Patents by Inventor Keith Jeffrey Hollingworth

Keith Jeffrey Hollingworth 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).

  • Tapered plug valve
    Patent number: 5779222
    Abstract: A tapered plug valve having a plug provided with a separate drive shaft and formed with a channel not connected to the plug but connecting the ends thereof to enable pressure equalization. The channel may be formed by being directly drilled through the plug, or comprise a tube, secured in position by welding in a groove cast in the outer surface of the plug. A non return valve is positioned in the channel to limit pressure equalization from the wider end to the smaller end of the plug.
    Type: Grant
    Filed: November 27, 1996
    Date of Patent: July 14, 1998
    Assignee: BTR plc
    Inventors: Keith Jeffrey Hollingworth, Peter Richard Jones