| 摘要 |
PURPOSE:To prevent abnormal abrasion at each side groove in the tread of a tire, when a ply stair are unavoidable, by providing many small holes at specific positions in the proximity of said groove. CONSTITUTION:The tread sheath has two zigzag tread central grooves 6 spaced apart by a center rib 5 and zigzag tread side grooves 8 provided at the outsides of said grooves 6 respectively while being separated from their respective grooves 6 by the side ribs 7, and subgrooves 9 extend laterally from the grooves 8 to the shoulders of the tire. Assuming the tire will rotate upwardly on the drawing, plurality of small holes K are provided at kickout sides h in region B on the a left half of the tread and step-in sides t in region A on the A right half thereof, along the subgrooves 9 and the groove walls of tread side grooves 8. Said small holes have a depth of 0.3-1.0 times that of the grooves and spaced from their respective grooves by a distance corresponding to said groove depth or less. |
