Granted Patent
Utility
US 5,428,407 · App. 08/167,105
Prescription lens attachable to safety glasses
Inventor:
Keith W. Sheffield
Patented Case
View Patent ↗
Granted: Jun 27, 1995
Filed: Dec 15, 1993
Inventor
Keith W. Sheffield
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.