COMBINATION HYDRAULIC HOLD-DOWN AND LIFT SYSTEM FOR AN AGRICULTURAL IMPLEMENT

摘要

A static hydraulic system provides yieldable hold-down force to the ground-engaging tools of an implement when the system is in its hold-down mode. Alternatively, the system can be operated in a way to lift the tools into an elevated ground-clearing position when placed in the lifting mode. An accumulator and pressure-reducing valve are incorporated into the hydraulic circuit in such a way that the system need not be an active hydraulic system in which a pump on the tractor would continuously circulate pressurized fluid in the system during ground-engaging operations in the hold-down mode.