US2495045A - Laminated plastic removable insole - Google Patents

Description

Jan. 17, 1950 R. 1 WOODBURY Er Al.

LAMINATED PLASTIC REMOVABLE INsoLE Filed Dec. 8, 1942 page INV ToRf ood mty 4,

, Ml p jffoR/vey Patented Jan. 17, 1950 LAMINATED PLASTIC REMUWABLE INSLE Robert L. Woodbury, United States-Army, Litchfield, Conn., and Earl P. Hanson, Long Island City, N. Y.

Appiicaticn December 8, 1942, Serial No. 463,192

(El. SG--MJ (stratified under the met of March 3, i883, as amended April 30, i928; 37?@ fl. G. "157) 6 Claims.

The invention described herein, if patented, may be manufactured and used by or for the Government for governmental purposes, Without the paymentto us of any royalty thereon.

The present invention relates to footwear, and more specifically to a removable insole adapted to be placed in any conventional type of shoe to provide greater comfort, aid in overcoming effects of excessive perspiration, make possible more effective control of foot infections, and to provide a more sanitary, more comfortable and generally more desirable insole than heretobefore lfnown or used.

The prime object of the present invention resides in the provision of a removable shoe insole comprising one or more layers of open weave, woven plastic fabric, the fabric being of the mono-filament type and of a plastic composition impervious to the effects of perspiration, so that although the individual strands of the fabric are entirely non-porous and non-absorbent, the open weave will permit unrestricted drainage and ample ventilation.

A further object of the invention resides in the provision of a removable shoe insole consisting of a plurality of layers of plastic fabric, the plastic being of a substantially non-hygroscopic composition, unaifected appreciably by temperatures in the range of 212 F. and of flexible mechanical characteristics, so that the insole may be cleansed and disinfected by boiling, without materially damaging the structure of the insole or altering the chemical composition of the plastic.

A further object of the invention resides in the provision of a removable insole of mono-filament plastic fabric adapted to retain reasonably its resilient characteristics and maintain an eiective air space between the foot of the wearer and the sole of the shoe to insulate the foot and provide greater comfort to the wearer under conditions of extremely high temperatures; as for example, combat conditions in tropical or desert cui l do not tend to accumulate.

These and other objects are accomplished in the present invention by the provision of an insole structure including one or more layers of open mesh fabric wherein the individual strands of the fabric are composed of a plastic composition that is insoluble and non-absorbent. Further, the present invention makes use of a mono-filament fabric; that is, a fabric wherein each individual strand is continuous, solid, resilient, non-porous, and non-absorbent, as distinguished from a thread made up of a multiplicity of relatively short hygroscopic strands of fibers.

The use of the mono-filament plastic fabric accomplishes certain unobvious and very desirable results in the reduction of foot infections and increase in foot comfort, for several reasons.

First, the individual strands of the fabric layers retain their springy resilient qualities even when the shoe is worn under conditions of extreme heat and humidity sumcient to cause excessive perspiration. Under such conditions, it is well known that any ordinary fabric becomes thoroughly soaked with moisture and matted into a soggy pad. having little or no cushioning effect, and entirely impervious to the circulation of air. In contrast, an insole manufactured according to the teachings of this disclosure'retains its full normal thickness and resiliency, since theindividual strands of the fabric absorb no moisture.

Further, since the mono-filament plastic fabric exhibits no tendency to flatten or mat, the interstices between the individual strands of the fabric are at all times open and unobstructed. This characteristic serves a dual function in that it provides full unobstructed drainage through the insole and since it permits a free and constant circulation of air throughout and between the individual insole layers, thus providing effective ventilation for the foot.

In addition, the characteristic of maintaining this air space within the insole provides a sufficient thermal insulating layer so that the shoe may be worn under excessively high temperature conditions without great discomfort.

3 Referring now more particularly to the drawing attached to and forming a part of the present specification:

Figure 1 is a plan view of an insole constructed in accordance with the teachings of this disclo-l sure.

Figure 2 is an enlarged detail sectional view taken substantially on the plane of the line 2-2 of Figure 1.

Figure 3 is an enlarged detail sectional view similar to Figure 3 and illustrating a modified form of edge binding for the insole.

The insole, generally indicated at I0, consists of a plurality of layers of fabric II, I2, I3, Il, and I5, formed to correspond with the shape of the inside of a shoe and bound together around their marginal edges. As illustrated in I and `i! of the drawings, the individual layers of fabric are united by a binding strip I8 stitched to the fabric layers by a line of stitches Il.

Any one of several types of binding may be used for the purpose, it being contemplated that the binding strip I6 may be of plastic, composition, rubber, fabric, leather, or any other flexible material having satisfactory wearing qualities. Further, the invention is not regarded as limited to a stitched edge binding and it is contemplated that the several layers of plastic fabric may be brought together at the edges and sealed by fusing the individual layers of the plastic together at the extreme edge, to form a fused binding I8 as illustrated in Figure 3, or by cementlng.

The novelty of the present invention resides particularly in the provision of a removable insole wherein the individual layers of fabric are composed of an insoluble and non-absorbent open mesh plastic fabric of the mono-filament type, having each individual thread of the fabric lformed of 'an extruded, solid, non-porous, and

non-absorbent' filament of plastic material.

It is contemplated that satisfactory results may be obtained by such a mono-illament plastic fabric in any one of a wide range of mesh gauges and strand sizes, but highly satisfactory results have been obtained by the use of a fabric of square mesh, sixteen or eighteen strands to the inch, and having an individual strand diameter of .016 inch. Satisfactory results have also been obtained by the use of a square mesh fabric of twenty-four strands to the inch, wherein the individual strands have a diameter of .0125 inch. It is to be noted, however, that each of these fabrics is of the open weave type, having the spaces between the individual strands wider than the diameter of the strands, so that air may circulate freely through the fabric.

Further, it is believed that any one of a number of commercially known plastics may be successfully used, though it may be stated that entirely satisfactory results have been obtained by the use of a copolymer vinyl ester (e. g. vinyl chloride) and vinylidene chloride plastic of the type described in U. S. Patent No. 2,160,931 and produced commercially by the Dow Chemical Company under the name of Saranl It is also contemplated to be within the scope of this invention to use any number of layers of fabric having the same or different mesh gauges and any possible combination of fine mesh and coarse mesh fabrics, but it is found advantageous under certain circumstances to provide a relatively fine mesh fabric II on the upper surface of the insole and a plurality of layers of abutting coarser mesh I 1 I3, I4 and I5 below the fabric II to space it above the sole of the shoe. When 4 so constructed, satisfactory results have been obtained by the use of plastic fabric of a mesh of 24) strands to the inch for the upper layer and a plastic fabric of 16 to 18 strands to the inch for the lower layers I 2, I3, I4, and I5.

It will be readily understood that when the liner fabric is used on the upper surface of the insole, any particles of dirt, sand or other foreign matter that may work through the finer fabric will easily pass through the coarser lower layers of fabric. Thus the dirt will eventually be discharged through the lower layer of fabric, and the porosity of the insole will not be apt to be lessened by excessive accumulation of dirt.

Further, it may be pointed out thatsince the chemical composition of the plastic utilized is such that it will not soften excessively in high temperature, the insole may be cleansed and sterilized by boiling. R f

It is also contemplated that, if desired, beneilcial results may be obtained by inserting a medicated fabric layer between the layers of fabric heretofore described, so that the medicament will be gradually dissolved or disseminated by means of heat and perspiration incident to use asthe insole is worn,'to provide a constant antiseptic tending to maintain the insole in a completely sterile condition at all times. Paraformaldehyde, trioxymethylene and menthol, with or without the addition of boric acid, are possible medicaments, though vother suitable substances may be employed. A` medicated pad as thus de'- scribed may be of any size and shape, though it is contemplated that it will probably be most satisi'a'ctory in the general conguration indicated at I9 in the drawings, spaced and located to provide medicament in the vicinity of the toes of the shoe. a

From the foregoing, it will be apparent that the practice of the present invention will result in an insole structure having properties not heretofore known in the art. Further, it is submitted that the new properties represent a substantial contribution to the art to which the invention relates, in that the result in a more comfortable device than heretofore known, as well as in a device that is more sanitary, more effective as an insulator, more easily cleaned, and capable of providing more effective drainage and ventilation.

In conclusion, it is believed pertinent to point out that the present preferred embodiment of the invention illustrated in this application has been developed with the view toward meeting present military requirements, but that the invention is believed to have great value in civilian and commercial fields as well. It is therefore requested that the scope of the inventive thought of this application be regarded as limited only by the terms of the appended claims.

Having thus described our invention, what we claim as new and desire to secure by United States Letters Patent is:

1. A shoe insole comprising a plurality of layers of open weave plastic fabric superimposed upon one another; each of the fabric layers consisting of a multiplicity of solid, resilient, nonporous, non-hygroscopic, extruded strands of temperature resistant, flexible plastic; the strands being woven together into an open mesh fabric having the interstices between the individual strands Wider than the diameter of the individual strands: all of the fabric layers being cut to a size and shape approximately the size and shape of a human foot and all of the layers being fused ether around their marginal edges.

4. An inner sole for a shoe or the like compris# ing a plurality of woven webs of thermoplastic threads having a welded joint about its periphery, the said inner sole when free of load being convex in cross-section and having a.` greater thickness within the welded vperipheral joint than at the welded peripheral Joint.

5. A .plastic inner sole comprising a plurality of superimposed layers of inner sole shapes fused together along the edges, said layers comprising relatively coarse intermediate layers and a ne outer layer.

6. A plastic inner sole comprising a. plurality of es superimposed woven layers of inner sole shapes fused together along the edges. said layers comprising relatively coarse intermediate layers and a iine outer layer. and a medicated pad positioned between two of said woven layers.

ROBERT L. WOODBURY. EARL P. HANSON.

REFERENCES CITED The following references are of record in the le of this patent:

UNITED STATES PATENTS Number Name Date 1,106,986 Stucki Aug. 11, 1914 2,121,604 Lynch June 21, 1938 2,183,602 Wiley Dec. 19, 1939 2,244,844 Margel June 10, 1941 2,312,089 Gobeille Feb. 23, 1943 FOREIGN PATENTS Number Country Date,l

25,781 Great Britain 1903 540,521 Germany Jan. 28, 1932

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