Granted Patent
Utility
US 4,810,192 · App. 07/137,168
Two-stage intra-oral protective system
Inventor:
Edward D. Williams
Patented Case
View Patent ↗
Granted: Mar 7, 1989
Filed: Dec 23, 1987
Inventor
Edward D. Williams
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.