Patents by Inventor John Thomas Stephens

John Thomas Stephens 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 string chuck
    Patent number: 6719303
    Abstract: A drill rod chuck in which the closing of the jaws is effected through the use of gas springs mounted in the slidable jaw actuating jaw bowl. Further the jaws are supported by bushings against cantilever loading during drilling and the jaws are positively advanced and retracted through slidable interengagement with the jaw bowl.
    Type: Grant
    Filed: October 26, 2001
    Date of Patent: April 13, 2004
    Assignee: Boart Longyear International Holdings, Inc.
    Inventor: John Thomas Stephens
  • Drill string chuck
    Publication number: 20030080520
    Abstract: A drill rod chuck in which the closing of the jaws is effected through the use of gas springs mounted in the slidable jaw actuating jaw bowl. Further the jaws are supported by bushings against cantilever loading during drilling and the jaws are positively advanced and retracted through slidable interengagement with the jaw bowl.
    Type: Application
    Filed: October 26, 2001
    Publication date: May 1, 2003
    Inventor: John Thomas Stephens