WO2012004452A1

WO2012004452A1 - Improved anti-skid stud of a vehicle

Info

Publication number: WO2012004452A1
Application number: PCT/FI2011/050589
Authority: WO
Inventors: Pekka PENKKIMÄKI
Original assignee: Sancus Oy
Priority date: 2010-07-08
Filing date: 2011-06-20
Publication date: 2012-01-12
Also published as: FI20105780A0; RU135588U1; FI20105780A

Abstract

Anti-skid stud (100) of a vehicle, which stud comprises an outer end extending towards the rolling surface and an inner end to be placed into a recess of the tyre, the inner end of which stud comprises a base flange (101) and the outer end comprises an upper dome (102), and the outer end of which stud comprises a tip arrangement of considerably harder material than the rest of the stud, and that the outer end of the stud comprises at least two hard-material tips (104a - 104e) of considerably harder material than the rest of the stud, which tips are fitted into a recess in the upper dome of the stud.

Description

IMPROVED ANTI-SKID STUD OF A VEHICLE

Field of technology and prior art

The object of this invention is an anti-skid stud of a vehicle.

The object of this invention is the tip of an anti-skid stud of a vehicle, which tip is made of a hard material and which comprises a top end extending outwards from the tyre and a bottom end fitted onto the body of the anti-skid stud.

Anti-skid studs are used, especially in winter, in the inflatable tyres of vehicles, such as automobiles, to prevent skidding and thereby to improve driving safety in slippery conditions.

The tyres of an automobile comprise a wearing layer with a rolling surface. Anti-skid studs (hereinafter studs) are installed in the wearing layer of the tyre with special installation tools into recesses (cavities) pre-manufactured in the tyre.

The studs comprise an outer end extending towards the rolling surface and an inner end to be placed into the cavity of the tyre. The inner end of the stud comprises a base flange, the outer end comprises an upper dome and between them can be a neck part that is narrower than both the upper dome and the base flange. In a case where the stud does not comprise a neck part, the upper dome in prior-art solutions extends with constant thickness from the base flange to the outer end. When the stud is installed in the wearing layer, its top flange is disposed in the wearing layer deeper from the rolling surface and the upper dome is disposed closer to the rolling surface.

The base flange is usually round but it can also be four-sided or oval. The outer end of the stud comprises a hard-ceramic or hard-metal tip of considerably harder material than the rest of the stud, which tip is fitted into the cavity in the upper dome of the stud, and which is of constant cross-sectional thickness and round, square or triangular in terms of its cross-section (see e.g. publications FI-B-114692 and EP-A2-1 798 068).

The FI publication in question, FI-B-114692, also presents a tool for installing an anti-skid stud, with which the tyre of a vehicle can be studded in an oriented manner such that some pre-defined direction or dimension of the studs is disposed at the desired angle in relation to the rolling plane of the tyre. For the purpose of orientation, the body of the stud can be provided with a notch on the side, such as is presented in publication EP-A2-1 798 069.

A particular drawback in prior-art anti-skid solutions is that the shaping and placement of the tip, which is of hard metal, do not enable a large frontal surface area in the longitudinal direction or in the lateral direction.

Summary of the invention

The purpose of this invention is to eliminate the drawbacks of prior art and to achieve an entirely new type of anti-skid stud of a vehicle tyre, with which particularly the grip of the studs is improved.

In the solution according to the invention the tip part comprises two or more tips, which can be such that the hard metals can be round, triangular, rectangular, pentagonal or hexagonal, et cetera, and wherein the placement of the hard metal tips enables a larger frontal surface area both in the longitudinal direction and in the lateral direction. In addition, with the shaping of the stud flange according to the invention the durability of attachment and point force of the stud can be influenced. By increasing the diameter of the stud flange, better durability of attachment is achieved. At the same time, however, the point force of the stud increases. By shaping the flange, better durability of attachment can be achieved without increasing the point force. At the same time the weight of the stud can be kept smaller, which also reduces the forces exerted on the stud. The safety and grip of wintertime driving is improved with the new type of shaping of the stud.

The characteristic features of the solution according to the invention are described in detail in the independent claim 1 and the preferred embodiments in the non-independent claims.

Short description of the drawings

In the following, the invention will be described in more detail by the aid of some examples of its embodiments with reference to the attached drawings, wherein

Figs, la - lc and 2a - 2c present different embodiments of the stud and the hard-metal tip according to the invention, as viewed from the side, from the top and as a perspective sketch

Figs. 3a - 3d present the operation of a stud according to prior art and according to the invention, and

Figs. 4a - 4b present the task of a hard metal to widen the aperture produced by the first hard metal and thus to enhance the operation, and

Figs. 5a - 5f present a stud according to one embodiment of the invention,

Figs. 6a - 6f present the operation of a stud according to Figs. 5a - 5f, and

Figs. 7a - 7e present an embodiment according to the invention, wherein the diameter of the stud flange is increased with respect to prior art. Description of preferred embodiments of the invention

Figs, la - lc and 2a - 2c present an anti-skid stud 100 according to the invention. The studs comprise an outer end extending towards the rolling surface and an inner end to be placed into the cavity of the tyre. The inner end of the stud comprises a base flange 101, the outer end comprises an upper dome 102 and between them can be a neck part 103 that is narrower than both the upper dome and the base flange. The outer end of the stud comprises hard-metal tips 104a - 104e of considerably harder material than the rest of the stud and rectangularly shaped at their top end, which tips are fitted into the recess in the upper dome of the stud. The upper dome is, for alignment purposes, a rounded rectangular shape, which comprises straight longer sides and rounded ends. The upper dome can comprise a notch on its side for orientation.

In the solution according to the invention there are two (Fig. la) or three (Fig. 2a) or even more tips 104a - 104b, 104c - 104e, and they can be square shaped. They are aligned and disposed in a slanted position with respect to each other such that in the direction of travel, e.g. in the lateral direction of the longer side, they are angular with respect to the direction of travel and they are disposed consecutively. The invention differs from prior art in that the solution presented functions to increase grip in only one direction, and the effect of the surface area on gripping ice is not taken into account. If, on the other hand, the hard metals are side by side, they both make their own narrow grooves in the ice, and do not form a functional unit for making the largest possible groove.

By dividing the hard metal into parts and by disposing the pieces in the manner indicated by the figure into two or more rows, the same functional width can be obtained with a smaller amount of hard metal than with a corresponding single piece. As a result of this, the stud can be made lighter compared to a single piece. Because the mass of the stud has an effect on the wearing of the road, the aforementioned placement reduces road wear compared to a stud with a single hard metal core and the same functional efficiency. Owing to its smaller mass, fewer forces trying to detach it from the tyre are exerted on a lighter stud, in which case the durability of attachment of the stud in the tyre is better.

In order for a stud to operate in the planned manner, it must be able to penetrate through ice. The larger the surface area of the hard metal of a stud, the larger the force (so-called point force) needed to achieve the intended penetration. A larger point force also means greater wearing of the road. Because the hard metal pieces are disposed consecutively with respect to each other, the piece that first comes into contact breaks the surface of the ice and, that being the case, good penetration can be achieved with a small point force. This is of assistance especially when the ice is hard, i.e. in extremely cold weather and on polished surfaces. When a wheel locks, the task of the hard metal that is second is to widen the aperture produced by the first hard metal and thus to enhance the operation, Figs. 4a - 4b below.

A shaping that supports the operation of the base can be further combined with the shaping mentioned above. By shaping the base 111, 112 of the stud 100 to be convex or concave, the stud can be made to incline at the moment of road contact, Figs. 5a - 5f.

Since the force exerted on the stud presses the stud downwards, the impact force produced by the stud on the road decreases. That being the case, the impact effect that wears the road is also smaller.

On the other hand, since the stud acts in a hinged-manner after the impact, the hard-metal piece farther to the rear rises upwards to enhance penetration through the ice. This does not, however, increase wearing of the road, because ice is significantly softer than the road material. Operation of the stud in a braking situation, Figs. 6a-6f.

The stud can be shaped to be symmetrical or it can be shaped to be suitable in relation to the desired longitudinal grip or lateral grip.

Additionally, by increasing the diameter of the stud flange better durability of attachment is achieved. At the same time, however, the point force of the stud increases. By shaping the flange, better durability of attachment can be achieved without increasing the point force. At the same time the weight of the stud can be kept smaller, which also reduces the forces exerted on the stud. Figs. 7a - 7e present an embodiment according to the invention, in which the diameter of the bottom flange 121, 122 of a stud 120 is increased with respect to prior art, and the tyre 123 and stud hole 124 are seen therein.

It is obvious to the person skilled in the art that the different embodiments of the invention are not limited solely to the example described above, but that they may be varied within the scope of the claims presented below.

Claims

Anti-skid stud (100) of a vehicle, which stud comprises an outer end extending towards the rolling surface and an inner end to be placed into a recess of the tyre, the inner end of which stud comprises a base flange (101) and the outer end comprises an upper dome (102), and the outer end of which stud comprises a tip arrangement of considerably harder material than the rest of the stud, c h a ra cte r i ze d in that the outer end of the stud comprises at least two hard- material tips (104a - 104e) of considerably harder material than the rest of the stud, which tips are fitted into a recess in the upper dome of the stud.

Stud according to claim 1, c h a ra cte ri zed in that the hard metals can be round, triangular, rectangular, pentagonal or hexagonal.

Stud according to claim 1, c h a ra cte ri zed in that the hard metals are angular, and one arris is in the direction of travel.

Stud according to claims 1-3, c h a ra cte r i z e d in that the hard-metal piece of the studs is square-shaped or polygonal and the bottom flange is four-sided, five-sided, and/or round.

Stud according to claims 1-4, c h a ra cte r i z e d in that the hard metal pieces of the studs are aligned and disposed in a slanting position with respect to each other such that in the direction of travel, e.g. in the lateral direction of the longer side, they are angular with respect to the direction of travel and are disposed consecutively.

Stud according to any of the previous claims, c h a ra ct e r i z e d in that the upper dome is, for alignment purposes, a rounded rectangular shape, which comprises straight longer sides and rounded ends, and preferably for orientation a side of the upper dome has a notch.

Stud according to any of the previous claims, c h a ra ct e r i z e d in that by shaping the base of the stud to be convex or concave the stud can be made to incline at the moment of road contact.

8. Anti-skid stud (120) of a vehicle, which stud comprises an outer end extending towards the rolling surface and an inner end to be placed into a recess of the tyre, the inner end of which stud comprises a base flange and the outer end comprises an upper dome, and the outer end of which stud comprises a tip arrangement of considerably harder material than the rest of the stud, c h a ra cte r i z e d in that the diameter of the bottom flange (122) of the stud is essentially greater than the other diameter of the body of the stud, in which case in particular better durability of attachment is achieved.