TIRE TREAD WITH SEVERAL WEARING PLIES Russian patent published in 2014 - IPC B60C11/00 B60C11/11 B60C11/12 B60C11/13 

FIELD: transport.

SUBSTANCE: tire tread has at least two wearing plies including outer wearing ply and at least one inner wearing ply located at mid tread under outer wearing ply, and at least one outer groove located in outer wearing ply. Besides, said tread features volumetric cavity ratio of 0.25-0.40 in sound state and of about 0.25-0.40 in worn-out state. External side interacting with ground extends along one of inner wearing ply in worn-out tread. Additionally, said tread features contact surface ratio of 0.66-0.72 in sound state and of about 0.56-0.66 in worn-out state.

EFFECT: enhanced performances.

15 cl, 19 dwg