“Rainbow” pallets 118, 120, 121, 122 are examples of heterogeneous material pallets that have been built of layers from several different homogeneous material supplies. Each different kind of material layer is labeled A-H in
Short orders from customers will result in smaller stacks, e.g., pallets 120, 121. Rather than run these individually down to the end for off-loading, the shorter stacked pallets 120, 121, can be placed on one another to allow the layer build cart to keep working.
A pallet 144 may be emptied by robot 102 to be picked up and carried on LBC 108 down to an empty pallet take-off conveyor 146. A take-off action 148 by conveyors 110, 122 rolls off stacks of empty pallets 150 for a pallet recycle 152. In some embodiments, the LBC 108 is provided with an empty pallet conveyer. Empty pallets are stacked on this and conveyed off together at the same time the full rainbow pallets are conveyed off on the other side.
After a run right 116, a pickup action 160 by robot 102 at the right side supply conveyors 140 will be followed by a deposit action 162 to build rainbow pallets 118, 120, and 122. Once all the pallets on LBC 108 are complete, the LBC 108 runs down layer build track 134 to a rainbow pallet take-off conveyor 170. A conveying action 172 transfers completed rainbow pallets 174, 176, and 178, from LBC 108 onto the take-off conveyor 170, and thence to an output 180 for wrapping and eventual loading on delivery trucks or return to storage.
Several pallet-building and empty-pallet conveyors 210-220 are located on both sides of robot 206, and each comprises individual conveyor beds that handle two stacks of half-pallets or one stack of full pallets. The half pallets are represented by the X-ed squares with dashed lines, and the full pallets by double-sized X-ed rectangles with dashed lines. Each conveyor bed typically has two outside chain drives and a non-powered roller conveyor. Such allows completed rainbow pallets to be conveyed on-off and across between them, as represented by double-headed arrows. Stacks of empty pallets can also be accumulated on-board and then conveyed off.
The center stop gate 310 is lowered to allow pallets to continue to the right into the second position where they can be picked by the robot. An end stop 312 positions pallets to be in reach of robot 102, 206 (
In general, the automated build-by-layer rainbow pallet system embodiments of the present invention comprise a layer build track and a layer build cart for carrying a layer build robot. The cart has a number of positions on-deck for building rainbow pallets. Many supply pallet conveyors for pallets of products are arrayed railside on one or both sides of the layer build track. These can be picked-from by the robot when building a rainbow pallet. Electric motors controlled by computer programs are used by the layer build robot to position itself in front of appropriate supply pallet conveyors for picking. The robot has a special vacuum and/or clamping device for picking layers from the supply pallets. This device is referred to as an end effector. The material is positioned on the target rainbow pallets to be built. The layer build cart is returned to an unloading area so all of the rainbow pallets built may be conveyed off to a pallet exit conveyor. Empty pallets may be collected from an empty pallet supply, and placed in individual rainbow pallet build locations by the robot or conveyed on.
Sensors on the LBC and robot are used to measure the heights of the supply and build pallets so the robot will not miss or crash into the product during picking. A computer and software program orchestrate the overall movement and building of pallets. The program includes a process for picking and building layers as the layer build cart repositions in front of an appropriate supply pallet conveyor. Such is repeatable until all the on-deck rainbow pallets have been built.
The material flow begins by placing a layer build robot on a layer build cart large enough to accommodate several rainbow pallets. Many supply pallet conveyors are arranged along the sides of a rail track provided for the layer build cart. A pallet exit conveyor is provided at a point along the rail track for separate off-loading of the rainbow pallets and empty pallets from the layer build cart.
A pallet storage area is staged next to the rail track so the layer build robot and layer build cart can pick-up or convey on empty pallets to build new rainbow pallets or drop-off empty pallets from the supply pallet conveyors. Empty pallets are loaded onto a layer build cart for building into rainbow pallets. The layer build cart is moved to a position along a rail track to position a supply pallet conveyor within reach of a layer build robot on-board the layer build cart. The layer build robot is used to pick a layer of material from the supply pallet conveyor and place it on one of the on-board rainbow pallets. The layer build cart is moved to a next position along a rail track to put a next supply pallet conveyor within reach of the layer build robot. The layer build robot is used to pick a next layer of material from the next supply pallet conveyor and place it on one of the on-board rainbow pallets. The steps of using and moving are repeated until each of the on-board rainbow pallets is complete according to a control program software. The completed rainbow pallets on-board the layer build cart are transported to pallet exit and empty supply pallet conveyors stationed along the rail track. These transfer the rainbow pallets from the laye˜ build cart to the pallet exit conveyor for wrapping and eventual shipment to customers or storage.
When the rainbow pallets are built up, they are off-loaded from cart 502 onto exit conveyors. If shrink wrapping or stretch wrapping is needed for stability, the pallets are wrapped-up in a wrapping station 532. They are then delivered to their ultimate destinations or placed in storage.
Although particular embodiments of the present invention have been described and illustrated, such is not intended to limit the invention. Modifications and changes will no doubt become apparent to those skilled in the art, and it is intended that the invention only be limited by the scope of the appended claims.