Granted Patent
Utility
US 6,616,721 · App. 10/079,225
Cyclone dust collector for preventing backflow
Inventor:
Jang-keun Oh
Patented Case
View Patent ↗
Granted: Sep 9, 2003
Filed: Feb 20, 2002
Inventor
Jang-keun Oh
Assignee (at issue)
Samsung Gwangju Electronics Co., 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.