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:
Apr. 20, 1993
Filed:
Jul. 08, 1991
Hiroyuki Iida, Kodaira, JP;
Hiroyuki Koseki, Kodaira, JP;
Bridgestone Corporation, Tokyo, JP;
Abstract
A pneumatic radial tire with high durable bead portions includes a pair of bead portions, a pair of sidewalls and a tread extending between the sidewalls, and further includes as a body reinforcement a carcass extending between the bead portions and consisting of plies whose cords are radially arranged. At least one ply being turned up about bead cores of the bead portions from inside to outside of the tire to form a turn-up portions. A carcass pass line in radial section of the tire in its self-holding position filled with 5% of a normal inner pressure under no-load condition includes curvature changing areas in a carcass profile curved toward the turned-up portions in the proximities of positions corresponding to a height of turn-up ends of the ply from a rim diameter line to cause compressive stresses in the bead portions near to the turn-up ends of the ply by deformations of the carcass when the normal inner pressure is filled in the tire. With the above arrangement, the durability at the bead portions of the tire is improved to an extent required for prolongation of life time obtained by recapping the tire repeatedly.