Granted Patent
Utility
US 4,257,778 · App. 06/070,469
Process for producing synthetic coking coal of high volatile matter content
Inventors:
Tadashi Murakami, Mamoru Yamane, Toshio Tokairin, Kenji Kawai
Patented Case
View Patent ↗
Granted: Mar 24, 1981
Filed: Aug 28, 1979
Inventors
Tadashi Murakami
Mamoru Yamane
Toshio Tokairin
Kenji Kawai
Assignee (at issue)
Nihon Kogyo Co., 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.