EP0766932A1

EP0766932A1 - Outer sole for footwear

Info

Publication number: EP0766932A1
Application number: EP96202737A
Authority: EP
Inventors: Johannes Hendricus Maas
Original assignee: Bata Nederland BV
Current assignee: Bata Nederland BV
Priority date: 1995-10-06
Filing date: 1996-10-04
Publication date: 1997-04-09
Also published as: NL1001364C2

Abstract

An outer sole for footwear is provided with one or more impact-damping and grip-improving means. The sole can for instance have a damping cavity which is provided under the forefoot portion, and in particular under the ball section portion, of the sole. Furthermore, the outer sole can be provided with means for increasing the grip of the sole, which means is provided on the lower side of the sole on the transition from the foot cavity portion of the sole to the ball section portion of the sole. The outer sole can also be provided with a damping cavity which is formed under the heel portion of the sole, which heel damping portion has in that direction side walls which taper towards each other, which side walls, in the presence of a downward loading force, deform in horizontal direction to absorb impact forces, and with almost vertical slots with almost vertical walls, which are present in the side walls with their longitudinal direction in the circumferential direction of the heel damping cavity. Finally, the outer sole can be provided with a forefoot portion, a heel portion and an intermediate hollow shank portion which, upon placement of the sole on a horizontal surface, forms a bridge and does not contact the surface, and with ridges which are formed substantially transverse to the longitudinal direction of the sole under the bridge and which extend in a position of rest slantingly from the bridge and are resiliently bendable from the position of rest into a position located nearer the bridge.

Description

The present invention relates to an outer sole for foot-wear.
The purpose of shoes, and in particular of sports shoes and safety shoes, apart from protecting the wearer's feet, is to damp the forces created by the impact of the wearer's feet on the surface as much as possible and moreover to provide as solid a grip as possible for the wearer's feet on the ground or for instance on steps or a ladder.
These last two objectives have turned out to be hard to realize in actual practice. Especially when tough demands are made on impact-damping and grip, such as for instance with sports shoes and safety shoes, these demands are difficult to combine.
The aim of the invention is to overcome these drawbacks.
For this purpose, the invented outer sole is provided on one or more locations with damping and grip improving means. The sole according to the invention can for instance have a damping cavity which is formed under the forefoot portion, and preferably under the ball section portion, of the sole, or it can be provided with a means formed on the bottom of the sole on the transition from the foot cavity portion of the sole to the ball section portion of the sole to increase the grip of the sole.
The invented outer sole offers an improved damping of the forefoot portion, while moreover a good grip can be provided of the sole on the surface.
The bottom of the front cavity is preferably constituted by the lower side of the sole and the front cavity is bounded in lateral direction by at least one protruding wall, integral with the sole, which run round the front cavity. The protruding wall then contributes to the grip of the sole on the surface. The wall can furthermore be interrupted by at least one opening. Through this opening liquids such as water and oil and more solid substances such as mud and dirt can be forced out, by which an a quaplaning effect is avoided and maximum grip and stability is created.
The sole preferably comprises a protruding elevation on the bottom of the front cavity, of which elevation the height is almost equal to that of the wall, so that the front cavity is shaped like a channel running round the elevation and inside the wall. The elevation contributes to the bearing surface of the sole which contacts the surface, as a consequence of which the direct contact with the surface becomes more firm.
The front cavity is preferably elongated in a direction transverse to the forefoot portion, and the wall and the elevation are therein preferably substantially formed as transverse ribs. These transverse ribs further contribute to the grip of the sole on the surface, in the longitudinal direction of the sole.
In the outer sole with integrated grip means, this grip means preferably comprises at least one protruding wall, formed integral with the sole, which wall runs round an inner space. The roundgoing wall contributes to the stability in lateral directions.
The wall is preferably interrupted by at least one opening. Through this opening liquids and more solid substances can be carried off so that aquaplaning is prevented.
The wall opening is preferably located at the forward side of the grip means, seen in the direction of run, and a wall portion on the rear side of the grip means, seen in the direction of run, is preferably formed substantially as a transverse rib running in transverse direction across the sole. This transverse rib provides extra grip in the sole's profile in order to prevent slipping on ladders and steps.
The invented sole can furthermore be provided with a damping cavity, which is formed under the heel portion of the sole, and has in that direction side walls which taper towards each other, and which, in the presence of a downward loading force, deform in horizontal direction to absorb impact forces, and with almost vertical slots with almost vertical walls, which are present in the side walls with their longitudinal direction in the circumferential direction of the heel damping cavity.
In this sole according to the invention, the side walls of the heel damping cavity can deform more easily under loading of the heel cavity. This greater horizontal deformability and reduced stiffness of the side walls causes the impact forces on the surface of the heel damping cavity of a shoe fitted with the sole to be absorbed more gradually, so that the joints of the wearer's legs and feet are less loaded. Furthermore, a greater part of the strain energy which is stored in the heel cavity is returned to the walking movement of the wearer when the foot is rolled off.
The slots in the heel damping cavity preferably have almost equal lengths and the slots are evenly distributed on the circumference of the heel damping cavity with almost equal interspaces. This results in an even deformation of the side walls on the circumference of the heel cavity.
It is furthermore preferred that the heel damping cavity has an almost flat horizontal bottom and that the slots have almost flat horizontal bottoms which lie at approximately the same depth in the sole as the bottom of the heel damping cavity. The side wall deformation is hereby advantageously distributed across the height of the side walls.
The sole can further comprise grooves in the lower side of the heel, which run at the rear in circumferential direction round the heel damping cavity. These grooves prevent a shoe equipped with the sole from slipping when the heel is put down on a slippery surface.
According to the invention an outer sole for footwear, provided with a forefoot portion, a heel portion and an intermediate hollow shank portion which, upon placement of the sole on a horizontal surface, forms a bridge and does not contact the surface, can furthermore be improved by ridges which are formed substantially transverse to the longitudinal direction of the sole under the bridge and which extend in a position of rest slantingly from the bridge and are resiliently bendable from the position of rest into a position located nearer the bridge.
These bridge ridges in themselves already improve the sole's grip on ladders and steps and they furthermore provide the hollow bridge, in side view, with the appearance of a lowered centre sole part, so that when viewed in profile, the sole has the appearance of a continuous wedge sole, while the sole yet offers an improved grip because of its hollow bridge. When the bridge ridges are loaded, for instance on a ladder or when descending steps, they are bent towards the bridge, creating a higher heel front. This heel front will then prevent slipping.
Such a sole can further be provided with banks formed along the side edges of the sole under the bridge, on which banks the ridges are formed the one behind the other and almost parallel to each other. Seen in profile, this will increase the sole's wedge-like appearance, while the hollow bridge function is maintained.
Preferably, the bank portions between the heel portion and the adjoining ridges lie deeper in the sole than the remaining bank portions. The ridges adjoining the heel front can then be bent further away under load, so that an even higher heel front is created.
The invention will hereafter be further elucidated with reference to an exemplary embodiment, illustrated in the accompanying drawings, in which:

figure 1 is a bottom view of an embodiment of an outer sole according to the invention;
figure 2 is a cross-sectional view of a shoe with the outer sole of figure 1, along the dash-dot line II-II;
figure 3 is a cross-sectional view of a shoe with the outer sole of figure 1, along the dash-dot line III-III;
figure 4 is a cross-sectional view of a shoe with the outer sole of figure 1, along the dash-dot line IV-IV;
figure 5 is a side view of the outer sole of figure 1, in the direction of the arrows V-V.

Figure 1 represents a bottom view of an embodiment of an outer sole 1 according to the invention. Under the ball section of the forefoot a damping cavity 2 is located. The bottom of the forefoot damping cavity 2 is constituted by the lower side of the sole. The front cavity 2 is bounded in lateral direction by a wall 3, integral with the sole, which runs round the front cavity, while leaving clear an opening 4. Inside the cavity 2 is located, at a distance from the wall 3, an elevation 5 which is formed integral with the sole 1. The height of the elevation is almost equal to the height of the wall 3. The front cavity 2 is hereby shaped like a channel running round the elevation inside the wall. Figures 2 and 4 show the wall 3 and the elevation 5 in cross-sectional views.
At the moment at which the forefoot, and in particular the ball section portion of the forefoot of a shoe with an outer sole 1 according to the invention, touches the ground, the bearing surface of the forefoot portion comes under great pressure from the body weight of the shoe's wearer. The design of the forefoot damping cavity 2 ensures maximum grip and impact absorption. The action of the forefoot damping cavity 2 can be combined, through an advantageous design, with the damping of a flexible intermediate sole 7 (see figures 2, 3 and 4) of the shoe for optimizing the impact-absorbing capacity. During the walking movement, the flexible intermediate sole 7 contributes to the elasticity of the forefoot damping cavity 2, the wall 3 and the elevation 5, so that the forefoot portion and the forefoot damping cavity 2 of the outer sole 1 tend to return to the unloaded shape. The forefoot damping cavity 2 according to the invention therefore damps the impact when the forefoot touches the ground. The forces on the joints in the wearer's forefoot are thereby reduced.
The forefoot damping cavity 2 is elongated in a direction transverse to the forefoot portion, and the wall 3 and the elevation 5 thereof are, to some extent, formed as transverse ribs. Furthermore, the outer sole is provided under its forefoot portion with grip ribs 6, which improve the grip of the shoe on the surface. The wall 3 and the elevation 5 further contribute, through their design as transverse ribs, to the improvement of the grip on the surface. The shape of the forefoot damping cavity 2 provides an enlarged bearing surface, thereby improving the stability of the shoe and reducing the chances of sprains. The presence of the elevation 5 enlarges the area of direct-contact with the surface and creates a firmer grip on the ground. Oil, water and dirt can be forced out through the opening 4. Slipping as a consequence of a-quaplaning is hereby avoided and maximum grip and stability are created.
On the transition from the foot cavity portion of the sole 1 to the ball section portion of the sole 1 a means 8 is integrally formed on the lower side of the sole 1 to increase the grip of the sole 1. The grip means 8 is constituted by a protruding wall 9 formed integral with the sole. This wall 9 runs round an inner space 10. The wall 9 is interrupted by an opening 11 located at the forward side of the grip means 8, seen in the direction of run. A wall portion 12 on the rear side of the grip means, seen in the direction of run, is formed as a transverse rib running in transverse direction across the sole 1. The grip means 9, and in particular the wall portion 12 thereof which is shaped like a transverse rib, offers an additional hold for the outer sole on ladders and steps, to prevent slipping on them. Oil, water and dirt can be forced out through the opening 11, so that slipping as a consequence of aquaplaning is prevented. In this way, the grip means 8 contributes, both on a flat surface and on ladders and steps, to the stability and hold of the outer sole 1.
Figures 1 and 2 further show a damping cavity 13 in the heel of the outer sole 1. This heel damping cavity 13 has a flat bottom 14 and tapering side walls 15. Vertical slots 16 are provided in the walls, which slots are so deep, that their bottoms (indicated in figure 2 with interrupted lines) lie at approximately the same depth in the sole 1 as the bottom 14 of the heel cavity 13. The slots 16 have almost equal lengths and are evenly distributed with almost equal interspaces on the circumference of the heel damping cavity 13.
When the heel damping cavity 13 is put on the ground during walking and is loaded with a vertical force, the side walls 15 are deformed in horizontal direction.
At the moment at which the hell damping cavity 13 of a shoe with an outer sole 1 according to the invention touches the ground, the heel damping cavity 13 is put under very great pressure by the descending body weight of the shoe's wearer. Through its design, the heel damping cavity 13 ensures maximum impact absorption, so that the load on the ankle joint and the knee joint of the wearer is reduced. The action of the forefoot damping cavity 13 can be combined, in an advantageously adapted design, with the damping of a flexible intermediate sole 7 (see figures 2, 3 and 4) of the shoe for optimizing the impact-absorbing capacity. During the walking movement, the flexible intermediate sole 7 contributes to the elasticity of the heel damping cavity 13, so that the heel portion and the heel damping cavity 13 of the outer sole 1 tend to return to their unloaded shape. The heel portion and in particular the heel damping cavity 13 of the sole 1 hereby ensure that the energy which is generated therein by compression when the wearer is walking is at least in part returned to the wearer's foot when the foot is rolled off during walking. The heel damping cavity 13 according to the invention therefore reduces the excessive force of putting down the heel, and supplies the greater part of the energy which is thereby generated back to the wearer. The forces on the joints in the wearer's foot and legs are significantly reduced, thereby reducing the risk of damaging the joints of the wearer, for instance by excessive forces being exerted by parts of joints onto each other or rubbing of parts of joints over each other, and reducing the risk of arthrosis.
The slots 16 reduce the stiffness of the side walls 15 and better damp the impact force of the heel on the ground.
The heel of the outer sole 1 is furthermore provided behind the heel damping cavity 13 with roundgoing grooves 17 (see figure 1). The grooves 17 prevent the outer sole 1 from slipping upon first putting down the rear of the heel on a slippery surface during the walking movement.
The heel of the sole 1 is furthermore provided at its rear with a drainage channel 18 which discharges into the heel damping cavity 13. Liquids (for instance water or oil) and more solid substances (for instance grease, mud or dirt) can be carried off through this channel from the heel damping cavity 13 which is compressed during walking, thereby prevent slipping as a consequence of an a-quaplaning effect.
As can be clearly seen in figure 2, the shoe with the outer sole 1 has a hollow shank portion between the forefoot portion and the heel portion which, upon placement of the sole on a horizontal surface, forms a bridge at a distance from the surface. Banks 19 are formed along the side edges of the sole 1 (see figures 1, 2 and 5). On the banks 19 ridges 20 are formed under the bridge, the one behind the other and approximately parallel to each other. The ridges 20 are formed in a direction substantially transverse to the longitudinal direction of the sole 1, and extend in a position of rest slantingly backwards from the bridge with the banks 19. The ridges 20 are resiliently bendable from their position of rest into a position located nearer the bridge.
When the shoe sole 1 is placed with the bridge on a ladder or for instance on the edge of a step and is loaded with the weight of the shoe's wearer, the ridges 20 are resiliently bent towards the banks 19 and the bridge, so that effectively a higher heel front 21 is created which stops the sole 1 from slipping off the rung of a ladder or a step in the forward direction.
For this purpose the bank portions 23 located between the heel front 21 and the adjoining ridges 22 are lower in the direction towards the sole 1 than the remaining bank portions (see figures 5 and 2). When loaded, the adjoining ridges 22 are bent away into the recessed bank portions 23 and further against these recessed bank portions 23. This results in a further localized elevation of the heel front 21 for stopping one from slipping off rungs of ladders and steps.
The banks 19 and the ridges 20 give the sole 1 the appearance of a continuous wedge sole (see figures 5 and 2), when seen in profile, so that a safety shoe designed with this sole can be made to look like a sports shoe, while yet maintaining the advantages of a hollow bridge with an improved grip.
The grip means 8, the forefoot damping cavity 2, the heel damping cavity 13 with the anti-slip grooves 17 and the resiliently bendable ridges 20 provide a significant improvement in comfort, impact absorption, grip and stability of a shoe equipped with the outer sole 2, while moreover contributing to the health of the wearer of such shoes.

Claims

Outer sole for footwear, characterized by a damping cavity (2) which is formed under the forefoot part of the sole (1).
Sole according to claim 1, characterized in that the front cavity (2) is formed under the ball section portion of the sole (1).
Sole according to claim 1 or 2, characterized in that the bottom of the front cavity (2) is constituted by the lower side of the sole (1) and the front cavity (2) is bounded in lateral direction by at least one protruding wall (3), which is integral with the sole (1) and runs round the front cavity (2).
Sole according to claim 3, characterized in that the wall (3) is interrupted by at least one opening (4).
Sole according to claim 3 or 4, characterized in that the sole (1) comprises a protruding elevation (5) on the bottom of the front cavity (2), of which elevation the height is almost equal to that of the wall (3), so that the front cavity (2) is shaped like a channel running round the elevation (5) and inside the wall (3).
Sole according to claim 5, characterized in that the front cavity (2) is elongated in a direction transverse to the forefoot portion, and in that the wall (3) and the elevation (5) are substantially formed as transverse ribs.
Outer sole for footwear, characterized by a grip means (8) for increasing the grip of the sole (1), which means is formed on the bottom of the sole (1) on the transition from the foot cavity portion of the sole (1) to the ball section part of the sole (1).
Sole according to claim 7, characterized in that the grip means (8) comprises at least one protruding wall (9), which is formed integral with the sole and runs round an inner space (10).
Sole according to claim 8, characterized in that the wall (9) is interrupted by at least one opening (11).
Sole according to claim 9, characterized in that the wall opening (11) is located at the foreward side of the grip means (8), seen in the direction of run.
Sole according to claim 8, 9 or 10, characterized in that a wall portion (12) which is located on the rear side of the grip means (8), seen in the direction of run, is formed substantially as a transverse rib running in transverse direction across the sole (1).
Outer sole for footwear, characterized by a damping cavity (13), formed under the heel portion of the sole (1), which heel damping cavity (13) has in that direction side walls (15) which taper towards each other and which, in case of the presence of a downward loading force, deform in horizontal direction to absorb impact forces,
and by almost vertical slots (16) with almost vertical walls, which are present in the side walls with their longitudinal direction in the circumferential direction of the heel damping cavity (13).
Sole according to claim 12, characterized in that the slots (16) have almost equal lengths and are evenly distributed across the circumference of the heel damping cavity (13) with almost equal interspaces.
Sole according to claim 12 or 13, characterized in that the heel damping cavity (13) has an almost flat horizontal bottom (14) and that the slots (16) have almost flat horizontal bottoms which lie at approximately the same depth in the sole (1) as the bottom of the heel damping cavity (13).
Sole according to claim 12, 13, or 14, characterized by grooves (17) in the bottom of the heel, which run at the rearside in circumferential direction round the heel damping cavity (13).
Outer sole for footwear, provided with a forefoot portion, a heel portion and an intermediate hollow shank portion which, upon placement of the sole on a horizontal surface, forms a bridge and does not contact the surface,
characterized by ridges (20) which are formed substantially transverse to the longitudinal direction of the sole (1) under the bridge and which extend in a position of rest slantingly from the bridge and are resiliently bendable from the position of rest into a position located nearer to the bridge.
Sole according to claim 16, characterized by banks (19) formed along the side edges of the sole (1) under the bridge, on which banks the ridges (20) are formed the one behind the other and almost parallel to each other.
Sole according to claim 17, characterized in that the bank portions between the heel portion and the adjoining ridges (22) lie deeper in the sole (1) than the remaining bank portion.
Sole according to two or more of the preceding claims.
Shoe with an outer sole according to any one of the preceding claims.