Granted Patent
Utility
US 4,955,326 · App. 07/336,789
Low emission dual fuel engine and method of operating same
Inventor:
Melvin J. Helmich
Patented Case
View Patent ↗
Granted: Sep 11, 1990
Filed: Apr 12, 1989
Inventor
Melvin J. Helmich
Assignee (at issue)
Cooper Industries Holdings
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.