Patent ID: 10857580

Abstract:
A method and apparatus for producing gun barrels having a grooved or ribbed inner surface with straight or helical grooves or ribs, by providing a metallic hollow cylindrical pre-form, placing the pre-form on a core mandrel being part of a flow forming machine having a main machine axis, the core mandrel having a structured outer surface comprising ribs and/or grooves extending straightly parallel to and/or helically around the main axis; and applying forming rollers, in a roller arrangement, to the outside surface of the pre-form so as to apply radial pressure on the pre-form such that its material begins to flow. As the rollers apply force upon the pre-form, a relative motion between the pre-form and the rollers is performed by moving the pre-form in axially parallel to the main axis through the roller arrangement or by moving the roller arrangement alongside the pre-form.