Granted Patent
Utility
US 6,318,447 · App. 09/544,585
Sand gate for use in a sand distribution apparatus
Inventor:
David Sheldon
Patented Case
View Patent ↗
Granted: Nov 20, 2001
Filed: Apr 6, 2000
Inventor
David Sheldon
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.