US Patent No. 9,387,729

PNEUMATIC TIRE


Patent No. 9,387,729
Issue Date July 12, 2016
Title Pneumatic Tire
Inventorship Naotoshi Aoki, Kodaira (JP)
Yukihiro Kiwaki, Kodaira (JP)
Assignee BRIDGESTONE CORPORATION, Tokyo (JP)

Claim of US Patent No. 9,387,729

1. A pneumatic tire, comprising:
land portions that are provided at a tread between a first circumferential main groove and a second circumferential main groove
and are segmented by the first circumferential main groove extending along a tire circumferential direction, by a circumferential
sipe, and by lateral main grooves that extend in a direction intersecting with the first circumferential main groove and that
open onto the first circumferential main groove and onto the circumferential sipe; and

raised bottom portions that are provided at the tread at end portions of the lateral main grooves where the lateral main grooves
open onto the first circumferential main groove, that are integrally provided continuously between a first of the land portions
and a second of the land portions that are adjacent to each other in the tire circumferential direction at each of the lateral
main grooves, and that are each formed with a top face forming a bottom surface of the lateral main groove and configured
by a sloping face that slopes in a tread depth direction as the top face extends away from the first land portion and the
second land portion, respectively;

wherein:
the circumferential sipe is the only circumferential sipe provided between the first circumferential main groove and the second
circumferential main groove;

the lateral main grooves extend at an angle to a tire width direction;
the first land portion is positioned on an acute angle side of an intersection angle at each of the bottom rising portions
between the first circumferential main groove and the lateral main groove;

the second land portion is positioned on an obtuse angle side of the intersection angle;
the sloping face of the first land portion intersects with the sloping face of the second land portion along the tire circumferential
direction as viewed from the lateral main groove extension direction;

the raised bottom portions overlap with each other along the tire width direction at side walls respectively extending out
from the first land portion and the second land portion;

at the raised bottom portions, the sloping face extending out from the second land portion extends between the first land
portion and the first circumferential main groove; and

a boundary between the first land portion and the second land portion is curved so as to be convex on the second land portion
side.