Patent ID: 7866041
Filing Date: 2011-01-11
Classification: F01D,F02K,F05D,Y10T

Abstract:
1. A method of manufacturing a duct for a gas turbine engine or the like from sheet metal material, wherein the duct has an irregular final duct shape in which either end of the duct is substantially elliptical and the ends are joined by a continuous surface, the method comprising the steps of: developing a ruled geometry by dividing each end ellipse into an equal number of divisions and joining corresponding points on a periphery of the ellipse by straight lines; fabricating a template of sheet material; marking on the sheet metal template a plurality of ruled lines to form a ruled surface geometry corresponding to the ruled geometry, rolling or folding the sheet metal template along the ruled lines, and during a rolling process, ensuring that the templates are fed through rolls of a rolling apparatus with the ruled lines maintained parallel to an axis of the rolls; joining the template to form an approximate duct shape;