Granted Patent
Utility
US 4,940,927 · App. 06/770,719
Three-phase A-C speed control for variable torque motor
Inventor:
Marvin J. Fisher
Patented Case
View Patent ↗
Granted: Jul 10, 1990
Filed: Aug 29, 1985
Inventor
Marvin J. Fisher
Assignee (at issue)
Mentzer Electronic GmbH
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.