Patents by Inventor Siegfried Starke

Siegfried Starke 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).

  • Drill bit
    Patent number: 4635738
    Abstract: A drill bit for drilling bore holes in underground formations comprising a bit body with a connecting spigot for connecting to a drill string or the like, and a cutting head which comprises a circumferential face extending parallel to its longitudinal axis and an end face having a drilling axis which is aligned with the axis of the connecting spigot. The drilling axis is parallel to and is offset relative to the axis of the cutting head. It is preferred that the end face is, at least in part, conical in shape.
    Type: Grant
    Filed: April 5, 1985
    Date of Patent: January 13, 1987
    Assignee: Norton Christensen, Inc.
    Inventors: Hans Schillinger, Klaus Pahlke, Siegfried Starke, Heinz-Juergen Panhorst, Hans-Eckhard Mengel