Granted Patent
Utility
US 5,806,810 · App. 08/980,569
Spring rail frog having switchable magnet for holding wing rail open
Inventors:
Kieth Young, Stephen R. Kuhn
Patented Case
View Patent ↗
Granted: Sep 15, 1998
Filed: Dec 1, 1997
Inventors
Kieth Young
Stephen R. Kuhn
Assignee (at issue)
ABC Rail Products 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.