Pneumatic tire having at least four sipes

Abstract

A pneumatic tire comprising a tread which comprises block-shaped land portions and a plurality of specific sipes formed on the block-shaped land portions is disclosed. At least in one portion in the direction of the depth of the sipe, the sipe has an amplitude in the direction of the width of the sipe and extends in the transverse direction of the tire, and at least one portion of each sipe in the direction of the depth of the sipe is disposed at an offset position relative to an other portion of the sipe in a circumferential direction of the tire. The amplitude of the sipe in the present invention may change in the direction of the depth and the change may alternate from an increase to a decrease or from a decrease to an increase at one or a plurality of node positions disposed in the sipe in the direction of the depth of the sipe. The cross-section of the sipe in a circumferential direction of the tire may have a specific shape, such as a shape which is substantially symmetrical with respect to the central line of the block-shaped land portion in the circumferential direction of the tire. Deterioration in the road holding property caused by an increase in the number of the sipe can be suppressed and the grip performance on wet surfaces, the acceleration and braking performance on ice and the resistance to irregular wear of the tire can all be improved by the above construction.