Granted Patent
Utility
US 4,355,208 · App. 06/204,151
Telephone call denial system
Inventors:
John A. Cribb, John R. Whitbread, Graham Neathway, Robert A. Durance
Patented Case
View Patent ↗
Granted: Oct 19, 1982
Filed: Nov 5, 1980
Inventors
John A. Cribb
John R. Whitbread
Graham Neathway
Robert A. Durance
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.