Bridgestone Corporation

Akio Kusano

Masato Hiruma

Toshiyuki Watanabe

Takayuki Fukunaga

Hiroshi Mouri

Hidetoshi Yokota

Yoshiyuki Waki

Seiji Ishikawa

Gen Suzuki

Taiga Ishihara

Kento Hirohata

Yasuyo Fujita

Tread portion of an automobile tire

A pneumatic tire in which a cavity resonance sound is reduced while punctures are easily repaired with a puncture sealant. The pneumatic tire has a fibrous region where short fibers are bonded onto an inner surface of the tire. A circumferential fiberless region where short fibers are not bonded onto the inner surface of the tire extends circumferentially between both ends of a tread ground contact area.

Pneumatic tire

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

There is provided a vulcanization mold for a pneumatic tire having a lug type or rib-lug type tread pattern, wherein a portion of the mold contributing to the formation of the tread pattern is comprised of many segments of n types (n&equals;2 to 4), and these segments are combined so as to have at least (n&plus;1) types of pitches each defined by an interval between mutual adjoining protrusions located on the same circumference and a difference between mutual pitches of not less than 0.5 as an index when a maximum value of the pitch is 10.

Vulcanization mold for tires

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

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Kodaira, Japan

Akio Kusano