Granted Patent
Utility
US 5,217,601 · App. 07/894,586
Method for impartation of blue color to aluminum or aluminum alloy
Inventors:
Norio Nakada, Hideo Fukui, Hatsuo Hirono, Seishiro Ito
Patented Case
View Patent ↗
Granted: Jun 8, 1993
Filed: Jun 5, 1992
Inventors
Norio Nakada
Hideo Fukui
Hatsuo Hirono
Seishiro Ito
Assignee (at issue)
Yoshida Kogyo K.K.
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.