Granted Patent
Utility
US 4,451,706 · App. 06/451,589
Telephone substation transmitter muting circuit
Inventor:
Eduard F. B. Boeckmann
Patented Case
View Patent ↗
Granted: May 29, 1984
Filed: Dec 20, 1982
Inventor
Eduard F. B. Boeckmann
Assignee (at issue)
GTE Automatic Electric Incorporated
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.