Granted Patent
Utility
US 4,904,189 · App. 07/318,758
Rotating contact assembly for electrical supply
Inventor:
Leonard L. Hallings
Patented Case
View Patent ↗
Granted: Feb 27, 1990
Filed: Mar 3, 1989
Inventor
Leonard L. Hallings
Assignee (at issue)
MDT CO.,LTD.
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.