Bridgestone Corporation

Shinji Usui

Naoto Yamagishi

Yasutoshi Aoki

Takashi Kukimoto

An uneven wear-resisting heavy duty pneumatic tire comprises main grooves continuously extending in a tread of the tire along a circumference thereof, land portions separated by the main grooves, and stepped zones each provided in the land. Each stepped zone has a surface located radially inside of the tread by a step a viewed sectionally. Each of said stepped zones is separated from the adajcent land portions via a pair of circumferentially extending grooves or narrow cuts. An uneven wearing-sacrificing portion is formed by the surface of the stepped zone. The uneven wear-sacrificed portion slide-contacts with the tread within the tread ground-contacting area for supporting the load exerted upon the tire.

Heavy duty pneumatic tires preventing uneven wearing

A pneumatic tire comprising a tread, wherein at least one circumferential groove having a width not greater than 0.1 times as much as that of the tread is formed in at least one end portion of the tread, thereby forming at least one narrow rib having a width not more than 0.2 times as much as that of the tread, and at least one of the above at least one narrow rib is projected radially outwardly from an extension line of a contour line of the tread by 0.3 times of a gauge of the tread at the maximum.

Pneumatic tires

An uneven wear-resisting heavy duty pneumatic tire comprises main grooves continuously extending in a tread of the tire along a circumference thereof, land portions separated by the main grooves, and stepped zones each provided in the land. Each stepped zone has a surface located radially inside of the tread by a step a viewed sectionally. Each of said stepped zones is separated from the adjacent land portions via a pair of circumferentially extending grooves or narrow cuts. An uneven wearing-sacrificing portion is formed by the surface of the stepped zone. The unever wear-sacrificed portion slide-contacts with the tread within the tread ground-contacting area for supporting the load exerted upon the tire.

Growing community of inventors

Tokyo, Japan

Shinji Usui