Control device for a valve flap

The device has a four-joint drive comprising a pivot arm (3) that is rotatable directly or indirectly by an electrical rotary switch (40). A transfer unit (5) is supported at a free end of the pivot arm in a rotatably movable manner, and operates another pivot arm (4). A spring socket (42) is provided for loading a valve flap with clamping force in an extended position of the drive, where a longitudinal axis of the former pivot arm runs parallel to the transfer element in the extended position. The spring socket is arranged between the rotary switch and the valve flap.