Granted Patent
Utility
US 4,935,909 · App. 06/940,251
Piezoelectric signaling device
Inventor:
Miroslav Matievic
Patented Case
View Patent ↗
Granted: Jun 19, 1990
Filed: Dec 10, 1986
Inventor
Miroslav Matievic
Assignee (at issue)
Emhart Industries, 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.