Patent ID: 6581662
Filing Date: 2003-06-24
Classification: B60C,Y10T

Abstract:
A pneumatic tire comprisinga carcass extending between bead portions through a tread portion and sidewall portions, a breaker disposed radially outside a crown portion of the carcass and made of cords laid at an angle of from 15 to 40 degrees with respect to the tire equator, a band disposed radially outside of the breaker and comprising a full-width band ply extending over the substantially overall width of the breaker and made of at least one cord forming a small angle with respect to the tire equator, wherein a cord or cords of said full-width band ply existing in a tread crown region satisfy the following conditions Eq.1-Eq.5, T>0.8â€ƒâ€ƒEq.1 0&lE;K+6.67Tâˆ’21.7â€ƒâ€ƒEq.2 0&lE;45âˆ’10Tâˆ’Kâ€ƒâ€ƒEq.3 0&lE;106.8âˆ’57.5Tâˆ’Kâ€ƒâ€ƒEq.4 7&lE;E&lE;13â€ƒâ€ƒEq.5 whereinthe tread crown region is defined as a region centered on the tire equator and having an axial width of either 30 mm or 25% of the axial width of the breaker which is not less than the other, the symbol â€œKâ€  is an stretch-resistance index (N) of a cord which is defined as the product of the sectional area S in sq.mm and 2% modulus M in N/sq.mm of the cord divided by 100, the symbol â€œTâ€  is an stretch in % of the cord in the tire being in its natural state without being mounted on a wheel rim, and the symbol â€œEâ€  is a cord count per 1 cm width of the full-width band ply.