The Toyo Rubber Industry Co., Ltd.

Toyo Tire Rubber Co., Ltd.

Katsuji Kishida

Keijiro Oda

Masakazu Onishi

Tetsuto Ueno

Hiroshi Takino

Yusho Fuchikami

Masakazu Oonishi

A tire having superior cut resistance and less belt separation comprising a tread with steel cord belts in which a center rubber for middle part of the tread and a side rubber for both sides thereof are respectively formed of different rubber compositions, and in which at least an inner portion of the center rubber is composed of a rubber composition of superior cut resistance wherein either a natural rubber of a SBR blended natural rubber is compounded with carbon black of large iodine absorption number, silica and silane coupling agent expressed by a formula of (OR).sub.3 SiCnH.sub.2 nSmCnH.sub.2 nSi(OR).sub.3 or (OR).sub.3 SiCnH.sub.2 nX, while the side rubber is composed of a rubber composition having small heat build up.

Tire of superior cut resistance

A pneumatic radial tire having highly durable bead structure is disclosed. One or more carcass ply layers of steel cords are turned up around a bead core from the inside to the outside. A reinforcing strip of steel cords is positioned outwardly adjacent to the turn-ups of carcass plies. A bead filler of approximately triangular sectional shape is disposed at the region enclosed by the carcass plies, the turn-ups of the carcass plies and the reinforcing strip of steel cords. The bead filler comprises high hardness rubber stock and medium hardness rubber stock. A cap of organic textile cord fabric covers an upper end of the reinforcing strip of steel cords. A fin-shaped rubber buffer having a hardness lower than that of the medium hardness rubber stock by 3.degree. to 20.degree. is disposed radially outwardly of the capped end and axially outwardly adjacent to the medium hardness rubber stock. A reinforcing strip of organic textile cords may be further disposed outwardly adjacent to the reinforcing strip of steel cords.

Pneumatic radial tire having durable bead structure

A pneumatic radial tire having highly durable bead structure is disclosed. One or more carcass ply layers of steel cords are turned up around a bead core from the inside to the outside. A reinforcing strip of steel cords is positioned outwardly adjacent to and without extending radially outwardly beyond the turn-ups of carcass plies. A bead filler of approximately triangular sectional shape is disposed at the region enclosed by the carcass plies and the turn-ups of the carcass plies. The bead filler comprises high hardness rubber stock and medium hardness rubber stock. A cap of organic textile cord fabric covers an upper end of the carcass plies. A fin-shaped rubber buffer having a hardness lower than that of the medium hardness rubber stock by 3.degree. to 20.degree. is disposed radially outwardly of the capped end and axially outwardly adjacent to the medium hardness rubber stock. A reinforcing strip of organic textile cords may be further disposed outwardly adjacent to the reinforcing strip of steel cords.

Pneumatic radial tire having highly durable bead structure

A pneumatic radial tire having highly durable bead structure is disclosed. A carcass ply layer of organic textile cords is turned up around a bead core from the inside to the outside. A reinforcing strip of steel cords is positioned outwardly adjacent to the turn-ups of carcass plies. An organic textile cord fabric is disposed outwardly adjacent to the reinforcing strip of steel cords. A bead filler of approximately triangular sectional shape is disposed at the region enclosed by the carcass plies, the turn-ups of the carcass plies and the reinforcing strip of steel cords. The bead filler comprises high hardness rubber stock and medium hardness rubber stock. A cap of organic textile cord fabric covers an upper end of the reinforcing strip of steel cords. A fin-shaped rubber buffer having a hardness lower than that of the medium hardness rubber stock by 3.degree. to 20.degree. is disposed radially outwardly of the capped end and axially outwardly adjacent to the medium hardness rubber stock.

Growing community of inventors

Osaka, Japan

Katsuji Kishida