Granted Patent
Utility
US 4,323,023 · App. 06/202,207
Instructional flip plate informational system
Inventors:
Howard L. Beckerman, Allan M. Dob
Patented Case
View Patent ↗
Granted: Apr 6, 1982
Filed: Oct 20, 1980
Inventors
Howard L. Beckerman
Allan M. Dob
Assignee (at issue)
The Singer Company Limited
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.