Granted Patent
Utility
US 4,711,623 · App. 06/862,729
Annular extrusion die with internal choke ring and spider mandrel
Inventors:
Jonathan Gross, O. James Marten
Patented Case
View Patent ↗
Granted: Dec 8, 1987
Filed: May 13, 1986
Inventors
Jonathan Gross
O. James Marten
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.