Granted Patent
Utility
US 4,688,591 · App. 06/925,862
Manual relief gas vent
Inventor:
Steven S. Edson
Patented Case
View Patent ↗
Granted: Aug 25, 1987
Filed: Oct 30, 1986
Inventor
Steven S. Edson
Assignee (at issue)
W. R. Grace & Co.
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.