Granted Patent
Utility
US 4,830,231 · App. 07/129,155
Composite disk valve for dispensing cartridges
Inventor:
Ernest L. Smith
Patented Case
View Patent ↗
Granted: May 16, 1989
Filed: Dec 7, 1987
Inventor
Ernest L. Smith
Assignee (at issue)
Sealright Co. 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.