Patent ID: 8006826

Claim:
A hub for a star wheel intended for transporting articles in an arcuate path, said hub comprising: a rim having an inner surface and an outer surface, said outer surface being adapted to receive a holder comprising a plurality of pockets, each pocket being shaped to receive an article intended for transport and provided with a vacuum opening for vacuum retention of said article; a pair of sidewalls at each side of said hub, one of said sidewalls being attached to said rim and rotatable therewith and an other of said sidewalls being unattached to said rim and fixable against rotation; a plenum within said hub defined by said rim and said pair of sidewalls, said rim having a plurality of circumferential openings interconnecting said plenum and said exterior surface of said rim at positions adapted to be in registry with said vacuum openings; a rotatable shaft fixed to said one of said sidewalls for rotation of said one of said sidewalls and said rim; a port in communication with said plenum and adapted for connection to a vacuum-generating apparatus for generation of a vacuum within said plenum; and a blocking surface within said plenum positioned adjacent to, but spaced at a distance from, the inner surface of the rim, said blocking surface partially blocking at least one but not all of said openings at said inner surface of said rim; wherein said other sidewall at a periphery thereof is spaced from said rim to form a gap effective to avoid contact with said rim while preventing substantial loss of vacuum from said plenum.