Patents by Inventor George M. Crawford

George M. Crawford 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).

  • Patent number: 4448267
    Abstract: This is a device for reverse flow drilling of water wells, elevator ram holes and other holes. It is constructed of a hollow metal tubing with doors to allow for the discharge of excavated materials. In operation the Kelly (drill stem) is rotated into the ground and an airlift is used to bring cuttings into the drill stem and then out the doors. The doors are usually hand opened and hand closed and are locked by turning the door locks with a wrench or other tool. As the Kelly is rotated into the ground each door is opened for discharge and then closed before submergence into the drilling fluid.
    Type: Grant
    Filed: August 30, 1982
    Date of Patent: May 15, 1984
    Inventors: Russell C. Crawford, III, George M. Crawford, Russell C. Crawford, Jr.