Granted Patent
Utility
US 4,871,146 · App. 07/152,730
Apparatus for heat treatment of steel rods
Inventors:
Katsuhiko Yamada, Kunio Ojima, Takashi Asakura, Yusuke Yamamori, Yukihiro Nakamura
Patented Case
View Patent ↗
Granted: Oct 3, 1989
Filed: Feb 5, 1988
Inventors
Katsuhiko Yamada
Kunio Ojima
Takashi Asakura
Yusuke Yamamori
Yukihiro Nakamura
Assignee (at issue)
SUMITOMO ELECTRIC INDUSTRIES, LTD.
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.