US Patent 7857239 Self-propelled walking spray boom

A self-propelled and self-contained shrouded walking boom unit including a small tank and pump mounted on the unit. The unit also has a small transmission and DC drive which makes the unit self-propelled. The configuration is such that the operator walks in front of the spray applicator system with the spray being applied behind the operator. The operator steers the applicator and controls the spray from a handle attached to a single front steering wheel.