Patents by Inventor Gerardus C. van der Graaf

Gerardus C. van der Graaf 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).

  • Drill pipe telemetering system with electrodes exposed to mud
    Patent number: 4220381
    Abstract: A drill string telemetry system of the hard-wired type wherein a separate conductor extends through each section of the drill pipe. The conductor is connected to connectors located in the ends of the drill pipe with the connectors completing the electrical circuit as the drill pipe is assembled. The connectors are designed to be exposed to the drilling fluid and include an amplifier.
    Type: Grant
    Filed: April 9, 1979
    Date of Patent: September 2, 1980
    Assignee: Shell Oil Company
    Inventor: Gerardus C. van der Graaf