Granted Patent
Utility
US 4,509,062 · App. 06/443,973
Ink reservoir with essentially constant negative back pressure
Inventors:
Robert N. Low, Frank L. Cloutier, Gary L. Siewell
Patented Case
View Patent ↗
Granted: Apr 2, 1985
Filed: Nov 23, 1982
Inventors
Robert N. Low
Frank L. Cloutier
Gary L. Siewell
Assignee (at issue)
Hewlett-Packard Company, L.P.
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.