Granted Patent
Utility
US 4,808,199 · App. 07/032,826
Apparatus and method for protecting gas separation membranes from damage due to a reversal of differential pressure
Inventor:
Jacob S. Yearout
Patented Case
View Patent ↗
Granted: Feb 28, 1989
Filed: Mar 31, 1987
Inventor
Jacob S. Yearout
Assignee (at issue)
W.R. Grace & Co. Conn.
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.