GB2092881A

GB2092881A - Footwear studded sole units

Info

Publication number: GB2092881A
Application number: GB8201848A
Authority: GB
Original assignee: STYLO MATCHMAKERS INT; Stylo Matchmakers International Ltd
Current assignee: STYLO MATCHMAKERS INT; Stylo Matchmakers International Ltd
Priority date: 1981-02-12
Filing date: 1982-01-22
Publication date: 1982-08-25

Abstract

A sole unit for a sports e.g. golf shoe has a flexible sole layer 10 to which is bonded a layer 11 of reinforcing material. An arrangement of inserts or studs 13 extends through the sole layer 10 and the layer 11 of reinforcing material. The reinforcement material has a greater tear strength than layer 10, but is no less flexible than layer 10. <IMAGE>

Description

SPECIFICATION Articles of footwear and sole units thereof This invention relates to articles of footwear and sole units therefor, and particularlyto articles of sporting footwear having spikes or studs projecting from the sole and/or heels. Typical examples of such articles are golf shoes and running shoes.

It is desirable for reasons of comfort and performance, that the soles of such shoes should be as light and as flexible as possible. One of the known ways of achieving a flexible sole is to use a low density synthetic plastics material such as a lightweight polyurethane or ethyl vinyl acetate (EVA).

These materials provide the necessary flexibility and also have the advantage of being relatively light in weight so that the weight of the shoe can also be minimised.

However, with such flexible plastics materials, it has been found that when the desirable qualities of flexibility and low weight are obtained, the materials lack sufficient tear strength to retain studs or spikes embedded therein. In practice, very heavy loads are imposed on the studs during running, twisting and turning on the shoes, which causes the studs to be twisted and torn out of the relatively soft sole material. Many attempts have been made to overcome this problem but they principally involve the provision of a stiffened sole or stiffened insert in the sole which negates the advantages of using the low density synthetic plastics material.

The present invention seeks to provide a sole unit for an article of footwear which substantially overcomes the disadvantages of known arrangements.

According to the present invention in its broadest aspect, there is provided a sole unit for an article of footwear having a flexible sole layer, a layer of reinforcing material of at least the same flexibility as the sole layer but with a greater tear strength, and at least one insert or stud extending through an being supported, at least in part, by the layer of reinforcing material.

In a preferred embodiment of the invention, the reinforcing layer comprises a welded or knitted mesh formed of a synthetic plastics material such as nylon or terylene. In an alternative embodiment, the layer of reinforcing material may consist of a thin sheet or film of a synthetic plastics material such as a polyester film. Woven fabrics of a natural fibre such as cotton or lightweight synthetic materials such as polyester may be used but these have a tendency to unravel and are therefore less preferable than the welded mesh. The qualities required for the layer of reinforcing material are that it just be substantially as flexible as the sole to avoid reducing the desirable properties of the sole, light in weight and of adequate tear resistance.

Qne standard test to measure the retaining strength or tear strength of inserts is to subject the inserts to a tensile axial load of 50 kilogrammes. It has been found that sole material having a density of less than 0.7 gm/cc, although possessing the desired characteristics of flexibility and light weight, lacks sufficient tear strength to pass this test. The use of reinforcing material in accordance with the present invention enables this test to be passed without significantly reducing the flexibility of the sole.

An embodiment of the invention will now be described by way of example with reference to the accompanying drawing in which: Figure 1 shows, in schematic form, a cross sectional view of a shoe sole including an insert having a screw-in stud, Figure 2 shows a similar cross-sectional view of part of a shoe sole having a one piece metal stud.

Figure 1 shows a cross section through a sole of a golf shoe. The illustration is in "exploded" form and it will be appreciated that in practice all the layers of the sole are bonded together in the finished product.

The shoe includes a main sole layer 10 which is formed of a lightweight synthetic material. Typically it may be a moulded 'blown' polyurethane sole or may be cut from a sheet of expanded ethyl-vinyl acetate. The material is chosen to have as low a density as possible whilst still possessing the necessary durability. In this way a lightweight flexible sole is provided.

A layer of reinforcing material 11 is then adequately bonded to the sole (in any suitable manner, such as using an isocynate polychloroprene bonding agent or a suitable primer followed by an ordinary cement such as polyurethane cement.) After this, holes 12 for receiving retaining studs are punched through the reinforcing layer 11 and the sole 10. A cement layer is then applied to the surface of the layer of reinforcing material 11 and inserts 13 made of metal or hard plastics and adapted to receive screw in studs 13a are pushed through the holes and secured to the reinforcing layer 11. The inserts 13 each have a backing flange which extends over the retaining layer and a cylindrical portion which extends at least partially through the hole 12. The cylindrical portions are internally threaded to receive associated studs 13a in a known manner.

The reinforcing layer preferably consists of a welded or knitted mesh of a synthetic plastics material such as nylon orterylene, but other materials having the necessary flexibility and tear resistance may be used instead.

Preferably, but not essentially, a protective layer 14 which may be EVA or a similar synthetic plastics material is bonded on top of the stud retainers 13 and the layer 11. This layer increases the comfort and water proofing characteristics of the sole.

Referring now to Figure 2 there is shown a sectional view through part of sole incorporating a one piece stud 15. Essentially, this embodiment has the same construction as the embodiment described with reference to the figure 1 and thus includes a sole 10 of flexible, relatively low density synthetic plastics material, to which is bonded the layer 11 of reinforcing material. As described previously holes are punched in the assembly of the sole 10 and reinforcing layer 11 and the studs 15 are pressed through the holes so that a flange 16 on the stud 15 abuts the reinforcing layer 11. The stud 15 has a tip 15a and flange 15b which abuts against the outer surface of the sole 10. The sole 10 and reinforced layer 11 have sufficient resilience to enable the flange 15a to be pressed through the holes 12 whilst still providing a snug fit around the shank of the spike extending between flange 1 spa and the flange 16.

As in the first embodiment a protective layer 14 is then bonded to the reinforcing layer 11. The shoe upper is secured to the sole unit thus formed in any known manner.

Claims

1. A sole unit for an article of footwear having a flexible sole layer, a layer of reinforcing material of at least the same flexibility as the sole layer but with a greater tear strength, and at least one insert or stud extending through and being supported, at least in part, by the layer of reinforcing material.

2. A sole unit according to claim 1 wherein the layer of reinforcing material is a mesh formed of a synthetic plastics material.

3. A sole unit according to claim 2 wherein the mesh is formed by welding or knitting.

4. A sole unit according to claim 1 wherein the layer of reinforcing material is a thin sheet or film of a synthetic plastic material.

5. A sole unit according to claim 2,3 or 4 wherein the synthetic plastics material comprises nylon, terylene or polyester.

6. A sole unit according to claim 1 wherein the layer of reinforcing material is of a natural fibre.

7. A sole unit according to claim 6 wherein the natural fibre is cotton.

8. A sole unit according to any one of claims 1 to 7 wherein the sole layer is formed of polyurethane or ethyl - vinyl acetate.

9. A sole unit according to any one of claims 1 to 8 wherein the layer of reinforcing material is bonded to the sole layer.

10. A sole unit according to any one of claims 1 to 9 wherein a protective layer of material is bonded to the layer of reinforcing material on the opposite side thereof to the sole layer.

11. A sole unit according to claim 10 wherein the protective layer is formed of a synthetic plastic mat erial.

12. A sole unit for an article of footwear substantially as described herein with reference to and as illustrated in Figure 1 or Figure 2 of the accompany ing drawings.

13. An article offootwear incorporating a sole unit as claimed in any one of the preceding claims.