Source: {"pile_set_name": "USPTO Backgrounds"}

The present invention relates generally to jewelry rings, and more particularly, is directed to jewelry rings having great strength and a method of making the same.
In making jewelry rings, such as wedding bands and the like, it is known to first invert a flat, annular washer in a first inversion forming machine, so as to form the washer into a frusto-conical or truncated cone shape. Thereafter, in a second inversion forming machine, the frusto-conical element is formed into a cylindrical element having a constant inner and outer diameter.
In order to present a rounded outer circumference to the cylindrical element, the outer surface can be shaved in a milling or other machine to provide the resultant ring. In such case, the inner surface has a flat, cylindrical shape, and is not rounded.
Alternatively, rounding machines are known for rolling rings in order to change the profile and/or size of rings. With these machines, an inner wheel is provided on which the cylindrical element or ring is mounted, with the inner wheel having a convex outer surface, and an outer wheel has a circumferential groove with a concave surface. Thus, when the inner wheel is rotated in one direction and the outer wheel is rotated in the opposite direction, a ring is formed with an arcuate inner and outer surface. This differs from the aforementioned shaved ring where the inner surface is flat, that is, with the latter arrangement, the inner and outer surfaces are both arcuate.
Although the rolling of the rings in a rounding machine increases the strength of such rings, the strength of such rings in a crush test is still not completely satisfactory.
It would therefore be desirable to substantially increase the strength of such rings, while providing a simple construction and a simple method of making the same.