Abstract: In series between pump and tank are two throttle devices, one of which includes a controllable throttle valve having a piston, of which one side supports a valve head, which forms the boundary of an annular gap between an inflow duct and an outflow duct. A hydraulic control path extends from the inflow duct through the throttle opening to the tank, running through a precontrol bore in the piston. To prevent an unwanted leakage fluid stream, one end of the precontrol bore at the annular gap in the region of the inflow duct is positioned so that it remains opened for a closed annular gap, and the other end of the precontrol bore on the other side of the piston is arranged where the piston, in response to the controllable throttle valve being completely opened, pushes against a stop face and, in so doing, automatically closes this other end.

Abstract: Provided in series between pump and tank in a control device for a hydraulic control motor are two throttle devices, between which a line leading to the control motor branches off. One of the throttle devices is made up of a controllable throttle valve having a piston, of which one side supports a valve head, which forms the boundary of an annular gap between an inflow duct and an outflow duct. The pressure drop at the annular gap is continuously controllable by a throttle needle, which is arranged on the other side of the piston, in a hydraulic control path. The hydraulic control path extends from the inflow duct through the throttle opening to the tank, running through a precontrol bore in the piston. When the control device functions according to the open-center principal, an unwanted leakage fluid stream through the precontrol bore to the tank is formed when the annular gap is completely opened.

Abstract: In order to improve a revolving storage facility for tape cassettes comprising a base and a rotary frame rotatable thereon about an axis of rotation and carrying shelf units with cassette compartments for tape cassettes such that the number of cassette compartments is increased while the space requirements is kept as small as possible, it is proposed that the rotary frame comprises a supporting frame which is rotatable about the axis of rotation relative to the base and on which subframes carrying the shelf units are mounted for rotation about subframe axes of rotation arranged sidewardly of the axis of rotation.