Granted Patent
Utility
US 5,239,202 · App. 07/621,323
Failsafe interlock switch
Inventor:
Fred L. Hostetler
Patented Case
View Patent ↗
Granted: Aug 24, 1993
Filed: Nov 30, 1990
Inventor
Fred L. Hostetler
Assignee (at issue)
Sentrol, 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.