Granted Patent
Utility
US 4,256,259 · App. 05/910,875
Insulated rail joint
Inventor:
William C. Gore
Patented Case
View Patent ↗
Granted: Mar 17, 1981
Filed: May 30, 1978
Inventor
William C. Gore
Assignee (at issue)
Portec, 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.