Granted Patent
Utility
US 4,309,191 · App. 06/184,566
Coal-oil mixture
Inventors:
Osamu Hiroya, Hiroyuki Ihara, Yoshitomo Sanami
Patented Case
View Patent ↗
Granted: Jan 5, 1982
Filed: Sep 5, 1980
Inventors
Osamu Hiroya
Hiroyuki Ihara
Yoshitomo Sanami
Assignee (at issue)
Mitsubishi Oil 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.