Transport trailer with unloading by a winding conveyor

The device has a three-dimensional stand for guiding and maintaining a rigid movable wall (6), and arranged on a side of the wall, where the side is not exposed to a transported load. The stand comprises a base that is spaced over a certain distance in a direction opposite to the wall. A guiding unit is formed of rollers, pads or pins. A flexible uniform hermetic bottom band and the guiding unit are displaced on a sliding surface formed by a case bottom (7), where longitudinal slats serve as the sliding surface and support slides.