Abstract: In the production of an internal contour with an internal arbor acting on the inner wall of a cup-shaped or annular rotationally symmetrical workpiece, expansion and length change of the workpiece are avoided during cold forming. Thus, gear components with internal teeth are produced that have greater symmetry and higher accuracy. A workpiece provided with a press fit on the outside or a prefabricated workpiece is inserted into the die, and during the cold forming is pressed tightly by friction and rotationally fixed with the rotationally driven internal arbor against the inner wall of the die. After completion of the rolling process of the profile, the workpiece is ejected with an axial ram. The internal arbor is provided with outside profiling and is cantilever-mounted and is fed axially and radially during the rolling.

Abstract: In the production of an internal contour with an internal arbor acting on the inner wall of a cup-shaped or annular rotationally symmetrical workpiece, expansion and length change of the workpiece are avoided during cold forming. Thus, gear components with internal teeth are produced that have greater symmetry and higher accuracy. A workpiece provided with a press fit on the outside or a prefabricated workpiece is inserted into the die, and during the cold forming is pressed tightly by friction and rotationally fixed with the rotationally driven internal arbor against the inner wall of the die. After completion of the rolling process of the profile, the workpiece is ejected with an axial ram. The internal arbor is provided with outside profiling and is cantilever-mounted and is fed axially and radially during the rolling.

Abstract: A crank has a crank arm (3) and a freewheel element (1, 2) for fastening the crank arm (3) on a crankshaft. When the crank arm (3) is rotated in a first direction, a torque is transmitted to the crankshaft. When the crank arm (3) is rotated in a second, opposite direction, the crank arm (3) rotates in freewheeling mode. The crank furthermore has at least one fixing means (6, 6?) for cancelling freewheeling, allowing the torque of the crank arm (3) to be transmitted to the crankshaft in both directions of rotation. This crank allows simple switching between one-way coupling and two-way coupling and significantly increases the available training and therapy options.