Granted Patent
Utility
US 4,178,539 · App. 05/930,763
Stepping AC line voltage regulator
Inventor:
Roland L. Crapo
Patented Case
View Patent ↗
Granted: Dec 11, 1979
Filed: Aug 3, 1978
Inventor
Roland L. Crapo
Assignee (at issue)
Superior Electron, 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.