Patents by Inventor Gebhard Lehmann

Gebhard 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).

  • Tunneling machine with center cutter and debris removing means
    Patent number: 5437500
    Abstract: The invention is directed to a tunnel-driving machine designed to bore a tunnel and having, in addition to a large outer cutter wheel, a smaller central cutter wheel which is mounted near the hub of the outer cutter wheel and which enables the formation of soil plugs and dead cores to be avoided along the longitudinal axis of the cutting wheel, thus reducing the resistance of the machine to forward motion.
    Type: Grant
    Filed: December 20, 1993
    Date of Patent: August 1, 1995
    Assignee: Herrenknecht GmbH
    Inventors: Gebhard Lehmann, Rolf Heerssen, Martin Herrenknecht