Pneumatic radial tires
AssigneeBridgestone Tire Company Limited
InventorsYujiro Umezawa, Yoshio Suzuki, Teruo Miura, Kiyohito Kawasaki
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Abstract
A pneumatic radial tire having an improved durable life is disclosed. In the pneumatic radial tire, a metal cord used in the carcass ply is characterized by having a layer construction of 3+9+1 wherein three filaments are twisted together to form a core, nine filaments each having the same diameter as in the filament for the core are twisted around the core to form a second layer and a single filament is wrapped around the second layer, and limiting a twisting angle .alpha. of the second layer to a range of 72.0.degree..ltoreq..alpha..ltoreq.78.0.degree..
Claims7
A pneumatic radial tire containing metal cords as a tire reinforcement comprising;
- a rubberized carcass ply having a metal cord coated with a coating rubber, said metal cord having a layer construction of 3+9+1 with three filaments twisted together to form a core, nine filaments each having the same diameter as in the filament for the core and twisted around the core to form a second layer and a single filament wrapped around the second layer, a twisting angle .alpha. of the second layer limited to a range of 72.0.degree..ltoreq..alpha..ltoreq.78.0.degree., and wherein the surfaces of the filaments forming said core are not covered with said coating rubber.
A pneumatic radial tire containing metal cords as a tire reinforcement comprising a rubberized belt ply having a metal cord coated with a coating rubber, said metal cord having a layer construction of 3+9+1 with three filaments twisted together to form a core, nine filaments each having the same diameter as in the filament for the core and twisted around the core to form a second layer and a single filament wrapped around the second layer, a twisting angle .alpha. of the second layer limited to a range of 72.0.degree..ltoreq..alpha..ltoreq.78.0.degree., and wherein surfaces of the filaments forming said core are not covered with said coating rubber.
Dependencies are inferred from the claim text.