Granted Patent
Utility
US 4,977,367 · App. 07/149,654
Range selector switch for ion chamber instrument
Inventor:
Joseph G. Johnston
Patented Case
View Patent ↗
Granted: Dec 11, 1990
Filed: Jan 28, 1988
Inventor
Joseph G. Johnston
Assignee (at issue)
Bicron 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.