Method and device for automatically centering and feeding beads onto a tire building drum

A device for centering and feeding beads onto a tire building drum mounted for rotation about a first axis, characterized by the fact that it comprises a grab ring coaxial with the said first axis and designed to move along the same for loading an annular package comprising an annular belt and a tread onto a tire carcass expanding on the said drum;

• two first guide means integral with the said grab ring and facing opposed axial surfaces of the same, each said first guide means extending transversely in relation to the said first axis and comprising a longitudinal end portion extending outwards of the said grab ring;
• second guide means extending between the said end portions of the said two first guide means and parallel with a second axis parallel with the said first axis;
• automatic means for centering two said beads in relation to the said second axis, the said automatic centering means being designed to move between the said two first guide means and along the said second guide means, for supporting two annular tire beads, each facing a respective one of said first guide means, and the said automatic centering means comprising, for each said bead, hanging means expansible between a first configuration, wherein they loosely engage the respective one of said beads, and a second configuration wherein they position the respective one of said beads coaxial with the said second axis;
• and an annular transfer body designed to move, along each said first guide means, between two positions respectively coaxial with the said first and the said second axis;
• each said annular transfer body presenting an inside diameter greater than the outside diameter of the said tire building drum;
• retaining means being carried by each said annular transfer body and being designed to cooperate with that one of the said two beads which is arranged facing the respective one of said first guide means;
• each said annular transfer body being divided into two semiannular bodies in a diametrical plane perpendicular to the respective one of said first guide means;
• and parting means being provided between the said two semiannular bodies, for displacing them mutually, along the respective one of said first guide means, out of and into a closed position wherein they define the said annular transfer body.