Tire building drum with rotatable bead holders

A drum (T) consists of two flanges (4, 4') with peripheral grooves (6, 6') to hold the beads of a tyre carcass, mounted on a shaft (1) so they can be moved axially along it by a driven threaded rod (2) and sliders (3) while the tyre is shaped by compressed air fed into the enclosed volume formed by the tyre and flanges. The drum (T) consists of two flanges (4, 4') with peripheral grooves (6, 6') to hold the beads of a tyre carcass, mounted on a shaft (1) so they can be moved axially along it by a driven threaded rod (2) and sliders (3) while the tyre is shaped by compressed air fed into the enclosed volume formed by the tyre and flanges. At least one of the flanges can be rotated about the axis of the drum relative to the other one, driven by the rotation of the tyre beads or by motorised components (7, 7') inside the flanges. The shaped carcass receives bracing plies of rubber-coated cords that lie at two different angles over the crown of the tyre and radially in its side walls.