Granted Patent
Utility
US 4,369,719 · App. 06/207,006
Vermiculite as a deposit modifier in coal fired boilers
Inventors:
Gary G. Engstrom, Douglas I. Bain
Patented Case
View Patent ↗
Granted: Jan 25, 1983
Filed: Nov 14, 1980
Inventors
Gary G. Engstrom
Douglas I. Bain
Assignee (at issue)
Dearborn Chemical Company 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.