Granted Patent
Utility
US 6,267,178 · App. 09/627,492
Built-up heat exchanger
Inventor:
Yun-Ching Chen
Patented Case
View Patent ↗
Granted: Jul 31, 2001
Filed: Jul 28, 2000
Inventor
Yun-Ching Chen
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.