STUD FOR TYRE

Abstract: The invention relates to a tyre stud comprising a substantially cylindrical shank (1) with a hard metal tip (2) at its one end and a locking flange (3) at its other end, the locking flange locking the stud to the tyre. The locking flange (3) is made of a resilient material, such as rubber or resilient plastic.

Description: Stud for tyre This invention relates to a tyre stud consisting of an essentially cylindrical shank with a hard metal tip at one end and a locking flange at the other end, which locks the stud to the tyre. All winter tyre manufacturers strive to reduce the tyre material, i.e. the rubber volume, in order to provide lighter and thus improved riding qualities. In addition, winter tyres equipped with studs cause lower wear of the road surface material. Lighter winter tyres have resulted in the stud locking flange getting very close to the fabric layer within a winter tyre. The stud locking flange and the fabric layer are spaced by only 2 to 3 mm. This, in turn, has resulted in the edge of the stud locking flange having caused such strong wear of the tyre rubber under the tilting move- ments of the stud that the internal fabric layer has been damaged and the tyre has even burst. The stud of the invention is characterised in that the locking flange is made of a resilient material, such as rubber or resilient plastic. By means of the invention, the locking flange is kept substantially in position despite the tilting movements of the stud. Thus, there will be none of the drawbacks and damages mentioned above. Various embodiments of the invention are set forth in the dependent claims of the set of claims. The locking flange can receive forces exerted on the hard metal tip of the stud especially when the road surface is molten, the stud tip being incapable of penetrating into the snow mass or the icy surface. The invention is described below by means of examples and with reference to the accompanying drawing, in which figures 1 to 4 illustrate four studs comprising dif- ferent locking flange applications. The stud consists of a cylindrical shank 1 with a hard metal tip 2 at its end. At the other end of the stud shank, a locking flange 3 is provided, which locks the stud to the tyre. The locking flange 3 is made of a resilient material, such as rubber or resi- lient plastic. In figure 1 the locking flange 3 is a disc which bends as indicated with the broken line when the stud tilts approx. 10°, for instance. The locking flange 3 locks the stud to the tyre. Owing to its resilience, the edges of the locking flange 3 do not damage the tyre rubber or the tyre fabric. Figure 2 illustrates an embodiment in which the locking flange is equipped with a pad 4. In figure 3, the locking flange and the pad have been combined to form a pad-like locking flange 3. The locking flange 3 has a cylindrical mantle 5, which surrounds the shank 1 of the stud. In this way, the locking flange is well fixed to the stud shank despite the tilting forces. The locking flange and the pad shown in figure 4 make up a combination which is an open cup 3 with a bellows-like shape.

Claims: Claims 1. A tyre stud consisting of a substantially cylindrical shank (1) with a hard metal tip (2) at one end and a locking flange (3) at the other end to lock the stud to the ty- re, characterised in that the locking flange (3) is made of a resilient material, such as rubber or resilient plastic. 2. A stud as claimed in claim 1, characterised in that a resilient pad (4) known per se has been connected to the locking flange (3). 3. A stud as claimed in claim 2, characterised in that the pad (4) consists of a bellows open at its end. 4. A stud as claimed in any of the preceding claims, characterised in that the locking flange (3) has a cylindrical mantle (5) which surrounds the stud shank (1).

Inventors: SALAKARI HEIKKI, SALAKARI, HEIKKI
Applicants: SALAKARI HEIKKI, TURVANASTA OY, SALAKARI, HEIKKI
Application year: 1999
Main classification: B60C11
IPC codes: B60C11