Patents by Inventor Dennis J. Fischer

Dennis J. Fischer 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).

  • Flexible mud excluder for borehole televiewer
    Patent number: 4711122
    Abstract: The present invention is an improved mud excluder fitted around a rotating acoustic transducer of a borehole televiewer to exclude mud from the borehole televiewer. This mud excluder has:(a) a flexible casing means attached to the borehole televiewer to form a fluid cavity adjacent to the rotating acoustic transducer,(b) an acoustically transparent fluid located within the fluid cavity,(c) an acoustic window means opposite the transducer and adjacent to the fluid cavity, and(d) a pressure compensating means within the fluid cavity to equalize the pressure within the fluid cavity with the pressure on the outside of the flexible casing means.
    Type: Grant
    Filed: August 21, 1986
    Date of Patent: December 8, 1987
    Assignee: Chevron Research Co.
    Inventors: Jorg A. Angehrn, Dennis J. Fischer