Hydraulic controller for a hydraulically actuated liftable and lowerable hook of a crane

The invention relates to a hydraulic controller for a hydraulically actuated liftable and lowerable hook of a crane, wherein the hydraulic system comprises at least one working machine, which is designed as a hydraulic motor and drives the winch, and at least one drive machine, which is designed, in particular, as a pump, wherein the working machine is connected indirectly or directly to at least one of the drive machines by means of two connections via corresponding working lines, which connections serve as a feed or return depending on the operating state of the working machine, and wherein a lowering brake valve is provided in the one working line, which lowering brake valve is connected to the other working line via a control line in such a way that the lowering brake valve can be moved against a restoring force by means of the pressure that is present in the other working line, which pressure is forwarded via the control line, from the blocking position of the lowering brake valve into a through-flow position for lowering the hook by means of the winch, in particular primary winch. In order to specify a hydraulic controller by means of which the risk of unstable states is reduced or even avoided, a discharge line leading back to a tank should branch off from the control line, wherein, for the adjustment of the control pressure acting on the lowering brake valve to different values, the discharge line is provided with a switching possibility, by means of which the effective hydraulic resistance in the discharge line can be by changed to at least two different values by means of open-loop or closed-loop control.