Granted Patent
Utility
US 4,354,878 · App. 06/232,932
Mineral article such as thermal insulation containing visual identification means
Inventors:
Ralph M. Hutchison, Phillip Charles Martin, Francis Y. Willingham
Patented Case
View Patent ↗
Granted: Oct 19, 1982
Filed: Feb 9, 1981
Inventors
Ralph M. Hutchison
Phillip Charles Martin
Francis Y. Willingham
Assignee (at issue)
Manville Service 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.