Granted Patent
Utility
US 4,830,438 · App. 07/233,083
Freight brake emergency valve
Inventors:
James E. Hart, Edward W. Gaughan
Patented Case
View Patent ↗
Granted: May 16, 1989
Filed: Aug 17, 1988
Inventors
James E. Hart
Edward W. Gaughan
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.