Patents by Inventor Steven H. Lawrence

Steven H. Lawrence 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: 6051534
    Abstract: A process for producing the 2223 phase of (Pb,Bi)SrCaCuO that is much faster than existing processes has the steps of: calcining a precursor powder mixture while maintaining intimate mixing of this precursor mixture by intermediate grindings during calcination; compressing the calcination product into a consolidated body; and heating the calcination product while maintaining intimate mixing of the calcination product, to form essentially phase pure 2223 (Pb,Bi)SrCaCu). A fast process for making a (Pb,Bi)SrCaCuO part with a high J.sub.c has the steps of: pressing calcined and reacted (Pb,Bi)SrCaCuO powder into a green body having the shaped of the part; and sintering the green body for a selected time, most preferably between 6 and 8 hours, that is long enough to establish superconducting electrical contact between grains of (Pb,Bi)SrCaCuO but short enough to prevent void formation or part shape distortion. The part made by this process has a high density, at least about 4 or 5 g/cm.sup.3.
    Type: Grant
    Filed: April 21, 1993
    Date of Patent: April 18, 2000
    Assignee: The United States of America as represented by the Secretary of the Navy
    Inventors: Roy Rayne, Louis E. Toth, Barry A. Bender, Steven H. Lawrence
  • Patent number: 5106829
    Abstract: A substantially single phase superconducting composition is formed from a of 1:2:3 molar ratio of fine powders of a superconducting rare earth oxide, CuO, and BaCo.sub.3. The mixed powders and shaped articles formed from the mixed powders are calcined, sintered, and cooled in an oxygen containing atmosphere. The cooling step is done slowly to convert the sample to the orthorhombic structure and to improve the superconducting properties. The article formed is a substantially single phase superconducting composition.
    Type: Grant
    Filed: September 19, 1990
    Date of Patent: April 21, 1992
    Assignee: The United States of America as represented by the Secretary of the Navy
    Inventors: Syed B. Quadri, Louis E. Toth, Michael S. Osofsky, Steven H. Lawrence, Donald U. Gubser, Stuart A. Wolf