Row crop tillage and planting unit guidance system

Claim 1

In combination with a tractor including a longitudinal center line and a lift hitch incorporating a pair of laterally spaced rearwardly projecting lower hitch arms, an elongated horizontal transverse tool bar including a longitudinal mid-portion and opposite end portions, first mounting means mounted to portions of said tool bar spaced longitudinally to either side of said longitudinal mid portion of said tool bar, said first mounting means pivotally mounting said tool bar from the rear ends of said lower arms for angular displacement relative thereto about generally aligned horizontal transverse axes, second mounting means including means operative to variably adjustably longitudinally shift said tool bar along said axes, a depending tillage unit supported from said tool bar, said tillage unit including sensing means for sensing lateral displacement of a row crop to either side of a predetermined path paralleling the longitudinal center line of said tractor and control means operatively associated with said row crop sensing means and said second mounting means operative to longitudinally displace said tool bar relative to said lower arm rear ends in the direction in which said row crop sensing means senses lateral displacement of said crop row laterally of said predetermined path, said row crop sensing means including a pair of laterally spaced depending control shafts mounted from said tool bar for oscillation about upstanding axes, the lower ends of said shafts including horizontally rearwardly directed and convergent plant sensing arms, a horiziontal switch arm mounted from said tool bar for oscillation about an upstanding axis, biasing means guidingly biasing said switch arm toward a predetermined central position of oscillation, a pair of control arms generally paralleling said switch arm and carried by the upper ends of said shafts, connecting means connecting the free ends of said control arms to the free end of said switch arm, switch means operatively associated with said switch arm and control means for relatively reversely actuating said control means responsive to opposite angular displacement of said switch arm from said predetermined position, said switch means, including a pair of laterally spaced contact bars extending longitudinally of said switch arm and a pair of upstanding switch contacts having base ends insulatively stationarily mounted from said tool bar and free ends disposed between said contact bars for engagement thereby upon oscillation of said switch arm.