Patents by Inventor Heikki J. Seppa

Heikki J. Seppa 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 apparatus for determining the size and shape of a slot by measuring a magnetic field produced along an edge thereof
    Patent number: 5530346
    Abstract: A method and an apparatus for determining the size and shape of a slot, for measuring, e.g., the profile of the discharge opening (slice) of a paper machine. In the method, using at least two magnetometers attached to an edge of the slot, the magnetic field depending on the size and shape of the slot is measured. An alternating electrical current is applied to a current conductor attached to the edge of the slot to create an alternating magnetic field, measurement of the alternating magnetic field is phase-locked with the applied electrical circuit, and the size and shape of the slot are calculated from the measured values of the magnetic field.
    Type: Grant
    Filed: December 30, 1994
    Date of Patent: June 25, 1996
    Assignee: Valmet-Tampella Oy
    Inventors: Timo T. Varpula, Heikki J. Seppa, Mayri O. Sundstrom