Patent ID: 6354351
Filing Date: 2002-03-12
Classification: B60C,Y10T

Abstract:
A heavy duty pneumatic radial tire comprising a carcass of one or more rubberized cord plies extending between a pair of bead cores each embedded in a bead portion and containing cords arranged along a plane inclusive of a rotating axial center of the tire, at least one of which plies being wound around the bead core from inside of the tire toward outside thereof to form a turnup portion, and a bead portion reinforcing layer comprised of a single rubberized steel cord layer covering a surface of the carcass ply over a region ranging from an outer position of the turnup portion in a radial direction of the tire along an outer surface of the turnup portion through the bead core up to an inside of the tire, in which an inclination angle of steel cord in the bead portion reinforcing layer with respect to a circumferential line of the tire is within a range of 22-35Â° in outermost end portions outside and inside the tire in the radial direction and an inclination angle of steel cord outside and inside of the tire in the vicinity of a straight line passing through a graphic center of gravity in the bead core at a section thereof and in parallel to the rotating axis of the tire is within a range of 5-50Â° added to the inclination angle range of the above outermost end portion.