Patents by Inventor Sven A. J. Liljendahl

Sven A. J. Liljendahl 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).

  • Heat-insulating roller-blind
    Patent number: 4502522
    Abstract: A heat insulating roller blind is made of two congruent sheets which are joined at their side and bottom edges by a soft elastic band. Valve means allow room air into the space between the sheets and permit the outflow of the air when the blind is rolled up. Tab means are connected to one of the sheets to add in separating them when the blind is unrolled.
    Type: Grant
    Filed: August 9, 1982
    Date of Patent: March 5, 1985
    Inventor: Sven A. J. Liljendahl