Granted Patent
Utility
US 4,955,762 · App. 07/380,686
Plenum fan assembly
Inventor:
Allen D. Hardman
Patented Case
View Patent ↗
Granted: Sep 11, 1990
Filed: Jun 14, 1989
Inventor
Allen D. Hardman
Assignee (at issue)
Raymond Production Systems 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.