Granted Patent
Utility
US 6,814,874 · App. 10/212,887
Claricone sludge level control system
Inventor:
Donald N. Ruehrwein
Patented Case
View Patent ↗
Granted: Nov 9, 2004
Filed: Aug 6, 2002
Inventor
Donald N. Ruehrwein
Assignee (at issue)
Chicago Bridge & Iron Co.
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.