A tire includes a plurality of main grooves extending in a tire circumferential direction and four or more rows of land portions defined by the main grooves. Moreover, a middle land portion and a center land portion have a plurality of through lug grooves that pass through the land portions in a tire width direction, respectively. Pitch lengths of the through lug grooves are in a range of from 7% or greater to 14% or less of a tire maximum ground contact length. Additionally, maximum groove depths of the through lug grooves are in a range of from 5% or greater to 65% or less of maximum groove depths of the main grooves.

The invention relates to a utility vehicle tyre having a tread with at least one circumferential channel (2, 2′, 2″) with a channel base (5) and channel walls (4, 4′), wherein base elevations (7, 7′, 7″) are formed on the channel base (5) in a manner distributed over the circumference and acting centrally as stone ejectors, with a height (h.sub.1, h.sub.3) of 25% to 60% of the profile height (T.sub.1) and a greater extent in the circumferential direction than in the axial direction, which base elevations (7, 7′, 7″) either contact the channel walls (4, 4′) or are at distances (a.sub.1) of up to 4.0 mm therefrom in the axial direction and are bounded in the radial direction by a top surface (8, 8′, 8″) having an encircling surface edge, wherein the channel walls (4, 4′) between the base elevations (7, 7′, 7″) have wall portions (4a, 4′a) which converge toward each other.

The top surface (8, 8′, 8″) of the base elevations (7, 7′, 7″) slopes downward uniformly toward the surface edge, wherein the channel walls (4, 4′) have, to the side of the base elevations (7, 7′, 7″), wall sections (4b, 4′b) which are convexly curved toward one another in a plan view, and wherein the surface edge of the top surface (8, 8′, 8″) follows the profile of the wall sections (4b, 4′b) which are convexly curved toward one another, such that the width of the base elevations (7, 7′, 7″) decreases toward those ends thereof which lie in the circumferential direction.

The invention relates to a utility vehicle tire having a tread with at least two circumferential channels (3), which are formed to a profile depth (T) and which separate central profile positives (1) and shoulder-side profile positives (2) from one another, the circumferential channels (3) having channel flanks (5a, 5b) toward the central profile positives (1) and the shoulder-side profile positives (2) having shoulder flanks (6) running toward the side wall.

At least one channel flank (5a, 5b) of at least one circumferential channel (3) and/or at least one shoulder flank (6) is provided with depressions (7, 7′) which extend into the profile positives (1, 2) and are open toward the surface of the tread and which, determined in each case at the periphery of the tread, have with respect to the level of the channel flank (5a, 5b) or shoulder flank (6) a depth (t.sub.1, t.sub.1′) of 2.0 mm to 5.0 mm and at the level of the channel flank (5a, 5b) or shoulder flank (6) a width (b.sub.1, b.sub.1′) of 4.0 mm to 15.0 mm,

each depression (7, 7′) being delimited by at least one surface (7c, 7d, 7′d), the surface(s) (7c, 7d, 7′d) being curved in such a way that, at its or their radially inner ends, it or they go(es) over without a kink into the channel flank (5a, 5b) at a depth (T.sub.1), determined in the radial direction, of 35% to 90% of the profile depth (T) or go(es) over without a kink into the shoulder flank (6) at a depth (T.sub.1′), determined in the radial direction, of 35% to 150% of the profile depth (T).

An outer shoulder land region includes first shoulder lateral grooves each extending axially inwardly from an outer tread ground contact edge to have a first inner end in the tyre axial direction within the outer shoulder land region, first outer shoulder lateral sipes each connecting between the first inner end and an outer shoulder main groove, and second outer shoulder lateral sipes each extending axially inwardly from the outer tread ground contact edge to have a second inner end positioned on an axially outer side of the first inner ends. An outer middle land region includes outer middle lateral sipes each smoothly connected with the respective first outer shoulder lateral sipe with the outer shoulder main groove therebetween. Each of the outer middle lateral sipes connects between the outer shoulder main groove and an outer crown main groove and has a third inner end within the outer middle land region.

A tyre includes a tread portion having a tread surface being provided with a plurality of lateral grooves extending in a tyre axial direction. In a cross-sectional view perpendicular to a longitudinal direction of the at least one of the plurality of lateral grooves, the at least one of the plurality of lateral grooves includes a pair of groove walls and a groove bottom. At least one of the pair of groove walls includes a serrated portion including first surfaces and second surfaces that are arranged alternately. Each first surface is inclined outwardly in a groove width direction toward the groove bottom and has a radially inner end thereof, and each second surface extends substantially parallel with the tread surface from the radially inner end of a respective one of the first surfaces toward a groove centerline of the at least one of the plurality of lateral grooves.

A tire includes a tread portion including first to third main grooves continuously extending in a tire circumferential direction. The first main groove has a groove centerline arranged on a side of the inboard tread edge with respect to a tire equator and the groove centerline is located at an axial distance L1 from the tire equator of from 5% to 25% of a tread half width. The second main groove is arranged between the first main groove and the inboard tread edge and has a groove centerline located at an axial distance L2 from the tire equator of from 35% to 65% of the tread half width. The third main groove is arranged between the tire equator and the outboard tread edge and has a groove centerline located at an axial distance L3 from the tire equator of from 25% to 55% of the tread half width.

Steering stability performance on dry road surfaces and steering stability performance on wet road surfaces are improved.

A land portion width Wcc of a center land portion (31) and a land portion width Wco of an outer side middle land portion (32) satisfy a relationship of Wcc<Wco. In addition, a ground contact surface (10) of each of the outer side middle land portion (32) and an outer side shoulder land portion (34) is formed to protrude toward an outer side in a tire radial direction with respect to a reference profile PRco, PRso, and a protruding amount Hco of the outer side middle land portion (32) and a protruding amount Hso of the outer side shoulder land portion (34) satisfy a relationship of Hco<Hso.

In a tire 2, an outer surface 52 of a crown rib 48e and an outer surface 54 of a shoulder rib 48s form a part of a tread surface 28. On a cross-section of the tire 2 along a plane that includes a rotation axis of the tire 2, an outline of the outer surface 52 of the crown rib 48e is represented as a first arc. A center of a circle to which the first arc belongs is disposed on the equator plane. An outline of the outer surface 54 of the shoulder rib 48s is represented as a second arc. A ratio of a distance from a center of a chord of the second arc to the second arc relative to a length of the chord of the second arc is not less than 0.03 and not greater than 0.05.

A first tire includes a tread having a circumferential center rib and a circumferential intermediate rib laterally adjacent the center rib, the intermediate rib being separated from the center rib by a first circumferential groove, a second circumferential rib bordering the intermediate rib opposite the first circumferential groove, the tread further including two other circumferential grooves; at least one stiffener element disposed within each of the four circumferential grooves, the stiffener elements having a reduced height relative to a height of the center and intermediate ribs; and the stiffener element having a circumferentially oriented cut extending into an upper surface of the stiffener element toward a bottom of the stiffener element, the cut extending circumferentially through the stiffener element with the cut bounded by opposite laterally inward facing cut sides.

A tire with noise-reducing main grooves includes: a groove portion which is formed to extend circumferentially along a circumference of a tire tread; and a knurled portion which is formed on bottom and side surfaces of the groove portion. The knurled portion is provided to reduce noise energy by narrowing an air path formed when the groove portion and the ground contact each other.