Patents by Inventor Douglas Wahren

Douglas Wahren 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: 4340011
    Abstract: In a device for producing from an outlet slot of constant width along its length, a flowing film of liquid with a velocity substantially constant over the length of the slot, a row of passageways, arranged in parallel with each other, connect a supply duct with the outlet slot. In order to reduce the demand for high precision and thus the associated cost of manufacture, the passageways are made of an elongate configuration and with a constant bore diameter along a length which is several times greater than the bore diameter. The restrictions preferably consist of tubes of varying length along the length of the outlet slot and a formula for determining the length of the tubes is given. The use of the device in a fountain applicator for coating webs is also described.
    Type: Grant
    Filed: December 9, 1980
    Date of Patent: July 20, 1982
    Assignee: Aktiebolaget Karlstads Mekaniska Werkstad
    Inventors: Douglas Wahren, Rolf A. L. Akesson
  • Patent number: 4324613
    Abstract: A moist, porous web is consolidated and dried by running it through the nip between two rotatable rolls, the surface of one of which is heated as it approaches the nip. One side of the web is in direct contact with the surface of the heated roll and the other side faces a permeable surface. The rolls are pressed together under high pressure to transfer heat from the heated roll to the web compressed therebetween to dry the same. The roll surface may be heated by hot gases from a fuel combustion burner or by a liquid medium. The dried and consolidated web may be removed from the heated roll by doctoring or it may be conveyed from the nip between the rolls to apparatus for processing it further.
    Type: Grant
    Filed: June 10, 1980
    Date of Patent: April 13, 1982
    Inventor: Douglas Wahren
  • Patent number: 4240872
    Abstract: A headbox for paper and pulp machines is pivotally mounted at the ends of a plurality of control links secured to the machine frame and pointing from the machine frame towards a center of rotation in the vicinity of the headbox slice opening. The angular relation and the vertical position of the headbox with respect to a web forming zone are accurately set by controlling the rotation and translation of the respective control links and the headbox thereafter is maintained rigidly fixed in the set position.
    Type: Grant
    Filed: March 13, 1979
    Date of Patent: December 23, 1980
    Assignee: AB Karlstads Mekaniska Werkstad
    Inventor: Douglas Wahren
  • Patent number: 4209360
    Abstract: Methods and apparatus for producing a web by injecting a jet of stock between two tensioned wires and running the wires over a circumferentially grooved forming cylinder. The cylinder grooves and a zone immediately on the other side of the wires extending from the forming throat where the web is injected to the web run-off point are in direct, open communication with the ambient atmosphere so that water is drained inwardly and outwardly of the forming cylinder as the web is being formed. The jet stock size, wire speed and wire tension are adjusted in relation to the radius of the forming cylinder so that the inward and outward drainage of liquid from the web occurs in relative amounts sufficient to avoid substantial two-sidedness of the web thus produced.
    Type: Grant
    Filed: February 9, 1979
    Date of Patent: June 24, 1980
    Assignee: AB Karlstads Mekaniska Werkstad
    Inventors: Erik G. Stenberg, Douglas Wahren, Carl Zotterman
  • Patent number: 4100018
    Abstract: A method and apparatus for continuously forming a fibrous web in which a fibrous suspension is injected into a tapered throat formed by two running wires pervious to the suspension and converging to the periphery of an impermeable roll; the wires and the injected suspension therebetween are transported over a portion of the periphery of the roll under tension to form and dewater the injected suspension; as the wires run off the forming and dewatering roll, the web is sucked loose from the outer wire and it and the wires are transported over a convexly curved surface under tension; and the web is separated from the outer wire by off-running in the direction away from the convexly curved surface while the inner wire runs off that surface with the web, the convexly curved surface being impermeable at least at the wire separation location.
    Type: Grant
    Filed: June 22, 1976
    Date of Patent: July 11, 1978
    Assignee: Aktiebolaget Karlstads Mekaniska Werkstad
    Inventors: Douglas Wahren, Erik Gunnar Stenberg, Berndt Erik Ingvar Klerelid
  • Patent number: 4081320
    Abstract: The transfer of a fibrous web in a paper-making machine from a first foraminous belt to a second foraminous belt is facilitated by applying water to the side of the first belt opposite from the side on which the web is carried partially to wet the web, leading the second belt into engagement with the fibrous web before or after wetting it, and after the web is wet, and while the second belt is in engagement with the web, causing the water or gas pressure on the side of the web adhering to the first belt to exceed the water or gas pressure on the side of the web adjacent to the second belt.
    Type: Grant
    Filed: November 26, 1975
    Date of Patent: March 28, 1978
    Assignee: Aktiebolaget Karlstads Mekaniska Werkstad
    Inventors: Douglas Wahren, Erik Gunnar Stenberg
  • Patent number: 4070238
    Abstract: Finely-mixed stock is produced in a headbox by delivering a multiplicity of separate stock streams at a relatively high velocity into passages defined between closely-spaced planar lamellae which extend parallel to the stock flow and oblique to a medial plane that lies axially and transversely of the fine-mixing stage that contains the lamellae. The stock flows at relatively low velocity in finely-mixed condition from the fine-mixing stage to a discharge nozzle, the axis of which lies at a substantial angle to the axis of the fine-mixing stage. The stock distribution and mixing section and the delivery nozzle of the headbox may be divided axially and transversely into two or more separate compartments for discharge of a jet composed of layers of the same or different stocks to form multi-ply webs.
    Type: Grant
    Filed: March 11, 1977
    Date of Patent: January 24, 1978
    Assignee: Aktiebolaget Karlstads Mekaniska Werkstad
    Inventor: Douglas Wahren