Granted Patent
Utility
US 4,979,721 · App. 07/444,672
Check valve having combined quick disconnect wrench flat defining ridge
Inventor:
Major H. Gilbert
Patented Case
View Patent ↗
Granted: Dec 25, 1990
Filed: Dec 1, 1989
Inventor
Major H. Gilbert
Assignee (at issue)
Bridge Products, 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.