Patent ID: 9616484
Date: 2017-04-11
CPC Classifications: B21D

Claim:
1. A method of forming a turbofan mixer, the method comprising: providing a single monolithic and generally flat annular sheet metal blank; providing a die surface substantially corresponding in shape to a turbofan mixer shape, the die surface including outwardly-projecting and circumferentially disposed lobes, each two adjacent of said lobes having a respective channel therebetween; positioning the blank with reference to the die surface by aligning a hole of the annular blank with an end of the die surface; forcing the entire circumference of blank against the die surface with the end of the die surface aligned with the hole by pressing a plurality of strikers against the blank substantially simultaneously to transform the blank into a tubular monolithic turbofan mixer having a plurality of circumferentially-disposed lobes on its circumferentially-outer surface; and removing the die surface from contact with a circumferentially-inner surface of the tubular monolithic turbofan mixer.