Granted Patent
Utility
US 6,830,843 · App. 10/051,389
Method for controlling the quality of the coolant for fuel cell systems
Inventors:
Anton Sonntag, Josef Sonntag, Hubert Urban
Patented Case
View Patent ↗
Granted: Dec 14, 2004
Filed: Jan 22, 2002
Inventors
Anton Sonntag
Josef Sonntag
Hubert Urban
Assignee (at issue)
BALLARD POWER SYSTEMS INC.
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.