Patent ID: 6138733
Filing Date: 2000-10-31
Classification: B60C,Y10T

Abstract:
A pneumatic radial tire for large-size vehicle comprising;a cylindrical crown portion,a pair of sidewall portions extending inward from both ends of the crown portion in a radial direction,a pair of bead portions extending inward from the sidewall portion,a radial carcass extending between the bead portions through the crown portion,a first protection rubber layer having a 100% modulus in the range of 25-40 kgf/cm.sup.2 disposed in a region ranging from a vicinity of a bead heel to a rim line along an outer surface of the tire when the tire is mounted onto a standard rim and inflated under an internal pressure,a second protection rubber layer having a 100% modulus in the range of 30-50 kgf/cm.sup.2 and higher than that of the first protection rubber layer and disposed in a region ranging from an inside of the first protection rubber layer in a widthwise direction of the tire to a bead base,an inner end of the first protection rubber layer in the radial direction of the tire being located between an outer end of a curved face of the bead heel in the radial direction and an end of a curved face of a rim flange,an outer end of the second protection rubber layer in the radial direction of the tire being located at such a position outward in the radial direction of the tire that an inclination angle defined between a line segment L connecting this end to a curvature center of the curved face of the rim flange and a phantom line BL passing through the curvature center and in parallel to a rotating axis of the tire is not less than 20.degree., andwherein the first protection rubber layer is arranged at the outside of the second protection rubber layer in a widthwise direction of the tire between the line segment L and the phantom line BL and extends to at least phantom line BL.