Granted Patent
Utility
US 4,191,806 · App. 05/937,505
Pressure vent for a sealed primary cell
Inventor:
Isaac Levy
Patented Case
View Patent ↗
Granted: Mar 4, 1980
Filed: Aug 28, 1978
Inventor
Isaac Levy
Assignee (at issue)
ESB Incorporated
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.