METHOD OF AIR DUCT PREPARATION Russian patent published in 2000 - IPC

FIELD: ventilation and air-conditioning systems, particularly, methods of preparation of air ducts used in ventilation systems of residential and industrial buildings. SUBSTANCE: method includes preparation of shell, hollow framework and hooks for suspension on external surface of framework. The latter is formed from intersecting threads with formation of openings between threads on entire surface of framework in the form of rhomboid geometrical bodies with acute and obtuse angles. Rhomboid openings are staggered. Hooks are made by preliminary making of three cuttings of thread. The first cutting is made in point of direct adjoining of two acute angles of adjacent rhomboid geometrical bodies. The second and third cuttings are carried out in region of angles of one of rhomboid geometric bodies along their external profile from which the first cutting is made, and subsequent bending of cut off framework part. EFFECT: extended range of technical means. 3 cl, 5 dwg