Patent ID: 6508285
Filing Date: 2003-01-21
Classification: B60C,Y10T

Abstract:
A pneumatic tire comprising a carcass having a carcass body portion extending from a tread portion to a bead core through a side wall portion, and a folded portion folded at the bead core, which is continuously formed with the carcass body portion, wherein:in a standard state that the tire is installed on a normal rim and the inner pressure of the tire is the normal, the contour of the tire outer surface in the meridian cross section between a tire cross section maximum width point P1, which is the most outer point of the tire surface in the tire axis direction, and a flange separating point P3 to leave from a flange of the rim, is defined as follows: the contour includes a substantially triangular formed projecting portion projecting outside in the direction of the tire axis direction with respect to a norm arc, which is an arc having its center on a line passing the tire cross section maximum width point P1, the norm arc passes through the point P1 and tangentially contacts with the flange, and a recessing portion recessing in the tire axis direction toward inside with respect to the norm arc, the recessing portion extends toward the inner side in the radial direction continuously with the projecting portion; the height (h1) of a maximum projecting point with respect to a bead base line is 0.85Ëœ1.15 times of the height (h0) of the outer end of the folded portion, where the maximum projecting point is a point on the projecting portion and is separating at most from the norm arc in the tire axis direction; the height (h2) of the maximum recessing point with respect to a bead base line is smaller than the height (h1), and is 0.30Ëœ0.90 times of the height (h0), where the maximum recessing point is a point on the recessing portion and is separating at most from the norm arc in the tire direction; and the maximum boss distance (q1) from the norm arc to the maximum projecting point and the maximum recess distance (q2) from the norm arc to the maximum recessing point are respectively 0.001Ëœ0.040 times of the tire cross section width (W), wherein the tire is formed so that the outer contour between the maximum projecting point and the maximum recessing point is a straight line having an inclination parallel to that of the folded portion, in the state that the tire is installed on a normal rim and the inner pressure of the tire is 50 kPa.