Granted Patent
Utility
US 4,912,700 · App. 07/265,821
Telecommunications digital switch
Inventors:
Thomas S. Maddern, Geoffrey Chopping
Patented Case
View Patent ↗
Granted: Mar 27, 1990
Filed: Nov 1, 1988
Inventors
Thomas S. Maddern
Geoffrey Chopping
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.