Patent ID: 7908898

Claim:
A method for integrally forming a flange to the end of a round or oval pipe made of thin-walled sheet metal, the pipe being clamped close to the end thereof such that it protrudes beyond the clamping with an axial sub-section, the axial sub-section being formed into a flange protruding outward from the pipe by means of an associated roller tool upon rotation of the pipe or of the roller tool, comprising the steps of: in a first stage for material accumulation purposes, forming the end of the axial sub-section of the pipe into a coil comprising at least one layer and having a substantially circular cross-section; and in a second stage, compressing the coil so as to produce a solid flange by a final-forming roller tool, comprising of mutually engaging forming rollers which are advanced toward the coil upon the rotation of at least one of the pipe or the final forming roller tool, whereby the forming rollers in their final positions delimit a gap that corresponds to a desired flange profile and whereby non-driven forming rollers are revolving freely.