1. Field of the Invention
The present invention relates to an automated system for handling a load on a pallet and more particularly to such a system which transfers a load from a first pallet to a second pallet, with or without a slip sheet, or to a slip sheet only.
2. Description of the Related Art
Manufacturers of products, such as powdered laundry soap, typically stack a preselected number of packages containing the product on a wood pallet for shipping. A load of product supported by a pallet is referred to as a palletized load. Such stacked products are often wrapped with a stretchable polymeric film for maintaining the stacked packages as a unit on the shipping pallet.
Sometimes the manufacturer initially stacks the packages on a captive pallet, so called because it is a high quality, durable pallet which is not shipped with a palletized load, but rather is retained by the manufacturer for repeated use. The captive pallet is loaded with product immediately after the product is packaged. The captive pallet is used for transporting the load from the manufacturing area to a warehouse or the like and from there to the point of shipment.
Immediately prior to shipping, the palletized load is transferred from the captive pallet to a cheaper, less durable shipping pallet. The captive pallet is then re-used by the manufacturer for transferring product from place to place as described above and the shipping pallet containing the product is loaded on a carrier for transporting the goods.
U.S. Pat. No. 3,123,232 to Postlewaite discloses a pallet load transfer mechanism in which a first pallet and a load of product stacked thereon are sandwiched between a pair of opposed clamps and pivoted over 90.degree. to permit removal of the first pallet and insertion of a second pallet beneath the load. The Postlewaite mechanism is complex and requires high-power motors for driving the mechanism.
U.S. Pat. No. 3,645,409 to Sinclair discloses a load transfer and pallet stacker which is used to transfer a load on a pallet to the forks of a forklift. Although a load so transferred may thereafter be deposited upon a second pallet by the forklift, it would be desirable to fully automate the process of transferring a load from a captive pallet to a shipping pallet.
The present invention comprises a substantially horizontal frame. A substantially planar push plate is spaced above and parallel to the frame and is mounted thereon for horizontal movement along a predetermined axis. A loaded captive pallet staged onto the frame and into the travel path of the plate.
In one aspect of the invention, a retainer restrains the load while the plate is moved against the captive pallet thereby pushing the pallet from beneath the load and transferring the load at the plate. A shipping pallet is staged onto the frame beneath the push plate. Continued plate movement withdraws the plate from beneath the load and transfers it from the plate to the shipping pallet. A slip sheet may be provided on the shipping pallet if desired.
In another aspect of the invention, a slip sheet is interposed between the load and the captive pallet. The captive pallet is staged onto the frame and onto the travel path of the plate. A slip sheet gripping assembly grips one side of the slip sheet while the plate moves against the pallet and pushes the same from beneath the slip sheet thereby transferring the slip sheet and the load thereon to the plate. A shipping pallet is staged onto the frame beneath the push plate so that continued plate movement withdraws the plate from beneath the slip sheet thereby transferring the slip sheet and the load supported thereon from the plate to the shipping pallet.
In still another aspect of the invention, the slip sheet gripping assembly operates as described above to remove the slip sheet and the load supported thereon from the captive pallet without transferring the same to another pallet.
It is a general object of the present invention to provide a pallet load transfer method and apparatus which overcomes the disadvantages associated with such prior art methods and apparatus.
It is another object of the present invention to provide such a method and apparatus which operates to transfer a load with or without a slip sheet on a first pallet to a second pallet.
It is a more specific object of the present invention to provide such a method and apparatus which operates to transfer a load without a slip sheet on a first pallet to a second pallet with or without a slip sheet.
It is still another object of the present invention to provide such a method and apparatus to transfer a load with or without a slip sheet on a first pallet to a slip sheet only.
It is yet another object of the present invention to provide such a method and apparatus which is fully automated and which performs such transfers at a relatively rapid rate.
It is still another object of the present invention to provide such a method and apparatus to transfer a load with a slip sheet on a first pallet to a second pallet with a slip sheet or to a slip sheet only without touching the sides of the load.
The foregoing and other objects, features and advantages of the invention will become more readily apparent from the following detailed description of a preferred embodiment which proceeds with reference to the drawings.