Granted Patent
Utility
US 3,972,123 · App. 05/531,466
Air-abrasive prophylaxis equipment
Inventor:
Robert B. Black
Patented Case
View Patent ↗
Granted: Aug 3, 1976
Filed: Dec 11, 1974
Inventor
Robert B. Black
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.