Patents by Inventor James P. Heffernan

James P. Heffernan 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).

  • Computer-controlled oil drilling rig having drawworks motor and brake control arrangement
    Patent number: 4187546
    Abstract: An oil drilling rig includes a racker, a power tongs, a drawworks having a motor and a brake, and a general purpose programmable digital computer associated with each to sequentially initiate the operation thereof. Closed-loop control systems for the drawworks motor and drawworks brake are included to provide control signals to a motor drive and to a brake actuator.
    Type: Grant
    Filed: March 15, 1977
    Date of Patent: February 5, 1980
    Assignee: B. J. Hughes Inc.
    Inventors: James P. Heffernan, Loren B. Sheldon, James R. Tomashek, Donald H. Ward