Granted Patent
Utility
US 6,820,720 · App. 10/049,344
Sound-absorbing article effective over a broad frequency range
Inventors:
Norbert Nicolai, Helmut Fuchs, Dinh-Quyen Chuong
Patented Case
View Patent ↗
Granted: Nov 23, 2004
Filed: Feb 11, 2002
Inventors
Norbert Nicolai
Helmut Fuchs
Dinh-Quyen Chuong
Assignee (at issue)
Clion Irland Ltd.
This patent predates the USPTO's electronic file wrapper — prosecution documents from this era exist only in the Patent Office's paper records. A certified copy of the file history can be ordered from the USPTO's paper archives.