Just found it interesting and a pretty original function, built with LEGO Technic.
One truck trailer with a belt conveyor, which can be filled with approx. 20 Kg of beans and unloads itself within 12 minutes.
It is part from a 1:13 scale model of a DAF 95XF truck designed by Dennis Bosman (legotrucks).
You can read all about this model, built in 2002, at 'LEGO Trucks & Heavy Equipment' website, where you will find also lot more about other Dennis' creations (Trucks and Construction Machinery).
And of course, Dennis was also featured in my favorite TBs post.