Bridgestone Corporation

Naotoshi Aoki

Yukihiro Kiwaki

A pneumatic tire in which a side reinforcement layer formed of a treated member is arranged, the treated member formed by coating with rubber organic fiber cords extending parallelly to ply cords of a carcass ply of the carcass main body, only on a sidewall portion of a half portion on one tire widthwise side; a tire radial inner end of the side reinforcement layer is located on a side inner in the tire radial direction than a tire radial outermost position of a rim flange, and a tire radial outer end of the side reinforcement layer overlaps the belt by 5 mm or more in a tire widthwise direction; and the tread portion has one or more circumferential main grooves, and a contact width of a tire widthwise outermost land portion is larger than a contact width of a tire widthwise outermost land portion.

Pneumatic tire

Each central land portion row () has at least one first narrow groove () that is open to the central main groove () and has a length a in a tire width direction and an angle &#x3b1; to the tire width direction, and at least one second narrow groove () has a length b in the tire width direction and an angle &#x3b2; to the tire width direction. Each outer land portion row () located on an outer side of a different one of the outer main grooves () in the tire width direction has at least one third narrow groove () that is open to the outer main groove () and has a length c in the tire width direction and an angle &#x3b3; to the tire width direction. In the tire, a&#x3c;b, and &#x3b1;&#x3c;&#x3b2;&#x3c;&#x3b3;.

Tread portion of automobile tire

Tread portion of an automobile tire

Both wet weather performance and steering stability performance are achieved. Lateral main grooves () formed in a tread () extend in a direction intersecting with circumferential main grooves () and open onto the circumferential main grooves (). Water between the tread () and a road surface during wet weather running is accordingly discharged through the lateral main grooves () to the circumferential main grooves (). The end portions of the lateral main grooves () opening onto the circumferential main groove () are provided with intersection portionswhere first land portions () and second land portions () adjacent to each other in the tire circumferential direction at a lateral main groove () support each other in the tire width direction. The end portions at the circumferential main groove () side of the first land portions () and the second land portions () do not therefore readily tilt over even when a large slip angle is imparted to the tire.

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Kodaira, Japan

Naotoshi Aoki