the position of the two shafts 4 and 8 and the dimensioning of the two gear portions the drive wheel 14 with the internal tooth arrangement and the axial journal 17 with the matching external tooth arrangement the gear in accordance with the invention can also be realized by other force transmitting means for example wheels and rollers with a frictional connection a basic advantage of the device in accordance with the invention lies in that gearing from the drive wheel 14 to the axial journal 17 takes place without a change in the rotational direction a further substantial advantage lies in that in spite of the achieved gearing the structural size of the drive mechanism 10 can be kept small so that the drive mechanism 10 can be housed without problems in the top part 2 making do without two continuous shafts the eccentric arrangement of the driveshaft 8 and the use of the internal tooth arrangement of the drive wheel 14 make it possible to place the secondary drive unit 102 on the central shaft 4 of the device and to simultaneously achieve the gearing by means of the larger drive wheel 14 without increasing the space required in the top part 2 laterally of the axial journal 17 by the diameter of the drive wheel 14 in the exemplary embodiment represented the bearing journal 9 is only fastened at an upper.