Patents by Inventor David N. Christenson

David N. Christenson 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).

  • Ashtray
    Patent number: 4148618
    Abstract: An ashtray having a top upon which lit cigarettes or the like may be rested and having a plurality of holes therethrough through which smoke from the cigarette may be drawn downwardly through odor-treating material. The holes in the top are such as to permit the smoke-entraining downward flow of air therethrough while yet substantially preventing the passage of cigarette ashes.
    Type: Grant
    Filed: December 15, 1976
    Date of Patent: April 10, 1979
    Assignee: Smoketray, Inc.
    Inventors: David N. Christenson, Frank A. Freeman, Joseph T. Foley