Patents by Inventor Bartholomeus G. G. Van Walstijn

Bartholomeus G. G. Van Walstijn 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).

  • Method and system for controlling vibrations in borehole equipment
    Patent number: 5117926
    Abstract: Vibrations in borehole equipment are controlled by defining the energy flow through the equipment as the product of an "across" variable and a "through" variable, wherein fluctuations in one variable are measured and the energy flow is controlled by adjusting the other variable in response to the measured fluctuations in said one variable. Suitable variables for defining the energy flow are voltage times current of an electrical drive, pressure times flow rate of a hydraulic drive, or torque times angular velocity of any rotary drive.
    Type: Grant
    Filed: February 20, 1991
    Date of Patent: June 2, 1992
    Assignee: Shell Oil Company
    Inventors: Robert N. Worrall, Ivo P. J. M. Stulemeijer, Johan D. Jansen, Bartholomeus G. G. Van Walstijn