Patent ID: 6543504
Filing Date: 2003-04-08
Classification: B60C,Y10T

Abstract:
A tire having a radial carcass reinforcement comprising a main part and an upturn, wherein said carcass reinforcement is anchored in each bead to an anchoring bead wire to form said upturn, said anchoring bead wire being surmounted radially by a first profiled member of vulcanized rubber mix and of a substantially triangular shape when viewed in meridian section, the upper edge of said upturn being separated from the main part of said carcass reinforcement by a second profiled member of vulcanized rubber mix, wherein the secant modulus of elasticity in tension M10 of said first profiled member is between 8 and 10 MPa, the secant modulus of elasticity in tension M10 of said second profiled member is between 3 and 5 MPa, a third profiled member of vulcanized rubber mix is arranged axially to the outside of said upturn and the secant modulus of elasticity in tension M10 of which is between 35 and 50 MPa, a fourth profiled member radially surmounting said third profiled member has a secant modulus of elasticity in tension M10 of between 3 and 5 MPa, the radially inner end of said fourth profiled member being radially inward of the end of said upturn, said third profiled member having a thickness e which decreases from a maximum thickness eM at a location radially inward of the end of said upturn towards the outside of said location, such that the thickness of said third profiled member is 10% of the maximum thickness eM at a point that is radially inward of the end of said upturn, and the main part of said carcass reinforcement having a substantially rectilinear meridian profile between its point of tangency T to the anchoring bead wire and a position between 35% and 65% of the radial distance HE defined as the distance between base D of said bead and the point of maximum axial width of said carcass reinforcement.