WO1996028058A1

WO1996028058A1 - Footwear sole with sandwich structure

Info

Publication number: WO1996028058A1
Application number: PCT/SK1996/000002
Authority: WO
Inventors: Igor Vanko; Ernest Vavrovic
Original assignee: Igor Vanko
Priority date: 1995-03-15
Filing date: 1996-03-11
Publication date: 1996-09-19
Also published as: AT1533U1; DE29680170U1

Abstract

Footwear sole with sandwich structure, comprising at least two layers with different density and/or hardness. The skeleton of the sole (3) includes at least one layer of material with density and/or hardness different from that of the skeleton material, wherein the layer consists of a toe part (2) and/or a heel part (1) and/or a continuous layer (4) under the whole foot.

Description

Footwear sole with sandwich structure

Field of the invention

The technical solution concerns a footwear sole, formed of a combination of materials with different hardness and density, embedded in a polyurethane skeleton.

Background of the invention

Designs of footwear with different density and hardness of the sole and midsole are known. The midsoles consist of light-weight materials, to which a harder sole material is attached either by gluing or injecting. The midsole is thus forming a compact layer between the bottom part of the sole and the foot or it is shaped into a form of a wedge. Light-weight polyurethane (PUR) materials with the density of 300 - 600 kg/m³ or light-weight ethylenevinylacetate (EVA) copoly ers with the density of 200 - 400 kg/m³ or other foamy materials are conventionally used as the midsoles.

The sole is usually made of PUR material with the density of 600 - 1100 kg/m³, of cured rubber, of thermoplastic rubber or of polyvinylchloride (PVC). Existing solutions require for higher demands for comfort embedding or inserting of various socks together with other components supporting mainly the shank part of the foot.

Summary of the technical solution

The above-mentioned disadvantages are eliminated by a sole with sandwich structure of at least two layers with different density and/or hardness, characterized in that the skeleton material with the density of 300 to 1100 kg/m³, and the hardness of 20 to 95 "ShA contains at least one layer wilth hardness and/or density different from that of the skeleton material, the layer being situated within the inner toe or heel part or under the whole foot, and the outer part is formed of the skeleton material, joining the shoe upper with the sole. Density, hardness, thickness and design of the skeleton material depend on the specification of the footwear (sporting, orthopedic, health, working or outdoor footwear) .

The advantage of the technical solution consists in the increased comfort of the sole with the possibility to choose the size, form, hardness and structure of the materials in the heel or toe part or in the whole area of the sole under the foot. It is possible to make a sole with a number of layers of damping materials included in various parts of the sole.

Under^' the term "sandwich structure" in this solution essentially a layer structure is understood, wherein the treading layer may be of various shapes, and the layer of the material with different hardness and/or density is not identical with the area of the treading layer.

Under the term "sole skeleton" a part of the sole is understood, which is joining the shoe upper with the treading part of the sole. The skeleton is formed of a skeleton material, which may comprise reaction polyurethane, natural or synthetic rubbers or other materials.

Under the term "materials with density and/or hardness different from that of the skeleton material" the following materials are understood: soft foamy materials, based on rubbers, polyurethanes, ethylenevinylacetate copolymers or other materials, or harder materials, based on rubbers, polyurethanes, polyvinylchloride (PVC), polyethylene (PE) or other hard materials with the density of 30 to 1200 kg/m³.

Brief description of pictures in the drawing

The technical solution will be explained in more detail by means of a drawing, in which Fig.l is a cross-sectional side view of the sole, and Fig.2 is a top view of the same sole, including the arrangement of inserted materials in its heel and toe parts, Fig.3 is a cross-sectional side view of a sole, and Fig.4 is a top view of the sole with different arrangement of materials with hardness different from that of the skeleton material.

Examples of embodiment

Example 1

An example of the sole with sandwich structure is illustrated schematically in Fig.l and Fig.2, wherein the heel layer 1_. of EVA copolymer with the density of 250 kg/m³, the hardness of 20 "ShA, and the thickness of 10 mm is fixed by gluing to the sock of the shoe upper, lasted in the heel part. Shaped material of whipped latex with the density of 300 kg/m³ and the thickness of 6 mm, forming the toe layer 2 , is fixed to the textile sock of the shoe upper, lasted in the toe part.

The last with the lasted shoe upper is gripped into a mould, wherein liquid polyurethane material is poured or injected into the bottom part of the cavity. The last with the lasted shoe upper closes the upper part of the form, and of the polyurethane material the actual skeleton of the sole

2 is forming in the course of foaming, with the density of 300 kg/m³ and the hardness of 60 °ShA, which is hereby linked to the shoe upper and other materials.

Example 2

Fig.3 and Fig.4 illustrate an example of a footwear sole with sandwich structure, wherein the shaped material of whipped latex with the density of 200 kg/m² and the thickness of 5 mm forms a continuous layer 4_. under the whole foot, and a toe layer 2 of EVA copolymer with the density of

300 kg/m³ is arranged in the toe part. The skeleton of the sole consists of polyurethane material with the density of 1100 kg/m³ and the hardness of 70 °ShA.

Example 3

Shaped material, extra for the heel part 1 and possibly extra for the toe layer 2 , is interposed between the last and the sock of the lasted shoe upper. The last with the lasted shoe upper is gripped into a mould, wherein into the bottom part of the cavity liquid polyurethane material is poured or injected, which expands in the mould, solidifies and forms the skeleton of the sole 2_* After removing the last a depression is formed in the heel part, and possibly in the toe' part, which is then filled by a softer material, and in this way the sandwich structure of the sole results.

Example 4

Shaped material of PVC with the density of 1200 kg/m³ and the thickness of 16 mm is fixed by gluing to the sock of the shoe upper, which is lasted in the heel part. The last with the lasted shoe upper is gripped into a mould, wherein into the bottom part of the cavity liquid polyurethane material is poured or injected, forming during its expansion the actual sole, which is at the same time linked to the shoe upper. In this case the density of the polyurethane material is 650 kg/m³, and it forms the skeleton of the sole 2, the PVC material forming the heel layer jL.

Claims

C L A I M S O F T H E P R O T E C T I O N

1. Footwear sole with sandwich structure, comprising at least two layers with different density and/or hardness, characterized in that the skeleton of the sole (3) with the density of 300 to 1100 kg/m³ and the hardness of 20 to 95 °ShA includes at least one layer of a material with density and/or hardness different from that of the skeleton material, wherein the layer consists of a toe part (2) and/or a heel part (1) and/or of a continuous layer (4) under the Whole foot.

2. Footwear sole with sandwich structure according to claim 1, characterized in that the skeleton of the sole (3) is formed of a reactive polyurethane material or a rubber material.

3. Footwear sole with sandwich structure according to claim 1, characterized in that the layers of materials with density and/or hardness different from that of the skeleton of the sole (3) are formed of materials with the density of 30 to 1200 kg/m³, preferably of rubber materials and ethylenevinylacetate copolymers.