Patents by Inventor David S. Dixon

David S. Dixon 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).

  • Patent number: 5413694
    Abstract: A method of improving the electromagnetic (EM) shielding performance of a mposite material is provided. The composite material has conductive and semi-conductive filler particles suspended in a non-conductive resin. The filler particles can be up to 40 weight percent of the composite material. The composite material is electroplated with a conductive material onto a portion of its surface to improve the electrical connection between the conductive material and a portion of the filler particles. EM shielding performance can be further enhanced by injecting an exponentially decaying electromagnetic pulse through the composite material that has been electroplated.
    Type: Grant
    Filed: July 30, 1993
    Date of Patent: May 9, 1995
    Assignee: The United States of America as represented by the Secretary of the Navy
    Inventors: David S. Dixon, Michael D. Obara, James V. Masi, William G. Bradley
  • Patent number: 5173871
    Abstract: A method of forming a composite material for EMI/EMP hardening protection at has a predictable EM shielding performance in terms of penetration depth is provided. A base material is doped with a predetermined volume fraction of filler particles such that the base material forms a separating contact region between each pair of adjacent filler particles. An electrical equivalent circuit for a filler particle pair and separating contact region is used to represent electrical properties associated with the filler particle pair and separating contact region. A network equivalent impedance of the base material doped with the filler particles is generated using the electrical equivalent circuit. The network equivalent impedance, dielectric constants of the base material and the filler particles, and the predetermined volume fraction of filler particles are used to predict the EM shielding performance of the base material doped with the filler particles in terms of penetration depth.
    Type: Grant
    Filed: June 20, 1990
    Date of Patent: December 22, 1992
    Assignee: The United States of America as represented by the Secretary of the Navy
    Inventors: David S. Dixon, James V. Masi
  • Patent number: 5066424
    Abstract: Composite material composed of conducting and semi-conducting oxide partis, fibers, or flakes suspended in a of polymeric material matrix for use in connectors, junction boxes, enclosures or similar electromagnetic shielding applications. The use of a composite material with electromagnetic shielding properties built into the material itself, combined with the use of a semi-conductive filler that minimizes the corrosive effect of an electrochemical potential difference, provides EM shielding and corrosion resistance for these materials when they are used in marine and aircraft environments. Oxide semiconductor materials and compatible conductive fillers also provides a basis for a new class of EMI and EMP composite materials that exhibit a stable current-controlled and voltage-controlled negative resistance (VCNR, CCNR) characteristic. Testing has shown that the conductivities of these materials increase as the field and/or the voltage increases.
    Type: Grant
    Filed: June 20, 1990
    Date of Patent: November 19, 1991
    Assignee: The United States of America as represented by the Secretary of the Navy
    Inventors: David S. Dixon, James V. Masi
  • Patent number: 5007847
    Abstract: An electromagnetically shielded connector assembly that enables connection rom any one of conduit and cable to any one of conduit, cable and ground plane irrespective of the particular sizes of the members to be connected.
    Type: Grant
    Filed: June 18, 1990
    Date of Patent: April 16, 1991
    Assignee: The United States of America as represented by the Secretary of the Navy
    Inventors: David S. Dixon, Nicholas Schade
  • Patent number: 4904826
    Abstract: An internal shield ground adapter uses spring contacts inside the kickpipe/stuffing tube to make a wideband, low impedance 360 degree contact between the shield of a cable passing through the kickpipe/stuffing tube and the kickpipe/stuffing tube itself. An environmental seal compresses the spring contacts against both the cable shield and kickpipe/stuffing tube while preventing degradation of the system by environmentally sealing the area between the cable and kickpipe/stuffing tube.
    Type: Grant
    Filed: October 5, 1988
    Date of Patent: February 27, 1990
    Assignee: The United States of America as represented by the Secretary of the Navy
    Inventor: David S. Dixon
  • Patent number: 4561784
    Abstract: Test apparatus for determining ignition characteristics of various metal in oxidizer environments simulating operating conditions for materials, the test apparatus has a chamber (6) through which the oxidizing agent flows, and means for mounting a stationary test sample (36) therein, a powered, rotating shaft (E) in the chamber rigidly mounts a second test sample (35). The shaft is axially movable to bring the samples into frictional engagement and heated to the ignition point. Instrumentation 16, 32, 48, 49, 50, 51, 52, 53, 54 connected to the apparatus provides for observation of temperatures, pressures, loads on and speeds of the rotating shaft, and torques whereby components of stressed oxygen systems can be selected which will avoid accidental fires under working conditions.
    Type: Grant
    Filed: January 17, 1984
    Date of Patent: December 31, 1985
    Assignee: The United States of America as represented by the Administrator of the National Aeronautics and Space Administration
    Inventors: Frank J. Benz, Randall C. Shaw, David S. Dixon