Patent ID: 6439284
Filing Date: 2002-08-27
Classification: B60C,Y10S

Abstract:
A tread for a pneumatic tire comprising elastomeric material, said tread having a central portion and two shoulders, said tread having a ground contacting width defining a treadwidth TW, said tread including three circumferentially extending grooves, wherein two of the circumferentially extending grooves, and a centermost circumferentially extending groove of the circumferentially extending grooves, define two circumferentially extending center ribs, each center rib having an axial width RW from 5% to 25% of the treadwidth TW of the ground contacting portion; at least one of the three circumferentially extending grooves having on both sides tapered groove sidewalls, which form with a radial plane (NP) angles &agr;1 and &agr;2characterized in that &agr;1, and &agr;2 are acute angles ranging between 1 and 10 degrees, such that the distance between the opposing sidewalls of the groove diminishes radially outwardly, and the tread height near both groove edges of the groove having the tapered sidewalls extending radially above the average tread height of the tread a maximum extra tread height comprised between 0.3 mm and 1.7 mm, this extra tread height diminishing progressively from the groove edges towards the respective nearest shoulder of the tire on a distance not exceeding 15% of the treadwidth (TW) and wherein the centermost groove is a circumferentially extending aqua channel cut into two equal halves by the equatorial plane (EP).