Granted Patent
Utility
US 4,848,396 · App. 07/186,104
Cast hopper tee
Inventor:
David E. Sisk
Patented Case
View Patent ↗
Granted: Jul 18, 1989
Filed: Apr 25, 1988
Inventor
David E. Sisk
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.