US Patent 7802610 Retractable closure apparatus for mobile containers

An apparatus for the safe closure of the open area of mobile containers, having a tarp connected to a spring loaded tarp assembly and to the container by brackets. These brackets allow the tarp to be lowered and raised using the spring loaded tarp assembly. A metal plate at the bottom of the tarp is used to secure the bottom of the trap while in the closed position. The spring loaded tarp assembly comprises three main components a sleeve, a rod, and tension springs. The rod allows the free flow rotation of the sleeve with the tension spring acting as a back stop.