Pneumatic radial tyre for heavy lorries

摘要

A radial tyre for heavy lorries is presented which has a carcass layer (4) of rubberised cords with radial or virtually radial direction of the cords, the two ends of the cord layer being folded back (4a) about a bead core (3). A reinforcement layer (5) of rubberised cords is arranged outside the folded-back section of the carcass layer and a bead rider (6) is seated between the main section of the carcass layer and the folded-over part of the same. The upper end of the folded-back part of the carcass layer or the upper end of the reinforcement layer, depending on whichever is at a higher position, is arranged at a height (h) of 30% to 60% of the cross-sectional height (H), measured from the base of the bead. Thus, the tendency of the cords to become detached from the surrounding rubber is reduced and the service life of the bead area is improved.