Row centering guide control device for bush bean harvester

Claim 1

In an agricultural harvesting machine having a chassis supported upon steerable ground engaging front wheels and ground engaging rear traction wheels, the improvement comprising: an underslung scow carried by the machine and extending lengthwise thereof, a frame pivotally attached to said scow and extending outwardly and rearwardly relative thereto for engagement with proximal row crops, a switch actuating arm pivotally attached at one of its ends to said frame and pivotally attached intermediate its ends to said scow, the forward end of said switch actuating arm movable between a first pair of spaced apart steering control switches and adapted to alternately actuate said switches upon right or left deviation in the course of travel of said machine along the row crops, said chassis including a steering yoke supporting said steerable front wheels, a tierod carried by said yoke and connected to said steering wheels for steering the same, a steering cylinder carried by said yoke and having a piston operable therein and connected to said tierod whereby movement of the piston to the right or left within said cylinder will impart corresponding steering angles to said steering wheels, a fluid pressure cylinder carried by said machine, a valve operable within said fluid pressure cylinder, one side of said fluid pressure cylinder in communication at both of its ends with the corresponding ends of said steering cylinder, the other side of said fluid pressure cylinder connected to a fluid pump and a fluid reservoir, said valve connected at each of its ends to a solenoid mounted upon each end of said fluid pressure cylinder, a second pair of electric switches each in circuit with a solenoid and each operable by movement of said tierod to maintain said steering wheels in alignment with the tractor centerline after return of the chassis to a desired path between the row crops causing deactivation of said steering control switches, all of said switches in electric circuitry with each other and with a source of electric current carried by said machine, each of said switches being of the single pole double throw type, each of said solenoids having a core connected to said valve, one end of each of said solenoids having a ground connection to said source of electric current, the opposite end of one solenoid electrically connected to one side of one switch in said first pair of switches and to the corresponding side of the other switch in said second pair of switches, and the opposite end of the other side of said solenoids electrically connected to one side of the other switch in said first pair of switches and to the corresponding side of the other switch in said second pair of switches.