Granted Patent
Utility
US 4,968,121 · App. 07/281,134
Hermetically sealed apparatus and method for maintaining crystals at a controlled operating temperature
Inventors:
Hans W. Bruesselbach, Robert H. Sipman
Patented Case
View Patent ↗
Granted: Nov 6, 1990
Filed: Dec 7, 1988
Inventors
Hans W. Bruesselbach
Robert H. Sipman
Assignee (at issue)
Hughes Aircraft 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.