Patents by Inventor Robert E. Wojcik

Robert E. Wojcik 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).

  • Method of determining filter pluggage by measuring pressures
    Patent number: 5320760
    Abstract: A method to determine differential filter pressure caused by filter pluggage in a high pressure liquid system operated by a computer-operated control valve without the need for a pressure sensor coupled to the filter by corerlating the percent the control valve is open with the differential pressure of the filter. A signal is provided when the percentage of time the control valve is open exceeds a predetermined time and the filter is replaced in response to the signal.
    Type: Grant
    Filed: December 7, 1992
    Date of Patent: June 14, 1994
    Assignee: E. I. Du Pont de Nemours and Company
    Inventors: Kenneth S. Freund, Elizabeth L. Frisbie, Robert E. Wojcik