Granted Patent
Utility
US 4,279,404 · App. 06/085,837
Guide arrangement for expanding gate valves
Inventor:
Alan R. Levin
Patented Case
View Patent ↗
Granted: Jul 21, 1981
Filed: Oct 17, 1979
Inventor
Alan R. Levin
Assignee (at issue)
ACF Industries Incorporated
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.