US3514880A - Extensible insoles - Google Patents

Description

June 2, 1970 P. STAPLETON 3,

EXTENSIBLE INSOLES Filed Sept. 26, 1967 z Sheets-Sheet 1 [III/6n f0!" RzfcrLSzapZe on By his Attorne June 2,1970 P. L. STAPLETON 3,

- EXTENSIBLE INSOLES Filed Sent. 26, 19s? a Sheets- 811991; 2

United States Patent 3,514,880 EXTENSIBLE INSOLES Peter L. Stapleton, Leicester, England, assignor to USM Corporation, Fiemington, N.J., a corporation of New Jersey Filed Sept. 26, 1967, Ser. No. 670,598 Int. Cl. A43b 1 3/ 88 US. Cl. 36-44 2 Claims ABSTRACT OF THE DISCLOSURE A novel insole comprising discrete forepart and heel portions joined by an extensible portion, the forepart and heel portions each having locating holes therein to facilitate positioning of the insole on the last. Preferably, the forepart and heel portions are joined by means of extensible material such as polyurethane foam interposed between overlapped margins of the two portions.

This invention relates to a novel shoe insole.

In the interest of good shoemaking it is desirabe, when attaching a shoe insole to the last, that both the toe and heel portions of the insole are correctly positioned with respect to the bottom of the last. When using tacks to attach an insole to a last it is a usual practice to position the toe and attach the toe portion of the insole before proceeding to the heel portion. Unless the insole has been made accurately to fit the last bottom an undesirable overlap between edge portions of the last and insole can occur.

One of the various objects of the present invention is to provide an insole which facilitates accurate positioning of toe and heel portions of the insole on the bottom of a last.

The invention provides, in accordance with one of its several features, a shoe insole comprising a forepart portion having a locating hole therein joined in overlapped relationship with a heel portion having a locating hole therein by means of material interposed between overlapped margins of said portions, the interposed material being extensible to allow relative movement between the forepart and heel portions to facilitate positioning of the insole against the bottom of a last.

There is hereinafter described an insole illustrative of certain features of this invention having extensible material in the form of a strip of polyurethane foam between overlapping margains of a flexible toe and forepart portion and a more rigid heel and waist portion. Insoles embodying the invention are made shorter lengthwise than the standard insole and are extended, through the provision of the extensible polyurethane foam portion, accurately to fit the bottom of a last at its toe and heel ends. While the insole hereinafter described includes a flexible toe and forepart portion it could include a flexible heel and waist portion joined in overlapped re lationship with a more rigid toe portion without departing from the scope of the invention. The insole is provided with locating holes at the toe and heel portions to facilitate practice of the method of this invention.

The above and other features of this invention will now be more particularly described with reference to the accompanying drawings and pointed out in the claims.

It is to be understood that the particular embodiments I referred to above and hereinafter described are delineated for illustration of the invention only and are not to be construed as limiting the scope thereof.

In the drawings:

FIG. 1 is a view of the bottom of an insole embodying certain aspects of the invention;

sole 10 is temporarily supported in position against'the FIG. 2 is a side view of the insole illustrated in FIG. 1 and attached to a last;

FIG. 3 is a plan view of a second illustrative insole; and

FIG. 4 is a plan view of a third illustrative insole.

The illustrative insole shown in FIGS. 1 and 2, referred to generally by the reference number 10, comprises a toe and forepart portion 12 made of conventional flexible insoling material. A more rigid heel and waist portion 14 has a leading edge face 16 (FIG. 2) skived to provide an underlay portion of a lap joint for joining the portions 12 and 14. The insole is moulded to accommodate the bottom contours of the last. The portion 12 has a scarfed face 20. The portions 12 and 14 have location holes 28 and 30 therein for use in locating the insole on a last, as hereinafter described.

Interposed in the lap joint is a piece of extensible joining material 18 made of suitable-density polyurethane foam and joined by means of suitable adhesive to the face 16 and to the scarf face 20 (FIG. 2) of the forepart portion 12. Thus the flexible portion of the insole is joined to the more rigid portion through the intermediary of the material 18.

The insole 10 is cut from a prepared composite sheet from which a plurality of insoles can be cut. To provide the composite sheet a strip of the joining material 18 is adhered to a longitudinal margin of a strip of material which provides the heel and waist portion 14 of the insole, said margin is skived to provide the face 16 and coated with adhesive for securing the material 18 thereto. The strip of joining material 18 has a width similar to the Width of the face 16. A strip of material which provides the flexible toe and forepart portion 12 of the insole is skived along one edge to provide the scarf face 20. This face 20 has a width similar to the width of the joining material and is coated with adhesive and applied to a face of the material 18 opposite to its face adhered to the face 16. The three layers are pressed together to form a composite sheet for use in making a plurality of insoles having flexible toe and forepart portions and more rigid heel and waist portions joined in overlapped relationship by means of an extensible material. The insoles are out about a half size undersize with respect to the lengths of the lasts with which they are to be assembled (i.e. about one sixth of an inch) for a purpose herein after explained.

The polyurethane foam joining material 18, aswell as being compressible and thus avoiding unnecessary thickess in the insole in a finished shoe, is extensible in directions of shear of the joining material. This extensibility permits limited relative movement between the insole portions 12 and 14, both in lengthwise and widthcrepancy in the lie of the toe and forepart portion 12 with respect to the bottom of the last can be corrected by moving the portion 12 relative to the portion 14.

An insole of the construction just described is attached to a last by means other than tacks which have the disadvantage that they have to be removed at a later stage in the manufacture of a shoe. The way in which the inbottom of a last 22 (FIG. 2) will now be described.

The last 22 is provided with a pair of location projections in the form of pins, 24 and 26 respectively, which project outwardly from the bottom of the last. The pin 24 is positioned a predetermined distance from the heel end of the last and the pin 26 is positioned a' predeterm ined' distance from the toe end of the last. Two location holes 28 and 30 (FIG. 1), of a size to fit the pins, are punched respectively in the portions 14 and 12 of the insole. The

hole 28 is positioned in the insole in relation to the heel end thereof at a position in the heel portion corresponding to the position occupied by the pin 24 in relation to the corresponding portion of the last bottom and the hole 30 is positioned in the insole in relation to the toe end thereof at a position in the toe portion corresponding to the position occupied by the pin 26 in relation to the corresponding portion of the last bottom and irrespective of the position of the hole 28.

The portion 14 of the insole is positioned on the bottom of the last 22 by locating the pin 24 in the hole 28. In the interests of accuracy and to provide an adequate attachment of the insole to the last the pin 24 is a push-fit in the hole 28. As hereinbefore mentioned, the insole is cut undersize in length and the insole is extended by moving the portion 12 relatively to the portion 14 so that the pin 26 can be inserted in the hole 30. Since the toe ends of the last and insole respectively are the datum points for positioning the pin 26 and hole the toe end of the insole is positioned correctly in alignment with the toe end of the last.

The polyurethane foam joining material 18 has an elastic characteristic such that the extended insole positioned on the last by the pins 24 and 26 tends to contract so that the insole is gripped on the pins which attach it to the last and retain it against the bottom of the last. The pin 26 has a recess 32 which helps to retain the insole in position.

So that the shoe can be readily removed from the last at a later stage in manufacture the pin 26 is chamfered to provide a sloping face 34. In removing the shoe from its last the back of the shoe is urged off the backpart of the last, the insole being lifted off the pin 24, and the shoe is then moved toewardly of the last, the insole being carried away from the last by the sloping face 34. The sloping face 34 makes it unlikely that the portion 12 of the insole will bind on the pin 26.

In a modification of the insole just described the joining material 18 is less in width than width of the face 16 and the scarf face 20. The faces 16 and 20 are completely coated with adhesive so that when the insole is supported in position on a last bottom the faces 16 and 20 are pressed together (compressing the polyurethane foam), portions thereof coming together rigidly to secure the portions 12 and 14 of the insole in overlapped relationship.

Instead of comprising a flexible toe and forepart portion and a more rigid heel and waist portion an insole may comprise a flexible forepart portion, and more rigid toe and heel and waist portions. In such an insole the flexible forepart portion is joined to the more rigid toe portion by a lap joint. If desired joining material 18 may be sandwiched in said lap joint instead of the lap joint joining the flexible portion to the heel and waist portion.

FIG. 3 shows a second insole embodying further features of this invention which facilitate use of the above described method comprising a flexible forepart portion joined in overlapped relationship with a more rigid heel and waist portion 42 and a more rigid toe portion 44.

Location holes 46 and 48 correspond respectively with the holes 28 and 30 to locate the insole on a last having locations pins similar to the pins 24 and 26. The forepart portion 40 provides an extensible portion, being rigidly secured in overlapped relationship with the portions 42 and 44 by means of adhesive. The heel and waist portion 42 is skived to form an underlay 50 and the toe portion is skived to forman underlay 52. To enable the forepart portion 40 to be extended to facilitate positioning of the insole on the last bottom a plurality of relatively short slashes 54 are made extending across the forepart portion. The slashes 54 extend completely through the substance of the forepart material so that lengthwise stressing of the insole causes the slashes to gap and thus effect extension of the forepart portion of the insole.

A third illustrative insole 60 shown in FIG. 4 is similar to the insole shown in FIG. 3 in that a forepart portion 62 is made extensible by being slashed completely through the substance of the forepart material. However, in this case a single slash 64 only is made extending across most of the width of the forepart portion. Holes 66 extending through the insole 60 at either end of the slash 64 minimize the likelihood of the slash running out to the opposite side edges of the insole. A covering in the form of a piece of readily compressible and extensible polyurethane foam 68 is stuck over the slash 64 on the top surface of the insole, i.e. the surface nearest to the foot in the finished shoe, to avoid the likelihood of discomfort or trapping of the foot of the wearer of the finished shoe.

Having thus described my invention, what I claim as new and desire to secure by Letters Patent 0f the United States is:

1. A shoe insole comprising a forepart portion joined in overlapped relationship with a heel portion by means of an extensible strip of polyurethane foam material interposed between overlapped margins of said portions to allow relative movement between the forepart and heel portions to facilitate positioning of the insole against the bottom of a last.

2. A shoe insole comprising a toe portion joined with a heel portion by means of an extensible portion comprising a forepart portion of the insole having a single slash extending across most of the forepart portion between two holes made through the forepart portion, and wherein the slash extends completely through the substance of the forepart material, a location hole in the heel portion and a location hole in the toe portion, said location holes being adapted to receive respectively location projections provided on heel and toe portions of a last bottom to support the insole in position against the last bottom, the location holes being respectively positioned in said portions of the insole at positions corresponding to the positions occupied by the projections in relation to the corresponding portions of the last bottom.

References Cited UNITED STATES PATENTS 2,346,27 9 4/ 44 Stritter 36-44 2,809,450 10/57 Stritter 36-44 2,185,993 1/40 Haskell 12-442. 2,211,509 8/40 Lumbard 36-43 3,144,669 8/64 Lamy.

PATRICK D. LAWSON, Primary Examiner US. Cl. X.R l 142

Images