Seed meter

Abstract

A seed meter for an agricultural planter in which the seed disc is rotatably mounted within a seed meter housing. As the seed disc rotates, the apertures in the disc rotate along a seed aperture path through a horizontally adjacent seed pool area. The seed disc includes cavities disposed along the seed aperture path to agitate the seeds in the seed pool area. A singulator having multiple co-planar singulator surfaces is biased against the seed side surface of the seed disc.

1 . A seed distribution element for precision pneumatic seed drills, comprising:
 a sowing disc which is rotated by a motor-driven transmission drive shaft at controlled speed;   a housing with a fixed portion and a portion which is movable relative to the fixed portion and can be closed against the fixed portion;   a seed collection chamber being defined in the fixed portion;   a pneumatic suction chamber being defined in the movable portion;   the sowing disc being interposed between the fixed and movable portions and having opposed surfaces delimiting the chambers;   the sowing disc having at least one ring of selector holes extending between the opposed surfaces; and   a seal which is arranged on the movable portion and is capable of sliding contact with the facing surface of the disc when the fixed and movable portions are closed against one another;   wherein a pressure differential is provided between the opposed surfaces in the region of a circumferential segment of the ring of holes;   wherein the seed distribution element further comprises a thrust-bearing element of the sowing disc, which thrust-bearing element is supported rotatably in the movable portion in order to withstand at least some of the axial load produced by the disc on the seal.   
     
     
         2 . The seed distribution element according to  claim 1 , wherein the thrust-bearing element is rotated with the disc when the fixed and movable portions are closed against one another. 
     
     
         3 . The seed distribution element according to  claim 1 , wherein the thrust-bearing element comprises a thrust-bearing plate which can bear on that surface of the sowing disc which faces the seal, in a zone radially inside of the ring of holes. 
     
     
         4 . The seed distribution element according to  claim 3 , wherein the thrust-bearing element comprises a drive element which is fixed for rotation with the plate and can be coupled with the drive shaft of the disc when the fixed and movable portions are closed against one another. 
     
     
         5 . The seed distribution element according to  claim 4 , wherein the drive element is self-centring relative to the drive shaft. 
     
     
         6 . The seed distribution element according to  claim 4 , wherein the drive element comprises a coupling member which rotates jointly with the thrust-bearing plate but has radial and/or circumferential clearance so as to be self-centred during rotational coupling with the drive shaft of the disc. 
     
     
         7 . The seed distribution element according to  claim 1 , wherein the movable portion is hinged to the fixed portion. 
     
     
         8 . A sowing element for precision seed drills comprising a frame on which a seed distribution element according to  claim 1  is mounted. 
     
     
         9 . A seed drill comprising a supporting structure on which a plurality of sowing elements according to  claim 8  are mounted. 
     
     
         10 . A kit for the retrofitting of seed distribution elements of precision pneumatic seed drills wherein the distribution elements are of the type including:
 a sowing disc which is rotated by a motor-driven transmission drive shaft at controlled speed;   a housing with a fixed portion and a portion which is movable relative to the fixed portion and can be closed against the fixed portion;   a seed collection chamber being defined in the fixed portion;   a pneumatic suction chamber being defined in the movable portion;   the sowing disc being interposed between the fixed and movable portions and having opposed surfaces delimiting the chambers;   the sowing disc having at least one ring of selector holes extending between the opposed surfaces; and   a seal which is arranged on the movable portion and is capable of sliding contact with the facing surface of the disc when the portions are closed against one another;   wherein a pressure differential is provided between the opposed surfaces in the region of a circumferential segment of the ring of holes;   wherein the kit comprises the movable portion pre-assembled with a thrust-bearing element of the sowing disc, which thrust-bearing element is supported rotatably in the movable portion in order to withstand at least some of the axial load produced by the disc on the seal.   
     
     
         11 . The kit according to  claim 10  wherein the movable portion and the thrust-bearing element comprise at least one feature according to  claim 2 . 
     
     
         12 . The kit according to  claim 10  wherein the movable portion and the thrust-bearing element comprise at least one feature according to  claim 3 . 
     
     
         13 . The kit according to  claim 10  wherein the movable portion and the thrust-bearing element comprise at least one feature according to  claim 4 . 
     
     
         14 . The kit according to  claim 10  wherein the movable portion and the thrust-bearing element comprise at least one feature according to  claim 5 . 
     
     
         15 . The kit according to  claim 10  wherein the movable portion and the thrust-bearing element comprise at least one feature according to  claim 6 . 
     
     
         16 . The kit according to  claim 10  wherein the movable portion and the thrust-bearing element comprise at least one feature according to  claim 7 . 
     
     
         17 . A seed meter for an agricultural planter, said seed meter comprising:
 a seed disc which is rotated by a motor-driven shaft at controlled speed;   a meter housing with a fixed portion and a portion which is movable relative to the fixed portion and can be closed against the fixed portion;   a seed pool area being defined in the fixed portion;   a vacuum area defined in the movable portion;   the seed disc being interposed between the fixed and movable portions and having opposed surfaces delimiting the seed pool area from the vacuum area;   the seed disc having at least one ring of seed apertures extending between the opposed surfaces; and   a seal which is arranged on the movable portion and is capable of sliding contact with the facing surface of the disc when the fixed and movable portions are closed against one another   wherein a pressure differential is provided between the opposed surfaces in the region of a circumferential segment of the ring of seed apertures;   wherein the seed meter further comprises a thrust-bearing element of the seed disc, which thrust-bearing element is supported rotatably in the movable portion in order to withstand at least some of the axial load produced by the disc on the seal.   
     
     
         18 . The seed meter according to  claim 17 , wherein the thrust-bearing element is rotated with the disc when the fixed and movable portions are closed against one another. 
     
     
         19 . The seed meter according to  claim 17 , wherein the thrust-bearing element comprises a thrust-bearing plate which can bear on that surface of the seed disc which faces the seal, in a zone radially inside of the ring of seed apertures. 
     
     
         20 . The seed meter according to  claim 19 , wherein the thrust-bearing element comprises a drive element which is fixed for rotation with the plate and can be coupled with the shaft of the disc when the fixed and movable portions are closed against one another. 
     
     
         21 . The seed meter according to  claim 20 , wherein the drive element is centered relative to the shaft. 
     
     
         22 . The seed meter according to  claim 20 , wherein the drive element comprises a coupling member which rotates jointly with the thrust-bearing plate. 
     
     
         23 . The seed meter according to  claim 17 , wherein the movable portion is mechanically coupled to the fixed portion. 
     
     
         24 . An agricultural planter comprising a frame on which a seed meter according to  claim 17  is mounted. 
     
     
         25 . An agricultural planter including a supporting structure on which a plurality of seed meters according to  claim 24  are mounted. 
     
     
         26 . An assembly for a seed meter of an agricultural planter wherein the seed meter is of the type including:
 a seed disc which is rotated by a motor-driven shaft at controlled speed;   a meter housing with a fixed portion and a portion which is movable relative to the fixed portion and can be closed against the fixed portion;   a seed pool area being defined in the fixed portion;   a vacuum area defined in the movable portion;   the seed disc being interposed between the fixed and movable portions and having opposed surfaces delimiting the seed pool area from the vacuum area;   the seed disc having at least one ring of seed apertures extending between the opposed surfaces; and   a seal which is arranged on the movable portion and is capable of sliding contact with the facing surface of the disc when the fixed and movable portions are closed against one another;   wherein a pressure differential is provided between the opposed surfaces in the region of a circumferential segment of the ring of seed apertures;   wherein the assembly comprises, in said movable portion, a thrust-bearing element of the seed disc, which thrust-bearing element is supported rotatably in the movable portion in order to withstand at least some of the axial load produced by the disc on the seal.   
     
     
         27 . The assembly according to  claim 26  wherein the thrust-bearing element is rotated with the disc when the fixed and movable portions are closed against one another. 
     
     
         28 . The assembly according to  claim 26  wherein the thrust-bearing element comprises a thrust-bearing plate which can bear on that surface of the seed disc which faces the seal, in a zone radially inside of the ring of seed apertures. 
     
     
         29 . The assembly according to  claim 26  wherein the thrust-bearing element comprises a drive element which is fixed for rotation with the plate and can be coupled with the shaft of the disc when the fixed and movable portions are closed against one another. 
     
     
         30 . The assembly according to  claim 29  wherein the drive element is centered relative to the shaft. 
     
     
         31 . The assembly according to  claim 29  wherein the drive element comprises a coupling member which rotates jointly with the thrust-bearing plate. 
     
     
         32 . The assembly according to  claim 26  wherein the movable portion is mechanically coupled to the fixed portion.