Abstract: The invention relates to a method and an apparatus for the manufacture of a poly-V-pulley, particularly with a toothed reference mark sensor. The method uses per se known spin forming and combines in one setting on a spinning machine with tool changers, the method steps of upsetting, profiling and gear cutting. The method according to the invention is preferably based on a tilted circular metal blank, which has a bevelled or angled marginal area with a clearly defined length and wall thickness. From the tilted or upset blank is formed a cup-shaped preform with an asymmetrically reinforced, cylindrical area with the aid of a spinning roll and subsequently in a radial setting is infed a spinning roll with a recess and an axially limited diameter reduction and material accumulation are obtained. This is followed by preprofiling, profiling of the thickened area and a gear cutting on a simultaneously constructed reference mark sensor of an outer flange.

Abstract: Method of manufacturing a belt pulley from a metal disk, e.g. a multiple-V-belt pulley, toothed belt pulley, flat belt pulley, etc., having a hub and an area that is provided with a profile which is basically hollow cylindrical and has a smooth or crowned outside. In a first operational step the metal disk is given a wave-like profile in its circumferential area and in following operational steps the respective final profile is completed. Known methods require numerous operational steps and a great force input to carry out the forming. Applicants' method permits high-quality belt pulleys to be manufactured from metal disks at a comparatively low amount of labor and cost involved in the working of the method.