| 摘要 |
1477210 Pneumatic tyres MICHELIN & CIE (COMPAGNIE GENERALE DES ETABS MICHELIN) 11 June 1974 [12 June 1973] 25912/74 Heading B7C A pneumatic tyre comprises at least one parallel cord carcass ply, the cords of which form an angle of 70 to 90 degrees with the circumferential direction in the sidewalls and in the crown a smaller angle with the circumferential direction, and three superposed oblique parallel cord breaker plies making respective angles with the circumferential direction, wherein the direction of the cords of the breaker ply next adjacent the carcass differs by at most approximately 30 degrees from the perpendicular to one diagonal of a parallelogram with sides parallel to the cords of the other two breaker plies, the other diagonal being parallel to the circumferential direction. As illustrated in Fig. 3, angles α, #, γ are + 23, - 16, and + 31 degrees respectively. The embodiment of Figs. 4 and 5 comprises a rayon cord carcass ply 1, and a breaker consisting of a rayon cord ply 53, a polyvinyl alcohol cord ply 4, and a steel cord ply 5. Initially the plies are wound in a cylindrical drum with cord angles #=80 degrees (the carcass ply has same cord angle over its whole width prior to shaping), α= +38, #= -31, γ= + 73 degrees. After shaping (with the tyre diameter being 1À5 times the diameter of the cylindrical blank) the cord angles were #= -55¢, α= +23, # = - 16, and γ= +31 degrees. Rubber strips 55 are positioned beneath folded edges 54. |
