Granted Patent
Utility
US 4,838,548 · App. 07/239,606
Four-bar variable resistance leg extension machine
Inventor:
Henry Maag
Patented Case
View Patent ↗
Granted: Jun 13, 1989
Filed: Sep 1, 1988
Inventor
Henry Maag
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.