Tire building apparatus and method

A method of manufacturing a pneumatic tire blank using a radially and axially expandable and contractable cylindrical building drum comprising the steps of applying about the periphery of the drum one or more plies to form a carcass, while the drum is in the radially contracted and axially expanded condition;

• applying annular bead wires having apex strips coaxially with the building drum and radially spaced from the receiving grooves on the drum;
• radially expanding the drum such that the bead wires are received into said grooves and become embedded in the carcass, such embedding causing marginal edges of the carcass located axially outwardly of the bead wires to be turned partially around the bead wires;
• advancing repsective first shaping rings axially inwardly from opposite ends of the drum to contact said marginal edges and turn them further around the bead wires and bring them into contact with the apex strips;
• radially expanding the carcass portion between the bead wires while axially contracting the building drum and moving the first shaping rings axially inwardly, thereby maintaining said marginal edges in contact with the apex strips, to shape the carcass to toroidal form and also to cause joining of said carcass portion between the bead wires with said marginal edges and apex strips;
• and advancing second shaping rings axially inwardly from opposite ends of the drum with the advance of the first shaping rings to cooperate with said first rings in turning the marginal edges of the carcass about the respective bead wires.