Layered tire tread design for improved coast by noise and traction performance

摘要

A tire tread having a layered design is provided. In a first layer of the tread, sipes extend transversely to provide traction in the first stage of the wear life of the tread. In a second layer of the tread, the width of the sipes along the circumferential direction is increased to provide for improved traction in a second stage of the wear life. The increased width is provided by a void that opens to a circumferential groove only along one end. Because the void opens only along one end, a decrease in acoustical effects such as drive by noise can be provided.

主权项

1. A tire tread having a contact surface and defining transverse, radial, and circumferential directions, the tire tread comprising:
a pair of first circumferential grooves extending along the circumferential direction and each having a depth D1 along the radial direction from the contact surface; a second circumferential groove extending along the circumferential direction and located between said pair of first circumferential grooves, wherein said second circumferential groove has a height along the radial direction that extends from a top depth D2 to a bottom depth D3 so that said second circumferential groove is covered in a first stage of wear life of the tire tread and is uncovered in a second stage of the wear life of the tread; a transverse sipe extending along the transverse direction between said second circumferential groove and one of said first circumferential grooves, said transverse sipe and having a depth along the radial direction that extends from the contact surface; a void positioned in the tread radially inward of said transverse sipe so that said void is hidden during the first stage of wear life of the tread and is revealed during the second stage of the wear life of the tread; wherein said void is open along one side at said second circumferential groove, extends for a predetermined distance along the transverse direction towards said first circumferential groove, and then ends along an opposing side that is connected to said transverse sipe such that said transverse sipe extends along the transverse direction between the opposing side of the void and said first circumferential groove, and wherein said void has a width along the circumferential direction that is greater than a width along the circumferential direction of said transverse sipe.