Abstract: In a separator for pneumatic single grade sowing machines, a supporting plate (1) is provided to which a plurality of fingers (8; 28; 41) are pivotally connected. One end of the fingers forms an effective area section (12) which engages passing seed grains clinging to suction holes (6) of an apertured plate 4. Each finger (8; 28; 41) is engaged by a respective spring (13; 20; 23; 30; 44) which acts on the fingers (8; 28; 41) and thus on their effective area sections (12) against the direction of rotation (10) of the apertured plate (4) (FIG. 1).

Abstract: A single seed drilling machine has a rotatable drum the interior of which is connected in use to a source of reduced pressure. The drum is closed by a plate which has a circle of suction holes, so that seed can be held at the holes against the outer surface of the plate. Within the drum an interrupter device engages the plate to close a hole in the lowest region of the plate. Adjacent that hole, outside the plate, is a seed ejector device. Thus in the lowest region of the rotatable plate, the suction holding seed at a hole is temporarily rendered ineffective, at which time the seed is directed away from the plate by the ejector device.