Filler-provided bead forming apparatus

A filler-provided bead forming apparatus comprising;

• a cylindrical drum, transport means for transferring a belt-shaped filler to the proximity of one end of the drum, the filler including two longitudinal opposed end portions, a thin edge portion widthwise of the filler and a thick edge portion having an obtuse edge portion, an acute edge portion, and a bottom side portion between the obtuse and acute edge portions, a pair of grasping units arranged on the transport means for grasping the longitudinal opposed end portions of the filler, respectively, with the end portions aligned horizontally with respect to the surface of the conveyor belt, moving means for moving the grasping units grasping the opposed end portions of the filler, respectively, along a pair of curved guide surfaces each formed by involute curves of the drum, respectively, and wrapping the filler around the drum with the thick edge portion of the filler being in register with the one end of the drum in such a manner that the filler is wrapped around the drum progressively from the longitudinal center to the opposed end portions of the filler, transfer means for transferring a bead to the one end of the drum, a bladder provided on the drum for raising the filler wrapped around the drum about the bottom end of the filler on the thicker side thereof upon being expanded to bring the bottom end of the filler into contact with an outer circumference of the bead, and pressure-joining means for urging the bottom side portion of the filler against the bead to pressure-join them.