U.S. patent number 3,895,405 [Application Number 05/501,554] was granted by the patent office on 1975-07-22 for adjustable insole and method.
Invention is credited to Clyde A. Edwards.
United States Patent |
3,895,405 |
Edwards |
July 22, 1975 |
Adjustable insole and method
Abstract
A polyurethane foam of comparatively high density for firmness,
and yet resilient and flexible, is provided with a cover of
simulated leather poromeric material. This is heated while in a
shoe, and formed by the foot, while still hot, to conform to
contours of the foot. Specific locations therein may be further
formed to accommodate for excrescencies, by localized heating,
manual deformation, to provide excrescency accommodating
concavo-convex features on the insole, the convex portion of which
is trimmed flush with the remainder of the insole, which is then
later reinserted in the shoe.
Inventors: |
Edwards; Clyde A. (Muncie,
IN) |
Family
ID: |
23994035 |
Appl.
No.: |
05/501,554 |
Filed: |
September 12, 1974 |
Current U.S.
Class: |
12/146M; 36/43;
36/93; D28/12; 36/88 |
Current CPC
Class: |
A43B
7/28 (20130101) |
Current International
Class: |
A43B
7/14 (20060101); A43B 7/28 (20060101); A43d () |
Field of
Search: |
;12/146M,146B,142N
;36/43 |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Guest; Alfred R.
Attorney, Agent or Firm: Woodard, Weikart, Emhardt &
Naughton
Claims
The invention claimed is:
1. A method of fitting an insole in a shoe and comprising the steps
of:
placing in a shoe a flexible insole member;
heating said member to a temperature sufficient to cause said
member to lose at least some of its resiliency;
placing a foot in the shoe before said member has regained its
resiliency; and
taking steps with the foot in the shoe until the member has
regained its resiliency.
2. The method of claim 1 wherein:
the step of heating said member includes the step of placing a heat
gun directly into the shoe and blowing hot air from the heat gun
into the shoe.
3. The method of claim 2 wherein:
the step of heating said member further includes the step of
keeping the heat gun in the shoe while blowing hot air therefrom
for thirty seconds.
4. The method of claim 3 and further comprising the steps of:
removing the foot from the shoe;
placing a pressure transferrable mark on an excrescency on the
bottom of the foot;
placing the foot in the shoe and stepping with the foot in the shoe
to transfer the mark to the insole;
removing the foot and insole;
applying localized heat to the bottom of the insole immediately
below the transferred mark;
placing pressure on the marked spot on the insole to produce a
bulge at the heated location only;
trimming off the bulge after the material cools; and
replacing the insole in the shoe.
5. The method of claim 4 wherein:
the bulge is trimmed off flush with the portion of the insole
adjacent thereto.
Description
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates generally to footwear, and more particularly
to means and a method of accommodating footwear to the individual
characteristics and features of the foot of the wearer.
2. Description of the Prior Art
It is known to use removable insoles, many of which are well known
and widely marketed. Typical of these is one made of foam rubber or
latex with some kind of cloth or fabric covering. While these serve
a purpose of filling an oversized shoe, and sometimes reduce some
pain and discomfort, they do not readily retain after use, the
shape which they have during use. In addition, they do not lend
themselves to modification in a meaningful way to particular
irregularities of the feet. There has remained a need for some way
in which a shoe can be better tailored to the foot on which it is
worn. While it is conceivable that shoes can be hand-made and
tailored to the particular foot on which they are to be worn, as a
practical matter, this is beyond the reach of most individuals. So
there has remained a need for tailoring factory made shoes to the
feet of the individual.
SUMMARY OF THE INVENTION
Described briefly, according to a typical embodiment of the present
invention, a firm, but resilient, flexible foam member is placed in
a shoe and conformed to the shoe. By heating the member while in
the shoe and then placing the foot on it in the shoe, and stepping
with the foot, the member is conformed to the foot. In the event
the foot has one or more excrescencies thereon, by localized
heating of the member, and manual deformation thereof at the
locality of such excrescency, and subsequent trimming of the convex
portion of the deformation from the member, and replacing the
member in the shoe, the insole is tailored not only to the shoe and
foot, but also to specific features of the foot.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a top plan view of an insole cut from a sheet of
material.
FIG. 2 is an elevational view thereof.
FIG. 3 is a side view of the insole conforming to a foot.
FIG. 4 is a view showing application of heat to the insole while in
the shoe.
FIG. 5 is a view showing the foot forming the insole in the
shoe.
FIG. 6 is a side view of the insole removed from the shoe.
FIG. 7 is a front view of the insole removed from the shoe.
FIG. 8 is a view showing the marking of the stocking at an
excrescency of the foot.
FIG. 9 is an illustration of the localized heating of a spot on the
insole bottom opposite the mark transferred to the insole top.
FIG. 10 is a perspective view of an insole adjusting tool.
FIG. 11 is an illustration of the application of the insole
thereto.
FIG. 12 is an illustration of the actual forming of a
concavo-convex irregularity or bulge in the insole to accommodate
the excrescency.
FIG. 13 is an illustration showing the removal of the convex
portion thereof.
FIG. 14 shows the foot in the shoe with the insole (shown in
section through the bulge) as thus modified to accommodate the
excrescency.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring to the drawings in detail, FIGS. 1 and 2 show the insole
assembly 10 in the flat condition as it is before application
thereto of the method of this invention. The insole assembly
includes the cushion member 11 made of a resilient, heat deformable
material. An example of a suitable material is a polyurethane foam
based material known as "Pelite" as marketed by Fillauer
Orthopedic, of 936 East Third Street, Chattanooga, Tennessee 37401,
as their stock number 6011-5F Pelite having a density of A-20 and a
five millimeter thickness. This foam member has a cover 12 which is
typically a poromeric material which is both flexible and porous
and absorbent. An example is "Poron 200" marketed by the Poron
Division of Rogers Corporation, of East Woodstock, Connecticut
06244. This cover is about one millimeter thick and is adhered to
the top of the foam member. This assembly may be cut from a large
sheet into the general shape of a shoe as shown in FIG. 1. For a
particular individual, the shape is adapted to the particular shoe
with which he will wear the insole.
FIG. 3 shows the insole assembly 10 conforming to the contours of
the foot 13, and the material is flexible enough to be easily
formed by holding it up against the bottom of the foot by the
hand.
FIG. 4 shows the insole assembly 10 in the shoe 16 and a heat gun
17 held in the hand with its nozzle 18 at the top of the shoe
directing hot air into the shoe. An example of a heat gun suitable
for this purpose is model HG301 flameless electric heat gun
marketed by the Master Appliance Corporation of Racine, Wisconsin.
With the air shutter of this gun open, the average temperature at
the nozzle face is 475.degree. F., the air flow is 15.5 cubic feet
per minute (C.F.M.) and the available air velocity is 2,250 feet
per minute (F.P.M.). With the gun so disposed, the insole in the
shoe is heated for thirty seconds. This makes the foam lose part of
its resiliency, but does not destroy or damage it. Then the foot is
placed in the shoe as shown in FIG. 5. The person takes a few steps
with his foot in the shoe and does so until the material has cooled
sufficiently for the resiliency to return to the foam. In this way,
the insole conforms to both the shoe and the foot and will remain
so, even though the foot is later removed. This is indicated in
FIGS. 6 and 7 which show the insole after removal from the shoe
after forming as described above. The portions 21 are at the sides
of the arch in the foot and portions 22 and 23 are at the toe and
heel, respectively. The material is such that it can be carved and
shaved or ground if desired for any further fitting.
After the above described procedure has been completed for one foot
and shoe, it is repeated for the other foot and shoe. This
procedure enables insoles to be conformed to the natural contour of
the foot in a short time. It provides a firm, yet soft, resilient
support.
In order to accommodate plantar excrescencies, such as corns,
callouses, and depressed metatarsal heads, a few additional steps
are taken. First, the steps previously described are performed.
Then, as shown in FIG. 8, a transferable mark 24 is placed on the
foot (or stocking if one is being worn at the time) at the location
of the excrescency 25. A material readily transferable is lipstick
26. Then the foot is placed in the shoe on top of the insole
therein, which was already formed as shown in FIGS. 5, 6 and 7, for
example. Then a few steps are taken, during which the lipstick mark
will transfer onto the insole. Then the insole is removed from the
shoe and the heat gun nozzle 18 is placed directly on the bottom of
the insole at 27, directly opposite the transferred lipstick mark.
It is thus heated locally until the foam loses its resiliency at
that spot. Thirty seconds is usually sufficient for this purpose
with the heat gun described above. Then the insole is placed on the
insole adjustor form 28. This form is a piece of plastic shaped
like an insole pattern, with three indentations in it. One is for
metatarsal depression; the second is for metatarsal raise; and the
third is for heel spur depression.
The insole is placed on the insole adjustor with the heated spot
directly over that one of the indentations of the adjustor which
most nearly matches the excrescency of the foot. The heated spot
(at the lipstick mark) is depressed directly into the depressed
area of the insole adjustor. The amount of pressure is according to
how deep the impression 29 is to be made. An example of this
operation is shown in FIG. 12 where the forefinger is used to apply
the pressure. The result is that the insole, when cooled with the
pressure still applied, has a concavo-convex irregularity or bulge
in it, which was maintained by the finger pressure until the
material cooled sufficiently for its resiliency to return. Then the
insole is removed from the insole adjustor and the portion 31 of
the bulge is removed by shaving or trimming with a knife 32 as
shown in FIG. 13. Thus, the convex portion is removed so that the
portion opposite the lipstick mark is again flush with the rest of
the bottom of the insole adjacent the heated spot.
Then the insole is placed back in the shoe and the shoe is placed
on the foot. The excrescency 25 fits comfortably into the concavity
29 as shown in FIG. 14. The insole no longer interferes with the
normal function of the foot. It thus relieves any excessive
pressure that would be caused by a flat, ordinary insole.
It may be recognized by those skilled in the art that for the
initial shaping of the material it is possible to first heat it in
an oven, and then place it in the shoe before cooling, instead of
first placing it in the shoe and heating it with a heat gun.
However, the heat gun method is much preferred from the standpoint
of its convenience and controllability. It is preferable that the
foam material not exceed 225.degree. to 325.degree. F. temperature,
and the specific temperature limit will depend on the specific
material used so that when it cools, the resiliency will not be
lost. Thus, while it is desired to permanently form it by stepping
on it with the foot in the shoe, to conform to the contours of the
foot, it is desirable that the material retain its cushioning
feature, when cooled.
* * * * *