Patents by Inventor Lasse Björkstedt

Lasse Björkstedt 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 controlling the operation of the short circulation of a paper, paperboard or the like production machine
    Patent number: 6736937
    Abstract: The present invention relates to a method of and an apparatus for controlling the operation of the short circulation of a paper, paper board or the like production machine. The method and apparatus according to the invention are especially preferably suitable for use in the approach system, i.e. so-called short circulation, of said production machines for regulating the headbox feed pressure. A characteristic feature of the method and apparatus according to the invention is that at a suitable location in the approach system of said production machine there is arranged a controllable parallel flow, by means of which at least one flow in the approach system is regulated so that the pressure in the headbox remains essentially constant.
    Type: Grant
    Filed: July 16, 2002
    Date of Patent: May 18, 2004
    Assignee: Andritz Oy
    Inventors: Lasse Björkstedt, Jouni Matula