Granted Patent
Utility
US 5,101,850 · App. 07/430,551
Filter change liquid shutoff safety interlock device
Inventor:
John A. Todd
Patented Case
View Patent ↗
Granted: Apr 7, 1992
Filed: Nov 1, 1989
Inventor
John A. Todd
Assignee (at issue)
Dresser 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.