Patent ID: 8657023

Claim:
An agricultural implement adapted to be moved by a vehicle in a forward direction of travel, the agricultural implement comprising: a first frame section; a first ground-engaging tool coupled to the first frame section; an electro-hydraulic controller configured to receive a source of hydraulic pressure; a lift device in fluid communication with the electro-hydraulic controller and coupled to the first frame section, the lift device configured for raising and lowering the first frame section with respect to the ground to move the first ground-engaging tool between a first ground-engaging tool transport position and a first pre-selected operating depth; a second frame section coupled to the first frame section forward of the first ground-engaging tool, wherein positioning of the second frame section is dependent upon positioning of the first frame section; a second ground-engaging tool coupled to the second frame section; an extendable and retractable cylinder in fluid communication with the electro-hydraulic controller and coupled to the first frame section and the second frame section, the extendable and retractable cylinder configured to move the second ground-engaging tool between a second ground-engaging tool transport position and a second pre-selected operating depth; and a depth control device having at least one sensor configured to sense an operating depth of the second ground-engaging tool, the at least one sensor being operatively coupled to the electro-hydraulic controller, wherein the electro-hydraulic controller receives from the depth control device an input signal based on a signal from the at least one sensor and controls at least one of the lift device and the extendable and retractable cylinder to compensate for movement of the first frame section as needed to maintain the second ground-engaging tool substantially at the second pre-selected operating depth.