A TIRE BUILDING APPARATUS

摘要

A tire building apparatus is provided having an improved mechanism for turning up the plies of the tire carcass and wrapping them around each tire bead ring. The mechanism is designed so that it can also be used to apply the sidewall pads to the expanded carcass of a radial tire. The improved mechanism includes a bladder that has a molded conical portion in its outer fold adjacent the building drum. This conical portion extends very close to the bead ring positioned adjacent the carcass at the sides of the drum shoulders. The improved mechanism also includes a control ring insert placed inside said bladder and radially inwardly from the conical portion of the outer bladder fold. When the bladder is inflated to wrap the carcass plies around the bead ring, the control ring insert and the molded conical portion of the outer bladder fold combine to provide an improved, tighter wrapping of the carcass plies around the bead ring. They also provide a smoother, more accurate positioning of a sidewall pad to an expanded radial tire carcass when the mechanism is employed for that purpose. There is also provided a method and apparatus for molding a bladder having a conical portion in its outer fold.