Hinge-type offset wheel harrow

A harrow comprising leading and trailing harrow units, means pivotally coupling said units near corresponding ends thereof for relative angular adjustment, a toggle linkage interconnecting said units near the other ends of the units, power means connected with the toggle linkage to open and close it for adjusting the angle between said units and for drawing said units into substantially parallel relationship for transport, spaced transport wheels on the trailing unit substantially at right angles thereto and being pivotally attached to the trailing unit for vertical swinging movement for raising and lowering the trailing unit relative to the ground, power means connected with the transport wheels to swing them on their pivots, a drawbar and tongue assembly pivotally coupled with said leading unit for vertical swinging relative thereto, said tongue adapted for coupling with a hitch of a towing vehicle for the harrow, power means on the leading unit coupled with said drawbar and tongue assembly to raise and lower the assembly on its pivot, thereby lowering and raising the leading unit relative to the ground through the reactive force of said hitch on said tongue, said power means on the leading unit comprising a single hydraulic cylinder having one end coupled to said drawbar and tongue assembly and its other end coupled to a rocker element which in turn is pivotally attached to said leading unit, and an adjustable stop element for the rocker element on said leading unit in the path of rocking movement of the rocker element.