GB2247657A

GB2247657A - Vehicle tyre

Info

Publication number: GB2247657A
Application number: GB9010174A
Authority: GB
Inventors: Andrew Langdon
Original assignee: Individual
Current assignee: Individual
Priority date: 1990-05-04
Filing date: 1990-05-04
Publication date: 1992-03-11
Also published as: GB9010174D0

Abstract

A vehicle tyre is characterised by having at least part of the tread region 15 provided with discrete cells each containing a working fluid. The fluid is one which, on exposure to air such as would arise from wear of the tyre, undergoes a chemical or physical transformation such as would provide for self-repair of the tyre in the vicinity of the cell from which the working fluid originates, indicate the extent of wear of the tread of the tyre, or act to modify the relationship between the tread and the ground surface with which it is engaged. The region can be a peripheral band substantially within the tread (Figs 1, 2, 4) or be formed of a series of separate components interpolated around the tread (Figs 3, 5). <IMAGE>

Description

VEHICLE TYRE This invention relates to a vehicle tyre.

A conventional vehicle tyre is made up of three particular parts: a tread which provides the contact area with the ground; a rim by means of which the tyre is mounted on a wheel; and a side wall part linking the tread part to the tyre rim and adapted to transmit accelerating and braking torques into the tread. The tread can include a patterned layout (such as to enhance grip or water transfer) or be smooth. In what follows a tyre of this general type is referred to as being 'of the type described1.

In use a vehicle tyre is subject to wear and a significant factor in tyre design is to maintain the tread pattern for as long as possible during wear of the tyre undergoing normal usage. The conventional method of establishing whether a tyre is worn to the extent that it needs replacement is to measure the tread depth over a range of locations.

While this is not difficult it can be difficult to undertake the check regularly and consequently it is known to build into the tyre a marker strip of contrasting colour so that on the tyre wearing to the level of the marker it is exposed so that a cursory inspection reveal the exposure of the marker and so of significant tyre wear.

According to the present invention there is provided a vehicle tyre of the type described characterised in that at least the tread part of the tyre is formed at least in part with a region of discrete cells each containing a working fluid. In this context working fluid covers a material which when stored in a discrete cell could be a liquid, a vapour or a gas or a mixture of two or more of these regardless of the state arising on, or following, transformation.

According to a first preferred form of the present invention there is provided a tyre wherein the working fluid is one which, on exposure to air such as would arise from wear of the tyre, undergoes a chemical or physical transformation such as would: 1 provide for self repair of the tyre in the vicinity of the cell from which the working fluid originates; 2 indicate wear or extent of wear of the tread of the tyre; 3 act to modify the relationship between the tread and the ground surface with which it is engaged; 4 other effects; or a combination of one or more of these.

According to a second preferred form of the present invention or the first preferred form thereof the region is in the form of a continuous peripheral band substantially within the tread.

According to a third preferred form of the present invention or the first preferred form thereof the region is in several parts incorporated in cavities within the tread.

Exemplary embodiments of the invention will now be described with reference to the accompanying drawings which are sections of vehicle tyres of which: Figure 1 is a section of a first embodiment, Figure 2 and 3 are sections of treaded tyres embodying second and third embodiments; and Figures 4 and 5 are sections of smooth tyres embodying fourth and fifth embodiments.

FIGURE 1 Figure 1 shows a tyre 10 made up of a rim 11 and a tread 12 linked to the rim by a side wall 13. Conventionally the tread 12 and the side wall are modified in their behaviour by the incorporation of strands or belts made up of wire or fabric or both. Such strands or belts and their effects being well known are not shown or further described.

In the tread 12, and extending into intermediate region 14 between the tread 12 and the side wall 13, there is provided a continuous region 15 (shown in broken outline with dotted filling ) of discrete cells each containing a liquid which, on exposure to air, results in the generation of enhanced grip between the tyre and the road over which it runs. Thus with the tread nearing the end of its useful life the consequent reduction in contact grip can be countered by the utilisation of cell born material in this way. As shown the contents of the cells in the region 15 are only exposed when the tyre 11 has been subjected to a degree of wear. If desired the location of the cells in the region 15 can be positioned so that the working fluid contained in them can generate its effect early in the life of the tyre if not indeed from the start of wearing.The cells in the region 15 can either be generated in situ in the material making up the bulk of the tyre or be included as a separately formed strip, band or whatever during fabrication of the tyre.

FIGURE 2 AND 3 In these two examples where items of similar form and function are involved the references are made by way of two numbers the second being in brackets. The first item refers to Figure 2, the bracketed item refers to Figure 3.

Treaded tyre 21 (22) has a patterned tread made up of projecting blocks 23 (24) and interstitial spaces 25 (26).

In the case of tyre 21 there is provided a continuous region 27 (shown dotted) of discrete cells each containing a liquid which, on exposure to air, results in the generation of enhanced grip between the tyre and the road over which it runs.

In the case of tyre 22 the interstitial spaces 26 are filled with blocks 28 (shown filled with dots) of material formed of discrete cells each containing a liquid which, on exposure to air, results in the generation of enhanced grip between the tyre and the road over which it runs. FIGURE 4 AND 5 In these two examples where items of similar form and function are involved the references are made by way of two numbers the second being in brackets. The first item refers to Figure 4, the bracketed item refers to Figure 5.

Smooth tyre 41 (42) are provided for use particularly in competitions or other applications where there is no need for a clearing action of water transfer action provided by a tread pattern.

In the case of tyre 41 there is provided a continuous region 43 (shown dotted) of discrete cells each containing a liquid which, on exposure to air, results in the generation of enhanced grip between the tyre and the road over which it runs.

In the case of tyre 42 the tread incorporates spaces 44 which are each filled with blocks 46 (shown filled with dots) of material formed of discrete cells each containing a liquid which, on exposure to air, results in the generation of enhanced grip between the tyre and the road over which it runs.

Apart from a working fluid which modifies a ground engaging effect some of the cells can contain a marker liquid whose exposure provides a clear indication of wear.

Another application of the invention would be in relation driving under icy conditions where the ambient temperature falls to a level at which the cells rupture to release a material serving to provide for enhanced road grip.

The size of the cells containing the working fluid will depend on the nature of the working fluid, its transformed function and the transformation required.

Claims

CLAIMS 1 A vehicle tyre of the type described characterised in that at least the tread part of the tyre is formed at least in part with a region of discrete cells each containing a working fluid. 2 A vehicle tyre as claimed in Claim 1 wherein the working fluid is one which, on exposure to air such as would arise from wear of the tyre, undergoes a chemical or physical transformation such as would:

1 provide for self repair of the tyre in the vicinity of the cell from which the working fluid originates;

2 indicate wear or extent of wear of the tread of the tyre;

3 act modify the relationship between the tread and the ground surface with which it is engaged;

4 other effects; or a combination of one or more of these.

3 A tyre as claimed in any preceding claim wherein the region is in the form of a continuous peripheral band substantially within the tread.

4 A tyre as claimed in Claim 1 or Claim 2 wherein the region is in several parts incorporated in cavities within the tread.

5 A tyre as hereinbefore described with reference to the accompanying drawing.