Granted Patent
Utility
US 5,225,144 · App. 07/851,962
Gas-carburizing process and apparatus
Inventors:
Keishichi Nanba, Yoshihiko Kitayama, Fukitaka Abukawa, Hitoshi Goi, Masahiko Watanabe
Patented Case
View Patent ↗
Granted: Jul 6, 1993
Filed: Mar 16, 1992
Inventors
Keishichi Nanba
Yoshihiko Kitayama
Fukitaka Abukawa
Hitoshi Goi
Masahiko Watanabe
Assignees (at issue)
Tokyo Heat Treating Company
MITSUBISHI JIDOSHA KOGYO KABUSHIKI KAISHA
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.