Granted Patent
Utility
US 4,190,733 · App. 05/808,571
High-voltage electrical apparatus utilizing an insulating gas of sulfur hexafluoride and helium
Inventor:
Roy E. Wootton
Patented Case
View Patent ↗
Granted: Feb 26, 1980
Filed: Jun 21, 1977
Inventor
Roy E. Wootton
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.