Granted Patent
Utility
US 4,641,045 · App. 06/670,243
Fail-safe one and only one signal checking circuit
Inventor:
John O. G. Darrow
Patented Case
View Patent ↗
Granted: Feb 3, 1987
Filed: Nov 13, 1984
Inventor
John O. G. Darrow
Assignee (at issue)
American Standard 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.