VENTILATION DUCT

摘要

A ventilation duct is produced from a fiber material and has a quadrangular, open and self-supporting cross section that can be compressed to a flat state by the presence of bending lines (5, 6) in the corner areas of the duct. The walls (1-4) of the duct have transverse relatively soft parts (7), stiffening parts (8) and likewise transverse hinge parts (9), all made from the fiber material of the duct. In order to be able to change the construction height of the duct, the cross-sectional shape can be converted from quadrangular to hexagonal owing to the fact that the two opposite walls (3, 4) have longitudinal folding lines (10). To keep the duct in its hexagonal shape it has a number of external or internal shape-holding elements (11) that can also be fastening or suspension means to the duct.