Patent ID: 6315018
Filing Date: 2001-11-13
Classification: B60C,Y10S

Abstract:
A pneumatic tire comprising; a tread on which a plurality of block-shaped land portions which are demarcated by a plurality of grooves intersecting each other and a rib are formed, and in which sipes are provided in a block-shaped land portion or the rib,wherein said sipe is structured by a narrow groove portion, which is formed at a tire ground-contact surface side of said sipe and has a first width, and a wide groove portion, which is formed at a bottom portion side of said sipe and has a second width greater than the first width, and said sipe is an open sipe in which at least one of the longitudinal direction end portions of said sipe is open at a groove of said plurality of grooves, and said wide groove portion is formed continuously in the longitudinal direction of said sipe from at least one of the end portions thereof, andtoward the bottom portion of said sipe, the proportion of said sipe accounted for by said narrow groove portion in a longitudinal direction of said sipe which is orthogonal to a depthwise direction of said sipe decreases, while the proportion of said sipe accounted for by said wide groove portion in the longitudinal direction of said sipe which is orthogonal to the depthwise direction of said sipe increases throughout the longitudinal direction of said sipe from one end portion of the sipe to the other end portion.