Granted Patent
Utility
US 4,723,902 · App. 06/899,038
Balanced flow extrusion crosshead and die assembly
Inventor:
Warren Erickson
Patented Case
View Patent ↗
Granted: Feb 9, 1988
Filed: Aug 21, 1986
Inventor
Warren Erickson
Assignee (at issue)
Wheeling Stamping Company
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.