Granted Patent
Utility
US 4,218,418 · App. 05/931,418
Processes of casting an ingot and making a silica container
Inventors:
Frederick Schmid, Chandra P. Khattak
Patented Case
View Patent ↗
Granted: Aug 19, 1980
Filed: Aug 8, 1978
Inventors
Frederick Schmid
Chandra P. Khattak
Assignee (at issue)
Crystal Systems 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.