Patents by Inventor Bertram Victor Howarth

Bertram Victor Howarth 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).

  • Twist drills
    Patent number: 6132149
    Abstract: A helical twist drill has fluted lands each having projecting from their radially outer faces a plurality of circumferentially spaced support margins. At least one of the support margins is asymmetrically spaced with respect to the other support margins.
    Type: Grant
    Filed: March 25, 1997
    Date of Patent: October 17, 2000
    Assignee: Dormer Tools (Sheffield) Limited
    Inventors: Bertram Victor Howarth, Richard Goodwin