Granted Patent
Utility
US 6,821,310 · App. 10/203,657
Device and method for air filtration
Inventor:
Anders Hedström
Patented Case
View Patent ↗
Granted: Nov 23, 2004
Filed: Oct 30, 2002
Inventor
Anders Hedström
Assignee (at issue)
Clair Finance AB
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.