| 摘要 |
763,816. Pneumatic tyres. UNITED STATES RUBBER CO. Jan. 28, 1955 [March 10, 1954], No. 2616/55. Class 144 (2). To eliminate or reduce tyre squeal and slap, a pneumatic tyre tread T is formed with a crown radius H of at least 145 per cent of the tyre section G and comprises at least five circumferential, functionally continuous ribs 13- 19 separated by circumferential straight, zigzag, or sinuous grooves 10, the tread rubber decreasing in thickness from the shoulders to the tread centre line, the outermost ribs 13, 19 each having a mean width less than that of each of the ribs 14, 18 next adjacent thereto and the remaining ribs 15, 16, 17 each having a mean width greater than that of each of the ribs 14, 18. As shown, the tread comprises seven ribs, with the centre rib 16 formed wider than the adjacent central ribs 15, 17. With this arrangement the widths of the ribs are dimensioned so that the cross-sectional areas of the tread portions defined by the tread surface, the carcase periphery or rubber line L, and the radial lines R-1, R-2 from the crown centre through the laterally outer edges of ribs 13, 19, and the centre of the grooves 10 respectively are substantially equal. Such an arrangement may be applied to a tread having any number of ribs from five upwards.
|
