Granted Patent
Utility
US 5,988,760 · App. 08/928,506
Process for hollowing out a cavity formed of a plurality of sub-cavities in a thin layer of salt
Inventors:
Jean-Gerard Durup, Guy Boris, Yvon Charnavel
Patented Case
View Patent ↗
Granted: Nov 23, 1999
Filed: Sep 12, 1997
Inventors
Jean-Gerard Durup
Guy Boris
Yvon Charnavel
Assignee (at issue)
Gaz de France-(GDF) Service National
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.