Granted Patent
Utility
US 4,845,741 · App. 07/186,602
Modem ringing supression circuit
Inventor:
John D. Fourdraine
Patented Case
View Patent ↗
Granted: Jul 4, 1989
Filed: Apr 27, 1988
Inventor
John D. Fourdraine
Assignee (at issue)
Control Data 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.