Patents by Inventor Willem Gerholt

Willem Gerholt 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).

  • Connections for insulated pipes
    Patent number: 3992237
    Abstract: A foam plastic layer is sprayed onto a metal pipe, whereafter a tape of polyethylene at the extrusion temperature is helically wound around the foam layer.
    Type: Grant
    Filed: February 6, 1975
    Date of Patent: November 16, 1976
    Assignee: Industriele Onderneming Wavin N.V.
    Inventors: Willem Gerholt, Gerrit Heidemann