Sumitomo Rubber Industries Limited

Hideaki Yoshikawa

Kiyoto Maruoka

Masayuki Sakamoto

Kiyoshi Ueyoko

Hideaki Sugihara

Mikio Takatsu

Shinzo Kajiwara

Kiyoshi Ochiai

Akihiro Takeuchi

Kiyohito Maruoka

Masahiro Tamura

Akira Manno

Yukihide Oya

Kouichi Horiuchi

Yasusuke Yonekawa

A pneumatic tire having an improved noise performance without deteriorating the drainage performance and having in a tread portion at least one circumferential main groovewhich extend continuously in the tire circumferential direction, wherein the circumferential main groovehas a pair of groove walls, and in at least one of the groove wallsare provided at intervals in the tire circumferential direction a plurality of fine grooveseach of which extends in the tire radial direction and is provided in at least a part of its inner surface with a non-flat portionextending in a wave-like form in its length direction.

Pneumatic tire with tread having radially extending fine grooves

A heavy duty tire comprises: a carcass ply of cords extending between bead portions; and a bead reinforcing layer disposed in each of the bead portion. The carcass ply has edges winded around the bead cores so that the winded portion has a base part extending along the bead core from the axially inside to the axially outside thereof, and a radially outer part extending axially inwards on the radially outside of the bead core. The bead reinforcing layer comprises: a curved portion extending along the base part; an axially outer portion extending radially outwardly, separation from the base part; and an axially inner portion extending radially outwardly along a main portion of the carcass ply. The bead reinforcing layer is composed of a ply of cords laid side by side, and the spacing Da of the cords in an axially outer part beneath the bead core, of the curved portion is not less than 1.5 times and not more than 3.0 times the spacing Db of the cords in the axially outer portion.

Heavy duty tire

A tirehas a beltand a hard rubber layer. The belthas a first ply, a second ply, a third plyand a fourth ply. A width Wof the third plyis smaller than a width Wof the first plyand a width Wof the second ply, and 75% of a width of a tread. Each of the plieshas a steel cord. The first plyand the second plyconstruct a cross-ply structure. A cord of the third plyis wound spirally. The third plyhas what is referred to as a jointless structure. The hard rubber layeris positioned between the first plyand the second ply, and outward of the third plyin an axial direction. A complex elastic modulus of the hard rubber layeris equal to or greater than 30 MPa.

Heavy duty pneumatic tire with belt hard rubber layer

A heavy duty tire having an improved durability in bead portions and comprising a carcass ply of steel cords, the end portions of which are turned up around bead cores from the axially inside to the axially outside of the tire, and a core protecting rubber having a complex elastic modulus of 50 to 80 Mpa, at least a part of which is located in a core inside region which is located axially inward of the bead core and is sandwiched between the axially inner surface of the bead core and the steel cords of the turnup portion of the carcass ply.

A heavy duty tire comprises a tread portion, a pair of sidewall portions, a pair of bead portions each with a bead core therein, the bead core with an aspect ratio (HC/WC) of from 0.43 to 0.58, and a carcass comprising a carcass ply of cords extending between the bead portions and turned up around a bead core in each bead portion from the inside to outside of the tire so as to form a pair of turnup portions and a main portion therebetween, the turnup portion comprising a turnup main-part extending along an axially inner surface, a radially inner surface and an axially outer surface of the bead core smoothly, and a turnup sub-part extending from the turnup main-part toward the main portion near the radially outer surface of the bead core.

A heavy duty tire comprises a bead core disposed in each bead portion, and a carcass ply of steel cords extending between the bead portions. The edges of the carcass ply are winded around the bead cores from the axially inside to outside of the tire to form a pair of winded portions and a main portion therebetween. The winded portion around the bead core comprises an axially inwardly extending turnback part above the bead core, and a base part under the bead core. The base part is curved concavely so as to form a space between the base part and the bead core, and an anchor rubber having a complex elastic modulus of from 20 to 80 MPa is disposed in the space to tightly pinch the carcass cords between the anchor rubber and the bead seat of the wheel rim.

Heavy duty tire with bead anchor rubber

A passenger radial tire which comprises a tread portion, a pair of axially spaced bead portions, a pair of sidewall portions extending therebetween, a pair of bead cores disposed one in each bead portion, and a carcass extending between the bead portions and turned up around the bead cores from the axially inside to the outside thereof to form two turned up portions and one main portion therebetween, wherein in at least the sidewall portions no bead apex exists to thereby the carcass turned up portions are located adjacently to the carcass main portion, and in each bead portion a bead reinforcement extending radially outwardly into the sidewall portion is disposed.

Passenger tire with low bead apex volume

A passenger radial tire which comprises a tread portion, a pair of axially spaced bead portions, a pair of sidewall portions extending therebetween, a pair of bead cores disposed one in each bead portion, and a carcass extending between the bead portions and turned up around the bead cores from the axially inside to the outside thereof to form two turned up portions and one main portion therebetween, wherein in at least the sidewall portions no bead apex exists and the carcass turned up portions are located adjacently to the carcass man portion, and in each bead portion a bead reinforcement extending radially outwardly into the sidewall portion is disposed.

Passenger radial tire including bead reinforcement

A high speed radial tire has a carcass and a belt layer, wherein; in the state of inflated with a standard internal pressure on a standard rim, a equator height H1 defined as a height of crossing point at which the inner surface of the belt layer intersects the surface of the tire equator is larger than an outer end height H2 defined as a height of the outermost end of the inner surface of the belt layer. Furthermore, a belt camber quantity H defined as a difference between the height H1 and the height H2 is set at 6% or more of the belt width W.

High-speed radial tire for heavy load with specified belt camber quantity

A high speed tire for heavy duty vehicles comprise a belt layer of a carcass with radial structure, wherein a profile of the outer circumference of the tire in the specified internal pressure state satisfies that the maximum width and radius ratio Ro/W is not more than 0.54. At this point, the ratio Ro/W is defined as the ratio of the radius Ro of curvature of the arc which passes through maximum width point C, a reference point Q and an intermediate height point M to tire maximum width W. The maximum width point C is defined as a point where the tire width is maximum W. The reference point Q is defined as a point which is apart from the bead bottom line by the length of 0.2 times the total sectional height H of the tire. And the intermediate height point M is defined as a point which is intermediate between the maximum width point C and the reference point Q.

High speed tire for heavy duty vehicles including bead part with side

A pneumatic radial tire having a new carcass profile, which is characterized in that a radius TR1 of the radially expansive tread surface produced when the tire is mounted on the rim officially specified for use and inflated with air having 5% pressure of the specified maximum pressure, and another radius TR2 of curvature produced when the tire is inflated with air of the specified maximum pressure always satisfy the relation of 1.2.ltoreq.TR2/TR1.ltoreq.1.5. An above-mentioned radius of curvature increase with increasing air pressure.

Growing community of inventors

Kobe, Japan

Hideaki Yoshikawa