Granted Patent
Utility
US 4,949,038 · App. 07/333,783
Optical fiber having a helical core for sensing a magnetic field
Inventors:
Robin D. Birch, David Neil Payne, Malcolm Paul Varnham
Patented Case
View Patent ↗
Granted: Aug 14, 1990
Filed: Apr 5, 1989
Inventors
Robin D. Birch
David Neil Payne
Malcolm Paul Varnham
Assignee (at issue)
NATIONAL RESEARCH DEVELOPMENT CORPORATION
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.