METHOD OF ASSEMBLY OF RADIAL FAN CASING Russian patent published in 2002 - IPC

FIELD: methods of assembly of thin-sheet casings for radial fans. SUBSTANCE: casing consists of front and rear walls, ferrule, tongue, frame and inlet branch pipe. Prior to assembly of casing, projections and recesses 20 mm in length and 15 to 20 mm in height and depth are cut out by die and rectangular holes of the same length at width equal to thickness of ferrule sheet are pierced over perimeter by another die. Conjugation of parts is effected through bringing projections of ferrule which were preliminarily twice bent through 90 deg into rectangular holes in walls followed by bending projections by 90 deg more. EFFECT: enhanced reliability; reduced labor consumption. 2 cl, 2 dwg