Granted Patent
Utility
US 4,594,477 · App. 06/586,926
PBX equipment with dial signal modification
Inventor:
Tamarra J. Noirot
Patented Case
View Patent ↗
Granted: Jun 10, 1986
Filed: Mar 7, 1984
Inventor
Tamarra J. Noirot
Assignee (at issue)
AT&T Technologies 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.