Granted Patent
Utility
US 6,484,451 · App. 09/766,795
Stackable riser resistant to soil movement
Inventor:
Norman W. Gavin
Patented Case
View Patent ↗
Granted: Nov 26, 2002
Filed: Jan 22, 2001
Inventor
Norman W. Gavin
Assignee (at issue)
United Concrete Products, Inc.
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.