Abstract: A ventilation unit for a motor vehicle is provided comprising a housing with air ducts for supplying air through panel openings into the interior of the vehicle. At least one draft tube is disposed in the housing adjacent said panel openings, where the at least one draft tube includes an outlet slot arranged to be exposed to the air stream exiting the panel openings. The draft created by the air stream crossing over the slot draws hot air from the interior of the draft tube to be mixed with the exiting air stream. The amount of drafting created by the air stream depends on the velocity of the exiting airflow. This relationship in turn makes the ventilation unit of the present invention perform as a passive device.

Abstract: A ventilation unit for a motor vehicle is provided comprising a housing with air ducts for supplying air through panel openings into the interior of the vehicle. At least one draft tube is disposed in the housing adjacent said panel openings, where the at least on draft tube includes an outlet slot arranged to be exposed to the air stream exiting the panel openings. The draft created by the air stream crossing over the slot draws hot air from the interior of the draft tube to be mixed with the exiting air stream. The amount of drafting created by the air stream depends on the velocity of the exiting airflow. This relationship in turn makes the ventilation unit of the present invention perform as a passive device.

Abstract: A method and apparatus is provided for forming bends in a tube. A set of bend forming elements are mounted on each of a pair of parallel guideways. Each set of bend forming elements are interconnected by lazy tongs and a motor is provided to drive each set of bend forming elements along the guideways so that each set of bend forming elements may be moved together or separated while maintaining equal spacing between the elements. When a straight tube is placed between the sets of bend forming elements and the bend forming elements are driven together while the guideways simultaneously are driven apart, bends are formed in the tube to form the tube into a serpentine configuration. The bend forming elements have at least two different curvatures on their external surfaces so that the bends in the tube are formed in two stages with each of the different curvatures being sequentially operative to form the final bends in the tube.