US 3895405 A
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.
Description (OCR text may contain errors)
United States Patent Edwards y July 22, 1975 ADJUSTABLE INSOLE AND METHOD Primary Examiner-Alfred R. Guest 2722 W. J k  Inventor g ac gg izg a ac son Attorney, Agent, or Firm-Woodard, WeIkart,
Emhardt & Naughton  Filed: Sept. 12, 1974 [2i] Appl. No.: 501,554 [57} ABSTRACT A polyurethane foam of comparatively high density  US. Cl. 12/146 M for firmness, and yet resilient and flexible, is provided  Int. Cl A43d V with a cover of simulated leather poromeric material.  Field of Search 12/l46 M, I46 B, I42 N; This is heated while in a shoe, and formed by the foot,
36/43 while still hot, to conform to contours of the foot. Specific locations therein may be further formed to ac-  References Cited commodate for excrescencies, by localized heating.
n STATES TENTS manual deformation, to provide excrescency accom- 2 136 815 [1938 Forster a 12" Mx modating concavo-convex features on the insole. the 2523339 7/1943 Hyland et al: 12/142 N Pom)" which is immed flush with 2:409:594 1/1946 Sherman I 12/146 M mainder of the insole, which is then later reinserted in 2,688.760 9/1954 Forte l2/l46 M the shoe 2,742.657 4/1956 Sloane.... l2/146 M 2,838,776 6/1958 Tax l2/l42 N 5 Claims, 14 Drawing Figures SREET PATENTED JUL 22 ms Fig.14
ADJUSTABLE INSOLE AND METHOD 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 de formation 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. I 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 concave-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 F illauer 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 R0- gers 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 I-IG301 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 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 to 325 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.
The invention claimed is: l. 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.