Patents by Inventor John Tschirky

John Tschirky 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).

  • Apparatus and method for enlarging underground arcuate bore holes
    Patent number: 4117895
    Abstract: A hole-opener and a hole-opener apparatus is provided for enlarging a pilot hole of the inverted arcuate type which bypasses an obstacle, the pilot hole having an entrance and terminal end, both ends usually being accessible to surface drilling equipment.
    Type: Grant
    Filed: March 30, 1977
    Date of Patent: October 3, 1978
    Assignee: Smith International, Inc.
    Inventors: Howard Ward, John Tschirky