Granted Patent
Utility
US 4,760,491 · App. 07/009,431
Fail-safe brake valve driver
Inventor:
Ralph J. Hurley
Patented Case
View Patent ↗
Granted: Jul 26, 1988
Filed: Feb 2, 1987
Inventor
Ralph J. Hurley
Assignee (at issue)
L'ORÉAL
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.