TIRE TREAD HAVING A PLURALITY OF WEAR LAYERS

摘要

Particular embodiments of the present invention include a multi-stage tire tread having two or more wear layers comprising an outer wear layer and one or more inner wear layers arranged within the thickness of the tread below the outer wear layer and one or more outer grooves are arranged within the outer wear layer. The tread further includes a volumetric void ratio equal to approximately 0.25 to 0.40 in the unworn condition and approximately 0.25 to 0.40 in a worn condition where the outer, ground-engaging side is arranged along one of the inner wear layers in the worn condition, the tread further having a contact surface ratio equal to approximately 0.66-0.72 in the unworn condition and approximately 0.56-0.66 in the worn condition.

主权项

1. A multi-stage tire tread comprising:
a thickness extending inward depthwise from an outer, ground-engaging side of the tread, the outer, ground-engaging side including an outer contact surface; two or more wear layers arranged within the tread thickness at different depths, the two or more wear layers comprising an outer wear layer and one or more inner wear layers arranged within the thickness of the tread below the outer wear layer; and, one or more outer grooves arranged within the outer wear layer, the one or more grooves exposed to the outer, ground-engaging side when the tread is in an unworn condition; the tread having a volumetric void ratio equal to approximately 0.25 to 0.40 in the unworn condition and approximately 0.25 to 0.40 in a worn condition where the outer, ground-engaging side is arranged along one of the inner wear layers in the worn condition, the tread further having a contact surface ratio equal to approximately 0.66 to 0.72 in the unworn condition and approximately 0.56 to 0.66 in the worn condition.