Granted Patent
Utility
US 5,440,540 · App. 07/855,795
Ring interworking between a bidirectional line-switched ring transmission system and another ring transmission system
Inventor:
Wilhelm Kremer
Patented Case
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Granted: Aug 8, 1995
Filed: Mar 26, 1992
Inventor
Wilhelm Kremer
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.