Granted Patent
Utility
US 4,618,429 · App. 06/682,441
Method of maintaining adequate seed crystal in preferential precipitation systems
Inventor:
Howard R. Herrigel
Patented Case
View Patent ↗
Granted: Oct 21, 1986
Filed: Dec 14, 1984
Inventor
Howard R. Herrigel
Assignee (at issue)
Resources Conservation, Inc.
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.