Bridgestone Corporation

Bridgestone Metalpha Corporation

Bridgestone Tire Company Limited

Motonori Bundo

Kazuma Morotomi

Naohiko Obana

Kazuto Fujita

Shuichi Onuma

Hideo Hara

Yoshihiro Makino

Itsuo Miyake

Keizo Okamoto

Akihiro Noda

A steel cord for the reinforcement of rubber articles exhibits largely different bending rigidities in two crossing directions at section of the cord and comprises a bundle of plural strands each being obtained by twisting 3 or more steel filaments and a wrapping filament helically wound around the bundle. The steel filaments have a twisting pitch in the range of 3.0 to 30.0 mm. A single wrapping filament is helically wound around the bundle at a twisting pitch of 2.0-15 mm. Various cord structures may be used, for example, 1.times.3, 1.times.5, 2+6 and 3.times.4.

Steel cords for the reinforcement of rubber articles having a wrapping

A steel cord for the reinforcement of rubber articles exhibits largely different bending rigidities in two crossing directions at section of the cord and comprises a bundle of plural strands each being obtained by twisting 3 or more steel filaments and a wrapping filament helically wound around the bundle.

Steel cords for the reinforcement of rubber articles and having a

A steel cord of 1+3 structure is formed by twisting three sheath steel filaments around a single core steel filament. In this case, the three sheath steel filaments are arranged so as to satisfy conditions at a section of the sheath perpendicular to a longitudinal direction of the cord that a maximum angle of a triangle formed by connecting central points of the these filaments to each other is not less than 90.degree. but less than 180.degree. and an apex defining the maximum angle is always located on the same filament and a distance between the central point of this filament and the central point of the filament adjacent thereto is 1.0-1.3 times of the diameter of the filament.

Steel cords for elastomer articles and pneumatic radial tires using the

A metal cord usable for the reinforcement of rubber articles is comprised of a helically formed single wire filament having a twisting angle of 75-84.5.degree. or a bundle of two twisted metal filaments each having a twisting angle of 75-84.5.degree.. Such metal cords are preferably used as a rubber reinforcement in each part of a pneumatic tire.

Metal cords for rubber reinforcement and tires using the same

A pneumatic radial tire for passenger car having an improved riding comfort against vibration without substantially degrading the cornering stability is disclosed, which comprises a bead filler disposed between the carcass and its turnup, at least a part of which has a complex modulus of elasticity of 1.times.10.sup.8 .about.8.times.10.sup.8 dyn/cm.sup.2 and a sin .delta. of not less than 0.28 under a strain energy of 10.sup.4 dyn/cm.sup.2.

Pneumatic radial tires for passenger cars

A rubber composition comprising rubber, novolak-type phenolic resin and carbon black is very rigid and is adapted to be used as a bead filler rubber of a tire. Tires using the rubber composition are excellent in the high speed performance, lateral rigidity, ride feeling and durability.

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