Granted Patent
Utility
US 4,530,347 · App. 06/641,585
Gas-fired water heaters
Inventors:
Michael John Baker, Geoffrey J. Hardwick
Patented Case
View Patent ↗
Granted: Jul 23, 1985
Filed: Aug 17, 1984
Inventors
Michael John Baker
Geoffrey J. Hardwick
Assignee (at issue)
British Gas
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.