Granted Patent
Utility
US 4,899,861 · App. 07/026,504
Variable speed drive for engine cooling fans
Inventor:
Gordon F. Cummings, III
Patented Case
View Patent ↗
Granted: Feb 13, 1990
Filed: Mar 16, 1987
Inventor
Gordon F. Cummings, III
Assignee (at issue)
Rockford Powertrain, 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.