PURPOSE: To minimize the reduction of recovering torque due to high-internal-pressurization of a tire and as well to prevent the drive feeling from deteriorating due to vibration accompanied with high-internal-pressurization of the tire, by specifying the tread width of a tire, and as well by appropriately changing the radiation surface profile of the carcass.
CONSTITUTION: Denoting, as B, the crossing point at which a line, in parallel with the tire rotating axis, passing through a departing point A with respect to the outer surface of the flange 9 bead part of a rim 8 intersects the carcass line, and, as C, the terminal point of a line perpendicularly extending from the crossing point B to the carcass line, a ratio R/R' between the radius R' of an imaginary reference circle having a line BC as its chord and the radius R of curvature of a shoulder section contour curve passing through the terminal point C of the carcass line is set at a value of 0.65 to 0.85. Further, the maximum distance (f) of the remaining part of the carcass line having an inflection point between the point at which the carcass line is contiguous with the above- mentioned curve and the crossing point B from the reference circle arc, is set at a value of 5 to 10mm. Further, the width of the tread section is set at a value of 55 to 62% of the width of the tire, thereby the tire is used with an internal pressure higher than the normal internal pressure by 25 to 50%.
TSUDA TOORU
KATOU KENSHIROU
FURUYA SHINICHI
Next Patent: PNEUMATIC TIRE