Granted Patent
Utility
US 4,233,520 · App. 05/940,068
Electro optical control to detect a filament passing through a guide eye and using a light emitting diode
Inventor:
Sheldon A. Canfield
Patented Case
View Patent ↗
Granted: Nov 11, 1980
Filed: Sep 7, 1978
Inventor
Sheldon A. Canfield
Assignee (at issue)
Owens-Corning Fiberglas 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.