Tilting device for a vehicle seat

The system has a flap (5) articulated on an upper edge of a cover plate (4) along a transverse axle (6). The flap is operated between a retractable position in which the flap is plated against the plate and a deployed position in which the flap extends the plate above the edge to form a flat floor by the flap and the plate when a backrest (2) is folded. A locking unit locks the flap in the retracted position. A spiral spring in form of elastically foldable metal strip deploys the flap in the deployed position when the unit is deactivated. The strip forms a hinge between the plate and the flap.