US2232767A - Manufacture of shoe bottom units - Google Patents

Description

Feb. 25, 1941.-- BRQPHY I 2,232,767

' MANUFACTURE OF SHOE BOTTOM'UNITS Filed Sept. 16, 1958 I 2 Sheets-Sheet 1 f Figl Feb. 25, 1941. J. J. BROPHY MANUFACTURE OF SHOE BOTTOM UNITS Filed Sept. 16, '1938 2 Sheets-Shee t 2 Fig.7 w

2 WI/E/VTUR- Patented Feb. 25, 1941 MANUFACTURE or snos no'r'rom om'rs John J. Bmphy, Salem, Mala, auignorto United Shoe Machinery Corporation, Borough of Flemlngton, N. 1., a' corporation of New Jersey Application September 1t, 1933:, Serial No. 230,299

3 Claims. (CL 12-146) This invention relates to the manufacture of shoe bottom units and is disclosed herein with reference to its applicability to the manufacture of reinforced insole units.

Heretofore various efforts have been made to provide for the shaping and stiffening of the shank portions of shoe bottoms to insure the imparting of desired bottom fitting and arch supporting characteristics to the shoes. Shank 1o stiffeners of metal, wood, leather, fiberboard and other materials have been commonly employed for this purpose. It is also customary to employ in a. shoe an insole unit comprising an insole the shank portion of which is molded to a desired shape, a heel and shank reinforcing piece of fiberboard or the like which is cemented to the insole to assist in preserving the molded contour of the insole, and a metallic shank stiffener which is interposed between the fiber piece and the insole and which further strengthens and 'stifi'ens the insole. Insole units of this type are expensive to manufacture, however, and in some other respects they are not entirely satisfactory.

In fact, the use of metallic shank stiileners is 5 often objectionable for various reasons.

The present invention provides a shoe bottom unit of simple and inexpensive construction hav v ing none of the disadvantages above referred to. In this unit the required stillness is secured without the use of metallic stiifeners and the unit will retain its shape and perform its intended functions effectively throughout the life of the shoe.

The composite shoe bottom unit 'herein illustrated consists of a sole and a formed shank reinforcing piece of fibrous material, containing a hardened thermoplastic substance, the shank piece being secured to the sole by means of an adhesive. Preferably I obtain the desired stillness by the use, in the reinforcing piece, of a.

hardened thermosetting resin which not only stifiens the piece but which also imparts a desired resiliency thereto and which renders unnec-' essary the use, with the sole and the reinforcing piece, of any additional element, such as a metallic shank stiffener. The shank reinforcing piece is preferably molded in conformity with the curvature-of the bottom of a last for the shoe in which the unit is to be incorporated, and accordingly the unit will accurately reproduce the lines of the last bottom in the finished shoe. The unit is of light weight and can be manufactured at low cost. Moreover, inasmuch as the stL ness and resiliency of its shank portion is preferably derived from a hardened thermosetting resin the stiffness will be retained permanently since the characteristics of the resin will be unaffected by any heat or pressure to which the unit may be subjected during the life of the shoe.

The invention will be described with when 5 ence to the accompanying drawings, in which Fig. 1 is a view, in longitudinal section, of a die and a cooperating cutting block illustrating the operation of dieing out a heel and shank piece blank from a flat sheet of fibrous material 10 containing a thermosetting resin;

Fig. 2 is a plan view of the heel and shank piece blank formed by the die shown in Fig. 1;

Fig. 2a is a cross-sectional view of a heel and shank piece blank illustrating a modified feature of construction;

Fig. 3 is a view partially in side elevation and partially in longitudinal section of a pair of cooperating molds or forms illustrating the operation of forming a molded heel and shank piece; 20

Fig. 4 is a. cross-sectional view taken on the line IV--IV of Fig. 3;

Fig. 5 is a perspective view of the molded heel and shank piece formed by the dies shown in Fi 3; 25

Fig. 6 is a perspective view of a completed insole unit embodying the molded heel and shank piece shown in Fig. 5;

Fig. 7 is a cross-sectionalv view 'on the line -VII-VII of P18. 6

Fig. 8 is a perspective view of an insole unit of modified construction in which a molded heel and shank piece is shown as having been applied to the upper or foot-facing side of the insole;

Fig- 9 is a cross-sectional view on the line 35 IX-IX of F g- Fig. 10 is a longitudinal sectional view of an insole unit illustrating a further modified construction;

Fig.- 11 is a cross-sectional view on the line 0 xr-xr of Fi '10';

Fig. 12 is a perspective view of a still further modified form of insole unit; and

Fig. 13 is a perspective view of another alternative form of insole unit. 4

Referring to the drawings, my improved shoe bottom unit is composed of two elements, a sole and a shank piece, these elements being firmly secured together to provide a composite unit. The sole may be formed by a rounding so or di ecutting operation from any desired sole material, such as leather or any of the wellknown composition or other substitute materials. Full length soles or short soles may be employed, the latter being shaped for application to the u foreparts only of shoe bottoms. The shank pieces which are preferably but not necessarily of a shape commensurate with that of the heel and shank portions of a shoe bottom and which are hereinafter referred to as heel andshank pieces may be out from full sheets of fibrous material containing athermosetting resin which during subsequent molding of theshank pieces with accompanying heat and pressure becomes hardened and set so that the molded pieces while having a certain amount of resiliency are, nevertheless, quite stiff and hard and are capable of retaining permanently their molded contours. The fibrous material which I prefer to use is composed largely or entirely of cotton fibers such as are employed in the manufacture of rag paper stock. I prefer to employ as the means for obtaining the desired hardness and resiliency of the fibrous material an alkyd resin, such for example as glycerol phthalic anhydride resin, although satisfactory results may be obtained by the use of other thermosetting resins.

The fibrous sheet material from which the heel and shank pieces are made is of laminated formation and the resin may be applied, for example, in powdered or pulverized form between the plies or layers as the sheets are being formed. Advantageously the heel and shank pieces are cut from the sheets by die-cutting operations as by means of a die l8 (Fig. 1) and a cooperat ing cutting block 20.

In the process of making an insole unit, which will now be described, a fiat heel and shank piece blank 22 is cut from a flat sheet 23, the blank 22 having a marginal contour corresponding to that of the heel and shank portion of the insole with which it is to be used so that when assembled with the insole with the edges of the heel and shank piece in registration with the corresponding edges of the insole the heel and shank piece will be coextensive with the heel and shank portion of the insole. I

The fiat heel and shank piece blanks 22 are then molded to provide heel and shank pieces 24 shaped in conformity with the contour of the heel and shank portions of the bottoms of lasts for shoes in which the insole units are to be used. As herein illustrated the molding is accomplished by means of cooperating dies or forms 26 and 28 (Fig. 3), the dies being shaped to impart to the molded heel and shank piece 24 longitudinal and transverse curvatures corresponding to those of the last bottom. If, as illustrated in Fig. 6, the heel and shank piece is to be applied to the lower or outsole facing side of the insole, the die 26 may be further so shaped as to form a longitudinal stiffening rib 30 upon the lower side of the heel and shank piece for increasing the stiifness of the shank portion of the piece.

In use the dies 25 and 28 are positioned between upper and lower presser members indicated conventionally at 32 and 34 by means of which the dies are forced toward one another under heavy pressure and the dies are heated by any suitable means, for example, they may be electrically heated, as indicated by the wiring terminals 35 and 38. The heated and pressureactuated dies mold the blank 22 into a form such as that shown in Figs. 3, 4 and 5. Under the action of the heat'and pressure the resin is caused thoroughly to permeate the fibers of the sheet material. After the piece has been molded the molds are permitted to cool and the molded piece is allowed to remain between the molds until the resin in the molded material has beaasancr I come set after which the piece is removed. The piece is then shaped as best shown in Fig. 5, having thin lateral edges which do not add perceptibly to the edge thickness of the unit. Because of the thermosetting characteristics of the resin it becomes infusible and insoluble after it has been heated in the molding operation and consequently the molded heel and shank piece will retain permanently its molded contour, being entirely unaffected by subsequent changes in temperature to which it may be subjected either before or after being incorporated in a shoe.

While the heel and shank piece blank is shown in Figs. 1 and 2 as having its edges perpendicular to its surfaces, it may be made as indicated in Fig. 2a wherein the blank 220 has preliminarily beveled edges 23 which facilitate the securing of the desired rounded thin edge formation shown in Fig. 4. In molding a blank having such beveled edges there will be some initial clearance between the curved margin of the work-engaging face of the upper mold 26 and the straight beveled edge of the blank so that the mold will exert less pressure along the margins than in the other portions of the work and thus while the central or body portions of the molded pieces will be quite hard and still! the marginal portions thereof will be less hard. In practice it has been found practicable thus to mold the pieces so that the marginal portions thereof will be readily penetrable by lasting fastenings, such as wire staples, while the other portions of the pieces will be substantially harder and stiffer.

The molded heel and shank piece 24 is then secured by means of cement, for example rubber latex, to the lower or outsole facing side of an insole 40, as shown in Fig. 6. Preferably the cement is supplied to both the heel and shank piece and to the insole throughout the areas of the surfaces which are to be interengaged and the parts, after being assembled with their edges in alinement, are pressed together as between suitable presser members (not shown) one or both of which may be made of yielding material, such as rubber, and shaped to conform readily to the contours of the opposite sides of the molded pieces. In practice it has been found that heel and shank pieces made of cotton fiber and containing glycerol phthalic anhydride resin are capable of receiving cement by which they are secured to insoles or other shoe bottom parts in such a manner that a very firm and satisfactory bonding together of the parts is insured. The molded heel and shank pieces may be made with or without a stiffening rib, such as the rib 30, and they may be applied to the lower or to the upper sides of the insoles as may be required. In Figs. 8 and 9, for example, an insole unit is shown comprising an insole 41M and a molded heel and shank piece 2 which has no stiffening rib and is secured, as by means of cement, to the upper or foot-facing side of the insole. Alternatively, as shown in Figs. 10 and 11, the insole unit may comprise an insole 402, the heel and shank portion of which has been split into upper and lower layers or flaps 404 and 406 between which is cemented a molded heel and shank piece 242, the insole layers or flaps covering and concealing the molded piece. Another alternative form is shown in Fig. 12 where; in a molded heel and shank piece 243, instead of overlying the heel and shank portion of a full length insole, is spliced to the rear portion of a short insole 403 which has no heel or shank portion, the forward extremity of the molded 2,232,767 piece 243 being beveled and being cemented to a correspondingly beveled surface formed at the rear extremity of the short insole as indicated at 42. In Fig. 13 I have shown an insole unit. which is of the same construction as the unit shown in Fig. 6 except that the heel and shank piece 244- is substantially smaller in size than the corresponding portion of the insole and is applied to the insole so as to leave a marginal portion 42 of the insole uncovered thereby and thus adapted for the reception of lasting fastenings.

In each of the several forms of insole units above described the desired strength and stillness are provided in the shank portion without the use of the usual metallic shank stiffener. This results in the making of substantial economies in manufacture since the expenses incident to the making of the metallic stiffener and the assembling of the stiffener and the insole are eliminated together with such disadvantages as the well-known tendencies of the metal stifiener to break, to become loosened and displaced or to cut into and damage the inner or outer soles of the shoe.

In the use of my improved insole units in the manufacture of shoes it is to be noted that not only are the molded heel and shank pieces capable of readily receiving wire staples or other metallic lasting fastenings but are likewise capable of receiving lasting cement in such a manneras to insure the secure bonding of the overlasted upper margins to the insole units by the cement.

The bottom of a shoe having incorporated therein an insole unit embodying the herein-described features of my invention will be shaped, in its-shank portion, to conform accurately to the longitudinal and transverse curvatures of the last upon which the shoe was made and the shoe bottom will be permanently strengthened and reinforced so that it will afford adequate support for the arched portion of the foot throughout the life of the shoe.

In making the shoe it will be unnecessary to employ separate shank stifiening or arch supporting devices such as the usual metallic shank stifieners or arch supporting plates. Since the latter are expensive to manufacture and apply, the use of my improved sole units will reduce to a substantial extent the expense of manufacturing the shoe.

Having described my invention, what I claim as new and desire to secure by Letters Patent of the United States is:

1. As an article of manufacture and sale, a composite insole unit consisting only of an insole of normal edge contour, and a molded heel and shank piece of fibrous material containing a hardened alkyd resin, said piece being coextensive with the heel and shank portion of said insole and being directly secured to the lower side of the insole by cement throughout the entire areas of the opposed surfaces of said parts, said heel and shank piece having its upper side shaped in conformity with the corresponding portions of the bottom of a last and having a solid longitudinally extending stiiiening rib formed integrally therewith upon its lower side.

2. That improvement in methods of making reinforcing pieces for the shank portions of insoles which consists in forming a reinforcing piece blank of a desired marginal contour from a sheet of fibrous material containing a thermosetting resin, molding said blank between heated molds one of which is shaped to provide for initial clearance between its working face and the margin of the blank so that the molds will exert less pressure upon the margins than upon the other portions of the blank, and allowing said molded material to set and'thereby to become hardened to a less extent in its marginal portions than in the other portions thereof.

3. That improvement in methods of making reinforcing pieces for the shank portions of insoles which consists in forming a reinforcing piece blank of a desired marginal contour from a sheet of fibrous material containing a thermosetting resin, beveling the margin of said blank, molding said blank between heated molds one of which'is shaped to provide for initial clearance between its working face and the beveled margin of the blank so that the molds will exert less pressure upon the margin than upon the other portions of the blank, and allowing said molded material to set and thereby to become hardened to a less extent in the marginal portions of the blank than in the other portions thereof.

JOHN J. BROPHY.

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