U.S. patent application number 11/743478 was filed with the patent office on 2008-11-06 for extruded cushioning insole.
Invention is credited to James R. Fischer.
Application Number | 20080271339 11/743478 |
Document ID | / |
Family ID | 39938525 |
Filed Date | 2008-11-06 |
United States Patent
Application |
20080271339 |
Kind Code |
A1 |
Fischer; James R. |
November 6, 2008 |
Extruded Cushioning Insole
Abstract
The invention is an extruded cushioning insole for footwear. The
insole disperses the weight of an individual more evenly across the
surface of their foot and reduces the impact forces on the feet
when walking, running or jumping. The insole is integrally extruded
in a one-piece construction. One insole embodiment includes a
flexible upper pad with a plurality of downwardly extending tubes
that each form a collapsible internal chamber. Another insole
embodiment has a solid main body with a flat upper surface and a
contoured lower surface formed by thinner and thicker regions of
the insole. Another insole embodiment has a flat upper surface and
a convex lower surface formed by a collapsible internal disc-shaped
chamber. The convex surface is generally flat when compressed.
Inventors: |
Fischer; James R.;
(Sheboygan, WI) |
Correspondence
Address: |
Jeffrey S. Sokol;COOK & FRANKE S.C.
660 East Mason Street
Milwaukee
WI
53202
US
|
Family ID: |
39938525 |
Appl. No.: |
11/743478 |
Filed: |
May 2, 2007 |
Current U.S.
Class: |
36/29 ; 12/146R;
36/44 |
Current CPC
Class: |
A43B 17/02 20130101;
A43B 13/206 20130101; A43B 13/181 20130101 |
Class at
Publication: |
36/29 ; 12/146.R;
36/44 |
International
Class: |
A43B 13/20 20060101
A43B013/20; A43B 13/38 20060101 A43B013/38 |
Claims
1. An extruded cushioning insole for footwear to provide cushioning
for a human foot with a bottom surface when a placing weight on
that foot, the footwear having a sole and an upper that forms the
sidewalls of the footwear, said extruded cushioning insole
comprising: a flexible pad having substantially planar and parallel
upper and lower surfaces and a perimeter, said pad having a
substantially uniform thickness of about 0.06 inch, said perimeter
being shaped to supportingly receive the entire bottom surface of
the human foot; a plurality of resilient tubes extending from said
lower surface of said pad, said tubes being substantially parallel,
uniformly spaced and extending continuously along said lower
surface of said pad, each of said tubes having a deformable wall
forming a channel with opposed ends; said pad and tubes being
integrally extruded from flexible PVC plastic to form a cushioning
insole with a single piece construction, said cushioning insole
having a perimeter adapted for placement inside the footwear, said
tubes resting on the sole of the footwear and said perimeter of
said insole engaging the sidewalls of the footwear to
longitudinally and laterally align said insole within the footwear,
said tubes and deformable wall being moveable between extended and
compressed positions, said flexible pad substantially conforming to
the shape of the bottom surface of the foot when in said compressed
position; and, wherein said cushioning insole distributes static
forces more evenly across the bottom surface of the foot when in
said compressed position, and reduces dynamic forces between the
foot and the footwear when placing weight on the foot to move said
insole from said extended position to said compressed position,
said tubes being resiliently biased to return to said extended
position within about 0.25 second when the weight is removed from
the foot and insole, said insole resiliently and fully returning to
said extended position from said compressed position during the
normal life of the footwear.
2. The extruded cushioning insole of claim 1, and wherein each of
said deformable walls extends directly from said lower surface of
said flexible pad.
3. The extruded cushioning insole of claim 2, and wherein each of
said channels is filled with ambient air.
4. The extruded cushioning insole of claim 3, and wherein said
deformable wall of each of said tubes includes spaced side wall
portions joined by a bottom wall portion, said bottom wall portion
being spaced from said lower surface of said pad to form said open
channel.
5. The extruded cushioning insole of claim 4, and wherein each of
said tubes is spaced apart from its adjacent tube.
6. The extruded cushioning insole of claim 5, and wherein each of
said tubes is spaced apart from its adjacent tubes about 0.18 inch,
has a height of about 0.25 inch and a width of about 0.38 inch, and
said deformable wall has a thickness of about 0.05 inch, and said
flexible PVC plastic has a Clash-Berg modulus of rigidity of about
18,000 psi.
7. The extruded cushioning insole of claim 6, and wherein each of
said tubes retains an air gap between its said bottom wall portion
and said pad when in said compressed position and supporting a 300
pound person.
8. The extruded cushioning insole of claim 4, and wherein adjacent
tubes share a common side wall portion.
9. The extruded cushioning insole of claim 8, and wherein said
bottom wall portion is arcuate when said insole is in said extended
position.
10. The extruded cushioning insole of claim 9, and wherein said pad
has a thickness of 0.03 inch, and each of said tubes has a height
of about 0.15 inch and a width of about 0.22 inch, and said
deformable wall has a thickness of about 0.03 inch, and aid
flexible PVC plastic has a Clash-Berg modulus of rigidity of about
1,000 psi.
11. The extruded cushioning insole of claim 8, and wherein said
bottom wall portion is flat when said insole is in said extended
position, and said flat bottom wall portions combine to form a
flexible lower layer parallel to said flexible pad.
12. The extruded cushioning insole of claim 3, and wherein said
deformable wall forms a substantially circular tube with a
substantially circular cross-sectional shape.
13. The extruded cushioning insole of claim 1, and wherein said
upper surface of said pad has a hardness of about 55 to 75
durometers.
14. The extruded cushioning insole of claim 1, and further
comprising a separate arch support portion, said cushioning insole
and said arch support having spaced apart tubes and matching
cross-sectional shapes, said arch support being inverted with its
tubes matingly receiving said tubes of said cushioning insole.
15. The extruded cushioning insole of claim 1, and wherein an
interior area of said extruded cushioning insole is removed to
reduce pressure on the foot in that said interior area.
16. The extruded cushioning insole of claim 1, and wherein said
upper surface of said pad has upwardly extending gripping ridges,
and is moisture and odor resistant.
17. The extruded cushioning insole of claim 1, and wherein said
extruded cushioning insole has demarcations for trimming said
perimeter to adapt said insole to fit snuggly inside the
footwear.
18. An extruded cushioning insole for footwear to provide
cushioning for a human foot with a bottom surface when a placing
weight on that foot, the footwear having a sole and an upper that
forms the sidewalls of the footwear, said extruded cushioning
insole comprising: a flexible pad having a main body, a planar
upper surface, a contoured lower surface and a perimeter, said main
body having toe, ball, arch, rearward, and heel regions, and said
perimeter being shaped to supportingly receive the entire bottom
surface of the human foot; said toe and rearward regions being
formed by said main body, and each having a substantially uniform
thickness of about 0.18 inch; said arch region having a first built
up portion extending from said main body, said arch region having a
substantially uniform thickness of about 0.28 inch; said heel
region having a second built up portion extending from said main
body, said heel region having a substantially uniform thickness of
about 0.24 inch; said main body and said first and second built up
portions being integrally extruded from flexible PVC plastic to
form a cushioning insole with a single piece construction, said
perimeter adapted for placement inside the footwear to engage the
sidewalls of the footwear to longitudinally and laterally align
said insole within the footwear, said insole being moveable between
at rest and compressed positions, said flexible pad substantially
conforming to the shape of the bottom surface of the foot when in
said compressed position; and, wherein said cushioning insole
distributes static forces more evenly across the bottom surface of
the foot when in said compressed position, and reduces dynamic
forces between the foot and the footwear when placing weight on the
foot to move said insole from said at rest position to said
compressed position, said cushioning insole being resiliently
biased to return to said at rest position within about 0.25 second
when the weight of the foot is removed from the insole, said insole
resiliently and fully returning to said extended position from said
compressed position during the normal life of the footwear.
19. The extruded cushioning insole of claim 18, and wherein said
FPVC plastic has a Clash-Berg modulus of rigidity of about 1,000
psi.
20. The extruded cushioning insole of claim 19, and wherein said
ball of foot region has a third built up portion extending from
said main body, said built up portion of said ball of foot region
being sloped between said arch and toe regions.
21. The extruded cushioning insole of claim 19, and wherein said
upper surface of said pad has a hardness of about 55 to 75
durometers.
22. The extruded cushioning insole of claim 21, and wherein said
upper surface of said pad has upwardly extending gripping
ridges.
23. The extruded cushioning insole of claim 18, and wherein said
extruded cushioning insole has demarcations for trimming said
perimeter to adapt said insole to fit snuggly inside the
footwear.
24. The extruded cushioning insole of claim 18, and wherein an
interior area of said extruded cushioning insole is removed to
reduce pressure on the foot in that said interior area.
25. An insole extrusion and forming process for making an integral,
plastic insole for placing within footwear for a human foot having
a bottom surface, the footwear having a sole and an upper that
forms the sidewalls of the footwear, said insole extrusion and
forming process consisting of the following steps: providing an
extruder, cooling bath, puller, punch press and wind-up roller,
said extruder having a material loading trough and a die; loading
FPVC plastic into said trough of said extruder; heating said FPVC
plastic to molten condition; extruding said molten FPVC plastic
through said die, said molten FPVC plastic having a die exit
temperature of about 380.degree. F., and said molten plastic
forming an extruded web as it exits said die; pulling said extruded
web via said puller through said cooling bath to cool said extruded
web to about 150.degree. F. to form a semi-solid, integrally
extruded sheet; cutting integral plastic insoles from said
semi-solid, integrally extruded sheet via a punch press, said punch
press cutting said insoles from an interior portion of said
integrally extruded sheet to leave excess trim in the form of a
continuous sheet that maintains its pullable condition; and,
winding up said continuous sheet of excess trim material via a
wind-up roller.
26. The insole extrusion and forming process of claim 25, and
wherein said extruder includes a barrel and screw and a gate, said
barrel and screw continuously pushing and heating the molten FPVC
plastic to a temperature of about 370-380.degree. F., and said
molten FPVC plastic being heated to a temperature of about
380.degree. F. at said gate.
27. The insole extrusion and forming process of claim 26, and
wherein said extruded web is continuously extruded from said die at
a speed of about 4 to 6 feet per minute, and continuously moves
through said cooling bath and punch press, and around said wind-up
roller.
28. The insole extrusion and forming process of claim 27, and
wherein said die has a thickness of about 13/4 inch.
Description
TECHNICAL FIELD OF THE INVENTION
[0001] This invention relates to an extruded cushioning insole for
footwear and a process of making the same, the insole having an
integral construction, a crush resistance and resilience to provide
effective cushioning for the useful life of the footwear.
BACKGROUND OF THE INVENTION
[0002] The human foot is a complicated structure with many bones,
muscles and tendons. People that are on their feet for long periods
of time recognize the benefit of a shoe or shoe insert that
provides a degree of cushioning to absorb the constant weight and
pounding experience by their feet throughout the day. This
cushioning is particularly appreciated when a person is on a hard
surface such as concrete floor, sidewalk or road. Yet, the bottom
of the foot is not flat, and includes a heel, arch, ball and toes
to form an undulating surface. This structure creates areas of high
or concentrated pressure and forces and areas of lower pressure and
forces. Areas of the foot that experience higher pressures can tire
and become sore more quickly.
[0003] Shoe insoles and inserts are typically placed over the sole
or mid sole of a shoe, and engage the bottom of the foot to provide
two types of cushioning. First, the insert should dissipate the
shock of any dynamic forces experienced by the foot when the shoe
strikes the ground, such as when a person is walking, running or
jumping. Instead of sudden jarring impacts by the foot against the
sole of the shoe, the forces are more gradually transmitted as the
insert compresses. Second, the insert should distribute forces and
pressures more evenly across the bottom of the foot. Lower portions
of the foot compress the insert more than higher areas of the foot
so that the insert tends to engage the entire bottom surface of the
foot, and distribute pressure more evenly across that surface. This
cushioning takes place even when the person is standing still.
[0004] A problem with cushioning insoles and inserts is their short
useful life. The useful life of the insert is typically shorter
than that of the associated footwear in which they are placed so
that the inserts need to be periodically inspected and replaced.
While conventional inserts have a typical useful life of one to six
months, tennis or jogging shoes have a typical or normal useful
life of about six months to two years and dress shoes and boots
have a typical or normal useful life of about one to five years
depending on a variety of factors such as the quality,
craftsmanship and materials used to make them, the frequency they
are worn, the environment in which they are worn, the activity
level and degree of ruggedness when worn, the care given them, and
the weight and perspiration of the wearer. Yet, consumers either
forget to inspect their inserts, or are ill-equipped to determine
when they should be replaced. Many people simply put inserts in
their shoes and forget about them. If they do think to inspect the
inserts, they have difficulty determining their unloaded thickness
and compression resistance when the inserts are inside the
footwear. People do not take the time to regularly remove the
inserts from their shoes, and properly inspect them. Moreover, even
when the inserts are removed, the inspection is more a matter of
guesswork than an informed decision. A person may not have a new
insert to use as a reference for comparing the shape and thickness
of the used insert. People simply guess if the insert looks like it
is crushed too much. Even if there is an available reference, they
have difficulty visually gauging the percentage of recovery
remaining in the insert or the degree to which it has been
permanently crushed. The sides of the insert can retain their
original cushioning shape and thickness while middle areas that
experience the higher pressures can be significantly crushed so
that its cushioning effectiveness is significantly reduced or lost.
In addition, even if the insert does return to its original
thickness, the insert may have lost its compression resistance or
load bearing capacity. For example, foam is typically measured in
units of indentation load deflection (ILD) or indentation force
deflection (IFD). Although many consumers are not even aware that
this type of cushioning loss can occur, those that are still likely
to rely on guesswork in evaluating the degree of this cushioning
loss. Testing labs with expensive machines are typically used to
measure compression resistance. As a result, consumers continue to
wear their cushioning inserts well after they deteriorate and
perform ineffectively. Even though people buying cushioning inserts
believe they are taking measures to improve their health, they can
still end up with and suffer from chronic foot, ankle, knee, hip
and back problems.
[0005] Cushioning insoles and inserts come in a wide range of
structural complexity and price. Less complex and expensive inserts
include a single sheet of resilient foam. Initially, the foam
sheets help dissipate impact forces from running, jumping and
walking, and also help distribute forces more evenly across the
bottom of the foot such as when the person is standing still.
However, as these foam sheets are compressed by the weight of the
person, and repeatedly cycled as the person shifts their weight
from one foot to the other, the sheets quickly lose their
cushioning effectiveness. The sheets experience a loss in unloaded
thickness due to crushing, particularly in higher pressure areas.
The sheets can also experience a loss in compression resistance as
measured in ILD/IFD. Significant cushioning losses can occur within
a few months. The rate at which the inserts lose their cushioning
effectiveness increases with the weight and activity level of the
person. Yet, the feet and joints of heavier and more active people
benefit the most from a proper cushioning insert. Consequently,
although these less complex cushioning inserts are generally
affordable, they are ill-equipped for many, if not most,
people.
[0006] More complex insoles or inserts typically include multiple
pieces of material. Each piece is separately formed. Individual
pieces may be made of different materials such as metal, rubber,
plastic, cloth fabric, foam or gel, and are shaped for a specific
purpose. Some pieces are for areas that experience higher
pressures, such as the heel or ball of the foot. Some pieces are
made to provide structural support or stability, such as an arch
support. The various pieces are then matched, placed in their
desired orientation, and glued or otherwise attached to each other.
The manufacturing process for more complex inserts require more
inventory, materials, labor, equipment and time. An example of such
an insert is disclosed in U.S. Pat. No. 4,674,204, the disclosure
of which is incorporated by reference. Accordingly, the cost of
these inserts is significant. Many people do not see the value of
the inserts, and avoid using them until they begin suffering from
chronic foot, knee or back pain. Unfortunately, the time for the
preventing these ongoing daily ailments has passed.
[0007] Some inserts include a gel in an elastic or stretchable
material to provide cushioning. A problem with these inserts is
leakage and cost. A gel leak can stain, gunk up or otherwise ruin
the footwear. Contact with liquid gel can also cause skin
irritation for some people. Yet, the insert is exposed to heat and
sweaty acids that can break down the material containing the gel or
cause the gel to tear or otherwise deteriorate. These insets must
also endure prolonged cyclical loading and unloading without
leaking or deteriorating. Trimming gel inserts is not typically
suggested, and can result in a leak of a liquid gel insert. Thus,
many people avoid these types of inserts because of possible leaks,
gel deterioration, damage to the footwear and the cost of the
insert.
[0008] A further problem with cushioning insoles and inserts is
adaptability. The inserts should be easily adaptable for use in a
wide variety of footwear, such as walking shoes, dress shoes,
boots, or tennis shoes. This is particularly problematic for more
complex or multi-piece inserts. These inserts can include metal or
hard molded pieces that are not generally intended to be cut or
trimmed. They can also include a cloth fabric that will unravel if
cut or trimmed. Other inserts are contoured with a raised perimeter
around the heel and arch regions sized for a specific foot having a
specific width. The contoured perimeter is not intended to be
trimmed, and restricts the movement of the foot in the footwear. As
a result, the inserts have a defined "take-it-or leave-it" shape
that is not adaptable to the shape of a specific shoe, boot or
sneaker. Forcing an insert that is too wide or too long into
footwear can kink the insert or shoe and result in discomfort, and
damage the shoe insert. Inserts that are too narrow or short
relative to the shoe can shift inside the shoe and result in
similar problems.
[0009] A still further problem with cushioning inserts is that they
do not accommodate a wide variety of people. While people come in
all shaped and sizes, inserts are often designed for the "average"
person. If the insert is contoured to the shape of a foot, the
contouring is for the foot of the average person. The thickness and
stiffness or rigidity of the insert is also intended for a person
of average weight. The inserts are not intended for children or
petit or larger adults. Heavier people will bottom out the insert,
which reduces the effectiveness of the insert and can damage the
insert and reduce its life. Lighter people do not compress the
rigid material significantly, which reduces the cushioning effect
of the insert.
[0010] A still further problem with insoles and inserts is that
they inhibit the flexibility of the foot and shoe. Components that
are intended to be stiff or rigid to provide an arch support or
absorb shock tend to resist bending.
[0011] A still further problem with insoles and inserts for
footwear is quick recovery. To perform properly, the insert must
quickly return to its normal or unloaded position so that it is
ready to provide cushioning for the next step or jump of the
person. Yet, many materials have a recovery rate that is too slow
for the pace of a person that is walking or running.
[0012] A still further problem with conventional insoles and
inserts is odor absorption. Inserts with cloth of leather materials
will absorb the sweat and odors of the feet. Some foam inserts also
tend to absorb moisture and odor. These inserts will have to be
disposed of for sanitary or hygiene reasons before the complete
cushioning life of the insert.
[0013] A still further problem with cushioning insoles or inserts
is heat and sweat resistance. The inserts should be made of
materials that withstand prolonged exposure to body heat and sweat.
The recovery rate and compression resistance of the material cannot
deteriorate when exposed to the heat and sweat of the human
body.
[0014] A still further problem with cushioning inserts is that they
should not contribute to the growth of mold and bacteria in the
shoe. The structure of the insert should not collect moister, so as
to cultivate the growth of mold and bacteria. Yet, many inserts
have a flat bottom surface that can trap moisture. The overall
structure of the insert does not allow the materials below the
insert to breath and dispel the moister that cultivates mold and
bacteria.
[0015] The present invention is intended to solve these and other
problems.
BRIEF DESCRIPTION OF THE INVENTION
[0016] The present invention pertains to an extruded cushioning
insole or insert for footwear. The insole disperses the weight of
an individual more evenly across the surface of their foot and
reduces the impact forces on the feet when walking, running or
jumping. The insole or insert is an integrally extruded, one-piece
insert. One insole embodiment includes a flexible upper pad with a
plurality of downwardly extending tubes that each form a
collapsible chamber. Another insole embodiment has a solid main
body with a flat upper surface and a contoured lower surface formed
by thinner and thicker regions of the insert. Another insole
embodiment has a flat upper surface and a convex lower surface
formed by a collapsible internal disc-shaped chamber. The convex
surface is generally flat when compressed.
[0017] An advantage of the present extruded plastic cushioning
insole or insert is its long life. Its useful life is typically
longer than that of the associated footwear. The FPVC plastic
material retains its compression resistance and resiliency for a
relatively long period of time, even when used by a relatively
active or heavier person. The insole should not need to be
periodically removed from their shoe, inspected and replaced. When
consumers throw away their old shoes or boots, they simply remove
the inserts, and insert them in a new pair of footwear. The
replacement of the footwear triggers the inspection of the inserts.
The consumer does not have to independently remember to inspect the
inserts during the life of the footwear.
[0018] Another advantage of the present extruded cushioning inserts
is ease of inspection. Prior to placing the inserts into a new pair
of shoes, the inserts are visually inspected to determine if they
have retained their proper shape. The extending tubes have a
uniform structure when the insert is in good working condition.
Non-uniformity caused by crushing of the tubes in the more central,
high pressure areas is easily noticed. The inserts should be
replaced when portions of the tubes lose their resilience, and fail
to quickly return to their fully extended position and uniform
configuration.
[0019] Another advantage of the extruded cushioning insole or
insert is its ease of manufacture and economical price. The
cushioning inserts are formed by a single extrusion process and a
punch press. No separate pieces need to be matched and glued or
otherwise secured together. Inventory, logistics, material costs,
labor, equipment and time are kept to a minimum. The extruded
inserts are made of solid materials and contain no substances that
can leak or create a mess. By keeping the cushioning inserts
economical, many people will begin using them before they start to
suffer from chronic foot, knee or back pain.
[0020] A further advantage of the present extruded cushioning
insole is its adaptability. The insoles or inserts are easily
adapted to obtain a proper fit inside a variety of footwear, such
as walking shoes, dress shoes, boots, or tennis shoes. Although
feet and footwear come in all shaped and sizes, the uniform
structure of the integrally extruded inserts and their use of soft
FPVC plastic material allows them to be easily cut and trimmed to
fit a wide variety of feet and footwear. The cushioning inserts can
be pre-cut for specific foot sizes such as for adults or children,
and trimmed by the consumer prior to inserting them into their
specific pair of shoes or boots. Cut or trimmed areas do not fray,
unravel or otherwise deteriorate. As a result, the inserts are
easily shaped to snuggly fit inside a wide variety of footwear,
without kinking. The inserts remain fixed in place inside the
footwear and do not shift around during use. The inserts should not
cause foot sores or damage the footwear.
[0021] A still further advantage of the present extruded cushioning
insert is its adaptability for persons of different weights. By
simply increasing the thickness of the flexible pad, height of the
tubes, or thickness of the deformable wall of the tubes, the
inserts can accommodate the forces associated with wide variety of
weights. The thickness and compression resistance of the insert can
be selected to accommodate people weighing 30 pounds or 300 pounds.
The inserts can be used by children or petit or larger adults.
Heavier people do not bottom out the inserts made for them. Lighter
people properly compress their inserts and receive the benefit of a
sufficient amount of cushioning.
[0022] A still further advantage of the present extruded cushioning
insole is its flexibility. The insole or insert is made of soft
flexible PVC plastic and is free of metal and rigid parts that
resist the natural bending of the foot and shoe. The compressible
tubes can be positioned laterally to further increase flexibility
and help the insert conform to the natural bending motion of a foot
or shoe.
[0023] A still further advantage of the present extruded cushioning
insole and insert is its quick recovery. The inserts quickly or
instantaneously return to their normal or unloaded position so that
it is ready to provide cushioning for the next step or jump of the
person. The recovery rate of the insert is believed to be less than
1/4 second, which allows for full recovery between each step even
when a person is walking, running or jumping at a fast pace.
[0024] A still further advantage of the present extruded cushioning
insole is its resistance to odor absorption. The extruded plastic
insole or insert does not absorb the sweat and odors of the feet.
The insert can be used for its entire useful life without needing
to be disposed of for sanitary or hygiene reasons.
[0025] A still further advantage of the extruded cushioning insole
is that it retains its integrity in the presence of body heat and
sweat. The FPVC plastic withstands prolonged exposure to heat and
sweat. The recovery rate and compression resistance of the material
do not deteriorate when exposed to human body heat or sweaty
acids.
[0026] A still further advantage of the extruded cushioning insert
is that it does not contribute to the growth of mold and bacteria
in the shoe. The structure of the insert does not collect moister,
so as to cultivate the growth of mold and bacteria. The overall
structure and uneven bottom surface of the insert allows moister to
escape and the shoe to breathe in a normal manner.
[0027] Other aspects and advantages of the invention will become
apparent upon making reference to the specification, claims and
drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0028] FIG. 1 is a side sectional view of the present cushioning
insole invention positioned inside a conventional shoe having a
sole and an upper.
[0029] FIG. 2 is a side sectional view of the present cushioning
insole invention inside a shoe and cushioningly supporting a foot,
and showing the longitudinal higher and lower pressure areas of the
foot compressing the shoe insert.
[0030] FIG. 3 is a front sectional view of FIG. 1 showing a first
embodiment of the cushioning insole inside the shoe.
[0031] FIG. 4 is a side sectional view of FIG. 4 showing the
lateral higher and lower pressure areas of the foot compressing the
shoe insole.
[0032] FIG. 5 is a side view of the extruder, water bath, puller,
punch press and take-off winder used in the process of forming the
various shoe insole.
[0033] FIG. 6 is a perspective view of the present cushioning
insole.
[0034] FIG. 7 is a side sectional view of the first embodiment of
the cushioning insole with an upper layer and a plurality of spaced
tubes.
[0035] FIG. 8 is a side sectional view of a second embodiment of
the cushioning insole with a plurality of joined tubes.
[0036] FIG. 9 is a side sectional view of a third embodiment of the
cushioning insole with a plurality of spaced semi-circular
tubes.
[0037] FIG. 10 is a side sectional view of a fourth embodiment of
the cushioning insole with a plurality of joined rectangular tubes
that form a lower layer.
[0038] FIG. 11A is a side sectional view of a fifth embodiment of
the cushioning insole with a plurality of spaced circular
tubes.
[0039] FIG. 11B is a side sectional view of FIG. 12 showing the
fifth embodiment of the cushioning insole joined to an extruded
arch support.
[0040] FIG. 12 is a top view of the cushioning insole with portions
of its heel and ball regions cut away, and an extruded arch support
placed under the mid portion of the insert, such as an upside down
portion of insole 170.
[0041] FIG. 13A is a top view of the fourth embodiment of the
cushioning insole.
[0042] FIG. 13B is a side sectional view of FIG. 13A showing the
rectangular shaped tubes of the cushioning insole.
[0043] FIG. 14 is a top view of the present cushioning insole
showing its upper surface marked with size and width designations
for trimming the insert to the desired size and width of the
individual user.
[0044] FIG. 15A is a top view of a sixth profiled embodiment of the
cushioning insole extruded from sheet extrusion die.
[0045] FIG. 15 B is a side sectional view of FIG. 15A showing its
thicker heel and arch regions.
[0046] FIG. 16A is a top view of a seventh profiled embodiment of
the cushioning insole.
[0047] FIG. 16 B is a side sectional view of FIG. 16A showing its
thicker heel and arch regions.
[0048] FIG. 17A is a side sectional view of an eighth embodiment of
the cushioning insole having a uniform thickness, solid interior
and flat lower surface.
[0049] FIG. 17B is a side sectional view of a eighth embodiment of
the cushioning insole having a uniform thickness, solid interior,
flat lower surface and a hardened upper surface layer.
[0050] FIG. 17C is a side sectional view of a ninth embodiment of
the cushioning insole having a solid interior and wavy lower
surface.
[0051] FIG. 18 is a side sectional view of a tenth embodiment of
the cushioning insole having a main body with a flat upper surface
and a convex lower surface formed by several internal chamber
located proximal to the lower surface.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0052] While this invention is susceptible of embodiments in many
different forms, the drawings show and the specification describes
in detail several preferred embodiments of the invention. It should
be understood that the drawings and specification are to be
considered an exemplification of the principles of the invention.
They are not intended to limit the broad aspects of the invention
to the embodiments illustrated.
[0053] As shown in FIGS. 1 and 2, a human foot 10 has a particular
shape with a narrowing front 11 with toes 12, a forward ball 13
from which the toes flex, a middle arch 14 that distributes weight,
and a heel 15 positioned below the ankle at the rear. The bottom
surface 16 of the foot 10 also has a particular shape with a wider
front or ball area 17, a narrowing arch area 18, and a rear heel
area 19. Footwear such as a shoe 20 is designed to fit and support
the foot 10. A conventional shoe has a closed front 22 that
surrounds and supports the front 11 and middle 14 of the foot, and
an open rear 23 that receives and supports the heel 15 of the foot.
The shoe 20 has opposed sides 26 and 27 that provide lateral
support and keep the foot 10 centered when in the shoe. The shoe 20
has a sole 31 that spans the length and width of the shoe. The sole
31 includes a heel 32 at its rear 25, which is frequently sized to
raise the heel 15 of the shoe. The sole 31 of the shoe 20 can
include a mid-sole that forms an arch support for the foot 10. The
shoe 20 includes an upper 35 to secure the foot 10 to the shoe. The
sole 31 and upper 35 combine to form the inside 40 of the shoe 20.
The top of the sole 31 generally forms the upper surface 42 of the
inside 40 of the shoe, against which the bottom surface 16 of the
foot 10 rests.
[0054] The present invention pertains to an extruded cushioning
insole or insert for footwear generally indicated by reference
number 50 in FIGS. 1 and 2. The extruded plastic insole 50 has an
integral, unibody construction. This integral or single piece
insert 50 has a front 51 a rear 52, sides 53 and 54 and a perimeter
55. The perimeter 55 is shaped in general conformity with the shape
of the bottom surface 16 of the foot 10 and inside surface 42 of
the shoe 20. The insert 50 is cut and trimmed to lay generally flat
against the inside surface 42 of the shoe 20. Similar to the shape
of the foot 10 and shoe 20, each insert 50 has a narrowing front
region 56, a wider ball of foot region 57, a narrower arch region
58 and a heel region 59 as shown in FIG. 6.
[0055] The insert 50 is formed by an extrusion and forming process
including a conventional plastic extrusion machine 61 as in FIG. 5.
The insole 50 is made of flexible vinyl compound (FPVC) plastic.
Pellets of FPVC plastic are poured into the extruder 61 and heated
to form a molten extrusion material. The barrel and screw of the
extruder 61 continuously pushes and heats the molten extrusion
material to about 370-380.degree. F. The molten material is at
about 380.degree. F. at the gate of the extruder. The hot molten
material passes through a die 62 having a desired extrusion
profile. The die has a thickness of about 13/4 inches. The molten
extrusion material exits the die 62 at a temperature of about
380.degree. F. in the form of an integral molten web or sheet 63
having an untrimed width of about four inches. The molten web 63
enters a conventional water bath 64 that cools and solidifies the
web 63 as it moves through the bath 64. The web 63 leaves the bath
64 in the form of a semi-solid, integrally extruded sheet 65 having
a temperature of about 150.degree. F. The sheet is pulled along a
path of travel through the bath 64 by a conventional puller 66 at a
continuous rate of speed of about 4 to 6 feet per minute. The
partially cooled, semi-solid sheet leaves the puller 66, and enters
a punch press 67 that cuts the sheet to form each of the individual
insoles 50. The punch press 67 includes a reciprocating punch that
moves both up and down, and back and forth so that the punch
travels in unison with the sheet along its path of travel during
its cutting engagement with the sheet 65. The punch 67 has a
cutting edge with a desired cutting perimeter shape to cut blanks
from the semi-cooled sheet 65. The wider ball region 57 is slightly
less than the 4 inch wide extruded web 65. After punching out the
individual inserts 50, the sheet 65 has a continuous outer web for
winding around a takeoff winder 68. These blanks form the extruded,
unibody, inserts 50 of the present invention. Each insole 50 has a
continuous, integral layer 70. This layer 70 can have a plurality
of integral, resilient tubes 80 extending from its lower surface.
The tubes 80 can take on different shaped and configurations in
different embodiments of the cushioning insole invention 50.
[0056] A first embodiment of the insole or insert 50 is shown in
FIGS. 3, 4, 6 and 7. This insert 50 has a continuous upper layer 70
and a plurality of hollow, lower tubes 80. The upper layer or
flexible pad 70 has a solid body with generally flat, parallel
upper and lower surfaces 72 and 74. The layer 70 has a uniform
thickness of about 0.06 inch. The upper surface 72 can have a
number of upwardly extending, uniformly spaced, gripping ridges,
about 10 per inch (not shown) to allow the bottom surface 16 of the
foot 10 or a sock to better grip the insert 50. Each ridge has a
height of about 0.007 inch. The upper layer 70 is preferably
continuous from one end of the insert to the other, and from one
side of the insert to the other. The insole 50 can include one or
more cutout areas 78 to relieve or avoid pressure from the bottom
16 of the foot 10 in those areas as in FIGS. 6 and 12.
[0057] The tubes 80 project down from and are uniformly spaced
across the lower surface 74 of the upper layer 70. Each tube 80 is
formed by a continuous wall 82 having a uniform thickness of about
0.05 inch. The wall 82 is arcuate and forms opposed side portions
83 and a joining bottom portion 84. The upper layer 70 forms an
upper portion or wall of the tube 80. The walls 83, 84 and 70 of
the tube 80 surround a hollow interior that forms a longitudinal
channel 90 with opposed vented ends 92 and 93. Although most tubes
80 and their channels 90 are continuous across the length of the
insert 50, given the particular arcuate shape of the foot 10 and
insert 50, some tubes 80 may be broken in the arch region 58, or
cut open along the perimeter 53 of the insert. Each tube 80 has a
height of about 0.25 inch, so the total uncompressed height of the
insert 50 is about 0.3 inch. Each tube 80 has a width of about 0.38
inch, which is the distance between the outside surfaces of its
opposed sidewalls 83. Each tube 80 is spaced a uniform distance
apart of about 0.18 from its adjacent tube or tubes. This is the
width of the spaced section 78 of the upper layer 70 between
adjacent tubes 80. Each sidewall 83 forms a deformable wall that
supports the upper layer 70. These tubes 80 and their deformable
walls 83 are evenly spaced across the width of the insert 50.
[0058] This insole 50 is preferably made of FPVC plastic having a
specific gravity of about 1.27 as per ASTM D792, and a hardness of
about 75 durometers (instantaneous) and 66 durometers (15 seconds)
as per ASTM D2240. The plastic has a tensile elongation at break of
about 420%, a tensile stress of about 740 psi, and a tensile
strength of about 1,800 psi as per ASTM D638, and a tear strength
of about 270 lbs/in as per ASTM D624. The plastic has a Clash-Berg
modulus or modulus of rigidity of about 18,000 psi as per ASTM
D1043, and a compression set of about 23% as per ASTM D395. The
plastic has a brittleness temperature of about -47.degree. F. as
per ASTM D746, an extrusion melting temperature of about
350.degree. F., and a mold shrinkage of about 0.02 in/in as per
ASTM D955. The FPVC plastic is available in pellet form from
PolyOne Corporation of Avon Lake, Ohio under its "Geon" B7500
mark.
[0059] As shown in FIGS. 3 and 7, the shoe insert 50 has a relaxed
position 100 with no weight being applied to its upper surface 72.
In this relaxed position 100, the tubes 80 are fully extended to a
uniform height of about 0.32 inch. The midpoint of the bottom
portion 84 of each tube 80 rests on the upper surface 42 inside the
shoe 20. The flexible pad 70 is flat and planar to the surface 42
inside the shoe. When the weight of a foot 10 is placed on the
upper layer 80, the bottom 16 of the foot 10 pushes down on the
insert 50 and forces it into a compressed position 105 as shown in
FIG. 4. In this compressed position 105, the sidewalls 83 of the
tubes 80 buckle, and the height of the tubes 80 decreases. The
sidewalls 83 tend to buckle outwardly relative to the center of the
insert 50 given that they are joined together by their outwardly
curved or convex bottom portion 84. This curved portion has an
outer radius of about 0.19 inch.
[0060] The stiffness or resistance to compression of the deformable
walls 83 resist this buckling to create a cushioning effect. The
greater the buckling, the greater the amount of upward force
exerted on the upper layer 70. In areas of lower pressure 110, the
sidewalls 83 of adjacent buckling tubes 80 remain separated and do
not touch each other. However, as the height of the tubes 80 is
greater than half the distance between adjacent tubes, in areas of
high pressure 115, the sidewalls 83 of adjacent tubes do touch each
other. A sudden compression of the insert 50 and its tubes 80 will
also cause the air inside the channels 90 to be forced out their
vent ends 92. Although various embodiments of the insert 50 have a
flexible upper layer 70 with the same general top profile view such
as that in FIG. 12 to securely fit inside a shoe, the bottom view
and tubes 80 can vary to achieve a desired degree of cushioning.
The height and width of the tubes 80 and the distance between them
can change.
[0061] A second embodiment of the insole or insert 150 is shown in
FIG. 8. This insert 150 also has a continuous, flexible pad 70 with
a uniform thickness of about 0.06 inch, and several evenly spaced
conjoined tubes 80. Each tube 80 is formed by a wall 82 having
opposed side portions 83 and an arced bottom portion 84. The wall
82 has a uniform thickness of about 0.03 to 0.04 inch. Each tube 80
has a height of about 0.18 inch and a width of about 0.25 inch. The
insert 150 has a total relaxed or uncompressed height of about 0.24
inch. Adjacent tubes 80 share a common side portion 83 so there are
about 16 longitudinal tubes in a 4 inch wide insole 150. When in a
relaxed or extended position 100, each tube 80 has a half circle or
hemisphere shape. When in a compressed position, the deformable
side walls 83 bend and the bottom wall 84 flattens and buckles.
[0062] A third embodiment of the insole 170 is shown in FIG. 9.
This insert 170 has a continuous, flexible pad 70 with a uniform
thickness of about 0.06 inch, and several evenly spaced tubes 80.
The tubes 80 are similar to those of insole 150. Each tube 80 is
formed by a wall 82 having opposed side portions 83 and an arcuate
bottom portion 84. The wall 82 has a uniform thickness of about
0.03 to 0.04 inch. Each tube 80 has a height of about 0.18 inch and
a width of about 0.36 inch. The insert 170 has a total uncompressed
height of about 0.24 inch. Adjacent tubes 80 are relatively close
together, but do not share a common side portion 83. There are
about 11 longitudinal tubes in a 4 inch wide insole 170. When in a
relaxed or extended position 100, each tube 80 has a half circle or
hemisphere shape. When in a compressed position, the deformable
side walls 83 bend outwardly and the bottom wall 84 flattens and
buckles.
[0063] Insoles 150 and 170 are preferably made of FPVC plastic
having a specific gravity of about 1.14 as per ASTM D792, and a
hardness of about 55 durometers (instantaneous) and 50 durometers
(15 seconds) as per ASTM D2240. The plastic has a tensile
elongation at break of about 440%, a tensile stress of about 400
psi, and a tensile strength of about 1,100 psi as per ASTM D638,
and a tear strength of about 180 lbs/in as per ASTM D624. The
plastic has a Clash-Berg modulus or modulus of rigidity of about
1,000 psi as per ASTM D1043, and a compression set of about 20% as
per ASTM D395. The plastic has a brittleness temperature of about
-70.degree. F. as per ASTM D746, an extrusion melting temperature
of about 330.degree. F., and a mold shrinkage of about 0.03 in/in
as per ASTM D955. The FPVC plastic is available in pellet form from
PolyOne Corporation of Avon Lake, Ohio under its "Geon" A5500
mark.
[0064] A fourth embodiment of the insole or insert 200 is shown in
FIGS. 10, 13A and 13B. This insert 200 has a continuous, flexible
pad 70 and several evenly spaced rectangular conjoined tubes 80.
Each tube 80 is formed by a wall 82 having opposed vertical side
portions 83 and a flat horizontal bottom portion 84. The wall 82
has a uniform thickness. Adjacent tubes 80 share a common side
portion 83. The bottom portions 84 form a flat lower layer 204 that
is parallel to the upper layer 70. When in a relaxed or extended
position 100, each tube 80 has a rectangular shape. When in a
compressed position, the deformable side walls 83 bend and the
bottom layer 204 remains flat. This insole 200 is preferably made
of FPVC plastic having characteristics similar to insole 50 or 150,
and available in pellet form from PolyOne Corporation of Avon Lake,
Ohio under its "Geon" A5500 or B7500 marks.
[0065] A fifth embodiment of the insert 300 is shown in FIG. 11A.
This insert 300 has a continuous, flexible pad 70 with a uniform
thickness, and several lower, evenly spaced circular tubes 80. Each
tube 80 is formed by a wall 82 having a uniform thickness. Adjacent
tubes 80 do not share a common portion. The upper end of each
circular tube 80 is joined to lower surface 74 of the flexible
layer 70. When in a relaxed or extended position 100, each tube 80
has a circular shape. When in a compressed position, the deformable
side wall 82 bends into a generally oval shape. This insole 300 is
preferably made of FPVC plastic having characteristics similar to
insole 150, and available in pellet form from PolyOne Corporation
of Avon Lake, Ohio under its "Geon" A5500 mark.
[0066] The inserts 50, 150, 170, 190, 200 and 300 can be customized
to meet the specific needs of an individual. The high pressure
areas 57' and 59' in the ball and heel regions 57 and 59 are marked
and cut away to relieve pressure in those areas as shown in FIG.
12. An arch support is formed by taking the sixth embodiment 300
and adding a portion of the third embodiment 170 in the arch region
58 as shown in FIG. 11B. This combined structure builds up the arch
region 58 to provide additional support to the arch 14 of the
individual. The flat upper surface 72 of the inserts 50, 150, 190,
200 and 300 are preferably marked with lines for trimming the
insert to fit the specific shoe sized of the individual as in FIG.
14.
[0067] Although the tubes 80, channels 90 and their deformable
walls 82-84 are shown extending longitudinally or from
front-to-rear of the insert 50 during the process of manufacturing
the inserts 50, the punch press 68 can be rotated 90.degree. so
that the tubes, channels and walls ran laterally or from
side-to-side. For example, the tubes 80 and channels 90 of the
insert 200 run from sided-to-side or laterally in FIGS. 13A and
13B. This lateral arrangement also applies for inserts 150, 170,
190, 200 and 300. The laterally extending tubes 80 channels and
walls 82-84 increase the flexibility of the inserts when walking,
running and jumping because the insert is more easily bent to
conform to the natural bending movement of the foot and shoe.
[0068] A sixth, solid profiled construction of the extruded
cushioning insert 400 is shown in FIGS. 15A and 15B. The profiled
insert 400 has a solid main body with a flat upper surface 472 and
a contoured, lower surface 474. The insert 400 has a thickness of
about 0.18 inch in its flat front and ball regions 456 and 457,
about 0.28 inch in its flat raised arch region 458, and about 0.24
inch in its flat rear heel region 459. A sloped arch region 458'
joins the flat raised arch region 458 to the ball region 457. A
flat recessed rearward region 459' between the arch and heel
regions 458 and 459 has a thickness of about 0.18 inch. The forward
and rearward ends of this region 459' are sloped to minimize any
concentrations of pressure during use. The body of the insert 400
is continuous from one end of the insert to the other, and from one
side of the insert to the other. A second, solid profiled insert
450 or seventh embodiment of the invention is shown in FIGS. 16A
and 16B. This insert 450 eliminates the sloped arch region 458'.
Instead, the forward end of the arch region 458 is sloped to
minimize any concentrations in pressure during use. Insoles 400 and
4500 are preferably made of FPVC plastic having characteristics
similar to insole 150, and available in pellet form from PolyOne
Corporation of Avon Lake, Ohio under its "Geon" A5500 mark.
[0069] In a eighth embodiment, the extruded cushioning insert 500
has a solid main body having parallel upper and lower surfaces 572
and 574, and a constant uniform thickness of about 0.17 inch as
shown in FIG. 17A. The insert 500 is preferably coextruded with a
hardened upper layer 520 as in FIG. 17B. The upper layer 520 has a
hardness of about 0.090 durometers. A ninth embodiment of the
extruded cushioning insert 550 has solid main body having a flat
upper surface 572 and a wavy lower surface 584 as in FIG. 17C. The
insert 550 has a thickness of about 0.03 inch at the troughs of the
waves, and about 0.13 inch at the crests of the waves. The insoles
500 and 550 are preferably made of FPVC plastic having
characteristics similar to insole 150, and available in pellet form
from PolyOne Corporation of Avon Lake, Ohio under its "Geon" A5500
mark.
[0070] In an tenth embodiment, the extruded cushioning insert 600
has a main body 610 with opposed upper and lower surfaces 672 and
674 as in FIG. 18. The insert 600 has a width of about 4 inch from
side to side. The upper surface 672 is flat and the lower surface
674 is bowed or convex. The solid side portions 612 of the insert
600 have a thickness of about 0.16 inch, and an expanded or divided
middle portion 615 has a thickness of about 0.28 inch. The divided
middle portion 615 includes a thicker flexible pad 620 with a
thickness of about 0.13 inch, and a thinner arcuate wall 630 with a
thickness of about 0.03 inch. The pad 620 and arcuate wall 630 are
separated by thin deformable walls 683 having a thickness of about
0.025-0.030 inch to from a collapsible chamber 690. The deformable
walls 683 divide the chamber 690 into three compartments 691, 692
and 693. The chambers 691-693 are aligned in side-by-side relation
so that their upper and lower surfaces 696 and 697, although
slightly curved, are generally linearly aligned. The chambers
691-693 are shaped to so as to form a "disc" shape having a
combined width of about 2.8 inch. The outer chambers 691 and 693
are "wedged" shaped, with each being a mirror image of the other.
The middle chamber 692 has a generally rectangular shape and a
width of about 0.78 inch. When compressed, the air in the chambers
691-693 is pushed out the vent ends of the insert 600 and the
chambers collapse. The deformable walls 683 also collapse. When the
insert 600 is in its compressed position, the upper and lower
surfaces 696 and 697 come together and abut each other. The lower
surface 674 is substantially flat and parallel to the upper surface
672 of the insert 600. Insole 600 is preferably made of FPVC
plastic having characteristics similar to insole 50 or 150, and
available in pellet form from PolyOne Corporation of Avon Lake,
Ohio under its "Geon" A5500 or B7500 marks.
[0071] While the invention has been described with reference to
several preferred embodiments, it will be understood by those
skilled in the art that various changes may be made and equivalents
may be substituted without departing from the broader aspects of
the invention.
* * * * *