US2346279A - Manufacture of insoles - Google Patents

Description

, April 11, 1944. K. A. sTRn'TER MANUFACTURE OF INSOLES Fild- Nov. :5, 1941 2 Shet-Sheet 2 Patented Apr. 11, 1944 UNITED O STATES ,PATEN'T OFFICE MANUFACTURE OF INSOLES I Karl A. Stritter, Nahant, Mass, assignor to United Shoe Machinery'Corporation, Flemington, N. 3., a corporation of New Jersey Application November 3, 1941, Serial No. 417,656

2 Claims. (c1. 36-44) This invention relates to improvements in the manufacture of insoles.

Reinforced insoles or insole units of a wellknown type have relatively flexible foreparts but they are made relatively stiff and strong in their heel and shank portions by the employment in each unit of a metallic shank stiffener and a heel and shank reinforcing piece of fiberboard or the like which overlies and covers the shank stifiener and is secured by cement or otherwise to the insole. An insole unit of this type usually comprises an insole body member of full insole length which is died out or rounded to insole edge contour, and a heel and shank reinforcing and shank stiffener covering piece which is formed by a separate die-cutting or roundin operation to correspond in edge contour with that of the heel and shank portion of the body member. Th separate cutting operations involved in the making of the body members and the reinforcing pieces add substantially to the expense of manufacturing such insole units and further expense is involved inasmuch as it is necessary to use considerable care to insure the subsequent as-' sembling and securing together of the parts with their rear and lateral edges in the desired accurate alinement.

One object of the present invention is to simplify and reduce the cost of manufacture of reinforced insole units of the above-mentioned type.

With this object in view the present invention, as herein illustrated, provides an improved article of manufacture consisting of a composite sheet adapted to be cut into a plurality of insoles each of which has a shank stiffener covering piece already attached to it with its edges in exact registration with the corresponding edges of the body of the insole, the covering piece, however, being attached throughout a portion only or its full surface area so that part of the covering piece will be free from the adjacent body portion of the insole to permit the subsequent insertion of a shank stiffener between the insole and the covering piece. This composite sheet, in accord,-

ance with one illustrated construction, comprises a strip from which insole body portions of full insole length are to be cut, and a second strip from which the Covering pieces are to be cut,- the second strip being superimposed upon that part of the first strip from which the shank or shank and heel portions of insole bodies are to be cut and having its inner lateral margin only attached to the first strip. The remainder of this covering piece strip is thus left unattached to the body strip and consequently, in the insoles cut from'the sheet, the covering pieces can be lifted so that the shank stiffeners can be inserted beneath them. Preferably the covering piece strip of the sheet is scored along a line located near its area of attachment to th other strip so that, in the insoles, the corresponding scored portions will function as hinges to facilitate the lifting or swinging of th coverin pieces away from the body strip. Preferably,

also, the insole body strip is of composite formation comprising arelatively flexible portion from which the foreparts of the insoles are to be cut and a relatively stifi portion from which the shank or heel and shank portions of the insole body are to be cut, these two strips being disposed in edge-to-edg relation in the same plane and having their contiguous margins beveled or skived and'spliced together by a cement joint.

The invention will be explained with reference to the accompanying drawings, in which Fig. 1 is a plan view of my improved composite sheet, dotted lines being employed in this view to indicate the locations of the cuts by means of which a plurality of fully length insoles are to be cut from the sheet;

Fig. 2 is a sectional view taken along the line IIII of Fig. 1;

= section, of a composite sheet of another modified construction;

Fig. 5 is a perspective view of an insole cut from a composite sheet of the form shown in Figs. 1 and 2, showing the lower or outsole-facing side 1 of the insole;

Fig. 6 is a perspective view of an insole cut from a composite sheet of the form shown in Fig. 4, the insole being shown with its lower side uppermost;

Fig. '7 is a longitudinal sectional View of the Fig. 10 is a bottom view of the composite sheet shown in Figs. 8 and 9);

Fig. 11 is a View in longitudinal section of an insoles, the sheet being of a width at least as great as the length of the insoles which are to be produced and comprising two longitudinally extending zones A and B, the zone A being relatively flexible and consisting of a strip 16 of manufactured or composition material, for ex ample, felted wood fibers bound together with rubber, such material being commonly employed as a substitute for leather, while the zone B is relatively stifi and comprises superimposed and substantially coextensive strips or layers l8 and 28, both of which are advantageously composed of fiberboard, leatherboard or the like. As shown, the inner lateral margin of the strip I8 is skived or beveled and secured by a cement joint 22 (Fig. 2) to the correspondingly skived inner lateral margin of the strip l6. It will be seen that the strips l6 and I8 lie in the same plane and inasmuch as their contiguous edges are spliced and cemented together they form a unitary ply or layer from which the body portions of full length insoles may be cut. The inner lateral margin of the strip 28 is also skived and secured to the strip l6 of the body layer by a cement joint 24 which is in line with the splice or joint 22. The layers or strips l8 and 20, however, are left unsecured to one another from their skived portions which are secured to the strip l6 to their outer extremities 25. To illustrate that the layers l8 and 20 of the composite sheet are entirely free one from the other except where they are joined to the strip 16, the layer 20 is shown displaced somewhat from the layer l8 but actually these two layers will be disposed with their opposed surfaces in contact where they are unattached. Preferably, the strip 20 is scored or grooved on its outer side along a line 28 which extends lengthwise of the sheet approximately at the junction of the skived margin with the body portion of the strip so that in each insole cut from the sheet the covering piece, despite its stiffness, may be easily separated from the insole body by bending it about its scored portion.

The above-described composite sheet is adapted to be cut by dies or otherwise in the localities indicated by the dotted lines 30 in Fig. 1 so as to produce a plurality of insoles, such as the insole 32 shown in Fig. 5, each insole having a flexible forepart 34 of single-ply formation cut from zone A of the sheet and a two-ply heel and shank portion 36 cut from zone B of the sheet comprising two layers 38 and 40, both of which are preferably composed of relatively stiff material. Moreover, while the forward extremities of the layers 38 and 4H constituting the heel and shank portion of the insole are permanently secured at their forward extremities to the flexible forepart 34, as indicated at 42, the remaining portions of these layers are unattached one to the other when the insoles are cut from the composite sheet. In order that the shank portion of the insole shall be sufficiently stiff and strong to afford adequate support forthe longitudinally arched portion of the foot, additional stiffening means may be inserted between the layers 38 and 40. For this purpose a conventional metallic shank stiffener, such as that indicated at 44 in Fig. 7, is employed. The layers 38 and 40 are separated more or less from the positions in which they are shown in Fig. 5 to permit the insertion of the shank stiffener and, as already indicated, such separation of the layers is facilitated by bending the layer 40- away from the layer 38 about the line 46 (Fig. 5) where that layer is scored. The score line insures that the layer 40 will bend abruptly at the joint between it and the body of the insole so that the shank stiffener can be located lengthwise of the insole my positioning the front end of the shank stiffener in the apex of the angle between the layer 40 and the insole body, or, in other words, against the joint between the layer or covering piece 40 and the insole. As shown, the shank stiffener 44 may be secured to the layer 38 by means of staples or tacks 41. Advantageously, the inner or opposed surfaces of the separated portions of the layers 38 and 40 are coated with cement, as indicated at 48 (Fig. 7), either before or after the shank stiffener has been applied, and subsequently the bent portion of the layer 40 is replaced and pressed against the layer 38 until the two layers have become firmly attached together by the cement with the shank stiffener 44 between them. Advantageously, the attaching pressure is applied by means of molds or forms suitably shaped to mold the shank portion of the insole to last conforming shape. The layer 40 and the cement thus serve to retain the shank portion of the insole permanently in its molded form and the layer 40 supplements the reinforcing and stiffening action of the shank stiffener 44. The layer 40 also covers the shank stiffener 44 and provides a continuous surface widthwise of the insole, at the lower or lasting side thereof, to which the upper of the shoe may be lasted and the outsole attached.

Instead of making my improved composite sheet with the skived lateral margins of the layers I8 and 20 of zone B secured to opposite sides of the layer l6 of zone A, as shown in Fig. 2, the skived margins of the layers I8 and 20 may-be secured to one another by a cement joint 50, as indicated in Fig. 3, in which case only one of the layers of zone B will be cemented to zone A layer, for example the layer l8, the cement joint being indicated at 52. The layer 20 is shown as being scored at 28 as in the sheet shown in Fig. 2.

Alternatively, the composite sheet may be constructed as illustrated in Fig. 4 wherein the main or body layer I of the sheet is of integral or one piece formation throughout the full width of the sheet and the layer 200 from which the covering pieces are to be out is composed of hardened plastic or thermoplastic material, this layer being scored, as indicated at 28, and :being secured at its inner lateral margin only to the main or body layer by a cement joint 53, leaving the rest of the plastic layer unsecured to the body layer. As shown, a thin facing of fabric 202 asecured to the outer side of the plastic layer An insole cut from a composite sheet constructed as illustrated by Fig. 4 is shown in Fig.

6 wherein the insole comprises a full length body layer 54 of one piece integral formation and a heel and shank reinforcing and shank piece covering layer 56, scored at 58 and faced on its outer side with a fabric layer 59. The plastic material employed in the sheet shown in Fig. 4

may be of an adhesive or bonding nature when activated either by heat or by means of a solvent so that in the insoles cut from the sheet it will be unnecessary to employ cement to secure the covering piece to the insole or the facing fabric to the covering piece inasmuch as the bonding together of these parts may be accomplished by merely pressing them together while the plastic material is in a softened or activated condition. It may even be found unnecessary to employ a metallic shank stiffener between the layers in the heel and shank portion of the insole having a heel and shank piece made of plastic material, inasmuch as this material itself, when hardened, may provide sufficient strength and stiffness in the heel and shank portions of the insole. The facing fabric '59 will provide an ideal surface at the lower side of the insole for the cement attachment thereto of the upper materials and the outsole of the shoe.

In Fig. i I have indicated a further modification in the construction of my improved composite sheet wherein zone B comprises three plies or layers 28 i, 286 and 208, these plies being unattached to any other portion of the sheet except along their inner lateral margins, and one or more of the plies of zone B being preferably composed of material which is stiffer than that of the ply of zone A. As shown, the ply 2534 is secured by a spliced cement joint 2 ill to the insole forepart forming ply M2, the ply 236 is secured by a spliced cement joint 2 i ito the ply 2 l2, and the ply 208 is secured by a cement joint M6 to the ply 265. In an insole cut from such a sheet the plies of zone B will be secured together as by means of cement in the molding of the insole so that the heel and shank portion of the insole will permanently retain its molded shape. In order to provide for even greater strength shank reinforcing members. may be inserted between the adjacent plies of zone B before these plies are fastened together. For example, a metallic shank stiffener may be introduced between plies 2M and 206 and a layer or coating of softened plastic material may be applied between plies 26B and 208, the plastic layer serving as a shank stiffening element after becoming hardened.

In making a sheet constructed as shown in Fig. 4; the ply 286 may be made of plastic material and in an insole out from such a sheet the plastic layer may be softened, by means of a suitable solvent or by means of heat if the material is of a thermoplastic nature, before the insole is molded, in which case the several layers or plies of the heel and shank portion of the insole will be secured together by the adhesive properties of the plastic layer without requiring the use of cement. In such an insole the hardened plas tic ply may provide sufficient stiffness but if desired a steel shank stiffener may be used between the plastic ply and one of the adjacent plies.

In order to provide for the cutting of insoles from composite strips with less waste of stock than would result from the use of sheets constructed as already described, I may construct the sheets as shown in Figs. 8, 9 and 10 and reverse end-for-end the position of the cutting die prior to the making of each insole cut so that successive cuts will be relatively disposed as indicated by the dotted lines 60 in Figs. 8 and. 10. A sheet constructed as shown in Figs. 8 to 10 comprises a relatively stiff intermediate or middle zone C from which the heel and shank portions of the insoles are to be cut and relatively flexible side or end zones D and E from which the foreparts of the insoles are to be cut. Each of the end zones D and E consists of a. single ply strip 66 offlexible insole material. As shown, the middle zone C is formed of superimposed layers consisting of an insole body layer 62 and a covering piece layer 64, these layers being preferably composed of fiberboard or like stiff material, although the layer 62 may be made of insole material and may be integral with the end zone layers or strips 66. As shown in Fig. 9, the opposite lateral margins of the body layer 62 are beveled or skived and secured by cement joints 68 and 10 to the correspondingly skived inner lateral margins of the.

forepart layers MS of zones D and E, respectively, while the opposite lateral margins of the covering piece layer 64 are secured by cement joints 12 and M to the plies or strips 66 of zones D' and E respectively. Inwardly of the joints l2 and i4, however, the covering piece layer 64 is left entirely unsecured to the rest of the composite sheet.

Preferably the layers 64 are scored along the lines 16 and 18.

When insoles are produced from a sheet such as that shown in Fig. 8 by cuts relatively disposed and located as indicated by the dotted lines fill,-

the layers constituting the heel and shank portions of the insoles, while secured at their forward extremities to the foreparts, will be unsecured to one another rearwardly of their forward extremities inasmuch as the rear extremities of the heel portions of the insole cuts will be spaced inwardly of the joints i2 and M. Consequently the layers of the heel and shank portions of each insole may be readily separated to facilitate the insertion of a shank stiffener between them.

An insole cut from a sheet of the form exemplified by Fig. 8 is shown. in Fig. 11 wherein the forepart of the insole is indicated at 81], the body of the heel and shank portion at 82, the heel and shank covering piece at 84, and the score line on the covering piece at 89. The covering piece 8 1 may be separated from the layer 32 to facilitate the insertion of a shank stifiener by bending the a covering piece backwardly about the portion The shank stifi-' weakened by the score line 85. ener having been positioned between the insole layers 82 and B4 and stapled or otherwise secured to one or the other of them, the opposed surfaces of the layers will be coated with cement, unless they have been previously coated, and the covering piece layer will be laid back against the other layer and the two layers pressed together and molded to last bottom conforming shape. Inasmuch as the joint between the covering piece 84 and the forepart layer 89 is located farther forward than the joint between the forepart layer and the heel and shank body layer 82, as shown, the shank stiffener may be located with the forward portion overlying the latter joint, a condition which tends to prevent that joint from opening up or becoming weakened during the wearing of the shoe in which the insole is incorporated. This relative arrangement of the joints also enables the forward extremity of the shank stiffener to be located substantially at or even slightly forward of the break line between the shank and forepart of the insole as is often desirable. At the completion of the above-described operations a reinforced insole unit will have been produced which will correspond in appearance and construction to that shown in Fig. '7 except as to the relative locations of the cement joints whereby the several layers of the unit are united.

.For use in making insoles with multi-ply heel and shank portions a composite sheet may be formed with two single ply end zones and a threeply middle zone. Such a sheet may be formed, for example, by adding to the two plies of the middle zone of the sheet shown in Fig. 8 a third ply and this third ply may be located at the side of the sheet opposite that to which the ply 64 is applied, the third ply being unsecured to the ply 64 and having its lateral margins secured to the end plies 66 by cement joints similar to and in line with the joints l2 and 14. Insoles cut from such a sheet will have three-ply heel and shank portions and may be reinforced by additional shank stiffening elements prior to the molding of the insoles as already described in connection with the making of insoles from sheets of the type shown in Fig. 4

In various figures of the drawings the invention has been illustrated in its application to the cutting of insoles for use in shoes for the right foot of a wearer and it is to be understood that insoles for shoes for the left foot can be cut by the use of another die which is properly shaped to cut left insoles. However, a single die, for example a right die, may be used for cutting both right and left soles by practicing the simple expedient of inverting the sheet after a right sole has been cut therefrom. The right die may then be used upon the inverted sheet to cut a left insole, the insole being in an inverted position, however, at the time it is cut. Moreover the composite sheets may be furnished in rights and lefts, for example, one sheet may be adapted to yield right soles upon cutting by having the cover forming layer applied to its lower side while another sheet may be adapted to yield left soles, when out by the same die, by having the cover forming layer applied to its upper side.

The spliced cement joints between the strips constitutingthe middle zone of the sheet and the strip or strips from which the insole foreparts are to be cut may be made as indicated at 94 and 96 in Fig, 13, wherein the insole forepart forming strip 92 is beveled at the same angle at each side to receive correspondingly beveled portions of the heel and shank piece forming layers 88 and 90. The layers 88 and 90 are of the same thickness and may be made of the same material and, as shown, the combined thickness of the layers 88 and 90 is the same as the thickness of the layer 92. If the layers 88 and 90 are of the same material the cutting of both right 1. As an article of manufacture, a composite sheet adapted to be cut into a plurality of insoles with attached shank stiifener covering pieces, said sheet comprising a strip from which the body portions of the insoles are to be out, and a second strip from which said covering pieces are to be cut, said second strip being disposed in superimposed relation to that portion of the first strip from which the shank portions of the insoles are to be cut and having its inner lateral margin beveled to a thin edge and said second strip having said beveled margin only secured by a cement joint to said first strip, and said second strip having a groove in its outer side extending along a line coincident with the inner extremity of said joint so that the cover piece of an insole cut from the composite sheet may be bent abruptly away from the other piece along the inner extremity of said joint to facilitate assembly of a shank stiffener with the insole.

2. A step product in the manufacture of reinforced insole units comprising a flexible insole forepart having its rear margin beveled to a thin edge, a stiff insole heel and shank part having its forward margin beveled to a thin edge, said parts having said beveled margins disposed in overlapping relation and secured together by a cement joint to form a composite insole body member, and a stiff heel and shank reinforcing and shank stiffener covering piece superimposed upon and coextensive with said heel and shank part and having its forward margin beveled to a thin edge, said beveled margin underlying the beveled margins of said forepart and said heel and shank part and being secured by a cement joint to the beveled margin of one of said parts and being entirely free of attachment to said part except at said joint, and said reinforcing and covering piece having a groove extending across its outer side in line with the rear extremities of the beveled margins of said forepart and said heel and shank part.

KARL A. STRITTER.

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