Abstract: A sorting machine comprising a transparent tube (16); a material supply member (15) from which material, which is to be sorted into desired and undesired portions, may pass through the transparent tube (16); a light-detector (20) disposed externally of the transparent tube (16) for receiving light from material passing through the latter; a discriminator (21), controlled by the light-detector (20), for discriminating between the desired and undesired portions; a separator (22), controlled by the discriminator (21), for separating the material which has been passed through the transparent tube (16) into the desired and undesired portions; a cleaning member (32); and a movement effecting device (36) for moving the cleaning member (32) against the wall of the transparent tube (16) characterized in that the cleaning member (16) forms part of a cleaning-calibration member (31) which is used in the calibration of the discriminator (21); and there is an actuator (30) operable so that each one of the material supply

Abstract: An apparatus for sorting material conveyed in a product stream and across a substantially level single layer on a conveyor, wherein the conveyor passes beneath an examination device which determines the presence and transverse location of any undesired material; a number of movable conduits are positioned transversely across the conveyor downstream from the examination device, and are arranged in staggered rows to transversely encompass the entire product stream on the conveyor; the suction device and movable conduits are respectively controlled by the examination device, to cause each conduit to selectively move toward the conveyor and remove undesired material from the conveyor as it passes beneath the suction device, and to move away from the conveyor when no undesired material is positioned beneath the suction device; a valve in the common suction line connected to all conduits stabilizes suction pressure during operation of the apparatus.