Patent ID: 7607226

Claim:
A method of manufacturing an internal manifold of a gas turbine engine, the method comprising: providing a solid ring; machining at least one annular channel in the ring using a turning process, including: rotating the ring about a central axis thereof; forming the annular channel with a cross-sectional area that varies around a circumference of the ring by engaging a tool bit with a peripheral surface of the rotating ring to remove material from said surface to provide said channel defined in said surface, and varying a position of the tool bit relative to the surface of the ring while said ring is rotated and the tool bit engaged with said surface in accordance with a predetermined channel area profile to thereby provide the channel with a varying cross-sectional area around the ring circumference; and sealingly fastening a sealing member to the ring to enclose the channel and define therewith at least one circumferential conduit having a cross-sectional area that varies around the circumference of the ring.