Positioning mechanism

The adjusting mechanism has an arm (1) pivoted around a pivot axis between two pivot angle-extreme positions. A flexible supply line (9) is coiled screw-shaped around a coil axis that is parallel to a pivot axis (2). The screw-shaped supply line is arranged in a start position at a radial distance from a cylindrical stop surface (8) of a stop element (6) that is arranged inside or outside the coil. The start position lies between two pivot angle-extreme positions. The coil axis coincides with the pivot axis.