PNEUMATIC SEEDING UNIT Russian patent published in 2007 - IPC A01C7/04 

FIELD: agricultural engineering.

SUBSTANCE: seeding unit has casing with seed chamber and cover provided with vacuum chamber. Stirrer and seeding disk with suction openings are mounted on drive shaft within casing. Excessive seed flicker is also mounted within casing. Vacuum chamber is provided with widened portions at its both sides in zone extending from the beginning of seed chamber to excessive seed flicker. Seeding disk has additional openings with diameter equal to that of suction openings. Additional openings are arranged radially, at equal distances from circle of suction opening centers. Radial distance between outer edges of additional openings is less than distance between outer edges of vacuum chamber widened portions but greater than distance between outer edges of non-widened portion of vacuum chamber. Layer positioned between seeding disk and vacuum chamber is equipped with cuts which are configured to conform to vacuum chamber having widened portions.

EFFECT: reduced quantity of gripping seeds by means of suction openings during withdrawal of seeds from seed layer, and improved quality of feeding single seeds.

4 dwg