Agricultural systems

Abstract

An agricultural implement includes at least one row unit having a plurality of support members, each of which is pivotably coupled to an attachment frame or another of the support members to permit vertical pivoting vertical movement of the support members, and a plurality of soil-engaging tools, each of which is coupled to at least one of the support members. A plurality of hydraulic cylinders are coupled to the support members for urging the support members downwardly toward the soil. A plurality of controllable pressure control valves are coupled to the hydraulic cylinders for controlling the pressure of hydraulic fluid supplied to the cylinders. A plurality of sensors produce electrical signals corresponding to predetermined conditions, and a controller is coupled to the sensor and the controllable pressure control valves. The controller receives the electrical signals from the sensors and produces control signals for controlling the pressure control valves.

1 - 21 . (canceled) 
     
     
         22 . An agricultural row unit comprising
 a frame having a gauge wheel that engages the soil to control the elevation of the frame,   a soil-engaging tool coupled to said frame to permit vertical movement of said tool relative to said frame,   a hydraulic cylinder having a movable ram and containing a pressurized hydraulic fluid for applying at least one of down pressure and up pressure to said tool,   an uplift energy storage device coupled to said hydraulic cylinder to permit upward movement of said tool in response to increased resistance by the soil to downward movement of said tool, while applying a force resisting said upward movement of said tool, and   a down pressure energy storage device coupled to said hydraulic cylinder to permit downward movement of said tool in response to decreased resistance by the soil to downward movement of said tool, while applying a force resisting said downward movement of said tool.   
     
     
         23 . The agricultural row unit of  claim 22  in which said hydraulic cylinder includes a double-acting ram to provide both up pressure and down pressure. 
     
     
         24 . The agricultural row unit of  claim 22  in which said energy storage devices are accumulators. 
     
     
         25 . A method of controlling down pressure in an agricultural row unit that includes a frame having a gauge wheel that engages the soil to control the elevation of the frame, a soil-engaging tool coupled to said frame to permit vertical movement of said tool relative to said frame, and a hydraulic cylinder having a movable ram and containing a pressurized hydraulic fluid for applying at least one of down pressure and up pressure to said tool,
 permitting upward movement of said tool in response to increased resistance by the soil to downward movement of said tool, while applying a force resisting said upward movement of said tool, and   permitting downward movement of said tool in response to decreased resistance by the soil to downward movement of said tool, while applying a force resisting said downward movement of said tool.   
     
     
         26 . The method of  claim 25  in which a double-acting ram in said hydraulic is used to provide both up pressure and down pressure. 
     
     
         27 . The method of  claim 25  in which said forces resisting said upward and downward movements of said tool are energy storage devices. 
     
     
         28 . The method of  claim 27  in which said energy storage devices are accumulators coupled to said hydraulic cylinder.