Abstract:
A pneumatic tire comprises a tread portion, the tread portion comprising blocks provided with fine grooves for preventing bareness of rubber, the fine grooves having a depth of 0.2 to 0.7 mm and a width of 0.3 to 1.0 mm. The fine groove extends from the angularly narrowest corner of the block to a block edge extending substantially in the circumferential direction. The angularly narrowest corner is provided with a slope having an angle of 30 to 60 degrees to the normal direction to the tread surface.
Abstract:
The radius of curvature of the end portion of the block of a tire at the equatorial plane side of the tire is the same as the radius of the tire thereat. On the other hand, the radius of curvature of the end portion of the block at the shoulder side is smaller than the radius of the tire thereat, and the point which protrudes furthest is between the center and the trailing edge portion of the block 16. The shape of the radially outward surface of the block protrudes further toward the shoulder side end portion, which is an area in which the wear of the leading edge portion progresses furthest. The ground contact pressure at the shoulder side becomes even lower. Accordingly, the leading edge portion can smoothly slide against the road surface. As a result, the progress of the wear from the leading edge portion is promoted, and the effect of preventing the heel-and-toe wear becomes higher.
Abstract:
A tire having a tread has tread elements which, when compressed radially, exhibit a net torque. The net torque so generated can be directed and designed so as to affect the tire's residual self-aligning torque (also known as RSAT). One embodiment of the invention features a tire tread having a tread element which has a shape resembling a top surface with the tread element being twisted relative to a bottom surface of the tread element. Upon radial loading, the tread element is compressed and generates the net torque about the centroid of the tread element.
Abstract:
A pneumatic tire is provided in the tread portion with a circumferential row of middle tread elements, wherein each of the middle tread elements is divided into four elemental blocks having different configurations, by three splitting grooves, and the three splitting grooves are: a longitudinal splitting groove extending between the lateral grooves; an axially inner lateral splitting groove extending axially outwardly from the axially inner circumferential main groove beyond the longitudinal splitting groove and terminating before the axially outer circumferential main groove; and an axially outer lateral splitting groove extending axially inwardly from the axially outer circumferential main groove beyond the longitudinal splitting groove and terminating before the axially inner circumferential main groove.
Abstract:
A tire has a tread on the outer circumferential surface. The tread has circumferential and lateral grooves defining tread blocks. In at least one tread block, one of the circumferentially extending sides of the block has a multi-planar chamfer.
Abstract:
A pneumatic tire has an aggressive tread pattern for use on both on-road and off-road vehicles having at least a pair of intermediate ribs and a pair of shoulder ribs providing the ground engaging tread lugs. A plurality of circumferentially extending lug groups are formed on and extend outwardly from and along the sidewalls of the tire. Each lug group preferably includes three separate lugs, each lug having a substantially flat outer surface lying in a different plane than the outer surfaces of the other two lugs. Two of the lugs are radially aligned with each other along the sidewall of the tire with the third lug lying intermediate spaced pairs of these aligned lugs. The lugs are formed with sharp corners offset from each other which extend outwardly from the sidewall to different levels. A top surface of one of the lugs aligns with the ground engaging surface of an adjacent shoulder rib tread lug and the top surface of the intermediate lug aligns with the inner tread surface of the road engaging tread pattern.
Abstract:
An end of a block 18 formed on a tread surface of a tire is chamfered in such a manner that a curvature of a chamfer increases toward the end of the block. Accordingly, a ground contact pressure which usually increases locally at the end of the block 18 is equalized and handling stability of the tire improves. Particularly, since the curvature changes, the ground contact pressure can be controlled corresponding to an actual distribution of ground contact pressure. As a result, the ground contact pressure can be equalized still further and an improvement in handling stability of the tire is achieved.
Abstract:
A pneumatic radial tire for passenger car has a directional tread pattern (with respect to a rotating direction of tire) defined by a circumferential center groove, a plurality of directional slant grooves disposed at intervals in the circumferential direction of the tire, and a plurality of blocks formed at intervals in both circumferential and axial directions of the tire, in which these blocks form a pair of central block rows and a pair of side block rows, and surfaces of acute corner portions of blocks constituting the central block row and the side block row located outward and inward in the axial direction of the tire at given length, and chamfered acute corner portions of blocks constituting the central block row and the side block row are connected to each other at their chamfered shallowest tips.
Abstract:
A pneumatic tire capable of obtaining a high tire performance on ice without decreasing the other performances can be provided. A plurality of narrow grooves each having a rectangular cross section are formed on one sipe side wall surface of a sipe in an inclined manner at a certain angle. Even when the sipe is closed under a load application to the tire, portions having the narrow grooves are not brought into contact with the other sipe side wall surface of the sipe so that water on an ice road surface can be absorbed and removed by the narrow grooves. Further, in the case of the narrow groove in which one end is opened to a road contact surface portion and the other end is opened to a side surface, the absorbed water can be continuously discharged to an outside of a block in serial order so that the water on the ice road surface can be further removed. Since the water removal can be performed without a great number of sipes, a decrease of a block rigidity due to employing a great number of sipes does not occur.
Abstract:
A studless tire with a tread pattern comprising blocks that are defined by longitudinal and transverse grooves and having at least one row of blocks that extends in the peripheral direction of the tire. The peripheral rows of blocks are such that at least one sub-block is provided within one pitch of the tread pattern outside an adjacent block in the tire's rotating axle. And the sub-block is separated from the block by a sub-groove less deep than the longitudinal and transverse grooves and has the longer side in the peripheral direction and the shorter side in the direction of the rotating axle.