| 摘要 |
There is described a furrow opener apparatus capable of operating in a furrowing mode and a carrying mode. The apparatus consists of a double acting hydraulic cylinder having one end connected to a furrow opener drag arm and the other end connectable to a drill rig. It incorporates a pressure cushioning system consisting of at least one pressure absorber and hydraulic lines communicating through a mode valve with both the thrust and draw sides of the double acting cylinder. It further communicates through a single or double acting hydraulic valve to the hydraulic pump and reservoir of an associated prime mover such as a tractor. The mode valve is hydraulically connected to both the thrust and draw sides of the double acting cylinder. In a first mode the mode valve is hydraulically connectable to the pressure cushioning system and in a second mode hydraulically connected through a double acting hydraulic valve to the hydraulic pump and hydraulic reservoir of the prime mover. In use when the mode valve is in the first mode the pressure absorber cushions forces transmitted hydraulically through the double acting hydraulic cylinder from the openers and maintains a substantially constant pressure on both the draw and thrust sides of the double acting cylinder to thereby create a net downward force from the ram onto the furrow opener arm. In the second mode the double acting hydraulic cylinder is operable by the double acting hydraulic valve to thrust or draw its ram to respectively lower or raise the furrow opener drag arm. |
