Granted Patent
Utility
US 6,067,893 · App. 09/037,613
Ribbed diaphragm
Inventor:
George Drahusz, Jr.
Patented Case
View Patent ↗
Granted: May 30, 2000
Filed: Mar 10, 1998
Inventor
George Drahusz, Jr.
Assignee (at issue)
Westinghouse Air Brake Co.
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.