (90) provided in the insole or midsole.
7. The shoe with an air circulation system of claim 4, wherein the pumping chamber is
in fluid communication with the porous middle layer of the upper by one or more peripherally
and upwardly extending channels (90) provided in the insole or midsole.