The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Sep. 01, 1987
Filed:
Dec. 18, 1985
Kiyohito Kawasaki, Akigawa, JP;
Bridgestone Corporation, Tokyo, JP;
Abstract
A radial tire has a combined reinforcement consisting of a belt composed of at least three piled cord layers with steel cords buried in parallel in rubber in which the cords in each of the layers are set at a relatively small angle with respect to a tire equatorial plane and the cords in at least one pair of the adjacent cord layers are intersectingly arranged at an angle from 15.degree. to 30.degree. and a carcass having cords arranged substantially at right angles with respect to the tire equatorial plane. The steel cords buried in the at least one pair of the cord-intersecting cord layers other than the outermost cord layer have Young's modulus of 6,000 to 16,000 kg/mm.sup.2 and a flexural rigidity of 150 to 250 g, and the initial stage elongation (P.L.E.) of the rubberized cords taken out from the tire is not more than 0.2%. A tire reinforcing steel cord of a two layer twisted construction is also disclosed, which cord is composed of a core consisting of from two to four steel filaments and a single sheath consisting of a plurality of the steel filaments surrounding the core in which the steel filaments have a tensile strength of not lower than 260 kg/mm.sup.2 and a filament diameter of from 0.32 to 0.42 mm; the twisting direction of the core is reversed to that of the sheath; the twisting angle of the sheath, P2, is 72.degree..ltoreq.P2.ltoreq.80.degree. and the core twisting angle (P1) and the sheath twisting angle P2 meet the relation of 1.0.ltoreq.P1/P2.ltoreq.1.1.