Granted Patent
Utility
US 5,358,031 · App. 08/048,981
Interlocking checker bricks and method and apparatus for making
Inventor:
Jack Hyde
Patented Case
View Patent ↗
Granted: Oct 25, 1994
Filed: Apr 16, 1993
Inventor
Jack Hyde
Assignee (at issue)
NORTH AMERICAN REFRACTORIES COMPANY
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.