Granted Patent
Utility
US 4,909,037 · App. 07/401,276
Control system for once-through boilers
Inventor:
Robert N. Hubby
Patented Case
View Patent ↗
Granted: Mar 20, 1990
Filed: Aug 31, 1989
Inventor
Robert N. Hubby
Assignee (at issue)
Federal Signal Corporation
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.