Granted Patent
Utility
US 4,898,503 · App. 07/215,175
Twist drill
Inventor:
Herman B. Barish
Patented Case
View Patent ↗
Granted: Feb 6, 1990
Filed: Jul 5, 1988
Inventor
Herman B. Barish
Assignee (at issue)
Lockheed Corporation
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.