Granted Patent
Utility
US 4,950,685 · App. 07/397,692
Wood preservatives
Inventor:
Hans A. Ward
Patented Case
View Patent ↗
Granted: Aug 21, 1990
Filed: Aug 23, 1989
Inventor
Hans A. Ward
Assignee (at issue)
KOP-COAT, INC.
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.