Granted Patent
Utility
US 4,352,750 · App. 06/289,140
Friction material for railroad brake shoes
Inventor:
Frank W. Eschen
Patented Case
View Patent ↗
Granted: Oct 5, 1982
Filed: Aug 3, 1981
Inventor
Frank W. Eschen
Assignee (at issue)
Manville Service Corporation
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.