Patent classifications
B60C2011/0313
Pneumatic tire
A pneumatic tire includes lug grooves having alternating first and second groove portions. The first groove portion intersects an equator, extends in a width direction, and communicates with an adjacent second groove portion. The second groove portion inclines from the first groove portion at a smaller angle relative to a circumferential direction smaller than that of the first groove portion and extends to a tread edge on one side. The first groove portion is on a stepping side with respect to an end on the tread edge side. The second groove portions curve or bend and have an average angle in an inner region smaller than that of the second groove portions in an outer region. A maximum length in the width direction of center blocks defined by narrow grooves connecting adjacent second groove portions and the lug grooves is 25%-35% of a development width.
TIRE COMPRISING A TREAD OPTIMIZED FOR GRIP ON SNOW-COVERED GROUND
A tire has a tread comprising at least two tread pattern elements (MA, MB) distributed periodically in the circumferential direction at pitches (PA, PB). Each tread pattern element is formed of three portions (Z1, Z2, Z3), each defining a volumetric element of which the leading edge corner is the one common to the tread surface and is the first to enter the contact patch in which the tire is in contact with the ground. With each leading edge corner being chamfered, in the portions Z1 and/or Z2, and/or Z3, the widths of the chamfers of the leading edge corners (LC.sub.i.sup.A, LC.sub.i.sup.B, i ranging from 1 to 3) satisfy the following inequalities: a) for the portion Z1:
b) for the portion Z2:
and c) for the portion Z3:
TIRE FOR ROUGH TERRAIN
A tire for running on rough terrain for which an intended tire rotational direction is specified. The tread portion is provided with blocks raised from a tread base portion. Each block has a first side wall surface comprising a radially outer portion extending substantially straight and radially inwardly, while inclining toward the toe side in the intended tire rotational direction, and a radially inner portion extending from the radially outer portion to the tread base portion while curving in an arc shape. The radially outer portion has a radial length of from 30% to 70% of a radial height of the block.
TIRE FOR ROUGH TERRAIN
A tire for running on rough terrain for which an intended tire rotational direction is specified, and which comprises a tread portion provided with crown blocks disposed on the tire equator. Each of the crown blocks comprises a V-shaped crown block main portion which bends convexly toward a circumferential direction opposite to the intended tire rotation direction, and only two crown fin portions projecting from the crown block main portion toward the above-said circumferential direction opposite to the intended tire rotation direction.
TIRE
A tire includes a main groove extending in a circumferential direction, a lug groove extending in a width direction, a land portion defined by the main groove and the lug groove, and a sipe that is a narrow groove that is formed in the land portion, extends in the width direction, and includes an end opening to the main groove. The lug groove includes a raised bottom portion formed in a central region of the land portion in the width direction. The sipe includes shallow and deep bottom portions having different depths from a tread contact surface. A deep bottom portion depth from the tread contact surface is greater than a shallow bottom portion depth and includes at least a part disposed in the central region. The raised bottom portion and the deep bottom portion are disposed overlapping each other in the circumferential direction.
TIRE
A tire comprises a tread portion 2 provided with a first main groove 3 and a second main groove 4 each extending in a zigzag manner and a land region 10 defined between them. The land region 10 is provided with a longitudinal sipe 15 extending in a zigzag manner in the tire circumferential direction, first lug grooves 16, and second lug grooves 17. The land region 10 comprises first blocks 21 divided by the longitudinal sipe 15 and the first lug grooves 16, and second blocks 22 divided by the longitudinal sipe 15 and the second lug grooves 17. Each of the first blocks 21 and the second blocks 22 is provided with not less than three transverse sipes 25 extending across the entire width of the each of the first blocks 21 and the second blocks 22.
TIRE HAVING A TREAD OPTIMIZED IN TERMS OF GRIP ON DRY GROUND
A tire has a tread comprising at least two tread pattern elements (MA, MB) distributed periodically in the circumferential direction at pitches (PA, PB). Each tread pattern element is formed of three portions (Z1, Z2, Z3), each defining a volumetric element of which the trailing edge corner is the one common to the tread surface and is the last to leave the contact patch in which the tire is in contact with the ground. With each trailing edge corner being chamfered, in the portions Z1 and/or Z2, and/or Z3, the widths of the chamfers of the trailing edge corners (LC.sub.i.sup.A, LC.sub.i.sup.B, i ranging from 1 to 3) ef satisfy the following inequalities: a)
for the portion Z1, b)
for the portion Z2, and c)
Tread comprising oblique blocks
A tread made of rubber-like material for a tire for winter travel having a plurality of blocks of a height H, each block comprising a contact face designed to come into contact with the ground when the tire travels and at least one lateral face, said lateral face being covered by a layer of covering material over at least 50% of the surface thereof, and a leading zone designed to come into contact first with the ground when the tire travels, and said block has an oblique direction of extension (J) such that the leading zone of said block is a leading corner, and a part which is not covered by the covering material, said covering material having a modulus of elasticity which is greater than the modulus of elasticity of the rubber-like material forming the block, said uncovered part extending from the leading corner over at least ⅓ of the height H of the block.
Pneumatic tire
A pneumatic tire, includes: an annular-shape tread portion; a sidewall portions; and bead portions. JIS hardness of tread rubber is within a range of 40 to 60 and snow traction index is 180 or higher. A rib positioned between circumferential grooves is demarcated in a center region of the tread portion. Closed grooves are formed in the rib. The closed grooves are inclined with regard to a tire axial direction such that a closed end faces a leading side. A groove wall of the closed groove on the leading side protrudes more outward in the tire axial direction than a groove wall on a trailing side. A difference between angles θ1 and θ2 of the groove walls on the leading and trailing sides of the closed grooves, respectively, with regard to the tire axial direction is within a range of 0°≤θ1-θ2≤5°.
TIRE COMPRISING A TREAD
A tire comprises a directional tread (10), said tread comprising a central axis (12) and two edges (14A, 14B) a tread width W being greater than or equal to 140 mm, said tread (10) comprising a plurality of patterns (13) which succeed one another in the circumferential direction, each pattern having a pitch P, the patterns (13) delimiting a plurality of oblique grooves (16A, 16B), each oblique groove extending from one of the edges (14A, 14B) of the tread as far as the central axis (12). In a central part of the tread centered on the central axis (12) and of a width corresponding to 80% of the width W of said tread, all or some of the oblique grooves (16A, 16B) of the plurality of oblique grooves have a prescribed slenderness ratio, and all or some of the patterns comprise at least one sipe and have a prescribed sipes density SD.