Granted Patent
Utility
US 4,911,554 · App. 07/133,568
Rotatable drum
Inventors:
Heinrich Henne, Hubert Grothaus
Patented Case
View Patent ↗
Granted: Mar 27, 1990
Filed: Dec 16, 1987
Inventors
Heinrich Henne
Hubert Grothaus
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.