Patent ID: 7604030

Claim:
A pneumatic tire ( 10 a ) including in a tread at least two circumferential major grooves ( 21 a , 22 a ) extending in a tire circumferential direction and a rib-shaped land section continuously extended in the tire circumferential direction via a sipe ( 40 a ) that extends in a tire width direction, the pneumatic tire comprising: lug grooves ( 30 a , 31 a , 30 a ) extending in the tire width direction, each of which includes an end closed by the rib-shaped land section and the other end open to one of the at least two circumferential major grooves ( 21 a , 22 a ), the open ends being arranged in the staggered fashion in the tire circumferential direction; and first sipes ( 40 a , 41 a ) which include the sipe ( 40 a ) extending in the tire width direction and another sipe ( 41 a ) extending in the tire circumferential direction, and connect the lug grooves ( 30 a , 31 a , 30 a ) arranged in the staggered fashion; wherein a block is defined by the one of the at least two circumferential major grooves ( 21 a , 22 a ), the lug grooves ( 30 a , 31 a , 32 a ), and the first sipes ( 40 a , 41 a ), the block includes two second sipes ( 50 a , 51 a ), the two second sipes ( 50 a , 51 a ) are extended in the tire width direction, one end thereof respectively open to one of the at least two circumferential major grooves ( 21 a , 22 a ), and the other end thereof respectively open to the first sipes ( 40 a , 41 a ), the second sipes ( 50 a , 51 a ) divide the block into two wide sections being wide in the tire circumferential direction and a narrow section being narrower than the two wide sections in the tire circumferential direction, the narrow section is arranged between the two wide sections, the lug grooves ( 30 a , 31 a , 30 a ) include a first lug groove ( 30 a ), a second lug groove ( 31 a ) and a third lug groove ( 32 a ), and the sipe ( 40 a ) extending in the tire width direction connects the first lug groove ( 30 a ) and the second lug groove ( 31 a ) arranged in the staggered fashion, and the other sipe ( 41 a ) extending in the tire circumferential direction connects the second lug groove ( 31 a ) and the third lug groove ( 32 a ) arranged in the staggered fashion.