Granted Patent
Utility
US 4,239,477 · App. 05/959,765
Furnace ignition system with draft control and loss-of-draft protection
Inventor:
Thomas E. Hayes
Patented Case
View Patent ↗
Granted: Dec 16, 1980
Filed: Nov 13, 1978
Inventor
Thomas E. Hayes
Assignee (at issue)
Johnson Controls, Inc.
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.