Abstract: A surface grading device adapted to be towed over a surface to be graded, capable of self adjustment in accordance with a pre-established signal such as a laser beam, capable of grading cross sloping surfaces, capable of minimizing blade deflection caused by carrier wheels hitting a flaw in grade, and adaptable for highway towing along a single lane of a highway.

Abstract: A hoisting mechanism for earth scraping equipment adapted for towing behind a vehicle, such mechanism including a plurality of pivotally connected links designed to pivot the scraper bed about rear wheels in a manner that provides for change in elevation of the scraper without affecting the elevation of the towing tongue at the point of towing connection. The hoisting mechanism is readily adaptable to include a pressurized accumulator selectively activated by scraper level by means of a cam operated valve to absorb shock while being towed in an elevated position. Further, the hydraulics utilized to move the rear wall forward for ejecting collected earth are the same hydraulics utilized to draw the rear wheels into the scraper bed for making the scraper narrower and therefore suitable for highway travel.