A combine harvester (10) is provided with a conveyance system (100, 200, 300, 400, 500, 600, 700) for transporting crop material discharged by overhead grain separating apparatus to a grain cleaning shoe (42). The conveyance system comprises a series of oscillating pans which move the grain in a generally longitudinal direction. A return pan (138, 238, 338, 438, 538, 638, 738, 838) conveys the collected material forwardly to a front discharge edge from where the material falls onto a stratification pan (40) below. The stratification pan conveys the collected material rearwardly to a rear discharge edge from where the material falls into the grain cleaning shoe (42). At least one of the return pan and the stratification pan is non-rectangular and has a non-transverse discharge edge. A combine harvester (10) is provided with a conveyance system (100, 200, 300, 400, 500, 600, 700) for transporting crop material discharged by overhead grain separating apparatus to a grain cleaning shoe (42). The conveyance system comprises a series of oscillating pans which move the grain in a generally longitudinal direction. A return pan (138, 238, 338, 438, 538, 638, 738, 838) conveys the collected material forwardly to a front discharge edge from where the material falls onto a stratification pan (40) below. The stratification pan conveys the collected material rearwardly to a rear discharge edge from where the material falls into the grain cleaning shoe (42). At least one of the return pan and the stratification pan is non-rectangular and has a non-transverse discharge edge.Selon linvention, une moissonneuse-batteuse (10) comprend un système de transport (100, 200, 300, 400, 500, 600, 700) permettant de transporter du matériau de récolte refoulé par un appareil de séparation de grain au-dessus dans des grilles de nettoyage de grain (42). Le système de transport comprend une série de bacs oscillants qui déplacent le grain dans une direction générale longitudinale. Un bac de retour (
