| 摘要 |
1491197 Pneumatic tyres DUNLOP Ltd 28 Oct 1974 [7 Nov 1973] 51754/73 Heading B7C A pneumatic tyre having an aspect ratio in the range 50 to 75% comprises a tread 1 having a substantially flat ground engaging surface, a carcass consisting of a single ply of radially disposed textile cords, e.g. made of an aromatic polyamide fibre or a rayon fibre and the sidewalls each having a minimum thickness of at least 5% of the maximum tyre section, and the tread having a width less than the section width but at least 20% greater than the distance between the heels of the beads, when the tyre is mounted on a wheel rim, and is inflated to its design pressure. In the tyre of Fig. 1 the carcass ply cords 4 are of an aromatic polyamide fibre (fibre B) the sidewall rubbers 6 have a resilience of 90% (Dunlop pendulum method at 50‹ C.) and hardness of 55 Shore A, and the liner 7 has a resilience of 87% and a hardness of 55 Shore A. In the tyre of Fig. 2, the carcass ply cords 9 are of fibre B, the rubber compound 12 has a hardness of 80 Shore A and a resilience of 66%, the sidewall rubbers 13 and liner 14 have a hardness of 52 Shore A and a resilience of 90%, and the liner, at the point of maximum tyre section width, has a thickness of at least 30% of the sidewall thickness at that point. |
