Granted Patent
Utility
US 4,999,018 · App. 07/557,947
Drill chuck key bearing
Inventor:
Otto D. Wenz, Jr.
Patented Case
View Patent ↗
Granted: Mar 12, 1991
Filed: Jul 25, 1990
Inventor
Otto D. Wenz, Jr.
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.