Granted Patent
Utility
US 5,318,489 · App. 07/849,286
Adjustable stepping structure for aerobic exercises
Inventor:
Lyle Ray Irwin
Patented Case
View Patent ↗
Granted: Jun 7, 1994
Filed: Mar 10, 1992
Inventor
Lyle Ray Irwin
Assignee (at issue)
The Step 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.