Patents by Inventor John Allan Skinner

John Allan Skinner 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).

  • Rotary driven retrieval tool for horizontal directional drilling operations
    Patent number: 6848506
    Abstract: A rotating inner member is used to drive operation of a retrieval tool connected to a dual-member drill string. The retrieval tool preferably has a gripping assembly adapted to receive rotational energy from the inner member. In a preferred embodiment, an electric actuator assembly operates the gripping assembly of the retrieval tool. In another preferred embodiment, the gripping assembly of the retrieval tool is mechanically operated by a screw driven cam assembly. In yet another embodiment, the retrieval tool is adapted to grip both the inside and outside of the object to be retrieved.
    Type: Grant
    Filed: June 28, 2002
    Date of Patent: February 1, 2005
    Assignee: The Charles Machine Works, Inc.
    Inventors: Richard Felix Sharp, Matthew L. Dock, H. Stanley Mullins, John Allan Skinner