Patent ID: 6866734
Filing Date: 2005-03-15
Classification: B60C,Y10T

Abstract:
1. A tire comprising a pair of substantially annular beads ( 12 ), at least one carcass ply ( 16 ) wrapped around said beads, tread ( 22 ) disposed over said carcass ply in a crown area of said tire, belt reinforcement ( 20 ) interposed between said tread and said carcass ply, and sidewalls ( 18 ) disposed between said tread ( 22 ) and said beads ( 12 ), each of said sidewalls in the tire having a lower sidewall region ( 18 b ), a mid-sidewall region ( 18 c ), and an upper sidewall region ( 18 a ), and a wedge ( 21 ) bridging each of said sidewalls and said tread ( 22 ), said tire ( 10 ) having said lower sidewall region ( 18 b ) which is integrally connected with a bead area ( 12 a ) of said tire and is stiffened with an apex ( 17 ), said lower sidewall ( 18 b ) being connected to said mid-sidewall ( 18 c ) having less stiffness than said lower sidewall, and said upper sidewall ( 18 a ) having a geometry and a low flexural stiffness such that it acts like a flexible coil connected to said mid-sidewall ( 18 c ) and providing a non-coupling bridge between the tread ( 22 ) at the crown of the tire and the mid-sidewall ( 18 c ), characterized in that said belt reinforcement ( 20 ) has a lateral stiffness equivalent to a belt reinforcement having two steel belts wherein each belt has 7.9 to 9.4 ends per centimeter (e.p.c.) steel cord reinforcement having a diameter of 0.042 cm at an angle of 21°, said apex having a length of 25% to 45% of the section height of the tire and a modulus of 4760 to 6160 Npscm, and said wedge ( 21 ) having a modulus of 396 to 594 Npscm bridging said sidewall and tread with a portion contiguous with said belts ( 20 ) comprising 37% to 43% of the tread width.