Patent attributes
A tillage shank assembly has one or more substance delivery tubes supported along the back edge of the generally upright shank of the assembly. A pair of side plates on opposite sides of the shank have rear margins that project rearwardly beyond the rear edge of the shank to define a protective gap within which the tubes are disposed. Laterally extending projections on the tubes are received within selected ones of a vertical series of holes in the side plates, depending upon the desired depth for the tubes. By temporarily removing a bolt that attaches the tops of the side plates to the shank, the side plates may be separated sufficiently to permit the projections of the tubes to be withdrawn from their current holes and reinserted into other holes to change their vertical locations. Replacing the bolt and tightening it down returns the side plates to their working positions.