Granted Patent
Utility
US 4,149,846 · App. 05/800,127
Method and means of insulating water-cooled pipes in a furnace
Inventor:
Thomas Drew
Patented Case
View Patent ↗
Granted: Apr 17, 1979
Filed: May 24, 1977
Inventor
Thomas Drew
Assignee (at issue)
United States Steel Corporation
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.