Air distribution assembly for vehicles

An air-distribution assembly for motor vehicles, comprises: a casing (12) defining an air-distribution chamber (14); a plurality of air-distribution ducts (16, 18) or openings (20), which communicate with the air-distribution chamber (14); a plurality of regulating vanes (22, 24, 26) associated to said air-distribution ducts or openings (16, 18, 20); and a control device for controlling said regulating vanes (22, 24, 26); characterized in that said control device comprises: a rotating control pin (34) fixed in rotation to a first vane (22); a rotating shaft (46) fixed in rotation to at least one cylindrical cam (44, 42), which controls at least one second regulating vane (26); a first gear transmission (48, 50) between the control pin (34) and the rotating shaft (46); and a third regulating vane (24) connected to the control pin (34) by means of a second gear transmission (50, 52).