Granted Patent
Utility
US 6,544,546 · App. 08/981,881
Ring-shaped devices
Inventors:
Rudolf Johannes Joseph Groenewegen, Antonius Paulus Sam, Herman Vromans, Hendrik de Nijs
Patented Case
View Patent ↗
Granted: Apr 8, 2003
Filed: Dec 31, 1997
Inventors
Rudolf Johannes Joseph Groenewegen
Antonius Paulus Sam
Herman Vromans
Hendrik de Nijs
Assignee (at issue)
AKZO NOBEL N.V.
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.