Patents by Inventor William E. Levers

William E. Levers 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).

  • Filter
    Patent number: 4189511
    Abstract: Improved tobacco smoke filters, particularly cigarette filters, are prepared from a web of synthetic polymeric fibers having applied to at least one surface thereof a film-forming derivative of cellulose. Continuous processes and apparatus for the production of the web and filter are also described.
    Type: Grant
    Filed: January 7, 1977
    Date of Patent: February 19, 1980
    Assignee: Celanese Corporation
    Inventors: William E. Levers, Charles H. Keith