Granted Patent
Utility
US 4,074,023 · App. 05/564,490
Primary dry cell with masked separator
Inventor:
Lewis F. Urry
Patented Case
View Patent ↗
Granted: Feb 14, 1978
Filed: Apr 2, 1975
Inventor
Lewis F. Urry
Assignee (at issue)
Union Carbide Corporation
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.