Patent ID: 7726369

Claim:
A pneumatic tire comprising a tread portion provided with at least two circumferential grooves and lateral grooves extending from the circumferential grooves so as to form blocks which are circumferentially divided by the lateral grooves and arranged in at least three circumferential rows axially divided by said at least two circumferential grooves, each said lateral groove provided with a tie-bar rising from the groove bottom to a certain height within the depth of the lateral groove so as to connect the opposite groove walls with each other, wherein said tie-bar extends along the lateral groove towards the adjacent circumferential grooves or groove but terminates before said circumferential grooves or groove so as to provide certain distances (D 1 , D 2 , D 3 , D 4 , D 5 ) therebetween, and an axial central part of the lateral groove has an inclination angle (α, α1, α2, β) with respect to the tire axial direction, wherein the distances (D 1 , D 2 , D 3 , D 4 , D 5 ) are gradually decreased from the axially outside to the axially inside of the tread portion, and the inclination angles (α, α1, α2, β) are gradually decreased from the axially outside to the axially inside of the tread portion, wherein said at least three circumferential rows are four or five or six circumferential rows, and in the case of the four circumferential rows, said certain distances are three different distances D 1 , D 2 , and D 3 in the order from the axially inside to the outside of the tire, and D 1 <D 2 <D 3 , and the inclination angles are two different angles α and β in the order from the axially inside to the outside of the tire, and 0 degrees≦α<β<45 degrees, in the case of the five circumferential rows, said certain distances are four different distances D 1 , D 2 , D 3 and D 4 in the order from the axially inside to the outside of the tire, and D 1 <D 2 <D 3 <D 4 , and the inclination angles are three different angles α1, α2 and β in the order from the axially inside to the outside of the tire, and 0 degrees≦α1≦α2<β<45 degrees, in the case of the six circumferential rows, said certain distances are five different distances D 1 , D 2 , D 3 , D 4 and D 5 in the order from the axially inside to the outside of the tire, and D 1 <D 2 <D 3 <D 4 <D 5 , and the inclination angles are three different angles α1, α2 and β in the order from the axially inside to the outside of the tire, and 0 degrees≦α1≦α2<β<45 degrees.