Granted Patent
Utility
US 4,602,236 · App. 06/699,725
Laminated ballast core
Inventors:
Billy L. Shelby, James R. Wirt
Patented Case
View Patent ↗
Granted: Jul 22, 1986
Filed: Feb 8, 1985
Inventors
Billy L. Shelby
James R. Wirt
Assignee (at issue)
FL 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.