Abstract: A rotary radial expand collapse tire building drum comprises segments defining an outer circumference of said drum, said segments being divided into two sets, one set being located to each opposite side of a transverse central plane of the drum, said central plane being disposed normal to a rotational axis of the drum, said two sets being adapted to be driven by a rotatable hub assembly between a collapsed position in which a formed tire carcass may be removed from the drum and an expanded position in which a tire carcass may be formed on said drum wherein each set of segments are mounted for selective relative axial using positioning means, and adjustment means is located outside of the rotational axis of the drum, which is arranged to adjust an overall working width of said drum. The invention allows for an axial positioning mechanism of a REC building drum.

Abstract: A rotary radial expand collapse tire building drum comprises segments defining an outer circumference of said drum, said segments being divided into two sets, one set being located to each opposite side of a transverse central plane of the drum, said central plane being disposed normal to a rotational axis of the drum, said two sets being adapted to be driven by a rotatable hub assembly between a collapsed position in which a formed tire carcass may be removed from the drum and an expanded position in which a tire carcass may be formed on said drum wherein each set of segments are mounted for selective relative axial using positioning means, and adjustment means is located outside of the rotational axis of the drum, which is arranged to adjust an overall working width of said drum. The invention allows for an axial positioning mechanism of a REC building drum.