Granted Patent
Utility
US 4,591,454 · App. 06/642,750
Apparatus and method for melting and treating metal wastes
Inventors:
Katsuyuki Ohtsuka, Ryukichi Mizuno, Koji Yanagida, Kazuo Kitagawa, Atsuhiro Ochiai, Minoru Harada, Hiroshi Matsumoto
Patented Case
View Patent ↗
Granted: May 27, 1986
Filed: Aug 21, 1984
Inventors
Katsuyuki Ohtsuka
Ryukichi Mizuno
Koji Yanagida
Kazuo Kitagawa
Atsuhiro Ochiai
Minoru Harada
Hiroshi Matsumoto
Assignee (at issue)
Doryokuro Kakunenryo Kaihatsu Jigyodan
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.