Granted Patent
Utility
US 4,308,968 · App. 06/155,929
Secondary seal for tank having floating roof
Inventors:
Roger W. Thiltgen, T. Richard Mathews, Walter Hurst
Patented Case
View Patent ↗
Granted: Jan 5, 1982
Filed: Jun 3, 1980
Inventors
Roger W. Thiltgen
T. Richard Mathews
Walter Hurst
Assignee (at issue)
HMT LLC
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.