Granted Patent
Utility
US 4,291,920 · App. 06/145,379
In situ exploitation of deep set porphyry ores
Inventors:
Peter J. Lingane, Michael J. Redman, Won C. Park, Robert A. Hard, Walter W. Harvey
Patented Case
View Patent ↗
Granted: Sep 29, 1981
Filed: Apr 30, 1980
Inventors
Peter J. Lingane
Michael J. Redman
Won C. Park
Robert A. Hard
Walter W. Harvey
Assignee (at issue)
Kennecott Holdings 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.