US Patent 7581503 Fertilizer opener/closer arrangement for an agricultural machine

An agricultural machine includes a tool bar and at least one opener/closer arrangement carried by the tool bar for opening a trench in soil. Each opener/closer arrangement includes an opener disc positioned at an angle relative to a working direction and defining a trench profile. The opener disc has an axis of rotation, a leading edge, and a trailing edge positioned adjacent one side of the trench profile. A gauge wheel is positioned generally inline with the opener disc adjacent to the trailing edge of the opener disc. The gauge wheel has a leading edge positioned between the leading edge and the trailing edge of the opener disc. A first closing wheel is positioned on a side of the trench profile opposite to the gauge wheel. The first closing wheel has a leading edge positioned between the axis of rotation and the trailing edge of the opener disc. A second closing wheel is positioned on a same side of the trench profile as the gauge wheel.