Dunnage handling system

Apparatus for handling multiple work pieces arranged in trays, said trays stacked vertically in horizontal layers from a bottom tray to a top tray and said stack of trays supported from beneath by a pallet, said apparatus comprising:

• a tray destacking station, a work piece unloading station, and a tray stacking station, said stations connected by a pallet transport system and a tray transport system to move the pallets and the trays sequentially from station to station, said destacking station and the stacking station each comprising a structural frame having at least a pair of vertically extending sides and a horizontally extending top interconnecting the sides to form a passage within the frame, and the pallet transport system and the tray transport system is positioned within the passage along a path interconnecting said stations, said unloading station being positioned in the tray transport system between the destacking station and the stacking station and further comprises means positioned and constructed to unload the workpieces from the trays;
• unloading station transport means to move the trays into the unloading station into an operative position with the unloading means, said unloading station transport means forming part of the tray transport system;
• first lift means at the destacking station to move vertically up and down to raise and lower the stack of trays;
• first rack means at the destacking station to move horizontally to engage, Suspend and release the stack of trays;
• system control means operatively associated with the first lift means to cause the lift means to raise and lower the stack of trays, and to cause the rack means to engage suspend and release the stack according to a predetermined sequence in which the stack of trays are lifted and suspended above the pallet to allow the pallet to be moved from under the stack by the pallet transport system and the stack is sequentially lifted and suspended above the bottom tray of the stack to allow the bottom tray to be moved from under the stack by the tray transport system while the upper trays are suspended;
• means in the tray transport system to direct the bottom tray into the workpiece unloading station after said bottom tray is removed from the bottom of the stack;
• means at the workpiece unloading station to unload the workpieces from the tray;
• means in the tray transport system to direct the unloaded tray from the unloading station into the stacking station;
• second lift means at the stacking station to move vertically up and down to raise and lower the stack of trays;
• second rack means at the stacking station to move horizontally to engage, suspend, and release the stack of trays;
• said system control means further operatively associated with the second lift means to cause the said second lift means to raise and lower the stack of trays, and with the second rack means to cause the second rack means to engage, suspend, and release said stack according to a predetermined sequence in which the stack of trays are lifted and suspended to allow the unloaded tray to be moved under the stack by the tray transport system and to raise said unloaded tray to said stack to add said unloaded tray as the bottom tray of the stack;
• and when the stack of unloaded trays are assembled, the stack of unloaded trays are sequentially lifted and suspended to allow the pallet to be moved Under the stack on the pallet transport system to allow the pallet to be raised to the stack of unloaded trays and the pallet and trays to be lowered onto the pallet transport system.