Granted Patent
Utility
US 5,203,681 · App. 07/748,145
Submerisble molten metal pump
Inventor:
Paul V. Cooper
Patented Case
View Patent ↗
Granted: Apr 20, 1993
Filed: Aug 21, 1991
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.