Granted Patent
Utility
US 6,689,310 · App. 09/569,461
Molten metal degassing device and impellers therefor
Inventor:
Paul V. Cooper
Patented Case
View Patent ↗
Granted: Feb 10, 2004
Filed: May 12, 2000
Inventor
Paul V. Cooper
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.