Patent ID: 6269856
Filing Date: 2001-08-07
Classification: B60C,Y10T

Abstract:
A pneumatic tire comprising:a tread portion,a pair of sidewall portions,a pair of bead portions with a bead core therein,a carcass extending between the bead portions through the tread portion and sidewall portions and turned up around the bead cores in the bead portions from the inside to the outside of the tire to form a pair of turnup portions and a main portion therebetween,in a standard condition in which the tire is mounted on a standard rim and inflated to a standard pressure but loaded with no tire load, the outer surface of the tire provided with a mid-lower sidewall contour and a lower side wall contour,the mid-lower sidewall contour extending radially inwardly from a maximum cross sectional width point of the tire to a point along a circular arc line having a single radius and a center on an axial line passing the maximal cross sectional width point,the lower sidewall contour extending on an inside of an imaginary circular arc line extending from the point along the circular arc line to a radially inner point where the lower sidewall contour contacts the rim,wherein a thickness perpendicular to the carcass ply measured from an outer surface of the tire to the main portion of the carcass gradually increases from the maximum cross sectional width point to the point along the circular arc line,the thickness measured from the outer surface of the tire to the main portion of the carcass is gradually increased from the point along the circular arc line to a point at which a depression of the lower sidewall contour from the circular arc line becomes maximum, anda maximum depression at the point at which the depression of the lower sidewall contour from the circular arc line becomes maximum is in a range of from 0.03 to 0.18 times the radial height of the maximum cross sectional width point, and (T2/T1)/h1 being not less than 0.03 whereinT1 is the thickness perpendicular to the carcass ply at the maximum cross sectional width point,T2 is the thickness perpendicular to the carcass ply at the point along the circular arc line, andh1 is the radial height difference between the maximum cross sectional width and the point along the circular arc line.