Granted Patent
Utility
US 5,546,992 · App. 08/183,146
Dual containment pipe rehabilitation system
Inventors:
Douglas K. Chick, F. Thomas Driver
Patented Case
View Patent ↗
Granted: Aug 20, 1996
Filed: Jan 18, 1994
Inventors
Douglas K. Chick
F. Thomas Driver
Assignee (at issue)
Insituform (Netherlands) B.V.
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.