RADIAL PASSENGER TIRE WITH IMPROVED TREAD CONTOUR WITH DECOUPLING GROOVES

摘要

A pneumatic radial ply passenger tire (10) having a tread (20). a casing wit h two sidewalls (14, 16). one or more radial plies (18) extending from and wrapped about two annular beads (13) and a belt reinforcement structure (15) located radially between the tread and the plies. The tread has a central rib (50) with a first contour-defining curve extending outwards from the centerline of the tire towards the sidewalls and a pair of side ribs (60) each having a second contour- defining curve disposed between the central rib and the sidewalls. The first and second contour-defining curves each have first and second radi i disposed such that the meeting point (72) of first and second adjacent contour-defining curves cannot contain a single line that is mutual ly tangential to the first and second adjacent contour-defining curves. First and second circumferential decoupling grooves (22) are dispose d on either side of the centerline at the meeting point of the first and second adjacent contour-defining curves and define a circumferenti al line at the bottom of the grooves which is a region of greater flexibility than the adjacent sections of the tire tread to decouple sidewal l bending stresses from the central rib.