Tire having improved tread portion for reducing formation of anomalies

Abstract

The invention is directed to a shoulder construction of the tread area of pneumatic tires which provides increased stability and reduced wear. The shoulder construction comprises a decoupling rib having an outer surface arranged circumferentially about the tire on an outer edge of the tread portion. A shoulder rib, which also has an outer surface, is arranged inwardly of an adjacent the decoupling rib. A groove, which is defined by the inner and outer side faces of the decoupling rib and the shoulder rib, extends from its base radially beneath the outer surface of the decoupling rib first diagonally toward and then away from the central radial axis of the shoulder rib. The groove configures the inner and outer side faces of the decoupling and shoulder ribs in conforming image and forms an unsupported outer surface area on the shoulder rib. This construction, under nominal pressure and load at the foot portion, provides radial stress which is substantially equalized from an outer edge over a major portion of the outer surface of the shoulder rib and provides for a portion of the inner side surface of the decoupling rib and a portion of the outer side surface of the shoulder rib to move into mutual contact providing reduced wear and increased lateral stability of the shoulder rib.