Depth control valve and system for agricultural implements

摘要: Disclosed is a representative agricultural implement towed by tractor equipped hydraulic power source connected to lift mechanism for raising and lowering the frame so as vary ground-working depth of working tools. The carries sensor responsive changes in above below preselected norm. This serves input inventive control valve system automatically. designed four-position valve, with one positions serving dual modes that produces fast slow raising, neutral or balanced position. has pressure port side via manual afford three four active setting valve. fourth position (fast raise) achieved changing reverse return ports Reversal these activates chamber pressure-receivable area on spool