Patents by Inventor Sigvard Winkle

Sigvard Winkle 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).

  • Method for restoring underground pipelines
    Patent number: 4930542
    Abstract: Method for restoring underground pipeline (11B) wherein short-pipes (17) are pressed one after the other intermittently into the pipeline end to end. An expansion piercer (18) or similar broaching tool is pushed through the pipeline at the leading end of the pipe string formed by the short-pipes and is brought to expand so as to split or, if splitting is not necessary, to widen the pipeline to substantially circular cross-sectional form.
    Type: Grant
    Filed: May 5, 1989
    Date of Patent: June 5, 1990
    Assignee: Entreprenadaktiebolaget E. & G. Jonsson
    Inventors: Sigvard Winkle, Henrik Persson