Granted Patent
Utility
US 4,842,788 · App. 07/140,443
Process of an apparatus for extruding a meltable composition
Inventor:
D. Emil Johnson
Patented Case
View Patent ↗
Granted: Jun 27, 1989
Filed: Jan 4, 1988
Inventor
D. Emil Johnson
Assignee (at issue)
Mobil Oil 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.