Granted Patent
Utility
US 5,520,424 · App. 08/380,308
Tamper-proof door switch and latch device
Inventors:
Kenyon A. Hapke, Spencer C. Schantz
Patented Case
View Patent ↗
Granted: May 28, 1996
Filed: Jan 30, 1995
Inventors
Kenyon A. Hapke
Spencer C. Schantz
Assignee (at issue)
U.S. Controls Copr.
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.