Granted Patent
Utility
US 4,885,769 · App. 07/289,905
Station controller for enhanced multi-line pick-up in centrex exchange telephone system
Inventor:
John D. Beierle
Patented Case
View Patent ↗
Granted: Dec 5, 1989
Filed: Dec 23, 1988
Inventor
John D. Beierle
Assignee (at issue)
Nynex 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.