Granted Patent
Utility
US 4,733,970 · App. 06/774,196
Extruder screw
Inventor:
Lucien D. Yokana
Patented Case
View Patent ↗
Granted: Mar 29, 1988
Filed: Sep 9, 1985
Inventor
Lucien D. Yokana
Assignee (at issue)
Sterling Extruder 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.