US3591879A

US3591879A - Method of attaching insoles

Info

Publication number: US3591879A
Application number: US871223*A
Authority: US
Inventors: Peter L Stapleton
Original assignee: USM Corp
Current assignee: Emhart Industries Inc
Priority date: 1967-09-26
Filing date: 1969-06-13
Publication date: 1971-07-13
Anticipated expiration: 1988-07-13

Abstract

A novel method of temporarily locating an insole on a last bottom. The insole comprises 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.

Description

United States Patent inventor Peter L. Stapieton Leicester, England Appl. No. 871,223 Filed June 13, 1969 Division of Ser; No. 670,598, Sept. 26.1967 Patented July 13, 1971 Assignee USM Corporation Flemington, NJ.

METHOD OF ATTACHING INSOLES 2 Claims, 4 Drawing Figs.

0.5. CI 12/142, '36/43 Int. Cl A43d 9/00, A431) 13/38 Field of Search 36/43, 44; 12/141, 142

[56] References Cited UNITED STATES PATENTS 2,691,227 10/1954 Sachs 36/43 X 3,144,669 8/1964 Lamy 12/141 3,187,358 6/1965 Roske .4 12/141 Primary Examiner-Patrick D. Lawson Attorneys-W. Bigelow Hall, Richard A. Wise and Richard B.

Megley ABSTRACT: A novel method of temporarily locating an insole on a last bottom. The insole comprises 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.

PATENTEB Jun 3l97l 3591,4879

sum 2 or 2 METHOD OF A'II'ACHING INSOLES This is a division of application Ser. No. 670,598. filed Sept. 26. i967 This invention relates to a novel method of locating and at- 5 taching an insole on a last.

In the interest of good shoemaking it is desirable, when attaching a shoe insole to a 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 end and attach the toe portion of the insole before proceeding to the heel portion. Unless the insole has been made accurately to flt 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 providean insole and method 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 margins 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 relationship 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.

There is hereinafter described a method, illustrative of method aspects of the invention, of temporarily attaching an insole, having a toe portion joined with a heel portion by means of an extensible portion, to a last without the use of tacks or other driven fasteners. In the illustrative method hereinafter described, a location pin provided on the bottom of the heel portion of the last is received in a location hole provided in the heel portion of the insole, the relationship of the positions of the hole and pin being such that the pin accurately positions the heel and waist portions of the insole. The toe portion of the insole is then extended toewardly to a location pin on the bottom of the toe portion of the last which is inserted into location hole in the toe portion of the insole, the relationship of the positions of the toeward hole and pin being such that said pin accurately positions the toe and forepart portion of the insole. Alternatively, the toe and forepart portion can be located initially and the insole extended toward the heel to locate the heel on the heel pin.

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 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;

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 ofa third illustrative insole.

LII

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 hereinafter explained.

The polyurethane foam joining material 18 as well as being compressible and thus avoiding unnecessary thickness 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 widthwise directions. Assuming the heel and waist portion 14 is correctly positioned on the bottom of a last,- any discrepancy 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 insole 10 is temporarily supported in position against the bottom 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 predetermined 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 10 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 30 the toe end of the insole is positioned correctly in alignment with the toe end of the last The polyurethane foam oining 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 back part 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 ofthe 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 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 40 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 to locate the insole on a last having location pins similar to the

pins

24 and 26. The forepart portion 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 form an 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 ofdiscomfort 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 of the United States is:

I claim:

1. A method of temporarily attaching a shoe insole having a toe portion joined with aheel portion by means of an extensible portion to a last provided with location projections of the bottom of heel and toe portions thereof to support the insole in position against the last bottom, a location hole being provided in the heel portion of the insole positioned in relation to the heel end thereof and a location hole being provided in the toe portion of the insole positioned in relation to the toe end thereof and irrespective of the position of the heel portion location hole, comprising inserting the appropriate projection into one of the location holes to support one end portion of the insole in position against the last bottom, extending the insole lengthwise to bring the other location hole into a position in which it is capable of receiving the other projection and inserting said other projection into said location hole to support the other end portion of the insole in position against the last bottom.

2. A method in accordance with claim No. 1 wherein the insole includes a forepart portion joined in overlapped relationship with a heel portion and said extensible portion is provided by a strip of polyurethane foam adhered between overlapped margins of said portions, the overlapped margins being wider than the strip of polyurethane foam, and wherein, following supporting of the insole in position against the last bottom, said margins are pressed together so that adhesively coated portions thereof come together rigidly to secure the forepart portion and heel portion in overlapped relationship.

Claims

1. A method of temporarily attaching a shoe insole having a toe portion joined with a heel portion by means of an extensible portion to a last provided with location projections of the bottom of heel and toe portions thereof to support the insole in position against the last bottom, a location hole being provided in the heel portion of the insole positioned in relation to the heel end thereof and a location hole being provided in the toe portion of the insole positioned in relation to the toe end thereof and irrespective of the position of the heel portion location hole, comprising inserting the appropriate projection into one of the location holes to support one end portion of the insole in position against the last bottom, extending the insole lengthwise to bring the other location hole into a position in which it is capable of receiving the other projection and inserting said other projection into said location hole to support the other end portion of the insole in position against the last bottom.