METHOD TO PRODUCE METAL RINGS FROM TUBULAR BILLETS Russian patent published in 2014 - IPC B21D7/16 B21D9/18 

FIELD: machine building.

SUBSTANCE: tubular billet is cropped on two sides, a hollow coupling connector of double nippel type is mounted in the end of a clamped tubular billet section by one end as per forced fit, the tubular billet section with the connector is clamped inside an outer master unit in the form of a cylindrical or ring drum corresponding to the diameter of the ring being produced. Local softening of the tubular billet is performed by a circular induction heater and by the application of bending moment with the tube upsetting force towards the outer master unit it is brought to the second tube end with the latter being mated with the free end of the connector. The ring is expanded inside by a roller at the master unit and the tube ends are welded with the respective sections of the coupling connector.

EFFECT: reduced radial and axial wobbling of metal rings from tubular billets thus providing for expanded velocity range of wheeled vehicles having such rings in the rim part of the wheels.