Abstract: A method for welding weldable parts together, for instance for welding annular objects (1), wherein the parts (IA, IB) are subjected to a thermal resistance upset welding process for making the parts (IA, IB) flow together at contact surfaces (S), wherein the welding process (W) depends on a number of input parameters, comprising a pressure exerted on the parts to be welded and a heating current fed through the parts (IA, IB), wherein a number of welding process output parameters, for instance a welding temperature and a displacement of the parts (IA, IB), depend on the input parameters, wherein, during the welding process (W), at least one welding temperature and/or electrical resistance of said parts (IA, IB) is determined, wherein the result of the welding temperature determination and/or resistance determination is used by at least one regulator (R) for automatically readjusting a number of welding process input parameters during the welding process (W), or for automatically adjusting the welding process

Abstract: A method for processing a preform for a rim wherein a ring-shaped rudimentary metal rim edge (5) is clamped in a slit (13) moving along the circumferential edge of the rim edge (5) between a profiled outer surface (8) of a mandrel (7) and a profiled outer surface (11) of a profiling roller (9), wherein the slit (13) is wedge-shaped and wherein an angle (a) included by the centerlines (6, 10) of mandrel (7) and profiling roller (9) is reduced, propelling material of the rudimentarily formed rim edge (5) to a wider portion of the slit (13). The invention also relates to an apparatus for processing a preform for a rim, and a rim.

Abstract: A method for manufacturing a substantially rotationally symmetric rim bed having a wall thickness varying along the longitudinal axis by means of cold forming, wherein the side walls of a substantially cylindrical metal bed having a substantially constant wall thickness are flared radially outwards in a pressing operation, and wherein the wall thickness of the flared side walls is varied along the longitudinal axis by means of flow-spinning, with axial stretching and profiling of the sides. The invention further relates to an apparatus for manufacturing a rim bed by means of cold forming.