Granted Patent
Utility
US 4,993,791 · App. 07/438,907
Powder metal mirror
Inventors:
Donald W. Burt, Gerald A. Hans
Patented Case
View Patent ↗
Granted: Feb 19, 1991
Filed: Nov 17, 1989
Inventors
Donald W. Burt
Gerald A. Hans
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.