Granted Patent
Utility
US 6,415,816 · App. 09/653,339
Air admittance valve assembly
Inventors:
Thomas J. Beckey, Richard T. Stone, Peter J. Nyvall
Patented Case
View Patent ↗
Granted: Jul 9, 2002
Filed: Aug 31, 2000
Inventors
Thomas J. Beckey
Richard T. Stone
Peter J. Nyvall
Assignee (at issue)
Cherne Industries Incorporated
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.