AGRICULTURAL ROW MARKER

摘要

A folding row marker for an agricultural implement includes a marker arm having two separate sections pivoted in the middle, the sections being extended and aligned in an unfolded or use position and being foldable to a storage position and being actuated between the use and storage position by an hydraulic cylinder. A swing link which is pivotally mounted to the frame of the implement guides the rod end of the cylinder about its pivotal connection to the frame, and a push/pull link connected to the swing link and pivotally connected to the base of the marker arm is generally aligned with the axis of the cylinder when the cylinder is retracted and pushes the base of the marker arm about its pivotal connection to the frame. During initial extension motion of the cylinder, equal increments of elongation of the cylinder cause generally equal angular displacement or rotation of the marker arm as it is moved to the use position. As the marker arm is moved toward the storage position and passes over top dead center, the push/pull link is placed in tension, holding the marker arm against its weight. As the marker arm approaches the storage position, the push/pull link is rotated to a position such that equal increments of extension of the cylinder caused progressively smaller increments of angular displacement of the marker arm, thereby causing the marker arm to decelerate as the cylinder reaches the end of an extension sequence.