| 摘要 |
1,213,645. Pneumatic tyres. DUNLOP CO. Ltd. 13 March, 1968 [17 March, 1967], No. 12616/67. Heading B7C. A pneumatic tyre is provided with a tread having generally circumferential ribs 1 and grooves 2, the ratio of the water flow drainage capacity of grooves 2 to the mean axial spacing between adjacent grooves progressively decreasing from the groove nearest the mid-circumferential plane X-X to a groove adjacent a shoulder of the tyre. As shown, the grooves 2 may be zig-zag in form and may be provided with side grooves 3. The pitch P of the zig-zags of each groove may be identical, although the amplitude A of the zig-zags of a groove may progressively increase from groove 2a to groove 2d, as may the lengths of the side grooves 3 associated with each groove 2. The grooves 2 may have bulbous bases, see Fig. 4 (not shown), and their widths may become progressively wider or narrower in a direction from groove 2a to groove 2d. In further embodiments, the pitch and amplitude of the zig-zags may be constant but the grooves 2 may be circumferentially offset from each other; or the pitch may be constant, the amplitude varying, and the grooves 3 may be circumferentially offset from each other, the angles of the side grooves 3 with respect to an axial line progressively increasing from the side grooves associated with groove 2a to those associated with groove 2d see Fig. 3 (not shown). |
