Patents by Inventor Corby J. Schefers

Corby J. Schefers 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).

  • Drilling rig equipped with pairs of block and tackle systems
    Patent number: 4423994
    Abstract: This invention relates to drilling rigs, and more particularly to novel apparatus for supporting a plurality of pairs of block and tackle systems with the tackle systems of each pair operable sequentially and alternately, the one being used to support a main drilling or tubing string while the other is being used to rack stands of tubing therefrom.
    Type: Grant
    Filed: October 26, 1981
    Date of Patent: January 3, 1984
    Inventors: Corby J. Schefers, Louis D. Barber