Granted Patent
Utility
US 4,732,320 · App. 06/863,416
Railroad grade crossing with transverse securing splines
Inventor:
S. Hudson Owen
Patented Case
View Patent ↗
Granted: Mar 22, 1988
Filed: May 15, 1986
Inventor
S. Hudson Owen
Assignee (at issue)
KOPPERS, 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.