Stack Lifting Assembly

Abstract

A stack lifting assembly for incrementally lifting stacks of flats loaded typically with produce to an unloading device and system. The assembly is configured to receive stacks of flats full of produce such as berries, and to lift the stacks to an unloader. The stack of flats is lifted allowing for the top flat to be removed and dumped, with the remaining stack of flats lifted and the process repeated. The stack lifting assembly has a frame, with two counter rotating belts that have flat support tabs that engage the bottom flat in a stack of flats, and lift the entire stack of flats. The dumping operation is allowed to proceed continuously, with no pauses to load stacks of flats. Throughput and safety are greatly improved.

What is claimed is: 
     
         1 . A stack lifting assembly for use in lifting a stack of flats for removing produce from the flats, said stack lifting assembly comprising:
 a stack lifting frame, said stack lifting frame defining a loading chamber having an opening configured for insertion therethrough of a stack of flats to a loading position in said loading chamber;   a pair of opposing lifting belts positioned on opposing sides of said loading chamber, said opposing lifting comprising a pair of opposing flat support tabs, wherein said pair of flat support tabs are configured to support the bottom flat of a stack of flats from opposing sides of said bottom flat, wherein said opposing lifting belts are configured for opposing rotation such that said pair of flat support tabs are configured for parallel upward movement to lift said stack of flats from said bottom flat;   wherein stack lifting assembly is configured to incrementally lift the stack of flats from the bottom flat of said stack positioned in said loading position to a launch position so that the top flat may be removed from the stack by a flat flipper assembly.   
     
     
         2 . The stack lifting assembly of  claim 1  further comprising an infeed conveyor positioned adjacent to said stack lifting frame and configured to deliver a stack of flats to said loading chamber. 
     
     
         3 . The stack lifting assembly of  claim 1  wherein said flat support tabs are configured to support a base of the bottom flat in a stack of flats. 
     
     
         4 . The stack lifting assembly of  claim 1 , wherein said opposing lifting belts each comprise two opposing chains, wherein said each of said flat support tabs extend between said opposing chains. 
     
     
         5 . The stack lifting assembly of  claim 1 , wherein said opposing lifting belts comprises a plurality of paired flat support tabs. 
     
     
         6 . The stack lifting assembly of  claim 1 , wherein said stack lifting assembly is configured to receive a second stack of flats in said loading position under a previous stack of flats before the last flat of said previous stack of flats has been engaged by the flat flipper assembly and removed, so that flats can continually be lifted and unloaded without stopping said stack lifting assembly to insert another stack of flats. 
     
     
         7 . The stack lifting assembly of  claim 5 , wherein said opposing lifting belts comprise two pairs of flat support tabs, wherein said pairs of flat support tabs are positioned in a spaced apart relationship to allow for said stack lifting assembly is configured to receive a second stack of flats in said loading position under a previous stack of flats before the last flat of said previous stack of flats has been engaged by the flat flipper assembly and removed, so that flats can continually be lifted and unloaded without stopping said stack lifting assembly to insert another stack of flats. 
     
     
         8 . The processing machine of  claim 4  in which said infeed conveyor further comprises a powered belt to feed stacks of flats laden with produce into the loading position in said stack lifting assembly. 
     
     
         9 . The processing machine of  claim 1  wherein said stack lifting assembly is configured to incrementally lift said stack of flats in increments of a height of a flat.