One-by-one pneumatic seeder

Claim 1

In a one-by-one pneuatic seeder including a hopper with a rotary dispenser disc forming a wall portion thereof, said rotary dispenser disc having a series of equidistant holes arranged in an annular zone concentric with the axis of rotation of said dispenser disc, a part-circular suction chamber adapted to be connected to a source of partial vacuum and disposed along the face of said dispenser disc remote from said hopper and in alignment with said annular zone on said disc, said suction chamber having first and second ends in the direction of said holes opposite said part-circular suction chamber at any given time being subjected to the partial vacuum while said holes beyond the ends of said part-circular suction chamber are subjected to atmospheric pressure, wherein the improvement comprises seed dislodging means for gradually rocking each seed loose in its hole before each seed arrives at said second end of said suction chamber with all seeds being released for substantially identical successive drop trajectories, said seed dislodging means being disposed on the side of said dispenser disc remote from said suction chamber and arranged along and juxtaposed to the annular zone of said dispenser disc, the annular zone being relatively rotatable with respect to said dislodging means, said dislodging means gradually approaching but without crossing the circle defined by the centers of said holes in said annular zone, the portion of said dislodging means closest to said circle being disposed substantially at and opposite the second end of said partcircular suction chamber.