Granted Patent
Utility
US 4,456,987 · App. 06/360,734
Digital switching network
Inventor:
Howard L. Wirsing
Patented Case
View Patent ↗
Granted: Jun 26, 1984
Filed: Mar 22, 1982
Inventor
Howard L. Wirsing
Assignee (at issue)
International Telephone and Telegraph 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.