Granted Patent
Utility
US 5,140,247 · App. 07/152,674
Control system for polyphase induction machines
Inventor:
Stephen P. Verbos
Patented Case
View Patent ↗
Granted: Aug 18, 1992
Filed: Feb 5, 1988
Inventor
Stephen P. Verbos
Assignee (at issue)
Lift-Tech International, Inc.
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.