| 摘要 |
<p>A tread pattern for radial tyres for heavy vehicles is asymmetric with circumferential channels on the outboard half of the tyre being much narrower than those on the inboard half of the tyre, as mounted in the vehicle for use. The narrow channels each have a width of 0.5-2% of the overall tread width, the wider channels each occupy 4-8% of the tread width. In an example, the respective widths of four circumference grooves across a tyre tread relative to the overall tread width were 7.5%, 6%, 1.5% and 1%, the latter pairs being in the outer half of the tread: after 50 000 km the residual tread depth for the inner and outer grooves respectively were 8.2 and 7.9 mm, compared with 8.3, and 4.2 mm having four channels each corresp. in width to 7.5% of the tread width. The narrow channels leave extra surface rubber to withstand the additional wear caused on the outer half of the steerage wheels on a heavy vehicle, so that the tyre wears down evenly across the face of the tread.</p> |
