US Patent 7520017 Street sweeper recirculation flap

A street sweeper system is used typically in a motorized vehicle. The sweeper utilizes a cylindrical brush rotating about an axis generally perpendicular to the vehicle's direction of motion. A conveyor belt catches debris thrown forwards and upward by the brush and moves the debris to a hopper. A recirculation flap is mounted contacting a lower rear portion of the brush. The recirculation flap deflects debris that has traveled over the top of the brush back into the brush to be recollected at the conveyor.