Patent ID: 7032635

Claim:
A pneumatic tire for use on iced and snowed road surfaces having a tread surface, the tread surface comprising: a plurality of main grooves extending in a circumferential direction of the tire and a plurality of lateral grooves extending in a width direction of the tire, blocks being defined by said main grooves and said lateral grooves, the blocks having a ground contact face which has a plurality of pairs of sipes comprising a left sipe and a right sipe extending in the tire width direction, the plurality of pairs of sipes being placed in a predetermined interval in the tire circumferential direction, each of the left and right sipes of each pair extending from a width-directional center portion of said ground contact face of the block toward each way of the tire width direction so as to open its outer end to each side face of the block, wherein said plurality of main grooves comprise five main grooves, six rows of blocks being defined by the five main grooves, the tread surface having a center portion and two shoulder portions, the center portion having four rows of blocks, each of the shoulder portions having one row of blocks, the ground contact face of each block in two inner rows of blocks of said four rows of blocks in the center portion having the plurality of pairs of left and right sipes, the left and right sipes of each pair having an inner end portion which extends beyond a centerline in said width-directional center portion of the block, the ground contact face of each block in two outer rows of blocks of said four rows of blocks in the center portion having the plurality of pairs of left and right sipes, the left and right sipes of each pair having an inner end which is located on said centerline, the ground contact face of each block in each of the two rows of blocks in the shoulder portions having the plurality of pairs of left and right sipes, the left and right sipes of each pair having an inner end portion which is spaced apart from said centerline.