Bias- or radial-carcass tyre

Abstract

The invention relates to a tyre for a rolling assembly comprising a rim and a tyre, said tyre including at least one carcass ply capped radially and externally with a crown ply itself disposed radially inside a tread, said crown ply being formed by at least one layer of reinforcement elements, said tread being connected to two beads by means of two sidewalls, said beads being intended to come into contact with a rim having upper hooks, each bead comprising at least one circumferential reinforcement element, said sidewalls comprising, on their outer surface, a series of projections alternated with recesses, said recesses and projections each having a central axis. The tyre is characterised in that each projection, having a defined or any geometric form, is disposed on the surface of a sidewall, the different projections being disposed discontinuously in a regular or irregular manner between points A and B and between points C and D, in which: point A is disposed at the intersection of the radially external surface of the tread and the sidewall, and a radial axis ZZ' at a distance from an equatorial plane AA' having a length LA between 1 / 2 (L-20mm) and 1 / 2 (L-80mm), L being the nominal tyre section width; point B is disposed in a radius greater than or equal to [R1 + 0,1 (RA - R1)] and less than RA, R1 being the radius of the nominal tyre section width, and RA being the radius from point A; point C is disposed in a radius less than or equal to [R1 - 0,1 (R1 - R2)], R2 being the radius of the upper hooks; and point D is disposed in a radius in the range R2 < D < R2 + 0,25(R1 - R2).

Description

technical field [0001] The present invention relates to bias ply tires or radial tires. Background technique [0002] Radial tires are gradually being used in various markets, especially the passenger car tire market. This success is due in particular to the qualities exhibited by radial tire technology in terms of durability, comfort and low rolling resistance. [0003] The main parts of a tire are the tread, sidewalls and beads. The bead is designed to make contact with the rim. In a radial tire, each of the main parts constituting the tire (ie, the tread, sidewalls, and beads) has functions significantly different from each other and thus has a known specific composition. [0004] A radial tire is substantially reinforced by a carcass reinforcement comprising at least one carcass ply arranged at an angle substantially equal to 90° with respect to the circumferential direction of the tyre. This carcass reinforcement is covered radially externally and below the tread by...

AI Technical Summary

Problems solved by technology

[0024] Furthermore, the present desire to use tires with ever shorter sidewall heights, another consequence of which is the fact that impacts on said sidewalls cause more severe wear than if the sidewalls were higher, thus more tire damage

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