Abstract: A material handling device comprises a roller conveyor component having rollers which are separated by gaps; a cage component which includes rows of uprights, the spacing and the thickness of the uprights in each row being such as to permit their insertion into said gaps and their movement through the gaps; crosspieces interconnecting the uprights of one row only with corresponding uprights of other rows, the crosspieces extending parallel to the axes of the rollers and being insertable in the gaps; a motor for effecting relative movement between the cage and the conveyor perpendicularly to each other such that the uprights and the crosspieces can move through the gaps.