The Yokohama Rubber Co., Ltd.

Kenichiro Sugitani

Kenichiro Endo

Hirohisa Hazama

Yukihiko Ohki

Yoshimasa Hashimoto

Tetsuya Kuze

Hiroshi Hata

Masakazu Niwa

Kunihiko Kakigi

Fumito Ishii

Provided is a run flat tire having an enhanced ride comfort in running on general road surfaces and an enhanced driving stability on snowy road surfaces at the time when the tire is not punctured, as well as an enhanced maneuverability, particularly starting ability, on icy road surfaces in run-flat running where the tire is punctured. Three belt layers () are disposed on an outer circumferential side of a carcass layer () in a tread portion (). In addition, as to the three belt layers, the cord angle &#x3b1; of the innermost belt layer () with respect to a circumferential direction of the tire is set at 15&#xb0; to 30&#xb0;, the cord angle &#x3b2; of the intermediate belt layer () with respect to the circumferential direction of the tire is set at not less than 40&#xb0;, and the cord angle &#x3b3; of the outermost belt layer () with respect to the circumferential direction of the tire is set at 35&#xb0; to 70&#xb0;.

Run flat tire

Automobile tire tread

Automobile tire

A pneumatic tire of the type wherein a plurality main grooves extending in a tire circumferential direction are so disposed on a tread surface as to define a plurality of rib lines and a plurality of lug grooves are so disposed in said rib lines as to define a plurality of blocks, characterized in that lug groove angles in each of the rib lines to the tire circumferential direction are changed within a range of a maximum-to-minimum ratio of 1.1 to 1.4 as a repeating unit of a geometric progression, and the lug groove angles in the rib lines positioned on the shoulder side to the tire circumferential direction are set to be greater than the lug groove angles in the rib lines positioned on the center side to the tire circumferential direction.

Pneumatic tire with varying angle lug grooves

Growing community of inventors

Hiratsuka, Japan

Kenichiro Sugitani