Abstract: A pulley is made by fixing an edge of an opening of a plate by using a first upper mandrel ring installed at a lower end of a first supporting pin of a first forming device. A supporting block disposed around an upper end of a first spindle is rotated with the first spindle. An inner hub of the pulley is formed by inwardly pressing an upper surface of the plate against a first pressing roller to reduce the thickness of the plate while drawing the plate around a first mandrel ring. The plate is fixed to a second spindle of a second forming device, so the plate rotates with the second spindle. An outer hub is formed by pressing a convex bead toward the inner hub by using a fourth pressing roller and by drawing the outer hub.

Abstract: A pulley is made by fixing an edge of an opening of a plate by using a first upper mandrel ring installed at a lower end of a first supporting pin of a first forming device. A supporting block disposed around an upper end of a first spindle is rotated with the first spindle. An inner hub of the pulley is formed by inwardly pressing an upper surface of the plate against a first pressing roller to reduce the thickness of the plate while drawing the plate around a first mandrel ring. The plate is fixed to a second spindle of a second forming device, so the plate rotates with the second spindle. An outer hub is formed by pressing a convex bead toward the inner hub by using a fourth pressing roller and by drawing the outer hub.

Abstract: A pulley is made by fixing an edge of an opening of a plate by using a first upper mandrel ring installed at a lower end of a first supporting pin of a first forming device. A supporting block is disposed around an upper end of a first spindle and is rotated with the first spindle. An inner nub is formed by inwardly pressing an upper surface of the plate against a first pressing roller to reduce the thickness of the plate while drawing the plate around a first upper mandrel ring. The plate is fixed to a second spindle of a second forming device, so the plate rotates with the second spindle. An outer hub is formed by pressing a convex bead toward the inner hub by using a fourth pressing roller and by drawing the outer hub.

Abstract: Method and device for forming a pulley are disclosed. The method of the present invention includes the first step to fix the plate working piece formed with the hole in the intermediate thereof to the first forming device; the second step to form the inner hub by rotating the plate working piece and pressing the upper surface of the plate works in drawing process; the third step to obtain the first semi-manufactured pulley by pressing the upper surface of the plate working piece and by forming the outer hub in drawing process.