Abstract: A planting unit which includes opening plows, seed chute, and covering devices, which are carried by a four link parallel motion linkage to the tool bar, has a novel spring arrangement. The spring extends from one of the junctions of the linkage to a spring lever mounted at midpoint of one of the links. The spring lever is adjusted about its pivot point by having an adjustment bar extending through an ear and held in place by a pin through one of a selected number of holes. The linkage is connected to a cylindrical tool bar by "U" bolts so that each of many planting units may be adjusted for proper alignment relative to all the other planting units. The cylindrical planter tool bar is journaled to a main tool bar so that all of the planting units upon the planter bar may be adjusted by rotating the cylindrical planter tool bar about its longitudinal axis, making it unnecessary to rotate the entire main tool bar.

Abstract: In a vacuum planter a second disc with standard perforations is placed within the housing so that twice as many seed may be dropped with the same rotational speed and perforation spacing.

Abstract: A grain drill has the planter disc pivot arms pivoted to a bracket. The bracket pivots are above or below a slotted bar whereby the planter discs may be adjusted longitudinally of the frame. The pivot arms may be raised or lowered by reversing the brackets.The seeder housings are clamped along a longitudinal slot in the bottom of the seed box so the housing may be adjusted to the position of the planter disc. The seeder discs are clamped to a square shaft so they can be adjusted to the position of the housing.