Granted Patent
Utility
US 4,681,401 · App. 06/779,297
Sheet material marker surface for roadways and the like
Inventor:
Charles W. Wyckoff
Patented Case
View Patent ↗
Granted: Jul 21, 1987
Filed: Sep 23, 1985
Inventor
Charles W. Wyckoff
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.