US Patent 10501912 Grading tool compatible with light duty work machine

A grading tool comprises a frame extending between a hitch and a ground contacting member. A first adjustment mechanism and a lever are coupled with the frame. A suspension assembly including a spring is coupled with the lever. A grading box assembly is coupled with the frame and with the suspension assembly. The spring is compressible to accommodate motion between the lever and the grading box assembly. A second adjustment mechanism is coupled with the frame and the grading box assembly and is adjustable to selectably increase and decrease in length. A fixation member is coupled with the grading box assembly and is selectably coupleable with the frame to fix a first side of the grading box assembly vertically relative to the frame while allowing vertical movement of a second side of the of the grading box assembly relative to the frame.