Granted Patent
Utility
US 4,927,297 · App. 07/253,238
Leak prevention structure, method and apparatus
Inventor:
William Howden Simpson
Patented Case
View Patent ↗
Granted: May 22, 1990
Filed: Oct 4, 1988
Inventor
William Howden Simpson
Assignee (at issue)
Clem Environmental Corp.
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.