U.S. patent application number 10/972596 was filed with the patent office on 2006-04-27 for molded foot support.
This patent application is currently assigned to Banyan Licensing LC. Invention is credited to Edmund Scott Davis, Aly Khalifa.
Application Number | 20060086004 10/972596 |
Document ID | / |
Family ID | 36204851 |
Filed Date | 2006-04-27 |
United States Patent
Application |
20060086004 |
Kind Code |
A1 |
Davis; Edmund Scott ; et
al. |
April 27, 2006 |
Molded foot support
Abstract
There is provided a foot support conforming to a user's foot.
The foot support includes a supportive member defining a front
portion, a rear portion and an arch portion for engagement against
the foot plantar arch. The rear portion has a concave periphery
formed for partial resting abutment of the person's heel. The
supportive member is fabricated from thermoplastic material formed
to shape in a custom application. Preferred materials are
thermoplastic materials providing easily formable shapes that
soften or react at a low temperature between and are capable of
being molded and shaped with hand pressure to the bottom of the
foot while the foot is in a non-weight bearing position.
Subsequently the thermoplastic material hardens retaining the
molded shape. In a second embodiment, a footbed assembly having a
cushioning top layer overlaying the upper surface of the molded
supportive member is provided. The invention also contemplates a
method for custom forming the supportive member.
Inventors: |
Davis; Edmund Scott; (Ft.
Lauderdale, FL) ; Khalifa; Aly; (Raleigh,
NC) |
Correspondence
Address: |
ALSTON & BIRD LLP;BANK OF AMERICA PLAZA
101 SOUTH TRYON STREET, SUITE 4000
CHARLOTTE
NC
28280-4000
US
|
Assignee: |
Banyan Licensing LC
|
Family ID: |
36204851 |
Appl. No.: |
10/972596 |
Filed: |
October 25, 2004 |
Current U.S.
Class: |
36/43 ; 36/145;
36/80 |
Current CPC
Class: |
A43B 17/14 20130101;
A43B 7/28 20130101; A43B 7/144 20130101; A43B 7/1465 20130101 |
Class at
Publication: |
036/043 ;
036/080; 036/145 |
International
Class: |
A43B 13/38 20060101
A43B013/38; A43B 23/28 20060101 A43B023/28 |
Claims
1. A foot support for fitting inside footwear and conforming to a
person's foot comprising; at least one customizable and supportive
member wherein said supportive member softens significantly at an
elevated but non-scalding temperature so that said supportive
member loses its material memory and is easily pliable by the user
to take on a desired three-dimensional surface; and when cooled to
normal use temperatures, said supportive member retains the desired
three-dimensional surface and provides support and comfort to the
user's foot when used inside a shoe.
2. The foot support according to claim 1 wherein said foot support
further comprises an assembly of members.
3. The foot support according to claim 2 wherein said assembly
includes at least one member made of textile, leather or synthetic
materials to provide comfort against the skin.
4. The foot support according to claim 2 wherein said assembly
includes at least one member is made of foam to cushion the foot
against the rigid supportive member.
5. The foot support according to claim 1 wherein said supportive
member includes a cut out in the heel portion and recesses to
provide extra shock-absorption and comfort to the user's foot.
6. The foot support according to claim 1 wherein said supportive
member is a thermoplastic material.
7. The foot support according to claim 1 wherein said supportive
member changes color and opacity when heated to it softening
temperature.
8. The foot support according to claim 6 wherein said thermoplastic
material is softened by placing said material in heated water.
9. The foot support according to claim 6 wherein the softening
temperature of said thermoplastic material is between 120.degree.
F. and 180.degree. F.
10. The foot support according to claim 6 wherein said
thermoplastic material in a softened state permanently deforms
under a load of 15 psi.
11. The foot support according to claim 1 wherein the desired
surface shape and detail of said supportive member is formed by
molding to the user's foot in a non-weight bearing position.
12. The foot support according to claim 1 wherein said supportive
member is formed by molding to the user's foot in a weight bearing
position.
13. The foot support according to claim 1 wherein the desired
surface shape said supportive member is created to form a
corrective effect on the posture or shape of user's foot.
14. The foot support according to claim 1 wherein said supportive
member is created to form an accommodative effect for the posture
or shape of the user's foot.
15. The foot support according to claim 1 wherein normal use
temperatures are between -20.degree. F. and 125.degree. F.
16. The foot support according to claim 1 wherein said
thermoplastic material, when cooled, will not permanently deform
under 25 psi at normal use temperatures.
17. The foot support according to claim 1 where material, when
cooled, has a flexural modulus of from about 300 to about 500 MPa
at normal use temperatures.
18. The foot support according to claim 1 wherein said foot support
comprises: a monolithic resilient supportive member defining inner
and outer lateral sides defining an arch portion between a front
portion and a rear portion conforming to the arch of the person's
foot; said front portion integrally frontwardly extending from said
arch portion for complementary engagement near the metatarsal
plantar region of the foot; said rear portion having a concave
periphery for partial resting abutment of the person's heel onto
said sides for complementary engagement around said heel; and said
monolithic resilient supportive member being formed of a softened
thermoplastic material that that is conformed directly to the
person's foot while said foot is in a non-weight bearing
position.
19. The foot support according to claim 18 wherein said
thermoplastic material is selected from the group consisting of
poly(ethyleneadipate), poly (epsilon-caprolactone), polyvinyl
stearate, cellulose acetate, butyl rubber and ethyl cellulose poly
(propylene oxide) containing co-monomers, trans polyisoprene and
cis polyisoprene based thermoplastic materials, and
polycaprolactone based materials.
20. The foot support according to claim 18 wherein said
thermoplastic material is poly (epsilon-caprolactone).
21. The foot support according to claim 18 wherein said
thermoplastic material is a polysilicone.
22. The foot support according to claim 18 wherein said front
portion has a plurality of frontwardly facing arcuate
concavities.
23. The foot support according to claim 18 wherein said resilient
supportive member has a hole in the heel area.
24. The foot support according to claim 18 wherein said resilient
supportive member has a plurality of ruts on the bottom
surface.
25. The foot support according to claim 18 further comprising a
second member positioned on top of said resilient supportive member
to provide a cushioning layer to cushion the foot.
26. The foot support according to claim 18 wherein said second
member is ethylene vinyl acetate.
27. A footbed assembly comprising at least one customizable and
supportive air-curable member wherein said supportive member is
initially in a soft and unhardened state, said supportive member
being easily pliable by the user to take on a desired
three-dimensional surface; whereby exposure to air allows said
supportive member having said desired three-dimensional surface to
harden and establish a material memory in said three-dimensional
surface and provides support and comfort to the user's foot.
28. The footbed assembly according to claim 27 further comprising a
member made of textile, leather or synthetic to provide comfort
against the skin.
29. The footbed assembly according to claim 27 further comprising a
member made of foam to cushion the foot against the rigid
supportive member.
30. The footbed assembly according to claim 27 wherein said
supportive member includes ruts and dimples to provide extra
shock-absorption and comfort.
31. The footbed assembly according to claim 27 wherein said
supportive member is a thermoset plastic.
32. The footbed assembly according to claim 27 wherein said
supportive member is a multi-component member.
33. The footbed assembly according to claim 31 wherein said
supportive member changes color and/or opacity when it reaches its
hardened state.
34. The footbed assembly according to claim 31 wherein said thermo
set material, in softened state, permanently deforms under a load
of 15 psi.
35. The footbed assembly according to claim 27 wherein the desired
surface of said supportive member is provided by the user's foot in
a non-weight-bearing position.
36. The footbed assembly according to claim 27 wherein the desired
surface of said supportive member is created to form a corrective
effect on the user's foot.
37. The footbed assembly according to claim 31 wherein said thermo
set material, when hardened, will not permanently deform under 25
psi at normal use temperatures.
38. The footbed assembly according to claim 27 wherein said
supportive member, when cooled, has a flexural modulus of from 300
to about a 500 MPa at normal use temperatures.
39. A footbed assembly comprising: at least one customizable and
supportive plastic member wherein said supportive member is
initially in a soft and unhardened state, said supportive member
being easily pliable by the user to take on a desired
three-dimensional surface; whereby mixture with a catalyst allows
said supportive member having said desired three-dimensional
surface to harden and establish a material memory in said
three-dimensional surface and provides support and comfort to the
user's foot.
40. Footwear that comprises: an item selected from the group
consisting of shoes, boots, skates and ski boots; and a footbed
assembly comprising at least one customizable and supportive member
wherein said supportive member is initially in a soft and
unhardened state, said supportive member being easily pliable by
the user to take on a desired three-dimensional surface, whereby
said supportive member is allowed to harden and establish a
material memory in said three-dimensional surface and provides
support and comfort to the user's foot.
41. The footwear according to claim 40 wherein said footbed
assembly includes at least one member made of textile, leather or
synthetic components to provide comfort against the skin.
42. The footwear according to claim 40 wherein said footbed
assembly includes at least one member is made of foam to cushion
the foot against the rigid supportive member.
43. The footwear according to claim 40 wherein said supportive
member includes cut outs and dimples to provide extra
shock-absorption and comfort to the user's foot.
44. The footwear according to claim 40 wherein said supportive
member is a thermoplastic material.
45. The footwear according to claim 40 wherein said supportive
member changes color and opacity when heated to it softening
temperature.
46. The footwear according to claim 44 wherein said thermoplastic
material is softened by placing said material in heated water.
47. The footwear according to claim 44 wherein the softening
temperature of said thermoplastic material is between 120.degree.
F. and 180.degree. F.
48. The footwear according to claim 44 wherein said thermoplastic
material in a softened state permanently deforms under a load of 15
psi.
49. The footwear according to claim 40 wherein the desired surface
shape and detail of said supportive member is formed by molding to
the user's own foot in a non-weight-bearing position.
50. The footwear according to claim 40 wherein the desired surface
shape and detail said supportive member is formed by molding to the
user's foot in a weight bearing position.
51. The footwear according to claim 40 wherein said supportive
member is created to form a corrective effect on the posture or
shape of user's foot.
52. The footwear according to claim 40 wherein said supportive
member is created to form an accommodative effect for the posture
or shape of the user's foot.
53. The footwear according to claim 40 wherein normal use
temperatures are between -20.degree. F. and 125.degree. F.
54. The footwear according to claim 40 wherein said thermoplastic
material, when cooled, will not permanently deform under 25 psi at
normal use temperatures.
55. The footwear according to claim 40 where material, when cooled,
has a flexural modulus of from about 300 to about 500 MPa at normal
use temperatures.
56. The footwear according to claim 40 wherein said foot support
comprises: a monolithic resilient supportive member defining inner
and outer lateral sides defining an arch portion between a front
portion and a rear portion conforming to the arch of the person's
foot; said front portion integrally frontwardly extending from said
arch portion for complementary engagement near the metatarsal
plantar region of the foot; said rear portion having a concave
periphery for partial resting abutment of the person's heel onto
said sides for complementary engagement around said heel; and said
monolithic resilient supportive member being formed of a softened
thermoplastic material that that is conformed directly to the
person's foot while said foot is in a non-weight bearing
position.
57. The footwear according to claim 56 wherein said thermoplastic
material is selected from the group consisting of
poly(ethyleneadipate), poly (epsilon-caprolactone), polyvinyl
stearate, cellulose acetate, butyl rubber and ethyl cellulose poly
(propylene oxide) containing co-monomers, trans polyisoprene and
cis polyisoprene based thermoplastic materials, and
polycaprolactone based materials.
58. The footwear according to claim 56 wherein said thermoplastic
material is poly (epsilon-caprolactone).
59. The footwear according to claim 56 wherein said thermoplastic
material is a polysilicone.
60. The footwear according to claim 56 wherein said front portion
has a plurality of frontwardly facing arcuate concavities.
61. The footwear according to claim 56 wherein said resilient
supportive member has a hole in the heel area.
62. The footwear according to claim 56 wherein said resilient
supportive member has a plurality of ribs on the bottom
surface.
63. The foot support according to claim 56 further comprising a
second member positioned on top of said resilient supportive member
to provide a cushioning layer to cushion the foot.
64. The foot support according to claim 56 wherein said second
member is ethylene vinyl acetate.
65. A process for customizing a footbed assembly comprising:
placing a supportive member from said footbed assembly in a forming
tray that can contain both the footbed and 500 ml of hot water;
filling said forming tray with water at a temperature between
120.degree. F. and 180.degree. F., and said supportive member and
allowing the internal temperature of said supportive member to rise
until said member reaches a pliable state; removing said supportive
member from said forming tray and shaping said supportive member to
the user's foot or other corrective shape; allowing said supportive
member to cool to a hardened state; and re-assembling said shaped
supportive member into said footbed assembly.
Description
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] This invention relates to a custom molded foot support and
footbed assembly for use in footwear. In addition, this invention
relates to a method for forming a custom fitted foot support.
[0003] 2. Description of Related Art
[0004] Podiatric orthosis, also a type of shoe insoles, are
frequently used to a support a person's foot and to aid or correct
the accommodative function of the foot when walking. Shoe insoles
are often made from a material formed from a resilient semi-rigid
sheet of thermoplastic material.
[0005] Orthotics serve to properly adjust the orientation of a
person's foot during gait, thereby controlling the motion of the
foot in view of mitigating the effects of persons having anomalies
in a foot. A patent that describes such a podiatric orthosis is
U.S. Pat. No. 6,173,511 to Perrault, which describes an insole
formed to conformingly fit against the plantar portion of a foot
extending from the anterior metatarsal region to the heel portion.
The orthosis is positioned inside a shoe against the plantar
portion of the foot with the intermediate portion engaging the foot
arch. The heel portion of the orthosis has inner and outer rearward
extending residually deformable arms defining a rearward-opened
notch therebetween. The front portion of the orthosis has
concavities which prevent foot plantar lesions while promoting
stabilization and positional self adjustment of the orthosis inside
the footwear. An advantage of this orthosis is that the cup-like
heel seat partly surrounding the heel serves to concurrently
support the foot while allowing positional self-adjustment of the
orthosis inside the footwear.
[0006] Another example of a shoe insole, that extends to the ball
of the foot is shown in U.S. Pat. No. 6,282,816 to Rosendahl and
describes a stiff outer plastic shell molded to a dual foam inner
layer of rubber-like material and a fabric upper layer engages the
underside of the entire foot. A fabric top layer is provided that
is cut to the size of the footwear. Under the fabric layer is a
composite foam rubber layer that has a main part of soft rubber and
an arch part of dense/foam rubber. The composite layer is a
polymer-type material such as ethyl vinyl acetate. These two layers
are molded into one piece that makes up a foam sub-layer. A rigid
plastic outer shell made of nylon or the like is injection molded
and extends to the ball of the foot.
[0007] A multi-layered insole that underlays the entire foot is
shown in U.S. Pat. No. 5,718,064 to Pyle. The insole has a flexible
PVC outer member containing on its upper surface a polyurethane
insert for shock absorption that increases cushioning. The insole
may also have on the upper surface of the outer member a contoured
footbed formed of ethylene vinyl acetate.
[0008] In U.S. Pat. No. 6,025,414 to Rich there is disclosed an
insert for use in an athletic shoe made from a novel heat moldable
polymeric composition. The inserts can be placed at the tongue of
the shoe, at the heel and/or upon all or some of the length of the
insole. The moldable compositions include a combination of a blend
of a thermoplastic polymer such as polycaprolactone, a resiliency
component such as styrene-butadiene copolymer or styrene-isoprene
copolymer, and a softening agent, such as mineral oils.
[0009] U.S. Pat. No. 6,110,134 to Clark, Jr., et al. describes gel
padded thermoplastic splints. In particular, the synthetic splint
materials have a layer of gel-like viscoelastic padding.
Preferably, materials for the splint base include those synthetic
casting materials providing lightweight cast of low temperature
thermoplastic material, i.e., materials that soften under
relatively low heat, say, below 200.degree. F., and are capable of
being molded with hand pressure and subsequently harden to retain
the molded shape on a cooling without undergoing chemical change.
Some of the low temperature materials include such things as
poly(ethylene adipate), trans polyisoprene and polycaprolactone.
The padding material is bonded to the splinting material. The
padding materials found to be particularly effective include a
viscoelastic having a gel-like property such as polyurethane, a
polyvinyl chloride or a silicone material.
[0010] There are two classes of custom orthotics available: those
that used a cast of foot (in an unloaded position) as an
intermediate step and those that are accommodative and mold to the
foot in a loaded state. A problem associated with most shoe insoles
is that they are not custom fitted to the wearer's foot. The
subject invention overcomes this problem by providing a custom
molded shoe insole and a method for making same that is molded
directly to the foot and thus addresses any abnormality of the
foot, heel, arch or toes.
BRIEF SUMMARY OF THE INVENTION
[0011] It has been found that a foot support manufactured as part
of a footwear or inserted into the footwear conforming to at least
a portion of a user's foot may be custom molded from thermoplastic
materials. The custom foot support is molded from a piece of
thermoplastic material that may cover the entire bottom of the foot
or any portion the foot such as the heel, arch or toe or
combinations thereof. Preferably the foot support extends from the
heel to just short of the ball of the foot, including the
metatarsal arch and is molded to conform to the plantar portion of
the user's foot and inserted on top of the existing shoe insole or
in some cases replace the existing insole. After custom molding,
the foot support defines a monolithic resilient supportive member
having inner and outer lateral sides, a front portion, a rear
portion and an arch portion. The inner side of the support member
has a generally convex shape and provides and corrects the
accommodative function of the foot when walking. The outer side of
the supportive member has a generally concave shape for occupying
less volume inside the footwear; thus enhancing comfort of the
person using the foot support.
[0012] In a preferred embodiment, the arch portion of the
supportive member is arched for complementary engagement against
the foot plantar arch. Moreover, under the resiliency of the
supportive member due to the arched shape of arch portion, the
latter will have a positive substantially vertical spring-back
effect on the foot arch portion during gait, for promoting
corrective foot positioning. The front portion is integrally
frontwardly extending from the arch portion for complementary
engagement near the metatarsal plantar region of the foot. The rear
portion has a raised concave periphery formed from the molded
material for partial resting abutment of the person's heel onto the
sides for engagement around the heel portion of the foot. The
cup-like heel seat surrounds the heel to concurrently support the
foot which allowing positional self-adjustment of foot support
inside the footwear.
[0013] In one embodiment, the supportive member is fabricated from
an injection molded blank or a sheet of thermoplastic material,
that may be formed to shape in a custom application. Preferred
materials for the foot support are those low temperature
thermoplastic materials providing easily formable shapes that
soften at a plastic temperature between 120.degree. F. and
180.degree. F. and are capable of being molded and shaped with hand
pressure, and subsequently harden retaining the molded shape on
cooling without undergoing chemical changes. A low temperature
material, suitable for use as a foot support should soften at
sufficiently low temperatures so as to allow for molding directly
on the foot without injury due to scalding or burning of the skin.
Suitable polymers include poly(ethyleneadipate),
poly(epsilon-caprolactone), polyvinyl stearate, cellulose acetate,
butrylate and ethyl cellulose poly (propylene oxide) containing
co-monomers, trans polyisoprene and cis polyisoprene based
thermoplastic materials, and polycaprolactone based materials.
[0014] The invention also contemplates a method for custom forming
the supportive member. The thermoplastic material is placed in hot
water and between 120.degree. F. and 180.degree. F. At this
temperature the thermoplastic material becomes very pliable. The
softened thermoplastic material is then applied to the bottom of
the foot, while the foot is preferably in a non-weight bearing
position. When the soft material is applied to the foot it is
molded by hand to all the curves and dimensions of the foot from
around the heel up to and including the metatarsal arch and toes,
if desired. After molding, the shaped foot support is allowed to
set. Setting takes place within about 60 seconds. It may take
another three to five minutes to fully cure and cool. Once cooled
the foot support is placed within the shoe and will support the
foot heel pain arch metatarsal arch comfortably. The foot support
comes in different sizes, but due to the unique moldability of the
thermoplastic material to fit different feet, multiple sizes may
not be necessary.
[0015] In addition to the use of thermoplastic materials that
soften at low temperature, the custom formed foot support of the
present invention may be made using chemicals that are reacted at
the time of custom molding that will polymerize to the desired
shape when molded to the bottom of a foot while the foot is in a
non-weight bearing position. Suitable thermoplastic materials
include materials for forming polysilicone polymers.
[0016] In yet another embodiment of the invention a footbed
assembly is formed of a plurality of members including a cushioning
top layer overlaying at least a portion of the resilient molded
thermoplastic foot support. The footbed assembly may include at
least one member made of textile, leather or synthetic material to
provide comfort against the skin. In addition, the footbed assembly
may include at least one member made of foam to cushion the foot
against the rigid supportive member. A suitable cushioning top
layer is one that may be readily bonded to the molded thermoplastic
foot support after the custom molded foot support formed. Bonding
may be accomplished by any of several known suitable systems. The
cushioning top layer may be ethyl vinyl acetate (EVA) foam, a
Plastizote.RTM. material or the like. The cushioning layer extends
continuously over the upper surface of the supportive member. The
supportive member may also include cut outs and dimples to provide
extra shock-absorption and comfort to the user's foot.
[0017] It is an object of the present invention is to provide a
foot support for engagement inside footwear and for conformingly
fitting against a user's foot for compensating podiatric
deficiencies.
[0018] Another object of the present invention is to provide a
footbed assembly having a plurality of layers that provide comfort
against the skin and cushion the foot against the rigid supportive
member.
[0019] Yet another object of the present invention is to provide
footwear having the supportive member of the present invention.
[0020] Still another object of the present invention is to provide
a method for forming a molded foot support that is conformingly
fitting against a user's foot made from a low temperature softening
thermoplastic material.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING(S)
[0021] The foregoing and other objects, advantages and features of
the invention, and manners in which the same are accomplished, will
become apparent from the following detailed description of the
invention taken in conjunction with the accompanying drawings which
illustrate preferred and exemplary embodiments wherein:
[0022] FIG. 1 illustrates the supportive member of the molded foot
support of the present invention conforming to the plantar region
of the right foot of a person;
[0023] FIG. 2 is a perspective view of the molded supportive member
of the foot support of a right foot conforming to the plantar
region of a user's foot according to the present invention;
[0024] FIG. 3 is a side view of the molded supportive member of the
present invention;
[0025] FIG. 4 is a top plan view of the molded supportive member of
the present invention;
[0026] FIG. 5 is a sectional view of the molded foot support taken
along lines 5-5 of FIG. 4; and
[0027] FIG. 6 is another embodiment of the present invention
illustrating an example of the footbed assembly.
DETAILED DESCRIPTION OF THE INVENTION
[0028] The present invention now will be described more fully
hereinafter with reference to the accompanying drawings, in which
some, but not all embodiments of the invention are shown. Indeed,
these inventions may be embodied in many different forms and should
not be construed as limited to the embodiments set forth herein;
rather, these embodiments are provided so that this disclosure will
satisfy applicable legal requirements. Like numbers refer to like
elements throughout.
[0029] There is shown in FIG. 1 a preferred embodiment of the
custom molded foot support 10 of this invention. Foot support 10 is
a piece of thermoplastic material that extends from the heel to
just short of the ball of the foot, but includes the metatarsal
arch molded to conform to the plantar portion of the user's foot
and inserted on top of the existing shoe insole or in some cases
replace the existing insole. The foot support 10 defines a
monolithic resilient supportive member 20 defining inner and outer
lateral sides 22, 23, a front portion 24, a rear portion 25 and an
arch portion 26 between the front portion 24 and the rear portion
25. One of the advantages of this invention is that because each
foot may not be a mirror image of the other each orthosis may be
custom molded to precisely correspond to the feet of each
individual. The inner side of supportive member 20 has a generally
convex shape and provides a corrective effect on the posture or
shape of the user's foot. The outer side of supportive member 20
has a generally concave shape for occupying less volume inside the
footwear; thus enhancing comfort of the person wearing the foot
support. The surface shape of the supportive member 20 may created
to form an accommodative effect for the posture or shape of the
user's foot. It will be understood by those skilled in the art that
the foot support 10 of the present invention may be used to address
any portion of the foot, the heel, the arch, the toes and the like.
While a preferred embodiment is shown in FIG. 1, it should be
understood that the invention is not limited to the length that is
shown in FIG. 1.
[0030] The arch portion 26 of supportive member 20 is arched for
complementary engagement against the foot plantar arch as shown in
FIG. 3. Moreover, due to the resiliency of supportive member 20 and
to the arched shape of arch portion 26, the latter will have a
positive substantially vertical spring-back effect on the foot arch
portion during gait, for promoting corrective foot positioning.
[0031] The front portion 24 is integrally frontwardly extending
from the arch portion 26 for complementary engagement near the
metatarsal plantar region of the foot. In a preferred embodiment,
the front portion 24 has a sinuous front edge 29 comprising a
series of or recesses 30, 30a, and 30b, to form a number of
frontwardly facing arcuate concavities. Front edge 29 is generally
frontwardly convex so as to conform to the forefoot configuration.
The upper surface of supportive member 20 may also have dimples
thereon to provide extra shock-absorption and comfort to the user's
foot.
[0032] The rear portion 25 has a raised concave periphery 28 formed
from the molded material for partial resting abutment of the
person's heel onto the sides for engagement around the heel portion
of the foot. The cup-like heel seat surrounds the heel to
concurrently support the foot which allowing positional
self-adjustment of supportive member 20 inside the footwear.
[0033] In use, foot support 10 is positioned inside a footwear (not
shown) against the plantar portion of the foot with the arch
portion 26 conformingly engaging the underface of the foot arch.
The rear portion 25 engages the heel of the person's foot. Raised
periphery 28 complementarily engages the heel of the foot so as to
partly surround the heel so as to form a cup-like seat for the heel
and thus assist positioning the foot support in its proper
position.
[0034] Thus, positional self-adjustment of the foot support is
accomplished during gait by the load of the person being applied on
his heel and against the raised periphery 28 that is yieldingly
resiliently moved apart and pressed against the footwear inner
walls to correctly re-position the support in the footwear if
accidental temporary displacement of the support occurs. The raised
periphery 28, in addition to promoting positional self-adjustment
of the supportive member 20 in the footwear, also provides positive
foot support to enhance corrective foot positioning in the
footwear. The supportive member 20 comes in different sizes, but
due to the unique moldability of the thermoplastic material to fit
different feet, multiple sizes are not necessary.
[0035] The supportive member 20 shown in FIG. 4 is another view of
the molded foot support of the present invention showing front
portion 26 and a rear portion 25. Located on the upper surface of
the foot support are a number of indentations or ribs 34 located on
the bottom surface. A cut out 32 is located toward the rear or arch
portion 26. The cut out or hole in the heel area allows a reduction
in height of the foot support in this region. This is important not
to increase the height of the foot and thus the user which may
cause close fitting footwear, such as shoes, boots, skates and ski
boots to fit improperly after the foot support is in place.
[0036] It will be understood by those skilled in the art that the
foot support 10 may be manufactured as a component of the footwear
on the interior thereof and removed from the footwear for custom
fitting replaced in the footwear. The foot support is normally used
at temperatures between -20.degree. F. and 125.degree. F.
[0037] Particular advantage is achieved in the present invention by
fabricating the supportive member 20 from an injection molded blank
or a sheet material (which has been precut to a preferred
configuration), so that the surface may be later shaped to form a
custom application. Preferred materials for the foot support are
those low temperature thermoplastic materials providing easily
formable shapes. Low temperature thermoplastic and thermoset
materials are those which soften at a plastic temperature between
120.degree. F. and 180.degree. F. and are capable of being molded
and shaped with hand pressure, and subsequently harden retaining
the molded shape on cooling without undergoing chemical changes.
Many of these materials change color and opacity when heated to
their softening point. A low temperature material, suitable for use
as a supportive member should soften at sufficiently low
temperatures so as to allow for molding directly on the foot
without injury due to scalding or burning of the skin. The
materials in its softened state should permanently deform under a
load of 15 psi. Suitable polymers which melt or soften at
temperatures between 120.degree. F. and 180.degree. F. include
poly(ethyleneadipate), poly(epsilon-caprolactone), polyvinyl
stearate, cellulose acetate, butrylate and ethyl cellulose poly
(propylene oxide) containing co-monomers, trans polyisoprene and
cis polyisoprene based thermoplastic materials, and
polycaprolactone based materials. In a preferred embodiment of the
present invention, the thermoplastic material is polycaprolactone.
The softening point of polycaprolactone is about 140.degree. F.
[0038] The invention also contemplates a method for custom forming
the supportive member 20. The thermoplastic material has a
softening point and molding temperature sufficiently low that the
material may be heated in a conventional manner such as in hot
water, in a microwave, or in a conventional oven, or with a heat
gun. Microwave ovens are particularly useful for heating and
softening the composition for fitting, as is heated water. In
practice, the supportive member may be placed in a forming tray
that can contain at least 500 ml of hot water and allowed to
soften. A conventional oven may also be used. Additionally, wire
filaments may be place into the thermoplastic material. When an
electric current is applied to the wire filaments the resulting
heat will soften the thermoplastic. The thermoplastic material can
be refitted and reused by simply reheating. The preferred
thermoplastic materials of this invention become pliable like a wet
noodle between the temperatures of 120.degree. F. and 180.degree.
F. The softened thermoplastic material is then shaped and detailed
to the bottom of the user's foot. The supportive member is
preferably formed while the user's foot is in a non-weight bearing
position but it should be understood that the molding may be
accomplished while the user's foot is in a weight bearing position.
The soft material is applied to the foot is molded by hand to all
the curves and dimensions of the foot from around the heel up to
and including the metatarsal arch and toes, if desired. After
molding, the material is allowed to set. Setting usually occurs
quickly, often within about 60 seconds. It may take another three
to five minutes to fully cure and cool. Once cooled, the foot
support is ready to use and may be placed within the shoe and will
support the foot heel pain arch metatarsal arch comfortably. Skin
burns during the molding process are avoided because of the low
molding temperature of the thermoplastic. Further, the
composition's low molding temperature allows the thermoplastic
material to be held against the user's foot. When cooled, the
thermoplastic material preferably will not permanently deform under
25 psi and will have a flexural modulus of CAPA 6500 of about 300
to 500 MPa (ASTM D790) at normal use temperatures.
[0039] In addition to the use of thermoplastic materials that
soften at low temperature, the custom formed supportive member 20
may be made using two chemicals that are reacted at the time of
custom molding that will polymerize to the desired shape when
molded to the bottom of a foot while the foot is in a non-weight
bearing position. Suitable thermoplastic materials include, for
example, polysiloxanes. Suitable materials for forming polysilicone
polymers are available from Silcones, Inc. and DowCorning.
[0040] The present invention also contemplates yet another
embodiment. This embodiment, that is shown in FIGS. 5 and 6,
provides a footbed having a cushioning top layer 35 overlaying the
resilient molded supportive member 20. The primary purpose of the
cushioning top is to form a cushion absorbing layer to cushion the
foot. The footbed assembly may include at least one member made of
textile, leather or synthetic material to provide comfort against
the skin. In addition, the footbed assembly may include at least
one member made of foam to cushion the foot against the rigid
supportive member. A suitable cushioning top layer is one that may
be readily bonded to the molded supportive member 20 after the
custom molded supportive member is formed. Bonding may be
accomplished by any of several known suitable systems including
adhesives such as elastomers, epoxies and the like. The cushioning
top layer 35 may be ethyl vinyl acetate (EVA) foam, a Plastizote
material or the like. A preferred material for the cushioning layer
35 is 9 pound ethylene vinyl acetate (EVA) having a specific
gravity in the range of 0.15 to 0.40 and a Shore C diameter range
of 25 to 45. The cushioning layer 35 extends continuously over the
upper surface of the foot support 10 and the insert 35 (shown in
FIG. 5) in cutout 32 to completely cover the same. The cushioning
top layer may also include a second material in the heal area that
is more suited to absorbing shock such as a visco gel material. The
cushioning layer 35 is trimmed to the proper shape of the foot
support. It should be understood that the custom molded monolithic
thermoplastic material resilient supportive member 20 does not
necessarily require the top layer of cushion absorbing
material.
[0041] Many modifications and other embodiments of the inventions
set forth herein will come to mind to one skilled in the art to
which these inventions pertain having the benefit of the teachings
presented in the foregoing descriptions and the associated
drawings. Therefore, it is to be understood that the inventions are
not to be limited to the specific embodiments disclosed and that
modifications and other embodiments are intended to be included
within the scope of the appended claims. Although specific terms
are employed herein, they are used in a generic and descriptive
sense only and not for purposes of limitation.
* * * * *