Patents by Inventor Robert W. Dahlgren

Robert W. Dahlgren 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).

  • Gas chromatograph sample and column-switching valve
    Patent number: 6453725
    Abstract: A multiport, diaphragm sealed valve suitable for use as both a sampling and column switching valve. The valve is constructed to internally block fluid communication between one or more pairs of ports in a valve operating mode. Such blocking may be used to conserve carrier gas when the valve is in the ON position.
    Type: Grant
    Filed: January 7, 1999
    Date of Patent: September 24, 2002
    Assignee: Siemens Energy & Automation
    Inventors: Robert W. Dahlgren, Robert K. Bade, Stephen B. Hunt
  • Gas chromatography
    Patent number: 4553985
    Abstract: A gas chromatograph in which a first portion of sample peaks are eluted in forward flow mode and a second portion of sample peaks are eluted in reverse flow mode without loss of resolution.
    Type: Grant
    Filed: February 24, 1984
    Date of Patent: November 19, 1985
    Assignee: Phillips Petroleum Company
    Inventors: Robert W. Dahlgren, William H. Dennis