Abstract: A pneumatic radial tire, wherein five main grooves extending in the circumferential direction of a tire are provided on a tread to divide into and form land portions of six rows, each land portion is divided into block rows constituted by a plurality of blocks by means of a plurality of subgrooves extending in the direction of width of the tire, and an area ratio of the blocks is set at a relationship of 1:0.9 to 1.1:1.8 to 2.2 from the block row of the shoulder side to the block row of the center side, in a region between ends of a belt layer having a maximum width embedded in said tread.

Abstract: A vehicle tire which has an aspect ratio of less than about 55% and comprises a tread portion having a profile whose radius of curvature decreases substantially continuously from the tire equator to each tread edges. The tread profile from the tire equator to each tread edge is substantially defined by a curve such as ellipse, cycloid, epicycloid, involute curves and the like, of which equation is differentiable in the range between the tire equator and each tread edge.

Abstract: The present invention relates to a radial ply tire (230) with a tread (232) subdivided transversely into a central portion (250) having central ribs (260a,260b), shoulder portions (254a, 254b) having shoulder ribs (270a,270b) and intermediate portions (252a, 252b) having intermediate ribs between the central portion and the shoulder portions. The tread has intermediate grooves (262a,262b) between the central ribs and the intermediate ribs (266a,266b) and shoulder decoupling grooves (264a,264b) between the intermediate ribs and the shoulder ribs (270a,270b). The shoulder decoupling grooves having a depth (D1) being less than the intermediate decoupling grooves whereby the footprint width of the tread surface can expand from first width (NLFPW) under normal load to a second width (HLFPW) under heavy load.

Abstract: A two-piece tire assembly has a removable tread belt 12 for installing about the circumference of a tire carcass 14. The tread belt has a pair of lateral ends each axially extending beyond the inflated unloaded carcass 14 at the circumferential surface by a distance of at least 4% of the width as measured at the tread belt 12 and carcass 14 interface. The carcass 14 has an abrasion resistant rubber layer 82 at the tread belt interface. The tread belt 12 also has the abrasion resistance tread compound 82 at the carcass 14 interface.

Abstract: A radial ply runflat tire (50) having a tread (52), a carcass (60) with two sidewalls (77,78), one or more radial plies (70,72), two annular beads (36a′,36b′), and a belt structure (56) located radially between the tread and the radial ply structure (58). The tread has laterally disposed tread ribs (64a,64b) whose contours are defined by circular curves intersecting nontangentially with the circular curve that defines the contour of the central portion of the tread. Each sidewall portion (77,78) has a rib (63a,63b) that is out of contact with the road during normal inflation operation and that engages the road during runflat operation. The tread ribs (64a,64b) are separated from the respective sidewall ribs (63a,63b) by decoupling grooves (65a,65b) which overlie the point of nontangential intersection of the circular curves that define the respective contours of the sidewall ribs and the laterally disposed tread ribs.

Abstract: Disclosed is a pneumatic tire adopting a bias ply structure in which plural carcass layers are disposed so that cords cross each other between the layers, and having an aspect ratio of 55% or less and an outer diameter of 300 mm or less, wherein a cord angle to a tire circumferential direction of said carcass layer is set to a range from 27 to 37° in the center line position, and a surface shape of a tread portion is formed to be straight to a tire width direction in the region of 60 to 75% of a tread width.

Abstract: A center rib and a second rib are formed at a tread surface of a pneumatic tire along an outer contour line L1 of a radius R1 whose center is at a tire inner side. A shoulder rib is formed at the tread surface along an outer contour line L2 of a radius R2 whose center is at a tire inner side. A step between the outer contour line L1 and a ground contact surface of the shoulder rib decreases toward a tire transverse direction outer end portion. Accordingly, when a heavy load is applied to the pneumatic tire, due to the step between, on the one hand, the shoulder rib, and on the other hand, the center rib and the second rib, uneven wear at the second rib can be suppressed. When a light load is applied, because the step decreases toward the tire transverse direction outer end portion, uneven wear of the shoulder rib can be suppressed. The pneumatic tire exhibits excellent uneven wear resistance at all land portions formed on the pneumatic tire.

Abstract: The present invention provides a tire with a sacrificial rib to protect the main ribs of the tire's tread by delaying the onset of irregular wear and the growth thereof. The improved tire tread comprises a plurality of main ribs formed by grooves extending generally circumferentially around an outer surface of the tire to form a main tread width for contacting the supporting surface. A sacrificial rib is provided for contacting the supporting surface at each lateral side of the main ribs. The sacrificial rib is separated from the main ribs by a narrow shoulder groove having a groove width not greater than about 1.5 millimeter. The sacrificial rib has a surface width in the range of about 2.5 percent to about 12 percent of said tread width. The sacrificial rib has a recess defined by a radial offset from a transverse or lateral profile of the main ribs. The offset has a value in the range of about 0.50 millimeter to about 2.0 millimeters when the tire is new.

Abstract: A heavy duty pneumatic radial tire comprises a carcass ply, a belt disposed at an outside of the carcass ply in the radial direction and comprised of two or more belt layers, at least one auxiliary belt layer disposed in a widthwise central portion of the belt at a width narrower than that of the belt, and a tread, wherein when the tire is mounted onto a design rim defined in TRA standard and inflated under an internal pressure corresponding to 10% of an air pressure defined in the TRA standard, a radius of curvature of an outer profile at both side regions of the tread (Rs) is made larger than a radius of curvature of the outer profile at a central region of the tread (Rc).

Abstract: A tire for vehicle wheels provided with a tread pattern includes at least one continuous central circumferential groove straddling an equatorial plane of the tire, at least two continuous lateral circumferential grooves having median planes substantially parallel to the equatorial plane of the tire, and a plurality of transverse grooves. These grooves delimit at least four circumferential rows of blocks, two central rows and two shoulder rows. Each block of the central rows is defined by a plurality of sides and at least four vertices, a pair of front vertices and a pair of rear vertices, in relation to a predetermined running direction of the tire. The blocks of the central rows include a first transverse notch having a first terminal end inside a respective block of the central rows and a first starting end communicating with the at least one central circumferential groove.

Abstract: A pneumatic tire for a multiple-tracked vehicle is asymmetrical and has a convex tread section that is curved radially inward and extends to a tire sidewall.

Abstract: A passenger tire having a tread, a casing with two sidewalls, one or more radial plies extending from and wrapped about two annular beads and a belt reinforcement structure located radially between the tread and the piles. The tread has a central rib with a first contour-defining curve extending outwards from the mid centerline of the tire towards the sidewalls and a pair of side ribs each having a second contour-defining curve disposed between the central rib and the sidewalls. The first and second contour-defining curves each have first and second radii disposed such that the meeting point of first and second adjacent contour-defining curves cannot contain a single line that is mutually tangential to the first and second adjacent contour-defining curves.

Abstract: A pneumatic radial tire combination for four-wheeled automobile or light truck vehicles. The tire combination has a pair of front steer position tires and a pair of rear position tires. The front steer position tire 10 has a first tread arc 46 when the tire is normally inflated for normal load but unloaded, of decreasing radii extending toward the lateral edges 42, 44 and a straight line 50 drawn between the intersection of the tread arc curvature and the centerplane is inclined at an angle &thgr;F of greater than 5° relative to a tangent line L, L being tangent to the tread arc at the centerplane and parallel to the axis of rotation R. The rear tire 20 when similarly measured has a tread arc having an angle &thgr;R of less than 5°.

Abstract: Disclosed is a pneumatic tire capable of effectively making even a contact pressure of land portions composed of blocks or ribs. In the pneumatic tire, the plurality of land portions defined by grooves are provided on a tread, curved chamfered portions are formed on end peripheries of the land portions, a relation between a groove width A of the groove on a tread surface, the groove being adjacent to the end periphery, and a curvature radius B on the chamfered portion is established as: B=kA, and a value of a constant k is set in a range of 0.2 to 0.3.

Abstract: A pneumatic radial tire having in axial cross-section a highly curved tread is reinforced by a breaker assembly with improved resistance to breaker edge looseness. The breaker assembly includes one breaker ply which extends between two bead regions and has its edges disposed between a carcass main portion and a carcass turn-up portion. An improved single-stage method may be employed for building the tire.

Abstract: A motorcycle tire comprises a tread portion curved convexly such that the maximum cross section width TW of the tire lies between the tread edges, a carcass ply of cords arranged radially at an angle of 70 to 90 degrees to the tire equator, and a belt ply of at least one cord laid at an angle of 0 to 35 degrees disposed radially outside the carcass ply in the tread portion. When the tire is mounted on a standard rim and inflated from 10% of a standard inner pressure to 100% thereof, the tread portion swells such that the amount of swelling is larger in a shoulder region than a crown region of the tread portion. The carcass cord tension Tcs in the shoulder region is 2.0 to 3.8 times the carcass cord tension Tcc in the crown region, and the belt cord tension Tbs in the shoulder region is 1.2 to 2.0 times the belt cord tension Tbc in the crown region.

Abstract: A run-flat tire comprises a carcass ply extending between the bead portions, and a sidewall reinforcing layer disposed axially inside said carcass ply in each sidewall portion, wherein in a normally inflated unloaded state, a profile line from a tire equator point (P) to a maximum tire section width point (D) is curved substantially along an involute curve so as to have a radius of curvature decreasing continuously from the tire equator point towards the sidewall portion, the basic circle of the involute curve is an ellipse whose major axis extends in the tire radial direction, the radial distance (h) between the tire equator point (P) and the maximum tire section width point (D) is more than 34% but less than 50% of the tire section height (H).

Abstract: A pneumatic tire for passenger cars which is improved in harshness noise without deteriorating the steering stability is disclosed, wherein a harshness factor HF is set in the range of from 3.2 to 3.5, the harshness factor HF is: HF=−0.133×(R1/100)+0.245×(R1/R2)−0.183×(Kv/10)+3.898 R1 is a radius of curvature (in mm) of a crown part of the tread profile, R2 is a radius of curvature (in mm) of shoulder parts of the tread profile, and Kv is the vertical spring constant in kN/mm of the tire.