Granted Patent
Utility
US 4,791,639 · App. 06/893,950
Communications switching system
Inventors:
Michael Afheldt, John A. Barsellotti, Lester Kirkland
Patented Case
View Patent ↗
Granted: Dec 13, 1988
Filed: Aug 6, 1986
Inventors
Michael Afheldt
John A. Barsellotti
Lester Kirkland
Assignee (at issue)
Mitel 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.