Granted Patent
Utility
US 6,506,302 · App. 09/784,956
Key system for ecological filter cartridge and element
Inventor:
Leon P. Janik
Patented Case
View Patent ↗
Granted: Jan 14, 2003
Filed: Feb 16, 2001
Inventor
Leon P. Janik
Assignee (at issue)
Stanadyne 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.