Granted Patent
Utility
US 4,176,972 · App. 05/932,302
Coaxial pump mixer
Inventor:
Rodney A. Stiling
Patented Case
View Patent ↗
Granted: Dec 4, 1979
Filed: Aug 9, 1978
Inventor
Rodney A. Stiling
Assignee (at issue)
National Gypsum Company
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.