Air flow distribution device provided with a hinged flap

The air distribution device consists of a box (3), with primary (5) and secondary (7) openings to communicate with primary and secondary ducts, and a third opening to communicate with a third duct. A valve (10) is mounted to rotate around a longitudinal axis (xx') to selectively close off the primary or secondary opening, so that the flow of air circulates between the third opening and either the primary or secondary openings. A control mechanism (20), fitted transversely to the rotation axis, controls the rotation of the valve