Granted Patent
Utility
US 4,364,408 · App. 06/183,584
Backflow prevention apparatus
Inventors:
David Griswold, Richard Veit
Patented Case
View Patent ↗
Granted: Dec 21, 1982
Filed: Sep 2, 1980
Inventors
David Griswold
Richard Veit
Assignee (at issue)
Griswold Controls, LLC
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.