Granted Patent
Utility
US 4,456,411 · App. 06/524,834
Twist drill
Inventor:
Burke Clement
Patented Case
View Patent ↗
Granted: Jun 26, 1984
Filed: Aug 19, 1983
Inventor
Burke Clement
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.