Granted Patent
Utility
US 4,233,077 · App. 05/792,422
Preparing extrudable refractory hard metal-wax blends
Inventor:
John G. Hazel
Patented Case
View Patent ↗
Granted: Nov 11, 1980
Filed: Apr 29, 1977
Inventor
John G. Hazel
Assignee (at issue)
PPG Industries, 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.