Device for loading and unloading merchandise

The system has parallel and pivoting arms mounted on a floor of a road vehicle. A basket (3) for reception of storage unit is suspended between the arms and has an open top (33), open bottom (34), and lateral walls (30) forming a retained clip. The walls are held together at their upper and lower ends by jacks (31, 32) that allow the walls to selectively occupy unit retaining and releasing positions.