Internal support to resist the flattening of a tire

A support arranged within the inflatable cavity of a tire comprising a crown having a tread extended on each side by a sidewall terminating in a bead mounted on a corresponding seat of a wheel rim for a vehicle, which support, when the tire is mounted and inflated to its normal pressure, comprises, on the one hand, an elastically deformable annular element for the radial support of the crown of the tire, the radially outward periphery of which radial support element extends axially at least between the equatorial plane of the tire and that sidewall of the tire arranged toward the outside of the vehicle over a width less than that of the inflatable cavity at the height of the radially outward periphery of the radial support element, and, on the other hand, an elastically deformable annular element for the axial holding of the sidewall at least between the radial support element and that sidewall of the tire arranged toward the outside of the vehicle, which axial holding element is connected to the radial support element and the radially outward periphery of which axial holding element has a developed length in the circumferential direction greater than the developed length in the circumferential direction of the radially outward periphery of the radial support element but less than the developed length in the circumferential direction of the radially facing portion of the inside of the tire, characterized by the fact that:

• the support comprises a device for fastening the radial support element to the wheel rim,
• the radial support element, which contacts the inside of the crown of the tire only when deflated or uninflated, has a radially inward lateral extension near the bead of that sidewall arranged toward the outside of the vehicle,
• the axial holding element, which contacts the inside of the axially outer sidewall of the tire only when deflated or uninflated to provide transverse stiffness of the deflated or uninflated tire, is formed essentially of a flexible ring and of a terminal annular protuberance radially outward of the ring and integral with it, the ring being provided at its radially inner end with a connection to the lateral extension of the radial support element, and the terminal annular protuberance being staggered axially toward the corresponding sidewall of the tire with respect to the connection of the ring to the lateral extension of the radial support element so that its axially outer surface is at a distance from the equatorial plane of the tire greater than the half-width of the rim but less than the maximum axial half-width of the inside of the tire.