Abstract: A ballast plow (1) comprises a machine frame (6) supported on on-track undercarriages (2), with which is associated a center plow (5) which is vertically adjustable by means of drives and on each longitudinal side of the machine a vertically adjustable shoulder plow (8) having a plow blade (20) which may be brought into contact with ballast. The shoulder plow is provided with an articulation point (13) and a telescopically extendable carrier frame (12) extending perpendicularly to the longitudinal direction of the machine. The articulation point (13) is situated in each case--viewed in the transverse direction of the machine--on the longitudinal side of the machine which is further away from the associated plow blade (20) of the shoulder plow (8). The plow blade (20) is mounted for pivoting about an axis (21) extending in the longitudinal direction of the machine and is connected to a shoulder angle adjustment drive (15).

Abstract: An external shutoff element for a multiple row pneumatic seed planter having a transverse frame, a plurality of seed planting elements thereon, a hollow rotary seed selector drum with a plurality of spaced apart rows of seed retaining perforations which correspond to the planting elements, an airblower forcing air outwardly from within the drum thereby suspending individual seeds in a depression associated with each perforation so long as the perforation is not blocked, a discharge portion for dislodging the seeds from the perforations and delivering them to the respective planting elements, the improvement comprising a shutoff element movably mounted on the frame above the discharge portion for selectively engaging the outside of the drum to cover a group of rows of perforations so that the usual radial pneumatic bias generated by the airblower ceases to hold the seeds in the covered rows of perforations and they fall before the discharge portion can deliver them for planting.