Patents by Inventor Willi Trojan

Willi Trojan 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).

  • Sound absorbent panel
    Patent number: 4351739
    Abstract: A composition for sound absorbent panels, which may be utilized in construction elements, comprises a mixture of 70 to 97 weight percent of carbon-contained material and a binder of synthetic plastic material. The carbon-contained material used in the composition contains 50-60% of pure carbon and 40-50% of inorganic constituents and may be obtained from residues of coal hydrogenation or pitch filtration. The material is treated at an elevated temperature and under pressure before the binder is added thereto and then the obtained compound is formed into a panel.
    Type: Grant
    Filed: September 6, 1979
    Date of Patent: September 28, 1982
    Assignee: Bergwerksverband GmbH
    Inventors: Ingo Romey, Willi Trojan