Granted Patent
Utility
US 4,409,569 · App. 06/317,438
Filter circuits having transformers as filter elements
Inventor:
Jerome Potash
Patented Case
View Patent ↗
Granted: Oct 11, 1983
Filed: Nov 2, 1981
Inventor
Jerome Potash
Assignee (at issue)
OPT 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.