Granted Patent
Utility
US 5,174,231 · App. 07/628,497
Water-barrier of water-swellable clay sandwiched between interconnected layers of flexible fabric needled together using a lubricant
Inventor:
Alec W. White
Patented Case
View Patent ↗
Granted: Dec 29, 1992
Filed: Dec 17, 1990
Inventor
Alec W. White
Assignee (at issue)
American Colloid 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.