Patent ID: 6598548
Filing Date: 2003-07-29
Classification: A01C

Abstract:
A seed metering device comprising:an upper member for mounting beneath a reservoir for holding granular material, said upper member having an aperture cooperating in fluid communication with said reservoir, first and second opposed facing nip forming surfaces mounted beneath said aperture so as to form a primary nip below said aperture so that granular material falls through said aperture into said primary nip, wherein said first nip forming surface is a radially-outer surface of a resilient cylindrical roller and said second nip forming surface is a rigid curved control surface on a lower wall mounted beneath said upper member and adjacent said roller, said roller rotatable about an axis of rotation by a roller drive driven by driving means in a first rotational direction so as to draw the granular material down through said primary nip, by frictional engagement of the granular material in said nip with said surface of said resilient roller, said control surface having a center of curvature offset from said axis of rotation of said roller so that said control surface and said roller are eccentric and said primary nip is elongate, curved and wedge-shaped, a vertex of said wedge-shape of said primary nip being at a lower end of said control surface beneath said roller, said vertex including at a lower, downstream-most end, a substantially horizontal flat spreader surface, extending as a uniformly flat surface substantially horizontally in said first rotational direction and across the width of said vertex so as to laterally spread granular material in said primary nip across said width of said vertex as said roller is rotated in said first rotational direction to thereby provide a laterally spread uniformly metered flow of the granular material cascading from said vertex, said seeds following a pathway from said first aperture, into a wide upper opening of said primary nip and into compressed engagement between said roller and said control surface so as to resiliently deform said roller as said roller resiliently urges said seeds into a single thickness layer as said primary nip converges to said vertex and the granular material is drawn through said primary nip so as to emerge downstream of said vertex for dropping into an outfeed chute.