Vacuum seed meter

Abstract

An air seed meter which dispenses individual seeds supplied by a seed hopper into a furrow at a controlled rate as the meter and others like it are advanced over the ground has a generally cylindrical housing containing a rotatable seed disk. As the seed disk is rotated past a mass of seeds on one side thereof, a plurality of seed cells formed by recesses in the surface of the seed disk at one or more circumferential rows of holes adjacent the outer periphery of the seed disk mechanically accelerate and eventually capture therein individual seeds from the seed mass. The individual seeds are held within the cells by a pressure differential created by a vacuum source coupled to the inside of the housing on the opposite side of the seed disk until the cells reach a discharge area. At the discharge area, the effects of the vacuum are cut off so as to release the individual seeds from the cells for discharge through a chute at the bottom of the housing to a seed furrow below. Agitation of seeds within the seed mass with the accompanying mechanical acceleration and capture of individual seeds within the cells may be enhanced by providing fins on the surface of the seed disk and is facilitated by a cell configuration which has a rear wall of greater slope than the front wall of the cell. Doubling of seeds within the individual cells is minimized by limiting the size and depth of the cells relative to the seed and also by use of a relatively low pressure differential which is made possible by the manner in which the cells agitate, mechanically accelerate and then capture the seeds. As a result there is no need for cumbersome and elaborate multiple seed eliminating arrangements.