US3689952A - Heel moulding bands - Google Patents

Abstract

A method of making moulding bands for shoemaking machines in which a thermoplastic lining material having a low coefficient of friction is secured to a resilient material forming the body of the moulding band through a fabric material. The band has a lining suitable for engagement with a shoe upper, the lining being bonded to a resilient body through a fabric and the body having a cavity filled with a particulate material so the band accommodates to various dimensions and contours of a shoe form.

Description

United States Patent Dawson et al.

[4 1 Sept. 12, 1972 [54] HEEL MOULDING BANDS [72] Inventors: Peter H. V. Dawson; Norman S. Smith, both of Union Works, Belgrave Rd., Leicester, England [22] Filed: April 13, 1970 [21] Appl. No.: 27,534

[30] Foreign Application Priority Data April 16, 1969 Great Britain ..l9,334/69 [52] US. Cl. ..12/l4.4, 161/84, 161/115,

[51] Int. Cl. ..A43d 21/12, B32b 5/16, B32b 27/12 [58] Field of Search..l2/14.4; 156/309; 161/84, 115, 161/160, 162, 190; 264/257, 273

[5 6] References Cited UNITED STATES PATENTS 3,082,485 3/1963 Thomas ..264/257 X 3,051,968 9/1962 Meier ..12/8.2

2,339,774 1/1944 Eppler ..12/14.4 X 2,593,553 4/1952 Francis ..161/115 X 2,750,321 6/1956 Koppelman 156/309 X 2,806,509 9/ 1957 Bozzacco et al ..161/161 3,510,392 5/1970 DEustachio et al. .....161/162 Primary ExaminerRobert F. Burnett Assistant ExaminerRobert A. Dawson Attorney-Richard A. Wise, Richard B.v Megley and Vincent A. White [5 7] ABSTRACT A method of making moulding bands for shoemaking machines in whicha thermoplastic lining material having a low coefficient of friction is secured to a resilient material forming the body of the moulding band through a fabric material. The band has a lining suitable for engagement with a shoe upper, the lining being bonded to a resilient body through a fabric and the body having a cavity filled with a particulate material so the band accommodates to various dimensions and contours of a shoe form.

4 Claims, 3 Drawing Figures HEEL MOULDING BANDS BACKGROUND OF THE INVENTION It is common to provide moulding bands which engage and closely conform shoe uppers particularly at the heel end to inner forms or shoe lasts. The inner, upper-engaging, surface of the band is usually substantially complementary in shape to that of the form or last. The upper-engaging surface must be of a suitable.

material so that, when the band embraces the upper on the form or last, no damage is caused to the upper through scufling. Accordingly, materials of low friction coefficient are suitable to construct the upper-engaging surface. However, it is often not desirable to manufacture the entire band of such material because of the requirements of flexibility, to permit continual opening and closing movements in order to embrace the form or last. Therefore, a flex-cracking resistant material must be used for the main portion of the heel band. Constructions of heel bands have therefore been suggested that involve the use of a relatively flexible body portion having an upper-engaging surface comprising a lining of material having a low friction coefficient. However, by its nature, such material presents problems of bonding since the lining should preferably not be permitted to shift relative to the main portion of the hand during use and therefore should be fixed securely thereto.

SUMMARY OF THE INVENTION It is therefore an object of the present invention to provide a method by which a surface layer of thermoplastic material of low friction coefficient is securely bonded to a flexible, moulded substrate for use as a forming device for conforming shoe parts to the shape of an inner'form or last.

It is a further object of the invention to provide an improved heel band for use in conforming a back-part of a shoe upper assembly to a form, the band comprising a lining of thermoplastic material, having a low coefficient of friction, particularly well bonded to a main band portion of flexible moulding material.

With these objects in mind, the invention provides a method of bonding thermoplastic sheet material having a low coefficient of friction to a flexible moulded material, to provide a forming device for conforming shoe parts to the shape of an inner form or last, comprising the steps of (a) assembling a layer of woven heat-resistant fabric in contact with one surface of said sheet material (b) applying conditions of elevated tem-' perature and pressure thereto such as to soften said thermoplastic material sufficiently to permit said fabric to become partially embedded therein, shaping the heated assembly of material and fabric so produced to the contour required for said forming device, (d) allowing the shaped assembly to cool (e) placing the cooled assembly in a mould device such that at least a portion of a cavity contained within the device is defined by a surface consisting of the fabric of said assembly and (f) filling said mould cavity with said flexible material in a mouldable condition.

The invention further provides a heel band. for use in conforming a back-part of a shoe upper assembly to the shape of a form or last, comprising a main portion of generally horseshoe configuration in plan view and consisting of moulded flexible material, and a lining of thermoplastic material having a low coefficient of friction provided around an inside curved surface of said main portion and bonded to said portion through a layer of fabric.

The main portion of the heel band may be moulded so as to be hollow, that is, provided with a horseshoeshaped cavity enclosed by moulded material. This cavity may be filled with a suitable medium to enhance the upper-conforming properties of the heel band, for example, particulate material which may be in the form of small glass pellets. A heel band is ideally so constructed as to be capable of operating on right or left shoes, the medium in the hollow cavity being capable of flowing within the cavity to accommodate various dimensions and contours of the inner form or last. i

There will now be given, with reference to the accompanying drawings, a detailed description, by way of illustration of the invention, of a method of bonding a layer of thermoplastic material of low friction coefficient to a flexible moulded substrate and of a heel band, also illustrative of the invention, constructed according to the illustrative method. It is to be understood that the illustrative method and heel band are selected for description merely by way of exemplification and not by way of limitation thereof.

In the drawings:

FIG. 1 is a perspective view of the illustrative heel band;

FIG. 2 is a section taken on line II II of FIG. I; and

- FIG. 3 is a diagrammatic representation of an assembly of thermoplastic sheet material and woven fabric during a step of the illustrative method.

In carrying out the illustrative method, a piece of thermoplastic sheet material (0.75 mm nominal thickness) consisting of ultra-high molecular weight (greater than one million) polyethylene and of a size suitable for operation in a convenient press, is included in a multilayer assembly comprising a layer of fine, knitted cotton fabric in immediate contact with the polyethylene. A layer of sheet rubber is then placed over the cotton fabric witha layer of plastic material between the rubber and the cotton to prevent sticking, the plastic material being, in the present example, polyethylene terephthalate film available under the trade name Melinex." The assembly of layers is held rigid by two thin gauge aluminum plates, each separated by inter-layer of Melinex from direct contact with the rubber layer or the polyethylene layer respectively. The multilayer assembly is shown in FIG. 3, which shows twoplatens 2, 4 of a press, and arranged therebetween the assembly comprising anupper aluminum plate 6, the layer ofsheet rubber 8, thecotton fabric 10, the layer of polyethylene l2 and alower aluminum sheet 14, there being provided inter-layers of Melinex 16 between these layers with' the exception of the cotton layer and the polyethylene which are to be bonded together. The assembly is heated to 210 C and subjected to a pressure of 400 p.s.i. for 20 minutes in the press. The assembly is then removed and allowed to cool in a flat condition, maintained if necessary with a light (for example 20 lb.) weight. The cotton fabric is now partially embedded in the polyethylene.

Where the polyethylene layer is to be used as the lin ing for use in the illustrative heel band, a portion of the polyethylene of somewhat larger dimensions than the amount of lining required for the band is placed around a heel form chosen of a size somewhat larger than a form the band will be required to be used with when complete. The use of this over-size form ensures that the correct size of lining is achieved despite shrinkage during the next step of the illustrative method in which the polyethylene/cotton layer is reheated and shaped around the oversize form. When cooled again, the polyethylene/cotton layer retains the horseshoe-configuration required for incorporation into the heel band.

The polyethylene/cotton layer (hereinafter referred to as the lining, indicated at 20) is to be temporarily secured at each of the two end portions thereof to the end portions of a spring steel horseshoe-shaped backing band 22. Each end portion of thelining 20 is provided with aflange 24 provided with a plurality ofholes 26, and these flanges are held in place against the end portions of the steel backing band. The lining and backing band are then in the arrangement of a double horseshoe one within the other, and the next step is to fill the horseshoe-shaped space between the lining and the backing band with a material which I is flexible enough to withstand repeated opening and closing of the completed heel band. A mould cavity is therefore constructed which comprises an upper mould plate and a lower mould plate, with remaining side surfaces of the cavity consisting of the fabric-lined surface of thelining 20 and the inner surface of the backing band22. The cavity is then filled with polyurethane according to known techniques of polyurethane moulding. The material flows into the interstices of the cotton fabric of thelining 20 and forms a strong mechanical bond; it flows into theholes 26 of theflanges 24 of the lining and intofurther holes 28 provided inlugs 30 of thelin ing 20 which are turned over against the moulding plate to provide extra keying surfaces for the polyurethane to bond to. The inner surface of each end portion of the backing band is coated with a primer to enhance the adhesion of the polyurethane to the steel, but, to ensure that the heel band will be flexible at the intermediate portion, i.e., the bight of the heel band, it is coated with a conventional mould release or parting agent, so that thepolyurethane 21 does not adhere to thebacking band 22 at this portion but is able to leave aslight gap 32 when the band is not in the fully closed position.

It will be seen that the illustrative heel band is provided with a horseshoe-shaped cavity 34 which extends within the polyurethane main portion of the band around the greater portion of the length thereof. This cavity is formed by inserting a core of low-melting point metal (in the illustrative method a metal alloy available under the trade'name Cerrobend") into the mould cavity before the polyurethane is moulded therein. The core is supported in the mould cavity by tours of the heel end of a shoe,

wood pegs attached thereto which are secured to one of the moulding plates. When moulding is complete, the Cerrobend is melted out by heating the band in an oven at C, the alloy running out through holes 36 (only one shown in FIG. 1) left after the removal of the e p Thecavity 34 is then filled with particulate material in the form of small (1/15)glass beads 38, and theholes 36 sealed. Thebacking band 22 is provided with hook-shaped lugs 40 by which it is attachable to a suita It will be understood that, alternatively, thecavity 34 may be connected to a source of compressed air so that the heel band may be inflated in order to provide the desired operating characteristics.

Having thus described our invention, what we claim as novel and desire to secure by Letters Patent of the United States is:

l. A heel moulding band for a shoe machine comprising a lining of material having a low coefficient of friction, said lining having an exposed shoe upper engaging surface shaped to conform generally to the cona main flexible body portion shaped to support said lining, and means for securing the lining to the body portion including a layer of fabric material having one face partially embedded in the inner surface of said lining so as to be mechanically attached thereto and having the other face of the fabric material bonded to the body portion.

2. A heel moulding band for a shoe machine comprising a main flexible body portion provided with a hollow core filled with a particulate material, a lining of material having a low coefficient of friction, and means for securing the lining and the body portion together comprising a layer of fabric material having one face partially embedded in the lining material so as to be mechanically bonded thereto and having the other face of the fabric material bonded to the body portion.

3. A heel moulding band according toclaim 2 in which the particulate material is in the form of glass beads.

4. A heel moulding band for a shoe machine comprising a main flexible body portion, a lining of material having a low coefficient of friction, and means for securing the lining and the body portion together comprising a layer of fabric material .having one face partially embedded in the lining material so as to be mechanically bonded thereto and having the other face of the fabric material bonded to the body portion, said body portion being formed of polyurethane and the lining material being formed of ultra-high molecular weight (greater than 1 million) polyethylene.

Claims (3)

1. A heel moulding banD for a shoe machine comprising a lining of material having a low coefficient of friction, said lining having an exposed shoe upper engaging surface shaped to conform generally to the contours of the heel end of a shoe, a main flexible body portion shaped to support said lining, and means for securing the lining to the body portion including a layer of fabric material having one face partially embedded in the inner surface of said lining so as to be mechanically attached thereto and having the other face of the fabric material bonded to the body portion.

2. A heel moulding band for a shoe machine comprising a main flexible body portion provided with a hollow core filled with a particulate material, a lining of material having a low coefficient of friction, and means for securing the lining and the body portion together comprising a layer of fabric material having one face partially embedded in the lining material so as to be mechanically bonded thereto and having the other face of the fabric material bonded to the body portion. 3. A heel moulding band according to claim 2 in which the particulate material is in the form of glass beads.

4. A heel moulding band for a shoe machine comprising a main flexible body portion, a lining of material having a low coefficient of friction, and means for securing the lining and the body portion together comprising a layer of fabric material having one face partially embedded in the lining material so as to be mechanically bonded thereto and having the other face of the fabric material bonded to the body portion, said body portion being formed of polyurethane and the lining material being formed of ultra-high molecular weight (greater than 1 million) polyethylene.

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