Granted Patent
Utility
US 4,389,014 · App. 06/254,774
Vent damper with emergency manual override
Inventor:
Ho Chow
Patented Case
View Patent ↗
Granted: Jun 21, 1983
Filed: Apr 16, 1981
Inventor
Ho Chow
Assignee (at issue)
Melnor Industries, 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.