Granted Patent
Utility
US 4,155,646 · App. 05/864,032
Printing head assembly
Inventor:
Walter Hrastnik
Patented Case
View Patent ↗
Granted: May 22, 1979
Filed: Dec 23, 1977
Inventor
Walter Hrastnik
Assignee (at issue)
Bell and Howell, LLC
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.