Granted Patent
Utility
US 6,468,052 · App. 09/756,378
Vacuum relief device for fluid transfer and circulation systems
Inventors:
Paul C. McKain, Mark Fritze
Patented Case
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Granted: Oct 22, 2002
Filed: Jan 8, 2001
Inventors
Paul C. McKain
Mark Fritze
Assignees (at issue)
Robert M. Downey
Paul C. McKain
Mark Fritze
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.