The invention relates to a cable drum for automatically winding up a cable having an inner drum part (2), an outer drum part (1) and a back panel (3). The inner drum part (2) is connected to a hollow cylindrical link (23), whose inner wall has at least one vaulting (24), wherein a brake lever (6) is mounted in a radially moveable manner to the back panel (3), having at least one slot hole (63), in which the axis (71) of a brake wheel (7) is guided, which protrudes into the link (23) and abuts on its inner wall, wherein the at least one slot hole (63) is positioned angularly in a way that the brake wheel (7) during rotation of the link (23) is pressed against the inner wall of the link in winding direction of the cable drum and wherein a locking element is arranged at the brake lever (6) downstream of the brake wheel (7) in winding direction of the cable drum, which interacts with at least one tuck bar arranged at the inner drum part (2) in a manner that it is only locked when passing the tuck bar in winding direction of the cable drum.