Patent ID: 7222488

Claim:
A fabricated cowl for a double annular combustor of a gas turbine engine having a longitudinal axis extending therethrough, comprising: (a) a middle annular portion including a plurality of circumferentially spaced radial slots formed therein; (b) an outer annular portion including a plurality of circumferentially spaced windows of desired size formed therein, wherein outer radial members connecting said outer annular portion and said middle annular portion are defined between adjacent windows; (c) an inner annular portion including a plurality of circumferentially spaced windows of desired size formed therein, wherein inner radial members connecting said inner annular portion and said middle annular portion are defined between adjacent windows; and, (d) a plurality of circumferentially spaced stiffening ribs, each said stiffening rib further comprising: (1) a middle portion including a forward edge configured to extend through one of said radial slots in said middle annular portion and a rear edge configured to substantially conform to a forward surface of said middle annular portion so that an area extending between said forward and rear edges is upstream of said middle annular portion; (2) an outer portion including a forward edge configured to conform to a rear surface of said outer annular portion; and, (3) an inner portion including a forward edge configured to conform to a rear surface of said inner annular portion; wherein each said radial slot in said middle annular portion is sealed and each said stiffening rib is connected to said outer, inner and middle annular portions.