Granted Patent
Utility
US 4,948,765 · App. 07/322,315
Refractory coating for making refractory shells
Inventor:
Robert Snook
Patented Case
View Patent ↗
Granted: Aug 14, 1990
Filed: Mar 10, 1989
Inventor
Robert Snook
Assignee (at issue)
Ashland Oil, 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.