Granted Patent
Utility
US 6,527,873 · App. 10/217,109
Composition and method for metal coloring process
Inventors:
Keith N. Ravenscroft, William V. Block
Patented Case
View Patent ↗
Granted: Mar 4, 2003
Filed: Aug 9, 2002
Inventors
Keith N. Ravenscroft
William V. Block
Assignee (at issue)
Birchwood Laboratories LLC
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.