Adjusting device for a hoisting crane including a work spindle, which is given an axial travel within a cylinder by a relative movement between a screw and a cooperating groove following a driving device. The work spindle has a free end, which is connected to a lifting arm of the hoisting crane through a connector or the like. In order to make it possible to move the work spindle axially without help of the driving device in the case of an emergency, the connector includes a connection which is stiff in the axial direction of the work spindle, and which includes two parts which are rotatable in relation to each other against a certain friction resistance around an axis, which is concentric to the work spindle.