Tire building apparatus

A tire building apparatus for building a complete tire in a single operation, the apparatus having an intermediate radially expandable drum, intermediate drum expanding and contracting means associated with the intermediate expandable drum to dispose the same in positions defining rigid supporting surfaces of different radii, an end drum assembly at each end of the intermediate drum with each end drum assembly including an axially movable carrier means having end drums secured thereto, ply turn up means and tire bead locating and supporting means for the beads of the tire carcass incorporated with the carrier means, the intermediate drum and end drum assemblies providing support of tire carcass material therearound, the intermediate drum expanding and contracting means having positive drive means for axially moving said carrier means toward and away from each other, said positive drive means including a rotatable shaft having right-hand and left-hand threaded sections and nut means threaded on said threaded sections and having connection with said carrier means, said tire bead locating and supporting means includes radially movable bead lock clamp means, axially movable bead lock clamp actuator means, parallelogram linkage means connected intermediate said bead lock clamp actuator means and said bead lock clamp means for transmitting force therebetween and for maintaining the center line of said bead lock clamp means parallel to said center line and reaction linkage means connected intermediate said bead lock clamp means and said carrier means whereby axial movement of said bead lock clamp actuator means effects through said parallelogram linkage means radial movement of said bead lock clamp means the combination including

• resilient expansion means as part of the intermediate drum expanding and contracting means and incorporated with said carrier means for effecting at least a partial actuation of the intermediate drum expansion means, and
• positive centering means for axially positioning the intermediate drum to maintain the center line of the carcass midway between the beads of the tire carcass.

A method of building a complete tire comprising the steps of:

• forming tire carcass material in substantially the form of a cylinder,
• positioning tire beads on said tire carcass material inwardly opposite ends of said tire carcass material,
• clamping said tire carcass material to said tire beads,
• tensioning radially outwardly said tire carcass material between said tire beads,
• moving positively said tire beads on said carcass material axially inwardly towards one another and expanding said tire carcass material between said tire beads with at least partial resilient expansion means while maintaining the centerline of said carcass material between said tire beads,
• stopping positively the expansion of said tire carcass material between said tire beads and axially inward movement of said tire beads towards one another, and
• turning up said opposite ends of said tire carcass material to encase said tire beads within said tire carcass material and applying breaker and tread components about the center line of the outer periphery of expanded position of the tire carcass material to produce a complete tire.