Granted Patent
Utility
US 4,501,981 · App. 06/311,754
Return-to-zero stepper motor
Inventor:
Charles Hansen
Patented Case
View Patent ↗
Granted: Feb 26, 1985
Filed: Oct 15, 1981
Inventor
Charles Hansen
Assignee (at issue)
Haydon Switch & Instrument, 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.