Granted Patent
Utility
US 4,936,493 · App. 07/124,298
Elastomeric valve and piston structure for product dispenser
Inventors:
Donald D. Foster, David Moore
Patented Case
View Patent ↗
Granted: Jun 26, 1990
Filed: Nov 23, 1987
Inventors
Donald D. Foster
David Moore
Assignee (at issue)
Calmar Holdings 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.