Bridgestone Corporation

Masato Hiruma

Toshio Hayakawa

Akio Kusano

Yasuo Himuro

Hiroshi Mouri

Toru Tsuda

Masahiro Takayama

Gen Suzuki

Yasuyo Fujita

A pneumatic tire comprising a tread portion which comprises a surface rubber layer which is disposed in an outer portion of the tread portion in the radial direction of said tire and has a specific resistance of 10 &OHgr;&middot;cm or more after curing by vulcanization and conductive rubber members which comprise a rubber composition having a specific resistance of 10 &OHgr;&middot;cm or less and replace a portion of the surface rubber layer, wherein the conductive rubber members are disposed in portions of the surface rubber layer extending from the outer surface to the inner surface in the radial direction of said tire discontinuously in the circumferential direction of said tire at the outer surface of the surface rubber layer in the radial direction of said tire, is provided. The pneumatic tire shows not only an excellent effect of static discharge but also excellent durability.

Pneumatic tire and method of making tire

A pneumatic tire comprising a silica-rich compound tread provided with an antistatic conductive rubber layer has improved safty based on durability and extrusion productivity. In this tire, the silica-rich compound rubber layer is divided at at least one portion in a width directional of the tire by a conductive rubber layer extended in a circumferential direction substantially over the whole thickness of said rubber layer. In this case, a thickness direction distance a in a width directional section of said rubber layer and an edge face length b of a divisional rubber layer consisting of said conductive rubber layer in a width directional section satisfy a relation formulated by the following expression, a<b.

Pneumatic tire and method of manufacturing the same

Automobile tire

A pneumatic radial tire for high-speed running vehicles has a directional tread pattern defined by one or two relatively wide circumferential grooves arranged in the central region and plural slant grooves arranged in each side region of the tread, and an aspect ratio of not more than 0.8. In this tire, the slant grooves are arranged in a herringbone form with respect to the equator without communicating with the circumferential groove, each of which extending from an initial end to a terminal end and being a folded line at a folding point corresponding to 0.3-0.45 times of the tread width that an inclination angle .alpha. of line segment inward from the folding point is 40.degree.-85.degree. with respect to the meridian of the tire and an inclination angle .beta. of line segment outward from the folding point is smaller than the inclination angle .alpha. and 0.degree.-50.degree. with respect to the meridian of the tire.

Pneumatic radial tire tread for high-speed running vehicles

Growing community of inventors

Tokyo, Japan

Masato Hiruma