Granted Patent
Utility
US 5,316,443 · App. 07/770,842
Reversible mixing impeller
Inventor:
John M. Smith
Patented Case
View Patent ↗
Granted: May 31, 1994
Filed: Oct 4, 1991
Inventor
John M. Smith
Assignee (at issue)
Chemineer, Inc.
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.