Granted Patent
Utility
US 4,173,774 · App. 05/858,863
Parallel AC electrical system with differential protection immune to high current through faults
Inventors:
Wayne E. Hyvarinen, Lloyd J. Rosell
Patented Case
View Patent ↗
Granted: Nov 6, 1979
Filed: Dec 8, 1977
Inventors
Wayne E. Hyvarinen
Lloyd J. Rosell
Assignee (at issue)
Westinghouse Electric Company LLC
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.