Granted Patent
Utility
US 4,285,728 · App. 06/083,061
Method of making low expansion crystallized glass-ceramics and telescope mirror blanks made thereby
Inventors:
Clarence L. Babcock, Robert A. Busdiecker, Erwin C. Hagedorn
Patented Case
View Patent ↗
Granted: Aug 25, 1981
Filed: Oct 9, 1979
Inventors
Clarence L. Babcock
Robert A. Busdiecker
Erwin C. Hagedorn
Assignee (at issue)
Owens-Illinois 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.