Granted Patent
Utility
US 5,681,143 · App. 08/562,146
Damper control system for centrifugal fan
Inventor:
David A. Ratner
Patented Case
View Patent ↗
Granted: Oct 28, 1997
Filed: Nov 22, 1995
Inventor
David A. Ratner
Assignee (at issue)
Brod & McClung--Pace Co.
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.