Patents by Inventor Ralf Viefhaus

Ralf Viefhaus has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Patent number: 6349642
    Abstract: In a conventional sheet-fed printing machine having a central drive, the dynamic positional deviation with respect to a setpoint value continually increases from printing unit to printing unit due to the elasticity (a vibratory multi-mass system). Thus, the precision is dependent on the number of printing units. A mechanical interconnection of the individual cylinders of the sheet-fed printing machine is partially removed and replaced by individual drives is, therefore, provided. In the multiple motor open-loop drive control described, the fault does not increase because in each printing unit, the torque is supplied separately, and all drives are closed-loop controlled using the same reference variable.
    Type: Grant
    Filed: February 1, 2000
    Date of Patent: February 26, 2002
    Assignee: Siemens Aktiengesellschaft
    Inventors: Jürgen Olomski, Hans-Peter Tröndle, Ralf Viefhaus