Patent ID: 7363951

Claim:
A rubber tread of a total thickness E for tires, comprising, when new: a running surface intended to be in contact with a roadway during travel; a plurality of cutouts of a depth less than the thickness E of the tread and defining tread pattern elements of a height less than the total thickness of the tread, the cutouts opening onto the running surface; a plurality of cavities devoid of tread rubber and totally under the running surface when new and extending over an average length L, each of these cavities being intended to form at least one new groove after partial wear of the tread, each cavity having two ends, both of said ends an end opening onto respective lateral sides of the tread pattern element; each cavity delimited by rubber of the tread and having an upper generatrix defined by all the points of each section delimiting said cavity and situated closest to the running surface when new, which generatrix is not fully contained in a surface parallel to the running surface when new; and wherein, for each cavity, the upper generatrix follows, along the length of the cavity, an undulating profile having radially elevated portions spaced apart along the length of the cavity by a radially recessed portion, the amplitude of these recessed and elevated portions being at least 10% of a greatest radial dimension of the new groove created by the cavity, and wherein all the points of the upper generatrix of the cavity which are situated in a middle third of the cavity's length are spaced farther from the running surface than are the other points of the upper generatrix, wherein each cavity comprises a lower generatrix which is not contained in a virtual surface parallel to the running surface when new.