Sumitomo Rubber Industries Limited

Sp Tyres UK Limited

David H Clarke

Nigel G Nock

Arthur R Williams

John Martin

A pneumatic tire for a vehicle comprises a carcass ply extending between two bead regions and passing through a tread region which extends between two tread contact edges, a tread region reinforcing breaker radially outwards of the carcass in the tread region and a ground contacting tread surface curved in the axial direction wherein the curvature of the outer tread surface when the tire is mounted on its design wheel rim and normally inflated has a continuously decreasing radius from a point P which is at a distance SP in the axial direction from the tire circumferential center line equal to 20% of the distance from the tread center to the adjacent tread contact edge.

Pneumatic tire with specified tread curvature and/or specified breaker

A pneumatic tire for a vehicle comprises a carcass ply extending between two bead regions and passing through a tread region which extends between two tread contact edges, a tread region reinforcing breaker radially outwards of the carcass in the tread region and a ground contacting tread surface curved in the axial direction wherein the outer surface of the widest breaker ply when the tire is mounted in its design wheel rim and normally inflated has a curved shape in the tire axial direction and has a continuously decreasing radius from a point B to the adjacent edge of the breaker wherein point B is at a distance SP in the axial direction from the tire circumferential centerline equal to 20% of the distance from the tread center to the adjacent tread contact edge.

A tire tread pattern comprising a central zone and two edge zones in which the edge zones are subdivided circumferentially of the tire by a series of transverse grooves each having an axially outer end open to the tread edge characterized by in each transverse groove a noise baffle comprising a circumferentially extending rib across the groove and having a height of 25% to 75% of the groove depth. The noise baffle is preferably quite narro so that it does not materially affect the stiffness of the blocks but acts as a noise baffle only. It may be a single baffle or two or more short baffles interlocking to block noise transmission.

Growing community of inventors

Walsall, United Kingdom

David H Clarke