Patents by Inventor Donald K. Chrise

Donald K. Chrise 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: 4299510
    Abstract: A drill steel and method of making the drill steel which includes a tube which is opened up at one end by a first punch strike after which a male insertion element with external indentations is mounted on a second punch and driven partially into the opened end of the drill steel while simultaneously striking the drill steel at the end to collapse the walls of the tube around the element and into the indentations to lock the element in the tube. The finished drill steel thus has a male end to insert telescopically into the end of a similar steel to provide necessary extension devices.
    Type: Grant
    Filed: December 7, 1978
    Date of Patent: November 10, 1981
    Assignee: Fansteel Inc.
    Inventors: Kenneth C. Emmerich, Donald K. Chrise