Granted Patent
Utility
US 4,418,247 · App. 06/265,717
Electrodynamic transducer
Inventor:
Kaj B. Hansen
Patented Case
View Patent ↗
Granted: Nov 29, 1983
Filed: May 20, 1981
Inventor
Kaj B. Hansen
Assignee (at issue)
International Standard Electric Corporation
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.