Granted Patent
Utility
US 5,599,097 · App. 08/572,679
Extruder screw for plastic extruders
Inventor:
Andrew Christie
Patented Case
View Patent ↗
Granted: Feb 4, 1997
Filed: Dec 14, 1995
Inventor
Andrew Christie
Assignee (at issue)
Black Clawson Company, 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.