Granted Patent
Utility
US 4,520,641 · App. 06/330,694
Combination lock with security feature
Inventor:
Lazlo Bako
Patented Case
View Patent ↗
Granted: Jun 4, 1985
Filed: Dec 14, 1981
Inventor
Lazlo Bako
Assignee (at issue)
Presto Lock, Inc.
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.