| 摘要 |
<p>625,925. Pneumatic tyres. FIRESTONE TIRE & RUBBER CO. Nov. 27, 1946, No. 35159. Convention date, July 10, 1941. [Class 144 (ii)] Tyre treads, particularly for use on tractor wheels, comprise two series of circumferentiallyspaced ribs 14, 15, Fig. 5 ; 14a, 15a, Fig. 6, overlapping-and staggered with respect to-the centre-line of the tread, the ribs being of similar curvature and diverging from the tread apex. The ribs taper radially outwards and, as shown in Fig. 5, the angle A of the centre-line zig-zag formation is less than 45 degrees. The height of the ribs at the centre-line is at least as great as their width which is uniform down to the flared ends at the shoulder-portions of the tyre. In the form shown in Fig. 6, the main ribs are braced by intermediate shorter ribs.</p> |
