Granted Patent
Utility
US 4,289,309 · App. 06/093,920
Work control assembly in an exerciser
Inventor:
Ralph Hoffmann
Patented Case
View Patent ↗
Granted: Sep 15, 1981
Filed: Nov 13, 1979
Inventor
Ralph Hoffmann
Assignee (at issue)
Perfection Manufacturing 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.