Granted Patent
Utility
US 5,217,407 · App. 07/714,002
Fire damper with auxiliary springs
Inventor:
William J. Bailey
Patented Case
View Patent ↗
Granted: Jun 8, 1993
Filed: Jun 11, 1991
Inventor
William J. Bailey
Assignee (at issue)
Tomkins 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.