Pneumatic radial tires for small-size passenger cars

摘要

In a bead portion of a pneumatic radial tire for a small-size passenger car having substantially the same structure as in a conventional tire, a bead core to be used is a monostrand bead core having a particular sectional shape obtained by spiral winding of a rubberized steel wire having a diameter of 1.2 - 2.2 mm, in which the ratio of the distance (H) between centre points of adjoining steel wires in the bead core to the diameter (D) of the steel wire is in the range of 1.01 - 1.2 and the length overlapping from the winding start point of the steel wire to the winding terminal point thereof is given by the equation: $\mathop{\mathrm{image}}$