Patents by Inventor Volker W. Hafner

Volker W. Hafner 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).

  • Vacuum drainage system
    Patent number: 6990993
    Abstract: A vacuum drainage system operable to remove waste from a source. The system includes an accumulator in fluid communication with the source and a substantially vertical riser having a first portion in fluid communication with the accumulator and a second portion downstream of the first portion and in fluid communication with a vacuum source. A first valve is disposed between the first portion and the second portion. The first valve is selectively operable to provide fluid communication between the first portion and the vacuum source. An air inlet is disposed a distance downstream of the first valve and is selectively operable to provide fluid communication between the outside atmosphere and the second portion.
    Type: Grant
    Filed: October 6, 2003
    Date of Patent: January 31, 2006
    Assignee: Acorn Engineering Company
    Inventors: Volker W. Hafner, Thomas K. Zinn, Enrique P. Loreto