US Patent 7152540 Seed tube for an agricultural planter

A seed tube for an agricultural planter having a rearwardly curving forward wall, a rearwardly curving rearward wall and opposing side walls defining a seed passageway which curves rearwardly from an upper ingress end toward a lower egress end. An aperture is disposed in the forward wall adapted to receive a seed sensor element. An overlap extends over a portion of the aperture. The tube has an upper portion and a lower portion. The forward wall of the lower portion disposed forwardly of the forward wall of the upper portion, such that an interior surface of the forward wall of the lower portion is disposed forwardly of an interior surface of the forward wall of the upper portion.