Ground tilling apparatus

Tilling apparatus comprising a supporting frame adapted to be coupled to a tractor having a drive axle, a tiller shaft journaled on said frame for rotation about an axis parallel with and spaced from said drive axle, said tiller shaft having fixedly secured thereto a plurality of circumferentially spaced-apart, radially extending, ground penetrating tines, each said tine having a pointed tip and a shank portion intermediate said shaft and tip, means drivingly coupling said tractor to said tiller shaft for rotating the tiller shaft in the same direction as and at a predetermined speed ratio with respect to said axle, said ratio being selected so that an imaginary circle concentric with said tiller shaft and defined by points on said shank portions rotates at a circumferential speed substantially equal to the ground speed of said tractor whereby said tips generate a curtate cycloidal curve as said tines rotate and said tiller shaft is moved forwardly, each of said tines being smoothly curved from its tip toward said shaft forwardly in the direction of rotation thereof generally along a true arc which approximates the segment of said curtate cycloidal curve generated as its tip enters the ground whereby said tips pierce the ground by curtate cycloidal movement with the respective shank portions following in the holes formed by the tips.