Depth and down pressure control of an agricultural fertilizer row unit
A fertilizer row unit including a toolbar coupling, first and second suspension members, a pressure applying device, a wheel assembly, a knife assembly and a wheel down pressure system. The first suspension member has a first end pivotally coupled to the toolbar coupling. The second suspension member is generally parallel to the first suspension member. The pressure applying device is coupled to the first or second suspension member. The wheel assembly has at least one wheel. The knife assembly is pivotally coupled to both the first and second suspension members. The wheel down pressure system is coupled to the wheel assembly, the wheel down pressure system substantially maintaining a selected pressure on the wheel assembly while the pressure applying device applies varying pressure to at least the first suspension member and the second suspension member.
1. A fertilizer row unit, comprising:
a toolbar coupling for coupling the fertilizer row unit to a toolbar of a fertilizer applicator;
a first suspension member having a first end pivotally coupled to the toolbar coupling about a generally horizontal axis;
a second suspension member generally parallel to the first suspension member;
a pressure applying device coupled to at least one of the first suspension member and the second suspension member;
a fertilizer delivery device;
a wheel assembly having a pivotable member, an actuator for tensioning the wheel assembly, a press wheel, and a gauge wheel for traversing across soil, the press wheel and the gauge wheel are coupled to the pivotable member by way of a walking axle member;
a knife assembly including a knife blade, the knife blade having the fertilizer delivery device coupled thereto, the knife assembly being pivotally coupled to both the first suspension member and the second suspension member;
a depth control system including a sensor connected to the pivotable member for measuring a position of the pivotable member, the depth control system controlling a depth of the knife blade; and
a wheel down pressure system coupled to the wheel assembly, the wheel down pressure system substantially maintaining a selected pressure on the press wheel, wherein while the pressure applying device applies a varying pressure to at least one of the first suspension member and the second suspension member, for maintaining a depth of the fertilizer delivery device, the selected pressure on the press wheel is maintained by the actuator, regardless of the varying pressure applied by the pressure applying device for maintaining the depth of the fertilizer delivery device.
2. The fertilizer row unit of claim 1 , wherein the wheel down pressure system additionally receives a pressure signal from an operator, the wheel down pressure system being configured to minimize a difference between the pressure signal and a measured pressure signal.
3. The fertilizer row unit of claim 2 , wherein the pivotable member is coupled between the gauge wheel and to the depth control system or to the knife assembly.
4. The fertilizer row unit of claim 1 , wherein the pivotable member is coupled between the gauge wheel and to the depth control system or to the knife assembly.
5. The fertilizer row unit of claim 1 , wherein the press wheel and the gauge wheel are on opposite sides of the walking axle member.
6. The fertilizer row unit of claim 5 , wherein the press wheel follows the knife assembly and the fertilizer delivery device in a direction in which the fertilizer row unit travels.
7. The fertilizer row unit of claim 1 , wherein the toolbar coupling is pivotal along a generally upright axis.
8. The fertilizer row unit of claim 7 , wherein part of the fertilizer row unit is fore of the generally upright axis relative to a direction in which the fertilizer row unit travels.
9. The fertilizer row unit of claim 8 , wherein the first end of the first suspension member is generally horizontally pivotally coupled to the toolbar coupling fore of the generally upright axis.