WO2008108662A1

WO2008108662A1 - Sole

Info

Publication number: WO2008108662A1
Application number: PCT/NO2008/000084
Authority: WO
Inventors: Jan Erik JØRGENSEN
Original assignee: Joergensen Jan Erik
Priority date: 2007-03-07
Filing date: 2008-03-07
Publication date: 2008-09-12
Also published as: EP2120621A1; NO20071241A; EP2120621A4; NO325807B1

Abstract

A sole for footwear with a convexly curved sole of a pressure/distributing and shock-absorbing continuous material providing a rolling gait including a bracer/shank (G) extending mainly over the entire length of the sole in the form of a layer in the continuous material of the sole provides an improved transverse stability of the footwear.

Description

SOLE

The present invention concerns the structure of a sole with step dampening action and for a rolling gait, wherein the sole is structured with a number of layers and has a convex curved shape towards the ground, wherein the sole comprises a continuous material of a soft polymeric material, e.g. polyurethane (PU) , synthetic rubber (TR) or rubber, and wherein the sole is characterized in that the general material is present from toe to heel, and wherein this general material includes several layers comprising:

A: A layer located over the total length of the sole an is made of a pressure-distributing/shock-absorbing material such as PU or HGP; B: a bracing layer of a rigid material such as steel or plastic placed over mainly the whole length of the sole; Ci: a shock-absorbing/pressure-distributing material such as HGP located in the heel area above the bracing layer; optionally C₂: a shock-absorbing/pressure-distributing material such as HGP located in the heel area below the bracing layer; and optionally

D: a shock-absorbing/pressure-distributing material such as HGP located in the fore-foot area below the bracing layer. The bracing layer provides overstepping and torque stability in the sole while the shock cushion in the heel area of the sole provides shock absorption together with a natural gait movement through the rounded shape of the sole bottom.

Background for the invention.

When walking or running, especially with a hard surface such as asphalt, rock or concrete, it is of importance that the feet, legs and back has sufficiently good shock absorption to avoid injuries in the form of joint wear, erroneous positioning of the feet, delayed injuries, stance injuries, etc.. A normal gait and running is performed by the heel first being placed on the ground whereby the weight of the body is transported over the longitudinal metatarsal area and forward to the toes that provide a counter-kick by the Achilles tendon/calf muscles pulling the heel up so that the foot rolls forward on the toe pad. Such a movement may be assisted by forming the sole of footwear with a convex shape so that the foot "rolls" with the gait movement .

However, a hard and convex shaped sole will, when walking or running, feel unstable in the longitudinal direction since the weight distribution becomes irregular, the normal weight distribution in such a position being that the weight is distributed on the heel and toe pad/toes simultaneously (with progressive weight transfer towards the toes) . Consequently it will be inappropriate to design/produce a sole of a too stiff/rigid material (hard plastic, wood, etc.). However, a sole made of a somewhat softer material (e.g. a polymeric material such as rubber, etc.), but that is able to maintain its curved shape through the step, will maintain its rounded form throughout the step. Such materials being sufficiently rigid to avoid being significantly deformed, but that still may provide an appropriate rolling gait with deformation during the progression of the step, are known. The deforming will normally be achieved by a load on the sole with a weight from a normal person (25-120 kg depending on age, build, etc. ) .

When walking, and especially when running, the heel section of a sole will be particularly subjected to shock and impact loads. Consequently it is of importance to provide shock absorption especially in the heel section of soles for shoes designed for walking and running. The addition of soft materials in the heel section of such shoes without any consideration of location and stability of the relevant shoe, will, however, create other problems than the shock absorption per se, such as problems relating to stability, torque, etc.. Thus one of the aspects of the present invention is to provide a sole with simultaneous rolling, shock-absorbing and stabilizing properties.

Prior art.

It is previously known shoe types with curved soles and shock-absorbing properties. Thus there is e.g. known from EP patent 1 124 462 a shoe for a rolling gait with a curved sole comprising a middle sole, and under-sole and a bottom sole, wherein the lower part of the middle sole has a hard insert (bracer/shank) covering 1/3 of the forward section of the sole between the middle sole and the bottom sole., and wherein the remainder of the sole between the middle sole and the bottom sole includes a soft shock-absorbing and pliant material.

Even if this patent deals with the same problem as the present invention with impact dampening in a sole providing a rolling gait, the solution to the problem according to this patent is significantly different from the solution according to the present invention, and the solution according to this prior art patent may actually create more problems than it solves such as problems with side stability and torque stability in the footwear.

General disclosure of the invention.

The present invention concerns, as indicated supra, the structure of a sole with thread dampening effect and for rolling gait, wherein the sole is formed with layers had has a convex curved form towards the ground, the sole comprising a continuous material of a soft polymeric substance extending from the external zone of the sole

(external sole/sole bottom) against the ground and towards the interior of the sole. The sole comprises within the continuous material further layers, one such further layer being formed by a bracer/shank (middle layer) extending along the mainly or completely the full length of the sole, and wherein the internal section of the heel includes an inserted impact cushion of a shock-absorbing material facing the heel of the wearer and being placed above the bracer. The bracer/shank provides overstepping and torque stability to the sole while the impact cushion in the heel section of the sole provides shock-absorbing properties together with a natural walking movement through the curved shape of the sole bottom. One of the aspects of this structure of a rolling sole is thus to provide an improved side stability during walking or running, and especially during the first stages of the progression of the step when the heel is placed against the ground.

The invention will be more closely explained infra under reference to the enclosed figures showing the structure of a sole according to the invention mounted on a leisure footwear.

Fig. 1 shows a cross-section of the structure of an embodiment of a sole according to the present invention.

Fig. 2 shows a sandal with a sole according to the present invention together with a side-view of a bracer/shank showing one embodiment of the structure of the bracer/shank located inside the continuous material of the sole.

Fig. 3 shows sole of footwear according to the invention observed from below with a corresponding view of an embodiment of a bracer/shank to be located inside the continuous material of the sole.

Soles according to the present invention may also be mounted on other types of footwear such as jogging or running shoes, shoes for walking, sandals, safety shoes, occupational footwear, working shoes, hiker shoes/boots, etc. When referring to Fig. 1, the sole according to the present invention is made of a continuous resilient material E of the type indicated supra such as a polymeric material, e.g. a PU-material (PU = polyurethane) or TR (TR = technical rubber, synthetic rubber) or natural rubber. Within this material E there is, counted from above (from the inside of the footwear) located an isolating and pressure- distributing material A which may be 1-10 mm thick, e.g. 6 mm thick and covering mainly or completely the entire threading surface of the foot. The material of the threading surface A may be PU, HGP (a polyurethane-based material) or latex or "Poron". To this threading surface A there is attached (glued/welded/cast etc.) a binding sole B of a conventional material, e.g. "Texon" for securing the upper of the footwear (not shown) to the sole. In the heel section of the sole, i.e. the area from the metatarsal and backwards, there is optionally located one or more layers of a shock-absorbing material C that is compressed and rebounding during walking or running. This optional shock- absorbing material C is located below the binding sole B but at a distance from the lower surface F of the sole E, e.g. at a distance from the lower surface of 2-25 mm so that there exists a mass of sole material E between the shock-absorbing layer C and the lower surface F of the sole. Below this shock-absorbing material there is located a rigid layer G in the form of a bracer/shank. This rigid layer extends over the length of the sole and assists in providing stability to the sole. The lower shape of the sole F is curved to distribute pressure during walking or running. In the area about the shock-absorbing material C and in the outer edges of the sole, the sole material will form a "wall" assisting the side stability of the sole.

By placing a bracer/shank G below the shock-absorbing material C and across mainly the full length of the sole, the effect will be that the shock-absorbing material will provide its impact-cushioning function without the footwear feeling unstable in the heel area. The length of the bracer/shank will preferably be, as mentioned supra, across mainly or completely the entire length of the sole, but its effect will also be maintained with a length of down to 20% of the sole length, with the lengths of the bracer may lie in the intervals 99-25% of the sole length, 80-30% of the sole length, 99-50% of the sole length, 80-50% of the sole length. The word "mainly" the entire length (or breadth) of the sole refers to a variance of the size of 0-10%, preferably + 2,5-5%.

The bracer/shank G of the sole according to the invention lies normally within the interval 30-60% of the breadth of the sole even if widths outside this range also may be used, e.g. a lower breadth of 10% of the sole width and up to mainly or completely 100% of the sole width. In normal footwear the breadth of the bracer/shank G will be in the size range 2 cm and up to mainly the entire breadth of the sole, and will normally be rectangular (even if other forms also may be relevant such as formed similarly as the sole, see Fig. 3) . The material of the bracing layer/shank G will be rigid, e.g. metal (steel) or a hard polymeric material such as hard plastic. The shank may have an even thickness of 0,5-7,0 mm if it is made of metal, with a preferred thickness within the interval 1-2 mm, whereas the thickness of the bracer shank may be varying within the interval 0,3-20 mm, preferably within 0,5-9 mm if it is made of plastic (see Fig. 3) . This is a significant improvement over the prior art represented by EP patent 1 124 462 where rolling gait is combined with shock- absorbing properties, but wherein the location of the shock-absorbing material makes the shoe feel unstable.

Also the location of a bracing layer over the entire length of the sole will make the footwear obtain a much better bracing effect and improved torque stability.

For further obtaining impact dampening in the heel area without decreasing the stability of the sole, in an alternaive embodiment of the invention it will be possible to include an extra layer of a shock-absorbing material below the bracer/shank G immediately below and close to this, however, not so close to the underside of the sole that the stability of the sole due to the bracer diminishes.

In an alternative embodiment of the sole according to the invention it will also be possible to obtain a dynamic metatarsal foot support through the included shock- absorbing materials. By including shock-absorbing cushions as disclosed supra (and infra) , when putting weight on the heel section so this is depressed while maintaining the structure of the sole in the metatarsal area of the sole through the action of the bracer/shank G so that the middle part remains elevated, it will be obtained the effect that the metatarsus remains stationary so that the foot curvature (metatarsus) obtains an improved support when the heel is depressed.

For further improving the side stability of the sole it may also be possible alternatively to equip the sole with an external sheath of a more rigid material of rubber or plastic. By placing the sole in such a material there will be formed bracing edges supporting the sole sideways. It may also be possible in an alternative embodiment to make the bottom of the sole wider than its internal stepping surface for providing additional side stability to the sole. The sole may thus be 0,5-10 mm wider in its bottom surface (against the ground) than in its stepping surface (towards the foot) .

The upper side (upper) of the footwear with a sole according to the present invention may be selected from conventional materials and shapes. Usually there will be used an upper of leather or a synthetic material.

Examples . Example 1 :

This example relates to a sandal with a sole of a maximal thickness of 50 mm under the heel and metatarsal area having a convex curved under sole being structured according to the invention. The sole material (E) per se in this sole is made of a polyurethane material wherein a binding sole (B) of "Texon" is glued to the PU material. In the heel area of the sole extending from the hindmost heel edge to the metatarsal area and below the binding sole, there are located two layers of a shock-absorbing material (HGP material) . Below the binding sole in the toe-pad area and in connection thereto there is located a bracer of reinforced (hard) plastic. This bracer/shank extends 85 % of the entire length of the sole and about 50% of the breadth of the sole and in the heel area below the shock-absorbing material (the bracer is here a sole-shaped plate with a transverse breadth relative to the sole, where the shape of the sole is wider in the toe-pad area than in the central area, wherein the breadth in the toe-pad area is 10 cm and the breadth of the middle area of the sole is 6,5 cm). The distance between the underside of the sole and the bracer/shank is 30 mm in the metatarsal area of the sole. The shape of the bracer corresponds to the curvature or the inner sole of the footwear. To the binding sole it is secured (glued/stitched) an upper of leather in the form of a conventional sandal with strips to the heel and forefoot in the form of straps or Velcro locks.

Example 2:

This example concerns a sole for a running shoe wherein the sole is structured in a corresponding manner as the sole in example 1, however with the addition that the sole in the edge area of the rear heel section and forwards to the metatarsal area of the foot (about half the length of the shoe) includes vertically extending edges of a harder latex material than the sole material (PU material) for obtaining further side stability of the sole. The upper is here made of a synthetic water-repellent material with airing holes covering the entire foot.

Example 3 :

This example concerns a sole for a leisure time/walking shoe that also may be used as a running shoe, wherein the sole is structured as in Example 2, but with the extra feature that the underside of the sole is 5 mm wider than the other breadth of the sole.

Claims

C l a i m s

1. Sole for a rolling gait, wherein the sole is structured with a number of layers and has a convex curved shape towards the ground, the sole comprising a continuous material of a soft polymer material such as PU, TR or rubber, c h a r a c t e r i z e d i n that the continuous material extends from toe to heel, and within this continuous material there being located a number of layers comprising

A: a layer provided across mainly the entire length of the sole of a pressure distributing/shock-absorbing material such as PU or HGP;

B: a bracer/shank (G) of a rigid material such as steel or plastic extending mainly across the entire length of the sole; optionally

Ci: a shock-absorbing/pressure distributing material such as HGP in the heel section located above the bracer; optionally C₂: a shock-absorbing/pressure distributing material such as HGP located in the heel area below the bracer; and optionally

D: a shock-absorbing/pressure distributing material such as HGP located in the fore-foot area below the bracer.

2. Sole according to claim 1, c h a r a c t e r i z e d i n that the under-side of the sole being wider than the upper side of the sole.

3. Sole according to claim 1 or 2, c h a r a c t e r i z e d i n that the sole comprises stiffening side walls for stabilizing the sole.

4. The use of a sole for rolling gait, wherein the sole is structured with a number of layers and has a convex curved form against the ground, the sole comprising a continuous material of a soft polymeric material such as PU, TR or rubber, wherein the continuous material extends from toe to heel and includes several layers comprising:

B: a bracer/shank (G) of a rigid material such as steel or plastic extending mainly across the entire length of the sole; optionally Ci: a shock-absorbing/pressure distributing material such as HGP in the heel section located above the bracer; optionally

C₂: a shock-absorbing/pressure distributing material such as HGP located in the heel area below the bracer; and optionally

D: a shock-absorbing/pressure distributing material such as HGP located in the fore-foot area below the bracer,

in footwear.

5. The use according to claim 4, wherein the footwear is selected from sandals, leisure shoes, jogging or running shoes, safety shoes, occupational footwear, working shoes or hiker shoes/boots.