Patents by Inventor Kari Pitkajarvi

Kari Pitkajarvi 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).

  • Patent number: 6402893
    Abstract: Control equipment for the headbox tip lath of a paper machine includes first actuators (12a1, 12a2 . . . ), which are located at different points along the headbox (100) width and connect functionally with a bendable intermediate part (14). At the different points along the headbox (100) width there are also second actuators (13a1, 13a2 . . . ) which are used in the tip lath control. These connect functionally with both the bendable intermediate part (14) and the tip lath (11). The first actuators (12a1, 12a2 . . . ) are used to perform rough control of the tip lath (11) whereas the second actuators (13a1, 13a2 . . . ) are used to perform fine control of the tip lath (11).
    Type: Grant
    Filed: February 23, 2001
    Date of Patent: June 11, 2002
    Assignee: Metso Paper, Inc.
    Inventors: Juhana Lumiala, Jarmo Kirvesmäki, Kari Pitkäjärvi, Tommi Korolainen, Ilkka Kemiläinen
  • Publication number: 20010027851
    Abstract: Control equipment for the headbox tip lath of a paper machine includes first actuators (12a1, 12a2 . . . ), which are located at different points along the headbox (100) width and connect functionally with a bendable intermediate part (14). At the different points along the headbox (100) width there are also second actuators (13a1, 13a2 . . . ) which are used in the tip lath control. These connect functionally with both the bendable intermediate part (14) and the tip lath (11). The first actuators (12a1, 12a2 . . . ) are used to perform rough control of the tip lath (11) whereas the second actuators (13a1, 13a2 . . . ) are used to perform fine control of the tip lath (11).
    Type: Application
    Filed: February 23, 2001
    Publication date: October 11, 2001
    Inventors: Juhana Lumiala, Jarmo Kirvesmaki, Kari Pitkajarvi, Tommi Korolainen, Ilkka Kemilainen
  • Patent number: 5800678
    Abstract: A system for combining a dilution flow with the stock flow passed from the inlet header of the headbox of a paper/board machine. The equipment comprises a valve which regulates the dilution flow and which consists of a valve housing, of a spindle, and of a flow duct placed in the spindle, which flow duct can be rotated into different regulation positions for the purpose of regulating the dilution flow departing from the valve. One end opening of the flow duct and the flow opening in the valve housing are placed in alignment with one another irrespective of the position of rotation of the spindle. The position of the other end opening of the duct placed in the spindle in relation to the flow opening in the valve housing can be regulated by rotating the spindle.
    Type: Grant
    Filed: December 31, 1996
    Date of Patent: September 1, 1998
    Assignee: Valmet Corporation
    Inventor: Kari Pitkajarvi
  • Patent number: 5674364
    Abstract: A method and device in the regulation of the headbox of a paper machine/board machine, in which additional flows are introduced into the pulp suspension at different points across the width of the headbox. The concentration of the additional flows is different than the average concentration of the pulp suspension. The additional flows are introduced through additional-flow pipes to the vicinity of inlet openings of turbulence tubes of a turbulence generator. The grammage profile of the web in the direction of width of the web is regulated in the headbox by adjusting the distance of the end of the additional-flow pipe/pipes from the turbulence generator, whereby the amount of the additional flow entering into the additional-flow pipes and, at the same time, the amount of the pulp suspension flow are regulated.
    Type: Grant
    Filed: July 1, 1994
    Date of Patent: October 7, 1997
    Assignee: Valmet Paper Machinery, Inc.
    Inventor: Kari Pitkajarvi
  • Patent number: 5578171
    Abstract: A movement compensator apparatus and method for compensating for movements taking place during tilting of a headbox of a paper machine and preventing transfer of strains from a pulp supply pipe in the headbox to a stationary pulp supply pipe. The movement compensator has a first pipe connected to the supply pipe by a connecting flange that permits rotation of the first pipe and the supply pipe relative to one another, and a second pipe connected to the first pipe by another connecting flange that permits rotation of the first pipe and the second pipe relative to one another. The second pipe is further connected to the stationary supply pipe by a third connecting flange that also permits rotation of the second pipe and the stationary supply pipe relative to one another.
    Type: Grant
    Filed: February 16, 1994
    Date of Patent: November 26, 1996
    Assignee: Valmet Corporation
    Inventor: Kari Pitkajarvi
  • Patent number: 4687548
    Abstract: Method and apparatus in the head box of a paper machine for controlling the distortion of fibre orientation in the paper web comprise an arrangement wherein by-pass flows of pulp suspension are passed through opposite passages lateral of the turbulence generator preceding the slice portion or discharge channel of the head box. The magnitude and/or the mutual relationship of the by-pass flows is adjusted to control the distortion of the fibre orientation in that the by-pass flows produce a transverse flow in the discharge flow of the pulp suspension from the head box, the speed of which compensates for the distortion of the fibre orientation.
    Type: Grant
    Filed: October 28, 1985
    Date of Patent: August 18, 1987
    Assignee: Valmet Oy
    Inventors: Erkki Ilmoniemi, Jouni Koskimies, Markku Lyytinen, Kari Pitkajarvi, Esa Ottelin
  • Patent number: 4683027
    Abstract: Method and apparatus for regulating pressure in a wedge-shaped space between the wall of the headbox lip beam or the like and the breast roll. An arrangement is provided by which air jets are directed in a direction opposite to the direction in which the forming wire moves on the breast roll to eject air out of the wedge-shaped space to maintain the pressure induced therein at a desired level. The apparatus includes a blow box coupled to a source of pressurized air and the box having a wall in opposed relationship to the forming wire in which nozzle openings or slots are formed through which the air jets are directed. The blow box has a wider side which substantially closes the wedge-shaped space. Water jets are directed into the wedge-shaped space by water supply devices provided on the blow box for cleaning purposes.
    Type: Grant
    Filed: October 24, 1985
    Date of Patent: July 28, 1987
    Assignee: Valmet Oy
    Inventor: Kari Pitkajarvi