Ground wheel driven oscillating harrow

Claim 1

A harrow comprising: an elongated main frame having spaced apart side frame members and transverse frame members; the main frame having a forward end section with a tow yoke spanning the side frame members, and having a trailing end section; a harrow assembly including a plurality of concentric rings each having a series of depending harrow points secured thereto; an axle assembly, comprising an axle transverse to the side frame members, ground wheels, and a differential gear assembly, the axle assembly supporting the main frame intermediate said forward and trailing end sections; a cross brace spanning the side frame members forward of the axle assembly, and carrying a vertical drive shaft with a first horizontally mounted sprocket; a second vertical shaft projecting from the differential gear assembly and having a second horizontally mounted sprocket therein spaced from the first sprocket, the second sprocket being of reduced diameter relative to the first sprocket; a drive chain trained about the first and second sprockets and driven by the differential gear assembly responsive to movement of the harrow; an arm extending outwardly from the vertical drive shaft; a pitman, having opposite ends, connected to the arm at one of said ends; a sway bar pivotally mounted on the main frame adjacent the forward end section; the outer end of the pitman being connected to the sway bar to alternately pivot the sway bar about the pivot thereof upon rotation of the drive shaft; and chains extending from the ends of the sway bar to spaced locations on the rings whereby alternate pivoting motion of the sway bar is transmitted to the rings.