Granted Patent
Utility
US 4,501,498 · App. 06/558,042
Method and apparatus for extruding thermoplastic material
Inventor:
James M. McKelvey
Patented Case
View Patent ↗
Granted: Feb 26, 1985
Filed: Dec 5, 1983
Inventor
James M. McKelvey
Assignee (at issue)
Luwa, 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.