Patent ID: 9221302
Filing Date: 2015-12-29
Classification: B60C

Abstract:
1. A pneumatic tire comprising a tread portion provided with a unidirectional tread pattern having an intended tire rotational direction, wherein said tread portion is provided on each side of the tire equator with: a circumferential groove extending continuously in the tire circumferential direction; and a plurality of main oblique grooves each extending from the tread edge to said circumferential groove, while inclining to the intended tire rotational direction and gradually decreasing its inclination angle with respect to the tire circumferential direction so as to form a row of circumferentially arranged shoulder blocks each axially delimited by the circumferential groove and circumferentially delimited by the main oblique grooves, the inclination angle of each said main oblique groove measured at the tread edge is in a range of from 60 to 120 degrees with respect to the tire circumferential direction, the width of each said main oblique groove is gradually increased toward the axially outside from the circumferential groove, the width of the circumferential groove is narrower at heel-side end positions of the shoulder blocks than at toe-side end positions of the shoulder blocks, and said shoulder blocks are provided with auxiliary oblique grooves each extending from one of said main oblique grooves toward the intended tire rotational direction and terminating at a distance of 2 to 7 mm from the next main oblique groove, wherein a central zone defined between the circumferential grooves on both sides of the tire equator is provided with first center oblique grooves and second center oblique grooves which are alternately arranged in the tire circumferential direction, the first center oblique grooves and the second center oblique grooves extend from one of the circumferential grooves to the other, while inclining with respect to the tire axial direction to one circumferential direction and the other circumferential direction alternately, toe-side open ends of the first and second center oblique grooves are respectively positioned on extensions of the widthwise center lines of the main oblique grooves on both sides of the tire equator, and said toe-side open ends are disposed adjacently to respective heel-side open ends of the first and second center oblique grooves, and the central zone is divided into a single row of circumferentially arranged triangular blocks.