Guiding device for a mobile unit

The guide (106) for an assembly with at least one sliding rail is fixed inside the vehicle and has at least one slideway (308) with fixed supports (304a, 304b) that face the rail and apply thrust forces (Fa, Fb) at right angles to the plane of the rail when the centre of gravity of the mobile assembly projects vertically beyond the interior interval of stability. The fixed supports can be located at both ends of the slideway and above and below the sliding rails, and they are extended by bars (306a, 306b) that diverge away from the rails.