Structure of tread portion of pneumatic tire

Abstract

Abstract PURPOSE:To enhance braking performance on a snowy road, an icy road or the like by providing specific relation between a circumferential component length and an axial component length on the outer surface of blocks by the effect of at least center block in a tread portion, and forming specific number or more of stepped projections in each block. CONSTITUTION:In a tread portion 11, the block area Ac of a center 16 is more than and equal to the block area As of a shoulder 17. In the grounded area of the tread portion 11, each real grounded area AE of blocks 12 and 13 and the total grounded area Ac thereof are set at 0.4<=AE/Ac<=0.7. The blocks 12 are laterally distributed on a tire equatorial line 0-0. Each block 12 has a circumferential component length (a) and an axial component length (b), and stepped slope edges laterally symmetrically projected on both sides outwardly in the axial direction are formed. Each block 12 has five or more stepped projections 12B. The component (a) has relation to secureness of circumferential rigidity and axial stoppage while the component (b) has relation to secureness of axial rigidity and circumferential stoppage so that the components (a) and (b) are set at 1/2<=(a)/(b)<=2. In the case of 2<(a)/(b)<1/2, a plowing effect of the projections 12B may deteriorate on a snowy or icy road,.

Inventors

• 👤 ▲しょう▼村　龍幸
• 👤 Tatsuyuki Shiyoumura

Bibliographic Details