Granted Patent
Utility
US 4,459,434 · App. 06/286,871
Home telephone exchange
Inventors:
Gordon D. Benning, Brian J. Pascas, Robert K. Blackhall, Paul S. Wilker, Graham Neathway
Patented Case
View Patent ↗
Granted: Jul 10, 1984
Filed: Jul 20, 1981
Inventors
Gordon D. Benning
Brian J. Pascas
Robert K. Blackhall
Paul S. Wilker
Graham Neathway
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.