A small contractor needs a mini dumpster attachment for his pickup truck. He has made several trash containers which are $4$ftx$4$ftx$3\mathrm{.}5$ft high. The empty container weighs $150$ lb$.$ he needs a mechanism which he can attach to his fleet of standard, full size pick up trucks $($chevy$,$ ford, dodge$).$ This mechanism should be able to pick up full trash containers from the ground,lift it over the closed tailgate of the truck, dump its contents into the truck bed, and then return it empty to the ground. He would like not to tip his truck over in the process. The mechanism should store permanently on the truck in such a manner as to allow the normal use of the pickup truck at all other times. You may specify any means of attachment of your mechanism to the container of the truck.

I need the graphical synthesis and any related info $($no need Solidworks model$)$