Granted Patent
Utility
US 4,278,937 · App. 06/014,139
Circuit arrangement for monitoring the phase sequence of a rotary field
Inventor:
Josef Immler
Patented Case
View Patent ↗
Granted: Jul 14, 1981
Filed: Feb 22, 1979
Inventor
Josef Immler
Assignee (at issue)
Siemens Aktiengesellschaft
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.