Several conveyor rollers of singulators are made to rotate by a fruit orientation belt causing fruit carried thereon to rotate in accordance with movement of the belt such that the rotational axes of the fruit, typically lemons, orient themselves along their stem axes, or substantially perpendicularly...http://www.google.com/patents/US4726898?utm_source=gb-gplus-sharePatent US4726898 - Apparatus for spinning fruit for sorting thereof
