Granted Patent
Utility
US 4,959,855 · App. 07/225,607
Directory assistance call processing and calling customer remote signal monitoring arrangements
Inventor:
Abraham N. Daudelin
Patented Case
View Patent ↗
Granted: Sep 25, 1990
Filed: Jul 25, 1988
Inventor
Abraham N. Daudelin
Assignee (at issue)
AT&T Bell Laboratories
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.