Grain drill opener with separate placement and a concave disk therefor

Abstract

A combination seed and fertilizer opener having separate placement includes a first angled flat disk with a gauge wheel arrangement providing an initial furrow for a first material such as fertilizer. A second opener disk, smaller than the first and concave rather than flat, includes an edge that projects forwardly along the trailing side of the first disk to a forwardmost edge location adjacent the hub of the first disk. The hub of the concave disk is very closely adjacent the trailing edge of the large disk. A tube and boot assembly terminates within the concavity of the second disk near the rear periphery of the first disk. The concave disk forms a seed furrow to receive seed or second material from the tube and boot assembly. The front of the concave disk runs in undisturbed soil but is sufficiently close to the fertilizer furrow to press and cover the fertilizer. The second disk concavity also prevents excessive soil throw. The boot lies within the shadow of the large disk so that the boot does not have to push soil aside but acts primarily to prevent dirt from prematurely filling in the second furrow. A closing wheel is supported from the opener assembly directly behind the large disk and is angled to toward the concavity of the second disk to break soil from the seed furrow wall and close the seed furrow. The concave disk not only provides closing and furrowing functions with limited soil throw but also provides a compact bearing-receiving area. The edge of the concave disk is beveled on the inside of the concavity, opposite that of a conventional concave disk, to reduce forces necessary to form the seed furrow and cover the fertilizer.