Granted Patent
Utility
US 4,291,953 · App. 06/071,171
Ocular membrane and method for preparation thereof
Inventor:
William S. Covington
Patented Case
View Patent ↗
Granted: Sep 29, 1981
Filed: Aug 31, 1979
Inventor
William S. Covington
Assignee (at issue)
Permavision
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.