Granted Patent
Utility
US 5,107,888 · App. 07/650,799
N-shaped backflow preventor
Inventor:
Charles W. Dunmire
Patented Case
View Patent ↗
Granted: Apr 28, 1992
Filed: Feb 5, 1991
Inventor
Charles W. Dunmire
Assignee (at issue)
CMB 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.