Granted Patent
Utility
US 4,333,841 · App. 06/184,609
Dithiophosphate lubricant additives
Inventors:
Andreas Schmidt, Rudolf Kirchmayr, Donald Richard Randell
Patented Case
View Patent ↗
Granted: Jun 8, 1982
Filed: Sep 5, 1980
Inventors
Andreas Schmidt
Rudolf Kirchmayr
Donald Richard Randell
Assignee (at issue)
Ciba-Geigy
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.