| 摘要 |
An improved radial ply pneumatic tire 30 is described. The improved tire 30 has a first annular surface 23 located between the heel 22B and toe 22A of each bead 33 and a second surface 24 extending radially outwardly from the bead heel 22B. The first surface 23 is designed to be in contact with the bead seat 42 of the design rim 40 when the tire 30 is mounted and inflated to normal pressure. The first annular surface 23, when the tire 30 is unmounted, forms an average angle beta with the axis of the tire, when the beads 33 are axially spaced a distance D equal to the design rim width as defined herein. The average angle beta is in the range of at least one-half degree and less than three degrees greater than the angle formed between the mating bead seat 42 of the design rim 40 and the axis of the tire. The second surface 24 is designed to be in contact with an annular flange 44 portion of the design rim 40 when the tire is mounted and inflated to normal pressure. The second surface 24 is perpendicular to the axis of rotation. Preferably the angle beta is in the range of 1 DEG to 2 DEG greater than the rim seat angle, more preferably the angle beta is 1.5 DEG greater. The angular relationships relative to the design rim flange 44 permit the bead 33 to exhibit uniform compression upon mounting to the design rim 40, thereby improving the stiffness and handling characteristics of the tire 30. <IMAGE> |
