Patents by Inventor Peter J. M. Hogarth

Peter J. M. Hogarth 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).

  • Cementing apparatus and methods
    Patent number: 4664192
    Abstract: In drilling a well, sections of casing are run down a borehole, preferably with a float shoe at the lower end which is equipped with a double valve enabling the casing to fill with drilling mud both while the casing is moving down and also while it is stationary. Within the casing is a baffle collar which defines a socket for a latching dart carried by a plug. The plug and dart are driven down to the collar, when the pumping of cement into the casing has been completed, by a launching dart which also closes the passageway through the plug.
    Type: Grant
    Filed: October 9, 1984
    Date of Patent: May 12, 1987
    Assignee: Easfind Limited
    Inventor: Peter J. M. Hogarth