Granted Patent
Utility
US 4,951,938 · App. 07/323,763
Exercise shoe
Inventor:
Christopher John Smith
Patented Case
View Patent ↗
Granted: Aug 28, 1990
Filed: Mar 15, 1989
Inventor
Christopher John Smith
Assignee (at issue)
Prostretch, 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.