Granted Patent
Utility
US 4,238,439 · App. 05/839,868
Process for producing self-crimping polyamide yarns
Inventor:
Jae-Chun Hyun
Patented Case
View Patent ↗
Granted: Dec 9, 1980
Filed: Oct 6, 1977
Inventor
Jae-Chun Hyun
Assignee (at issue)
Monsanto Company
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.