Granted Patent
Utility
US 4,647,674 · App. 06/784,979
Bis-(dibenzo[b,d]pyranyloxy) propanes
Inventor:
Ronald C. Griffith
Patented Case
View Patent ↗
Granted: Mar 3, 1987
Filed: Oct 7, 1985
Inventor
Ronald C. Griffith
Assignee (at issue)
Pennwalt Corporation
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.