| 摘要 |
950,224. Pneumatic tyres. E. I. DU PONT DE NEMOURS & CO. July 27, 1961 [Aug. 8, 1960], No. 27290/61. Heading B7C. A low profile pneumatic tyre comprises at least two bead to bead carcase plies 16a, 16b of parallel nylon cords disposed at angles of not less than 75 degrees to the circumferential, and a tread reinforcement of at least four plies 18b-18e of parallel nylon cords, each having a cord angle of less than 40 degrees to the circumferential, the nylon cords in the carcase and tread reinforcement plies each having at least a 19.5% elongation at break. As shown, two additional nylon cord plies 18a, 18b, each having a cord angle of not more than 40 degrees sandwich the plies 18b-18e which each have a cord angle of less than 20 degrees. The low profile tyre is moulded to provide an internal height to width ratio of between 0.5 and 0.75. In specific examples the nylon cords of the tread reinforcing plies 18a-18f may comprise two lengths of 840 denier yarn each Z-twisted to 13 turns per inch, the two lengths being S-twisted together and the cords sheeted to 32 cords to the inch. Alternatively, cords of 840 denier/3/2 construction with yarn and cable twists of 7 turns per inch may be sheeted into plies of 20 ends per inch. The reinforcement plies are rubberized with natural or synthetic rubber stock having a 200% elongation modulus of 1000 or 1200 p.s.i. |
