METHOD AND APPARATUS FOR PRODUCING ANNULAR METALLIC BLANKS FOR METALLIC RINGS

摘要

An apparatus for producing annular metallic blanks for metallic rings having a desired inner diameter wherein a length of elongated metallic material having a predetermined cross-sectional configuration is formed into a spiral shape having an inner diameter smaller than the desired diameter of the ring and such formed material is forcibly and coaxially disposed around a cylindrical portion of a holding means having a diameter larger than the inner diameter of the ring. Thereafter, the spiral formed material around the cylindrical portion is cut along a straight line parallel to the axis of the cylindrical portion to provide a plurality of metallic bends, and the bends are removed from the cylindrical portion to be used as annular metallic blanks for the metallic rings. In order to obtain a desired ring from the annular blank formed as described above, the ends of the annular blank are later joined together by welding such as by a butt welding operation.