Granted Patent
Utility
US 4,837,187 · App. 07/058,129
Alumina-based core containing yttria
Inventors:
Gregory R. Frank, Kenneth A. Canfield, Thomas R. Wright
Patented Case
View Patent ↗
Granted: Jun 6, 1989
Filed: Jun 4, 1987
Inventors
Gregory R. Frank
Kenneth A. Canfield
Thomas R. Wright
Assignee (at issue)
HOWMET CORPORATION
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.