Patents by Inventor Kurt Schellnack

Kurt Schellnack 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: 4759766
    Abstract: An intervertebral disc endoprothesis comprises two symmetrical, concave end plates with an intermediate convex spacing piece. The end plates and the spacing piece have a plane guide rim. The end plates either have an edge shoulder or an annular groove for a toroid provided on the spacing piece. Alternatively, the intervertebral disc endoprothesis comprises two asymmetric end plates and a spacing piece, however, the two areas of movement are offset by 90.degree. in relation to each other and are partial surfaces of a cylinder. In the third variation, the two symmetrical end plates are convex, the spacing piece is cylindrical as well as concave at the two ends and has a durable cover.
    Type: Grant
    Filed: September 9, 1987
    Date of Patent: July 26, 1988
    Assignee: Humboldt-Universitaet zu Berlin
    Inventors: Karin Buettner-Janz, Bernd Derr, Klaus-Peter Erkel, Hans-Joachim Helisch, Kurt Schellnack, Roland Schumann