Granted Patent
Utility
US 4,742,540 · App. 06/931,410
Circuit for switching between balanced networks
Inventor:
Pierre J. Schingh
Patented Case
View Patent ↗
Granted: May 3, 1988
Filed: Nov 14, 1986
Inventor
Pierre J. Schingh
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.