Granted Patent
Utility
US 6,043,741 · App. 09/079,648
Threshold warning system for wheelchair lifts
Inventor:
Sean Whitmarsh
Patented Case
View Patent ↗
Granted: Mar 28, 2000
Filed: May 15, 1998
Inventor
Sean Whitmarsh
Assignee (at issue)
Ricon Corp.
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.