Planter height and marker control system

Abstract

The planter height and control system is adapted for use with an agricultural planter assembly which is adapted to be mechanically and hydraulically coupled to a tractor and which includes a frame, a plurality of equally spaced planter units mounted to the frame, and at least two wheel assemblies on each side of the planter assembly. Each wheel assembly is pivotally mounted to the frame and includes a piston and cylinder mechanism which, when the piston rod thereof is extended, pivots the wheel assembly downwardly to effect raising of the planter units. The system includes an electrical-hydraulic control circuit for parallel coupling the piston and cylinder mechanisms of the at least two wheel assemblies on each side of the planter assembly and for limiting the retraction of each piston rod of each piston and cylinder mechanism to a predetermined limit less than the full return stroke of the piston rod on the lowering of the planters thereby to control the height of the planter frame above the ground and thereby to provide limited relative movement of the piston rods of the piston and cylinder mechanisms for the at least two wheel assemblies on each side of the planter assembly as the planter assembly traverses uneven ground.