Granted Patent
Utility
US 5,220,318 · App. 07/570,072
Apparatus for selectively varying keyboard switching force
Inventor:
Darrell S. Staley
Patented Case
View Patent ↗
Granted: Jun 15, 1993
Filed: Aug 20, 1990
Inventor
Darrell S. Staley
Assignee (at issue)
Ampex 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.