WO2004006709A1

WO2004006709A1 - Shoe, especially a sports shoe, and method for producing the same

Info

Publication number: WO2004006709A1
Application number: PCT/EP2003/007501
Authority: WO
Inventors: Frank Volke; Werner Hasenstab
Original assignee: Fraunhofer Gesellschaft zur Förderung der angewandten Forschung e.V.
Priority date: 2002-07-12
Filing date: 2003-07-10
Publication date: 2004-01-22
Also published as: DE10231882B4; DE10231882A1; EP1524924A1

Abstract

The invention relates to a shoe, especially a sports shoe, comprising a sole provided with a damping system which has at least one spring element and by which means the forces acting on the sole can be at least partially absorbed. The inventive shoe is characterised in that the at least one spring element is embodied in the form of a linear slit spring or at least as a plate spring which contains at least one local camber.

Description

Shoe, in particular sports shoe, and method for manufacturing a shoe

Technical field

The invention relates to a shoe, in particular a work or sports shoe, with a sole in which at least one damping system having a spring element is provided, through which force inputs acting on the sole are at least partially absorbable. A method for producing such a shoe is also described.

State of the art

When designing and manufacturing footwear, especially heavy-duty work and sports shoes, the main focus is on the targeted examination of mechanical loads caused by standing, walking and running movements, and especially those in the foot and leg area act on existing body parts. In order to prevent orthopedic damage to joints, tendons, ligaments and bones caused by possible incorrect loads, effective measures must be taken on and in the footwear to at least minimize incorrect or excessive loads.

In particular, it is important to absorb as much as possible the high acceleration moments associated with each abrupt placement of the foot on the floor by the footwear itself. This is essentially due to the sole of the shoe, which is not only responsible for the adhesion of the shoe to the floor, but also for the wearing comfort and the associated damping properties.

For these reasons, great efforts have been made for many years to at least optimize the properties of shoe soles mentioned under dynamic loads. Essentially, the development goals focus on the further improvement regarding elasticity and damping properties of the shoe soles.

The elasticity of a shoe sole ensures reversible deformability of the sole, i.e. the sole is deformed in the short or long term by an external force input. After the loss of force, for example when the shoe is pressed off the ground, the energy stored by the deformation is released to the runner essentially without loss. The shoe sole also has damping components that are, as it were, deformable, but the deformation energy inherent in these components is essentially irreversibly converted into heat and can therefore not be returned to the movement system.

It has now emerged in the course of studies in this regard that the targeted provision of components which determine the elasticity within the shoe sole causes unexpected complications which are closely linked to the special choice of shape and size and the type, structure and arrangement of these components within the shoe sole , This also seems to be the reason that most shoes today mainly use damping materials and components, which however lose the forces acting on the shoe or the sole of the shoe for the movement of a runner.

The most common cushioning materials used in shoe soles are mainly plastics, gels or foams. In addition, at high-quality sports shoes also integrated air chambers in soles in such a way that spring effects are achieved through such air cushions, whereby the elasticity of shoe soles can be slightly improved.

Multi-layer soles are also known which have so-called midsoles or midsoles with which a desired coordination between elasticity and cushioning is possible within certain limited limits.

Such shoe soles have an element, usually made of a foamed plastic, which has both elastic and damping properties. However, with such shoe soles, changes in the elastic properties occur over the course of their lifespan, as a result of which the elasticity of the foamed material decreases significantly. However, this leads to the shoe becoming noticeably "soft", so that the function supporting the foot is also lost and the risk of injury increases.

For this reason, several approaches are known for equipping shoe soles with spring elements in order to positively influence the elastic properties and to increase their service life.

DE 41 22 086 A1 describes a device for heel suspension and stabilization for a sports shoe which provides a thin plate of heel size, which is made of a composite material made of a thermoplastic resin and a carbon fiberglass material. The plate has a front and a rear end as well as an integrally formed, rearwardly extending and upwardly inclined spring part acting in the vertical direction. The problem with this proposed heel suspension is that a constant pressure point is set for the entire heel area. The individual adjustment of the suspension to the geometry of the foot is not possible with this device. In addition, the device only provides cushioning in the heel area. An absorption of forces in the front area of the shoe, in which the forces act on the foot, especially when running faster over the balls of the foot, cannot be achieved with this suspension.

WO 00/74515 A1 also describes a shoe and a spring damping device for a shoe. In the shoe described, a leaf spring device is provided between a sole and a footbed, which extends in the effective direction from the footbed to the sole. The leaf spring part is formed from a thermoplastic elastomer and has at least one friction section which rubs during a relative movement between the footbed and the sole. With this damping device, too, only the damping of a shoe in the heel area is possible, since this device requires a relatively large design, which requires a lot of space in the shoe sole.

In deviation from the above damping systems, US Pat. No. 6,055,747 describes a damping system which, owing to the use of coil springs, is also able to convert energy stored in the springs back into kinetic energy when the foot moves forward. For this purpose, there is a base plate in the heel area within the sole, on which a large number of coil springs are arranged. The springs are held between the base plate and an upper cover plate. However, shoes provided with coil springs are very problematic when running, since the distance between the sole and the footbed due to the relatively long spring travel and the resulting instability of the sprung shoe represents a high risk of injury to the wearer. In addition, shoes fitted with such coil springs return the shock energy stored in the compression to the joints practically unimpeded. For this reason alone, the use of coil springs, for example for running shoes, is completely ruled out.

In addition to the problems already described, all springs previously used for damping in shoes have the disadvantage that they tire relatively quickly and soon, especially with heavily used sports or running shoes, the desired cushioning can no longer be guaranteed.

Presentation of the invention

Based on the known prior art, the object of the invention is to provide a shoe with an improved damping system in which damping of shock loads is ensured and at the same time at least part of the energy of the shocks to be damped can be used for a more economical running movement. In addition, a user-specific optimization of the pressure points within the shoe sole should be possible and the damping system should be characterized by extreme durability, stability and resilience.

The solution to the problem on which the invention is based is specified in claim 1. The subject of claim 21 is an inventive method for manufacturing the shoe. Features which advantageously further develop the inventive idea are the subject matter of the subclaims and the description with reference to the exemplary embodiments.

The shoe according to the invention, in particular sports shoe, with a sole in which a damping system having at least one spring element is provided, through which force inputs acting on the sole can be at least partially absorbed, is characterized in that the at least one spring element in the manner of a linear slot spring or a plate spring, which has at least one local elevation within the plate spring area.

According to the invention, it has been recognized that slot springs, such as those used mainly in mechanical engineering and described, for example, in EP 0318669 A1, are particularly suitable for use in shoe cushioning systems due to the linear damping characteristics, stability and durability. Tests have shown that slotted springs can withstand up to 4 million load changes without sacrificing the mechanical linear response. This spring is characterized in particular by the fact that it is light, robust, recyclable and easy to pour into rubber and / or plastic. Slotted springs, which are proposed according to the invention for use in shoes as a damping system, each consist of a solid cylindrical base body which is provided with slots which are arranged transversely to the longitudinal axis of the cylindrical body and each extend beyond the center or the longitudinal axis of the cylindrical body. In addition, the slotted spring preferably has a longitudinal bore running coaxially to the longitudinal axis, at least in the region of the slits and the disc regions lying between them. This longitudinal bore also passes through the two axial end parts and expediently has a smaller diameter there.

Thus, a spring element designed as a linear slot spring preferably has a cylindrical base body, which has at least one cross-sectional area oriented perpendicular to the cylinder center axis, along which at least one slot runs, which covers an area that is larger than half the cross-sectional area of the cylindrical base body.

However, it is also conceivable, instead of or in combination with the above linear slotted spring, to integrate plate springs into the damping system according to the invention for a shoe, as they emerge from DE 202 05 139 U1. The term "plate spring" used in the following relates to the spring arrangement described in the above publication DE 202 05 139 U1. Such plate springs are made or shaped from a flat material which has curved or shaped areas which represent local elevations or depressions with respect to an imaginary plane through the plate spring. In a preferred embodiment, the plate spring in question is designed as an annular spring, ie it has an annular spring cross section. The ring spring material, be it based on metallic or fiber-reinforced materials, has at least one, preferably three or more local ring curvatures protruding from the plane of the ring along the ring shape, each of which is located on the ring curvature ring areas adjoining on both sides rise. A plate spring shaped in this way is able to absorb forces directed perpendicularly to the plane of the ring spring particularly well with a minimal spring travel.

Such a plate spring, which, as shown above, can be designed as a ring spring or can also be provided as a plate spring with any n-edged contour, is for integration into the damping system designed according to the invention, preferably between two counter bearings, for example in the form of two robust layers or Plates, position. It is also possible to stack several of the above-mentioned diaphragm springs of the above-mentioned type in order to obtain an individual damping characteristic. In this way it is possible to form a spring assembly from a plurality of plate springs stacked one above the other. Of course, it is also possible to arrange a large number of such spring assemblies formed from plate springs within a shoe sole, the arrangement of the spring assemblies depending on the anatomical shape of the foot. It is also conceivable to arrange spring assemblies, which have different spring properties, such as spring stiffness, distributed according to anatomical aspects within the sole of the shoe.

In order to achieve the best possible distribution of the forces acting on the shoe sole, a plurality of slotted springs can also be arranged next to one another between an upper and a lower boundary plane, which are formed, for example, by two shoe sole areas. In this way, a cushioning system is implemented within the sole of the shoe.

The at least one spring element preferably has an adjustment unit with which the spring stiffness can be changed. In this way it is possible to individually adjust the damping properties of a shoe sole to the expected stress. The adjustment can be carried out, for example, by means of a tool that is brought into operative connection with the adjustment unit, or with an adjustment element that is firmly connected to the adjustment unit. In a further variant of the shoe according to the invention with a damping system, the at least one spring element is detachably integrated within the sole. It is thus possible to replace the spring element as soon as the load on the shoe changes, for example as a result of changed external influences.

Of course, it is also possible to arrange a large number of spring elements distributed over the entire surface of the sole, primarily in the heel region of the sole. The spring elements are preferably divided into groups, at least one spring element being contained in each group and the spring elements within a group having uniform spring properties. The spring elements of different groups preferably have different spring properties.

In a further embodiment, a plurality of spring elements are arranged in a carrier matrix. The carrier matrix serves on the one hand to stabilize individual spring elements at least along a linear axis, and on the other hand to guarantee a certain flat arrangement of the linear slot springs. The carrier matrix is preferably in the form of a plate on which a plurality of recesses or bulges are provided. The individual spring elements are inserted into the corresponding recesses or bulges and are thus stabilized in their longitudinal spring axis.

The spring elements are preferably provided with such a plate with both their lower and their upper end, so that the spring elements are enclosed between the two plates.

Both the spring elements enclosed by two carrier matrices and the design in the form of a single carrier matrix equipped with spring elements are preferably designed as a module unit and can be easily implemented in a shoe sole. So it is possible to have module units with different To provide spring properties, e.g. soft, medium, hard, which can be incorporated into a shoe depending on the runner characteristics. This considerably simplifies and reduces the cost of producing sports shoes and / or work shoes that have different damping and elastic properties.

In a further embodiment, the shoe sole has at least one engagement opening through which the at least one spring element can be integrated into the shoe sole. In this way it is ensured that the spring element, which is preferably made of metal, can be adjusted to the individual requirements and can also be recycled when worn. In contrast to damping materials commonly used for shoe soles, the damping system according to the invention can thus be reused without problems, for example in another sports shoe.

The spring element is preferably arranged in a chamber within which it is surrounded by a gaseous, liquid and / or solid medium. The medium that is located in the chamber and is surrounded by the spring element can be an inert gas, such as argon or krypton, or a gel-like fluid. The chamber in this case represents a cavity within the sole. It is also possible to exchange the medium filled into the chamber in addition to the spring element or the spring element including the carrier matrix. This offers a further possibility of individually adapting the cushioning system according to the invention for shoes to its user or to the corresponding requirements of use.

In a special embodiment, the cavity is lined with a fluid-tight layer, so that when the medium in the chamber is exchanged, the entire medium can be changed at once.

The spring element itself is preferably made of a recyclable material, such as metal. In addition, it is also conceivable that Manufacture spring element from other materials that ensure the stability and longevity of the spring element.

A method according to the invention for producing a shoe with a sole, in which a damping system having at least one spring element is provided, through which force inputs acting on the sole are at least partially absorbable, is characterized in that the at least one spring element is poured into the sole. A plurality of spring elements are preferably first integrated into a carrier matrix, the carrier matrix including spring elements is introduced into a recess in the sole and the carrier matrix including spring element is cast with the sole.

Due to the modular structure of the cushioning system in the form of a carrier matrix, in which linear slit springs, individually designed in terms of their spring properties, are combined and integrated depending on the desired cushioning characteristics, a pre-machined sole is easily assembled, in which a recess adapted to the carrier matrix is provided, with which Damping module possible. Otherwise, identical shoes with different cushioning and elasticity properties can be manufactured inexpensively.

In this way it is possible to wear sports shoes with user-specific damping or To offer elasticity properties that are tailored to the anatomy of your foot and at the same time have pressure points that enable the user to run optimally, gently and comfortably. The cushioning system according to the invention can also be used advantageously in the field of work shoes or safety shoes with additional protective elements, such as steel caps, insoles, etc.

In addition, it is of course possible, for example for high-performance sports, to individually design a shoe that has active linear cushioning properties for an athlete. Brief description of the invention

The invention is described below by way of example without limitation of the general inventive concept using exemplary embodiments with reference to the drawings. Show it:

1 highly schematic shoe with carrier matrix and spring elements,

2a slotted spring made of a solid cylindrical body,

2b diaphragm spring stack,

Fig. 3 cross section through a shoe sole with linear damping

Spring elements.

WAYS OF IMPLEMENTING THE INVENTION, INDUSTRIAL APPLICABILITY

Fig. 1 shows a highly schematic of a sports shoe with a sole So, in which a carrier matrix T with a plurality of linear slot springs S is used. The carrier matrix T is cast in a rubber mixture in the form of the sole.

Fig. 2a shows a typical linear slot spring S, which can be used as a spring element for the damping system that can be integrated in a sports shoe. The slot spring S consists of a solid cylindrical body and is penetrated by slots 1 which are arranged transversely to the longitudinal axis of the cylindrical body and extend beyond the center or the longitudinal axis of the cylindrical body. At the level of the individual slots 1 there remain webs 2 which are arranged asymmetrically over the entire length of the slot spring. These webs 2 ensure the power transmission from the upper to the lower end of the spring. In the area of the slots 1 and the disk areas lying between them, the slot spring can be regarded as a hollow cylinder. In this area, the body thus has a longitudinal bore 3 running coaxially with the longitudinal axis. The upper and the lower end part of the Slotted spring serves as a stop, via which power is transmitted to the sole area above or below.

2b shows a spring assembly which consists of three plate springs 4 arranged vertically one above the other. Of course, each individual plate spring 4 has an effective spring force on its own, so that in a simplest embodiment the provision of a single plate spring would be sufficient. To illustrate a combination of several plate springs, however, reference is made to the exemplary embodiment in FIG. 2b.

For reasons of a clearer representation, the three plate springs 4 are arranged somewhat spaced apart between two robust layers 8 and 9. The latter serve as preferred mechanical counter bearings, which, however, do not necessarily have to be provided individually for each spring stack. How the embodiment according. 2c shows, a large number of such spring stacks can also be placed between such layers 8 and 9.

Each individual one of the three plate springs 4 shown is designed as an annular spring and has three annular spring sections 5 which are flat in a common plane. The individual ring spring sections 5 are delimited by curvatures which represent elevations 6 with respect to the common plane. In the illustrated case, the three plate springs 4 are arranged in such a way that their elevations 6 each come to lie vertically above the flat ring spring sections 5 of the respective lower or upper plate spring. Of course, different stack arrangements are also conceivable, for example a contour-covering arrangement of the plate springs.

Deviating from the specific embodiment of the diaphragm springs shown in FIG. 2b, diaphragm springs with a spring cross section deviating from the ring shape are fundamentally also suitable, for example a triangular or n-square spring cross section with and without inner recesses. Local joints are used for the mutual connection of the plate springs 4 in the stacked arrangement shown. The height or the spring properties of such a spring assembly can be changed almost arbitrarily by adding or removing further plate springs.

FIG. 2c shows a spring arrangement 7 which is characterized in that it has an upper 8 and a lower plate 9. A large number of spring elements (10) of the aforementioned type are inserted between the plates 8, 9. If a force acts on the upper plate 8, which is designed, for example, as a carrier matrix and is integrated in the heel of a shoe, the force is distributed over a large number of spring elements. In this way it is also possible to absorb forces acting obliquely on the spring elements.

FIG. 3 shows a top view of a plurality of spring elements 10, which are arranged distributed over the surface of the sole So. This arrangement of the spring elements 10 makes it possible to individually set the pressure point required by the user in the shoe.

LIST OF REFERENCE NUMBERS

1 slots

2 bridges

3 longitudinal bore

4 diaphragm

5 Flat ring spring section

6 cant

7 spring arrangement

8 Top plate

9 Lower plate

10 spring element

So sole

S slot spring

T carrier matrix

Claims

claims

1. Shoe, in particular sports shoe, with a sole (So) in which a damping system having at least one spring element (10) is provided, through which force inputs acting on the sole (So) are at least partially absorbable, characterized in that the at least one Spring element (10) is designed in the manner of a linear slot spring (S) or at least is designed as a plate spring (4) which has at least one local elevation (6) within the plate spring area.

2. Shoe according to claim 1, characterized in that the spring element designed as a linear slot spring (S) has a cylindrical base body which has at least one cross-sectional area oriented perpendicular to the cylinder center axis, along which at least one slot (1) extends which covers an area , which is larger than half of the cross-sectional area of the cylindrical base body.

3. Shoe according to claim 1, characterized in that the plate spring (4) is designed as a disk-like flat structure and along its surface areas has at least one elevation (6) which rises above an imaginary surface plane.

4. Shoe according to one of claims 1 to 3, characterized in that the at least one spring element (10) has an adjusting unit with which the spring stiffness can be changed.

5. Shoe according to one of claims 1 to 4, characterized in that the at least one spring element (10) is detachably integrated within the sole (So).

6. Shoe according to claim 5, characterized in that a plurality of spring elements (10) are distributed over the entire surface in the sole (So), primarily in the heel area of the sole (So).

7. Shoe according to claim 6, characterized in that the spring elements (10) can be divided into groups, each of which contains at least one spring element (10), that the spring elements (10) within a group have uniform spring properties and the spring elements are different Groups have different spring properties.

8. Shoe according to claim 6 or 7, characterized in that the plurality of spring elements (10) is arranged in a carrier matrix (T).

9. Shoe according to claim 8, characterized in that the carrier matrix (T) stabilizes each individual spring element (10) at least along a linear axis.

10. Shoe according to claim 8 or 9, characterized in that the carrier matrix (T) is designed as a module unit and can be interchangeably implemented in the sole (So).

11. Shoe according to one of claims 1 to 10, characterized in that in the sole (So) at least one engagement opening is provided through which the at least one spring element (10) is interchangeable.

12. Shoe according to one of claims 1 to 11, characterized in that the at least one spring element (10) is arranged in a chamber and is surrounded within the chamber by a gaseous, liquid and / or solid medium.

13. Shoe according to claim 12, characterized in that the chamber is a cavity within the sole.

14. Shoe according to claim 13, characterized in that the cavity is lined with a fluid-tight layer.

15. Shoe according to claim 12, characterized in that the medium consists of rubber and / or plastic material.

16. Shoe according to one of claims 1 to 15, characterized in that the spring element (10) consists of a recyclable material, preferably metal.

17. Shoe according to claim 3, characterized in that the plate spring (4) is a spring element (10), which is described in DE 202 05 139 U1.

18. Shoe according to claim 3 or 17, characterized in that the plate spring (4) is designed as a ring spring and wenbisgtens has an elevation (6) along the ring shape.

19. Shoe according to one of claims 3, 17 or 18, characterized in that the plate spring (4) is disc-shaped with a round or n-shaped peripheral contour.

20. Shoe according to claim 19, characterized in that the plate spring provides one or no inner recess.

21. A method for producing the shoe according to one of claims 1 to 20, characterized in that the at least one spring element (10) is poured into the sole (So).

22. The method according to claim 21, characterized in that a plurality of spring elements (10) in one

Carrier matrix (T) is integrated such that the carrier matrix (T) together with spring elements (10) is introduced into a recess within the sole (So), and that the carrier matrix (T) including spring elements (10) is cast with the sole (So) ,