the roller moves fairly precisely along the rotational path for the first opening cylinder 1 a drive 8 may be used for swiveling the guide elements 12 and or the rollers wherein this drive preferably is a mechanical drive in principle the illustrated drive 8 can be replaced with a different drive for example the transport rollers 12 can also be swiveled with the aid of a suitable motor control wherein a mechanical drive is preferred according to fig4 the drive 8 is provided with a rod 15 that extends parallel and at a distance to the shaft b as also shown in fig1 one end of the rod 15 is provided with a roller 14 for positioning the rod 15 in a bearing part 36 such that rod 15 can rotate a lever 19 is clamped immovably onto the other end of rod 15 so as to rotate along wherein a cam roller 18 is attached to this lever the cam roller 18 travels along a cam 6 which is fixedly connected to the bearing plate 4 and thus to the machine frame the cam roller 18 is pressed with the aid of a spiral spring 17 onto a running surface 7 of the cam 6 the spiral spring 17 rests on the rod 15 as can be seen and is fixedly connected to a clamping element 37 at one end the clamping element 9 is fixedly connected to the shaft b and forms an additional bearing for the.