Patent attributes
A control device has a control drive for operating a valve or some other apparatus, for example an adjustment device for the pitch angle of a wind rotor, by means of a control element. This control drive is associated with an emergency operating device, via which the control element can be reset in the event of a disturbance, essentially independently of the operation of the control drive. This emergency operating device has an energy store, whose stored energy can be released for resetting. The emergency operating device has a piston, on one side of which the energy store acts and on the other side of which a pressure in a pressure area acts, which pressure area can be connected via a switching valve to a tank or the like, in order to release the energy stored in the energy store. In this case, the piston is designed such that it moves the control element in a resetting direction when the pressure in the pressure is relieved.
