Granted Patent
Utility
US 5,174,254 · App. 07/806,884
Coolant circuit with a heater for a vehicle engine
Inventor:
Michael Humburg
Patented Case
View Patent ↗
Granted: Dec 29, 1992
Filed: Dec 12, 1991
Inventor
Michael Humburg
Assignee (at issue)
J. Eberspaecher GmbH & Co. KG
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.