Granted Patent
Utility
US 4,862,846 · App. 07/171,655
Cooling water heater for internal combustion engines
Inventor:
Herbert Langen
Patented Case
View Patent ↗
Granted: Sep 5, 1989
Filed: Mar 22, 1988
Inventor
Herbert Langen
Assignee (at issue)
J. Eberspaecher
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.