A double walled riser sump has an annular space between the two walls. According to the method, a copy of data files stored locally at each user device is received at a server via a respective network communication link. Only one motor is needed to drive the cutting rollers and the paper feeding mechanism. , secretin, neuropeptides, peptides andor digestive enzymes. A particularly compact and cost-effective steering servo arrangement with few components is permitted, whereby the ball nut of the recirculating-ball drive is mounted coincidentally with the rotor, which is arranged as an external rotor.