Patents by Inventor Osvaldo F. Lopez

Osvaldo F. Lopez 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 continuously determining crack length
    Patent number: 5227731
    Abstract: A crack length sensor is fabricated in a rectangular or other geometrical form from a conductive powder impregnated polymer material. The long edges of the sensor are silver painted on both sides and the sensor is then bonded to a test specimen via an adhesive having sufficient thickness to also serve as an insulator. A lead wire is connected to each of the two outwardly facing silver painted edges. The resistance across the sensor changes continuously as a function of the crack length in the specimen and sensor.
    Type: Grant
    Filed: May 24, 1991
    Date of Patent: July 13, 1993
    Assignee: The United States of America as represented by the Administrator of the National Aeronautics and Space Administration
    Inventors: Ramamurthy Prabhakaran, Osvaldo F. Lopez