Granted Patent
Utility
US 4,412,141 · App. 06/217,098
Three state loop keyer
Inventor:
Christian C. Jacobsen
Patented Case
View Patent ↗
Granted: Oct 25, 1983
Filed: Dec 16, 1980
Inventor
Christian C. Jacobsen
Assignee (at issue)
General DataComm Industries, 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.