A transfer device for loading/unloading of a cargo such as wheelchair from a structure such as a vehicle the device having a platform movable from a deposit position at the level of the ground level to an access position at the floor level keeping the platform substantially horizontal. The platform is provided with a front safety barrier rotatable to serve as a ramp when the platform is at ground level, and with side safety barriers each substantially constituted by an articulated quadrilateral, such that when the platform is at the ground level, the side safety barriers fold down by kinematic mechanisms while preferably corresponding side ramps are made available. This arrangement allows transition of the wheelchair from/to the ground from any side of the platform, by virtue of the automatic folding of both the front and side barriers and the simultaneous presentation of the corresponding ramps.
