Granted Patent
Utility
US 4,554,412 · App. 06/633,478
Resistive line circuit
Inventor:
Douglas C. Smith
Patented Case
View Patent ↗
Granted: Nov 19, 1985
Filed: Jul 23, 1984
Inventor
Douglas C. Smith
Assignee (at issue)
AT&T Information Systems 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.