Granted Patent
Utility
US 4,645,148 · App. 06/735,017
Fail-safe voltage-limiting circuit for an audio frequency overlay track circuit
Inventor:
Dick J. Kolkman
Patented Case
View Patent ↗
Granted: Feb 24, 1987
Filed: May 16, 1985
Inventor
Dick J. Kolkman
Assignee (at issue)
American Standard 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.