Abstract:
The tread of a rib type tire is modified to provide draft angles in lateral grooves of selected ribs to compensate the tire's residual aligning torque (RAT). This allows the vehicle to have straight ahead motion with no steering pull. The draft angles are achieved by inclining the radial centerline of the lateral grooves to be sloped forward on one side of the midcircumferential plane and sloped backward on the other side of the midcircumferential plane. The centerline draft angle results in tread blocks sloped forward and backward during forward motion of the vehicle. The sloping tread blocks produces an effective rolling radius change on selected ribs of the tread pattern. Effective rolling radius of selected ribs is a concept introduced to explain the physical relationships that exist in the contact patch of the tire with the ground surface. The resulting contact change introduces longitudinal tangential stress changes that induce a torque to compensate for the inherent residual aligning torque due to the unmodified tire's construction and tread pattern.
Abstract:
A tire that has a tread base compound and a tread cap compound that have synergistic properties, an extra wide center rib, stiff shoulder lugs, and lateral grooves between shoulder lugs that do not vary significantly in width has a superior combination of rolling resistance properties, traction properties, noise properties, and wear properties. Also the RSAT of the tire can be fine tuned by chamfering edges of lugs in the tire.
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 pneumatic tire comprises a tread portion having a plurality of slant grooves, in which each slant groove has a steeply slant groove portion and a gently slant groove portion, and the steeply slant groove portion comprises a pseudo-land part of a given shape, and can improve a drainage performance without sacrificing the other tire performances.
Abstract:
A vehicle having a profiled tread, having tread blocks (1) in at least some regions of its circumference, characterized in that for at least some of the tread blocks (1) at least the tread block edges (2) running into the tire contact patch (11) and extending at an angle to the central plane of the tire are lowered over their entire length with respect to the central plateau (3) of the respective tread block (1).
Abstract:
One each wide main groove is disposed on each side of a tire equator on a tread surface, the area interposed between these right and left two main grooves is used as ribs, two kinds of large and small sub-grooves having mutually different groove widths and extending from the main grooves to a ground contact end in a tire width-wise direction are disposed alternately in both outside areas of the main grooves throughout one circumference of a tire, and sub-main grooves extending in the tire circumferential direction are disposed between the main grooves and the ground contact end in the tire width-wise direction.
Abstract:
A pneumatic tire includes a tread portion provided with shoulder blocks in a row along each tread edge. The shoulder blocks are provided in a row divided by a circumferential groove and first shoulder grooves and second shoulder grooves. The first and second shoulder grooves alternate in the tire circumferential direction and each extend from the circumferential groove to the tread edge. A circumferential width (WLo) of the first shoulder groove at the tread edge is larger than a circumferential width (WSo) of the second shoulder groove at the tread edge. The ratio (WLo/WSo) of the circumferential width (WLo) to the circumferential width (WSo) is larger than a ratio (WLi/WSi) of a circumferential width (WLi) of the first shoulder groove to a circumferential width (SWi) of the second shoulder groove, each measured at the circumferential groove.
Abstract:
A tread (12) for a light truck or automobile tire (10) has a continuous rib (30, 32) between an adjacent piece of circumferentially continuous grooves (20, 22, 24). The tread (12) has a plurality of hook-shaped semi-blind grooves (40) originating from the circumferentially continuous grooves (20, 22, 24). Each rib (30, 32) has two rows of circumferentially spaced hook-shaped semi-blind grooves (40).
Abstract:
A pneumatic tire comprises: a tread rubber having a Shore A hardness of not more than 65 degrees at 20 degrees C.; a tread portion provided with at least one circumferential row of blocks having circumferential edges adjacent to lateral grooves; each of the circumferential edges having a mean inclination angle of 0 to 60 degrees with respect to the tire axial direction; sidewalls of the lateral grooves on one side in the tire circumferential direction each comprising a first upper slope extending from the top of the adjacent block to a first point at a depth h1, while inclining at an angle .alpha.1, and a first lower slope extending from said first point towards the groove bottom, while inclining at an angle .alpha.2 smaller than the angle .alpha.1,; the remaining sidewalls of the lateral grooves on the other side each comprising a second upper slope extending from the top of the adjacent block to a second point at a different depth h2 than said depth h1, while inclining at an angle .beta.1, and a second lower slope extending straight from the second point towards the groove bottom, while inclining at an angle .beta.2 smaller than the angle .beta.1; and the lateral grooves comprising a portion (A) in which the depth h1 is more than the depth h2 but not more than 0.8 times the lateral groove depth, and a portion (B) in which the depth h2 is more than the depth h1 but not more than 0.8 times the lateral groove depth.
Abstract:
The present invention relates to a tire designed to be fitted on the driving axles of a motor vehicle for medium or heavy load. This tire is provided with a tread comprising a plurality of full-depth transverse grooves and four circumferential series of inclined grooves and four circumferential series of inclined incisions which delimit five circumferential rows of blocks, namely two axially outer rows, two intermediate rows, and one central row lying essentially across the equatorial plane.Each transverse groove extends across the whole width of the tread, and consists of a central portion, located between a pair of consecutive blocks of the central row, and a pair of lateral portions, located between pairs of consecutive blocks of the intermediate and shoulder rows.The two lateral portions of each transverse groove are staggered circumferentially with respect to each other and penetrate into the body of the central row of blocks. The central portion of the transverse groove has a depth of 3 mm, while the depth of the incisions located between the shoulder blocks and the intermediate blocks is less than the depth of the inclined incisions located between the intermediate blocks and the central blocks.