Run-flat tire having an additional sidewall reinforcement

A run-flat tire configured to be mounted on a rim, comprising:

• a crown comprising a crown reinforcement surmounted by a tread;
• two sidewalls extending the crown radially inward;
• two beads radially internal to the sidewalls and each comprising at least one annular reinforcing structure;
• a carcass reinforcement anchored in each of the beads by a portion turned back around the annular reinforcing structure so as to form, in each bead, an incoming portion extending from the crown through the sidewalls toward the bead, and a wrapped-around portion;
• and
• at least one sidewall insert axially internal to the carcass reinforcement, comprising at least one polymeric compound;
• wherein at least one sidewall of the tire further comprises:
• (i) at least one additional sidewall reinforcement comprising at least one layer of reinforcing elements and positioned axially on the inside of the carcass reinforcement, this additional sidewall reinforcement extending radially at least between:
• (a) a radial height H1 of 30 mm, H1 being measured from the radially innermost point of the annular reinforcing structure;
• and
• (b) a radial height H2 equal to 30% of the height H of the tire;
• and
• (ii) a layer of polymeric compound positioned between the additional sidewall reinforcement and the carcass reinforcement, over at least a portion of the additional sidewall reinforcement, the maximum axial thickness EM of the layer being greater than or equal to 3% of the height H of the tire,
• wherein the additional sidewall reinforcement comprises, in any radial section, in the radial region contained between the radial heights H1 and H2, at least one concave portion with the concave side facing axially outward,
• wherein the additional sidewall reinforcement comprises a single layer of threadlike reinforcing elements, the threadlike reinforcing elements being oriented radially.

A run-flat tire configured to be mounted on a rim, comprising:

• a crown comprising a crown reinforcement surmounted by a tread;
• two sidewalls extending the crown radially inward;
• two beads radially internal to the sidewalls and each comprising at least one annular reinforcing structure;
• a carcass reinforcement anchored in each of the beads by a portion turned back around the annular reinforcing structure so as to form, in each bead, an incoming portion extending from the crown through the sidewalls toward the bead, and a wrapped-around portion;
• and
• at least one sidewall insert axially internal to the carcass reinforcement, comprising at least one polymeric compound;
• wherein at least one sidewall of the tire further comprises:
• (i) at least one additional sidewall reinforcement comprising at least one layer of reinforcing elements and positioned axially on the inside of the carcass reinforcement, this additional sidewall reinforcement extending radially at least between:
• (a) a radial height H1 of 30 mm, H1 being measured from the radially innermost point of the annular reinforcing structure;
• and
• (b) a radial height H2 equal to 30% of the height H of the tire;
• and
• (ii) a layer of polymeric compound positioned between the additional sidewall reinforcement and the carcass reinforcement, over at least a portion of the additional sidewall reinforcement, the maximum axial thickness EM of the layer being greater than or equal to 3% of the height H of the tire,
• wherein the additional sidewall reinforcement comprises, in any radial section, in the radial region contained between the radial heights H1 and H2, at least one concave portion with the concave side facing axially outward,
• wherein the additional sidewall reinforcement comprises two layers of threadlike reinforcing elements, the reinforcing elements of each layer being parallel to one another, and the reinforcing elements of one layer extending crosswise with respect to those of the next.