Granted Patent
Utility
US 4,989,752 · App. 07/016,153
Frangible roof joint for storage tanks
Inventors:
John V. Birtwistle, E. Ernest Morgenegg, Jr., Marvin W. Ringer, Jr.
Patented Case
View Patent ↗
Granted: Feb 5, 1991
Filed: Feb 18, 1987
Inventors
John V. Birtwistle
E. Ernest Morgenegg, Jr.
Marvin W. Ringer, Jr.
Assignee (at issue)
Monsanto Company
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.