Granted Patent
Utility
US 4,448,412 · App. 06/285,257
Exercising device with double acting hydraulic cylinder
Inventor:
Jerry D. Brentham
Patented Case
View Patent ↗
Granted: May 15, 1984
Filed: Jul 20, 1981
Inventor
Jerry D. Brentham
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.