(under the class definition) Apparatus, comprising a scraper associated with a frame for traversing the earth whose position relative to the frame is controlled by a mechanical linkage arrangement so that when the scraper passes over a raised section of earth it is lowered relative to the frame and when it passes over a low section of earth it is raised relative to the frame whereby an approximately level surface of the earth is created as the scraper traverses the earth, all without the intervention of a human operator.
(1) Note. Typically in apparatus under this definition a ground wheel may move relative to a frame carrying the grading scraper and a linkage connects the wheel and grading scraper so that as the wheel moves up relative to the frame the scraper moves down relative to the frame and as the wheel moves down relative to the frame the scraper moves up relative to the frame.
SEE OR SEARCH THIS CLASS, SUBCLASS:
4.5, for automatically controlled power means for shifting the position of a scraper in order to achieve a level surface.
239, for apparatus having a linkage whereby the position of an earth working element is controlled in certain ways in response to draft forces, pitching of a propelling device or ground level.
398, for a vertically adjustable ground support interconnected with a tool by linkage so movement of one influences movement of the other.
811+, for a scraper positioned in front of a motor vehicle and maintained in a horizontal position as the ground supports of the vehicle move over irregular terrain so that the vehicle tilts sidewise.
