Patents by Inventor Robert A. Bertelsen

Robert A. Bertelsen 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).

  • Cross-flow filtration membrane test unit
    Patent number: 4846970
    Abstract: A cross-flow filtration membrane test unit having a bottom cell body, a top cell body and a pair of laterally spaced O-rings forming a seal therebetween. The bottom cell body is provided with a feed spacer cavity and the top cell body is provided with a permeate carrier cavity. A mechanism for receiving a test sample of membrane enables the membrane performance and characteristics to be tested in a manner which closely simulates actual full-scale operation.
    Type: Grant
    Filed: June 22, 1987
    Date of Patent: July 11, 1989
    Assignee: Osmonics, Inc.
    Inventors: Robert A. Bertelsen, Douglas L. Olsen
  • Tapered, spirally wound filter cartridge and method of making same
    Patent number: 4839037
    Abstract: A spirally wound filter cartridge and a method of making the same in which the cartridge includes an elongated, centrally disposed tube or mandrel, and a sheet of filtration material spirally wound around the tube such that the cartridge has a tapered configuration with a first end of the cartridge being greater in diameter than the second end. The present invention also relates to a filtration device having a filter cartridge housing adapted to receive the above mentioned tapered filter cartridge.
    Type: Grant
    Filed: April 6, 1987
    Date of Patent: June 13, 1989
    Assignee: Osmonics, Inc.
    Inventors: Robert A. Bertelsen, David J. Paulson