Patents by Inventor Lennart .ANG.gren

Lennart .ANG.gren 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).

  • Pipe for relining underground pipelines
    Patent number: 5148837
    Abstract: Pipe for relining underground pipelines, which is of the composite type having an annularly rigid corrugated outside wall (10) of polymer material, which is connected to the outside surface of a smooth inside wall (11) which consists of a thermoplastic elastomer so that it can be stretched and compressed. According to the invention there is provided on the inside of the smooth inside wall (11) a thin layer (13) of the thermoplastic having a lower frictional coefficient and/or greater wear-resistance than the material of the inside wall.
    Type: Grant
    Filed: January 8, 1991
    Date of Patent: September 22, 1992
    Assignee: Uponor N.V.
    Inventors: Lennart .ANG.gren, Eino Holso