US 2599317 A
Abstract available in
Claims available in
Description (OCR text may contain errors)
`lune 3, 1952 D R, BRADY 2,599,3l7
SHOE INSOLE Filed Aug. 2, 1946 Flzl.
A TTORNEYJ Preferably the fabries 24 are woven of yarns of glass fibers of the continuous type, that is, yarns in which a multiplicity of fine glass fibers or filaments, usually about .0003 inch or less in diameter, are intertwisted and are of such length as to extend substantially continuously throughout any 'given length yarn. Fabrics made from these yarns may be of a thickness no greater than several thousandths of an inch and are ideally suited for incorporation in the present insole construction because three or four or more layers of fabric may be employed to obtain the desired flexibility and strength while still providing a sole as thin or thinner and lighter in weight than previous leather insoles.
The insole IB is constructed by impregnating a plurality of fabric layers with a selected ordinary laminating resinous material, then drying the resin impregnant, if desired, and then laying up the fabric layers in superposed relation over a form of desired shape. The superposed layers are then held in intimate contact with each other and held to the form by pressure exerted by means of an expansible rubber-bag or in other suitable fashion.
At the arch portion of the insole additional layers of resin-impregnated fabric 29 may be laid up over the previously applied fabric layers to thicken the arch portion as shown in Figures 1 and 3 and form a rib 3| that serves to stiifen the arch portion of the insole and provide support for the arch of the wearer's foot. Adjacent the arched portion the fabric layers may also be cut and fitted to form flanges 32, 33 that will closely fit the arch of the wearer's foot to provide additional support so that the arch of the foot is fully engaged by a supporting surface corresponding in shape closely to the shape of the arch.
If desired, however, the insole of the present invention may vbe made substantially flat throughout, similar to conventional leather insoles, and metal or other stiffeners may be fastened to the insole at the lower side of the arched portion following conventional practice. Also in certain cases as in the manufacture of insoles for athletic shoes it may be desirable to employ less fabric layers in the instep portion, as in the region 35 of the insole U8 of Fgure 4, than in the balance of the insole to provide the greater flexibility at the arch portion of the insole that has been found desirable in these and certain other types of shoes. In such cases, the portions 36 and 31 of the sole underlying the ball and heel of the foot are desirably of sufficient thickness to be rigid underthe stresses accompanying use of the shoe, with the portion 35 being suiciently flexible to permit flexing of this portion during fiexing of the foot.
As shown in Figure 5, wherein similar parts are designated by similar reference numerals, a layer 4| of intermatted fibrous glass may overlie the upper face of the insole 18. This intermatted layer has a cover 42 thereover of conventional material and the intermatted layer has sufficient resiliency to provide a cushion for the foot of the wearer.
While it is possible to fasten the upper IO and the Welt ll to the insole by stitches passing directly through the body of the insole following the practice sometimes employed in present day shoe construction, it is preferable to provide the flange |9 about the edge of the insole to form a means for connecting the Welt and upper by stitchin'g to the insole.
The flange 19 may be formed at the time the insole is molded as above described or it may be formed by a strip of fabric or leather cemented over part of its width to the insole proper along its margin. If the flange is formed at the time the insole is molded, it is possible to lay strips of fabric over the insole about its margin, each strip being resin impregnated over a part of its width and the other part of the width of the strip being separated from the other fabric layers during curing of the resin 'by interposing a sheet of cellophane between the unimpregnated part of the strip and the next adjacent layer of resinimpregnated'fabric. After the resin impregnant of the insole has been cured the unimpregnated part of the strip may be bent up from the surface of the insole to form the fiange IQ.
While the resin impregnant of the present insole may be any ordinary laminating resin it is preferred to employ those resins known as the low pressure-curing thermosetting resins. The use of these resins permits the resin impregnant to be cured with the application of relatively low pressure on the superposed layers of fabric, pressures in the neighborhood of 15 to 25 pounds per square inch usually being ample.
The low pressure-curing resins particularly adapted to the present invention comprise the modified phenolic type resins, urea formaldehyde, melamine formaldehyde and aniline formaldehyde, as well as allyl resins and lignin plastics or mixtures of such compounds. The nature of the modification step is varied, for example, by modifying phenolic resins or those of the cresylic acid derivative type by the use of a suitable catalyst or by refiuxing the materials to the neutral or basic conditions or by compounding them with phlobaphene or other thermoplastlc derivatives. Low pressure melamine and urea formaldehyde type plastics may be formed by modification with resorcinol or other suitable compounds. Others of the thermosetting plastics such as those of the allyl type need no preliminary treatment for materials of this class are already capable of being cured at low pressure. These lowV pressurecuring thermosetting plastics are known in the art and need no further description.
The combination of fibrous glass and resins employed in the present invention provides an insole of permanent shape and form since the resins have no cold flow and are not affected by the heat nor the moisture to which a shoe is normally subjected.
Various modifications may be made within the spirit of the invention and the scope of the claims.
1. A shoe comprising an upper, an insole made up of a plurality of layers of fibrous glass interwoven fabric impregnated with a thermosetting resin extending as a continuous body throughout the insole, and a layer of intermatted fibrous glass overlying the upper face of the insole and having a covering thereover, said intermatted fibrous glass having a resiliency providing a cushion for the foot of the wearer.
2. A shoe comprising an upper, an insole made up of a body of thermosetting Synthetic resin reinforced with' glass fibers, and a layer of intermatted fibrous glass overlying the upper face of the insole and having a covering thereover, said intermatted fibrous glass having a resiliency providing a cushion for the foot of the wearer.
DAVID R. BRADY.
(References on following page) REFERENCES CITED The following references are of record in the file of this patent:
UNITED STATES PATENTS Number Name Date Roberts Apr. 2, 1907 Egerton Oct. 22, 1918 Egerton Jan. 6, 1920 Marshall Dec. 13, 1932 10 Churchill et al. Nov. 7, 1933 Knapp May 11, 1937 Number Number Name Date Richter et al. Nov. 25, 1941 Meharg May 30, 1944 Miller July 9, 1946 Miller et al Jan. 21, 1947 Oestricher Aug. 12, 1947 Collins Oct. 7, 1947 Gray Dec. 16, 1947 FOREIGN PATENTS Country Date Great Britain Oct. 2, 1930