Granted Patent
Utility
US 4,734,015 · App. 07/067,389
Axial-flow fan
Inventor:
Guenter Wrobel
Patented Case
View Patent ↗
Granted: Mar 29, 1988
Filed: Jun 26, 1987
Inventor
Guenter Wrobel
Assignee (at issue)
Papst Motoren GmbH & Co KG
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.