| 摘要 |
1,253,216. Pneumatic tyres. B. F. GOODRICH CO. 13 Dec., 1968 [15 Dec., 1967], No. 59473/68. Heading B7C. An uncured pneumatic tyre blank comprises radial carcase cords 14, beads 11, and two pairs of tread reinforcing layers 16 and 17 of stretchable cords 15 disposed in generally parallel relationship in each layer, with the cords in adjacent layers making equal but opposite angles with circumferential direction of the drum, the said angle being in the range 0-30 degrees, the cords 15 each comprising a core 15a of cured elastomer with at least one inextensible textile yarn 15b wrapped helically therearound to permit stretching of the cords 15 a predetermined amount to straighten the coiled yarns and thus enable the subsequent expansion of the blank to take place. The diameters of the core 15a and yarn 15b are equal and do not exceed 0À050 inch. The layers 16 may extend into the sidewalls of the tyre. |
