Granted Patent
Utility
US 4,864,487 · App. 07/291,776
Control for three terminal power semiconductor devices
Inventors:
Harold Robert Schnetzka, Frank E. Wills
Patented Case
View Patent ↗
Granted: Sep 5, 1989
Filed: Dec 29, 1988
Inventors
Harold Robert Schnetzka
Frank E. Wills
Assignee (at issue)
York International Corporation
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.