Granted Patent
Utility
US 4,648,090 · App. 06/697,230
Arrangement for controlling switched speech or data communication in a communications exchange
Inventors:
Thomas S. Maddern, Alexander S. Philip
Patented Case
View Patent ↗
Granted: Mar 3, 1987
Filed: Feb 1, 1985
Inventors
Thomas S. Maddern
Alexander S. Philip
Assignee (at issue)
The Plessey Company PLC
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.