摘要 |
<p>A cylindrical housing is divided by a rotating disk 48 into a vacuum chamber and a seed chamber. The disk has a circumferential row of apertures and, as it rotates, individual seeds are held onto the apertures by virtue of the vacuum on the opposite side of the disk 48. Over one sector of the disk the vacuum is not applied by virtue of a suitably shaped partition. On the feed chamber side, a barrier 88 partitions the seed reservoir 76 from a discharge chute 44. Because the vacuum is interrupted, the seeds 150 drop off the disk and down the chute. In order to promote reliable picking up of single seeds only, each aperture opens into a tear drop shaped recess forming a seed cell 144. Adjacent each cell there is an agitating fin 146 on the disk 48. The barrier 88 comprises a brush wiping against the disk, except at the top where the loaded seed cells 144 pass over towards the chute 44.</p> |