Granted Patent
Utility
US 6,711,856 · App. 10/251,553
Door opener assist device
Inventor:
Drew Hoffman
Patented Case
View Patent ↗
Granted: Mar 30, 2004
Filed: Sep 19, 2002
Inventor
Drew Hoffman
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.