Granted Patent
Utility
US 4,562,935 · App. 06/648,618
Inside protector for bottom wall portion of underground tank beneath fill tube
Inventor:
Mark E. Greenwood
Patented Case
View Patent ↗
Granted: Jan 7, 1986
Filed: Sep 10, 1984
Inventor
Mark E. Greenwood
Assignee (at issue)
Owens-Corning Fiberglas Corp.
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.