Patents by Inventor Edward J. Seiffert

Edward J. Seiffert 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).

  • Extrusion die
    Patent number: 4518343
    Abstract: A thermoplastic pipe extrusion die having an adjustment section in a radial portion of the die channel provides excellent control of final pipe wall thickness uniformity.
    Type: Grant
    Filed: March 7, 1983
    Date of Patent: May 21, 1985
    Assignee: E. I. Du Pont de Nemours and Company
    Inventor: Edward J. Seiffert