(under subclass 452) Apparatus in which the earth working element during its vertical movement maintains substantially the same angular position with respect to the ground.
SEE OR SEARCH THIS CLASS, SUBCLASS:
415+, for vertically adjustable translatable wheels.
460, and the subclasses there noted for a tool independently vertically adjustable at transversely spaced points and also capable of vertical translation.
661, for plural, relatively movable tools in which a tool is vertically translatably adjustable.
739+, for devices wherein the tool is carried by a mast-type hitch which is generally connected to a vehicle for raising and lowering by vertically spaced substantially parallel
