winding area 70 located in the interior of the cable drum and reaches the outer cable drum wall 102a winding surface through a conduit 100a the other cable end fastened on the cable fitting 50b is passed through the conduit 100b to the exterior of the outer cable drum wall 102a if the diameter d of the winding element is substantially 30 to substantially 70 of the diameter d of the cable drum 10a see fig9 d this ratio leads to a favorable leverage to compensate for occurring cable slackness and guarantees at the same time an optimum initial stress of the cable thus an optimum relation between friction factors on the one hand and some clearance on the other hand can be achieved in the unloaded state as shown in fig9 a a gap 80 exists between the inner cable drum wall 103 and the supporting jacket surface 203 of the rotatable part 20a to ensure a certain mobility of the jacket area the cable drum 10a has a radially extending slit 101a so that the inner cable drum wall 103 and the jacket surface 203 of the rotatable part 20a can be brought into engagement with each other preferably these surfaces 103 203 have segments with toothing elements 8 which are evenly distributed over the circumference a provision of the inner cable drum wall with toothing elements 8b in the form of segments is particularly advantageous while the toothing 8a covers the entire circumference of the jacket surface 203 of the movable part 20a in this way it is ensured that the toothing elements can dependably come into engagement with each.