| 摘要 |
<p>Tire comprising two beads comprising an annular reinforcing structure, a carcass reinforcement anchored in the two beads so as to form a main portion and a wrapped-around portion, each wrapped-around portion extending radially outwards as far as an end situated at a radial distance DEC that is less than or equal to 10% of the radial height H of the tire; each bead comprising an apex made of a rubber composition having an elastic modulus greater than 40 MPa, extending radially as far as a radial distance DEE1 comprised between 10% and 15% of the height H; each bead further comprising an outer strip made of a rubber composition that has an elastic modulus G' less than or equal to 15 MPa and a viscous modulus G'' such that: G''[MPa]@0.2·G'[MPa]-0.2 MPa, extending at least between 20% and 25% of the height H, the apex having an axial thickness E(r) that is substantially a linear function of r, r denoting the distance with respect to the radially innermost point of the annular structure, wherein the entity formed by the apex and outer strip has a thickness ET(r) such that, in the range of distances r comprised between 25 and 45% of the height H of the tire, the variation in thickness∂ET ( r )∂r is negative and has an absolute value that is greater than or equal to 0.25 mm/mm over at least 4% of the height H; and wherein said annular structure has a maximum axial width DE such that the ratio ET ( r ) max - DE ET ( r ) max , where ET(r)max is the maximum value of the thickness ET(r), is less than 10%.</p> |
