A PROCESS FOR BUILDING TYRES FOR VEHICLE WHEELS, TYRE FOR VEHICLE WHEELS AND A METHOD FOR OPTIMIZING THE DISTRIBUTION OF LOADS IN THE CARCASS STRUCTURE OF A TYRE

摘要

In a tyre for vehicle wheels a carcass ply (3a, 3b) is obtained by depositing on a radially outer surface (15) with respect to a forming drum (13) a plurality of strip- like elements (14) in circumferential side by side relationship with each other, superimposing a lateral longitudinal portion (18) of a strip-like element (14) on the lateral longitudinal portion (18) of an adjacent strip-like element (14). A central part (17) of each of the strip-like elements (14) comprises a plurality of parallel first cords (15a) having a first average diameter (d1). The two lateral longitudinal portions (18) each having a reduced thickness (S2), with respect to a thickness (S1) of the central part (17), and having at least one second end cord (15b) with a second average diameter (d2) smaller than the first average diameter (d1). The superimposition of the lateral longitudinal portions (18) provided with a reduced thickness (S2) and the smaller second cords (15b) allows providing the carcass ply (3a, 3b) with a substantially uniform thickness and maintaining, in the working conditions, the neutral axis (NA) of the radial section of the sidewall (12) of the tyre (1) inside the tyre (1) and outside the carcass structure (2).