US Patent 9144189 Integrated implement downforce control systems, methods, and apparatus

A downforce controller for an agricultural implement having a double-acting hydraulic cylinder. The cylinder is configured to be coupled to an agricultural row unit and an agricultural toolbar for transmitting a net downforce between the agricultural toolbar and the agricultural row unit. A first pressure in a first chamber of the cylinder and a second pressure in a second chamber of the cylinder have counteracting effects on the net downforce. A manifold coupled to the cylinder is in fluid communication with the first chamber. A pressure control valve coupled to the manifold is in fluid communication with the manifold and the first chamber.