| 摘要 |
<p>A PNEUMATIC TIRE A pneumatic tire having a ground-engaging, tread portion. The tread portion has at least two circumferentially extending grooves, each groove having a pair of oppositely disposed sidewalls. One groove sidewall having a first portion extending radially outward in a substantially vertical direction from the base of the groove to a first point spaced a distance from the bottom of the groove a distance no greater than about one-half of the groove depth and a second portion extending from the first point radially outward to the tread surface at an inclined angle. The second groove sidewall extending from the base of the groove to the tread surface at an inclined angle. The included angle between the second portion of the first groove sidewall and the second sidewall being at least thirty degrees (30.degree.).</p> |
