GB2257616A

GB2257616A - Gripping element for sports shoe soles.

Info

Publication number: GB2257616A
Application number: GB9212638A
Authority: GB
Inventors: Hans-Peter Zepf; Manfred Dietrich; Norbert Fechter; Werner Seifriz
Original assignee: UHL SPORTARTIKEL KARL; Sportartikelfabrik Karl Uhl GmbH
Current assignee: UHL SPORTARTIKEL KARL; Sportartikelfabrik Karl Uhl GmbH
Priority date: 1991-07-13
Filing date: 1992-06-15
Publication date: 1993-01-20
Anticipated expiration: 2012-06-15
Also published as: DE4123302C2; GB9212638D0; GB2257616B; DE4123302A1

Description

2237A 6 - 1 GRIPPING ELEMENT FOR SPORTS SHOE SOLES

The invention relates to a gripping element for sports shoe soles according to the generic term of Claim 1, and also to a sole provided with at least one such gripping element, and to a sports shoe provided with such a sole.

The use of sports shoes with relatively few, prominently protruding gripping elements of small surface area, for example shoes with replaceable studs as used in football, rugby and American football, leads to a heavy concentration of all the treading and push-off forces in a corresponding small number of regions of small surface area on the sole of the foot. This results at least in a poor level of comfort for the wearer. In many cases it even results in irritation of and pains in the stressed regions of the foot. Therefore, there has for a long time been a requirement for measures for damping dynamic treading forces for sports shoes of the type concerned. However, the known attempts which have hitherto been made to solve this problem effectively have not led to a satisfactory result.

Thus DE 39 24 360 A1 describes a solution for which a detachable gripping element is fastened in a ltpressure distribution plate" on the sole, wherein the pressure distribution plate rests on a damping element disposed in a recess in the sole. However, due to its construction from several inlaid parts, this solution is extraordinarily expensive, and is associated with serious functional disadvantages. In particular, sealing the mechanical assembly is against the ingress of dirt and moisture can only be achieved with difficulty.

A gripping element of the form described at the outset has become known from DE 38 33 193 Al. This document discloses a gripping element formed as one piece with the sole and comprising the same material as the latter, wherein the gripping element has an annular groove at its periphery in which a ring of elastic material is disposed. Corresponding to this, the base and upper part of the gripping element are attached here by means of a core of hard material, which penetrates the elastic ring. This hard core prevents effective damping of the forces in the axial direction due to pressure, and in all cases permits a certain amount of lateral yielding.

The object of this invention is to create a gripping element which has a damping effect, particularly in the axial direction (vertical direction), with comparatively simple means and at low cost, for which at the same time an inseparable attachment of the damping element to the hard components of the gripping element is ensured.

According to a first aspect of the invention there is provided a gripping element for sports shoe soles, comprising a base on the sole side which can be detachably joined to or formed as one piece with the sole, an upper part forming the contact surface with the ground, and a damping element which is elastically deformable under pressure, with the damping element comprising vulcanised rubber and (chemically) bonded to the base, which comprises thermoplastic synthetic material, during the vulcanisation process, and as a result covers the 3 - whole of the cross-sectional area of the base (Figures 1 - 5 and 7).

According to a second aspect of the invention there is provided a gripping element for sports shoe soles, comprising a base on the sole side which can be detachably fastened to or is formed as one piece with the sole, an upper part forming the contact surface with the ground, and a damping element which is elastically deformable under pressure, with the damping element comprising vulcanised rubber, also forming the base, and its face which is remote from the sole being covered by a cap-like upper part, and being (chemically) bonded to the latter during the vulcanisation process (Figure 6).

According to a third aspect of the invention, there is is provided a sports shoe sole incorporating at least one gripping element in accordance with the first or second aspect.

According to a fourth aspect of the invention, there is provided a sports shoe incorporating a sole in accordance with the third aspect.

The invention utilises the outstanding damping properties of vulcanised elastomers. For this, use is made of the advantageous fact, which has fundamentally become known from EP 0 196 407, that special combinations of thermoplastic synthetic materials and vulcanised rubbers form very strong chemical bonds during the vulcanisation process. This means that bonding of the components comprising hard plastic to the soft material of the damping zone takes place inseparably, based on the process, known from EP 0 196 407, certain thermoplastics to special elastomers, chains of which have certain terminal groups.

It has surprisingly been shown that gripping elements made of these types of plastics with interspersed layers of rubber confer the mechanical strength necessary to accommodate the very high forces which are specific to different types of sport, if the structural parts are suitably shaped.

Claims

Claims 2 - 4 comprise advantageous forms of the invention according to Claim 1. One form of the gripping element according to the invention of this type makes the gripping element particularly suitable for football, since it facilitates grip on soft playing surfaces, as is generally customary for football studs. However, the damping element, which is embedded in the base on one side and in the cap-like upper part on the other side, also ensures the effective damping of dynamic forces due to pressure and significant protection of the foot. Moreover, the reduction of the maximum forces leads to reduced abrasion on the bearing surface of the gripping element (stud). A further significant advantage of the design of the gripping element according to the features of Claims 2 - 4 is that a constant overall thickness of the damping zone is maintained, by means of which a reduction in the lateral tilting movements of the gripping element is obtained. However, since the axially pre-curved core of the base runs into the "pot" formed by the inner wall of the cap-like upper part, the movement during the damping process is actually for bonding the polymer 1 guided in the axial dir6cti6n. For the athlete, this results on the one hand in-no feeling of irstability arising despite the softness of the gripping element, and on the other hand in shear and tensile forces only arising to a small extent in the region of the rubber zone (damping element). Moreover, in its'form'accOrding to Claims 2 - 4, the damping element according.to the invention given in Claim 1 is outstandingly' suitable'for sports shoe soles supporting sole parts, preferably formed as parts, which are surrounded by a rubber welt base of the gripping element can be anchored moulded) in a recess in the supporting sole This -variant'can advantageously be-fashioned with one or more fibre-reinforced For this, the (e.g. injection part concerned. further by means of the features which can be inferred from Claim 5. The variant which can-bC5.- inferred from Claim 6 represents a modification.of the embodiment shown in Figures 2 to 4. This utilises, in an ideal way, both the favourable anchoring properties of the hard base or the material of the upper part and the superior frictional and abrasion-resistant properties of the rubber material of which the damping element consists. However, according to a further embodiment of the invention the gripping element canalso be formed according to the featuies of Claim 7. The embodiment fulfils the damping function striven for 'articularly effectively, because a p larger amount of damping material is used. Moreover, it has functional advantages wh.en used on hard surfaces (asphalt, sand, etc.); on the one hand, because the abrasion-resistant 6 behaviour of vulcanised elastomers is superior to that of thermoplastic synthetic materials on surfaces of this type, and on the other hand because in general a higher coefficient of friction, i.e. a greater degreeof grip, arises. The measure cited as an advantageous further form of the invention -in the characterising part of Claim 8 is proposed for the (preferred) case, where the gripping element according to the invention is fitted with a connection element, e.g. threaded pins, for detachably fastening it to a shoe sole. By means of this measure, both the seating in the sole (e.g. a threaded socket) and the fastening element on the gripping element (e.g. a threaded pin) effectively protect against the ingress of moisture and dirt and hence against corrosion. Claim 9 comprises an advantageous form of the concept according to Claim 8. By means of this it is possible to manufacture the sealing ring with the damping element in one operation (by injection moulding). Polyamide 6,12, alternatively in fibre-reinforced form also, is suitable as a plastic material for the production of the plastic/rubber composite which is used for the manufacture of the gripping elements according to the invention. This material is also of excellent suitability for the manufacture of highly-stressed threaded connections, for example. Thus the gripping element according to the invention can also be designed in association with a plastic connection element which is constructed in one piece with the plastic base. Claims 10, 11 and 12 refer to these aspects. 7 - However, it is also possible to manufacture the base and/or the cap-like upper part from polyphenyl ether, wherein this material can also be fibre- reinforced. The embodiment according to Claim 10 has the advantage that a threaded pin can be dispensed with as an additional component (reference is made to German Patent Application P 41 04 071.6 for further advantages of such a connection system). The advantages of the alternative to the invention according to Claim 13 are particularly useful for the so- lo called studded soles of football boots. In the known studded football soles the gripping elements (studs) consist of rubber, just like the outsole itself, and are joined to the latter as one piece. However, for some applications, for example when playing on relatively soft, rough ground, it is desirable to utilise the damping properties of the rubber whilst obtaining a better anchorage of the outer surface of the studs on the ground by the use of a harder material. The features cited in the characterising part of Claim 13 correspond in the optimum way to this requirement. For this, the damping element which also forms the base can be joined as one piece by vulcanisation to a rubber welt which surrounds a supporting sole part, preferably a fibre-reinforced part. The advantage of this embodiment rests in particular on its facilitating the simple, inexpensive manufacture of the sole, including the studs. The drawings illustrate examples of embodiments of the invention, which are described below, and where: Figure 1 is a vertical cross-section - shown on an enlarged scale - of one embodiment of a gripping element (stud) for a sports shoe sole, e.g. the sole of a football boot; Figure 2 shows another embodiment of a gripping element, illustrated as in Figure 1; Figure 3 shows a modification of the embodiment shown in Figure 1, illustrated as in Figure 1; Figure 4 shows a further variant of the embodiment shown in Figure 1, illustrated as in Figure 1; Figure 5 shows a further embodiment of a gripping element, illustrated as in Figure 1; Figure 6 is a vertical longitudinal section through one embodiment of a sports shoe sole, e.g. a football boot sole; and Figure 7 shows another embodiment of a sports shoe sole, e.g. a football boot sole, illustrated as in Figure 6. In Figure 1, 10 denotes the stud body and 11 denotes a complete connection element, constructed as a threaded pin 12 and anchored in the stud body 10 by means of the square section 13, for fastening the gripping element in a corresponding threaded socket (not shown) in a sports shoe sole. The stud body 11 consists of a base 14, a damping element 15 which can deform elastically under pressure, and a cap-like upper part 16. The base 14 and the upper part 16 consist of a relatively hard plastic material, e.g. a suitable thermoplastic, preferably (fibre-reinforced) polyamide 6,12. In contrast, the damping element 15 consists of rubber material, which is firmly bonded by vulcanisation to the base 1 9 - 14 on one side and to the upper part 16 on the other side. For this, a pre-curved core 17 of the base 14 extends into the region of the damping element 15, so that the latter is given a somewhat pot-shaped form with its edge 18 bent outwards. In a corresponding manner, a core 19 of the damping element 15 extends into the plastic upper part 16, by means of which the latter is given its cap-like form mentioned above. The bearing surface of the upper part 16, and thus of the complete gripping element, is denoted by 20. Overall, as shown in Figure 1, the damping element 15 has a wall thickness which is approximately constant over the total cross-section of the gripping element. For the embodiment shown in Figure 2, the parts which correspond to those of the embodiment shown in Figure 1 are denoted by the same reference numerals for the sake of clarity. One special feature is that a separate cap-like upper part is not provided in Figure 2; rather, the upper part and the damping element - denoted here by 15a - are formed as one piece and consist of vulcanisable rubber. Thus the damping properties of the gripping element shown in Figure 2 are particularly high. For the embodiment shown in Figure 3, the parts corresponding to Figure 1 or Figure 2 are again denoted by the same reference numerals. In Figure 3 a cap-like upper part is again provided, similar to the embodiment shown in Figure 1, but is here denoted by 16a, and has a central recess 21, in contrast to Figure 1. This is penetrated by the material of the damping element 15b (see reference numeral 22). By this - means a (central) part 20a of the bearing surface is formed by the elastic damping element 15b, and the remaining (annular) part 20b of the bearing surface of the gripping element is formed by the cap-like upper part 16a. Thus the embodiment shown in Figure 3 utilises in an ideal manner both the favourable anchoring properties of the hard upper part 16a and the superior frictional and abrasion-resistant properties of the rubber material of the damping element 15b. The variant shown in Figure 4 represents an advantageous further form of the embodiment shown in Figure 1. The same reference numerals have therefore been used to denote corresponding parts. The special feature of the embodiment shown in Figure 4 is that the base 14 has a sealing ring 24 on its contact surface 23 with the sole, surrounding the fastening element (connection element 11) concentrically. This sealing ring consists of rubber material, just like the damping element 15, and is joined as one piece to the damping element 15 via channels 25 in the base 14. The advantages of the sealing ring 24 are particularly worthwhile when the connection element 11 and/or the seating in the sole for the latter do not consist of material which is completely corrosion-resistant. The sealing ring 24 can be produced by a simple manufacturing technique by means of the channels 25 in the base 14, namely it is manufactured in one operation with the damping element 15 when the latter is injection moulded. However it should be explained for the sake of completeness that such a sealing ring (24, Figure 4) can also be provided for the embodiments shown in Figure 2 and 3, if required. The embodiment shown in Figure 5 fundamentally differs from the embodiments previously described and shown in Figures 1 - 4 in that the base 14a and the connection element 11a are constructed from plastic as one piece. This has the advantage that a threaded pin can be dispensed with as an additional component. Moreover, this special feature is a subject of the prior German Patent Application P 41 04 071.6 (= GB 2252488A), so that reference may be made to the latter document for further details. In its remaining aspects, the embodiment shown in Figure 5 essentially corresponds to that shown in Figure 1, and therefore the reference numerals used in Figure 1 are also used for the corresponding parts here. In Figure 6, 26 denotes a complete so-called studded sole for football boots (or for sports shoes for a comparable type of sport). Two fibre-reinforced parts 27 and 28, which are surrounded by a welt 29 of vulcanisable rubber material, form the supporting parts of the studded sole. Several gripping elements 30 (so-called studs) are formed on the sole 26. Each gripping element 30 consists of an elastic rubber base 31 and an upper part 32 of hard plastic material, e.g. polyamide 6,12, which covers the base and is bonded to it by vulcanisation. The rubber bases 31 are advantageously formed as one piece with the rubber welt 29. Another embodiment of a studded sole - denoted here by 26a - is shown in Figure 7. For the sake of simplicity and 12 - clarity, however, the parts of Figure 7 which correspond to those of Figure 6 are denoted by the same reference numerals. The special feature of the variant shown in Figure 7 is as follows. Cores 34 of comparatively hard thermoplastic material are injection moulded in recesses 33 in the fibrereinforced parts 27, 28. These cores form the basis for the gripping elements denoted in their entirety by 30a. Each of the plastic cores 34 is covered by rubber material which forms damping elements 35 and each core is bonded to the latter by vulcanisation, which can form a one-piece composite with the rubber welt 29. Upper parts 32 made of comparatively hard plastic material are again seated on the damping elements 35, similar to the embodiment shown in Figure 6. Particular functional advantages of the embodiment is shown in Figure 7 can be seen, in that a shape is made possible for the gripping elements 30a which is just as narrow and high as that which is customary for plastic studs or knobs. A further advantage of the embodiment shown in Figure 7 is that a telescopic type of resilient behaviour is obtained for the gripping elements 30a, so that these are predominantly only resilient in the axial direction, whilst lateral movements are as good as excluded due to the particular construction. By this means, good resilient behaviour is obtained by the use of rubber materials of a soft quality, without the athlete feeling that the sports shoe concerned is behaving unstably. - 13 Claims:

1. A gripping element for sports shoe soles, comprising a base on the sole side which can be detachably joined to or formed as one piece with the sole, an upper part forming the contact surface with the ground, and a damping element which is elastically deformable under pressure, with the damping element comprising vulcanised rubber and (chemically) bonded to the base, which comprises thermoplastic synthetic material, during the vulcanisation process, and as a result covers the whole of the cross-sectional area of the base (Figures 1 - 5 and 7).

2. A gripping element according to Claim 1, within the base has a central core which is pre-curved in the direction of the damping element and as a result extends into the material of the damping element, in such a way that the core is surrounded on all sides by the damping element, which is formed approximately pot-shaped.

3. A gripping element according to Claims 1 or 2, wherein the damping element is covered by a cap-like upper part made of a hard thermoplastic and is (chemically) bonded to the latter during the vulcanisation process (Figures 1 and 3 - 7).

4. A gripping element according to Claims 1, 2 or 3, wherein the damping element has substantially the same wall thickness over the whole of the cross-sectional area of the gripping element (Figures 1, 4, 5 and 7).

5. A gripping element according to one or more of the preceding Claims, wherein the base is anchored in a recess in a supporting sole part which is preferably formed as a fibre- reinforced part, and the supporting sole part is surrounded by a rubber welt wherein the damping element bonded at its edge as one piece to the rubber welt by vulcanisation (Figure 7).

6. A gripping element according to Claim 3, wherein that the cap-like upper part has a central recess which is penetrated by the material of the damping element in such a way that the damping element forms a central part and the caplike upper part forms an annular part of the total bearring surface of the gripping element (Figure 3).

7. A gripping element according to Claims 1, 2 or 4, wherein the damping element at the same time forms the upper part of the gripping element and thus forms the total bearing surface of the latter (Figure 2).

8. A gripping element according to one or more of Claims 1 - 4, 6 and 7, with a connection element, e.g. a threaded pin for detachably fastening it to a sports shoe sole, wherein the base has a sealing ring made of elastomeric material on its contact surface with the sole, which sealing ring surrounds the connecting element concentrically or substantially concentrically (Figure 4).

9. A gripping element according to Claim 8, wherein the sealing ring comprises the same vulcanised rubber material as the damping element and is joined to t he latter as one piece, preferably by means of one or more channels in the base.

10. A gripping element according to one or more of the preceding Claims, wherein the base and/or the cap-like upper part comprise polyamide 6,12.

11. A gripping element according to one or more of Claims 1 - 9, wherein the base and/or the caplike upper part comprise fibrereinforced polyamide 6,12.

12. A gripping element according to Claims 10 or 11, for detachably fastening to a sports shoe sole, wherein the base and the connection element are manufactured as one piece from polyamide 6,12, which is preferably fibre-reinforced.

13. A gripping element for sports shoe soles, comprising a base on the sole side which can be detachably fastened to or is formed as one piece with the sole, an upper part forming the contact surface with the ground, and a damping element which is elastically deformable under pressure, with the damping element comprising vulcanised rubber, also forming the base, and its face which is remote from the sole being covered by a cap-like upper part, and being (chemically) bonded to the latter during the vulcanisation process (Figure 5).

14. A gripping element according to Claim 13, wherein that the damping element which also forms the base is joined as one piece by vulcanisation to a rubber welt which surrounds a supporting sole part, preferably a fibre-reinforced part.

15. A gripping element substantially as hereinbefore described with reference to Figure 1 of the accompanying drawings.

16. A gripping element substantially as hereinbefore described with reference to Figure 2 of the accompanying - 16 drawings.

17. A gripping element substantially as hereinbefore described with reference to Figure 3 of the accompanying drawings.

18. A gripping element substantially as hereinbefore described with reference to Figure 4 of the accompanying drawings.

19. A gripping element substantially as hereinbefore described with reference to Figure 5 of the accompanying drawings.

20. A sports shoe sole incorporating at least one gripping element as defined in any preceding Claim.

21. A sports shoe sole substantially as hereinbefore described with reference to Figure 6 of the accompanying drawings.

22. A sports shoe sole substantially as hereinbefore described with reference to Figure 7 of the accompanying drawings.

23. A sports shoe provided with at least one gripping element as defined in any one of Claims 1 to 19.

24. A sports shoe provided with a sole as defined in any one of Claims 20 to 22.