Patent ID: 9205709
Filing Date: 2015-12-08
Classification: B60C

Abstract:
1. A tire comprising: two beads designed to come into contact with a mounting rim, each bead comprising at least one annular reinforcing structure; two sidewalls extending the beads radially outwards, the two sidewalls meeting in a crown comprising a crown reinforcement surmounted by a tread; a single carcass reinforcement, extending from the beads, through the sidewalls to the crown, the carcass reinforcement comprising a plurality of carcass reinforcing elements, the carcass reinforcement being anchored in the two beads by a turn-up around the annular reinforcing structure, so as to form, in each bead, a main portion and a wrapped-around portion, each wrapped-around portion extending radially on the outside as far as an end situated at a radial distance DEC from the radially innermost point of the annular reinforcing structure of the bead, the radial distance DEC being greater than or equal to 5% of the radial height H of the tire and less than or equal to 85% of the radial height H of the tire; wherein each bead comprises a bead filler made of a rubber composition and situated mostly radially on the outside of the annular reinforcing structure and at least partially between the main portion and the wrapped-around portion of the carcass reinforcement, the bead filler extending radially as far as a radially outer end of the bead filler, the radially outer end of the bead filler being situated at a radial distance DEE wherein each bead further comprises an outer strip, made of a rubber composition and situated axially on the outside of the wrapped-around portion of the carcass reinforcement, the outer strip extending between a radially inner end of the outer strip and a radially outer end of the outer strip, the radially inner end of the outer strip being situated at a radial distance DE wherein the rubber compositions which form the bead filler and the outer strip have an elastic modulus G′ of less than or equal to 15 MPa and a viscous modulus G″ such that: the elastic and viscous modules being measured at 23° C. , wherein the bead filler has a thickness E(r), this thickness corresponding to the length of the intersection of the direction perpendicular to the main portion of the carcass reinforcement with the bead filler, r denoting the distance separating the point of intersection of the said direction perpendicular to the main portion of the carcass reinforcement with the carcass reinforcement from the radially innermost point of the annular reinforcing structure, wherein the assembly formed by the bead filler and the outer strip has a thickness ET(r), this thickness corresponding to the length of the intersection of the direction perpendicular to the main portion of the carcass reinforcement with the said assembly, r denoting the distance separating the point of intersection of the said direction perpendicular to the main portion of the carcass reinforcement with the carcass reinforcement from the radially innermost point of the annular reinforcing structure, wherein the thickness ET(r) changes such that, in the range of distances r comprised between 25and 45% of the height H of the tire, the variation in thickness is greater than or equal to 0.25 mm/mm over at least 4% of the height H of the tire, wherein, for all the points of intersection of the said direction perpendicular to the main portion of the carcass reinforcement with the carcass reinforcement of which the distance r from the radially innermost point of the annular reinforcing structure is greater than or equal to 10% and less than or equal to 35% of the radial height H of the tire, the ratio E(r)/ET(r) is greater than or equal to 0.3and less than or equal to 0.5; wherein, in any radial section, the bead filler has a cross section of area S wherein said at least one annular reinforcing structure has a maximum axial width DE such that the ratio where ET(r) max is the maximum value of the thickness ET(r), is less than or equal to 10%.