Radial carcass tire which can be particularly used without an independent inner tube

Claim 1

A tire without an independent inner tube, having a radial carcass reinforcement, a crown reinforcement formed of at least two plies of cables which are parallel in each ply and crossed from one ply to the next, and two beads each reinforced by at least one bead ring around which the carcass reinforcement is anchored, which can be mounted on a standard rim provided, between the well base and the frustoconical bead seat, with a circumferential hump having radially a cylindrical generatrix, characterized by the fact that, on the one hand, the base of the beads, of an axial width L 2 , has, seen in radial section and from the equatorial plane towards the outside of the tire, a profile comprising a frustoconical zone having an axial width l 24 of between 0.45 L 2 and 0.65 L 2 , the generatrix of which forms with the axis of rotation of the tire an angle β such that the value of the tangent of the angle β is between 0.5 and 0.6; a cylindrical zone having an axial width l 23 of between 0.15 L 2 and 0.25 L 2 and having a diameter D 2 equal to the diameter D 1 of the cylindrical hump of the rim; and a circular arc connecting zone between the cylindrical zone and the vertical wall of the bead; and on the other hand, the reinforcing bead ring, seen in radial section, has an interior diameter D 3 at least equal to the diameter D 1 of the cylindrical hump of the rim but at most equal to 1.004 times said diameter, and a cross section, the circumscribed circle of which has its center located, axially with respect to the vertical wall of the bead, at a distance away L 3 such that the ratio ##EQU3## is at least equal to 0.45, D J , D B , D T being the diameter of the rim, the diameter of the base of the bead and the diameter of the bead ring, respectively, measured in a plane parallel to the equatorial plane of the tire and passing through said center.