Granted Patent
Utility
US 4,753,546 · App. 06/286,430
Pressure balanced stylographic pen
Inventors:
Wolfgang Witz, Fortunato J. Micale, John P. Leuenberger
Patented Case
View Patent ↗
Granted: Jun 28, 1988
Filed: Jul 24, 1981
Inventors
Wolfgang Witz
Fortunato J. Micale
John P. Leuenberger
Assignee (at issue)
Koh-I-Noor Rapidograph, 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.