1. Field of the Invention
This invention relates to mechanical devices for dismantling wooden pallets by prying the cross-members loose from the pallet stringers to which they are nailed, and more particularly devices of this type wherein hydraulically or pneumatically powered rotatable prying elements are utilized to pry the cross-members from the stringers.
2. Description of the Prior Art
Machinery, equipment, goods, wares and materials of every conceivable kind and description are transported, stored, displayed and even sometimes mounted for operation on wooden pallets. Essentially these pallets comprise a series of boards nailed at intervals to two or more wooden stringers. Often, in heavy use one or more of the cross-members is broken, but the pallet is useable if the broken member can be replaced. Frequently pallets are so badly damaged they cannot be repaired economically, but they still contain valuable lumber which is reuseable if they can be dismantled.
The high cost of labor is rapidly making the use of the conventional hammer and pinch-bar for the removal of broken boards and dismantling of pallets prohibitively expensive. Machines have been devised to perform or assist in these tasks. Some of these devices, such as that shown in U.S. Pat. No. 2,029,885, utilize movable claw-like means to remove individual nails. Others utilize blades or grippers such as those shown in U.S. Pat. Nos. 2,446,741 and 2,704,198 to cut or pull the nails. Still others use a variety of sawing means to cut the nails holding the lumber, or wedging mechanisms to force the lumber pieces apart. None of these machines has proved to be fully satisfactory.