Granted Patent
Utility
US 4,243,852 · App. 06/030,470
Membrane switch with means for impeding silver migration
Inventor:
Willis A. Larson
Patented Case
View Patent ↗
Granted: Jan 6, 1981
Filed: Apr 16, 1979
Inventor
Willis A. Larson
Assignee (at issue)
Oak Industries 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.