TECHNICAL FIELD
[0001] The present invention relates generally to footwear. More particularly, the present
invention relates to methods and structures for removing heat, odors, and/or moisture
from an article of footwear such as a shoe or a boot.
BACKGROUND OF THE INVENTION
[0002] As is well known, feet generate heat like other body parts. When feet are enclosed
in shoes, for example, the shoes tend to retain the heat, which causes the feet to
sweat. Sweat or perspiration is a mechanism for the body to flush wastes, regulate
body temperature, and help keep the skin clean and pliant. Sweating can be a response
to hard working muscles, a hot environment, or over stimulated nerves. It is the evaporation
of perspiration from the skin that is the means of heat transfer. Because evaporative
heat loss is the major mechanism of cooling, the body is constantly sweating as heat
is transferred away from the core to the skin's surface. This is also referred to
as insensible water loss, and is so named because it usually goes unnoticed. Insensible
water loss, occurring via respiration and the skin (transepithelial) cannot be prevented,
is a major source of heat loss for the body, and is not controlled by the body's regulatory
system.
[0003] Eccrine sweat glands are the most numerous type of sweat glands and are found all
over the body. They are particularly concentrated in the palms of the hands, soles
of the feet and the forehead. There are approximately 250,000 sweat glands in a pair
of feet. This represents more sweat glands per square inch of skin than any other
part of the body. On average, sweat glands in the feet excrete as much as a half-pint
of moisture a day. Moisture (also referred to herein as moisture vapor) includes a
liquid that is diffused or condensed in relatively small quantity and dispersed through
a gas as invisible vapor. Although sweat's main function is to control body temperature
by evaporation, it also serves to keep the skin moist. As such, the skin covering
the foot can withstand the constant flexing and friction that happens with locomotion,
preventing the skin from rapidly becoming dry, irritated, and uncomfortable.
[0004] In the footwear industry the 'in shoe' experience of the foot is often referred to
as the microclimate of the foot- so called due to the environment that is created
when a foot is covered, even partially, by footwear. This zone includes the air trapped
by footwear underneath and around the foot. When the footwear substantially covers
the foot or just covers the forefoot, and especially if the entire foot is covered
in a traditional shoe, boot or like type of footwear, the foot microclimate is a factor
in both foot comfort and foot health. The feet experience the highs and lows of temperature
and humidity with greater variation than elsewhere on the surface of the body. In
part, this is because the feet are further from the heart than any other part of the
body. Consequently, by the time the blood arrives to the feet, there has already been
considerable cooling.
[0005] The core temperature of the body varies only slightly with large changes in environmental
temperature, but there is a much greater effect on the feet. For example, with an
air temperature of sixty-eight degrees, the surface temp of the foot at rest, without
covering (protection) is approximately seventy-two degrees while the core body temperature
remains constant at approximately ninety-eight degrees. In this instance, it is necessary
to provide thermal insulation to the foot in order to maintain a comfortable foot
temperature. Providing a waterproof barrier can also be extremely important feature
of footwear in a wet environment as cold water temperatures and the resulting evaporative
heat loss can leave the feet very cold and uncomfortable. In extreme situations, this
can lead to frostbite and other deleterious conditions.
[0006] In the opposite environment, requirements for protective and other footwear are quite
different. During activity in hot environments, foot temperature becomes elevated
and the humidity within the shoe increases sharply. Of course, materials used in the
upper and in the sock will affect both the in-shoe temperature and humidity. Materials
that form a barrier to air permeability and water vapor transmission quickly create
moist, hot, uncomfortable environments as evaporation of sweat is severely limited,
as is air movement within the shoe microclimate. This can also result in an undesirable,
malodorous condition.
[0007] In warm environments, most protective footwear creates an uncomfortable micro environment,
and only the most breathable footwear can provide reasonable comfort for the wearer.
A major factor that influences the rate of evaporation is the relative humidity of
the air around the foot. If the air is humid, then it already has water vapor in it,
probably near saturation, and cannot take any more. Therefore, sweat does not evaporate
and cool the body as efficiently as when the air is dry.
[0008] Moist, hot air commonly creates a very uncomfortable experience for the foot. This
is generally regarded as a compromise in footwear between protection and comfort.
An ideal shoe would provide all the needed protection without reducing air flow around
the foot. More ideally, air flow should be limited when the foot is cool and increased
as foot temperature increases.
[0009] Two dynamic factors heavily influence footwear comfort, namely the external environment
and the internal environment or microclimate. Protection from the external environment
is important for several reasons, including protection from ground level objects or
surfaces, moving objects and external climate (temperature and weather conditions).
Protection may be provided through design and/or use of materials having characteristics
such as insulation, durability, waterproofing and breathability.
[0010] Typically, the type of footwear (sandal, work boot, hiker, casual, golf shoe, running
shoe, sneaker, etc.) is chosen based on intended use and climate considerations. For
example, a runner would likely choose an insulated, waterproof running shoe during
cold, wet weather and a light, breathable shoe for use in warm weather. A hiking shoe
is commonly chosen for protection from objects in the hiking environment and external
climate. Regulation of the footwear's internal environment is extremely important
in order to provide a consistently comfortable micro environment as external and internal
conditions change during activity. The internal environment is heavily influenced
by heat and sweat produced by the body, which, as discussed above, is a method of
controlling body temperature.
[0011] It is well known that a critical problem with protective and/or enclosed footwear
is that moisture vapor from perspiration is trapped and cannot escape the footwear.
In order to provide increased comfort, wicking characteristics have been applied to
sock and liner materials. At least some of the moisture is absorbed within the footwear,
the sock and/or the liner materials. Once such materials become saturated they can
loose their effectiveness and create an unpleasant environment for the foot.
[0012] Such materials can quickly reach a saturation point as the moisture within the shoe
typically does not have an efficient method of evaporation. Skin also absorbs moisture
when in a saturated environment. Skin is softened by the absorbed moisture, becomes
more sensitive to pressure, and also becomes prone to abrasion and fungal infection.
Thus, the reduction in airflow around the foot and within an article of footwear presents
a significant number of challenges to creating a comfortable environment for the foot.
[0013] Another consideration is that although there have been advances in materials that
claim a level of breathability or airflow through (stand alone) material, testing
has proven that when such materials are combined with traditional constructions of
protective footwear, the breathability is greatly reduced due to construction types
and the necessity of the materials to be used in combination with additional 'non-breathable'
materials and adhesives during the construction process. Therefore, a need exists
for advanced footwear and foot covering materials and methods of manufacture that
enhance air flow and convective cooling of the foot while providing comfort, support
and other common features of footwear.
DISCLOSURE OF THE INVENTION
[0014] In accordance with one embodiment of the present invention, an article of footwear
is provided. The article of footwear comprises an outsole, an upper, and a chimney
structure. The upper is attached to the outsole and defines a cavity for receiving
a wearer's foot. The chimney structure comprises a plurality of chimneys defining
pathways for moving heat or moisture from within the cavity to outside the article
of footwear.
[0015] In one alternative, the chimney structure is disposed along a side panel of the upper.
In another alternative, the chimney structure comprises a plurality of channels arranged
in a row along the upper.
[0016] In a further alternative, the chimney structure comprises two rows of chimneys adjacent
to one another. Here, the pathways of a first one of the rows face the cavity and
the pathways of a second one of the rows face away from the cavity. In this case,
the first row is preferably adjacent to a wearer's foot and the second row is preferably
adjacent to the outside of the article of footwear. Optionally, each of the chimneys
of the first row shares a common wall with a corresponding one of the chimneys of
the second row. In this case, the common wall preferably includes at least one opening
therein to enable the heat or moisture to pass from one of the pathways in the first
row to one of the pathways in the second row.
[0017] In yet another alternative, the upper includes a collar and a body connected to the
collar. The body defines the cavity and the collar providing an opening to the cavity.
Selected pathways of at least some of the chimneys each have a first end disposed
along the upper below the collar and a second end disposed along the collar. In this
case, the first end of each selected pathway is preferably positioned at or below
ankle height. Here, the first end of each selected pathway is desirably located to
be adjacent to the bottom of foot. In yet another alternative, the movement of heat
or moisture occurs by convection.
[0018] In accordance with another embodiment of the present invention, a chimney structure
for convection of heat or moisture out of the microclimate of an article of footwear
is provided. The chimney structure comprises a plurality of chimneys. Each of the
chimneys includes a first end open to receive the heat or moisture from an interior
of the article of footwear and a second end open to move the heat or moisture from
within the interior to outside the article of footwear.
[0019] In one example, the chimneys are removably insertable into the article of footwear.
In another example, the chimneys are integrally formed in the article of footwear.
[0020] In one alternative, each of the chimneys includes first and second sidewalls and
an endwall connecting the first and second sidewalls. The sidewalls and the endwall
define a pathway between the first and second ends of the chimney. In another alternative,
each of the chimneys has a cross-sectional area of at least 16 mm
2. In a further alternative, the chimney structure comprises molded fabric with poured
polyurethane. In yet another alternative, the chimneys have a hardness of at least
15 Asker C.
[0021] In accordance with a further embodiment of the present invention, an article of footwear
is provided. The article of footwear comprises an outsole and an upper attached to
the outsole. The upper includes an outer material defining a cavity for receiving
a wearer's foot and a collar region for insertion of the wearer's foot into the cavity.
The article of footwear also comprises a plurality of chimneys arranged in a row along
an interior side of the outer material for moving heat or moisture from within the
cavity to outside the article of footwear.
[0022] In one alternative, the article of footwear further comprises a plurality of elongated
vents formed by overlapping sections of the outer material. The plurality of elongated
vents intersect with the plurality of chimneys to promote movement of the heat or
moisture from within the cavity to outside the article of footwear. In this case,
at least one of plurality of the elongated vents preferably intersects the row of
chimneys at an angle between 15° and 75°, whereby venting of the heat and moisture
is enhanced. In another example, the article of footwear further includes a footbed
having a porous chassis operable to permit airflow from underneath the wearer's foot
into the row of chimneys.
[0023] In accordance with yet another embodiment of the present invention, an article of
footwear is provided. The article of footwear comprises an outsole and an upper attached
to the outsole. The upper defines a cavity for receiving a wearer's foot and includes
a tongue. The article of footwear also includes a chimney structure comprising means
for moving heat or moisture from within the cavity to outside the article of footwear.
Desirably, moving the heat or moisture occurs by convection. Preferably the chimney
structure is disposed along the tongue.
[0024] The tongue chimney structure desirably comprises a chimney having a pair of sidewalls
and an endwall connecting the sidewalls. Here, the chimney may have a first opening
at a toe region of the upper and a second opening along an upper portion of the tongue,
whereby heat and moisture are vented out from the toe region. Alternatively, the chimney
mayhave a first opening at an instep region of the upper and a second opening along
an upper portion of the tongue, whereby heat and moisture are vented out from the
instep region.
[0025] The tongue chimney structure preferably comprises a row of chimneys. Alternatively,
the chimney structure comprises two rows of chimneys adjacent to one another. In this
case, a first one of the rows faces the cavity and a second one of the rows faces
away from the cavity. Here, at least some of the chimneys of the first row preferably
share a common wall with corresponding chimneys of the second row. Preferably, the
common wall includes at least one opening therein to enable the heat and/or moisture
to pass from one of the chimneys in the first row to one of the chimneys in the second
row. In another alternative, the chimney structure is removably insertable in the
tongue.
[0026] In accordance with yet another embodiment of the present invention, an article of
footwear is provided. The article of footwear comprises an outsole, an upper and a
chimney. The upper is attached to the outsole and defines a cavity for receiving a
wearer's foot and including a tongue. The chimney is disposed in the tongue to enable
movement of heat and moisture from within the cavity to outside the article of footwear.
[0027] In one example, the chimney has a substantially semicircular cross-sectional shape.
In another example, the chimney has a substantially rectangular cross-sectional shape.
In a further example, the chimney comprises a flexible material, whereby the chimney
flexes in response to movement by a wearer. In yet another example, the movement of
the heat or moisture occurs by convection.
[0028] In accordance with another embodiment of the present invention, a chimney structure
for ventilating the microclimate of article of footwear is provided. The article of
footwear includes a tongue. The chimney structure comprises a chimney disposed in
the tongue to move heat or moisture from within an interior region of the article
of footwear to outside the article of footwear. The chimney includes a pair of sidewalls
and an endwall disposed between the pair of sidewalls. The sidewalls and the endwall
define a pathway therealong. The heat or moisture is moved through the pathway from
the interior region to outside the article of footwear.
[0029] In one alternative, the chimney structure further comprises a wicking material covering
at least a portion of the chimney. The wicking material draws the moisture away from
the wearer's skin. In this alternative, the chimney structure desirably further comprises
a waterproof membrane. The wicking material covers an interior surface of the chimney
facing the interior region of the article of footwear and the waterproof membrane
covers an exterior surface of the chimney. Here, the waterproof member may include
one or more openings to promote venting of the heat or moisture out of the pathway.
[0030] In another alternative, the chimney structure further comprises a covering substantially
enclosing the chimney. The covering includes a pocket for storing laces of the article
of footwear. In yet another alternative, the chimney structure further comprises a
cushioning material disposed at a top region of the chimney structure facing the interior
region of the article of footwear.
[0031] In accordance with another embodiment of the present invention, a form fitting foot
covering is provided. The foot covering includes a heel region, a toe region, and
a sole region disposed between the heel region and the toe region. It also includes
a collar region providing an opening for insertion of a wearer's foot into the heel,
toe and sole regions of the foot covering, as well as a chimney structure comprising
a chimney for moving heat or moisture from within the foot covering out of the collar.
[0032] In an alternative, the chimney structure comprises a plurality of chimneys. Each
of the chimneys includes a pair of elongated supports and braces connecting the pair
of elongated supports. In this case, the foot covering preferably further comprises
a covering disposed on a first side of the pair of elongated supports. Here, the covering
desirably includes a pair of coverings. The first covering is disposed on the first
side of the pair of elongated supports and the second covering is disposed on a second
side of the pair of elongated supports opposite the first side. Optionally, the first
covering is positioned for direct contact with the wearer's foot and comprises a wicking
material.
[0033] In another alternative, each of the chimneys is flexible and the braces are movable
from an at-rest position to a stretched position or a compressed position as the foot
moves. In this case, the braces are preferably positioned in the at-rest position
at a predetermined angle relative to the elongated supports. Desirably the predetermined
angle is at least 15 degrees. In a further alternative, moving the heat or moisture
occurs by convection.
[0034] In accordance with yet another embodiment of the present invention, a foot covering
adapted for covering a wearer's foot comprises a body, a collar, a plurality of chimneys
and a skirt section. The body has a heel region, a toe region, and a sole region disposed
between the heel region and the toe region. The collar region is connected to the
body for insertion of a wearer's foot into body. The plurality of chimneys provide
movement of heat or moisture from within the body out of the collar. The skirt section
is formed at the connection of the body and the collar. The skirt section is adapted
to prevent debris from entering a shoe when the foot covering is positioned therein.
[0035] In an example, the skirt section is positioned at ankle height. In another example,
the skirt section includes a pocket to receive the laces of the shoe. In this case,
the pocket may comprise a stretchable material.
[0036] In an alternative, the chimneys each include a first opening in the body and a second
opening in the collar region, whereby heat or moisture enter the chimneys at the first
opening and exit at the second opening. In one example, at least some of the first
openings are disposed in the toe region. In another example, at least some of the
first openings are disposed in the heel region. In a further example, at least some
of the first openings are disposed in the sole region. Optionally, the plurality of
chimneys comprises a chimney structure that at least partly surrounds the toes of
the foot during wear.
[0037] In accordance with another embodiment of the present invention, a ventilated article
of clothing is provided. The ventilated article of clothing comprises a covering for
enclosing a portion of a wearer's body, and a chimney structure. The chimney structure
includes a plurality of chimneys that vent heat or moisture by convection from a first
region within the covering to a second region outside of the covering. In one example,
the article of clothing comprises a sock. In another example, the article of clothing
comprises a glove.
BRIEF DESCRIPTION OF THE DRAWINGS
[0038]
FIGS. 1(a)-(b) illustrate an exemplary shoe in accordance with aspects of the present
invention.
FIGS. 2(a)-(h) illustrate chimney structures in accordance with aspects of the present
invention.
FIGS. 3(a)-(d) illustrate alternative chimney structures in accordance with aspects
of the present invention.
FIGS. 4(a)-(g) illustrate additional chimney structures in accordance with aspects
of the present invention.
FIGS. 5(a)-(e) illustrate further chimney structures in accordance with aspects of
the present invention.
FIG. 6 illustrates a boot utilizing chimneys in accordance with aspects of the present
invention.
FIGS. 7(a)-(g) illustrate an alternative boot utilizing chimneys in accordance with
aspects of the present invention.
FIGS. 8(a)-(e) illustrate another boot utilizing chimneys in accordance with aspects
of the present invention.
FIGS. 9(a)-(h) illustrate yet another boot utilizing chimneys in accordance with aspects
of the present invention.
FIGS. 10(a)-(c) illustrate an alternative chimney structure in accordance with aspects
of the present invention.
FIG. 11 illustrates a chimney material in accordance with aspects of the present invention.
FIGS. 12(a)-(j) illustrate further chimney structures in accordance with aspects of
the present invention.
FIGS. 13(a)-(e) illustrate a sock utilizing chimneys in accordance with aspects of
the present invention.
FIGS. 14(a)-(e) illustrate exemplary chimney structures in accordance with an aspect
of the present invention.
FIGS. 15(a)-(e) illustrate a footbed in accordance with aspects of the present invention.
DETAILED DESCRIPTION/MODES FOR CARRYING OUT THE INVENTION
[0039] In describing the preferred embodiments of the invention illustrated in the appended
drawings, specific terminology will be used for the sake of clarity. However, the
invention is not intended to be limited to the specific terms used, and it is to be
understood that each specific term includes equivalents that operate in a similar
manner to accomplish a similar purpose. By way of example only, the term "footwear"
is used herein to include, without limitation, all manner of foot coverings such as
boots, shoes, sandals, athletic sneakers, loafers etc.
[0040] Both experience and research illustrate the need to preferentially handle heat and
moisture removal from footwear. The inventors of the present invention conducted live
trials using volunteer subjects to evaluate how airflow in the shoe microclimate affects
heat and moisture retention, and, ultimately, shoe comfort. A first testing phase
focused on climate control and moisture management within a hiking shoe structure.
Human subjects were asked to evaluate four different hiking shoes having different
upper constructions.
[0041] The first hiking shoe included an all mesh upper designed for maximum breathability.
The second hiking shoe included a mesh upper with a waterproof membrane capable of
venting moisture designed for average breathability. The third hiking shoe was a conventional
off-the-shelf hiking shoe including an integral waterproof membrane capable of venting
moisture designed for average breathability. The fourth hiking shoe included a mesh
upper having a polyurethane ("PU") lining designed for minimum breathability. Table
1 provided below compares the four shoe structures.
Table 1:
Shoe Number |
Shoe Type |
Designed Breathability |
1 |
All mesh upper |
Maximum breathability |
2 |
Mesh upper with waterproof/venting lining |
Average breathability |
3 |
Conventional hiking shoe with waterproof/venting lining |
Average breathability |
4 |
Mesh upper with PU lining |
Minimum breathability |
[0042] Ten subjects tested each of the four shoes. For each test, the subject wore a pair
of thin socks having the composition 42% cotton, 14.5% spandex, 21.5% nylon, and 22%
polyester. Each test included a warm-up period, a test period, and a cool down period.
During the warm-up period the subject wore his or her own shoes. After warm-up, the
subject walked on a treadmill for a period of 15 minutes at a speed of 4mph. Shoe
weight and sock weight were recorded before and after the 15 minute walking period.
At the conclusion of the test the subject stepped off of the treadmill and was allowed
a five minute cool down period. Each subject wore a fresh pair of socks for each shoe
tested.
[0043] During the 15 minute walking period the temperature of the foot was monitored with
a thermocouple mounted in the location of the in-step. While walking, the subjects
were asked a series of questions pertaining to the microclimate of the shoes being
worn. Subjects answered the questions by evaluating aspects of the microclimate on
a scale of one through three, including temperature and humidity. A description of
this rating scale can be found in Table 2.
Table 2:
Rating |
Temperature Definition |
Humidity Definition |
1 |
Colder than Body Temperature |
Dry |
2 |
Same as Body Temperature |
Clammy |
3 |
Hotter than Body Temperature |
Soaked |
[0010] Immediately after stepping off the treadmill, the left shoe was removed and internal
shoe temperature and humidity measurements were taken. Shoe and sock weights were
also measured (in grams) and recorded. The test results are shown in Table 3.
Table 3:
Shoe Number |
Human Trial Testing |
Subjective Rating (Scale:1-3) |
Mean Foot Temp @ 15 min. |
ΔT |
Sock Weight Gain |
Shoe Weight Gain Including Footbed |
Temp |
Humidity |
(°C) |
(°C) |
(g) |
(g) |
1 |
1.45 |
1.29 |
35.3 |
1.4 |
0.64 |
0.43 |
2 |
2.29 |
1.73 |
36 |
2.1 |
1.32 |
0.43 |
3 |
2.56 |
2.07 |
36.6 |
3.1 |
2.11 |
1.11 |
4 |
2.35 |
1.90 |
36.6 |
2.6 |
1.86 |
0.96 |
[0044] The test results presented in Table 3 demonstrate the wearers' perception of comfort
as it relates to moisture retention around the foot. Wearers perceived the all mesh
upper of shoe one as being the coolest and driest after the test. The production shoe
was perceived as being the hottest and most damp shoe after the test. The column entitled
"ΔT" pertains to the increase in temperature during the trial and supports the wearers'
assessments as to heat retention by the shoes. The time in the ΔT column runs from
when the wearer initially placed his or her foot in the shoe to the end of the test
after the cool down period. Here, the smallest temperature increase occurred in the
all mesh upper, and the largest temperature increase occurred in the production shoe.
The columns entitled "Sock Weight Gain" and "Shoe Weight Gain Including Footbed" provide
statistical data confirming the wearers' assessments as to how much moisture was retained
within the sock and the shoe. The all mesh upper caused the least amount of moisture
to be retained in the sock and in the shoe itself. The production shoe caused the
most moisture to be retained in the sock and in the shoe.
[0045] Table 4 illustrates a ranking of the four shoe structures based upon the subjective
ratings by the test subjects. The rankings ranged from 1 to 4, with 1 being the best
performance among all of the shoes and 4 being the poorest performance among all of
the shoes.
Table 4:
Shoe # |
Subjective Rankings: Human Trial Testing |
Temp |
Humidity |
Mean Foot Temp @ 15 min. |
ΔT |
Sock Gain |
Shoe Gain w/ Footbed |
Cool to Hot |
Dry to Wet |
Cool to Hot |
Low to High |
Low to High |
Low to High |
1 |
1 |
1 |
1 |
1 |
1 |
1 |
2 |
2 |
2 |
2 |
2 |
2 |
1 |
3 |
4 |
4 |
3 |
4 |
4 |
4 |
4 |
3 |
3 |
3 |
3 |
3 |
3 |
[0046] As seen by the results of Table 4, the all mesh upper of the first shoe had the highest
performance ranking among all of the shoes in all of the categories, whereas the conventional
production shoe had the worst, or a tie for the worst, ranking in each category. As
seen in the mean foot temperature column, the mesh upper with the PU lining was ranked
the same as the production shoe.
[0047] The inventors of the present invention also conducted laboratory tests separate from
the human trials to evaluate how airflow in the shoe microclimate affects heat and
moisture retention. The same four shoe structures used in the human trials were tested
in the laboratory. Testing was conducted using standards developed by the SATRA Technology
Centre.
[0048] Specifically, advanced moisture management testing using the SATRA Advanced Moisture
Management ("AMM") test was conducted using the four hiking shoe structures discussed
above. Testing simulated the generation of heat and sweat by the foot in a shoe, quantifying
the distribution of sweat output by absorption, evaporation loss, and energy usage,
as will be explained below.
[0049] Testing was conducted under laboratory conditions of 20°C and 65% relative humidity.
A simulated foot was used to conduct the test. The simulated foot was covered in a
simulated skin membrane. A sock was then placed on foot and inserted into one of the
four test shoe structures. The sock had the same composition as in the human trials.
The simulated foot was maintained at a temperature of 34° C with a nominal sweat rate
of 5mL/hr.
[0050] The sweat rate was controlled in a closed loop such that the only means of egress
was into the footwear being tested. A constant airspeed of 2 m/s was maintained across
the shoe during the test. The mass of water input to the system in each test was approximately
13.5 g ± 0.3g. Once the system was brought to equilibrium, the test lasted for a period
of 180 minutes. The results of the test indicated the amount of moisture retained
in the simulated skin, the sock, the footbed, and the shoe itself, as well as the
evaporated mass of water and the amount of energy required to maintain the foot at
34°C. A low thermal energy input value would indicate a high degree of thermal insulation
within the shoe. The laboratory test results are shown in Table 5.
Table 5:
Shoe # |
Laboratory Testing With AMM Test |
Skin Gain |
Sock Gain |
Shoe Weight Gain w/ Footbed |
Footbed Gain Only |
Evaporated Loss |
Thermal Energy Input |
(g) |
(g) |
(g) |
(g) |
(g) |
(kJ) |
1 |
0.39 |
1.75 |
1.95 |
1.28 |
10.91 |
83.8 |
2 |
0.46 |
2.82 |
3.33 |
1.79 |
8.39 |
67.4 |
3 |
0.64 |
4.75 |
6.46 |
1.74 |
3.15 |
48.4 |
4 |
0.51 |
5.00 |
5.43 |
1.80 |
4.06 |
61.9 |
[0051] As seen by the results in Table 5, the all mesh upper of the first shoe had the least
amount of moisture gain in the simulated skin membrane of the foot, in the sock, in
the footbed by itself, and in the shoe including the footbed. The shoe with the all
mesh upper also had a much greater amount of evaporative moisture loss than any of
the other shoes tested. The evaporation results correlate with the data for thermal
energy input as shown in the rightmost column. Here, the all mesh upper required the
most amount of input energy to maintain the simulated foot at a temperature of 34°C.
[0052] Table 6 illustrates a ranking of the four shoe structures based upon the objective
test results from the laboratory experiments. As with the rankings of Table 4, the
rankings in Table 6 range from 1 to 4, with 1 being the best performance among all
of the shoes and 4 being the poorest performance among all of the shoes.
Table 6:
Shoe # |
Objective Rankings: Laboratory Testing With AMM Test |
Skin Gain |
Sock Gain |
Shoe Weight Gain w/Footbed |
Footbed Gain Only |
Evaporated Loss |
Thermal Energy Input |
Low to High |
Low to High |
Low to High |
Low to High |
High to Low |
High to Low |
1 |
1 |
1 |
1 |
1 |
1 |
1 |
2 |
2 |
2 |
2 |
3 |
2 |
2 |
3 |
4 |
3 |
4 |
2 |
4 |
4 |
4 |
3 |
4 |
3 |
4 |
3 |
3 |
[0053] As seen by the results of Table 6, the all mesh upper of the first shoe had the highest
performance ranking among all of the shoes in all of the categories, whereas the conventional
production shoe had the worst ranking in most of the categories. While the production
shoe had the second best ranking in the column labeled "Footbed Gain Only," it ranked
the lowest in four of the six total categories.
[0054] At the conclusion of the laboratory AMM testing, the laboratory results were compared
with those obtained from the human trials to look for correlation. The assumption
is that a high degree of correlation between the human and laboratory tests allows
for the assessment of the moisture management properties of subsequent footwear designs
using laboratory tests only, without the need for conducting many expensive and time
consuming human trials.
[0055] The laboratory tests and human trials were compared for two criteria, moisture and
heat. In a first comparison with regard to moisture, the average subjective humidity
ratings in the human trials were compared to the average evaporated loss in the laboratory
tests. In a second comparison with regard to heat, the average subjective temperature
ratings in the human trials were compared to the average energy used in the laboratory
tests.
[0056] The data were compared using a regression analysis technique involving the coefficient
of determination ("R
2"), which is a well known and often used statistical analysis tool. The coefficient
of determination is a measure of the correlation between the two variables in the
regression analysis. Here, the variables were either the average subjective humidity
as compared to the averaged evaporated loss, or the average subjective temperature
as compared to the average energy used. The R
2 value ranges between 0 and 1. A 0 value indicates no correlation, and a 1 value indicates
strong correlation. The R
2 value in the moisture comparison was 0.9077. The R
2 value in the heat comparison was 0.8899. Thus, it can be seen that the human and
laboratory test results are highly correlated.
[0057] The analysis also involved a statistical examination as to the interdependence of
the variables from the human and laboratory tests. This involved calculating a correlation
coefficient ("r"), which is expresses as r = √R
2. The correlation coefficient may range from -1 to 1. As with the coefficient of determination,
it is desirable for the correlation coefficient to be as close to 1 as possible. The
r value in the moisture comparison was 0.95. The r value in the heat comparison was
0.94. Thus, the correlation coefficients in both analyses confirm that the human and
laboratory tests are highly correlated. Therefore, footwear that performs well in
laboratory testing should be more than acceptable to actual wearers. In particular,
footwear configurations that lower moisture absorption in the sock, in the shoe, and/or
in the footbed or sockliner should have a perceptibly drier fee. Footwear configurations
that have a higher thermal energy input should have a perceptibly cooler feel.
[0058] In addition to the human and laboratory testing discussed above, research demonstrates
that the movement of air (airflow), as exemplified by convection, enhances the evaporation
transfer of heat by the movement of air from a hot region to a cool region. By creating
an environment around the foot that allows for airflow, such as by convective transport,
of heat or moisture away from the skin and out of the shoe, the foot will be kept
drier and more comfortable. Convention, or convective transport, is a passive process
that does not require an active mechanical action. While the terms heat and moisture
are referred to in the alternative, it should be understood that this also includes
airflow of both heat and moisture together. Evaporation of moisture facilitates cooling,
improves functional performance, and reduces the likelihood of a foot-related injury
- especially those related directly to the skin such as abrasion, swelling, and blisters.
Proper evaporation also reduces the chance of fungal and skin infections, and reduces
malodorous conditions.
[0059] In accordance with aspects of the present invention, channel or chimney devices,
hereinafter referred to as "chimneys," can be employed with articles of footwear including
shoes, foot coverings such as socks, etc., to provide cooling and to remove moisture
away from the foot.
[0060] FIGS. 1(a)-(b) illustrate an exemplary shoe 10 suitable for use with chimneys and
other ventilation structures in accordance with the present invention. The shoe 10
may be any type of conventional or specialty footwear, including, but not limited
to dress shoes, loafers, athletic shoes such as sneakers, work boots, hiking boots,
etc. Here, the exemplary shoe is shown having an outsole 12 and an upper 14. The outsole
12 may include a tread 16 on the bottom thereof. As shown, a region 18 connects the
outsole 12 to the upper 14. The region 18 may be integral with the outsole 12, or
may comprise a separate midsole, a lasting board, etc. Alternatively, the outsole
12 and the upper 14 may be integrally formed as a single piece. Additional features
such as a shank piece, arch support, etc. (not shown), may be fixed as part of the
shoe 10 or may be removable therefrom.
[0061] The upper 14 may include a body 20 as well as a collar or collar region 22, which
defines an opening that enables a wearer to insert his or her foot into an interior
cavity 24 of the body 20. The body includes sidewalls or side panels of the upper,
which may be formed from multiple pieces or as an integral unit. The sidewalls/side
panels may also include a heel region. The upper 14 may have a tongue 26, which may
be part of the body 20 and which may be attached, at least in part, to the collar
or collar region 22. The body 20 may also include fasteners 28, such as laces 28a,
eyelets 28b, and/or other structures such as hook and loop fastening straps, snaps,
clips, etc. to adjustably and comfortably secure the foot within the shoe 10.
[0062] As seen in the top view of FIG. 1(b), the shoe 10 may also include a footbed 30 that
is configured to receive the wearer's foot within the interior cavity 24. Any type
of footbed 30 may be used in accordance with the present invention, including custom
orthotics, sockliners, etc.; although specially constructed footbeds as discussed
herein may also be employed. The footbed 30 may be formed from resilient materials
such as ethyl vinyl acetate ("EVA") and polyurethane PU foams or other such materials
commonly used in shoe midsoles, insoles or sockliners. The footbed 30 may be fabricated
using multiple material layers, regions and/or segments, which may each have a different
thickness and/or a different rigidity. For example, the footbed 30 may comprise multiple
layers of different rigidity. Alternatively, the footbed 30 may have different levels
of rigidity in the forefoot, instep and heel regions, respectively. The footbed 30
could also have a first segment about the first metatarsal of a first rigidity and
a second segment about the fifth metatarsal of a second rigidity. In all cases, footbed
rigidity can be adapted to footwear function.
[0063] FIG. 2(a) illustrates a partial cutaway view of the shoe 10, revealing chimneys 32
disposed along the sides of the body 20 and chimneys 34 disposed in the tongue 26.
As will be discussed below, FIGS. 2(b)-2(g) illustrate the chimneys 32 and 34 in more
detail. FIG. 2(b) illustrates an example of a body chimney structure 36 including
multiple body chimneys 32 with portions of the upper 14 shown in outline form for
the sake of clarity. As shown here, nine body chimneys 32 may be arranged in the chimney
structure 36 along a side of the body 20. However, any number of body chimneys 32
may be used, including a single chimney. The specific number utilized, such as 2,
5, 10, 20, etc., may vary depending upon the type of footwear, the sizing of the footwear,
and the chimney dimensions, which will be discussed in more detail below.
[0064] FIG. 2(c) illustrates a top view of a preferred body chimney structure 36, which
includes a number of the body chimneys 32 in a set. As seen in this figure, each individual
body chimney 32 preferably includes first and second sidewalls 38a,b connected by
a central portion 40 in a substantially semicircular arrangement. The sidewalls 38a,b
may be curved or arced to achieve the semicircular configuration, although any other
geometrical configuration is possible. Adjacent body chimneys 32 are connected by
a wall 39. The sidewalls 38a,b and the wall 39 may comprise a single integral structure
or multiple components fastened together. The substantially semicircular arrangement
defines a pathway 42 having an opening 44 opposite the central portion 40. As shown
in FIG. 2(c), the chimney structure 36 may include two rows of body chimneys 32 that
share a common central portion 40, although a single row of body chimneys 32 can also
be used.
[0065] FIG. 2(d) illustrates a perspective view of a segment of the chimney structure 36.
As shown in this figure, the central portion 40 preferably includes one or more openings
46 and one or more braces 48 therebetween. While not required, the openings 46, if
used, act as passageways between the opposing rows of body chimneys 32. As seen by
the arrows in FIGS. 2(d) and 2(e), the pathways 42 promote convective venting of heat
and/or moisture upward away from the bottom of the shoe near the outsole 12, midsole
18, and/or the footbed 30 and toward the collar 22. The openings 46 permit heat and/or
moisture to move between pairs of the body chimneys 32. Specifically, hot and/or moist
air may migrate from the interior row of body chimneys 32 out to the exterior row
of body chimneys 32 via the openings 46.
[0066] As best seen in FIGS. 2(b) and 2(e), the body chimneys 32 in this example are preferably
positioned generally vertically along the body 20 and the collar 22 of the upper 14.
Such a configuration promotes efficient migration of heat and/or moisture up from
lower regions of the shoe 10. However, the pathways 42 may be arched, angled, curved,
s-shaped, etc (see FIGS. 14(a)-(e)). Regardless of specific pathway alignment, the
body chimneys 32 are desirably positioned so that some or all of the pathways 42 have
a first end 42a disposed along the upper 14 below the collar 22 and a second end 42b
at or near the top of the collar 22 to evacuate heat and/or moisture out of the microclimate
of the shoe 10. The first end 42a is preferably positioned at or near the foot, more
preferably at or below the ankle. While the ankle height differs for different people,
the typical ankle height for an adult male is, for instance, less than about seven
inches when measured relative the bottom or sole of the foot. Desirably, the first
end 42a is placed as close to the footbed or the bottom/sole of the foot as possible.
By way of example only, the first end 42a may be placed 1-2 inches or less from the
bottom of the foot. More preferably, the opening at the first end 42a is less than
one inch from the bottom of the foot. The opening 42a of the first end should be positioned
above the insole, if any. However, if a ventilating insole is used, the opening 42a
may be placed at the height of the ventilating insole. It is important that the second
end 42b or other portion(s) of the pathway 42 higher than the first end 42a be exposed
to the external climate to promote effective heat/moisture evacuation.
[0067] FIGS. 2(e)-(h) illustrate a set of tongue chimneys 34 in more detail. The tongue
chimneys 34 may include structures that are substantially equivalent to the body chimneys
32. For example, as seen on FIG. 2(f), the tongue chimneys 34 may include includes
first and second sidewalls 50a,b connected by a central portion 52 in a substantially
semicircular arrangement, although any other geometrical configuration is possible.
The substantially semicircular arrangement defines a pathway 54 having an opening
56 opposite the central portion 52. The tongue chimneys 34 may be arranged as a connected
set in a chimney structure 60. As shown, the chimney structure 60 may include two
rows of tongue chimneys 34 that share a common central portion 52, although a single
row can be used.
[0068] The central portion 52 of the tongue chimney 34 preferably includes one or more openings
62 and one or more braces 64 therebetween. While not required, the openings 62, if
used, act as passageways between the opposing rows of tongue chimneys 34. As seen
in FIGS. 2(e) and 2(h), the pathways 54 promote conduction of heat and/or moisture
away from the bottom of the upper 14 near the toe and instep regions and toward the
upper part of the tongue 26. The openings 62 permit the heat and/or moisture to move
between pairs of the tongue chimneys 34. For instance, hot and/or moist air may migrate
from the inner row of tongue chimneys 34 out to the exterior row of tongue chimneys
34 via the openings 62.
[0069] The tongue chimneys or tongue vents 34 are preferably positioned to promote efficient
migration of heat and/or moisture upward away from the front/toe region of the shoe
10. The tongue chimneys 34 are desirably positioned so that each pathway 54 has a
first end 68 disposed along the upper 14 in the front/toe region and a second end
70 at or near the top of the tongue 26 to evacuate heat and/or moisture out of the
microclimate of the shoe 10. The first end 68 is preferably positioned at or near
the toes or the front portion of the foot. It is important that the second end 70
or other portion(s) higher than the first end 68 of the pathway 54 be exposed to the
external climate, for instance at or near the top of the tongue 14, to promote effective
heat/moisture evacuation.
[0070] When a single row of one or more body chimneys or body vents 32 is employed, the
opening 44 of each pathway 42 preferably faces inward towards the foot. Similarly,
when a single row of one or more tongue chimneys 34 is employed, the opening 56 of
each pathway 54 preferably faces inward towards the foot. When a second row of body
and/or tongue chimneys 32, 34 is employed, the pathway openings 44, 56 help promote
air exchange between the shoe microclimate and the external climate, as seen in FIGS.
2(d) and 2(h).
[0071] FIG. 3 (a) illustrates an alternative body chimney structure 36'. Here, a material
72 is added to a top region of the body chimney structure 36'. The material 72 is
preferably adhered or otherwise affixed to the body chimneys 32 as shown or integrally
formed therewith. The material 72 desirably includes one or more openings 74, which
align with the pathways 42 of the body chimneys 32. FIG. 3(b) is a cross-sectional
view of the body chimney structure 36' along line 3A-3A, which is taken through the
wall 39 between adjacent chimneys 32. FIG. 3(c) is a cross-sectional view of the body
chimney structure 36' along line 3B-3B, which is taken through the pathway 42. As
seen in these cross-sectional views, a liner 75 may cover at least part of the chimney
structure 36'. Preferably, the liner 75 covers the side of the chimney structure 36'
facing the interior of the shoe 10.
[0072] FIG. 3(d) is a cross-sectional view of the body chimney structure 36' along line
3C-3C. As seen in this figure, the body chimney structure 36' may include two rows
of oppositely facing body chimneys 32a and 32b. The material 72 desirably faces the
interior cavity 24 of the shoe 10, and can be used to provide cushioning for the wearer's
leg. The material 72 may include one or more layers of foam, such as PU or EVA and
can vary in hardness.
[0073] FIG. 4(a) illustrates an alternative tongue chimney structure 60'. Here, a material
76 can be added to a top region of the tongue chimney structure 60 discussed above.
The material 76 is preferably adhered or otherwise affixed to the tongue chimneys
34. The material 76 desirably includes one or more openings 78, which preferably substantially
align with the pathways 54 of the tongue chimneys 34.
[0074] FIG. 4(b) is a cross-sectional view of the tongue chimney structure 60' along line
4A-4A, which is taken through the pathway 54. As seen here, the material 76 may only
be on one side of the tongue chimney structure 60'. FIG. 4(c) is a cross-sectional
view of the tongue chimney structure 60' along line 4B-4B. As seen in this figure,
the tongue chimney structure 60' may include two rows of oppositely facing tongue
chimneys 34a,b. The material 76 desirably faces the interior cavity 24 of the shoe
10, and can be used to provide cushioning for the wearer's leg. The material 76, like
the material 72, may include one or more layers of foam, such as PU or EVA. FIG. 4(d)
illustrates the cross-sectional view of FIG. 4(c) with the tongue chimney structure
60' curved or arched as it may be during wear. Here, it can be seen that curving the
tongue chimney structure 60' does not unduly obstruct the pathways 54, permitting
convection of heat/moisture as discussed above.
[0075] FIGS. 4(e)-(g) illustrate an alternative wherein one or both sides of the tongue
chimney structure 60' or 60 are covered by a material 80. The material 80 may be permanently
or removably attached to the tongue chimney structure 60' or 60. Preferably, the material
80 comprises a first lining 80a, which faces the wearer's leg during use and a second
lining 80b, which faces away from the leg during use. The first lining 80a has one
or more layers of material, preferably including at least one layer of wicking material
in immediate exposure to the shoe microclimate. Examples of this type of lining include
a chemically treated brushed polyester, rayon, nylon, cotton or combination of companion
fibers or a specialty woven or knit material used in combination to maximize breathability
by absorbing moisture next to the skin and wicking away moisture from the surface
of skin to allow for evaporation. Wicking materials sold under the brand names COOLMAX,
DRITEX, and POWER DRY are commonly known in the industry. The second lining 80b has
one or more layers of material, preferably including at least one layer of non-wicking
material, such as a mesh. The mesh could comprise one or more layers of coated nylon,
polyester, and/or cotton. The second lining 80b may also include a pocket 82, which
may be disposed at or near the top of the lining. The pocket 82 is preferably sized
to permit the wearer to store at least a segment of the laces therein. The pocket
82 may be formed of a stretch mesh or other suitable material. For example, the pocket
82 may comprise nylon, synthetic leather, or, preferably, a non woven material with
an elongation value of at least 150%.
[0076] FIGS. 5(a)-(e) illustrate cross sections of alternative chimney structures suitable
for use in alternative embodiments of the present invention. FIG. 5(a) presents a
chimney structure 100 that may comprise one or more substantially square-shaped chimneys
102. The chimneys 102 may be formed by supports 104 having substantially parallel
sidewalls 106 that are connected to a wall 108. The supports 104 and the wall 108
may be integrally formed, for example, by a molding process. In this configuration,
width 110 and depth 112 are substantially the same.
[0077] FIG. 5(b) presents a chimney structure 120 that may comprise one or more substantially
rectangular-shaped chimneys 122. The chimneys 122 may be formed by supports 124 having
substantially parallel sidewalls 126 that are connected to a wall 128. The supports
124 and the wall 128 may be integrally formed in a molding process. In this configuration,
width 130 and depth 132 are different.
[0078] In FIG. 5(c), chimney structure 140 may comprise one or more chimneys 142 formed
by connecting substantially rounded or circular supports 144 to a wall 146. The wall
146 may include one or more holes 148. The supports 144 and the wall 146 may be integrally
formed by a molding process. The holes 148 may be disposed partly or substantially
along the length of the chimney structure 140. For example, if the chimney structure
140 comprises a body chimney structure 36, the holes 148 may run substantially the
length of the pathways 42 from the first end 42a to the second end 42b. The holes
148 permit the chimney structure 140 to flex or bend without compromising the ability
of the chimneys 142 to vent heat and/or moisture.
[0079] FIG. 5(d) illustrates additional support structures that may be used in accordance
with aspects of the present invention to create different chimney configurations.
Each of the chimneys in this figure is preferably connected to a wall 160, which functions
as the back of the chimney. For instance, chimney 162a is formed by adjacent trapezoid-shaped
supports 164. An equivalent shape is achieved with chimney 162b having one trapezoid-shaped
support 164 on one side and a parallelogram-shaped support 166 on the other side.
Placing two parallelogram-shaped supports 166 adjacent to one another forms a parallelogram-shaped
chimney 168. Chimneys 170, 172, 174 and 176 are obtained by placing substantially
oval-shaped supports 178,180 and rounded rectangular-shaped supports 182,184 in the
positions shown in the figure. Of course, it should be understood that many other
chimney shapes can easily be achieved by using supports and adjacent wall members
of varying geometrical shapes. The key criterion is that the chimney pathways have
sufficient cross-sectional area to permit adequate heat/moisture conduction. The pathways
of such chimneys need not be entirely or substantially straight. Instead, they may
be angled, curved, arched, s-shaped, etc., at one or more sections along their length.
[0080] In each of the chimney configurations shown in FIGS. 5(a)-(d), the chimneys are partly
or fully open along one side. However, in alternative embodiments for the chimney
structures disclosed herein, some or all of the chimneys may be substantially or completely
closed on all sides. By way of example only, FIG. 5(e) illustrates a cross sectional
view of a chimney structure 190 having a first wall 192a, a second wall 192b and supports
194 disposed therebetween to form chimneys 196.
[0081] While enclosed on all sides, the chimneys 196 preferably include one or more openings
198 in one or both of the walls 192a,b. In body chimney structures such as the body
chimney structure 36, the openings 198 are preferably formed at the first and second
ends 42a,42b of the pathways 42. Additional openings 198 may be positioned similar
to the openings 46 shown in FIGS. 2(d),(e). Additional openings 198 are particularly
suitable when two parallel rows of chimneys 196 are used, such as those described
above with respect to FIGS. 2(c) and 3(d). If used, such additional openings 198 may
act as passageways between the rows of chimneys 196.
[0082] While the chimney structures in the embodiments presented above illustrate multiple
chimneys along the body 20 and collar 22 of the upper 14 or along the tongue 26, other
embodiments of the present invention contemplate the use of a single chimney, which
may be positioned anywhere within the upper 14. Alternatively, one chimney may be
positioned adjacent to each side and/or the rear or front of the foot within the upper
14. Here, a first end of the chimney should be open at or near the foot bed region,
for instance below ankle level or as close to the bottom of the foot as possible.
A second end or portion of the chimney should be open to the external climate.
[0083] The chimneys of the present invention may be incorporated into footwear in different
ways. For example, body chimneys and/or tongue chimneys may be integral with the upper
14, or may be removably coupled to the upper 14 as separate components. Chimneys can
be molded or otherwise inserted into the interior walls of a shoe. While chimneys
could be positioned in a number of layers of an article of footwear, it is most preferable
to position at least some of the chimneys in one or more layers as close to the foot
as possible in order to reduce the distance that heat and moisture generated from
the foot have to travel before evacuation via the chimneys. Convective air movement
facilitates evaporation and other forms of cooling.
[0084] In one example, the chimneys are formed by molding a foam layer and then covering
the foam layer with a comfortable lining material. Additional examples of chimney
materials are discussed below. Chimneys are desirably constructed of a geometry that
provides a sufficient surface against the foot and ankle to prevent discomfort and
pinching, for example, from sharp edges and high pressure areas through the reduction
of surface area between the foot and shoe.
[0085] Because convection is the primary mechanism guiding air movement from inside the
microclimate of the shoe to the outside environment, the evacuation of warm, moist
air occurs without requiring user intervention or mechanical devices when employing
chimneys in accordance with the present invention. Convective currents become more
powerful as the relative temperature difference between two objects increases. During
low activity, foot temperature and internal shoe temperature remain relatively low.
As activity increases, foot temperature and in-shoe temperature can increase very
rapidly. The increase in temperature creates a correspondingly increased thermal gradient
between the in-shoe microclimate and the external environment, which creates stronger
convection currents and greater heat and humidity evacuation from the shoe. Pumps
or other mechanical apparatus are thus unnecessary.
[0086] The channels discussed above may be implemented in a wide variety of footwear. Several
exemplary articles of footwear implementing chimneys are shown and described below.
For instance, FIG. 6 illustrates a boot 200 having an outsole 202 and an upper 204.
The outsole 202 may include a tread 206 on the bottom thereof. As shown, a region
208 connects the outsole 202 to the upper 204. The upper 204 includes a body 210 as
well as a collar 212, which defines an opening that enables a wearer to insert his
or her foot into an interior cavity of the upper 204. The upper 204 includes a tongue
214. The body 210 includes laces 216 and eyelets 218.
[0087] The body 210 includes a body chimney structure 220 having multiple chimneys 222 having
pathways 224 therein. The body chimney structure 220 is preferably same as the body
chimney structure 36, although any chimneys and chimney structures in accordance with
the present invention may be employed in the boot 200. The body chimney structure
220 is shown having openings 226 near the ends of the pathways 224 along the collar
212. The body chimney structure 220 may include opposing rows of body chimneys 222
(such as are body chimneys 32 a,b of FIG. 3(d)), with one row facing inward towards
the wearer's foot and the other row facing in the opposite direction. However, a single
row can also be employed.
[0088] The portion of the body chimney structure 220 along the collar 212 provides venting
to the external climate. Other portions of the body chimney structure 220 are shown
being covered by a layer of material 228. The material layer 228 is preferably leather
or a leather/fabric combination. This material layer may be substantially non-permeable
to heat and/or moisture. In this case, it is particularly desirable for the body chimney
structure 220 to include the openings 226 positioned at or near the collar 212 above
the material layer 228 to enhance ventilation.
[0089] The tongue 214 preferably includes a tongue chimney structure 230. The tongue chimney
structure 230 is preferably same as the tongue chimney structure 60 or 60', although
any chimneys and chimney structures in accordance with the present invention may be
employed in the boot 200. The exterior of the tongue chimney structure 230 is shown
being covered by a material 232, which is preferably the same as the material 80 discussed
above with regard to FIGS. 4(e)-(g). A pocket 234 may also be included is also shown
as part of the material 232. The pocket 234 is designed to permit the wearer to store
the laces 216 therein.
[0090] FIG. 7(a) illustrates a boot 300 similar to the boot 200 of FIG. 6. The boot 300
includes an outsole 302 and an upper 304. The outsole 302 may include a tread 306
on the bottom thereof. As shown, a region 308 connects the outsole 302 to the upper
304. The upper 304 includes a body 310 as well as a collar 312, which defines an opening
that enables a wearer to insert his or her foot into an interior cavity of the upper
304. The upper 304 includes a tongue 314. The body 210 includes laces 316 and eyelets
318.
[0091] The body 310 includes a body chimney structure 320 having multiple chimneys 322 having
pathways 324 therein. The body chimney structure 320 is preferably same as the body
chimney structure 220, although any chimneys and chimney structures in accordance
with the present invention may be employed with the boot 300. The body chimney structure
320 is shown having openings 326 near the ends of the pathways 324 along the collar
312. As will be described in more detail below, the body chimney structure desirably
includes opposing rows of body chimneys 322 (such as the body chimneys 32a,b of FIG.
3(d)), with one row facing inward towards the wearer's foot and the other row facing
in the opposite direction. Alternatively, a single row may suffice.
[0092] The portion of the body chimney structure 320 along the collar 312 provides venting
to the external climate. Other portions of the body chimney structure 320 are shown
being covered by a material 328. The material 328 is preferably leather or a leather/fabric
combination or any other commonly used material within footwear. This material may
be substantially non-permeable to heat and/or moisture. The material 328 desirably
includes one or more openings 330. The openings may come in any shape desired, including,
but not limited to the substantially triangular, trapezoidal, and oval shapes presented.
[0093] FIG. 7(b) illustrates a cross-sectional view of the body 310 along the 7A-7A line
of FIG. 7(a). As seen in FIG. 7(b), two rows of body chimneys 322 may be provided,
with a first row 332a facing inward towards the wearer's foot and a second row 332b
facing in the opposite direction. The material 328 is preferably positioned adjacent
to the second row 332b.
[0094] The material layer 328 may comprise multiple layers, including a material 334 that
is a substantially waterproof membrane. More preferably, the material 334 comprises
a substantially waterproof membrane capable of venting moisture from the shoe microclimate
to the outside environment. By way of example only, the material 334 may comprise
an expanded PTFE material, such as the materials shown and described in
U.S. Patent Nos. 6,108,819,
6,228,477,
6,410,084,
6,676,993, and
6,854,603, the entire disclosures of which are hereby expressly incorporated by reference herein.
As seen in FIG. 7(b), the material 334 preferably lies between the openings 330 and
the body chimney structure 320. One or more of the openings 326 of the body chimney
structure 320 are desirably positioned facing the openings 330 to help promote venting.
[0095] The material layer 328 may also include an exterior structure 336, with the openings
330 therein. The exterior structure 336 may be formed, for example, of PE or any of
the commonly used materials in footwear such as leather, synthetic leather or a waterproof
version of the same. Overlying the exterior structure 336 there may be a covering
338, such as a highly porous material, e.g., mesh. The covering 338 preferably covers
the openings 330 as well as the exterior structure 336.
[0096] The tongue 314 preferably includes a tongue chimney structure 340, as shown in the
exterior view of FIG. 7(c). The tongue chimney structure 340 may be the same as the
tongue chimney structure 230, although any chimneys and chimney structures in accordance
with the present invention may be employed. FIG. 7(d) illustrates a cross-sectional
view of the tongue chimney structure 340 along the 7B-7B line of FIG. 7(c). In FIG.
7(d), it can be seen that the tongue chimney structure 340 includes two rows of tongue
chimneys 342, with a first row 342a facing inward towards the wearer's leg and a second
row 342b facing in the opposite direction. Alternatively, a single row 342 may be
employed.
[0097] The first row 342a is desirably covered by a material 344, which may comprise a wicking
material for removing or pulling moisture away from the wearer's skin and/or away
from a sock. The second row 342b is desirably covered by a material 346, which may
be a substantially waterproof membrane. More preferably, the material 346 comprises
a substantially waterproof membrane capable of venting moisture from the shoe microclimate
to the outside environment, such as the material 334 discussed above. The membrane
of the material 346 may include a tricot material, such as a monofilament tricot.
[0098] Exterior structure 348 preferably overlies the material 346. As seen in FIG. 7(c),
the exterior structure 348 may include one or more openings 350 therein. The openings
350 help promote the convective venting process. Additional openings 350' may be disposed
on the vamp 352. The exterior structure 348 may comprise the same material as the
exterior structure 336 of the material layer 328. Referring back to FIG. 7(d), a covering
354 may optionally overly the exterior structure 348. The covering 354 is preferably
the same material as the covering 338. The covering 354 preferably covers the openings
350 as well as the exterior structure 348. The covering 354 may also include a pocket
356, which is designed to permit the wearer to store the laces 316 therein.
[0099] FIG. 7(e) is a partial cutaway view illustrating the tongue 314 and the tongue chimney
structure 340. As shown, the tongue 314 may be formed of an outer layer 314a and an
inner layer 314b. In this case, the tongue chimney structure 340 is preferably removably
insertable between the layers 314a,b. Alternatively, the tongue chimney structure
340 may be permanently attached to one or both of the layers 314 a,b.
[0100] FIG. 7(f) is a cross-sectional view along the 7C-7C line of FIG. 7(e). The tongue
chimney structure 340 may be substantially similar to the tongue chimney structure
60' of FIG. 4(a). A material 358, like the material 76, is preferably added to a top
region of the tongue chimney structure 340. The material 358 desirably provides cushioning
for the wearer's leg. The material 358 may include one or more layers of foam, such
as PU, EVA, or latex, any of which may be of varying hardness. The material 358 is
preferably adhered or otherwise affixed to the tongue chimney structure 340. FIG.
7(g) illustrates a cross-sectional view of the tongue chimney structure 340 as it
would look within the boot 300 or other footwear.
[0101] FIG. 8(a) illustrates a boot 400, which includes an outsole 402 and an upper 404.
The outsole 402 may include a tread 406 on the bottom thereof. As shown, a region
408 connects the outsole 402 to the upper 404. The upper 404 includes a body 410 as
well as a collar 412, which defines an opening that enables a wearer to insert his
or her foot into an interior cavity of the upper 404. The upper 404 includes a tongue
414. The body 410 includes laces 416 and eyelets 418 for securing the foot within
the boot 400.
[0102] The body 410 includes a body chimney structure 420 having one or more chimneys 422
having pathways 424 therein. The body chimney structure 420 is preferably same as
the body chimney structure 220, although any chimneys or chimney structures in accordance
with the present invention may be employed with the body 400. The body chimney structure
420 is shown having openings 426 near the ends of the pathways 424 along the collar
412. As will be described in more detail below, the body chimney structure 420 desirably
includes opposing rows of body chimneys 422, with one row facing inward towards the
wearer's foot and the other row facing in the opposite direction. However, a single
row can be used.
[0103] The portion of the body chimney structure 420 along the collar 412 provides venting
to the external climate. Portions of the body chimney structure 420 are shown being
covered by a material 428. The material 428 is preferably leather or a leather/fabric
combination, although other materials may be used. The material 428 may be substantially
waterproof. The material 428 desirably includes one or more vents 430, which each
may include one or more vent holes 430' thereon.
[0104] FIG. 8(b) illustrates a cross-sectional view of the body 410 along the 8A-8A line
of FIG. 8(a). As seen in FIG. 8(b), two rows of body chimneys 422 are provided, with
a first row 432a facing inward towards the wearer's foot and a second row 432b facing
in the opposite direction. The material 428 is preferably positioned adjacent to the
second row 432b. The vents 430 in the material layer 428 may be formed by overlapping
sections of adjacent material layers 428. This is akin to the overlapping scales on
a shark.
[0105] The material layer 428 may comprise multiple layers, including a material 434 that
is a substantially waterproof membrane. More preferably, the material 434 comprises
a substantially waterproof membrane capable of venting moisture from the shoe microclimate
to the outside environment, as described above with respect to the material 334. By
way of example only, the material 434 may comprise expanded polytetrafluroethylene.
As seen in FIG. 8(b), the material 434 preferably lies between the vents 430 and the
body chimney structure 420. The material 434 helps prevent rain and other moisture
from entering the microclimate of the boot 400, while permitting heat and sweat to
vent out of the boot 400. At least some of the openings 426 and the pathways of the
body chimney structure 420 are desirably positioned near the vents 430 to help promote
venting. The material layer 428 may also include a covering 436 such as a mesh overlying
the material 434. The vents 430 are desirably placed in an outermost layer of the
material layer 428.
[0106] The tongue 414 preferably includes a tongue chimney structure 438, as shown in the
exterior view of FIG. 8(c). The tongue chimney structure 438 may be the same as the
tongue chimney structures 230 and 340, although any chimneys and chimney structures
in accordance with the present invention may be employed. One or more tongue chimneys
can be used. While the tongue 414 may incorporate vents similar to the vents 430,
it is more preferable to instead include one or more openings 440 to promote heat
and moisture expulsion from within the boot 400.
[0107] FIG. 8(d) illustrates a cross-sectional view of the tongue chimney structure 438
along the 8B-8B line of FIG. 8(c). In FIG. 8(d), it can be seen that the tongue chimney
structure 438 includes two rows of tongue chimneys 442, with a first row 442a facing
inward towards the wearer's foot and a second row 442b facing in the opposite direction.
However, a single row can be used.
[0108] The first row 442a is desirably covered by a material 444, which may comprise a wicking
material for removing or pulling moisture away from the wearer's skin and/or away
from a sock. The second row 442b is desirably covered by a material 446, which may
be a substantially waterproof membrane. More preferably, the material 446 comprises
a substantially waterproof membrane capable of venting moisture from the shoe microclimate
to the outside environment, such as the material 334 discussed above. The membrane
of the material 446 may include a tricot material, such as a monofilament tricot.
[0109] A covering 448 may optionally overly the material 446. The covering 448 is preferably
a non-wicking material that may be the same material as the covering 338 or the covering
354. The covering 448 preferably underlies the openings 440. An outermost material
layer 450 overlies the covering 448, the material 446, and the tongue chimney structure
438. The openings 440 are formed in the outermost material layer 450. As can be seen
in FIG. 8(d), one or more pathways of the tongue chimney structure 438 are positioned
directly behind an opening 440 to promote venting.
[0110] A gusset 452 may be attached to the tongue 414 adjacent or near to the end of the
tongue chimney structure 438. The gusset 452 may be sewn or otherwise connected at
one end thereof to the outermost material layer 450. The other end of the gusset 452
connects the upper 404 to the tongue 414. The connection or attachment to the upper
404 may be at a height up to and including the collar. The gusset 452 may comprise
any material, preferably a stretchable material. A lining 454 may be placed behind
the gusset 452. The lining 454 preferably comprises a waterproof membrane, with or
without a monofilament tricot. In a preferred embodiment, the lining 454 is a continuation
of the material 446.
[0111] FIG. 8(e) is a partial see-through view of the boot 400 with an outermost portion
of the material layer 428 omitted for clarity. As seen in this figure, the body chimneys
422 of the body chimney structure 420 can cover the most or all of the length of the
body 410 and the collar 412 of the upper 404. Preferably, the body chimneys 422 span
the length from the heel of the foot up to the ball of the foot, and from the footbed
of the boot 400 to the collar 412. The vents 430 may be positioned at any location
along the body chimney structure 420. While not necessary, rows of the vents 430 are
preferably angled with an angle α relative to the pathways of the chimneys 422. The
angle α is preferably between 15° and 75°. More preferably, the vents 430 are generally
or substantially perpendicular to the pathways of the chimneys 422, for example, with
α being at least 60°. The tongue chimney structure 438 is also shown in FIG. 8(e),
wherein the tongue chimneys 442 have pathways running from the toe region of the upper
404 up to the top portion of the tongue 414.
[0112] FIG. 9(a) illustrates a boot 500 that is similar to the boot 300 of FIG. 7(a). The
boot 500 includes an outsole 502 and an upper 504. The outsole 502 may include a tread
506 on the bottom thereof. As shown, a region 508 connects the outsole 502 to the
upper 504. The upper 504 includes a body 510 as well as a collar 512, which defines
an opening that enables a wearer to insert his or her foot into an interior cavity
of the upper 504. The upper 504 includes a tongue 514. The body 510 includes laces
516 and eyelets 518.
[0113] The body 510 includes a body chimney structure 520 having one or more chimneys 522
having pathways 524 therein. The body chimney structure 520 is preferably same as
the body chimney structure 220 described above, although any chimneys and chimney
structures in accordance with the present invention may be employed. The body chimney
structure 520 is shown having openings 526 near the ends of the pathways 524 along
the collar 512. As will be described in more detail below, the body chimney structure
desirably includes opposing rows of body chimneys 522, with one row facing inward
towards the wearer's foot and the other row facing in the opposite direction. A single
chimney or row of chimneys can also be used.
[0114] The portion of the body chimney structure 520 along the collar 512 provides venting
to the external climate. Portions of the body chimney structure 520 are shown being
covered by a material 528. The material 528 preferably comprises PE, although other
materials may be used. The material 528 desirably includes one or more openings 530.
The openings may come in any shape desired, including, but not limited to the substantially
triangular, trapezoidal, and oval shapes presented.
[0115] FIG. 9(b) illustrates a cross-sectional view of the body 510 along the 9A-9A line
of FIG. 9(a). As seen in FIG. 9(b), two rows of body chimneys 522 may be provided,
with a first row 532a facing inward towards the wearer's foot and a second row 532b
facing in the opposite direction. The material 528 is preferably positioned adjacent
to the second row 532b.
[0116] The material 528 may comprise multiple layers; however, unlike the material 328 of
FIG. 7(b), the material 528 does not include a substantially waterproof membrane.
Overlying the exterior structure/PE layer 533 of the material 528 is a covering 534,
such as bug netting. The covering 534 preferably covers material 528 well as the openings
530. One or more of the openings 526 of the body chimney structure 520 are desirably
positioned facing the openings 530 to help promote venting through the covering 534.
[0117] The tongue 514 preferably includes a tongue chimney structure 536, as shown in the
exterior view of FIG. 9(c). The tongue chimney structure 536 may be the same as the
tongue chimney structures 230 or 340, although any chimneys and chimney structures
in accordance with the present invention may be employed. FIG. 7(d) illustrates a
cross-sectional view of the tongue chimney structure 536 along the 9B-9B line of FIG.
9(c). In FIG. 9(d), it can be seen that the tongue chimney structure 536 includes
two rows of tongue chimneys 538, with a first row 538a facing inward towards the wearer's
foot and a second row 538b facing in the opposite direction, although a single tongue
chimney or row of chimneys can be used.
[0118] The first row 538a is desirably covered by a material 540, which may comprise a wicking
material for removing or pulling moisture away from the wearer's skin and/or away
from a sock. As with the body 510 of the upper 504, the tongue 514 need not covered
by a waterproof membrane. Instead, an exterior structure 542 preferably overlies the
tongue chimney structure 536. As seen in FIG. 9(c), the exterior structure 542 may
include one or more openings 544 therein. Additional openings 544' may be disposed
on the tongue vamp 546 below where the tongue chimney structure 536 is positioned.
The exterior structure 542 preferably comprises PE, although other materials may be
used. Referring back to FIG. 9(d), a covering 548 may optionally overly the exterior
structure 542. The covering 548 is preferably the same material as the covering 338
or the covering 354. The covering 548 preferably covers the openings 544 and 544'
as well as the exterior structure 542.
[0119] FIGS. 9(e)-(h) illustrate alternative placement of the body chimneys 32 and tongue
chimneys 34 in a shoe. The view of FIG. 9(e) shows the interior of the body 20, which
may be a removable insert. As seen in FIG. 9(e), the interior of the body 20 may include
one or more regions 545, which may be padded or otherwise cushioned to minimize irritation
of the wearer's foot or leg. For instance, the regions 545 may be oval shaped and
placed about the ankle. In this case, the ankle regions 545 may be recesses in the
chimney structure, padding such as a soft foam material, or a combination of both.
Thus, chafing or irritation of the ankle is avoided.
[0120] FIG. 9(f) illustrates a cutaway of the tongue 26 along line 9C - 9C of FIG. 9(e).
FIGS. 9(g)(1) and 9(g)(2) illustrate the exterior and interior of the tongue 26 of
FIG. 9(e), respectively. FIG. 9(h) illustrates the back/heel portion of the upper
14 with a pair of body chimneys 32 therein. Here, the tongue chimneys 34 are omitted
for the sake of clarity.
[0121] While FIGS. 1-5 illustrated many types of chimneys and chimney structures, and FIGS.
6-9 illustrate boots incorporating some selected chimney structures therein, there
are many other types of chimneys and structures that can be used in accordance with
aspects of the present invention. FIGS. 10 and 11 illustrate two such alternative
chimney types. Specifically, FIGS. 10(a)-(c) illustrate a ridged or waffle-like chimney
structure 600 having numerous individual chimneys 602 providing pathways to vent heat
and moisture. As best seen in FIG. 10(a), the waffle-like chimney structure 600 includes
alternating sets of opposing chimneys 602a and 602b. The side and perspective views
of FIGS. 10(b)-(c) show the chimneys 602 having numerous openings 604 disposed there
along. The openings 604 permit supplemental venting out of the interior microclimate
as heat and moisture are convectively channeled up the chimneys 602. The chimney structure
600 may comprise PE, but any low density foam can be used. Preferably, the PE or other
foam may be compression molded, milled, or fabricated by any other method that exists
now or in future.
[0122] FIG. 11 is an electron micrograph of a reticulated foam structure 620. The reticulated
foam structure 620 may be, for example, PE, PU, EVA, or any foam having an amorphous
structure. The reticulated foam structure can be molded to form chimneys in accordance
with many of the embodiments described above, including, but not limited to the chimneys
illustrated in FIGS. 2-5. Furthermore, the porous structure of the reticulated foam
promotes enhanced venting of moisture out from the shoe.
[0123] The chimneys described in the embodiments above are generally applicable to all manner
of footwear. However, foot coverings designed to snugly fit about the wearer's foot,
such as socks, create special needs that should be addressed in order to effectively
vent heat and moisture. One obvious issue with conformal or form-fitting foot coverings
is the need for comfort. While the chimneys are structures described above may be
used, if the chimney structure is too rigid or firm, it will likely be uncomfortable
to the wearer. However, if the chimney structure is too soft or pliable, the pathways
of the chimneys will collapse and prevent heat and moisture evacuation. Therefore,
the chimney structure should be capable of retaining its venting abilities even after
repeated cleanings.
[0124] FIG. 12(a) illustrates an elasticized chimney structure 700 for use with form-fitting
footwear such as socks or leggings. The elasticized chimney structure 700 has supports
702 connected to one another by braces 704. The supports 702 are preferably substantially
parallel to one another. While shown as elongated cylinders or tubes, the supports
702 may have any other cross-sectional shape. Individual chimneys 706 are formed by
an adjacent pair of the supports 702 and attendant braces 704. One or more chimneys
706 may be provided.
[0125] Heat and/or moisture are vented along the chimneys 706 as seen by the arrows in FIG.
12(a). Covers 708 and/or 710 may be placed on either side of the chimneys 706. The
covers 708 and 710 are preferably formed of an elastic material, for instance, lycra,
mesh, or a fabric with elastic properties. This allows movement, airflow and comfort.
If used, the covers 708 and 710 are preferably connected to the supports 702 on the
outsides of the braces 704.
[0126] FIGS. 12(b) and 12(c) illustrate the elasticized chimney structure 700 in compressed
and stretched positions, respectively. As seen in FIG. 12(b), the braces 704 are preferably
positioned at an angle γ relative to the supports 702. In one alternative, when the
elasticized chimney structure 700 is at rest and not compressed or stretched, the
angle γ is preferably between 22° and 67°. More preferably, at rest, the angle γ is
approximately 45°, such as between 40° and 50°. When compressed, the angle γ may become
close to 90°, for example at least 67°. When stretched, the angle γ may become close
to 0°, for example less than 22°.
[0127] In another alternative shown in FIG. 12(d), the elasticized chimney structure 700
may be at rest in a substantially compressed state, wherein the angle γ is preferably
less than 37°. In the partially stretched state of FIG. 12(e), the angle γ may be
between 30° and 75°. In the fully stretched state shown in FIG. 12(f), the braces
704 may be mostly or completely perpendicular to the supports 702, and the angle γ
may be between 75° and 90°.
[0128] FIGS. 12(g) and 12(h) illustrate perspective and top views of the elasticized chimney
structure 700 with the covers 708 and 710 omitted. FIG. 12(i) illustrates a single
support 702 with alternating columns of braces 704a,b thereon. FIG. 12(j) illustrates
the elasticized chimney structure 700 along the 12A-12A line of FIG. 12(g). Heat and/or
moisture are vented along the chimney 706 around the braces 704 as seen by the arrow
in the figure.
[0129] FIG. 13(a) illustrates a sock 720 incorporating a chimney structure such as the chimney
structure 700, therein. As seen in the figure, the sock 720 includes a sock body 722
and a collar 724 attached thereto. The sock body 722 includes a heel region 726, a
sole region 728, and a toe region 730, and may include an outer covering 732 over
the chimney structure. The outer covering 732 may comprise the cover 708 or 710 discussed
above. The outer covering 732 may comprise a waterproof material. Optionally, an inner
lining (not shown) may overlie the interior surface of the chimney structure 700 and
may directly contact the foot. In this case, the inner lining preferably permits heat
and moisture to escape away from the foot and into the chimneys 706.
[0130] The collar 724 includes an opening 734 at a first end thereof for receiving the foot.
The collar 724 is preferably formed of a breathable material which can be flexible
and/or elastic. The height of the collar 724 and/or the height of the body 722 may
vary depending on the type of sock or legging, e.g., crew sock, running sock, skiing
sock, tube sock. By way of example only, the height of the collar 724 may be on the
order of 40 mm and the height of the body may be on the order of 90 mm. The collar
724 typically is positioned at or above the ankle. The chimneys 706 of the chimney
structure 700 desirably extend at least partly into the collar 724, and may extend
all the way to the top of the collar 724.
[0131] Optionally, the sock 720 may include a scree skirt 736. The scree skirt 736 may be
disposed at or near the wearer's ankle, and may delineate the transition between the
sock body 722 and the collar 724. When worn in conjunction with a shoe, such as a
climbing shoe, the scree skirt 736 helps prevent rocks, dust, and other debris from
entering the shoe and causing discomfort to the wearer. The scree skirt 736 may include
a pocket 738 to hold the laces of the shoe. The pocket is preferably a rubberized
stretch pocket that can be formed using mesh or other suitable materials.
[0132] FIG. 13(b) illustrates the sock 720 with the outer covering 732, scree skirt 736
and collar 724 in outline form. Here, the elasticized chimney structure 700 is shown
as being generally arced, angled, or "L" shaped, although the elasticized chimney
structure 700 may conform to any shape of the wearer's foot and/or leg. The elasticized
chimney structure 700 may be open at the toe region 730 of the sock 720. Alternatively,
the chimney structure 700 may extend fully into the toe region 730, and may partially
or completely surround the wearer's toes.
[0133] FIG. 13(c) illustrates an exploded view of the chimney structure 700 and adjacent
components. An inner lining 740 may be disposed between the chimney structure 700
and the wearer's foot. If used, the inner lining 740 preferably includes one or more
layers of wicking material for removing sweat from the foot. An outer lining 742 may
be disposed opposite the inner lining on the other side of the chimney structure remote
from the foot. The outer lining may be the same or a different layer than the outer
covering. The outer lining may include one or more layers of material. For example,
a first layer 744 immediately adjacent to the chimney structure may comprise a PU
film. A second layer 746 covering the first layer may comprise a non-wicking jersey
material such as LYCRA
® brand synthetic fiber material.
[0134] The chimney structure 700, inner lining 740 and/or outer lining 742 may be integral
with or removable from the sock or legging 720. For example, in one embodiment, the
chimney structure 700, the inner lining 740 and the outer lining 742 are all integrally
formed as part of the sock 720. In another embodiment, the outer covering 732 comprises
the outer lining 742, and the chimney structure 700 and the inner lining 740 are removably
insertable into the outer covering 732. In this case, the chimney structure 700 and
the inner lining 740 may be integrally formed or may comprise separate components.
[0135] FIG. 13(d) illustrates an exemplary cutaway view from the collar to the heel region
along the 13A-13A line of FIG. 13(a). As seen in this view, the inner lining 740 is
positioned on one side of the chimney structure 700 and the collar material and heel
region material are positioned on the other side of the chimney structure 700. Thus,
in this example, the outer lining 742 may include multiple sections of material, which
may include different materials in the collar 724, the heel region 726, the sole region
728, and/or the toe region 730. Finally, the arrows in FIG. 13(e) illustrate how heat
and/or moisture are directionally vented out of the sock 720 by the chimneys 706.
[0136] Many different chimneys and chimney structures have been illustrated and described
above. These structures should be designed so that the pathways therein provide efficient
evacuation from the shoe microclimate. The effectiveness of the pathways is tied to
their cross-sectional area. While it might be assumed that the larger the cross-sectional
area the better, in reality one cannot design footwear having arbitrarily large chimneys,
as this may impinge on the structural characteristics of the footwear.
[0137] In order to determine suitable chimney sizes, various laboratory tests were performed.
Testing was conducted using SATRA standard tests. Specifically, the AMM testing discussed
above was performed using SATRA Test Method 376dV. The tests were conducted on footwear
implementing chimneys in accordance with aspects of the invention. Testing compared
the effects of the chimneys in various footwear structures against a control structure
without chimneys. Testing simulated the generation of heat and sweat by the foot in
a shoe, quantifying the distribution of sweat output by absorption (e.g., absorption
by the skin, sock, footbed, shoe upper, etc.), evaporation, and energy usage.
[0138] Experiments were carried out to examine effect of chimneys on moisture management.
These experiments were also used to characterize chimney geometry in an effort to
optimize performance. Lastly, testing was designed to look at the performance of different
fabrication techniques and the effect of chimney hardness on moisture management performance.
[0139] Moisture management testing was conducted under the same laboratory conditions discussed
above with regard to Tables 5 and 6. The external environment was maintained at 20°
C and 65% relative humidity. A simulated foot was used to conduct the test. The simulated
foot was covered in a simulated skin membrane. A sock having the composition 42% cotton,
14.5% spandex, 21.5% nylon, and 22% polyester was placed on simulated foot and inserted
in shoe under test. The foot was maintained at a temperature of 34°C with a nominal
sweat rate of 5mL/hr. A constant airspeed of 2 m/s was maintained across the shoe
during the test.
[0140] The chimney moisture management test compared five different hiking shoes. One of
the shoes was a commercial off the shelf hiking shoe. Another shoe was fabricated
by taking the commercial hiking shoe and removing the lining package in the upper.
An EVA foam insert without chimneys replaced the lining package. The other three shoes
employed EVA foam inserts with the open-ended rectangular chimney structures discussed
above with regard to FIG. 5(b). The chimney inserts were used in place of the non-chimney
foam insert. Each of the three chimney structures had a depth of 4mm. The widths in
the respective chimney structures were 4mm, 8mm, and 12mm. FIG. 14(a) illustrates
the three chimney structure inserts and the shoe they were used with. FIG. 14(b) illustrates
another view of the chimney inserts. FIGS. 14(c)-(e) show chimney structure inserts
within the shoe. Table 7 illustrates the test results.
Table 7:
Shoe Description |
Skin Gain |
Sock Gain |
Shoe Gain w/Footbed |
Footbed Uptake |
Evaporated Loss |
Energy Used |
(g) |
(g) |
(g) |
(g) |
(g) |
(kJ) |
Commercial Shoe |
0.69 |
4.17 |
6.81 |
1.58 |
3.34 |
48.6 |
EVA Insert w/o chimneys |
1.33 |
6.93 |
3.66 |
0.93 |
3.08 |
43.7 |
EVA Insert w/16 mm2 chimneys |
1.18 |
5.69 |
4.06 |
1.44 |
4.07 |
47.2 |
EVA Insert w/32 mm2 chimneys |
0.59 |
4.19 |
4.06 |
1.43 |
6.16 |
54.5 |
EVA Insert w/48 mm2 chimneys |
0.60 |
3.50 |
3.65 |
1.28 |
6.95 |
58.7 |
[0141] Data showed an increase in ventilation performance as chimney pathway cross section
increased from 0 mm
2 to 48 mm
2. For example, as compared to the commercial shoe, the shoe having pathways 8 mm wide
and 4 mm deep (32 mm
2) was found to create approximately an 84.4% increase in the evaporative moisture
loss. Similarly, compared to the commercial shoe, the shoe having pathways 12mm wide
and 4 mm deep (48 mm
2) was found to create more a 108% increase in the evaporative moisture loss. Notably,
in the commercial shoe the moisture was not absorbed by the synthetic skin or the
sock to the degree found in the insert without chimneys or the insert having the 4mm
x 4mm structure. However, in the commercial shoe test a substantial amount of moisture
was absorbed by the shoe and by the footbed itself. Furthermore, the control shoe
having the EVA insert without chimneys performed slightly worse than the commercial
shoe, with an evaporation loss on the order of 8% worse than the commercial shoe.
[0142] Overall, it is clearly seen that the larger area chimneys provided significant and
substantial improvement in the microclimate of shoes when compared against the commercially
available shoe. However, even the smallest chimney structure produced at least a 21%
increase in evaporation loss as compared to the commercial shoe. Thus, the testing
shows that small, medium and large size chimneys can greatly improve moisture evaporation
[0143] While the use of chimneys in footwear and foot coverings is important to regulate
the microclimate, how the chimneys are made and what they are made from can impact
their performance. It has been determined that common manufacturing techniques may
be used for chimney construction.
[0144] Multiple potential fabrication techniques were analyzed to determine if there was
a difference in performance. These fabrication techniques included molded fabric with
poured PU, compression molded EVA with a sprayed flocking, and compression molded
EVA with a fabric laminate. Boots fabricated using the aforementioned techniques were
tested in accordance with the SATRA AMM test. Table 8 illustrates these test results.
Table 8:
Boot Description |
Skin Gain |
Sock Gain |
Shoe Gain w/Footbed |
Footbed Uptake |
Evaporated Loss |
Energy Used |
(g) |
(g) |
(g) |
(g) |
(g) |
(kJ) |
Molded fabric with poured PU |
0.41 |
3.97 |
4.97 |
1.38 |
5.65 |
56.6 |
Compression molded EVA with a sprayed flocking |
0.57 |
4.57 |
5.42 |
1.34 |
4.45 |
54.4 |
Compression molded EVA with a fabric laminate |
0.71 |
4.78 |
4.35 |
1.40 |
5.17 |
56.6 |
[0145] All of the fabrication techniques demonstrated substantial improvement over a conventional
production shoe without chimneys, as shown above with regard to Table 7. In particular,
the molded fabric with poured PU demonstrated the greatest performance increase in
evaporated moisture loss, approximately 69% increase over production footwear. The
compression molded EVA with sprayed flocking had approximately a 33% increase in moisture
loss, and the compression molded EVA with fabric laminate had nearly a 55% increase.
[0146] In addition to chimney materials, the effect of chimney hardness on moisture management
performance was also examined in view of durability and comfort. Different footwear
were created and tested with finished chimney hardness chosen as 10, 20, and 30 on
the Asker C scale. Table 9 illustrates the chimney hardness moisture accumulation
and evaporation test results.
Table 9:
Chimney Hardness |
Skin Gain |
Sock Gain |
Shoe Gain w/Footbed |
Footbed Uptake |
Evaporated Loss |
Energy Used |
(g) |
(g) |
(g) |
(g) |
(g) |
(kJ) |
10 |
0.85 |
4.79 |
4.67 |
1.72 |
4.69 |
52.1 |
20 |
0.72 |
4.44 |
4.15 |
1.69 |
5.70 |
51.0 |
30 |
0.75 |
4.63 |
4.43 |
1.78 |
5.20 |
51.3 |
[0147] In each test, the evaporative loss was substantially greater than in the commercial
shoe of Table 7. Although not statistically significant in terms of evaporative moisture
loss, chimneys with an Asker C hardness on the order of 20 offered an improvement
over similar chimneys with different hardness. In one preferred example includes chimneys
having a hardness of at least 15-20 Asker C. In another example, the chimneys desirably
have a harness of between 25 and 35 Asker C.
[0148] As discussed earlier, chimneys in accordance with the present invention have proven
to provide superior ventilation, allowing warm air to rise out of the boot and carry
moisture away. In general, a variety of chimney widths can be used. Construction type,
materials, footwear design and end use play a role in the optimal placement and dimensions
of channels. Testing has proven that evaporation and the removal of moisture increases
as chimney width increases. This results in dryer socks and skin and, in general terms,
increased comfort. Chimneys may be incorporated into all types of footwear, including
but not limited to protective footwear, in varying geometries and placements.
[0149] Channels incorporated into the tongue area of a boot or other shoe may be wider than
channels incorporated into the heel area. One reason is that there are more sweat
glands located on the top of the foot than in the heel. Another reason is that air
circulation from the medial and lateral surface areas of the foot benefit greatly
from placement of wider channels on the tongue to allow for enhanced overall evaporation
of moisture.
[0150] A variety of materials can be used for construction of the chimneys such as PU and
EVA foams as well as polymer gels. Additionally, a variety of liner materials can
be used to enhance the moisture management, the heat transfer process and/or provide
additional insulation, comfort or protection. Synthetic materials such as spandex,
nylon, polyester, polypropylene or natural fibers such as wool can be used as lining
material. In most cases, the traditional materials used for footwear manufacturing
do not need to be altered in order to incorporate the current invention. The only
requirement is that one of the layers includes a material that can be molded into
a shape that forms a chimney. Moldable materials, such as moldable foams and plastics
commonly used in contemporary footwear, may be utilized.
[0151] As discussed above, any type of footbed may be used in accordance with the chimneys
of the present invention. However, it can be desirable in many situations to utilize
specialty footbeds to enhance the convection and vent heat and moisture away from
the foot. FIGS. 15(a)-(f) illustrate an exemplary footbed 800 that may be used in
conjunction with the chimneys of the present invention. As seen in the top view of
FIG. 15(a), the footbed 800 includes a toe region 802, a sole region 804 and a heel
region 806.
[0152] As seen in the side view of FIG. 15(b), the regions of the footbed 800 are preferably
formed with multiple layers. Bottom plate 808 preferably contacts the bottom of the
inside of a shoe, and may rest on a midsole, an insole or the outsole depending upon
the construction of the shoe. The bottom plate 808 is desirably formed of TPU, although
other materials or combinations of materials can be used.
[0153] A heel cup 810 is preferably disposed over the bottom plate 808 at least along the
heel region 806. The heel cup 810 may extend forward into the sole region 804. The
heel cup 810 may comprise EVA foam or other material. The bottom plate 808 and the
heel cup 810 may be cemented and compression molded together during fabrication.
[0154] Overlying the bottom plate 808 and the optional heel cup 810 is an airflow chassis
812. The airflow chassis 812 preferably comprises a mesh-like material such as nylon,
plastic, polyester, etc. The porous structure of the airflow chassis 812 enables heat
and moisture to vent away from the foot. The airflow chassis 812 may include a top
liner 814, a bottom liner 816, or both. Preferably, the hardness of the material of
the airflow chassis 812 is between 40-70 on the Asker C scale. More preferably, the
hardness is between 50-55 on the Asker C scale. The airflow chassis 812 may be cemented
or otherwise affixed to the bottom plate 808 and the heel cup 810.
[0155] As best seen in the bottom view of FIG. 15(c), the bottom plate 808 may include one
or more longitudinal openings 818, which may be in the toe region 802, the sole region
804, and/or the heel region 806. The bottom plate 808 may also include one or more
transverse openings 820, which may intersect the longitudinal opening 818. Also, it
can be seen in this figure that the airflow chassis 812 preferably includes a lip
822 which overhangs the bottom plate 808.
[0156] The longitudinal opening 818, the transverse openings 820 and the lip 822 all help
to promote movement of air away from the bottom of the foot. For example, FIG. 15(d)
illustrates a cross-sectional view of the footbed 800 with a foot placed thereon.
The arrows in the cross-sectional view illustrate how air is expelled outwards towards
the sides of the footbed 800. When used in combination with chimney structures, the
footbed 800 is capable of directing hot, moist air near the bottom of the foot towards
the chimney pathways.
[0157] Returning to FIG. 15(c), the heel cup 810 desirably includes exterior perforations
824. The exterior perforations 824 preferably extend around the perimeter of the heel
cup 810. Interior perforations 826 may also be provided in the heel cup 810. As seen
in the cutaway view of FIG. 15(e) along the 15A-15A line of FIG. 15(c), the interior
perforations 826 preferably extend completely through the heel cup 810 and the bottom
plate 808 as well. The exterior and interior perforations 824, 826 further enable
the footbed 800 to transfer hot, moist air away from the foot.
[0158] It should be understood that while the footbed 800 is preferably used in combination
with chimneys and chimney structures as disclosed herein, it is possible to utilize
the footbed 800 without chimneys. In this case, the footbed 800 will provide the benefit
of air circulation under and around the foot. The footbed 800 could be used with footwear
that may not lend itself to the use of chimneys. By way of example only, open-toed
sandals or similar structures may not derive substantial benefit from large chimney
structures; however, the footbed 800 would still be quite suitable in this situation.
It should also be understood that the footbed may be removable or permanently secured
to an article of footwear.
[0159] The present invention was developed, in part, to enhance the natural processes of
sweating and evaporation that the body uses to regulate temperature, thus breaking
the traditional, unsuccessful compromise that exists today in conventional footwear.
By incorporating chimneys in accordance with various embodiments of the invention
in the sidewalls and tongue portions of the footwear, or in the foot covering worn
with or without such footwear, these natural processes are effectively promoted to
ensure a more consistent range of temperature, moisture and comfort. Testing of various
embodiments of the invention has proven that chimneys are an effective means of temperature
regulation without interfering with the integrity of the particular protective characteristics
of the shoe, such as waterproofing, insulation, durability, support, etc. An air permeable
footbed, for example a mesh footbed, can also be used in conjunction with the chimneys
and structures discussed herein to further promote airflow around the foot.
[0160] It can be seen that chimneys of various geometries can effectively vent heat and
moisture from footwear. The different geometries can be mixed and matched within a
given shoe to optimize ventilation and to enhance comfort. By way of example only,
the chimneys may be squared, rounded, rectangular or mixed. The chimneys may be open
on one or both sides. They may be substantially vertical, or angled, arched, s-shaped,
curved, etc. A covering, if used, can be a breathable, wicking material, such as mesh.
Depending on construction type, footwear design, materials, and comfort requirements,
an open channel may be suitable, or a covered channel may be preferred. Alternatively,
there may be a combination of open and covered chimneys in the same article of footwear.
[0161] It is possible to replace a chimney or a chimney structure with another chimney or
chimney structure. For instance, the chimney or chimney structure may be a removable
insert, providing interchangeability depending on the type of activity, the external
environment, etc. For example, the wearer may replace a chimney or chimney structure
for cleaning. Alternatively, the in shoe chimney or chimney structure may be exchanged
for another chimney or chimney structure having different characteristics or parameters.
In this case, the wearer could select the chimney or chimney structure to have a particular
cross-sectional area, shape, material, etc. based upon environmental conditions, a
sport or activity, or a personal preference.
[0162] Footwear can be constructed in such a way as to provide an upper and bottom that
can receive a variety of inserts depending on activity and climate requirements. By
way of example only, a hiking boot with a leather or synthetic upper that has been
combined with a breathable, waterproof membrane such as a hydrophobic PTFE may be
purchased with two channel inserts. One insert can be used for warm weather and is
made of low density foam with perforations for ventilation (e.g., holes or slits).
The foam may be laminated with a lightweight breathable material (e.g., polyester,
spandex, nylon, polypropylene or blend) that is appropriate given the climate requirements
and promotes heat and moisture transfer/evaporation that is needed to assist in regulating
the microclimate within the shoe. The second insert may be preferable in cold, wet
weather conditions and can be made of foam having a higher density than the first
insert. This foam insert can be laminated to an insulating material such as wool,
fleece, and/or a non-woven batting material to provide insulation from the external
climate while the chimneys regulate heat and moisture transfer/evaporation to provide
a more constant and comfortable internal microclimate.
[0163] The chimneys and chimney structures disclosed herein may be incorporated into all
manner of footwear, such as shoes, and foot coverings such as socks and leggings,
and can also be incorporated into apparel such as gloves, pants, shirts, jackets,
hats, helmets, etc. PU chimneys may be incorporated into the sock material, for example
placed between two layers of a wicking breathable material such as polyester, which
allows for the evaporative moisture loss enhanced by convection. In this case, the
sock could be worn with conventional shoes, or could also be worn with shoes incorporating
chimney structures themselves.
[0164] A wide variety of materials can be used to achieve the chimneys of the present invention.
Materials such as reticulated foam may be used to form chimneys, and the porous structure
can enhance ventilation. The materials can be molded and formed appropriately to the
design of the footwear. For example, foam materials can be exposed in surface areas
on the upper and/or the top opening of the shoe remains open or exposed to allow for
ventilation of heat.
[0165] Although the invention herein has been described with reference to particular embodiments,
it is to be understood that these embodiments are merely illustrative of the principles
and applications of the present invention. It is therefore to be understood that numerous
modifications may be made to the illustrative embodiments and that other arrangements
may be devised without departing from the spirit and scope of the present invention
as defined by the appended claims. By way of example only, while different embodiments
described above illustrate specific features, it is within the scope of the present
invention to combine or interchange different features among the various embodiments
to create other variants. Any of the features in any of the embodiments can be combined
or interchanged with any other features in any of the other embodiments. The invention
can be used in combination with new or uncommon materials in addition to the materials
specified above, as well as with new or uncommon manufacturing techniques.
INDUSTRIAL APPLICABILITY
[0166] The present invention enjoys wide industrial applicability including, but not limited
to, footwear having chimney structures for ventilating the wearer's feet, which can
be used in all manner of shoes and in a wide variety of activities and conditions.
1. An article of footwear, comprising:
an outsole;
an upper attached to the outsole, the upper defining a cavity for receiving a wearer's
foot; and
a chimney structure comprising a plurality of chimneys defining pathways for moving
heat or moisture from within the cavity to outside the article of footwear.
2. The article of footwear of claim 1, wherein the chimney structure is disposed along
a side panel of the upper.
3. The article of footwear of claim 1, wherein the chimney structure comprises a plurality
of channels arranged in a row along the upper.
4. The article of footwear of claim 1, wherein the chimney structure comprises two rows
of chimneys adjacent to one another, the pathways of a first one of the rows facing
the cavity and the pathways of a second one of the rows facing away from the cavity.
5. The article of footwear of claim 1, wherein the upper includes a collar and a body
connected to the collar, the body defining the cavity and the collar providing an
opening to the cavity, wherein selected pathways of at least some of the chimneys
each have a first end disposed along the upper below the collar and a second end disposed
along the collar.
6. The article of footwear of claim 1, wherein the movement of heat or moisture occurs
by convection.
7. A chimney structure for convection of heat or moisture out of the microclimate of
an article of footwear, the chimney structure comprising a plurality of chimneys,
each of the chimneys including a first end open to receive the heat or moisture from
an interior of the article of footwear and a second end open to move the heat or moisture
from within the interior to outside the article of footwear.
8. The chimney structure of claim 7, wherein the chimneys are removably insertable into
the article of footwear.
9. The chimney structure of claim 7, wherein each of the chimneys has a cross-sectional
area of at least 16 mm2.
10. An article of footwear, comprising:
an outsole;
an upper attached to the outsole, the upper including an outer material defining a
cavity for receiving a wearer's foot and a collar region for insertion of the wearer's
foot into the cavity; and
a plurality of chimneys arranged in a row along an interior side of the outer material
for moving heat or moisture from within the cavity to outside the article of footwear.
11. The article of footwear of claim 10, further comprising a plurality of elongated vents
formed by overlapping sections of the outer material, the plurality of elongated vents
intersecting with the plurality of chimneys to promote movement of the heat or moisture
from within the cavity to outside the article of footwear.
12. The article of footwear of claim 10, further including a footbed having a porous chassis
operable to permit airflow from underneath the wearer's foot into the row of chimneys.
13. An article of footwear, comprising:
an outsole;
an upper attached to the outsole, the upper defining a cavity for receiving a wearer's
foot and including a tongue; and
a chimney structure comprising means for moving heat or moisture from within the cavity
to outside the article of footwear.
14. The article of footwear of claim 13, wherein the chimney structure is disposed along
the tongue.
15. The article of footwear of claim 14, wherein the chimney structure comprises a chimney
having a pair of sidewalls and an endwall connecting the sidewalls.
16. The article of footwear of claim 15, wherein the chimney has a first opening at a
toe region of the upper and a second opening along an upper portion of the tongue,
whereby heat and moisture are vented out from the toe region.
17. The article of footwear of claim 15, wherein the chimney has a first opening at an
instep region of the upper and a second opening along an upper portion of the tongue,
whereby heat and moisture are vented out from the instep region.
18. The article of footwear of claim 14, wherein the chimney structure comprise a row
of chimneys.
19. An article of footwear, comprising:
an outsole;
an upper attached to the outsole, the upper defining a cavity for receiving a wearer's
foot and including a tongue; and
a chimney disposed in the tongue to enable movement of heat and moisture from within
the cavity to outside the article of footwear.
20. A chimney structure for ventilating the microclimate of an article of footwear including
a tongue, the chimney structure comprising:
a chimney disposed in the tongue to move heat or moisture from within an interior
region of the article of footwear to outside the article of footwear, the chimney
including a pair of sidewalls and an endwall disposed between the pair of sidewalls,
the sidewalls and the endwall defining a pathway therealong;
whereby the heat or moisture is moved through the pathway from the interior region
to outside the article of footwear.
21. The chimney structure of claim 20, further comprising a covering substantially enclosing
the chimney, the covering including a pocket for storing laces of the article of footwear.
22. The chimney structure of claim 20, further comprising a cushioning material disposed
at a top region of the chimney structure facing the interior region of the article
of footwear.
23. A form fitting foot covering, comprising:
a heel region;
a toe region;
a sole region disposed between the heel region and the toe region;
a collar region providing an opening for insertion of a wearer's foot into the heel,
toe and sole regions of the foot covering; and
a chimney structure comprising a chimney for moving heat or moisture from within the
foot covering out of the collar.
24. The foot covering of claim 23, wherein the chimney structure comprises a plurality
of chimneys, each of the chimneys including a pair of elongated supports and braces
connecting the pair of elongated supports.
25. The foot covering of claim 24, further comprising a covering disposed on a first side
of the pair of elongated supports.
26. The foot covering of claim 25, wherein the covering includes a pair of coverings,
a first one of the coverings being disposed on the first side of the pair of elongated
supports and a second one of the coverings being disposed on a second side of the
pair of elongated supports opposite the first side.
27. The foot covering of claim 24, wherein each of the chimneys is flexible and the braces
are movable from an at-rest position to a stretched position or a compressed position
as the foot moves.
28. The foot covering of claim 23, wherein moving the heat or moisture occurs by convection.
29. A foot covering adapted for covering a wearer's foot, comprising:
a body having a heel region, a toe region, and a sole region disposed between the
heel region and the toe region;
a collar region connected to the body for insertion of a wearer's foot into body;
a plurality of chimneys providing movement of heat or moisture from within the body
out of the collar; and
a skirt section formed at the connection of the body and the collar;
whereby the skirt section is adapted to prevent debris from entering a shoe when the
foot covering is positioned therein.
30. The foot covering of claim 29, wherein the skirt section includes a pocket to receive
the laces of the shoe.
31. A ventilated article of clothing, comprising:
a covering for enclosing a portion of a wearer's body; and
a chimney structure including a plurality of chimneys that vent heat or moisture by
convection from a first region within the covering to a second region outside of the
covering.
32. The ventilated article of clothing of claim 31, wherein the article of clothing comprises
a sock.
33. The ventilated article of clothing of claim 31, wherein the article of clothing comprises
a glove.