Conveying system for work pieces

A circuit-like conveyor system which includes:

• a lower conveyor line having an entrance and an exit end;
• a first lift mechanism positioned adjacent the exit end of the lower line;
• an upper conveyor line spaced from the lower line and having an entrance end and an exit end, with the first lift mechanism positioned adjacent the entrance end of the upper conveyor line;
• a second lift mechanism positioned adjacent the exit end of the upper line and the entrance end of the lower line;
• and constructed for the simultaneous and discontinuous movement of a plurality of work pieces to and between a plurality of treatment stations:
• an elongated and stationary frame;
• said plurality of treatment stations positioned in spaced relation to the frame, and said lower conveyor line;
• a travel mechanism carried on the frame and movable relative to the frame between adjacent treatment stations;
• a hoist mechanism carried on the travel mechanism and having retractable and extendable supports;
• an elongated beam which extends along the frame and which is connected to the hoist mechanism by the retractable and extendable supports and which is constructed for movement between a lower position and an upper position and to releasably engage each of a plurality of work pieces;
• and which is constructed for movement toward the entrance end or toward the exit end of the lower conveyor so that the beam can be lowered and work pieces delivered to the treatment stations;
• moved one station toward the entrance end of the lower conveyor, raised, and moved one station toward the exit end so as to move the work pieces forwardly one station;
• and
• wherein each of the lift mechanisms is constructed to retrieve a work piece on a hanger from a first position and transport the work piece to a second vertically different position, and each mechanism includes:
• a substantially vertical frame-like structure;
• a carrier assembly mounted in the frame-like structure for movement upwardly and downwardly and includes a pair of generally horizontally positioned arm assemblies mounted to the carrier, each of said arms including a section which is horizontally extendable and retractable for movement toward and away from the carrier assembly;
• and
• a work piece receiving structure mounted to the extendable and retractable portion of each arm for movement with the arm to a position toward the end thereof when the arm is extended from the carrier.