Granted Patent
Utility
US 4,420,657 · App. 06/316,230
Adjustable headset
Inventor:
Wallace Keith Larkin
Patented Case
View Patent ↗
Granted: Dec 13, 1983
Filed: Oct 29, 1981
Inventor
Wallace Keith Larkin
Assignee (at issue)
ACS Communications, 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.