METHOD OF FORMING A BELT STRUCTURE IN A TYRE, IN PARTICULAR FOR MOTORCYCLE WHEELS

摘要

Formation of a belt structure (2) takes place by laying down, directly on the carcass structure (3) of a tyre being processed (1), a laying layer (16) formed of a continuous strip-like element (16) of elastomer material directly coming from an extrusion die. The strip-like element (16a) has a differentiated thickness at its opposite edges to give rise to circumferential grip recesses (18) on the laying layer (16). Then, on the laying layer (16) a primary belt strip (6) is formed which is obtained by winding up of a continuous bare cord into coils (6a) disposed in axial side by side relationship. A cord of the high starting elongation type is preferably employed and it is wound up substantially in the absence of tensioning. A covering layer (19) made in the same manner as the laying layer (16) can be subsequently laid down on the primary belt strip (6).