Granted Patent
Utility
US 5,265,318 · App. 07/882,440
Method for forming an in-line water heater having a spirally configured heat exchanger
Inventor:
William K. Shero
Patented Case
View Patent ↗
Granted: Nov 30, 1993
Filed: May 13, 1992
Inventor
William K. Shero
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.