Granted Patent
Utility
US 6,230,981 · App. 09/147,732
Steel railroad sleepers
Inventors:
Kerry Hill, Sidney Relph
Patented Case
View Patent ↗
Granted: May 15, 2001
Filed: Jun 11, 1999
Inventors
Kerry Hill
Sidney Relph
Assignee (at issue)
Corus UK Limited
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.