Granted Patent
Utility
US 4,619,950 · App. 06/833,573
Method and material for plugging an ingot mold
Inventor:
Walter H. Carlson
Patented Case
View Patent ↗
Granted: Oct 28, 1986
Filed: Feb 25, 1986
Inventor
Walter H. Carlson
Assignee (at issue)
Graphite Sales, 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.