Granted Patent
Utility
US 4,919,239 · App. 07/133,005
Shoe return spring
Inventor:
John A. Urban
Patented Case
View Patent ↗
Granted: Apr 24, 1990
Filed: Dec 15, 1987
Inventor
John A. Urban
Assignee (at issue)
Lucas Industries public limited 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.