Patents by Inventor Per V. Peterson

Per V. Peterson 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: 6435421
    Abstract: A camera dolly track designed for dual purpose use, providing radiused running surfaces for grooved wheeled dollies and a tensioner wheel surface for flat wheeled dollies.
    Type: Grant
    Filed: September 1, 2000
    Date of Patent: August 20, 2002
    Inventor: Per V. Peterson
  • Patent number: 4635864
    Abstract: Refiner disc segments for use in connection with disc refiners are disclosed. The refiner disc segments include in a radial portion thereof raised bars extending outwardly from the center of the segment with grooves defined between the raised bars, the raised bars having a width B, and the grooves having a width S and a depth D such that the ratio B.multidot.S.multidot.D/S+D is greater than about 2.7 mm and less than about 4.3 mm, and wherein the width B is from about 1 to 4 mm, the width S is from about 2 to 5 mm, and the depth D is from about 1 to 7 mm. Overall refining apparatus including a pair of refining members which includes such refining disc segments are also disclosed as is a method for producing these refining disc segments.
    Type: Grant
    Filed: September 24, 1985
    Date of Patent: January 13, 1987
    Assignee: SCA Development Aktiebolag
    Inventors: Per V. Peterson, Hans E. Hoglund, Alf O. K. Johansson
  • Patent number: 4597872
    Abstract: The invention relates to a method of treating wastewater from closed manufacture of mechanical or chemi-mechanical cellulose pulp, which treatment is carried out in a hydrolysis and acid fermentation step and a methane fermentation step with subsequent sludge separation and recycling of separated sludge.
    Type: Grant
    Filed: August 6, 1984
    Date of Patent: July 1, 1986
    Assignee: Purac Aktiebolag
    Inventors: Per-Erik Andersson, Goran E. Annergren, Hans E. Hoglund, Per V. Peterson
  • Patent number: 4357208
    Abstract: Lignocellulose material is pretreated with steam, heat, lignin softening chemicals or combinations thereof. The pretreated material is then refined in a disc refiner. Water is added to the material in the refining zone of the disc refiner to form a suspension at concentration of 8-15% at the point of discharge from the gap between the discs of the refiner. Steam development and steam backflow from the gap is reduced.
    Type: Grant
    Filed: October 17, 1979
    Date of Patent: November 2, 1982
    Assignee: SCA Development Aktiebolag
    Inventors: Per V. Peterson, Hans E. Hoglund
  • Patent number: 4356213
    Abstract: A treatment for wood chips in the manufacture of pulp is described. Prior to chip washing, the chips are placed in contact with an impregnation liquid such that all readily fillable cavities in the chips become filled with the liquid. The chips can be steamed prior to the impregnation process to increase the liquid absorption. After the impregnated chips are drained of the excess liquid, no appreciable amount of washing liquid is absorbed by them during a subsequent washing cycle used to remove included gravel and sand.
    Type: Grant
    Filed: February 23, 1981
    Date of Patent: October 26, 1982
    Assignee: SCA Development Aktiebolag
    Inventors: Hans E. Hoglund, Per V. Peterson
  • Patent number: 4280868
    Abstract: A method and apparatus for use in making refiner pulp by refining lignocellulose-containing materials in a disc refiner. In accordance with the method and apparatus, the retention time of the material in a gap between a pair of refining discs is increased by diluting the refined material exiting from the gap so as to form a fiber suspension having an easily pumpable concentration and maintaining a predetermined amount of the fiber suspension adjacent to the outlet of the gap.
    Type: Grant
    Filed: August 23, 1979
    Date of Patent: July 28, 1981
    Assignee: Sunds Defibrator Aktiebolag
    Inventors: Hans E. Hoglund, Per V. Peterson