Granted Patent
Utility
US 4,293,872 · App. 06/059,214
Production of printing blocks or forms
Inventors:
Hans W. Keller, Hans-Georg Knop
Patented Case
View Patent ↗
Granted: Oct 6, 1981
Filed: Jul 20, 1979
Inventors
Hans W. Keller
Hans-Georg Knop
Assignee (at issue)
Dr. Ing. Rudolf Hell GmbH
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.