Patents by Inventor Leo-Heinz Quillmann

Leo-Heinz Quillmann 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).

  • Patent number: 4010821
    Abstract: A sound reproduction device formed of an enclosure of expanded or foamed polymeric material, preferably polystyrene, which houses a centrally suspended speaker system, preferably a wafer multi-range speaker system. The enclosure is substantially closed and is acoustically excited by the speaker system to propagate sound thus requiring only a small ventilation opening to permit movement of the enclosure walls.
    Type: Grant
    Filed: May 2, 1975
    Date of Patent: March 8, 1977
    Inventor: Leo-Heinz Quillmann