Patents by Inventor Hazel Farquhar

Hazel Farquhar 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).

  • Method of controlling flow through a drill string using a valve positioned therein
    Patent number: 8069926
    Abstract: A downhole valve comprises a tubular body and a valve member. The valve member is normally closed and in the closed position may prevent or restrict passage of a working fluid through the body. The valve member is movable to an open position, a first working fluid pressure differential being necessary to move the valve member from the closed position and a lower second working fluid pressure differential being necessary to maintain the valve member in the open position.
    Type: Grant
    Filed: May 7, 2010
    Date of Patent: December 6, 2011
    Assignee: Andergauge Limited
    Inventors: Alan Martyn Eddison, Hazel Farquhar
  • Valve
    Publication number: 20100212912
    Abstract: A downhole valve comprises a tubular body and a valve member. The valve member is normally closed and in the closed position may prevent or restrict passage of a working fluid through the body. The valve member is movable to an open position, a first working fluid pressure differential being necessary to move the valve member from the closed position and a lower second working fluid pressure differential being necessary to maintain the valve member in the open position.
    Type: Application
    Filed: May 7, 2010
    Publication date: August 26, 2010
    Inventors: Alan Martyn Eddison, Hazel Farquhar
  • Valve
    Publication number: 20090032261
    Abstract: A downhole valve comprises a tubular body and a valve member. The valve member is normally closed and in the closed position may prevent or restrict passage of a working fluid through the body. The valve member is movable to an open position, a first working fluid pressure differential being necessary to move the valve member from the closed position and a lower second working fluid pressure differential being necessary to maintain the valve member in the open position.
    Type: Application
    Filed: January 16, 2006
    Publication date: February 5, 2009
    Inventors: Alan Martyn Eddison, Hazel Farquhar