Patent ID: 7128111
Filing Date: 2006-10-31
Classification: B60C,Y10S

Abstract:
1. A pneumatic tire comprising: a tread portion with tread edges, said tread portion provided on each side of the tire equator with a circumferential groove and axial grooves extending from the circumferential groove to the adjacent tread edge so as to form shoulder blocks disposed along the tread edge, said axial grooves extending straight so that each said shoulder block has a pair of axially extending straight edges formed by two of said axial grooves, said circumferential groove extending zigzag in the tire circumferential direction so that each said shoulder block has an axially inner edge having an axially inwardly protruding V-shape consisting of two straight segments formed by the zigzag circumferential groove, each said shoulder block having an axially outer surface which is curved convexly such that: a curvature of the axially outer surface measured on a cylindrical surface centered on the tire axis and intersecting said axially outer surface has, at the tread surface, a radius of 1.5 to 4.5 times a circumferential length of the shoulder block; and the radius of the curvature gradually increases as the measuring depth from the tread surface gradually increases so that the axially outer surface merges into a surface of a tire shoulder portion immediately radially inside the shoulder blocks, and a part of the tread portion between the zigzag circumferential grooves being divided into second blocks, whereby the tread portion is divided into the shoulder blocks and second blocks only.