Granted Patent
Utility
US 5,586,721 · App. 08/522,298
Dual-circuit vehicle heater
Inventor:
Michael Humburg
Patented Case
View Patent ↗
Granted: Dec 24, 1996
Filed: Aug 17, 1995
Inventor
Michael Humburg
Assignee (at issue)
J. Eberspacher
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.