Granted Patent
Utility
US 5,199,825 · App. 07/803,444
Grid composite for longwall shield recovery in underground coal and trona mines
Inventor:
Brian Travis
Patented Case
View Patent ↗
Granted: Apr 6, 1993
Filed: Dec 6, 1991
Inventor
Brian Travis
Assignee (at issue)
Tensar Corporation, 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.