Loading assembly comprising a rolling chassis and a loading box which is suitable for being removably mounted on the rolling chassis by being hinged so as to be able to rotate with respect to the rolling chassis about a horizontal axis of rotation, and said rolling chassis is provided with at least one jack which comprises a movable rod and which makes it possible, when the loading box is mounted on the chassis and is coupled to the movable rod of the jack, for the loading box to be pivoted relative to the chassis about said horizontal axis of rotation, characterized in that said assembly further comprises at least one of the following technical features (a) or (b): (a) said assembly includes first, self-locking coupling means which comprise first automatic locking means, said first coupling means being suitable for adopting a locked closed position, under the effect of pressure exerted in a coupling direction and with automatic locking in their closed position by the first locking means, the first coupling means being secured to the loading box or being secured to the rod of the jack, such that the rod of the jack is suitable for being moved, and preferably extended, so as to exert, on the first coupling means, pressure in the coupling direction that automatically brings them into their locked closed position, in which they rotationally couple the rod of the jack to the loading box, the first coupling means also being unlockable, so as to be able to decouple the rod of the jack and the loading box by moving the rod of the jack relative to the loading box, and said assembly includes second coupling means which make it possible to rotationally, and removably, couple the loading box to the rolling chassis about said horizontal axis of rotation, or (b) said assembly includes first coupling means which make it possible to rotationally and removably couple the rod of the jack to the loading box, and second, self-locking coupling means which comprise second locking means, said second coupling means being suitable for adopting a locked closed position, under the effect of pressure exerted in a coupling direction and with automatic locking in their closed position by the second locking means, the second coupling means being secured to the loading box or being secured to the rolling chassis such that the rolling chassis is suitable for being moved so as to exert, on the second coupling means, pressure in the coupling direction that automatically brings them into their locked closed position, in which they rotationally couple the loading box to the rolling chassis about said axis of rotation, the second coupling means also being unlockable, so as to be able to decouple the rolling chassis and the loading box by moving the rolling chassis relative to the loading box. (a) said assembly includes first, self-locking coupling means which comprise first automatic locking means, said first coupling means being suitable for adopting a locked closed position, under the effect of pressure exerted in a coupling direction and with automatic locking in their closed position by the first locking means, the first coupling means being secured to the loading box or being secured to the rod of the jack, such that the rod of the jack is suitable for being moved, and preferably extended, so as to exert, on the first coupling means, pressure in the coupling direction that automatically brings them into their locked closed position, in which they rotationally couple the rod of the jack to the loading box, the first coupling means also being unlockable, so as to be able to decouple the rod of the jack and the loading box by moving the rod of the jack relative to the loading box, and said assembly includes second coupling means which make it possible to rotationally, and removably, couple the loading box to the rolling chassis about said horizontal axis of rotation, or (b) said assembly includes first coupling means which make it possible to rotationally and removably couple the rod of the jack to the loading box, and second, self-locking coupling means which comprise second locking means, said second coupling means being suitable for adopting a locked closed position, under the effect of pressure exerted in a coupling direction and with automatic locking in their closed position by the second locking means, the second coupling means being secured to the loading box or being secured to the rolling chassis such that the rolling chassis is suitable for being moved so as to exert, on the second coupling means, pressure in the coupling direction that automatically brings them into their locked closed position, in which they rotationally couple the loading box to the rolling chassis about said axis of rotation, the second coupling means also being unlockable, so as to be able to decouple the rolling chassis and the loading box by moving the rolling chassis relative to the loading box.