Patents by Inventor Joel Ham

Joel Ham 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).

  • Screw thread structure for percussion drill driver sub and case
    Patent number: 5163523
    Abstract: A driver sub and a case for enclosing a piston chamber of a percussion drill are threadedly connected by respective identical male and female screw threads. Each of the identical male and female screw threads includes a root portion, the shape of which is defined by portions of two axially overlapping ellipses interconnected by a flat.
    Type: Grant
    Filed: September 27, 1991
    Date of Patent: November 17, 1992
    Assignee: Sandvik Rock Tools, Inc.
    Inventors: Faisal J. Yousef, Robert F. Kane, Joel Ham, David Mildren
  • Screw thread coupling
    Patent number: 5060740
    Abstract: A thread coupling comprises two interconnected screw threads. Each of the screw threads has a root portion shaped as a portion of an ellipse. With respect to one of the threads having such a shape, the major axis of the ellipse is longer than that of the other thread.
    Type: Grant
    Filed: May 29, 1990
    Date of Patent: October 29, 1991
    Assignee: Sandvik Rock Tools, Inc.
    Inventors: Faisal J. Yousef, Robert F. Kane, Joel Ham, David Mildren
  • Screw thread structure
    Patent number: 5056611
    Abstract: A screw thread structure includes a root portion, the shape of which is defined by portions of two axially overlapping ellipses interconnected by a flat.
    Type: Grant
    Filed: May 29, 1990
    Date of Patent: October 15, 1991
    Assignee: Galloway Trust
    Inventors: Faisal J. Yousef, Robert F. Kane, Joel Ham, David Mildren