Patent ID: 8555944
Filing Date: 2013-10-15
Classification: B29D

Abstract:
1. A rotatable, expandable and collapsible drum useful in the manufacture of vehicle tires and having a main shaft defining a rotational axis of the drum comprising: a plurality of segments, said segments being divided into first and second sets of segments, one set of segments being disposed on each of opposite sides of a transverse center plane of the drum, a central control mechanism controlling the radial positions of the segments in relation to the rotational axis of the drum while permitting axial movement of the two sets of segments relative to one another, whereby said segments are selectively positionable between expanded and collapsed positions radially of the drum, a plurality of lugs, each lug being fixedly attached to an inside surface of a corresponding segment, each lug of the first set of segments defining a through opening in axial alignment with a through opening defined by a lug of the second set of segments; a plurality of cylindrical rods, each cylindrical rod defining mirrored first and second helical grooves along an outer surface of the cylindrical rod, each cylindrical rod being received within a pair of axially-aligned through openings of the plurality of lugs; a plurality of gap shield supports, each gap shield support being located proximate a midsection of a corresponding cylindrical rod and defining a clamping lock through which the corresponding cylindrical rod is inserted, each clamping lock being configured to selectively lock the corresponding cylindrical rod against rotation in relation to the first and second sets of segments and to selectively unlock the corresponding cylindrical rod to allow rotation in relation to the first and second sets of segments; and a plurality of hardened dowels, each hardened dowel protruding through a corresponding lug and into a corresponding helical groove of a corresponding cylindrical rod; whereby rotation of each said cylindrical rod within corresponding through openings and clamping lock allows each hardened dowel to travel along a corresponding helical groove, thereby allowing axial movement of the two sets of segments relative to one another, and whereby locking of each said cylindrical rod prevents rotation within corresponding through openings and clamping lock, thereby preventing each hardened dowel from travelling along a corresponding helical groove and thereby preventing axial movement of the two sets of segments relative to one another.