Granted Patent
Utility
US 4,915,285 · App. 07/378,751
Apparatus for making a diaphragm assembly and method of making the apparatus
Inventor:
Ledu Nguyen
Patented Case
View Patent ↗
Granted: Apr 10, 1990
Filed: Jul 12, 1989
Inventor
Ledu Nguyen
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.