Patents by Inventor John Douglas Crabtree

John Douglas Crabtree 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: 7172369
    Abstract: A deformed thermoplastic liner is drawn through a cut host pipe and split sleeve halves attached to it and then reformed to its cylindrical configuration using pressurized steam. The split sleeve halves are removed, and an adapter flange is fused onto a cut end of the liner portion. The split sleeves halves are then re-attached with the adapter flange between bolted flanges of the split sleeve halves and a section welded to the adjacent host pipe to provide a permanent pressure sealed connection. The lined host pipe can also be connected to a lateral pipe using a lateral extension fused to the rerounded liner and a third split sleeve half with a lateral pipe extension that receives the lateral extension and is attached to the lateral pipe, either directly, or through a second split sleeve.
    Type: Grant
    Filed: March 28, 2006
    Date of Patent: February 6, 2007
    Assignees: Pipe Liners, Inc., Weatherford U.S.L.P.
    Inventors: John Douglas Crabtree, James Lewis Tate
  • Patent number: 7037043
    Abstract: A section of a host pipe is removed, a flange is placed at one end of the host pipe section and split sleeve halves are secured to one another and at one end to the flange to cantilever the split sleeve from the end of the host pipe. A deformed thermoplastic liner is drawn through the host pipe and split sleeve and reformed to its cylindrical configuration by introducing steam under pressure. Once reformed, the split sleeve halves are removed, the end portion of the rerounded liner is cut and an adapter flange is fused on the end of the cut liner portion. The split sleeve halves are reapplied about the rounded liner with the flange on the adapter bearing against an end face of the flanges of the split sleeve. A cylindrical section is welded to the adjacent host pipe section and a flange thereof is bolted to the distal end flange of the split sleeve whereby a permanent pressure sealed connection is provided between a lined host pipe section and a non-lined host pipe section.
    Type: Grant
    Filed: February 14, 2005
    Date of Patent: May 2, 2006
    Assignee: Pipe Liners, Inc.
    Inventors: John Douglas Crabtree, James Lewis Tate