Granted Patent
Utility
US 4,886,590 · App. 07/116,479
Chemical process control system
Inventor:
Douglas L. Tittle
Patented Case
View Patent ↗
Granted: Dec 12, 1989
Filed: Nov 2, 1987
Inventor
Douglas L. Tittle
Assignee (at issue)
Man-Gill Chemical Company
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.