Granted Patent
Utility
US 6,374,824 · App. 09/290,512
Device for improving breathing
Inventor:
W. Keith Thornton
Patented Case
View Patent ↗
Granted: Apr 23, 2002
Filed: Apr 12, 1999
Inventor
W. Keith Thornton
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.