Granted Patent
Utility
US 4,433,680 · App. 06/347,596
Polyurethane casting material
Inventor:
Hee Kyung Yoon
Patented Case
View Patent ↗
Granted: Feb 28, 1984
Filed: Feb 10, 1982
Inventor
Hee Kyung Yoon
Assignee (at issue)
Johnson & Johnson Products, 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.