Patents by Inventor Siegbert Lehmann

Siegbert Lehmann 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).

  • Sintered molding
    Patent number: 5830816
    Abstract: Zirconium dioxide containing 2 to 40 vol. % of stabilizing oxides is embedded in the matrix material of a sintered molding consisting of an aluminum oxide/chromium oxide mixed crystal. The quantity of stabilizing oxides added is chosen so that the zirconium dioxide is predominantly tetragonal. The molar ratio of the zirconium dioxide containing the stabilizing oxides to the chromium oxide is between 1000:1 and 20:1 and the zirconium dioxide has a maximum particle size of 2 .mu.m.
    Type: Grant
    Filed: July 2, 1996
    Date of Patent: November 3, 1998
    Assignee: Cerasiv GmbH Innovatives Keramik-Engineering
    Inventors: Wolfgang Burger, Stefan Gernsheimer, Hans Andersch, Kilian Friederich, Siegbert Lehmann, Johannes Schneider, Michael Fripan
  • Multi-layer compensator with spacers arranged between the layers
    Patent number: 4848408
    Abstract: Multi-layer compensator with spacers arranged between the layers and with the spacers having the shape of flat strips distributed parallel to the longitudinal axis of the compensator over the circumference, with a gap between spacers.
    Type: Grant
    Filed: July 23, 1984
    Date of Patent: July 18, 1989
    Assignee: Internationale Atomreaktorbau GmbH
    Inventors: Manfred Fortmann, Siegbert Lehmann