Granted Patent
Utility
US 4,826,422 · App. 07/143,658
Restriction insert for an extrusion die
Inventor:
Stephen Hunter
Patented Case
View Patent ↗
Granted: May 2, 1989
Filed: Jan 13, 1988
Inventor
Stephen Hunter
Assignee (at issue)
The Firestone Tire & Rubber 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.