Granted Patent
Utility
US 6,668,971 · App. 09/825,384
Pneumatic hand tool exhaust muffler having inner and outer tubes
Inventor:
Robert E. Sterling
Patented Case
View Patent ↗
Granted: Dec 30, 2003
Filed: Apr 2, 2001
Inventor
Robert E. Sterling
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.