Patents by Inventor Charles D. Hollar

Charles D. Hollar 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 for reverse drilling
    Patent number: 5743345
    Abstract: A drill bit for reverse drilling in a drill hole being produced by a percussive, fluid-actuated drill includes an elongated drill bit body having a bore extending there through for transmission of a fluid, the body terminating in a head end portion and a shank end portion. Abrasive resistant drilling buttons are arrayed on both the head end portion and the shank end portion to resist abrasion by the material being drilled, during either forward or reverse drilling.
    Type: Grant
    Filed: July 30, 1996
    Date of Patent: April 28, 1998
    Assignee: Ingersoll-Rand Company
    Inventors: Charles D. Hollar, Stuart A. Connell
  • Back drilling threaded bit
    Patent number: D382887
    Type: Grant
    Filed: May 31, 1996
    Date of Patent: August 26, 1997
    Assignee: Ingersoll-Rand Company
    Inventors: Charles D. Hollar, Stuart A. Connell