Patent ID: 8042370

Claim:
A method of forming a ring gear from a ring blank, comprising the steps of: providing a mandrel having a central axis and an outer forming surface defining a plurality of forming elements each forming element having a forming element axis offset from the central axis of the mandrel; placing the ring blank having a ring axis over the mandrel and generally aligning the central axis of the mandrel with the ring axis of the ring blank; providing a roll having a roll axis being generally parallel with the forming element axis of the forming element interposed between the roll and the mandrel central axis; and forcing the roll radially inwardly relative to the mandrel central axis and circumscribing the mandrel central axis while rotating the roll about the roll axis thereby deforming the ring blank radially inwardly and forming a plurality of teeth with each tooth being spaced from the adjacent tooth on an inner surface of the ring blank, the formed tooth being substantially parallel with the forming element axis and angularly offset from the mandrel central axis.