Granted Patent
Utility
US 4,899,932 · App. 07/183,055
Capped highway grade crossing
Inventors:
Dale K. Beachy, Robert B. Dehls, S. Hudson Owen, James H. Simpson
Patented Case
View Patent ↗
Granted: Feb 13, 1990
Filed: Apr 19, 1988
Inventors
Dale K. Beachy
Robert B. Dehls
S. Hudson Owen
James H. Simpson
Assignee (at issue)
Koppers Industries, 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.