A positioning device for a positioning element, which is rotationally displaceable about a first axis, including a positioning member engaged with the positioning element. The positioning member is rotatable about a second axis perpendicular to and spaced from the first axis. The positioning device further includes a slotted link disposed on the positioning element and arranged radially about the first axis, a threaded spindle rotatable about a fixed point, and a link block inserted into the slotted link it cannot be turned. The link block is defined by a spindle nut engaged with the threaded spindle. The thread pitch of the threaded spindle corresponds to a predefined range of the positioning angle of the positioning element such that the positioning element is displaceable within the range of the positioning angle by two rotations of the threaded spindle or less.