Luftreifen mit einem Gürtel: Stahl-Aramide

摘要

The mass of a tire (10) can be reduced by the use of a belt package (12) having a combination of a steel reinforced inner (first) belt ply (14) and an aromatic polyamide reinforced outer (second) belt ply (16). The belt plies are to be made without the cost of having folded belts or any other non-standard construction features. The improved endurance of the tire (10) of this invention is assured by the physical features of the individual belt plies as well as required physical relationships between belt plies. The breaking strength t, the spacing P and the angle A with respect to the tire's mid-plane M for the reinforcing members in each belt ply are defined. In particular, the strength T2 per unit width of the aromatic polyamide reinforced second belt ply (16) is made to be within zero to 30 percent greater than the strength T1 per unit width of the steel reinforced first belt ply (14) to improve tire endurance. The tire (10) of this invention uses angles A2 of the aromatic polyamide reinforcing members (17) from the mid-plane M greater than the angles A1 of the steel reinforcing members (15) from the same mid-plane M, preferably by 1 to 8 degrees.