Granted Patent
Utility
US 4,419,700 · App. 05/970,442
Dual-track spiral recording and associated system
Inventors:
Herbert U. Ragle, Norman S. Blessum
Patented Case
View Patent ↗
Granted: Dec 6, 1983
Filed: Dec 18, 1978
Inventors
Herbert U. Ragle
Norman S. Blessum
Assignee (at issue)
Burroughs, 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.