Bridgestone Tire Company Limited

Toshiyuki Sogi

Shigeo Watanabe

Kenichi Motomura

Mitsuhisa Yahagi

Hidenori Takahashi

Shigeo Makino

Muneyoshi Maeda

Hiroshi Tamura

A pneumatic radial tire having an improved bead portion reinforcing construction is disclosed. The radial tire comprises a bead portion reinforcing band disposed along the bead portion formed by folding the ply of the carcass body around the bead ring. The bead portion reinforcing band comprises at least one chipper layer. The chipper is composed of a reinforcing element embedded in rubber and formed of 1 to 50 helically formed filaments. The reinforcing element has a modulus of elasticity of 0.029.times.10.sup.4 kg/mm.sup.2 to 1.60.times.10.sup.4 kg/mm.sup.2 and is inclined at a given angle with respect to the ply cords of the carcass body so as to make the chipper as a whole extensible and rigid.

Pneumatic radial tire having an improved bead portion reinforcing

A radial tire provided with a tread pattern suitable for travel on paved roads at a high speed is disclosed. The tread pattern is of a block-rib type which is constructed to satisfy the following conditions, i.e.

Pneumatic tires for heavy vehicles

Reinforcing structure at bead sections of radial tires for heavy load comprising

Structure for reinforcing bead sections of radial tires for heavy loads

A reinforced construction of bead portions of radial tires for heavy load vehicles such as trucks, buses etc., which is well balanced in rigidity and which has an excellent durability is disclosed. The construction includes a first reinforcing layer and a second reinforcing layer, the first reinforcing layer being substantially continuously extended from a height covering both the upper ends of the second reinforcing layer and of the turned-up portion of the carcass ply to the inside surface of the carcass ply, the second reinforcing layer being interposed between the turned-up portion of the carcass ply and the first reinforcing layer, the axially inside portion of said first reinforcing layer which is disposed along the inside of the carcass ply having an upper end whose height h.sub.1 from the bead base portion is given by

Reinforced construction of bead portions of radial tires for heavy load

A pneumatic radial tire for heavy load vehicles comprises a carcass and a belt for reinforcement of the carcass, said belt including tension members composed of at least two rubberized metal cords crossing with each other at a cord angle of not more than 25.degree. with respect to equatorial plane of tire, in which said metal cords is coated with a rubber having a modulus of elasticity of 40-80 Kg/cm.sup.2, a distance between the cords in each tension member is widened to 0.2-0.75 d based on a diameter d of the cord, and an interlaminar cord distance D between the tension members is uniformly shortened to 0.2-0.4 d at a central region extending within 50-80% of a superposed width of the tension members.

Pneumatic radial tire for heavy load vehicles

A radial tire having a highly durable bead structure, comprising a carcass ply having a high modulus of elasticity is disclosed. The bead is constructed to satisfy the following conditions, i.e.,

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Higashiyamato, Japan

Toshiyuki Sogi