Granted Patent
Utility
US 6,435,269 · App. 09/443,607
Heat exchanger with intertwined inner and outer coils
Inventor:
Stephen S. Hancock
Patented Case
View Patent ↗
Granted: Aug 20, 2002
Filed: Nov 19, 1999
Inventor
Stephen S. Hancock
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.