WO1999022618A1

WO1999022618A1 - Ceramic cleat for sport shoes

Info

Publication number: WO1999022618A1
Application number: PCT/DE1998/003160
Authority: WO
Inventors: Peter Greiner
Original assignee: Peter Greiner
Priority date: 1997-10-30
Filing date: 1998-10-27
Publication date: 1999-05-14
Also published as: EP0948272B1; DE29719312U1; JP2000516128A; ES2177113T3; JP3445803B2; EP0948272A1; DE59804047D1

Abstract

The invention relates to a cleat for sport shoes, comprising a body made of plastic material and a ceramic insert (2) forming the tread surface of the cleat and embedded in the body of said cleat. Part of the longitudinal extension of the ceramic insert is encompassed by a metal jacket (3) that is also embedded in the body of the cleat. A plastic layer (14) is formed between the periphery of the ceramic insert and the inner surface of the metal jacket. In order to provide said plastic layer (14) with an even thickness, at least the section of the periphery of the ceramic insert (2) encompassed by the metal jacket has a smooth surface whilst the tread surface is tapered.

Description

Ceramic gripping element for sports shoes

description

The invention relates to a gripping element for sports shoes, with a gripping element body made of plastic and with a ceramic insert forming the tread of the gripping element and embedded in the gripping element body, which is encompassed within the gripping element body over part of its length by a metal sleeve likewise embedded in the gripping element body. A plastic layer is formed between the peripheral surface of the ceramic insert and the inner surface of the metal sleeve.

There are already numerous proposals for ceramic inserts on gripping elements of sports shoes, e.g. B. made of aluminum oxide,

Silicon carbide, tungsten carbide, etc., to use by

Utilization of the very high wear resistance of the ceramic significantly extends the service life of the gripping elements and the occurrence of wear-related sharp edges and nicks on the gripping elements

Avoid risk of injury. So far, however, it has proven difficult, on the one hand, to connect the ceramic insert so firmly to the gripping element body that the connection can withstand the forces acting on it when the sports shoe is used, and on the other hand to keep the manufacturing outlay so low that a ceramic gripping element is actually worthwhile in comparison to the conventionally designed gripping elements.

A known ceramic gripping element of the type mentioned at the outset (EP-A 231 797) already results in a relatively favorable ratio of stability / cost price. In this gripping element, the ceramic insert has recesses and / or projections on its circumferential surface encompassed by the metal sleeve, preferably ring ribs and ring grooves, which are filled or enveloped by the plastic layer within the metal sleeve. In addition to the form-fitting mounting of the ceramic insert, these ring ribs / ring grooves serve primarily, by means of the thicker portions of the plastic layer between the peripheral surface of the ceramic insert and the inner surface of the metal sleeve, the forces acting on the ceramic insert when used more uniformly on the metal sleeve and through this on the gripping element body transferred to. However, even with this known gripping element, the risk of local overloading of the connection between the ceramic insert and the gripping element body in the region of the metal sleeve cannot be eliminated in all cases.

The object of the invention is therefore to design a gripping element of the type specified at the outset such that the stability is increased with a simple and therefore inexpensive construction.

According to the invention this object is achieved in that at least the part encompassed by the metal sleeve

The peripheral surface of the ceramic insert is smooth and tapered towards the tread surface.

Since, according to the invention, the ceramic insert does not have any recesses or projections on its peripheral surface, but rather is largely largely smooth and at least slightly tapered in the direction of the tread surface, one is formed during the manufacturing process Plastic layer between this circumferential surface and the inner surface of the metal sleeve, the thickness of which decreases very uniformly in accordance with the tapering of the ceramic insert towards the end surface facing away from the tread surface. It has been shown that when the ceramic insert is subjected to a lateral load, the reveal pressure generated in this way is transmitted in the critical region of the front edge of the metal sleeve in such a way that there is no tendency to loosen the ceramic insert due to local destruction of the plastic, even under heavy load. Furthermore, since a very slight taper is sufficient for the form-fitting holding of the ceramic insert in the gripping element body, in particular within the metal sleeve, so that the shape of the ceramic insert comes close to a cylinder, a favorable tension field is established in the ceramic insert even under load, so that its tendency to break is very slight. According to a preferred embodiment, the taper angle does not exceed a value of 6 °. Finally, the effort required to manufacture the ceramic insert according to the invention, in particular if it is expediently smooth and tapered continuously up to its tread surface, is significantly less than that required to produce the ceramic insert with recesses or projections on its circumferential surface described at the outset. Because of its simple shape, the ceramic insert can be dimensionally stable immediately after the ceramic is fired. Even if a grinding process is considered to be advantageous in order to achieve the smooth circumferential surface, this can easily be carried out due to the slim taper.

The dimensions of the metal sleeve and the ceramic insert are matched to one another so that the ceramic insert can be inserted into a bottom of the metal sleeve. As a result of the tapering of the ceramic insert and the expediently cylindrical inner surface of the metal sleeve In any case, an annular gap arises in the area of the sleeve edge, through which the plastic which is flowable at that time can enter the interior of the sleeve during the manufacture of the gripping element and can form the plastic layer mentioned. The width of the annular gap naturally depends on the play that exists between the inner surface of the metal sleeve and the end of the ceramic insert facing away from the tread surface. This should be only a few tenths of a millimeter and advantageously be so small that the inner surface of the metal sleeve almost abuts the end of the ceramic insert facing away from the tread surface. In order to ensure that the plastic of the gripping element body also embeds the ceramic insert perfectly in this case during the manufacturing process, it is expedient to provide openings in the wall of the metal sleeve which are evenly distributed over the circumference. Through this, the plastic can penetrate into the interior of the sleeve and can also perfectly form the plastic layer in the area in which its thickness is small.

According to an advantageous development of the invention, it is provided that the ceramic insert has in its end surface facing away from the tread surface a recess which penetrates the peripheral surface. This recess is filled with plastic during the manufacturing process due to its connection to the peripheral surface, which in this way connects the ceramic insert on the end face with the gripping element body. In the simplest case, the depression can be a rectilinear groove which runs across the end face and passes through the circumferential surface of the ceramic insert with both ends. However, it is also possible to design the recess in a cross or star shape, the arms of the cross or star penetrating the peripheral surface of the ceramic insert. By means of the corresponding connection, the ceramic insert is also positively connected to the gripping element body with respect to torques acting about its longitudinal axis. In order to the ceramic insert also withstands the frequently occurring attempts to detach the gripping element from the sole of a sports shoe with a pair of pliers when the tool surfaces provided on the gripping element body are already worn out.

The gripping element according to the invention can in the usual way either be releasably connected to a sports shoe sole or can be molded directly and then in the material unit of the gripping element body and the sole thereon. In order to absorb the load caused by the weight of the athlete in the vertical direction and pass it on to the sports shoe sole, it is advantageous if the metal sleeve supports the ceramic insert on its end face facing away from the tread surface and has a floor for this purpose. In the releasable embodiment of the gripping element, which has a metal shaft protruding from the gripping element body for releasable fastening, the metal sleeve is expediently crimped around a flange-like extension of the metal shaft and welded to it. In this case, this extension forms the bottom of the metal sleeve. In the one-piece design of the gripping element with the sole, the upper edge of the metal sleeve engages around a disc forming the base and is connected to it, expediently pressed or welded.

The ceramic insert and in particular the part of which is encompassed by the metal sleeve is normally circular in cross section, the shape of the metal sleeve being adapted accordingly. However, a cross-sectional design deviating from the circular shape is also fundamentally conceivable, for example an oval or elongated cross-section, provided a smooth peripheral surface is guaranteed.

Further advantages and features of the invention result from the following description of Exemplary embodiments with reference to the accompanying drawings and from further subclaims. The drawings show:

1 shows a longitudinal section through a lug-shaped gripping element.

2 shows an analogous longitudinal section through a gripping element which is inseparably connected to a sole in the manner of a cam;

Fig. 3 shows a further analog longitudinal section through a spike-shaped releasable gripping element, for example for a golf shoe.

4 shows a further analogous longitudinal section through an elongated design of a gripping element which is inseparably connected to a sole in the manner of a cam;

Fig. 5 is a section along the line V-V in Fig. 4 and

6 shows a section along the line VI-VI in FIG. 4th

The gripping elements shown in FIGS. 1 to 3 on an enlarged scale are consistently rotationally symmetrical in their essential parts and in their shape, so that the representation of a front view is unnecessary. However, as already explained above, the rotationally symmetrical shape is not essential for the invention, but can be modified in favor of an oval or elongated cross-sectional shape, for example.

The cleat shown in Fig. 1, for example for a soccer shoe, consists essentially of a gripping element body 1, a ceramic insert 2 and a metal sleeve 3, which continues on its top in the form of a threaded metal shaft 4. The gripping element body 1 consists of a relatively hard plastic, e.g. B. polyamide or polyurethane, which is flowable in the manufacturing process and can be processed, for example, by injection molding. The shape of the gripping element body 1 is of a type known from conventional gripping elements, in particular studs, and therefore does not require any detailed explanation here. This applies in particular in view of the fact that this shape on the outside of the gripping element body 1 is also not critical, but can be any conical or cylindrical. In addition, in a known manner, engagement surfaces 11 are provided for a turning tool, and the support surface 12 coming into contact with the running side of the outsole (not shown) can carry a profile that makes it difficult or impossible to involuntarily twist the gripping element in the state attached to the sole.

The ceramic insert 2 is an impact-resistant ceramic part and consists, for example, predominantly (96%) of aluminum oxide (Al2O3), silicon carbide (SiC), silicon nitride, zirconium oxide, steatite or other oxidic or non-oxide high-performance ceramics. It has a tread surface 21 which can be flat or slightly lenticularly curved and merges into the peripheral surface 23 with a strong rounding 22. The peripheral surface 23 is slightly conical, that is to say tapering towards the tread surface 21; the taper angle α (or half the cone angle) is approximately 1.5 ° in the exemplary embodiment and expediently does not exceed 2 °. The upper end face 24 of the ceramic insert 2 facing away from the tread surface 21, the edge of which is also rounded, has a rectilinear groove 25 with a substantially rectangular cross-section which extends across it and is open towards the peripheral surface 23 on both sides. In the exemplary embodiment shown, the diameter of the ceramic insert 2 is at its upper end about 10 mm, its length about 11 mm and the depth of the groove 25 about 1.5 mm.

The metal sleeve 3 is made of steel and overlaps the upper part of the ceramic insert 2 to about 40% of its length. At the lower end of the metal shaft 4, this is shaped into a flange-like extension 41, over the edge of which the upper end of the metal sleeve 3 is flanged and welded to it. As a result, the extension 41 forms a flat floor on which the flat end face 24 of the ceramic insert 2 is supported directly. The inner surface 31 of the metal sleeve 3 is approximately cylindrical and its diameter is selected so that the ceramic insert 2 rests almost or completely against the inner surface 31 in the region of the transition to its peripheral surface 23. Furthermore, the metal sleeve 3 has six circular openings 32 evenly distributed over its circumference, which are so large that they allow the plastic to enter the space created by the rounding of the end face 24 and thus to the ends of the groove 25. The lower end section 33 of the metal sleeve 3 is offset by an increased wall thickness and thereby reinforced.

As can be seen from FIG. 1, both the ceramic insert 2 and the metal sleeve 3 are embedded in the plastic of the gripping element body 1 over the largest part of its length and are positively held by the latter. The plastic of the gripping element body continues into the space between the inner wall of the metal sleeve 3 and the peripheral surface 23 of the ceramic insert and forms a plastic layer 14 there, over which the ceramic insert 2 extends in the radial direction, that is to say transversely, when the gripping element is loaded its longitudinal axis is supported on the metal sleeve 3. In accordance with the shape of the space mentioned, the thickness of the plastic layer 14, apart from the connection to the gripping element body 1 via the openings 32, increases in the direction to the end face 24 and is in any case largely constant in the thickened area 33 of the metal sleeve 3 in the circumferential direction. The edges of the openings 32 can be rounded in a manner not shown in order to minimize shear effects on the plastic connections with the gripping element body 1 which extend through the openings 32.

As a result of the direct abutment of the upper end face 24 of the ceramic insert 2 on the bottom 41 of the metal sleeve 3, no plastic layer forms there outside the groove 25 during the manufacturing process of the gripping element, so that there is ceramic / metal contact and vertical loads consequently directly on the metal sleeve 3 or the threaded shaft 4 are transmitted. Within the framework of the unavoidable manufacturing tolerances both with regard to the ceramic insert 2 and the metal sleeve 3, however, it can happen that the end face 24 does not lie evenly against the bottom 41. This makes it possible for plastic to be embedded outside the groove 25 between the end face 24 and the bottom 41. However, this is desirable because it fills the plastic with the "dead space" that arises and thus makes the power transmission more uniform. In addition, occurring shocks are damped according to the elasticity of the plastic. If this effect is to be emphasized, the end face 24 can also be shaped in a lenticular convex manner.

The cam-shaped gripping element shown in FIG. 2 has a gripping element body 1 'which is made of the same plastic as the outsole 5, which is only partially shown, and is integral with it. This plastic differs from that of which the gripping element body 1 according to FIG. 1 consists, in order to meet the demands placed on the function of an outsole by a corresponding softness and flexibility. The ceramic insert 2 'is with the ceramic insert 2 identical to FIG. 1 and therefore requires no further description. This also applies to the part of the metal sleeve 3 'which overlaps the ceramic insert 2 and which differs from the embodiment described in connection with FIG. 1 in that its bottom 41' is formed by a flat disc which is in contact with the flanged upper edge of the metal sleeve 3 'is welded or pressed.

The basic structure of the embodiment according to FIG. 3 largely corresponds to that according to FIG. 1.

It has a gripping element body 1 '' made of a relatively hard plastic, e.g. B.

Polyamide, is made and has a conical shape. He points

Attack surfaces 11 '' for actuation by a corresponding turning tool and is widened to an edge 12 '' at its upper end intended for bearing against the outsole, not shown.

The ceramic insert 2 '' made of the materials mentioned above is in this embodiment due to the

Purpose designed as a golf shoe spike relatively slim, that is, it has a diameter of about 3 mm at the upper end and 0.6 mm at the tread

21 '' a length of about 12.5 mm. The taper angle α (or half cone angle), under which the ceramic insert

2 '' tapered, here is about 6 °. The

In this exemplary embodiment, tread area 21 ″ is relatively small owing to the small diameter and the rounding that can be seen in FIG. 3, and acts as a tip.

The metal sleeve 3 ″ is connected at its upper end to a metal shaft 4 ″ by being pressed into a groove 42 ″ machined into its lower end face. Its bottom is therefore formed directly by the end face 41 ″ of the metal shaft 4 ″. The metal shaft 4 ″ has an external thread in the usual way in order to match a corresponding golf shoe sole with a threaded insert to be able to be connected. The metal sleeve 3 ″ has in its wall four openings 32 ″ evenly distributed on the circumference, which extend so far upwards that the plastic entering during the production process flows around the upper end of the ceramic insert 2 ″ and into a provided therein, not specified groove can occur in the end face of the ceramic insert.

The metal sleeve 3 ″ has a cylindrical shape in accordance with the previously described exemplary embodiments

Inner surface 31 ", so that due to the tapering of the ceramic insert 2" between this inner surface and the peripheral surface of the ceramic insert

Plastic layer 14 '' arises during the manufacturing process, the thickness of which decreases more rapidly towards the top. In the area of the lower edge of the metal sleeve 3 '' the

Ceramic insert 2 '' therefore over a relatively thick annular part of the plastic layer 14 '' on the

3 '' metal sleeve. As a result of the slenderness of the ceramic insert 2 ″ and its length, this is produced in it

Range of relatively high lateral loads, which, however, are better distributed by the thicker plastic layer 14 ″ and passed on to the metal sleeve 3 ″.

The gripping element shown in FIGS. 4 to 6 has a gripping element body 101 which, as in the exemplary embodiment according to FIG. 2, is made of the same plastic as the outsole 105 which is only partially shown and is integral therewith. The ceramic insert 102 enclosed by the gripping element body 101, however, has an elongated cross section with mutually parallel longitudinal sides which are connected to one another at their ends by circular arcs. The ceramic insert 102 tapers downward on the front and side surfaces with the taper angle α, which here is approximately 2 °. The tread surface 121 is slightly spherical, while the flat upper end face 124 has three sides and the side faces which run transversely to the longitudinal axis of the ceramic insert 102 has penetrating grooves 125. The grooves 125 are rounded at their transitions into the side surfaces 123, as can be seen from FIG. 6. In the exemplary embodiment shown, the length of the ceramic insert 102 at its upper end is approximately 17 mm, its width approximately 4 mm and its height (which corresponds to the length of the exemplary embodiments according to FIGS. 1 to 3) approximately 8.5 mm.

The ceramic insert 102 is encompassed over approximately 2/3 of its height by a metal sleeve 103 which forms an interior shaped according to the cross section of the ceramic insert. The inner surface 131 of the metal sleeve 103 is formed by generatrices running parallel to one another in the direction from top to bottom. The metal sleeve 103 is formed in one piece from steel, for example by compression molding or deep drawing, and has a base 141, in which four circular openings 142 are incorporated, evenly distributed in the longitudinal direction of this base. Furthermore, the metal sleeve 103 has a circular opening 132a on its opposing circular cylindrical end faces and three uniformly distributed circular openings 132b at the same height in the mutually parallel side surfaces. The openings 142 in the base 141 are arranged such that they correspond at least partially with the grooves 125 of the ceramic insert 102, so that plastic can penetrate into the grooves through the openings 142 during the casting process.

With its upper end face 124, the ceramic insert 102 lies against the bottom outside of the grooves 125 or the openings 142 and is otherwise embedded in the plastic of the gripping element body 101. Here, too, the plastic of the gripping element body 101 continues into the interior of the metal sleeve 103, so that a plastic layer 114 is established between the inner wall of the metal sleeve and the side or peripheral surface 123 of the ceramic insert 102. According to the shape of the sleeve interior, the Thickness of the plastic layer 114, apart from the connection to the gripping element body 101 via the openings 132a, 132b, in the direction of the end face 124 and is in any case largely constant in the lower edge region of the metal sleeve 103 in the circumferential direction.

There are various ways of departing from the exemplary embodiments discussed above, without departing from the scope of the invention: As already mentioned at the beginning, openings in the metal sleeve are not absolutely necessary, because due to the tapering of the ceramic insert, an annular gap at the lower edge of the metal sleeve in any case is created, can pass through the plastic to form the desired plastic layer, provided that the inner surface of the metal sleeve is cylindrical. However, the latter is also not absolutely necessary, that is to say the metal sleeve can in turn be tapered upwards or downwards. In this case, appropriate dimensioning and / or breakthroughs must ensure that the plastic can properly embed the ceramic insert during the manufacturing process.

Although the invention relates exclusively to the use of ceramic inserts because it has the property of not producing sharp edges when worn, the use of inserts made of hard metal is considered equivalent here.

The term smoothness of the peripheral surface of the ceramic insert used in the present description does not primarily refer to a specific one; Roughness of the ceramic surface, but that this peripheral surface does not have any recesses or projections that clearly determine its geometric shape. Under this condition, however, a certain roughness of the ceramic surface can bind the plastic to the Promote the peripheral surface of the ceramic insert, so that preferably the ceramic insert is used in the fired state without reworking its peripheral surface.

Claims

Expectations

1. Gripping element for sports shoes, with a

Gripping element body (1, 1 ', 1' '; 101) made of plastic and with a ceramic insert (2, 2', 2 '' forming the tread surface (21, 21 ', 21' '; 121) of the gripping element, embedded in the gripping element body ; 102), which is encompassed within the gripping element body over part of its length by a metal sleeve (3, 3 ', 3' '; 103) likewise embedded in the gripping element body, between the peripheral surface (23; 123) of the ceramic insert and the Inner surface (31, 31 ''; 131) of the metal sleeve is formed from a plastic layer (14, 14 ', 14' '; 114), characterized in that at least the part of the peripheral surface of the ceramic insert which is encompassed by the metal sleeve is smooth and tapers towards the tread surface .

2. Gripping element according to claim 1, d a d u r c h g e k e n n z e i c h n e t that the ceramic insert is smooth and tapered continuously up to its tread.

3. gripping element according to claim 1 or 2, characterized in that the ceramic insert is circular and tapered in cross-section, the taper angle (α) being a maximum of 6 °, preferably a maximum of 2 °.

4. Gripping element according to one of claims 1 to 3, d a d u r c h g e k e n n z e i c h n e t that the inner surface of the metal sleeve is cylindrical, in particular circular cylindrical.

5. gripping element according to one of claims 1 to 4, d a d u r c h g e k e n n z e i c h n e t that the metal sleeve is thickened at its edge facing the tread surface (33).

6. Gripping element according to claim 5, d a d u r c h g e k e n n z e i c h n e t that the metal sleeve has a portion of greater wall thickness starting from its edge facing the tread.

7. gripping element according to one of claims 1 to 6, d a d u r c h g e k e n n z e i c h n e t that the metal sleeve has openings (32, 32 ''; 132a, b) in its wall.

8. gripping element according to claim 7, d a d u r c h g e k e n n z e i c h n e t that the openings are evenly distributed on the circumference of the metal sleeve.

9. gripping element according to one of claims 1 to 8, characterized in that the inner surface of the metal sleeve bears against the end of the ceramic insert facing away from the tread surface.

10. Gripping element according to one of claims 1 to 9, that the ceramic insert has at least one recess (25; 125) penetrating the peripheral surface in its end face (24; 124) facing away from the tread surface.

11. Gripping element according to claim 10, d a d u r c h g e k e n n z e i c h n e t that the recess is a rectilinear groove that passes through the circumferential surface of the ceramic insert with both ends.

12. Gripping element according to claim 10, d a d u r c h g e k e n n z e i c h n e t that the recess has a cross or star shape and with its arms penetrates the peripheral surface of the ceramic insert.

13. Gripping element according to one of claims 10 to 12, so that the end face of the ceramic insert facing away from the tread surface rests on a bottom (41, 41 ', 41 I I 141) of the metal sleeve.

14. Gripping element according to claim 13, d a d u r c h g e k e n n z e i c h n e t that the end face is slightly convex.

15. Gripping element according to one of claims 1 to 14 with a metal shaft (4, 4 '') projecting from the gripping element body for releasably fastening the gripping element to a sole, characterized in that the metal sleeve is fastened to the metal shaft.

16. Gripping element according to claim 15, so that the metal sleeve is flanged by a flange-like extension (41, 41 '') of the metal shaft and the extension forms the bottom of the metal sleeve.

17. Gripping element according to one of claims 1 to 14, which is formed in one piece with a sole and of the same material with respect to the gripping element body, so that the metal sleeve is flanged around the edge of a disk forming the base of the metal sleeve.

18. Gripping element according to one of claims 1 to 14, which is formed in one piece with a sole and uniform in terms of material with respect to the gripping element body, so that the bottom (141) of the metal sleeve (103) has at least one opening (142).