METHOD AND APPARATUS FOR MAKING HUBLESS V-GROOVED PULLEY

摘要

A one-piece tubular walled spun sheet metal pulley having a V-shaped pulley groove formed by a single V-groove wall ant a partial double fold V-groove wall. An integral tubular pulley mounting flange wall extends axially from the double flange wall located intermediate the crests and valley of the V-groove forming walls in cross section. The tubular spun sheet metal V-grooved pulley product is made by drawing from a sheet blank a cup-shaped stage blank having a bottom wall, ant a primary cylindrical flange wall connected by an offsetting shoulder with an enlarged secondary cylindrical flange wall terminating in an open end; then knocking out the bottom wall of the cup-shaped stage blank to form a tubular stage blank having offset primary ant secondary cylindrical flange walls; and then spinning a V-shaped pulley groove in the secondary flange wall of the tubular blank which groove in cross section has a single Vgroove wall and a partial double fold V-groove wall conected with the primary cylindrical flange wall intermediate the crests and valley of the V-groove forming walls. The apparatus for spinning a V-groove in the hubless offsot cylindrical stage blank includes means for supporting the stage blank on its open ends at spaced locations on relatively axially movable headstock ant tailstock die means assemblies; means for internally and externally telescopically supporting a stage blank primary cylindrical flange wall in tailstock tie means during relative axial movement between the headstock and tailstock tie means and while spinning a V-groove in the enlarged stage blank secondary cylindrical flange wall; and internally supporting the pulley Vgroove walls on headstock and tailstock die means as the V-groove is being spun.